Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1 335 1 30
POLYESTER COMPOSITION CONTAINING AN ESTER OF
AN ETHO~YLATED AROMATIC ALCOHOL
~ACRGROUND OF THE INVENTION
This invention relates to linear saturated poly-
ester compositions. More particularly, the invention is
5 directed to a linear saturated polyester composition
containing at least one ester of an ethoxylated aromatic
alcohol.
Molding formulations based on linear saturated
polyesters, such as polyethylene terephthalate, should
10 result in a molded product having good physical proper-
ties including flexural strength, modulus, tensile
strength, and impact proper,ties. The molding compound
should have good molding properties, including a melt
flow index for sufficient flow into the mold, good mold
15 release properties and good surface finish appearance.
The molded article should be crystalline and warp
resistant.
It is desirable that satisfactory properties be
attained using water heated molds. That is, molds
heated to temperatures between 76.7C (170F) to about
110C (230F). In order to accomplish this, it is
desirable for crystallization to begin at as high a
temperature as possible upon the cooling of the molten
polyester which was fed into the mold, and continue
during the cooling to as low a temperature as pos-
sible. TCc is a measurement to determine at what
temperature crystals first appear upon cooling from the
melt. TCh is a measurement which indicates the
temperature at which crystallization is no longer
occurring upon cooling. It has been found that mold
appearance and mold release properties can be related to
TCh. TCh is determined by measuring the temperature at
which crystals appear upon heating an amorphous piece of
polyester. TCc and and TCh can be measured using a
Differential Scanning Calorimeter.
$'
_ I
~ 1 335~ 30
-2-
A variety of additives are disclosed in the art for
use with linear saturated polyester compositions. Two
important classes of additives include nucleators and
plasticizers. Plasticizers include a variety of low
molecular weight esters such as those disclosed in U.S.
5 Patent Nos. 4,223,125 and 4,435,546. These patents
describe the use of esters of alcohols having up to 20
carbon atoms and preferably having a carbon bond to
ester bond ratio of between 4 and 15, inclusive of the
carbonyl atom.
It is known to use nucleating agents in crystalliz-
able polymers, such as linear saturated polyesters of
aromatic dicarboxylic acids. U.S. Patent Nos.
3,435,093; 3,516,957; and 3,639,527 disclose various
approaches to molding thermoplastic compositions of
linear saturated polyesters of aromatic dicarboxylic
acids, and are particularly applicable to polyethylene
terephthalate. These patents generally disclose the use
of salts of hydrocarbon and polymeric carboxylic acids
as nucleating agents for linear saturated polyesters.
20 Great Britain Patent No. 1,315,699 discloses the use of
low molecular weight sodium, lithium or barium salts of
mono- or polycarboxylic acids used with solid, inert
inorganic substances.
The use of organic esters in combination with
nucleators is disclosed in U.S. Patent Nos. 3,516,957;
4,352,904; 4,486,564; 4,429,067; 4,223,125; 4,435,546;
and 4,548,978. These patents disclose the use of a
variety of plasticizers including specific ester
compounds used in combination with other materials.
3 SUMMARY OF THE INVENTION
The present invention is a composition comprising a
linear saturated polyester and from 0.5 to 30 percent by
weight of the polyester of at least one ester of an
ethoxylated aromatic alcohol, preferably ethoxylated
Risphenol A. The ester has a molecular weight of from
~ _3_ 1 335 ~ 3~
500 to about 1,500. The ethyxolated aromatic alcohol
has the formula
HO - (R )n ~ Rl - (OR)n - OH
wherein R is the same or different hydrocarbon radicals
of from 2 to 4 carbon atoms, n can be the same or a
different integer of from 2 to 15. By the "same or
different" it is meant that where the symbol R or n
appear more than once in a general formula it can be the
same or different in that formula. The alcohol has
greater than 20 carbon atoms. Rl is an aromatic
diradical preferably derived from an aromatic dialcohol,
most preferably bisphenol A. Ethoxylated bisphenol A
has the formula
CH3
HO - (R )n - \ ~ C ~ (OR)n ~ OH
CH3
The acid is a carboxylic acid of from 1 to 25 and
20 preferably 3 to 10 carbon atoms, and from 1 to 10
carboxyl groups. Pre~erably the acid is alphatic and
has from 3 to 10 carbon atoms and one carboxyl group.
The composition of the present invention preferably
contains a nucleating agent and optionally filler or
25 reinforcing material, an impact modifier, an epoxy com-
pound, and other conventional additives such as antioxi-
dants, colorants, flame retardants and the like.
Objects, features, and advantages of the present
invention will become apparent by reference to the
following specification:
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a composition comprising a
linear saturated polyester, and from 0.5 to 30,
preferably 1.0 to 10, and more preferably 1.5 to 8, and
35 most preferably 1.5 to 5 percent by weight of the
polyester of at least one ester of an ethoxylated
_4_ l 335t 30
aromatic alcohol and wherein the ethoxylated aromatic
alcohol has the formula
HO - (RO)n ~ Rl ~(OR)n -OH
wherein R is the same or different hydrocarbon radicals
5 of from 2 to 4 carbon atoms, and n can be the same or a
different integer of from 2 to 15. By the "same or
different" it is meant that where the symbol R or n
appear more than once in a general formula it can be the
same or different in that formula. Rl is an aromatic
10 radical, preferably derived from an aromatic dialcohol,
most preferably bisphenol A. The ethoxylated alcohol
has greater than 20 carbon atoms and preferably 25 to 50
carbon atoms. The alcohol is esterified with an acid
which is a carboxylic acid of from 1 to 25 carbon atoms,
15 preferably 3 to 10 carbon atoms. The acid is preferably
an alphatic acid. The acid has from 1 to 3 carboxyl
groups and preferably 1 to 2 carboxyl groups with one
carboxyl group most preferred. The ester formed has a
molecular weight of from 500 to 1500 preferably 700 to
20 about 1,200, and more preferably 800 to 1,000.
The preferred ethoxylated aromatic alcohol are
derived from aromatic dialcohols having from at least
six carbon atoms and preferably from 6 to about 15
carbon atoms. The aromatic portion of the aromatic
25 dialcohol can contain substituents groups which do not
make the plasticizer ineffective. Such groups could
include hydrocarbons such as methyl groups, ester
groups, halogen containing groups and the like.
Preferred aromatic dialcohols, include bisphenol A,
30 resorcinol, dihydroxynapthalene (i.e., 2,6
dihydroxynapthalene), and biphenol, with bisphenol A
being most preferred. The ethoxylated bisphenol A has
the formula
_5_ 1 335 1 3~
CH3
HO - ( RO ) n ~ C ~ ( OR ) n -OE~
CH3
Preferably R is -CH2CH2- and n is 5.
The carboxylic acid has from 1 to 25 and preferably
from 3 to 10 carbon atoms and preferably from 1 to 3,
and most preferably one carboxyl group. The most
preferred carboxylic acid is an aliphatic carboxylic
acid with from 3 to 10 carbon atoms and 1 carboxyl
group. Useful acids include, but are not limited to,
acetic acid, butyric acid, caproic acid, caprylic acid,
pelargonic acid, 2-ethylhexanoic acid, lauric acid,
myristic acid, palmitic acid, stearic acid, oleic acid,
ricinolic acid, 2-ethyl butyric acid, tall oil acids,
fatty acids, and the like. The most preferred acid is
2-ethylhexanoic acid. ~i- and tri-carboxylic acids
which are useful include adipic acid, azelyic acid,
20 citric acid, fumaric acid, maleic acid, glutaric acid,
succinic acid, tartaric acid, and sebacic acid. The
above list of acids is illustrative rather than
limiting.
A preferred ester of the present composition is di-
25 2-ethylhexoate of an ethoxylated Bisphenol A having the
formula:
CH3 CH3
CH2 CH3 CH2
1 0 0 1
3 2) 3 CH C ( CH2CH2) 5 ~>--C--<~> ( OCH2CH2 ) 5--O-C--CH ( CH2 ) 3CH3
I
CH3
35 having a molecular weight of 876.
The composition of the present invention includes
linear, saturated polyesters of aromatic dicarboxylic
-6- ~ 3~
acids. The preferred linear saturated polyesters in-
clude polyethylene terephthalate, polybutylene tereph-
thalate, and poly(l,4-cyclohexane dimethylene tereph-
thalate), and mixtures thereof. Polyethylene tereph-
thalate is the most preferred due its ability to be
molded at low molding temperatures. The polyethylene
terephthalate has an intrinsic viscosity range between
about 0.3 and about 1.20, with a preferred intrinsic
viscosity range between about 0.4 and 0.7. Intrinsic
viscosity is obtained by extrapolation of viscosity
10 values to zero concentration of solutions of
poly(ethylene terephthalate) in a 60 to 40 weight/volume
ratio of phenol and tetrachloroethane. The measurements
are normalized to 25C. The preferred polyethylene
terephthalate melts between about 250C and 275C. The
15 polyethylene terephthalate can contain minor amounts, up
to 10%, of other comonomers such as 1,4-
cyclohexyldimethyldiol, butylenediol, neopentyldiol,
diethylene glycol, or glutaric acid.
It has been found that the ester of the present
20 invention acts as plasticizer in that they lower the TCh
thereby allowing crystallization to take place as the
polyester composition cools to lower temperatures. The
plasticizing effect has been found to improve mold
release properties and molded appearance of molded poly-
25 ester, preferably polyethylene terephthalate articles.
TCh is the temperature at which crystal formation occurs
upon heating an amorphous piece of polyester. TCh is
measured as the maximum of the peak of the curve formed
when the amorphous polyester is heated in a Differential
30 Scanning Colorimeter (DSC). Typically the polymer is k
heated at 10C/minute. The use of a plasticizer reduces
the TCh. The TCh for pure polyethylene terephthalate
(0.5 intrinsic viscosity) is approximately 125C-
130C. It is desirable to lower this value as much as
35 possible for the best mold release and molded article
release properties. The TCh is preferably not greater
than about 110C. It has been decreased to about 94C
~ 5 ~ 3 ~
--7--
using 5 percent, based on the weight of the polyethylene
terephthalate, of the present invention.
The use of the relatively high molecular weight
ester of the present invention as plasticizers has been
found to improve plasticization as indicated by the low
TCh. Additionally, the use of high molecular weight
ester of the present invention has been found to provide
advantages including low volatility, attributed to its
relatively high molecular weight and at the same time
results excellent molded surface appearance.
It is believed that the presence of the aromatic
group enhances compatibility of the esters with
polyesters containing aromatic groups such as
polyethylene terephthalate resulting in easier
incorporation of the ester of the ethoxylated aromatic
15 alcohol. It has been found that consistent with the
disclosure of U.S. Patent 4,223,125 that this material
is somewhat difficult to uniformly incorporate into the
polyester composition. This is believed to be the
results of it not being as compatible as plasticizers
20 such as those disclosed in the U.S. Patent 4,223,125.
The composition of the present invention preferably
contains nucleating agents in combination with the
polyester and plasticizer. The most useful nucleating
agent is at least one compound containing a sodium
25 cation or a potassium cation. The nucleating agent is
preferably the sodium salt of a carboxylic acid, which
is most preferably a hydrocarbon carboxylic acid.
Useful nucleating agents include the sodium or potassium
salts of hydrocarbon acids containing from 3 to at least
30 54 carbon atoms and from 1 to 3 carboxyl groups. The
hydrocarbon acids can be aromatic or aliphatic acids.
Preferred nucleating agents include the sodium salts of
a carboxyl containing organic polymer. Such a polymer
can contain one or more sodium neutralized carboxyl
35 group. Preferred polymeric sodium salts include
copolymer acids which are the copolymers of an a -olefin
-8- 1 335 t 30
and an ~,~-ethylenically unsaturated carboxylic
acid. The copolymer molecule can include additional
materials including esters and other substituents.
The ~-olefin is preferably ethylene. The
concentration of ethylene in the copolymer is at
least 50 mol percent and preferably from 80 to 95
percent by weight. The ~,~-ethyleneically
unsaturated carboxylic acid can be a monocarboxylic
acid, or have more than one carboxylic group. The
~ ,B-ethylenically unsaturated carboxylic acid which
can be copolymerized with the ~-alpha olefin
preferably has 3 to 8 carbon atoms. Examples of such
acids include acrylic acid, methacrylic acid,
ethacrylic acid, itaconic acid, meleic acid, furmaric
acid, and monoesters of other dicarboxylic acids,
such as methyl hydrogen maleate, methyl hydrogen
furmarate, ethyl hydrogen furmarate, and maleic
anhydride which is considered to behave like an acid
and be an acid in the present invention. Useful
copolymer salts include those disclosed in U.S.
Patent No. 4,412,040 and U.S. Patent No. 3,435,093.
Preferred nucleators are the sodium salts of
copolymers of ethylene and ~,~-ethylenically
unsaturated carboxylic acids having a number average
molecular weight of from 500 to 6000 as described in
U.S. Patent No. 4,412,040. These salts are
preferably neutralized from 50 to 100%.
Another preferred nucleator for use in combin-
ation with the present invention are nucleating
agents which are of the type described in U.S. Patent
No. 4,357,268. These include sodium or potassium
salts of dimer acids, trimer acids, or mixtures of
the two. The dimer acid has at least 36 carbon atoms
and 2 carboxyl groups and the trimer acid has at
least 54 carbon atoms and 3 carboxyl groups. The
definition of dimer acid is a high molecular weight
dibasic acid, which is liquid (viscous), stable,
resistant to high temperatures. It is produced by the
dimerization of unsaturated fatty acids, at mid-molecule
i D
J~ 9 1 33~ 1 3Q
and usually contains 36 carbon atoms. Trimer acids,
which usually contain 3 carboxyl groups and 54 carbon
atoms are similarly prepared.
The temperature at which crystal formation occurs
is indicated by TCc. The TCc is measured using a
Differential Scanning Calorimeter which measures the
heat evolved versus temperature. ~etween 5 and 10
milligrams of sample is prepared. The sample can be
made in the form of a compression molded film which is
vacuum dried or as a pellet which is hammered flat. The
sample is placed in the Differential Scanning Calorim-
eter and heated to 280C where it is held for two
minutes. The sample is cooled at 10C per minute. The
TCc is the temperature at which the crystallization
takes place. The TCC is approximately 195C to 200C
for polyethylene terephthalate having an intrinsic
viscosity normalized to about 0.50. It is desirable for
crystallization from the melt to begin at as high a
temperture as possible without adversely affecting other
properties. This allows crystal nucleation to begin
earlier and for crystallization to take place over a
greater temperature range. The TCc is preferably at
least 205C, and more preferably at least 210C.
The preferred polyethylene terephthalate composi-
tion should have as high a TCc as possible and as low a
TCh as possible, allowing crystal formation and growth
over the widest possible temperature range. The TCh is
preferably not greater than about 110C. Therefore, the
temperature range over which crystallization can occur
is from about 220C to about at least as low as 110C
3 during cooling of the composition of the present inven-
tion. The range for pure polyethylene terephthalate is
about 195C to 125C.
The composition can optionally contain other addi-
tives such as inert nucleating agents (i.e., talc),
filler or reinforcing materials, impact modifiers,
epoxies, antioxidants, colorants, flame retardants, and
the like.
~ 1 ~3~ ~ 3~
--10--
Any suitable filler and/or reinforcing agent can be
used. The fillers may optionally be treated with
various coupling agents or adhesion promotors as is
known to those skilled in the art. Such fillers may be
selected from a wide variety of minerals, metals, metal
oxides, siliceous materials, metal salts, and materials
thereof. Examples of fillers include glass fibers,
alumina, feldspar, asbestos, talc, calcium carbonates,
clay, carbon black, quartz, novaculite and other forms
of silica, kaolinite, bentonite, garnet, mica, saponite,
etc. The foregoing recited fillers are illustrative
only an~ are not meant to limit the scope of the fillers
that can be utilized in this invention. As noted above,
the most preferred filler is glass fibers. There is up
to 150 percent by weight of the polyethylene terephthal-
ate of filler, and preferably 30 percent to 90 percent
by weight of the polyethylene terephthalate of filler,
preferably fiberglass.
The composition preferably includes impact modifi-
ers known for use in polyester compositions. Preferred
input modifiers are ethylene copolymers and terpolymers
having carboxylic acids or derivatives. Pre~erably
copolymers of ethylene and carboxylic acids, their
esters or salts can be used as impact modifiers.
Included among those impact modifiers are the following
copolymers: ethylene-acrylic acid, ethylene-methacrylic
acid, ethylene-ethyl acrylate, ethylene-vinyl acetate,
and mixtures thereof. Useful impact modifiers include
copolymers of a -olefins and the metal salts of carboxy-
lic acids and particularly the sodium and potassium
salts. These compolymer salts both nucleate and improve
impact resistance. There can be used up to about 30
percent, and preferably from about 2 percent and about
10 percent of the impact modifier, based on the weight
of the poly(ethylene terephthalate).
The composition can contain up to about 5 percent
based on the weight of the polyethylene terephthalate,
of a polyepoxide. Useful polyepoxides are epoxy cresol
~ -11- 133513~
novolac resins of the type produced by Ciba-Geigy
Corporation, and include ECN~ 1234, 1273 and 1299, and
those formed from bisphenol-A and glycidyl ether. A
preferred polyepoxide is an epoxy formed from bisphenol-
A and glycidyl ether. Pre~erably, there is from 0.5
percent to 4.0 percent, based on the weight of the
polyethylene terephthalate, of a polyepoxide formed from
a diglycidyl ether and bisphenol A having a molecular
weight of from about 1500 to 4000 and most preferably
about 200n. The polyepoxides act as chain extenders and
help compensate for polyethylene terephthalate chains
broken by hydrolysis.
~ preferred ~illed composition comprises polyethy-
lene terephthalate, from 3096 to 90 percent glass fibers
and 2% to 8% of the ester of the present invention from,
0.6 to about 3 percent of a polyepoxide and from about
0.1 to about 10 percent of a sodium carboxylate salt as
described above. The percents are based on the weight
of the polyethylene terphthalate.
As indicated in the examples to follow, the use of
20 the ester of the present invention results in the poly-
linear saturated polyester, such as polyethylene
terephthalate, molding composition which can be
injection molded into water heated molds as temperatures
as low as 76.7C (170F). As the mold temperature
25 increases, there is an improvement in molded article
appearance. The ester of the present invention, the
carboxylate salt and polyethylene terephthalate are melt
blended. In the most preferred embodiment, they can be
melt blended in an extruder at a temperature above the
melt temperature of the polyester. In a preferred
embodiment, the components are melt blended at a
temperature between 260C (500F) and 316C (600F) in
an extrude r.
The polyethylene terephthalate composition of the
35 present invention can be formed by blending the compo-
nents together by any convenient means to obtain an
intimate blend. Neither temperature nor pressure are
-12- 1 3351 3~
critical. For example, the polyethylene terephthalate
can be mixed dry in a suitable blender or tumbler with
the other components and the mixture melt extruded. The
exudate can be chopped. If desired, a reinforcing or
filing agent can be omitted initially and added after
the first melt, and the resulting mixture can be melt
extruded. It has been observed that the composition can
be uniformly extruder blended. Uniform blends were made
when all the ingredients were fed into the throat of the
extruder. Uniform blends were made with the polyester
was fed into the throat and all of the additives
including small amounts of polyester, the fiberglass and
the plasticizer were added together downstream of the
throat. A third method is to inject the plasticizer
after all of the materials are added downstream. This
method results in uniform blends under high shear
conditions such as are present in a twin screw extruder.
The general incompatibility of the higher molecular
plasticizer of the present invention makes its uniform
incorporation an important consideration. It has been
found that the aromatic plasticizer was easier to
incorporate than the aliphatic diester plasticizers such
as used in Comparatives 2 and 3 below. Poor dispersion
is evidenced by the appearance of fiberglass showing at
the surface.
The composition of the present invention is
particularly useful to make injection molded articles.
The examples and compositions set forth below
illustrate the nature of the invention and the manner of
carrying it out. ~owever, the invention should not be
considered as being limited to the details thereof. All
parts are percent by weight unless otherwise indicated.
EXA~PLE~
All of the following examples were made using poly-
ethylene terephthalate having an intrinsic viscosity
(IV) in the range of 0.66 to 0.72. Intrinsic viscosity
is measured by extrapolation of the viscosity values to
zero concentration of solutions of polyethylene
~ -13- 1 3 3 5 1 3 ~
terephthalate in a 60 to 40 volume ratio of phenol and
tetrachloroethane. The measurements are normalized to
25C. In the results that follow the IV was measured on
extruded pellets and molded parts. Unless otherwise
indicated, the parts were 1/8 inch thick tensile bars
molded at 1.5 ounce Arburg injection molding machine at
about 590C barrel melt temperature with the mold
temperature between about 200F to 230F.
The fiberglass used was 1/8 inch long short glass
fibers made by Pittsburgh Plate Glass as PPG 3540. The
epoxy compound used in the compositions was a diglycidyl
ether of Bisphenol A sold by Ciba-Geigy as Araldite
7074. The ethylene acryclic acid (EAA) copolymer used
was manufactured by Dow Chemical Corporation as Dow EAA-
445 which is described as having 8 percent by weight
acrylic acid and a melt index of 5.5g/10 min. The
ethylene ethyl acrylate copolymer (EEA) used was made by
Union Carbide as ~akelite~ flexible ethylene copolymer
DPD-6169 which is described as having a melt index of
6g/min and an ethyl acrylate content of 18 weight
percent. The ethylene methyl acrylate copolymer (EMA)
used was 80 mol percent ethylene, but a density of 0.942
and had a melting point of 59C and was produced by
Chevron Chemical. Irganox~ 1010 which is tetrakis
[methylene 3-(3,5 di-tertiary butyl 4 hydroxyphenyl)
proprionate] methane made by Ciba-Geigy, was used as an
antixoidant. A processing aid S-160 which is butyl
benzyl phthalate made by Monsanto Corporation was used
to prevent powder/pellet separation prior to extrusion.
In each of the Examples and comparatives that used
a sodium dimerate salt as the nucleator, a dimer acid
was used which was 100% sodium neutralized with sodium
cation. The dimer acid is sold by Emery Corp. as Empol~
1024. The dimer salt was used as a preblend (PB)
contained 0.6% dimer acid sold, 0.6% EEA, 2.8% EAA, and
0.1% S-160. Alternately, as indicated, the nucleator
was the sodium salt of ethylene methacrylic acid sold by
the DuPont Company as Surlyn~ 8920.
1 33~ 1 30
-14-
Unless otherwise indicated, the compositions were
made by melt extruding using a 2 1/2" Egan single screw
extruder having a 40 L/D ratio. The temperatures in
Zones 1-7 were Zone 1-500F/Zone 2-540F/Zone 3-
530F/Zones 4-7 -525F with the die at 540F. The
5 fiberglass was fed into Zone 2 and a vacuum of 10 inches
was applied to Zone 3.
~ ifferential Scanning Calorimeter (DSC) values were
measured in accordance with the above-described proced-
ure. ~etween a 5 and 10 milligram sample is prepared.
10 The sample is made in the form of a film which is vacuum
dried. The sample is placed in the DSC and heated at
10C/min. to 280C where it is held for 2 minutes. The
sample is cooled at 10C per minuted. The TCC appears
as the peak in the cooling branch of the curve. Tg is
the glass transition temperature of the composition.
TCh is measured using similar sample preparation.
The sample was melted and then quenched to assure that
the samp]e was substantially amorphous. The sample was
heated at 10C per minute and a crystallization curve
forms when crystallization takes place. The TCh was the
temperature at the peak of the curve.
The volatility was measured as percentage weight
loss upon heating at the indicated temperature. Mold
surface ratings are based on visual appearance ratings
of 1 to 10 with 1 being the best and 10 being the worst.
The following ASTM test procedures were used to
measure physical properties: Tensile Strength - ASTM
D638; Flexural Strength and Modulus - ASTM D790; and
Notched Izod Impact Testing - ASTM D256.
Compositions were made using a preferred
plasticizer and various comparative plasticizers. The
amounts of the plasticizers was varied as indicated.
The examples illustrates the use of plasticizer "P"
made by C. P. ~all and which is the di-2-ethyhexoate of
ethoxylated Bisphenol A having a molecular weight of 876
and the formula
1 3351 3~
CH3 CH3
CH2 CH3 CH2
l O l O
I n I n I
C~3- (C~2)3 - ~ C ~ (C~2CH20)5 ~ C~ C~2CH2)s ~ C-CH(C~2)3CH3
CH3
In variou~ Comparative Example~, the plasticizer
used wa~ polyethylene glycol di-2-ethylhexoate (PE
diester) having a molecular weight of 652 and sold by C.
P. Hall as ~egmer 80~.
Another Comparative u~ed was an aliphatic
ethoxylated trie~ter (PE trie~ter) made by C.P. ~all
having a molecular weight of 998 and having the formula
c~3
O CH2
n
CH2- ( OCH2CH2 ) 4-O-C- C- ( CH2 ) 3-CH3
¦ CH3
¦ O CH2
l
CH2- ( OCH2CH2 ) 4--O--C-C- (CH2)3--CH3
I C~3
I
3 0 1 0 CH2
n I
CH2-(OCH2(~2)4-~-C-C-(CH2)3-CH3
EXAMPLE 1
Example 1 illu~trate~ a compo~ition u~ing
pla~ticizer P compared to PE trie~ter. The compo~ition
and result~ are ~ummarized in Table 1.
*Trademark
n
L~,
-16-1 33~ ~ 3~
TABLE I
Ex 1 Comp 1
PET 61.15 61.15
Fiberglass 30.00
pBl 4.10 4.10
Epoxy 1.0 1.0
Antioxidant .15 .15
10 Plasticizer 3.6 3.6
(96)
Plasticizer P PE
triester
Plasticizer MW 876 998
15 Molded surface
@225F Mold ~2-3 2
@ 215F mDld 6 5
Flex Str.(psi) 28,800 31,000
Mbd x 106(psi) 1.16 1.18
20 Notched Izod 1.86 1.76
ft lbs/in notch
rv Molded Bar
1/8" thick .60 .59
1/16" thick .52 .48
1PB is a preblend of sodium dimer salt, EEA and EAA.
The above results indicate that the plasticizer P
and the PE triester both resulted in a satisfactory
composition. As the mold temperature was reduced from
225F surface appearance was poorer.
E~AMPLES 2-5
Examples 2-5 are a comparison of PET compositions
melt blended using a 1 inch single screw extruder having
a 25 L/D ratio. The extruder was run at barrel
temperature of about 540F. The plasticizer P used in
Example 5 was the same ester of ethoxylated bisphenol A
but from a different batch than the plasticizer used in
-17- 1 3351 30
Examples 2-4 to check lot to lot variation. The
plasticizer in Comparatives 2 and 3 used the PE diester
(MW-652) as described above. The compositions and test
results are summarized in Table 2 below.
TABLE II
Ex . 2 Ca[lp 2 Ex . 3 Ex . 4Ex . 5 Canp 3
PET 61.15 61.15 59 .25 59 .2559 .25 59 .25
Fiberglas 30.00 30.00 30.00 30.0030.00 30.00
PB 4 .10 4 .10 4 .10 ---- 4 .10 4 .10
Surlyn 8920 --- --- --- 4.10 --- ---
Epoxy 1.0 1.10 1.00 1.00 1.00 1.00
1 5 Antioxidant .15 .15 .15 .15 .15 .15
Plasticizer 3.6 3.6 5.5 5.5 5.5 5.5
Plasticizer Type P PE P P P PE
diester diester
Molded Surface@
200F --- --- --- 7 7 4
215F --- --- 5 1 1/2 5
225F 3 Bestl --- 1 Bestl Best 1
Flex Str
(psi ) 30,600 29 ,60028,50031,00028 ,700 27,300
Flex 6Mod 1.21 1.18 1.13 1.17 1.15 1.11
xlO (psi)
Tensile (psi )19 ,60018 ,60018 ,30020,30018,700 17,700
Notched Izod
( ft-lb/in
Notch) 1.66 1.75 1.59 1.86 1.53 1.47
l~SC Tg 56 ------ 58 ------ 56 49
Tch 101 ----- 102 ----- 100 90
Tcc 209 ----- 205 ------ 210 208
lBest indicates that these samples were the Best of the samples
rated as "1".
The above results indicate that at lower levels of
plasticizer, 3.6%, the PE diester plasticizer has a
-18- 1 3351 30
better surface appearance than the plasticizer P, with
comparable physical properties. At higher levels of
plasticizer, 5.5% the physical properties when using the
PE diester are poorer than when using plasticizer P of
the present invention. Additionally, the molded surface
when using 5.5% plasticizer of the present invention is
almost equal to the molded surface when using
plasticizer PE diester.
EXAMPLE 6
In Example 6 and Comparatives 4 and 5 the short
glass fiber was fed into the throat of the extruder.
Volatility was measured in an oven at a vacuum of 27-28
inches of mercury at the indicated time and temperature.
1 335 1 30
--19--
TABLE III
E~. 6 COMP. 4 oOMP. 5
PET 62.05 62.05 62.05
Fiberglass 30.00 30.00 30.00
Surlyn 8920 4.00 4.00 4.00
Sodium Stearate 0.2 0.2 0.2
Epo~ 1.0 1.0 1.0
10 Antioxidant .15 .15 .15
Plasticizer 2.6 2.6 2.6
Plasticizer P PE PE
Type diester triester
Molded Surface@
215F 2 1/2 1 1/2 1 1/2
225F 1 Best
Flex Str (psi) 34,300 34,000 32,800
Flex M~d (psi) 1.24 1.21 1.24
20 Tensile (psi) 22,000 22,200 21,700
Unnotched Izod 1.7 1.19 1.6
(ft-lb/in)
IV - Pellets .50 .50 .47
molded part .49 .52 .46
Volatility %
weight loss
in 5 hours @
127C 05 090 033
124C .045 .090 033
116C .017 .050 .016
30 D6C Tg (F) 60 58
Tc~ 99 97
Tcc 209 209
The plasticizer P of the present invention resulted
in a composition which was generally comparable in
physical properties with compositions containing the PE
diester (Comp. 4) and the PE triester (Comp. 5). The
composition with the PE diester had the Best surface
appearance. The composition of Ex. 6 and Comp. 5 had
~ -20- 1 3351 30
similar volatility results with Comp. 5 being slightly
better. Comp. 4 had the poorest volatility.
EXAMPL~S 7-12
Examples 7-12 illustrate preferred compositions
using a low molecular weight sodium ionomer salt as a
5 nucleator. There was variation in the amount of
neutralization with sodium cations of a low molecular
weight ethylene acrylic acid copolymer sold as A-C~ 120
by Allied Corp. (NaAC) which was neutralized to the
precent indicated . Example 12 contained 1.2 weight
10 percent of a masterbatch tMB) which was made from 80
parts of PET, 20 parts of sodium stearate (SST), and 40
parts of ~MA. Results are summarized in Table 4 below:
-21- ~ ~35 1 30
Table 4
Ex 7 Ex 8 Ex 9 Ex 10 Ex 11 Ex 12
PET 62.05 62.00 62.00 61.75 61.45 60.95
Fiberglas 30.00 30.00 30.00 30.00 30.00 30.00
EMA 2.2 2.2 2.2 2.2 2.2 2.2
SST 0.10 .15 .15 .10 .10
Epoxy .9 .9 9 9 9 9
Antioxident.15 .15 .15 .15 .15 .15
Plasticizer
"P" 2.6 2.6 2.6 2.6 2.6 2.6
MB - - - - - 1.2
90% NaAC 2.0
80~ NaAC - 2.0 - 2.3
15 70% NaAC ~ ~ 2.0 - 2.fi 2.0
Molded Surface
@220F 2 2 2 2 2 2
Ash (%) 29.2 28.1 28.8 28.4 29.3 28.2
Min Pressure
(psi) to fill
a 1/16"
Flex Bar m~ld 690 530 540 580 540 525
Flex Str (psi) 36,30034,10034,200 33,60035,000 34,200
Flex Mod (psi) 1.31 1.22 1.22 1.17 1.26 1.22
25 Tensile (psi) 23,60021,80022,200 21,60022,250 22,600
Notched Izod 2.02 2.10 2.06 2.05 2.04 2.11
(ft-lbs/in notch)
Unnotched Izod 22.4 22.7 21.8 20.6 20.6 20.9
(ft-lbs/in)
DSC Tg 69 69 70 67 68 66
Tch 106 105 105 103 103 105
Tcc 214 216 217 218 218 215
rv Pellets .56 .56 .56 .55 .57 .56
rV Parts.60 .57 .61 .57 .56 .57
-22- ~ 335 1 30
These results illustrate a composition containing the
preferred plasticizer and nucleator.
EXAMPLES 13-19
Examples 13 to 19 were extruded as above except
that the fiberglass, and the additives were added at
20ne 2 followed by the addition of plasticizer
downstream from the other additives fed into Zone 2 of
the extruder. The PET (hot) was heated and dried at
275F and added in the throat. A small amount of room
temperature (cold) PET was added with the additives
other than the plasticizers. The compositions evaluated
and results are summarized in Table 6 below:
-23-1 3351 30
Table 6
Ex 13 Ex 14 Ex 15 Ex 16
PET (hot) 58.4 58.4 58.4 58.4
PET (cold) 3.6 3.6 3.6 3.6
Epoxy 1.0 1.0 1.0 1.0
Antioxidant .15 .15 .15 .15
NaAC (90%N) 2.0 2.4 1.8 ---
SST .2 --- .2 .2
Surlyn 8920 --- --- --- 4.0
EMA 2.0 2.0 2.2 ---
Plasticizer "P" 2.6 2.6 2.6 2.6
Fiberglass 30 30 30 30
Dioctyladipate .08 .08 .08 .08
Paraffin Wax --- --- --- ---
Molded Surface
@220F 2~/2 3 2~2 4
DSC Tg 67 --- --- 67
Tch 106 --- --- 107
Tcc 213 --- --- 212
Flex Str (psi) 36,10035,500 35,400 35,900
Flex Mbd (psi)xlO~ 1.28 1.26 1.26 1.27
Notched Izod 2.02 2.13 2.03 2.24
Unnotched Izod 20.6 21.3 21.5 22.6
25 rv Pellet .64 --- .57
Part .52 .75 --- .60
% Ash 29.9 29.8 29.9 30.4
-24- 1 3 ~ 5 1 3 0
Table 6 (con't)
Ex 17 Ex 18 Ex 19
PET (hot) 58.4 56.4 47.8
PET (cold) 3.6 3.6 2.95
Epoxy 1.0 1.0 .82
Antioxidant .15 .15 .12
NaAC (90%N) --- --- ---
SST .2 .2 .16
Surlyn 8920 4.0 4.0 3.27
~MA ------ ------ ------
10 Plasticizer "P" 2.6 4.6 2.1
Fiberglass 30 30 45
~ioctyl adipate .08 .08 .08
Paraffin Wax .35 -- ---
Molded Surface
@220oF 2'~2 1 6
~SC Tg 64 61 ---
Tch 105 102 ---
Tcc 213 213 ---
Flex Str (psi) 34,600 32,400 42,400
Flex Mbd (psi) X1061.23 1.18 1.88
Notched Izod 2.19 2.16 2.38
Unnotched Izod 21.0 17.5 27.0
rv Pellet --- --- ___
~- r
Part --- --- ---
% Ash 29.6 29.5 44.8
EXAMPLES 20-21
Examples 20-21 illustrate and impact modified
version using an Acryloid~ KM-330 shell/core impact
modifier produced by Rohm and Haas. This is believed to
have a polybutylacrylate core and a
polymethylmethacrylate shell. The compositions
evaluated and results are summarized in Table 7.
-25-1 33~ ~ 30
Table 7
Ex 20 Ex 21
PET 51.6 51.7
Epoxy 1.25 1.25
Antioxidant .15 .15
Surlyn 8920 --- 3.7
SST --- 1.7
NaAC (9096N) .9 ---
EMA 2.1 ----
10 Plasticizer "P" 3.0 3.0
KM330 10 10
Fiberglass 30 30
Flex Str (psi) 28,300 29,700
Flex Mod x 106 (psi)1.16 1.13
Tensile St (psi)19,400 20,000
Notched Izod
ft lbs/in notch 2.16 2.41
Unnotched Izod
ft lbs/in 23.3 24.9
The above evaluation of various example composi-
tions and comparative compositions indicate that the
plasticizer of the present invention is a significantly
less volatile plasticizer than the esters of
difunctional polyethylene oxides as used in Comparative
2. The plasticizer of the present invention is
preferred over the PE triester as used in Comparative 1
because it is believed that it is more compatible and
therefore is easier to melt blend into a uniform
composition. The plasticizier of the present invention
had satisfactory molded surface appearance and was
easily moldable.
While exemplemary embodiments of the invention have
been described, the true scope of the invention is to be
determined from the following claims.
