JP2017179204A - Polybutylene terephthalate resin composition and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polybutylene terephthalate resin composition less in gas generation amount during molding, excellent in cold heat impact resistance and flowability and having no generation of bleedout when used under a high temperature high humidity environment.SOLUTION: There is provided a polybutylene terephthalate resin composition by blending 100b pts.wt. of (A) polybutylene telephthalate, 1 to 7 pts.wt. of (B) an aliphatic acid ester compound consisting of 3 to 6 valent aliphatic alcohol and aliphatic acid and having molecular weight of 400 to 3000, 5 to 60 pts.wt. of (C) an elastomer and 10 to 110 pts.wt. of (D) a reinforced fiber.SELECTED DRAWING: None

Description

  The present invention relates to a polybutylene terephthalate resin composition. The resin composition of this invention is used suitably for the molded article which consists of insert molding with a metal component.

  Polybutylene terephthalate resin (hereinafter sometimes abbreviated as PBT) is excellent in heat resistance, electrical properties, chemical resistance, dimensional stability, etc., so it can be used in various electrical and electronic equipment parts, automobiles, trains, and trains. It is widely used as an interior / exterior member for vehicles such as automobiles and other general industrial products.

  When used for electrical and electronic equipment parts and automotive electrical parts, metal parts such as electrodes may be manufactured by insert molding. Resin molding due to the difference in linear expansion coefficient between resin and metal due to temperature changes in the usage environment. It is required that the product does not crack, that is, thermal shock resistance. In recent years, with the reduction in the thickness of resin molded products accompanying the reduction in size and weight of molded products, there has been a need for higher thermal shock resistance.

  Also, when the insert metal is a relatively brittle metal such as a sintered magnet, if excessive pressure is applied during resin filling, cracks will occur in the insert metal due to the stress strain remaining inside the molded product. In addition to thermal and thermal shock resistance, fluidity is also required.

  In response to such problems, for example, Patent Document 1 proposes a resin composition obtained by blending a thermoplastic polyester with a hyperbranched polyester.

  In addition, as a method for improving the thermal shock resistance, for example, Patent Document 2 includes PBT and polyethylene terephthalate resin (hereinafter sometimes abbreviated as PET), an elastomer having a glycidyl group, an unmodified elastomer, and glass fiber. The proposal of the resin composition formed is made | formed.

JP 2011-102391 A Japanese Patent Laid-Open No. 2006-17104

  As described above, the resin material used for the metal insert molded product is required to have cold-heat shock resistance and fluidity, but the technique described in Patent Document 1 has insufficient cold-heat shock resistance. Further, when an elastomer having a glycidyl group is added to improve the thermal shock resistance as in Patent Document 2, the fluidity is lowered, and it is difficult to achieve both the thermal shock resistance and the fluidity. It was. In addition, if the amount of gas generated during molding is large, the contamination of the mold is accelerated, so that the number of times of maintenance of the mold increases and the productivity decreases. Furthermore, when a molded product is used in a hot and humid environment, if a bleed-out occurs, there is a risk of product failure due to a defective metal contact.

  Therefore, the present invention solves the above-mentioned problems, generates a small amount of gas during molding, has excellent cold shock resistance and fluidity, and does not generate bleed out when used in a hot and humid environment. It is an object to provide a polybutylene terephthalate resin composition.

  The inventors of the present invention have reached the present invention as a result of intensive studies and studies in order to solve such problems.

That is, the present invention
(1) (A) 1 to 7 parts by weight of (B) a fatty acid ester compound having a molecular weight of 400 to 3000 composed of a trivalent to hexavalent aliphatic alcohol and a fatty acid with respect to 100 parts by weight of polybutylene terephthalate, (C) A polybutylene terephthalate resin composition comprising 5 to 60 parts by weight of an elastomer and (D) 10 to 110 parts by weight of a reinforcing fiber;
(2) The polybutylene terephthalate resin composition according to (1), wherein the aliphatic alcohol is a pentavalent or hexavalent aliphatic alcohol,
(3) The polybutylene terephthalate resin composition according to (1) or (2), wherein the aliphatic alcohol is a hexavalent aliphatic alcohol,
(4) The polybutylene terephthalate resin composition according to any one of (1) to (3), wherein the elastomer (C) contains at least ethylene as a copolymerization component,
(5) Three (E) at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, a glycidyl group, an isocyanate group and an amide group is added to 100 parts by weight of the (A) polybutylene terephthalate. The polybutylene terephthalate resin composition according to any one of (1) to (4), wherein 0.05 to 2 parts by weight of the polyfunctional compound having the above is blended,
(6) A molded article comprising the polybutylene terephthalate resin composition according to any one of (1) to (5),
(7) The molded product according to (6), wherein the molded product is an insert molded product in which a metal is inserted.
Is to provide.

  The polybutylene terephthalate resin composition of the present invention has a small amount of gas generation at the time of molding, and by molding this, a molded product having excellent thermal shock resistance and fluidity can be obtained. Furthermore, an insert-molded product that does not cause bleed-out even when used in a hot and humid environment can be obtained.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention. .

  The polybutylene terephthalate resin composition of the present invention comprises (A) polybutylene terephthalate, (B) a fatty acid ester compound having a molecular weight of 400 to 3000 consisting of a trivalent to hexavalent aliphatic alcohol and a fatty acid, (C) an elastomer, and ( D) A reinforcing fiber is blended. The polybutylene terephthalate resin composition of the present invention includes a reaction product obtained by reacting individual components constituting the resin composition, but the reaction product is generated by a complex reaction between polymers. There are circumstances where it is impractical to specify the structure. Therefore, this invention specifies invention with the component to mix | blend.

[Component A]
The polybutylene terephthalate (A) used in the present invention is prepared from a raw material mainly composed of terephthalic acid or an ester-forming derivative thereof and 1,4-butanediol or an ester-forming derivative thereof. It is a polymer obtained by a polymerization reaction. Examples of ester-forming derivatives of terephthalic acid include lower alkyl esters of terephthalic acid. More specifically, methyl ester, ethyl ester, propyl ester, butyl ester and the like can be mentioned.

  The polybutylene terephthalate (A) is copolymerized with terephthalic acid or its derivative and 1,4-butanediol or its derivative together with other dicarboxylic acid or its derivative, as long as the object of the present invention is not impaired. It may be one obtained by copolymerization with other diols or derivatives thereof. Examples of the dicarboxylic acid or derivative thereof used as a copolymerization component include isophthalic acid, adipic acid, oxalic acid, sebacic acid, dodecanedioic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and the like. Examples of the diol component or derivative thereof used as a copolymerization component include ethylene glycol, 1,3-trimethylene glycol, 1,5-pentanediol, 1,6-hexanediol, cyclohexanediol, polyethylene glycol, polypropylene glycol, polytetra And methylene glycol. The copolymer component is preferably 20 mol% or less based on the polyester obtained by polycondensation of terephthalic acid or its ester-forming derivative and 1,4-butanediol or its ester-forming derivative.

  (A) Preferable examples of polybutylene terephthalate and copolymer include polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decane dicarboxylate) ), Polybutylene (terephthalate / naphthalate), and the like. Here, “/” represents a copolymerization component. Two or more of these may be blended.

  The (A) polybutylene terephthalate used in the present invention preferably has a melt flow rate (hereinafter sometimes abbreviated as MFR) at 250 ° C. and 1 kgf in the range of 5 to 80 g / 10 minutes. If MFR is 5 g / 10min or more, fluidity | liquidity can be improved more. 8 g / 10 min or more is more preferable. On the other hand, if the MFR is 80 g / 10 min or less, a molded product having excellent mechanical properties can be obtained. 70 g / 10 min or less is preferable, and 60 g / 10 min or less is more preferable. In addition, MFR in this invention is the value measured based on ISO1133.

  The manufacturing method of (A) polybutylene terephthalate used for this invention is not specifically limited, A well-known polycondensation method, ring-opening polymerization method, etc. can be used. Either batch polymerization method or continuous polymerization method may be used, and both the method of obtaining polybutylene terephthalate by transesterification reaction and polycondensation reaction, and the direct polymerization method of obtaining polybutylene terephthalate by esterification reaction and polycondensation reaction are applied. can do. The continuous polymerization method is preferable in that the amount of carboxy terminal group can be reduced and the fluidity improving effect is increased, and the direct polymerization method is preferable in terms of cost.

  In order to effectively advance the polycondensation by the esterification reaction and the polycondensation by the transesterification reaction, it is preferable to add a catalyst during these reactions. Specific examples of the catalyst include organic titanium compounds, tin compounds, zirconia compounds, antimony compounds and the like.

  More specific examples of the organic titanium compounds include methyl titanate, tetra-n-propyl ester, tetra-n-butyl ester, tetraisopropyl ester, tetraisobutyl ester, tetra-tert-butyl ester, cyclohexyl ester. , Phenyl ester, benzyl ester, tolyl ester, or mixed ester thereof.

  More specific examples of the tin compound include dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethyldistin oxide, cyclohexahexyldistin oxide, didodecyltin oxide, triethyltin hydroxide, triphenyltin hydro gen. Alkyl such as oxide, triisobutyltin acetate, dibutyltin diacetate, diphenyltin dilaurate, monobutyltin trichloride, dibutyltin dichloride, tributyltin chloride, dibutyltin sulfide, butylhydroxytin oxide, methylstannic acid, ethylstannic acid, butylstannic acid Stannic acid and the like can be mentioned.

  More specific examples of the zirconia compound include zirconia compounds such as zirconium tetra-n-butoxide.

  More specific examples of the antimony compound include antimony trioxide and antimony acetate.

  Of these, organic titanium compounds and tin compounds are preferable from the viewpoint of catalytic effect, and tetra-n-propyl ester, tetra-n-butyl ester, tetraisopropyl of titanic acid are further preferable because they have higher catalytic effect. Esters are preferred, and tetra-n-butyl ester of titanic acid is particularly preferred. These catalysts can be used in combination of two or more.

  The amount of the catalyst added is (A) based on 100 parts by weight of polybutylene terephthalate in order to improve the moldability when making an insert-molded product and the mechanical properties and color tone when making an insert-molded product. The range of 0.005 to 0.5 parts by weight is preferable, and the range of 0.010 to 0.2 parts by weight is more preferable.

[B component]
The (B) fatty acid ester compound used in the present invention is composed of a tri- to hexavalent aliphatic alcohol and a fatty acid.

  Examples of the tri- to hexavalent aliphatic alcohol include glycerol, diglycerol, erythritol, sorbitol, triglycerol, dipentaerythritol, and tetraglycerol. These aliphatic alcohols can be used alone or in combination of two or more. Preferred aliphatic alcohols are pentavalent or hexavalent aliphatic alcohols such as triglycerol, dipentaerythritol, and tetraglycerol. More preferred is a hexavalent aliphatic alcohol.

  The fatty acid is preferably a linear or branched saturated fatty acid having 5 to 30 carbon atoms, such as pentanoic acid, hexanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid. , Isostearic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, melissic acid and the like, but not limited thereto.

  In order to avoid the transesterification reaction with (A) polybutylene terephthalate, the (B) fatty acid ester compound is preferably a full ester substantially free of free hydroxyl groups and carboxyl groups. From the viewpoint of suppressing hydrolysis of (A) polybutylene terephthalate, the acid value of (B) fatty acid ester compound is preferably 0 to 10 KOHmg / g, more preferably 0 to 5 KOHmg / g. .

  The molecular weight of the (B) fatty acid ester compound is large in the amount of gas generated during molding, the presence or absence of bleed-out generated during use in a hot and humid environment, and the handleability during melt-kneading for producing a resin composition. affect. The molecular weight of the fatty acid ester compound used in the present invention is 400 to 3000. Preferably it is 500-2500. When the molecular weight of the fatty acid ester compound is less than 400, the amount of gas generated during molding increases, and bleed-out may occur during use in a hot and humid environment. When the molecular weight is larger than 3000, the dispersibility in the resin is lowered, so that mechanical properties may be lowered, and the viscosity is increased, so that the handling property at the time of melt kneading is also deteriorated.

  (B) A fatty acid ester compound can also be used individually by 1 type, and can also be used in combination of 2 or more type. Particularly preferred (B) fatty acid ester compounds are from ADEKA Corporation, for example, “Adekasizer” (registered trademark) UL-6, from Riken Vitamin Co., Ltd., for example, “Riquester” (registered trademark) L8483. Available.

  In the polybutylene terephthalate resin composition of the present invention, the blending amount of the (B) fatty acid ester compound is 1 to 7 parts by weight, preferably 2 to 6 parts by weight with respect to 100 parts by weight of the (A) polybutylene terephthalate. Part. When the blending amount of the (B) fatty acid ester compound is less than 1 part by weight, the thermal and thermal shock resistance and fluidity of the insert molded product are lowered. On the other hand, when the amount exceeds 7 parts by weight, the amount of gas generated at the time of molding increases, and bleed out occurs when used in a high temperature and high humidity environment.

[C component]
The (C) elastomer is blended for the purpose of improving the thermal shock resistance, and the following monomers: ethylene, propylene, 1-butene, vinyl acetate, isoprene, butadiene, styrene, acrylonitrile, acrylic acid or (Co) heavy composed of at least one of monocarboxylic acids such as methacrylic acid or compounds having a polymerizable double bond such as ester acids thereof, or dicarboxylic acids such as maleic acid, fumaric acid or itaconic acid It is a coalescence.

  A core-shell type elastomer can also be used, and examples thereof include an acrylic core-shell polymer having a multilayer structure in which an acrylic polymer is a core layer and a vinyl (co) polymer is a shell layer.

  From the viewpoint of easy availability, a (co) polymer containing ethylene as a monomer is preferable. Examples of the ethylene (co) polymer include high-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, and ethylene / propylene copolymer. Polymer, ethylene / 1-butene copolymer, ethylene / vinyl acetate copolymer, ethylene / 1-octene copolymer, ethylene / propylene / conjugated diene copolymer, ethylene / ethyl acrylate copolymer, ethylene / Examples thereof include a butyl acrylate copolymer, an ethylene / methyl methacrylate copolymer, and an ethylene / ethyl methacrylate copolymer. Further, a (co) polymer obtained by grafting or copolymerizing an acid anhydride or glycidyl methacrylate to the above ethylene (co) polymer is also preferably used. These may be used alone or in combination of two or more, and may be used in combination with one or more of the above ethylene (co) polymers. Among the ethylene (co) polymers, ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, and ethylene / butyl acrylate copolymer are among the ethylene (co) polymers from the viewpoint of both thermal shock resistance and fluidity. It is particularly preferably used, and can be obtained, for example, under the trade name “Elvalloy” (registered trademark) AC22534 from Mitsui DuPont Polychemical Co., Ltd.

  In the polybutylene terephthalate resin composition of the present invention, the blending amount of the (C) elastomer is 5 to 60 parts by weight, preferably 10 to 50 parts by weight with respect to 100 parts by weight of the (A) polybutylene terephthalate. is there. (C) If the compounding quantity of an elastomer is less than 5 weight part, the cold-heat shock resistance at the time of setting it as an insert molded product will fall. Moreover, when it exceeds 60 weight part, the mechanical characteristic at the time of setting it as an insert molded product will fall, and the gas generation amount at the time of shaping | molding will increase.

[D component]
As the (D) reinforcing fiber used in the present invention, glass fiber, carbon fiber, metal fiber and organic fiber (nylon, polyester, aramid, polyphenylene sulfide, liquid crystal polymer, acrylic, etc.) and the like can be used. Alternatively, two or more types can be used in combination. (D) As the reinforcing fiber, glass fiber is preferable because it can reduce the molding shrinkage rate and linear expansion coefficient of the molded product, can improve the thermal shock resistance, and is easily available. The glass fiber can be obtained, for example, from Nippon Electric Glass Co., Ltd. under the trade name T-120H. Moreover, it is preferable that the fiber diameter of (D) reinforcement fiber is 4-25 micrometers in diameter, More preferably, it is 6-20 micrometers.

  In the present invention, (D) the reinforcing fiber is preferably opened in the polybutylene terephthalate resin composition. Here, the opened state means a state in which (D) the reinforcing fiber is opened to a single fiber in the polybutylene terephthalate resin composition, specifically, the reinforcing in the resin composition. It means that the number of reinforcing fibers bundled 10 or more when the fibers are observed is 40% or less of the total number of reinforcing fibers.

  The (D) reinforcing fiber used in the present invention is preferably treated with a sizing agent or a surface treatment agent. Examples of the sizing agent or surface treatment agent include functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, and titanate compounds, and among these, epoxy compounds are particularly preferable from the viewpoint of improving the heat and moisture resistance of the reinforcing fibers.

  In the polybutylene terephthalate resin composition of the present invention, the blending amount of the (D) reinforcing fiber is 10 to 110 parts by weight, preferably 20 to 90 parts by weight with respect to 100 parts by weight of the (A) polybutylene terephthalate. It is. (D) When the compounding quantity of a reinforced fiber is less than 10 weight part, it is inferior to the mechanical characteristic of a molded article, and also is inferior in the thermal-thermal shock resistance at the time of setting it as an insert molded article. (D) When the compounding quantity of a reinforcing fiber exceeds 110 weight part, it is inferior to the fluidity | liquidity of a polybutylene terephthalate resin composition.

[E component]
In addition, the polybutylene terephthalate resin composition of the present invention is a group further comprising (E) a hydroxyl group, a carboxyl group, an amino group, a glycidyl group, an isocyanate group, and an amide group with respect to 100 parts by weight of the (A) polybutylene terephthalate. It is preferable to blend 0.05 to 2.0 parts by weight of a polyfunctional compound having at least three functional groups selected from 3 or more (hereinafter sometimes referred to as (E) polyfunctional compound). .

  By blending the (E) polyfunctional compound, the fluidity of the polybutylene terephthalate resin composition can be further improved. (E) The polyfunctional compound may be a low molecular compound or a high molecular weight polymer.

  Such (E) polyfunctional compound has at least three functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, a glycidyl group, an isocyanate group, and an amide group.

  (E) As a preferable example of the polyfunctional compound, when the functional group is a hydroxyl group, 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1 , 2,3,6-hexanetetraol, glycerol, diglycerol, triglycerol, tetraglycerol, pentaglycerol, hexaglycerol, triethanolamine, trimethylolethane, trimethylolpropane, ditrimethylolpropane, trimethylolpropane, 2- Methylpropanetriol, 2-methyl-1,2,4-butanetriol, pentaerythritol, dipentaerythritol, tripentaerythritol, methylglucoside, sorbitol, mannitol, sucrose, 1,3,5-trihydroxybenzene, 1 Polymers such as polyhydric alcohol or a polyvinyl alcohol having a carbon number of 3 to 24 such as 2,4-hydroxy benzene.

  Among these, the structure of the polyfunctional compound (E) is more preferable in terms of excellent mechanical properties when used as an insert-molded product and fluidity as a polybutylene terephthalate resin composition. Glycerol, diglycerol, trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol. In addition, the compound in which a part of hydroxyl group is esterified is not substantially contained.

  The (E) polyfunctional compound is a bleed-out in which the fluidity of the polybutylene terephthalate resin composition is further improved and the (E) polyfunctional compound appears on the surface of the insert-molded product in a high temperature and high humidity environment. Is preferably a (E) polyfunctional compound having a trivalent or tetravalent hydroxyl group, and more preferably (E) a polyfunctional compound having a trivalent hydroxyl group. It is. By suppressing the bleed-out, for example, when an insert molded product is used as a terminal block component, the risk that the bleed-out substance adheres to the electrode and causes contact failure can be reduced.

  Moreover, it is preferable that (E) polyfunctional compound contains one or more alkylene oxide units from a viewpoint of improving the fluidity | liquidity of the mechanical property at the time of setting it as an insert molded article, and a polybutylene terephthalate resin composition. Preferred examples of the alkylene oxide unit include aliphatic alkylene oxide units having 1 to 4 carbon atoms. Specific examples include a methylene oxide unit, an ethylene oxide unit, a trimethylene oxide unit, a propylene oxide unit, a tetramethylene oxide unit, Examples include 1,2-butylene oxide units, 2,3-butylene oxide units and isobutylene oxide units. In particular, in the present invention, it is more preferable to use a polyfunctional compound (E) containing an ethylene oxide unit or a propylene oxide unit as an alkylene oxide unit, and on the surface of a molded article in a fluidity and high temperature and humidity environment ( It is more preferable to use (E) a polyfunctional compound containing a propylene oxide unit in terms of suppressing bleeding out from which E) the polyfunctional compound appears. In the present invention, when the (E) polyfunctional compound contains one or more alkylene oxide units, the number of alkylene oxide units per functional group in the polyfunctional compound is preferably from 0.1 to 20, More preferably, it is 5-10, and it is further more preferable that it is 1.0-5.0. Here, the alkylene oxide unit per functional group is obtained by dividing the number of alkylene oxides in one molecule by the number of functional groups in the same molecule. As a preferred example of the (E) polyfunctional compound containing one or more alkylene oxide units, when the functional group is a hydroxyl group, (poly) oxymethylene glycerol, (poly) oxyethylene glycerol, (poly) oxy trimethylene glycerol, (Poly) oxypropyleneglycerol, (poly) oxyethylene- (poly) oxypropyleneglycerol, (poly) oxytetramethyleneglycerol, (poly) oxymethylenediglycerol, (poly) oxyethylenediglycerol, (poly) oxytrimethylene Diglycerol, (poly) oxypropylene diglycerol, (poly) oxymethylenetrimethylolpropane, (poly) oxyethylenetrimethylolpropane, (poly) oxytrimethylenetrimethylolpropane, (poly) oxy Propylene trimethylolpropane, (poly) oxyethylene- (poly) oxypropylene trimethylolpropane, (poly) oxytetramethylenetrimethylolpropane, (poly) oxymethyleneditrimethylolpropane, (poly) oxyethyleneditrimethylolpropane, (poly ) Oxytrimethylene ditrimethylolpropane, (poly) oxypropylene ditrimethylolpropane, (poly) oxymethylene pentaerythritol, (poly) oxyethylene pentaerythritol, (poly) oxytrimethylene pentaerythritol, (poly) oxypropylene pentaerythritol, (Poly) oxyethylene- (poly) oxypropylene pentaerythritol, (poly) oxytetramethylene pentaerythritol, (poly Oxymethylene dipentaerythritol, (poly) oxyethylene dipentaerythritol, (poly) oxypropylene trimethylolpropane ether, (poly) oxytrimethylene dipentaerythritol, (poly) oxypropylene dipentaerythritol, (poly) oxymethylene glucose (Poly) oxyethylene glucose, (poly) oxytrimethylene glucose, (poly) oxypropylene glucose, (poly) oxyethylene- (poly) oxypropylene glucose, (poly) oxytetramethylene glucose, and the like.

  The (E) polyfunctional compound may react with the (A) polybutylene terephthalate component and may be introduced into the main chain and side chain of the (A) polybutylene terephthalate component, and (A) the polybutylene terephthalate component You may keep the structure at the time of mixing | blending, without reacting.

  The reaction rate between the functional group of the (E) polyfunctional compound and the (A) polybutylene terephthalate component is preferably 40% or more, more preferably 50% or more, and particularly preferably 60% or more.

  (E) The viscosity of the polyfunctional compound is preferably 15000 m · Pa or less at 25 ° C. By setting the pressure to 15000 m · Pa or less, the fluidity of the polybutylene terephthalate resin composition can be further improved. From the viewpoint of excellent mechanical properties when used as an insert-molded product and fluidity of the polybutylene terephthalate resin composition, it is more preferably 5000 m · Pa or less, and particularly preferably 2000 m · Pa or less. Although there is no particular lower limit, it is preferably 100 m · Pa or more from the viewpoint of suppressing bleeding out during molding.

  The molecular weight or weight average molecular weight (Mw) of the (E) polyfunctional compound is preferably 50 or more and 10,000 or less in terms of fluidity of the polybutylene terephthalate resin composition, and the amount of gas generated during molding is From the viewpoint of decreasing, 150 or more is more preferable, and 200 or more is more preferable. Further, from the viewpoint of improving dispersibility in the resin and handling during melt-kneading, it is more preferably 8000 or less, and still more preferably 3000 or less. In the present invention, Mw of (E) a polyfunctional compound is a value in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography (GPC) using hexafluoroisopropanol as a solvent.

  The water content of the (E) polyfunctional compound is preferably 1.0% by weight or less. More preferably, it is 0.5 weight% or less, More preferably, it is 0.1 weight% or less.

  A particularly preferred (E) polyfunctional compound is available from Nippon Emulsifier Co., Ltd. under the trade name TMP-F32.

  The blending amount of the (E) polyfunctional compound is preferably in the range of 0.05 to 2.0 parts by weight with respect to 100 parts by weight of (A) polybutylene terephthalate, and the effect of improving fluidity is large. In view of the above, 0.10 parts by weight or more is more preferable. Moreover, 1.0 weight part or less is more preferable from a viewpoint of not spoiling mechanical characteristics and reducing the gas generation amount at the time of shaping | molding.

[Other ingredients]
In the polybutylene terephthalate resin composition of the present invention, the usual addition of other resin components, flame retardants, inorganic fillers, mold release agents, stabilizers, colorants, lubricants, etc., as long as the effects of the present invention are not impaired. An agent can be blended. Two or more of these may be blended.

  Any other resin component may be used as long as it is a melt-moldable resin. For example, AS resin (acrylonitrile / styrene copolymer), hydrogenated or unhydrogenated SBS resin (styrene / butadiene / styrene triblock copolymer) Coalescence), hydrogenated or non-hydrogenated SIS resin (styrene / isoprene / styrene triblock copolymer), polyethylene resin, polypropylene resin, polymethylpentene resin, cyclic olefin resin, cellulose resin such as cellulose acetate, polyamide resin , Polyacetal resin, polysulfone resin, polyphenylene sulfide resin, polyether ether ketone resin, polyimide resin, polyether imide resin, and the like. Further, for the purpose of improving hydrolysis resistance, an epoxy resin having a glycidyl ether, an epoxy resin having a glycidyl ester, or a novolac type epoxy resin in the molecule may be blended. Two or more of these may be blended.

  As the flame retardant, any of those used for the flame retardant of the polyester resin composition can be used. For example, halogen flame retardants, specifically, halogenated polycarbonate (for example, carbonate oligomer of tetrabromobisphenol A), halogenated acrylic resin, halogenated epoxy resin, halogenated phenoxy resin, halogenated polystyrene, tetrabromobisphenol A · High molecular weight organic halogen compounds such as ethyl ether oligomer and halogenated polyphenylene ether (for example, polydibromophenylene oxide); decabromodiphenyl ether, hexabromophenol, tetrabromobisphenol A, epoxidized tetrabromobisphenol A, tetrabromobisphenol A Bis (2,3-dibromopropyl ether), tetrabromobisphenol A bis (allyl ether), tetrabromobisphenol Brominated bisphenol A such as diol A, 2-hydroxyethyl ether, hexabromobenzene, tetrabromophthalic anhydride, tribromophenol, bis (tribromophenoxy) ethane, bis (pentabromophenoxy) ethane, ethylenebistetrabromophthalimide And low molecular weight organic halogen compounds such as brominated styrene, tetrabromobisphenol S, and bis (2,3-dibromopropyl ether) of tetrabromobisphenol S. These organic halogen flame retardants may be used alone or in combination of two or more. Moreover, phosphorus-based and inorganic flame retardants can also be used.

  As the inorganic filler, any filler such as a plate shape, a powder shape, and a granular shape can be used. Specifically, fibrous or whisker-like fillers such as rock wool, potassium titanate whisker, barium titanate whisker, aluminum borate whisker, silicon nitride whisker, mica, talc, kaolin, silica, calcium carbonate, glass beads, Examples include glass flakes, glass microballoons, clay, molybdenum disulfide, wollastonite, montmorillonite, titanium oxide, zinc oxide, calcium polyphosphate, graphite, barium sulfate, and the like. Two or more of these may be blended.

  As the mold release agent, any of those used for the mold release agent of the polyester resin composition can be used. Examples thereof include mineral waxes such as montan wax, petroleum waxes such as paraffin wax and polyethylene wax. Two or more of these may be blended. Moreover, about a mold release agent, what corresponds to (B) component of this invention is included in (B) component.

  As the stabilizer, any of those used for stabilizers in polyester resin compositions can be used. For example, an antioxidant, a light stabilizer, a catalyst deactivator, etc. can be mentioned. Two or more of these may be blended.

  Examples of the colorant include organic dyes, organic pigments, and inorganic pigments. Two or more of these may be blended.

  In the polybutylene terephthalate resin composition of the present invention, it is preferable that the components (A) to (D) and other components blended as necessary are uniformly dispersed.

  As a method for producing the polybutylene terephthalate resin composition of the present invention, for example, each component is melt-kneaded using a known melt-kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll. A method can be mentioned. Each component may be mixed in advance and then melt kneaded. In addition, it is better that the amount of water contained in each component is small, and it is desirable to dry in advance if necessary.

  In addition, as a method of charging each component into the melt-kneader, for example, using a single-screw or twin-screw extruder, the above components (A) to (C) and necessary from the main charging port installed on the screw base side The component (E) is supplied according to the above, and the component (D) is supplied from the auxiliary input port installed between the main input port and the tip of the extruder and melt mixed.

  The melt kneading temperature is preferably 110 ° C. or higher, more preferably 210 ° C. or higher, and further preferably 240 ° C. or higher in terms of excellent fluidity and mechanical properties. Moreover, 360 degrees C or less is preferable, 320 degrees C or less is more preferable, and 280 degrees C or less is further more preferable. Here, the melt kneading temperature refers to the set temperature of the melt kneader, and refers to the cylinder temperature in the case of a twin screw extruder, for example.

  The polybutylene terephthalate resin composition of the present invention can be processed and used for various molded parts by molding by any method such as known injection molding, extrusion molding, blow molding, press molding, and spinning. The temperature at the time of injection molding is preferably 240 ° C. or higher from the viewpoint of further improving fluidity, and preferably 280 ° C. or lower from the viewpoint of improving mechanical properties.

  Examples of molded parts include injection molded parts, extrusion molded parts, blow molded parts, films, sheets, fibers, and the like. Since the polybutylene terephthalate resin composition of the present invention is excellent in retention stability, it is preferably used for large molded parts.

  In the present invention, the above-mentioned various molded products can be used for various applications such as automobile members, electrical / electronic members, building members, various containers, daily necessities, household goods and hygiene items. In particular, the polybutylene terephthalate resin composition of the present invention is particularly suitable as a metal insert part such as a terminal block of an electric / electronic device part or a motor part because a molded article having excellent resistance to thermal shock can be obtained.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. It shows below about the raw material used by each Example and a comparative example.
(A) Polybutylene terephthalate A-1: Polybutylene terephthalate (MFR: 55 g / 10 min (250 ° C., 1 kgf))
(B) Fatty acid ester compound B-1: Dipentaerythritol ester (“ADEKA SIZER” (registered trademark) UL-6 (trade name) manufactured by ADEKA Corporation, hexavalent aliphatic alcohol full ester, molecular weight: 966, acid value : 1 or less)
B-2: Dipentaerythritol ester (“RIQUESTER” (registered trademark) L8483 (trade name) manufactured by Riken Vitamin Co., Ltd., full ester of hexavalent aliphatic alcohol, molecular weight: 1846, acid value: 3 or less)
B-3: Triglycerol ester (“Rikemar” (registered trademark) TS75 (trade name) manufactured by Riken Vitamin Co., Ltd.), full ester of pentavalent aliphatic alcohol, molecular weight: 1570, acid value: 5 or less
B-4: Pentaerythritol ester ("Rikenstar" (registered trademark) EW440A (trade name), full ester of tetravalent aliphatic alcohol, molecular weight: 1200, acid value: 3 or less) manufactured by Riken Vitamin Co., Ltd.)
B-5: Glycerol ester (Coconard ML (trade name) manufactured by Kao Corporation, full ester of trivalent aliphatic alcohol, molecular weight: 470-638, oxidation: 1 or less)
B-6: Dipentaerythritol ester ("Rikemar" (registered trademark) SL-02 (trade name) manufactured by Riken Vitamin Co., Ltd.), full ester of hexavalent aliphatic alcohol, molecular weight: 1800, acid value: 25 30)
(C) Elastomer C-1: Ethylene / ethyl acrylate copolymer (“Elvalloy” (registered trademark) AC22534 (trade name) manufactured by Mitsui DuPont Polychemical Co., Ltd.)
(D) Reinforcing fiber D-1: Chopped strand (manufactured by Nippon Electric Glass Co., Ltd. T-120H (trade name) 3 mm long, average fiber diameter 10.5 μm)
(E) Polyfunctional compound E-1: Polyoxypropylene trimethylolpropane ether (TMP-F32 (trade name) manufactured by Nippon Emulsifier Co., Ltd.).

  An evaluation method in each example and comparative example will be described. The number of evaluation n was n = 3 unless otherwise specified, and the average value was obtained.

(1) Fluidity (flow length)
The fluidity was judged from the flow length of a spiral molded product having a thickness of 2 mm and a width of 5 mm. Using Nippon Steel's injection molding machine “J55AD”, the pellets of the polybutylene terephthalate resin composition having the compositions shown in the examples and comparative examples were dried in a hot air dryer at 130 ° C. for 3 hours or more, then injection molded. The length of the formed spiral mold product was defined as the flow length. The injection conditions were a cylinder temperature of 260 ° C., a mold temperature of 80 ° C., an injection pressure of 50 MPa, an injection time of 5 seconds, and a cooling time of 5 seconds. If the flow length is 300 mm or more, it can be judged that the fluidity of the polybutylene terephthalate resin composition is good. The flow length is more preferably 320 mm or more.

(2) Thermal shock resistance (number of cracks)
An iron core made of S35C and having a length of 48.8 mm, a width of 48.8 mm, and a height of 26.5 mm was placed in a mold for insert molding. Next, using a Nippon Steel Works injection molding machine "J55AD", after drying the pellets of the polybutylene terephthalate resin composition of the composition shown in each Example and Comparative Example for 3 hours or more in a hot air dryer at 130 ℃, The mold was injection molded to obtain an insert molded article in which the iron core was coated with a resin having a thickness of 0.6 mm. The injection conditions were a cylinder temperature of 260 ° C., a mold temperature of 80 ° C., an injection pressure of 100 MPa, an injection time of 10 seconds, and a cooling time of 10 seconds. Using the THERMAL SHOCK CHAMBER TSA-103-ES-W cold heat tester manufactured by Tabai Espec Co., Ltd., the above-mentioned insert molded product is set to one cycle of cooling at −40 ° C. × 1 hour and heating at 130 ° C. × 1 hour. Under conditions, the number of cycles in which cracks occur in the insert molded product was measured. The presence or absence of cracks was checked once every 10 cycles. If the number of cycles in which cracks occur is 120 cycles or more, it can be determined that the resistance to cold shock of the insert-molded product is good. The number of cycles in which the crack occurs is preferably 120 cycles or more, and more preferably 200 cycles or more.

(3) Gas amount (heat loss)
10 g of pellets of the polybutylene terephthalate resin composition having the composition shown in each example and comparative example were placed in an aluminum cup and pre-dried in a hot air dryer at 130 ° C. for 3 hours. 10 g of the resin composition pellets after preliminary drying are put in an aluminum cup, treated for 1 hour in an atmosphere at 260 ° C., and then the pellet weight is measured again. The weight loss at this time was gradually reduced by the weight of the pellets before the treatment at 260 ° C. for 1 hour to obtain the heat loss. It can be said that the resin composition with less heat loss is superior in low gas properties. The loss on heating is preferably less than 0.6%.

(4) Bleed-out property (presence / absence of bleed-out)
According to ISO294-1, the dumbbell-type test piece of the polybutylene terephthalate resin composition of the composition shown in each Example and a comparative example was created. These test pieces were subjected to hydrolysis treatment at 121 ° C. and 100% RH for 50 hours with HAST CHAMBER EHS-221M manufactured by Tabai Espec Co., Ltd., and then the surface of the test piece was visually observed and touched by hand. If there was no occurrence and no stickiness on the hand, it was judged that there was no bleed-out, and if there was water droplets or stickiness on the hand, there was a bleed-out.

(5) Mechanical properties (tensile strength)
A test piece was prepared according to ISO294-1, and the tensile strength of the test piece was measured in accordance with ISO527-1,2. If the tensile strength of the test piece is 70 MPa or more, it can be judged that the mechanical properties of the insert molded product are good. 100 MPa or more is more preferable.

(6) Hydrolysis resistance A test piece was prepared according to ISO294-1, and the test was conducted after 100 hours of hydrolysis at 121 ° C. and 100% RH with HAST CHAMBER EHS-221M manufactured by TABI ESPEC. The tensile properties of the pieces were measured by the same method as in (5), the tensile strength retention was determined from the following calculation formula, and the hydrolysis resistance was evaluated.
Tensile strength retention (%) = tensile property (after hydrolysis treatment) (MPa) × 100 / tensile property (before hydrolysis treatment) (MPa)
If the tensile strength retention is 40% or more, it can be judged that the hydrolysis resistance is good. 50% or more is more preferable.

[Examples 1 to 11]
As shown in Table 1, the composition of the resin composition was changed, and the components (A), (B), (C) and (E) were supplied from the main charging port of the twin-screw extruder, and the component (D) Then, melt kneading was carried out with a twin screw extruder (ZSK57 manufactured by WERNER & Pfeiderer) having a screw diameter of 57 mmφ supplied from a sub-inlet installed between the main inlet and the tip of the extruder and set at a cylinder temperature of 260 ° C.

  The strand discharged from the die was cooled in a cooling bath and then pelletized with a strand cutter. Each pellet obtained was dried with a hot air dryer at 130 ° C. for 3 hours or more, then a test piece was prepared, and fluidity and cold shock resistance were evaluated by the above evaluation methods. All of the obtained test pieces were excellent in cold-heat shock resistance, and no bleed-out occurred even in a high-temperature and high-humidity environment. Moreover, the obtained polybutylene terephthalate resin composition had a small amount of gas generation and excellent fluidity.

[Comparative Examples 1-4]
The composition of the resin composition is changed as shown in Table 1, and the components (A), (B) and (C) are supplied from the main input port of the twin-screw extruder, and the component (D) is supplied to the main input port. Were melt-kneaded with a twin screw extruder (ZSK57 manufactured by WERNER & Pfeiderer) having a screw diameter of 57 mm and supplied from a sub-inlet installed between the front ends of the extruder and a cylinder temperature of 250 ° C.

  The strand discharged from the die was cooled in a cooling bath and then pelletized with a strand cutter. Each pellet obtained was dried with a hot air dryer at 130 ° C. for 3 hours or more, then a test piece was prepared, and fluidity, cold shock resistance, and tensile strength were evaluated by the above evaluation methods. The obtained test piece was inferior in cold-heat shock resistance. In addition, when the blending amount of the component (B) is large, bleed out occurs in a high temperature and humidity environment, and the resulting polybutylene terephthalate resin composition has a large amount of gas generation and is inferior in fluidity. There was also.

  The polybutylene terephthalate resin composition of the present invention is excellent in fluidity, and further excellent in thermal shock resistance in an environment where it is repeatedly exposed to low and high temperatures, and thus is useful for an insert molded product in which a metal is inserted. In addition, the insert-molded product of the present invention is excellent in cold-heat shock resistance and mechanical properties, and thus is useful for mechanical mechanism parts, electrical / electronic parts, or automobile parts.

Claims (7)

(A) 1 to 7 parts by weight of a fatty acid ester compound having a molecular weight of 400 to 3000 consisting of (B) a trivalent to hexavalent aliphatic alcohol and a fatty acid with respect to 100 parts by weight of polybutylene terephthalate, and (C) 5 elastomers. A polybutylene terephthalate resin composition comprising -60 parts by weight and (D) 10-110 parts by weight of reinforcing fibers. The polybutylene terephthalate resin composition according to claim 1, wherein the aliphatic alcohol is a pentavalent or hexavalent aliphatic alcohol. The polybutylene terephthalate resin composition according to claim 1 or 2, wherein the aliphatic alcohol is a hexavalent aliphatic alcohol. The polybutylene terephthalate resin composition according to claim 1, wherein the (C) elastomer contains at least ethylene as a copolymer component. More than (E) 100 parts by weight of polybutylene terephthalate, (E) a polymer having at least three functional groups selected from the group consisting of hydroxyl group, carboxyl group, amino group, glycidyl group, isocyanate group and amide group The polybutylene terephthalate resin composition according to any one of claims 1 to 4, comprising 0.05 to 2 parts by weight of a functional compound. A molded article comprising the polybutylene terephthalate resin composition according to any one of claims 1 to 5. The molded product according to claim 6, wherein the molded product is an insert molded product in which a metal is inserted.