KR100330352B1 - Syndiotactic Polystyrene Compositions having Improved Impact Strength - Google Patents

Abstract

Syndiotactic polystyrene resin composition excellent in impact resistance of the present invention is (A) syndiotactic polystyrene (sPS); (B) hydrogenated styrene / butadiene / styrene block copolymers (SEBS), polypropylene (PP) or ethylene / propylene / diene rubber (EPDM); (C) hydrogenated styrene / butadiene / styrene-maleic anhydride copolymer (hydrogenated styrene / butadiene / styrene-maleic anhydride copolymer: SEBS-MA), polypropylene-graft-maleic anhydride (PP-g-MA), ethylene / Propylene / diene rubber-graft-polystyrene (EPDM-g-PS) or ethylene / propylene / diene rubber-graft-maleic anhydride (EPDM-g-MA); (D) polyphenylene oxide (PPO); (E) syndiotactic polystyrene-maleic anhydride (sPS-MA); (F) diamine compounds; And optionally (G) glass fibers (GF). The resin composition according to the present invention may optionally further include ethylene vinyl acetate (EVA).

Description

Syndiotactic Polystyrene Compositions having Improved Impact Strength

Field of invention

The present invention relates to a syndiotactic polystyrene resin composition excellent in impact resistance. More specifically, the present invention provides syndiotactic polystyrene-maleic anhydride (sPS-MA) and hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) which are rubber components as a compatibilizer in a composition comprising syndiotactic polystyrene. The present invention relates to a syndiotactic polystyrene resin composition having excellent mechanical properties and particularly excellent impact strength by adding a diamine compound. PP-g-MA, EPDM-g-PS or EPDM-g-MA may be used instead of the SEBS-MA.

Background of the Invention

Syndiotactic polystyrene, a polymer having a crystalline structure, has a high melting point (T _m ) of about 270 ° C., and is of interest because of its excellent mechanical properties including thermal stability and rigidity. However, its use has been extremely limited because of its low impact resistance. In order to solve this problem, many studies have been conducted on the technology of improving the impact strength by introducing a rubber-based impact modifier and various compatibilizers. 5,270,353 5,391,603 and 5,352,727).

The conventional techniques are phase separation by improving the interfacial properties between rigid syndiotactic polystyrene and rubber components by using a rubber component as a compatibilizer and a method of reinforcing elasticity through simple kneading of syndiotactic polystyrene and rubber components. Can be categorized in two ways to prevent it from happening. Of these, the latter method is more preferable for workability and reproducibility of physical properties. However, in the latter case, since the mechanism of applying the compatibilizer is limited to improving the polarity of the rubber component, the impact strength has been limited.

The present inventors apply syndiotactic polystyrene-maleic anhydride (sPS-MA) and hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) as compatibilizers between syndiotactic polystyrene and rubber components, or the SEBS Syndiotactic polystyrene and PP-g-MA, EPDM-g-PS or EPDM-g-MA instead of -MA and by adding a diamine compound and also adding a polar substance such as ethylene vinyl acetate (EVA) It is to develop a syndiotactic polystyrene resin composition excellent in impact resistance by imparting polarity to all rubber components and improving interfacial properties.

It is an object of the present invention to apply syndiotactic polystyrene-maleic anhydride (sPS-MA) and hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) as compatibilizers, or PP-g instead of SEBS-MA. By applying -MA, EPDM-g-PS or EPDM-g-MA and adding a diamine compound, the compatibility between syndiotactic polystyrene and rubber components is increased to provide a syndiotactic polystyrene resin composition having excellent impact resistance. will be.

Another object of the present invention is to provide a syndiotactic polystyrene resin composition having excellent miscibility by mixing a polar polymer such as ethylene vinyl acetate (EVA).

The above and other objects of the present invention can be achieved by the present invention described below. Hereinafter, the content of the present invention will be described in detail.

1 is an electron microscope (SEM) photograph of the shape of an interface of a syndiotactic polystyrene (sPS) / polypropylene (PP) compound.

2 is an electron micrograph (SEM) photograph of the shape of the interface of the syndiotactic polystyrene (sPS) / polypropylene (PP) / diamine compound.

Syndiotactic polystyrene resin composition of the present invention is syndiotactic polystyrene maleic anhydride (sPS-MA) and hydrogenated styrene / butadiene / styrene maleic anhydride (SEBS) as a rubber component as a compatibilizer for impact reinforcement in syndiotactic polystyrene as a main component. By applying -MA) and adding a diamine compound, it has excellent properties of impact resistance and improved interfacial properties. PP-g-MA, EPDM-g-PS or EPDM-g-MA may be used instead of the SEBS-MA.

Coupling reaction between syndiotactic polystyrene-maleic anhydride (sPS-MA), a compatibilizer in which syndiotactic polystyrene is treated with maleic anhydride, and the hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) Compatibility with each other is increased. PP-g-MA, EPDM-g-PS or EPDM-g-MA may be used instead of the SEBS-MA. In addition, using a polar polymer such as ethylene vinyl acetate (EVA), syndiotactic polystyrene-maleic anhydride (sPS-MA) and diamine (diamine) are basically miscible with hydrogenated styrene / butadiene / styrene (SEBS). ) Compound (sPS-MA-diamine-MA-SEBS) so that the miscibility is good, and finally a syndiotactic polystyrene resin composition excellent in miscibility can be obtained.

The coupling reaction between syndiotactic polystyrene and the compatibilizer is shown in Scheme (1):

In Scheme (1), R is to be.

As shown in the formula (1), through the chemical bonding of the diamine compound between the syndiotactic polystyrene as a main component and the rubber component added as a compatibilizer, the interfacial property is improved, so that the impact of the rubber component blended is also possible. The effect can be increased depending on the kind of diamine.

Hereinafter, each component of the resin composition of the present invention will be described in detail.

(A) Syndiotactic Polystyrene (sPS)

Syndiotactic polystyrene is polymerized in a catalyst system consisting of a novel metallocene catalyst and a cocatalyst. The metallocene catalyst has a structure in which an auxiliary ligand of a transition metal compound and a functional group of the compound are linked to each other, and vary greatly depending on the kind of the transition metal compound or the kind of the compound having two or more functional groups and the molar ratio of each reactant. May exist in the form.

(B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS)

It is an impact modifier added to increase the impact strength of syndiotactic polystyrene as a rubber component. Polypropylene (PP) or ethylene / propylene / diene rubber (EPDM) may be used instead of SEBS to increase impact strength.

(C) hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA)

SEBS-MA is a compatibilizer added to increase the compatibility between syndiotactic polystyrene and rubber components, and was prepared by treating styrene / butadiene / styrene with maleic anhydride. Polypropylene-graft-maleic anhydride (PP-g-MA), ethylene / propylene / diene rubber-graft-polystyrene (EPDM-g-PS) or ethylene / propylene / diene rubber-graft instead of SEBS-MA Maleic anhydride (EPDM-g-MA) may be used. PP-g-MA is a compatibilizer added to increase the compatibility between the syndiotactic polystyrene and the rubber component, and is prepared by treating polypropylene (PP) with maleic anhydride. EPDM-g-PS is prepared by graft polymerization of EPDM with polystyrene, and EPDM-g-MA is prepared by graft polymerization of EPDM with maleic anhydride.

(D) polyphenylene oxide (PPO)

PPO is added to increase the compatibility of syndiotactic polystyrene with the rubber component.

(E) syndiotactic polystyrene-maleic anhydride (sPS-MA)

sPS-MA is a compatibilizer added to increase the compatibility between syndiotactic polystyrene and rubber components, and is prepared by treating syndiotactic polystyrene with maleic anhydride.

(F) diamine compounds

The diamine compound represented by the following formula was used and added to increase the compatibility by increasing the compatibility between the components:

(G) glass fiber (GF)

Glass fiber was applied as an inorganic filler.

(H) Ethylene Vinyl Acetate (EVA)

In order to prepare a polystyrene resin composition having excellent impact characteristics at a specific content, ethylene vinyl acetate having polarity was applied.

(I) Other Ingredients

Syndiotactic polystyrene resin composition of the present invention may be added dropping inhibitors, nucleating agents, impact modifiers, processing aids, thermal stabilizers, antioxidants, light stabilizers and the like, pigments, dyes and sulfates, asbestos, talc, silica Inorganic fillers such as ceramics, and the like may also be added.

One embodiment of the syndiotactic polystyrene resin composition of the present invention is (A) 50 to 95 parts by weight of syndiotactic polystyrene (sPS), (B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS) (B1) 2 to 20 parts by weight, (C) hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) (C1) 1 to 10 parts by weight; (D) 1 to 10 parts by weight of polyphenylene oxide (PPO); (E) 1 to 10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA), 0.02 to 20 parts by weight of (F) diamine compound, and optionally 5 to 30 parts by weight of (G) glass fiber (GF).

Another specific example of the syndiotactic polystyrene resin composition of the present invention is (A) 50 to 96 parts by weight of syndiotactic polystyrene (sPS), (B) polypropylene (PP) (B ₂ ) or ethylene propylene diene rubber ( EPDM) (B ₃ ) 1 to 20 parts by weight, (C) polypropylene-g-maleic anhydride (PP-g-MA) (C ₂ ), ethylene / propylene / diene rubber-g-maleic anhydride (EPDM-g- MA) (C ₃ ) or ethylene / propylene / diene rubber-g-polystyrene (EPDM-g-PS) (C4) 1 to 20 parts by weight, (D) 0 to 10 parts by weight of polyphenylene oxide (PPO), ( E) 1 to 10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA), and 0.02 to 30 parts by weight of (F) diamine compound.

Another embodiment of the syndiotactic polystyrene resin composition of the present invention is (A) 2 to 90 parts by weight of syndiotactic polystyrene, (B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS) (B ₁ ) 0 to 10 parts by weight, (C) hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) (C ₁ ) 2 to 10 parts by weight, (D) 2 to 10 parts by weight of polyphenylene oxide (PPO), (E) 0 to 10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA), 0.02 to 20 parts by weight of (F) diamine compound, and (H) 6 to 90 parts by weight of ethylene vinyl acetate (EVA).

Another embodiment of the syndiotactic polystyrene resin composition of the present invention is (A) 2 to 93 parts by weight of syndiotactic polystyrene, (B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS) (B ₁ ) 0-10 parts by weight, (D) 0-10 parts by weight of polyphenylene oxide (PPO), (E) 0-10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA), (G) glass fiber (GF ) 1 to 50 parts by weight, and (H) 5 to 90 parts by weight of ethylene-vinyl-acetate (EVA).

Syndiotactic polystyrene composition of the present invention can be more clearly understood by the following examples, the following examples are merely illustrative purposes of the present invention and are not intended to limit the scope of the invention.

Example

(A) syndiotactic polystyrene (sPS), (B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS) (B ₁ ), polypropylene (PP) used in the resin compositions of the following examples and comparative examples (B ₂ ) or ethylene propylene diene rubber (EPDM) (B ₃ ), (C) hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) (C ₁ ), polypropylene-g-maleic anhydride (PP- g-MA) (C ₂ ), ethylene / propylene / diene rubber-g-maleic anhydride (EPDM-g-MA) (C ₃ ) or ethylene / propylene / diene rubber-g-polystyrene (EPDM-g-PS) ( C ₄ ) 1 to 20 parts by weight, (D) polyphenylene oxide (PPO), (E) syndiotactic polystyrene-maleic anhydride (sPS-MA), (F) diamine compound and other additives Same as

(A) Syndiotactic Polystyrene (sPS)

Styrene polymerization was carried out in a glass reactor equipped with a valve capable of supplying monomers and nitrogen, using an external temperature controller, a magnetic stirrer or a mechanical stirrer. After the addition of methyl aluminum oxane as a promoter and stirred for 30 minutes sufficiently, the required amount of catalyst was injected to initiate polymerization at 70 ℃. After the reaction for 1 hour, a little methanol was added to terminate the polymerization. The obtained mixture was washed with a large amount of methanol added with sodium hydroxide and then filtered, and the polymer thus obtained was dried at 90 DEG C for at least 4 hours in a vacuum to obtain syndiotactic polystyrene.

(B) (B ₁ ) hydrogenated styrene / butadiene / styrene block copolymer (SEBS)

SEBS used Kraton G-1651, a commercial product from Shell.

(B ₂ ) Polypropylene (PP)

PP used Samsung General Chemical's HJ400. (B ₃ ) Ethylene propylene diene rubber (EPDM) EPDM used KEPCO's KEP-570P.

(C) (C ₁ ) hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA)

As SEBS-MA, M-1913, a commercial product of Asahi Japan, was used.

(C ₂ ) polypropylene-graft-maleic anhydride (PP-g-MA) (C ₃ ) ethylene / propylene / diene rubber-graft-polystyrene (EPDM-g-PS)

EPDM-g-PS was synthesized by reacting EPDM with a styrene monomer at a temperature of 70 ° C. in the presence of an initiator (AIBN). (C ₄ ) Ethylene / propylene / diene rubber-graft-maleic anhydride (EPDM-g EPDM-g-MA used Unilor's Excellor product.

(D) polyphenylene oxide (PPO)

As the PPO, P401, a commercial product of Asahi Corp., was used.

(E) syndiotactic polystyrene-maleic anhydride (sPS-MA)

sPS-MA was prepared by stirring syndiotactic polystyrene (A), dicumyl peroxide (DCP) and maleic anhydride (1.05 wt%) polymerized above in a 10 L reactor.

(F) diamine compounds

As the diamine compound, a diamine compound represented by the following formula was used:

(G) glass fiber (GF)

Glass fiber was used by Owin-Corning 492A.

(H) Ethylene Vinyl Acetate (EVA)

EVA used E220F (vinyl acetate content: 22%) product of Samsung Total Chemical.

In addition, the primary / secondary antioxidant (S25 / S29) applied to the resin composition of the present invention is used in 0.01 parts by weight, and a general styrene additive may also be used. All resin compositions used in the following Examples and Comparative Examples are formulated with antioxidants.

Example 1 and Comparative Example 1-4: Resin composition 1

Each of the components was prepared in the resin compositions of Example 1 and Comparative Examples 1 to 4 with the composition shown in Table 1. The resin compositions of Example 1 and Comparative Examples 1 to 4 were prepared in the amounts shown in Table 1 below. In a batch-type mixer of Haake, Germany, 0.1 wt% of styrene-based antioxidants (primary and secondary) were added and kneaded at 50 rpm for 7 minutes at a temperature of 280 ° C., followed by ASTM D-256. Measurement specimens were prepared at a molding temperature of 300 ° C. in a mold. The prepared specimens were measured for Izod impact strength with 1/8 "notched specimens and the results are shown in Table 1.

For the compositions of Example 1 and Comparative Example 2 (Idemitsu Co., Ltd .; US Pat. No. 5,777,028), the processing temperature of 280 ° C. in a conventional twin screw extruder was evaluated to evaluate the applicability of other mechanical properties and the continuous process of blending, respectively. Extruded in the form of pellets. The prepared pellets were dried for 3 hours at a temperature of 80 ° C., and then injected under a condition of a molding temperature of 300 ° C. in a 6Oz injection machine to prepare a physical specimen, and the mechanical properties thereof were measured and the results are shown in Table 2 below.

⁽¹⁾ Measured according to ASTM D638, ⁽²⁾ ASTM D790.

When the syndiotactic polystyrene-maleic anhydride (sPS-MA) (E) or the diamine compound (F) was added, the notched Izod impact strength was better than that of the non-added compound, especially when the diamine compound was not added. Izod impact strength was higher than that. In addition, the break strength, yield strength, flexural stiffness and flexural strength were all better than those without the addition of the components (E) and (F).

Example 2-8

(G) Glass fiber (GF) was further used in Example 2-5, and EPDM-g-PS (C ₂ ) was used instead of SEBS-MA (C ₁ ) in Example 6-8 and (G) It was prepared in the same manner as in Resin Composition 1, except that glass fiber (GF) was further used. Molding and evaluation method for the impact strength evaluation was measured in the same manner as the resin composition 1, the composition and the results are shown in Table 3.

When EPDM-g-PS was used as a compatibilizer for the rubber component from Table 3, a slight impact strength improvement was observed as the content was increased, and hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS) was used as the compatibilizer. In the case of using -MA), when the diamine compound was used while the content of sPS-MA was small, the improvement in impact strength was rapidly increased to almost three times.

Examples 9-17 and Comparative Example 5: Resin Composition 2

Except for using polypropylene (PP) as a rubber component and polypropylene-g-maleic anhydride (PP-g-MA) instead of SEBS-MA as a compatibilizer, was prepared in the same manner as the resin composition 1 and impact The strength was measured, and the composition and the results are shown in Table 4.

As shown in Table 4, in Examples 9-17, the impact strength of the compound was improved as the content of the diamine compound increased and the amount of the rubber component (PP) treated with maleic anhydride (MA) increased. Particularly, as can be easily distinguished from the SEM images of FIGS. 1 and 2, when a simple mixture of syndiotactic polystyrene and PP, a rubber component, the shape of the interface has a nonuniform particle size and a discontinuous surface appears. As shown in Example 5, it can be verified that the low impact strength is shown.

Examples 18-19 and Comparative Examples 6-12

Except for further applying EPDM and EPDM-g-MA as a compatibilizer was prepared in the same manner as in the resin composition 1, the impact strength was measured. The compositions and results are shown in Table 5.

As in Example 18-19, as the amount of the diamine compound applied and the rubber component ethylene propylene diene rubber (EPDM) treated with MA increased, the impact strength of the resin composition was improved. On the other hand, when the diamine compound was not applied as in Comparative Example 6-12, the rubber component was treated with or without MA, or both were found to have lower impact strength than Example 18-19.

Example 20-27 Resin Composition 3

Except that ethylene vinyl acetate (EVA) was further applied as a compatibilizer was prepared in the same manner as in the resin composition 1, the impact strength was measured. The compositions and results are shown in Table 6.

In order to observe the composition ratio of the rubber component EVA showing excellent impact strength, an experiment was conducted for each content of EVA. Except in the case of non-cutting during the impact test as shown in Table 6, the resin composition that maintains the highest impact strength was the case of 35 to 40 parts by weight of sPS and 55 to 60 parts by weight of EVA.

Example 28-35 Resin Composition 4

30 parts by weight of glass fiber (GF) was added to carry out additional experiments corresponding to the composition, and the results are shown in Table 7.

As shown in Table 7, the resin composition added with sPS, SEBS, PPO and sPS-MA showed the highest impact strength than the composition consisting of the rubber components EVA and GF only. That is, EVA is a new impact reinforcing rubber component of syndiotactic polystyrene, and it can be seen that it can be applied more economically than the existing impact reinforcing material SEBS.

The present invention applies syndiotactic polystyrene maleic anhydride (sPS-MA) and hydrogenated styrene / butadiene / styrene maleic anhydride (SEBS-MA) as compatibilizers and adds a polar polymer such as a diamine compound or ethylene vinyl acetate (EVA) As a result, the interfacial property is improved to have excellent miscibility and to provide a syndiotactic polystyrene resin composition having improved impact strength.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (10)

(A) 50-95 parts by weight of syndiotactic polystyrene (sPS); (B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS) (B ₁ ), polypropylene (PP) (B ₂ ) and ethylene / propylene / diene rubber (EPDM) (B ₃ ) 2 to 20 parts by weight of the compound; (C) hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) (C ₁ ), ethylene / propylene / diene rubber-graft-polystyrene (EPDM-g-PS) (C ₂ ), ethylene / propylene / 1-10 weight compound selected from the group consisting of diene rubber-graft-maleic anhydride (EPDM-g-MA) (C ₃ ) and polypropylene-graft-maleic anhydride (PP-g-MA) (C ₄ ) part; (D) 1 to 10 parts by weight of polyphenylene oxide (PPO); (E) 1 to 10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA); And (F) 0.02-20 weight part of diamine compounds; Syndiotactic polystyrene resin composition excellent in impact resistance, characterized by consisting of. The syndiotactic polystyrene resin composition according to claim 1, wherein (G) glass fiber (GF) is further added in an amount of 5 to 30 parts by weight. (A) 50-95 parts by weight of syndiotactic polystyrene (sPS); (B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS) (B ₁ ), polypropylene (PP) (B ₂ ) and ethylene / propylene / diene rubber (EPDM) (B ₃ ) 2 to 20 parts by weight of the compound; (C) hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) (C ₁ ), ethylene / propylene / diene rubber-graft-polystyrene (EPDM-g-PS) (C ₂ ), ethylene / propylene / 1-10 weight compound selected from the group consisting of diene rubber-graft-maleic anhydride (EPDM-g-MA) (C ₃ ) and polypropylene-graft-maleic anhydride (PP-g-MA) (C ₄ ) part; (E) 1 to 10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA); And (F) 0.02-20 weight part of diamine compounds; Syndiotactic polystyrene resin composition excellent in impact resistance, characterized by consisting of. The syndiotactic polystyrene resin composition according to claim 3, wherein (G) glass fiber (GF) is further added in an amount of 5 to 30 parts by weight. (A) 50-95 parts by weight of syndiotactic polystyrene (sPS); (C) hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) (C ₁ ), ethylene / propylene / diene rubber-graft-polystyrene (EPDM-g-PS) (C ₂ ), ethylene / propylene / 1-10 weight compound selected from the group consisting of diene rubber-graft-maleic anhydride (EPDM-g-MA) (C ₃ ) and polypropylene-graft-maleic anhydride (PP-g-MA) (C ₄ ) part; (D) 2 to 10 parts by weight of polyphenylene oxide (PPO); (E) 1 to 10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA); (F) 0.02-20 weight part of diamine compounds; And (H) 6 to 90 parts by weight of ethylene vinyl acetate (EVA); Syndiotactic polystyrene resin composition excellent in impact resistance, characterized by consisting of. The syndiotactic polystyrene resin composition according to claim 5, wherein (G) glass fiber (GF) is further added in an amount of 5 to 30 parts by weight. The method according to any one of claims 1 to 6, wherein the nucleating agent, anti-dripping agent, impact modifier, processing aid, heat stabilizer, antioxidant, light stabilizer, pigment, dye and sulfate, asbestos, talc, silica, and / or ceramic Syndiotactic polystyrene resin composition excellent in impact resistance, further comprising the same inorganic filler. (A) 2-93 parts by weight of syndiotactic polystyrene; (B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS) (B ₁ ), polypropylene (PP) (B ₂ ) and ethylene / propylene / diene rubber (EPDM) (B ₃ ) 0.01 to 10 parts by weight of the compound; (D) 2 to 10 parts by weight of polyphenylene oxide (PPO); (E) 0.01 to 10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA); (G) 1 to 50 parts by weight of glass fiber (GF); And (H) 5-90 parts by weight of ethylene vinyl acetate (EVA); Syndiotactic polystyrene resin composition excellent in impact resistance, characterized by consisting of. The impact resistance according to claim 8, further comprising 2 to 10 parts by weight of hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) (C ₁ ) and 0.02 to 20 parts by weight of the diamine compound (F). This excellent syndiotactic polystyrene resin composition. 10. The inorganic filler according to claim 8 or 9, which is a nucleating agent, anti-dripping agent, impact modifier, processing aid, heat stabilizer, antioxidant, light stabilizer, pigment, dye and sulfate, asbestos, talc, silica, and / or ceramic Syndiotactic polystyrene resin composition excellent in impact resistance, further comprising a.