Note: Descriptions are shown in the official language in which they were submitted.
BACKC.R~UND OF TH~ INVENTI~N
In block polymerization, there is substantially effect-
ed a combination of the best physical and chemical properties of
two or more polymers, for example, the combination of those of
polyproplyene with those of polyethylene. Thus, polyethylene,
while not possessing melting points or tensile stren~ths as
high as those of polypropylene, does in fact possess excellent
low temperature properties such as brittleness and impact: When
the outstanding properties of both of these polymers are combined
~I in the technique of block pol~merizationf there results at once
¦ a heteropolymer useful in many applications for which neither
homopolymer was practically useful.
A group of block copolymers, which have excellen~
physical properties, are the ethylene-propylene block copolymers,
e.g. those of the type P-EP, where P denotes a propylene homo-
polymer preblock and EP is a post-block of ethylene-propylene
; copolvmer. By v~rying the proportions of the blocks and the
polymerized ethylene content, the physical properties can be
closely controlled to fit the particular application for which
the polymer products are intended. In general, at constant melt
B ~
~l--
67
flow rates the impact strength at roo~ temperature of the block
copolymer is substantially directly proportional to the amount
of polymerized ethylene in the total product.
Block copolymers are advantageously produced on a
commercial scale by the process disclosed in U.S. Patent No.
3,514,501. Briefly, this process involves preparation of the
preblock, preferably in the liquid phase, by catalytic poly-
meri~ation of propylene in a hydrocarbon diluent such as liquid
; propylene to form a slurry. After separation of the slurry,
the prepolymer which still contains active catalyst residues is
introduced into at least one reaction zone, where it is reacted
with monomer vapors for a sufficient period of time to form the
polymer post block onto the polymer preblock in the desired
proportions.
In the past, the conventional catalyst system used in
such a polymerization process has been an unmodified or an
electron donor-modified titanium halide component, activated
with an organoaluminum cocatalyst. Typical examples of con-
ventional propylene polymerization catalyst systems include
cocrystallized titanium trichloride-aluminum trichloride
catalysts of the general formula n.TiC13.AlC13 activated with
diethyl aluminum chloride or triethyl aluminum. The cocryst-
allized titanium trichloride-aluminum trichloride can have been
subjected to a modification treatment with a suitable electron
donor compound to increase its activity or stereospecificity.
Such compounds include phosphorus compounds, esters of inorganic
and organic acid ethers and numerous other compounds.
One major drawback, however, in using the aforementioned
conventional catalysts, has been the low catalyst productivity,
which has necessitated the subse~uent deashing of the product
67
to reduce the content of catalyst residues, which otherwise
would detrimentally affect the product quality.
Recently new catalysts have ~een developed which are
- 2a -
L067
,
far more active than the aforementioned conventional satalysts
in the polymerization of alpha-olefins. Briefly described,
,~ these catalysts are comprised of a titanium halide catalyst
, component suppcrted on maanesium dihalide and an alkylaluminum
1I compound, which can be present as a complex ~ith an electron
' donor compound. These catal~st components have been described
in the patent literature, e.y. in U.S. Patents No. 3,830,787,
j No. 3,953,414, No. 4,051,313, No. 4,115,319 and No. 4,149,990.
¦ The productivities obtained with these new catalysts
¦j are extremely high resulting in polymers containing such small
quantities of residual catalyst that the conventional deashing
~¦ step can be dispensed with. The catalysts function well in the
Il homopolymerization of propylene and in the copolymerization of
¦l a mixture of propylene and another alpha-olefin such as ethylene, ¦
, provided that the polymerization reaction is carried out in a
¦¦ liquid diluent, e.g. liquid propylene monomer. However, in the
¦¦ vapor phase polymerization used in preparing the EP copolymer
1¦ block of P-EP block copolymer described above, using convention-
,, al operating conditions, 1~ has been found that the product
~ !~ quality of the resulting block polymer has been substantially
¦l inferior. Specificially, in order to achieve a desired impact
¦I strenyth at a desired melt flow, it was found that considerably
¦¦ more ethylene had to be in~orporated into,the total polymer
than is the case when employing conventional catalysts. The
I necessary increase in ethylene content to achieve the impact
strength detrimentally a~fects other desirable properties of the
final product such as stiffness, heat deflection temperature,
¦ tensile properties, etc.
! I-t is therefore an ob1ect of the present invention to
, provide a hiyhly e ficient process for the vapor phase poly-
merization of ethylene-propylene blocks onto a preformed propy-
lene polymer yielding polymer Froducts having improved impact ~`
strength ~ithout siyllificant1~ affectiny other desirable
.
,
Il physical polymer properties.
1, ~nother object of the invention is to provide a
process for the preparation of ethylene-propylene block co-
, polymers wherein the polymerized ehtylene content of the ,otal
il polymer product is minimized to achieve a desired impact
jl strength.
~, Still another object of the present invention is to
provide a novel ethylene-propylene block copolymerswhich ex-
hibits improved processability when extruded or injection mold-
!~ ed as compared to conventional ethylene-propylene block co-
polymers of the same total ethylene content-. ¦
Another object of the present invention is to provide
¦ a novel ethylene-propylene block copol~mer which can be proces-
¦¦ sed at lower extrusion or molding temperatures and/or lower
,¦ extrusion or molding pressures than conventional resins of the
same meltflows and total ethylene content.
Further objects will become apparent from a reading of
¦¦ the specification and appended claims.
'11
I THE IN~IENTION
; 20 The above objects are accomplished in a continuous
I, sequential vapor phase block copolymerization process which
I comprises: I,i (A) providing a preformed propylene polymer in finely divided
¦I form, said preformed polymer containing active catalyst
25 1¦ residues and having been prepared by polymerizing propylene
¦l in the presence of a catalyst composition containing the
components
(a) an aluminum trialkyl or an alurninum trialkyl at least
, partially complexed with an electron donor componnd,
and l~
(b) titallium tri- or tetrahalide supported on magneslum
"
~ I
31 ~41~67
dihalide, or a complex of a titanium tri- or tetra-
halide with an electron donor compound supported on
magnesium dihalide;
Il (B~ introducing said preformed polymer into at least one
5 ¦¦ continuously agitated reaction zone,
(C) introducing ethylene and propylene monomers to said
reaction zone in a molar ratio of ethylene to propylene
of from about 0.15 to about 0.3,
~ (D) polymerizing said ethylene and propylene monomers in the
1I vapor phase in the reaction zone onto said preformed
! propylene prepolymer.
,i As used throughout this specification and the claims
¦¦of this invention, the following terms are intended to have the
Il following meanings:
15ll (a) "preformed polymer" means a propylene polymer which
¦ is suitable for independent use, but which contains
¦¦ active catalyst residues;
~1 (b) "active catalyst residues" as used herein indicates
catalytic components in the polymer which function
20 j to polymerize added monomeric substances ~ithout
¦ the need of adding further quantities of catalyst.
¦I The active catalyst residues referred to herein are
¦~i preferably those initially employed in the poly-
Il merization to produce the preformed polymer;
25i, (c) a "block polymer" has the same significance as hereto-
! fore understood in the prior art, that is, a polymer
. j molecule consisting of a single section of an alpha-
l olefin polymer or copolymer attached to a single
I section of another alpha~olefi.n polymer or copol~me~-.
Bloc]~ polymers are i.ntended to include t~o or more co-
polymers sequen.ially polymerized one onto the o.`ner;
a homopolymer followed by a co~olymer, or al~erna~
holno or copolymer bloc~s of t~o or more alph.~-ole-i,n
1,
;!
rnonomers;
', (d) "~701atile constituents" include unpolymerized alpha- j
olefin monomers, as well as inert hydrocarbon diluents
such as ethane, propane, butane, pentane, hexane,
l heptane, octane, aromatic hydrocarbons, diesel oils
Il and the like;
,~ (e) by polymerization in a "hydrocarbon diluent", it is
intended that polymerization can occur in the presence
~¦ of inert hydrocarbon diluents such as those named
above in (d) or polymerizations wherein the monomer,
¦i i.e. propylene, under conditions of temperatures and
pressure is kept in liquid form during the polymeriz-
jl ation, thereby servin~ as its own dispersing medium or
mi~ture of inert hydrocarbons and olefin monomers in
¦l liquid form;
(f~ by "vapor phase" block polymerization and "substantial-
ly dry prepolymer" it is intended to mean that a pre-
formed polymer contains in the order of 5% or less of
volatile constituents, is reacted with gaseous monomers
;~ 20 1! in the absence of added inert hydrocarbon diluents.
Propylene, optionally in admixture with mlnor amounts
¦ of other alpha-olefins of from about 2 to 10 carbon atoms or
¦ more can be employed to form a prepolymer. Such other alpha-
olefins include ethylene, hutene-l, isobut~éne-l, pentene-l,
I~ hexene-l, and hiqher, as well as branched alpha-olefins such as
¦l 2-methyl butene-l, 4-methyl pentene-l and hi~her. Of these
~¦ monomers, propylene and mixtures of propylene and ethylene are
¦ of special interest and most preferred. When ethylene is a
1~ component, it is preferred that it be limited to a concentration
~ of from about 0.3 to about 2 ~it ~ of the total monomer feed.
The prepolymer is formed in a reaction zone employin~
a hydrocarbon diluent and a catalyst for the polymerization,
carryin~ out the polymerizatioo to a solids content of from 5 to
,
~. ~
il I
4~06~
60~, but preferably 20 to 40~. The preferred diluent is li~uid
propylene.
In the preferred process for the prepolymer formation,
i.e. the well known "liquid pool" process, the propylene
functions as the liquid diluent as well as feed to the reaction,
except for small quantities of inert hydrocarbons, e.g. hexane,
mineral oil, petrolatum, etc., that may be used for the intro-
duction of the catalyst components into the reaction zone.
The reaction is continuous and monomer feed and
catalyst components are continuously fed to the reactor and a
slurry of polymer product and liquid propylene is withdrawn,
preferably through a cyclic discharge valve which simulates
continuous operation. Various modifiers such as hydrogen may
be added to alter the properties of the polymer product. Such
modifiers are well known in the art and need not be discussed
in any further detail since they form no part of this invention.
The catalyst components used in the process for pre-
paring the prepolymer can be any one of the recently developed,
high activity magnesium halide supported catalyst components
and organoaluminum cocatlayst components disclosed e.g. in ~.S.
Patents No. 3,830,787, No. 3,953,414, No. 4,051,313, No. 4,115,
319, and No. 4,149,990.
Typically, such a catalyst composition is a two
component composition where the components are introduced
separately into the polymerization reactor. Component (a) of
such a composition is advantageously selected from trialkyl
aluminums containing from 1 to 8 carbon atoms in the alkyl
group, such as triethyl aluminum, trimethyl aluminum, tri-n-butyl
aluminum, tri-isobutyl aluminum, triisohexyl aluminum, tri-n-
octyl alumirum and triisooctyl aluminum. Most preferably, the
trialkyl aluminum is complexed ~ith an electron donor prior to
introduction into the polymerization reactor. Best results are
,~
-7-
6~7
achieved when esters of carboxylic acids or diamines, particular-
ly esters of aromatic acids are used as the electron donors.
Some typical examples of such compounds are methyl-
and ethylbenzoate, methyl- and ethyl-p-methoxybenzoate, diethyl-
carbonate, ethylacetate, dimethylmaleate, triethylborate, ethyl-
o-chlorobenzoate, ethylnaphthenate, methyl-p-toluate, ethyl-
toluate, ethyl-p-bu~oxy benzoate, ethyl-cyclohexanoate, ethyl-
pivalate, N,N,N',N'-tetramethylenediamine, 1,2,4,-trimethyl-
piperazine, 2,5-dimethylpiperazine and the like. The molar ratio
of aluminum alkyl to electron donor can range between 1 and 100,
preferably between 2 and 5. Solutions of the electron donor and
the trialkyl aluminum compound in a hydrocarbon such as hexane
or heptane are preferably prereacted for a certain period of
time generally less than 1 hour prior to feeding the mixture
into the polymerization reaction zone.
The other component of the catalyst composition is
either a titanium tri-or tetrahalide supported on magnesium
dihalide, or a complax of a titanium tri-or tetrahalide with an
electron donor compound supported on magnesium dihalide. The
halogen in the respective halides can be chlorine, bromine or
iodine, the preferred halogen being chlorine. The electron
donor, if it is used in forming a complex, is suitably selected
from the esters of inorganic and organic oxygenated acids and
the polyamines. Examples of such compounds are the esters of
aromatic carboxylic acids, such as benzoic acid, p-methoxybenzoic
acid and p-toluic acids and particularly the alkyl esters of
said acids; the alkylene diamines, e.g. N',N",N"', N""-
tetramethylethylene-diamine. The Magnesium to electron donor
molar ratio are equal to or higher than 1 and preferably
3~ between 2 and 10. Generally the titanium content expressed as
~s~
~ 8 ~
6~
titanium metal ranges between 0.1 and 20 wt % in the supported
catalyst component and preferably between 1 and 3 wt ~.
The preparation of such supported catalyst components
- 8a ~
~14~7
has been described in the prior art and are commerclally avail- ¦
able.
The catalyst components (a) and (b) are fed to the
' prepolymer reaction zone in amounts such that the Al/Ti molar ~,
il ratio is maintained in the broad range between about 1 and about
10,000 and preferably between about 10 and 200.
! Temperatures at which the prepolymer formation can be
Ii carried out are those known in the art, for example, from 50 to
¦¦ 250F~ preferably from 115 to 165F and most preferably from
l 125F to about 155F. The pressures in the prepolymer formation
¦ can range from atmospheric or below where normally liquid inert
I j! hydrocarbon diluents are used (heptane or hexane) to pressures
i up to 500 psig or higher where propylene is used as its own
dispersing agent or the propylene in admixture with a normally
~15 gaseous hydrocarbon diluent such as propane or butane, which
¦ are liquid under the conditions of the reaction.
- I¦ The prepolymer from the reaction zone is taken to a
~ ¦I separation zone, sach as a cyclone or a bag filter, wherein the
; ¦¦ volatile constituents are separated from the polymer and proces-
1 sed according to known techniques and recycled to the reaction
zone, the amount of volatiles removed being su~ficient so that
¦ less than 10% and preferably no more than 5~ volatile content
remains in the prepolymer. ,
~, In the vapor phase block polymerization, the polymer
~I recovered from the separation zone and containing active
catalyst residues, is taken to a continuously agitated reaction
Il zone containing provisions therein for introducing the ethylene
¦¦ monomer and propylene monomer at one or more points along the
j' length of the zone (and inert gases such as nitrogen) so that
~ the active catalyst residues in the prepolymer polymerize said
mono~ers to a block thereby modifying the ultimate properties
of the resin produced. The polymeri~ation in the continuousl~ I
a~itated reaction zone is ~lenerally carried out at press~lres
;'' ,ii
,, ~
_ q 1,
ll ~14~
lower than those used for the prepolymer preparation, i.e.
pressures of 10 to 50 psig or somewhat higher. Polymerization
temperatures can range, for example, from about 50~F to about
210F, but preferably from about 130 to about 200F.
The ethylene and propylene monomers do not require
premixing prior to introduction into the vapor phase zone; in
fact, it is more advantageous to separately introduce each of
the monomers at one or preferably several points along the
reactor length. Liquid propylene can be introduced, which upon
vaporization will remove some of the heat of polymerization
generated in the reaction zone. The molar ratio of the total
ethylene to total propylene introduced to the reaction zone
should, however, be restricted within the range of ~rom about
0.15 to about 0.3. If higher ratios are employed, it has been
found that the effectiveness of the ethylene content in the
total polymer product on the impact properties is severely de-
creased. For instance, at a ratio of 0.5 it is required to
incorporate about twice the amount of ethylene into the total
polymer in order to obtain the same impact strength as that of
a final product prepared at a ratio o about 0.2.
Generally from about 5 to about 40 percent by weight
of block based on the weight of the total polymer is produced
in the total block poly~erization reactor system.
Suitable continuously agitated reaction zones include
those disclosed in U.S. Patent No. 3,514,501.
The reaction zone can be one or
more pipe line reactors in series with optional jacketing for
heat removal and suitable monomer introduction points as ~ell
as agitating means. According to the preferred embodiment of
this invention, one or more horizontal ribbon blender reactors
are provided for the continuous operation. Such reactors are
equipped internally with a series of ribbon blades and/or
paddles rotated by a power drive. By suitable arran~ement of
; I the agitation equipment the polvmer can be moved continuously
from the inlet to the outlet. The polymer powder substantially
independent of any agitation, behaves much like a fluid and
"flows" or moves from the inlet end of the reactor to the out-
1 let end, that is, flo~s along -the length of the reactor in
¦I much the same manner as a fluid like a liquid would.
¦ Propylene is provided at-]east to the inlet of tne
reactor and if liquid propylene monorner is used, it is prefer- !
¦ ably also provided through inlet spray nozzles spaced along the
I upper portion of the reactor. Ethylene monomer feed in vapor
form can be introduced in similar fashion at points along the
¦! length of the reactor. The reactor is advantageously provided
i with an external cooling jacket for removal of heat through the
¦ reactor wall. Additional vapor-phase reactors can be provided
11 in series wlth the block polymerization reactor for the purpose
Il of increasing residence time. If desired, any of the various
¦I known modifiers may be added to one or more reactor for their
intended purpose.
Because of the generally high productivity of the
¦¦ supported catalyst system expressed in terms of pounds of
¦I polymer produced per pound of titanium metal r which productivity
has been further enhanced by the present invention, there is no
I need to remove catalyst residues from the polymer in a deashing
¦ step as is the case ~ith conventional catàlyst.
2 I The polymer products provided in accordance with
¦ this invention and produced by the preferred "liquid pool"
li method have a meltflow range between about 0.1 and about
¦¦ 10 g/lOmin., ratio of weight-average molecular weignt to
~I number-average rnolecular weight of above about 6.5, ethvlene
3 content of at least about 1 preferrabl~- above about d w. Q`, Ti
content not exceeding about 3ppm, .~g content not exceeding
, about 40ppm, C1 contellt not exceeding about lOOpprn and to~al
~sh content not exceeding about 4no~p~.
6~
Specific advantages of the ~olymers of this invention
' compared to conventional po1vmers include wider ~rocessabilit.y
range, lo~^~er processing energy re~uire~ents, superior ability
~I to fill thin sections and multiple cavitv molds, better draw-
ll down, easier drawabilitv and higher processing speed in the
¦¦ continuous filament and staple fiber ~roduction.
1, For example, hased on spiral meltflow measurements, i
it was found that polymers o.f this invention having meltflows
I (ASTM-1238 Condition L) in the range of about 2-lOg/lOmin. can
be processed at 50~30F lower molding temperatures, or 350-150
I psi lower molding pressures than conventional polymers of the
!I same meltflows (ASTM-1238) and total ethylene content.
I It is believed that the molecular weiqht distribution, ¦
1l Mw/Mn is the ~roperty that best relates to the improvements in
1l impact strength as well as polymer rheological properties and
!I Drocessability. Typically, polymerization with a conventional
Y !¦ catalyst system would result 1n a polymer product having a
¦I Mw/Mn ratio of at most 6.5 and generally below 6, while the
polymers of this invention have Mw/~n ratios of at least 6.5
2~ j e.g. between about 7 and about 10.
Various additives can, i.f desired, be incorporated
¦ into the polypropylene resin, such as fibers, fillers, anti-
¦ oxidants, metal deactivating agents, heat and light stabilizers,
~ dyes, pi~ments, lubricants and the like.
Ij The polymers can be used with advantaqe in the
, manufacture of fibers, filaments and films by extrusion; of
! rigid articles by injection moldinq; and of bottles by blow
¦l molding techniques.
'~ The followinq examples further illustrate the
advantages obtained by the invention.
.,
I~-l2- ,
E~MPLES 1-7
` The experiments were conducted in large scale contin-
uous pilot plant operations. For the prepolymer pre~aration,
propylene and catalyst components were continuously charged to
a stirred reactor, the monomer feed rate was adjusted correspond
ing to 2 hours residence time in the reactor. The organo-
aluminum compound G~ the catalyst system was a hexane solution
of triisobutyl aluminum (TIBA) which had been treated prior to
1~ introduction into the reactor with a hexane solution of methyl-
p-toluate 5MPT), an electron donor ~ompound. The solid support-
ed titanlum hal~e cata~yst ox~nent was a o~c~ly available catalyst.
The supported catalyst component contained about 1.5 wt
titanium, 20.3 wt % magnesium, 60.0 wt % chlorine and 9.6 wt %
hydrocarbon volatiles. Ethylbenzoate had been used in the
manufacture of ~he supported catalyst-component. The two
catalyst compvnents were added at ra~es directly proportional to
the polymer produ~tion rates and in amounts su~ficient to main-
tain a polymer ~olids concentration in the reactor slurry at a
2Q nominal value of about 40%. The catalyst productivity (lb
polymer/lb of Ti metal) was calculated in each case from the
polymer slurry withdrawal rate, solids content in the slurry
and the ti anium catalyst component addition rate.
After separation of ~he prepolymer from unreacted
propylene, ~aid prepolymer which still contained active catalyst
residues was fed sequentially to two serially connected, water-
csoled jacketed horizontal reactors, each provided with
ribbon blades as agitation means. Pro~ylene was introduced
near the inlet of each of the reactors and ethvlene monomer
3~ through three inlets spaced evenly across each of the reactors.
The block copolymer product was recovered from the outlet o~
the second reactor. ~he operating conditions in each of the
~'
-13-
reactors were essentially the same unless otherwise noted.
Pertinent operating conditions and results are shown in Table 1
In the Figure, the relationship of wt % ethylene in the product !
1 is plotted against the notched Izod impact strength (at room
1I temperature). Curve A denotes the typical relationship ob- ¦
¦l tained when preparing the prepolymer with conventional catalys "
e.y. Stauffer ~A catalyst (3~iC13 AlC13) with diethyl aluminum
chloride as cocatalyst (at Al/Ti molar ratio of about 3) and
~¦ under conditions to produce a final product melt flow of about
¦¦ 2 grams/10 mins. It has been found that in such a conventional
; ,I process the ethylene/propylene molar ratios used in the vapor
l~ phase reaction zone may be varied considerably, e.g. from about
¦¦ 0.2 - 0.8, without having any material effect on the relation-
` ¦! ship shown by curve A.
1! Curve B depicts the ethylene content I~od impact
¦! strength relationships obtained in Comparative Examples 1-6. The
¦ polymers of these examples were all prepared with a catalyst of
¦¦ the composition required in this invention, however, the vapor
II phase block copolymerization reactions were each carried out
~l at ethylene/propylene ratios outside the limits of this invent-
¦l ion. As seen from curve B of the graph, the ethylene incorporat-
¦l ed in each of the block copolymers was not very efficient in
¦l achieving impact resistance; in fact, about double the ethylene
I incorporation is needed to obtain products of a desired impact
1l as compared to conventionally prepared block copolymers (curve A).
Example 7, however, which was prepared according to
¦ the present invention, resulted in a block copolymer having a
much improved ethylene content-impact resistance relationship
(point is indicated in the Figure).
,; I
I' -14-
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~ . ,
1, , ''
i,
,1 ,
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P~ (`~ n . I_ ~ c o ~J ~ I
i
i O t~
' O
ll
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j I. O O O Lll O O O ~ N ~ U~ C
o~ o
I i. C O O CO ~1 0 0 0 ~r ~D In ~ I
i l~ ~ ~r Lf . ~ CO O ~r
, ~ ~ ~ ~ ~ o ~ ~ o .
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- 1
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a) o E~ J ~I cl o
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O ~ ) U.Q t~ :~a) ~, C) ~ C~ i
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O ~ E~ u~o t~ Q) ,C _C O ~ ~
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. ~ ~ P~ G~l g ~ P~ ~ ~`1 m ~: z
~ ~ j 'm
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~.
EX~PLES 8 Ar~7~ 9
~,
¦ p The polymer products from two continuous polymerization
runs conducted essentially according to the technique described
1l in Examples 1 - 7 were subjected to a detailed analysis except
j that 1.4 mol percent ethylene was present in the prepolymer
reactor feed stream in Example 9 and triethyl aluminum was used
; 1l as the cocatalyst. The results are shown in Table 2 together
¦¦ with pertinent operating conditions.
¦¦ As indicated in Table 2, standard ASTM test methods
lG ~~! were used to determine the majority of the properties of the
~` polymer products.
The Mw/~n ratio was determined by liquid chromatography
using o-dichlorobenzene as solvent.
The contents of Ti, Mg and Al were determined by
1 atomic absorption analysis of polymer ash dissolved in hydro-
chloric acid and the chlorine content by colorimetric determinat-
on of combusteù polyLer san~le uslng a Parr oxygen bomb.
' ~ ~
~ , .
'' ~
,~ .
~
, I
Il -l6-
i
TABLE 2
EX~1~5PLE NO. 8 9
Catalyst FT-1 FT-l
Alkyl aluminum TEA TEA
Trialkyl aluminum/MPT-
mol ratio 3.4 3.1
Al/Ti-mol ratio 150 150
First Reactor
Temperature F 130 130
Pressure - psig 335 350
Residence Time - hrs. 1.7 1.7
E/P mol. ratlo - 0.014
Productivity kg/gTi 353 437
Second Reactor
Temperature F 175 175
Pressure - psig 40.7 40.
Residence Time - hrs. 2.0 2.0
E/P mol. ratio 0.3 0.3
. Additives:
BHT - ppm 1200 1200
Irganox 1010-ppm 500 500
Calcium stearate-ppm 1000 1000
Hydrotalcite-ppm1000 1000
Properties:
Total ethylene
content - wt % 4.2 6.7
Melt Flow g/lOmin. (1) 0.8 2.1
Density gm/cc (2) 0.897 0.895
Mn 46,100 38,000
30 Mw 367,000 325,000
Mw/Mn 8.0 8.6
* Trademark
,.,"~
-17-
ll TABLE 2 (CONTINUED)
~ - !
. EX~IPLE_NO. 8 9
Tensile Strength .
~ @ Yield - psi (3) 4290 3S30
¦l @ Break - psi (3) 3080 3015
. Elongation at
~ Break - ~ (3) 516 485
il Flexural ;ioclulus-
!' psi x 105 (4) 1. 55 1.16
; 10 Tensile Modulus- ¦
psi x 105 (3) 1.67 1.29
HDT - at 66 psi
C (5) 81 80
Crystalline
Melting Point - C 168 162
. Hardness --
(Rockwell) (6) 51.5 38.4
LTB - C (7) -12.8 -20. 4
Izod Impact
ll ft lbs/in (8) 5.2 5.4
i!
il Polymer Impur.ities:
¦~ Ash - ppm 395 350
! Mg - ppm 37 33
I Ti - ppm 3 2
, C1 - ppm 98 95
A1 - ppm 255 194
j~ (1) ASTP1 D1238, Cond. L (2) ASTN D1505
l~ (3) ASTM D638 (4) ASTM D790
; ll (5) ASTP~ D648 t6) ASTM D785
(7) AST!~I D746 ~8) ASTM D256
I
! ,
It is obvious to those skilled in the art that ~an~
variations and modi-ications can be made to the pro~ylene poly~er
! of this invention ~11 such departures from the .oregoing
specification and considered within the scope of this invention
5 1l as defined bv the specification and the appended claims.
