JP2007291161A - Thermoplastic resin composition and molded product comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition excellent in weld strength, dimensional accuracy, heat resistance, rigidity and lasting antistatic property, and to provide a molded product thereof. <P>SOLUTION: The thermoplastic resin composition incorporates 5-45 pts.wt. of glass fibers (D) and 5-30 pts.wt. of platy glass flakes (E) based on 100 pts.wt. of a resin composition (I) consisting of 83-60 pts.wt. of a rubber-reinforced styrenic resin (A), 7-20 pts.wt. of a polyamide elastomer (B) and 10-20 pts.wt. of a modified vinyl copolymer containing a carboxy group (C). The molded product comprising it is also provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin composition and a molded article comprising the same.

    More specifically, the present invention relates to a thermoplastic resin composition comprising a rubber-reinforced styrenic resin blended with a polyamide elastomer and a carboxyl group-containing modified vinyl copolymer alloy resin with flat glass flakes and glass fibers.

    The molded article made of the thermoplastic resin composition has excellent weld strength of a resin-resin association part at the time of molding, for example, a boss for inserting a component assembly screw, and a banknote represented by a banknote discriminator or a copying machine. The present invention relates to a thermoplastic resin composition excellent in dissipating static electricity generated when paper is passed, and having excellent dimensional stability, high rigidity, heat resistance and molding processability, and a molded article comprising the same.

  In recent years, in a wide range of fields such as home electrical equipment, OA equipment, automobiles, etc., replacement of some metal sheets with resin products has been promoted for the purpose of reducing the weight, reducing the price, and handling complex shapes. It has been. Problems with resin products include the impact on electronic functions and the reduction in commercial value due to dust adhesion when the product is charged.

    In order to continually improve these charging defects, a method of kneading polyether ester amide into another thermoplastic resin has been proposed. However, polyether ester amide is another thermoplastic resin such as polystyrene or styrene. -Poor compatibility with vinyl polymers such as acrylonitrile copolymer, acrylonitrile-butadiene-styrene terpolymer, etc., and low tensile elongation and impact strength make it impossible to obtain desirable mechanical properties.

    Therefore, a resin composition in which polyether ester amide and a modified vinyl copolymer containing a carboxyl group are mixed to improve delamination (thousand turnover) and impact strength has been proposed (Patent Literature). 1) No description or suggestion regarding weld strength is found in Patent Document 1.

    Further, the features of sheet metal include dimensional stability, high rigidity, and heat distortion resistance. Engineering resin reinforced with a reinforcing material has been proposed as a method for imparting these features to resin products. For example, polybutylene terephthalate resin, which is a crystalline resin, polyamide resin, resin composition in which glass fiber is blended with polyester resin, polycarbonate resin which is non-crystalline resin, and resin composition in which glass fiber is blended with ABS resin have been proposed. Yes. However, when only a fibrous material such as glass fiber is added as a reinforcing material, the rigidity and heat resistance are improved, but the glass fiber is oriented in the flow direction at the time of injection molding. (The value obtained by dividing the rate by the shrinkage rate in the vertical direction), which causes problems in terms of warpage and dimensional stability. Therefore, as a method for improving the warpage and dimensional stability of the reinforcing material-filled resin, for example, a resin composition in which a flat glass flake is blended with an aromatic polyester resin has been proposed (Patent Document 2), and the amorphous rubber modified A resin composition (Patent Document 3) in which flat glass flakes are blended with a styrene-acrylonitrile copolymer resin has been proposed (Patent Document 3).

However, when flat glass flakes are blended alone with a crystalline resin such as an aromatic polyester resin, an improvement effect is recognized in the shrinkage ratio, but a considerable amount of blending is required to obtain an improvement effect in rigidity and heat resistance. Is required, resulting in deterioration of molding processability and toughness. In addition, when flat glass flakes and fibrous reinforcing materials such as glass fibers are used in combination, a significant effect of improving the rigidity and heat resistance is recognized due to the synergistic effect of the crystalline resin and glass fibers, but the glass fibers are a resin flow. Due to the orientation in the direction, a large difference in shrinkage rate appears in the direction perpendicular to the flow direction with the crystallization of the crystalline resin, causing warping of the molded product. When the flat glass flakes are blended alone with the amorphous rubber-modified styrene-acrylonitrile copolymer resin, an improvement effect is recognized in the shrinkage ratio, but the rigidity and heat resistance are poor. In addition, when a flat glass flake and a fibrous reinforcing material, for example, glass fiber are used in combination, an improvement effect of the shrinkage ratio as well as an improvement in rigidity is recognized. Glass flakes or glass fibers need to be blended, and when glass flakes are frequently used, molding processability and toughness are reduced. Moreover, when glass fiber is used frequently, since the glass fiber is oriented in the flow direction, a shrinkage difference appears in the direction perpendicular to the flow direction, resulting in a large shrinkage ratio and lack in dimensional stability. Furthermore, since these resin compositions are not provided with antistatic technology, they are not suitable for use in medical applications such as banknote discriminators and paper-passing parts of copiers where parts that generate electrification and dust do not adhere. It was.
JP 62-241945 A Japanese Patent Publication No. 60-17223 JP-A-8-231812

An object of the present invention is to provide a thermoplastic resin composition having excellent weld strength, dimensional accuracy, heat resistance, rigidity, and sustained antistatic properties.

    More specifically, the object of the present invention is to blend glass fibers and flat glass flakes with an alloy resin of a rubber-reinforced styrene resin, a polyamide elastomer, and a carboxyl group-containing modified vinyl copolymer. Provided are a thermoplastic resin composition having high weld strength of a molded article, a low shrinkage ratio and warp, heat resistance, high rigidity, excellent sustained antistatic properties and molding processability, and a molded article comprising the same. There is.

  As a result of intensive studies to solve the above problems, the present invention has an alloy resin of a rubber-reinforced styrene resin, a polyamide elastomer, and a carboxyl group-containing modified vinyl copolymer with a maximum diameter of 1000 μm or less and an aspect ratio (long diameter and In addition to providing excellent weld strength, dimensional stability, rigidity, and heat resistance, blending flat glass flakes and glass fibers with a thickness ratio of 5 or more provides sustained antistatic properties. I have found what I can do.

  That is, according to the present invention, (A) 83 to 60 parts by weight of a rubber-reinforced styrene resin, (B) 7 to 20 parts by weight of a polyamide elastomer, and (C) a modified vinyl copolymer 10 to 20 containing a carboxyl group. Thermoplastic resin composition comprising (D) 5 to 45 parts by weight of glass fiber and (E) 5 to 30 parts by weight of flat glass flakes with respect to 100 parts by weight of resin composition (I) comprising parts by weight. Things are provided.

  In the thermoplastic resin composition of the present invention, the (B) polyamide elastomer containing a crystal unit in the polymer in order to greatly improve heat resistance with a small amount of reinforcing material and to provide sustained antistatic properties. Is important. Further, in order to impart dimensional stability and low warpage, the maximum diameter of the (E) flat glass flakes is 1000 μm or less and the aspect ratio (ratio of major axis to thickness) is 5 or more, It is mentioned as a preferable condition that the compounding ratio of E) flat glass flakes and (D) glass fibers is 1: 1 to 1: 1.5.

  According to the present invention, it has excellent weld strength, is excellent in the dissipation of static electricity generated during the passage of banknotes and paper typified by banknote identification machines and copiers, and has dimensional stability, high rigidity, heat resistance, A thermoplastic resin composition and a molded product excellent in moldability are obtained.

  Below, the thermoplastic resin composition and molded article of the present invention will be described in detail.

The present invention comprises (A) 83 to 60 parts by weight of a rubber-reinforced styrene resin, (B) 7 to 20 parts by weight of a polyamide elastomer, and (C) 10 to 20 parts by weight of a modified vinyl copolymer containing a carboxyl group. Resin composition (I), (D) glass fiber,
(E) It is a thermoplastic resin composition composed of flat glass flakes, and (D) glass fiber is 5 to 45 parts by weight with respect to 100 parts by weight of the resin composition (I). Glass flakes are composed of a composition ratio of 5 to 30 parts by weight.

  The (A) rubber-reinforced styrenic resin used in the present invention is a graft polymer in which a rubber-like polymer is dispersed in the form of fine particles in a matrix made of a vinyl aromatic polymer. A monomer mixture in which an aromatic vinyl monomer and, if necessary, a vinyl monomer copolymerizable therewith are added in the presence of a polymer, known bulk polymerization, bulk suspension polymerization, solution polymerization, emulsion polymerization, etc. It is a polymer obtained by subjecting to.

  Specific examples of such (A) rubber-reinforced styrene resin include, for example, impact-resistant polystyrene, ABS resin, AAS resin (acrylonitrile-acrylic rubber-styrene copolymer) and AES resin (acrylonitrile-ethylenepropylene rubber- Styrene copolymer).

  Such (A) rubber-modified styrenic resins include those having a structure in which a (co) polymer containing a styrene monomer is grafted to a rubbery polymer, and those containing a styrene monomer (co-polymer). ) A polymer having a structure in which a rubbery polymer is not grafted is included.

  Specifically, it is obtained by graft polymerization of 95 to 20 parts by weight of a monomer or monomer mixture containing 20% by weight or more of an aromatic vinyl monomer to 5 to 80 parts by weight of a rubbery polymer. (A-1) It is obtained by polymerizing a monomer or a monomer mixture containing 5 to 100% by weight of a graft (co) polymer and 20% by weight or more of an aromatic vinyl monomer (A-2). ) A vinyl (co) polymer consisting of 0 to 95% by weight is preferred.

  As the rubber polymer, those having a glass transition temperature of 0 ° C. or lower are suitable, and diene rubber is preferably used. Specifically, polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene block copolymer, diene rubber such as butyl acrylate-butadiene copolymer, polybutyl acrylate, etc. Examples include acrylic rubber, polyisoprene, and ethylene-propylene-diene terpolymer. Of these, the use of polybutadiene or butadiene copolymer is preferred.

  The rubber particle diameter of the rubber polymer is not particularly limited, but the rubber particles having an average particle diameter of 0.15 to 0.60 μm, particularly 0.2 to 0.55 μm, have excellent impact resistance. To preferred. Among them, the weight ratio of rubber particles having an average particle diameter in the range of 0.20 to 0.25 μm and that in the range of 0.50 to 0.65 μm is 90:10 to 60:40. The coalescence is more preferable because the impact resistance and the falling weight impact of the thin molded product are remarkably excellent.

  Specific examples of the aromatic vinyl monomer include styrene, α-methylstyrene, vinyltoluene, o-ethylstyrene, pt-butylstyrene, and the like, and styrene is particularly preferably used.

  As monomers other than aromatic vinyl monomers, vinyl cyanide monomers are used for the purpose of further improving impact resistance. A (meth) acrylic acid ester monomer is preferably used.

  Specific examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like, and acrylonitrile is particularly preferable. Specific examples of (meth) acrylic acid ester monomers include esterification products of acrylic acid and methacrylic acid with methyl, ethyl, propyl, n-butyl, i-butyl, etc. Is preferred.

  Further, if necessary, other vinyl monomers such as maleimide monomers such as maleimide, N-methylmaleimide and N-phenylmaleimide can also be used.

  (A-1) The monomer or monomer mixture used in the graft (co) polymer preferably has an aromatic vinyl monomer of 20% by weight or more, more preferably 50% by weight or more. is there. When the ratio of the aromatic vinyl monomer is less than 20% by weight, the impact resistance of the resin composition may be inferior. When a vinyl cyanide monomer is mixed, it is preferably 60% by weight or less, particularly 50% by weight or less from the viewpoint of moldability of the resin composition. When a (meth) acrylic acid ester monomer is mixed, it is preferably 80% by weight or less, particularly 75% by weight or less from the viewpoint of toughness and impact resistance. The total amount of the aromatic vinyl monomer, vinyl cyanide monomer and (meth) acrylate monomer in the monomer or monomer mixture is in the range of 95 to 20% by weight. The range of 90 to 30% by weight is more preferable.

  (A-1) The ratio of the rubber polymer and the monomer mixture in obtaining the graft (co) polymer is such that the rubber polymer is 5 parts by weight or more and 80 parts by weight in 100 parts by weight of the total graft copolymer. The range of less than or equal to parts is preferable, and the range of 10 to 70 parts by weight is more preferable. The ratio of the monomer or monomer mixture is preferably 95 parts by weight or less and 20 parts by weight or more, more preferably 90 parts by weight or less and 30 parts by weight or more. From the viewpoint of the impact resistance of the resin composition, the ratio of the rubbery polymer is preferably 5 parts by weight or more, and from the viewpoint of the impact resistance of the resin composition and the appearance of the molded product, it is 80 parts by weight or less. It is preferable that

  (A-1) The graft (co) polymer can be obtained by a known polymerization method. For example, it can be obtained by a method in which a mixture of a monomer and a chain transfer agent and a solution of a radical generator dissolved in an emulsifier are continuously supplied to a polymerization vessel in the presence of a rubbery polymer latex and subjected to emulsion polymerization.

  (A-1) The graft (co) polymer contains a non-grafted copolymer in addition to a material having a structure in which a monomer or a monomer mixture is grafted to a rubbery polymer. is there. (A-1) The graft ratio of the graft (co) polymer is not particularly limited, but in order to obtain a resin composition having excellent balance of impact resistance and gloss, the graft ratio is 20 to 80% by weight. In particular, it is preferably in the range of 25 to 50% by weight. The graft ratio here is a value calculated by the following formula.

Graft rate (%) = {<Amount of vinyl copolymer graft-polymerized to rubbery polymer> / <Rubber content of graft copolymer>} × 100
The properties of the uncografted (co) polymer are not particularly limited, but the intrinsic viscosity [η] (measured at 30 ° C.) of methyl ethyl ketone solubles is 0.25 to 0.60 dl / g, particularly 0.25. A range of ˜0.50 dl / g is preferable because a resin composition having excellent impact resistance can be obtained.

  (A-2) A vinyl (co) polymer is a copolymer essentially comprising an aromatic vinyl monomer. Specific examples of the aromatic vinyl monomer include styrene, α-methyl styrene, p-methyl styrene, t-butyl styrene, vinyl toluene and o-ethyl styrene, and styrene is particularly preferably used. . These can use 1 type (s) or 2 or more types.

  As the monomer other than the aromatic vinyl monomer, a vinyl cyanide monomer is preferably used for the purpose of further improving impact resistance. For the purpose of improving toughness and color tone, (meth) acrylic acid ester monomers are preferably used.

  Specific examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like, and acrylonitrile is particularly preferably used. Specific examples of the (meth) acrylic acid ester monomer include esterified products of acrylic acid and methacrylic acid with methyl, ethyl, propyl, n-butyl, i-butyl, etc., and methyl methacrylate is particularly preferred. Used.

  Specific examples of other vinyl monomers copolymerizable with these used as needed include maleimide monomers such as maleimide, N-methylmaleimide and N-phenylmaleimide.

  (A-2) The proportion of the aromatic vinyl monomer that is a constituent component of the vinyl (co) polymer is preferably 20% by weight or more, more preferably 50% by weight or more based on the total monomers. . When the ratio of the aromatic vinyl monomer is less than 20% by weight, the impact resistance of the resin composition may be inferior. In the case of mixing a vinyl cyanide monomer, it is preferably 60% by weight or less, particularly preferably 50% by weight or less from the viewpoint of impact resistance and fluidity. Moreover, when mixing a (meth) acrylic acid ester-type monomer, it is preferable that it is 80 weight% or less from the surface of toughness and impact resistance, Most preferably, it is 75 weight% or less. When other vinyl monomers copolymerizable with these are mixed, it is preferably 60% by weight or less, particularly preferably 50% by weight or less.

  (A-2) Although there is no restriction | limiting in the characteristic of a vinyl type | system | group (co) polymer, Intrinsic viscosity [(eta)] (methyl ethyl ketone solvent, 30 degreeC measurement) is 0.40-0.65dl / g, Especially 0.45. In the range of ~ 0.55 dl / g, also in N, N-dimethylformamide solvent, measured at 30 ° C, 0.35 to 0.85 dl / g, especially in the range of 0.45 to 0.70 dl / g Is preferable because a resin composition having excellent impact resistance and molding processability can be obtained.

  (A-2) There are no particular limitations on the method for producing the vinyl (co) polymer, and usual methods such as bulk polymerization, suspension polymerization, emulsion polymerization, bulk-suspension polymerization, and solution-bulk polymerization are used. The method can be used.

  As the (B) polyamide elastomer used in the present invention, known ones can be used, but an aminocarboxylic acid or lactam having 6 or more carbon atoms, or a salt of a diamine and dicarboxylic acid having 6 or more carbon atoms (B- A graft or block copolymer containing 1) and a poly (alkylene oxide) glycol (B-2) having a number average molecular weight of 200 to 6000 as constituent components is preferred, and the poly (alkylene oxide) glycol (B-2) is polyethylene oxide. More preferred is glycol.

  Here, aminocarboxylic acids or lactams having 6 or more carbon atoms, or salts of diamines and dicarboxylic acids having 6 or more carbon atoms, specifically, ω-aminocaproic acid, ω-aminoenanthic acid, ω-aminocapryl. Acids, aminocarboxylic acids such as ω-aminopergonic acid, ω-aminocapric acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, or lactams such as caprolactam, enantolactam, capryllactam, laurolactam, hexamethylenediamine-adipine Examples thereof include nylon salts such as acid salts, hexamethylenediamine-sebacate, and hexamethylenediamine-isophthalate.

  Examples of poly (alkylene oxide) glycols include polyethylene oxide glycol, poly (1,2-propylene oxide) glycol, poly (1,3-propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) ) Glycol, ethylene oxide and propylene oxide block or random copolymer, ethylene oxide and tetrahydrofuran block or random copolymer, and the like. Further, bisphenol A, an alkylene oxide adduct of fatty acid, and the like may be copolymerized. The number average molecular weight of the poly (alkylene oxide) glycol is preferably 200 to 6000, particularly preferably 300 to 4000. Further, if necessary, both ends of the poly (alkylene oxide) glycol component may be aminated or carboxylated.

  In the present invention, an aminocarboxylic acid or lactam having 6 or more carbon atoms, or a diamine having 6 or more carbon atoms and a dicarboxylic acid salt (C-1) and a poly (alkylene oxide) glycol are usually linked by an ester bond or an amide bond. However, the present invention is not limited to these. A third component such as dicarboxylic acid or diamine can also be used as a reaction component. In this case, the dicarboxylic acid component preferably has 4 to 20 carbon atoms, and examples thereof include terephthalic acid and isophthalic acid. , Phthalic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4-dicarboxylic acid, diphenoxyethanedicarboxylic acid, aromatic dicarboxylic acid such as sodium 3-sulfoisophthalate, 1,4-cyclohexanedicarboxylic acid, Alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, dicyclohexyl-4,4-dicarboxylic acid, succinic acid, oxalic acid, adipic acid, sebacic acid, 1,10-decanedicarboxylic acid are polymerizable, color tone From the physical properties, it is preferable. On the other hand, as the diamine component, aromatic, alicyclic, and aliphatic diamines are used, and among them, aliphatic diamine hexamethylenediamine is preferable.

  The method for producing the (B) polyamide elastomer used in the present invention is not particularly limited, and a known method can be used. For example, an aminocarboxylic acid or lactam or a diamine having 6 or more carbon atoms and a dicarboxylic acid salt (ii) and a dicarboxylic acid (b) are reacted to form a polyamide prepolymer having carboxylic acid groups at both ends. Oxide) glycol (c) reacts under vacuum, or (b), (b), (c) compounds are charged into a reaction vessel and heated at high temperature in the presence or absence of water A method is known in which a carboxylic acid-terminated polyamide elastomer is produced by the above-described method, and then polymerization is carried out under normal pressure or reduced pressure. There is also a method in which the compounds (a), (b), and (c) are charged into a reaction vessel at the same time, melt polymerization is performed, and then polymerization is advanced at a time under high vacuum.

  The modified vinyl polymer containing a carboxyl group (C) used in the present invention (hereinafter abbreviated as a modified vinyl polymer) is a polymer of one or more vinyl monomers. It is a polymer having a structure obtained by copolymerization and having a carboxyl group in the molecule.

  This carboxyl group may be an anhydrous carboxyl group. The content of these carboxyl groups is not limited and may be very small, and can be contained in a large amount as long as the performance as a resin is not impaired. Usually, if one molecule of the modified vinyl copolymer contains substantially one or more carboxyl groups on average, the effect of the present invention is efficiently expressed. The method for introducing a carboxyl group into the modified vinyl polymer is not particularly limited, but carboxyl groups such as acrylic acid, methacrylic acid, maleic acid, maleic acid monoethyl ester, maleic anhydride, phthalic acid and itaconic acid, Alternatively, a method of copolymerizing a vinyl monomer having an anhydrous carboxyl group with a predetermined vinyl monomer, γ, γ′-azobis (γ-cyanovaleric acid), α, α′-azobis (α-cyanoethyl)- Polymerization generators and / or thioglycolic acid, α-mercaptopropionic acid, β-mercaptopropionic acid, α-mercapto-isobutyric acid and 2,3 or 4- having a carboxyl group such as p-benzoic acid and peroxysuccinic acid Using a polymerization degree regulator having a carboxyl group such as mercaptobenzoic acid, (Co) polymerization method, and (meth) acrylic acid ester monomers such as methyl methacrylate and methyl acrylate, aromatic vinyl monomers, and optionally vinyl cyanide monomers A method of saponifying a polymer with an alkali can be used. The vinyl monomer used for the polymerization of the modified vinyl polymer is not particularly limited. For example, aromatic vinyl monomers such as styrene and α-methylstyrene, vinyl cyanide such as acrylonitrile and methacrylonitrile. Monomers, (meth) acrylic acid ester monomers such as methyl methacrylate and butyl acrylate, α, β-unsaturated carboxylic acids (anhydrides) such as maleic acid and maleic anhydride, ethylene, propylene, etc. One or two or more of these olefin monomers and vinyl monomers such as vinyl chloride, vinyl acetate and butadiene can be selected and used for the purpose. In particular, aromatic vinyl monomers such as styrene, (meth) acrylic acid ester monomers such as methyl methacrylate, maleimide monomers such as N-phenylmaleimide, and vinyl cyanide monomers such as acrylonitrile The body is preferably used in that the mechanical properties of the resin composition are excellent. If necessary, a rubbery polymer such as polybutadiene, acrylonitrile / butadiene copolymer, styrene / butadiene copolymer, polybutyl acrylate and ethylene / propylene / diene rubber may be combined with the above vinyl monomer. It can also be used. The production method of the modified vinyl polymer is not particularly limited, and usual polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, or bulk-suspension polymerization can be used.

    The amount of (A) rubber-reinforced styrene resin, (B) polyamide elastomer, and (C) a modified vinyl copolymer containing a carboxyl group is (A) component: (B) component: (C) component = 83. The range of -60: 7-20: 10-20 weight part is preferable, More preferably, it is the range of 78-68: 10-15: 12-17 weight part.

  When the amount of the polyamide elastomer used is 7 parts by weight or less, the antistatic property is low and the effect of improving the heat resistance is low. Further, when the amount of the polyamide elastomer used exceeds 20 parts by weight, the rigidity is lowered, which is not preferable.

  When the amount of the modified vinyl copolymer containing a carboxyl group is 10 parts by weight or less, the weld strength of the molded product is low. Moreover, when the usage-amount of the modified vinyl type copolymer containing a carboxyl group exceeds 20 weight part, since a moldability and antistatic property become low, it is unpreferable.

  The (D) glass fiber used in the present invention preferably has a C glass composition when used in an acidic atmosphere, and preferably has an E glass composition when used in a neutral to weakly alkaline atmosphere. It is. C glass and E glass are classified according to JIS R3410. (D) Although a commercially available glass fiber can be used, the average diameter of the glass fiber is preferably 0.3 to 20 μm, and the average length is preferably 0.1 to 10 mm, and more preferably 5 to 13 μm. An average length of 0.5 to 5 mm is more preferable. (D) The amount of the glass fiber used is a resin composition comprising a resin composition comprising (A) a rubber-reinforced styrene resin, (B) a polyamide elastomer, and (C) a modified vinyl copolymer containing a carboxyl group ( I) It is usually 5 to 45 parts by weight, preferably 7 to 30 parts by weight, more preferably 8 to 20 parts by weight with respect to 100 parts by weight.

  When the amount of the (D) glass fiber used in the present invention is less than 5 parts by weight, the effect of improving the rigidity and heat resistance is low, and when it is 45 parts by weight or more, the shrinkage ratio of the molded product increases and the dimensional stability decreases. However, it is not preferable because molding processability is lowered.

  The (E) flat glass flakes used in the present invention preferably have a maximum diameter of 1000 μm or less and an aspect ratio (ratio of major axis to thickness) of 5 or more. More preferably, the maximum diameter is in the range of 1 to 500 μm, and the aspect ratio (ratio of major axis to thickness) is 10 or more, and most preferably 20 or more. (E) If the maximum diameter of the flat glass flakes exceeds 1000 μm, it is difficult to uniformly disperse at the time of blending, causing uneven appearance in the appearance of the molded product, and at the same time, the mechanical properties may be inferior in uniformity. Because there is, attention is necessary. In addition, it should be noted that those having an aspect ratio of less than 5 have a small effect of improving the shrinkage ratio and are not suitable for some applications. Here, the term “flat plate” refers to a “flat plate” having an aspect ratio (major axis to thickness ratio) of 2 or more when glass flakes are projected from all angles.

  The amount of (E) flat glass flake used in the present invention is a resin comprising (A) a rubber-reinforced styrene resin, (B) a polyamide elastomer, and (C) a modified vinyl copolymer containing a carboxyl group. The amount is usually 5 to 30 parts by weight, preferably 7 to 20 parts by weight, and more preferably 8 to 15 parts by weight with respect to 100 parts by weight of the composition (I).

  When the amount of (E) flat glass flake used in the present invention is less than 5 parts by weight, the effect of improving the shrinkage ratio is low, and when it is 30 parts by weight or more, the toughness of the molded product is lowered and the moldability is also improved. Since it falls, it is not preferable. (E) The compounding ratio of the flat glass flakes and (D) glass fibers is more preferably in the range of 1: 1 to 1: 1.5.

The method for producing the thermoplastic resin composition of the present invention is not particularly limited and comprises (A) a rubber-reinforced styrene resin, (B) a polyamide elastomer, and (C) a modified vinyl copolymer containing a carboxyl group. The resin composition, (D) glass fiber, and (E) flat glass flakes can be produced by, for example, melt-kneading with a Banbury mixer, roll, extruder, kneader, or the like.
In the thermoplastic resin composition of the present invention, the lower limit value of the deflection temperature under load (ISO75: maximum surface stress 1.8 MPa) of the thermoplastic resin composition is preferably 100 ° C. or higher. This is because a product such as a bill validator or a copying machine may be exposed to a use environment of 60 to 80 ° C. when paper is passed. In order to obtain a thermoplastic resin composition having a deflection temperature under load (ISO75: maximum surface stress 1.8 MPa) of 100 ° C. or more with a glass fiber reinforcing material, (B) a polyamide elastomer containing a crystal unit in the polymer is added. Can be achieved. The upper limit of the deflection temperature under load is not particularly limited, but is preferably 125 ° C. or less from the viewpoint of moldability.
In the thermoplastic resin composition of the present invention, the flexural modulus (ISO178) of the thermoplastic resin composition is preferably 3000 MPa or more. This is because it is preferable for suppressing creep deformation of the product. In order to obtain a thermoplastic resin composition having a flexural modulus (ISO 178) of 3000 MPa or more, it can be achieved by adding (D) glass fibers. (D) Although a commercially available glass fiber can be used, the average diameter of the glass fiber is preferably 0.3 to 20 μm, and the average length is preferably 0.1 to 10 mm, and more preferably the average diameter is 5 to 5. 13 μm and an average length of 0.5 to 5 mm are more preferable. Further, it is preferable that the thermoplastic resin composition obtained by melt-kneading has a melt-kneading condition in which the number average length of (D) glass fibers is 250 μm or more, and (D) the number average length of glass fibers is 1 mm. The above is more preferable, and 2 mm or more is more preferable. (D) If the number average length of the glass fibers is less than 250 μm, the heat resistance and the flexural modulus are not preferred. Although it does not specifically limit as an upper limit of a bending elastic modulus, 5000 MPa or less is preferable from the surface of a moldability.
In the thermoplastic resin composition of the present invention, the surface specific resistance value (ASTM D257) is preferably 9 × 10 ¹³ Ω or less. This is because it is a product typified by a bill discriminator, a copying machine, and the like, and is preferable for preventing malfunction of the device due to static electricity applied during paper passing, for example. In particular, in order to obtain a thermoplastic resin composition having a surface specific resistance value (ASTMD 257) of 9 × 10 ¹³ Ω or less, (B) 10-15 parts of polyamide elastomer can be added. The lower limit of the surface specific resistance value is not particularly limited, but is preferably 1 × 10 ⁹ Ω or more from the viewpoint of cost.

  The thermoplastic resin composition of the present invention has very good weld strength (strength). Weld strength (strength) is determined by measuring tensile strength with a test piece molded using a mold in which a weld line is formed in the center of ASTM No. 1 dumbbell. The thermoplastic resin composition of the present invention generally has a weld strength (strength) of 29 to 34 MPa, which prevents weld boss cracking that occurs when a boss designed for assembling a substrate, a component, or the like on a molded product is tightened. Effective in terms.

The thermoplastic resin composition of the present invention is very excellent in terms of Charpy impact strength. The Charpy impact strength is measured under the conditions of 80 × 10 × 4 mm, type A notch, 23 ° C., in accordance with ISO 179. The Charpy impact strength of the thermoplastic resin composition of the present invention is generally 8 to 12 kJ / m ² . This is effective in preventing cracking against an impact generated during product conveyance and an impact during assembly.

The thermoplastic resin composition of the present invention includes various thermoplastic resins, for example, a polyolefin resin such as polyethylene and polypropylene, a polyester resin such as polyethylene terephthalate and polybutylene terephthalate, and nylon, as long as the effects of the present invention are not impaired. By blending polyamide resin such as 6 or nylon 6,6, modified PPE resin, polycarbonate resin, polyacetal resin, or modified products and elastomers thereof, the performance as a molding resin composition can be further improved.
In addition, the thermoplastic resin composition of the present invention includes, as necessary, antioxidants such as hindered phenols, sulfur-containing compounds, and phosphorus-containing organic compounds, thermal stabilizers such as phenols and acrylates, Various stabilizers such as UV absorbers such as benzotriazole, benzophenone, and succinate, light stabilizers such as organonickel and hindered amines, lubricants such as metal salts of higher fatty acids, higher fatty acid amides, and phthalates , Plasticizers such as phosphate esters, various flame retardants such as brominated compounds, phosphate esters and red phosphorus, flame retardant aids such as antimony trioxide and antimony pentoxide, metal salts of alkylcarboxylic acids and alkylsulfonic acids , Carbon black, pigments and dyes, and neutralizing agents in the case where each component is acid / basic can be added.

  The thermoplastic resin composition of the present invention obtained by the above is molded by known methods used for molding thermoplastic resins such as injection molding, extrusion molding, blow molding, vacuum molding, compression molding, and gas assist molding. The molding method itself is not particularly limited.

  The molded product of the present invention thus obtained has a high weld strength, a small warp of the molded product, and excellent heat resistance and anti-static properties. Therefore, a screw is inserted in order to assemble the parts by taking advantage of such characteristics. It can be expected to be applied to products with bosses or products that do not like the adhesion of static electricity or dust, such as bill discriminators and parts of copying machines.

  Specific examples of the molded product of the present invention include, for example, bill discriminators, copying machine paper passing parts, sensors, connectors, relay cases, switches, coil bobbins, capacitors, optical pickup chassis, tuners, speakers, computers, VTRs, TVs, DVD chassis, disk drives, fax machines, transformer members, personal computer parts, notebook personal computers, pachinko parts, and mobile phones.

  As described above, the thermoplastic resin composition of the present invention and a molded product made thereof have not only weld strength, dimensional stability, heat resistance and antistatic properties, but also high rigidity, impact resistance, and moldability. Because of its excellent characteristics, it can be suitably used as chassis and housing for bill discriminator parts, copier parts, electrical / electronic parts, OA equipment, home appliances, miscellaneous goods, and parts thereof. it can.

  In order to describe the present invention more specifically, examples and comparative examples will be described below, but the present invention is not limited thereby. In Examples and Comparative Examples, unless otherwise specified, “parts” and “%” represent “parts by weight” and “% by weight”, respectively.

First, the evaluation method of the characteristic of a thermoplastic resin composition is described below.
(1) Weld Strength Tensile strength was measured with a test piece molded using a mold in which a weld line was formed in the center of ASTM No. 1 dumbbell.
(2) Charpy impact strength The Charpy impact strength was measured under the conditions of 80 × 10 × 4 mm, type A notch, 23 ° C. in accordance with the provisions of ISO 179.
(3) Flexural modulus The flexural modulus was evaluated according to the provisions of ISO 178.
(4) Deflection temperature under load (heat resistance)
The heat resistance was evaluated according to the regulations of ISO 75 (load: 1.8 MPa).
(5) Surface resistivity value A square plate test piece having a thickness of 40 × 50 × 3 mm obtained by injection molding with a PS60E molding machine manufactured by Nissei Plastic Industry Co., Ltd. set to a cylinder set temperature of 230 ° C. and a mold temperature of 40 ° C. After being allowed to stand for 24 hours in an environment of 23 ° C. and 50% Rh, measurement was performed in accordance with ASTM D257.

The applied voltage was 500 V, and the value after 1 minute was read.
(6) Melt flow rate The melt flow rate was evaluated according to ISO 1133 (temperature: 220 ° C., load: 98 N).
(7) Mold Shrinkage A flat plate of 150 mm (W) x 150 mm (L) x 3 mm (t) by injection molding with a PS60E molding machine manufactured by Nissei Plastic Industry Co., Ltd., set at a cylinder temperature of 230 ° C and a mold temperature of 40 ° C. A specimen was obtained. The obtained test piece was allowed to stand for 24 hours in an environment of 23 ° C. and 50% Rh, and then the shrinkage in the direction perpendicular to the flow direction of the molded product was measured with a caliper. The shrinkage rate is preferably 0.4% or less as the dimensional accuracy.
(8) Shrinkage ratio The value obtained by dividing the shrinkage in the horizontal direction by the shrinkage in the vertical direction. The closer the shrinkage ratio is to 1.0, the smaller the warp of the molded product.
[Reference Example 1] Preparation of rubber-reinforced styrene resin <A-1> Graft (co) polymer A method for preparing a graft copolymer is shown below. The graft ratio was determined by the following method. Acetone was added to a predetermined amount (m) of the graft copolymer and refluxed for 4 hours. This solution was centrifuged at 8000 rpm (centrifugal force 10,000 G (about 100 × 10 ³ m / s ² )) for 30 minutes, and then insoluble matter was filtered. This insoluble matter was dried under reduced pressure at 70 ° C. for 5 hours, and the weight (n) was measured.

Graft rate (%) = {[(n) − (m) × L] / [(m) × L]} × 100
Here, L means the rubber content of the graft copolymer.

  In the presence of 60 parts (in terms of solid content) of polybutadiene latex (average rubber particle size 0.3 μm, gel content 85%), 40 parts of a monomer mixture composed of 70% styrene and 30% acrylonitrile was added to carry out emulsion polymerization. . The obtained graft copolymer was coagulated with sulfuric acid, neutralized with sodium hydroxide, washed, filtered, and dried to prepare a powdery graft copolymer <A-1>.

  The graft ratio of the obtained graft copolymer <A-1> was 36%. This graft copolymer <A-1> contained 18.1% of a non-graft copolymer composed of 70% styrene structural units and 30% acrylonitrile structural units. The intrinsic viscosity of the N, N-dimethylformamide-soluble component was 0.48 dl / g.

<A-2> Preparation of vinyl-based (co) polymer A monomer mixture consisting of 70% styrene and 30% acrylonitrile was subjected to suspension polymerization to prepare a vinyl-based copolymer <A-2>. The intrinsic viscosity of the N, N-dimethylformamide-soluble component of the obtained vinyl copolymer <A-2> was 0.73.
[Reference Example 2] (B) Polyamide Elastomer 60 parts of nylon 6,6 salt, 30 parts of polyethylene glycol having a number average molecular weight of 800 and 10 parts of adipic acid were used at 250 ° C. for 4 hours in the presence of an antimony trioxide catalyst. Polymerized. The obtained polymer was discharged in a strand shape and cut to obtain a pellet-like polyamide elastomer.
[Reference Example 3] (C) Modified Vinyl Copolymer Containing Carboxyl Group 70 parts of styrene, 25 parts of acrylonitrile and 5 parts of methacrylic acid were subjected to suspension polymerization to prepare a bead-like modified vinyl copolymer. .
[Reference Example 4] (D) Glass fiber ECS03T-351 (manufactured by Nippon Sheet Glass Co., Ltd.) (number average length 3 ± 1 mm) was used.
[Reference Example 5] (E) Flat glass flake REFG-301 (manufactured by Nippon Sheet Glass Co., Ltd.) (average diameter 140 μm, aspect ratio 28) was used.
Examples 1-5
(A) rubber reinforced styrene resin, (B) polyamide elastomer, (C) modified vinyl copolymer containing carboxyl group, (D) glass fiber, (E) flat glass flakes shown in Reference Example A pellet-shaped thermoplastic resin composition was produced by blending at a blending ratio shown in 1 and performing melt-kneading and extrusion using a vented 30 mmφ twin-screw extruder (PCM-30 manufactured by Ikegai Co., Ltd.). . Then, using an injection molding machine, a test piece was molded at a cylinder temperature of 230 ° C. and a mold temperature of 40 ° C. The test pieces were measured for physical properties under the above conditions, and the results are shown in Table 1.
Comparative Examples 1-8
(A) rubber reinforced styrene resin, (B) polyamide elastomer, (C) modified vinyl copolymer containing carboxyl group, (D) glass fiber, (E) flat glass flakes shown in Reference Example The physical properties of the test pieces obtained by mixing at the blending ratio shown in FIG. 2 and molding by the same method as in the examples were measured, and the measurement results are also shown in Table 2.

  As shown in Tables 1 and 2, the thermoplastic resin compositions (Examples 1 to 5) of the present invention all have weld strength, molding shrinkage ratio, shrinkage ratio, heat resistance, antistatic property, bending elastic modulus, Excellent impact resistance and moldability.

  On the other hand, (C) a modified vinyl polymer containing a carboxyl group is less than 10 parts by weight (Comparative Example 1) has low weld strength. Further, (C) a modified vinyl polymer containing a carboxyl group exceeds 20 parts by weight (Comparative Example 2) has a low melt flow rate and a low surface resistivity. (E) In the case of using flat glass flakes alone (Comparative Example 3), the bending elastic modulus and the deflection temperature under load are low and the effect of the reinforcing material is insufficient. (D) A glass fiber alone used as a reinforcing material (Comparative Example 4) has a large shrinkage ratio and is insufficient in terms of warpage. (E) The ratio of flat glass flakes and (D) glass fibers exceeding 1: 1 to 1: 1.5 (Comparative Example 7) has a large shrinkage ratio and is insufficient in terms of warpage. A resin using polybutylene terephthalate, which is a crystalline resin, as the base resin (Comparative Example 8) has a large molding shrinkage ratio and shrinkage ratio and is insufficient in terms of dimensional stability and warpage.

  The thermoplastic resin composition of the present invention and a molded product comprising the thermoplastic resin composition are characterized by not only weld strength, dimensional stability, heat resistance and antistatic properties, but also excellent rigidity, impact resistance, and molding processability. Therefore, it can be suitably used as a chassis and a housing and parts thereof for banknote discriminator parts, copier parts, electric / electronic parts, OA equipment, home appliances, miscellaneous goods, and the like.

  Specific examples of the end use of the molded product of the present invention include, for example, bill discriminators, copying machine paper passing parts, sensors, connectors, relay cases, switches, coil bobbins, capacitors, optical pickup chassis, tuners, speakers, computers, VTRs, TVs, DVD chassis, disk drives, fax machines, transformer members, personal computer parts, notebook personal computers, pachinko parts, mobile phones, and the like can be mentioned and are effective for these various applications.

Claims (7)

    (A) A resin composition comprising 83 to 60 parts by weight of a rubber-reinforced styrene resin, (B) 7 to 20 parts by weight of a polyamide elastomer, and (C) 10 to 20 parts by weight of a modified vinyl copolymer containing a carboxyl group ( I) A thermoplastic resin composition comprising 100 parts by weight of (D) 5 to 45 parts by weight of glass fibers and (E) 5 to 30 parts by weight of flat glass flakes.     2. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition has a deflection temperature under load (ISO 75: maximum surface stress of 1.8 MPa) of 100 ° C. or more and 125 ° C. or less. The thermoplastic resin composition according to claim 1 or 2, wherein the thermoplastic resin composition has a flexural modulus (ISO178) of 3000 MPa or more and 5000 MPa or less. The thermoplastic property according to any one of claims 1 to 3, wherein the thermoplastic resin composition has a surface resistivity (ASTMD 257) of 1 x 10 ⁹ Ω or more and 9 x 10 ¹³ Ω or less. Resin composition.     5. The flat glass flake (E) has a maximum diameter of 1000 μm or less and an aspect ratio (ratio of major axis to thickness) of 5 or more. 5. Thermoplastic resin composition.     The heat according to any one of claims 1 to 5, wherein a blending ratio of the (E) flat glass flakes and (D) glass fibers is in a range of 1: 1 to 1: 1.5. Plastic resin composition.     A molded article comprising the thermoplastic resin composition according to any one of claims 1 to 6.