JP3392179B2 - Thermoplastic resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition having permanent antistatic properties and excellent balance of physical properties such as strength, rigidity and moldability. . [0002] In general, styrene resins represented by ABS resins are widely used in electric, electronic equipment parts, OA equipment and the like. Characteristics are required. On the other hand, styrenic resins
Since the electrical resistivity is high, there is a drawback that dust adheres to the molded product and an electronic device causes an electrostatic failure due to charged electricity. Therefore, as these antistatic methods, a method of kneading an antistatic agent, carbon black, and metal powder is generally known. [0003] A method of kneading an antistatic agent into a resin is effective as a method for imparting antistatic properties, but has the disadvantage that the performance is not sufficient and the antistatic effect is not permanent.
On the other hand, the method of kneading carbon black or metal powder can impart a sufficient antistatic property, but has a disadvantage in that appearance, molding workability, impact resistance and the like are deteriorated. As a method for imparting permanent antistatic properties, a method in which a polyetheresteramide elastomer is mixed with a thermoplastic resin is known. However, the compatibility is extremely poor, so that the strength is reduced and laminar peeling occurs. JP-A-62-24
No. 1945 discloses polyetheresteramides,
Although a thermoplastic composition comprising an ABS-based graft copolymer and a carboxyl group-containing modified vinyl-based polymer is disclosed, the fluidity, heat resistance and rigidity are insufficient. Japanese Patent Application Laid-Open No. 64-26774 discloses an antistatic resin composition comprising a high-molecular-weight ethylene oxide / propylene oxide copolymer and an ABS resin. Insufficient strength. [0005] From the current situation,
The object of the present invention is to improve the resin composition without impairing the properties possessed by the styrenic resin, thereby improving the antistatic properties,
An object of the present invention is to provide a permanent antistatic resin composition having strength, rigidity, moldability and heat resistance and exhibiting a good appearance without delamination of a molded article. The antistatic performance of antistatic resins currently on the market is 10 ¹¹ to 10 ^{13 in} terms of surface resistance (eg, Science and Industry Vol. 63, p. 272).
(1989)), and the goal is to satisfy this characteristic value as permanent antistatic performance. The present inventors have made intensive studies for this purpose, and as a result, have found that a vinyl-based graft copolymer having a specific composition ratio and a copolymer of a vinyl-based monomer having a specific composition ratio have been obtained. By blending a copolymer of ethylene oxide and propylene oxide, and a copolymer of a vinyl monomer and a copolymer of a specific olefin monomer and an acrylate monomer, It has been found that a thermoplastic resin composition can be obtained. That is, the present invention relates to a process for producing an aromatic vinyl monomer 50 in the presence of component A: 10 to 60 parts by weight of a diene rubber polymer.
80 to 80% by weight, 20 to 50% by weight of vinyl cyanide monomer and, if necessary, 40 to 90% by weight of a monomer mixture comprising 0 to 20% by weight of a vinyl monomer copolymerizable with these monomers. 10 to 55% by weight of a graft copolymer obtained by graft polymerization of
And B component: 50 to 80% by weight of an aromatic vinyl monomer, 20 to 50% by weight of a vinyl cyanide monomer, and if necessary, a vinyl monomer 0 to 20 copolymerizable with these monomers. 0% to 80% by weight of a copolymer obtained by copolymerizing 1% by weight, and a C component: a copolymer comprising ethylene oxide and propylene oxide,
A copolymer having a weight average molecular weight of 50,000 or more and containing 80 to 96% by weight of an ethylene oxide polymer in the copolymer.
30% by weight, D component: 60 to 90 parts by weight of a copolymer composed of an olefin monomer and an acrylate monomer, 50 to 80% by weight of an aromatic vinyl monomer, 20 to 20 parts by weight of a vinyl cyanide monomer 50
% Of a vinyl monomer 10 to 40% by weight and optionally 0 to 20% by weight of a vinyl monomer copolymerizable with these monomers.
Graft copolymer 1 obtained by graft polymerization of parts by weight
The above object can be attained by preparing a thermoplastic resin composition characterized by comprising up to 15% by weight. Hereinafter, the present invention will be described in detail. The rubber component of the graft copolymer which is the component A in the present invention includes homopolymerization of a conjugated diene monomer such as butadiene, isoprene, chloroprene, and cyclopentadiene;
Homopolymerization of non-conjugated diene monomer such as cyclohexadiene and 2,5-norbornadiene, or aromatic vinyl such as styrene, α-methylstyrene, vinyltoluene and the above conjugated diene monomer or non-conjugated diene monomer Monomer, acrylonitrile, vinyl cyanide monomer such as methacrylonitrile, acrylate monomer such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate,
A copolymer of a methacrylic acid ester monomer such as hexyl methacrylate and an olefin monomer such as ethylene, propylene, 1-butene, isobutylene and 2-butene can be used. As the rubber component, a copolymer obtained by copolymerizing a conjugated diene monomer or a non-conjugated diene monomer with a polyfunctional vinyl monomer as a crosslinking monomer can also be used. Examples of the polyfunctional vinyl monomer include divinylbenzene, ethylene glycol dimethacrylate, triallyl cyanurate, allyl acrylate, and vinyl acrylate. Further, the rubber component used in the graft copolymer of the present invention needs to have a graft active site, and specifically has a carbon-carbon double bond in a rubber molecule. Is preferred. Known polymerization techniques such as emulsion polymerization and solution polymerization can be used as the method for polymerizing the monomer and the copolymer. The rubber component may be a mixture of two or more rubber components. Examples of the aromatic vinyl monomer used for producing the graft copolymer include styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylvinyltoluene, dimethylstyrene, chlorostyrene and the like. Styrene, vinyl naphthalene and the like can be mentioned. The vinyl cyanide monomer includes, for example, acrylonitrile, methacrylonitrile and the like. Further, vinyl monomers copolymerizable with these monomer components include acrylic ester monomers,
Examples include methacrylic acid ester monomers, vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid, acrylamide, methacrylamide, and the like. The above-mentioned monomers can be used alone or in combination of two or more. The polymerization method of the graft copolymer is preferably emulsion polymerization. Examples of the emulsifier used for emulsion polymerization include fatty acid soaps such as sodium stearate and potassium oleate, disproportionated potassium rosinate, and sodium dodecylbenzenesulfonate. And organic sulfonic acids such as The method of adding the monomers for graft polymerization during the graft polymerization includes a method of adding all at once, a part of the monomers for graft polymerization, and a method of continuously adding all the monomers for graft polymerization in a divided manner. For effective graft copolymerization, continuous split addition is preferred. The polymerization temperature is preferably in the range of 40 to 90 ° C. As the polymerization initiator, a redox system using a polyfunctional radical initiator and a metal salt such as ferrous sulfate or a chelating agent such as pyrophosphoric acid or disodium ethylenediaminetetraacetate in combination is preferable. The amount of the initiator is 0.05 to 100 parts by weight of the polymerizable monomer.
1.0 parts by weight is preferred. The diene rubber polymer contained in the graft copolymer of the component A is 10 to 60 parts by weight. If the amount is less than 10 parts by weight, the impact strength is low. If it exceeds 60 parts by weight, the moldability and rigidity are low. It is not preferable because it decreases. The aromatic vinyl monomer accounts for 50 to 80 of all monomers.
%, And less than 50% by weight impairs moldability and dimensional stability. The vinyl cyanide monomer accounts for 20 to 20 of all monomers.
If it is less than 20% by weight, heat resistance is low, and if it exceeds 50% by weight, moldability is reduced. The aromatic vinyl monomer used in the component B of the present invention includes, for example, styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylvinyltoluene, dimethylstyrene, chlorostyrene And vinyl naphthalene. Examples of the vinyl cyanide monomer include acrylonitrile and methacrylonitrile. The monomers copolymerizable with these monomer components include the above-mentioned vinyl carboxylic acid monomers such as acrylic acid ester monomers, methacrylic acid ester monomers, acrylic acid and methacrylic acid; Acrylic amide, methacrylic amide and the like can be mentioned. Among the monomers used for the component B, the amount of the aromatic vinyl monomer is 50 to 80% by weight, and if it is less than 50% by weight, moldability and dimensional stability are impaired. Among the monomers used for the component B, the amount of the vinyl cyanide monomer is 20 to 50% by weight. If the amount is less than 20% by weight, the heat resistance is low, and if it exceeds 50% by weight, the moldability deteriorates, which is not preferable. . The copolymer comprising ethylene oxide and propylene oxide used in the component C of the present invention has a weight average molecular weight of 50,000 or more and contains 80 to 96% by weight of the ethylene oxide polymer in the copolymer. It is a polymer. The weight average molecular weight is a weight average molecular weight measured by GPC (Gel Permea-tion Chromatograhy) using polystyrene as a standard molecular weight. When the weight average molecular weight is less than 50,000, the copolymer of the component C is a viscous liquid at room temperature, and when the thermoplastic resin composition is formed into a molded product, it bleeds out to the surface of the molded product. It is not preferable because it may come. However, the properties of the copolymer of the present invention having a weight average molecular weight of 50,000 or more are solid and easy to handle. The component C is a copolymer of ethylene oxide and propylene oxide, and the content of ethylene oxide is 80 to 96% by weight. If the amount is less than 80% by weight, the antistatic property is inferior, and if it exceeds 96% by weight, the compatibility as a thermoplastic resin composition is remarkably reduced, and thus the strength is inferior, which is not preferable. The copolymer of the component C of the present invention may be either a block copolymer or a random copolymer, but is preferably a random copolymer. This copolymerization is performed using an inert diluent and a coordination catalyst system. In the polymerization process,
The catalyst, the monomer and the inert diluent can be added at the same time during the polymerization, dividedly, or continuously added during the polymerization. However, ethylene oxide and propylene oxide may be added to the reactor preferably from separate lines, or as a mixture, or may be premixed with an inert diluent prior to adding the mixture into the reactor, allowing for random copolymerization. It is desirable to obtain coalescence. As the inert diluent, for example, toluene, heptane, hexane, cyclohexane, diethyl ether, methylene chloride and the like can be used. The polymerization is carried out by solution polymerization, and the polymerization temperature is generally in the range of 60 to 120 ° C. The component D of the present invention is obtained by adding the aromatic vinyl monomer used for polymerizing the copolymer of the component B to the copolymer obtained by using the olefin monomer and the acrylate monomer described above. Monomer, a vinyl cyanide monomer, and a vinyl monomer copolymerizable with these monomers. The copolymer comprising the olefin monomer and the acrylate is 60 to 90 parts by weight, preferably 65 to 80 parts by weight.
Parts by weight. The aromatic vinyl monomer to be grafted to the copolymer, the vinyl cyanide monomer and a graft component composed of a vinyl monomer copolymerizable with these monomers are 10 to
It is 40 parts by weight, preferably 20 to 35 parts by weight. The aromatic vinyl monomer of the graft component is 50 to 80% by weight, the vinyl cyanide monomer is 20 to 50% by weight, and the vinyl monomer copolymerizable with these monomers is 0 to 80% by weight. 20
% By weight is preferred. The thermoplastic resin composition of the present invention comprises 10 to 55% by weight of a vinyl graft copolymer as the component A, 0 to 80% by weight of a copolymer of a vinyl monomer as the component B, 5 to 30% by weight of a copolymer of ethylene oxide and propylene oxide, and a copolymer obtained by graft-polymerizing a vinyl monomer to a copolymer of an olefin monomer and an acrylate monomer as component D 1 to 15% by weight. The amount of the vinyl graft copolymer of the component A is 10 to 55% by weight, preferably 15 to 40% by weight. The component C is 5 to 30% by weight, preferably 7 to 20% by weight. If it is less than 5% by weight, the antistatic property is insufficient,
If it exceeds 30% by weight, heat resistance and rigidity are undesirably reduced. Further, the D component is 1 to 15% by weight, preferably 2 to 10% by weight.
% By weight. If it is less than 1% by weight, the compatibility is insufficient, and
Exceeding the weight percentage is not preferred because heat resistance and rigidity decrease. The thermoplastic resin composition of the present invention can be prepared by melting and kneading the components A, B, C, and D all at once.
Split melting and kneading may be performed. For example, the thermoplastic resin composition is prepared by melt-kneading a specified amount of the C component and the D component into a resin composition having a specified amount of a vinyl graft copolymer of the A component and a copolymer of the vinyl monomer of the B component. The order of mixing these components and melt-kneading is not limited. [0035] In addition to the above components, additives such as an antioxidant, an ultraviolet absorber, a lubricant, and a pigment can be added to the resin composition of the present invention as needed. The production of the resin composition of the present invention is not particularly limited, but the components A, B, and C in the form of powder or pellets are mixed using a mixer such as a Henschel mixer, a V-type blender and a tumbler. , D component and additives as required, and then melt-kneaded using a single screw extruder, a twin screw extruder, a Banbury mixer, a co-kneader or the like. Further, the components A and B are mixed at a predetermined ratio, and then mixed and melt-kneaded, and then the components C and D and, if necessary, additives are mixed and mixed with the resin composition, and then the mixture is extruded by a single screw. Can also be obtained by melt-kneading using an extruder, a twin-screw extruder, a Banbury mixer, a kneader and the like. The order of mixing and melt-kneading of the components is not particularly limited. EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The parts and percentages described in Examples and Comparative Examples are:
All are based on weight. Example 1 Production of Component A Graft Copolymer Polybutadiene latex (solid content) was placed in an autoclave.
333 parts of 30%, weight average particle diameter 0.35 μm) were charged, and 234 parts of pure water, 0.005 part of ferrous sulfate, 0.01 part of disodium ethylenediaminetetraacetate and 0.3 part of sodium aldehyde sulfoxylate were added. While stirring the content at 50 ° C., a monomer mixture consisting of 25 parts of acrylonitrile, 75 parts of styrene, 0.6 parts of t-dodecylmercaptan and 0.2 parts of benzoyl peroxide was continuously added to the latex over 5 hours. After the addition of the monomer mixture, 0.1 part of benzoyl peroxide was added, and further
The polymerization was completed by stirring at 70 ° C. for 2 hours. The obtained latex was octadecyl-3
After adding 1.0 part of-(3,5-di-t-butyl-4-hydroxyphenyl) propionate (manufactured by Ciba Geigy, trade name: Irganox 1076), an aqueous solution containing 8 parts of calcium chloride was added, and the mixture was heated to 95 ° C. By stirring for 3 minutes to obtain a slurry. This slurry was dehydrated, washed with water, and dried to obtain a graft copolymer (A component). Production of Component B Copolymer In an autoclave, 100 parts of pure water, 2.5 parts of a 0.2% aqueous potassium persulfate solution, 0.07 parts of tribasic calcium phosphate, 30 parts of styrene
Parts, acrylonitrile 25 parts, t-dodecyl mercaptan
Add 0.6 parts and 0.1 parts of benzoyl peroxide and stir the contents in a nitrogen atmosphere at 100 ° C.
45 parts were continuously added over 2 hours at 100 ° C., 2 hours at 103 ° C., and 3 hours at 107 ° C. over a total of 7 hours. After the addition, 117 ° C
Then, the mixture was heated and stirred for 2 hours to complete the polymerization. After cooling, hydrochloric acid was added to the polymerization solution, neutralized, dehydrated and dried to obtain beads of a copolymer (component B). As the C component, a copolymer composed of ethylene oxide and propylene oxide (trade name: Zeospan 8100, manufactured by Zeon Corporation) was used. As the D component, a graft copolymer (trade name: MODIPER A5400, manufactured by NOF Corporation) was used. Examples 1 to 5 and Comparative Examples 1 to 5 The above components were mixed in the mixing ratio shown in Table 1 using a Henschel mixer, and then the mixture was extruded using a 40 mm extruder.
Pellets were prepared by melting and kneading at 220 ° C. The obtained pellet is injected into an injection molding machine (IS-80) manufactured by Toshiba Machine Co., Ltd.
It was molded at 220 ° C. using CNV) to produce test pieces corresponding to various tests. Using these test pieces, the physical properties shown in Table 2 were evaluated. Example 6 An C resin and a D component used in Example 1 were blended in an ABS resin composed of the A component and the B component (trade name: Denka ABS GR2000, manufactured by Denki Kagaku Kogyo KK) in the proportions shown in Table 1. The properties were evaluated in the same manner as in Example 1, and the physical properties are shown in Table 2. [Table 1] [Table 2] The physical properties were measured according to the following methods. (1) Izod Impact Strength Izod impact strength was measured according to ASTM D-256. (2) Flexural Modulus The flexural modulus was measured according to ASTM D-790. (3) Melt flow rate (MFR) According to JIS K-6874, the temperature is 220 ° C. and the load is 10 k.
The melt flow was measured by gf. (4) Antistatic Effect A disk having a thickness of 2 mm × 100 mmΦ was prepared under the above-described injection molding conditions, and evaluated by the surface resistivity measured under the following two conditions. (A) Immediately after molding: The disk immediately after molding is washed in pure water for 1 minute, dried sufficiently, and then condition-conditioned for 24 hours at room temperature of 230 ° C. and 50% RH in accordance with JIS K-6911. After that, the surface specific resistance was measured using a super insulation resistance meter manufactured by Toa Denpa Kogyo KK. (B) After standing for 150 days; the molded disk is kept at room temperature 23 ° C and humidity
After leaving it in a 50% RH atmosphere for 150 days, it was washed in pure water for 1 minute, dried sufficiently, and conditioned in a room temperature of 23 ° C. and a humidity of 50% RH for 24 hours in accordance with JIS K-6911. The surface resistivity was measured. (5) Compatibility A square plate having a thickness of 2 mm × 50 mm × 90 mm was prepared under the above-mentioned injection molding conditions. This square plate was bent, and the presence or absence of laminar peeling was visually determined by observing the fracture surface. ○: good ×: delamination occurs in the molded product [Effect of the Invention] As described above, the thermoplastic resin composition of the present invention is excellent in balance of strength, rigidity and moldability, and is permanently charged. A resin composition having prevention properties, which has a feature that it can be widely used as a molding material in the fields of electronic equipment parts and OA equipment.

Claims (1)

(57) [Claims 1] The following A component 10-55% by weight, B component 0-
A thermoplastic resin composition excellent in permanent antistatic properties, comprising 80% by weight, 5 to 30% by weight of component C and 1 to 15% by weight of component D. A component: In the presence of 10 to 60 parts by weight of a diene rubber polymer,
Monomer consisting of 50 to 80% by weight of an aromatic vinyl monomer, 20 to 50% by weight of a vinyl cyanide monomer and, if necessary, 0 to 20% by weight of a vinyl monomer copolymerizable with these monomers. B-copolymer obtained by graft-polymerizing 40 to 90 parts by weight of a mixture of components, component B: 50 to 80% by weight of an aromatic vinyl monomer, 20 to 50% by weight of a vinyl cyanide monomer, and if necessary. A copolymer obtained by copolymerizing 0 to 20% by weight of a vinyl monomer copolymerizable with these monomers. Component C: a copolymer composed of ethylene oxide and propylene oxide, and the weight average of the copolymer The molecular weight is 50,000 or more, and the ethylene oxide polymer is 80 to 80% in the copolymer.
A copolymer containing 96% by weight, D component: 60 to 90 parts by weight of a copolymer composed of an olefin monomer and an acrylate monomer, and an aromatic vinyl monomer
50 to 80% by weight, 20 to 50% by weight of vinyl cyanide monomer and, if necessary, 10 to 40% by weight of a monomer mixture comprising 0 to 20% by weight of a vinyl monomer copolymerizable with these monomers. A graft copolymer obtained by graft polymerization of a part.