JPS63304041A - Polymer composition - Google Patents

Abstract

PURPOSE:To obtain a polymer composition having improved miscibility and excellent tensile and impact strength, by blending a polystyrene based polymer with a polyalkylene terephthalate based polymer and specific graft polymer. CONSTITUTION:A polymer composition obtained by blending 100pts.wt. total amount of (A) 5-80pts.wt. polystyrene based polymer and (B) 95-20pts.wt. polyalkylene terephthalate based polymer (e.g. polyethylene terephthalate polymer having >=0.4 intrinsic viscosity with (C) 2-30pts.wt. graft polymer, containing units (vinyl polymer segments) having compatibility with the component (A) and units (polyester segments) having compatibility with the component (B) at 5/95-70/30 weight ratio by a macromonomer method.

Description

Detailed Description of the Invention (a) Purpose of the Invention [Field of Industrial Application] The present invention relates to a resin composition that is used in a wide range of applications for general consumption and industrial use. The present invention relates to a resin composition comprising a polystyrene resin used in the present invention and a polyalkylene terephthalate resin used in molding materials, films, synthetic fibers, etc.

[Prior art and its problems]

BACKGROUND OF THE INVENTION With the remarkable development of the polymer chemical industry in recent years, many polymer materials are being used in large quantities in daily life products, industrial products, vehicle parts, building materials, and the like.

Particularly after the oil crisis, the need for higher performance and higher functionality of products has increased, and even in the field of polymer materials, engineering plastics have shown remarkable growth potential, showing that consumer trends are also showing signs of the times. Can be done. Under these circumstances, even in the field of conventional plastics, efforts are being made to improve and modify them in various ways in order to meet the diversifying demands of the market.

Polystyrene resin is a representative general-purpose plastic, along with polyolefin and polyvinyl chloride, and has excellent moldability, transparency, and water resistance, and is also highly dimensionally accurate, lightweight, and inexpensive, making it suitable for use in everyday miscellaneous goods. However, it has limitations due to its low impact strength.

High-impact polystyrene, which is made by dispersing elastomer components in polystyrene, is not transparent, but has 5 to 10 times better impact resistance than regular polystyrene.
It is often used in fields that do not require much transparency.

On the other hand, polyalkylene terephthalate resins are popular as synthetic fibers along with nylon and acrylic, but recently they have also been consumed in large quantities as films and molding materials. For example, demand for polybutylene terephthalate (hereinafter sometimes abbreviated as PBT) has increased in recent years as a new general-purpose engineering plastic, and it is expected to maintain high growth potential in the future.PBT is a crystalline engineering plastic. It has various desirable properties such as heat resistance, weather resistance, mechanical strength, oil resistance, chemical resistance, etc. On the other hand, it has poor dimensional stability due to high molding shrinkage rate, impact resistance, alkali resistance, etc. There are problems with paintability, adhesion, etc., and efforts are being made to overcome these problems.In particular, to improve heat resistance and strength,
Composites are generally made by blending glass fibers.

However, even in this case, new problems such as wear of the kneading machine, warping of the molded product, and anisotropy of strength have arisen.

In addition to synthetic fibers that have traditionally been consumed in large quantities, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) has recently been in demand for blow molded products such as bottles and molding materials reinforced with glass fiber. It is expected that it will continue to increase and maintain its high growth potential as a general-purpose engineering plastic along with PBT. Like PBT, PET has both advantages and disadvantages as a crystalline engineering plastic, but in particular, poor moldability and poor dimensional stability due to slow crystallization rate are problems.

Polystyrene resins and polyalkylene terephthalate resins have different properties as mentioned above, so we are trying to develop a practical resin composition that balances the properties of both by blending them. Technology orientation is currently attracting attention.

Polymer blending is a method that has recently attracted attention as a method of improving and modifying existing resins to make them suitable for diversifying uses.By mixing different resins, it is possible to improve and modify the characteristics of individual resins. This method can flexibly respond to the diversifying needs of resin users, avoid wasting resources due to excessive quality, and is essential for the research and development of new resins. It has the advantage of being able to reduce the investment burden.

Attempts to use polymer alloys or blends have been made for a long time, but due to the recent diversification of market needs and the need to conserve resources and energy, they have recently become more popular, especially in the field of engineering plastics.

Although the number of resin compositions containing polystyrene resin and polyalkylene terephthalate resin as main components is not large, several inventions have been proposed. For example, by blending 15 to 25% polystyrene resin,
A proposal to improve the rigidity, heat distortion temperature and impact strength of PBT (Japanese Patent Publication No. 47-30421), by blending polystyrene, glass fiber reinforced PBT
Proposal to improve warpage during molding
No. 2378), acrylonitrile-butadiene-
By blending styrene terpolymer, PB
Proposal to improve the impact strength of T
261), a proposal to improve the moldability, dimensional stability, and adhesion of PET by blending a styrene-maleic anhydride copolymer (Japanese Unexamined Patent Publication No. 57-18)
No. 755) and a proposal to use a graft polymer obtained by polymerizing vinyl hexamer in the presence of an unsaturated polyester as a compatibilizer when blending polyalkylene terephthalate and a vinyl polymer (Japanese Patent Laid-Open Publication No. 755). 61
-231015) etc.

When blending different types of polymers, the most important thing is how to mix and sufficiently mix the polymers, which are inherently poor in compatibility. However, since these resins have significantly different solubility parameter values and are inherently poor in compatibility with each other, simply blending them will result in an impractical composition with extremely poor physical properties. Even in the previously mentioned known inventions, two types of resins are simply mixed together, or a graft polymer with an unclear structure or containing many impurities is used as a compatibilizer, so it is not practical. There have been problems in that the range of blend compositions that are economically valuable is narrowly limited, or that the balance of physical properties is likely to be impaired.

Generally, methods for improving the miscibility of immiscible polymer blends include using a compatibilizing agent, or modifying one or both components of the blended resin by a method such as grafting to increase compatibility. is possible.

However, the radiation grafting method, which is known as a grafting reaction to polyalkylene terephthalate,
The grafting efficiency is extremely poor, and it is impossible to control the molecular weight and composition of the resulting grafted polymer. Also,
In the method of using a compatibilizer, it is effective to use a block polymer or a graft polymer that has constituent segments of different polymers to be blended in the same molecule as a compatibilizer, but it is effective to use a block polymer or a graft polymer that has constituent segments of different polymers to be blended as a compatibilizer. It is very difficult to synthesize block polymers having these segments at a low cost using generally known ionic polymerization methods and polycondensation methods, and similarly graft polymers having these segments can be synthesized using known chain transfer methods and radiation grafting methods. Alternatively, even if synthesis was attempted using a polymer initiator method or the like, there were problems such as extremely poor grafting efficiency and difficulty in controlling the molecular weight and composition.

Therefore, it would be possible to synthesize block polymers and graft polymers that can be used as compatibilizers when blending different types of polymers at low cost and easily, and in which the molecular structure, composition, molecular weight, etc. can be controlled as desired. If so, its technical and economic value would be enormous.

(B) Structure of the Invention [Means for Solving the Problems] Taking into consideration the problems of the prior art as described above, the present inventors have developed a resin composition with improved miscibility and excellent performance. As a result of intensive studies aimed at obtaining this, it was discovered that when blending polystyrene resin and polyalkylene terephthalate resin, the performance of the resin composition can be improved by using a graft polymer produced by the macromonomer method as a compatibilizer. and completed the present invention.

That is, the present invention provides a polystyrene resin (A), a polyalkylene terephthalate resin (B), and a macromonomer method having both a unit compatible with the resin (A) and a unit compatible with the resin (B). This is a resin composition consisting of a graft polymer according to.

(Graft polymer by macromonomer method) The graft polymer by macromonomer method (hereinafter simply referred to as graft polymer) in the present invention means a polyalkylene terephthalate graft polymer produced using a macromonomer.

The method for producing a graft polymer using such a macromonomer method has the following features: ri) There is little possibility that the polymer to be the main component exists as a non-grafted polymer.

ii) The molecular weight of the branch components, the molecular weight of the entire graft polymer, and the ratio of the technique and the trunk can be easily controlled.

iii) Combinations of branch components and trunk components can be freely selected depending on the purpose. It has been attracting a lot of attention recently because it can easily obtain high-performance graft polymers that cannot be obtained by conventional methods.

The graft polymer in the present invention has the following molecular structure:
It is a graft polymer that has a vinyl polymer segment that is compatible with polystyrene derived from a macromonomer as a branch component, and a polyester segment that is compatible with polyalkylene terephthalate as a backbone component. Examples of the vinyl polymer segment which is a branch component include a segment consisting of a homopolymer or copolymer having a styrene monomer unit as a main unit, as described in detail in the macromotomer section below.

On the other hand, as the polyester segment which is the main component, one or two types selected from terephthalic acid and alkylene glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, hexamethylene glycol, neopentyl glycol, and cyclohexane dimetatool are used. Examples include polyester segments whose main components are various polyalkylene terephthalates obtained by polycondensation with more than one type of diol.

The polyester segment may contain a diol other than the alkylene glycol, such as diethylene glycol, bisphenol A, etc., as a diol component unit, and may contain an acid component other than terephthalic acid, such as isophthalic acid, p- It may contain a small amount of units consisting of acid components such as oxybenzoic acid, diphenylmethanedicarboxylic acid, naphthalene dicarboxylic acid, adipic acid, and sebacic acid, and the amount shall be 10% by weight or less based on the total amount of acid component units. It is preferable.

In addition, the polyester segment may contain a small amount of a unit consisting of a trifunctional or higher-functional polycarboxylic acid, an alkyl polycarboxylate, a polyhydric alcohol, or the like having polycondensation properties for the purpose of increasing the molecular weight of the segment. However, the amount thereof is preferably 5% by weight or less based on the total amount of units consisting of polyester forming components other than the macromonomer.

In the present invention, the composition of the vinyl polymer segment which is a branch component of the graft polymer and the polyester segment which is a trunk component is preferably 5/95 to 70/30 in weight ratio, and 10/90 to 60/40. It is even more preferable that there be. If the proportion of the branch component is less than 5% by weight, the physical properties are virtually the same as those of a polymer containing only the polyester component, while if the proportion of the branch component exceeds 70%, the heat resistance tends to be insufficient.

The graft polymer in the present invention can be produced in the same manner as known polyester production methods.

- For example, when synthesizing polyester from monomers by the melt polycondensation method, a predetermined amount of dibasic acid and/or
Alternatively, the dibasic acid diester and diol are further added with the following macromonomers and catalysts, heated to 150 to 200'C to esterify, and then heated under reduced pressure to distill off the diol present in excess with respect to the acid. The graft polymer can be easily obtained by polycondensation at ~280°C for several hours.

Conventionally known catalysts include Ca, Mg, Zn, and Cd.
, Ti, Ge, Sn, Pb, Sb, Mn,
Compounds such as Co and Zr may be used, and phosphorous esters may be added as stabilizers.

In addition to the melt polycondensation method at high temperatures as described above, graft polymers may also be produced by solution polycondensation methods, interfacial polycondensation methods, etc. at low temperatures. You can use the legal one.

The method and conditions for producing the graft polymer in the present invention can be appropriately selected depending on the type of the intended graft polymer and the intended use.

(Macromonomer) The macromonomer used in the present invention is a polycondensable polymer having a functional group capable of polycondensation at one end of the molecular chain, which is composed of a relatively low molecular weight vinyl polymer that is compatible with polystyrene. Typical examples of the terminal structure of the macromonomer in the present invention include terminal structures each having two carboxyl groups, carboxylic acid ester groups, or hydroxyl groups, but other examples include amine groups, etc. Examples of terminal structures each having two carboxyl groups, carboxylic acid diester groups, or hydroxyl groups include -CH-COOH -CH-COOR -CHt CH-OH.In the formula (I[), R is Straight chain or branched alkyl groups having up to 10 carbon atoms are suitable.

Further, the vinyl polymer portion forming the skeleton of the macromonomer in the present invention is composed of one radically polymerizable vinyl seven unit, and the polymer is compatible with polystyrene, and a specific example is styrene monomer. Examples include homopolymers consisting of mer units or styrene derivative monomer units, and copolymers consisting of styrene monomer units or styrene derivative monomer units as the main unit and other copolymerizable monomer units. .

Suitable examples of the copolymerizable monomer unit include acrylic ester monomer units, methacrylic ester monomer units, acrylonitrile monomer units, and methacrylonitrile monomer units. The content of the copolymerizable units in the skeleton is suitably 40 to 0 weight percent based on the total amount of all monomer units.

The molecular weight of the macromonomer in the present invention may be within a range that does not impair the polymerizability of the produced macromonomer, and the number average molecular weight is suitably 1000 to 20000, preferably 2000 to 150oO. If the macromonomer has a number average molecular weight of less than 1,000, the degree of polymerization as a single polymer unit will be too low, and the physical properties of the vinyl polymer segment will not be easily reflected in the graft polymer obtained using the macromonomer, and if the molecular weight exceeds 20,000. This tends to cause problems such as a decrease in polycondensation properties during the production of graft polymers and a tendency to cause phase separation in the reaction system.

The number average molecular weight of the macromonomer is a polystyrene equivalent number average molecular weight measured by gel permeation chromatography (hereinafter referred to as GPC), and the measurement conditions are as follows.

Apparatus: High performance liquid chromatography (for example, manufactured by Toyo Soda Kogyo, part name: HLC-802UR) Column: Polystyrene gel (for example, manufactured by Toyo Soda Kogyo, part name: G4000H)
8 and G3000H8) Elution solvent: Tetrahydrofuran Outflow rate: 1.0 ml/akin Column temperature: 40°C Detector: RI detector As an example of the method for producing the macromonomer of the present invention, it is possible to Examples include a method of radically polymerizing a nil monomer in the presence of a chain transfer agent having a corresponding functional group.

Chain transfer agents used in the above method include:
Mercaptan compounds are preferred because they have appropriate chain transfer constants, 1,000 malic acid is suitable for macromonomers having two carboxyl groups at the ends, and mercaptan compounds have two carboxylic acid ester groups at the ends. Specific examples of the compound include dimethyl thiomalate, and thioglycerin is an example of the macromonomer having two hydroxyl groups at the terminal.

Further, as the polymerization method, any of solution polymerization, bulk polymerization, emulsion polymerization, and suspension polymerization can be used in the presence or absence of a conventionally known radical polymerization initiator.

According to the above method, a macromonomer can be obtained by a single-stage polymerization reaction, but it is also possible to synthesize a macromonomer by a two-stage reaction of polymerization (first stage) and end group introduction reaction (second stage). In this case, a functional group is introduced at the end of the polymer by using a known mercaptan chain transfer agent containing one functional group such as a carboxyl group or a hydroxyl group in the first stage of polymerization, and the group is used in the reaction. A terminal structure that can be polycondensed in the second stage reaction may be formed as a scaffold.

[Polystyrene resin]

The polystyrene resin used in the present invention is a polymer consisting only of styrene monomer units or having the styrene monomer unit as the main unit, or a resin composition comprising the polymer as the main component. Polystyrene, styrene-acrylonitrile copolymer used as molding material,
Styrene-maleic anhydride copolymer, styrene-phenylmaleimide copolymer, styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer, etc., and resin compositions comprising these polymers and elastomers, etc. can be mentioned.

When the polystyrene resin is a copolymer consisting of styrene monomer units and other monomer units, the copolymerized monomer units include acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, acrylonitrile, Methacrylonitrile, maleic anhydride, N-111 maleimide such as phenylmaleimide, aliphatic vinyl ester such as vinyl acetate, aromatic vinyl ester, vinyl ether, α
Examples thereof include α-substituted styrene such as -methylstyrene and aromatic ring-substituted styrene derivatives such as P-alkylstyrene. The amount of copolymerized monomer units in the copolymer is preferably 40% by weight or less, more preferably 30% by weight or less, based on the total amount of monomer units.

Examples of the elastomer that the polystyrene resin in the present invention can contain include polybutadiene, polyisoprene, polychloroprene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, styrene-butadiene block copolymer, and hydrogenated styrene. - Butadiene rubbers such as butadiene copolymers and styrene-isoprene block copolymers, ethylene-propylene copolymers, ethylene-propylene-diene monomer terpolymers, ethylene-vinyl acetate copolymers, ethylene-
Examples include polyolefin rubbers such as acrylic acid ester copolymers and chlorinated polyethylene, acrylic rubbers, and urethane rubbers. The amount of such elastomer contained in the polystyrene resin is preferably 30% by weight or less based on the entire resin composition.

The main purpose of using the elastomer as one of the components of the polystyrene resin is to improve the impact strength of the resin.

Furthermore, the polystyrene resin in the present invention may contain a small amount of resin additives such as flame retardants, ultraviolet absorbers, lubricants, stabilizers, and antistatic agents, and the amount is 20% by weight based on the polystyrene resin. The following is preferable.

[Polyalkylene terephthalate resin] The polyalkylene terephthalate resin in the present invention is a polyester resin containing polyalkylene terephthalate as a main component, and specific examples include terephthalic acid, ethylene glycol, propylene glycol, and 1,4-butanediol. , various polyalkylene terephthalates obtained by polycondensation with one or more diols selected from alkylene glycols such as hexamethylene glycol, neopentyl glycol, and cyclohexane dimetatool, terephthalic acid, and the above-mentioned alkylene glycols. In addition, acid components include isophthalic acid, p-oxybenzoic acid,
Diphenylmethane dicarboxylic acid, naphthalene dicarboxylic acid, adipic acid or sebacic acid, etc., and diethylene glycol or bisphenol A as the diol component.
Examples include a polyalkylene terephthalate copolyester obtained by copolymerizing a combination of polyesters, etc., or a polyester resin composition in which alkylene terephthalate repeating units are the main component resulting from a blend of two or more polyesters.

Further, the polyalkylene terephthalate copolyester may contain a small amount of units consisting of a compound containing three or more ester-forming functional groups within a range that does not impair moldability.

In addition, as for the polyalkylene terephthalate resin in the present invention, the alkylene terephthalate repeating unit is preferably 80 mol% or more, more preferably 90 mol% or more, based on all repeating units, and polyethylene terephthalate and polyethylene terephthalate are preferred. Particular preference is given to butylene terephthalate.

In addition, it is appropriate for the polyalkylene terephthalate resin to have an intrinsic viscosity of usually 0.4 or more when measured at 30°C in a mixed solvent of phenol/tetrachloroethane (6/4 weight ratio), and more preferably 0. .5 or more.

The polyalkylene terephthalate resin used in the present invention contains well-known additives such as plasticizers, pigments, flame retardants, reinforcing fibers such as glass fibers or carbon fibers, inorganic/organic fillers, and stabilizers. It's okay.

[Production method of resin composition]

The resin composition of the present invention has both a polystyrene resin (A), a polyalkylene terephthalate resin (B), and a unit compatible with the resin (A) and a unit compatible with the resin (B). A resin composition consisting of a graft polymer determined by a macromonomer, and the blending ratio of resin (A) and resin (B) is preferably 5 to 80 parts by weight of resin (A) and 95 to 20 parts by weight of resin (B). Further, the blending ratio of the graft polymer is preferably 2 to 30 parts by weight based on the total of 1100 parts by weight of resin (A) and resin (B).

In the blending ratio of resin (A) and resin (B), resin (
If the amount of A) is less than 5 parts by weight or the amount of resin (B) is less than 10 parts by weight, the characteristics of those resins will be difficult to appear in the resin composition, and the total amount of resin (A) and resin (B) will be reduced. 1
If the amount of the graft polymer is less than 2 parts by weight relative to 00 parts by weight, the effect of compatibilization is difficult to appear, while if it exceeds 30 parts by weight, it tends to be disadvantageous in terms of cost.

The resin composition of the present invention can be obtained by melting and kneading the three components of resin (A), resin (B), and graft polymer using a known blending method using an extruder such as a Ni-Goo or open roll extruder. can be easily obtained by A preferred method is to mix using a Henschel mixer or the like, melt and knead with an extruder, extrude, and then cut into pellets. The pelletized resin composition obtained by this method can be molded into a desired shape by, for example, injection molding, press molding, extrusion molding, blow molding, or the like.

[Effect]

In the resin composition of the present invention, the graft polymer blended therein has units compatible with the resin (A) and the resin (A).
Since it is a graft polymer that has both units that are compatible with B), resin (A) and resin (B) are finely dispersed and mixed by the graft polymer, and the interface between these different polymers is firmly bonded. be done.

Therefore, according to the present invention, polystyrene resin has excellent dimensional stability, electrical properties, water resistance, low cost, etc., and polyalkylene terephthalate resin has excellent weather resistance, oil resistance, A resin composition that has chemical resistance, heat resistance, and mechanical strength can be obtained.

The present invention will be explained in more detail below by showing Reference Examples, Examples, and Comparative Examples.

It should be noted that % and parts on each side mean % and parts by weight, respectively, in each case.

Reference Example 1 Production of a macromonomer having a styrene polymer skeleton and two methyl ester groups at one end (hereinafter referred to as one-end dimethyl ester type styrene macromonomer) Stirrer, reflux condenser, dropping funnel, and temperature A glass flask equipped with a meter was charged with 333 parts of styrene and 2.67 parts of dimethyl thiomalate, and a mixture of 667 parts of styrene and 12.46 parts of dimethyl thiomalate was placed in the dropping funnel. The temperature of the flask was raised to reflux the contents. The solution in the dropping funnel was added dropwise thereto over 4 hours. Thereafter, 2.67 parts of dimethyl thiomalate was added in portions of 1/12th part at 15 minute intervals.

After the completion of the split preparation, the mixture was further aged for 2 hours. The polymerization conversion rate of styrene was 95.7%. Thereafter, the pressure of the reaction system was reduced to remove residual monomers, thereby obtaining 945 parts of a solid one-end dimethyl ester type styrene macromonomer. During this time, the reaction temperature gradually increased from the initial reflux temperature of 146°C, and was kept constant when it reached 160'C. G.P.
The average molecular weight of the macromonomer determined by C is M
n-9,800, Mw-22,500.

Reference Example 2 Production of polybutylene terephthalate-polystyrene graft polymer In a separable flask equipped with a stirrer, reflux condenser, temperature system, and nitrogen gas inlet, 117.6 parts of dimethyl terephthalate and 120 parts of 1.4-butanediol were added. ．．
1 part, 66.7 parts of the one-end dimethyl ester type styrene macromonomer produced in Reference Example 1, and 0.27 parts of tetrabutyl titanate were charged, and methanol produced by the transesterification reaction was removed by heating and raising the temperature under a nitrogen stream. I reacted while doing so.

During this time, the reaction temperature rose from 150°C to 220'C.

After that, the temperature of the reaction system was raised to 260°C, and the pressure was simultaneously reduced to 1
．． The internal pressure was reduced to 5 mmHg or less over about 10 minutes while distilling 4-butanediol. Polycondensation was carried out for 1.5 hours under distillation of 1,4-butanediol.The pressure inside the thread reached 0.5+amHg.After the reaction, nitrogen was introduced to return to normal pressure, and the resulting graft polymer A high viscosity liquid was taken out.

Next, in order to remove a small amount of low molecular weight compounds contained in the graft polymer, the graft polymer was pulverized, and the pulverized product was placed in a glass flask and heated for 0.5s+s+Hg.
Stirring was performed at 180°C for 20 hours under the following reduced pressure. The melt flow index of the obtained graft polymer at 240°C and under a load of 2.16 kg was 3.1 (g/1
0 minutes).

Example 1 Commercially available general polystyrene resin (manufactured by Mitsui Toatsu Chemical Co., Ltd.,
Product name Tobolex 525-51) 83.3 parts, glass fiber reinforced polybutylene terephthalate (manufactured by Toshi ■,
366.7 parts of PBT II0IG-30) and 50 parts of the polybutylene terephthalate-polystyrene graft polymer of Reference Example 2 were added using a twin-screw extruder (vent type, co-rotating, diameter 29 mm, L/D = 25). The strands obtained by melt-blending at a resin temperature of 250'C were cooled and then cut to obtain pellet-shaped resin compositions. Tensile strength and elongation at break of the resulting resin composition (
A dumbbell-shaped test piece was made from a sheet obtained by press-molding a resin composition pellet at 250°C, and JIS K7
113, at a tensile speed of 5 ms+/sin) and impact strength (instead of the above dumbbell-shaped test piece,
An impact test piece without a notch was prepared in the same manner, and J
) was measured using a Charpy impact tester in accordance with IS K7111.

The results are shown in Table 1. In Table 1, the polymer segment composition refers to the content ratio of each polymer segment to the entire resin, assuming that the polystyrene segment and polybutylene terephthalate segment in the graft polymer are polystyrene and polybutylene terephthalate, respectively. It is something that

Comparative Examples 1 to 2 Regarding resin compositions obtained by melt-blending 100 parts of the same polystyrene resin used in Example 1 and 400 parts of glass fiber reinforced polybutylene terephthalate resin in the same manner as in Example 1. Results of measuring physical properties (Comparative Example 1) and 200 parts of similar polystyrene resin and 40 parts of glass fiber reinforced polybutylene terephthalate resin
The results of measuring the physical properties of the resin composition consisting of 0 parts (Comparative Example 2) are as shown in Table 1.

Example 2 183.3 parts of the same polystyrene resin used in Example 1, 266.7 parts of glass fiber reinforced polybutylene terephthalate resin, and 50 parts of the graft polymer were melt-blended in the same manner as in Example 1. The physical properties of the obtained resin composition were measured and the results were as shown in Table 1.

(c) Effects of the invention The resin composition of the present invention is a resin composition with improved miscibility, and as specifically shown in Examples and Comparative Examples, the blending method of the prior art having the same composition. Compared to the resin composition made of polystyrene resin and polyalkylene terephthalate resin, it has excellent tensile strength and impact strength, and is industrially useful.

Claims (1)

[Claims] 1. Polystyrene resin (A), polyalkylene terephthalate resin (B), and a graft polymer produced by a macromonomer method having both units compatible with the resin (A) and units compatible with the resin (B). A resin composition consisting of.