KR910003257B1 - Thermoplastic resin composition - Google Patents

Abstract

The thermoplastic resin composition comprises (A) 40-90 wt. pts. of polyamide resin; (B) 5-30 wt. pts. of core-shell type polymer contg. 20-90 wt.% of acrylic or diene rubber and 80-10 wt.% unsatd. polymer to be grafted that rubber component; and (C) 0.5-30 wt. pts of bisphenol A-epichlorohydrin copolymer. Pref. the polyamide resin is one or more the copolymer or blend of nylon 6, nylon 66, nylon 11, or nylon 12. The obtd. resin compsn. has good mechanical properties, workability, apperance and impact resistance.

Description

Thermoplastic resin composition

The present invention relates to a thermoplastic resin composition having excellent mechanical strength, excellent workability and appearance, and excellent impact resistance. More specifically, the present invention relates to a polyamide resin and a core-shell resin copolymer and bisphenol A-. It relates to a thermoplastic resin composition composed of an epichlorohydrin (bisphenol A-epichlorohydrine) copolymer.

In general, polyamide resins are predominant in the engineering plastics because of their excellent abrasion resistance, chemical resistance and mechanical properties, but they exhibit very low impact strength below the secondary transition temperature (hereinafter referred to as Tg) and require impact resistance. Has been subject to many constraints.

In order to make up for this drawback, a method such as "water treatment" of a molded article is used. However, since the process is cumbersome and the impact resistance can be improved only in a limited range, in recent years, the impact modifier is copolymerized or blended to improve the resistance of polyamide resin. There is extensive research to improve impact properties.

Most of the impact modifiers are elastomers: ethylene-propylene elastomers (EPR), ethylene-propylene-diene elastomers (EPDM), styrene-butadiene elastomers (SBR), acrylonitrile-butadiene elastomers (NBR), acrylonitrile Butadiene-styrene copolymer (ABS), methyl methacrylate-butadiene-styrene copolymer (MBS) and the like have been mainly used, but it is difficult to improve the impact resistance of the resin composition due to the low compatibility with polyamide resins. .

Truly compatible mixtures do not separate as individual phases and form a homogeneous composition, while incompatible polymer mixtures are characterized by their interphase coupling. It is weak and cannot produce a good resin composition with high impact strength.

As a method for preventing phase separation, the formation of cross-linking using a peroxide compound, a thermal crosslinking or a redistribution technique in two minutes, or an amide on a rubber core It is known to increase the impact resistance of a polyamide resin by grafting a monomer containing a carboxyl group capable of reacting with a group. US Pat. No. 4,221,879 discloses the use of polybutadiene as a grafting substrate and the use of acrylates, methacrylates, acrylonitrile and acrylamides as shells to increase the impact strength. In addition, in the case of EPDM and EPR, the impact strength cannot be increased due to incompatibility with nylon resin, so that the impact resistance is improved by forming a covalent bond with the amide group of the polyamide after grafting monomers such as maleic anhydride or acid. Methods are also known, but these methods require a strong shear force iintensive shear iorce to homogeneously disperse the rubber or elastomers used in the polyamide resin, and in the final composition, the molecular weight increases rapidly, resulting in low fluidity and processability. The disadvantages of this have a negative effect on the appearance and the beautiful appearance, as well as difficulties in reinforcements with fiberglass or inorganic fillers. In addition, the heat deflection temperature of the nylon itself was 60 ° C. at 264 psi, which made it difficult to apply in high temperature applications.

In order to solve the above problems, the present inventors have copolymerized a polyamide resin, bisphenol A-epichlorohydrin (bisphenolA) and a copolymer obtained by grafting two or more different monomers to different core structures of acrylic rubber or butadiene rubber. As a result of blending the -epichlorohydrine) copolymer, it was found that not only the impact strength was improved but also the fluidity was improved, and the workability was improved, and the heat resistance was significantly increased, thereby completing the present invention.

That is, the present invention provides a core-shell comprising 40-90 parts by weight of (A) polyamide resin, (B) 20-90% by weight of acrylic rubber or diene rubber and 80-10% by weight of unsaturated compound graftable to rubber component. The resin composition comprised as 5-30 weight part of copolymers of the form, and 0.5-30 weight part of (C) bisphenol A- epichlorohydrin copolymer.

Hereinafter, the present invention will be described in detail.

In the present invention, the polyamide resin as the component (A) is a linear crystalline polymer having a common amide group, and examples thereof include nylon 6, nylon 66, nylon 11, nylon 12 and copolymers or blends thereof. 6, or nylon 66 and blends thereof are particularly preferred.

In addition, the component (B) used in the present invention is a core-shell copolymer, which is prepared by a conventional emulsion polymerization method, and each component is as follows. The rubber component constituting the core component is acrylic, which is acrylic acid ethyl ester, acrylic acid butyl ester, acrylic acid propyl ester, acrylic acid-2-ethylhexyl ester, and the like, butadiene type is butadiene, isopten, chloroprene, cyanobutadiene It can be used, the preferred amount to improve the impact resistance is 40 to 80 parts by weight relative to the total (B) component. In addition, unsaturated compounds which can be grafted to rubber, which is a core component for forming a shell, include styrene, α-methylstyrene, halostyrene, p-ethylstyrene, acrylonitrile, methyl methacrylate, N-phenylmaleimide, and methacryl. Ronitrile, butyl methacrylonitrile, butyl methacrylate, etc. are used, and it is preferable to form a copolymer using 2 or more types of the said monomers.

-OH), P, P'-디페닐케톤 (HO-

-OH), P, P'-디페닐에테르(HO-

-O-

-OH),비스페놀 A(HO-

-OH),등과 에피클로히드린(

-CH₂Cl)이 탈염산화 반응(dehydrochlorination)에 의해, 형성된 비스페놀 A-에피클로로히드린 공중합체로서 페녹시 수지(phenoxy resin)라는 상품으로 시판되고 있다. 이 공중합체의 분자랑은 대체로 500-300,000까지 사용될 수 있다.Bisphenol A-epichlorohydrin copolymer used as component (C) of the present invention is P, P'-diphenylsulfone (HO-

-OH), P, P'-diphenyl ketone (HO-

-OH), P, P'-diphenyl ether (HO-

-O-

-OH), bisphenol A (HO-

-OH), etc. and epichlorohydrin (

-CH ₂ Cl) is a bisphenol A-epichlorohydrin copolymer formed by dehydrochlorination and is commercially available as a phenoxy resin. The molecular weight of this copolymer can generally be used up to 500-300,000.

In this experiment, nylon 6 and MBS (methyl methacrylate-butadiene-styrene) copolymer and Union Carbide phenoxy (molecular weight 25,000) were used. Due to transesterification and hydrogen bonding of nylon 6 and phenoxy, there is a compatibility between MBS and phenoxy resins in which a large amount of methyl methacrylate is grafted. The formation of hydrogen bonds increased the compatibility between the two phases. Therefore, MBS is evenly distributed between both phases, which greatly improves impact resistance. In addition, since the compatibility was increased by hydrogen bonding rather than chemical bonding, it did not significantly affect the melt flow, thereby improving high meltability and processability, and the thermal deformation temperature was large due to the heat resistance of the phenoxy resin itself. Improved.

The preparation of the polyamide resin composition of the present invention is obtained by conventional melt mixing such as Banbury mixing, kneader, twin screw milling or extrusion and required Depending on the pigments, dyes, mold release agents, heat stabilizers, antioxidants, lubricants, heat-retardant and the like can be added and can be reinforced with glass fibers or inorganic fillers to obtain excellent mechanical strength.

It will be described in detail by the following examples.

Example 1

80 g of nylon 6, 20 g of MBS, and 0.5 g of phenoxy resin were kneaded for 30 seconds at a barrel temperature of 240-260 ° C. in a busnider, and the die temperature was adjusted to 250 ° C. for die-passing. It was passed through cooling water and pelleted. All compositions made of pellets were manufactured in specimens conforming to the ASTM standard at a temperature of 250 ° C. through an injection molding machine, and the melt index and heat deflection temperature (HDT) of impact strength were measured and the results are shown in Table III.

Example 2

Except that 80g nylon 6 and 20g MBS 3g phenoxy resin was used to prepare a specimen in the same manner as in Example 1, the physical properties were measured and the results are shown in Table III.

Example 3

Except that 80 g of nylon 6, 20 g of MBS, and 5 g of phenoxy resin were used to prepare the specimens in the same manner as in Example 1, the physical properties thereof were measured and the results are shown in Table III.

Example 4-8

Except for using nylon 6, MBS, and phenoxy resin as shown in Table I, after the specimen was prepared in the same manner as in Example 1, the physical properties were measured and the results are shown in Table [I].

TABLE 1

Except that 80 g of nylon 6 and 20 g of MBS were prepared, the specimens were prepared in the same manner as in Example 1, and the physical properties thereof were measured. The results are shown in Table III.

Comparative Example 2-4

After the specimens were prepared in the same manner as in Example 1 except that MBS and nylon 6 or nylon 6 and phenoxy, MBS and phenoxy resins were used as shown in Table II, the physical properties thereof were measured and the results are shown in Table III. It was.

TABLE 2

TABLE 3

As described above, the composition having the composition of the present invention is not only improved in impact strength, but also has high fluidity and improved workability, and heat resistance is significantly increased as compared with the comparative example.

Claims (5)

(A) 40-90 parts by weight of polyamide resin, (B) 20-90% by weight of acrylic rubber or diene rubber and 80-10% by weight of unsaturated compound grafted to the rubber component. A thermoplastic resin composition composed of 30 parts by weight and (C) bisphenol A-epichlorohydrin copolymer 0.5-30 parts by weight. The thermoplastic resin composition according to claim 1, wherein the polyamide resin is at least one selected from nylon 6, nylon 66, nylon 11, nylon 12 and copolymers or blends thereof. The core-shell copolymer according to claim 1, wherein the core-shell copolymer is selected from acrylic acid ethyl ester, acrylic acid butyl ester, acrylic acid propyl ester, acrylic acid 2-ethyl hexyl ester, butadiene, isoprene, tallowoprene, cyanobutadiene. 1 or more and the shell component is selected from styrene, α-methylstyrene, halostyrene, p-methylstyrene, acrylonitrile, methyl methacrylate, N-phenylmaleimide, methacrylonitrile, butyl methacrylate A thermoplastic resin composition characterized by being a copolymer prepared by copolymerizing more than one species. The bisphenol A-epichlorohydrin copolymer according to claim 1, wherein the bisphenol A-epichlorohydrin copolymer is P, P'-diphenylsulfone, P, P'-diphenylether, P, P'-diphenylketone, bisphenol A and epichlorohydrin (

-CH ₂ Cl) thermoplastic resin composition characterized in that produced by the dechlorination reaction. The thermoplastic resin composition according to claim 1, wherein the bisphenol A-epichlorohydrin copolymer has a molecular weight of 500-300,000.