JPH09249780A - Styrene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition having permanent antistatic properties without detriment to a balance among properties and having excellent fabricability such as printability and bondability by mixing a styrene resin with a specified diblock copolymer. SOLUTION: This composition comprises 100 pts.wt. styrene resin and 0.3-30 pts.wt. diblock copolymer comprising block prepared by (co)polymerizing 30-100mol% aromatic vinyl monomer with 70-0mol% at least one vinylically unsaturated monomer copolymerizable therewith and a block comprising quat. ammonium salt structural units (i) represented by the formula (wherein R1 is H or methyl; R2 is an alkylene; R3 to R5 are each H, an alkyl or the like; X is COO or the like; and Y is a halogen or the lile) and 10-100mol% vinylically unsaturated monomer units (ii) having a polyalkylene glycol chain in a (i)/(ii) molar ratio of 1/10 to 100/1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a styrene-based resin which has good permanent antistatic properties and high mechanical properties, and is excellent in printability and secondary processability such as hot stamping property and adhesive property. It relates to a resin composition.

[0002]

2. Description of the Related Art Generally, an injection-molded article made of a thermoplastic resin has a large electric resistance and easily generates static electricity, so that it is prone to electrification due to friction and, therefore, has a drawback that dust is likely to adhere. . Such adhesion of dust not only impairs the appearance of injection-molded products, but can also be a factor that causes electrostatic damage to electric and electronic parts, etc.Therefore, in recent years, research has been conducted to improve the antistatic property of thermoplastic resins. Is thriving. As a means for improving the antistatic property of the thermoplastic resin, generally, a method of adding a surfactant type antistatic agent (for example, JP-A-48-80142) is generally used. Although it has excellent short-term antistatic properties after molding, it is difficult to maintain its long-term antistatic properties afterwards, and its antistatic properties drop sharply, especially after wiping with a dust cloth or after washing with water. The problem arises.

Therefore, studies have been attempted to improve the above-mentioned phenomenon and to make the antistatic property permanent. For example, a polyether amide elastomer and a modified vinyl-based polymer, which apply the conductive characteristics of a polyamide elastomer, have been tried. (Japanese Patent Publication No. 4-72855), a method using a polyetheramide elastomer and a maleimide copolymer resin (Japanese Patent Laid-Open No. 63-227648), and a polyamideimide elastomer and a modified styrene resin. A method (Japanese Patent Laid-Open No. 2-255850) is known, and a method using polyethylene oxide having a number average molecular weight of 50,000 to 1,000,000 and a sulfonate is applied by applying the conductive property of polyalkylene oxide (Japanese Patent Laid-Open No. 2-255850).
No. 233743) and an average molecular weight of 2,000,000 to 500
The method of using various polyethylene oxides and organic sulfonic acid metal salts (JP-A-4-218555), polyethylene glycol having a molecular weight of 5000 or more and styrene
A method using a polyethylene wax grafted with 0% or more (JP-A-4-23847) is known.

However, in order to prevent the generation of static electricity and the accompanying adhesion of dust by using the polyamide elastomer or polyethylene oxide, it is not effective unless these resins are added in a large amount. In that case, there are problems that various characteristics of the thermoplastic resin are greatly deteriorated and the material price is increased. In addition, the mechanism of antistatic manifestation by polyamide elastomer or polyethylene oxide is governed by the moisture absorption rate of these resins, so that there is a problem that the antistatic effect is difficult to manifest immediately after molding.

Therefore, as a method for exhibiting an antistatic effect immediately after molding, a random copolymerization of a quaternary ammonium salt group and a vinyl monomer or vinylidene monomer copolymerizable therewith with a thermoplastic resin is used. A method of adding coalescence (Japanese Patent Laid-Open No. 63-54467) is known.
However, this method is easily affected by the molding conditions and the shape of the molded product, and in order to enhance the antistatic effect of the thermoplastic resin composition for injection molding, a sufficient effect is obtained unless a large amount of the random copolymer is added. Therefore, there are drawbacks in terms of cost and deterioration in mechanical properties of the thermoplastic resin. In addition, it is difficult to allow a polar functional group such as a quaternary ammonium salt group to be present on the surface of a molded article in a high concentration, which improves the printability of the resin composition and the secondary workability such as hot stamping and adhesiveness. It also has the drawback of being difficult.

On the other hand, JP-A-6-136210 discloses that (a) a polystyrene resin and (b) a component is a polymer composed of (meth) acrylic acid ester units.
A polystyrene resin composition is disclosed in which the B component is an AB block copolymer, which is a polymer containing 50% by weight or more of an aromatic vinyl unit. This proposed one relates to a novel polystyrene resin composition having excellent impact resistance, excellent fluidity at high temperature, high modulus and strength at room temperature, and hard to block at around room temperature. However, no disclosure concerning antistatic properties is found at all, and the polystyrene-based resin composition disclosed in this publication has an insufficient antistatic effect.

[0007]

The problem to be solved by the present invention is to satisfy the permanent antistatic property without deteriorating the balance of mechanical properties while maintaining a sufficiently inexpensive price. It is to obtain a styrene resin composition having excellent secondary processability such as hot stamping property and adhesive property.

[0008]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that a vinyl-based polymer having a styrene-based resin and a special quaternary ammonium salt structural unit and a polyalkylene glycol chain is used. By combining with a diblock copolymer containing a saturated monomer unit, it was found that the permanent antistatic property and the like can be satisfied,
The present invention has been completed. That is, the present invention relates to (a) 30 to 100 mol% of an aromatic vinyl-based monomer and vinyl-based copolymerizable with the aromatic vinyl-based monomer, relative to 100 parts by weight of the styrene-based resin (A). One or more unsaturated monomers 70
A block (a) obtained by (co) polymerizing 0 to 0 mol% and (b) a vinyl type having a quaternary ammonium salt structural unit (i) represented by the following general chemical formula (I) and a polyalkylene glycol chain. 10 unsaturated monomer units (ii)
Block (b) having a molar ratio of structural unit (i) / structural unit (ii) of 1/10 to 1000/1.
A diblock copolymer (B) composed of 0.3 to 30
The present invention relates to a styrene resin composition obtained by mixing parts by weight.

[0009] (In the formula, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents an alkylene group or an alkylene group containing at least one —OH group, and R _{3 to} R ₅ represent a hydrogen atom, an alkyl group or a substituent, respectively. The benzyl group which it may have is shown.
X is -COO -, - CONH -, - SO 2 NH- or -C ₆ H ₄ SO ₂ NH- and, Y is a halogen atom, ROSO ₃
, ROSO ₂ , RSO ₃ , R-C ₆ H ₄ -SO ₃ , (R
O) ₂ PO ₂ (wherein R in Y represents an alkyl group or an alkyl group containing at least one or more —OH groups). )

Hereinafter, the present invention will be described specifically. The styrene-based resin (A) in the present invention is one containing 10% by weight or more of a styrene residue or a substituted styrene residue (hereinafter collectively referred to as a styrene-based residue) as an essential constituent component, and preferably 50%. The content is at least wt%. Examples of the monomer forming the styrene-based residue include styrene, α-methylstyrene, p-methylstyrene, p-
Aromatic vinyl-based monomers such as tert-butyl styrene and 3,4-dimethyl styrene may be mentioned, and these may be used alone or in combination of two or more. The styrene resin (A) is obtained by copolymerizing an aromatic vinyl monomer and one or more other vinyl unsaturated monomers copolymerizable with the aromatic vinyl monomer. May be.

Examples of vinyl unsaturated monomers copolymerizable with aromatic vinyl monomers include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, and methyl, ethyl and propyl acrylic acid or methacrylic acid. , N-butyl, i-butyl, hexyl, 2-ethylhexyl, dodecyl, octadecyl and other C ₁ -C ₁₈ alkyl esters and ethylene glycol, propylene glycol
And esters such as vinyl butanediol, vinyl esters of C _{1 to} C ₆ carboxylic acids such as acetic acid and propionic acid, unsaturated carboxylic acids such as acrylic acid, methacrylic acid and maleic acid, and unsaturated dicarboxylic acids such as maleic anhydride. (Meth) acrylamides such as acid anhydrides, acrylamides, methacrylamides, N, N-dimethylacrylamides, maleimides, N-methylmaleimides, N-ethylmaleimides, N
N-substituted maleimides such as -phenylmaleimide and N-cyclohexylmaleimide, and conjugated dienes such as butadiene are preferred, and acrylonitrile, methyl methacrylate, butyl acrylate, N-phenylmaleimide, maleic anhydride and butadiene are preferred.
These unsaturated monomers may be used alone or in combination of two or more.

The styrene resin (A) may be a rubber-containing polystyrene resin containing a rubbery polymer. The rubbery polymer as referred to herein is one having a glass transition temperature of preferably 0 ° C. or lower, more preferably −20 ° C. or lower, polybutadiene, styrene / butadiene copolymer, and (meth) acryl up to 30% by weight. A styrene / butadiene copolymer containing an acid lower alkyl ester, and a diene rubber such as polyisoprene or polychloroprene are preferred. Other examples of suitable rubbery polymers include C ₁ -C ₈ alkyl acrylates, especially alkyl acrylate rubbers based on ethyl acrylate, butyl and ethylhexyl. Alkyl acrylate rubber is up to 30% by weight vinyl acetate,
Methyl methacrylate, styrene, acrylonitrile, vinyl ether, etc. may be copolymerized, and further 5
Up to wt% of alkylenediol (meth) acrylate
And a crosslinkable unsaturated monomer such as divinylbenzene, triallyl cyanurate and the like may be copolymerized.

The alkyl acrylate rubber may be a core-sheath type rubber containing, as a core, one or more cross-linked diene rubbers such as polybutadiene, butadiene / styrene copolymer and acrylonitrile / butadiene copolymer. . Other preferred rubbery polymers include ethylene / propylene / ethylidene norbornene copolymers and other ethylene / propylene / non-conjugated diene copolymers, hydrogenated styrene / butadiene block copolymers, hydrogenated styrene / isoprene block copolymers. Examples thereof include polymers. Among these rubbers, polybutadiene, styrene / butadiene copolymers, polybutyl acrylate rubbers, and ethylene / propylene / non-conjugated diene copolymers are particularly preferable. Two or more kinds of these rubbers may be used in combination, if necessary. Further, these rubbers may be graft (co) polymerized with various unsaturated monomers depending on the matrix resin. Examples of the unsaturated monomer that is graft-copolymerized include unsaturated monomers that form the styrene resin (A).

Preferred specific examples of the styrene resin (A) are polystyrene, rubber-containing polystyrene, acrylonitrile / styrene copolymer, rubber-containing acrylonitrile / styrene copolymer, styrene / methyl methacrylate copolymer, rubber-containing. Styrene / methyl methacrylate copolymer, styrene / butyl acrylate copolymer, rubber-containing styrene / butyl acrylate copolymer, styrene-
Butadiene block copolymer, styrene-butadiene-
Examples thereof include styrene / diene block copolymers such as styrene block copolymers and styrene-isoprene-styrene block copolymers, and hydrogenated products thereof. These resins may be used alone or in combination of two or more. Among these, the rubber-containing polystyrene resin and the rubber-containing acrylonitrile / styrene copolymer resin are preferable from the viewpoint of balance of various physical properties.

Preferred specific examples of the rubber-containing polystyrene resin in the present invention include polystyrene, polybutadiene rubber (PBR) optionally grafted with an aromatic vinyl monomer, and styrene / butadiene random copolymer (SBR). A resin or resin composition composed of at least one rubber selected from the group consisting of a styrene / butadiene block copolymer (b-SBR), a hydrogenated styrene / isoprene block copolymer and a styrene / isoprene block copolymer is typical. Of these, high impact polystyrene (HIPS) composed of polystyrene and SBR grafted with styrene is most preferable from the viewpoint of various physical property balance.

Preferred examples of the rubber-containing acrylonitrile / styrene copolymer resin in the present invention include acrylonitrile / styrene copolymer, an aromatic vinyl monomer and another vinyl unsaturated compound capable of copolymerization. Representative is a resin or resin composition comprising at least one rubber selected from PB, SB, polybutyl acrylate rubber, ethylene / propylene / non-conjugated diene copolymer, which may be grafted with a monomer. Among them, acrylonitrile / butadiene / styrene copolymer (ABS) made of PB graft-copolymerized with acrylonitrile / styrene copolymer (AS) and acrylonitrile / styrene is most preferable from the viewpoint of various physical property balance. .

When a resin containing a rubber is used as the styrene resin (A) in the present invention, a rubber-containing polystyrene or a rubber-containing acrylonitrile / styrene copolymer is exemplified as a general-purpose one. Here, when the rubber-containing polystyrene is used, the preferable content of the rubber in the resin used is preferably 1 to 30% by weight, more preferably 3 to 20% by weight of the rubber-containing polystyrene. In the case of a rubber-containing acrylonitrile / styrene copolymer, the rubber content is preferably 1 to 60% by weight, more preferably 5 to 50% by weight.

Further, in the above HIPS resin, the weight average molecular weight of polystyrene, which is a matrix, is usually 10
Those having a weight ratio of 50,000 to 500,000 are used, and those having a weight loss of 200,000 to 400,000 are more preferable. As the ABS resin, one having a weight-average molecular weight of acrylonitrile / styrene copolymer as a matrix of 50,000 to 300,000 is usually used, and one having a weight average molecular weight of 70,000 to 250,000 is used. More preferable.

Diblock copolymer (B) in the present invention
And 30 to 100 mol% of an aromatic vinyl monomer and at least one vinyl unsaturated monomer copolymerizable therewith 7
Block (a) formed by (co) polymerizing 0 to 0 mol%
And a block (b) containing 10 to 100 mol% of a quaternary ammonium salt structural unit represented by the general chemical formula (I) and a vinyl unsaturated monomer unit having a polyalkylene glycol chain. Is. As the aromatic vinyl-based monomer in the block (a),
Examples thereof are the same as those described in the section of the styrene resin (A), and among them, styrene is preferable. Further, examples of the vinyl unsaturated monomer copolymerizable with the aromatic vinyl monomer include those similar to those described in the section of the styrene resin (A), and among them, acrylonitrile and methyl methacrylate. , Ethyl acrylate, butyl acrylate,
Butyl methacrylate, N, N-dimethyl acrylamide and the like are preferred.

Further, the block (a) comprises 30 to 100 mol% of an aromatic vinyl monomer and one or more 70 to 0 mol% of a vinyl unsaturated monomer copolymerizable therewith (co). It is preferable to polymerize, but 50 to 100 mol% of an aromatic vinyl-based monomer and one or more 50 to 0 mol% of a vinyl-based unsaturated monomer copolymerizable therewith are (co) polymerized. It is more preferable that The ratio of the aromatic vinyl monomer in the block (a) is 30 mol%
When the amount is less than the above range, the compatibility between the styrene resin and the diblock copolymer (B) is deteriorated, so that mechanical properties are deteriorated, which is not preferable.

The block (b) comprises 10 units of the quaternary ammonium salt structural unit (i) represented by the general chemical formula (I) and vinyl unsaturated monomer units (ii) having a polyalkylene glycol chain. ~ 100 mol% contained,
Preferably 30 to 100 mol%, more preferably 50.
.About.100 mol%. Content is 10
If it is less than mol%, a sufficient antistatic effect cannot be obtained.
In the block (b), the structural unit (i) / the structural unit (i
The molar ratio of i) is 1/10 to 1000/1, and 1/1 to
500/1 is more preferable, and 5/1 to 200
Most preferably, it is / 1. When the ratio of the structural unit (i) to the structural unit (ii) is within the above range, a synergistic effect derived from each structural unit is obtained and a sufficient antistatic effect is exhibited.

[0022]

The quaternary ammonium salt structural unit represented by the general chemical formula (I) in the present invention means that R _{1 in} the formula is a hydrogen atom or a methyl group, and R ₂ is an alkylene group or at least one or more. Is an alkylene group containing an —OH group, R _{3 to} R ₅ are each a hydrogen atom, an alkyl group or a benzyl group which may have a substituent, and X is —COO—, —CONH—, -SO ₂ NH- or -C ₆
H ₄ SO ₂ NH-, Y is a halogen atom, ROS
_{O 3, ROSO 2, RSO 3} , R-C 6 H 4 -SO 3, (R
O) ₂ PO ₂ (where R is an alkyl group or at least 1
It represents an alkyl group containing one or more —OH groups. ) Is a quaternary ammonium salt structural unit. Here, R ₂ in the general formula (I) is preferably an alkylene group having 1 to 10 carbon atoms, and R _{3 to} R ₅ are preferably hydrogen atoms or alkyl groups having 1 to 10 carbon atoms, R is preferably an alkyl group having 1 to 10 carbon atoms or an alkyl group having 1 to 10 carbon atoms and having at least one or more —OH groups.

The vinyl unsaturated monomer unit having a polyalkylene glycol chain in the present invention is not particularly limited, but a preferable monomer unit is represented by the following general chemical formula (II) (meta). ) Mention may be made of acrylate units. (In the formula, R ₆ is a hydrogen atom or a methyl group, R ₇ is an alkyl group having 2 to 4 carbon atoms, n is an integer of 1 to 500, and R is
₈ represents hydrogen or an alkyl group having 1 to 18 carbon atoms. The (meth) acrylate unit represented by the general chemical formula (II) is, for example, polyethylene glycol [4] mono (meth) acrylate, polyethylene glycol [9] mono (meth) acrylate, polyethylene glycol [1].
4] mono (meth) acrylate, polyethylene glycol [23] mono (meth) acrylate, polyethylene glycol [30] mono (meth) acrylate, polyethylene glycol [300] mono (meth) acrylate,
Polypropylene glycol [4] mono (meth) acrylate, polypropylene glycol [9] mono (meth) acrylate, polypropylene glycol [14] mono (meth) acrylate, polypropylene glycol [2
3] Mono (meth) acrylate, polypropylene glycol [30] mono (meth) acrylate, polypropylene glycol [300] mono (meth) acrylate, polybutylene glycol [23] mono (meth) acrylate, and their monomethyl ethers, monopropyl Ether, monobutyl ether, monononyl ether,
It is derived from monolauryl ether, monostearyl ether and the like (the number in [] indicates the degree of polymerization [n] of the polyalkylene glycol chain). Among these, monomers having a degree of polymerization [n] of 4 to 100, R ₇ being an alkyl group having 2 or 3 carbon atoms, and R ₈ being an alkyl group having 1 to 12 carbon atoms are particularly preferable.

The block (b) may consist only of a quaternary ammonium salt structural unit represented by the general chemical formula (I) and a vinyl unsaturated monomer unit having a polyalkylene glycol chain. If the vinyl unsaturated monomer unit having a quaternary ammonium salt structural unit and a polyalkylene glycol chain is contained in an amount of 10 mol% or more,
It may also include other structural units. Such structural units include styrene, α-methylstyrene,
p-methylstyrene, p-tert-butylstyrene,
Derived from an aromatic vinyl monomer such as 3,4-dimethylstyrene or a vinyl unsaturated monomer copolymerizable with the aromatic vinyl monomer described in the section of the styrene resin (A). Structural unit. Among them, styrene, acrylonitrile, methyl methacrylate, ethyl acrylate, butyl acrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, vinyl acetate, vinyl alcohol, acrylamide, N, N-dimethylacrylamide, Preferable examples include β-hydroxyethyl methacrylate and the like. These structural units are appropriately selected from the viewpoints of antistatic ability, moldability, impact resistance, secondary processing characteristics and the like of the resin composition of the present invention.

The block (b) has the general chemical formula (II
The structural unit before quaternization of the quaternary ammonium salt structural unit represented by I) may be included. (In the formula, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents an alkylene group or an alkylene group containing at least one or more —OH groups, and R ₃ and R ₄ represent a hydrogen atom, an alkyl group or a substituent, respectively. A benzyl group which may be possessed is shown.
Is -COO -, - CONH -, - SO 2 NH- or -
C ₆ H ₄ shows the SO ₂ NH-. )

The general chemical formula (II
The ratio of the structural unit before quaternization represented by I) is 30 mol%
The following is preferred. Here, R ₂ in the general chemical formula (III) is preferably an alkylene group having 1 to 10 carbon atoms or an alkylene group having 1 to 10 carbon atoms having at least one or more —OH groups, and R ₃ , R Each of ₄ is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

In the present invention, the number average degree of polymerization M of the block (a) in the diblock copolymer (B) is preferably 4 to 1000, more preferably 6 to 700. On the other hand, the number average degree of polymerization N of the block (b) is preferably 4 to 3000, and 10 to 2
It is more preferably 000. Further, the ratio M / N of the number average polymerization degrees of the block (a) and the block (b) in the diblock (B) is preferably 0.01 to 10, and more preferably 0.02 to 9. preferable.

The diblock copolymer (B) must be used in an amount of 0.3 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the styrene resin (A). Is more preferable. When the amount of the diblock copolymer (B) used is less than 0.3 part by weight, a sufficient antistatic effect cannot be obtained, and when it is more than 30 parts by weight, mechanical properties, printability, and hot stamping property are obtained. And the secondary workability such as seal adhesion is deteriorated.

In the styrenic resin composition of the present invention, an inorganic filler such as glass fiber, carbon fiber, ceramic fiber, mica, talc, calcium carbonate, barium sulfate, etc. is added within a range not impairing the object of the invention. It can be added. The type of inorganic filler used is not particularly limited, but barium sulfate and calcium carbonate are often used among the above inorganic filler fillers. In addition to the above, in the present invention, even if a plasticizer, a release agent, a weather resistance agent, an antioxidant, a flame retardant, a colorant, a stabilizer, and the like are used in combination for various purposes, the purpose of the present invention is not limited. It does not hinder.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The styrene resin (A) can be produced by various known methods, for example, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method or the like. The method for producing the diblock copolymer (B) is not particularly limited, but when radically polymerizing a monomer component constituting one block (a) or block (b), a thiolcarboxylic acid or 2 -Acetylthioethylthiol, 1
A compound containing a thioester group and a mercapto group in the molecule such as 0-acetylthiodecanethiol is allowed to coexist and polymerized, and the obtained polymer is treated with an alkali such as sodium hydroxide or ammonia or an acid such as hydrochloric acid or sulfuric acid. A method of obtaining a polymer having a mercapto group at one end by treatment and subjecting the monomer component constituting the other block (b) or block (a) to radical polymerization in the presence thereof is simple and highly efficient. Is the preferred method. This manufacturing method is described in detail in Japanese Patent Laid-Open No. 58-62671. Further, in the production method, instead of using a monomer that gives a quaternary ammonium salt structural unit forming the block (b),
A method of using the monomer before quaternization of the monomer and quaternizing the obtained polymer to obtain the diblock copolymer is also preferable because of its simple and high efficiency.

The method for producing the styrenic resin composition of the present invention is not particularly limited, but a commonly known general-purpose single-screw extruder or twin-screw extruder is used, and the styrene-based resin (A) and diblock copolymer It is preferable that the combined product (B) is blended in a predetermined ratio and melt kneaded and extruded into pellets by a known kneader such as a Henschel mixer, a Banbury mixer, a single-screw extruder or a twin-screw extruder. The styrene-based resin composition of the present invention is extremely useful as a plastic molding material for injection molding, extrusion molding, etc., which is particularly used for automobile interior parts and home appliances that require permanent antistatic property. .

[0033]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples. The examples of the present invention were evaluated based on the following evaluation methods.

[0034] Surface Measurement of the evaluation surface resistance value Y ₀ of the resistance value Y ₀ were produced by injection molding 10
Immediately after molding, a flat plate of 0 mm x 100 mm x 3 mm is placed
It was carried out under the conditions of an applied voltage of 1000 V and a charging time of 10 seconds using a super insulation meter (SM8203 type) manufactured by Toa Denpa Kogyo Co., Ltd. under conditions of 50 ° C. and 50 RH% (relative humidity).

[0035] Surface Measurement of the evaluation surface resistance value Y ₂ of the resistance value Y ₂ was prepared by injection molding 10
0 mm x 100 mm x 3 mm flat plate at 23 ° C, 50R
After leaving it under H% (relative humidity) conditions for about 1 day, rinse it with tap water, then wipe off the water on the surface, and further dry it in the room for 1 hour. Applied voltage of 100 with a super insulation meter (SM8203 type) manufactured by Denpa Kogyo.
It was performed under the conditions of 0 V and a charging time of 10 seconds.

[0036] Surface Measurement of the evaluation surface resistance Y ₃ of the resistance value Y ₃ were prepared by injection molding 10
0 mm x 100 mm x 3 mm flat plate at 23 ° C, 50R
After leaving it under H% (relative humidity) condition for about 3 months,
A super insulation meter (SM8203 type) manufactured by Toa Denpa Kogyo was used under the conditions of an applied voltage of 1000 V and a charging time of 10 seconds.

Evaluation of Tobacco Ash Adhesion In addition, the antistatic property of tobacco ash adhesion was evaluated. Evaluation is 100 mm x 1 created by injection molding
A flat plate of 00 mm x 3 mm is left in the room for about 1 hour, and the surface of the flat plate is rubbed by rubbing it with a dry cotton cloth 10 times to give a rub on it.
The interval was maintained for 5 seconds, and the ash adhesion of the tobacco was visually evaluated. ○ ・ ・ No ash adhesion occurs. △ ... Slight ash adhesion occurs. ×: A large amount of ash adheres.

Evaluation of mechanical properties As the mechanical properties, the falling weight impact strength of the resin composition was evaluated. The drop weight impact strength was evaluated by injection molding 1
A plate of 60 mm x 160 mm x 3 mm is 23 ° C and 50R
After leaving it under H% (relative humidity) condition for about 1 day, JIS-
It carried out according to K7211.

Evaluation of printability The printability was evaluated based on the strength of the adhesiveness of silk screen printing. First, the evaluation was performed by using a printing ink for polystyrene, 160 mm x 1 prepared by injection molding.
Perform silk screen printing on a 60 mm x 3 mm plate, dry at 90 ° C for 1 hour, and then at room temperature for 1 hour.
After leaving it for a day, next, after making a checkerboard-like scratch on the printing surface of this flat plate with a cutter, a cellophane tape was attached, and it was pressed sufficiently with the finger force to bring it into close contact, and then 45 ° from the surface. By pulling at once at an angle, the peeling condition of the printed surface was visually evaluated. ○ ・ ・ Peeling of the printed surface does not occur at all. Δ: The printed surface is slightly peeled off. × ・ Peels off a wide area on the printed surface.

Examples 1 to 4, Comparative Examples 1 to 4 Rubber-containing polystyrene having a rubber content of 6% by weight (HIP
After 100 parts by weight of S resin) was dry-blended with the random copolymer 1 of diblock polymers 1, 2 and (3) shown in the following (1) to (2) at a ratio shown in Table 1,
Using a 30 mmφ twin-screw extruder manufactured by Ikegai Co., Ltd., the mixture was kneaded at a cylinder temperature of 210 ° C. to obtain pellets of the target styrene resin composition.

(1) Diblock Polymer 1 A block (a) part having a number average degree of polymerization of 10 consisting of 100 mol% of styrene units, 95 mol% of quaternary ammonium salt units represented by the chemical formula (IV) and polyethylene glycol [23] ] Monomethacrylate monomethyl ether unit 5
A diblock polymer composed of a block (b) part consisting of mol% and having a number average degree of polymerization of 60. (2) Diblock Polymer 2 A block (a) part consisting of 100 mol% of styrene units and having a number average degree of polymerization of 10, 60 mol% of quaternary ammonium salt units represented by the chemical formula (IV), and polyethylene glycol [9] monomethacrylate. Monomethyl ether unit 20
A diblock polymer composed of a block (b) part having a number average degree of polymerization of 60 consisting of mol% and 20 mol% of methyl methacrylate unit.

(3) Random Copolymer 1 15 mol% of styrene units and the fourth group represented by the chemical formula (IV)
A random copolymer having a number average degree of polymerization of 70 and comprising 85 mol% of a primary ammonium salt unit.

After pre-drying the pellets obtained,
Using a 100t injection molding machine manufactured by Japan Steel Works, Ltd. 1
A 00 mm × 100 mm × 3 mm flat plate was molded, and the surface resistance value and cigarette ash adhesion test by the above method, printability evaluation, and falling weight impact strength were measured. In the evaluation of various physical properties, in order to confirm the influence of the injection speed on the physical properties, the flat plate was injection molded under the following three injection speed conditions. The results are shown in Table 1. -Injection speed conditions In molding a flat plate, injection molding was performed under the following three injection speed conditions: high speed, medium speed, and low filling speed. High speed filling: injection time 0.15 seconds Medium speed filling: injection time 0.50 seconds Low speed filling: injection time 1.50 seconds

[0044]

[Table 1]

From the comparative examples in Table 1, it can be seen that when the amount of the diblock polymer added is less than 0.3, the surface resistance is high and a large amount of ash adheres to the tobacco. on the other hand,
When the amount of the diblock polymer added is more than 30 parts by weight, not only the drop weight impact value is lowered, but also the printability is greatly lowered, and preferable secondary processing characteristics cannot be obtained. In addition, in the case of adding a random copolymer, the dependency of the injection speed condition on the manifestation of various physical properties is large, and although a good surface resistance value can be obtained with high-speed filling, the printability decreases, but conversely, with low-speed filling. , The printability is improved, but a good surface resistance value cannot be obtained, and thus it is difficult to maintain the balance of physical properties of both. On the other hand, from the examples of Table 1, it can be seen that, when the amount of the diblock polymer added is within the range of the present invention, the surface resistance value is low, and good antistatic property without causing ash adhesion of tobacco can be realized. . Further, it can be seen that the falling weight impact value is excellent and good secondary processing characteristics can be realized. From the above, a diblock polymer containing a specific quaternary ammonium salt unit and a vinyl unsaturated monomer unit having a polyalkylene glycol chain was added to a styrene resin according to the method of the present invention. It can be seen that the material has good antistatic properties, mechanical properties and secondary processing characteristics.

Examples 5 to 16 and Comparative Examples 5 to 7 Rubber-containing polystyrene having a rubber content of 6% by weight (HIP
S resin) to 100 parts by weight, the following (4) to (10)
5 parts by weight of diblock polymer-3 to 17 shown in
30mmφ-2 made by Ikegai Co., Ltd. after dry blending
Using a shaft extruder, the mixture was kneaded at a cylinder temperature of 210 ° C. to obtain pellets of the target styrene resin composition.

(4) Diblock Polymer 3 to 10 Block (a) part consists of 100 mol% of styrene unit, block (b) part contains 80 mol% of quaternary ammonium salt unit shown in chemical formula (V) and Table 2 Vinyl unsaturated monomer unit 5 having a polyalkylene glycol chain shown in
A diblock polymer consisting of mol% and ethyl methacrylate unit of 15 mol% and each block having various number average degrees of polymerization shown in Table 2.

[0048] (In the formula, Ph represents a phenylene group.)

(5) Diblock Polymer 11 Block (a) part consists of 100 mol% of styrene units, and block (b) part contains 70 mol% of quaternary ammonium salt units shown in chemical formula (V) and shown in Table 2. 0.5 mol% of a vinyl unsaturated monomer unit having a polyalkylene glycol chain and a methyl methacrylate unit of 29.5.
A diblock polymer consisting of mol% and each block having a number average degree of polymerization shown in Table 2.

(6) Diblock Polymer 12 The block (a) part comprises 75 mol% of styrene units and 25 mol% of acrylonitrile units, and the block (b)
Part is a quaternary ammonium salt unit 60 represented by the chemical formula (V)
A diblock polymer comprising 40% by mole of a vinyl-based unsaturated monomer unit having a polyalkylene glycol chain shown in Table 2 and each block having a number average degree of polymerization shown in Table 2.

(7) Diblock Polymer 13 The block (a) part is composed of 75 mol% of styrene units and 25 mol% of methyl methacrylate unit, and the block (b) part is a quaternary ammonium salt represented by the chemical formula (V). The unit consists of 30 mol%, 50 mol% of a vinyl unsaturated monomer unit having a polyalkylene glycol chain shown in Table 2 and 20 mol% of N, N-dimethylacrylamide unit, and each block has a number average shown in Table 2. A diblock polymer having a degree of polymerization.

(8) Diblock polymer 14 Block (a) part consists of 75 mol% of styrene units and 25 mol% of acrylonitrile units, and block (b)
A part of the quaternary ammonium salt unit 70 represented by the chemical formula (V)
Mol% and 10 mol% of a vinyl unsaturated monomer unit having a polyalkylene glycol chain shown in Table 2 and 20 mol% of a tertiary amine unit represented by the chemical formula (VI), and each block has the number shown in Table 2. A diblock polymer having an average degree of polymerization.

[0053]

(9) Diblock Polymer 15 Block (a) part consists of 100 mol% of styrene unit, while block (b) part consists of 100 mol% of tertiary amine unit represented by the chemical formula (VI). A diblock copolymer having the number average degree of polymerization shown in Table 2. (10) Diblock polymer 16 to 17 Block (a) part consists of 100 mol% of styrene units, while block (b) part consists of butyl acrylate units 1
A diblock polymer consisting of 00 mol% and each block having various number average degrees of polymerization shown in Table 2.

After pre-drying the pellets obtained,
Using a 100t injection molding machine manufactured by Japan Steel Works, Ltd. 1
A flat plate of 00 mm × 100 mm × 3 mm was prepared, and the surface resistance value and cigarette ash adhesion test by the above method, printability evaluation, and falling weight impact value were measured. Table 2 shows the types of various diblock polymers synthesized and the results.

[0056]

[Table 2]

From the examples of Table 2, diblock polymers containing a specific quaternary ammonium salt unit and a vinyl unsaturated monomer unit having a polyalkylene glycol chain were found to be excellent with respect to the styrene resin. It is understood that not only the antistatic property can be realized, but also the drop weight impact value is excellent and the good secondary processing characteristics can also be realized. Also,
The number average degree of polymerization M of the block (a), the number average degree of polymerization N of the block (b) and the ratio M / N value of the number average degree of polymerization of the block (a) and the block (b) are selected in a specific range. It is understood that the physical property balance can be further improved by selecting various vinyl unsaturated monomer units having a polyalkylene glycol chain. On the other hand, from the comparative example, in the diblock polymer containing no quaternary ammonium salt unit and vinyl unsaturated monomer unit having a polyalkylene glycol chain in the block (b) part, permanent antistatic property and falling weight impact value were obtained. In addition, the physical property balance of secondary processing characteristics such as printability cannot be maintained well, and the material cannot be said to be preferable.

[0058]

EFFECTS OF THE INVENTION According to the present invention, not only is it excellent in permanent antistatic property and is excellent in preventing dust from adhering to the surface of an injection-molded article, it also has impact resistance characteristics such as a falling weight impact value. It is possible to provide a plastic material for injection molding, extrusion molding, etc., which is made of a styrene resin composition having excellent secondary processing characteristics such as printability.
Therefore, the styrene-based resin composition of the present invention is extremely useful as a plastic material used for automobile interior parts and home electric appliances which require permanent antistatic properties.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Honest Kawabe 2775-17 Ozenji, Aso-ku, Kawasaki-shi, Kanagawa (72) Inventor Kiichi Yoneya 19-15, Kakinodai, Aoba-ku, Yokohama-shi, Kanagawa (72) Shinji Inaba, Kanagawa 1618 Ida 1618, Nakahara-ku, Kawasaki-shi, Japan Within the Technology Development Division, Nippon Steel Co., Ltd. (72) Inventor Ikuo Yamaoka 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Within the Technology Development Division, Nippon Steel Co., Ltd. (72) Inventor Kenji Yoshihara 1621 Sakazu, Kurashiki, Okayama Prefecture Kuraray Co., Ltd. (72) Inventor Masanari Uno, 1621 Sakazu, Kurashiki City Okayama Prefecture, Kuraray Co., Ltd. (72) Inventor Kazutoshi Terada 1-12-39 Umeda, Kita-ku, Osaka, Osaka Kuraray Co., Ltd. Within

Claims (3)

[Claims] 1. An aromatic vinyl monomer (b) 30 to 100 mol% relative to 100 parts by weight of a styrene resin (A).
And a block (a) obtained by (co) polymerizing 70 to 0 mol% of one or more vinyl unsaturated monomers copolymerizable with an aromatic vinyl monomer, and (b) the following general chemical formula ( Quaternary ammonium salt structural unit (i) represented by I)
And 10 to 100 mol% of the vinyl unsaturated monomer unit (ii) having a polyalkylene glycol chain, and the molar ratio of structural unit (i) / structural unit (ii) is 1 to 10 to 1000
A styrene-based resin composition obtained by mixing 0.3 to 30 parts by weight of a diblock copolymer (B) composed of a block (b) having a ratio of 1/1. (In the formula, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents an alkylene group or an alkylene group containing at least one —OH group, and R _{3 to} R ₅ represent a hydrogen atom, an alkyl group or a substituent, respectively. A benzyl group which may be possessed is shown.
Is -COO -, - CONH -, - SO 2 NH- or -
C ₆ H ₄ SO ₂ NH-, Y is a halogen atom, ROSO
₃ , ROSO ₂ , RSO ₃ , R-C ₆ H ₄ -SO ₃ ,
(RO) ₂ PO ₂ (wherein R represents an alkyl group or an alkyl group containing at least one or more —OH groups). ) 2. The styrene resin (A) is polystyrene, rubber-containing polystyrene, acrylonitrile / styrene copolymer, rubber-containing acrylonitrile / styrene copolymer, styrene / methyl methacrylate copolymer, rubber-containing styrene / methacrylic acid. Methyl copolymer, styrene /
The styrene according to claim 1, which is one or more selected from a butyl acrylate copolymer, a rubber-containing styrene / butyl acrylate copolymer, a styrene / diene block copolymer and a hydrogenated product thereof. -Based resin composition. 3. The number average degree of polymerization M of the block (a) in the diblock copolymer (B) is 4 to 1000, and the number average degree of polymerization N of the block (b) is 4 to 3000.
Moreover, the ratio M / N of the number average degree of polymerization of the block (a) and the block (b) is 0.01 to 10, and the styrene resin composition according to claim 1 or claim 2.