KR100372567B1 - Permanent Anti-Static Styrene Thermoplastic Resin Composition - Google Patents

Abstract

The styrenic antistatic thermoplastic resin composition of the present invention comprises (A) (a ₁ ) aminocarboxylic acids having 6 or more carbon atoms; Lactams; Or diamines and salts of dicarboxylic acids having 6 or more carbon atoms, (a ₂ ) poly (alkylene oxide) glycols, and (a ₃ ) dicarboxylic acids having 4 to 20 carbon atoms, and polyethers 5 to 25 parts by weight of a polyether ester amide polymer having 10 to 95% by weight of ester units; (B) (b ₁ ) Graphene 25 to 70% by weight of the rubber polymer (b ₂ ) 75 to 30% by weight of a monomer mixture composed of 40 to 90% by weight of an aromatic vinyl monomer and 60 to 10% by weight of a vinyl cyanide monomer. 20 to 90 parts by weight of the graft rubber graft copolymer; 20 to 70 parts by weight of a vinyl copolymer comprising (C) 40 to 90% by weight of an aromatic vinyl monomer and 60 to 10% by weight of a vinyl cyanide monomer; And (D) 2 to 20 parts by weight of an N- (substituted) maleimide copolymer composed of 40 to 60% by weight of a mixture of an N- (substituted) maleimide monomer and a maleic anhydride monomer and 60 to 40% by weight of an aromatic vinyl monomer.

Description

Styrene-based antistatic thermoplastic resin composition {Permanent Anti-Static Styrene Thermoplastic Resin Composition}

Field of invention

The present invention relates to a styrene thermoplastic resin composition. More specifically, the present invention relates to a styrenic antistatic thermoplastic resin composition having permanent antistatic properties, improving peelability and excellent mechanical strength such as impact strength.

Background of the Invention

In general, plastic materials have high surface resistance and volume resistance, and thus are widely used as insulating materials for various electric and electronic components. However, such high resistance causes electrostatic phenomena on the surface of plastic materials, which causes contamination from dust and malfunction of circuits in the use of products in the processing and packaging of various electronic components, which is a limitation in application deployment. As a conventional method for solving this problem, methods of lowering surface resistance and volume resistance by adding a surfactant, conductive carbon black, or a metal filler have been used.

Among them, a method of adding conductive carbon black or a metal filler may obtain desired antistatic properties, but may limit the coloring of the resin composition and may deteriorate mechanical properties such as impact strength. In addition, the method using the surfactant uses a method in which the added surfactant is transferred to the plastic surface to discharge the static electricity accumulated through moisture in the atmosphere. However, this method has a problem that its action is not stable according to the surrounding environment, in particular humidity, and implies that the permanent antistatic property cannot be maintained due to the loss due to the continuous surface transfer of the surfactant during the use of the product. have.

In order to improve such conventional methods, there is a method of imparting permanent antistatic property by blending a polyamide-based elastomer with a resin, as described in 1981 Plastics Rubber Weekly. Inventions using such polyamide-based elastomers as permanent antistatic agents include Japanese Patent Laid-Open Nos. 62-116652, 63-79653, and 63-312342. However, in the case of the present invention, it is possible to obtain a permanent antistatic effect, but when blending with a resin that is not compatible, such as styrene-based resin has a limit in the application of the product due to the impact strength degradation and peeling caused by phase separation. As a method for solving such a problem, there is a method of using hydrotalside as disclosed in Japanese Patent Laid-Open No. 63-33456, but there is some effect on preventing delamination but the problem of lowering impact strength has not been solved. Also, among the methods for improving the impact strength, there are Japanese Patent Publication Nos. 62-250049, 63-312342, 63-95251 and Korea Patent Publication No. 95-13363. Substantially, only their use has a problem of lowering mechanical properties and lowering of thermal stability during processing, particularly during sheet forming.

Accordingly, the present inventors have led to the development of a thermoplastic resin and a method of manufacturing the same having excellent surface appearance by having a permanent antistatic property and having good thermal stability even during sheet molding as a method for solving the conventional problems as described above.

An object of the present invention is a styrene-based antistatic thermoplastic resin composition having a permanent antistatic property by mixing a rubber graft copolymer and a vinyl copolymer with a polyether ester amide polymer and adding an N- (substituted) maleimide copolymer It is to provide.

Another object of the present invention is to provide a styrene-based antistatic thermoplastic resin composition in which the polyether ester unit of the polyether ester amide polymer has a range of 10 to 95% by weight, so that the antistatic effect and the mechanical properties thereof are not deteriorated.

Still another object of the present invention is to provide a styrene-based antistatic thermoplastic resin composition excellent in hardness, tensile strength, flexural strength, heat resistance and impact resistance by adding an appropriate amount of rubbery polymer included in the rubbery graft copolymer. .

Still another object of the present invention is to provide a styrene-based antistatic thermoplastic resin composition in which the surface peelability between the resin phases is remarkably improved by applying an appropriate amount of N- (substituted) maleimide copolymer.

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

Styrene-based antistatic thermoplastic resin composition of the present invention

(A) (a ₁ ) aminocarboxylic acids having 6 or more carbon atoms; Lactams; Or diamines and salts of dicarboxylic acids having 6 or more carbon atoms, (a ₂ ) poly (alkylene oxide) glycols, and (a ₃ ) dicarboxylic acids having 4 to 20 carbon atoms, and polyethers 5 to 25 parts by weight of a polyether ester amide polymer having 10 to 95% by weight of ester units;

(B) (b ₁ ) Graphene 25 to 70% by weight of the rubber polymer (b ₂ ) 75 to 30% by weight of a monomer mixture composed of 40 to 90% by weight of an aromatic vinyl monomer and 60 to 10% by weight of a vinyl cyanide monomer. 20 to 90 parts by weight of the graft rubber graft copolymer;

20 to 70 parts by weight of a vinyl copolymer comprising (C) 40 to 90% by weight of an aromatic vinyl monomer and 60 to 10% by weight of a vinyl cyanide monomer; And

(D) It consists of 2-20 weight part of N- (substituted) maleimide copolymers which consist of 40-60 weight% of mixtures of N- (substituted) maleimide monomer and a maleic anhydride monomer, and 60-40 weight% of aromatic vinyl monomers.

Hereinafter, the component which comprises the resin composition of this invention is demonstrated in detail below.

(A) polyether ester amide polymer

The polyether ester amide polymer (A) used in the preparation of the resin composition of the present invention is an antistatic polymer, which includes (a ₁ ) aminocarboxylic acids having 6 or more carbon atoms; Lactams; Or a salt of diamine and dicarboxylic acid having 6 or more carbon atoms, (a ₂ ) poly (alkylene oxide) glycol and (a ₃ ) dicarboxylic acid having 4 to 20 carbon atoms. The polyether ester amide polymer (A) is represented by the following formula (1):

Wherein R ₁ and R ₂ are H, CH ₃ or C ₂ H ₅ , PA is a polyamide, PE is a polyalkylene oxide, and n is an integer of 1 or greater.

Examples of the aminocarboxylic acids having six or more carbon atoms include ω-aminocapronic acid, ω-aminoenanthate, ω-aminocaprylic acid, ω-aminofelconic acid, ω-aminocapric acid, and 1,1. Aminoundecanoic acid and 1,2-aminododecanoic acid. The lactams include caprolactam, enanthlactam, capryllactam and lauryllactam. Further salts of the diamines and dicarboxylic acids having six or more carbon atoms include salts of hexamethylenediamine-adipic acid and salts of hexamethylenediamine-isophthalic acid. Preferred are salts of caprolactam, 1,2-aminododecanoic acid, or hexamethylenediamine-adipic acid.

The poly (alkylene oxide) glycol (a ₂ ) is poly (ethylene oxide) glycol, poly (1,2- and 1,3-propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) Glycols, block or random copolymers of ethylene oxide and propylene oxide, copolymers of ethylene oxide and tetrahydrofuran, and the like. Preferably, poly (ethylene oxide) glycol or a copolymer of polyethylene oxide and propylene oxide is used.

The components (a ₁ ) and (a ₂ ) form an ester or amide bond, and in this bond, dicarboxylic acid (a ₃ ) or diamine having ₄ to 20 carbon atoms can be applied. The dicarboxylic acids include terephthalic acid, 1,4-cyclohexacarboxylic acid, sebacic acid, adipic acid and dodecanoic acid. The diamines include hexamethyldiamine and the like.

The polyether ester amide polymer (A) may be prepared by a conventional polymerization method in the art, and is disclosed in Japanese Patent Publication No. 56-45419 and Japanese Patent Publication No. 55-133424.

It is preferable that the unit of the polyether ester of the said polyether ester amide polymer (A) has a range of 10 to 95 weight%. This is because if the unit of the polyether ester is less than 10% by weight, the antistatic effect is inferior. It is preferable that the said polyether ester amide polymer is comprised in the range of 5-25 weight part with respect to the whole resin composition. It is because the antistatic effect of a resin composition falls when it is less than 5 weight part, and the mechanical property of a resin composition falls when it is 25 weight part or more.

(B) rubbery graft copolymer

The rubbery graft copolymer (B) used in the thermoplastic resin composition of the present invention comprises 40 to 90% by weight of an aromatic vinyl monomer and 60 to 10% by weight of a vinyl cyanide monomer in 25 to 70 parts by weight of the rubbery polymer (b ₁ ). a monomer mixture (b ₂₎ 75~30 parts by weight of a graft copolymer in which.

The content (b ₁ ) of the rubbery polymer may be 25 to 70 parts by weight, and more preferably 35 to 60 parts by weight, based on 100 parts by weight of the rubbery graft copolymer (B). Hardness, tensile strength, flexural strength, and heat resistance are improved, but the impact resistance is sharply lowered, and if it is 60 parts by weight or more, the impact resistance is excellent, but the productivity is lowered and the strength of the resin composition is lowered.

The rubbery polymer may be at least one rubber selected from the group consisting of silicone rubber, diene rubber, ethylene rubber and ethylene / propylene / diene terpolymer rubber. The average particle diameter of the rubber particles may be used 10 to 500㎛, preferably in the range of 200 ~ 400 ㎛. If the average particle diameter is 200 ㎛ or less, the impact reinforcing effect is not very much, if 400 ㎛ or more there is little impact enhancement effect through the appropriate morphological control.

In addition, the aromatic vinyl monomers used in the graft copolymer (B) include styrene, pt-butylstyrene, alpha-methylstyrene, beta-methylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene, Chlorostyrene, ethylstyrene, vinylnaphthalene and divinylbenzene. Preferred are styrene and alpha-methylstyrene. Acrylonitrile, methacrylonitrile, ethacrylonitrile, or the like may be used as the vinyl cyanide monomer, and double acrylonitrile is preferable.

The method for preparing the graft copolymer (B) is well known to those skilled in the art, and any of emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization may be used. As a preferable manufacturing method, it is preferable to add the vinyl monomer described above in the presence of a rubbery polymer, and to perform emulsion polymerization or bulk polymerization using a polymerization initiator.

(C) vinyl copolymer

Copolymers of aromatic vinyl monomers and vinyl cyanide monomers that can be used in the thermoplastic resin composition of the present invention are well known to those skilled in the art and may be suspended or bulk polymerized. Among them, it is preferable to use a copolymer prepared by the bulk polymerization method with little additive content added to the polymerization step and less gel generation. When the additive content is high during the polymerization manufacturing process, appearance defects such as gas defects are likely to occur in the molded products during injection molding, and when the copolymer contains gel, it protrudes on the surface of the final molded product and deteriorates the quality of the molded products. There is a problem. Meanwhile, in polymerizing the vinyl copolymer (C), other vinyl monomers capable of polymerizing with these vinyl monomers may be further added within the range of 0 to 30 parts by weight based on 100 parts by weight of the total vinyl copolymer (C). It may include.

The aromatic vinyl monomers used in the vinyl copolymer (C) include styrene, pt-butylstyrene, alpha-methylstyrene, beta-methylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene, and chloro. Styrene, ethylstyrene, vinylnaphthalene and divinylbenzene. Preferred are double styrene and alpha-methylstyrene. Acrylonitrile, methacrylonitrile, ethacrylonitrile, or the like may be used as the vinyl cyanide monomer, and double acrylonitrile is preferable.

Preferred specific examples of the vinyl copolymer (C) used in the present invention include a styrene content of 65 to 80% by weight and an acrylonitrile content of 35 to 20% by weight and a weight average molecular weight of 100,000 to 200,000. It is a SAN resin having a range. If the weight average molecular weight is 100,000 or less, the unmelted phenomenon of the N- (substituted) maleimide copolymer occurs due to the difference in glass transition temperature and fluidity with the N- (substituted) maleimide copolymer, and the weight average molecular weight is 200,000 or more. In this case, the fluidity of the heat enhancer is significantly lowered, so that excellent physical property balance of the product cannot be expected.

(D) N- (substituted) maleimide copolymer

The N- (substituted) maleimide copolymer (D) used in the present invention is a copolymer obtained by combining an N- (substituted) maleimide monomer and maleic anhydride with an aromatic vinyl monomer. The N-phenyl maleimide copolymer used in the present invention is represented by the following formula (2):

The aromatic vinyl monomers used in the N- (substituted) maleimide copolymer include styrene, alpha-methylstyrene, vinyl toluene, t-butyl styrene, chlorostyrene, and the like, of which styrene is preferable. The N- (substituted) maleimide monomers include N-methyl maleimide, N-ethyl maleimide, N-cyclohexyl maleimide, N-phenyl maleimide, and the like, of which N-phenyl maleimide is preferable.

The content of the N- (substituted) maleimide, maleic anhydride and aromatic vinyl monomer may be changed as necessary, but in general, the sum of the N- (substituted) maleimide and maleic anhydride content is 40 to 60 parts by weight, double anhydride The content of maleic acid is 2 to 15 parts by weight, and the content of the aromatic vinyl monomer is preferably 60 to 40 parts by weight.

When the content of N- (substituted) maleimide and maleic anhydride is less than 40 parts by weight, the glass transition temperature of the N- (substituted) maleimide copolymer is too low, which makes no sense as a heat-resistant enhancer for the purpose of the present invention. In addition, when the content thereof exceeds 60 parts by weight, the glass transition temperature is too high to produce a thermoplastic resin that is a heat enhancer by a general method.

The content of the N- (substituted) maleimide copolymer used in the present invention is preferably 2 to 20 parts by weight. If it is less than 2 parts by weight, the peelability between the resin phases does not improve due to lack of compatibility, and when used in excess of 20 parts by weight, no further improvement in physical properties is achieved.

The resin composition of the present invention may be added a variety of fillers such as thermal stabilizer, light stabilizer, flame retardant, lubricant, glass fiber according to the respective applications.

Example

The specifications of (A) polyether ester amide polymer, (B) rubber graft copolymer, (C) vinyl copolymer and (D) N- (substituted) maleimide copolymer used in Examples and Comparative Examples As follows.

(A) polyether ester amide polymer

As the polyether ester amide polymer, ATOCHEM's PEBAX MV-1074 was used.

(B) rubbery graft copolymer

The vinyl graft copolymer used in the examples of the present invention was prepared by graft polymerization of 50 parts by weight of rubbery polymer, 36 parts by weight of styrene and 14 parts by weight of acrylonitrile, with a graft ratio of 45 to 62%.

(C) vinyl copolymer

As the vinyl copolymer used in the embodiment of the present invention, a copolymer of an aromatic vinyl-based vinyl cyanide monomer was used. The vinyl copolymer is a SAN resin composed of 72 parts by weight of styrene and 28 parts by weight of acrylonitrile, and has a weight average molecular weight of 120,000.

(D) N- (substituted) maleimide copolymer

As the N- (substituted) maleimide copolymer, MS-L2A manufactured by Nippon Electrochemical Corporation was used.

The thermoplastic resin compositions of Examples 1 to 3 were prepared using the coverage of each component of the resin composition of the present invention as shown in Table 1 below. Comparative Examples 1 and 2 were prepared in the same manner as in Example 1 except that the amounts of the vinyl copolymer and the N- (substituted) maleimide copolymer were applied differently as shown in Table 1.

(Unit: parts by weight) Example Comparative Example One 2 3 One 2 (A) polyether ester amide polymer 16 16 16 16 16 (B) Rubbery Graft Copolymer 42 42 42 42 42 (C) Vinyl Copolymer 53 48 32 58 38 (D) N- (substituted) maleimide copolymer 5 10 16 0 20

The thermoplastic resin compositions prepared in Examples 1-3 and Comparative Examples 1-2 were evaluated under the same extrusion conditions. The pellet was manufactured using a twin screw extruder having L / D = 36 and φ = 45MM, and the cylinder temperature was set at 230 to 250 ° C. When the cylinder temperature was low, the cylinder temperature was maintained at least 250 ° C because it was not effective in dissolving the N-phenyl maleimide copolymer.

Tensile strength and elongation were measured according to ASTM D 638. The half-life is maintained for 48 hours at 23 ℃ and 50% relative humidity, and then used STATIC HONESTEMETER (SHISHDO Electric Co., Ltd., Type S-5109) for an applied voltage of 8000 V, an applied voltage of 10 mm, and an application time of 60 The measurement was performed under the condition of seconds and a distance of 5 mm between the detection electrode and the sample. In addition, the size of the polyether ester amide polymer (A) phase in the resin composition was measured by immersing the injection specimen in liquid nitrogen for 5 minutes and then breaking, etching the fracture surface with formic acid to observe the morphology under a scanning microscope. .

The physical properties such as tensile strength and elongation of the resin compositions of Examples 1 to 3 and Comparative Examples 1 to 2, which consist of the contents described in Table 1, were measured under the same conditions, and the results are shown in Table 2.

Example Comparative Example One 2 3 One 2 Tensile Strength (kgcm / kg) 357 371 371 340 37 % Elongation 53 55 50 45 55 Half-life (sec) 0.8 0.9 0.8 0.9 0.8 (A) Phase size (μ) 0.9 0.8 0.7 2.0 0.7

As can be seen in Table 2, the use of N- (substituted) maleimide copolymer has improved the tensile strength and elongation due to improved compatibility without changing the half-life, in particular the polyether ester amide polymer (A It was confirmed that the size of the) phase was greatly reduced, thereby improving the surface peeling between the phases.

The present invention provides a permanent solution by mixing a rubbery graft copolymer and a vinyl-based copolymer with a polyether ester amide polymer having a polyether ester unit in the range of 10 to 95% by weight and adding an N- (substituted) maleimide copolymer. It has the effect of the invention which has antistatic property, the surface peeling property between resin phases improves drastically, and a styrene type antistatic thermoplastic resin composition which mechanical property does not fall.

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 (6)

(A) (a ₁ ) aminocarboxylic acids having 6 or more carbon atoms; Lactams; Or diamine and a salt of dicarboxylic acid having 6 or more carbon atoms, (a ₂ ) poly (alkylene oxide) glycol, and (a ₃ ) dicarboxylic acid having 4 to 20 carbon atoms, 5 to 25 parts by weight of a polyether ester amide polymer having 10 to 95% by weight of ester units; (B) (b ₁ ) Graphene 25 to 70% by weight of the rubber polymer (b ₂ ) 75 to 30% by weight of a monomer mixture composed of 40 to 90% by weight of an aromatic vinyl monomer and 60 to 10% by weight of a vinyl cyanide monomer. 20 to 90 parts by weight of the graft rubber graft copolymer; 20 to 70 parts by weight of a vinyl copolymer comprising (C) 40 to 90% by weight of an aromatic vinyl monomer and 60 to 10% by weight of a vinyl cyanide monomer; And (D) 2 to 20 parts by weight of an N- (substituted) maleimide copolymer comprising 40 to 60% by weight of a mixture of an N- (substituted) maleimide monomer and a maleic anhydride monomer and 60 to 40% by weight of an aromatic vinyl monomer; Styrene-based antistatic thermoplastic resin composition, characterized in that consisting of. The aminocarboxylic acids of claim 1, wherein the aminocarboxylic acids having 6 or more carbon atoms of (a ₁ ) are ω-aminocapronic acid, ω-aminoenanthate, ω-aminocaprylic acid, ω-aminofelconic acid. , ω-aminocapric acid, 1,1-aminoundecanoic acid or 1,2-aminododecanoic acid; The lactams are caprolactam, enanthlactam, capryllactam or lauryllactam; And a salt of the diamine and a dicarboxylic acid having 6 or more carbon atoms is a salt of hexamethylenediamine-adipic acid or a salt of hexamethylenediamine-isophthalic acid. The rubbery polymer (b ₁ ) is at least one rubber selected from the group consisting of silicone rubber, diene rubber, ethylene rubber and ethylene / propylene / diene terpolymer rubber, and Styrene-based antistatic thermoplastic resin composition, characterized in that the average particle diameter is 10 to 500㎛. According to claim 1, wherein the vinyl copolymer (C) is polymerized by further comprising 0 to 30 parts by weight of the other vinyl monomer capable of polymerizing with the vinyl monomer, based on 100 parts by weight of the total vinyl copolymer (C). Styrene-based antistatic thermoplastic resin composition, characterized in that. The styrene-based antistatic thermoplastic resin composition according to claim 1, wherein the vinyl copolymer (C) has a weight average molecular weight of 100,000 to 200,000. The N- (substituted) maleimide monomer is selected from the group consisting of N-methyl maleimide, N-ethyl maleimide, N-cyclohexyl maleimide and N-phenyl maleimide. Styrene-based antistatic thermoplastic resin composition.