KR100749670B1 - Styrenic Thermoplastic Resin Composition with Good Chemical Resistance - Google Patents

Abstract

Styrene-based thermoplastic resin composition excellent in the chemical resistance of the present invention (A) 5 to 50 parts by weight of rubber-modified styrene graft copolymer resin; (B) 20 to 95 parts by weight of styrene copolymer resin; And (C) 1 to 70 parts by weight of a polymethyl methacrylate (PMMA) resin.

Chemical resistance, scratch resistance, rubber modified styrene graft copolymer resin, styrene copolymer resin, acrylonitrile, polymethyl methacrylate

Description

Styrenic Thermoplastic Resin Composition with Good Chemical Resistance

Field of invention

The present invention relates to a styrene-based thermoplastic resin composition excellent in chemical resistance. More specifically, the present invention relates to a styrenic thermoplastic resin composition including rubber-modified styrenic graft copolymer resin, styrene copolymer resin, and polymethyl methacrylate resin, and having excellent chemical and scratch resistance. .

Background of the Invention

Acrylonitrile-butadiene-styrene copolymer resins are prepared by graft polymerization of styrene monomers, which are aromatic vinyl compounds, and acrylonitrile monomers, which are unsaturated nitrile compounds, in the presence of butadiene-based rubbery polymers. At this time, the desired resin can be obtained by adjusting the physical properties of the rubbery polymer, g-ABS resin, and matrix polymer used. The ABS resin thus prepared is widely used in parts, interior and exterior materials, automotive parts and general merchandise of electric and electronic products due to its excellent impact resistance, chemical resistance, heat resistance, mechanical strength, and easy molding process.

However, when the resin is used as an exterior material, scratches generated from the external appearance such as scratches due to impact or friction from the outside may reduce the quality of the product and reduce the value of the product. Therefore, most of them are supplemented with this weakness by additional coating process.

In particular, the interior and exterior materials of electrical and electronic products that are repeatedly stressed by the operation of a motor such as a mixer, a washing machine, a fan, and the like must be endured without breaking or breaking for a certain period of time, so they have excellent impact resistance and strong chemicals such as acetic acid. In addition, ABS resins with a certain degree of crack-resistant properties are required.

Accordingly, the present inventors use a mixture of two kinds of SAN resins having different acrylonitrile content and weight average molecular weight as a matrix resin, but by adjusting the acrylonitrile content and weight average molecular weight to be within a specific range, impact from the outside However, it has been developed to develop a styrene-based thermoplastic resin composition that is resistant to scratches due to friction and does not have a great influence on appearance, and has excellent scratch resistance and chemical resistance to 2BC (butyl cellosolve, 2-butoxy ethanol).

An object of the present invention is to provide a styrene-based thermoplastic resin composition having scratch resistance excellent in pencil hardness.

Another object of the present invention is to provide a styrene-based thermoplastic resin composition excellent in chemical resistance to 2BC (butyl cellosolve).

Another object of the present invention is to provide a suitable use of the styrene-based thermoplastic resin composition excellent in scratch resistance and chemical resistance.

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

Summary of the Invention

Styrene-based thermoplastic resin composition excellent in scratch resistance and chemical resistance of the present invention (A) 5 to 50 parts by weight of rubber-modified styrene graft copolymer resin; (B) 20 to 95 parts by weight of styrene copolymer resin; And (C) 1 to 70 parts by weight of a polymethyl methacrylate (PMMA) resin.

In another embodiment of the present invention, the styrene copolymer resin (B) is (b ₁ ) 10 to 90% by weight of a styrene resin having an acrylonitrile content of 22 to 28% by weight and a weight average molecular weight of 130,000 to 200,000. b ₂ ) 10 to 90% by weight of a styrene resin having an acrylonitrile content of 30 to 36% by weight and a weight average molecular weight of 100,000 to 160,000.

In another embodiment of the present invention the styrene-based thermoplastic resin composition is from the group consisting of antioxidants, lubricants, impact modifiers, light stabilizers, dyes, pigments, flame retardants, fillers, stabilizers, lubricants, antibacterial agents, mold release agents, plasticizers, antistatic agents It may further comprise a selected additive.

Detailed Description of the Invention

(A) Rubber modified styrene graft copolymer resin

Rubber-modified styrenic graft copolymers used in the preparation of the resin composition of the present invention are (a ₁ ) (a ₁₁ ) styrene, α-methylstyrene, halogen or alkyl substituted styrene or a mixture thereof 50 to 95% by weight and ( a ₁₂ ) acrylonitrile, methacrylonitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ acrylic acid alkyl esters, maleic anhydride, C ₁ -C ₄ alkyl or phenyl N-substituted maleimides Or 5 to 95 parts by weight of a mixture of monomers composed of 5 to 50% by weight of (a ₂ ) butadiene rubber, acrylic rubber, ethylene / propylene rubber, styrene / butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber, ethylene- Obtained by graft polymerization of 5 to 95 parts by weight of a polymer selected from one of propylene-diene terpolymers (EPDM) and polyorganosiloxane / polyalkyl (meth) acrylate rubber composites or mixtures thereof The.

The C ₁ -C ₈ methacrylic acid alkyl esters or C ₁ -C ₈ acrylic acid alkyl esters are esters of methacrylic acid or acrylic acid, respectively, obtained from monohydryl alcohols containing 1 to 8 carbon atoms. Ryu. As these specific examples, methacrylic acid methyl ester, methacrylic acid ethyl ester, acrylic acid ethyl ester, or methacrylic acid propyl ester is mentioned, Among these, methacrylic acid methyl ester is especially preferable.

Preferred examples of the rubber-modified styrenic graft copolymer (A) of the present invention include butadiene rubber, acrylic rubber, or styrene / butadiene rubber in the form of a mixture of styrene and acrylonitrile and optionally (meth) acrylic acid alkyl ester monomers. The thing copolymerized by transcript is mentioned. More preferred rubber-modified styrenic graft copolymer (A) is an ABS graft copolymer.

In the present invention, the rubber-modified styrene graft copolymer resin (A) is preferably used at about 5 to 50 parts by weight. If the rubber-modified styrenic graft copolymer resin is used in an amount less than 5 parts by weight, it is difficult to exhibit a shock resistance or more required by the present invention. If it is more than 50 parts by weight, the scratch characteristics may be reduced to complete the present invention.

(B) Styrene Copolymer Resin

The styrenic copolymer resin (B) of the present invention constitutes a matrix in the resin composition. That is, by controlling the acrylonitrile content and molecular weight of the styrene copolymer resin (B) as a matrix to the rubber-modified styrene graft copolymer resin to which polymethyl methacrylate (hereinafter referred to as PMMA) is added, excellent pencil hardness is achieved. The chemical resistance to 2BC (butyl cellosolve) can be improved while maintaining scratch resistance.

Styrene-based copolymers used in the preparation of the resin composition of the present invention are those having a total acrylonitrile content of 22 to 36% by weight and a weight average molecular weight of 100,000 to 200,000.

When the acrylonitrile content is used at less than 22% by weight, the chemical resistance cannot be improved. When the acrylonitrile content is used below 36% by weight, the impact resistance is improved, but the moldability is remarkably deteriorated. 22-36 weight% is preferable. If the weight average molecular weight of the styrene resin is less than 100,000, the resin tends to be easily broken. If the weight average molecular weight of the styrenic resin is more than 200,000, the molecular weight is high, so that it is difficult to prepare a linear structure, so the weight average molecular weight of the styrene resin is preferably 100,000 to 200,000. .

Preferably, the styrene resin (b ₁ ) having an acrylonitrile content of 22 to 28% by weight and a weight average molecular weight of 130,000 to 200,000, and the acrylonitrile content of 30 to 36% by weight and a weight average molecular weight of 100,000 to 160,000 to use a mixture of a styrene based resin (b _2). More preferably, the styrene resin (b ₁ ) and the styrene resin (b ₂ ) are mixed with 10 to 90 wt% of the styrene resin (b ₁ ) and 90 to 10 wt% of the styrene resin (b ₂ ). Do.

When the weight average molecular weight and acrylonitrile content of the styrene copolymer resin (B) and the mixing ratio of the styrene resins (b ₁ ) and (b ₂ ) are out of the above ranges, It is difficult to expect an improvement in chemical properties and may reduce fluidity.

The styrene resins (b ₁ ) and (b ₂ ) may each copolymerize styrene, α-methylstyrene, halogen or alkyl substituted styrene or a mixture thereof and acrylonitrile, or may use a mixture of these copolymers.

In another embodiment of the present invention, together with the acrylonitrile, methacrylonitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ acrylic acid alkyl esters, maleic anhydride, C ₁ -C ₄ alkyl nuclei It may further include a monomer selected from the group consisting of substituted maleimide, phenyl nuclear substituted maleimide, and mixtures thereof.

In one embodiment of the present invention, the styrene resins (b ₁ ) and (b ₂ ) are 50 to 95% by weight of styrene, α-methylstyrene, halogen or alkyl substituted styrene or a mixture thereof and acrylonitrile and meta, respectively. With chloronitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ acrylic acid alkyl esters, maleic anhydride, C ₁ -C ₄ alkyl nucleosubstituted maleimide, phenyl nucleosubstituted maleimide and mixtures thereof 5 to 50% by weight of a mixture of monomers selected from the group consisting of, or a mixture of these copolymers is used.

The acrylonitrile and methacrylonitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ acrylic acid alkyl esters, maleic anhydride, C ₁ -C ₄ alkyl nuclear substituted maleimide, phenyl nuclear substituted male The mixture of monomers selected from the group consisting of meads and mixtures thereof is preferably used at 20 to 50% by weight.

The C ₁ -C ₈ methacrylic acid alkyl esters or C ₁ -C ₈ acrylic acid alkyl esters are esters obtained from monohydryl alcohols containing 1 to 8 carbon atoms as esters of methacrylic acid or acrylic acid, respectively. to be. As these specific examples, methacrylic acid methyl ester, methacrylic acid ethyl ester, acrylic acid ethyl ester, or methacrylic acid propyl ester is mentioned, Among these, methacrylic acid methyl ester is especially preferable.

In one embodiment of the invention the styrene resin (b ₁ ) and (b ₂ ) is a monomer mixture of styrene and acrylonitrile and optionally methacrylic acid methyl ester; monomer mixtures of α-methylstyrene with acrylonitrile and optionally methacrylic acid methyl ester; Or those prepared from monomer mixtures of styrene, α-methylstyrene and acrylonitrile and optionally methacrylic acid methylester.

In the present invention, the styrene copolymer resin (B) is used in an amount of about 20 to 95 parts by weight, preferably about 55 to 80 parts by weight.

(C) PMMA resin

The PMMA resin (C) used in the preparation of the styrene-based thermoplastic resin composition of the present invention is obtained by polymerizing methyl methacrylate (MMA), which is an acrylic resin, and is well known to those skilled in the art. It can be easily purchased commercially.

In the present invention, by adding polymethyl methacrylate resin (hereinafter referred to as PMMA), it is possible to have scratch resistance excellent in pencil hardness.

The PMMA resin is used in 1 to 70 parts by weight. When used in excess of 70 parts by weight, the impact strength may be lowered, and when used in less than 1 part by weight, sufficient scratch resistance may not be obtained.

In addition to the above components, the present invention may further include conventional additives such as antioxidants, lubricants, impact modifiers, light stabilizers, dyes, pigments, flame retardants, fillers, stabilizers, lubricants, antibacterial agents, mold release agents, plasticizers, antistatic agents, and the like. As the antioxidant, a hindered phenol-based antioxidant or a phosphite-based antioxidant may be used. As the lubricant, a steramid lubricant or a metal stearate lubricant may be preferably used.

The resin composition of the present invention may be manufactured by injection molding through the usual melt kneading process by adding the above components.

In the present invention, the injection-molded molded article not only has excellent scratch resistance, but also has excellent chemical resistance to 2BC (butyl cellosolve), and thus may be repeated by driving a motor such as a blender, a washing machine, and a fan of various products. It can be usefully used for interior and exterior materials of stressed electrical and electronic products.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

Specifications of each component used in the following Examples and Comparative Examples are as follows.

(A) Rubber modified styrene graft copolymer resin

Cheil Industries Co., Ltd. brand name CHT was used.

(B) Styrene Copolymer Resin

(b ₁ ) A SAN resin having an acrylonitrile content of 24% by weight and a weight average molecular weight of 156,000 was used.

(b ₂ ) SAN resin having an acrylonitrile content of 32% by weight and a weight average molecular weight of 135,000 was used.

(b ₃ ) A styrene resin having an acrylonitrile content of 24% by weight and a weight average molecular weight of 180,000 was used.

(b ₄ ) A styrene resin having an acrylonitrile content of 24% by weight and a weight average molecular weight of 80,000 was used.

(b ₅ ) A styrene resin having an acrylonitrile content of 32% by weight and a weight average molecular weight of 90,000 was used.

(C) PMMA resin

LG PMMA IH830 was used.

Examples 1-2

Each of the components was added in an amount as shown in Table 1, followed by melting and kneading extrusion to prepare pellets. At this time, the extrusion was used L / D = 29, 45 mm diameter twin screw extruder and the cylinder temperature was set to 220 ℃. Injection molding of the prepared pellets to prepare a 6 inch × 6 inch hardness measurement specimens and chemical resistance evaluation specimens.

Comparative Example 1

A specimen was prepared in the same manner as in Example 1 except that the styrene resin (b ₁ ) was used alone.

Comparative Example 2

A specimen was prepared in the same manner as in Example 1 except that the styrene resin (b ₃ ) was used alone.

Comparative Example 3

A specimen was prepared in the same manner as in Example 1 except that styrene resin (b ₂ ) was used alone.

Comparative Example 4

A specimen was prepared in the same manner as in Example 1 except that the styrene resin (b ₄ ) was used alone.

Comparative Example 5

A specimen was prepared in the same manner as in Example 1 except that the styrene resin (b ₅ ) was used alone.

division Component (parts by weight) (A) Rubber modified styrene graft copolymer resin (B) styrene-based copolymer resin (C) PMMA (b ₁ ) (b ₂ ) (b ₃ ) (b ₄ ) (b ₅ ) Example One 20 20 30 - - - 30 2 20 35 15 - - - 30 Comparative Example One 20 50 - - - - 30 2 20 - - 50 - - 30 3 20 - 50 - - - 30 4 20 - - - 50 - 30 5 20 - - - - 50 30

Each 6 inch × 6 inch specimens and the chemical resistance specimens prepared by the above Examples and Comparative Examples were measured for the pencil hardness and chemical resistance to 2BC (butyl cellosolve) by the following method.

(1) After leaving for 48 hours at 23 ° C. and 50% relative humidity, pencil hardness was measured according to JIS K 5401 standard.

(2) Chemical resistance: Fix the chemical resistance test specimen of 50 mm × 200 mm × 2.0 mm in a 1/2 oval jig with a ratio of horizontal radius to vertical radius of 4: 3, and apply 2BC (butyl cellosolve) solution on the specimen. After 10 minutes after application of 5ml, the specimen was removed from the jig and washed with water to observe the change of the surface.

The measurement results are shown in Table 2 below.

Pencil hardness Chemical resistance (surface state) Example One H Good 2 H Good Comparative Example One H Fine cracks 2 H Fine cracks 3 H Fine cracks 4 F crack 5 F crack

From the results in Table 2, a styrene resin (b ₁ ) having an acrylonitrile content of 24 wt% and a weight average molecular weight of 156,000 and a styrene resin having an acrylonitrile content of 32 wt% and a weight average molecular weight of 135,000 (b ₂₎ It can be confirmed that Examples 1 to 2 using a mixture of) show the same scratch resistance and excellent chemical resistance to 2BC compared to Comparative Examples 1 to 5.

The styrene-based thermoplastic resin composition according to the present invention not only has excellent scratch resistance, but also has an effect of providing a thermoplastic resin composition having improved chemical resistance to 2BC.

Simple modifications and variations of the present invention can be readily used by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

Claims (6)

(A) 5 to 50 parts by weight of rubber-modified styrene graft copolymer resin; (B) 20 to 95 parts by weight of styrene copolymer resin; And (C) 1 to 70 parts by weight of a polymethyl methacrylate (PMMA) resin; The styrene-based copolymer resin (B) is a (b ₁ ) acrylonitrile content of 22 to 28% by weight and a weight average molecular weight of 130,000 to 200,000 styrene resin and (b ₂ ) acrylonitrile content A styrene-based thermoplastic resin composition having excellent chemical resistance, characterized in that it comprises a styrene-based resin having a weight average molecular weight of 30 to 36% by weight of 100,000 to 160,000. The chemical resistance of claim 1, wherein the styrenic copolymer resin (B) comprises 10 to 90 wt% of the styrene resin (b ₁ ) and 10 to 90 wt% of the styrene resin (b ₂ ). Excellent styrene thermoplastic resin composition. The method according to claim 1, wherein the styrene resin (b ₁ ) and (b ₂ ) is 50 to 95% by weight of styrene, α-methyl styrene, halogen or alkyl substituted styrene or a mixture thereof and acrylonitrile and methacryl Group consisting of ronitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ acrylic acid alkyl esters, maleic anhydride, C ₁ -C ₄ alkyl substituted maleimides, phenyl nucleosubstituted maleimides, and mixtures thereof Styrene-based thermoplastic resin composition having excellent chemical resistance, characterized in that the styrene copolymer obtained by copolymerizing a mixture of 5 to 50% by weight of the monomer selected from. The method of claim 1, wherein the resin composition further comprises an additive selected from the group consisting of antioxidants, lubricants, impact modifiers, light stabilizers, dyes, pigments, flame retardants, fillers, stabilizers, lubricants, antibacterial agents, mold release agents, plasticizers, and antistatic agents. Styrene-based thermoplastic resin composition excellent in chemical resistance comprising a. The pellet which extruded the composition of any one of Claims 1-4. A method of using the composition of any one of claims 1 to 4 as a material for interior and exterior of an electrical and electronic product.