Polyester resin compositions

A polyester resin composition obtained by blending 60 to 99 parts by weight of a thermoplastic polyester resin (component A), 1 to 40 parts by weight of a polyorganosiloxane graft copolymer (component B) of 0.08 to 0.6 .mu.m in average particle size obtained by graft-polymerizing one or more kinds of vinyl monomer onto a compound rubber having such a structure that 1 to 99 wt. % of a polyorganosiloxane rubber component and 99 to 1 wt. % of a polyalkyl (meth)acrylate rubber component, the total amount of both the rubber components being 100 wt. %, have been inseparably entangled with each other, the total amount of the components A and B being 100 parts by weight, and 0.01 to 10 parts by weight of an organic silane compound having an epoxy group (component C). The polyester resing composition of the present invention is excellent in impact resistance, particularly impact strength at low temperatures, gives molded products having a good appearance, and also can be used under severer conditions and in a wider range than before.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a polyester resin composition which has 
been improved in impact resistance, particularly impact resistance at low 
temperatures while maintaining its mechanical properties such as strength, 
stiffness and the like, and also which gives molded products having 
excellent appearance. 
2. Description of the Related Art 
Hitherto, there have been proposed many methods for improving the 
mechanical properties (e.g. impact resistance) of thermoplastic polyester 
resins. Among these, a method of blending a polyester and an 
.alpha.-olefin/glycidyl methacrylate/vinyl acetate copolymer, described in 
Japanese Patent Application Kokoku No. 58-47419 and U.S. Pat. No. 
4,172,859, is a relatively excellent method. Also, the present applicants 
disclosed a method of adding a polyorganosiloxane graft copolymer to a 
polyester in Japanese Patent Application Kokai No. 2-150446. These methods 
are both relatively good, but their improvement in impact strength is 
still insufficient. Further, the present applicants proposed a method of 
adding a particular polyorganosiloxane rubber and a particular organic 
silane compound to a polyester in EP-A2-393,616. This method is in a 
satisfactory level in terms of development of impact strength, but there 
still remains a problem that the appearance of molded products obtained 
therefrom is poor. 
SUMMARY OF THE INVENTION 
In view of the situation mentioned above, the present inventors have 
extensively studied to obtain a polyester resin in which the impact 
resistance of a thermoplastic polyester resin has been improved over a 
wider range of temperature, and besides which gives molded products having 
excellent appearance. As a result, the present inventors have found that 
by blending a thermoplastic polyester resin with a polyorganosiloxane 
graft copolymer obtained by graft-polymerizing a vinyl monomer onto a 
compound rubber comprising a polyorganosiloxane rubber and a polyalkyl 
(meth)acrylate rubber and an organic silane compound containing an epoxy 
group, a resin composition having an improved impact resistance over a 
wide temperature range and also giving molded products having excellent 
appearance, can be obtained. The present inventors thus achieved the 
present invention. 
The present invention comprises a polyester resin composition obtained by 
blending 
99 to 60 parts by weight of a thermoplastic polyester resin (component A), 
1 to 40 parts by weight of a polyorganosiloxane graft copolymer (component 
B) of 0.08 to 0.6 .mu.m in average particle size obtained by 
graft-polymerizing one or more kinds of vinyl monomer onto a compound 
rubber having such a structure that 1 to 99 wt. % of a polyorganosiloxane 
rubber component and 99 to 1 wt. % of a polyalkyl (meth)acrylate rubber 
component, the total amount of both the rubber components being 100 wt. %, 
have been inseparably entangled with each other, the total amount of the 
components A and B being 100 parts by weight, and 
0.01 to 10 parts by weight of an organic silane compound having an epoxy 
group (component C). 
The polyester resin composition of the present invention is excellent in 
impact resistance, particularly impact strength at low temperatures, gives 
molded products having a good appearance, and also can be used under 
severer conditions and in a wider range than before. 
To this polyester resin composition may be added if necessary a reinforcing 
filler (component D) as an additional component in amounts of 10 to 300 
wt. % based on the total amount of the components A, B and C.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The thermoplastic polyester resin (A) used in the present invention refers 
to one comprising, as a main constituent, 
(a) an aromatic polyester formed from an aromatic dicarboxylic acid, a 
dihydric phenol and a lower aliphatic diol or alicyclic diol, 
(b) an aromatic polyester formed from an aromatic hydroxycarboxylic acid or 
(c) a copolymer of the above-mentioned (a) and (b). 
The aromatic dicarboxylic acid used in the present invention is represented 
by the formula, 
EQU HO--CO--R.sup.1 --CO--OH 
wherein R.sup.1 represents a substituted or unsubstituted phenylene group, 
a group represented by the formula, 
##STR1## 
(in which Z represents a direct bond, --CH.sub.2 -- or --CO--) or a 
naphthylene group. The substituent of the phenylene group includes for 
example chlorine, bromine, a methyl group and the like, and the phenylene 
group may be substituted with one to four of these substituents. Examples 
of this aromatic dicarboxylic acid include for example terephthalic acid, 
isophthalic acid, biphenyl-3,3'-dicarboxylic acid, 
biphenyl-4,4'-dicarboxylic acid, diphenylmethane-m,m'-dicarboxylic acid, 
diphenylmethane-p,p'-dicarboxylic acid, benzo-phenone-4,4'-dicarboxylic 
acid, naphthalenedicarboxylic acid and the like. These aromatic 
dicarboxylic acids may be used alone or in mixture of two or more of them. 
Further, a small amount of an aliphatic dicarboxylic acid such as adipic 
acid, sebacic acid or the like may be used together. 
The dihydric phenol includes for example hydroquinone, resorcinol, 
dihydroxynaphthalene, biphenyldiol, 1,8-dihydroxyanthraquinone and a 
dihydric phenol represented by the formula, 
##STR2## 
wherein R.sup.2 represents an oxygen atom, a sulfur atom, CO, SO.sub.2 or 
an alkylene group having 5 or less carbon atoms which may be substituted 
with a halogen. 
This dihydric phenol includes for example 2,2-bis(4-hydroxphenyl)-propane 
(bisphenol A), 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl 
ether, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 
4,4'-dihydroxydiphenylmethane, 1,1-bis(4-hydroxyphenyl)ethane, 
1,1-bis(4-hydroxyphenyl)butane, 
1,1-bis(4-hydroxyphenyl)-2,2,2-trichloroethane and the like. These 
dihydric phenols may be used alone or in mixture of two or more of them. 
The lower aliphatic diol refers to an alkylenediol having 2 to 6 carbon 
atoms. Its examples include ethylene glycol, propylene glycol, 
1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol and the like. The 
alicyclic diol includes cyclohexanediol, cyclohexanedimethanol and the 
like. These diols may be used alone or in mixture of two or more of them. 
The aromatic hydroxycarboxylic acid used in the present invention is 
represented by the formula, 
EQU HO--R.sup.3 --COOH 
wherein R.sup.3 represents a phenylene group, a group represented by the 
formula, 
##STR3## 
(in which X represents a direct bond, an oxygen atom or an alkylene group 
having 5 or less carbon atoms) or a naphthylene group. 
Examples of such the aromatic hydroxycarboxylic acid include 
m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 
2-(4-hydroxyphenyl)-2-(4'-carboxyphenyl)propane, 
4-hydroxyphenyl-4'-carboxyphenyl ether and the like. These aromatic 
hydroxycarboxylic acids may be used alone or in mixture of two or more of 
them. 
Among thermoplastic polyesters obtained from these dicarboxylic acids, 
diols and hydroxycarboxylic acids, particularly polyethylene 
terephthalate, polybutylene terephthalate and 
poly(1,4-cyclohexylene-dimethylene terephthalate) clearly exhibit the 
effect of the present invention. 
The polyorganosiloxane graft copolymer (B) used in the present invention 
refers to a graft copolymer [hereinafter referred to as graft copolymer 
(B)] obtained by graft-polymerizing one or more kinds of vinyl monomer 
onto a compound rubber composed of 1 to 99 wt. % of a polyorganosiloxane 
rubber component and 99 to 1 wt. % of a polyalkyl (meth)acrylate rubber 
component, the total amount of both the rubber components being 100 wt. %, 
and having such a structure that both the rubber components have been 
entangled with each other and are substantially inseparable from each 
other. 
If either one of the polyorganosiloxane rubber component or polyalkyl 
(meth)acrylate rubber component, or a simple mixture of the both is used 
as a rubber source in place of the above compound rubber, the resin 
composition of the present invention is not obtained. Resin compositions 
giving excellent impact resistance and molded products having excellent 
surface appearance can be obtained only by using the compound rubber in 
which the polyorganosiloxane rubber component and the polyalkyl 
(meth)acrylate rubber component have been entangled and united with each 
other. 
When the amount of the polyorganosiloxane rubber component constituting the 
compound rubber exceeds 99 wt. %, the resin composition obtained gives 
molded products having a bad surface appearance. When the amount of the 
polyalkyl (meth)acrylate rubber component exceeds 99 wt. %, the resin 
composition obtained gives molded products having a bad impact resistance. 
Because of this, the amount of any one of the rubber components 
constituting the compound rubber needs to be 1 to 99 wt. %, provided that 
the total amount of the rubber components is 100 wt. %. More preferably, 
the amount is in a range of 10 to 90 wt. %. Further, it is desirable that 
the average particle size of the compound rubber is in a range of 0.08 to 
0.6 .mu.m. 
For producing the compound rubber having such an average particle size, the 
emulsion polymerization method is most suitable. Firstly, the latex of the 
polyorganosiloxane rubber is prepared, and then materials for synthesizing 
the alkyl (meth)acrylate rubber are polymerized in the presence of the 
polyorganosiloxane rubber. That is, it is desirable to swell the 
polyorganosiloxane rubber particles with the materials for synthesizing 
the alkyl (meth)acrylate rubber and then polymerize the materials. 
The polyorganosiloxane rubber component constituting the compound rubber 
can be prepared by emulsion-polymerizing the following organosiloxane and 
crosslinking agent for the polyorganosiloxane rubber [hereinafter referred 
to as crosslinking agent (I)]. In this case, a graft-linking agent for the 
polyorganosiloxane rubber [hereinafter referred to as graft-linking agent 
(I)] may be used together. 
As the organosiloxane, there are given various three or more-membered 
cyclic organosiloxanes, among which three to six-membered ones are 
preferably used. Examples of such the cyclic organosiloxane include 
hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, 
decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, 
trimethyltriphenylcyclotrisiloxane, 
tetramethyltetraphenylcyclotetrasiloxane, octaphenylcyclotetrasiloxane and 
the like. These cyclic organosiloxanes may be used alone or in mixture of 
two or more of them. The amount of these cyclic organosiloxanes used is 
preferably 50 wt. % or more, more preferably 70 wt. % or more of the 
polyorganosiloxane rubber component. 
As the crosslinking agent (I), trialkoxysilanes or tetraalkoxysilanes are 
used. Specific examples of these tri- or tetraalkoxysilanes include 
triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, 
tetra-n-propoxysilane, tetrabutoxysilane and the like. Among these, 
tetraalkoxysilanes are preferred, and tetraethoxysilane is particularly 
preferred. The amount of the cross-linking agnet (I) used is 0.1 to 30 wt. 
% of the polyorganosiloxane rubber component. 
The graft-linking agent (I) refers to a monomer having both of the 
following functional groups, one of them being a functional group which 
acts to incorporate the agent (I) polymerized together at the step of 
preparation of the polyorganosiloxane rubber by polymerization into the 
structure of the resulting rubber, i.e. an alkoxy group attached to a 
silicon atom, and the other of them being a functional group which does 
not react at the above step, but reacts at the subsequent step in which 
the polyalkyl (meth)acrylate rubber is prepared by polymerization in the 
presence of the polyorganosiloxane rubber, to form a graft bond between 
the polyalkyl (meth)acrylate rubber and the polyorganosiloxane rubber, 
there being given for example a C.dbd.C unsaturated bond, a mercapto group 
and the like. 
As such the graft-linking agent (I), compounds which can form an 
organosiloxane unit represented by either one of the formulae (I), (II), 
(III) and (IV) are used: 
##STR4## 
wherein R.sup.4 represents a methyl, ethyl, propyl or phenyl group, 
R.sup.5 represents a hydrogen atom or a methyl group, n represents an 
integer of 0, 1 or 2, and p represents an integer of 1 to 6. 
(Meth)acryloyloxysiloxane which can form the unit of the formula (I) has a 
high grafting efficiency which makes it possible to form effective graft 
chains, so that it is advantageous in terms of development of impact 
resistance. Of those which can form the unit of the formula (I), 
methacryloyloxysiloxane is particularly preferred. Specific examples 
thereof include .beta.-methacryloyloxyethyldimethoxymethylsilane 
.gamma.-methacryloyloxypropylmethoxydimethylsilane, 
.gamma.-methacryloyloxyproplydimethoxymethylsilane, 
.gamma.-methacryloyloxypropyltrimethoxysilane, 
.gamma.-methacryloyloxypropylethoxydiethylsilane, 
.gamma.-methacryloyloxypropyldiethoxymethylsilane, 
.delta.-methacryloyloxybutyldiethoxymeyhylsilane and the like. The amount 
of the graft-linking agent (I) used is 0 to 10 wt. % of the 
polyorganosiloxane rubber component. 
For preparing the polyorganosiloxane rubber component by polymerization, 
methods described, for example, in U.S. Pat. Nos. 2,891,920, 3,294,725, 
etc. can be used. 
In the present invention, it is preferred to produce the polyorganosiloxane 
rubber, for example, by the method in which a mixed solution of 
organosiloxane, the graft-linking agent (I) and the crosslinking agent (I) 
is shear-mixed with water using, for example, a homogenizer in the 
presence of a sulfonic acid emulsifier such as an alkylbenzenesulfonic 
acid, an alkylsulfonic acid or the like. The alkylbenzenesulfonic acid is 
desirable because it acts as an emulsifier for organosiloxane and at the 
same time acts as a polymerization initiator. In this case, it is 
preferred to use the metal salt of the alkylbenzenesulfonic acid or 
alkylsulfonic acid together with the above sulfonic acid because the metal 
salt has an effect to keep the polymer stable during the graft 
polymerization. 
The polyalkyl (meth)acrylate rubber component constituting the compound 
rubber can be synthesized using the following alkyl (meth)acrylate, 
crosslinking agent for the polyalkyl (meth)acrylate rubber [(hereinafter 
referred to as crosslinking agent (II)] and graft-linking agent for the 
same [hereinafter referred to as graft-linking agent (II)]. 
The alkyl (meth)acrylate includes alkyl acrylates (e.g. methyl acrylate, 
ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl 
acrylate) and alkyl methacrylates (e.g. hexyl methacrylate, 2-ethylhexyl 
methacrylate, n-lauryl methacrylate). Particularly, n-butyl acrylate is 
preferred. 
As the crosslinking agent (II), there are given for example ethylene glycol 
dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol 
dimethacrylate, 1,4-butylene glycol dimethacrylate and the like. 
The graft-linking agent (II) refers to a monomer having both of the 
following functional groups, one of them being a functional group which 
acts to incorporate the agent (II) polymerized together at the step of 
preparation of the polyalkyl (meth)acrylate rubber by polymerization into 
the structure of the resulting rubber, and the other of them being a 
functional group which remains unreacted at the above step, but reacts at 
the subsequent step in which the vinyl monomer is polymerized in the 
presence of the compound rubber, to form a graft chain to the compound 
rubber. In other words, the graft-linking agent (II) refers to a monomer 
having a plural number of polymerizable functional groups different in 
reactivity. 
Such the graft-linking agent (II) include for example allyl methacrylate, 
triallyl cyanurate, triallyl isocyanurate and the like. Allyl methacrylate 
can also be used as the crosslinking agent (II). Any of these crosslinking 
agent (II) and graft-linking agent (II) is used alone or in mixture of two 
or more of them. The amount of any one of these crosslinking agnet (II) 
and graft-linking agent (II) used is 0.1 to 10 wt. % of the polyalkyl 
(meth)acrylate rubber component. When allyl methacrylate is used as both 
the crosslinking agent (II) and the graft-linking agent (II), it will 
suffice to use it in an amount of 0.2 to 20 wt. %. 
For preparing the polyalkyl (meth)acrylate rubber component by 
polymerization, the above alkyl (meth)acrylate, crosslinking agent (II) 
and graft-linking agent (II) are added to the latex of the 
polyorganosiloxane rubber component previously neutralized by adding the 
aqueous solution of an alkali (e.g. sodium hydroxide, potassium hydroxide, 
sodium carbonate), thereby swelling the polyorganosiloxane rubber 
particles with these components and then these components are polymerized 
by the action of a common radical polymerization initiator. With the 
progress of the polymerization, the crosslinked network of the polyalkyl 
(meth)acrylate rubber entangled with that of the polyorganosiloxane rubber 
is formed at the interface of both the rubbers. Thus, a compound rubber 
particle comprising the polyorganosiloxane rubber component and the 
polyalkyl (meth)acrylate rubber component which are substantially 
inseparable from each other, is obtained. 
The compound rubber thus produced by emulsion polymerization can be 
graft-copolymerized with a vinyl monomer. Also, the polyorganosiloxane 
rubber component and the polyalkyl (meth)acrylate rubber component have 
been strongly entangled with each other, so that they cannot be extracted 
to separate from each other with usual organic solvents such as acetone, 
toluene and the like. On extracting this compound rubber with toluene at 
100.degree. C. for 12 hours, its gel content is 80 wt. % or more. 
As the vinyl monomer to be graft-polymerized onto this compound rubber, 
there are given various vinyl monomers such as aromatic vinyl compounds 
(e.g. styrene, .alpha.-methylstyrene), (meth)acrylates (e.g. methyl 
methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate, 
butyl acrylate), vinyl cyanide compounds (e.g. acrylonitrile, 
methacrylonitrile) and the like. These monomers are used alone or in 
combination of two or more of them. Of these vinyl monomers, 
(meth)acrylates are preferred, and methyl methacrylate is particularly 
preferred. 
Referring to the proportion of the above vinyl monomer and compound rubber, 
the compound rubber is preferably 30 to 95 wt. % based on the weight of 
the graft copolymer (B), and the vinyl monomer is preferably 5 to 70 wt. % 
based on the same. More preferably, the compound rubber is 70 to 95 wt. %, 
and the vinyl monomer is 5 to 30 wt. %. When the proportion of the vinyl 
monomer is less than 5 wt. %, the dispersion of the graft copolymer (B) in 
the resin composition is not sufficient, and when it exceeds 70 wt. %, the 
development of impact strength lowers, so that such the proportions are 
not preferred. 
The latex of the graft copolymer (B) can be obtained by one-stage or 
multi-stage polymerization of the above vinyl monomer by the radical 
polymerization technique. The average particle size of the graft copolymer 
(B) particle in the latex needs to be in a range of 0.08 to 0.6 .mu.m. 
When the average particle size is less than 0.08 .mu.m, the resin 
composition obtained gives molded products having a poor impact 
resistance, and when it exceeds 0.6 .mu.m, the surface appearance of the 
molded products becomes poor. 
From the latex of the graft copolymer (B) thus obtained can be separated 
and recovered the graft copolymer (B) by pouring the latex into a hot 
water in which a metal salt (e.g. calcium chloride, magnesium sulfate) has 
been dissolved, to salt-out and coagulate the graft copolymer (B). 
The organic silane compound having an epoxy group (C) used in the present 
invention refers to a mixture of one or more compounds represented by the 
formula (V), 
##STR5## 
wherein m represents an integer of 1 to 3, R.sup.6 represents a direct 
bond or an alkylene group having 1 to 3 carbon atoms, R.sup.7 represents a 
methyl or ethyl group, and Y and Z are groups represented below, 
##STR6## 
(in which R.sup.8 represents an alkylene group having 1 to 3 carbon atoms, 
and R.sup.9 represents a methyl or ethyl group). 
As specific examples of these organic silane compounds having an epoxy 
group, there are given .gamma.-glycidoxypropyltrimethoxysilane, 
.gamma.-gylcidoxypropylmethyldiethoxysilane, 
.beta.-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and the like. 
The polyester resin composition of the present invention is obtained by 
blending 60 to 99 parts by weight of the thermoplastic polyester resin 
(component A), 1 to 40 parts by weight of the graft copolymer (component 
B), the total amount of the components A and B being 100 parts by weight, 
and 0.01 to 10 parts by weight of the organic silane compound having an 
epoxy group (component C). When the amount of the component B blended is 
less than 1 part by weight, development of the impact strength tends to 
become insufficient, and when it exceeds 40 parts by weight, the heat 
resistance tends to lower, so that such the amounts are not preferred. 
Further, when the amount of the component C based on 100 parts by weight 
of the total amount of the components A and B is less than 0.01 part by 
weight, development of the impact strength tends to become insufficient, 
and when it exceeds 10 parts by weight, the flowability is adversely 
affected, so that such the amounts are not preferred. 
If desired, into the polyester resin composition of the present invention 
may be incorporated a reinforcing filler (component D) in an amount of 10 
to 300 wt. % based on the total amount of the components A, B and C. The 
reinforcing filler includes fibrous reinforcing fillers such as glass 
fibers, carbon fibers, potassium titanate, asbestos, silicon carbide, 
ceramics fibers, metal fibers, silicon nitride, aramide fibers, etc.; and 
granular reinforcing fillers such as barium sulfate, calcium sulfate, 
kaolin, clay, pyrophyllite, bentonite, sericite, zeolite, mica, nepheline 
syenite, talc, attapulgite, wollastonite, PMF, ferrite, calcium silicate, 
calcium carbonate, magnesium carbonate, dolomite, antimony trioxide, zinc 
oxide, titanium oxide, magnesium oxide, iron oxide, molybdenum disulfide, 
graphite, gypsum, glass beads, glass balloons, quartz powders, etc. By 
incorporating the reinforcing fillers, the mechanical strength can further 
be improved. When these reinforcing fillers are blended, known silane 
coupling agents can be used. 
If necessary, into the polyester resin composition of the present invention 
may further be incorporated dyes, pigments, stabilizers to light and heat, 
known flame retardants (e.g. brominated epoxy, brominated polycarbonate, 
decabromodiphenyl ether, antimony oxide), crystal-nucleating agents, 
various modifiers, mold-release agents (e.g. waxes) and the like. 
The present invention will be illustrated specifically with reference to 
the following examples. In the examples, all parts are by weight. 
Various physical properties in the examples and comparative examples were 
measured by the following methods. Izod impact strength: 
According to the method described in ASTM D 256 1/8" in thickness, notched. 
Appearance: 
Evaluated by visual assessment. 
.largecircle.: Good 
.times.: Pearly luster is present or surface smoothness is bad. 
REFERENTIAL EXAMPLE 1 
Preparation of graft copolymer S-1 
Two parts of tetraethoxysilane, 0.5 part of 
.gamma.-methacryloyloxypropyldimethoxymethylsilane and 97.5 parts of 
octamethylcyclotetrasiloxane were mixed to obtain 100 parts of a siloxane 
mixture. One part of sodium dodecylbenzenesulfonate and 1 part of 
dodecylbenzenesulfonic acid were dissolved in 200 parts of distilled 
water, and the resulting solution was added to 100 parts of the above 
siloxane mixture. The resulting mixture was preliminarily stirred at 
10,000 rpm with a homomixer and then emulsified and dispersed with a 
homogenizer under a pressure of 300 kg/cm.sup.2 to obtain an 
organosiloxane latex. This mixed solution was transferred to a separable 
flask equipped with a condenser and a stirring blade, and heated at 
80.degree. C. for 5 hours with stirring and mixing and then allowed to 
stand at 20.degree. C. for 48 hours. Thereafter, this latex was 
neutralized to a pH of 7.0 with an aqueous sodium hydroxide solution to 
complete polymerization. Thus, a polyorganosiloxane rubber latex was 
obtained (hereinafter referred to as PDMS-1). The conversion of the 
siloxane mixture to the polyorganosiloxane rubber was 89.7%, and the 
number average particle size of the polyorganosiloxane rubber was 0.16 
.mu.m. 
Thirty three parts of this PDMS-1 was sampled and put in a separable flask 
equipped with a stirrer. After 267 parts of distilled water was added 
thereto and the atmosphere of the flask was replaced by nitrogen, the 
contents of the flask were heated to 50.degree. C. At this temperature, a 
mixed solution of 80 parts of n-butyl acrylate, 1.6 parts of allyl 
methacrylate and 0.192 part of tert-butylhydroperoxide was added to allow 
this mixed solution to soak into the polyorganosiloxane rubber particles. 
Thereafter, a mixed solution of 0.001 part of ferrous sulfate, 0.003 part 
of disodium ethylenediaminetetraacetate, 0.24 part of Rongalite and 10 
parts of distilled water was added, and radical polymerization was carried 
out at an inner temperature of 70.degree. C. for 2 hours to complete the 
polymerization. Thus, the polyorganosiloxane compound rubber latex was 
obtained. 
To this compound rubber latex was added a mixed solution of 10 parts of 
methyl methacrylate and 0.024 part of tert-butylhydroperoxide, and graft 
polymerization onto the compound rubber was carried out while maintaining 
the inner temperature at 70.degree. C. for 4 hours. The conversion of 
methyl methacrylate was 97.5%, and the average particle size of the graft 
copolymer latex was 0.20 .mu.m. This latex was dropwise added to 600 parts 
of hot water containing 1.5 wt. % of calcium chloride, and the coagulated 
product obtained was separated, repeatedly washed with water and dried at 
80.degree. C. for 24 hours to obtain 97.7 parts of the dry powder of S-1. 
REFERENTIAL EXAMPLES 2 to 7 
Preparation of Graft Copolymers S-2 to S-7 
Graft copolymers S-2 to S-7 were produced in the same manner as in 
Referential Example 1 except that the conditions were changed as shown in 
Table 1. The physical properties of these graft copolymers are shown 
together in Table 1. 
REFERENTIAL EXAMPLE 8 
Preparation of Graft Copolymer S-8 
Two hundreds parts of distilled water and 1 part of sodium 
dodecylbenzenesulfonate were added to a separable flask equipped with a 
stirrer. After the atmosphere of the flask was replaced by nitrogen, 88.2 
parts of n-butyl acrylate, 1.8 parts of allyl methacrylate and 0.2 part of 
tert-butylhydroperoxide were added. Thereafter, the contents of the flask 
was heated to 50.degree. C., and at this temperature, a mixed solution of 
0.001 part of ferrous sulfate, 0.003 part of disodium 
ethylenediaminetetraacetate, 0.24 part of Rongalite and 10 parts of 
distilled water was added, and radical polymerization was carried out at 
an inner temperature of 70.degree. C. for 1 hour. Thereafter, a mixed 
solution of 10 parts of methyl methacrylate and 0.24 part of 
tert-butylhydroperoxide was added thereto, and the inner temperature was 
kept at 70.degree. C. for 3 hours to complete the polymerization. 
Coagulation and drying were carried out in the same manner as in 
Referential Example 1 to obtain 97.9 parts of a graft copolymer dry powder 
(S-8). The average particle size of the latex was 0.18 .mu.m, and the 
conversion of methyl methacrylate was 98.1%. 
TABLE 1 
__________________________________________________________________________ 
Referential Example No. 
2 3 4 5 6 7 
__________________________________________________________________________ 
Polyorganosiloxane rubber latex 
100 150 200 267 133 117 
(part) 
Distilled water (part) 
220 185 150 103 197 208 
n-Butyl acrylate (part) 
60 45 30 10 40 35 
Allyl methyacrylate (part) 
1.2 0.9 0.6 0.2 0.8 0.7 
Methyl methacrylate (part) 
10 10 10 10 20 30 
Conversion of methyl methacrylate 
97.8 
98.3 
97.1 
96.9 
98.0 
98.1 
(%) 
Average particle size of the graft 
0.20 
0.19 
0.18 
0.18 
0.19 
0.19 
copolymer latex (.mu.m) 
Yield of the graft copolymer dry 
96.3 
97.4 
96.9 
97.1 
96.5 
97.2 
powder (part) 
__________________________________________________________________________ 
REFERENTIAL EXAMPLE 9 
One hundred and ninety four parts of dimethyl terephthalate, 288 parts of 
1,4-cyclohexanedimethanol and 0.1 part of tetrabutoxytitanium were charged 
into a stainless steel reactor, and heated to 200.degree. C. with 
stirring. After methanol was completely distilled out of the reactor, the 
temperature was raised to 270.degree. C., and the pressure in the reactor 
was reduced to 1 mmHg. After further raising the temperature to 
300.degree. C. in 1 hour, the pressure was returned to normal pressure 
with nitrogen to obtain polycyclohexyldimethylene terephthalate (PCT). The 
melting point of the resulting polymer was 290.degree. to 300.degree. C., 
and the intrinsic viscosity thereof was 0.8. 
EXAMPLES 1 to 17 
Using as a thermoplastic polyester resin, polybutylene terephthalate (trade 
name, Tufpet PBTN-1000; produced by Mitsubishi Rayon Co., Ltd.), 
polyethylene terephthalate (trade name, Dianite PA-210; produced by 
Mitsubishi Rayon Co., Ltd.) and polycyclohexyldimethylene terephthalate 
obtained in Referential Example 9, the above thermoplastic polyester 
resins, the polyorganosiloxane graft copolymers S-1 to S-7 obtained in 
Referential Examples 1 to 7 and organic silane compounds were blended in 
proportions shown in Table 3. Each blend was pelletized on a twin-screw 
extruder (TEM-35B produced by Toshiba Machine Co., Ltd.) at a cylinder 
temperature of 240.degree. C. The pellets obtained were dried and molded 
into test pieces on an injection molding machine (Promat injection molding 
machine produced by Sumitomo Heavy Industries, Ltd.) at a cylinder 
temperature of 240.degree. C. and a mold temperature of 80.degree. C. 
Impact resistance was then evaluated using the test pieces. The results 
are shown in Table 2. 
TABLE 2 
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Example No. 1 2 3 4 5 6 7 
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Graft copolymer (B) 
Kind S-1 S-2 S-3 S-4 S-5 S-6 S-7 
Amount (part) 
20 20 20 20 20 20 20 
Polyester Kind PBT PBT PBT PBT PBT PBT PBT 
Amount (part) 
80 80 80 80 80 80 80 
Organic silane 
Kind (a) (a) (a) (a) (a) (a) (a) 
compound Amount (part) 
1 1 1 1 1 1 1 
Izod impact strength (1/8" in 
thickness, notched), (kg .multidot. cm/cm) 
23.degree. C. 106 101 99 86 85 85 85 
-20.degree. C. 100 97 95 81 80 80 79 
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Example No. 8 9 10 11 12 13 14 15 16 17 
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Graft copolymer (B) 
Kind S-1 
S-1 
S-1 
S-1 
S-1 
S-1 
S-1 
S-1 
S-1 
S-1 
Amount (part) 
5 10 30 
20 20 
20 
20 20 20 20 
Polyester Kind PBT 
PBT 
PBT 
PBT 
PBT 
PBT 
PBT 
PBT 
PET 
PCT 
Amount (part) 
90 90 70 80 80 
80 
80 80 80 80 
Organic silane 
Kind (a) 
(a) 
(a) 
(a) 
(a) 
(a) 
(b) 
(c) 
(a) 
(a) 
compound Amount (part) 
1 1 1 0.5 
2 5 1 1 1 1 
Izod impact strength (1/8" in 
thickness, notched), (kg .multidot. cm/cm) 
23.degree. C. 35 50 110 
90 107 
107 
105 
103 
65 50 
-20.degree. C. 30 44 102 
85 100 
100 
99 98 50 39 
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Note: 
PBT: Polybutylene terephthalate 
PET: Polyethylene terephthalate 
PCT: Polycyclohexyldimethylene terephthalate 
(a): Glycidoxypropyltrimethoxysilane ("KBM 403" produced by ShinEtsu 
Chemical Co., Ltd.) 
(b): Glycidoxypropylmethyldiethoxysilane ("KBE 402" produced by ShinEtsu 
Chemical Co., Ltd.) 
(c): (3,4-epoxycyclohexyl)ethyltrimethoxysilane ("KBM 303" produced by 
ShinEtsu Chemical Co., Ltd.) 
TABLE 3 
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Comparative Example No. 
1 2 3 4 5 6 7 8 9 10 
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Graft copolymer (B) 
Kind S-1 PDMS-1 
S-1 
S-1 Ethylene/glycidyl 
S-8 
Amount (part) 
-- 20 -- 20 20 20 -- -- methacrylate copolymer, 
20 
Polyester Kind PBT 
PBT 
PBT 
PBT PBT 
PBT 
PET 
PCT 
PBT PBT 
Amount (part) 
100 
80 100 
80 80 80 100 
100 
80 80 
Organic silane 
Kind (a) 
(a) (d) 
(e) (a) 
Compound Amount (part) 
-- -- 1 1 1 1 -- -- -- 1 
Izod impact strength (1/8" in 
thickness, notched) (kg .multidot. cm/cm) 
23.degree. C. 4 37 5 27 35 33 3 3 84 34 
-20.degree. C. 3 25 3 22 27 25 2 2 42 21 
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Note: 
(a): Glycidoxypropyltrimethoxysilane ("KBM 403" produced by ShinEtsu 
Chemical Co., Ltd.) 
(d): Mercaptopropyltrimethoxysilane ("KBM 803" produced by ShinEtsu 
Chemical Co., Ltd.) 
(c): Aminopropyltrimethoxysilane ("KBE 903" produced by ShinEtsu Chemical 
Co., Ltd.) 
COMATIVE EXAMPLES 1 to 10 
For comparison, using compositions blended as shown in Table 3, test pieces 
for evaluation were prepared in the same manner as in Example 1 and 
evaluated. The results are shown together in Table 3. In Comparative 
Example 4, the polyorganosiloxane rubber latex obtained in the course of 
Referential Example 1 was coagulated as it was, dried and used. In 
Comparative Example 9, an ethylene/glycidyl methacrylate copolymer 
(Bondfast E produced by Sumitomo Chemical Co., Ltd.) was used as the 
rubber. 
EXAMPLES 18 to 26 AND COMATIVE EXAMPLES 11 to 20 
Test pieces for evaluation having compositions shown in Tables 4 and 5 were 
prepared in the same manner as in Example 1 and evaluated. The results are 
shown together in Tables 4 and 5. 
TABLE 4 
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Example No. 18 19 20 21 22 23 24 25 26 
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Graft copolymer 
Kind S-1 
S-1 
S-1 
S-1 
S-1 
S-1 
S-1 
S-1 
S-1 
(B) Amount (part) 
20 20 20 20 20 20 20 20 20 
Polyester Kind PBT 
PBT 
PBT 
PBT 
PBT 
PBT 
PBT 
PET 
PCT 
Amount (part) 
80 80 80 80 80 80 80 80 80 
Organic silane 
Kind (a) 
(a) 
(a) 
(a) 
(a) 
(b) 
(c) 
(a) 
(a) 
compound Amount (part) 
1 1 1 1 1 1 1 1 1 
Reinforcing 
Kind GF GF GF CF Talc 
GF GF GF GF 
filler Amount (part) 
43 25 67 43 43 43 43 43 43 
Izod impact strength (1/8" 
in thickness, notched) 
(kg .multidot. cm/cm) 
23.degree. C. 33 29 32 25 19 30 30 27 23 
-20.degree. C. 28 25 28 22 15 27 27 23 20 
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Note: 
(a): Glycidoxypropyltrimethoxysilane ("KBM 403" produced by ShinEtsu 
Chemical Co., Ltd.) 
(b): Glycidoxypropylmethyldiethoxysilane ("KBE 402" produced by ShinEtsu 
Chemical Co., Ltd.) 
(c): 3,4-Epoxycyclohexyl)ethyltrimethoxysilane ("KBM 303" produced by 
ShinEtsu Chemical Co., Ltd.) 
CF: Carbon fiber 
GF: Glass fiber 
TABLE 5 
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Comparative Example No. 
11 12 13 14 15 16 17 18 19 20 
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Graft copolymer (B) 
Kind S-1 PDMS-1 Ethylene/glycidyl 
S-8 
Amount (part) 
-- 20 -- 20 -- -- -- -- methacrylate copolymer, 
20 
Polyester Kind PBT 
PBT 
PBT 
PBT PBT 
PBT 
PET 
PCT 
PBT PBT 
Amount (part) 
100 
80 100 
100 100 
100 
100 
100 
80 80 
Organic silane 
Kind (a) 
(a) (a) 
compound Amount (part) 
-- -- 1 1 -- -- -- -- -- 1 
Filler Kind GF GF GF GF CF Talc 
GF GF GF GF 
Amount (part) 
43 43 43 43 43 43 43 43 43 43 
Izod impact strength (1/8" in 
thickness, notched) (kg .multidot. cm/cm) 
23.degree. C. 8 12 8 20 5 4 7 7 26 20 
-20.degree. C. 6 9 6 18 3 3 5 5 17 14 
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Note: 
(a): Glycidoxypropyltrimethoxysilane ("KBM 403" produced by ShinEtsu 
Chemical Co., Ltd.) 
CF: Carbon fiber 
GF: Glass fiber