KR100586743B1 - Method of Preparing Thermoplastic Resin Composition with Good Chemical-Resistance and Molding Properties - Google Patents

Abstract

The present invention provides 10 to 30 parts by weight of a vinyl cyanide compound (B), 20 to 85 parts by weight of an aromatic vinyl compound (C) in the presence of 30 to 60 parts by weight of a rubbery polymer (A), and 5 to 40 parts by weight of a vinyl ester monomer (D). Graft copolymer resin (I) consisting of 0.01 to 3 parts by weight of a mixture of 1 to 99% by weight of the polyfunctional mercaptan (F) and 99 to 1% by weight of the vinylbenzene compound (G). Graft copolymer resin (II) consisting of 10 to 50 parts by weight of a vinyl cyanide compound (B) and 90 to 20 parts by weight of an aromatic vinyl compound (C) in the presence of 10 to 100% by weight, and 30 to 60 parts by weight of the rubbery polymer (A). 5 to 45 parts by weight of a resin composition (I + II), consisting of 90 to 0% by weight; And

95 to 55 parts by weight of copolymer resin (III) comprising 10 to 50% by weight of vinyl cyanide compound (B) and 90 to 50% by weight of aromatic vinyl compound (C);

The present invention relates to a thermoplastic resin composition having excellent chemical resistance and moldability.

Description

Method of Preparing Thermoplastic Resin Composition with Good Chemical Resistance and Moldability {Method of Preparing Thermoplastic Resin Composition with Good Chemical-Resistance and Molding Properties}

Field of invention

The present invention relates to a method for producing a thermoplastic resin composition having excellent chemical resistance and moldability. More specifically, in preparing the acrylonitrile-butadiene-styrene copolymer resin (hereinafter referred to as "ABS resin") composition, the vinyl ester compound is copolymerized non-linearly to the acrylonitrile-butadiene-styrene copolymer, which is ABS The present invention relates to a method for producing a thermoplastic resin composition by adding during the production of a resin and having excellent moldability during extrusion or injection processing and having chemical resistance to various chemicals after molding.

Background of the Invention and Prior Art

Rubber-reinforced styrene resins are widely used in electrical and electronic parts, office equipment, automobile parts, etc. because of their excellent mechanical properties. Most of these molded products are manufactured by injection molding, and in the case of a large molded article or a curved surface outside the molded article, the molded articles are manufactured by vacuum molding.

Vacuum molding is a plastic sheet that obtains a product of a desired shape by sheet extruding a resin to first prepare a sheet of sheet, and then softening the sheet in a vacuum molding machine and simultaneously performing vacuum or compression and vacuum to adhere the softened sheet to a mold. It is a kind of molding method. This method is widely used for making inner sheets of refrigerators, etc., and ABS resins are widely used. This is because not only the mechanical properties and workability of rubber-reinforced styrene resins such as ABS resin are good, but also the appearance and gloss are excellent.

However, the conventional general ABS resin is not resistant to various chemicals (oil, fatty acids, weak alkaline detergents and neutral detergents), and is manufactured by a molding method such as injection molding or vacuum molding, and is actually used as a product. The mechanical strength of the contact portion in the product with respect to the chemical by the contact of the branch chemicals has a problem in use that the breakage or softening of the product occurs.

This problem is known to be more pronounced when the residual stress is present in the product due to poor moldability during injection molding or vacuum molding. In order to solve this problem, to improve the chemical resistance of the ABS resin itself and to minimize the residual stress that can be generated during processing, by adjusting the molecular weight of the resin to improve the fluidity to lower the residual stress or graft ABS resin (G- It is common to take the method of increasing the chemical resistance by increasing the content of ABS). However, when the flowability is improved as described above, the residual stress is reduced due to the decrease in molecular weight, but the crack resistance of the resin is reduced, so that the crack proceeds at a higher speed when the chemical is affected. Its chemical resistance is lowered. In addition, when increasing the content of the graft ABS resin there is a problem that the fluidity is lowered, the productivity is lowered due to the extruder overload during compounding and extrusion, and the strength of the product is lowered. In particular, because of the low fluidity during injection molding requires high-temperature processing in the production of the product, there is a disadvantage that the physical properties of the product due to discoloration due to high temperature and deterioration of the resin itself. In addition, a method of increasing the content of acrylonitrile (AN) in the ABS resin may also be used. In this case, when the content of acrylonitrile is increased, the limit of the fluidity of the resin and a large change in color during processing are found. .

Prior art for increasing the chemical resistance by adjusting the molecular design of the rubber-reinforced styrene resin is as follows.

U.S. Patent No. 4,144,204 discloses the use of monovinylaromatic compounds which have been modified using rubber to increase impact resistance and have increased stress crack resistance for use in internal liners of refrigerators. A thermoplastic molding composition as a component is disclosed. In this patent, the content of rubber in the polymer (2-15%), the particle size of the rubber (5-10 μm) and the swelling degree of the rubber phase (11-13) based on toluene have a significant influence on the increase in stress breakdown resistance. The tensile strength of the modified thermoplastic polymer is 10 to 50% higher than the yield strength, and the chemical resistance is disclosed to be improved.

In order to improve the chemical resistance by the molecular design of the resin itself, it is common to use additives to improve the chemical resistance in most cases due to physical limitations such as the production method of the polymer or the constraints of the production conditions. As follows.

Japanese Patent Publication No. 62-164751 discloses a latex having a glass transition temperature of 20 ° C. or higher copolymerized with an acrylic ester having a glass transition temperature of 20 ° C. or lower and mixed with a high impact polystyrene latex having a molecular weight of 20,000 or more, followed by melt mixing to chemical resistance. It is disclosed a technique to increase the. However, in order to increase the chemical resistance, when the above method is applied, productivity is reduced because a process of precipitating and drying latex and melting and kneading should be added.

U.S. Patent No. 3,883,614 discloses a technique for increasing chemical resistance by adding a polymer having a vinyl acetate content of between 0.5 and 50% to ABS, while the polymer is processed through an extrusion or injection process for post-processing the polymer. As the polymer is processed at a very high temperature, the compatibility of ABS and vinyl acetate decreases, and as phase separation proceeds, peeling or surface defects may occur as long as the compatibilizer is not used in excess, and the compatibilizer used at this time Is very expensive and therefore disadvantageous in price.

US Patent No. 4,740,553 discloses a technique for improving chemical resistance by adding a polymer polymerized with an acrylate monomer to a styrene resin and a polycarbonate resin including an elastomer.

Japanese Patent Publication No. 62-084140 relates to a thermoplastic resin composition having high impact and high heat resistance, wherein the glass transition temperature obtained from an acrylic ester monomer by adding polycarbonate to high-impact polystyrene or ABS is 20 ° C or less and has a gel content. A blend is disclosed in which a polymer of 70 or less is added.

U.S. Patent No. 4,959,434 discloses a technique for improving chemical resistance to olive oil / oleic acid by adding unsaturated ethylene nitrile and alpha methyl styrene having a gel content of 23% or less to the impact resistant styrene copolymer. Since the solubility constant of styrene itself is not large compared to styrene, the improvement effect cannot be seen as a great improvement.

U. S. Patent No. 5,229, 457 relates to a resin composition suitable for the interior of a refrigerator, in which graft copolymerized vinyl cyanide and aromatic vinyl compound monomers having a specific monomer ratio for acrylic rubber are composed of essential components, and HCFC-123 and HCFC A resin composition having improved chemical resistance to -141b is disclosed.

US Pat. No. 5,324,589 describes polyamides and ABS in the manufacture of thin films of ABS resins and amorphous polyamide resins, which can be thermoformed to produce liners of such things as refrigerator liners, dishwasher liners, car interior panels and consumer electronics. Disclosed is a multilayer ABS film and an amorphous polyamide resin having a gas barrier property using an adhesive layer comprising a.

U.S. Patent No. 5,489,633 discloses a chemically resistant molding material in which a blend of polymethylmethacrylate and styrene-acrylonitrile is added with a derivative such as triarylphosphite, benzotriazole or phenol to increase chemical resistance. It is.

U.S. Pat.No. 5,543,461 relates to high impact polystyrene (HIPS) with excellent chemical resistance. In order to increase chemical resistance in high impact styrene polymers, impact modifiers having a large particle size and low molecular weight (900 number average molecular weight) To 2000), 1 to 4% by weight of polybutene and using a number average particle diameter of 6 to 12 microns, it was shown that the chemical resistance of the resin composition is uniformly distributed, but the resin composition is injected However, after being manufactured as a product through extrusion, there is a problem in that the glossiness is greatly reduced and the tensile strength is decreased.

As such, various studies have been conducted such as modification of molecular design of ABS resin itself or addition of additives in order to improve defects caused by deterioration of chemical resistance generated after processing of the resin.

US Pat. No. 4,918,159 proposes a method for producing a non-linear styrene resin using a multifunctional mercaptan. However, when the polyfunctional mercaptan is used alone, the dispersion system becomes very unstable as the polymerization progresses. There is a problem in controlling the polymerization reaction such as a problem that the whole polymerization system is hardened.

On the other hand, Japanese Patent Laid-Open No. 59-149912 discloses a copolymer made of a polyaromatic compound copolymerizable with a vinyl aromatic compound and a vinyl cyanide compound, and in the case of the copolymer, improvement of fluidity and mechanical properties can be achieved. Is showing.

Therefore, the present inventors include a non-linear acrylonitrile-butadiene-styrene-vinyl ester copolymer resin by mixing and adding a vinyl ester resin in the graft copolymer polymerization in order to solve the problems shown in the modification of the ABS resin, By producing an ABS resin composition copolymerized by adding a small amount of a mixture consisting of a polyfunctional mercaptan and a vinyl dibenzene compound, a thermoplastic resin composition having greatly improved chemical resistance and moldability has been developed.

An object of the present invention is to provide a method for producing a thermoplastic resin composition excellent in chemical resistance to prevent damage or softening of the site where various chemicals contact.

It is another object of the present invention to provide a method for producing a thermoplastic resin composition having excellent moldability since the stretching characteristics are greatly improved in the case of vacuum molding after processing into a sheet because the thickness deviation of the molded article is small.

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

The thermoplastic resin composition of the present invention is a graft copolymer (I) or a rubbery polymer obtained by copolymerizing vinyl cyanide (B), an aromatic vinyl compound (C), and a vinyl ester monomer (D) in the presence of a rubbery polymer (A). Graft copolymer (II) in which vinyl cyanide (B) and aromatic vinyl (C) are copolymerized in the presence of (A), and a copolymer (III) consisting of vinyl cyanide (B) and an aromatic vinyl compound (C). It is a resin composition comprised. A small amount of a mixture of the polyfunctional mulcaptan and the vinylbenzene compound is included in the composition of the copolymer (I). In addition, the monomer (E) which is selectively polymerized can be copolymerized with vinyl cyanide (B), aromatic vinyl compound (C), and vinyl ester monomer (D) in copolymer (I), and copolymer (III) It can copolymerize with vinyl cyanide (B) and an aromatic vinyl compound (C) inside.

Graft Copolymer (Ⅰ)

The graft copolymer (I) constituting the resin composition of the present invention comprises 10 to 30 parts by weight of the vinyl cyanide compound (B) and 20 to 85 parts by weight of the aromatic vinyl compound (C) in the presence of 30 to 60 parts by weight of the rubbery polymer (A). And graft copolymers emulsion-polymerized or bulk-polymerized using 5 to 40 parts by weight of the vinyl ester monomer (D). The copolymer of vinyl cyanide (B), aromatic vinyl compound (C), and vinyl ester monomer (D) grafted to the rubbery polymer (A) is 30 to 70 parts by weight, of which the vinyl ester compound (D) ) Is appropriately 5 to 30 parts by weight. If the content of the vinyl ester monomer in the copolymer of the grafted vinyl cyanide (B), the aromatic vinyl compound (C), and the vinyl ester monomer (D) is out of the above range, the ungrafted acryl It is not good because the compatibility with the nitrile-styrene copolymer (III) is insufficient and the degradation of mechanical properties may occur. Vinyl ester monomers (D) used in the graft copolymer (I) include acrylate-based compounds such as methyl acrylate, ethyl acrylate and butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl meta Methacrylate-based compounds such as acrylates, vinyl acetate, and vinyl propionate. In particular, due to the nature of the vinyl esters used as monomers, the chain transfer phenomenon due to the transfer of radicals during polymerization is large, and thus the molecular weight of the grafted acrylonitrile-styrene-vinyl ester copolymer becomes an important factor.

Non-linear graft copolymers, not general linear graft copolymers, by adding a mixture of a polyfunctional mercaptan (F) and a vinylbenzene compound (G) to control the molecular weight and molecular structure of the copolymer as described above. 3 parts by weight or less based on 100 parts by weight of the vinyl cyanide (B), the aromatic vinyl compound (C), and the vinyl ester monomer (D) to be grafted. The mixture of (G) is added. The polyfunctional mercaptans (G) used to obtain a copolymer having a nonlinear structure include trivalent functional mercaptans and tetravalent functional mulcaptans. Examples of the trifunctional mercaptan include trimethylolpropane tri (3-mercaptopropionate), trimethylolpropane tri (3-mercaptoacetate), trimethylolpropane tri (4-mercaptobutanate) and trimethylol Propane tri (5-mercaptopentanate), trimethylolpropane tri (6-mercaptohexaone) and the like. Examples of the tetravalent functional mercaptan include pentaerythryl tetrakis (2-mercaptoacetate), pentaerythryl tetrakis (3-mercaptopropionate), and pentaerythryl tetrakis (4-mercaptobuta). Nate), pentaerythryl tetrakis (5-mercaptopentanate), and pentaerythryl tetrakis (6-mercaptohexanate). The polyfunctional mercaptan that can be used in the present invention may be used alone or in combination of two or more of the above compounds, and is a graph of the vinyl cyanide compound (B), the vinyl aromatic compound (C), and the vinyl ester monomer (D). In the copolymerization problem of polymerization reaction control is important. Therefore, in order to smoothly control the polymerization reaction, it is more effective to mix two or more of the above-mentioned multifunctional mulcaptans (F) as compared with using a single mulcaptan.

In addition, the vinylbenzene compound (D) which can be used in the present invention includes divinylbenzene and the like.

The above compounds are described for the purpose of illustrating the present invention and are not intended to limit the scope of the present invention.

According to the present invention, the divinylbenzene exemplified as the multifunctional compound in the copolymerization of the vinyl cyanide compound (B), the vinyl aromatic compound (C), and the vinyl ester monomer (D) has a high reactivity to control the molecular structure of the copolymer. If it is not easy, and the range of PS reduction weight average molecular weight and intrinsic viscosity by gel permeation chromatography (GPC) of the grafted copolymer is not limited, the effect of improving chemical resistance and moldability cannot be expected. Preferably the weight average molecular weight is 80,000 or more and the intrinsic viscosity is limited to 0.6 or more.

In the present invention, in the preparation of the graft copolymer (I), the reactivity is controlled by using one or two or more kinds of polyfunctional multicaptans which are highly reactive with divinylbenzene, which are slow in reactivity and easy to gel. By limiting the range of the weight average molecular weight and the intrinsic viscosity of the copolymer, it is possible to produce an ABS resin having excellent compatibility and stretching properties, and improved chemical resistance and moldability.

The content of the mixture consisting of the polyfunctional mercaptan (F) and the vinylbenzene compound (G) used in the present invention is an air of the vinyl cyanide compound (B), the aromatic vinyl compound (C), and the vinyl ester monomer (D). It is 0.01-3 weight part with respect to 100 weight part of copolymers, More preferably, it is 0.1-2 weight part, and the mixing ratio of a polyfunctional multicaptan (F) and a vinylbenzene type compound (G) is polyfunctional multicaptan (F) 1 It is the ratio of 99-1 weight% of vinylbenzene compound (G) with respect to -99 weight%. When the content of the mixture is 0.01 parts by weight or less, the effect of improving chemical resistance is not obvious, and when 3 parts by weight or more, gelation proceeds and cannot be used. In addition, when the PS reduction weight average molecular weight by gel permeation chromatography (GPC) is 80,000 or less or the intrinsic viscosity in a tetrahydrofuran solvent is 0.6 or less, the effect of improving moldability is not apparent. However, the upper limit of the allowable weight average molecular weight and the intrinsic viscosity may be differently applied depending on the intended use, so that the range is not limited unless gelation proceeds sufficiently. The weight average molecular weight of the grafted copolymer (I) is preferably 90000 to 500000 when expressed in terms of styrene by gel permeation chromatography (GPC). If the weight average molecular weight is less than 90000, the drawdown is so severe that it is difficult to obtain a molded article having a uniform thickness distribution, and improvement in chemical resistance cannot be expected. If the molecular weight exceeds 500000, the extrusion load is high during molding, resulting in a decrease in productivity and a change in color.

Graft Copolymer (II)

The graft copolymer (II) is emulsified in a conventional manner using 10 to 50 parts by weight of the vinyl cyanide compound (B) and 90 to 20 parts by weight of the aromatic vinyl compound (C) in the presence of 30 to 60 parts by weight of the rubbery polymer (A). Graft copolymers polymerized or bulk polymerized. The copolymer of the vinyl cyanide compound (B) -aromatic vinyl compound (C) grafted to the rubbery polymer (A) is 35 to 60 parts by weight, of which the content of the vinyl cyanide compound (B) is 15 to 45 weight Denial is appropriate. If the copolymer of grafted vinyl cyanide compound (B)-aromatic vinyl compound (C) is 35-60 weight part, and in the copolymer of grafted vinyl cyanide compound (B)-aromatic vinyl compound (C) If the content of the vinyl cyanide compound (B) is out of the above range, the compatibility with the copolymer (III) of the ungrafted vinyl cyanide compound (B) -aromatic vinyl compound (C) becomes poor and the mechanical properties decrease. May be generated. Preferably the weight average molecular weight of the copolymer (II) has a value in the range of 90000 to 300000.

Graft Copolymer (III)

The graft copolymer (III) is a copolymer obtained by emulsion polymerization, suspension polymerization or bulk polymerization by a conventional method using 10 to 50 parts by weight of a vinyl cyanide compound (B) and 90 to 50 parts by weight of an aromatic vinyl compound (C). For example, the copolymer has a weight average molecular weight of 80000 to 400,000 in gel permeation chromatography (GPC) on a polystyrene basis.

The rubbery polymer (A) used in the resin composition of the present invention includes diene-based rubbery polymers such as polybutadiene, butadiene-styrene copolymer, and butadiene-acrylonitrile copolymer; Acrylic rubber such as butyl acrylate and methyl methacrylate-methacrylic acid ester copolymer; And saturated rubber polymers such as ethylene-propylene copolymer rubber; Etc. The content of the rubbery component in the resin may be 10 to 30 parts by weight, and if less than 10 parts by weight, impact resistance may be lowered.

Acrylonitrile or methacrylonitrile may be used as the vinyl cyanide compound (B) constituting the copolymers (I), (II), and (III) in the thermoplastic resin composition of the present invention. The amount of the vinyl cyanide compound unit in the resin is preferably 10 to 50 parts by weight in the resin component except for the rubbery polymer. If the amount is less than 10 parts by weight, stress cracking may occur due to paint or thinner, and the appearance of the molded product may be problematic. If the amount is more than 50 parts by weight, problems such as discoloration of the resin may occur.

In addition, the aromatic vinyl compound (C) includes styrene, alphamethyl styrene or a mixture thereof.

In particular, the monomer (E) can be selectively copolymerized with the vinyl cyanide compound (B), the aromatic vinyl compound (C) and the vinyl ester compound (D) in the copolymer (I), and in the copolymer (III), It can selectively copolymerize with a vinyl compound (B) and an aromatic vinyl compound (C). As said monomer (E), Methacrylic acid ester compounds, such as methyl methacrylate and butyl acrylate; N phenylmaleimide; N cyclohexylmaleimide; And maleic anhydride.

The resin composition (I + II + III) of the present invention is 10 to 100% by weight of the graft copolymer (I) and 5 to 45% by weight of the resin composition (I + II), which is 90 to 0% by weight of the graft copolymer (II). Part and 95 to 55 parts by weight of copolymer (III).

The invention will be further elucidated by the following examples which are set forth for the purpose of illustrating the invention and are not intended to limit the scope of the invention.

Example

Example 1 Preparation of Graft Copolymer (I)

45 parts by weight of polybutadiene latex (average particle diameter of rubber 0.32 µm) and 200 parts by weight of deionized water are added to a polymerization reactor equipped with a stirring device, a reflux cooler, a thermometer, and a preparation device, and stirred under a nitrogen stream. Along with this, 7 parts by weight of 4% aqueous potassium perchlorate solution and 56 parts by weight of styrene, 23 parts by weight of acrylonitrile, and 21 parts by weight of vinyl acetate were added to the monomer mixture, followed by trivalent trimethylolpropane tri (3-mercapto). Propionate) 0.03 parts by weight, 0.03 parts by weight of pentaerythryl tetrakis (2-mercaptoacetate) and 0.1 parts by weight of divinylbenzene were continuously added for 3 hours to polymerize at 70 ° C. The latex obtained here was dropwise precipitated in 4% aqueous sulfuric acid solution heated to 90 ° C, washed, dehydrated and dried to obtain a graft copolymer. The graft ratio of the copolymer was 83% and the weight average molecular weight of the ungrafted acrylonitrile-styrene-vinylacetate copolymer was 98000.

Example 2 Preparation of Graft Copolymer (II)

45 parts by weight of polybutadiene latex (average particle diameter of rubber: 32 µm) and 200 parts by weight of deionized water were added to a polymerization reactor equipped with a stirring device, a reflux cooler, a thermometer, and a preparation device, and stirred under a nitrogen stream. While stirring, 7 parts by weight of 4% aqueous potassium perchlorate solution and 60 parts by weight of styrene and 40 parts by weight of acrylonitrile were added to the monomer mixture, and 0.1 parts by weight of t-dodecyl mercaptan was continuously added for 3 hours to polymerize at 70 ° C. The latex obtained here was dropwise precipitated in 4% aqueous sulfuric acid solution heated to 90 ° C, washed, dehydrated and dried to obtain a graft copolymer. The graft ratio of the copolymer was 50% and the weight average molecular weight of the grafted acrylonitrile-styrene copolymer was 45000.

Example 3: Copolymer (III-1)

An acrylonitrile-styrene copolymer having a weight average molecular weight of 260000 to 350000 and an acrylonitrile content of 23 to 28% by weight was obtained.

Example 4: Copolymer (III-2)

An acrylonitrile-styrene copolymer having a weight average molecular weight of 100000 to 160000 and an acrylonitrile content of 36 to 42% by weight was obtained.

Example 5: Copolymer (III-3)

An acrylonitrile-styrene copolymer having a weight average molecular weight of 100000 to 120000 and an acrylonitrile content of 23 to 28% by weight was obtained.

Example 6

Acrylonitrile-styrene-vinylacetate graft copolymer (I), acrylonitrile-styrene graft copolymer (II), and acrylonitrile-styrene copolymer (III-1) in a ratio of 30:10:60. 1 part by weight of calcium chloride and a small amount of thermal stabilizer were mixed with respect to 100 parts by weight of the resin, and pellets were prepared using a twin screw extruder having a diameter of 40 mm. After the prepared pellets were pressed to prepare compressed specimens of 300 mm × 200 mm × 2 mm, the prepared specimens were processed to a width of 200 mm × 50 mm × 2 mm and evaluated for chemical resistance. . The evaluation value of the chemical resistance expressed the minimum strain at which the crack occurs when the chemical was applied in 100 fractions. The chemical was used by mixing a weak alkaline detergent and cottonseed oil / oleic acid in a ratio of 50/50.

In addition, after forming a compression specimen of 400 mm x 400 mm x 2 mm by using a press, vacuum forming was evaluated. The evaluation of vacuum forming can be said to be excellent in vacuum forming when the minimum thickness of the vacuum molded specimen and the standard deviation are small, and the measured thicknesses and deviations are given in Table 1 together with general properties.

Example 7

The same procedure as in Example 1 was carried out except that the acrylonitrile-styrene copolymer (III-1) was replaced with (III-2), and the results are shown in Table 1.

Example 8

The same procedure as in Example 2 was carried out except that the acrylonitrile-styrene copolymer (III-2) was replaced with (III-3), and the results are shown in Table 1.

Comparative Example 1

The graft copolymer (II) and acrylonitrile-styrene copolymer (III-1) were mixed in the same manner as in Example 1 except that the ratio was 40:60, and the results are shown in Table 1. It was.

2 in comparison

Graft copolymer (II) and acrylonitrile-styrene copolymer (III-2) were mixed in the same manner as in Example 1 except that the ratio was 40:60, and the results are shown in Table 1. It was.

 Comparative Example 3

The graft copolymer (II) and the acrylonitrile-styrene copolymer (III-3) were mixed in the same manner as in Example 1 except that the ratio was 40:60, and the results are shown in Table 1. It was.

 division          Chemical resistance Thickness (mm) Standard deviation (mm)  Cottonseed oil / Oleic acid  Weak alkaline detergent  Example 6       1.2%       0.8%      0.48      0.11  Example 7       2.0%       1.5%      0.51      0.13  Example 8       1.0%       0.5%      0.49      0.14  Comparative Example 1       0.7%       0.4%      0.48      0.16  Comparative Example 2       1.5%       0.7%      0.31      0.25  Comparative Example 3       0.6%       0.3%      0.28      0.27

The thermoplastic resin composition of the present invention is a graft copolymer (I) or a rubbery polymer (A) comprising a vinyl cyanide (B), an aromatic vinyl compound (C), and a vinyl ester monomer (D) in the presence of a rubbery polymer (A). Graft copolymer (II) consisting of vinyl cyanide (B) and aromatic vinyl (C) and copolymer (III) consisting of vinyl cyanide (B) and aromatic vinyl compound (C) in the presence of As a composition, it has excellent chemical resistance to prevent breakage or softening of various chemical contact areas, and has small thickness variation of the molded article, so that the stretching property is greatly improved when forming into a vacuum after processing into a sheet, thereby providing excellent moldability. Has an effect.

Simple modifications or variations of the present invention can be readily understood 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 (4)

10 to 30 parts by weight of the vinyl cyanide compound (B), 20 to 85 parts by weight of the aromatic vinyl compound (C) in the presence of 30 to 60 parts by weight of the rubbery polymer (A), 5 to 40 parts by weight of the vinyl ester monomer (D), and 10-100 weight% of graft copolymer resin (I) which consists of 0.01-3 weight part of mixtures mixed at the ratio of 1-99 weight% of polyfunctional mercaptan (F) and 99-1 weight% of a vinylbenzene type compound (G). And 90 to 0 weight of graft copolymer resin (II) consisting of 10 to 50 parts by weight of a vinyl cyanide compound (B) and 90 to 20 parts by weight of an aromatic vinyl compound (C) in the presence of 30 to 60 parts by weight of a rubbery polymer (A). 5 to 45 parts by weight of the resin composition (I + II) consisting of%; And 95 to 55 parts by weight of copolymer resin (III) comprising 10 to 50% by weight of vinyl cyanide compound (B) and 90 to 50% by weight of aromatic vinyl compound (C); Thermoplastic resin composition excellent in chemical resistance and moldability, characterized in that consisting of. The thermoplastic resin composition of claim 1, wherein the graft copolymer (I) has a weight average molecular weight of 90000 to 500000. The method of claim 1, wherein the vinyl ester monomer (D) is methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, vinyl acetate, and vinyl propionate It is selected from the group consisting of a thermoplastic resin composition excellent in chemical resistance and moldability. The compound of claim 1, wherein the vinylbenzene compound (G) is divinylbenzene, and the polyfunctional mulcaptan (F) is trimethylolpropane tri (3-mercaptopropionate), trimethylolpropane tree (3 Mercaptoacetate), trimethylolpropane tri (4-mercaptobutanate), trimethylolpropane tri (5-mercaptopentanate), trimethylolpropane tri (6-mercaptohexaonate), pentaerythrylol Tetrakis (2-Mercaptoacetate), Pentaerythryl Tetrakis (3-Mercaptopropionate), Pentaerythryl Tetrakis (4-Mercaptobutanate), Pentaerythryl Tetrakis (5- A thermoplastic resin composition excellent in chemical resistance and moldability, characterized in that the mixture is at least one selected from the group consisting of mercaptopentanate) and pentaerythryl tetrakis (6-mercaptohexanate).