JP2017210609A - Polybutylene terephthalate resin-based resin composition and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polybutylene terephthalate-based resin composition which is excellent in strength because of hardly causing voids in its inside when formed into a molded article, can achieve the strength and flame retardancy even when adding a flame retardant, and is also excellent in releasability and hydrolysis resistance, and to provide a molded article.SOLUTION: A polybutylene terephthalate-resin composition contains, with respect to 100 pts.mass of (A) a polybutylene terephthalate resin, (B) 30-60 pts.mass of the total of at least two or more different bromine-based flame retardant selected from a brominated epoxy compound, a brominated polycarbonate compound and a brominated polystyrene compound, (C) 5-15 pts.mass of an antinomy compound, (D) 5-30 pts.mass of an elastomer, and (E) 0.5-3 pts.mass of a releasing agent.SELECTED DRAWING: None

Description

  The present invention relates to a polybutylene terephthalate-based resin composition and a molded product, and more specifically, protrusions provided on the molded product (hereinafter referred to as a boss portion) are less likely to generate internal voids and have an excellent boss portion strength. The present invention relates to a polybutylene terephthalate-based resin composition excellent in flame retardancy and releasability, and further in hydrolysis resistance, and a molded product thereof.

  Polybutylene terephthalate resin is excellent in mechanical strength, chemical resistance, electrical insulation, etc., and has excellent heat resistance, moldability, and recyclability. Widely used in electrical parts and machine parts.

  In the automotive field, for example, as an electronic control device, a microcomputer, an electromagnetic valve, and an electric motor that are equipped with an engine control unit (ECU) that detects the behavior of the vehicle and executes various controls based on the detection result, and performs arithmetic processing. An external control device such as an input / output circuit connected to a sensor for detecting a state quantity, and a power supply circuit for supplying power to the microcomputer and the input / output circuit are arranged on a control board. It is accommodated in a resin case. In addition, the housing case is also provided with an external connection connector section for performing input / output with a power supply, an external control device, a sensor and the like on the control board.

  The ECU is often arranged in the engine room of the automobile. The attachment with the vehicle body has a problem that the method using a fixing screw has problems in terms of workability and weight reduction, and that the screw is easily corroded by a snow melting agent such as calcium chloride. Therefore, in recent years, a boss portion is usually provided on an outer peripheral wall or an inner peripheral wall of a resin case and is fixed to an attachment portion provided on the vehicle body side.

  As such a casing case, it is conceivable to use a polybutylene terephthalate resin material from the viewpoints of mechanical strength, chemical resistance, electrical insulation, heat resistance, moldability, and lightness as described above. Flammability is required. As a method for flame-retarding polybutylene terephthalate resin, a brominated flame retardant is used (for example, Patent Documents 1 to 3), and a brominated flame retardant and an antimony compound as a flame retardant aid are used. A method used in combination (for example, Patent Documents 4 to 6) has also been adopted.

  Certainly, by using a brominated flame retardant together with an antimony compound, high flame retardancy is possible. However, as a result of the study by the present inventors, the strength of the boss portion (hereinafter referred to as boss strength) tends to be insufficient due to the internal voids generated in the boss portion simply by using both together. It turned out that the fixation to the car body tends to be uncertain.

JP 2003-26904 A JP 2013-234326 A JP-A-11-162330 JP 2004-263174 A JP 2006-45544 A JP 2006-56997 A

  In view of the above circumstances, the object (problem) of the present invention is that the occurrence of internal voids in the boss portion provided in the molded product is small, the strength of the boss portion is excellent, flame retardancy and releasability, and hydrolysis resistance. The object is to provide an excellent polybutylene terephthalate resin composition.

The present inventors have made various studies on a resin composition containing a brominated flame retardant and an antimony compound in polybutylene terephthalate resin, and as a result, selected from brominated epoxy compounds, brominated polycarbonate compounds, and brominated polystyrene compounds. The present inventors have found that a polybutylene terephthalate resin composition containing a combination of at least two different brominated flame retardants and further containing an elastomer and a release agent can solve the above-mentioned problems.
The present invention relates to the following polybutylene terephthalate resin composition and molded article.

[1] At least two different bromines selected from the group consisting of (B) a brominated epoxy compound, a brominated polycarbonate compound, and a brominated polystyrene compound with respect to 100 parts by mass of (A) polybutylene terephthalate resin 30 to 60 parts by mass of the total flame retardant, 5 to 15 parts by mass of (C) antimony compound, 5 to 30 parts by mass of (D) elastomer, and 0.5 to 3 parts by mass of (E) release agent A polybutylene terephthalate-based resin composition comprising:
[2] Brominated flame retardant (B1) in which (B) brominated flame retardant is selected from brominated epoxy compound or brominated polycarbonate compound and weight average molecular weight is 1000 to 8000, and brominated epoxy compound or bromine The polybutylene terephthalate-based resin composition according to the above [1], which is a brominated flame retardant (B2) selected from a modified polystyrene compound and having a weight average molecular weight of more than 8000 to 70000.
[3] The polybutylene terephthalate resin composition according to the above [1] or [2], wherein the crystallization temperature is 193 ° C. or lower.
[4] The polybutylene terephthalate resin composition according to any one of [1] to [3], wherein each of the two or more brominated flame retardants (B) is a brominated epoxy compound.
[5] The polybutylene terephthalate resin composition according to any one of [1] to [4], wherein the brominated epoxy compound is end-capped with tribromophenol.
[6] The polybutylene terephthalate resin composition according to the above [2], wherein the mass ratio (B1) / (B2) of the flame retardant (B1) to the flame retardant (B2) is 90/10 to 30/70.
[7] The polybutylene terephthalate resin composition according to any one of the above [1] to [6], wherein the (D) elastomer is an ethylene elastomer.
[8] The polybutylene terephthalate resin composition according to [7], wherein the ethylene elastomer is an ethylene-acrylic acid alkyl ester-glycidyl methacrylate copolymer.
[9] The polybutylene terephthalate resin composition according to any one of [1] to [8], wherein the (E) release agent is a montanic acid ester release agent.
[10] The polybutylene terephthalate-based resin composition according to any one of [1] to [9], wherein the water content in the resin composition is 500 ppm or less.
[11] A molded article of the polybutylene terephthalate resin composition according to any one of [1] to [10].
[12] The molded product according to [11], which is a vehicle electrical component.

The polybutylene terephthalate-based resin composition of the present invention is excellent in strength because there are few voids inside when formed into a molded product, and even when a flame retardant is added, both strength and flame retardancy are possible It is also excellent in releasability and hydrolysis resistance.
The resin composition of the present invention is a resin composition obtained by using a combination of at least two flame retardants selected from brominated epoxy compounds, brominated polycarbonate compounds and brominated polystyrene compounds having different types or different molecular weights. It is possible to lower the crystallization temperature of the product, thereby increasing the time until crystallization of the molten resin filled at the time of molding, improving the filling of the boss part or its vicinity, and improving the boss part strength. It will be excellent. When the crystallization temperature is high, the solidification is accelerated, and it becomes difficult to fill the boss portion or the vicinity thereof, and it becomes easy to form a void by solidification, and the strength of the boss portion is deteriorated.

FIG. 1 is a diagram showing the shape of a test piece used for measurement of boss strength in Examples. FIG. 2 is a perspective view showing the shape of a box-shaped product used for evaluation of releasability in Examples and Comparative Examples of the present invention. FIG. 3 is a top view showing the box-shaped product and the ejector pins shown in FIG. FIG. 4 is an explanatory view showing the position of the ejector pin at the bottom of the box-shaped product.

  The polybutylene terephthalate resin composition of the present invention is selected from the group consisting of (B) a brominated epoxy compound, a brominated polycarbonate compound, and a brominated polystyrene compound with respect to (A) 100 parts by mass of the polybutylene terephthalate resin. 30 to 60 parts by mass of a total of at least two different brominated flame retardants, (C) 5 to 15 parts by mass of antimony compound, (D) 5 to 30 parts by mass of elastomer, and (E) a release agent. Is contained in an amount of 0.5 to 3 parts by mass.

Hereinafter, the contents of the present invention will be described in detail.
The description of each constituent element described below may be made based on typical embodiments and specific examples of the present invention, but the present invention is interpreted to be limited to such embodiments and specific examples. It is not a thing. In the specification of the present application, “to” is used in the sense of including the numerical values described before and after it as the lower limit value and the upper limit value.

[(A) Polybutylene terephthalate resin]
The (A) polybutylene terephthalate resin used in the resin composition of the present invention is a polyester resin having a structure in which a terephthalic acid unit and a 1,4-butanediol unit are ester-bonded, and is a polybutylene terephthalate resin (homopolymer). In addition, the polybutylene terephthalate copolymer containing other copolymerization components other than a terephthalic acid unit and a 1, 4- butanediol unit, and the mixture of a homopolymer and the said copolymer are included.

(A) Specific examples of other dicarboxylic acids in the case where the polybutylene terephthalate resin contains a dicarboxylic acid unit other than terephthalic acid include isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5 -Naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis (4,4'- Carboxyphenyl) methane, anthracene dicarboxylic acid, aromatic dicarboxylic acids such as 4,4′-diphenyl ether dicarboxylic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 4,4′-dicyclohexyldicarboxylic acid, And aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, dimer acid, etc. Kind, and the like.
In addition, it is preferable that the copolymerization amount in the case of containing other dicarboxylic acids other than these terephthalic acids is 1 mol% or more and less than 50 mol% in the polybutylene terephthalate resin all segments. Among them, the copolymerization amount is preferably 2 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%.

(A) When the polybutylene terephthalate resin contains other diol units in addition to 1,4-butanediol, specific examples of the other diol units include aliphatics or fats having 2 to 20 carbon atoms. Examples thereof include cyclic diols and bisphenol derivatives. Specific examples include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexanedimethanol, 4,4′-dicyclohexylhydroxymethane, 4,4. Examples include '-dicyclohexylhydroxypropane, bisphenol A ethylene oxide addition diol, and the like. If the amount is small, one or more long-chain diols having a molecular weight of 400 to 6000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, and the like may be copolymerized.
In addition to the above-mentioned bifunctional monomers, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane are introduced to introduce a branched structure, and fatty acids are used for molecular weight control. A small amount of a monofunctional compound can be used in combination.
The copolymerization amount when other diol units are included in addition to these 1,4-butanediols is preferably 1 mol% or more and less than 50 mol% in all segments of the polybutylene terephthalate resin. . Among them, the copolymerization amount is preferably 2 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%.

  (A) The polybutylene terephthalate resin is preferably a polybutylene terephthalate homopolymer obtained by polycondensation of terephthalic acid and 1,4-butanediol. In addition, as the carboxylic acid unit, a dicarboxylic acid 1 other than the terephthalic acid is used. The polybutylene terephthalate copolymer containing 1 or more types of diols other than the said 1, 4- butanediol as a seed | species and / or diol unit may be sufficient. In the (A) polybutylene terephthalate resin, from the viewpoint of mechanical properties and heat resistance, the proportion of terephthalic acid in the dicarboxylic acid unit is preferably 50 mol% or more, more preferably 70 mol% or more, Preferably it is 90 mol% or more. Similarly, the ratio of 1,4-butanediol in the diol unit is preferably 50 mol% or more, more preferably 70 mol% or more, and further preferably 90 mol% or more.

  (A) When a copolymer is used as the polybutylene terephthalate resin, those obtained by copolymerization of polyalkylene glycols such as isophthalic acid, dimer acid and polytetramethylene glycol (PTMG) are preferable. It is preferable to use a resin obtained by copolymerization of The proportion of the tetramethylene glycol component in the copolymerization is preferably 3 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 25% by mass.

(A) Polybutylene terephthalate resin is a melt polymerization of a dicarboxylic acid component containing terephthalic acid as a main component or an ester derivative thereof and a diol component containing 1,4-butanediol as a main component in a batch or continuous manner. Can be manufactured. Further, after the low molecular weight polybutylene terephthalate resin is produced by melt polymerization, the degree of polymerization (or molecular weight) can be increased to a desired value by further solid-phase polymerization under a nitrogen stream or under reduced pressure.
(A) The polybutylene terephthalate resin is obtained by a production method in which a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing 1,4-butanediol as a main component are melt polycondensed in a continuous manner. Is preferred.

  The catalyst used in performing the esterification reaction may be a conventionally known catalyst, and examples thereof include a titanium compound, a tin compound, a magnesium compound, and a calcium compound. Of these, titanium compounds are particularly preferred. Specific examples of the titanium compound as the esterification catalyst include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

  In (A) polybutylene terephthalate resin, the amount of terminal carboxyl groups may be appropriately selected and determined. Usually, it is 60 eq / ton or less, preferably 50 eq / ton or less, and 30 eq / ton or less. More preferably. If it exceeds 60 eq / ton, gas is likely to be generated during melt molding of the resin composition, or the hydrolysis resistance of the obtained molded product is lowered. Although the lower limit of the amount of terminal carboxyl groups is not particularly defined, it is usually 10 eq / ton in consideration of the productivity of production of polybutylene terephthalate resin.

  The amount of terminal carboxyl groups of the polybutylene terephthalate resin is a value measured by titration using a 0.01 mol / l benzyl alcohol solution of sodium hydroxide by dissolving 0.5 g of the polyalkylene terephthalate resin in 25 mL of benzyl alcohol. is there. As a method for adjusting the amount of terminal carboxyl groups, a conventionally known arbitrary method such as a method for adjusting polymerization conditions such as a raw material charge ratio during polymerization, a polymerization temperature, a pressure reduction method, a method for reacting a terminal blocking agent, etc. Just do it.

(A) The intrinsic viscosity of the polybutylene terephthalate resin is preferably 0.5 to 2 dl / g. From the viewpoint of moldability and mechanical properties, those having an intrinsic viscosity in the range of 0.6 to 1.5 dl / g are more preferable. If the intrinsic viscosity is lower than 0.5 dl / g, the resulting resin composition tends to have a low mechanical strength. On the other hand, if it is higher than 2 dl / g, the fluidity of the resin composition may deteriorate and the moldability may deteriorate.
The intrinsic viscosity of (A) polybutylene terephthalate resin is a value measured at 30 ° C. in a 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

[(B) Brominated flame retardant]
The polybutylene terephthalate resin composition of the present invention contains a brominated flame retardant. In the present invention, at least two different brominated flame retardants selected from the group consisting of (B) brominated epoxy compounds, brominated polycarbonate compounds, and brominated polystyrene compounds are used as brominated flame retardants. . Here, “different at least two or more brominated flame retardants” means (i) using two or more different types of brominated flame retardants among the above three types of brominated flame retardants, (Ii) Select one of the above three types and use two or more of them having different molecular weights, or (iii) Use a combination of (i) and (ii) above Means.

  Specific examples of the brominated epoxy compound include bisphenol A-type brominated epoxy compounds represented by tetrabromobisphenol A epoxy compounds.

The brominated epoxy compound is preferably end-capped with tribromophenol, particularly when the molecular weight of the brominated epoxy compound is low (hereinafter, a brominated flame retardant having a weight average molecular weight of 1000 to 8000 described in detail ( Particularly effective for the epoxy compound B1).
In addition, the brominated epoxy compound preferably has an epoxy equivalent of 3000 to 40000 g / eq, more preferably 4,000 to 35,000 g / eq, and particularly preferably 10,000 to 30,000 g / eq. preferable.
In addition, the mass mean molecular weight (Mw) of a brominated epoxy compound is a value (polystyrene conversion) measured by GPC (gel permeation chromatography) method. As a solvent at the time of measurement, a brominated epoxy compound, a brominated polycarbonate compound, a brominated polystyrene compound is THF (tetrahydrofuran), and a brominated acrylic compound is ODCB (orthodichlorobenzene). The column temperature during measurement is set to 40 ° C. for brominated epoxy compounds, brominated polycarbonate compounds, and brominated polystyrene compounds, and 135 ° C. for brominated acrylic compounds.

  Specifically, the brominated polycarbonate compound is preferably a brominated polycarbonate obtained from, for example, brominated bisphenol A, particularly tetrabromobisphenol A. Examples of the terminal structure include a phenyl group, 4-t-butylphenyl group, 2,4,6-tribromophenyl group, etc., and particularly those having a 2,4,6-tribromophenyl group in the terminal group structure. Is preferred.

  The average number of carbonate repeating units in the brominated polycarbonate compound may be appropriately selected and determined, but is usually 2 to 30, preferably 3 to 15, and particularly preferably 3 to 10. If the average number of carbonate repeating units is small, the molecular weight of the polybutylene terephthalate resin may be lowered during melting. On the other hand, if it is too large, the melt viscosity becomes high, causing poor dispersion in the molded body, and the appearance of the molded body, particularly glossiness, may be lowered.

Brominated polystyrene may be either brominated polystyrene or produced by polymerizing brominated styrene monomers, but the brominated styrene polymerized is free bromine (atoms). This is preferable because of the small amount.
The brominated polystyrene may be a copolymer obtained by copolymerizing another vinyl monomer. Examples of the vinyl monomer in this case include styrene, α-methylstyrene, acrylonitrile, methyl acrylate, butadiene, and vinyl acetate.

  Specific examples of brominated polystyrene include, for example, poly (4-bromostyrene), poly (2-bromostyrene), poly (3-bromostyrene), poly (2,4-dibromostyrene), poly (2,6 -Dibromostyrene), poly (2,5-dibromostyrene), poly (3,5-dibromostyrene), poly (2,4,6-tribromostyrene), poly (2,4,5-tribromostyrene) , Poly (2,3,5-tribromostyrene), poly (4-bromo-α-methylstyrene), poly (2,4-dibromo-α-methylstyrene), poly (2,5-dibromo-α- Methyl (styrene), poly (2,4,6-tribromo-α-methylstyrene), poly (2,4,5-tribromo-α-methylstyrene) and the like, and poly (2,4,6-tribromostyrene). And poly (2,4,5-tribromostyrene) and polydibromostyrene and polytribromostyrene containing an average of 2 to 3 bromine groups in the benzene ring are particularly preferably used.

(B) Brominated flame retardant is selected from brominated epoxy compounds or brominated polycarbonate compounds, brominated flame retardant (B1) having a weight average molecular weight (Mw) of 1000 to 8000, brominated epoxy compound or brominated A combination of a brominated flame retardant (B2) selected from a series polystyrene compound and having a weight average molecular weight (Mw) of more than 8000 to 70000 is preferred.
The mass ratio (B1 / B2) of the brominated flame retardant (B1) to the brominated flame retardant (B2) is preferably 90/10 to 30/70, more preferably 90/10 to 40/60. More preferably, it is 90 / 10-50 / 50. By setting it as such mass ratio, it becomes possible to lower the crystallization temperature of the resin composition obtained, and to improve hydrolysis resistance more.

  (B) At least one of the two or more brominated flame retardants is preferably a brominated epoxy compound, and more preferably both brominated flame retardants (B1) and (B2) are brominated epoxy compounds. .

  (B) Content of 2 or more brominated flame retardants is 30-60 mass parts in total with respect to 100 mass parts of (A) polybutylene terephthalate resin, Preferably it is 35 mass parts or more, More preferably, it is 40. It is at least part by mass, preferably at most 55 parts by mass, more preferably at most 50 parts by mass. (B) If the content of the brominated flame retardant is less than 30 parts by mass, the crystallization temperature becomes high and the boss strength becomes insufficient, or the flame retardancy of the resin composition becomes insufficient. There arises a problem of deterioration of characteristics and releasability and bleeding out of the flame retardant.

[(C) Antimony compound]
The polybutylene terephthalate resin composition of the present invention contains (C) an antimony compound which is a flame retardant aid. Examples of the (C) antimony compound include antimony trioxide (Sb ₂ O ₃ ), antimony pentoxide (Sb ₂ O ₅ ), and sodium antimonate. In particular, antimony trioxide is preferable from the viewpoint of impact resistance.

  The content of the (C) antimony compound is 5 to 15 parts by mass, preferably 7 parts by mass or more, more preferably 8 parts by mass or more, with respect to 100 parts by mass of the (A) polybutylene terephthalate resin. , Preferably 13 parts by mass or less, more preferably 12 parts by mass or less. If it falls below the lower limit, the flame retardancy is lowered. Moreover, when it exceeds the said upper limit, mechanical strength will fall.

  In the polybutylene terephthalate resin composition of the present invention, the mass concentration of (B) bromine atom derived from brominated flame retardant and (C) antimony atom derived from antimony compound is 3 to 25 mass% in total. It is preferably 4 to 22% by mass, more preferably 5 to 20% by mass, and particularly preferably 10 to 20% by mass. If it is less than 3% by mass, the flame retardancy tends to decrease, and if it exceeds 25% by mass, the mechanical strength tends to decrease. The mass ratio (Br / Sb) of bromine atom to antimony atom is preferably 0.3 to 5, more preferably 0.3 to 4.5, and preferably 0.3 to 4. Is more preferable. By setting it as such a range, it exists in the tendency for a flame retardance to express easily, and it is preferable.

In the polybutylene terephthalate-based resin composition of the present invention, the (C) antimony compound is preferably used in advance as a master batch, and is preferably a thermoplastic resin, preferably (A) as a master batch with the polybutylene terephthalate resin. It is preferable to mix. Thereby, (C) antimony trioxide is likely to be present in the (A) polybutylene terephthalate resin phase, the thermal stability at the time of melt-kneading and molding is improved, the reduction in impact resistance is suppressed, Variations in flame retardancy and impact resistance tend to be reduced.
The content of the (C) antimony compound in the master batch is preferably 20 to 90% by mass. When the (C) antimony compound is less than 20% by mass, the ratio of the antimony compound in the flame retardant masterbatch is small, and the effect of improving the flame retardancy to the (A) polybutylene terephthalate resin containing this tends to be small. On the other hand, when (C) the antimony compound exceeds 90% by mass, the dispersibility of the (C) antimony compound is likely to be lowered, and if this is blended with the (A) polybutylene terephthalate resin, the flame retardancy of the resin composition is not good. It becomes stable and the workability at the time of producing the master batch is likely to deteriorate. For example, when producing using an extruder, the strands are not stable, and problems such as easy breakage are likely to occur.
Content of (C) antimony compound in a masterbatch becomes like this. Preferably it is 20-85 mass%, More preferably, it is 25-80 mass%.

[(D) Elastomer]
The polybutylene terephthalate resin composition of the present invention contains (D) an elastomer. (D) The elastomer may be a thermoplastic elastomer used to improve impact resistance by blending with (A) polybutylene terephthalate resin. For example, rubber elastomer or rubber polymer may be used. A compound obtained by copolymerizing a compound that reacts with this is used. The glass transition temperature of the elastomer is preferably 0 ° C. or less, particularly preferably −20 ° C. or less.

Specific examples of the elastomer include, for example, polybutadiene, polyisoprene, diene copolymers (styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, acrylic-butadiene rubber, etc.), ethylene and α- having 3 or more carbon atoms. Copolymers with olefins (ethylene-propylene copolymers, ethylene-butene copolymers, ethylene-octene copolymers, etc.), copolymers of ethylene and unsaturated carboxylic acid esters (ethylene-methacrylate copolymers, Ethylene-butyl acrylate copolymer), copolymers of ethylene and aliphatic vinyl compounds, terpolymers of ethylene, propylene and non-conjugated dienes, acrylic rubber (polybutyl acrylate, poly (2-ethylhexyl acrylate), butyl Acrylate-2-ethylhexyl acrylic Over preparative copolymers), silicone rubber (a polyorganosiloxane rubber, a polyorganosiloxane rubber and a polyalkyl (meth) IPN type composite rubber consisting of acrylate rubber), and the like. These may be used alone or in combination of two or more.
In the present invention, (meth) acrylate means acrylate and methacrylate, and (meth) acrylic acid means acrylic acid and methacrylic acid.

  The elastomer (D) used in the present invention is a copolymer of an olefin and an unsaturated monomer having an epoxy group or a glycidyl group, and an unsaturated monomer having an epoxy group or a glycidyl group with respect to the olefin polymer. Those copolymerized are preferred. Such a copolymer may be a graft copolymer, a random copolymer, or a block copolymer.

  Further, for example, the terminal of the olefin polymer, or the unsaturated bond existing in the copolymer of olefin and other unsaturated monomer and the composite thereof, hydrogen peroxide, organic peracid, etc. An epoxy group may be introduced by oxidation with benzoic acid, performic acid, peracetic acid, or the like. That is, any olefin polymer may be used as long as an epoxy group or a glycidyl group is introduced.

As the olefin, ethylene, propylene, 1-butene, isobutylene, 2-butene, cyclobutene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-butene, 4-methyl-1- Examples include butene, cyclopentene, 1-hexene, cyclohexene, 1-octene, 1-decene, and 1-dodecene. These may be used alone or in combination of two or more.
Of these, ethylene is particularly preferred as the olefin, and ethylene elastomer is preferred as the (D) elastomer.

  Examples of the unsaturated monomer having an epoxy group or glycidyl group include glycidyl acrylate, glycidyl methacrylate, vinyl glycidyl ether, allyl glycidyl ether, methacryl glycidyl ether, 2-methylpropenyl glycidyl ether, styrene-p-glycidyl ether, glycidyl cinna Mate, glycidyl itaconate, N- [4- (2,3-epoxypropoxy) -3,5-dimethylbenzyl] methacrylamide and the like. These may be used alone or in combination of two or more. Among these, glycidyl acrylate and glycidyl methacrylate are preferable.

The ethylene-based elastomer was copolymerized with an unsaturated monomer having no epoxy group or glycidyl group, such as alkyl acrylate or alkyl methacrylate, together with the unsaturated monomer having these epoxy group or glycidyl group. A copolymer is preferred.
The ethylene elastomer is particularly preferably an ethylene-alkyl acrylate ester-glycidyl methacrylate copolymer.

  (D) Content of an elastomer is 5-30 mass parts with respect to 100 mass parts of (A) polybutylene terephthalate resin. If the elastomer content is less than 5 parts by mass, the effect of improving impact resistance and hydrolysis resistance tends to be small, and if it exceeds 30 parts by mass, the strength, heat aging resistance, rigidity, and fluidity of the boss part are further increased. The flame retardancy tends to decrease. The content of the elastomer is more preferably 7 parts by mass or more, further preferably 10 parts by mass or more, particularly preferably 16 parts by mass or more, more preferably 28 parts by mass or less, further preferably 26 parts by mass or less, and 22 parts by mass or less. Particularly preferred.

[(E) Release agent]
The polybutylene terephthalate resin composition of the present invention further contains (E) a release agent. (E) The release agent is at least one selected from the group consisting of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15000, and polysiloxane silicone oils. And the like.

  Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acid. Here, the aliphatic carboxylic acid includes alicyclic carboxylic acid. Among these, preferable aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms are more preferable. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, mellicic acid, tetrariacontanoic acid, montanic acid, adipine Examples include acids and azelaic acid.

  As the aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol, the same one as the aliphatic carboxylic acid can be used. On the other hand, examples of the alcohol include saturated or unsaturated monovalent or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, a monovalent or polyvalent saturated alcohol having 30 or less carbon atoms is preferable, and an aliphatic saturated monohydric alcohol or polyhydric alcohol having 30 or less carbon atoms is more preferable. Here, aliphatic includes alicyclic compounds. Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol and the like. Is mentioned.

  In addition, said ester compound may contain aliphatic carboxylic acid and / or alcohol as an impurity, and may be a mixture of a some compound.

  Specific examples of the ester of an aliphatic carboxylic acid and an alcohol include montanic acid ester, beeswax (mixture based on myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate. Glycerol monostearate, glycerol distearate, glycerol tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate and the like.

  Examples of the aliphatic hydrocarbon having a number average molecular weight of 200 to 15000 include liquid paraffin, paraffin wax, microwax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomer having 3 to 12 carbon atoms. Here, as the aliphatic hydrocarbon, alicyclic hydrocarbon is also included. Moreover, these hydrocarbon compounds may be partially oxidized. Among these, paraffin wax, polyethylene wax, or a partial oxide of polyethylene wax is preferable, and paraffin wax and polyethylene wax are more preferable. The number average molecular weight is preferably 200 to 5,000. These aliphatic hydrocarbons may be a single substance, or may be a mixture of various constituent components and molecular weights, as long as the main component is within the above range.

  Examples of the polysiloxane silicone oil include dimethyl silicone oil, phenylmethyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone. Two or more of these may be used in combination.

  (E) As a mold release agent, among the above, montanic acid ester wax is preferable. In particular, it is preferable to use a montanic acid ester wax in the resin composition system of the present invention because the effect of reducing the release resistance is great and the release property is particularly improved.

  (E) Content of a mold release agent is 0.1-3 mass parts with respect to 100 mass parts of (A) polybutylene terephthalate resin, Preferably it is 0.6 mass part or more, More preferably, it is 1. It is 0 mass part or more, Preferably it is 2.0 mass parts or less, More preferably, it is 1.5 mass parts or less. If the content of the release agent is not less than the above lower limit value, the effect of improving the releasability can be sufficiently obtained, and if it is not more than the above upper limit value, degradation of hydrolysis resistance due to excessive mixing of the release agent, injection Problems such as mold contamination during molding can be prevented.

[Epoxy compound]
The polybutylene terephthalate resin composition of the present invention preferably contains an epoxy compound. The epoxy compound is used to suppress polybutylene terephthalate resin from being hydrolyzed by water vapor and the like, causing a decrease in molecular weight and at the same time reducing mechanical strength and the like. By containing this, (D) elastomer The blending effect is further promoted, and the hydrolysis resistance and heat shock resistance can be further improved.

The epoxy compound is not particularly limited as long as it has one or more epoxy groups in one molecule, and is usually a glycidyl compound which is a reaction product of alcohol, phenol or carboxylic acid and epichlorohydrin, or an olefinic compound. A compound obtained by epoxidizing a heavy bond may be used. However, as the epoxy compound, the brominated epoxy compound and the elastomer into which the epoxy group is introduced are excluded.
Examples of the epoxy compound include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, resorcinol type epoxy compounds, novolac type epoxy compounds, alicyclic epoxy compounds, glycidyl ethers, glycidyl esters, epoxidized butadiene polymers, and the like. Can be mentioned.

Examples of the bisphenol A type epoxy compound include bisphenol A-diglycidyl ether and hydrogenated bisphenol A-diglycidyl ether. Examples of the bisphenol F type epoxy compound include bisphenol F-diglycidyl ether and hydrogenated bisphenol F-diglycidyl ether. Examples of the resorcin type epoxy compound include resorcin diglycidyl ether.
Moreover, as a novolak-type epoxy compound, a phenol novolak-type epoxy resin, a cresol novolak-type epoxy resin, etc. can be illustrated.

  Examples of alicyclic epoxy compounds include vinylcyclohexene dioxide, dicyclopentadiene oxide, 3,4-epoxycyclohexyl-3,4-cyclohexylcarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, vinylcyclohexene di Examples thereof include epoxide and 3,4-epoxycyclohexyl glycidyl ether.

  Specific examples of glycidyl ethers include monoglycidyl ethers such as methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, phenyl glycidyl ether, butylphenyl glycidyl ether, and allyl glycidyl ether; Examples include diglycidyl ethers such as pentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, propylene glycol diglycidyl ether, and bisphenol A diglycidyl ether. Examples of the glycidyl esters include monoglycidyl esters such as benzoic acid glycidyl ester and sorbic acid glycidyl ester; diglycidyl esters such as adipic acid diglycidyl ester, terephthalic acid diglycidyl ester, and orthophthalic acid diglycidyl ester. .

  Examples of the epoxidized butadiene polymer include epoxidized polybutadiene, epoxidized styrene-butadiene copolymer, and epoxidized hydrogenated styrene-butadiene copolymer.

  The epoxy compound may be a copolymer having a glycidyl group-containing compound as one component. For example, a copolymer of glycidyl ester of α, β-unsaturated acid and one or two or more monomers selected from the group consisting of α-olefin, acrylic acid, acrylic ester, methacrylic acid, methacrylic ester It is done.

  As the epoxy compound, an epoxy compound having an epoxy equivalent of 100 to 10000 g / eq and a mass average molecular weight of 8000 or less is preferable. When the epoxy equivalent is less than 100 g / eq, the viscosity of the resin composition is high because the amount of the epoxy group is too large. Conversely, when the epoxy equivalent exceeds 10000 g / eq, the amount of the epoxy group decreases. The effect of improving the hydrolysis resistance and heat shock resistance of the thermoplastic polyester resin composition tends to be hardly exhibited. The epoxy equivalent is more preferably 300 to 7000 g / eq, and further preferably 500 to 6000 g / eq. Moreover, when the mass average molecular weight exceeds 8000, the compatibility with the thermoplastic polyester resin is lowered, and the mechanical strength of the molded product tends to be lowered. The mass average molecular weight is more preferably 7000 or less, and still more preferably 6000 or less.

  The content of the epoxy compound is preferably 0.1 to 2 parts by mass, more preferably 0.2 parts by mass or more, and 0.3 parts by mass or more with respect to 100 parts by mass of the (A) polybutylene terephthalate resin. More preferred is 0.4 part by mass or more. Moreover, 1.5 mass parts or less are more preferable, 1.4 mass parts or less are further more preferable, and 1.3 mass parts or less are especially preferable. If the content of the epoxy compound is less than 0.1 parts by mass, the hydrolysis resistance tends to decrease, and if it exceeds 2 parts by mass, the crosslinking proceeds and the fluidity during molding tends to deteriorate.

  Furthermore, (A) It is preferable that the equivalent ratio (epoxy group / COOH group) of the epoxy group of the epoxy compound with respect to the terminal COOH group of the thermoplastic polyester resin is in the range of 0.2 to 2.7. If the equivalent ratio is less than 0.2, the hydrolysis resistance tends to be poor, and if it exceeds 2.7, the moldability tends to be unstable. The epoxy group / COOH group is more preferably 0.3 or more and 2.5 or less.

[Inorganic filler]
The polybutylene terephthalate-based resin composition of the present invention preferably contains an inorganic filler, and is preferably contained in a range of 30 to 100 parts by mass with respect to 100 parts by mass of (A) polybutylene terephthalate resin. The content of the inorganic filler is more preferably 40 parts by mass or more, further preferably 50 parts by mass or more, more preferably 90 parts by mass or less, and further preferably 80 parts by mass or less.
In the present invention, the term “inorganic filler” refers to a material that is contained in a resin component to improve strength and rigidity, and may be any form such as fibrous, plate-like, granular, and amorphous.

  When the form of the inorganic filler is fibrous, it may be either inorganic or organic. For example, glass fiber, carbon fiber, silica / alumina fiber, zirconia fiber, boron fiber, boron nitride fiber, silicon nitride potassium titanate fiber, metal fiber, organic fiber such as wollastonite, fluorine resin fiber, aramid fiber, etc. Fiber is included. When the inorganic filler is fibrous, inorganic fibers are preferable, and glass fibers are particularly preferable among them. The inorganic filler may be a single type or a mixture of two types.

  When the form of the inorganic filler is fibrous, the average fiber diameter, average fiber length, and cross-sectional shape are not particularly limited, but the average fiber diameter is preferably selected in the range of 1 to 100 μm, for example, It is preferable to select in the range of 0.1 to 20 mm. The average fiber diameter is more preferably about 1 to 50 μm, more preferably about 5 to 20 μm. The average fiber length is preferably about 0.12 to 10 mm. In addition, when the fiber cross section is a flat shape such as an oval, an ellipse, or a bowl, the flatness ratio (major axis / minor axis ratio) is preferably 1.4 to 10, more preferably 2 to 6. 5 to 5 is more preferable. It is preferable to use glass fibers having such an irregular cross section because dimensional stability such as warpage of the molded product and anisotropy of the shrinkage rate is easily improved.

  In addition to the fibrous inorganic filler described above, other inorganic fillers that are plate-like, granular, or amorphous can also be contained. The plate-like inorganic filler exhibits a function of reducing anisotropy and warping, and examples thereof include glass flakes, talc, mica, mica, kaolin, and metal foil. Among the plate-like inorganic fillers, glass flakes are preferable.

  Other inorganic fillers that are granular or amorphous include ceramic beads, asbestos, clay, zeolite, potassium titanate, barium sulfate, titanium oxide, silicon oxide, aluminum oxide, magnesium hydroxide, and the like.

In order to improve the adhesion at the interface between the inorganic filler and the resin component, the surface of the inorganic filler is preferably treated with a surface treatment agent such as a sizing agent. Examples of the surface treating agent include epoxy resins, acrylic resins, urethane resins, and functional compounds such as isocyanate compounds, silane compounds, and titanate compounds.
In the present invention, it is preferable to use an epoxy resin for the surface treatment. The epoxy resin is preferably a novolak type epoxy resin such as a phenol novolak type or a cresol novolak type, or a bisphenol A type epoxy resin. Among them, it is preferable to use a novolac type epoxy resin and a bisphenol type epoxy resin in combination, and it is preferable to use a phenol novolac type epoxy resin and a bisphenol A type epoxy resin in terms of alkali resistance, hydrolysis resistance and mechanical properties. .

As the functional compound, silane coupling agents such as amino silane, epoxy silane, allyl silane, and vinyl silane are preferable. Of these, amino silane compounds are preferable.
As the aminosilane compound, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ- (2-aminoethyl) aminopropyltrimethoxysilane are preferable. γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane are preferred.

In the present invention, it is possible to use a novolac type epoxy resin and a bisphenol type epoxy resin as a so-called sizing agent, and additionally use an inorganic filler surface-treated with an aminosilane compound as a coupling agent. Are particularly preferred. By having such a surface treatment agent, the inorganic functional group of the aminosilane compound is rich in reactivity with the surface of the inorganic filler, and the organic functional group of aminosilane is highly reactive with the glycidyl group of the epoxy resin. The glycidyl group reacts appropriately with the (A) polybutylene terephthalate resin, whereby the interfacial adhesion between the inorganic filler and the epoxy resin is easily improved. As a result, it is considered that the hydrolysis resistance and mechanical properties of the resin composition of the present invention tend to be improved.
Further, within the range not departing from the gist of the present invention, urethane resin, acrylic resin, antistatic agent, lubricant, water repellent and the like can be included in the surface treatment agent, and when these other components are included, It is preferable to use a urethane resin.

The inorganic filler can be surface-treated by a conventionally known method. For example, the inorganic filler may be previously surface-treated with the above-mentioned surface-treating agent, and when the polybutylene terephthalate resin composition of the present invention is prepared, it is untreated. In addition to the inorganic filler, a surface treatment agent may be added for surface treatment.
0.01-5 mass% is preferable and, as for the adhesion amount of the surface treating agent with respect to an inorganic filler, 0.05-2 mass% is further more preferable. By making it 0.01% by mass or more, the mechanical strength tends to be more effectively improved, and by making it 5% by mass or less, a necessary and sufficient effect can be obtained, and the production of the resin composition Tends to be easy, and is preferable.

[Carbon black]
The polybutylene terephthalate resin composition of the present invention preferably contains carbon black.
There are no restrictions on the type, raw material type, and manufacturing method of carbon black, and any of furnace black, channel black, acetylene black, ketjen black, and the like can be used. The number average particle diameter is not particularly limited, but is preferably about 5 to 60 nm.

  The content of carbon black is preferably 0.1 to 4.0 parts by mass, more preferably 0.2 to 3.0 parts by mass with respect to 100 parts by mass of (A) polybutylene terephthalate resin. If the amount is less than 0.1 parts by mass, a desired color may not be obtained or the weather resistance improving effect may not be sufficient. If the amount exceeds 4.0 parts by mass, the mechanical properties may decrease.

Carbon black is preferably blended in advance as a master batch containing carbon black at a high concentration in order to improve the handling property during the production of the resin composition and the uniform dispersibility in the resin composition. In this case, the resin used for the carbon black masterbatch may be (A) polybutylene terephthalate resin, other resin, polycarbonate resin, polyethylene terephthalate resin, styrene resin (for example, AS resin), polyethylene It may be a resin or the like. From the viewpoint of easy dispersion of high concentration carbon black and easy masterbatch formation, it is preferable to use (A) polybutylene terephthalate resin or styrene resin. Among these, it is desirable to use a styrene resin from the viewpoint of blackness.
The carbon black concentration of the carbon black masterbatch is usually about 10 to 60% by mass.

[Stabilizer]
It is preferable that the polybutylene terephthalate resin composition of the present invention further contains a stabilizer because it has effects of improving thermal stability, preventing mechanical strength, and deterioration of hue. As the stabilizer, a phosphorus stabilizer and a phenol stabilizer are preferable.
Examples of phosphorus stabilizers include phosphorous acid, phosphoric acid, phosphite ester (phosphite), trivalent phosphate ester (phosphonite), and pentavalent phosphate ester (phosphate). Among them, phosphite , Phosphonite and phosphate are preferred.

  Examples of the phosphite include triphenyl phosphite, tris (nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris (2-ethylhexyl) phosphite, tris (tridecyl) phosphite. Phyto, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite, water Bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-butyl) Ruphenyldi (tridecyl) phosphite), tetra (tridecyl) 4,4'-isopropylidene diphenyldiphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, dilaurylpentaerythritol diphosphite Phosphite, distearyl pentaerythritol diphosphite, tris (4-tert-butylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite 2,2'-methylenebis (4,6-di -tert- butylphenyl) octyl phosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite and the like.

  Examples of phosphonites include tetrakis (2,4-di-iso-propylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-n-butylphenyl) -4,4′-biphenyl. Range phosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylene diphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3'-biphenylene diphospho Knight, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite, Tetrakis (2,6-di-n-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,6- -Tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,3'-biphenylenediphosphonite, and tetrakis (2,6-di-) tert-butylphenyl) -3,3′-biphenylenediphosphonite.

Examples of the phosphate include methyl acid phosphate, ethyl acid phosphate, propyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, and lauryl acid phosphate. , Stearyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonyl phenyl acid phosphate, cyclohexyl acid phosphate, phenoxyethyl acid phosphate, alkoxy polyethylene glycol acid phosphate, bisphenol A acid phosphate , Dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, Acid phosphate, bisnonylphenyl acid phosphate, etc. are mentioned.
One type of phosphorous stabilizer may be contained, or two or more types may be contained in any combination and ratio.

  Specific examples of the phenol-based stabilizer include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl- 4-hydroxyphenyl) propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexane-1,6-diylbis [3- (3 5-di-tert-butyl-4-hydroxyphenyl) propionamide], 2,4-dimethyl-6- (1-methylpentadecyl) phenol, diethyl [[3,5-bis (1,1-dimethylethyl)- 4-hydroxyphenyl] methyl] phosphoate, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert- Til-a, a ′, a ″-(mesitylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3 5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert -Butyl-4- (4,6-bis (octylthio) -1,3,5-triazin-2-ylamino) phenol and the like.

Among them, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate preferable.
In addition, 1 type may contain the phenol type stabilizer, and 2 or more types may contain it by arbitrary combinations and a ratio.

  The content of the stabilizer is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and usually 1.5 parts by mass or less, relative to 100 parts by mass of the (A) polybutylene terephthalate resin. Preferably it is 1 mass part or less. If the amount is less than 0.001 part by mass, the effect as a stabilizer is insufficient, and molecular weight reduction and hue deterioration during molding are likely to occur. Deterioration tends to occur more easily.

[Other ingredients]
The polybutylene terephthalate resin composition of the present invention may further contain various additives as long as the effects of the present invention are not impaired. Such additives include anti-dripping agents, UV absorbers, dyes and pigments, fluorescent brighteners, antistatic agents, antifogging agents, lubricants, antiblocking agents, fluidity improvers, plasticizers, dispersants, antibacterial agents. Agents and the like.

In addition, the polybutylene terephthalate resin composition in the present invention can contain a thermoplastic resin other than the above-described resins within a range that does not impair the effects of the present invention.
As other thermoplastic resins, specifically, for example, polyethylene terephthalate resin, polycarbonate resin, polyacetal resin, polyamide resin, polyphenylene oxide resin, polystyrene resin, polyphenylene sulfide ethylene resin, polysulfone resin, polyether sulfone resin, Examples include polyetherimide resins, polyether ketone resins, and polyolefin resins.

[Crystallizing temperature]
The polybutylene terephthalate resin composition of the present invention comprises (B) at least two different brominated flame retardants selected from the group consisting of a brominated epoxy compound, a brominated polycarbonate compound, and a brominated polystyrene compound. By containing, the crystallization temperature (Tc) is low, preferably 193 ° C. or lower, more preferably 192 ° C. or lower, more preferably 191 ° C. or lower, particularly 190 ° C. or lower, particularly preferably 189 ° C. or lower. Have. Further, the lower limit of Tc is preferably 170 ° C, more preferably 175 ° C, and further preferably 180 ° C.
By setting such a crystallization temperature, it becomes easy to fill the resin sufficiently before the resin in the boss portion is solidified, and the boss strength can be increased.

  In the present invention, the crystallization temperature (Tc) is a differential scanning calorimeter (DSC), and the resin composition or a molded body made of the resin composition is molded at a rate of 20 ° C./min from 30 ° C. to 300 ° C. in a nitrogen atmosphere. The temperature is raised and held at 300 ° C. for 3 minutes, and then the temperature is lowered at a rate of 20 ° C./min.

[Method for Producing Resin Composition]
As a method for producing the polybutylene terephthalate resin composition of the present invention, the respective components and various additives to be added as desired are mixed well, and then melt-kneaded in a single-screw or twin-screw extruder. Moreover, it is also possible to prepare the resin composition of the present invention by mixing each component in advance or by mixing only a part of the components in advance and supplying them to an extruder using a feeder and melt-kneading them. Furthermore, a masterbatch is prepared by melting and kneading a part of the polybutylene terephthalate resin with a part of the other ingredients, and then blending the remaining polybutylene terephthalate resin and other ingredients to the melt. You may knead. In addition, when using fibrous things, such as glass fiber, as an inorganic filler, it is also preferable to supply from the side feeder in the middle of the cylinder of an extruder.

  In addition, as described above, the (C) antimony compound used in a master batch is preliminarily used in terms of thermal stability at the time of melt kneading and molding, flame retardancy, and variations in impact resistance. preferable. The method of masterbatching is not particularly limited, and examples thereof include a method of melt-kneading a thermoplastic resin, preferably a polybutylene terephthalate resin and an antimony compound, using a kneader such as a twin screw extruder. In addition, various additives such as stabilizers can be blended as necessary when forming a masterbatch.

  Moreover, it is preferable that the melting temperature of the resin composition at the time of melt-kneading is 180-350 degreeC, and it is more preferable that it is 190-320 degreeC. When the melting temperature is less than 180 ° C., melting is insufficient and unmelted gel tends to occur frequently. Conversely, when it exceeds 350 ° C., the resin composition is thermally deteriorated and easily colored, which is not preferable.

[Molding]
The polybutylene terephthalate resin composition of the present invention is usually molded into an arbitrary shape and used as a molded product. There is no restriction on the shape, pattern, color, size, etc. of the molded product, and it may be set arbitrarily according to the application of the molded product.
The method for producing the molded product is not particularly limited, and a molding method generally employed for the polybutylene terephthalate resin composition can be arbitrarily adopted. For example, injection molding method, ultra-high speed injection molding method, injection compression molding method, two-color molding method, hollow molding method such as gas assist, molding method using heat insulating mold, rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermoforming method, rotational molding method, laminate molding method, press molding method, Examples thereof include a blow molding method, and an injection molding method is particularly preferable.

Hereinafter, the injection molding method will be described.
The drying conditions before injection molding are a drying temperature of 100 ° C. to 180 ° C. and a drying time of 1 hour to 36 hours. More preferably, the range of the drying temperature is 120 ° C. or more and 160 ° C. or less, and the range of the drying time is 4 hours or more and 24 hours or less. The drying step is preferably performed in a vacuum atmosphere, but other atmospheres may be used. For example, the drying process may be performed in an inert gas atmosphere or an air atmosphere, and the drying method in the drying process is not particularly limited. A conventionally known dryer may be used. Moreover, what is necessary is just to use a vacuum dryer, for example, when performing a drying process in a vacuum atmosphere.
When the drying temperature is increased and the drying time is lengthened, the moisture content in the polybutylene terephthalate resin composition is decreased, and the boss strength tends to be increased by reducing the generation of voids in the boss portion. However, when the drying temperature is excessively high or the drying time is excessively long, the polybutylene terephthalate resin or the oxidative deterioration of the resin proceeds.

  Further, the water content of the resin composition before injection molding is preferably 500 ppm or less, more preferably 300 ppm or less, further preferably 200 ppm or less, and particularly preferably 100 ppm or less. When the moisture content exceeds 500 ppm, voids are likely to be generated in the boss portion, and the strength of the boss portion is likely to be reduced. In addition, the hydrolysis resistance tends to decrease.

  At the time of molding, the cylinder temperature is preferably less than 280 ° C. and the cooling time is less than 40 seconds. When the cylinder temperature is lowered, the generation of gas is suppressed, the generation of voids in the boss portion is reduced, and the boss strength tends to increase. Moreover, if the cooling time is shortened, the gas generated during molding decreases, and the boss strength tends to increase in the same manner. In particular, it is preferable to adjust the cylinder temperature in the range of 240 ° C. or more and less than 270 ° C., and to adjust the cooling time in the range of 5 seconds or more and less than 30 seconds.

  The holding pressure value at the time of injection molding is preferably 50% to 10% of the injection peak pressure. From the viewpoint of moldability and mechanical properties, it is more preferable to set the pressure holding value within the range of 60% to 90% of the injection peak pressure. If the holding pressure value is lower than 50% of the injection peak pressure, the boss strength tends to be low. On the other hand, if it is higher than 100%, the polybutylene terephthalate resin material may be overfilled and the mold release property may deteriorate.

The polybutylene terephthalate-based resin composition of the present invention is less likely to generate internal voids in the boss portion and its vicinity when the boss portion is provided in the molded product, has excellent boss portion strength, flame retardancy and mold release It is particularly suitable as an electric device, electronic device or an insulating part thereof, for example, a relay case, a variable capacitor case, a capacitor case, a power module case, an intelligent power module case, etc. Preferred examples include vehicle electrical components such as an engine control unit (ECU) case, an engine computer unit case, an ABS unit case, and an airbag control unit, or a casing and a case thereof.
Since such vehicle electrical components (casing, case) are highly likely to be exposed to water, it is required to waterproof the mounted circuit board and the like. It is preferable that a silicone resin-based sealant layer having flexibility is provided on the surface for sealing.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not construed as being limited to the following examples.
In the following description, “parts” means “parts by mass” based on mass standards unless otherwise specified.
In the following Examples and Comparative Examples, the components used are as shown in Table 1 below.

(Examples 1-24 and Comparative Examples 1-6)
Each component other than the glass fibers listed in Table 1 above was blended in the proportions (all parts by mass) shown in Tables 2 to 4 below, and this was blended with a 30 mm vent type twin screw extruder (Nippon Steel Works). Glass fiber is supplied from a side feeder using a twin screw extruder TEX30α), melt kneaded at a barrel temperature of 270 ° C., extruded into a strand, pelletized by a strand cutter, and polybutylene terephthalate resin composition A product pellet was obtained.

<Measurement of crystallization temperature (Tc)>
The obtained pellets were dried at 120 ° C. for 5 hours using a hot air dryer, and then the conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. using an injection molding machine (“J85AD” manufactured by Nippon Steel) Then, the ISO test piece obtained by injection-molding the ISO test piece was raised from 30 ° C. to 300 ° C. at a rate of 20 ° C./minute using “PYRIS Diamond DSC” manufactured by PerkinElmer. After warming and holding at 300 ° C. for 3 minutes, the temperature was lowered at a rate of 20 ° C./min, and DSC measurement was performed. The temperature at the top of the exothermic peak observed when the temperature was lowered was defined as the crystallization temperature (Tc).

<Molding of test piece with boss>
FIG. 1B is a top view of the test piece 1, and a boss portion 2 is provided at the center of the test piece 1. FIG. 1 (a) is a view of the test piece 1 with the boss 2 side facing down from the side marked 1 in FIG. 1 (b), and FIG. 1 (c) is the boss portion of FIG. 1 (b). 2 is a cross-sectional view taken along line AA along a center line AA passing through FIG. The boss portion 2 has a height of 2 mm, and is formed in a cutout columnar shape in which a circle of R = 2 mm is partially cut out as shown in the drawing. Further, a rib 3 having a height of 2 mm is linearly provided at the lower part of the test piece 1.
The test piece was molded using a hot air dryer at 120 ° C. for the time shown in Tables 2 to 4 (1.5 to 5 hours) to obtain pellets having different moisture contents, and then an injection molding machine ( Nissei Resin Kogyo "NEX80"), cylinder temperature 260 ° C, mold temperature 80 ° C, cooling time 20 seconds, filling time 1.5 seconds, injection peak pressure 80% of the pressure holding value Then, a resin was injected from the film gate provided on the 3 side of FIG. 1B to form a test piece with a boss portion shown in FIG.

<Moisture content>
The moisture content (unit: mass ppm) of the dried pellet was measured using a Karl Fischer coulometric moisture measuring device ("CA-200" manufactured by Mitsubishi Chemical Analytech Co., Ltd.). The heating temperature was set to 200 ° C., and nitrogen gas was used as the carrier gas.
The above evaluation results are shown in Tables 2 to 4 below.

<Measurement of boss strength>
The boss strength is measured by holding the test piece 1 between the rib 3 and the boss portion 2 with a pedestal fixture (not shown), and then (b) a metal indicated by a broken line in the figure. Using a tensile jig 4 made of steel, the boss 2 is inserted into the hole 5, the tensile jig 4 is pulled up in the direction of the arrow at a test speed of 20 mm / min, and the strength (unit) when the boss 2 is broken : N) was determined and used as the boss strength.

<Evaluation of releasability>
Using the obtained pellet, using a FANUC "α100iA type" injection molding machine, with a cylinder temperature of 250 ° C and a mold temperature controller set temperature of 80 ° C, a partition is provided at the center as shown in FIG. A side gate (gate thickness of 1. mm) provided with a box-shaped product (vertical 30 mm, width 54 mm, depth 34 mm, wall thickness 1.5 mm) in the vicinity of the front-most center of the left side wall indicated by the arrow of the box-shaped product in FIG. 5 mm × gate width 3 mm), resin was injected and molded.

  FIG. 3 is a top view of the box-shaped product and the ejector pin shown in FIG. 2 as viewed from above. FIG. 4 is an explanatory diagram showing a position where the ejector pin hits the bottom of the box-shaped product. The molded product was extracted by bringing out a total of four ejector pins with pressure sensors shown in FIG. 3 into contact with the bottom plate of the box-shaped product as shown in FIG.

Molding was performed by setting the cooling time to 10 seconds, and a box-shaped product was ejected from the mold by ejecting with an ejector pin.
Judgment was made based on the following three-stage criteria based on the sound generated when the bottom plate of the resulting box-shaped product was deformed and protruded.
“◎: No deformation of the bottom plate and no sound when protruding”
“○: There is deformation of the bottom plate and noise is generated when protruding”
“×: There is a break through the bottom plate”

<Measurement of mold release resistance value>
The obtained pellets were dried at 120 ° C. for 5 hours using a hot air dryer, and then a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C. using an injection molding machine (clamping force 50T) manufactured by Sumitomo Heavy Industries, Ltd. The maximum resistance value when a box-shaped molded product having a thickness of 1.5 mm and an outer dimension of 30 × 50 × 15 mm depth is molded under the condition of a cooling time of 10 sec and released by the protrusion of the ejector pin is the release resistance. The value (unit: MPa) was evaluated.

<Tensile strength retention after 200 hours of treatment: Evaluation of hydrolysis resistance>
The obtained pellets were dried at 120 ° C. for 5 hours using a hot air dryer, and then subjected to conditions of cylinder temperature 250 ° C. and mold temperature 80 ° C. with an injection molding machine (“NEX80” manufactured by Nissei Plastic Industrial Co., Ltd.). An ISO multipurpose test piece (4 mm thick) was injection molded.
Using an ISO multipurpose test piece, the tensile strength (before treatment) was measured in accordance with ISO 527 under the condition of a tensile speed of 5 mm / min (unit: MPa).
In addition, the ISO multi-purpose test piece was treated for 200 hours under the conditions of a temperature of 121 ° C., a relative humidity of 100%, and a pressure of 2 atm using a pressure cooker (PCT) testing machine (manufactured by Hirayama Seisakusho). The strength retention after the treatment (unit:%) relative to that before the treatment was calculated.

<Charpy impact strength with notch>
A 4.0 mm thick notched test piece was prepared from the ISO multipurpose test piece (4.0 mm thick), and the notched Charpy impact strength (unit: kJ / m ² ) was measured in accordance with the ISO 179 standard.

<Shrinkage rate>
The obtained pellets were dried at 120 ° C. for 5 hours using a hot air dryer, and then subjected to conditions of a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C. with an injection molding machine (“NEX80” manufactured by Nissei Plastic Industry Co., Ltd.). Then, a flat plate having a length of 100 mm, a width of 100 mm, and a thickness of 2 mm was molded using a film gate mold, and a molding shrinkage rate in the direction perpendicular to the flow (TD direction shrinkage rate, unit:%) was obtained.
The above evaluation results are shown in Table 2 below.

  The polybutylene terephthalate-based resin composition of the present invention is excellent in strength because there are few voids inside when formed into a molded product, and even when a flame retardant is added, both strength and flame retardancy are possible In addition, since it is excellent in releasability and hydrolysis resistance, it can be suitably used as an electric device, an electronic device, or a component thereof.

Claims (12)

  (A) At least two different brominated flame retardants selected from the group consisting of (B) brominated epoxy compounds, brominated polycarbonate compounds, and brominated polystyrene compounds with respect to 100 parts by mass of polybutylene terephthalate resin 30-60 parts by mass in total, (C) 5-15 parts by mass of antimony compound, (D) 5-30 parts by mass of elastomer, and (E) 0.5-3 parts by mass of release agent. A polybutylene terephthalate resin composition characterized by the above.   (B) Brominated flame retardant (B1) whose bromine-based flame retardant is selected from brominated epoxy compounds or brominated polycarbonate compounds and whose weight average molecular weight is 1000 to 8000, and brominated epoxy compounds or brominated polystyrene compounds The polybutylene terephthalate resin composition according to claim 1, which is a brominated flame retardant (B2) having a weight average molecular weight of more than 8000 to 70000.   The polybutylene terephthalate resin composition according to claim 1 or 2, wherein the crystallization temperature is 193 ° C or lower.   The polybutylene terephthalate resin composition according to any one of claims 1 to 3, wherein each of the two or more brominated flame retardants (B) is a brominated epoxy compound.   The polybutylene terephthalate resin composition according to any one of claims 1 to 4, wherein the brominated epoxy compound is end-capped with tribromophenol.   The polybutylene terephthalate resin composition according to claim 2, wherein a mass ratio (B1) / (B2) of the flame retardant (B1) to the flame retardant (B2) is 90/10 to 30/70.   (D) An elastomer is an ethylene-type elastomer, The polybutylene terephthalate-type resin composition of any one of Claims 1-6.   The polybutylene terephthalate resin composition according to claim 7, wherein the ethylene elastomer is an ethylene-alkyl acrylate-glycidyl methacrylate copolymer.   (E) A mold release agent is a montanic acid ester type mold release agent, The polybutylene terephthalate type resin composition in any one of Claims 1-8.   The water content in a resin composition is 500 ppm or less, The polybutylene terephthalate-type resin composition in any one of Claims 1-9.   A molded article of the polybutylene terephthalate resin composition according to any one of claims 1 to 10.   The molded product according to claim 11, which is a vehicle electrical component.