JPH06340787A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition having excellent permanent antistaticity and useful for molded article, etc., by compounding a specific graft copolymer, a copolymer composed of an aromatic vinyl monomer, etc., a copolymer of ethylene oxide, etc., and a graft copolymer composed of an olefin monomer, etc., at specific ratios. CONSTITUTION:The resin composition is composed of (A) 10-55wt.% of a graft copolymer produced by the graft-polymerization of a monomer mixture composed of an aromatic vinyl monomer, a vinyl cyanide monomer and optionally a vinyl monomer copolymerizable with the above monomers in the presence of a diene rubber polymer, (B) 0-80wt.% of a copolymer produced by copolymerizing an aromatic vinyl monomer, a vinyl cyanide monomer and a vinyl monomer copolymerizable with the above monomers, (C) 5-30wt.% of a copolymer composed of ethylene oxide and propylene oxide and (D) 1-15wt.% of a graft copolymer obtained by the graft-polymerization of a vinyl monomer to a copolymer of an olefinic monomer and an acrylic acid ester monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition having a permanent antistatic property and having an excellent balance of physical properties such as strength, rigidity and moldability.

[0002]

2. Description of the Related Art Generally, a styrene resin represented by ABS resin is widely used in electric and electronic equipment parts, OA equipment and the like, and various properties such as impact resistance and moldability are required for the physical properties of the resin. Has been done. On the other hand, styrene resin is
Since the electrical resistivity is high, there are drawbacks such that dust adheres to the molded product, and in an electronic device, electrostatic damage due to charged electricity occurs. Therefore, as these antistatic methods, a method of kneading an antistatic agent, carbon black, and metal powder is generally known.

The method of kneading an antistatic agent into a resin is effective as a method of imparting an antistatic property, but has the drawbacks that the performance is not sufficient and the antistatic effect is not permanent.
On the other hand, the method in which carbon black or metal powder is kneaded can provide sufficient antistatic property, but has a drawback that the external appearance, moldability, impact resistance and the like are deteriorated.

As a method for imparting a permanent antistatic property, a method of mixing a polyetheresteramide elastomer with a thermoplastic resin is known, but the compatibility is remarkably poor and strength reduction and delamination occur. JP-A-62-24
In 1945, a polyether ester amide,
A thermoplastic composition comprising an ABS graft copolymer and a carboxyl group-containing modified vinyl polymer is disclosed, but the fluidity, heat resistance and rigidity are insufficient. Further, Japanese Patent Application Laid-Open No. 64-26674 discloses an antistatic resin composition comprising a high molecular weight ethylene oxide / propylene oxide copolymer and an ABS resin. The antistatic property is good, but the rigidity, heat resistance and Insufficient strength.

[0005]

[Problems to be Solved by the Invention]
An object of the present invention is to improve the antistatic property by improving the resin composition without impairing the properties of the styrene resin.
It is an object of the present invention to provide a permanent antistatic resin composition having strength, rigidity, moldability and heat resistance, and exhibiting a good appearance without delamination of a molded product. In addition, the antistatic performance of the antistatic resin currently available on the market is 10 ¹¹ to 10 ^{13 in} terms of the surface resistance value (eg, Science and Industry Vol.63 P272.
(1989)), so the goal is to satisfy this characteristic value even for permanent antistatic performance.

[0006]

Means for Solving the Problems As a result of intensive research for this purpose, the present inventor has found that a vinyl-based graft copolymer having a specific composition ratio, a vinyl-based monomer copolymer having a specific composition ratio, and ethylene oxide are used. The propylene oxide copolymer, and a copolymer of a specific olefin monomer and an acrylic acid ester monomer are blended with a copolymer obtained by graft-polymerizing a vinyl-based monomer It has been found that a composition is obtained.

That is, in the present invention, the aromatic vinyl monomer 50 is used in the presence of component A: diene rubber polymer in an amount of 10 to 60 parts by weight.
40 to 90 parts by weight of a monomer mixture comprising -80% by weight, vinyl cyanide monomer 20 to 50% by weight, and vinyl monomer copolymerizable with these monomers 0 to 20% by weight, if necessary. Graft copolymer obtained by graft polymerization of 10-55% by weight
And component B: aromatic vinyl monomer 50 to 80% by weight, vinyl cyanide monomer 20 to 50% by weight and, if necessary, 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 of ethylene oxide and propylene oxide,
Copolymer 5 having a weight average molecular weight of 50,000 or more and containing 80 to 96% by weight of ethylene oxide polymer in the copolymer.
30% by weight, component D: 60 to 90 parts by weight of a copolymer composed of an olefin monomer and an acrylic acid ester monomer, 50 to 80% by weight of an aromatic vinyl monomer, 20 to 20% of a cyanide vinyl monomer 50
10 to 40% by weight and a monomer mixture of 0 to 20% by weight of a vinyl monomer copolymerizable with these monomers
Graft copolymer 1 obtained by graft-polymerizing 1 part by weight
The above object is achieved by using a thermoplastic resin composition characterized by comprising ˜15% by weight.

The present invention will be described in detail below. The rubber component of the graft copolymer which is the component A in the present invention is a homopolymerization of a conjugated diene monomer such as butadiene, isoprene, chloroprene, or cyclopentadiene, 1,4-
Homopolymerization of non-conjugated diene monomer such as cyclohexadiene and 2,5-norbornadiene, or aromatic vinyl such as styrene, α-methylstyrene and vinyltoluene with the above conjugated diene monomer or non-conjugated diene monomer Monomers, acrylonitrile, vinyl cyanide monomers such as methacrylonitrile, acrylic acid ester monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate,
It is possible to use those copolymerized with a methacrylic acid ester monomer such as hexyl methacrylate and an olefin monomer such as ethylene, propylene, 1-butene, isobutylene and 2-butene.

Further, as the rubber component, a copolymer obtained by copolymerizing the above-mentioned conjugated diene monomer or non-conjugated diene monomer with a polyfunctional vinyl monomer as a crosslinking monomer can be used. Examples of the polyfunctional vinyl monomer include divinylbenzene, ethylene glycol dimethacrylate, triallyl cyanurate, allyl acrylate, vinyl acrylate and the like.

Further, the rubber component used in the graft copolymer of the present invention is required to have a graft active site, specifically, it has a carbon-carbon double bond in the rubber molecule. Is preferred. As the method for polymerizing the above-mentioned monomer homopolymers and copolymers, known techniques such as emulsion polymerization and solution polymerization can be used. 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 and chloro. Examples thereof include styrene and vinylnaphthalene.

The vinyl cyanide monomer may, for example, be acrylonitrile or methacrylonitrile.

Further, as the vinyl monomer copolymerizable with these monomer components, acrylic ester monomers,
Examples thereof include methacrylic acid ester monomers, vinylcarboxylic acid monomers such as acrylic acid and methacrylic acid, acrylic acid amides, and methacrylic acid amides. The monomers listed above can be used alone or in combination of two or more.

The polymerization method of the graft copolymer is preferably emulsion polymerization, and as the emulsifier used in the emulsion polymerization, sodium stearate, fatty acid soap such as potassium oleate, disproportionated potassium rosinate and sodium dodecylbenzenesulfonate are used. Such organic sulfonic acid and the like can be mentioned.

The method for adding the monomer for graft polymerization at the time of graft polymerization includes batch addition, partial division addition, and continuous division addition of all the graft polymerization monomers to be used. In order to effectively carry out the graft copolymerization, continuous divided addition is preferable. The polymerization temperature is preferably in the range of 40 to 90 ° C.

The polymerization initiator is preferably a redox system in which a polyfunctional radical initiator and a metal salt such as ferrous sulfate, a chelating agent such as pyrophosphoric acid or ethylenediaminetetraacetic acid disodium salt are used in combination. The amount of the initiator used is 0.05 to 100 parts by weight of the polymerizable monomer.
1.0 part by weight is preferred.

The diene rubber polymer contained in the graft copolymer of the component A is 10 to 60 parts by weight. When it is less than 10 parts by weight, impact strength is low, and when it exceeds 60 parts by weight, moldability and rigidity are low. It is not preferable because it decreases.

The aromatic vinyl monomer is 50 to 80% of all monomers.
%, And if it is less than 50% by weight, moldability and dimensional stability are impaired.

Vinyl cyanide monomer is 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 deteriorated.

Examples of the aromatic vinyl monomer used as the component B of the present invention include styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylvinyltoluene, dimethylstyrene and chlorostyrene. , Vinyl naphthalene, etc. can be mentioned. Examples of vinyl cyanide monomers include acrylonitrile and methacrylonitrile.

As the monomer copolymerizable with these monomer components, the above-mentioned acrylic acid ester monomers, methacrylic acid ester monomers, vinylcarboxylic acid monomers such as acrylic acid and methacrylic acid, Examples thereof include acrylic acid amide and methacrylic acid amide.

The amount of the aromatic vinyl monomer in the monomer used as the component B is 50 to 80% by weight, and if it is less than 50% by weight, moldability and dimensional stability are impaired.

Of the monomers used as the component B, the vinyl cyanide monomer is 20 to 50% by weight. If it is less than 20% by weight, the heat resistance is low, and if it exceeds 50% by weight, the moldability is deteriorated. .

The copolymer composed of ethylene oxide and propylene oxide used as 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 means the weight average molecular weight measured by GPC (Gel Permea-tion Chromatograhy) using polystyrene as the 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 bleeds out on the surface of the molded product when the thermoplastic resin composition is molded. It may come and is not preferable. However, the copolymer of the present invention having a weight average molecular weight of 50,000 or more is 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 it 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 lowered, and therefore the strength is inferior, which is not preferable.

The component C copolymer of the present invention may be either a block copolymer or a random copolymer, but a random copolymer is preferred. This copolymerization is carried out using an inert diluent and a coordination catalyst system. In the polymerization process,
The catalyst, the monomer and the inert diluent can be added simultaneously during the polymerization, dividedly added, or continuously added during the polymerization. However, ethylene oxide and propylene oxide should be added to the reactor at the same time, or as a mixture, if possible from separate lines, or premixed with an inert diluent prior to adding the mixture into the reactor to obtain random co-polymerization. It is desirable to obtain coalescence.

As the inert diluent, for example, toluene, heptane, hexane, cyclohexane, diethyl ether, methylene chloride or the like can be used. The polymerization method is carried out by solution polymerization, and generally the polymerization temperature is in the range of 60 to 120 ° C.

Component D of the present invention is a copolymer obtained by using the above-mentioned olefin monomer and acrylic acid ester monomer, and the aromatic vinyl monomer used when polymerizing the copolymer of component B. It is obtained by graft polymerization of a monomer, a vinyl cyanide monomer and a vinyl monomer copolymerizable with these monomers.

The copolymer comprising an olefin monomer and an acrylic ester is 60 to 90 parts by weight, preferably 65 to 80 parts by weight.
Parts by weight. Aromatic vinyl monomer to be grafted to this copolymer, vinyl cyanide monomer and the grafting component consisting of vinyl monomer copolymerizable with these monomers is 10 to
It is 40 parts by weight, preferably 20 to 35 parts by weight.

The aromatic vinyl monomer as 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 50% by weight. 20
Weight percent is preferred.

The thermoplastic resin composition of the present invention comprises 10 to 55% by weight of the vinyl graft copolymer as the A component, 0 to 80% by weight of the copolymer of the vinyl monomer as the B component, and the C component. 5 to 30% by weight of a copolymer composed of ethylene oxide and propylene oxide, and a copolymer obtained by graft-polymerizing a vinyl monomer onto a copolymer composed of an olefin monomer and an acrylic acid ester monomer as component D It is composed of 1 to 15% by weight.

The content of the vinyl graft copolymer as the component A is 10 to 55% by weight, preferably 15 to 40% by weight. The C component 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 deteriorated, which is not preferable. Further, the D component is 1 to 15% by weight, preferably 2 to 10%.
% By weight. If the amount is less than 1% by weight, the compatibility is insufficient and 15
If it exceeds 5% by weight, heat resistance and rigidity are deteriorated, which is not preferable.

In the thermoplastic resin composition of the present invention, the components A, B, C and D may be melt-kneaded together,
It may be divided and melt-kneaded. For example, a thermoplastic resin composition prepared by melt-kneading a specified amount of a component A vinyl graft copolymer and a component B vinyl monomer copolymer in specified amounts with component C and D components. Can be obtained, and the order of mixing and melt-kneading these components is not limited.

In addition to the above components, additives such as antioxidants, ultraviolet absorbers, lubricants and pigments can be added to the resin composition of the present invention as required.

The production of the resin composition of the present invention is not particularly limited, but the components A, B and C in powder or pellet form are mixed with 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 cokneader or the like.

Further, the component A and the component B are mixed at a predetermined ratio, and the resin composition obtained by mixing and melting and kneading is mixed and mixed with the component C, the component D and, if necessary, additives, and then uniaxial extrusion. It can also be obtained by melt-kneading using a machine, a twin-screw extruder, a Banbury mixer, a co-kneader or the like. The order of mixing the components and melt-kneading is not particularly limited.

[0038]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. The parts and% described in Examples and Comparative Examples are
All are by weight.

Example 1 Preparation of Component A Graft Copolymer A polybutadiene latex (solid content was added in an autoclave).
30%, weight average particle diameter 0.35 μm) 333 parts were charged, and then 234 parts of pure water, 0.005 parts of ferrous sulfate, 0.01 parts of ethylenediaminetetraacetic acid disodium and 0.3 parts of sodium aldehyde sulfoxylate were added, and the mixture was placed in a nitrogen atmosphere. The stirred contents were kept at 50 ° C., and a monomer mixture consisting of 25 parts of acrylonitrile, 75 parts of styrene, 0.6 parts of t-dodecyl mercaptan and 0.2 parts of benzoyl peroxide was continuously added to the above latex over 5 hours. After the addition of the monomer mixture, add 0.1 part of benzoyl peroxide, and
Polymerization was completed by stirring at 70 ° C. for 2 hours.

The obtained latex is 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 to 95 ° C. The mixture was stirred for 3 minutes to break the emulsion and obtain a slurry. The slurry was dehydrated, washed with water, and dried to obtain a graft copolymer (component A).

Preparation of Component B Copolymer 100 parts of pure water, 2.5 parts of 0.2% potassium persulfate aqueous solution, 0.07 parts of tribasic calcium phosphate and 30 parts of styrene were put into an autoclave.
Part, acrylonitrile 25 parts, t-dodecyl mercaptan
0.6 parts and 0.1 part of benzoyl peroxide were added, and the contents were stirred under a nitrogen atmosphere, and the contents were kept 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. 117 ° C after addition
After the temperature was raised to 0, the mixture was stirred for 2 hours to complete the polymerization, and after cooling, hydrochloric acid was added to the polymerization solution for neutralization, dehydration and drying to obtain beads of the copolymer (component B).

As the component C, a copolymer of ethylene oxide and propylene oxide (manufactured by Nippon Zeon Co., Ltd., trade name Zeospan 8100) was used.

A graft copolymer (manufactured by NOF CORPORATION, trade name: MODIPER A5400) was used as the component D.

Examples 1 to 5 and Comparative Examples 1 to 5 The above components were mixed in the proportions shown in Table 1 in a Henschel mixer, and then the extrusion temperature was adjusted using a 40 mm extruder.
Pellets were prepared by melting and kneading at 220 ° C. The pellets thus obtained were injection-molded by Toshiba Machine Co., Ltd. (IS-80
CNV) was used for molding at 220 ° C. to prepare test pieces according to various tests. The physical properties shown in Table 2 were evaluated using these test pieces.

Example 6 A component A and a component B ABS resin (manufactured by Denki Kagaku Kogyo KK: trade name DENKA ABS GR2000) were blended with the components C and D used in Example 1 at the ratios shown in Table 1. Then, evaluation was made in the same manner as in Example 1, and the physical properties are shown in Table 2.

[0046]

[Table 1]

[0047]

[Table 2]

The physical properties were measured according to the following methods. (1) Izod Impact Strength The 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, temperature 220 ° C, load 10k
The melt flow rate was measured by gf.

(4) Antistatic effect A disc having a thickness of 2 mm and a diameter of 100 mm was produced under the above injection molding conditions, and evaluated by the surface resistivity value measured under the following two conditions. (A) Immediately after molding; the disk immediately after molding is washed in pure water for 1 minute and sufficiently dried, and then the condition is adjusted in accordance with JIS K-6911 at room temperature of 230 ° C and humidity of 50% RH for 24 hours. After that, the surface specific resistance value was measured using a super insulation resistance meter manufactured by Toa Denpa Kogyo Co., Ltd. (B) After standing for 150 days; the disk after molding is at room temperature of 23 ° C and humidity.
After leaving it in a 50% RH atmosphere for 150 days, wash it in pure water for 1 minute, dry it thoroughly, and adjust it to a room temperature of 23 ° C and a humidity of 50% RH for 24 hours according to JIS K-6911. The surface specific resistance value was measured.

(5) Compatibility A square plate having a thickness of 2 mm × 50 mm × 90 mm was prepared under the above injection molding conditions. The square plate was bent and the fracture surface was observed to visually determine the presence or absence of delamination. ○: Good ×: Delamination occurred in the molded product

[0053]

INDUSTRIAL APPLICABILITY As described above, the thermoplastic resin composition of the present invention is a resin composition having an excellent balance of physical properties such as strength, rigidity and moldability, and also having a permanent antistatic property. It has a feature that it can be widely used as a molding material in the field of equipment.

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Claims (1)

[Claims] 1. The following component A is 10 to 55% by weight, and component B is 0 to
80% by weight, C component 5 to 30% by weight, and D component 1 to 15% by weight, which is a thermoplastic resin composition excellent in permanent antistatic property. Component A: In the presence of 10 to 60 parts by weight of diene rubber polymer,
Amount consisting of 50-80% by weight of aromatic vinyl monomer, 20-50% by weight of vinyl cyanide monomer and 0-20% by weight of vinyl monomer copolymerizable with these monomers as required. Graft copolymer obtained by graft-polymerizing 40 to 90 parts by weight of the mixture, B component: 50 to 80% by weight of aromatic vinyl monomer, 20 to 50% by weight of vinyl cyanide monomer and, if necessary, A copolymer obtained by copolymerizing 0 to 20% by weight of a vinyl monomer copolymerizable with these monomers, C component: 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 in the copolymer is 80-
Copolymer containing 96% by weight, Component D: 60 to 90 parts by weight of a copolymer composed of an olefin monomer and an acrylic acid ester monomer, an aromatic vinyl monomer
10-40% by weight monomer mixture consisting of 50-80% by weight, 20-50% by weight of vinyl cyanide monomer and 0-20% by weight of vinyl monomer copolymerizable with these monomers A graft copolymer obtained by graft-polymerizing a part.