Note: Descriptions are shown in the official language in which they were submitted.
THERMOFORMABLE FILM
FIELD OF THE INVENTION
The present disclosure provides polyethylene compositions which are useful
in film thermoforming applications. The polyethylene compositions have a good
(i.e.
relatively low) area Dimensional Thermoformability Index (aDTI). The
polyethylene
compositions comprise two polyethylene components which are each made with a
single site polymerization catalyst and one polyethylene component which is
made
with a multi-site polymerization catalyst.
BACKGROUND OF THE INVENTION
Multicomponent polyethylene compositions are well known in the art. One
method to access multicomponent polyethylene compositions is to use two or
more
distinct polymerization catalysts in one or more polymerization reactors. For
example, the use of single site and Ziegler-Natta type polymerization
catalysts in at
least two distinct solution polymerization reactors is known. Such reactors
may be
configured in series or in parallel.
Solution polymerization processes are generally carried out at temperatures
above the melting point of the ethylene homopolymer or copolymer product being
made. In a typical solution polymerization process, catalyst components,
solvent,
monomers and hydrogen are fed under pressure to one or more reactors.
For solution phase ethylene polymerization, or ethylene copolymerization,
reactor temperatures can range from about 80 C to about 300 C while pressures
generally range from about 3MPag to about 45MPag. The ethylene homopolymer or
copolymer produced remains dissolved in the solvent under reactor conditions.
The
residence time of the solvent in the reactor is relatively short, for example,
from
about 1 second to about 20 minutes. The solution process can be operated under
a
wide range of process conditions that allow the production of a wide variety
of
ethylene polymers. Post reactor, the polymerization reaction is quenched to
prevent
further polymerization, by adding a catalyst deactivator, and optionally
passivated, by
adding an acid scavenger. Once deactivated (and optionally passivated), the
polymer solution is passed to a polymer recovery operation (a devolatilization
system) where the ethylene homopolymer or copolymer is separated from process
solvent, unreacted residual ethylene and unreacted optional a-olefin(s).
1
Date Recue/Date Received 2020-10-01
Regardless of the manner of production, there remains a need to improve the
performance of multicomponent polyethylene compositions in film applications
such
as the use of such compositions in thermoforming processes. Thermoforming is a
process in which a plastic sheet or film is heated to a pliable state under a
forming
temperature, then stretched into or onto a mold to form a part shape after
cooling.
Thermoforming can be used to make films into packages for foodstuffs,
medicines,
or medical and electronic devices.
SUMMARY OF THE INVENTION
An embodiment of the disclosure is a thermoformable film comprising a
polyethylene composition comprising:
from 5 to 80 wt% of a first polyethylene which is an ethylene copolymer, the
first polyethylene having a weight average molecular weight Mw of from 70,000
to
250,000, a molecular weight distribution Mw/Mn of <2.3 and from 5 to 100 short
chain branches per thousand carbon atoms;
from 5 to 80 wt% of a second polyethylene which is an ethylene copolymer or
an ethylene homopolymer, the second polyethylene having a weight average
molecular weight Mw of from 15,000 to 100,000, a molecular weight distribution
Mw/Mn of < 2.3 and from 0 to 20 short chain branches per thousand carbon
atoms;
and
from 5 to 80 wt% of a third polyethylene which is an ethylene copolymer or an
ethylene homopolymer, the third polyethylene having a weight average molecular
weight Mw of from 70,000 to 250,000, a molecular weight distribution Mw/Mn of
> 2.3
and from 0 to 50 short chain branches per thousand carbon atoms; wherein
the number of short chain branches per thousand carbon atoms in the first
polyethylene (SCBpE-1) is greater than the number of short chain branches per
thousand carbon atoms in the second polyethylene (SCBpE-2) and the third
polyethylene (SCBpE-3);
the number of short chain branches per thousand carbon atoms in the third
polyethylene (SCBpE-3) is greater than the number of short chain branches per
thousand carbon atoms in the second polyethylene (SCBpE-2); and
the weight average molecular weight of the second polyethylene is less than
the weight average molecular weight of the first polyethylene and the third
polyethylene; wherein,
2
Date Recue/Date Received 2020-10-01
the polyethylene composition has a density of less than or equal to 0.939
g/cm3, a Tm2 ¨ Tml of less than 30 C, a melt index 12 of from 0.1 to 10
dg/min, a melt
flow ratio, 121/12 of less than or equal to 50, and a soluble fraction in a
crystallization
elution fractionation (CEF) analysis of at least 10 weight percent.
An embodiment of the disclosure is a thermoformable film comprising a
polyethylene composition comprising:
from 5 to 80 wt% of a first polyethylene which is an ethylene copolymer, the
first polyethylene having a weight average molecular weight Mw of from 70,000
to
250,000, a molecular weight distribution Mw/Mn of < 2.3 and from 5 to 100
short
chain branches per thousand carbon atoms;
from 5 to 80 wt% of a second polyethylene which is an ethylene copolymer or
an ethylene homopolymer, the second polyethylene having a weight average
molecular weight Mw of from 15,000 to 100,000, a molecular weight distribution
Mw/Mn of < 2.3 and from 0 to 20 short chain branches per thousand carbon
atoms;
and
from 5 to 80 wt% of a third polyethylene which is an ethylene copolymer or an
ethylene homopolymer, the third polyethylene having a weight average molecular
weight Mw of from 70,000 to 250,000, a molecular weight distribution Mw/Mn of
> 2.3
and from 0 to 50 short chain branches per thousand carbon atoms; wherein
the number of short chain branches per thousand carbon atoms in the first
polyethylene (SCBpE-1) is greater than the number of short chain branches per
thousand carbon atoms in the second polyethylene (SCBpE-2) and the third
polyethylene (SCBpE-3);
the number of short chain branches per thousand carbon atoms in the third
polyethylene (SCBpE-3) is greater than the number of short chain branches per
thousand carbon atoms in the second polyethylene (SCBpE-2); and
the weight average molecular weight of the second polyethylene is less than
the weight average molecular weight of the first polyethylene and the third
polyethylene; wherein,
the polyethylene composition has a density of less than or equal to 0.939
g/cm3, a Tm2 ¨ Tml of less than 30 C, a melt index 12 of from 0.1 to 10
dg/min, a melt
flow ratio, 121/12 of less than or equal to 50, a soluble fraction in a
crystallization
elution fractionation (CEF) analysis of at least 10 weight percent, and an
area
Dimensional Thermoformability Index (aDTI) at 105 C of less than 15.
3
Date Recue/Date Received 2020-10-01
Brief Description of the Figures
Figure 1 shows the gel permeation chromatographs (GPC) of polyethylene
compositions made according to the present disclosure. Differential refractive
index
.. detectors were used.
Figure 2 shows the gel permeation chromatographs with Fourier transform
infra-red (GPC-FTIR) detection obtained for polyethylene compositions made
according to the present disclosure. The comonomer content, shown as the
number
of short chain branches per 1000 carbons (y-axis), is given relative to the
copolymer
.. molecular weight (x-axis). The upwardly sloping line (from left to right)
is the short
chain branching (in short chain branches per 1000 carbons atoms) determined by
FTIR. As can be seen in the Figure, for Examples 1-3, the number of short
chain
branches initially increases at higher molecular weights and then decreases
again at
still higher molecular weights, and hence the comonomer incorporation is said
to be
.. "partially reversed" with a peak or maximum present.
Figure 3 shows the differential scanning calorimetry (DSC) analysis and
profile of polyethylene compositions made according to the present disclosure.
Figure 4 shows a plot of the phase angle (8) vs. the complex modulus (G*) for
polyethylene compositions made according to the present disclosure as well as
for
.. some other polyethylenes. The value of the phase angle (8) at a complex
modulus
(G*) of 10,000 Pa, is thought to be indicative of the presence of long chain
branching
in the polyethylene material.
Figure 5 shows an example in which a plot of time, t (in seconds) vs.
transient
extensional viscosity, TIE* (in Pa.$) is used to determine the average Melt
Strain
Hardening Index, the "MSHI".
Figure 6 shows a diagram which illustrates the planar deformation and the
biaxial deformation which occur when a plastic sheet or film is subjected to
thermoforming in a mold.
Figure 7 illustrates the shape and dimensions of a test specimen before and
after subjecting the specimen to high temperature tensile experiments. In
Figure 7,
"d" is the thickness of the specimen and "W" is the width of the specimen.
Figure 8 shows the area Dimensional Thermoformability Index (aDTI) values
at 95 C, 100 C and 105 C for polymers known to have varying levels of
performance
when used in thermoforming applications: a Nylon polymer, a cyclic olefin
4
Date Recue/Date Received 2020-10-01
copolymer, a linear low density polyethylene copolymer and its blend with a
cyclic
olefin copolymer; and a high density ethylene homopolymer.
Definition of Terms
Other than in the examples or where otherwise indicated, all numbers or
expressions referring to quantities of ingredients, extrusion conditions,
etc., used in
the specification and claims are to be understood as modified in all instances
by the
term "about." Accordingly, unless indicated to the contrary, the numerical
parameters set forth in the following specification and attached claims are
approximations that can vary depending upon the desired properties that the
various
embodiments desire to obtain. At the very least, and not as an attempt to
limit the
application of the doctrine of equivalents to the scope of the claims, each
numerical
parameter should at least be construed in light of the number of reported
significant
digits and by applying ordinary rounding techniques. The numerical values set
forth
in the specific examples are reported as precisely as possible. Any numerical
values, however, inherently contain certain errors necessarily resulting from
the
standard deviation found in their respective testing measurements.
It should be understood that any numerical range recited herein is intended to
include all sub-ranges subsumed therein. For example, a range of "1 to 10" is
intended to include all sub-ranges between and including the recited minimum
value
of 1 and the recited maximum value of 10; that is, having a minimum value
equal to
or greater than 1 and a maximum value of equal to or less than 10. Because the
disclosed numerical ranges are continuous, they include every value between
the
minimum and maximum values. Unless expressly indicated otherwise, the various
numerical ranges specified in this application are approximations.
All compositional ranges expressed herein are limited in total to and do not
exceed 100 percent (volume percent or weight percent) in practice. Where
multiple
components can be present in a composition, the sum of the maximum amounts of
each component can exceed 100 percent, with the understanding that, and as
those
skilled in the art readily understand, that the amounts of the components
actually
used will conform to the maximum of 100 percent.
In order to form a more complete understanding of this disclosure the
following terms are defined and should be used with the accompanying figures
and
the description of the various embodiments throughout.
5
Date Recue/Date Received 2020-10-01
As used herein, the term "monomer" refers to a small molecule that may
chemically react and become chemically bonded with itself or other monomers to
form a polymer.
As used herein, the term "a-olefin" or "alpha-olefin" is used to describe a
monomer having a linear hydrocarbon chain containing from 3 to 20 carbon atoms
having a double bond at one end of the chain; an equivalent term is "linear a-
olefin".
As used herein, the term "polyethylene" or "ethylene polymer", refers to
macromolecules produced from ethylene monomers and optionally one or more
additional monomers; regardless of the specific catalyst or specific process
used to
make the ethylene polymer. In the polyethylene art, the one or more additional
monomers are called "comonomer(s)" and often include a-olefins. The term
"homopolymer" refers to a polymer that contains only one type of monomer. An
"ethylene homopolymer" is made using only ethylene as a polymerizable monomer.
The term "copolymer" refers to a polymer that contains two or more types of
monomer. An "ethylene copolymer" is made using ethylene and one or more other
types of polymerizable monomer. Common polyethylenes include high density
polyethylene (HDPE), medium density polyethylene (MDPE), linear low density
polyethylene (LLDPE), very low density polyethylene (VLDPE), ultralow density
polyethylene (ULDPE), plastomer and elastomers. The term polyethylene also
includes polyethylene terpolymers which may include two or more comonomers in
addition to ethylene. The term polyethylene also includes combinations of, or
blends
of, the polyethylenes described above.
The term "heterogeneously branched polyethylene" refers to a subset of
polymers in the ethylene polymer group that are produced using a heterogeneous
.. catalyst system; non-limiting examples of which include Ziegler-Natta or
chromium
catalysts, both of which are well known in the art.
The term "homogeneously branched polyethylene" refers to a subset of
polymers in the ethylene polymer group that are produced using single-site
catalysts;
non-limiting examples of which include metallocene catalysts, phosphinimine
.. catalysts, and constrained geometry catalysts all of which are well known
in the art.
Typically, homogeneously branched polyethylene has narrow molecular
weight distributions, for example gel permeation chromatography (GPC) Mw/Mn
values of less than 2.8, especially less than 2.3, although exceptions may
arise; Mw
and Mn refer to weight and number average molecular weights, respectively. In
6
Date Recue/Date Received 2020-10-01
contrast, the Mw/Mn of heterogeneously branched ethylene polymers are
typically
greater than the Mw/Mn of homogeneous polyethylene. In general, homogeneously
branched ethylene polymers also have a narrow comonomer distribution, i.e.
each
macromolecule within the molecular weight distribution has a similar comonomer
content. Frequently, the composition distribution breadth index "CDBI" is used
to
quantify how the comonomer is distributed within an ethylene polymer, as well
as to
differentiate ethylene polymers produced with different catalysts or
processes. The
"CDBI50" is defined as the percent of ethylene polymer whose composition is
within
50 weight percent (wt%) of the median comonomer composition; this definition
is
consistent with that described in WO 93/03093 assigned to Exxon Chemical
Patents
Inc. The CDBI50 of an ethylene interpolymer can be calculated from TREF curves
(Temperature Rising Elution Fractionation); the TREF method is described in
Wild, et
al., J. Polym. Sci., Part B, Polym. Phys., Vol. 20 (3), pages 441-455.
Typically the
CDBI50 of homogeneously branched ethylene polymers are greater than about 70%
or greater than about 75%. In contrast, the CDBI50 of a-olefin containing
heterogeneously branched ethylene polymers are generally lower than the CDBI50
of
homogeneous ethylene polymers. For example, the CDBI50 of a heterogeneously
branched ethylene polymer may be less than about 75%, or less than about 70%.
It is well known to those skilled in the art, that homogeneously branched
ethylene polymers are frequently further subdivided into "linear homogeneous
ethylene polymers" and "substantially linear homogeneous ethylene polymers".
These two subgroups differ in the amount of long chain branching: more
specifically,
linear homogeneous ethylene polymers have less than about 0.01 long chain
branches per 1000 carbon atoms; while substantially linear ethylene polymers
have
greater than about 0.01 to about 3.0 long chain branches per 1000 carbon
atoms. A
long chain branch is macromolecular in nature, i.e. similar in length to the
macromolecule that the long chain branch is attached to. Hereafter, in this
disclosure, the term "homogeneously branched polyethylene" or "homogeneously
branched ethylene polymer" refers to both linear homogeneous ethylene polymers
and substantially linear homogeneous ethylene polymers.
The term "thermoplastic" refers to a polymer that becomes liquid when
heated, will flow under pressure and solidify when cooled. Thermoplastic
polymers
include ethylene polymers as well as other polymers used in the plastic
industry;
non-limiting examples of other polymers commonly used in film applications
include
7
Date Recue/Date Received 2020-10-01
barrier resins (EVOH), tie resins, polyethylene terephthalate (PET), polyam
ides and
the like.
As used herein the term "monolayer film" refers to a film containing a single
layer of one or more thermoplastics.
As used herein, the terms "hydrocarbyl", "hydrocarbyl radical" or "hydrocarbyl
group" refers to linear or cyclic, aliphatic, olefinic, acetylenic and aryl
(aromatic)
radicals comprising hydrogen and carbon that are deficient by one hydrogen.
As used herein, an "alkyl radical" includes linear, branched and cyclic
paraffin
radicals that are deficient by one hydrogen radical; non-limiting examples
include
methyl (-CH3) and ethyl (-CH2CH3) radicals. The term "alkenyl radical" refers
to
linear, branched and cyclic hydrocarbons containing at least one carbon-carbon
double bond that is deficient by one hydrogen radical.
As used herein, the term "aryl" group includes phenyl, naphthyl, pyridyl and
other radicals whose molecules have an aromatic ring structure; non-limiting
examples include naphthylene, phenanthrene and anthracene. An "arylalkyl"
group
is an alkyl group having an aryl group pendant there from; non-limiting
examples
include benzyl, phenethyl and tolylmethyl; an "alkylaryl" is an aryl group
having one
or more alkyl groups pendant there from; non-limiting examples include tolyl,
xylyl,
mesityl and cumyl.
As used herein, the phrase "heteroatom" includes any atom other than carbon
and hydrogen that can be bound to carbon. A "heteroatom-containing group" is a
hydrocarbon radical that contains a heteroatom and may contain one or more of
the
same or different heteroatoms. In one embodiment, a heteroatom-containing
group
is a hydrocarbyl group containing from 1 to 3 atoms selected from the group
consisting of boron, aluminum, silicon, germanium, nitrogen, phosphorous,
oxygen
and sulfur. Non-limiting examples of heteroatom-containing groups include
radicals
of imines, amines, oxides, phosphines, ethers, ketones, oxoazolines
heterocyclics,
oxazolines, thioethers, and the like. The term "heterocyclic" refers to ring
systems
having a carbon backbone that comprise from 1 to 3 atoms selected from the
group
consisting of boron, aluminum, silicon, germanium, nitrogen, phosphorous,
oxygen
and sulfur.
As used herein the term "unsubstituted" means that hydrogen radicals are
bounded to the molecular group that follows the term unsubstituted. The term
"substituted" means that the group following this term possesses one or more
8
Date Recue/Date Received 2020-10-01
moieties that have replaced one or more hydrogen radicals in any position
within the
group; non-limiting examples of moieties include halogen radicals (F, Cl, Br),
hydroxyl groups, carbonyl groups, carboxyl groups, amine groups, phosphine
groups, alkoxy groups, phenyl groups, naphthyl groups, Ci to C30 alkyl groups,
C2 to
Co alkenyl groups, and combinations thereof. Non-limiting examples of
substituted
alkyls and aryls include: acyl radicals, alkylamino radicals, alkoxy radicals,
aryloxy
radicals, alkylthio radicals, dialkylamino radicals, alkoxycarbonyl radicals,
aryloxycarbonyl radicals, carbomoyl radicals, alkyl- and dialkyl-carbamoyl
radicals,
acyloxy radicals, acylamino radicals, arylamino radicals and combinations
thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the present disclosure, a thermoform able film will comprise a polyethylene
composition and the polyethylene composition will comprise at least the
following
types of polymers: a first polyethylene which is an ethylene copolymer and
which
has a Mw/Mn of less than about 2.3; a second polyethylene which is an ethylene
copolymer or an ethylene homopolymer which is different from the first
polyethylene
and which has a Mw/Mn of less than about 2.3; and a third polyethylene which
is an
ethylene copolymer or an ethylene homopolymer which has a Mw/Mn of greater
than
about 2.3. Each of these polyethylene components, and the polyethylene
composition of which they are each a part are further described below.
The First Polyethylene
In an embodiment of the disclosure, the first polyethylene is made with a
single site catalyst, non-limiting examples of which include phosphinimine
catalysts,
metallocene catalysts, and constrained geometry catalysts, all of which are
well
known in the art.
In an embodiment of the disclosure, the first polyethylene is an ethylene
copolymer. Suitable alpha-olefins which may be copolymerized with ethylene to
make an ethylene copolymer include 1-propene, 1-butene, 1-pentene, 1-hexene
and
1-octene.
In an embodiment of the disclosure, the first polyethylene is a homogeneously
branched ethylene copolymer.
In an embodiment of the disclosure, the first polyethylene is an ethylene/1-
octene copolymer.
9
Date Recue/Date Received 2020-10-01
In an embodiment of the disclosure, the first polyethylene is made with a
phosphinimine catalyst.
In an embodiment of the disclosure, a phosphinimine catalyst is represented
by formula:
(LA)aM(PI)b(Q)n
wherein (LA) represents is cyclopentadienyl-type ligand; M represents a metal
atom
selected from the group consisting of Ti, Zr, and Hf; PI represents a
phosphinimine
ligand; Q represents an activatable ligand; a is 0 or 1; b is 1 or 2; (a+b) =
2; n is 1 or
.. 2, and; the sum of (a+b+n) equals the valance of the metal M.
As used herein, the term "cyclopentadienyl-type" ligand is meant to include
ligands which contain at least one five-carbon ring which is bonded to the
metal via
eta-5 (or in some cases eta-3) bonding. Thus, the term "cyclopentadienyl-type"
includes, for example, unsubstituted cyclopentadienyl, singly or multiply
substituted
.. cyclopentadienyl, unsubstituted indenyl, singly or multiply substituted
indenyl,
unsubstituted fluorenyl and singly or multiply substituted fluorenyl.
Hydrogenated
versions of indenyl and fluorenyl ligands are also contemplated for use in the
current
disclosure, so long as the five-carbon ring which bonds to the metal via eta-5
(or in
some cases eta-3) bonding remains intact. Substituents for a cyclopentadienyl
.. ligand, an indenyl ligand (or hydrogenated version thereof) and a fluorenyl
ligand (or
hydrogenated version thereof) may be selected from the group consisting of a
C1-30
hydrocarbyl radical (which hydrocarbyl radical may be unsubstituted or further
substituted by for example a halide and/or a hydrocarbyl group; for example a
suitable substituted C1-30 hydrocarbyl radical is a pentafluorobenzyl group
such as ¨
.. CH2C6F5); a halogen atom; a C1_8 alkoxy radical; a C6-10 aryl or aryloxy
radical (each
of which may be further substituted by for example a halide and/or a
hydrocarbyl
group); an amido radical which is unsubstituted or substituted by up to two C1-
8 alkyl
radicals; a phosphido radical which is unsubstituted or substituted by up to
two C1-8
alkyl radicals; a silyl radical of the formula -Si(R')3 wherein each R' is
independently
.. selected from the group consisting of hydrogen, a C1-8 alkyl or alkoxy
radical, C6-10
aryl or aryloxy radicals; and a germanyl radical of the formula -Ge(R')3
wherein R' is
as defined directly above.
The phosphinimine ligand, PI, is defined by formula:
(RP)3 P = N -
Date Recue/Date Received 2020-10-01
wherein the RP groups are independently selected from: a hydrogen atom; a
halogen
atom; C1-20 hydrocarbyl radicals which are unsubstituted or substituted with
one or
more halogen atom(s); a C1_8 alkoxy radical; a C6-10 aryl radical; a C6-10
aryloxy
radical; an amido radical; a silyl radical of formula -Si(Rs)3, wherein the Rs
groups are
independently selected from, a hydrogen atom, a C1-8 alkyl or alkoxy radical,
a C6-10
aryl radical, a C6-10 aryloxy radical, or a germanyl radical of formula -
Ge(RG)3,
wherein the RG groups are defined as Rs is defined in this paragraph.
In an embodiment of the disclosure, the metal, M in the phosphinimine
catalyst is titanium, Ti.
In an embodiment of the disclosure, the single site catalyst used to make the
first polyethylene is cyclopentadienyl tri(tertiarybutyl)phosphinimine
titanium
dichloride, Cp((t-Bu)3PN)TiCl2.
In an embodiment of the disclosure, the first polyethylene is made with a
metallocene catalyst.
In an embodiment of the disclosure, the first polyethylene is made with a
bridged metallocene catalyst.
In an embodiment of the disclosure, the first polyethylene is made with a
bridged metallocene catalyst having the formula I:
R1
4' Q
R4
\V
ivi - Q
,G
,,, / R3
rx5 ilk
R2 I%
(I)
In Formula (I): M is a group 4 metal selected from titanium, zirconium or
hafnium; G is a group 14 element selected from carbon, silicon, germanium, tin
or
lead; Ri is a hydrogen atom, a C1-20 hydrocarbyl radical, a C1-20 alkoxy
radical or a
C6-10 aryl oxide radical; R2 and R3 are independently selected from a hydrogen
atom,
a C1-20 hydrocarbyl radical, a C1-20 alkoxy radical or a C6-10 aryl oxide
radical; R4 and
R5 are independently selected from a hydrogen atom, a C1-20 hydrocarbyl
radical, a
11
Date Recue/Date Received 2020-10-01
C1-20 alkoxy radical or a C6-10 aryl oxide radical; and Q is independently an
activatable leaving group ligand.
In the current disclosure, the term "activatable", means that the ligand Q may
be cleaved from the metal center M via a protonolysis reaction or abstracted
from the
metal center M by suitable acidic or electrophilic catalyst activator
compounds (also
known as "co-catalyst" compounds) respectively, examples of which are
described
below. The activatable ligand Q may also be transformed into another ligand
which
is cleaved or abstracted from the metal center M (e.g. a halide may be
converted to
an alkyl group). Without wishing to be bound by any single theory,
protonolysis or
abstraction reactions generate an active "cationic" metal center which can
polymerize olefins.
In embodiments of the present disclosure, the activatable ligand, Q is
independently selected from the group consisting of a hydrogen atom; a halogen
atom; a C1-20 hydrocarbyl radical, a C1-20 alkoxy radical, and a C6-10 aryl or
aryloxy
radical, where each of the hydrocarbyl, alkoxy, aryl, or aryl oxide radicals
may be un-
substituted or further substituted by one or more halogen or other group; a C1-
8 alkyl;
a C1-8 alkoxy; a C6-10 aryl or aryloxy; an amido or a phosphido radical, but
where Q is
not a cyclopentadienyl. Two Q ligands may also be joined to one another and
form
for example, a substituted or unsubstituted diene ligand (e.g. 1,3-butadiene);
or a
delocalized heteroatom containing group such as an acetate or acetamidinate
group.
In a convenient embodiment of the disclosure, each Q is independently selected
from the group consisting of a halide atom, a C1-4 alkyl radical and a benzyl
radical.
Particularly suitable activatable ligands Q are monoanionic such as a halide
(e.g.
chloride) or a hydrocarbyl (e.g. methyl, benzyl).
In an embodiment of the disclosure, the single site catalyst used to make the
first polyethylene is diphenylmethylene(cyclopentadienyl)(2,7-di-t-
butylfluorenyl)hafnium dichloride having the molecular formula: [(2,7-
tBu2Flu)Ph2C(Cp)HfC12].
In an embodiment of the disclosure the single site catalyst used to make the
first polyethylene has is diphenylmethylene(cyclopentadienyl)(2,7-di-t-
butylfluorenyl)hafnium dimethyl having the molecular formula [(2,7-
tBu2Flu)Ph2C(Cp)HfMe2].
In addition to the single site catalyst molecule per se, an active single site
catalyst system may further comprise one or more of the following: an
12
Date Recue/Date Received 2020-10-01
alkylaluminoxane co-catalyst and an ionic activator. The single site catalyst
system
may also optionally comprise a hindered phenol.
Although the exact structure of alkylaluminoxane is uncertain, subject matter
experts generally agree that it is an oligomeric species that contain
repeating units of
the general formula:
(R)2A10-(Al(R)-0)n-Al(R)2
where the R groups may be the same or different linear, branched or cyclic
hydrocarbyl radicals containing 1 to 20 carbon atoms and n is from 0 to about
50. A
non-limiting example of an alkylaluminoxane is methylaluminoxane (or MAO)
wherein each R group is a methyl radical.
In an embodiment of the disclosure, R of the alkylaluminoxane, is a methyl
radical and m is from 10 to 40.
In an embodiment of the disclosure, the co-catalyst is modified
methylaluminoxane (MMAO).
It is well known in the art, that the alkylaluminoxane can serve dual roles as
both an alkylator and an activator. Hence, an alkylaluminoxane co-catalyst is
often
used in combination with activatable ligands such as halogens.
In general, ionic activators are comprised of a cation and a bulky anion;
wherein the latter is substantially non-coordinating. Non-limiting examples of
ionic
activators are boron ionic activators that are four coordinate with four
ligands bonded
to the boron atom. Non-limiting examples of boron ionic activators include the
following formulas shown below;
[R9[B(R7)4]-
where B represents a boron atom, R5 is an aromatic hydrocarbyl (e.g. triphenyl
methyl cation) and each R7 is independently selected from phenyl radicals
which are
unsubstituted or substituted with from 3 to 5 substituents selected from
fluorine
atoms, C1-4 alkyl or alkoxy radicals which are unsubstituted or substituted by
fluorine
atoms; and a silyl radical of formula -Si(R9)3, where each R9 is independently
selected from hydrogen atoms and C1-4 alkyl radicals, and
[(R5)tZH][B(R7)4]-
where B is a boron atom, H is a hydrogen atom, Z is a nitrogen or phosphorus
atom,
t is 2 or 3 and R9 is selected from C1-8 alkyl radicals, phenyl radicals which
are
unsubstituted or substituted by up to three C1-4 alkyl radicals, or one R9
taken
13
Date Recue/Date Received 2020-10-01
together with the nitrogen atom may form an anilinium radical and R7 is as
defined
above.
In both formula a non-limiting example of R7 is a pentafluorophenyl radical.
In
general, boron ionic activators may be described as salts of
tetra(perfluorophenyl)
boron; non-limiting examples include anilinium, carbonium, oxonium,
phosphonium
and sulfonium salts of tetra(perfluorophenyl)boron with anilinium and trityl
(or
triphenylmethylium). Additional non-limiting examples of ionic activators
include:
triethylammonium tetra(phenyl)boron, tripropylammonium tetra(phenyl)boron,
tri(n-
butyl)ammonium tetra(phenyl)boron, trimethylammonium tetra(p-tolyl)boron,
trimethylammonium tetra(o-tolyl)boron, tributylammonium
tetra(pentafluorophenyl)boron, tripropylammonium tetra(o,p-
dimethylphenyl)boron,
tributylammonium tetra(m,m-dimethylphenyl)boron, tributylammonium tetra(p-
trifluoromethylphenyl)boron, tributylammonium tetra(pentafluorophenyl)boron,
tri(n-
butyl)ammonium tetra(o-tolyl)boron, N,N-dimethylanilinium tetra(phenyl)boron,
N,N-
diethylanilinium tetra(phenyl)boron, N,N-diethylanilinium tetra(phenyl)n-
butylboron,
N,N-2,4,6-pentamethylanilinium tetra(phenyl)boron, di-(isopropyl)ammonium
tetra(pentafluorophenyl)boron, dicyclohexylammonium tetra(phenyl)boron,
triphenylphosphonium tetra(phenyl)boron, tri(methylphenyl)phosphonium
tetra(phenyl)boron, tri(dimethylphenyl)phosphonium tetra(phenyl)boron,
tropillium
tetrakispentafluorophenyl borate, triphenylmethylium tetrakispentafluorophenyl
borate, benzene(diazonium)tetrakispentafluorophenyl borate, tropillium
tetrakis(2,3,5,6-tetrafluorophenyl)borate, triphenylmethylium tetrakis(2,3,5,6-
tetrafluorophenyl)borate, benzene(diazonium) tetrakis(3,4,5-
trifluorophenyl)borate,
tropillium tetrakis(3,4,5 -trifluorophenyl)borate, benzene(diazonium)
tetrakis(3,4,5-
trifluorophenyl)borate, tropillium tetrakis(1,2,2-trifluoroethenyl)borate,
triphenylmethylium tetrakis(1 ,2,2-trifluoroethenyl)borate, benzene(diazonium)
tetrakis(1,2,2-trifluoroethenyl)borate, tropillium tetrakis(2,3,4,5-
tetrafluorophenyl)borate, triphenylmethylium tetrakis(2,3,4,5-
tetrafluorophenyl)borate, and benzene(diazonium) tetrakis(2,3,4,5
tetrafluorophenyl)borate. Readily available commercial ionic activators
include N,N-
dimethylanilinium tetrakispentafluorophenyl borate, and triphenylmethylium
tetrakispentafluorophenyl borate.
Non-limiting example of hindered phenols include butylated phenolic
antioxidants, butylated hydroxytoluene, 2,6-di-tertiarybuty1-4-ethyl phenol,
4,4'-
14
Date Recue/Date Received 2020-10-01
methylenebis (2,6-di-tertiary-butylphenol), 1,3, 5-trimethy1-2,4,6-tris (3,5-
di-tert-buty1-
4-hydroxybenzyl) benzene and octadecy1-3-(3',5'-di-tert-butyl-4'-
hydroxyphenyl)
propionate.
To produce an active single site catalyst system the quantity and mole ratios
of the three or four components: the single site catalyst, the
alkylaluminoxane, the
ionic activator, and the optional hindered phenol are optimized.
In an embodiment of the disclosure, the single site catalyst used to make the
first polyethylene produces no long chain branches, and the first polyethylene
will
contain no measurable amounts of long chain branches.
In an embodiment of the disclosure, the single site catalyst used to make the
first polyethylene produces long chain branches, and the first polyethylene
will
contain long chain branches, hereinafter 'LOB'. LOB is a well-known structural
phenomenon in polyethylenes and well known to those of ordinary skill in the
art.
Traditionally, there are three methods for LCB analysis, namely, nuclear
magnetic
resonance spectroscopy (NMR), for example see J.C. Randall, J Macromol. Sci.,
Rev. Macromol. Chem. Phys. 1989, 29, 201; triple detection SEC equipped with a
DRI, a viscometer and a low-angle laser light scattering detector, for example
see
W.W. Yau and D.R. Hill, Int. J. Polym. Anal. Charact. 1996; 2:151; and
rheology, for
example see W.W. Graessley, Acc. Chem. Res. 1977, 10, 332-339. In this
disclosure, a long chain branch is macromolecular in nature, i.e. long enough
to be
seen in an NMR spectra, triple detector SEC experiments or rheological
experiments.
In embodiments of the disclosure, the upper limit on the molecular weight
distribution, Mw/Mn of the first polyethylene may be about 2.8, or about 2.5,
or about
2.4, or about 2.3, or about 2.2. In embodiments of the disclosure, the lower
limit on
the molecular weight distribution, Mw/Mn of the first polyethylene may be
about 1.4,
or about 1.6, or about 1.7, or about 1.8, or about 1.9.
In embodiments of the disclosure, the first polyethylene has a molecular
weight distribution, Mw/Mn of < 2.3, or < 2.1, or < 2.0 or about 2Ø In
embodiments
of the disclosure, the first polyethylene has a molecular weight distribution,
Mw/Mn of
from about 1.7 to about 2.2.
In an embodiment of the disclosure, the first polyethylene has from Ito 200
short chain branches per thousand carbon atoms (SCBpE-1). In further
embodiments,
the first polyethylene has from 3 to 150 short chain branches per thousand
carbon
Date Recue/Date Received 2020-10-01
atoms (SCBpE-1), or from 5 to 100 short chain branches per thousand carbon
atoms
(SCBpE-1), or from 10 to 100 short chain branches per thousand carbon atoms
(SCBpE-1), or from 5 to 75 short chain branches per thousand carbon atoms
(SCBpE_
1), or from 10 to 75 short chain branches per thousand carbon atoms (SCBpE-1),
or
from 15 to 75 short chain branches per thousand carbon atoms (SCBpE-1), or
from 20
to 75 short chain branches per thousand carbon atoms (SCBpE-1). In still
further
embodiments, the first polyethylene has from 20 to 100 short chain branches
per
thousand carbon atoms (SCBpE-1), or from 25 to 100 short chain branches per
thousand carbon atoms (SCBpE-1), or from 30 to 100 short chain branches per
.. thousand carbon atoms (SCBpE-1), or from 35 to 100 short chain branches per
thousand carbon atoms (SCBpE-1), or from 35 to 75 short chain branches per
thousand carbon atoms (SCBpE-1), or from 30 to 75 short chain branches per
thousand carbon atoms (SCBpE-1), or from 30 to 60 short chain branches per
thousand carbon atoms (SCBpE-1), or from 30 to 50 short chain branches per
.. thousand carbon atoms (SCBpE-1), or from 35 to 60 short chain branches per
thousand carbon atoms (SCBpE-1), or from 35 to 55 short chain branches per
thousand carbon atoms (SCBpE-1).
The short chain branching (i.e. the short chain branching per thousand
carbons, SCBpE_i) is the branching due to the presence of an alpha-olefin
comonomer in the polyethylene and will for example have two carbon atoms for a
1-
butene comonomer, or four carbon atoms for a 1-hexene comonomer, or six carbon
atoms for a 1-octene comonomer, etc.
In an embodiment of the disclosure, the number of short chain branches per
thousand carbon atoms in the first polyethylene (SCBpE-1), is greater than the
number of short chain branches per thousand carbon atoms in the second
polyethylene (SCBpE-2).
In an embodiment of the disclosure, the number of short chain branches per
thousand carbon atoms in the first polyethylene (SCBpE-1), is greater than the
number of short chain branches per thousand carbon atoms in the third
polyethylene
(SCBpE-3).
In an embodiment of the disclosure, the number of short chain branches per
thousand carbon atoms in the first polyethylene (SCBpE-1), is greater than the
number of short chain branches per thousand carbon atoms in each of the second
polyethylene (SCBpE-2) and the third polyethylene (SCBpE-3).
16
Date Recue/Date Received 2020-10-01
In embodiments of the disclosure, the upper limit on the density, dl of the
first
polyethylene may be about 0.975 g/cm3; in some cases about 0.965 g/cm3 and; in
other cases about 0.955 g/cm3. In embodiments of the disclosure, the lower
limit on
the density, dl of the first polyethylene may be about 0.855 g/cm3, in some
cases
about 0.865 g/cm3, and; in other cases about 0.875 g/cm3.
In embodiments of the disclosure the density, dl of the first polyethylene may
be from about 0.855 to about 0.965 g/cm3, or from 0.865 g/cm3 to about 0.965
g/cm3,
or from about 0.870 g/cm3 to about 0.960 g/cm3, or from about 0.865 g/cm3 to
0.950
g/cm3, or from about 0.865 g/cm3 to about 0.940 g/cm3, or from about 0.865
g/cm3 to
about 0.936 g/cm3, or from about 0.860 g/cm3 to about 0.932 g/cm3, or from
about
0.865 g/cm3 to about 0.926 g/cm3, or from about 0.865 g/cm3 to about 0.921
g/cm3,
or from about 0.865 g/cm3 to about 0.918 g/cm3, or from about 0.865 g/cm3 to
about
0.916 g/cm3, or from about 0.870 g/cm3 to about 0.916 g/cm3, or from about
0.865
g/cm3 to about 0.912 g/cm3, or from about 0.865 g/cm3 to about 0.910 g/cm3, or
from
about 0.865 g/cm3 to about 0.905 g/cm3, or from about 0.865 g/cm3 to about
0.900
g/cm3, or from about 0.855 g/cm3 to about 0.900 g/cm3, or from about 0.855
g/cm3 to
about 0.905 g/cm3, or from about 0.855 g/cm3 to about 0.910 g/cm3, or from
about
0.855 g/cm3 to about 0.916 g/cm3.
In embodiments of the disclosure, the upper limit on the CDBI50 of the first
polyethylene may be about 98 weight%, in other cases about 95 wt% and in still
other cases about 90 wt%. In embodiments of the disclosure, the lower limit on
the
CDBI50 of the first polyethylene may be about 70 weight%, in other cases about
75
wt% and in still other cases about 80 wt%.
In embodiments of the disclosure the melt index of the first polyethylene 121
may be from about 0.01 dg/min to about 1000 dg/min, or from about 0.01 dg/min
to
about 500 dg/min, or from about 0.01 dg/min to about 100 dg/min, or from about
0.01
dg/min to about 50 dg/min, or from about 0.01 dg/min to about 25 dg/min, or
from
about 0.01 dg/min to about 10 dg/min, or from about 0.01 dg/min to about 5
dg/min,
or from about 0.01 dg/min to about 3 dg/min, or from about 0.01 dg/min to
about 1
dg/min, or less than about 5 dg/min, or less than about 3 dg/min, or less than
about
1.0 dg/min, or less than about 0.75 dg/min, or less than about 0.50 dg/min.
In an embodiment of the disclosure, the first polyethylene has a weight
average molecular weight, Mw of from about 50,000 to about 300,000, or from
about
50,000 to about 250,000, or from about 60,000 to about 250,000, or from about
17
Date Recue/Date Received 2020-10-01
70,000 to about 250,000 or from about 60,000 to about 220,000, or from about
70,000 to about 200,000, or from about 75,000 to about 200,000, or from about
75,000 to about 175,000; or from about 70,000 to about 175,000, or from about
70,000 to about 150,000.
In an embodiment of the disclosure, the first polyethylene has a weight
average molecular weight, Mw which is greater than the weight average
molecular
weight, Mw of the second polyethylene.
In an embodiment of the disclosure, the first polyethylene has a weight
average molecular weight, Mw which is greater than the weight average
molecular
weight, Mw of the third polyethylene.
In an embodiment of the disclosure, the first polyethylene has a weight
average molecular weight, Mw which is within 30 percent of the weight average
molecular weight, Mw of the third polyethylene. For clarity, this means that:
the
absolute difference between the weight average molecular weight, Mw of the
first
polyethylene and the weight average molecular weight, Mw of the third
polyethylene
divided by the weight average molecular weight, Mw of the third polyethylene
and
converted to a percentage (i.e. [ I Mw1- Mw3 I / Mw3 ] x 100%) is within 25
percent.
In an embodiment of the disclosure, the first polyethylene has a weight
average molecular weight, Mw which is within 25 percent of the weight average
molecular weight, Mw of the third polyethylene. In an embodiment of the
disclosure,
the first polyethylene has a weight average molecular weight, Mw which is
within 20
percent of the weight average molecular weight, Mw of the third polyethylene.
In an
embodiment of the disclosure, the first polyethylene has a weight average
molecular
weight, Mw which is within 15 percent of the weight average molecular weight,
Mw of
the third polyethylene. In an embodiment of the disclosure, the first
polyethylene has
a weight average molecular weight, Mw which is within 10 percent of the weight
average molecular weight, Mw of the third polyethylene.
In embodiments of the disclosure, the upper limit on the weight percent (wt%)
.. of the first polyethylene in the polyethylene composition (i.e. the weight
percent of
the first polyethylene based on the total weight of the first, the second and
the third
polyethylene) may be about 80 wt%, or about 75 wt%, or about 70 wt%, or about
65
wt%, or about 60 wt%, or about 55 wt% or about 50 wt%, or about 45%, or about
40
%, or about 35%. In embodiments of the disclosure, the lower limit on the wt %
of
18
Date Recue/Date Received 2020-10-01
the first polyethylene in the polyethylene composition may be about 1 wt%, or
about
wt%, or about 10 wt%, or about 15 wt%, or about 20 wt%, or about 25 wt% or in
other cases about 30 wt%.
5 The Second Polyethylene
In an embodiment of the disclosure, the second polyethylene is made with a
single site catalyst, non-limiting examples of which include phosphinimine
catalysts,
metallocene catalysts, and constrained geometry catalysts, all of which are
well
known in the art.
In an embodiment of the disclosure, the second polyethylene is an ethylene
homopolymer.
In an embodiment of the disclosure, the second polyethylene is an ethylene
copolymer. Suitable alpha-olefins which may be copolymerized with ethylene to
make an ethylene copolymer include 1-propene, 1-butene, 1-pentene, 1-hexene
and
1-octene.
In an embodiment of the disclosure, the second polyethylene is a
homogeneously branched ethylene copolymer.
In an embodiment of the disclosure, the second polyethylene is an ethylene/1-
octene copolymer.
In an embodiment of the disclosure, the second polyethylene is made with a
phosphinimine catalyst.
In an embodiment of the disclosure, a phosphinimine catalyst is represented
by formula:
(LA)aM(P0b(Q)n
wherein (LA) represents is cyclopentadienyl-type ligand; M represents a metal
atom
selected from the group consisting of Ti, Zr, and Hf; PI represents a
phosphinimine
ligand; Q represents an activatable ligand; a is 0 or 1; b is 1 or 2; (a+b) =
2; n is 1 or
2, and; the sum of (a+b+n) equals the valance of the metal M.
As used herein, the term "cyclopentadienyl-type" ligand is meant to include
ligands which contain at least one five-carbon ring which is bonded to the
metal via
eta-5 (or in some cases eta-3) bonding. Thus, the term "cyclopentadienyl-type"
includes, for example, unsubstituted cyclopentadienyl, singly or multiply
substituted
cyclopentadienyl, unsubstituted indenyl, singly or multiply substituted
indenyl,
19
Date Recue/Date Received 2020-10-01
unsubstituted fluorenyl and singly or multiply substituted fluorenyl.
Hydrogenated
versions of indenyl and fluorenyl ligands are also contemplated for use in the
current
disclosure, so long as the five-carbon ring which bonds to the metal via eta-5
(or in
some cases eta-3) bonding remains intact. Substituents for a cyclopentadienyl
ligand, an indenyl ligand (or hydrogenated version thereof) and a fluorenyl
ligand (or
hydrogenated version thereof) may be selected from the group consisting of a
C1-30
hydrocarbyl radical (which hydrocarbyl radical may be unsubstituted or further
substituted by for example a halide and/or a hydrocarbyl group; for example a
suitable substituted C1-30 hydrocarbyl radical is a pentafluorobenzyl group
such as ¨
CH2C6F5); a halogen atom; a C1-8 alkoxy radical; a C6-10 aryl or aryloxy
radical (each
of which may be further substituted by for example a halide and/or a
hydrocarbyl
group); an amido radical which is unsubstituted or substituted by up to two C1-
8 alkyl
radicals; a phosphido radical which is unsubstituted or substituted by up to
two C1-8
alkyl radicals; a silyl radical of the formula -Si(R')3 wherein each R' is
independently
selected from the group consisting of hydrogen, a C1-8 alkyl or alkoxy
radical, C6-10
aryl or aryloxy radicals; and a germanyl radical of the formula -Ge(R')3
wherein R' is
as defined directly above.
The phosphinimine ligand, PI, is defined by formula:
(RP)3 P = N -
wherein the RP groups are independently selected from: a hydrogen atom; a
halogen
atom; C1-20 hydrocarbyl radicals which are unsubstituted or substituted with
one or
more halogen atom(s); a C1_8 alkoxy radical; a C6-10 aryl radical; a C6-10
aryloxy
radical; an amido radical; a silyl radical of formula -Si(Rs)3, wherein the Rs
groups are
independently selected from, a hydrogen atom, a C1-8 alkyl or alkoxy radical,
a C6-10
aryl radical, a C6-10 aryloxy radical, or a germanyl radical of formula -
Ge(RG)3,
wherein the RG groups are defined as Rs is defined in this paragraph.
In an embodiment of the disclosure, the metal, M in the phosphinimine
catalyst is titanium, Ti.
In an embodiment of the disclosure, the single site catalyst used to make the
second polyethylene is cyclopentadienyl tri(tertiarybutyl)phosphinimine
titanium
dichloride, Cp((t-Bu)3PN)TiCl2.
In an embodiment of the disclosure, the second polyethylene is made with a
metallocene catalyst.
Date Recue/Date Received 2020-10-01
In an embodiment of the disclosure, the second polyethylene is made with a
bridged metallocene catalyst.
In an embodiment of the disclosure, the second polyethylene is made with a
bridged metallocene catalyst having the formula I:
Ri
Q
R4 \,-'"
,G ivi_Q
R5/ R3
INk
R2 %
(I)
In Formula (I): M is a group 4 metal selected from titanium, zirconium or
hafnium; G is a group 14 element selected from carbon, silicon, germanium, tin
or
lead; Ri is a hydrogen atom, a C1-20 hydrocarbyl radical, a C1-20 alkoxy
radical or a
C6-10 aryl oxide radical; R2 and R3 are independently selected from a hydrogen
atom,
a C1-20 hydrocarbyl radical, a C1-20 alkoxy radical or a C6-10 aryl oxide
radical; R4 and
R5 are independently selected from a hydrogen atom, a C1-20 hydrocarbyl
radical, a
C1-20 alkoxy radical or a C6-10 aryl oxide radical; and Q is independently an
activatable leaving group ligand.
In the current disclosure, the term "activatable", means that the ligand Q may
be cleaved from the metal center M via a protonolysis reaction or abstracted
from the
metal center M by suitable acidic or electrophilic catalyst activator
compounds (also
known as "co-catalyst" compounds) respectively, examples of which are
described
below. The activatable ligand Q may also be transformed into another ligand
which
is cleaved or abstracted from the metal center M (e.g. a halide may be
converted to
an alkyl group). Without wishing to be bound by any single theory,
protonolysis or
abstraction reactions generate an active "cationic" metal center which can
polymerize olefins.
In embodiments of the present disclosure, the activatable ligand, Q is
independently selected from the group consisting of a hydrogen atom; a halogen
atom; a C1-20 hydrocarbyl radical, a C1-20 alkoxy radical, and a C6-10 aryl or
aryloxy
21
Date Recue/Date Received 2020-10-01
radical, where each of the hydrocarbyl, alkoxy, aryl, or aryl oxide radicals
may be un-
substituted or further substituted by one or more halogen or other group; a C1-
8 alkyl;
a C1-8 alkoxy; a C6-10 aryl or aryloxy; an amido or a phosphido radical, but
where Q is
not a cyclopentadienyl. Two Q ligands may also be joined to one another and
form
for example, a substituted or unsubstituted diene ligand (e.g. 1,3-butadiene);
or a
delocalized heteroatom containing group such as an acetate or acetamidinate
group.
In a convenient embodiment of the disclosure, each Q is independently selected
from the group consisting of a halide atom, a C1-4 alkyl radical and a benzyl
radical.
Particularly suitable activatable ligands Q are monoanionic such as a halide
(e.g.
chloride) or a hydrocarbyl (e.g. methyl, benzyl).
In an embodiment of the disclosure, the single site catalyst used to make the
second polyethylene is diphenylmethylene(cyclopentadienyl)(2,7-di-t-
butylfluorenyl)hafnium dichloride having the molecular formula: [(2,7-
tBu2Flu)Ph2C(Cp)HfC12].
In an embodiment of the disclosure the single site catalyst used to make the
second polyethylene has is diphenylmethylene(cyclopentadienyl)(2,7-di-t-
butylfluorenyl)hafnium dimethyl having the molecular formula [(2,7-
tBu2Flu)Ph2C(Cp)HfMe2].
In addition to the single site catalyst molecule per se, an active single site
catalyst system may further comprise one or more of the following: an
alkylaluminoxane co-catalyst and an ionic activator. The single site catalyst
system
may also optionally comprise a hindered phenol.
Although the exact structure of alkylaluminoxane is uncertain, subject matter
experts generally agree that it is an oligomeric species that contain
repeating units of
the general formula:
(R)2A10-(Al(R)-0)n-Al(R)2
where the R groups may be the same or different linear, branched or cyclic
hydrocarbyl radicals containing 1 to 20 carbon atoms and n is from 0 to about
50. A
non-limiting example of an alkylaluminoxane is methylaluminoxane (or MAO)
wherein each R group is a methyl radical.
In an embodiment of the disclosure, R of the alkylaluminoxane, is a methyl
radical and m is from 10 to 40.
In an embodiment of the disclosure, the co-catalyst is modified
methylaluminoxane (MMAO).
22
Date Recue/Date Received 2020-10-01
It is well known in the art, that the alkylaluminoxane can serve dual roles as
both an alkylator and an activator. Hence, an alkylaluminoxane co-catalyst is
often
used in combination with activatable ligands such as halogens.
In general, ionic activators are comprised of a cation and a bulky anion;
wherein the latter is substantially non-coordinating. Non-limiting examples of
ionic
activators are boron ionic activators that are four coordinate with four
ligands bonded
to the boron atom. Non-limiting examples of boron ionic activators include the
following formulas shown below;
[R5][B(R7).4]-
where B represents a boron atom, R5 is an aromatic hydrocarbyl (e.g. triphenyl
methyl cation) and each R7 is independently selected from phenyl radicals
which are
unsubstituted or substituted with from 3 to 5 substituents selected from
fluorine
atoms, C1-4 alkyl or alkoxy radicals which are unsubstituted or substituted by
fluorine
atoms; and a silyl radical of formula -Si(R9)3, where each R9 is independently
selected from hydrogen atoms and C1-4 alkyl radicals, and
[(R5)tZH][B(R7).4]-
where B is a boron atom, H is a hydrogen atom, Z is a nitrogen or phosphorus
atom,
t is 2 or 3 and R5 is selected from C1-8 alkyl radicals, phenyl radicals which
are
unsubstituted or substituted by up to three C1-4 alkyl radicals, or one R5
taken
together with the nitrogen atom may form an anilinium radical and R7 is as
defined
above.
In both formula a non-limiting example of R7 is a pentafluorophenyl radical.
In
general, boron ionic activators may be described as salts of
tetra(perfluorophenyl)
boron; non-limiting examples include anilinium, carbonium, oxonium,
phosphonium
and sulfonium salts of tetra(perfluorophenyl)boron with anilinium and trityl
(or
triphenylmethylium). Additional non-limiting examples of ionic activators
include:
triethylammonium tetra(phenyl)boron, tripropylammonium tetra(phenyl)boron,
tri(n-
butyl)ammonium tetra(phenyl)boron, trimethylammonium tetra(p-tolyl)boron,
trimethylammonium tetra(o-tolyl)boron, tributylammonium
tetra(pentafluorophenyl)boron, tripropylammonium tetra(o,p-
dimethylphenyl)boron,
tributylammonium tetra(m,m-dimethylphenyl)boron, tributylammonium tetra(p-
trifluoromethylphenyl)boron, tributylammonium tetra(pentafluorophenyl)boron,
tri(n-
butyl)ammonium tetra(o-tolyl)boron, N,N-dimethylanilinium tetra(phenyl)boron,
N,N-
diethylanilinium tetra(phenyl)boron, N,N-diethylanilinium tetra(phenyl)n-
butylboron,
23
Date Recue/Date Received 2020-10-01
N,N-2,4,6-pentamethylanilinium tetra(phenyl)boron, di-(isopropyl)ammonium
tetra(pentafluorophenyl)boron, dicyclohexylammonium tetra(phenyl)boron,
triphenylphosphonium tetra(phenyl)boron, tri(methylphenyl)phosphonium
tetra(phenyl)boron, tri(dimethylphenyl)phosphonium tetra(phenyl)boron,
tropillium
tetrakispentafluorophenyl borate, triphenylmethyli urn
tetrakispentafluorophenyl
borate, benzene(diazonium)tetrakispentafluorophenyl borate, tropillium
tetrakis(2,3,5,6-tetrafluorophenyl)borate, triphenylmethylium tetrakis(2,3,5,6-
tetrafluorophenyl)borate, benzene(diazonium) tetrakis(3,4,5-
trifluorophenyl)borate,
tropillium tetrakis(3,4,5 -trifluorophenyl)borate, benzene(diazonium)
tetrakis(3,4,5-
trifluorophenyl)borate, tropillium tetrakis(1,2,2-trifluoroethenyl)borate,
triphenylmethylium tetrakis(1 ,2,2-trifluoroethenyl)borate, benzene(diazonium)
tetrakis(1,2,2-trifluoroethenyl)borate, tropillium tetrakis(2,3,4,5-
tetrafluorophenyl)borate, triphenylmethylium tetrakis(2,3,4,5-
tetrafluorophenyl)borate, and benzene(diazonium) tetrakis(2,3,4,5
tetrafluorophenyl)borate. Readily available commercial ionic activators
include N,N-
dimethylanilinium tetrakispentafluorophenyl borate, and triphenylmethylium
tetrakispentafluorophenyl borate.
Non-limiting example of hindered phenols include butylated phenolic
antioxidants, butylated hydroxytoluene, 2,6-di-tertiarybuty1-4-ethyl phenol,
4,4'-
methylenebis (2,6-di-tertiary-butylphenol), 1,3, 5-trimethy1-2,4,6-tris (3,5-
di-tert-buty1-
4-hydroxybenzyl) benzene and octadecy1-3-(3',5'-di-tert-butyl-4'-
hydroxyphenyl)
propionate.
To produce an active single site catalyst system the quantity and mole ratios
of the three or four components: the single site catalyst, the
alkylaluminoxane, the
ionic activator, and the optional hindered phenol are optimized.
In an embodiment of the disclosure, the single site catalyst used to make the
second polyethylene produces no long chain branches, and the second
polyethylene
will contain no measurable amounts of long chain branches.
In an embodiment of the disclosure, the single site catalyst used to make the
second polyethylene produces long chain branches, and the second polyethylene
will contain long chain branches, hereinafter `LCB'. LCB is a well-known
structural
phenomenon in polyethylenes and well known to those of ordinary skill in the
art.
Traditionally, there are three methods for LCB analysis, namely, nuclear
magnetic
resonance spectroscopy (NMR), for example see J.C. Randall, J Macromol. Sci.,
24
Date Recue/Date Received 2020-10-01
Rev. Macromol. Chem. Phys. 1989, 29, 201; triple detection SEC equipped with a
DRI, a viscometer and a low-angle laser light scattering detector, for example
see
W.W. Yau and D.R. Hill, Int. J. Polym. Anal. Charact. 1996; 2:151; and
rheology, for
example see W.W. Graessley, Acc. Chem. Res. 1977, 10, 332-339. In this
disclosure, a long chain branch is macromolecular in nature, i.e. long enough
to be
seen in an NMR spectra, triple detector SEC experiments or rheological
experiments.
In embodiments of the disclosure, the upper limit on the molecular weight
distribution, Mw/Mn of the second polyethylene may be about 2.8, or about 2.5,
or
about 2.4, or about 2.3, or about 2.2. In embodiments of the disclosure, the
lower
limit on the molecular weight distribution, Mw/Mn of the second polyethylene
may be
about 1.4, or about 1.6, or about 1.7, or about 1.8, or about 1.9.
In embodiments of the disclosure, the second polyethylene has a molecular
weight distribution, Mw/Mn of < 2.3, or < 2.1, or < 2.0 or about 2Ø In
embodiments
of the disclosure, the second polyethylene has a molecular weight
distribution, Mw/Mn
of from about 1.7 to about 2.2.
In an embodiment of the disclosure, the second polyethylene has from 0 to
100 short chain branches per thousand carbon atoms (SCBpE-2). In further
embodiments, the second polyethylene has from 0 to 30 short chain branches per
thousand carbon atoms (SCBpE-2), or from 0 to 20 short chain branches per
thousand carbon atoms (SCBpE-2), or from 0 to 15 short chain branches per
thousand carbon atoms (SCBpE-2), or from 0 to 10 short chain branches per
thousand carbon atoms (SCBpE-2), or from 0 to 5 short chain branches per
thousand
carbon atoms (SCBpE-2), or fewer than 5 short chain branches per thousand
carbon
atoms (SCBpE-2), or fewer than 3 short chain branches per thousand carbon
atoms
(SCBpE-2), or fewer than 1 short chain branches per thousand carbon atoms
(SCBpE2) , or about zero short chain branches per thousand carbon atoms (SCBpE-
2).
The short chain branching (i.e. the short chain branching per thousand
carbons, SCBpE-1) is the branching due to the presence of an alpha-olefin
comonomer in the polyethylene and will for example have two carbon atoms for a
1-
butene comonomer, or four carbon atoms for a 1-hexene comonomer, or six carbon
atoms for a 1-octene comonomer, etc.
In embodiments of the disclosure, the upper limit on the density, d2 of the
second polyethylene may be about 0.985 g/cm3; in some cases about 0.975 g/cm3
Date Recue/Date Received 2020-10-01
and; in other cases about 0.965 g/cm3. In embodiments of the disclosure, the
lower
limit on the density, d2 of the second polyethylene may be about 0.921 g/cm3,
in
some cases about 0.932 g/cm3, and; in other cases about 0.949 g/cm3.
In embodiments of the disclosure the density, d2 of the second polyethylene
may be from about 0.921 g/cm3 to about 0.980 g/cm3, or from about 0.921 g/cm3
to
about 0.975 g/cm3, or from about 0.926 g/cm3 to about 0.975 g/cm3, or from
about
0.930 g/cm3to about 0.975 g/cm3, or from about 0.936 g/cm3to about 0.975
g/cm3,
or from about 0.940 g/cm3 to about 0.975 g/cm3, or from about 0.940 g/cm3to
about
0.980 g/cm3, or from about 0.945 g/cm3 to about 0.975 g/cm3, or from about
0.950
g/cm3 to about 0.975 g/cm3, or from about 0.951 g/cm3 to about 0.975 g/cm3, or
from
about 0.953 g/cm3 to about 0.975 g/cm3, or from about 0.953 g/cm3 to about
0.985
g/cm3.
In embodiments of the disclosure the melt index of the second polyethylene
122 may be from about 0.01 dg/min to about 1000 dg/min, or from about 0.01
dg/min
to about 500 dg/min, or from about 0.01 dg/min to about 100 dg/min, or from
about
0.01 dg/min to about 50 dg/min, or from about 0.1 dg/min to about 100 dg/min,
or
from about 0.1 dg/min to about 75 dg/min, or from about 0.1 dg/min to about 50
dg/min, or from about 1 dg/min to about 50 dg/min, or from about 1 dg/min to
about
40 dg/min, or from about 1 dg/min to about 30 dg/min, or from about 1 dg/min
to
about 25 dg/min, or from about 3 dg/min to about 25 dg/min, or from about 5
dg/min
to about 20 dg/min.
In an embodiment of the disclosure, the second polyethylene has a weight
average molecular weight, Mw of from about 10,000 to about 150,000, or from
about
10,000 to about 125,000, or from about 15,000 to about 100,000, or from about
15,000 to about 90,000, or from about 15,000 to about 80,000 or from about
20,000
to about 75,000, or from about 25,000 to about 90,000, or from about 25,000 to
about 80,000, or from about 25,000 to about 75,000.
In an embodiment of the disclosure, the weight average molecular weight of
the second polyethylene is less than the weight average molecular weight of
the first
polyethylene.
In an embodiment of the disclosure, the weight average molecular weight of
the second polyethylene is less than the weight average molecular weight of
the third
polyethylene.
26
Date Recue/Date Received 2020-10-01
In an embodiment of the disclosure, the weight average molecular weight of
the second polyethylene is less than the weight average molecular weight of
both the
first polyethylene and the third polyethylene.
In embodiments of the disclosure, the upper limit on the weight percent (wt%)
of the second polyethylene in the polyethylene composition (i.e. the weight
percent
of the second polyethylene based on the total weight of the first, the second
and the
third polyethylene) may be about 80 wt%, or about 75 wt%, or about 70 wt%, or
about 65 wt%, or about 60 wt%, or about 55 wt%, or about 50 wt%, or about 45
wt%,
or about 40 wt%. In embodiments of the disclosure, the lower limit on the wt %
of
the second polyethylene in the polyethylene composition may be about 5 wt%, or
about 10 wt%, or about 15 wt%, or about 20 wt%.
The Third Polyethylene
In an embodiment of the disclosure, the third polyethylene is made with a
multi-site catalyst system, non-limiting examples of which include Ziegler-
Natta
catalysts and chromium catalysts, both of which are well known in the art.
In an embodiment of the disclosure, the third polyethylene is made with a
Ziegler-Natta catalyst.
Ziegler-Natta catalyst systems are well known to those skilled in the art. A
Ziegler-Natta catalyst may be an in-line Ziegler-Natta catalyst system or a
batch
Ziegler-Natta catalyst system. The term "in-line Ziegler-Natta catalyst
system" refers
to the continuous synthesis of a small quantity of an active Ziegler-Natta
catalyst
system and immediately injecting this catalyst into at least one continuously
operating reactor, wherein the catalyst polymerizes ethylene and one or more
optional a-olefins to form an ethylene polymer. The terms "batch Ziegler-Natta
catalyst system" or "batch Ziegler-Natta procatalyst" refer to the synthesis
of a much
larger quantity of catalyst or procatalyst in one or more mixing vessels that
are
external to, or isolated from, the continuously operating solution
polymerization
process. Once prepared, the batch Ziegler-Natta catalyst system, or batch
Ziegler-
Natta procatalyst, is transferred to a catalyst storage tank. The term
"procatalyst"
refers to an inactive catalyst system (inactive with respect to ethylene
polymerization); the procatalyst is converted into an active catalyst by
adding an
alkyl aluminum co-catalyst. As needed, the procatalyst is pumped from the
storage
tank to at least one continuously operating reactor, wherein an active
catalyst
27
Date Recue/Date Received 2020-10-01
polymerizes ethylene and one or more optional a-olefins to form a
polyethylene. The
procatalyst may be converted into an active catalyst in the reactor or
external to the
reactor, or on route to the reactor.
A wide variety of compounds can be used to synthesize an active Ziegler-
Natta catalyst system. The following describes various compounds that may be
combined to produce an active Ziegler-Natta catalyst system. Those skilled in
the
art will understand that the embodiments in this disclosure are not limited to
the
specific compounds disclosed.
An active Ziegler-Natta catalyst system may be formed from: a magnesium
compound, a chloride compound, a metal compound, an alkyl aluminum co-catalyst
and an aluminum alkyl. As will be appreciated by those skilled in the art,
Ziegler-
Natta catalyst systems may contain additional components; a non-limiting
example
of an additional component is an electron donor, e.g. amines or ethers.
A non-limiting example of an active in-line (or batch) Ziegler-Natta catalyst
system can be prepared as follows. In the first step, a solution of a
magnesium
compound is reacted with a solution of a chloride compound to form a magnesium
chloride support suspended in solution. Non-limiting examples of magnesium
compounds include Mg(R1)2; wherein the R1 groups may be the same or different,
linear, branched or cyclic hydrocarbyl radicals containing Ito 10 carbon
atoms.
Non-limiting examples of chloride compounds include R2CI; wherein R2
represents a
hydrogen atom, or a linear, branched or cyclic hydrocarbyl radical containing
Ito 10
carbon atoms. In the first step, the solution of magnesium compound may also
contain an aluminum alkyl. Non-limiting examples of aluminum alkyl include
Al(R3)3,
wherein the R3 groups may be the same or different, linear, branched or cyclic
hydrocarbyl radicals containing from Ito 10 carbon atoms. In the second step a
solution of the metal compound is added to the solution of magnesium chloride
and
the metal compound is supported on the magnesium chloride. Non-limiting
examples of suitable metal compounds include M(X) n or MO(X)n; where M
represents
a metal selected from Group 4 through Group 8 of the Periodic Table, or
mixtures of
metals selected from Group 4 through Group 8; 0 represents oxygen, and; X
represents chloride or bromide; n is an integer from 3 to 6 that satisfies the
oxidation
state of the metal. Additional non-limiting examples of suitable metal
compounds
include Group 4 to Group 8 metal alkyls, metal alkoxides (which may be
prepared by
reacting a metal alkyl with an alcohol) and mixed-ligand metal compounds that
28
Date Recue/Date Received 2020-10-01
contain a mixture of halide, alkyl and alkoxide ligands. In the third step a
solution of
an alkyl aluminum co-catalyst is added to the metal compound supported on the
magnesium chloride. A wide variety of alkyl aluminum co-catalysts are
suitable, as
expressed by formula:
Al(R4)p(0R9)q(X)r
wherein the R4 groups may be the same or different, hydrocarbyl groups having
from
1 to 10 carbon atoms; the OR9 groups may be the same or different, alkoxy or
aryloxy groups wherein R9 is a hydrocarbyl group having from Ito 10 carbon
atoms
bonded to oxygen; X is chloride or bromide, and; (p+q+r) = 3, with the proviso
that p
is greater than 0. Non-limiting examples of commonly used alkyl aluminum co-
catalysts include trimethyl aluminum, triethyl aluminum, tributyl aluminum,
dimethyl
aluminum methoxide, diethyl aluminum ethoxide, dibutyl aluminum butoxide,
dimethyl aluminum chloride or bromide, diethyl aluminum chloride or bromide,
dibutyl
aluminum chloride or bromide and ethyl aluminum dichloride or dibromide.
The process described in the paragraph above, to synthesize an active in-line
(or batch) Ziegler-Natta catalyst system, can be carried out in a variety of
solvents;
non-limiting examples of solvents include linear or branched C5 to C12 alkanes
or
mixtures thereof.
In an embodiment of the disclosure, the third polyethylene is an ethylene
copolymer. Suitable alpha-olefins which may be copolymerized with ethylene to
give
the third polyethylene include 1-propene, 1-butene, 1-pentene, 1-hexene and 1-
octene.
In an embodiment of the disclosure, the third polyethylene is an ethylene
homopolymer.
In an embodiment of the disclosure, the third polyethylene is a
heterogeneously branched ethylene copolymer.
In an embodiment of the disclosure, the third polyethylene is an ethylene/1-
octene copolymer.
In embodiments of the disclosure, the third polyethylene has a molecular
weight distribution, Mw/Mn of 2.3, or > 2.3, or 2.5, or > 2.5, or 2.7, or >
2.7, or
2.9, or > 2.9, or 3.0, or 3Ø In embodiments of the disclosure, the third
polyethylene has a molecular weight distribution, Mw/Mn of from 2.3 to 6.5, or
from
2.3 to 6.0, or from 2.3 to 5.5, or from 2.3 to 5.0, or from 2.3 to 4.5, or
from 2.3 to 4.0,
29
Date Recue/Date Received 2020-10-01
or from 2.5 to 6.0, or from 2.5 to 5.5, or from 2.5 to 5.0, or from 2.5 to
4.5, or from 2.5
to 4.0, or from 2.7 to 6.0, or from 2.7 to 5.5, or from 2.7 to 5.0, or from
2.7 to 4.5, or
from 2.9 to 6.5, or from 2.9 to 6.0, or from 2.9 to 5.5, or from 2.9 to 5.0,
or from 2.9 to
4.5.
In an embodiment of the disclosure, the third polyethylene has from 0 to 100
short chain branches per thousand carbon atoms (SCBpE-3). In further
embodiments,
the third polyethylene has from 0 to 50 short chain branches per thousand
carbon
atoms (SCBpE-3), or from 0 to 35 short chain branches per thousand carbon
atoms
(SCBpE-3), or from 3 to 30 short chain branches per thousand carbon atoms
(SCBpE_
3), or from 5 to 30 short chain branches per thousand carbon atoms (SCBpE-3),
or
from 5 to 25 short chain branches per thousand carbon atoms (SCBpE-3), or from
3 to
25 short chain branches per thousand carbon atoms (SCBpE-3), or from Ito 25
short
chain branches per thousand carbon atoms (SCBpE-3), or from 0.1 to 20 short
chain
branches per thousand carbon atoms (SCBpE-3).
The short chain branching (i.e. the short chain branching per thousand
carbons, SCBpE_3), if present, is the branching due to the presence of alpha-
olefin
comonomer in the polyethylene and will for example have two carbon atoms for a
1-
butene comonomer, or four carbon atoms for a 1-hexene comonomer, or six carbon
atoms for a 1-octene comonomer, etc.
In an embodiment of the disclosure, the number of short chain branches per
thousand carbon atoms in the third polyethylene (SCBpE-3) is greater than the
number of short chain branches per thousand carbon atoms in the second
polyethylene (SCBpE-2).
In embodiments of the disclosure, the upper limit on the density, d3 of the
third polyethylene may be about 0.975 g/cm3; in some cases, about 0.965 g/cm3
and
in other cases about 0.955 g/cm3. In embodiments of the disclosure, the lower
limit
on the density, d3 of the third polyethylene may be about 0.855 g/cm3, in some
cases about 0.865 g/cm3, and in other cases about 0.875 g/cm3.
In embodiments of the disclosure the density, d3 of the third polyethylene may
be from about 0.875 g/cm3 to about 0.965 g/cm3, or from about 0.875 g/cm3 to
about
0.960 g/cm3, or from about 0.875 g/cm3 to 0.950 g/cm3, or from about 0.865
g/cm3 to
about 0.940 g/cm3, or from about 0.865 g/cm3 to about 0.936 g/cm3, or from
about
0.865 g/cm3 to about 0.932 g/cm3, or from about 0.865 g/cm3 to about 0.926
g/cm3,
or from about 0.865 g/cm3 to about 0.921 g/cm3, or from about 0.865 g/cm3 to
about
Date Recue/Date Received 2020-10-01
0.918 g/cm3, or from about 0.875 g/cm3 to about 0.916 g/cm3, or from about
0.875
g/cm3 to about 0.916 g/cm3, or from about 0.865 g/cm3 to about 0.912 g/cm3, or
from
about 0.880 g/cm3 to about 0.912 g/cm3, or from about 0.890 g/cm3 to about
0.916
g/cm3, or from about 0.900 g/cm3 to about 0.916 g/cm3, or from about 0.880
g/cm3 to
about 0.916 g/cm3, or from about 0.880 g/cm3 to about 0.918 g/cm3, or from
about
0.880 g/cm3 to about 0.921 g/cm3, or from about 0.880 g/cm3 to about 0.926
g/cm3,
or from about 0.880 g/cm3 to about 0.932 g/cm3, or from about 0.880 g/cm3 to
about
0.936 g/cm3.
In an embodiment of the disclosure, the third polyethylene is an ethylene
copolymer which has a composition distribution breadth index, CDBI50 of 75 wt%
or
less, or 70 wt% or less. In further embodiments of the disclosure, the third
polyethylene is an ethylene copolymer which has a CDBI50 of 65 wt% or less, or
60
wt% or less, or 55 wt% or less, or 50 wt% or less, or 45 wt% or less.
In embodiments of the disclosure the melt index of the third polyethylene 123
may be from about 0.01 dg/min to about 1000 dg/min, or from about 0.01 dg/min
to
about 500 dg/min, or from about 0.01 dg/min to about 100 dg/min, or from about
0.01
dg/min to about 50 dg/min, or from about 0.01 dg/min to about 25 dg/min, or
from
about 0.01 dg/min to about 10 dg/min, or from about 0.01 dg/min to about 5
dg/min,
or from about 0.01 dg/min to about 3 dg/min, or from about 0.01 dg/min to
about 1
dg/min, or less than about 5 dg/min, or less than about 3 dg/min, or less than
about
1.0 dg/min, or less than about 0.75 dg/min, or less than about 0.50 dg/min.
In an embodiment of the disclosure, the third polyethylene has a weight
average molecular weight, Mw of from about 50,000 to about 300,000, or from
about
50,000 to about 250,000, or from about 60,000 to about 250,000, or from about
70,000 to about 250,000, or from about 75,000 to about 200,000, or from about
80,000 to about 275,000; or from about 80,000 to about 250,000, or from about
80,000 to about 200,000, or from 70,000 to about 200,000, or from about 80,000
to
about 175,000.
In an embodiment of the disclosure, the third polyethylene has a weight
average molecular weight, Mw which is greater than the weight average
molecular
weight, Mw of the first polyethylene.
In an embodiment of the disclosure, the third polyethylene has a weight
average molecular weight, Mw which is greater than the weight average
molecular
weight, Mw of the second polyethylene.
31
Date Recue/Date Received 2020-10-01
In embodiments of the disclosure, the upper limit on the weight percent (wt%)
of the third polyethylene in the polyethylene composition (i.e. the weight
percent of
the third polyethylene based on the total weight of the first, the second and
the third
polyethylene) may be about 90 wt%, or about 85 wt%, or about 80 wt%, or about
75
wt%, 0r65 wt%, in other cases about 60 wt%, in other cases about 55 wt%, or
about
50 wt%, or about 45 wt%. In embodiments of the disclosure, the lower limit on
the wt
% of the third polyethylene in the final polyethylene product may be about 5
wt%, or
about 10 wt%, or about 15 wt%, or about 20 wt%, or about 25 wt%, or about 30
wt%,
or about 35 wt%, or in other cases about 40 wt%.
In embodiments of the disclosure, the third polyethylene has no long chain
branching present or does not have any detectable levels of long chain
branching.
The Polyethylene Composition
The polyethylene compositions disclosed herein can be made using any well-
known techniques in the art, including but not limited to melt blending,
solution
blending, or in-reactor blending to bring together a first polyethylene, a
second
polyethylene and a third polyethylene.
In an embodiment, the polyethylene composition of the present disclosure is
made by melt blending or solution blending three different polyethylene
components:
i) a first polyethylene, ii) a second polyethylene, and iii) a third
polyethylene.
In an embodiment, the polyethylene composition of the present disclosure is
made by melt blending or solution blending two different polyethylene
components: i)
a first polyethylene component comprising a first polyethylene and a second
polyethylene, and ii) second polyethylene component comprising a third
polyethylene.
In an embodiment, the polyethylene composition of the present disclosure is
made by melt blending or solution blending two different polyethylene
components: i)
a first polyethylene component comprising a first polyethylene and ii) a
second
polyethylene component comprising a second polyethylene and a third
polyethylene.
In an embodiment, the polyethylene composition of the present disclosure is
made by melt blending or solution blending two different polyethylene
components:
i) a first polyethylene component comprising a first polyethylene and a third
polyethylene, and ii) a second polyethylene component comprising a second
polyethylene.
32
Date Recue/Date Received 2020-10-01
In an embodiment, the polyethylene composition of the present disclosure is
made using the same single site catalyst in two different reactors, where each
reactor is operated under different polymerization conditions to give a first
polyethylene and a second polyethylene, and using a multi-site catalyst in
another
reactor to give the third polyethylene.
In an embodiment, the polyethylene composition of the present disclosure is
made using a different single site catalyst in two different reactors, where
each
reactor is operated under similar or different polymerization conditions to
give a first
polyethylene and a second polyethylene, and using a multi-site catalyst in
another
reactor to give the third polyethylene.
It is also contemplated by the present disclosure, that the polymer
compositions comprising a first, second and third polyethylene could be made
in one
or more polymerization reactor, using two different single site polymerization
catalysts and a multi-site polymerization catalyst, where each catalyst has a
different
response to one or more of hydrogen concentration, ethylene concentration,
comonomer concentration, and temperature under a given set of polymerization
conditions, so that the first polyethylene is produced by the first single
site catalyst,
the second polyethylene is produced by the second single site catalyst, and
the third
polyethylene is produced by the multi-site catalyst.
It is also contemplated by the present disclosure, that the polymer
compositions comprising a first, second and third polyethylene could be made
in one
or more polymerization reactors, using one or more single site polymerization
catalysts, and one multi-site catalyst, where each catalyst has a similar or
different
response to one or more of hydrogen concentration, ethylene concentration,
comonomer concentration, and temperature under a given set of polymerization
conditions, and where one or more of hydrogen concentration, ethylene
concentration, comonomer concentration, and temperature are cycled through a
range so that a first, second and a third polyethylene is produced by the one
or more
single site catalysts and the one multi-site catalyst present in the one or
more
polymerization reactors.
In an embodiment, the polyethylene composition of the present disclosure is
made by forming a first polyethylene in a first reactor by polymerizing
ethylene and
an alpha olefin with a single site catalyst; forming a second polyethylene in
a second
reactor by polymerizing ethylene and optionally an alpha olefin with a single
site
33
Date Recue/Date Received 2020-10-01
catalyst, and forming a third polyethylene in a third reactor by polymerizing
ethylene
and optionally an alpha olefin with a multi-site catalyst.
In an embodiment, the polyethylene composition of the present disclosure is
made by forming a first polyethylene in a first reactor by polymerizing
ethylene and
an alpha olefin with a single site catalyst; forming a second polyethylene in
a second
reactor by polymerizing ethylene and optionally an alpha olefin with a single
site
catalyst, and forming a third polyethylene in a third reactor by polymerizing
ethylene
and optionally an alpha olefin with a multi-site catalyst, where at least two
of the first,
second and third reactors are configured in series with one another.
In an embodiment, the polyethylene composition of the present disclosure is
made by forming a first polyethylene in a first solution phase polymerization
reactor
by polymerizing ethylene and an alpha olefin with a single site catalyst;
forming a
second polyethylene in a second solution phase polymerization reactor by
polymerizing ethylene and optionally an alpha olefin with a single site
catalyst, and
forming a third polyethylene in a third solution phase polymerization reactor
by
polymerizing ethylene and optionally an alpha olefin with a multi-site
catalyst.
In an embodiment, the polyethylene composition of the present disclosure is
made by forming a first polyethylene in a first solution phase polymerization
reactor
by polymerizing ethylene and an alpha olefin with a single site catalyst;
forming a
second polyethylene in a second solution phase polymerization reactor by
polymerizing ethylene and optionally an alpha olefin with a single site
catalyst, and
forming a third polyethylene in a third solution phase polymerization reactor
by
polymerizing ethylene and optionally an alpha olefin with a multi-site
catalyst, where
at least two of the first, second and third solution phase polymerization
reactors are
configured in series with one another.
In an embodiment, the polyethylene composition of the present disclosure is
made by forming a first polyethylene in a first solution phase polymerization
reactor
by polymerizing ethylene and an alpha olefin with a single site catalyst;
forming a
second polyethylene in a second solution phase polymerization reactor by
polymerizing ethylene and optionally an alpha olefin with a single site
catalyst, and
forming a third polyethylene in a third solution phase polymerization reactor
by
polymerizing ethylene and optionally an alpha olefin with a multi-site
catalyst, where
the first and second solution phase polymerization reactors are configured in
series
with one another.
34
Date Recue/Date Received 2020-10-01
In an embodiment, the polyethylene composition of the present disclosure is
made by forming a first polyethylene in a first reactor by polymerizing
ethylene and
an alpha olefin with a single site catalyst; forming a second polyethylene in
a second
reactor by polymerizing ethylene and optionally an alpha olefin with a single
site
catalyst, and forming a third polyethylene in a third reactor by polymerizing
ethylene
and optionally an alpha olefin with a multi-site catalyst, where each of the
first,
second and third reactors are configured in parallel to one another.
In an embodiment, the polyethylene composition of the present disclosure is
made by forming a first polyethylene in a first solution phase polymerization
reactor
by polymerizing ethylene and an alpha olefin with a single site catalyst;
forming a
second polyethylene in a second solution phase polymerization reactor by
polymerizing ethylene and optionally an alpha olefin with a single site
catalyst, and
forming a third polyethylene in a third solution phase polymerization reactor
by
polymerizing ethylene and optionally an alpha olefin with a multi-site
catalyst, where
each of the first, second and third solution phase polymerization reactors are
configured in parallel to one another.
In an embodiment, the polyethylene composition of the present disclosure is
made by forming a first polyethylene in a first reactor by polymerizing
ethylene and
an alpha olefin with a single site catalyst; forming a second polyethylene in
a second
reactor by polymerizing ethylene and optionally an alpha olefin with a single
site
catalyst, and forming a third polyethylene in a third reactor by polymerizing
ethylene
and optionally an alpha olefin with a multi-site catalyst, where the first and
second
reactors are configured in series to one another, and the third reactor is
configured in
parallel to the first and second reactors.
In an embodiment, the polyethylene composition of the present disclosure is
made by forming a first polyethylene in a first solution phase reactor by
polymerizing
ethylene and an alpha olefin with a single site catalyst; forming a second
polyethylene in a second solution phase reactor by polymerizing ethylene and
optionally an alpha olefin with a single site catalyst, and forming a third
polyethylene
in a third solution phase reactor by polymerizing ethylene and optionally an
alpha
olefin with a multi-site catalyst, where the first and second solution phase
reactors
are configured in series to one another, and the third solution phase reactor
is
configured in parallel to the first and second reactors.
Date Recue/Date Received 2020-10-01
In an embodiment, the solution phase polymerization reactor used as a first
solution phase reactor, a second solution phase reactor, or a third solution
phase
reactor is a continuously stirred tank reactor.
In an embodiment, the solution phase polymerization reactor used as a first
solution phase reactor, a second solution phase reactor, or a third solution
phase
reactor is a tubular reactor.
In a solution phase polymerization reactor, a variety of solvents may be used
as the process solvent; non-limiting examples include linear, branched or
cyclic C5 to
C12 alkanes. Non-limiting examples of a-olefins include 1-propene, 1-butene, 1-
pentene, 1-hexene and 1-octene. Suitable catalyst component solvents include
aliphatic and aromatic hydrocarbons. Non-limiting examples of aliphatic
catalyst
component solvents include linear, branched or cyclic C5-12 aliphatic
hydrocarbons,
e.g. pentane, methyl pentane, hexane, heptane, octane, cyclohexane,
cyclopentane,
methylcyclohexane, hydrogenated naphtha or combinations thereof. Non-limiting
examples of aromatic catalyst component solvents include benzene, toluene
(methylbenzene), ethylbenzene, o-xylene (1,2-dimethylbenzene), m-xylene (1,3-
dimethylbenzene), p-xylene (1,4-dimethylbenzene), mixtures of xylene isomers,
hemellitene (1,2,3-trimethylbenzene), pseudocumene (1,2,4-trimethylbenzene),
mesitylene (1,3,5-trimethylbenzene), mixtures of trimethylbenzene isomers,
prehenitene (1,2,3,4-tetramethylbenzene), durene (1,2,3,5-tetramethylbenzene),
mixtures of tetramethyl benzene isomers, pentamethyl benzene,
hexamethylbenzene
and combinations thereof.
In embodiments of the disclosure, the polyethylene composition has a density
which may be from about 0.880 g/cm3 to about 0.965 g/cm3, or from about 0.885
g/cm3 to about 0.960 g/cm3, or from about 0.890 g/cm3 to 0.950 g/cm3, or from
about
0.895 g/cm3 to about 0.940 g/cm3, or from about 0.900 g/cm3 to about 0.936
g/cm3,
or from about 0.905 g/cm3 to about 0.934 g/cm3, or from about 0.910 g/cm3 to
about
0.932 g/cm3, or from about 0.910 g/cm3 to about 0.930 g/cm3, or from about
0.910
g/cm3 to about 0.926 g/cm3, or from about 0.890 g/cm3 to about 0.924 g/cm3, or
from
about 0.890 g/cm3 to about 0.922 g/cm3, or from about 0.890 g/cm3 to about
0.920
g/cm3, or from about 0.890 g/cm3 to about 0.918 g/cm3, or from about 0.880
g/cm3 to
about 0.922 g/cm3, or from about 0.880 g/cm3 to about 0.926 g/cm3, or from
about
0.880 g/cm3 to about 0.932 g/cm3, or 0.948 g/cm3, or < 0.948 g/cm3, or 0.945
36
Date Recue/Date Received 2020-10-01
g/cm3, or < 0.945 g/cm3, or 0.940 g/cm3, or < 0.940 g/cm3, or 0.939 g/cm3, or
<
0.939 g/cm3, or 0.935 g/cm3, or < 0.935 g/cm3, or 0.932 g/cm3, or < 0.932
g/cm3.
In embodiments of the disclosure the melt index 12 of the polyethylene
composition may be from about 0.01 dg/min to about 1000 dg/min, or from about
0.01 dg/min to about 500 dg/min, or from about 0.01 dg/min to about 100
dg/min, or
from about 0.01 dg/min to about 50 dg/min, or from about 0.01 dg/min to about
25
dg/min, or from about 0.01 dg/min to about 10 dg/min, or from about 0.01
dg/min to
about 5 dg/min, or from about 0.01 dg/min to about 3 dg/min, or from about
0.01
dg/min to about 1 dg/min, or from about 0.1 dg/min to about 10 dg/min, or from
about
0.1 dg/min to about 5 dg/min, or from about 0.1 dg/min to about 3 dg/min, or
from
about 0.1 dg/min to about 2 dg/min, or from about 0.1 dg/min to about 1.5
dg/min, or
from about 0.1 dg/min to about 1 dg/min, or less than about 5 dg/min, or less
than
about 3 dg/min, or less than about 1.0 dg/min.
In embodiments of the disclosure the high load melt index 121 of the
polyethylene composition may be from about 15 dg/min to about 10,000 dg/min,
or
from about 15 dg/min to about 1000 dg/min, or from about 15 dg/min to about
100
dg/min, or from about 15 dg/min to about 75 dg/min, or from about 15 dg/min to
about 50 dg/min, or from about 10 dg/min to about 100 dg/min, or from about 10
dg/min to about 75 dg/min, or from about 10 dg/min to about 50 dg/min, or from
about 10 dg/min to about 45 dg/min, or from about 10 dg/min to about 40
dg/min, or
from about 10 dg/min to about 35 dg/min, or from about 10 dg/min to about 32
dg/min, or from about 10 dg/min to about 36 dg/min.
In embodiments of the disclosure the melt flow ratio 121/12 of the
polyethylene
composition is 50 or < 50, or 45, or <45. In an embodiment of the disclosure
the
melt flow ratio 121/12 of the polyethylene composition is 40. In embodiments
of the
disclosure the melt flow ratio 121/12 of the polyethylene composition may be
from
about 15 to about 40, or from about 15 to about 38, or from about 18 to about
40, or
from about 20 to about 40, or from about 25 to about 40, or from about 28 to
about
40.
In an embodiments of the disclosure, the polyethylene composition has a
weight average molecular weight, Mw of from about 50,000 to about 300,000, or
from
about 50,000 to about 250,000, or from about 60,000 to about 250,000, or from
about 70,000 to about 225,000, or from about 70,000 to about 200,000, or from
37
Date Recue/Date Received 2020-10-01
about 75,000 to about 175,000, or from about 75,000 to about 150,000, or from
about 100,000 to about 130,000.
In embodiments of the disclosure, the polyethylene composition has a lower
limit molecular weight distribution, Mw/Mn of 2.0, or 2.1, or 2.3, or 2.5. In
embodiments of the disclosure, the polyethylene composition has an upper limit
molecular weight distribution, Mw/Mn of 6.0, or 5.5, or 5.0, or 4.5, or 4.0,
or 3.5, or
3Ø In embodiments of the disclosure, the polyethylene composition has a
molecular weight distribution, Mw/Mn of from 2.1 to 6.0, or from 2.3 to 6.0,
or from 2.5
to 6.0, or from 2.1 to 5.5, or from 2.3 to 5.5, or from 2.1 to 5.0, or from
2.3 to 5.0, or
from 2.1 to 4.5, or from 2.3 to 4.5, or from 2.1 to 4.0, or from 2.3 to 4.0,
or from 2.1 to
3.5, or from 2.3 to 3.5, or from 2.1 to 3.0, or from 2.3 to 3Ø
In embodiments of the disclosure, the polyethylene composition has a Z-
average molecular weight distribution, Mz/Mw of 4.0, or <4.0, or 3.5, or <
3.5, or
3.0, or <3.0, or 2.75, or <2.75, or 2.50, or < 2.50. In embodiments of the
disclosure, the polyethylene composition has a Z-average molecular weight
distribution, Mz/Mw of from 1.5 to 4.0, or from 1.75 to 3.5, or from 1.75 to
3.0, or from
2.0 to 4.0, or from 2.0 to 3.5, or from 2.0 to 3.0, or from 2.0 to 2.5.
In an embodiment of the disclosure, the polyethylene composition has a
unimodal profile in a gel permeation chromatograph generated according to the
method of ASTM D6474-99. The term "unimodal" is herein defined to mean there
will be only one significant peak or maximum evident in the GPC-curve. A
unimodal
profile includes a broad unimodal profile. In contrast, the use of the term
"bimodal" is
meant to convey that in addition to a first peak, there will be a significant
secondary
peak or shoulder which represents a higher or lower molecular weight component
(i.e. the molecular weight distribution, can be said to have two maxima in a
molecular
weight distribution curve). Alternatively, the term "bimodal" connotes the
presence
of two maxima in a molecular weight distribution curve generated according to
the
method of ASTM D6474-99. The term "multi-modal" denotes the presence of two or
more, typically more than two, maxima in a molecular weight distribution curve
generated according to the method of ASTM D6474-99.
In an embodiment of the disclosure the polyethylene composition may have a
largely unimodal profile in a differential scanning calorimetry (DSC) graph.
In the
context of DSC analysis, the term "largely unimodal" connotes a DSC profile in
which
one distinct melting peak is observable.
38
Date Recue/Date Received 2020-10-01
In an embodiment of the disclosure the polyethylene composition may have a
multimodal profile in a differential scanning calorimetry (DSC) graph. In the
context
of DSC analysis, the term "multimodal" connotes a DSC profile in which two or
more
distinct melting peaks are observable.
In an embodiment of the disclosure the polyethylene composition may have a
bimodal profile in a differential scanning calorimetry (DSC) graph. In the
context of
DSC analysis, the term "bimodal" connotes a DSC profile in which two distinct
melting peaks are observable.
In an embodiment of the disclosure, the polyethylene composition has a
.. melting peak temperature in a differential scanning calorimetry (DSC)
analysis at
above 120 C. For clarity sake, by the phrase "has a melting peak temperature
in an
DSC analysis" it is meant that in a DSC analysis, although there may be one or
more
melting peaks evident, at least one such peak occurs at above the indicated
temperature. In an embodiment of the disclosure, the polyethylene composition
has
a melting peak temperature in a differential scanning calorimetry (DSC)
analysis at
above 123 C. In an embodiment of the disclosure, the polyethylene composition
has
a melting peak temperature in a differential scanning calorimetry (DSC)
analysis at
above 125 C.
In an embodiment of the disclosure, the polyethylene composition will have a
.. reverse or partially reverse comonomer distribution profile as measured
using GPC-
FTIR. If the comonomer incorporation decreases with molecular weight, as
measured using GPC-FTIR, the distribution is described as "normal". If the
comonomer incorporation is approximately constant with molecular weight, as
measured using GPC-FTIR, the comonomer distribution is described as "flat" or
"uniform". The terms "reverse comonomer distribution" and "partially reverse
comonomer distribution" mean that in the GPC-FTIR data obtained for a
copolymer,
there is one or more higher molecular weight components having a higher
comonomer incorporation than in one or more lower molecular weight components.
The term "reverse(d) comonomer distribution" is used herein to mean, that
across
the molecular weight range of an ethylene copolymer, comonomer contents for
the
various polymer fractions are not substantially uniform and the higher
molecular
weight fractions thereof have proportionally higher comonomer contents (i.e.
if the
comonomer incorporation rises with molecular weight, the distribution is
described as
"reverse" or "reversed"). Where the comonomer incorporation rises with
increasing
39
Date Recue/Date Received 2020-10-01
molecular weight and then declines, the comonomer distribution is still
considered
"reverse", but may also be described as "partially reverse". A partially
reverse
comonomer distribution will exhibit a peak or maximum.
In an embodiment of the disclosure the polyethylene composition has a
reversed comonomer distribution profile as measured using GPC-FTIR.
In an embodiment of the disclosure the polyethylene composition has a
partially reversed comonomer distribution profile as measured using GPC-FTIR.
In an embodiment of the disclosure, the polyethylene composition has a
soluble fraction of at least 10 wt% in a crystallization elution fractionation
(CEF)
analysis, where the soluble fraction is defined as the weight percent (wt%) of
material which elutes at 30 C and below. In an embodiment of the disclosure,
the
polyethylene composition has a soluble fraction of at least 15 wt% in a
crystallization
elution fractionation (CEF) analysis, where the soluble fraction is defined as
the
weight percent (wt%) of material which elutes at 30 C and below. In an
embodiment
of the disclosure, the polyethylene composition has a soluble fraction of at
least 17
wt% in a crystallization elution fractionation (CEF) analysis, where the
soluble
fraction is defined as the weight percent (wt%) of material which elutes at 30
C and
below. In an embodiment of the disclosure, the polyethylene composition has a
soluble fraction of at least 20 wt% in a crystallization elution fractionation
(CEF)
analysis, where the soluble fraction is defined as the weight percent (wt%) of
material which elutes at 30 C and below. In an embodiment of the disclosure,
the
polyethylene composition has a soluble fraction of at least 25 wt% in a
crystallization
elution fractionation (CEF) analysis, where the soluble fraction is defined as
the
weight percent (wt%) of material which elutes at 30 C and below. In an
embodiment
of the disclosure, the polyethylene composition has a soluble fraction of from
10 to
40 wt% in a crystallization elution fractionation (CEF) analysis, where the
soluble
fraction is defined as the weight percent (wt%) of material which elutes at 30
C and
below. In an embodiment of the disclosure, the polyethylene composition has a
soluble fraction of from 15 to 35 wt% in a crystallization elution
fractionation (CEF)
analysis, where the soluble fraction is defined as the weight percent (wt%) of
material which elutes at 30 C and below.
Without wishing to be bound by theory, the homogeneity of the polyethylene
composition may be indicated by a difference in the first and second melting
points
measured by differential scanning calorimetry (DSC). The melting points in a
DSC
Date Recue/Date Received 2020-10-01
curve may be indicated by Tml for a first, or lowest melting point, by Tm2 for
a second
melting point, which may occur at the same or higher temperature than the
first
melting point, by Tm3 for a third melting point, which may occur at the same
or higher
temperature than the second melting point, and so on.
In embodiments of the disclosure, the polyethylene composition has a Tm2 ¨
Tml of less than 30 C, or less than 25 C, or 25 C, or less than 20 C, or 20 C,
or
less than 15 C, or 15 C, or 12.5 C.
In embodiments of the disclosure, the polyethylene composition has a Tm2 ¨
Tml of from 0 to 30 C, or from 0 to 25 C, or from 0 to 20 C, or from 0 to 15
C, or from
.. 0 to 12.5 C (note: by a Tm2 ¨ Tml = 0, it is meant that there is no
separate or distinct
Tm2 peak measured by DSC, with only a Tml being observed; effectively the Tm2
and the Tml are equal).
In an embodiment of the disclosure, the polyethylene composition has a
stress exponent, defined as Logio[16/12]/Logio[6.48/2.16], which is 1.50. In
further
embodiments of the disclosure the polyethylene composition has a stress
exponent,
Logio[16/12]/Logio[6.48/2.16] of less than 1.48, or less than 1.45, or less
than 1.43.
In an embodiment of the disclosure, the polyethylene composition has a
hexane extractable value of 5.0 weight percent, or less than 4.0 wt%, or less
than
3.0 wt%, or less than 2.0 wt%, or less than 1.0 wt%.
The polyethylene composition disclosed herein may be converted into flexible
manufactured articles such as monolayer or multilayer films, such films are
well
known to those experienced in the art; non-limiting examples of processes to
prepare such films include blown film and cast film processes.
In the blown film extrusion process an extruder heats, melts, mixes and
conveys a thermoplastic, or a thermoplastic blend. Once molten, the
thermoplastic
is forced through an annular die to produce a thermoplastic tube. In the case
of co-
extrusion, multiple extruders are employed to produce a multilayer
thermoplastic
tube. The temperature of the extrusion process is primarily determined by the
thermoplastic or thermoplastic blend being processed, for example the melting
temperature or glass transition temperature of the thermoplastic and the
desired
viscosity of the melt. In the case of polyolefins, typical extrusion
temperatures are
from 330 F to 550 F (166 C to 288 C). Upon exit from the annular die, the
thermoplastic tube is inflated with air, cooled, solidified and pulled through
a pair of
nip rollers. Due to air inflation, the tube increases in diameter forming a
bubble of
41
Date Recue/Date Received 2020-10-01
desired size. Due to the pulling action of the nip rollers the bubble is
stretched in the
machine direction. Thus, the bubble is stretched in two directions: the
transverse
direction (TD) where the inflating air increases the diameter of the bubble;
and the
machine direction (MD) where the nip rollers stretch the bubble. As a result,
the
physical properties of blown films are typically anisotropic, i.e. the
physical properties
differ in the MD and TD directions; for example, film tear strength and
tensile
properties typically differ in the MD and TD. In some prior art documents, the
terms
"cross direction" or "CD" is used; these terms are equivalent to the terms
"transverse
direction" or "TD" used in this disclosure. In the blown film process, air is
also blown
on the external bubble circumference to cool the thermoplastic as it exits the
annular
die. The final width of the film is determined by controlling the inflating
air or the
internal bubble pressure; in other words, increasing or decreasing bubble
diameter.
Film thickness is controlled primarily by increasing or decreasing the speed
of the nip
rollers to control the draw-down rate. After exiting the nip rollers, the
bubble or tube
is collapsed and may be slit in the machine direction thus creating sheeting.
Each
sheet may be wound into a roll of film. Each roll may be further slit to
create film of
the desired width. Each roll of film is further processed into a variety of
consumer
products as described below.
The cast film process is similar in that a single or multiple extruder(s) may
be
used; however, the various thermoplastic materials are metered into a flat die
and
extruded into a monolayer or multilayer sheet, rather than a tube. In the cast
film
process the extruded sheet is solidified on a chill roll.
Depending on the end-use application, the disclosed polyethylene
composition may be converted into films that span a wide range of thicknesses.
Non-limiting examples include, food packaging films where thicknesses may
range
from about 0.5 mil (13 pm) to about 4 mil (102 pm), and; in heavy duty sack
applications film thickness may range from about 2 mil (51pm) to about 10 mil
(254
pm).
The polyethylene composition disclosed herein may be used in monolayer
films; where the monolayer may contain more than one polyethylene composition
and/or additional thermoplastics; non-limiting examples of thermoplastics
include
polyethylene polymers and propylene polymers. The lower limit on the weight
percent of the polyethylene composition in a monolayer film may be about 3
wt%, in
other cases about 10 wt% and in still other cases about 30 wt%. The upper
limit on
42
Date Recue/Date Received 2020-10-01
the weight percent of the polyethylene composition in the monolayer film may
be 100
wt%, in other cases about 90 wt% and in still other cases about 70 wt%.
The polyethylene composition disclosed herein may also be used in one or
more layers of a multilayer film; non-limiting examples of multilayer films
include
three, five, seven, nine, eleven or more layers. The thickness of a specific
layer
(containing the polyethylene composition) within a multilayer film may be
about 5%,
in other cases about 15% and in still other cases about 30% of the total
multilayer
film thickness. In other embodiments, the thickness of a specific layer
(containing
the polyethylene composition) within a multilayer film may be about 95%, in
other
cases about 80% and in still other cases about 65% of the total multilayer
film
thickness. Each individual layer of a multilayer film may contain more than
one
polyethylene composition and/or additional thermoplastics.
In an embodiment of the disclosure, the polyethylene composition disclosed
herein is used in a thermoform able film.
Thermoforming is a process in which a thermoplastic film or sheet is heated to
a temperature at which the film or sheet is pliable and then stretched over
and into
the opening of a single-sided mold. The film is held in place over the
contours of the
mold while it cools and solidifies into the corresponding mold shape. During
thermoforming, the film may be clamped in place on the mold and heated using
convective or radiant heat to soften the film. The film or sheet, which is
held
horizontally over a mold cavity is then pressed, stretched or pulled into the
mold
using air pressure (applied to the back side of the film to push it into the
mold cavity)
or mechanical force (in which a die physically forces the film into the mold
cavity by
direct contact) optionally together with vacuum pressure (applied between the
mold
cavity and the film to pull the film into the mold cavity). The softened film
then takes
up the shape of the mold and is held in place until it cools and solidifies.
Excess
material is trimmed away from the edges of the mold, and the part released
from the
mold.
Thermoforming is also a known packaging process in which a container (e.g.
a tray) is formed from a plastic film in a mold by application of vacuum, air
pressure
or a plug under increased temperature. Foodstuff is placed in the container
and air
is drawn from the packaging prior to sealing it with another film which is
separate
from the film used to make the container or tray. In foodstuff packing
applications
then, a thermoforming process generally involves two packaging films: a top
lid film
43
Date Recue/Date Received 2020-10-01
which seals (optionally under vacuum) to a bottom film which is made into a
container; and a bottom thermoformable film which is formed into a tray during
the
first step of the packaging process and wherein the food is placed prior to
the sealing
step.
It is known to persons skilled in the art that nylon polymers have good
performance in multilayer film thermoforming applications. It is also known,
that
when used in blends with polyethylene, cyclic olefin copolymers (e.g. TOPASTm
COC) enhance performance in film thermoforming applications. As these cyclic
olefin copolymers have relatively high cost, it would be desirable to produce
other
polyethylene copolymers affording good performance in film thermoforming
applications. Especially useful would be novel ethylene rich polyethylene
copolymers (e.g. ethylene copolymers which contain less than about 30 wt% of
comonomer) which could be used in the absence of nylons in all polyethylene
film
structures for enhanced recyclability.
Thermoforming can be applied to both rigid and flexible packaging.
Somewhere in-between, semi-rigid packaging exists. Typical thermoforming
temperatures for multilayer packaging films involving polyethylenes is from 85
C to
110 C.
Techniques have been used to predict polymer thermoformability, and these
methods are available to persons skilled in the art. For a semi-crystalline
polymer, it
is desirable that such a screening tool reflect the total contributions of
both the melt
state (as represented by the amorphous phase) and the solid state (as
represented
by the crystalline phase) of the polymer. Failure to recognize the
contributions from
both phases cannot reflect the true physical state of a specimen in a real
thermoforming process involving semi-crystalline polymers. One such method to
reflect the total contributions of both amorphous and crystalline phases in
the whole
sample for a semi-crystalline polymer is concerned with the dimensional
uniformity of
a film when the film is subjected to conditions which approximate those
encountered
in a thermoforming process. This proxy test method determines the so-called
"area
Dimensional Thermoformability Index" or the "aDTI" and serves as a useful tool
to
predict the expected performance of a given film in a thermoforming
application (see
for example, XiaoChuan Wang and Mini Boparai, Annual Technical Conference of
the Society of Plastics Engineers, May 16 -20, 2010, Orlando, Florida, USA).
In the
present disclosure, a modified version of this methodology is used to predict
the
44
Date Recue/Date Received 2020-10-01
thermoformability of a polyethylene composition or an ethylene-comprising
polymer
with respect to thickness distribution uniformity or tendency of corner
thinning, and
this method is described below in the Examples section. Use of the modified
method
allows a person skilled in the art to assess or rank the dimensional
thermoformability
of an ethylene copolymer against commercially available resins known to have
good
or bad thermoformability using typical thermoforming conditions for films
comprising
polyethylenes. The lower the area DTI, the better the dimensional
thermoformability.
A lower aDTI value suggests that the film of a polymer may have a higher
thickness
distribution uniformity or less tendency toward corner thinning during
thermoforming
compared to another polymer with a higher aDTI value under the same
deformation
conditions.
In an embodiment of the disclosure, a thermoformable film is a single layer
film (i.e. a monolayer film).
In an embodiment of the disclosure, a thermoformable film is a multilayer
film.
In embodiments of the disclosure, a thermoformable film or sheet or
thermoformable film layer has a thickness of from 3 to 20 mils.
In embodiments of the disclosure, a thermoformable multilayer film or sheet
structure has a thickness of from 3 to 20 mils.
In embodiments of the disclosure, a thermoformable film or sheet or
.. thermoformable film layer comprises the polyethylene composition described
above.
In an embodiment of the disclosure, a thermoformable multilayer film or sheet
structure comprises a film layer comprising the polyethylene composition
described
above.
In embodiments of the disclosure, a thermoformable film or sheet or
thermoformable film layer comprises the polyethylene composition described
above
and has a thickness of from 3 to 20 mils.
In an embodiment of the disclosure, a thermoformable multilayer film or sheet
structure comprises a film layer comprising the polyethylene composition
described
above and the multilayer film or sheet structure has a thickness of from 3 to
20 mils.
In embodiments of the disclosure, the polyethylene composition will have an
area Dimensional Thermoformability Index ("aDTI") determined at 105 C, of less
than 20, or less than 15, or less than 10, or less than 5, or 15, or 10, or 5,
or
4.
Date Recue/Date Received 2020-10-01
In embodiments of the disclosure, the polyethylene composition will have an
area Dimensional Thermoformability Index ("aDTI") determined at 105 C, of from
1
to 20, or from Ito 15, or from Ito 10, or from Ito 5, or from 2 to 15, or from
2 to 10,
or from 2 to 5.
The films used in the manufactured articles described in this section may
optionally include, depending on its intended use, additives and adjuvants.
Non-
limiting examples of additives and adjuvants include, anti-blocking agents,
antioxidants, heat stabilizers, slip agents, processing aids, anti-static
additives,
colorants, dyes, filler materials, light stabilizers, light absorbers,
lubricants, pigments,
plasticizers, nucleating agents and combinations thereof.
The following examples are presented for the purpose of illustrating selected
embodiments of this disclosure; it being understood that the examples
presented do
not limit the claims presented.
EXAMPLES
Test Methods
Prior to testing (those proper tests that are not for high temperature tensile
experiments described later), each specimen was conditioned for at least 24
hours at
23 2 C and 50 10% relative humidity and subsequent testing was conducted at
23
2 C and 50 10% relative humidity. Herein, the term "ASTM conditions" refers
to a
laboratory that is maintained at 23 2 C and 50 10% relative humidity; and
specimens to be tested were conditioned for at least 24 hours in this
laboratory prior
to testing. ASTM refers to the American Society for Testing and Materials.
Density was determined using ASTM D792-13 (November 1,2013).
Melt index was determined using ASTM D1238 (August 1, 2013). Melt
indexes, 12, 16, ho and 121 were measured at 190 C, using weights of 2.16 kg,
6.48 kg,
10 kg and a 21.6 kg respectively. Herein, the term "stress exponent" or its
acronym
"S.Ex.", is defined by the following relationship: S.Ex.= log
(16/12)/log(6480/2160);
wherein 16 and 12 are the melt flow rates measured at 190 C using 6.48 kg and
2.16
kg loads, respectively.
Mn, Mw, and Mz (g/mol) were determined by high temperature Gel Permeation
Chromatography (GPC) with differential refractive index (DRI) detection using
universal calibration (e.g. ASTM ¨D6474-99). GPC data was obtained using an
instrument sold under the trade name "Waters 150c", with 1,2,4-
trichlorobenzene as
46
Date Recue/Date Received 2020-10-01
the mobile phase at 140 C. The samples were prepared by dissolving the polymer
in this solvent and were run without filtration. Molecular weights are
expressed as
polyethylene equivalents with a relative standard deviation of 2.9% for the
number
average molecular weight ("Mn") and 5.0% for the weight average molecular
weight
("Mw"). The molecular weight distribution (MWD) is the weight average
molecular
weight divided by the number average molecular weight, Mw/Mn. The z-average
molecular weight distribution is Mz/Mn. Polymer sample solutions (1 to 2
mg/mL)
were prepared by heating the polymer in 1,2,4-trichlorobenzene (TCB) and
rotating
on a wheel for 4 hours at 150 C in an oven. The antioxidant 2,6-di-tert-butyl-
4-
methylphenol (BHT) was added to the mixture in order to stabilize the polymer
against oxidative degradation. The BHT concentration was 250 ppm. Sample
solutions were chromatographed at 140 C on a PL 220 high-temperature
chromatography unit equipped with four Shodex columns (HT803, HT804, HT805
and HT806) using TCB as the mobile phase with a flow rate of 1.0 mL/minute,
with a
differential refractive index (DRI) as the concentration detector. BHT was
added to
the mobile phase at a concentration of 250 ppm to protect the columns from
oxidative degradation. The sample injection volume was 200 mL. The raw data
were processed with Cirrus GPC software. The columns were calibrated with
narrow
distribution polystyrene standards. The polystyrene molecular weights were
converted to polyethylene molecular weights using the Mark-Houwink equation,
as
described in the ASTM standard test method D6474.
The short chain branch frequency (e.g. the short chain branching per
thousand backbone carbon atoms, or the SCB/1000C) of ethylene copolymer
samples was determined by Fourier Transform Infrared Spectroscopy (FTIR) as
per
the ASTM D6645-01 method. A Thermo-Nicolet 750 Magna-IR Spectrophotometer
equipped with OMNIC version 7.2a software was used for the measurements.
Unsaturations in the polyethylene composition were also determined by Fourier
Transform Infrared Spectroscopy (FTIR) as per ASTM D3124-98.
High temperature GPC equipped with an online FTIR detector (GPC-FTIR)
was used to measure the comonomer content as the function of molecular weight.
Crystallization Elution Fractionation (CEF): A polymer sample (20 to 25 mg)
was weighed into the sample vial and loaded onto the auto-sampler of the
Polymer
CEF unit. The vail was filled with 6 to 7 ml 1,2,4-trichlorobenzene (TCB),
heated to
the desired dissolution temperature (e.g. 160 C) with a shaking rate of level
number
47
Date Recue/Date Received 2020-10-01
3 for 2 hours. The solution (0.5 ml) was then loaded into the CEF columns (two
CEF
columns purchased from Polymer Char and installed in series). After allowed to
equilibrate at a given stabilization temperature (e.g. 115 C) for 5 minutes,
the
polymer solution was allowed to crystallize with a temperature drop from the
stabilization temperature to 30 C. After equilibrating at 30 C for 10 minutes,
the
soluble fraction was eluted at 30 C for 10 minutes, followed by the
crystallized
sample eluted with TCB with a temperature ramp from 30 C to 110 C. The CEF
columns were cleaned at the end of the run for 5 minutes at 150 C. The other
CEF
run conditions were as follows: cooling rate 0.5 C/minute, flow rate in
crystallization
.. 0.02 mL/minute, heating rate 1.0 C/minute and flow rate in elution 2.0
mL/minute.
The data were processed using Excel spreadsheet. The "CDBI50" is defined as
the
weight percent of ethylene polymer whose composition is within 50% of the
median
comonomer composition (50% on each side of the median comonomer composition).
The "CDBI50" may be calculated from the composition distribution curve,
determined
by the CEF procedure described above, and the normalized cumulative integral
of
the composition distribution curve, as illustrated in U.S. Pat. No. 5,376,439
or WO
93/03093.
The "Composition Distribution Branching Index" or "CDBI" may alternatively
by determined using a crystal-TREF unit commercially available form Polymer
ChAR
(Valencia, Spain). The acronym "TREF" refers to Temperature Rising Elution
Fractionation. A sample of the polyethylene composition (80 to 100 mg) was
placed
in the reactor of the Polymer ChAR crystal-TREF unit, the reactor was filled
with 35
ml of 1,2,4-trichlorobenzene (TCB), heated to 150 C and held at this
temperature for
2 hours to dissolve the sample. An aliquot of the TCB solution (1.5 mL) was
then
.. loaded into the Polymer ChAR TREF column filled with stainless steel beads
and the
column was equilibrated for 45 minutes at 110 C. The polyethylene composition
was then crystallized from the TCB solution, in the TREF column, by slowly
cooling
the column from 110 C to 30 C using a cooling rate of 0.09 C per minute. The
TREF column was then equilibrated at 30 C for 30 minutes. The crystallized
polyethylene composition was then eluted from the TREF column by passing pure
TCB solvent through the column at a flow rate of 0.75 mL/minute as the
temperature
of the column was slowly increased from 30 C to 120 C using a heating rate of
0.25 C per minute. Using Polymer ChAR software a TREF distribution curve was
generated as the polyethylene composition was eluted from the TREF column,
i.e. a
48
Date Recue/Date Received 2020-10-01
TREF distribution curve is a plot of the quantity (or intensity) of
polyethylene
composition eluting from the column as a function of TREF elution temperature.
A
CDBI50 may be calculated from the TREF distribution curve for each
polyethylene
composition analyzed. The "CDBI50" is defined as the weight percent of
ethylene
polymer whose composition is within 50% of the median comonomer composition
(50% on each side of the median comonomer composition); it is calculated from
the
TREF composition distribution curve and the normalized cumulative integral of
the
TREF composition distribution curve. Those skilled in the art will understand
that a
calibration curve is required to convert a TREF elution temperature to
comonomer
content, i.e. the amount of comonomer in the polyethylene composition fraction
that
elutes at a specific temperature. The generation of such calibration curves
are
described in the prior art, e.g. Wild, et al., J. Polym. Sci., Part B, Polym.
Phys., Vol.
(3), pages 441-455: hereby fully incorporated by reference. Note: The "CDBI25"
is
defined as the weight percent of polyethylene composition whose composition is
15 within 25% of the median comonomer composition (25% on each side of the
median
comonomer composition).
Dynamic mechanical analyses were carried out with a rheometer, namely
Rheometrics Dynamic Spectrometer (RDS-II) or Rheometrics SRS or ATS
Stresstech, on compression molded samples under nitrogen atmosphere at 190 C,
20 using 25 mm diameter cone and plate geometry. The oscillatory shear
experiments
were done within the linear viscoelastic range of strain (10% strain) at
frequencies
from 0.05 to 100 rad/s. The values of storage modulus (G'), loss modulus (G"),
complex modulus (G*) and complex viscosity (yr) were obtained as a function of
frequency. The same rheological data can also be obtained by using a 25 mm
diameter parallel plate geometry at 190 C under nitrogen atmosphere. The Zero
shear viscosity is estimated using the Ellis model, i.e. ri(co) = o/(1 +
Thit2r1, where
'no is the zero shear viscosity. T1/2 is the value of the shear stress at
which 11 = rio/2
and Ot is one of the adjustable parameters. The Cox-Merz rule is assumed to be
applicable in the present disclosure.
The DRI, is the "Dow rheology index", and is defined by the equation: DRI =
[365000(To/no)-1]/10, wherein To is the characteristic relaxation time of the
polyethylene and no is the zero shear viscosity of the material. The DRI is
calculated
by least squares fit of the rheological curve (dynamic complex viscosity
versus
applied frequency e.g. 0.01-100 rads/s) as described in U.S. Pat. No.
6,114,486 with
49
Date Recue/Date Received 2020-10-01
the following generalized Cross equation, i.e. n(w)=n0/[1+(w-ro)l; wherein n
is the
power law index of the material, n(w) and w are the measured complex viscosity
and
applied frequency data respectively. When determining the DRI, the zero shear
viscosity, roused was estimated with the Ellis model, rather than the Cross
model.
The crossover frequency is the frequency at which storage modulus (G') and
loss modulus (G") curves cross with each other, while G'@G"=500Pa is the
storage
modulus at which the loss modulus (G") is at 500 Pa.
Primary melting peak ( C), melting peak temperatures ( C), heat of fusion
(J/g) and crystallinity (%) was determined using differential scanning
calorimetry
(DSC) on a TA Instrument DSC Q2000 Thermal Analyzer as follows: the instrument
was first calibrated with indium; after the calibration, a polymer specimen is
equilibrated at 0 C and then the temperature was increased to 200 C at a
heating
rate of 10 C/min; the melt was then kept isothermally at 200 C for five
minutes; the
melt was then cooled to 0 C at a cooling rate of 10 C/min and kept at 0 C for
five
minutes; the specimen was then heated to 200 C at a heating rate of 10 C/min.
The
DSC Tm, heat of fusion and crystallinity are reported from the 2nd heating
cycle.
The hexane extractable content of a polymer sample was determined
according to the Code of Federal Registration 21 CFR 177.1520 Para (c) 3.1
and
3.2; wherein the quantity of hexane extractable material in a film is
determined
gravimetrically. Elaborating, 2.5 grams of 3.5 mil (89 M) monolayer film was
placed
in a stainless steel basket, the film and basket were weighed (wi), while in
the basket
the film was: extracted with n-hexane at 49.5 C for two hours; dried at 80 C
in a
vacuum oven for 2 hours; cooled in a desiccator for 30 minutes, and; weighed
(we).
The percent loss in weight is the percent hexane extractable w( C6): wC6 = 100
x
w)/w'.
The average Melt Strain Hardening Index (the "MSHI"): The transient
extensional rheology of resins was studied using a host rotational rheometer
sold
under the name SentmanatTM Extensional Rheometer ("S ER"). Rectangular
samples with pre-measured dimensions were mounted between the fixing clamps
and were heated up to the measurement temperature. The resulting torques M was
then monitored upon stretching of the mounted sample as a function of time at
a
constant Hencky strain rate (H) ranging between 0.01-10 5-1. The transient
extensional viscosity Ti'.(t) was calculated using the following equation:
Date Recue/Date Received 2020-10-01
M(t)
11(t) = 2ReHA(T)exp (¨Ht)
in which R is the SER drum radius (5.155 mm) and A(T) is the corrected cross-
sectional area of the sample as a function of temperature. The cross-sectional
area
of the sample at the testing temperature was estimated using the equation in
below:
2/3
A(T) = A0 ( Ps
1)772(T))
in which Ao, Ps and pm are the measured cross-sectional area in solid-sate,
the
sample solid-state density and the melt-state density at temperature T. A
parameter, the Melt Strain Hardening Index (MSHI) or riE* / flunear*, is
calculated as
follows using the transient extensional viscosity data tested at 150 C and 0.3-
1 Henky
strain rate:
a) The data from 1 to 4 seconds are fitted to obtain a linear equation of
TILinear*
vs time (flunear*= a + b*time). If the slope (b value) is less than 0, the
average MSHI is defined as "< 0.98".
b) The data starting from 4 seconds to the end point (tf) where the data is
still
reliable are selected. Then the Melt Strain Hardening Index (MSHI) = riE*/
flunear* for each experimental point is calculated, where riE*is the tested
extensional viscosity and TILinear* is the calculated value using the above
fitted equation, for each experimental point between 4 to tf seconds.
c) The average MSHI (time = 4 to tf seconds) is then obtained by averaging
the MSHI data from 4 to tf seconds.
An example of calculating the average melt strain hardening index (MSHI) is
shown
in Figure 5.
Polyethylene Compositions
Polyethylene compositions comprising a first, second and third polyethylene
were made by melt blending polyethylene composition A with polyethylene B in
different amounts. Another polyethylene composition comprising a first, second
and
third polyethylene was made by melt blending polyethylene composition C with
polyethylene D.
Each of polyethylene composition A and C ("PE Composition A" and "PE
Composition C") were made using two different single site catalysts in a dual
parallel
reactor solution polymerization process. As a result, polyethylene
compositions A
and C comprised a first polyethylene made with first single site catalyst (a
51
Date Recue/Date Received 2020-10-01
metallocene) and a second polyethylene made with a second single site catalyst
(a
phosphinimine catalyst). A parallel mode solution phase polymerization reactor
process, has been described in USP 10,442,920. Basically, in parallel mode the
exit
streams exiting each of a first reactor (R1) and a second reactor (R2) are
combined
downstream of each reactor and the polymer product is obtained after
devolatilization.
The following examples illustrate the continuous solution copolymerization of
ethylene and 1-octene at medium pressure in a dual reactor system connected in
parallel. The first and second reactor pressure was about 16,000 kPa (about
2.3x103 psi). The first reactor was operated at a lower temperature than the
second
reactor. The first reactor had a volume of 12 liters and the second reactor
had a
volume of 24 liters. Both reactors were agitated to ensure good mixing of the
reactor
contents. The process was continuous in all feed streams (i.e. solvents, which
were
methyl pentane and xylene; monomers and catalyst and cocatalyst components)
and
in the removal of product. Monomer (ethylene) and comonomer (1-octene) were
purified prior to addition to the reactor using conventional feed preparation
systems
(such as contact with various absorption media to remove impurities such as
water,
oxygen and polar contaminants). The reactor feeds were pumped to the reactors
at
the ratios shown in Table 1. Average residence times for the reactors are
calculated
by dividing average flow rates by reactor volume. The residence time in each
reactor
for all of the experiments was less than 10 minutes and the reactors were well
mixed. The catalyst deactivator used was octanoic acid (caprylic acid),
commercially
available from P&G Chemicals, Cincinnati, OH, U.S.A.
The following single site catalyst (SSC) components were used to prepare the
first polyethylene in a first reactor (R1) configured in parallel to a second
reactor
(R2): diphenylmethylene(cyclopentadienyl)(2,7-di-t-butylfluorenyl)hafnium
dimethide
[(2,7-tBu2Flu)Ph2C(Cp)HfMe2]; methylaluminoxane (MMA0-07); trityl
tetrakis(pentafluoro-phenyl)borate (trityl borate), and 2,6-di-tert-butyl-4-
ethylphenol
(BHEB). Methylaluminoxane (MMA0-07) and 2,6-di-tert-butyl-4-ethylphenol are
premixed in-line and then combined with
diphenylmethylene(cyclopentadienyl)(2,7-
di-t-butylfluorenyl)hafnium dimethide and trityl tetrakis(pentafluoro-
phenyl)borate just
before entering the polymerization reactor (R1).
The following single site catalyst (SSC) components were used to prepare the
second polyethylene in a second reactor (R2) configured in parallel to a first
reactor
52
Date Recue/Date Received 2020-10-01
(R1): cyclopentadienyl tri(tertiary butyl)phosphinimine titanium dichloride
[Cp((t-
Bu)3PN)TiC12]; methylaluminoxane (MMA0-07); trityl tetrakis(pentafluoro-
phenyl)borate (trityl borate), and 2,6-di-tert-butyl-4-ethylphenol (BHEB).
Methylaluminoxane (MMA0-07) and 2,6-di-tert-butyl-4-ethylphenol are premixed
in-
line and then combined with cyclopentadienyl tri(tertiarybutyl)phosphinimine
titanium
dichloride [Cp((t-Bu)3PN)TiC12] and trityl tetrakis(pentafluoro-phenyl)borate
just
before entering the polymerization reactor (R2).
Polyethylene B or D ("PE B" or "PE D") on the other hand were each made in
a single solution polymerization reactor using a Ziegler-Natta catalyst as
described
below; however, in these examples the in-line formed Ziegler-Natta catalyst
was fed
only to a first reactor (R1) to prepare polyethylene B or polyethylene D in a
single
reactor. For the sake of clarity, polyethylene B, or polyethylene D becomes
the third
polyethylene within the final polyethylene composition. The following Ziegler-
Natta
(ZN) catalyst components were used to prepare the third polyethylene: butyl
ethyl
magnesium; tertiary butyl chloride; titanium tetrachloride; diethyl aluminum
ethoxide;
and triethyl aluminum. Methylpentane was used as the catalyst component
solvent
and the in-line Ziegler-Natta catalyst formulation was prepared using the
following
steps. In step one, a solution of triethylaluminum and butyl ethyl magnesium
(Mg:Al
= 20, mol:mol) was combined with a solution of tertiary butyl chloride and
allowed to
react for about 30 seconds to produce a MgCl2 support. In step two, a solution
of
titanium tetrachloride was added to the mixture formed in step one and allowed
to
react for about 14 seconds prior to injection into reactor (R1). The in-line
Ziegler-
Natta catalyst was activated in the reactor by injecting a solution of diethyl
aluminum
ethoxide into R1. The quantity of titanium tetrachloride added to the reactor
is
shown in Table I. The efficiency of the in-line Ziegler-Natta catalyst
formulation was
optimized by adjusting the mole ratios of the catalyst components.
Table 1, shows the reactor conditions used to make polyethylene composition
A, polyethylene B, polyethylene composition C, and polyethylene D. The
properties
of polyethylene composition A, polyethylene B, polyethylene composition C, and
polyethylene D are shown in Table 2.
53
Date Recue/Date Received 2020-10-01
TABLE 1
Reactor Operating Conditions
Blending Component PE Composition A PE B PE
Composition C PE D
SSC in R1 and
SSC in R1 and SSC
ZN in R1 (single SSC in
R2 (dual ZN in R1 (single
Description in R2 (dual reactor
reactor) reactor
in parallel reactor)
in parallel mode)
mode)
Reactor 1 (R1) metallocene ZN
metallocene ZN
TSR (kg/hr) 300 375
306.2 375
Ethylene concentration (wt%) 7.9 9.3
10.2 6.9
1-Octene/ethylene in fresh feed
0.82 0.65
0.77 2.0
(g/g)
Primary feed temperature ( C) 35.0 35.0
35.0 35.0
Mean Temperature ( C) 130.2 150.8
146.4 131.5
Ethylene conversion 80.1 91.3
75.0 90.5
Hydrogen Feed (ppm) 0.49 3.75
0.51 0.5
Catalyst (ppm) to R1 0.84 4.7
0.59 4.1
SSC - Al/Hf (mol/mol) 31 N/A
31 N/A
SSC - BHEB/AI (mol/mol) 0.4 N/A
0.4 N/A
SSC - B/Hf (mol/mol) 1.22 N/A
1.22 N/A
54
Date Recue/Date Received 2020-10-01
ZN ¨ tertbutylchloride/Mg
N/A 2.1 N/A
2.1
(mol/mol)
ZN ¨ Mg/Ti (mol/mol) N/A 7.0 N/A
7.0
ZN ¨ diethyl aluminum
N/A 1.35 N/A
1.35
ethoxide/Ti (mol/mol)
Reactor 2 (R2) phosphinimine
phosphinimine N/A
TSR (kg/hr) 300 N/A
343.9 N/A
Ethylene concentration (wt%) 13.4 N/A
14.2 N/A
1-Octene/ethylene in fresh feed
0.0 N/A 0.0
N/A
(g/g)
Primary feed temperature ( C) 35.3 N/A
35.0 N/A
Mean Temperature ( C) 190.9 N/A
192.4 N/A
Ethylene conversion 90.0 N/A
86.2 N/A
Hydrogen Feed (ppm) 5.31 N/A
21.95 N/A
Catalyst (ppm) to R2 0.24 N/A
0.25 N/A
SSC - Al/Ti (mol/mol) 65 N/A 65
N/A
SSC - BHEB/AI (mol/mol) 0.3 N/A 0.3
N/A
SSC - B/Ti (mol/mol) 1.5 N/A 1.5
N/A
Date Recue/Date Received 2020-10-01
TABLE 2
Blend Component Properties
Blending Component PE Composition A PE B PE
Composition C PE D
SSC in R1 and SSC in
R1 and
SSC in R2 (dual ZN in R1 SSC
in R2 (dual ZN in R1
Description
reactor in parallel (single reactor)
reactor in parallel (single reactor)
mode)
mode)
Catalysts SSC/SSC ZN
SSC/SSC ZN
Density (g/cm3) 0.9152 0.9164
0.9246 0.8944
Melt Index 12 (g/10 min) 1.49 0.33 2.72
0.11
Melt Index 16 (g/10 min) 6.95 1.36
17.80 0.49
Melt Index ho (g/10 min) 13.4 2.46
38.70 0.91
Melt Index 121 (g/10 min) 52.2 8.74
209.42 3.64
Melt Flow Ratio (121/12) 35 26.50 74
32.3
Stress Exponent 1.40 1.28 1.67
1.33
Melt Flow Ratio (1102) 9.12 7.70
14.30 8.27
Branch Frequency - FTIR
Branch Freq/1000C 21.5 15.7
18.40 34.5
Comonomer 1-octene 1-octene 1-
octene 1-octene
Comonomer Content (mole%) 4.30 3.10 3.70
6.90
56
Date Recue/Date Received 2020-10-01
Comonomer Content
15.2 11.5 13.30 22.80
(weight%)
Internal Unsat/100C 0.013 0.005 0.009
0.008
Side Chain Unsat/100C 0.002 0.002
0.003 0.003
Terminal Unsat/100C 0.006 0.025 0.006
0.014
GPC - Conventional
Mn 49016 34317
23929 49653
Mw 105906 135987
84290 200282
Mz 215295 338832
216306 513335
Polydispersity Index (Mw/Mn) 2.16 3.96
3.52 4.03
57
Date Recue/Date Received 2020-10-01
The properties of two different polyethylene compositions which were
obtained from melt blending polyethylene composition A with polyethylene B at
two
different weight fractions is provided in Table 3 as Examples 1 and 2. The
properties
.. of a polyethylene compositions which was obtained from melt blending
polyethylene
composition C with polyethylene D is also provided in Table 3 as Examples 3.
The
materials were melt blended using a Coperion ZSK 26 co-rotating twin screw
extruder with an L/D of 32:1. The extruder was fitted with an underwater
pelletizer
and a Gala spin dryer. The materials were co-fed to the extruder using
gravimetric
feeders to achieve the desired ratios of polyethylene composition A to
polyethylene
B. The blends were compounded using a screw speed of 200 rpm at an output rate
of 15-20 kg/hour and at a melt temperature of 225-230 C.
58
Date Recue/Date Received 2020-10-01
TABLE 3
Polyethylene Composition Properties
1 2 3
(70 wt% PE (40 wt% PE (70 wt% PE
Example No.
Composition A Composition A Composition C /
/ 30 wt% PE B) / 60 wt% PE B) 30 wt% PE D)
Density (g/cm3) 0.9159 0.9162 0.9156
Melt Index 12 (g/10 min) 0.73 0.48 0.68
Melt Index 16 (g/10 min) 3.48 2.14 3.93
Melt Index ho (g/10
6.68 4.02 8.52
min)
Melt Index 121 (g/10
26.4 15.5 50
min)
Melt Flow Ratio (121/12) 36.3 32.5 73.53
Stress Exponent 1.42 1.36 1.6
Melt Flow Ratio (110/12) 9.52 8.72 13.2
Rheological Properties
Zero Shear Viscosity -
19940 23400 21640
190 C (Pa-s)
Crossover Frequency -
80.53 50.76 22.13
190 C (rad/s)
DRI 1.78 0.78 1.80
G'@G"500Pa = 133.18 82.92 89.97
Branch Frequency -
FTIR
Branch Freq/1000C 19.7 17.7 22.4
Comonomer 1-octene 1-octene 1-octene
Comonomer Content
3.9 3.5 4.5
(mole%)
Comonomer Content
14.1 12.8 15.8
(wt%)
Internal Unsat/100C 0.009 0.007 0.008
Side Chain Unsat/100C 0.006 0.005 0.008
59
Date Recue/Date Received 2020-10-01
Terminal Unsat/100C 0.012 0.02 0.01
CEF
Soluble fraction (%),
30.33 19.4 40
30 C
DSC
First Melting Peak ( C) 128.100 113.600 68.900
Second Melting Peak
( C) -- 126 128.3
Third Melting Peak ( C) -- -- __
Tm2 ¨ Tml (Second
Melting Peak ( C)
0 12.36 59.41
minus First Melting
Peak ( C))
Heat of Fusion (J/g) 127 126.3 122.1
Crystallinity (%) 43.8 43.6 42.1
GPC ¨ Conventional
Mn 45974 46076 28915
Mw 119291 123764 124152
Mz 277605 284944 427023
Polydispersity Index
2.59 2.69 4.29
(Mw/Mn)
Mz/Mw 2.33 2.30 3.44
Hexane Extractables
3.17 0.87 4.78
(%) ¨ Plaque
Details of the polyethylene composition components: the first polyethylene,
the second polyethylene, and the third polyethylene, are provided in Table 4.
With
the exception of the weight percentages, w1 and w2 (which are found by
adjusting
the de-convoluted values, w1' and w2', as is further discussed below) the data
in
Table 4 includes the mathematically de-convoluted component properties of
polyethylene composition A (which comprised the first polyethylene which was
made
with a single site metallocene catalyst and the second polyethylene which was
made
with a single site phosphinimine catalyst) as well as the experimentally
determined
Date Recue/Date Received 2020-10-01
properties of polyethylene B (the third polyethylene which was made with a
Ziegler-
Natta catalyst).
High temperature GPC equipped with an online FTIR detector (GPC-FTIR)
was used to measure the comonomer content as a function of molecular weight.
In
.. order to de-convolute the polyethylene composition A (which results from
use of a
SSC in R1 and R2 in parallel mode polymerization) into components, the
mathematical deconvolution model described in U.S. Pat. No. 8,022,143 was
used.
The mathematical deconvolution of the GPC and GPC-FTIR data, the molecular
weight distribution of the first polyethylene (the SSC component made in R1,
considered one catalyst site) and the second polyethylene (the SSC component
made in R2, considered one catalyst site) was modeled using a single Schultz
Flory
distribution (where the Mw/Mn was assumed to be 2; the Mn was Mw/2 and the Mz
was 1.5 x Mw) as described in U.S. Pat. No 8,022,143. To improve the
deconvolution accuracy and consistency, as a constraint, the melt index, 12,
of the
modeled composition (i.e. the dual-reactor polyethylene composition A) was set
and
the following relationship was satisfied during the deconvolution:
Logio(12) = 22.326528 + 0.0034671Logio(Mn)]3 - 4.322582*Logio(Mw) -
0.1800611Logio(Mz)]2 + 0.0264781Logio(Mz)]3
where the experimentally measured overall melt index (i.e. of polyethylene
composition A), 12, was used on the left side of the equation. Hence, a total
of two
sites (one for each SSC) were used to de-convolute polyethylene composition A.
The w(i) and Mn(i), i = 1 to 2, were obtained while Mw(i) and Mz(i) of each
site were
calculated using the above relationships using Mn(i) for each site. During the
deconvolution, the overall Mn, Mw and Mz of polyethylene composition A was
.. calculated with the following relationships: Mn = 1/Sum(wi/Mn(i)), Mw =
Sum(wixMw(i)),
Mz = Sum(wixMz(i)2), where i represents the i-th component and wi represents
the
relative weight fraction of the i-th component in the composition from the
above 2-
site deconvolution. The GPC-FTIR chromatograph profile was subsequently
deconvoluted using the w(i) results to obtain SCB(i), i = 1 to 2.
The Mn, Mw, Mz and SCB/1000C of the first and second polyethylenes made
with a SSC in each of R1 and R2 were then calculated using the above
relationships,
with the above data of Mn(i), Mw(i), Mz(i), SCB(i) for each catalyst site.
When the polymer made with the single site catalyst in R2 was an ethylene
homopolymer, as is the case in the present examples, then during the
deconvolution
61
Date Recue/Date Received 2020-10-01
analysis the SCB/1000C for the modeled SSC site was set as zero. If however,
the
polymer made by the SSC was a copolymer, then the SCB value would be
determined for the SSC site using the deconvolution model presented above.
In order to calculate the melt index, 12 of each of the first and second
.. polyethylenes in polyethylene composition A, or polyethylene composition C,
the
following melt index, 12 model was used:
Logio(melt index, 12) = 22.326528 + 0.003467*[Logio(Mn)]3 - 4.322582*Logio(Mw)
-
0.180061*[Logio(Mz)]2 + 0.026478*[Logio(Mz)]3
where the Mn, Mw and Mz were the deconvoluted values of the first or second
.. polyethylene components present in polyethylene composition A, or
polyethylene
composition C, as obtained from the results of the above GPC deconvolution.
The density of the first polyethylene which was an ethylene copolymer made
using a single site catalyst in R1 was calculated using the following density
model:
density of the first polyethylene made with a SSC = 0.979863 ¨0.00594808*(FTIR
SCB/1000C) .65¨ 0.000383133*[Logio(Mn)]3
¨ 0.00000577986*(Mw/Mn)3+0.00557395*(msmw)O.25
where the Mn, Mw and Mz were the deconvoluted values of the first polyethylene
as
obtained from the results of the above GPC deconvolution and the SCB/1000C was
obtained from the GPC-FTIR deconvolution. The density of the second
.. polyethylene which was an ethylene homopolymer made with a single site
catalyst in
R2 was determined using the same equation used above for finding the density
of
the first polyethylene, but with the value for the short chain branching set
to zero to
cancel out the corresponding term:
density of the second polyethylene made with a SSC = 0.979863 ¨
0.0003831331Logio(Mn)]3-0.00000577986*(Mw/Mn)3+0.00557395*(msmw)O.25.
The de-convolution provided the density (d1, and d2), melt index (121 and
122),
short chain branching (SCB1 with the SCB2 being set as zero for an ethylene
homopolymer) the weight average and number average molecular weights (Mw1,
.. Mn1, Mw2 and Mn2), and the weight fraction (w1' and w2') of the first and
second
polyethylenes The resulting deconvoluted properties as well as the relative
weight
percentages w1, w2 (which for the first and the second polyethylenes,
respectively,
are found by modifying the deconvoluted weight fractions w1' and w2' to match
the
amount of polyethylene composition A, or polyethylene composition C in the
final
62
Date Recue/Date Received 2020-10-01
melt blended polyethylene composition, as determined by the blending rules
discussed further below) are provided in Table 4.
The following basic blending rules were used to achieve the desired
polyethylene compositions comprising a first, a second and a third
polyethylene:
w1 = weight percentage of the first polyethylene in the final polyethylene
composition;
w2 = weight percentage of the second polyethylene in the final polyethylene
composition;
w3 = weight percentage of the third polyethylene in the final polyethylene
composition;
w1* = weight percentage of polyethylene composition A, or polyethylene
composition C, in the melt blend;
w2* = weight percentage of polyethylene B, or polyethylene C in the melt
blend;
w1' = weight percentage of the first polyethylene in polyethylene composition
A, or polyethylene composition C (i.e. the w1' determined from the
mathematical
deconvolution of polyethylene composition A, or polyethylene composition C);
w2' = weight percentage of the second polyethylene in polyethylene
composition A, or polyethylene composition C (i.e. the w2' determined from the
mathematical deconvolution of polyethylene composition A, or polyethylene
composition C);
where,
w1 + w2 + w3 = 1;
w1* + w2* = 1; and
+ w2' = 1;
so that,
w1 = w1* X w1';
w2 = w1* x w2'; and
w3 = w2*.
63
Date Recue/Date Received 2020-10-01
TABLE 4
Polyethylene Composition Component Properties
Example No. 1 2 3
Polyethylene
Composition
Density (g/cm3) 0.9159 0.9162 0.9156
12 (dg/min) 0.73 0.48 0.68
Stress Exponent 1.42 1.36 1.6
MFR (121/12) 36.3 32.5 73.58
Mn 45974 46076 28915
Mw 119291 123764 124152
Mz 277605 284944 427023
Mw/Mn 2.59 2.69 4.29
Mz/Mw 2.33 2.30 3.44
The First Polyethylene
Single Site Single Site Single Site
Catalyst Type 1 Catalyst Catalyst Catalyst
(metallocene) (metallocene)
(metallocene)
0.308 0.176 0.308
(note: w1'= (note: w1' = 0.44 (note:
w1'=
weight fraction, w1
0.44 from from 0.440 from
deconvolution) deconvolution) deconvolution)
Mn1 65750 65750 66450
Mw1 131500 131500 132900
2 (Mw1/Mn1 < 2 (Mw1/Mn1 < 2 (Mw1/Mn1 <
Mw1/Mn1
2.3) 2.3) 2.3)
short chain branches per
1000 carbons 49 49 42.73
121 (g/10min.) 0.3 0.3 0.28
dl (g/cm3) 0.8685 0.8685 0.8747
64
Date Recue/Date Received 2020-10-01
The Second
Polyethylene
Single Site Single Site Single Site
Catalyst Type 2 Catalyst Catalyst Catalyst
(phosphinimine) (phosphinimine) (phosphinimine)
0.392 0.224 0.392
(note: w2' = (note: w2' = 0.56 (note: w2' =
weight fraction, w2
0.56 from from 0.560 from
deconvolution) deconvolution) deconvolution)
Mn2 25450 25450 12550
Mw2 50900 50900 25100
2 (Mw2/Mn2 < 2 (Mw2/Mn2 < 2 (Mw2/Mn2 <
Mw2/Mn2
2.3) 2.3) 2.3)
short chain branches per
1000 carbons 0 0 0
122 (g/10min) 11.67 11.67 205.2
d2 (g/cm3) 0.9532 0.9532 0.9596
The Third Polyethylene
Ziegler-Natta Ziegler-Natta Ziegler-Natta
Catalyst Type 3
Catalyst Catalyst Catalyst
weight fraction, w3 0.300 0.600 0.300
Mn3 34317 34317 49653
Mw3 135987 135987 200282
3.96 (Mw3/Mn3 3.96 (Mw3/Mn3 4.03 (Mw3/Mn3
Mw3/Mn3
> 2.3) > 2.3) > 2.3)
short chain branches per
1000 carbons 15.7 15.7 34.5
123 (g/10min) 0.33 0.33 0.11
d3 (g/cm3) 0.9164 0.9164 0.8944
With reference to Figure 1, a person skilled in the art will recognize that
the
polyethylene compositions of Examples 1 and 2 have a largely unimodal GPC
profile.
Date Recue/Date Received 2020-10-01
With reference to Figure 1, a person skilled in the art will recognize that
the
polyethylene composition of Example 3 has a distinctly bimodal GPC profile.
With reference to Figure 2, a person skilled in the art will recognize that
the
polyethylene compositions of Examples 1-3 have a partially reverse comonomer
incorporation, where the comonomer incorporation first rises as molecular
weight
increases, and then falls as the molecular weight increases still further.
With reference to Figure 3, a person skilled in the art will recognize that
the
polyethylene compositions of Examples 1 and 2 each have a melting peak which
occurs at above 125 C. For Example 1 the DSC profile is unimodal. For Example
2,
the DSC profile is bimodal.
With reference to Figure 3, a person skilled in the art will recognize that
for the
polyethylene composition of Example 3 the DSC profile is bimodal.
The data in Table 3, clearly shows that the polyethylene compositions of
Examples 1-3 have a significant amount of material eluting at lower
temperature in a
crystallization elution fractionation (CEF) analysis. Examples 1 and 2, each
have a
soluble fraction in a crystallization elution fractionation (CEF) analysis of
greater than
10 weight percent (Example 1, is 30.3 weight percent; Example 2, is 19.4
weight
percent). Example 3 has a soluble fraction in a crystallization elution
fractionation
(CEF) analysis of greater than 15 weight percent (Example 3, is 40 weight
percent).
A van Gurp-Palmen analysis is a means by which to study a polymer
architecture (e.g. molecular weight distribution, linearity, etc.) as
reflected by the
polymer melt rheology. A VGP curve is simply a plot of the phase angle (8)
versus
complex modulus (G*), where the two rheological parameters are obtained using
the
frequency sweep test in dynamic mechanical analysis (DMA). A shift of a VGP
curve
from a baseline curve or a decrease in the phase angles around the mid-range
of
complex modulus (e.g. at a G* of around 10,000 Pa) suggests changes in the
polymer melt rheology resulting from changes in polymer molecular structure
and
may be indicative of the presence of long chain branching. Without wishing to
be
bound by theory, the value of the phase angle (8) at a complex modulus (G*) of
10,000 Pa, is indicative of the presence of long chain branching in the
polymers of
the present disclosure.
Figure 4 shows a plot of the phase angle (8) vs. the complex modulus (G*) for
the polyethylene compositions of Examples 1-3. Figure 4 also shows the
corresponding data for other polymeric materials. Example A is Surpass FPs016-
C,
66
Date Recue/Date Received 2020-10-01
is a linear polyethylene with no long chain branching, and is commercially
available
from NOVA Chemicals. Example B is NOVAPOL LF-Y320-A. NOVAPOL LF-
Y320-A is a low density polyethylene (a "LDPE") which is made under high
pressure
gas phase conditions and is known to contain significant amounts of long chain
branching.
As can be seen from the curves in Figure 4, Example A, which is a linear
polymer having no long chain branching has a curve with no inflexion point and
a
phase angle (8) of 77.1 , at a complex modulus (G*) of 10,000 Pa. In contrast,
Example B, which is a low density polyethylene having significant amounts of
long
chain branching, has a low phase angle (8) of 46.4 , at a complex modulus (G*)
of
10,000 Pa.
When examining the curves in Figure 4 for Examples 1-3, a person skilled in
the art will recognize that they are consistent with the presence of some
degree of
long chain branching. The curves for Examples 1-3 all have a phase angle (8)
at a
complex modulus (G*) of 10,000 Pa of less than 75 , which represents a
downward
deflection of the curve from that observed for the linear polymer, Example A,
and
toward that observed for the polyethylene having significant amounts of long
chain
branching, Example B.
In a plot of the transient extension viscosity (7,1(t) in Pa. s) vs time
(seconds)
for an ethylene polymer which is known to contain long chain branching, the
average
MSHI (as defined above; at time = 4 to tf seconds at 0.3 5-1 strain rate) is
believed to
be related to the length and amount of long chain branches (See Figure 5 and
the
examples in Table 5 below). Without wishing to be bound by theory, the larger
the
value for the average MSHI, the longer the length and amount of the long chain
branches present.
Table 5 shows the average melt strain hardening index (MSHI) for
polyethylene compositions of Examples 1-3 as well as the corresponding data
for
other polymeric materials. Example C is Eastman 808P, a low density
polyethylene
(LDPE). Example D is ExxonMobil LD201.48, a low density polyethylene (LDPE).
Example E is DuPont LDPE 1640, a low density polyethylene (LDPE). Example F
is Novapol LC-0522-A, a low density polyethylene (LDPE). Low density
polyethylene (LDPE) which is made under high pressure gas phase conditions is
well known to have relatively large amount of long chain branches and the
lengths of
some of the long chain branches is believed similar to that of the polymer
backbone.
67
Date Recue/Date Received 2020-10-01
TABLE 5
The Average Melt Strain Hardening Index (MSHI) of the Polyethylene
Compositions and Comparative Resins
Average Melt
Test temperature of Strain Hardening
Slope of Fitting, b
Example No. extensional viscosity Index (time from 4 value (1 to 4
(degree C) to tf seconds at 0.3 seconds, 0.3 s-1)
5-1 strain rate)
C 150 1.69 3092.5
D 150 1.65 5918
E 150 1.34 6518
F 150 1.28 6501
1 150 0.96 11812
2 150 0.97 14719
3 150 0.97 11585
It can be seen in the Table 5 that each of Examples C, D, E, and F exhibit
MSHI values which are higher than 1Ø The MSHI values of the polyethylene
compositions of Examples 1-3 are below 1.0, which is less than that observed
for
Examples C, D, E, and F (all substantially greater than 1.0). Hence, although
the
polyethylene compositions of Examples 1-3 have been shown to contain long
chain
branching (see Figure 4 and the phase angle (8) vs complex modulus (G*) data
discussed above), the long chain branches, at least for Examples 1-3, are
believed
to be shorter long chain branches than those present in conventional LDPE
polymers.
Without wishing to be bound by theory, it is believed that some degree of long
chain branching may enhance the thermoformability of a polyethylene
composition.
During the thermoforming process, a sample exists in two phases for a semi-
crystalline resin: an amorphous phase that can melt or soften well below the
resin
melting point and a solid phase that can remain in such a state until the
resin melting
point is reached. It is believed that a certain amount of long chain branching
can
increase the melt strength of the amorphous phase, helping the amorphous phase
to
maintain its integrity under the deformation stresses encountered during the
thermoforming process. Meanwhile, it is believed that the mechanical strength
of the
68
Date Recue/Date Received 2020-10-01
solid phase is also an important consideration when the solid phase is
subjected to
the deformation stresses of a thermoforming process. Without wishing to be
bound
by theory, it is believed that if the content of the long chain branching
and/or the
length of the long chain branches within of a polyethylene composition is too
large or
.. too long, the long chain branching may negatively affect the mechanical
strength of
the solid phase of a semi-crystalline resin, leading to poorer performance of
a resin
in a thermoforming application. Hence, it is possible that that intermediate
levels of
long chain branching and/or long chain branching length observed for the
polyethylene compositions of Examples 1-3 (See Table 5 and Figure 4), relative
to a
LDPE, are useful for thermoforming applications.
Compression Molded Monolaver Film Samples
A laboratory scale compression molding press, Wabash G304, from Wabash
MPI was used to prepare compression molded films from the polyethylene
compositions of Examples 1-3 as well as from other polymeric materials.
A Nylon-6 polymer (one of the polymers used to build the screening tool) was
ground using a Thomas Wiley mill, into granular form, and then dried in a
vacuum
oven at 90 C under 20 mmHg of vacuum for 4 hours. Next, the nylon sample was
removed from the oven and placed in a desiccator, which was sealed by applying
a
vacuum to the desiccator. The nylon sample was cooled for at least 1 hour in
the
desiccator before it was compression molded.
A metal shim was used as a mold. It was a brass shim (10 inch x 10 inch), in
which was carefully cut out four windows of 4 inch x 4 inch to serve as the
mold to
be used. The thickness of the shim was about 0.018 to 0.019 inch which led to
a final
film thickness of approximately 0.015 inch or 15 mil. The mold was filled with
a
measured quantity of resin (e.g. pellets of a polyethylene composition or a
nylon
granular sample) and sandwiched between two polished metal plates. The
measured polymer quantity used was sufficient to obtain the desired film
thickness of
15 mils or 0.381 mm. For the polyolefin resins, polyester sheets (Mylar) were
used
.. on top of the metal backing plates to prevent the resin from sticking to
the metal
plates. For the nylon 6 resin, Teflon sheets were used to prevent sticking.
The metal shim assembly with the resin sample was loaded into the
compression molding press and preheated to 200 C in the case of polyethylene
materials and polyethylene-cyclic olefin copolymer blend materials, each in
the
69
Date Recue/Date Received 2020-10-01
absence of applied pressure and for 4 minutes. In the case of nylon 6, the
sample
was loaded into the compression molding press and preheated to 260 C in the
absence of an applied pressure for four minutes. To compression mold the
sample
the following sequence was carried out: a) the pressure was increased to 1 ton
of
pressure and the pressure was maintained at 1 ton for 1 minute; b) the
pressure was
then increased to 2 tons of pressure, and the pressure was maintained at 2
tons for
1 minute; c) the pressure was then increased to 3 tons of pressure, and the
pressure
was maintained at 3 tons for 1 minute; d) the pressure was then decreased to 1
ton,
and the pressure was maintained at 1 ton of pressure for 1 minute; e) next the
pressure was increased to 5 tons and the pressure was maintained at 5 tons for
2
minutes; f) the pressure was then increased to 28 tons, and the pressure was
maintained at 28 tons for 3 minutes; g) finally, the compression molding press
was
cooled to about 45 C at a rate of about 15 C per minute, and then the pressure
was
released. On completion of the forgoing compression molding cycle, the metal
shim
.. assembly was taken out of the compression molding press to provide a
compression
molded film (or plaque). In the case of Nylon-6, the compression molded film
was
stored in a desiccator until cut into a specified shape (see below).
A punch die was used on the compression molded films made as described
above, to "punch" out a rectangular specimen (4 inches in length x 1 inch in
width)
having specific dimensions, see Figure 7, and suitable for use in high
temperature
tensile experiments (see below). Again, the nylon-6 film specimens were placed
in a
desiccator prior to testing. Each sample was conditioned at room temperature
and
pressure for a least 48 hours, following compression molding and prior to high
temperature tensile experiments.
Area Dimensional Thermoformabilitv Index (aDTI)
A diagram depicting the general thermoforming process and deformations
which occur is shown in Figure 6. The diagram illustrates the planar
deformation
and the biaxial deformation which occurs when a plastic sheet or film is
subjected to
thermoforming in a mold.
The presently presented method, which determines the so called "area
Dimensional Thermoformability Index" (aDTI) was developed to approximate the
deformations which occur during thermoforming and so serves as a laboratory
scale
proxy test method to assess the relative theromoformability of various resins
with
Date Recue/Date Received 2020-10-01
respect to thickness distribution uniformity or tendency of corner thinning.
The proxy
test employed to determine the aDTI is essentially a high temperature tensile
experiment carried out on a test specimen having specific dimensions. An
Instron
5965 Universal Testing Machine equipped with an oven chamber was used to carry
out the tensile test. The test specimen used was a 15-mil thickness
compression
molded monolayer film having a length of 4 inches and width of 1 inch and
prepared
as described above. Once the test specimen was prepared it was marked with an
ink dot at specific intervals along the mid-point of the sample's width, and
along the
length of the test specimen (See Figure 7). The first position was 0.79375 cm
(or
5/16") from the middle position (i.e., the position which is 2 inches from
both edges of
the 4-inch long specimen). The second position was 0.79375 cm (or 5/16") away
from the above first position, and the third position was 0.79375 cm (or
5/16") away
from the above second position. Symmetrically, the other three positions,
relative to
the middle position, can be identified in the opposite direction on the 4-inch
long test
specimen. Hence, a total of seven positions were identified and the data
collected
for these seven positions were used for the aDTI calculation. The upper and
lower
gripping positions are at 1.905 cm from the top and bottom edges of the 4-inch
long
specimen. A person skilled in the art will recognize that a different number
of
symmetrically marked positions could be devised in order to change the number
of
data points employed for the testing (in this case, the distance between two
adjacent
positions would need to be adjusted accordingly). The test specimen was then
mounted in the oven chamber of the Instron instrument. The pulling speed of
the
machine was 20 in/min (8.47 mm/sec) using a 1-kN load cell with 2.5" grip
separation. The specimen was pulled up to a 300% elongation and the test was
stopped even though the specimen might have the potential for higher
elongation
than 300% at the test temperature. The upper limit of a 300% elongation was
due to
the limitation imposed by the internal height of the oven chamber. Each
specimen
was mounted and conditioned inside the chamber for 3 minutes at the desired
temperature (e.g., 105 C) prior to the pulling test at that temperature. Five
specimens were generally used in the testing procedure to determine the aDTI
value
for a given polymer. Typically, the thermoforming temperature for a multilayer
film
containing a polyethylene copolymer lies somewhere in the range of from 80 to
110 C (and rarely reaches up to 120 C). Accordingly, the temperatures of 95 C,
100 C and 105 C were used to screen various polymers during the development of
71
Date Recue/Date Received 2020-10-01
the aDTI test method. However, once it became clear that the present method of
determining the aDTI worked better to distinguish resins in experiments
performed at
105 C, this temperature was used for further testing. A figure illustrating
the test
specimen before and after the tensile test was carried out is shown in Figure
7.
Parameters such as the thickness Dimensional Thermoformability Index
("dDTI"), the width Dimensional Thermoformability Index ("wDTI"), and the area
Dimensional Thermoformability Index ("aDTI") were calculated from the pre-
deformation (represented by the dimensions at room temperature prior to the
high
temperature tensile test) and post-deformation dimensions of the test
specimen. It
was found that aDTI worked better than dDTI and wDTI (although not all of this
data
are included here). The aDTI is calculated in the following way. Note that for
the
present disclosure, and the calculations provided below, seven locations were
marked at the width's mid-point along the length of the test specimen, so that
n = 7,
but a person a skilled in the art would know that the number of locations
included
could be varied, i.e. that n = x points. Several test specimens were also
used,
usually five, so that m = 5, but a person a skilled in the art would know that
the
number of test specimens included could be varied, i.e. that m = y specimens.
The
final aDTI value then, determined as shown in the calculation below,
encompasses
the sum of all the specimens and positions and reflects the overall change in
cross-
sectional area between an original unstretched state to final stretched state
over
each ith location (n) over each jth specimen (m).
Area DTI Calculation:
For the ith position (i = 1 to n) on each specimen and the jth specimen (j = 1
to
m); where j is the number of specimens tested and i is the number locations
for
which the cross-sectional area was determined on each specimen (as marked by
an
ink dot):
Step 1: For each specimen, a value X; (j = 1 to m) is calculated as follows.
This is to
estimate the average change of the cross-sectional area prior to and after the
tensile
test for each specimen:
0 0 0
X. S= um[(A.. - A ..) / A ..] / n = Sum[(d.. x W..¨ d x W0 ..) / (d
x W..)] / n
72
Date Recue/Date Received 2020-10-01
where,
0 0 0
A ..= d x W
It it Ii
A..= d.. x W..
It it it
and where n is the number of the positions on each specimen where the
dimensions (thickness and width) were measured prior to and after the tensile
test;
d ij is the initial specimen thickness at the ith position of the jth specimen
prior to the
tensile test; W ij is the initial specimen width at the ith position of the
jth specimen prior
to the tensile test; dij is the specimen thickness at the Rh position of the
jth specimen
after the tensile test; Wij is the specimen width at the Rh position of the
jth specimen
after tensile the test; gij is the initial cross-sectional area prior to the
tensile test at
the ith position of the jth specimen; and Aij is the cross-sectional area at
the ith position
of the jth specimen after the tensile test;
Step 2: For the area DTI of the jth specimen:
0 0
Area j DTI. = 100 * Sum {ABS[X. -
(A.. - A .. ) / A .. ) / n
where the absolute value is taken to ensure that the value of aDTI is
positive,
and where for convenience, the area DTI is reported as a multiple of 100;
Step 3: Average area DTI from all the specimens and all the positions tested
for a
sample:
Area DTI = Sum (Area DTI) / m
Note: Similar calculations may be completed to determine thickness
Dimensional Thermoformability Index ("dDTI") if considering only the thickness
dimension, and the width Dimensional Thermoformability Index ("wDTI") if
considering only the width dimension.
73
Date Recue/Date Received 2020-10-01
Without wishing to be bound by theory, a smaller measured aDTI value,
should correspond to a smaller change in the dimensions (e.g., the thickness
at the
corners of a film after thermoforming) of a film or sheet subjected to
deformation
stresses during thermoforming. Hence, a smaller aDTI value should correspond
to
an improved thermoformability with regard to a film's thickness distribution
uniformity
or its tendency to thin or lose corner thickness during a thermoforming
process.
The aDTI method was validated by determining the aDTI values for polymers
having known good or poor thermoformability under traditional thermoforming
temperatures and conditions. For example, nylon polymers are known to be much
better than traditional polyolefins in the thermoformability of multilayer
films, including
for example the reduction of corner thinning. Also known to persons skilled in
the
art, is that TOPASTm 8007 (a cyclic olefin copolymer) may be used to improve
the
thermoformability of traditional polyethylenes in thermoforming applications.
Accordingly, and as known to persons skilled in the art, TOPAS 8007 has been
used
as a component in a polymer blend with a traditional polyethylene to enhance
the
thermoformability of multilayer films. Conversely, HPs167-AB is a nonpolar
polyethylene resin with a high melting point and high crystallinity,
properties which
are thought to be detrimental to the thermoformability of a nonpolar polymer.
To generate the data in Figure 8, which plots the aDTI against three different
temperatures, a polymer such as nylon 6 (commercially available from BASF as
Ultramid0 B4OL) was used. Prior to forming the compression molded films used
for
the tensile testing, the nylon sample was ground into a powder. The powder was
compression molded into 15-mil thick, compression-molded films (see above) and
stored in a desiccator with a desiccant to prevent moisture absorption. The
nylon
film, so stored were used in the high temperature tensile experiments.
To establish a baseline ranking system, the calculated area DTI values for 15
mil thick, monolayer films made from a nylon polymer (e.g. nylon 6), a cyclic
olefin
copolymer (e.g. TOPAS 8007F), a traditional unimodal polyethylene copolymer
(e.g.
FP-120-C) and its melt blend with a cyclic olefin copolymer (e.g. 80wt% FP120-
C +
20 wt% TOPS 8007F), and a polyethylene homopolymer (e.g. HPs167-AB), were
plotted for 95 C, 100 C and 105 C, as shown in Figure 8. At all three of the
temperatures tested, the ranking of the area DTI values, was found to be
consistent
with what is known from to persons skilled in the art with regard to the
performance
74
Date Recue/Date Received 2020-10-01
of these materials in industrial thermoforming processes (e.g. the
thermoforming of
the materials into multilayer film structures). Hence, as shown in Figure 8,
the aDTI
values established for these resins followed what is generally known to
persons
skilled in the art with regard to thermoformability: Nylon-6 had a relatively
low aDTI;
.. TOPAS 8007 and its blend with a traditional unimodal polyethylene copolymer
had
an intermediate aDTI; the traditional unimodal polyethylene copolymer had an
even
higher aDTI; and the HPs167-AB had the highest aDTI. Accordingly, these resins
establish some benchmark values for the aDTI parameter against which a
polyethylene composition (or other resin) could be compared. Figure 8 also
shows
that aDTI values have a greater difference between materials when measured at
a
higher temperature such as 105 C. As a result, when determining how other
polymer materials would perform, relative to those plotted in Figure 8, their
aDTI
values were measured at 105 C (which is slightly lower than the upper
temperature
typically used for the thermoforming of a polyethylene multilayer film).
Table 6 shows the aDTI of the three polyethylene compositions of the present
disclosure as well as for several other polymers for comparison purposes. In
addition to TOPAS 8007F, and Nylon 6, the data in Table 6 shows the relative
aDTI
values for a conventional polyethylene copolymer (FP120-C, a linear low
density
ethylene copolymer with a density of 0.920 g/cm3 and a melt index, 12 of about
1
.. g/10min, commercially available from NOVA Chemicals), a polyethylene
homopolymer (HPs167-AB, an ethylene homopolymer with a density of 0.967 g/cm3
and a melt index, 12 of about 1 g/10min, commercially available from NOVA
Chemicals) and a blend of a traditional polyethylene copolymer with a cyclic
olefin
copolymer (80 wt% FP120-C + 20 wt% TOPAS 8007F).
TABLE 6
Area Dimensional Thermoformability Index (aDTI) of Thermoformable
Film
Example No. Area DTI at 105 C
1 (Inventive)
2.19
(70 wt% PE Composition A / 30 wt% PE B)
2 (Inventive)
3.3
(40 wt% PE Composition A /60 wt% PE B)
Date Recue/Date Received 2020-10-01
3 (Comparative)
20.23
(70 wt% PE Composition C / 30 wt% PE D)
Nylon 6 (Comparative) 1.67
TOPAS 8007F (Comparative) 9.24
FP120-C (Comparative) 17.12
80 wt% FPs120-C + 20 wt% TOPAS 8007F
(Comparative) 12.68
HPs167-AB (Comparative) 29.80
A person skilled in the art will recognize from the data provided in Table 6,
that the polyethylene compositions of Examples 1 and 2 have an aDTI at 105 C
which is dramatically lower than the comparative traditional polyethylenes,
and
dramatically lower than that of Example 3. The area DTI at 105 C for Examples
1
and 2 which both have a relatively low 121/12 (i.e. <50) and a Tm2 ¨ Tml of
less than
30 C was well below about 15 at about 2.2 and 3.3 respectively, while the area
DTI
at 105 C for Example 3 which has relatively high 121/12 (i.e. > 50) ) and a
Tm2 ¨ Tml of
greater than 50 C was about 20. Indeed, as shown by the data in Table 6, the
polyethylene compositions of Examples 1 and 2, have an area DTI at 105 C value
which is comparable to that measured for a nylon polymer, which is known in
the
prior art for its superior performance in thermoformable film applications
(see for
example, XiaoChuan Wang and Mini Boparai, Annual Technical Conference of the
Society of Plastics Engineers, May 16 -20, 2010, Orlando, Florida, USA).
Accordingly, a person skilled in the art would expect the polyethylene
compositions
of Examples 1 and 2 to perform relatively well when used in thermoforming
applications.
Non-limiting embodiments of the present disclosure include the following:
Embodiment A. A thermoformable film, the film comprising a polyethylene
composition comprising:
from 5 to 80 wt% of a first polyethylene which is an ethylene copolymer, the
first polyethylene having a weight average molecular weight Mw of from 70,000
to
250,000, a molecular weight distribution Mw/Mn of <2.3 and from 5 to 100 short
chain branches per thousand carbon atoms;
from 5 to 80 wt% of a second polyethylene which is an ethylene copolymer or
an ethylene homopolymer, the second polyethylene having a weight average
76
Date Recue/Date Received 2020-10-01
molecular weight Mw of from 15,000 to 100,000, a molecular weight distribution
Mw/Mn of < 2.3 and from 0 to 20 short chain branches per thousand carbon
atoms;
and
from 5 to 80 wt% of a third polyethylene which is an ethylene copolymer or an
.. ethylene homopolymer, the third polyethylene having a weight average
molecular
weight Mw of from 70,000 to 250,000, a molecular weight distribution Mw/Mn of
> 2.3
and from 0 to 50 short chain branches per thousand carbon atoms; wherein
the number of short chain branches per thousand carbon atoms in first
polyethylene (SCBpE-1) is greater than the number of short chain branches per
thousand carbon atoms in the second polyethylene (SCBpE-2) and the third
polyethylene (SCBpE-3);
the number of short chain branches per thousand carbon atoms in the third
polyethylene (SCBpE-3) is greater than the number of short chain branches per
thousand carbon atoms in the second polyethylene (SCBpE-2); and
the weight average molecular weight of the second polyethylene is less than
the weight average molecular weight of the first polyethylene and the third
polyethylene; wherein,
the polyethylene composition has a density of 0.939 g/cm3, a Tm2 ¨ Tml of
less than 30 C, a melt index 12 of from 0.1 to 10 dg/min, a melt flow ratio,
121/12 of
50, and a soluble fraction in a crystallization elution fractionation (CEF)
analysis of at
least 10 weight percent.
Embodiment B. The thermoformable film of Embodiment A wherein the
polyethylene composition has an area Dimensional Thermoformability Index
(aDTI)
at 105 C of less than 15.
Embodiment C. The thermoformable film of Embodiment A or B wherein the
polyethylene composition has a unimodal profile in a gel permeation
chromatograph
(GPC).
Embodiment D. The thermoformable film of Embodiment A, B or C wherein
the polyethylene composition has a soluble fraction in a crystallization
elution
fractionation (CEF) analysis of at least 15 weight percent.
Embodiment E. The thermoformable film of Embodiment A, B, C or D
wherein the polyethylene composition has a melting peak temperature in a
differential scanning calorimetry (DSC) analysis at above 125 C.
77
Date Recue/Date Received 2020-10-01
Embodiment F. The thermoformable film of Embodiment A, B, C, D or E
wherein the first polyethylene has from 30 to 75 short chain branches per
thousand
carbon atoms.
Embodiment G. The thermoformable film of Embodiment A, B, C, D, E or F
wherein the second polyethylene is an ethylene homopolymer.
Embodiment H. The thermoformable film of Embodiment A, B, C, D, E, F or
G wherein the third polyethylene is an ethylene copolymer and has from 5 to 30
short chain branches per thousand carbon atoms.
Embodiment I. The thermoformable film of Embodiment A, B, C, D, E, F, G or
H wherein the first polyethylene has a weight average molecular weight, Mw of
from
75,000 to 200,000.
Embodiment J. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H or I wherein the second polyethylene has a weight average molecular weight,
Mw
of from 25,000 to 75,000.
Embodiment K. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I or J wherein the third polyethylene has a weight average molecular
weight, Mw
of from 80,000 to 200,000.
Embodiment L. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J or K wherein the first polyethylene has a density of from 0.855 to
0.910 g/cm3.
Embodiment M. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K or L wherein the second polyethylene is an ethylene homopolymer
having a
density of from 0.940 to 0.980 g/cm3.
Embodiment N. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L or M wherein the third polyethylene is an ethylene copolymer
having a
density of from 0.880 to 0.936 g/cm3.
Embodiment 0. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M or N wherein the first polyethylene is present in from 5 to
50 wt%.
Embodiment P. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N or 0 wherein the second polyethylene is present in from 5
to 60
wt%.
Embodiment Q. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, 0 or P wherein the third polyethylene is present in from
15 to 85
wt%.
78
Date Recue/Date Received 2020-10-01
Embodiment R. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M or N wherein the first polyethylene is present in from 10 to
40 wt%.
Embodiment S. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, or R wherein the second polyethylene is present in from
15 to 45
wt%.
Embodiment T. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, R or S wherein the third polyethylene is present in from
20 to 80
wt%.
Embodiment U. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, 0, P, Q, R, S or T wherein the first polyethylene has a
CDBI50 of
at least 75 wt%.
Embodiment V. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, 0, P, Q, R, S, T or U wherein the third polyethylene is a
copolymer with a CDBI50 of less than 75 wt%.
Embodiment W. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, 0, P, Q, R, S, T, U or V wherein the first polyethylene
is a
homogeneously branched ethylene copolymer.
Embodiment X. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V or W wherein the third
polyethylene is a
heterogeneously branched ethylene copolymer.
Embodiment Y. The thermoformable film of A, B, C, D, E, F, G, H, I, J, K, L,
M, N, 0, P, Q, R, S, T, U, V, W or X wherein the first polyethylene is a made
with a
single site catalyst.
Embodiment Z. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X or Y wherein the second
polyethylene
is made with a single site catalyst.
Embodiment AA. The thermoformable film of Embodiment A, B, C, D, E, F,
G, H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X, Y or Z wherein the third
polyethylene is made with a Ziegler-Natta catalyst.
Embodiment BB. The thermoformable film of Embodiment A, B, C, D, E, F,
G, H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X, Y, Z, or AA wherein the
polyethylene composition has a molecular weight distribution Mw/Mn of from 2.1
to
5.5.
79
Date Recue/Date Received 2020-10-01
Embodiment CC. The thermoformable film of Embodiment A, B, C, D, E, F,
G, H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X, Y, Z or AA wherein the
polyethylene composition has a molecular weight distribution Mw/Mn of from 2.1
to
4.5.
Embodiment DD. The thermoformable film of Embodiment A, B, C, D, E, F,
G, H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X, Y, Z, AA, BB or CC
wherein the
polyethylene composition has a density of < 0.935 g/cm3.
Embodiment EE. The thermoformable film of Embodiment A, B, C, D, E, F,
G, H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X, Y, Z, AA, BB or CC
wherein the
polyethylene composition has a density of from 0.880 to 0.932 g/cm3.
Embodiment FF. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X, Y, Z, AA, BB, CC, DD, or EE
wherein
the polyethylene composition has a melt index, 12 of from 0.1 to 3.0 dg/min.
Embodiment GG. The thermoformable film of Embodiment A, B, C, D, E, F,
G, H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X, Y, Z, AA, BB, CC, DD,
EE, or FF
wherein the polyethylene composition has a Mz/Mw of less than 3Ø
Embodiment HH. The thermoformable film of Embodiment A, B, C, D, E, F,
G, H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X, Y, Z, AA, BB, CC, DD,
EE, FF or
GG wherein the polyethylene composition has a melt index ratio, 121/12 of from
20 to
40.
Embodiment II. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X, Y, Z, AA, BB, CC, DD, EE,
FF, GG,
or HH wherein the film is a single layer film.
Embodiment JJ. The thermoformable film of Embodiment A, B, C, D, E, F, G,
H, I, J, K, L, M, N, 0, P, Q, R, S, T, U, V, W, X, Y, Z, AA, BB, CC, DD, EE,
FF, GG or
HH wherein the film is a multilayer film.
Date Recue/Date Received 2020-10-01
