Note: Descriptions are shown in the official language in which they were submitted.
~124~18
BACKGROUND OF THE INVENTION
This invention relates to blends of polyphenylene sulfides
and linear aromatic carboxylic polyesters comprising a bisphenol
wherein the carboxylic acid component can be an aromatic dicar-
boxylic acid or an aliphatic saturated dicarboxylic acid such asoxalic or adipic acids.
Linear aromatic polyesters prepared from aromatic dicarboxylic
acids and bisphenols are well known for their suitability for mold-
ing, extrusion, casting, and film-forming applications. For ex-
ample, U.S. Patent 3,216,970 to Conix, disclose linear aromatic
polyesters prepared from isophthalic acid, terephthalic acid, and
a bisphenolic compound. Such high molecular weight compositions
are known to be useful in the preparation of various films and
fibers. Further, these compositions, when molded into useful
articles using conventional techniques, provide properties super-
ior to articles molded from other linear polyester compositions.
For instance, aromatic polyesters are known to have a variety of
useful properties, such as good tensile, impact, and bending
strengths, high thermal deformation and thermal decomposition
temperatures, resistance to UV irradiation and good electrical
properties.
Aromatic polyesters which are particularly well suited for
molding applications may also be prepared by reacting an organic
diacid halide with a difunctional aliphatic reactive modifier,
such as a glycol, and subsequently reacting this product with a
bisphenol compound. The resulting polyesters have reduced melt
viscosities and melting points which permits molding at temper-
atures within the operable limits of conventional molding ap-
paratus (i.e. less than about 300C.) This type of glycol-
modified polyester is more fully disclosed in U.S. Patent3,471,441, to Hindersinn.
, ~
~12~18
In order to form a successful molding resin on a commercial
scale, a polymer should be capable of being molded conveniently
without significant degradation in physical properties. In this
respect, although the aforementioned aromatic polyesters generally
display excellent physical and chemical properties, a persistent
and troublesome problem has been their sensitivity to hydrolytic
degradation at elevated temperatures. This sensitivity to the com-
bined effects of heat and moisture is also exhibited in conlmercial-
ly available polycarbonate resins as evidenced by the desirability
of reducing the water content of the resin to less that about 0.05%
prior to molding. Unfortunately, however, the aromatic polyester
resins often display a more pronounced tendency to rapidly degrade
and embrittle than do polycarbonate resins. This is demonstrated
by the loss of tensile strength which can occur when an aromatic
polyester resin is molded and subsequently immersed in boiling
water. This tendency may be explained, in part, by the hydrolysis
of the ester linkages under these conditions. In the event, it is
to be appreciated that sensitivity to moisture represents a sig-
nificant problem in aromatic polyester resins that would signif-
icantly limit their commercial utility in applications such as inautoclaves or at elevated temperatures in humid atmospheres.
Accordingly, it is a principal object of this invention to
prepare aromatic polyester compositions having superior physical
and chemical properties as well as improved hydrolytic stability.
SUMMARY OF THE INVENTION
It has now been found that polyester molding compositions
having improved hydrolytic stability may be prepared by blending
a linear aromatic polyester with polyphenylene sulfide. In other
words, the invention is directed to a thermoplastic polymeric com-
position coMprising, in admixture, (a) a linear aromatic polyester
of components comprising a bisphenol and a dicarboxylic acid, and
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(b) polyphenylene sulfide. The preferred aromatic polyesters of
this invention, are prepared from bisphenols and at least one aro-
matic dicarboxylic acid, most preferably selected from the group
consisting of isophthalic acid, terephthalic acid, or mixtures
thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The linear aromatic polyesters of the present invention can
be prepared by condensing a diacid halide of a dicarboxylic acid,
dissolved in an organic liquid which is a solvent for the polyes-
ter to be formed, with a metal phenolate of a bisphenol, dissolvedin a liquid which is immiscible with the solvent for the diacid
halide. This process is more fully described in US Patent
3,216,970 to Conix.
The bisphenols which can be used in this process are known in5 the art and correspond to the general formula:
HO - Ar - (E)x ~ Ar - OH
Tb Gm Tb
wherein Ar is aromatic, preferably containing 6-18 carbon atoms
(including phenyl, biphenyl and napthyl); G is alkyl, haloalkyl,
aryl, haloaryl, alkylaryl, haloalkyaryl, arylalkyl, haloarylalkyl,
cycloalkyl, or halocycloalkyli E is a divalent (or di-substituted)
alkylene, haloalkylene, cycloalkylene, halocycloalkylene, arylene,
or haloarylene, -O-, -S-, -SO-, -S02-, -S03-, -CO-, GP=O or GN
T and T' are independently selected from the group consisting of
halogen, such as chlorine or bromine, G and OG; m is an integer
from O to the number of replaceable hydrogen atoms on E; b is an
integer from O to the number of replaceable hydrogen atoms on Ar,
and x is O or 1. When there is plurality of G substituents in the
bisphenols, such substituents may be the same or different. The T
and T' substituents may occur in the ortho, meta or para-positions
with respect to the hydroxyl radical. The foregoing hydrocarbon
radicals preferably have carbon atoms as follows:
1124918
alkyl, haloalkyl, alkylene and haloalkylene of 1 to 14 carbons;
aryl, haloaryl, arylene and haloarylene of 6 to 14 carbons; alkyl-
aryl, haloalkylaryl, arylalkyl and haloarylalkyl of 7 to 14 carbons;
and cycloalkyl, halocycloalkyl, cycloalkylene and halocycloalkylene
of 4 to 14 carbons. Additionally, mixtures of the above described
bisphenols may be employed to obtain a polymer with especially
desired properties. The bisphenols generally contain 12 to about
30 carbon atoms, and preferably 12 to about 25 carbon atoms.
Typical examples of bisphenols having the foregoing formula
include bis(4-hydroxyphenyl)methane, bis(2-hydroxyphenyl)methane,
(4-hydroxyphenyl-, 2-hydroxyphenyl)-methane, and mixtures thereof;
bis(4-hydroxy-3,5-dichlorophenyl)methane, bis(4-hydroxy-3,5-di-
bromophenyl)methane, bis(4-hydroxy-3,5-difluorophenyl)methane,
bisphenol-A [bis(4-hydroxyphenyl)-2,2-propane] bis-(4-hydroxy-3,
5-dichlorophenyl)-2,2-propane. bis(3-chloro-4-hydroxyphenyl)-2,2-
propane, bis(4-hydroxynaphthyl)-2,2-propane, bis(4-hydroxynaphthyl)-
2,2-propane, bis(4-hydroxyphenyl)-phenyl methane, bis(4-hydroxy-
phenyl) diphenyl methane, bis(4-hydroxyphenyl)-4'-methyl phenyl
methane, bis(4-hydroxyphenyl)-4'-chlorophenyl methane, bis(4-
hydroxyphenyl)-2,2,2-trichloro-1,1,2-ethane, bis(4-hydroxyphenyl)-
l,l-cyclohexane, bis(4-hydroxyphenyl)cyclohexyl methane, 4,4-di-
hydroxyphenyl, 2,2'-dihydroxydiphenyl, dihydroxynaphthalenes, bis
(4-hydroxyphenyl)-2,2-butane, bis(2,6-dichloro-4-hydroxyphenyl)-
2,2-propane, bis(2-methyl-4-hydroxyphenyl)-2,2-propane, bis(3-
methyl-4-hydroxyphenyl)-1,1-cyclohexane, bis(2-hydroxy-4-methyl-
phenyl)-l,l-butane, bis(2-hydroxy-4-tertiary butylphenyl)-2,2-
propane, bis(4-hydroxyphenyl)-1-phenyl-1,1-ethane, 4,4'-dihydroxy-
3-methyl diphenyl-2,2-propane, 4,4'-dihydroxy-3-methyl-3'-iso-
propyl diphenyl-2,2-butane, bis(4-hydroxyphenyl)sulfide, bis
(4-hydroxyphenyl)ketone, bis(4-hydroxyphenyl)oxide, bis(4-
hydroxyphenyl)sulfone, bis(4-hydroxyphenyl) sulfoxide, bis(4-
~Z49 ~8
hydroxyphenyl)sulfonate, bis(4-hydroxyphenyl)amine, bis(4-
hydroxyphenyl)phenyl phosphine oxide. 2,2-bis(3-chloro-4-
hydroxyphenyl) propane, 4,4'-(cyclomethylene) bis-(2,6-dichloro-
phenoli 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane, 2,2-bis-
3,5-dibromo-4-hydroxyphenyl)-propane, 1,1-bis-(3,5-dichloro-4-
hydroxyphenyl)-l-phenylethane, 2,2-bis-(3,5-dibromo-4-hydroxy-
phenyl-hexane, 4,4'-dihydroxy-3,3',5,5'-tetra-chlorodiphenyl,
2,2-bis-(3-chloro-4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dibromo-
4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-
propane, tetra-chlorodiphenylolsulfone, bis(3,5-dibromo-4-hydroxy
phenyl)-phenyl phosphine oxide, bis(3,5-dibromo-4-hydroxyphenyl)
sulfoxide, bis(3,5-dibromo-4-hydroxyphenyl)sulfone, bis(3,5-di-
bromo-4-hydroxyphenyl)-sulfonate, bis(3,5-dibromo-4-hydroxyphenyl)-
sulfide, bis(3,5-dibromo-4-hydroxyphenyl)-amine, bis(3,5-dibromo-
4-hydroxyphenyl)-ketone, and 2,3,5,6,2',3',5',6',-octochloro-4-4'-
hydroxy biphenyl. Representative biphenols are o,o'-biphenol, m,m'-
biphenol; p,p'-biphenol; bicresols, such as 4,4'-bi-o-cresol, 6,6'-
bi-o-cresol, 4,4'-bi-m-cresol; dibenzyl biphenols such as a,a'-di-
phenol-4,4'-bi-o-cresol; diethyl biphenols such as 2,2'-diethyl-
p,p'-biphenol, and 5,5'-diethyl-o,o'-biphenol; dipropyl biphenols
such as 5,5'-dipropyl-o,o'-biphenol and 2,2'-diisopropyl-p,p'-bi-
phenol; dially biphenols such as 2,2'-diallyl-p,p'-biphenol; and
dihalobiphenols, such as 4,4'-dibromo-o,o'-biphenol. Mixtures of
isomers of the foregoing bisphenols can be used.
The dicarboxylic acids which are useful in this process are
also well known and are represented by the formula:
O O
HX - C ~ (Z)n ~ C XH
in which X is oxygen or sulfur, Z is alkylene, -Ar- or -Ar-Y-Ar-
where Ar has the same definition as given with respect to the bis-
phenols, Y is a alkylene, of 1 to 10 carbons, haloalkylene, -0-,
-S-, -S0-, -S02-, -S03-, -C0-, GP=0 or GN = ; and n is 0 or 1.
Suitable dicarboxylic acids include aromatic dicarboxylic
acids such as phthalic acid, isophthalic acid, terephthalic acid,
bis(4-carboxy)-diphenyl, bis(4-carboxyphenyl)-ether, bis(4-car-
boxyphenyl)-sulfone, bis(4-carboxyphenyl)-carbonyl, bis(4-carboxy-
phenyl)-methane, bis(4-carboxyphenyl)-dichloromethane,1,2- and
l-bis(4-carboxyphenyl)-ethane, 1,2- and 2,2-bis(4-carboxyphenyl)-
propane, 1,2- and 2,2-bis(3-carboxyphenyl)-propane, 2,2-bis(4-car-
boxyphenyl)-l, l-dimethyl propane, 1,1- and 2,2-bis(4-carboxyphenyl)-
butane, 1,1- and 2,2-bis(4-carboxyphenyl)-pentane, 3,3-bis(4-car-
boxyphenyl)-heptane, 2,2-bis(4-carboxyphenyl)-heptane, and alipha-
tic acids such as oxalic acid, adipic acid, succinic acid, malonic
acid, sebacic acid, glutaric acid, azelaic acid and the like. Iso-
phthalic acid and terephthalic acid are preferred due to their
availability and low cost. Most preferably, the dicarboxylic acid
component comprises a mixture of about 75 to about 100 mol percent
isophthalic acid and about 25 to about 0 mole percent terephthalic
acid.
When the dicarboxylic acids used in preparing a polyester of
the invention consist of both isophthalic and terephthalic acids
in accordance with an especially preferred embodiment of the in-
vention, a weight proportion of isophthalic to terephthalic acid
residues in the polyester ranging from about 75:25 to about 90:10
provides an especially satisfactory result.
An alternate process for preparing suitable aromatic polyes-
ters, disclosed in US Patent 3,471,441, to Hindersinn et al., com-
prises the homogeneous reaction of an aliphatic modifier, prefer-
ably a glycol of 2 to about 100 carbon atoms, with a diacid halide
of a dicarboxylic acid, followed by an interfacial polymerization
of the resultant prepolymer with a bisphenol. Compositions pre-
pared by this process have an aliphatic modifier, i.e. a glycol,
.:~
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incorporated into the structure of the reaction product of the
bisphenol and diacid halide, and possess excellent engineering
properties such as high impact strength, high modulus, improved
moldability, and high softening points.
The bisphenol and dicarboxylic acid components which may be
employed in the Hindersinn et al., preparatory process correspond
to those described above. The aliphatic modifier is a reactive
difunctional component which may be represented by the formula:
HnD - A - D'Hn
wherein D and D' are independently selected from the group consis-
ting of 0, S, and N; A is a bivalent or disubstituted aliphatic
radical, free of tertiary carbon atoms, selected from the group
consisting of alkylene, cycloalkylene, arylalkylene, alkyleneoxy-
alkyl, poly(alkyleneoxy)alkyl, alkylene-carboxyalkalene-carboxy-
alkyl, and poly(alkylene carboxylakylene-carboxy)alkyl; n is an
integer from 1 to 2 with n being 2 when D and D' is N. Typical
examples of aliphatic modifiers having the foregoing formula in-
clude ethylene glycol, diethylene glycol, neopentyl glycol, 1,4-
cyclohexane, dimethanol, l,4-butane dithiol, dipropylene glycol,
polypropylene glycol, l,l-isopropylidene bis(p-phenyleneoxy)di-
2-ethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, bis(4-hydroxy-
cyclohexane)-2,2-propane, di(hydroxyethyl)adipate, di(hydroxy-
propyl) glutarate, di(hydroxyethyl) poly(ethylene glycol) adipate,
ethane dithiol, ethanolamine, methylethanolamine, hexamethylene-
diamine, 1,3-propanediol, 2-mercaptoethanol, and 2-aminopropane-
diol. Combinations of the above-described aliphatic modifiers
can also be employed, usually to obtain special properties.
Solution processes can also be employed in the preparation of
suitable aromatic polyesters, such as disclosed in US Patents
4,051,107 and 4,051,106.
~'``;~
^
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The polyester components of the invention are preferably
prepared by a process, described as melt polymerization, involving
an ester interchange, i.e. transesterification reaction, between a
diphenolic reactant and a diaryl ester of a dicarboxylic acid car-
ried out in the melt (i.e. without use of a reaction solvent or
diluent). Such a process is described in British Patent 924,607,
to Imperial Chemical Industries Limited.
A further melt polymerization process which can be used to
prepare a linear aromatic polyester suitable for use in this in-
vention is described and claimed in Belgian Patent 837,725, issued
July 20, 1976. This process basically comprises first mixing a
bisphenol, a diaryl ester of a dicarboxylic acid and diol, then
reacting the resulting mixture in the presence of a transester-
ification catalyst.
The polyphenylene sulfide component of the instant invention
is a crystalline polymer with a repeating structural unit compri-
sing a para-substituted benzene ring and a sulfur atom which may
be described by the formula, where n has a value of at least about
100. _ .
~ S - l
The preparation of polyphenylene sulfide is illustrated in US
Patent 3,354,129, to Edmonds, Jr., et al., wherein at least one
E
1 i24~18
-- 10 --
polyhalo-substituted cyclic compound is reacted with an alkali
metal sulfide in a polar organic solvent reaction medium. Suit-
able polyphenylene sulfide compositions are available commercial-
ly under the trademark RYTON of the Phillips Petroleum Company,
and include compositions which are either unfilled, or filled with
glass or some such conventional material. Preferably, the poly-
phenylene sulfide component has a melt flow index, measured at
600~F. using a 5 Kg. weight and a standard orifice, within the
range of from about 40 to about 7000.
The novel resin compositions of the instant invention are
prepared by blending the linear aromatic polyester with polyphenyl-
ene sulfide. The blending or mixing process can be performed using
conventional mixing equipment such as, for example, a Banbury* mix-
er, mixing roll, kneader, screw extruder, or injection molding
machine. Although the mixing ratio may vary depending on the
physical properties desired in the resultant polymer blend, the
polyphenylene sulfide component is present preferably in an amount
of about 5 parts to about 95 parts by weight of blended polymer,
and most preferably, about 5 parts to about 30 parts by weight of
polyblend.
The novel polymer compositions of the present invention may
also include various additives such as organic or inorganic fillers,
stabilizers, antistatic agent, and flame retardants.
According to a particular embodiment of the invention, the
novel polymer compositions of the present invention contain an
effective flame retardant proportion of a halogen-containing Diels
Alder adduct of (A) a cyclopentadiene wherein all of the hydrogen
atoms of the carbon atoms joined by carbon-to-carbon double bonds
have been replaced by halogen, e.g. fluorine, chlorine, or bromine
and (B) an ethylenically unsaturated organic compound containing
one or two carbon-to-carbon double bondsi the molar proportion of
the cyclopentadienyl residue to unsaturated compound residue in
said adduct being 1:1 when the unsaturated compound contains one
*trademark
1~24918
"
carbon-to-carbon double bond, and 2:1 when the unsaturated com-
pound contains two carbon-to-carbon double bonds.
Preferably the Diels Alder adduct employed as flame retardant
agents according to the invention is derived from a cyclic com-
pound having two intracyclic carbon-to-carbon double bonds and
has the structural formula:
X X
XX ~ Q V ~ Xx
X X
wherein X is selected from chlorine, bromine and fluorine, V is
selected from chlorine, bromine, fluorine, alkyl of 1 to 10 carbon
atoms, alkyloxy wherein the alkyl group contains 1 to 10 carbon
atoms, haloalkyl and haloalkyloxy wherein the alkyl groups contain
1 to 10 carbon atoms and halo is chloro, bromo, or fluoro; Q is
a tetravalent saturated cyclic radical having at least 4 carbon
atoms which may be substituted by alkyl groups of 1 to 6 carbon
atoms, chlorine, bromine or fluorine. The alkyl and alkoxy
radicals preferably have 1 to 6 carbon atoms. Q is preferably
a tetravalent homocyclic radical of 5 to 18 carbon atoms or a
tetravalent heterocyclic radical of 4 to 18 carbon atoms and
preferably has 1 to 5 cyclic structures. When Q is a plurality
of cyclic structures, they are fused, that is, share carbon atoms.
In especially preferred halogen-containing fire retardant agents
of the invention Q is a homocyclic radical, more preferably a
homocyclic monocyclic radical and especially is a homocyclic,
monocyclic radical containing only hydrogen substituents. In
especially preferred adducts of the invention Q has no more than
10 carbon atoms.
11249iL8
The fire retardant additives of the invention are known com-
pounds prepared by the Diels Alder reaction of halogenated cyclo-
pentadiene and an open chain unsaturated compound (such as ar-
tetrabromostyrene), a di-unsaturated homocyclic aliphatic compound
(such as 1,5-cyclooctadiene, cyclopentadiene, 1,4-cyclohexadiene,
bicyclo(2.2.1)heptadiene and 1,2,3-trichloro-1,4-cyclohexadiene)
or a di-unsaturated heterocyclic aliphatic compound containing
divalent sulfur or oxygen as the hetero-ring atom constituent
as exemplified by furan or thiophene. Also there may be employed
as the heterocyclic reactant a mono alkyl or di-alkyl derivative
of furan or thiophene wherein one or both of the carbon atoms
attached to the hetero-ring atom contain an alkyl substituent
of 1 to 6 carbon atoms such as l-methyl furan, l-hexyl furan,
1,4 dipropyl furan, l-methyl thiophene, 1,4-dihexyl thiophene and
the like.
Illustrative of halogenated cyclopentadiene compounds suitable
for preparing the fire retardant additive are hexachlorocyclopenta-
diene, 5,5-dimethoxytetrachlorocyclopentadiene, hexabromocyclo-
pentadiene, 5,5-difluorotetrachlorocyclopentadiene, 5,5-dibromo-
tetrachlorocyclopentadiene and 5,5-diethoxytetrachlorocyclopenta-
diene.
Typical of the Diels Alder adducts described hereinabove which
can be used in the practice of the invention are: ~ ~
1,2,2,4,7,8,9,10,13,13,14,14-dodecachloro-1,4,4a,5,6,6a,7,10,
lOa,11,12,12a-dodecahydro-1,4:7,10-dimethanodibenzo[a,e] cyclo-
octene;
1,2,3,4,6,7,8,9,13,13,14,14-dodecachloro-1,4:5,10:6,9-tri-
methano-llH-benzo[b]-fluorene;
1,2,3,4,5,6,7,8,10,11,11-dodecachloro-1,4:5,8-dimethano-
fluorene;
1,2,3,4,5,6,7,8,12,12,13,13-dodecachloro-1,4:5,8:9,10-tri-
methano-anthracene;
~L1%~
- 13 -
1,2,3,4,5,6,7,8,11,11,12,12-docecachloro-1,4,4a,5,8,8a,9,9a,
lO,lOa,decahydro-1,4,5,8-demethanoanthracene;
1,2,3,4,6,7,8,9,10,10,11,11-dodecachloro-1,4,4a,5,5a,6,9,9a,
9b-octahydro-1,4:6,9-demethanodibenzothiophene; and
1,2,3,4,6,7,8,9,10,10,11,11-dodecachloro-1,4,4a,5,5a,6,9,9a,
9b-octahydro-1,4:6,9-dimethanodibenzofuran.
Mixtures of these and equivalent adducts can also be employed.
The preparation of the aforementioned known halogen-containing
Diels Alder adducts is more particularly described in R.D. Carlson
et al., US Patent 3,711,563 (especially at Column 8), W. Seydl, US
Patent 3,923,728 (to B.A.S.F.-A.G.), I. Gordon et al., US Patent
4,000,114, R.R. Hindersinn et al., US Patent 3,535,253 and J.L.
Dever et al., US Patent 3,687,983.
The proporation of the halogen-containing flame retardant
adduct compound employed according to the invention is generally
from about 1 to less than about 50 weight percent, preferably
about 2 to about 30 weight percent, based on the combined weight
of the polyester and polyphenylene sulfide. An especially good
result is obtained employing about 3 to about 15 weight percent
of the halogen-containing adduct based on the combined weight of
the polyester and the sulfide polymer components.
According to another embodiment of the invention the flame
retardant properties of the present polyester-polyphenylene sul-
fide mixtures are enhanced when the bisphenol reactant employed
to prepare the polyester comprises from about 1 to less than about
50 mole percent of a bisphenol wherein at least one carbon atom is
substituted with halogen the balance of said bisphenol reactant be-
ing bisphenol devoid of halogen substitution.
The halogen-containing bisphenol of the invention corresponds
to the above generic structural formula which defines the bis-
phenol or bisphenols employed in preparing the polyesters of the
112~918
- 14 -
invention. According to a preferred embodiment of the invention
the halogen substituents are chlorine or bromine. Preferably the
halogen-substituted bisphenol component contains 1 to 20, more
preferably 2 to 8, and especially 4 halogen substituents. Pre-
ferably at least one of the T and T' in the aforementioned genericbisphenol structural are halogen. In an especially preferred em-
bodiment of the invention all of the halogen substituents of the
halogen-substituted bisphenol component are present as T and T'.
The bisphenol component of the invention which is devoid of
halogen substitution corresponds to the aforementioned generic
structural, (which is pointed out above, broadly defines bis-
phenols of the invention) when G in the generic formula is alkyl-
aryl, alkylaryl, arylalkyl or cycloalkyl, E is divalent alkylene,
cycloalkylene or arylene, -O-, -S-, -SO-, -S02-, -S03-, -CO-,
GP _ =0, or GN _ , and T and T' are independently selected from
the group consisting of G and OG, (with Ar, m, b, and x of said
generic formula having the previously assigned meanings).
While residues of the halogen-substituted bisphenol and the
halogen free bisphenol can be present in the same polyester con-
stitutent of the present blend it is preferred that the residue
of the halogen-containing bisphenol and the residue of the halogen-
devoid bisphenol be present in different polyester components of
the polyester-sulfide polymer mixture, i.e. the polyester component,
of the blend preferably comprises:
A) a polyester of said halogen-substituted bisphenol, and
B) a polyester of said bisphenol devoid of halogen sub-
stituents.
Generally when the aforementioned mixture of polyesters is
employed according to the foregoing preferred embodiment, the
halogen-containing bisphenol polyester is present in an amount
of from about 3 to about 40 weight percent, and especially from
about 5 to about 20 weight percent, based on the combined weight
of the polyphenylene sulfide and all of the polyesters of the
present polymer blend.
In the mixture of polyesters preferably employed as the poly-
ester component of the invention, either or both the halogen-
containing bisphenol polyester and the halogen polyester may
contain residues of aliphatic hydroxy compounds as modifying
constituents. However, in accordance with an especially preferred
embodiment of the invention the halogen-containing bisphenol poly-
ester constituent of said mixture contains said aliphatic modifier
whereas the halogen-free bisphenol polyester constituent is devoid
of said aliphatic modifier.
The presence of the above-described halogen-containing Diels
Alder adduct and/or the halogen-substituted bisphenol in the linear
aromatic polyesters according to the invention greatly enhances the
flame retardancy of the polyester-sulfide polymer blend without
detrimentally affecting the other desirable properties of these
compositions. The flame retardance is enhanced to the extent that
excellent fire retardant performance is achieved even when the
compositions are molded in extremely thin sections, (e.g. of thick-
nesses less than about 1/16 of an inch). This excellent flame
retardance performance makes the present composition especially
suitable for the fabrication of electrical components such as
miniature circuit boards and the like.
The additive-containing resin mixture of the invention may
be prepared, if desired, by charging the polyester and sulfide
polymer with the additive to a conventional mixing apparatus,
such as a premix mixer, or melt extruder. The resultant addi-
tive-containing composition can then be molded directly in an
injection molding apparatus or an extruder. The molded articles
thus formed have excellent hydrolytic stability and tensile
strength.
4~
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The fillers which may be employed in the invention are pre-
ferably particulate fillers such as particulate glass (e.g. chopped
glass fiber, glass rovings, glass microballoons or microspheres and
pulverulent glass) particulate clay, talc, mica, inorganic natural
fibers, alimina, graphite, silica, calcium carbonate, carbon black,
magnesia and the like. Generally such fillers are added to re-
inforce the structural integrity of a polymer, e.g. to inhibit
sagging and/or to improve the tensile strength and stiffness of
the polymer composition and also to reduce shrinkage, minimize
crazing, lower material costs, impart color or opacity, and im-
prove the surface finish of the polymer composition. Generally
the amount of particulate filler employed in the composition of
the invention is in the range of about 5 to about 70 weight per-
cent, preferably about 5 to about 40 weight percent and espec-
ially about 8 to about 30 weight percent based on the combinedweight of the polyester and the phenylene sulfide polymer. The
filler employed is preferably inorganic.
It is found according to the invention that use as filler of
particulate glass, advantageously glass fibers, is especially
desirable since the presence of the particulate glass filler
further enhances the fire retardancy of polymer mixture of the
invention.
The presence of the particulate glass component in the com-
positions of the invention generally enhances the flame retardance
of the polyester-sulfide polymer blend to the extent that excell-
ent fire retardant performance is achieved even when the compo-
sitions are molded in extremely thin sections, (e.g. of thick-
nesses less than about 1/16 of an inch). This excellent flame
retardance performance makes the glass filled compositions of
the invention especially suitable for the fabrication of elect-
rical components such as miniature circuit boards and the like.
~2d~
The glass filling, especially glass fiber filling, employed
in the invention preferably contains an organic coupling agent as
a very thin coating on the glass particles. The coupling agent
forms an adhesive bridge between the glass and the polymer blend
thereby enhancing the strength properties of the filled polymer
blend. Typically, organic coupling agents employed in the art in-
clude transition metal complexes of unsaturated aliphatic acids
such as the methacrylate chromic chloride complex as well as var-
ious organic silane compounds including vinyl trichlorosilane,
vinyl triethoxysilane, gamma amino-propyl triethoxysilane, ally
trichlorosilane resorcinol, vinyltrimethoxysilane, amyltrimeth-
oxysilane, phenyltriethoxysilane, B-cyclohexylethyltrimethoxy-
silane, ~-methacryloxypropyltrimethoxysilane, ~-iodopropyltrimeth-
oxysilane, ~-chloropropyltrimethoxysilane, ~-chloroisobutyltrieth-
oxysilane, ~-glyxidoxypropyltrimethoxysilane, N-~-aminoethyl-~-
aminopropyltrimethoxysilane, N-bis-(~-bydroxyethyl)-~-amino-pro-
pyltriethoxysilane, and ~-(3,4-epoxycyclohexylethyltrimethoxysilane.
Preferably the coupling agent employed with the glass filler
according to the invention is a silane coupling agent.
Glass fillers are frequently manufactured and sold so as to
contain the coupling agent as a proprietary ingredient on the sur-
face of the glass. The coupling agents and their uses with glass
fillers are discussed in more detail in W.V. Titow and B.J. Lanham,
"Reinforced Thermoplastics", Halstead Press, 1975, pp. 83-88 and
L. Mascia, "The Role of Additives in Plastics", J.Wiley and Sons,
1974, pp. 89-91.
It has been found according to the invention that the presence
of antimony additives (such as metallic antimony and compounds of
antimony) is generally undesirable since the presence
~249i~
- 18 -
of the antimony constituent generally is detrimental to the flame
retardance of the polymer mixture as is illustrated in the examples
below.
The following examples further illustrate the various aspects
of the invention but are not intended to limit it. Various modi-
fications can be made in the invention without departing from the
spirit and scope thereof. Where not otherwise specified in this
specification and claims, temperatures are given in degrees centi-
grade, and all parts and percentages are by weight.
EXAMPLE 1 PREPARATION OF LINEAR AROMATIC POLYESTER
A) By Solution Polymerization
A mixture of 165.7 parts isophthaloyl chloride, 29.2 parts
terephthaloyl chloride, and 223.5 parts bisphenol-A ~2.2-bis(4-
hydroxyphenyl)propane) were dissolved in 2270 parts methylene
chloride (having a moisture content of 10 ppm of water) in a
reactor at 25C. 200.7 parts triethyl amine were added at a
constant rate to the reaction mixture over a period of 7.5 hours,
under nitrogen purge with stirring. The reacti~on mixture was
maintained at 15C. After completion of the triethylamine addi-
tion, the mixture was stirred for two hours at 20C. 6.8 partsof benzoyl chloride were then added to react with the end-groups
of the polymer. After one hour, 13.7 parts of isopropanol were
added to react with any excess benzoyl chloride. After 1/2 hour,
dilute aqueous hydrogen chloride (570 parts of a 0.5 wt.% sol.)
was added to react with any excess triethylamine for an additional
1/2 hour with stirring. The two phases were then allowed to
separate by gravity, and the water phase was removed. Additional
washes of the polymer solution with equal amounts of water were
carried out until the chloride ion in the polymer solution measured
less than 0.1 ppm. The polymer was then precipitated from solution
and dried in a vacuum oven until the moisture concentration was less
- l9 -
than 0.1 wt.%. The resultant high molecular weight polynler had
an intrinsic viscosity of 0.74 dl/g in sym. tetrachloroethane (at
30C.)
B) By Melt (transesterification) Polymerization
: Bisphenol-A (1319.1 g), diphenyl terephthalate (275.9 9) and
diphenyl isophthalate (1562.9 g) were dried for several hours at
75 in a vacuum oven and charged with 0.07 9. of anhydrous lithium
hydroxide transesterfication catalyst to a 5-liter resin kettle
under nitrogen. The kettle was equipped with a thermometer, a
nitrogen inlet on a Y-tube, a mechanical stirrer, a short
Vigreaux column, a distillation head and 3 necked flask receiver.
The kettle was heated to 210 to melt the reactants and
vacuum was applied gradually to the stirred molten mass. The
temperature of the reaction mass was increased gradually to re-
move phenol overhead to the receiver. After 1.4 hours the tem-
perature of the reaction mass reached 228 and the reaction mass
pressure was about 0.5 mm Hg. The reaction mass was then flooded
with dry nitrogen to relieve the vacuum and the viscous reaction
mass was poured into a foil-lined glass tray and allowed to cool
to ambient temperature.
The bisphenol A-isophthalate-terephthalate prepolymer thus
obtained was broken up and dried overnight at 70 in a vacuum
oven. The dried prepolymer (1070 9.) was changed to a two gallon
oil-heated stainless steel reactor equipped with agitation means
under dry nitrogen and heated with agitation to 210. Agitation
of the molten mass was commenced after 1 hour. After 1.3 hours
from the commencement of heating, vacuum (about 0.6 mm of ~Ig.)
was applied to the agitated mass. The reaction temperature was
raised gradually over a period of about 2 hours to 305. The
30 agitated reaction mass was then maintained under vacuum at 305
for 6.7 hours. The reactor was opened and the polyester obtained
was discharged from the reactor and allowed to cool to ambient
- 20 -
temperature. A clear yellow bisphenol A-isophthalate-terephthalate
polyester having a relative viscosity of 1.36 (measured in tetra-
chloroethane at 30) was obtained.
The foregoing procedure was repeated with 1100 9. of pre-
polymer being employed in the polymerization reaction. A similar
polymer was obtained having a relative viscosity of 1.35 (measured
in tetrachloroethane at 30).
EXAMPLE 2 PREPARATION OF MOLDING COMPOSITION
A linear aromatic polyester was prepared according to the
procedure of Example 1 (A) and dried for four hours at 120C.
100 parts of polyphenylene sulfide (commercially sold under the
trademark RYTON V-l by the Phillips Petroleum Company), having
a melt flow index of 6,000 as determined at 600F. with a 5 Kg.
weight using a standard orifice, was added to 900 parts of poly-
ester and tumble mixed for 0.5 to 1 hour. The blend was milledon a two roll Farrell Mill (front roll heated to 480C., back
roll heated to 425F.) for 1.5-3.0 minutes at 45 r.p.m. The
blend was then sheeted, and ground to 4 mm. granule size on a
granulator. The granules were dried for 1-2 hours at 120C. and
injection molded to produce tensile and flex bars. The injection
molding conditions were as follows:
MOLDING PARAMETERS
Barrel Temperature (F) 600
Nozzle Temperature (F) 580
Mold Temperature (F) 250
Screw Speed (rpm) 120
Back Pressure (psi) 625
Injection Pressure (psi)11,200
Plasticating Time (secs) 8
Fill Time (secs) 3
Total Injection Time (secs) 10
The tensile bars thus prepared were tested and found to have
the following physical properties. By way of comparison, a control
which does not include polyphenylene sulfide, is also shown.
- 21 -
PROPERTIES
Example 2 Control
Tensile Strength (psi) 10,150 10,000
Tensile Modulus (psi x 105)3.09 3.34
After 7 days immersion in boiling H20:
Tensile Strength (psi) 10,800 1,700
Tensile Modulus (psi x 105)3.34 2.75
EXAMPLES 3-6 PREPARATION OF MOLDING COMPOSITIONS
A linear aromatic polyester was prepared according to the
procedure of Example l(A) and dried for four hours at 120C. The
procedure of Example 2 was followed to produce 4 mm. granules.
The granules were dried for 4 hours at 120C. and were then
blended with polyphenylene sulfide pellets (commercially sold by
the Phillips Petroleum Corp. under the trademark RYTON 6), having
a melt flow index of 50 as determined at 600F. with a 5 Kg. weight
using a standard orifice in various mixing ratios. Tensile bars
were prepared and tested, and the results are summarized in Table
1 below.
The aromatic polyesters of the invention generally have an
intrinsic viscosity of at least l.S dl/g when measured in sym.
tetrachloroethane at 30C., and preferably at least 1.6 dl/g.
~ ~,
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- 24 -
EXAMPLt 7
About 450 parts of a bisphenol A-isophthalate polyester resin
having an isophthalate:terephthalate ratio of 5.67 which was pre-
pared substantially as described in Example 1 (A) was dried for
about 4 hours at 120 and charged gradually to the Farrell Mill
described in Example 2 which was operated with its front roll at
450F. and its back roll at 410F. until fusion of the resin was
completed and a band of clear resin formed on the front roll.
About 50 parts of the polyphenylene sulfide resin of Example 2
was then added until a homogeneous resin band formed on the front
roll.
The mixture of resins was milled for about 1.5 to 3 minutes
and then sheeted from the mill. The milled resin blend was ground
to granules of about 4 mm granule size as described in Example 2
which were then dried at about 120 for about 4 hours.
The dried resin mixture granules were mixed with 58.3 parts
of chopped glass fiber (3/16 inch length, manufactured by Owens
Corning Fiberglass Corporation under the designation 419AA, which
contains a proprietary silane coupling agent). The resultant mix-
ture was then added to an Arburg Alrounder 200 injection molding
machine operated at a barrel temperature of 600F., a mold temper-
ature of 215-225 F. and an injection pressure of about 14,000 psi.
The mixture was molded as bar specimens which were subsequently
reground and dried substantially as described hereinabove to insure
that a homogeneous blend was obtained. The dried reground glass
fiber-resin mixture was then charged to an Arburg 221E/150 Injection
molding machine operated at a barrel temperature of 550F., a mold
temperature of about 290-295 F., and an injection pressure of about
16,760 psi to injection mold the resin-glass fiber blend into
specimen bars of about 5 inches length, 1/2 inch width and 1/16
inch thickness. Several of the 1/16 inch thickness specimen bars
were reserved for the flame retardant test described herein below.
f'''
,~!
.'..~
~24~
- 25 -
The remainder of the 1/16 inch thick specimen bars were dried
at 120 for about 2 hours and compression molded between steel
plate backed aluminum sheets in a Carver Four Paten Laboratory
Press operated at 400-430 F. and a pressure of about 30,000 to
35,000 psi to obtain specimen bars 5 inches in length, 1/2 inch
in width and 1/32 inch in thickness.
The 1/16 inch- and 1/32 inch-thick bar specimens are evaluated
in flame retardant properties according to the Vertical Burning
Test described in "UL-94-Standards for Safety", Underwriters
Laboratory Inc., Second Revised Edition, May 2, 1975, pages 6-8.
In accordance with the evaluation technique of the aforementioned
test the specimens are rated V-O, V-l or V-2, with V-O indicating
the greatest degree of flame retardancy and V-2 indicating the
poorest degree of flame retardancy. The Oxygen Index of a sample
of the injected resin product obtained from the latter Arburg mold-
ing apparatus was also determined.
The results of the aforementioned flame retardant tests upon
the excellent glass fiber-filled resin blend obtained in this
Example are reported in Table 2 below.
EXAMPLE 8
To provide a basis for comparing the flame retardancy of the
aforementioned glass fiber-filled resin blend with tha~ of an un-
filled resin blend of the invention, an unfilled resin blend of
the invention containing the polyester of Example l-A was milled
and injected molded substantially as described hereinabove at
Examples 2 and 7 to provide the 1/16 inch- and 1/32 inch-bar
specimens described in Example 7~ As a glass-fiber component was
not employed, it was unnecessary to regrind and remold the product
as described in Example 7 to provide a homogeneous blend of the
product components.
, ./
~24C~8
- 26 -
The specimen bars were evaluated for flame retardance according
- to the UL-94 Vertical Burning Test and their Oxygen Index was deter-
mined as described in Example 7. The resultant test data is com-
pared with that of the Example 7 product in Table 2.
EXAMPLE 9
The procedure of Example 7 was repeated substantially as
described except that the bisphenol A-isophthalate-terephthalate
polyester employed was prepared by melt polymerization as described
in Example l(B) and the flame retardance of a 1/16 inch thickness
specimen and the Oxygen Index of the product were not measured.
The results of this example are also presented in the Table below.
EXAMPLE 10
The procedure of Example ~ was repeated substantially as
described with the same proportions of polyester and polyphenylene
sulfide as in Example ~ except that the bisphenol-A-isophthalate-
terephthalate polyester employed was prepared by melt polymerization
as described in Example l(B) and the flame retardance of a 1/16 inch
thickness specimen and the product Oxygen Index were not determined.
The results of this Example are also presented in the Table below.
EXAMPLES 11-13 (Controls)
Examples 11-13, which employ the polyester of Example l(A) and
which are summarized in Table 2 below, are Control Examples substan-
tially comparable to Examples 7 and ~. The products of Examples 11-
13 are compositions substantially comparable to those described in
Examples 7 and 8 except that one or more of the components of the
Examples 7 and 8 products were omitted. Control Examples 11-12
illustrate the effect on flame retardance resulting from addition
of an antimony compound ~Sbz03J to the resin compositions of the
invention.
',~
1L9i8
Where a glass fiber filler constituent is employed in these
Control Examples, the mixtures were milled, molded and tested for
flame retardancy substantially in accordance with the procedure
of Example 7. Where glass fiber filler is not employed, the Con-
trol Example was carried out by the procedure of Example 8 sub-
stantially as described. The antimony additive employed in Examples
11-12 was added to the resin mixture during the milling of the lat-
ter in the Farrell Mill (substantially in accord with the method of
addition of the polyphenylene sulfide constituent described in
Example 7 and subsequent to the addition of the latter polymer).
.~
~124~18
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_ . ~ ~n~
,_ ~VO~ . ~ ~ ~ c
v _ O ~ ~ ~ ~O L i Q
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~1 ~ u o ~ ~ ~ ~
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~2~.8
- 29 -
In Example 8 of Table 2 the proportion of polyester and poly-
phenylene sulfide is 9:1 corresponding to the proportions of these
constituents in Examples 7, 10, 12 and 13.
As is evident from the data of Table 2 by comparison of the
results of Example 7 with those of Example 8, the use of a parti-
culate glass filler in the present resin blend enhances significant-
ly the flame retardant property of the resin blend according to
both the UL-04-test evaluation described above and Oxygen Index.
The results of Examples 9 and 10 indicate that a similar
1~ effect from use of filler is obtained when the polyester is pre-
pared by melt polymerization.
By comparison of the test results of the product of Example 8
with those of the product of Example 11, the unfilled product of
the invention as prepared in Example 8 has a flame retardance su-
perior to that of its polyester component.
Comparison of the test results of Examples 7 and 8 with those
of Examples 12 and 13 indicate that the presence of an antimony
constituent in the resin blends of the invention (both filled and
unfilled) is deleterious to the flame retardance of the blends.
It will be appreciated by those skilled in the art that
procedural modifications of the above-described experimental
- technique can be made without departing from the spirit and
scope of the invention.
For example, in Example 7 a similar result providing a homo-
geneous glass filler-resin mixture can be obtained without the
necessity of regrinding the molded glass fiber-containing resin
product. In this alternative procedure the Farrell Mill resin
product, after being ground to granules and dried, is added to
the hopper end of a screw resin extruder (such as a Haake Polytest
45 single screw extruder or a Werner Pfleider ZDS-K28 twin screw
extruder) which the particulate glass component is added downstream
on the extruder. (Alternatively, the particulate glass can be
~ ~;
''~L.`
~ 24918
- 30 -
mixed with the dried ground granules with the resultant mixture
being added to the hopper end of the extruder). The resultant
extruded resin containing a homogeneous dispersion of the glass
component is then sliced into pellets which are then injection
molded as described in Examples 2 and 8.
Also, instead of separate addition of the particulate glass
constituent as described in Example 7, the latter constituent can
be homogeneo~sly blended with the sulfide polymer constituent of
the resin blend before the said sulfide polymer is added to the
polyester.
In place of the chopped glass fiber employed in the above
Examples, other forms of particulate glass filler agents such as
uncut glass strands, glass rovings, glass pellets, pulverulent
glass, and glass micro-balloons can be used.
EXAMPLE 14
About 450 parts of bisphenol A-isophthalate-terephthalate
polyester resin having an isophthalate:terephthalate ratio of 5.67
which is prepared substantially as described in Example 1 (A) was
dried for about 4 hours at 120 and charged gradually to the
Farrell Mill described in Example 2 which is operated with its front
roll at 450F. and its back roll at 410F. until the fusion of the
resin was complete and a band of clear resin formed on the front
roll. About 50 parts of the polyphenylene sulfide resin of Examp~e~ ~
2 was then added until a homogeneous resin band was formed on the
front roll. In a similar manner, 20 parts of 1,2,3,4,7,8,9,10,13,
14,14-dodecachloro-1,4,4a,5,6,6a,7,10,10a,11,12,12a-dodecahydro-
1,4:7,10-dimethanodobenzo[a,e~cyclooctene herein referred to for
brevity as "C.O.D." was added to the resin mixture in the mill.
The mixture of resins and C.O.D. was milled for about 1.5 to
3 minutes and was then sheeted from the mill, ground to granules
of about 4 mm. granule size as described in Example 2 and dried
at 120 for 4 hours.
gi8
- 31 -
The dried resin blend granules were charged to an Arburg
221E/150 Injection molding machine operated at a barrel temperature
of 550F., a mold temperature of 275-280F. and an injection pres-
sure of 20,000 psi to injection mold the C.O.D.-containing blend
into specimen bars of about 5 inch length, 1/2 inch width and 1/16
inch thickness. Several of 1/16 inch thickness specimen were re-
served for the flame retardant test described hereinbelow. The
remainder of the 1/16 inch thick specimen bars were dried at 120
for 2 hours and compression molded between steel plate-backed
aluminum sheets in a Carver Four Paten Laboratory Press operated
at 400-430F. at a pressure of 30,000 to 35,000 psi to obtain
specimen bars 5 inches in length, 1/2 inch in width and 1/32 inch
in thickness.
The 1/16 inch- and 1/32 inch-thick bar specimens were evaluated
in fire retardant properties according to the Vertical Burning Test
described in "UL94-Standards For Safety", Underwriters Laboratories,
Inc., Second Revised Edition, May 2, 1975, pages 6-8. In accordance
with evaluation technique of the aforementioned test, the specimens
were rated V-O, V-l, or V-2 with V-O indicating the greatest degree
of flame retardancy and V-2 indicating the poorest degree of flame
retardancy. The Oxygen Index of a sample of injected molded resin
blend obtained from Arburg Injection molding machine is also de-
termined.
The results of these experiments are reported in Table 3 below.
EXAMPLE 15
:
The procedure of Example 14 was followed substantially as des-
cribed through the step wherein the sheet of the blend of C.O.D.,
polyester and polyphenylene sulfide was obtained from the Farrell
Mill was ground to granules of 4 m.m. granule size and dried at 120
for 4 hours.
The dried granules were mixed with 58.3 parts of chopped glass
fiber (3/16 inch length, manufactured by Owens Corning Fiberglass
1~24918
- 32 -
Corporation under the designation 419AA). The resultant mixture was
then added to an Arburg Alrounder 200 injection molding machine
operated at a barrel temperature of 550F., a mold temperature of
215-225F., and an injection pressure of about 20,000 psi.
The mixture was molded as bar specimens which were subsequently
reground and dried substantially as described hereinabove to ensure
that a homogeneous mixture of the glass fibers with the resin blend
was obtained. The dried reground mixture was then charged to the
Arburg 221E1150 Injection molding machine (operated at a barrel
temperature of 550F., at a mold temperature of 290-295F., and an
injection pressure of about 20,000 psi) and molded as 5 inch x 1/2
inch x 1/16 inch specimen bars as described in Example 7. As in
Example 14, a portion of the latter specimen bars were reserved for
flame retardant testing and the remainder were compression molded
to obtain 5 inch x 1/2 inch x 1/32 inch bar specimens. Both the
1/16 inch and 1/32 inch bar samples were tested for flame retard-
ance as described in Example 14. The results of this Example are
reported in Table 3 below.
EXAMPLE 16 (Control)
The procedure of Example 15 was repeated substantially as des-
cribed except that following the addition of polyphenylene sulfide
and C.O.D. to the Farrell Mill 5 parts of particulate antimony tri-
oxide were added and the determination of Oxygen Index was omitted.
The resultant molded product was characterized by an unsatisfactory
degree of brittleness, i.e. its bar specimens could be broken
manually with only a slight flexing pressure. The flame retardant
testing results of this product are reported in Table 3 below.
EXAMPLES 17-27 (Controls)
In these Examples there were prepared and tested for flame re-
tardance compositions which were substantially comparable to those
~2~918
- 33 -
of Examples 14, 15, and 16 except that one or more of the consti-
tuents of the compositions described in Examples 14, 15, and 16
were omitted. Where glass fibers were present as a constituent
in these compositions, the procedure of Example 15 was employed
substantially as described. Where glass fiber was absent, the
procedure of Example 14 was employed substantially as described.
The flame retardant results of these comparative Examples are
compared to those of Examples 14-16 in Table 3 below.
~lZ49~8
- 34 -
_ U~ ~ :~ Cl~
_ ~ O t~ N N ¦ .0
C C m~lCOI 0~0~ ~ OU
<~ _ _ O O ' N N l
~, ~
7-r~ ~
X ,C o O NO o~ , ~ O ~ C
.l rJ O
u~ u~ m o l I ~ ; I! ~-- u
v~O~
Y-~ '
~¦ e u ~ O a - ~ c c~ C _ ¦ o ~ ~ o
~ ~ ~ o ~ N~ ~ * * *
l 'c~ C~ o ~ ~ c ~J >~ I O ~ *
llZ4918
- 35 -
Of the examples presented in foregoing Table 3, Control Examples
17, 19, and 21 are identical to Control Examples 11, 13, and 12 above
respectively, and Control Examples 18 and 20 are identical to illus-
trative Examples 8 and 7 above, respectively. (The data of the earlier
Examples 7, 8, 11, 12 and 13 is presented in Table 2 above).
In Control Example 18 the proportion of the polyester and the
polyphenylene sulfide is 9:1 corresponding to the proportions of these
constituents in Examples 14 and 15 and Control Examples 16, 19-21.
As is evident from the data of Table 3, Examples 14 and 15 pro-
vide excellent resin compositions according to the invention which by
virtue of their C.O.D. constituent are additionally characterized by
excellent flame retardance even at low specimen thickness, i.e. at
specimen thicknesses less than 1/16 inch, as compared to comparable
compositions devoid of C.O.D. (Control Examples 18-21).
The data of Control Examples 16, 19, and 21 indicate that the
presence of an antimony constituent in admixture with the polyester
and polyphenylene sulfide is undesirable either because the antimony
constituent increases the flammability of the compositions so as to
render their low thickness flame retardancy unsatisfactory (as in
Control Examples 19 and 21) or because the antimony oxide renders
the composition undesirably brittle (as in Control 16).
The flammability behavior of resin mixtures containing both
Bisphenol A-isophthalate-terephthalate polyester and polyphenylene
sulfide is indicated by the data of Table 3 to be distinctive from~
the flammability behavior of resin compositions devoid of the poly-
phenylene sulfide component. Thus, for example, the introduction of
the halogenated organic flame retardant additive into the polyester-
polyphenylene sulfide blend enhances the flame retardancy of the
blend to provide satisfactory flame retardance at low specimen thick-
ness (as is indicated by a comparison of Examples 14 and 15 andControl Example 16 with Control Example 18). In contrast, the intro-
duction of the halogenated organic flame retardant into the poly-
ester in the absence of the sulfide polymer fails to enhance the
1~24~18
- 36 -
resin flame retardance sufficiently to provide a satisfactory flame
retardance at low specimen thickness (as is evident from a compari-
son of the data of Control Examples 22 and 23 with the results of
Control Example 17).
It will be appreciated by those skilled in the art that pro-
cedural modifications of the above-described experimental technique
in Examples 14-27 can be made without departing from the spirit
and scope of the invention.
For example, in Example 14 a similar result providing a homo-
geneous glass filler-resin mixture can be obtained without the
necessity of regrinding the molded glass fiber-containing resin pro-
duct. In this alternative procedure the Farrell ~ill resin product,
after being ground to granules and dried, is added to the hopper end
of a screw resin extruder (such as Haake Polytest 45 single screw
extruder or a Werner Pfleider ZDS-K28 twin screw extruder) while the
particulate glass component is added downstream on the extruder
(alternatively, the particulate glass can be mixed with the dried
ground granules with the resultant mixture being added to the hopper
end of the extruder). The resultant extruded resin containing a
homogeneous dispersion of the glass component is then sliced into
pellets which are then injection molded as described in Example 14.
In place of the chopped glass fiber employed in the above Ex-
amples 14-27, other forms of particulate glass reinforcement agents
such as uncut glass strands, glass rovings, glass pellets, pulveru- ,
lent glass, and glass microballoons can also be used.
Instead of separate addition of the particulate glass constit-
uent as described in Example 15, the latter constituent can be homo-
geneously blended with the sulfide constituent of the resin blend
before the said sulfide polymer is added to the polyester.
In place of the halogenated organic additive C.O.D. substan-
tially similar results in the above Examples are obtained employing
another halogenated organic additive of the same generic structural
formula as C.O.D. (said generic structural being delineated in the
~12491~
- 37 -
specification above), for example:
1,2,3,4,5,6,7,8,9,13,13,14,14-dodecachloro-1,4:5, 10:6,
9-trimethano-llH-benzo[b] fluorene,
1,2,3,4,5,6,7,8,10,10,11,11,-dodecachloro-1,4:5,
8-dimethano-fluorene,
1,2,3,4,5,6,7,8,12,12,13,13-dodecachloro-1,4:5, 8:9,
10-trimethanoanthracene,
1,2,3,4,5,6,7,8,11,11,12,12-doclecachloro-1,4,4a,5,8-,
8a,9,9a,10,1Oa,decahydro-1,4,5,8-dimethanoanthracene;
1,2,3,4,6,7,8,9,10,11,11-dodecachloro-1,4,4a,5-,
5a,6,9,9a,9b-octahydro-1,4:6,9-dimethanodibenzothiophene;
and
1,2,3,4,6,7,8,9,10,11,11-dodecachloro-1,4,4a,5-,
5a,6,9,9a,9b-octahydro-1,4:6,9-dimethanodibenzofuran, and
The Diels Alder adduct of hexachlorocyclopentadiene and
(ar) tetrabromostryene.
These and similar halogenated organic compounds within the fore-
going generic structural formula can be employed alone or in admixture
with each other or the aforementioned C.O.D.
EXAMPLE 28 PREPARATION OF A LINEAR AROMATIC POLYESTER OF
A HALOG N-CONTAINING BISPHENOL _ _
A mixture of 7.443 kg. of isophthaloyl chloride, 7.443 ky. of
terephthaloyl chloride and 227 kg. of methylene chloride were charged
under an atmosphere oF dry nitrogen to a 100 gallon glass lined
Pfaudler reactor equipped with agitation means. In a 50 gallon glass
lined Pfaudler reactor also equipped with agitation means and con-
nected by a delivery tube to the previously described reactor, a
mixture oF 29.91 kg. of 2,2-bis(4-hydroxy-3,5 dibromophenyl) propane,
2.17 kg. of 1,6-hexane diol and 136 kg. of methylene chloride under
an atmosphere of dry nitrogen was agitated to dissolve the halogen-
containing bisphenol in the methylene chloride solvent. A 2 gallon
addition tank also connected by a delivery tube to the larger
Pfaudler reactor was charged with 22.5 liters of triethylamine under
~124918
an atmosphere of dry nitrogen. The triethylamine and the bisphenol
solution were added simultaneously over a period of 2 hours and 10
minutes to the mixture in the larger Pfaudler reactor, which was
maintained at a temperature of about 13 to 19 under vigorous
agitation. On completion of the addition of the bisphenol solution,
the smaller PFaudler reactor was rinsed with 45.4 kg. of methylene
chloride and the methylene chloride rinse was added to the mixture
in the larger Pfaudler reactor. The agitation of the reaction
mixture in the larger Pfaudler reaction vessel was continued for
about 1~ hours.
About 2 liters of concentrated aqueous hydrochloric acid which
had been diluted by addition of about 25 gallons of distilled water
was then added to the reaction mixture in the larger Pfaudler reactor
to terminate the esterification reaction. The resultant reaction
mixture which consisted of a lower organic liquid phase containing
the polyester product and an upper aqueous phase was removed from the
reaction vessel and the layers thereof were separated. The recovered
organic layer was washed clean of chloride anion with water.
The polyester product was recovered by drowning the washed
organic layer gradually in about 50 gallons of vigorously agitated
water at about 60 to 70 in a vessel equipped with a bottom outlet.
During the drowning operation the methylene chloride was flashed from
the drowned mixture and the polyester precipitated as a white solid;
The product was withdrawn from the aforementioned bottom outlet as
an aqueous slurry which was centrifuged to separate the water from
the solid product. The product was dried with agitation in vacuo at
about 100 for about 16 hours. The recovered polyester was obtained
in a yield of about 90% of theory.
The resultant polyester product contains halo bisphenol hexane
diol isophthalate and terephthalate residues in the molar propor-
tions 0.75:0.25:0.5:0.5, has an intrinsic viscosity of 0.41, a glass
transition temperature of 198-207, a weight average molecular
weight of 60,200 and a number average molecular weight oF 21,400.
11249~ 8
~ 39 ~
By analysis the actual bromine content of the polyester product
is 41.89,o (theoretical: 42.2//o).
EXAMPLE 29
About 324 parts of a bisphenol A-isophthalate polyester resin
having an isophthalate:terephthalate ratio of 5.67 which was pre-
pared substantially as described in Example l (A) was dried for
about 4 hours at 120 and charged gradually to the Farrell Mill des-
cribed in Example 2 which was operated with its front roll at 450 F.
and its back roll at 410 F. until fusion of the resin was completed
and a band of clear resin formed on the front roll.
On completion of the addition of the halogen-free bisphenol
polyester, 40 parts of the halogen-containing bisphenol polyester of
Example 28 which had been dried for about 4 hours at 80 C. were
gradually charged to the mill until fusion of the resin was completed
and a band of clear resin formed on the front roll.
On completion of addition of the halogen-containing bisphenol
polyester about 36 parts of the polyphenylene sulfide oF Example 2
were added to the mill.
The mixture of resins was milled for about 1.5 to 3 minutes and
then sheeted from the mill. The milled resin blend was ground to
granules of about 4 m.m. granule size as described in Example 2 which
were then dried at about 120 for about 4 hours.
The dried resin blend granules were charged to an Arburg 221E/150
Injection molding machine operated at a barrel temperature of 590 F.,
a mold temperature of 250 F. and an injection pressure of about
25,000 psi to injection mold the resin blend into specimen bars of
about 5 inch length, l/2 inch width and 1/16 inch thickness. Several
of 1/16 inch thickness specimen were reserved for the flame retardant
test described hereinbelow. The remainder of the l/16 inch thick
specimen bars were dried at 120 for 2 hours and compression molded
in a Carver four Paten Laboratory Press operated at 400-420 F. at
a pressure of 30,000 to 35,000 psi to obtain specimen bars 5 inches
in length, 1/2 inch in width and 1/32 inch in thickness.
~24918
- 40 -
The l/16 inch- and l/32 inch-thick bar specimens were evaluated
in flame retardant properties according to the Vertical Burning Test
described in "UL94-Standards For Safety", Underwriters Laboratories,
Inc., Second Revised Edition, May 2, 1975, pages 6-8. In accordance
with the evaluation technique of the aforementioned test, the speci-
mens were rated V-O, V-l, or V-2 with V-O indicating the greatest
degree of flame retardancy and V-2 indicating the poorest degree of
flame retardance. The Oxygen Index of a sample of injected molded
resin blend obtained from the Arburg Injection molding machine is
also determined.
The results of these experiments are reported in Table 4 below.
EXAMPLE 30
The procedure of Example 29 was repeated substantially as des-
cribed except that the amount of the halogen-free bisphenol polyester,
the halogen containing bisphenol polyester and the polyphenylene sul-
fide were 288 parts, 80 parts and 32 parts, respectively. The results
of this Example are also presented in Table 4 below.
EXAMPLE 31
A glass fiber filled polyester-polyphenylene sulfide blend was
prepared by charging 450 parts o-f the halogen-free bisphenol poly-
ester of Example l (A), 55.6 parts of the halogen-containing bisphenol
polyester of Example 28 and 50 parts of the polyphenylene sulfide oF
Example 2 to the Farrell Mill operated at the conditions described
in Example 29. The addition and milling procedure used was sub-
stantially that described in Example 29. The sheet of resin blendrecovered from the mill was ground to granules and dried substan-
tially as described in Example 29.
The dried granules were mixed with 61.7 parts of chopped glass
fiber (3/16 inch length, manufactured by Owens Corning Fiberglass
Corporation under the designation 419AA). The resultant mixture was
then added to an Arburg Alreounder 200 injection molding machine
operated at a barrel temperature of 590 F., a mold temperature of
210-220 F., and an injection pressure of about 18,000 psi.
~124~18
- 41 -
The mixture was molded as bar specimens which were subsequently
reground and dried substantially as described hereinabove to ensure
that a homogeneous mixture of the glass fibers with the resin blend
was obtained. The dried reground mixture was then charged to the
Arburg 221E/150 Injection molding machine (operated at a barrel tem-
perature of 580 F., at a mold temperature of 250 F., and an in-
jection pressure of about 20,000 psi) and molded as 5 inch x l/2
inch x 1/16 inch specimen bars as described in Example 29. As in
Example 29, a portion of the latter specimen bars were reserved for
glame retardant testing and the remainder were compression molded
to obtain 5 inch x l/2 inch x 1/32 inch bar specimens. Both the
1/16 inch and 1/32 inch bar samples were tested for flame retardance
as described in Example 29. The Oxygen Index of the product was also
determined as in Example 29. The results of this Example are reported
in Table 4 below.
EXAMPLE 32
The procedure of Example 31 was repeated substantially as des-
cribed except 63.0 parts of the glass filler was employed and ll parts
of antimony trioxide were added to the resin mixture in the Farrell
Mill following the addition of the polyphenylene sulfide. The re-
sultant molded product was tested for flame retardance substantially
as described in Example 29. The results of this Example are also
presented in Table 4 below.
EXAMPLES 33-45
In these Examples there were prepared and tested for flame re-
tardance compositions which were substantially comparable to those of
Examples 29, 31, and 32 except that one or more of the constituents
of the compositions described in the latter Examples were omitted.
Where glass fibers were present as a constituent in the compositions
of the present Examples, the preparatory procedure of Example 31
was employed substantially as described. Where antimony trioxide was
present as a constituent in the compositions of the present Examples,
918
- 42 -
the antimony compound addition procedure of Example 32 was followed
substantially as described. Where a glass constituent and an anti-
mony additive were not employed, the compositions of the present
Examples were prepared substantially as described in Example 29.
The results of these experiments are also presented in Table 4
below.
- ~124~18
- 43 -
_ In ~ I ~ N 1~
_ O . N N C~l t-
_ Ltl ~ I N I , ~ > O C
_ In n I u~ ol o' ~ ~_
Cl 1n o W 01 01 D C
~0" 0,, tO . ~ O C
tr NO 00 O . O N E
. ~ t~ ~0 0~, ~, ll 0, O, _~ _O
C ~ O n N N r O
_ _ O ~ Ir> t N N :7~ ~ ~
d ; t~ t~ ~t ) UO~ ~ ~ V ~ o
X _ , O~ N O L ~
V _ O . ~ ~ N ~ ~ L
t~ N O ~ O '~ O O O V V ~
x tO UO~ O O ~ ~ ~:1 L
~Oq t tO t ~ ~ ~ O O O ~O U C L
cn ~-- .a ~VI ICJ V D v O O N ~ tJ
L c. o ~ O c rO ~ .a tu ~ tu tu . t~ CJ ~:: ~ O
~ tO ~ L ,C cu c c~ v~. tu C ~ ~C . C ~ ' o c~
o _ ~ ~ ~ ~ _ _ _ !
',
~i
2~9~8
- 44 -
Of the Examples presented in foregoing Table 4, Control Examples
33, 36, 37, 43, 44 and 45 are identical to Control Examples 17, 19,
21, 25, 26 and 27, above, respectively (of the latter, Control Ex-
amples 17, 19 and 21 are equivalent to the earlier Control Examples
11, 13 and 12, respectively, as noted on page 35). Control Examples
34 and 35 are equivalent to Control Examples 18 and 20 above, re-
spectively, (which, in turn, are equivalent to the earlier illustra-
tive Examples 8 and 7, respectively, as noted on page 35). The data
of the earlier Examples 17, 18, 19, 20, 21, 25, 26 and 27 is pre-
sented in Table 3 above while the data of the earlier Examples 7, 8,
11, 12 and 13 is presented in Table 2 above.
The invention has been described in the above specification and
illustrated by reference to specific embodiments in the illustrative
examples. However it is to be understood that these embodiments are
not intended to limit the invention since, as illustrated, changes
and modifications in the specific details disclosed hereinabove can
be made without departing from the scope or spirit of the invention.
1~249~8
- 45 -
SUPPLEMENTARY DISCLOSURE
This disclosure and the Principal Disclosure are
concerned with blends of polyphenylene sulfides and linear
aromatic carboxylic polyesters.
Polyester molding compositionsof the invention
have improved hydrolytic stability. In addition to enhanced
resistance to hydrolytic degradation the blends of the
latter application are characterized by excellent molding
properties, i.e., the admixing of polyphenylene sulfide
with the polyester improves the processability of the poly-
ester, excellent tensile properties, excellent impact
strength and excellent electrical properties such as volume
resistivity, dielectric strength, dielectric constant, arc
resistance and dissipation factors.
It has now been found that when a blend of the
polyester and polyphenylene sulfide contains the con-
stituents in particular proportions within the originally
described ranges, the blend exhibits an unexpected, sub-
stantial enhancement in an important electrical property,
namely dielectric strength.
The invention particularly contemplates a thermo-
plastic polymeric composition comprising, in admixture, (a)
a linear aromatic polyester of components comprising a bis-
phenol and a dicarboxylic acid, and (b) a polyphenylene
sulfide present in a proportion of more than about 5 weight
percent to less than about 60 weight percent based on the
combined weight of said polyester and said polyphenylene
sulfide with the proviso that when particulate glass filler
-~ 7
llZ4918
- 46 -
is present in the composition, the proportion of said
glass is sufficient to provide a weight ratio of poly-
phenylene sulfide to the glass of at least about 1.5 to
1. The invention also contemplates molded articles
formed from the composition.
As is illustrated by the data set forth in
Tables 3, 4 and 5 below, these particular compositions,
within the described class of the Principal Disclosure
exhibit a substantial enhancement in dielectric strength.
The preferred aromatic polyesters of the
invention, are prepared from bisphenols and at least one
aromatic dicarboxylic acid, most preferably selected
from the group consisting of isophthalic acid, tere-
phthalic acid or mixtures thereof.
1 1124918
- 47 -
~ 5 i_
The preparation of polyphenylene sulfide is illustrated in U.S.
Patent 3,354,129, to Edmonds, Jr. et al., the disclosure of which is
incorporated herein by reference, wherein at least one polyhalo-
substituted cyclic compound is reacted with an alkali metal sulfide
in a polar organic solvent reaction medium. Suitable polyphenylene
sulfide compositions are ava;lable commercially under the trademark
RYTON of the Phillips Petroleum Company, and include compositions
I lo which are eithér unfilled, or filled with glass or some such con-
ventional material. Preferably, the polyphenylene sulfide component
has a melt flow index, measured at 600F. using a 5 Kg. weight and
a standard orifice, within the range of from about 40 to about 7000.
The novel resin compositions of the invention are suitably pre-
pared by blending the linear aromatic polyester with polyphenylene
sulfide. The blending or mixing process can be performed us;ng
conventional mixing equipment such as, for example, a~ anbury mixer,
I mixing rolls, kneader, screw extruder, or injection molding machine.
! Although the mixing ratio may vary depending on the physical pro-
erties desired in the resultant polymer blend, to achieve enhance-
ment of dielectric strength according to the invention, the poly-
! phenylene sulfide component is present in an amount of above about
¦ 5 weight percent to less than about 60 weight percent. Preferably,
the polyphenylene sulfide component is present in an amount of about
¦ 25 7 to less than about 45 weight percent and especially in an amount
I of about 8 to about 35 weight percent, the aforementioned proportions
of polyphenylene sulfide being based on the combined weight of the
polysulfide and the polyester present in the blend.
918
- 48 -
When the polyester of the blend is prepared by
the afore-mentioned solution polymerization technique, i.e.
by reaction of a diacid halide of a dicarboxylic acid with
a bisphenol, an especially good result is achieved in
employing in the blend about 10 to about 30 weight per-
cent of polyphenylene sulfide based on the combined weight
of the polysulfide and the polyester.
When the polyester of the blend is prepared by
the afore-mentioned preferred transesterification or melt
polymerization technique an especially good result is
achieved in accordance with the invention in employing
about 8 to about 25 weight percent of polyphenylene sul-
fide based on the combined weight of the polysulfide
and the polyester.
The novel polymer compositions of the invention
may also include various additives such as organic or
inorganic fillers, stabilizers, antistatic agents and
flame retardants.
D~
~249~3
- 49 -
Suitable halogen-containing flame retardant
agents are described in the Principal Disclosure.
The additive-containing resin mixture of the
invention may be prepared, if desired, by charging the
polyester and sulfide polymer with the additive to a con-
ventional mixing apparatus, such as a premix mixer, or
melt extruder. The resultant additive-containing com-
position can then be molded directly in an injection
molding apparatus or an extruder. The molded articles
thus formed have excellent hydrolytic stability and
tensile strength.
The fillers which may be employed in the
invention are preferably particulate fillers such as
particulate glass (e.g. chopped glass fiber, glass rovings,
glass microballoons or microspheres and pulverulent
glass) particulate clay, talc, mica, inorganic natural fibers,
synthetic organic fibers, alumina, graphite, silica, calcium
~Z4918
- 50 -
carbonate, carbon black, magnesia and the like. Generally such
fillers are added to reinforce the structural integrity of a polymer,
e.g. to inhibit sagging and/or to improve the tensile strength and
stiffness of the polymer composition and also to reduce shrinkage,
minimize crazing, lower material costs, impart color or opacity, and
improve the surface finish of the polymer composition. No filler
need be employed, but generally the amount of particulate filler
employed in the compositions of the invention is in the range of
about 5 to about 70 weight percent, preferably about 5 to about 40
weight percent and especially about 8 to about 30 weight percent
based on the combined weight of the polyester and the phenylene
sulfide polymer. The filler employed is preferably inorganic.
It is found that use as a filler of particulate glass, advanta-
geously glass fibers, is desirable in the composition of the invention
since the presence of the particulate glass filler further enhances
the fire retardancy of polymer mixture of the invention.
The presence of the particulate glass component in the com-
positions of the invention generally enhances the flame retardance
of the polyester-sulfide polymer blend to the extent that excellent
fire retardant performance is achieved even when the compositions are
molded in extremely thin sections, (e.g. of thicknesses less than
about l/16 of an inch). This excellent flame retardance performance
makes the glass filled compositions of the invention especially suit-
able for the fabrication of electrical components such as miniture
circuit boards and the like.
While the use of particulate glass as filler in the blend of
¦ the invention is generally desirable for enhancing the fire retar-
dancy of the blend, the use of particulate glass as filler generally
lowers the dielectric strength of the present polymer mixture. How-
ever it is found that when the proportion of the particulaté glass
filler in the blend is sufficient to provide a weight ratio of
particu1ete 91ass to polyphenylene sulfide ir the present blend of
!
11~4'3~8
at least about 1.5 to 1 and preferably at least about 1.8 to 1,
the dielectric strength of the blend is enhanced in accord with
the invention.
The glass filling, especially glass fiber filling, employed in
the invention preferably contains an organic coupling agent as very
thin coating on the glass particles. The coupling agent forms an
adhesive bridge between the glass and the polymer blend thereby
enhancing the strength properties of the filled polymer blend.
Typically, organic coupling agents employed in the art include tran-
sition metal complexes of unsaturated aliphatic acids such as meth-
acrylate chromic chloride complex as well as various organic silane
compounds including vinyl trichlorosilane, vinyl triethoxysilane,
gamma amino-propyl triethoxysilane, ally trichlorosilane resorcinol,
vinyltrimethoxysilane, amyltrimethoxysilane, phenyltriethoxysilane,
~-cyclohexylethyltrimethoxysilane, `n-methaacryloxypropyltrimethoxy-
silane, ~-iodopropyltrimethoxysilane, ~-chloropropyltrimethoxysilane,
~-chloroisobutyltriethoxysilane,`n-glycidoxypropyltrimethoxysilane,
N-~-aminoethyl-~-aminopropyltriethoxysilane, N-bis-(~-hydroxyethyl)-
~-aminopropyltriethoxysilane, and ~-(3,4-epoxycyclohexylethyltri-
methoxysilane.
Preferably the coupling agent employed with the glass filleraccording to the invention is a silane coupling agent.
Glass fillers are frequently manufactured and sold so as to
contain the coupling agent as a proprietary ingredient on the
surface of the glass. The coupling agents and their use with glass
I fillers are discussed in more detail in W. V. Titow and B. J. Lanaham,
¦ "Reinforced Thermoplastics", Halstead Press, 1975, p. 83-88 and L.
- Mascia, "The Role of Additives in Plastics", J. Wiley & Sons, 1974,
p. 89-91.
~D
.. .
` ~%49~8
- 52 -
It has also been found according to the invention that the
presence of antimony additives (such as metallic antimony and com-
pounds of ant;mony) is generally undesirable since the presence of
the antimony constituent generally is detrimental to the flame re-
tardance of the polymer m;xture as is illustrated in the examplesbelow.
Because of the enhanced dielectric strength achieved in the
~ blends of the invention, these blends are excellent electrical
; insulators, and as such, are particularly useful in manufacture
of electrical apparatus.
The following examples further illustrate the var;ous aspects
of the invention but are not intended to limit it. Various modifi-
cations can be made in the invention without departing from the
spirit and scope theréof. Where not otherwise specified in this
specification and claims, temperatures are given in degrees centi-
grade, and all parts and percentages are by weight.
q~24~18
- 53 -
EXAMPLES 46-48
In Examples 46 and 47, employing the blending
and molding techniques described in the Principal
Disclosure there were prepared blends of the polyphenylene
sulfide of Example 2 (i.e. RYT0~ V-l (trademark), manu-
factured by Phillips Petroleum Co.) and a bisphenol-A-
isophthalate-terephthalate polyester having about a 1:1
molar ratio of isophthalic and terephthalic acid residues
which was prepared by a solution polymerization technique
similar to that described in Example lA. The proportions
of the polyphenylene sulfide in the blends of Examples 46
and 47 were about 10 weight percent and about 20 weight per-
cent, respectively, based on the combined weight of the
sulfide polymer and the polyester.
In example 48, as a control, a sample of a bis-
phenol-A-isophthalate-terephthalate polyester of about a
1:1 molar ratio of terephthalic and isophthalic acid
residue which was also prepared by solution polymerization
was molded under substantially the same condition employed
in Examples 46 and 47.
Molded disc samples of about 1/8 inch thickness
of the product of Examples 46, 47 and 48 were tested under
the same conditions for short time dielectric strength,
step by step dielectric strength (employing-the test
methods for short time and step by step dielectric strength
described in ASTM D-149); the volume resistivity, arc
resistance, dielectric constant, and dissipation factor.
'i' "~' d .
,
~1~4918
_ 54 -
The afore-mentioned electrical properties of
the blends of Examples 46 and 47 and the polyester con-
trol of Example 48 are compared in Table 3 below with
the corresponding electrical properties of the polyphenylene
sulfide employed in preparing these blends. The afore-
mentioned dielectric strength of the latter polyphenylene
sulfide, according to the manufacturer of the "RYTON"*
series of polyphenylene sulfides is substantially the
same as the short time dielectric strength of a similar
polyphenylene sulfide, RYTON R-6, as determined by sub-
stantially the same testing method as that described
above. The latter dielectric strength is given in the
bulletin "Technical Information on RYTON Polyphenylene
Sulfide Resins - 100 - Properties --- Processing`' of
Phillips Petroleum Co., page 2, next to the last line.
trademark
..~ ~
J~2~918
_ 55_
_
r-
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C~ o o ~ ~
~ o o~ o~ I I I I I I I I I I
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U~ ~r) o V'
Q C~
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~ N O O O O O O
1~ OC~J ~t ~ ~ CO C~ ~ ~ O O O ~>
d~ C~ N ~O CO C~l ~ ~-
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t~ ~)
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C~ , ~
o ~ ~o o
a) o ^ o Q
tr)~ C~ ~ I~ ~ ~ E
1~1LLI ~ o ~Y~ X C_~
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D ~ O
c ~ ~ ~ O o ~ u~
o ~ I
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a) ~ . . ~ ~'> C ~ E X X X X X X
O a) a~ c u) co s : ~
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X ~ , ~ ~ ~ ~ ~ ~ O cn
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~ 49~8
_ 56 -
EXAMPLES 49-53
In Examples 49-53 blends of the polyester of
: Examples 46-48 and the polyphenylene sulfide of Examples
46-47 were prepared with various weight proportions of
the proprietary particulate glass filler of Example 7
employing a blending and molding technique substantially
similar to that described in Example 7.
The filled blends were tested for short time
dielectric strength and the other electrical properties
described in Examples 46-48 substantially as described
in the latter Examples. The results of these tests are
presented i~ Table 4 below.
-
18
-- 5 7
~o
~o
o X C~l N
C~l ~ D ~ 15~ LO O O O
~) O ~ C~J O O O ~ N ~ a~ t ~) ~ ~ O O O
u~ ~ ~ ~ oo ~ o c~ ~
D
. o
X O O O ,_ O
C~ O O O
v~ ~ O ~O ~ o o ~ ~ C~i ~ oo ~ ~ ~ ~ o o o
~t ~ ~
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X o~ 00 0O ~ O
O C~ ~ o 1~ ~ ~ '
~0 ~ t~ r~ CO N C~
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0
QJ ~ O
LLI ¦ O C-- ~) I~ 0~ C~l t~ ~ O D ~ ~ ~ O O O
J~ aJ Ir') ~ ~D ~ O ~ N ~D
CC ~ ~ ~t ~ .
_
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a) cn .
s a~
o~ >, ~
n
C
I a) .....
o ~ E cr
E ~o
~ ~) ~ O C S_ Q
< ~ ~ ~ a) o Q~ I
.. u~ ~ '- ~ E X X X X X X
a v, ~ ~ 07 ~ S
Q ~ ~ a) c _~ ~ o
r- ~ ~ C~ ~ ~n , s v~ S S ..
C a 4- Q ~ ~ ~ >, a~ C
. x ~ a~ ~ ~ >, ~ CJ) ~ ~ V) ~ ~ O
o v~ o ~ a) >
aJ c ~ c~ o ~ ~ a) s c n:~
o ~ ~ 3 o LL
.~ ~ ~n s ~ c ~ v~ C-- > o ~
o c ~ ~ Q o al o ~ E E ~ ~ I ~: J c
o ' ~ ~ O ~, o ~ .~ u. .~ ~ v~ ~ ~ o
~ ~ o o ~ c , ~ ~ ~ ~ ~ ~
.~ ~ c a ~ u o c~ o a~ a~ ~ Q
o~ = = ty Q ~ ~ ~ ~ aJ ~ E ~ ~ ~
n ~ ~ ~ ~ ~
E , . . ~ ~) ~ u.
o ~ ~ v ~ ~ o ,-
3 = = 3 3 Cl ~ ~ ~ c~
7"'~
~1249~8
-- 58 --
EXAMPLES 54- 5 8
In Examples 54-57 the procedure of Examples 46-
47 is repeated substantially as described in preparing
and molding polyester-polyphenylene sulfide blends contain-
ing 5%~ 10%~ 15% and 20% of the polyphenylene sulfide of
Example 2 ~ based on the combined weight of the polyester
and polyphenylene sulfide. As the polyester there was
employed a bisphenol-isophthalate-terephthalate polyester
having a molar ratio of isophthalate to terephthalate
residues of about 75/25 which was prepared by a melt, i.e.
transesterification, polymerization procedure similar to
that described in Example lB.
In Example 58 ~ as a control, a sample of the
above-described melt polymerization prepared polyester
which was employed in the foregoing blends was molded
under substantially the same molding conditions as were
employed in molding the blends of Examples 54-57.
The short time dielectric strength and other
electrical properties were determined for the compositions
of Examples 54-58 substantially in accord with the ~ro--
cedure in Examples 46-471 except that the dielectric
constant and dissipation factor were measured at lOHz
instead of at 60 Hz as in Examples 46-47, These results
are presented in Table 5 below.
~'
llZ4918
_ 59
_
o
u
_, o o o~ ~ ,... . . . .
0 O
U~ ,
~o
_ o
Ln Ln
C~
a~ . . x c~
o L~ C~l o
U~ CO ~ ,` ~ ~ ~ ~ o o
al ~ ~ o ~ ~ ~ o o o
>, o o , U~~o ~ ~ ~ ~ ~ ~ o o o
o ~ ~ C~ ,~ C~J ,~
Q U~ U-)Ir)
a)
O ~ ~D
., ~-
U~ ~ O
_~
t- ~ O O
qJ ~ ~ ~ X O O~ D C`~ ~ ~>
cn a~ ~ . O O
~ ~ r~a~ o o o o o
O ~ In Lr) ", ~, ~ ~ D C`l ~ C~i ~ ~ O O O
t~
a~ aJ
., ~=
~ Q D
a~ ~ o
~ O ~ ,_
O Q
. ~) X C~J ~- I~
. L~~ O
C ~ cn d t~ ~D CO ~ O O
~_ _ ~t cn o o o o o
U ~ U~ O O ~ i ~ ~ O o o
n ~ ,o n ~ ~ I~ oo ~ o~
LLI ~ ~
_I U ~ ~O
) N ~
" ~ ~ O
LL~ ~. ~ ~
E ~ X ~ 1~ ~n
~ >~ Ln . ~ oo C~ ~ o
s ~- ~ ~ oo~ o ~ O o o
oQ
d' ~ ~ Lo ~> o c~ o C~.l ~ ~ o o o
~ aJ
s aJ
~ :~ ~ ^ Q
S~ . ~ Q~
c ~ a~ ~ _
~1 ~ E ~n
a) ~ .~ N N N N N N
Q o ~ E O O O O o
~ o ~ ~ ~ ~ ,_ ~
< Q .. < , s ~? E x x X X X X
Q~ a~ n s
,_ ~ C _, ~ o
E a.) s s s A ~
a) .c~ ~ Q ~ ~ ~ al c <
., X ~ ~ ~ d O
0 2~ 0 ~ C C ~ ~ ~ ~>
. . ~ ~ a~ s ~ c .;s
O ~ ~ 4- r-- ~ ~ ~> 1.) ~n a) 3 O 1
c o o o ~ u) ~n ~ ~ c > o ~
o ~ ~~ ~ E~ E v~ O
., o o , , ~ u7 ,- .,
., ~ ~ ~ ~ ~ ~ v~ ~ ~
o o ~ o ~ ~ o ~ o E ~: ~ .-
~3 ~ 3
E o o al ~,-- o a~ ~"
o ~ , .-- o ~ --- .--
~) C~ Q O O ~ ~: O O
~i~4918
-- 60 --
Comparison of the short time dielectric strength data in Table
3 above indicates that the present blends of the polyphenylene sulfide
and the polyester are characterized by an unexpected synergistic
enhancement in short time dielectric strength compared to the poly-
ester and the polyphenylene sulfide components. As illustrative ofsaid enhancement the blend of Example 46 containing 90.7% by volume
of a polyester (comparable to a polyester of a short time dielectric
strength of 391 volts/mil) and 9.3% by volume of a phenylene sulfide
of a short time dielectric strength of 380 volts/mil would be expected
to have a short time dielectric strength of 391 ~0.907~ + 380 (0.093)=
390 volts/mil. However as shown in Table 3 the actual or measured
short time dielectric strength of the Example 46 is 613 volts/mil.
This is indicative that a substantial synergistic enhancement of
the dielectric strength is achieved by blending the polyester and the
polyphenylene sulfide in accordance with the invention.
By similar evaluation the blend of Example 47is calculated to
have an expected dielectric strength of 389 volts/mil, whereas the
data of Table 3 indicates the Example 47blend to have an actual short
time dielectric strength of 560 volts/mil. This result also indicates
a substantial synergistic enhancement in the aforementioned dielectric
strength property.
Comparison of the short time dielectric strength data of the
particulate glass filled blends of Table 4 with the corresponding
data of Table 3 indicates that the addition of particulate glass,
e.g. as a reinforcement filler, generally lowers the short time
dielectric strenght of the polyester-polyphenylene sulfide blend.
However, the aforementioned substantial enhancement of the short
time dielectric strength in accordance with the invention is
achieved when the weight ratio of polyphenylene sulfide component
to the particulate glass component in the blend is at least about
1.5:1, e.g. about 1.8:1 as in Example 51.
1~24~18
_ 61 -
Evaluation of the short time dielectric strength data in Table
5 in accord with the procedure illustrated above for the Table 3
data indicates that an unexpected synergistic enhancement in the
dielectric strength (corresponding to that described with respect
to the blends of Table 3) also is achieved in blends of melt poly-
merization-prep~red polyester and the polyphenylene sulfide which
contain more than about 5 weight percent of the latter component.
For example, the blend of Example 56containing 86~ by volume of
polyester of a short time dielectric strength of 468 volts/mil and
14 % by volume of the polyphenylene sulfide of a short time di-
electric strength of 380 volts/mil would be expected to have a short
time dielectric strength of 468 (0.86) + 380 (0.14) = 456 volts/
mil. However, as is seen from the Table 5 data, the measured short
time dielectric strength is 579 volts/mil indicative of an unexpected
synergistic enhancement in the aforementioned dielectric strength
property.
It will be appreciated by those skilled in the art that pro-
cedural modifications of the above-described experimental technique
can be made without departing from the spirit and scope of the in-
vention.
For example, in Example 7 a similar result providing a homo-
geneous glass filler-resin mixture can be obtained without the
necessity of regrinding the molded glass fiber-containing resin
product. In this alternative procedure the Farrell-Mill resin
product, after being ground to granules and dried, is added to the
hopper end of a screw resin extruder ~such as a Haake Polytest 45*
single screw extruder or a ~erner Pfleider ZDS-K2~ twin screw ex-
truder) while the particulate glass component is added downstream
on the extruder. (Alternatively, the particulate glass can be
mixed with the dried ground granules with the resultant mixture
being added to the hopper end of the extruder). The resultant
* trademark
~124918
- 62 -
extruder resin containing a homogeneous dispersion of the glass
component is then sliced into pellets which are then injection
molded as described in Examples 2 and 8.
Also, instead of separate addition of the particulate glass
constituent as described in Example 7, the latter constituent can be
homogeneously blended with the sulfide polymer constituent of the
resin blend before the said sulfide polymer is added to the polyester.
In place of the chopped glass fiber employed in the above
Examples, other forms of particulate glass filler agents such as
¦ 10 uncut glass strands, glass rovings, glass pellets, pulverulent glass,
and glass micro-balloons can be used.
