JPH08239530A - Styrene-based resin composition - Google Patents

Abstract

PURPOSE: To obtain the subject composition, excellent in permanent antistatic properties, preventing properties of dust sticking, impact resistance, printability, etc., and useful as interior automobile trims and household appliances by blending a styrene-based resin with a specific diblock copolymer in a specific proportion. CONSTITUTION: This resin composition is obtained by blending (A) 100 pts.wt. styrene-based resin with (B) 0.3-30 pts.wt. diblock copolymer comprising (B1 ) a block prepared by copolymerizing 30-100mol% aromatic vinyl with 70-0mol% vinylic unsaturated monomer copolymerizable therewith and (B2 ) a block containing 10-100mol% structure unit of the formula R1 is H or methyl; R2 is an (OH-substituted)alkylene; R3 to R5 are each H, an alkyl or a (substituted) benzyl; X is COO, CONH, SO2 NH or C6 H4 SO2 NH; Y is a halogen or a group of the formula ROSO3 [R is an (OH-substituted)alkyl], an ROSO2 , an RSO3 or an R-C6 H4 -SO3 or an (RO)2 PO2 }.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a styrene-based resin which has good permanent antistatic property 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 liable to be charged by friction, and as a result, dust is likely to adhere to it. Have. 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 excellent in short-time antistatic properties after molding, it is difficult to maintain long-term antistatic properties after that, and especially after wiping with a dust cloth or after washing with water, the antistatic properties drop sharply. 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 a polyamide elastomer or polyethylene oxide, the effect will not be exhibited unless a large amount of these resins is added, and therefore various properties of the thermoplastic resin are greatly affected. There is a problem that the material price will increase as well as decrease. 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, the method of adding the random copolymer to the thermoplastic resin 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, the thermoplastic resin On the other hand, since sufficient effects cannot be obtained unless a large amount of the random copolymer is added, there are disadvantages in terms of cost and deterioration of 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 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 while maintaining a sufficiently inexpensive price and without impairing the balance of mechanical properties, and further To provide a styrene-based resin composition having excellent secondary processability such as heat resistance, 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 styrene resin and a diblock copolymer containing a special quaternary ammonium salt structural unit are used. It was found that by combining them, the permanent antistatic property and the like can be satisfied, and the present invention was completed. That is, the present invention relates to 100 to 100 parts by weight of the styrene resin (A), 30 to 100 mol% of aromatic vinyl, and one or more 70 to 70 of vinyl unsaturated monomer copolymerizable therewith.
A block (a) obtained by (co) polymerizing 0 mol% and a block (b) containing 10 to 100 mol% of a quaternary ammonium salt structural unit represented by the following general formula (I).
A diblock copolymer (B) composed of 0.3 to 30
A styrene-based resin composition containing parts by weight.

[0009]

Embedded image (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. Represents a benzyl group which may have X is —COO—, —CONH—, —SO ₂ NH— or —C ₆ H ₄ SO ₂ NH—, Y is a halogen atom, RO
_{SO 3, ROSO 2, RSO 3} , R-C 6 H 4 -SO 3,
(RO) ₂ PO ₂ (R represents an alkyl group or an alkyl group containing at least one —OH group). )

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 styrenic unsaturated monomer forming the styrenic residue include styrene, α-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 3,4.
-Substituted styrene such as dimethyl styrene may be mentioned, and these may be used alone or in combination of two or more. The styrene resin may be copolymerized with one or more other vinyl unsaturated monomers copolymerizable with styrene or substituted styrene.

The vinyl unsaturated monomer copolymerizable with the styrene unsaturated monomer includes 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,
C ₁ -C ₁₈ alkyl esters such as dodecyl and octadecyl, and ethylene glycol and 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. Examples of other suitable rubbery polymers include C ₁ -C ₈ alkyl acrylates,
In particular, alkyl acrylate rubbers based on ethyl acrylate, butyl and ethylhexyl are mentioned. The alkyl acrylate rubber may be copolymerized with up to 30% by weight of vinyl acetate, methyl methacrylate, styrene, acrylonitrile, vinyl ether, and the like, and further 5% by weight or less of an 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 (PB) which may be grafted with a styrene unsaturated monomer, and styrene / butadiene random copolymer (SB). A resin or resin composition comprising at least one rubber selected from the group consisting of a styrene / butadiene block copolymer, a hydrogenated styrene / isoprene block copolymer, and a styrene / isoprene block copolymer is typical. However, high-impact polystyrene (HIPS) composed of polystyrene and PB grafted with styrene is most preferable from the viewpoint of balance of various physical properties.

Preferred examples of the rubber-containing acrylonitrile / styrene copolymer resin in the present invention include acrylonitrile / styrene copolymer, styrene unsaturated monomer and other copolymerizable unsaturated monomer. A resin or resin composition comprising at least one rubber selected from the group consisting of PB, SB, polybutyl acrylate rubber, ethylene / propylene / non-conjugated diene copolymer, which may be grafted, is typical. Among them, acrylonitrile / butadiene / styrene copolymer (A) composed of acrylonitrile / styrene copolymer (AS) and PB graft-copolymerized with acrylonitrile / styrene
BS) is most preferable from the viewpoint of balance of various physical properties.

When polystyrene containing rubber in the styrene resin (A) is used in the present invention, rubber-containing polystyrene and rubber-containing acrylonitrile / styrene copolymer are exemplified as general-purpose products. Here, when the rubber-containing polystyrene is used, the preferable rubber content in the resin used is 1 to 30 of the rubber-containing polystyrene.
It is preferably in the range of% by weight, more preferably 3 to 20% by weight.
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. The styrene resin is
It can be produced by various known methods, for example, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method and the like. In addition, the above resin composition or blend,
It can be obtained by a known kneader such as a Henschel mixer, a Banbury mixer, a single-screw extruder or a twin-screw extruder.

Diblock copolymer (B) in the present invention
The block (a) obtained by (co) polymerizing 30 to 100 mol% of aromatic vinyl and 70 to 0 mol% of one or more vinyl unsaturated monomers copolymerizable therewith, and
It is composed of the block (b) containing 10 to 100 mol% of the quaternary ammonium salt structural unit represented by the general formula (I). As the aromatic vinyl in the block (a), styrene, α-methylstyrene, p-
Methyl styrene, p-tert-butyl styrene, 3,
4-dimethylstyrene and the like can be mentioned, with styrene being preferred. The vinyl-based monomer copolymerizable with the aromatic vinyl is equivalent to the vinyl-based unsaturated monomer copolymerizable with the styrene-based unsaturated monomer in the section of the styrene-based resin (A). Among them, acrylonitrile, methyl methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate, N, N-dimethylacrylamide and the like are preferable.

The block (a) is formed by (co) polymerizing 30 to 100 mol% of aromatic vinyl and 70 to 0 mol% of one or more vinyl unsaturated monomers copolymerizable therewith. Aromatic vinyl 50 to 10 is preferable.
It is more preferable to (co) polymerize 0 mol% and 50 to 0 mol% of one or more vinyl unsaturated monomers copolymerizable therewith. When the proportion of the aromatic vinyl in the block (a) is less than 30 mol%, the compatibility between the styrene resin and the diblock copolymer (B) is lowered, so that the mechanical properties are lowered, which is preferable. Absent.

The block (b) has the general formula (I)
The quaternary ammonium salt structural unit represented by
It is essential to contain 0 mol%, more preferably 30 to 100 mol%, most preferably 50 to 10 mol% of the quaternary ammonium salt structural unit represented by the general formula (I).
It is preferably a polymer containing 0 mol%. The quaternary ammonium salt structural unit of the block (b) is 10 mol%
If it is less than the above range, a sufficient antistatic effect cannot be obtained, which is not preferable.

[0022]

Embedded image The quaternary ammonium salt structural unit represented by the general 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 —OH. Is an alkylene group containing a 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-
And Y is a halogen atom, ROSO ₃ , ROSO ₂ ,
_{RSO 3, R-C 6 H} 4 -SO 3, (RO) 2 PO 2 (R
Represents an alkyl group or an alkyl group containing at least 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
Is preferably a hydrogen atom or a carbon number of 1 to 10
Is preferable, and 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 group.

The block (b) may be composed of only the quaternary ammonium salt structural unit represented by the general formula (I), but the quaternary ammonium salt structural unit is 10 mol%.
Other structural units may be contained as long as the above content is contained. Such structural units include styrene,
α-methylstyrene, p-methylstyrene, p-ter
Aromatic vinyl such as t-butyl styrene and 3,4-dimethyl styrene, and a monomer similar to the vinyl unsaturated monomer copolymerizable with the styrene unsaturated monomer in the section of the styrene resin (A). Structural units derived from the monomers are mentioned. Among them, styrene, acrylonitrile, methyl methacrylate, ethyl acrylate, butyl acrylate, ethyl methacrylate, butyl methacrylate, 2-methacrylic acid
Ethylhexyl, dodecyl methacrylate, vinyl acetate,
Preferable examples include vinyl alcohol, acrylamide, N, N-dimethylacrylamide, β-hydroxyethyl methacrylate and the like. These structural units are appropriately selected from the viewpoints of antistatic performance, moldability, impact resistance, secondary processing characteristics and the like of the resin composition of the present invention.

Further, the block (b) may contain a structural unit before quaternization of the quaternary ammonium salt structural unit represented by the general formula (II).

[Chemical 4] (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. .X showing a benzyl group that may have is -COO -, - CONH -, - shows the SO ₂ NH- or _{-C 6 H 4 SO 2 NH-)} .

The proportion of the structural unit before quaternization represented by the general formula (II) in the block (b) is preferably 30 mol% or less. Here, R ₂ in the general formula (II) 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 group is preferable, and R ₃ and R ₄ are preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, respectively. Is good.

The method for producing the diblock copolymer (B) is not particularly limited, but a thiolcarboxylic acid is used when radically polymerizing the monomer component constituting the block (a) (or (b)). Alternatively, a compound containing a thioester group and a mercapto group in the molecule such as 2-acetylthioethylthiol, 10-acetylthiodecanethiol, etc. is allowed to coexist and polymerized, and the obtained polymer is alkali such as sodium hydroxide or ammonia. Alternatively, it is treated with an acid such as hydrochloric acid or sulfuric acid to give a polymer having a mercapto group at one end, and in the presence thereof, a monomer component constituting the block (b) (or (a)) is radically polymerized. The method of obtaining is a simple, highly efficient and preferable method. This manufacturing method is described in detail in Japanese Patent Laid-Open No. 58-62671. In addition, in the manufacturing method, a fourth component which constitutes the block (b) is used.
A method for obtaining the diblock copolymer by quaternizing the obtained polymer by using a monomer before quaternization of the monomer instead of using the monomer which gives a quaternary ammonium salt structural unit. Also,
It is preferable because it is simple and highly efficient.

In the present invention, the number average degree of polymerization M of the block (a) in the diblock copolymer (B) is M.
Is preferably 4 to 1000, and 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,
It is more preferably 2000. 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, and 1 to 20 parts by weight, based on 100 parts by weight of the styrene resin (A). It is preferable. When the amount of the diblock copolymer (B) used is less than 0.3 parts 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 increased. 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.
The method for producing the styrene-based resin composition of the present invention is not particularly limited, but a commonly known general-purpose single-screw extruder or 2
It is preferably produced by kneading and melting with a shaft extruder.

[0030]

EXAMPLES The present invention will be specifically described below based on 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.

[0031] Surface Measurement of the evaluation surface resistivity Y ₁ of the resistance value Y ₁ were prepared by injection molding 10
0 mm x 100 mm x 3 mm flat plate at 23 ° C, 50R
After left for about 1 day under H% (relative humidity) conditions, it was measured with a super insulation meter (SM8203 type) manufactured by Toa Denpa Kogyo Co., Ltd. under the conditions of applied voltage of 1000 V and charging time of 10 seconds.

[0032] 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.

[0033] 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 by Tobacco Ash Adhesion In addition, the antistatic property was evaluated by the cigarette ash adhesion. 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 adhesion in 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 and Comparative Examples 1 to 4 A diblock polymer and a random copolymer shown below were dried at a ratio shown in Table 1 with respect to 100 parts by weight of a HIPS resin having a rubber content of 6% by weight. After blending
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 a target styrene resin composition. After pre-drying the obtained pellets, a flat plate of 100 mm x 100 mm x 3 mm was prepared using a 100 t injection molding machine manufactured by Japan Steel Works, Ltd., and a surface resistance value and a cigarette ash adhesion test according to the above method, The printability was evaluated and the falling weight impact strength was 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.

(1) Diblock Polymer 1 A number average polymerization comprising a block (a) part having a number average degree of polymerization of 10 composed of 100 mol% of styrene units and 100 mol% of a quaternary ammonium salt unit represented by the formula (III). A diblock polymer composed of a block (b) part of 60 degrees.

(2) Diblock Polymer 2 A block (a) part having a number average degree of polymerization of 10 consisting of 100 mol% of styrene units, 60 mol% of a quaternary ammonium salt unit represented by the formula (III) and a methyl methacrylate unit. Four
A diblock polymer composed of 0 part of a block (b) having a number average degree of polymerization of 60.

(3) Random Copolymer 1 A random copolymer having a number average degree of polymerization of 70 and comprising 15 mol% of styrene units and 85 mol% of quaternary ammonium salt units represented by the general formula (III).

[0041]

Embedded image

-Injection speed conditions In the production of the flat plate, injection molding was performed under three injection speed conditions of 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

[0043]

[Table 1]

It can be seen from Table 1 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 addition amount of the diblock polymer is more than 30 parts by weight, not only the drop weight impact value is lowered but also the printability is greatly lowered, and a preferable secondary processing property 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, when the amount of the diblock polymer added is within the range of the present invention, it can be seen that the surface resistance value is low and good antistatic property that does not cause 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 material obtained by adding a diblock polymer containing a specific quaternary ammonium salt group to a styrenic resin according to the method of the present invention has good antistatic properties, mechanical properties and secondary processing properties. I understand.

Examples 5 to 16 and Comparative Examples 5 to 7 To 100 parts by weight of a HIPS resin having a rubber content of 6% by weight, 5 parts by weight of a diblock polymer shown below was added and dry blended. 30mmφ made by Ikegai Co., Ltd.
-Using a twin-screw extruder, the mixture was kneaded at a cylinder temperature of 210 ° C to obtain pellets of the target styrene resin composition. After pre-drying the obtained pellets, 100 mm x 1 using a 100 t injection molding machine manufactured by Japan Steel Works, Ltd.
A flat plate of 00 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.

(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 represented by the formula (IV) and methacrylic acid. Ethyl unit 2
A diblock polymer comprising 0 mol% and each block having various number average degrees of polymerization shown in Table 2.

[0047]

[Chemical 6] (In the formula, Ph represents a phenylene group.)

(5) Diblock Polymer 11 Block (a) part consists of 100 mol% of styrene unit, and block (b) part contains 70 mol% of quaternary ammonium salt unit shown in formula (IV) and methyl methacrylate unit. Three
A diblock polymer consisting of 0 mol% and each block having a number average degree of polymerization shown in Table 2.

(6) Diblock Polymer 12 Block (a) part consists of 75 mol% of styrene units and 25 mol% of acrylonitrile units, and block (b)
A diblock polymer in which each part comprises 60 mol% of a quaternary ammonium salt unit represented by the formula (IV) and 40 mol% of a styrene unit, and each block has 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 units, and the block (b) part is a quaternary ammonium salt unit represented by the formula (IV). Three
0 mol% and N, N-dimethylacrylamide units 7
A diblock polymer consisting of 0 mol% and each block having a number average degree of polymerization shown in Table 2.

(8) Diblock Polymer 14 Block (a) part consists of 75 mol% of styrene units and 25 mol% of acrylonitrile units, and block (b)
A diblock in which each part comprises 70 mol% of a quaternary ammonium salt unit represented by the formula (IV) and 30 mol% of a tertiary amine unit represented by the formula (V), and each block has a number average degree of polymerization shown in Table 2. polymer.

[0052]

[Chemical 7]

(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 formula (V), and each block 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 unit, while block (b) part consists of butyl acrylate unit 1
A diblock polymer consisting of 00 mol% and each block having various number average degrees of polymerization shown in Table 2.

[0055]

[Table 2]

From Table 2, it can be seen that the diblock polymer containing a specific quaternary ammonium salt group can realize good antistatic property with respect to the styrene resin, and also has an excellent drop weight impact value. It can be seen that excellent secondary processing characteristics can also be realized. Further, 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 / of the number average degree of polymerization of the block (a) and the block (b).
It can be seen that if the N value is selected within a specific range, further improvement in physical property balance can be realized. On the other hand, a diblock polymer that does not contain a quaternary ammonium salt group in the block (b) part is preferable because it cannot maintain a good balance of physical properties such as permanent antistatic property, falling weight impact value and printability. It cannot be called a material.

[0057]

EFFECTS OF THE INVENTION According to the resin composition of 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 product, It is possible to provide an injection molding material made of a styrene-based resin composition having excellent impact resistance and secondary processing characteristics such as printability. Therefore, the injection molding material comprising the styrene resin composition of the present invention is extremely useful particularly as a plastic material used for automobile interior parts and home electric appliances.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Inaba 4-61-4 Kamoi, Midori-ku, Yokohama, Kanagawa Prefecture (72) Inventor, Shiji Yoshihara 1621 Sakata, Kurashiki, Okayama (72) Inventor, Terada Kazutoshi 1-12-39 Umeda, Kita-ku, Osaka City, Osaka Prefecture Kuraray Co., Ltd. (72) Inventor Toshiaki Sato 1621 Sakata, Kurashiki-shi, Okayama Kuraray Co., Ltd.

Claims (3)

[Claims] 1. One or more kinds of vinyl unsaturated monomers copolymerizable with 30 to 100 mol% of aromatic vinyl and aromatic vinyl based on 100 parts by weight of styrene resin (A) 7.
Block (a) formed by (co) polymerizing 0 to 0 mol%
And a diblock copolymer (B) 0.3 composed of a block (b) containing 10 to 100 mol% of a quaternary ammonium salt structural unit represented by the following general formula (I).
A styrene-based resin composition containing 30 to 30 parts by weight. Embedded image (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. Represents a benzyl group which may have X is —COO—, —CONH—, —SO ₂ NH— or —C ₆ H ₄ SO ₂ NH—, Y is a halogen atom, RO
_{SO 3, ROSO 2, RSO 3} , R-C 6 H 4 -SO 3,
(RO) ₂ PO ₂ (R represents an alkyl group or an alkyl group containing at least one —OH group). ) 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.