JPH04285649A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition of a polypropylene-based resin/polystyrene-based resin, excellent in impact resistance, mechanical strength and molding processability and simultaneously having suppressed surface peeling of molded products. CONSTITUTION:A thermoplastic resin composition containing (a) 5-98wt.% polypropylene-based resin containing >=1wt.% modified polypropylene modified with an epoxy group-containing monomer, (b) 95-2wt.% polystyrene-based resin, (c) an olefinic elastomer modified with an unsaturated carboxylic acid or its anhydride in an amount of 5-100 pts.wt. based on 100 pts.wt. total amount of the aforementioned components (a) and (b), and (d) a polystyrene-based block copolymer in an amount of 1-30 pts.wt. based on 100 pts.wt. total amount of the above-mentioned components (a), (b) and (c).

Description

Description [0001] [Industrial Application Field] The present invention relates to a thermoplastic resin composition containing a polypropylene resin and a polystyrene resin. The present invention relates to a thermoplastic resin composition containing a polypropylene resin that has excellent impact resistance and good mechanical strength such as ductility and flexural modulus, and a polystyrene resin. [Prior Art] Polypropylene resin has mechanical strength,
It has excellent moldability and chemical resistance, and is widely used in various industrial fields such as inner and outer layer parts of automobiles, home appliance parts, and housings. However, since polypropylene is a non-polar polymer, it has difficulties in secondary processability, particularly in solid phase adhesion and paintability. As a method of modifying such polypropylene, blending polystyrene resin with good paintability into polypropylene has been carried out. However, in addition to being easy to paint, polystyrene resin
Although it has high rigidity and good dimensional stability, it does not have good compatibility with polypropylene, so there is a problem that the physical properties deteriorate significantly. [0003] Therefore, various compositions have been proposed in which a compatibilizer is added to a composition of polypropylene and polystyrene resin for the purpose of improving the compatibility thereof (Japanese Patent Laid-Open No. 87645/1983). No., Japanese Patent Publication No. 1-1745
No. 50). [0004] However, all of the above compositions contain a styrene-nonconjugated diene block copolymer or the like as a compatibilizing agent between the polypropylene resin and the polystyrene resin. However, since it is difficult to sufficiently compatibilize polypropylene and polystyrene with the compatibilizing agent described above, there is a problem that the impact resistance, mechanical strength, surface peeling resistance of the molded article, etc. are not necessarily sufficient. Furthermore, a rubber component such as an olefin elastomer has been added to a composition containing a polypropylene resin and a polystyrene resin for the purpose of improving its impact resistance. is not introduced as a uniform phase, resulting in a problem in that the surface peeling resistance of the molded product decreases. Therefore, an object of the present invention is to have excellent impact resistance, good mechanical strength and moldability, and
Polypropylene resin that suppresses surface peeling of molded products/
An object of the present invention is to provide a thermoplastic resin composition of polystyrene resin. [Means for Solving the Problem] As a result of intensive research in view of the above object, the present inventors have found that in a composition containing a polypropylene resin and a polystyrene resin, the polypropylene resin contains an epoxy group. By using a product containing a certain amount of polypropylene modified by a monomer and further adding an olefin elastomer modified with an unsaturated carboxylic acid or its anhydride and a polystyrene block copolymer, surface peeling of the molded product can be suppressed. is,
It was discovered that a material with excellent impact resistance and good mechanical properties could be obtained, and the present invention was conceived. That is, the thermoplastic resin composition of the present invention comprises (a) a polypropylene resin 5 containing 1% by weight or more of polypropylene modified with an epoxy group-containing monomer;
~98% by weight, and (b) polystyrene resin 95~2
weight% and the total of the above (a) + above (b) 100
Based on parts by weight, (c) olefinic elastomer modified with unsaturated carboxylic acid or its anhydride: 5 to 1
00 parts by weight and the above (a) + above (b) + above (c
) 1 to 30 parts by weight of polystyrene-based block copolymer (d). The present invention will be explained in detail below. In the present invention, (a) polypropylene resin is polypropylene containing 1% by weight or more of polypropylene modified with an epoxy group-containing monomer. In the above-mentioned modified polypropylene, the polypropylene to be modified is a crystalline polymer polymerized with propylene monomer as the main component, and is not limited to a homopolymer, but may also be a block copolymer of propylene and other α-olefins such as ethylene. or random copolymers. As the copolymer, a propylene-ethylene random copolymer is preferred. A propylene random copolymer (hereinafter referred to as PPDM) containing a non-conjugated diene comonomer may also be used. Examples of the above-mentioned non-conjugated diene include:
2-methyl-1,4-pentadiene, 1,4-hexadiene, 4-methylidene-1-hexene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,4-heptadiene, 4-ethyl-1,
4-hexadiene, 4,5-dimethyl-1,4-hexadiene, 4-methyl-1,4-heptadiene, 4
-ethyl-1,4-heptadiene, 5-methyl-1,
4-heptadiene, 5-methyl-1,4-octadiene, 1,5-heptadiene, 1,5-octadiene,
5-methyl-1,5-heptadiene, 6-methyl-1,
5-heptadiene, 2-methyl-1,5-hexadiene, 1,6-octadiene, 6-methyl-1,6-
Octadiene, 7-methyl-1,6-octadiene,
Examples include 2-methyl-1,6-heptadiene, 1,9-decadiene, and 1,13-tetradecadiene. Among these, 1,4-hexadiene, 2-methyl-1,5-hexadiene, 7-methyl-1,6-
Preferred are octadiene, 1,9-decadiene, 1,13-tetradecadiene, and the like. Two or more types of these non-conjugated diene comonomers can also be used. As explained above, the term "polypropylene" used herein is not limited to homopolymers of propylene, but should be understood to include each of the above-mentioned copolymers. Examples of the epoxy group-containing monomer for modifying polypropylene include glycidyl methacrylate and glycidyl acrylate. [0014] Also, the following general formula (1): [Formula 2] (wherein, R is H or an alkyl group having 1 to 6 carbon atoms,
Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms and having at least one glycidyloxy group, and n is 1 to 4.
represents an integer. ) Glycidyl compounds represented by the following can also be used as modifying monomers. Preferred glycidyl compounds include those represented by the following general formula (2). [Formula 3] (In the formula, R is H or an alkyl group having 1 to 6 carbon atoms.) Such a glycidyl compound can be produced, for example, by the method shown in JP-A-60-130580. Can be done. The polypropylene modified with an epoxy group-containing monomer may be a block copolymer, a graft copolymer, a random copolymer or an alternating copolymer. The content of the epoxy group-containing monomer in the modified polypropylene is preferably within the range of 0.1 to 50% by weight, more preferably 1 to 1% by weight.
0% by weight. If the amount of modification by the epoxy group-containing monomer is less than the above lower limit, there will be no sufficient effect on improving the compatibility between the polypropylene resin and the polystyrene resin, and if it exceeds the upper limit, the mechanical strength will decrease. The modified polypropylene can be produced by either a solution method or a melt-kneading method. In the case of the melt-kneading method, polypropylene, an epoxy group-containing monomer for modification, and a catalyst are charged into an extruder, twin-screw kneader, etc.
The mixture is heated to a temperature of 250° C. and kneaded while melting. In the case of a solution method, the starting material is dissolved in an organic solvent such as xylene, and the solution is stirred at a temperature of 80 to 140°C. In either case, a conventional radical polymerization catalyst can be used as a catalyst, such as benzoyl peroxide, lauroyl peroxide, ditertiary butyl peroxide, acetyl peroxide, tertiary butyl peroxybenzoic acid, dicumyl peroxide, peroxybenzoic acid, peroxyacetic acid,
Peroxides such as tert-butyl peroxypivalate and 2,5-dimethyl-2,5-di-tert-butyl peroxyhexine, and diazo compounds such as azobisisobutyronitrile are preferred. Furthermore, a phenolic antioxidant can be added during the graft reaction. The content of the above-mentioned modified polypropylene in the polypropylene resin is 1% by weight or more based on 100% by weight of the polypropylene resin (a). If the content of the modified polypropylene is less than 1% by weight, there is no sufficient effect in improving the compatibility between the polypropylene resin and the polystyrene resin. The preferred content of modified polypropylene is about 3 to 60% by weight. However, the entire polypropylene resin is 10
It is preferable that the content of the epoxy group-containing monomer is 0.01% by weight or more. If the content of the epoxy group-containing monomer is less than 0.01% by weight based on the entire polypropylene resin, there is no sufficient effect in improving the compatibility between the polypropylene resin and the polystyrene resin. [0023] In the polypropylene resin, polypropylene other than modified polypropylene is not particularly limited as long as it is a polymer containing propylene as a main component;
It may also be copolymerized with other α-olefins such as ethylene, butene, 4-methylpentene-1, etc. up to about % by weight. The copolymer may be either a random copolymer or a block copolymer. Further, a copolymer rubber of two or more α-olefins such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-pentene, or α-
It may contain up to about 40% by weight of an olefin thermoplastic elastomer such as a copolymer rubber of olefin and other monomers. [0024] The copolymer rubber of two or more α-olefins typically includes ethylene-propylene copolymer rubber (EPR), ethylene-butene copolymer rubber (EBR), and ethylene-propylene copolymer rubber (EBR). Examples include propylene-diene copolymer rubber (EPDM). In the present invention, the polystyrene resin (b) is a homopolymerized styrene monomer;
Alternatively, it may be copolymerized with about 5 to 50% by weight of other monomers. As a comonomer for copolymerization,
Examples include α-methylstyrene, acrylonitrile, maleic anhydride, methyl methacrylate, and the like. Further, rubber-modified polystyrene obtained by emulsion polymerizing about 10 to 30% by weight of a rubbery polymer such as polybutadiene or butadiene-styrene copolymer to styrene can also be used. [0026] Further, polyphenylene ether resin is added in an amount of about 1 to 99% by weight, based on 100% by weight of polystyrene.
(PPO) can also be used. The above polyphenylene ether resin is represented by the following general formula (3). [Formula 4] (wherein, R1 and R2 are an alkyl group having 1 to 4 carbon atoms, an aryl group having 4 to 8 carbon atoms, a halogen atom, or a hydrogen atom, and may be the same or different, and n represents a number from 50 to 500.) Examples of such polyphenylene ether resins include poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,
4-phenylene) ether, poly(2-methyl-6
-ethyl-1,4-phenylene) ether, poly(2
-methyl-6-isopropyl-1,4-phenylene)
Ether, poly(2-methyl-1,4-phenylene)
Ether, poly(2,6-dichrome-1,4-phenylene) Ether, poly(2-ethyl-6-bromo-1,
4-phenylene) ether, poly(2-phenyl-1
, 4-phenylene) ether and the like. Melt index of polystyrene resin as described above (MI: 190°C, 2.16 kg load)
is preferably about 0.5 to 20 g/10 minutes. The blending ratio of (a) polypropylene resin and (b) polystyrene resin as described above is (
When a) + (b) is 100% by weight, (a) is 5
-98% by weight, preferably 10-90% by weight, (
b) is 95-2% by weight, preferably 90-10% by weight
It is. (a) If the polypropylene resin is less than 5% by weight (if (b) exceeds 95% by weight), the mechanical strength, moldability, chemical resistance, etc., which are the characteristics of polypropylene, will decrease; If the content of the resin exceeds 98% by weight (if (b) is less than 2% by weight), the effect of improving the elastic strength of the posttyrene resin will not be sufficient. In the present invention, (c) the olefin elastomer modified with an unsaturated carboxylic acid or its anhydride, the olefin elastomer includes ethylene, propylene, 1-butene, 1-hexene, 4-methyl-pentene, etc. It means a copolymer rubber of two or more types of α-olefins, or a copolymer of α-olefins and other types of monomers. Two or three of the above α-olefins
The copolymer rubber is typically ethylene-
Examples include propylene copolymer rubber (EPR) and ethylene-propylene-diene copolymer rubber (EPDM). Ethylene-propylene-diene copolymer (EPDM
) The dienes include dicyclopentadiene, 1,
Non-conjugated dienes such as 4-hexadiene, cyclooctadiene, methylene norbornene or conjugated dienes such as butadiene, isoprene can be used. Particularly preferred is EPDM containing a non-conjugated diene. Further, as other monomers to be copolymerized with the α-olefin, vinyl acetate, acrylic ester, etc. can be used. A typical example of a copolymer of α-olefin and other monomers is ethylene-vinyl acetate copolymer (EV
A) is mentioned. Ethylene-propylene-diene copolymer (EPDM) and ethylene-propylene-diene copolymer (EPDM) used in the present invention
Propylene copolymers (EPR) may contain other repeating units, such as repeating units derived from alpha-olefins such as butene-1 or 4-methylpentene-1, to the extent that the properties of these copolymers are not impaired. Unit: 10
It may be included up to a proportion of mol% or less. Examples of unsaturated carboxylic acids or anhydrides thereof that modify olefinic elastomers include monocarboxylic acids such as acrylic acid and methacrylic acid, dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, and maleic anhydride. acid, itaconic anhydride, endo-bicyclo-[2
, 2, 1] -5-heptene-2,3-dicarboxylic anhydride (himic anhydride) and other dicarboxylic acid anhydrides, and dicarboxylic acids and their anhydrides are particularly preferred. The olefin elastomer modified with an unsaturated carboxylic acid or its anhydride may be a block copolymer, a graft copolymer, a random copolymer or an alternating copolymer. The content of the unsaturated carboxylic acid or its anhydride in the modified olefin elastomer is in the range of 0.01 to 20% by weight, preferably 0.2 to 10% by weight. Preferably, specifically, when modifying with maleic anhydride, the content of maleic anhydride is 0.1 to 10% by weight, and when using Himic anhydride, the content is 0.2% by weight. ~10% by weight
shall be. If the amount of modification by unsaturated carboxylic acid or its anhydride is less than the above lower limit, there will be no sufficient effect on improving the compatibility between polypropylene resin and polystyrene resin, and if it exceeds the upper limit, the mechanical strength will deteriorate. descend. [0036] The melt flow rate of the modified olefin elastomer as described above is 0.05 to 100 g/
Within 10 minutes. The modified olefin elastomer can be produced by either a solution method or a melt-kneading method. In the case of the melt-kneading method, the olefin elastomer, unsaturated carboxylic acid (or acid anhydride) for modification, and catalyst are put into an extruder, twin-screw kneader, etc., and heated to a temperature of 150 to 260 ° C. while melting. Knead. In addition, in the case of a solution method, the above starting material is dissolved in an organic solvent such as xylene, and 80 to 14
It is carried out with stirring at a temperature of 0 °C. In either case,
Usual radical polymerization catalysts can be used as catalysts, such as benzoyl peroxide, lauroyl peroxide, ditertiary butyl peroxide, acetyl peroxide, tertiary butyl peroxybenzoic acid, dicumyl peroxide, peroxybenzoic acid, and peroxyacetic acid. , tertiary-butylperoxypivalate, 2,5-dimethyl-2,5-ditertiarybutylperoxyhexine, and other peroxides, and azobisisobutyronitrile and other diazo compounds are preferred. The amount of the catalyst added is about 1 to 100 parts by weight per 100 parts by weight of the unsaturated carboxylic acid for modification or its anhydride. The amount of the above (c) olefin elastomer modified with an unsaturated carboxylic acid or its anhydride added is 5 parts by weight per 100 parts by weight of the total amount of (a) polypropylene resin and (b) polystyrene resin. ~10
0 parts by weight. If the amount of the polystyrene copolymer modified with an unsaturated carboxylic acid or its anhydride is less than 5 parts by weight, the effect of improving compatibility due to its addition is insufficient, resulting in poor impact resistance and surface peeling resistance. Sexuality, etc. becomes insufficient. 10 more
If it exceeds 0 parts by weight, fluidity and rigidity will decrease. Preferably (c) the amount of olefin elastomer modified with unsaturated carboxylic acid or its anhydride is 10 to 5.
It is 0 parts by weight. In the present invention, the polystyrene block copolymer (d) is a copolymer consisting of a polystyrene block and a polyolefin block, or a hydrogenated product thereof. Examples of such polystyrene copolymers include styrene-isoprene-styrene block copolymers and styrene-isoprene block copolymers (SIS
), styrene-butadiene-styrene block copolymer and styrene-butadiene block copolymer (SBS
), hydrogenated styrene-isoprene-styrene block copolymer and hydrogenated styrene-isoprene block copolymer (
Styrene-ethylene/propylene-styrene block copolymer: SEPS), hydrogenated styrene-butadiene-styrene block copolymer and hydrogenated styrene-butadiene block copolymer (styrene-ethylene/butylene-styrene block copolymer: SEBS) etc. Among the above polystyrene copolymers, hydrogenated styrene-isoprene-styrene block copolymer (SEPS) and hydrogenated styrene-butadiene-styrene block copolymer (SEBS) are preferred from the viewpoint of weather resistance. Particularly preferred is hydrogenated styrene-isoprene-styrene block copolymer (SEPS). The above hydrogenated styrene-isoprene-styrene block copolymer (SEPS) has the following general formula (4).
It is expressed by (S-EP)n-Sm・
...(4) (wherein, S represents a polystyrene moiety, EP represents a hydrogenated polyisoprene moiety (ethylene/propylene moiety), n is an integer from 1 to 20, and m is 0 or 1. ) The above-mentioned hydrogenated styrene-isoprene-styrene block copolymer includes a two-block type (SEP when n=1 and m=0) and a three-block type (SEP when n=1 and m=0). 1), and a multi-block type (in the case of n=2 to 20), but any of them can be used in the present invention. The hydrogenated styrene-isoprene-styrene block copolymer is prepared by treating the styrene-isoprene-styrene block copolymer with a styrene-isoprene-styrene block copolymer in the presence of a catalyst obtained by reducing a cobalt or nickel alkoxide with an alkyl aluminum compound. By hydrogenating at a temperature of 175°C, only the isoprene portion was selectively hydrogenated, forming a structure corresponding to an ethylene-propylene copolymer. [0045] In the hydrogenated styrene-isoprene-styrene block copolymer, it is not necessary that all of the isoprene portion is hydrogenated, as long as 5% or more is hydrogenated. The preferred hydrogenation ratio is 50% or more, more preferably 80% or more. The hydrogenated styrene-isoprene-styrene block copolymer has been explained above, but the hydrogenated styrene-butadiene-styrene block copolymer (SEB
S) or hydrogenated styrene-butadiene block copolymer
(SEB) is the same as in the above explanation except that isoprene is replaced with butadiene. In the present invention, the content of styrene moieties in such a polystyrene block copolymer is 40%.
It is about 80% by weight, preferably 50 to 70% by weight. If the styrene portion is less than 40% by weight, the effect of improving the compatibility between (a) polypropylene resin and (b) polystyrene resin will not be sufficient, while if it exceeds 80% by weight, it will become brittle. The content of the polystyrene moiety in the polystyrene block copolymer is usually about 15 to 35% by weight, but in the present invention, the content of the polystyrene moiety is about 15 to 35% by weight.
It is preferable to use at least % by weight. [0048] In the polystyrene block copolymer, the polystyrene portion is not limited to only styrene, but may also be composed of substituted styrene such as methylstyrene. The amount of the polystyrene block copolymer added (d) above is the same as that of (a) the polypropylene resin and (b) the polystyrene block copolymer.
) The total amount of polystyrene resin and (c) olefin elastomer modified with unsaturated carboxylic acid or its anhydride is 1 to 30 parts by weight based on 100 parts by weight. If the amount of the polystyrene block copolymer added is less than 1 part by weight, the effect of improving compatibility by its addition will not be sufficient, resulting in insufficient impact resistance, surface peeling resistance, etc. Moreover, if it exceeds 30 parts by weight, fluidity and rigidity will decrease. The preferred amount of polystyrene block copolymer added is 3 to 20 parts by weight. The thermoplastic resin composition of the present invention may further contain inorganic fillers such as talc and calcium carbonate, reinforcing materials such as glass fiber and carbon fiber, thermal stabilizers, and antioxidants for the purpose of modifying the composition. , light stabilizers, flame retardants, plasticizers,
Antistatic agents, mold release agents, foaming agents, etc. can be added. The thermoplastic resin composition of the present invention as described above can be prepared by mixing the above-mentioned components in a kneading machine such as a single screw extruder, a twin screw extruder, a Banbury mixer, a kneading roll, a Brabender, a kneader, or a Henschel mixer. Using a machine, 1
It can be obtained by heating and kneading in a molten state at 80 to 320°C, preferably 230 to 280°C. Alternatively, each of the above components may be divided and kneaded, and the resulting masterbatches may be kneaded together. [Operation] The thermoplastic resin composition of the present invention is a composition containing a polypropylene resin and a polystyrene resin, in which the polypropylene resin contains a certain amount of polypropylene modified with an epoxy group-containing monomer. Furthermore, since it is made by adding an olefin elastomer modified with an unsaturated carboxylic acid or its anhydride and a polystyrene block copolymer, surface peeling of the molded product is suppressed, and it has excellent impact resistance. Good mechanical properties. The reason why such an effect is obtained is not necessarily clear, but polystyrene block copolymers
In addition to strengthening the adhesion at the interface between the polypropylene resin and the polystyrene resin, the olefin elastomer modified with an unsaturated carboxylic acid or its anhydride and the polypropylene modified with an epoxy group-containing monomer are grafted together. This is thought to be because, since a polymer is formed, it becomes possible to introduce a rubber phase into polypropylene without causing surface peeling. EXAMPLES The present invention will be explained in more detail with reference to the following examples. Note that the following resins were used as raw material resins in each of the Examples and Comparative Examples. [1] Polypropylene resin HPP: Propylene homopolymer [melt flow rate (MFR, 230 °C, 2.16 kg load) 8.5 g
/10 minutes] [2] Ethylene-propylene copolymer rubber EPR: [manufactured by Japan Synthetic Rubber Co., Ltd., EP02P] [3]
Polystyrene resin PS: [GP-666, manufactured by Asahi Kasei Corporation] [4
] Modified olefin elastomer CMEPR with unsaturated carboxylic acid or its anhydride: Maleic anhydride (MAH) Modified ethylene-propylene copolymer rubber [manufactured by Nippon Gosei Rubber Co., Ltd.,
EP02P modified with maleic anhydride, maleic anhydride content 0.6% by weight] [5] Polystyrene block copolymer SEPS: [
Hydrogenated styrene-isoprene-styrene block copolymer, manufactured by Kuraray Co., Ltd.: KL-2104, styrene content 65% by weight] SEBS: [Hydrogenated styrene-butadiene-styrene block copolymer, manufactured by Shell Chemical Co., Ltd.: Clayton G-165
2. Styrene content: 29% by weight] [6] Epoxy group-containing modifying monomer AXE: glycidyl compound represented by the following chemical formula [Kanebuchi Chemical Co., Ltd.]
Synthesis Example 1 Synthesis of epoxy-modified polypropylene Polypropylene homopolymer (melt flow rate (M
FR, 230℃2.16kg load) 1.5g/10
) 100 parts by weight, 3 parts by weight of AXE mentioned above and P
Mixed with 0.1 part by weight of OX (radical generator: Perhexine 2-5B, manufactured by Nippon Oil & Fats Co., Ltd.), and
Using a twin-screw extruder of
-1) was obtained. The melt flow rate of the obtained modified polypropylene was 28.0 g/10 minutes, and the grafting rate of AXE was 2.4% by weight. [0057] The grafting rate of AXE is determined by dissolving modified polypropylene in boiling xylene and removing insoluble matter.
Dissolved components were precipitated with methanol, and this was
The infrared absorption spectrum of the AXE was measured and the peak (16
48 cm-1) and one of the peaks (840 cm-1) characteristic of isotactic polypropylene. Synthesis Example 2 Synthesis of Epoxy Modified Polypropylene Epoxy modified polypropylene (CMPP-2
) was obtained. The melt flow rate of the obtained modified polypropylene was 33.0 g/10 minutes, and the grafting rate of AXE was 1.0% by weight. Examples 1 to 7 and Comparative Examples 1 to 8 Polypropylene (HPP), ethylene-propylene copolymer rubber (EPR), polystyrene (PS), epoxy modified polypropylene (CMPP-1 or 2), unsaturated carboxylic acid The pellets of modified olefin elastomer (CMEPR) and polystyrene block copolymer (SEPS or SEBS) modified with olefin elastomer (CMEPR) or its anhydride were mixed at room temperature in a Henschel mixer in the proportions shown in Table 1, and then mixed in a Henschel mixer at room temperature. 200 to 260 using a shaft kneader
The mixture was kneaded at a temperature of 0.degree. C., and the extruded material was rapidly cooled in water to obtain pellets of the thermoplastic resin composition. For each thermoplastic resin composition obtained,
Melt flow rate, tensile elongation, flexural modulus, Izod impact strength and surface peelability were measured. The results are shown in Table 2. [0061]
Table 1 Composition


(Parts by weight) Example 1 Example 2 Example 3 Example 4 Example 5 HP
P50 55
30 20 2
0 PS
20 20 20
20 30
CMPP-1 15
10 35
35 35
CMPP-2 −
− − −
- CMEPR
15 15
15 25 15
SEPS 5
5 5
5 10
[0062] No.
1 Table (continued) Composition


(Parts by weight) Example 6 Example 7
Comparative example 1 Comparative example 2 Comparative example 3
HPP 50 50
80 80
80PS
20 20
20 20 20
CMPP-1
-15-
− −
CMPP-2 15
− − −
- CMEPR
15 15
− − −
SEPS 5
15 - -
5 SE
BS - -
- 5 -
[0063] No.
1 Table (continued) Composition


(Parts by weight) Comparative example 4 Comparative example 5
Comparative example 6 Comparative example 7 Comparative example 8
HPP 65 65
50 65
65 EPR
15-1
5 15 15
PS20
20 20
20 20
CMPP-1-
-15-
-CMPP-2
− −
− − −
CMEPR-
15-
− −
SEPS 5 5
− − −
SEBS-
-5 5
10 0064
Table 2 Physical properties
Example 1 Example 2
Example 3 MFR
(g/10 minutes) (1) 9.0
9.0 12.5
Tensile elongation (%) (2)
42 28
46
Flexural modulus (3) 121
00 12200 1200
0 (kg/cm2
)

Izod impact strength (4)
16.3 15.8
16.5 (k
gf cm/cm)

Surface removability (5
) 100/100
98/100 100/100
[0065] No.
2 Table (continued) Physical properties
Example 4 Example 5
Example 6 Example 7 MFR (g/
10 minutes) (1) 11.0
12.0 8.8
7.3 Tensile elongation (%) (2)
80 30
34 135 Flexural modulus (3) 9900
14200 12000
11000 (kg/cm2)


Izod impact strength (4)
21.0 13.2 1
2.2 31.3 (kgf c
m/cm)

Surface removability (5)
100/100 100/1
00 100/100 100/10
0 0066
2 Table (continued)
physical properties
Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 MFR (g/10
minutes) (1) 14 8.3
15.1 12.8
Tensile elongation (%) (2)
5 90 73
69 Flexural modulus (
3) 15500 1
4300 16200 12
600 (kg/cm2)


Izod impact strength (4) 1.5
3.4 3.1
9.0 (kgf cm/cm)


Surface removability (5)
0/100 33/100 100/1
00 70/100 0067] No.
2 Table (continued)
physical properties
Comparative example 5 Comparative example 6 Comparative example 7 Comparative example 8 MFR (g/10 min) (1)
14.0 16.2
7.9 7.3 Tensile elongation (%) (2) 65
60 156
165 Flexural modulus (3)
12600 12500
10600 9500
(kg/cm2)

Izod impact strength (4) 8.5
8.1 7.8 8
．． 3 (kgf cm/cm)


Surface removability (5) 62/1
00 65/100 38/10
0 48/100 0068 (1) Melt flow rate: JIS K
Measured at 230°C and 2.16kg load according to 6758. (2) Tensile elongation: Measured according to JIS K7113. (3) Flexural modulus: Measured according to JIS K7203. (4) Izod impact strength: Measured at 23°C in accordance with JIS K7110 (notched). (5) Surface releasability: Molded product (70 mm x 120 m
Use a razor to cut 1mm onto the surface of the injection material (m x 3mm)
100 x 1 mm squares were formed, cellophane tape (manufactured by Nichiban Co., Ltd.) was attached to the squares, and then removed. Out of 100 squares, the number of squares that did not adhere to the cellophane tape and remained on the surface of the molded product was counted. As is clear from Table 2, Examples 1 to 7
The thermoplastic resin composition has suppressed surface peeling,
In addition to being excellent in impact resistance, mechanical strength such as tensile elongation and flexural modulus was also good. On the other hand, the thermoplastic resin composition of Comparative Example 1, which is an example of a two-component system of polypropylene and polystyrene, had extremely poor surface peeling resistance, and also had poor elongation at break and impact resistance values. Furthermore, the thermoplastic resin compositions of Comparative Examples 2 and 3, which are examples of three-component systems of polypropylene, polystyrene, and polystyrene block copolymers, had poor impact resistance. Furthermore, the thermoplastic resin compositions of Comparative Examples 4 to 8 did not have sufficient surface peeling resistance and impact resistance. This is thought to be because although it contains a rubber component, its compatibility is insufficient. Effects of the Invention As detailed above, the thermoplastic resin composition of the present invention is a composition containing a polypropylene resin and a polystyrene resin. A material containing a certain amount of modified polypropylene is used, and an olefin elastomer modified with an unsaturated carboxylic acid or its anhydride and a polystyrene block copolymer are added. Therefore, surface peeling of the molded product is suppressed, and the molded product has excellent impact resistance and good mechanical properties. The thermoplastic resin composition of the present invention is suitable for use as an engineering plastic material, particularly for parts of automobiles and home appliances.

Claims (5)

[Claims] Claim 1: (a) 5 to 98% by weight of a polypropylene resin containing 1% by weight or more of polypropylene modified with an epoxy group-containing monomer; (b) 95 to 2% by weight of a polystyrene resin; and (a) + (b) above
(c) 5 to 100 parts by weight of an olefinic elastomer modified with an unsaturated carboxylic acid or its anhydride, and (a) + (
For a total of 100 parts by weight of b) + above (c),
(d) A thermoplastic resin composition comprising 1 to 30 parts by weight of a polystyrene block copolymer. 2. The thermoplastic resin composition according to claim 1, wherein the content of the polystyrene moiety in the polystyrene block copolymer (d) is 40 to 80% by weight. Resin composition. 3. The thermoplastic resin composition according to claim 1 or 2, wherein the content of the epoxy group-containing monomer is 0.01 to 20% by weight based on 100% by weight of the entire polypropylene resin (a). A thermoplastic resin composition characterized in that: 4. The thermoplastic resin composition according to claim 1, wherein the polystyrene block copolymer is a styrene-isoprene-styrene block copolymer or a styrene-butadiene-styrene block copolymer. Coalescence, styrene-isoprene block copolymer, styrene-butadiene block copolymer, hydrogenated styrene-
It is characterized by being selected from isoprene-styrene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, hydrogenated styrene-isoprene block copolymer, and hydrogenated styrene-butadiene block copolymer. thermoplastic resin composition. 5. The thermoplastic resin composition according to claim 1, wherein the epoxy group-containing monomer has the following general formula: [Formula 1] (wherein R is H or has 1 to 6 carbon atoms is an alkyl group of
A thermoplastic resin characterized in that it is a glycidyl compound represented by Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms and having at least one glycidyloxy group, and n represents an integer of 1 to 4. Composition.