JP7454343B2 - Flame retardant polybutylene terephthalate resin composition - Google Patents

Description

The present invention relates to a flame-retardant polybutylene terephthalate resin composition and molded articles thereof.

Polybutylene terephthalate resin (PBT resin) has excellent mechanical properties, electrical properties, heat resistance, and other properties, so it is widely used as an engineering plastic in various applications such as automobile parts and electric/electronic equipment parts. Among these, materials used in electrical and electronic equipment parts are required to be flame retardant to prevent ignition due to tracking, etc. Also, with regard to automobile parts, as a result of hybridization and electrification in recent years, As a variety of electrical and electronic components are being installed, the demand for flame-retardant materials is increasing. Here, since polybutylene terephthalate resin itself lacks flame retardancy, it is used as a flame retardant resin composition to which a flame retardant is added.

One type of flame retardant added to such polybutylene terephthalate resin is a halogenated epoxy flame retardant, and Patent Document 1 introduces a method for producing a brominated epoxy compound flame retardant. This production method includes diglycidyl ethers of aromatic nucleus-containing alcohols, di- or polyglycidyl ethers of polyhydric phenols, diglycidyl esters of aromatic dibasic acids, monoglycidyl ethers of alkylphenols, and monoglycidyl ethers of hydroxybenzoic acids. Epoxy compounds having aromatic groups, such as ether esters, (β-methyl)epichlorohydrin addition products of p-aminophenol, or polyglycidylamines based on aromatic di- or polyamines, or their precursors. A chlorohydrin compound is brominated by bromine addition, and the obtained brominated bromohydrin compound or brominated chlorohydrin compound is subjected to ring-closing epoxidation through dehydrogenation or dehydrochlorination using an alkali metal hydroxide. It is characterized by

Further, Patent Document 2 introduces a brominated epoxy compound flame retardant for engineering thermoplastics. It is said that the molecular weight of this flame retardant is 7,000 to 50,000 Daltons, and the epoxy equivalent weight is preferably over 10,000 g/eq.

Furthermore, it is known that brominated epoxy compound flame retardants can increase in viscosity due to their own reactions, and the increase in viscosity during melt-kneading can cause deposits to form on the screws, and their carbides can be mixed into molded products. In order to suppress the occurrence of black speck (BS) due to this, the range of molecular weight and epoxy equivalent has been adjusted. For example, Patent Document 3 introduces that by using an epoxy compound having an epoxy equivalent of 600 to 1500 g/eq, the generation of foreign matter in a molded article of a polybutylene terephthalate resin composition can be suppressed.

By the way, since polybutylene terephthalate resin is a crystalline thermoplastic resin, it tends to undergo molding shrinkage due to crystallization after molding and post-shrinkage in the usage environment, and also has a larger coefficient of linear expansion than metals. Therefore, when a molded product made of a polybutylene terephthalate resin composition used in combination with a metal member is exposed to an environment of repeated heating and cooling, molding shrinkage and post-shrinkage of the resin may occur, and the bond between the metal and the resin may occur. Combined with the strain caused by the difference in coefficient of linear expansion, the molded product is more likely to suffer damage such as cracks (so-called heat shock destruction). Therefore, as a technique for improving the heat shock resistance of polybutylene terephthalate resin, Patent Document 4 discloses that in order to improve the heat shock resistance of insert molded products using polybutylene terephthalate, etc., A technique for creating a stress concentration area has been disclosed, but if the above-mentioned foreign matter is mixed into the molded product, this becomes a stress concentration area or a weak area, which becomes a starting point for failure, reducing heat shock resistance. There is a risk. Therefore, from the viewpoint of improving heat shock resistance, it is required to suppress the contamination of foreign matter.

Special Publication No. 60-016952 Patent No. 5143419 Patent No. 6100983 Japanese Patent Application Publication No. 2013-103472

The present invention provides a flame-retardant polybutylene terephthalate resin composition that uses a halogenated epoxy flame retardant as a flame retardant, suppresses the incorporation of foreign matter into a molded article made of the composition, and allows the molded article to be heated and cooled. The objective is to suppress damage caused by heat shock when used in repeated environments.

In the course of research aimed at the above problem, the present inventors used a halogenated epoxy flame retardant as a flame retardant, and in a flame retardant polybutylene terephthalate resin composition containing a specific heat shock resistance improver, halogen The above problems are solved by keeping the content of organic solvent in the epoxy-based flame retardant below a certain amount and keeping the total content of epoxy groups in the entire flame-retardant polybutylene terephthalate resin composition below a certain amount. We have discovered that this can be done, and have completed the present invention.

That is, the present invention relates to the following (1) to (7).
(1) A halogenated epoxy flame retardant containing 100 parts by mass of (A) polybutylene terephthalate resin and (B) an organic solvent selected from the group consisting of toluene, methyl isobutyl ketone, methyl ethyl ketone, and acetone at 50 ppm or less. , (C) 5 to 100 parts by mass of a resin for improving heat shock resistance, (D) 10 to 200 parts by mass of a filler for improving heat shock resistance, and (E) 0.0 parts by mass of an additive for improving heat shock resistance. 1 to 30 parts by mass, and the total content of epoxy groups in the entire composition is 0.0155 mol/kg or less, and the heat shock resistance improver is carbodiimide. A flame-retardant polybutylene terephthalate resin composition, characterized in that it contains one or more selected from the group consisting of a compound, an epoxy compound, an oxazoline compound, an oxazine compound, an aromatic polycarboxylic acid ester, and a combination thereof.
(2) The flame-retardant polybutylene terephthalate resin composition according to (1), wherein the epoxy equivalent of the halogenated epoxy flame retardant (B) is 30,000 g/eq or more.
(3) The flame-retardant polybutylene according to (1) or (2), wherein the content of the halogenated epoxy flame retardant (B) is 3 to 50 parts by mass based on 100 parts by mass of the polybutylene terephthalate resin. Terephthalate resin composition.
(4) The flame-retardant polybutylene terephthalate resin composition according to any one of (1) to (3), wherein the halogenated epoxy flame retardant is a brominated epoxy flame retardant.
(5) The flame-retardant polybutylene terephthalate resin according to any one of (1) to (4), further containing a flame-retardant aid selected from the group consisting of antimony pentoxide, antimony trioxide, and sodium antimonate. Composition.
(6) A molded article obtained by injection molding the flame-retardant polybutylene terephthalate resin composition according to any one of (1) to (5).
(7) The molded article according to (6), which is formed by insert molding a metal and/or an inorganic solid.

According to the present invention, in a polybutylene terephthalate resin composition using a halogenated epoxy flame retardant as a flame retardant, the content of an organic solvent in the flame retardant is set to a certain amount or less, and the flame retardant polybutylene terephthalate resin composition By controlling the total content of epoxy groups in the entire product to a certain amount or less, it is possible to suppress the incorporation of foreign substances into the molded product using the flame-retardant polybutylene terephthalate resin composition, and to prevent the molded product from entering the molded product. It is possible to suppress heat shock destruction in an environment where heating and cooling are repeated.

It is a figure which shows the test piece used in the heat shock resistance test, Comprising: (A) is a perspective view, (B) is a top view. It is a figure which shows the insert member of the test piece shown in FIG. 1, Comprising: (A) is a perspective view, (B) is a top view.

Hereinafter, one embodiment of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within a range that does not impede the effects of the present invention.

[Flame retardant polybutylene terephthalate resin composition]
Hereinafter, details of each component of the flame-retardant polybutylene terephthalate resin composition of the present embodiment will be explained using examples.

((A) Polybutylene terephthalate resin)
(A) Polybutylene terephthalate resin (PBT resin) contains a dicarboxylic acid component containing at least terephthalic acid or its ester-forming derivative (C _1-6 alkyl ester, acid halide, etc.) and an alkylene component having at least 4 carbon atoms. It is a polybutylene terephthalate resin obtained by polycondensation with a glycol component containing glycol (1,4-butanediol) or its ester-forming derivative (acetylated product, etc.). In the present embodiment, the polybutylene terephthalate resin (A) is not limited to a homopolybutylene terephthalate resin, but may be a copolymer containing 60 mol% or more of butylene terephthalate units.

The amount of terminal carboxyl groups in the polybutylene terephthalate resin (A) is not particularly limited as long as it does not impede the object of the present invention, but is preferably 30 meq/kg or less, more preferably 25 meq/kg or less.

(A) The intrinsic viscosity of the polybutylene terephthalate resin is not particularly limited as long as it does not impede the object of the present invention, but it is preferably 0.60 dL/g or more and 1.5 dL/g or less, and 0.65 dL/g or more and 1. More preferably, it is .2 dL/g or less. When a polybutylene terephthalate resin having an intrinsic viscosity within this range is used, the resulting polybutylene terephthalate resin composition has particularly excellent moldability. The intrinsic viscosity can also be adjusted by blending polybutylene terephthalate resins having different intrinsic viscosities. For example, a polybutylene terephthalate resin with an intrinsic viscosity of 0.9 dL/g is prepared by blending a polybutylene terephthalate resin with an intrinsic viscosity of 1.0 dL/g and a polybutylene terephthalate resin with an intrinsic viscosity of 0.7 dL/g. I can do it. The intrinsic viscosity of polybutylene terephthalate resin can be measured, for example, in o-chlorophenol at a temperature of 35°C.

(A) In the preparation of polybutylene terephthalate resin, when an aromatic dicarboxylic acid other than terephthalic acid or an ester-forming derivative thereof is used as a comonomer component, for example, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4, C _8-14 aromatic dicarboxylic acids such as 4'-dicarboxydiphenyl ether; C _4-16 alkanedicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid; C _5-10 dicarboxylic acids such as cyclohexanedicarboxylic acid; Cycloalkanedicarboxylic acid: Ester-forming derivatives (C _1-6 alkyl ester derivatives, acid halides, etc.) of these dicarboxylic acid components can be used. These dicarboxylic acid components can be used alone or in combination of two or more.

Among these dicarboxylic acid components, C _8-12 aromatic dicarboxylic acids such as isophthalic acid, and C _6-12 alkanedicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid are more preferred.

(A) In the preparation of polybutylene terephthalate resin, when using a glycol component other than 1,4-butanediol as a comonomer component, for example, ethylene glycol, propylene glycol, trimethylene glycol, 1,3-butylene glycol, hexamethylene glycol _C2-10 alkylene glycols such as , neopentyl glycol, and 1,3-octanediol; polyoxyalkylene glycols such as diethylene glycol, triethylene glycol, and dipropylene glycol; alicyclics such as cyclohexanedimethanol and hydrogenated bisphenol A; Diols; Aromatic diols such as bisphenol A and 4,4'-dihydroxybiphenyl; _C2-4 alkylene oxides of bisphenol A, such as 2 moles of ethylene oxide adducts of bisphenol A, and 3 moles of propylene oxide adducts of bisphenol A. Adducts; or ester-forming derivatives (acetylated products, etc.) of these glycols can be used. These glycol components can be used alone or in combination of two or more.

Among these glycol components, _C2-6 alkylene glycols such as ethylene glycol and trimethylene glycol, polyoxyalkylene glycols such as diethylene glycol, or alicyclic diols such as cyclohexanedimethanol are more preferred.

Comonomer components that can be used in addition to dicarboxylic acid components and glycol components include, for example, 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 4-carboxy-4'-hydroxybiphenyl, etc. Aromatic hydroxycarboxylic acids; aliphatic hydroxycarboxylic acids such as glycolic acid and hydroxycaproic acid; _C3-12 lactones such as propiolactone, butyrolactone, valerolactone, caprolactone (ε-caprolactone, etc.); esters of these comonomer components Formative derivatives (C _1-6 alkyl ester derivatives, acid halides, acetylated products, etc.) can be mentioned.

(A) The content of polybutylene terephthalate resin is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, and 30 to 70% by mass of the total mass of the resin composition. is even more preferable.

((B) Halogenated epoxy flame retardant)
The epoxy compound used in the halogenated epoxy flame retardant of the present invention contains one or more epoxy groups in one molecule. As the epoxy compound, it is preferable to use an aromatic epoxy compound from the viewpoint of improving thermal stability and hydrolysis resistance. Examples of aromatic epoxy compounds include biphenyl type epoxy compounds, bisphenol A type epoxy compounds, phenol novolac type epoxy compounds, and cresol novolac type epoxy compounds. It is also possible to use any combination of two or more compounds as the epoxy compound.

The epoxy equivalent of the above epoxy compound is preferably 30,000 g/eq or more, more preferably 32,000 g/eq or more, even more preferably 34,000 g/eq or more. , more preferably 36,000 g/eq or more, particularly preferably 36,500 g/eq or more. By setting the epoxy equivalent within this range, the appearance of the molded product obtained from the flame-retardant polybutylene terephthalate resin composition of the present invention can be made good, and the screw of the extruder or molding machine during molding can be improved. It is possible to suppress the occurrence of deposits on the surface. Moreover, the mechanical properties of molded articles obtained from the flame-retardant polybutylene terephthalate resin composition of the present invention can be made to have good values.

Further, the halogenated epoxy flame retardant of the present invention is preferably a brominated epoxy flame retardant.

As described above, the content of the organic solvent selected from the group consisting of toluene, methyl isobutyl ketone, methyl ethyl ketone, and acetone in the halogenated epoxy flame retardant of the present invention is 50 ppm or less. Further, the content of the organic solvent is preferably 40 ppm or less, more preferably 30 ppm or less, even more preferably 20 ppm or less, even more preferably 10 ppm or less, and even more preferably 8 ppm or less. Particularly preferred. By controlling the content of the organic solvent in the halogenated epoxy flame retardant within this range, the appearance of the molded product obtained from the flame-retardant polybutylene terephthalate resin composition of the present invention can be improved. It is possible to suppress the occurrence of deposits on the extruder or the screw of the molding machine during molding, and the contamination of the carbide. Moreover, the mechanical properties of molded articles obtained from the flame-retardant polybutylene terephthalate resin composition of the present invention can be made to have good values.

(Total content of epoxy groups in the entire flame-retardant polybutylene terephthalate resin composition)
As mentioned above, the total content of epoxy groups in the entire flame-retardant polybutylene terephthalate resin composition of the present invention is 0.0155 mol/kg or less. Further, the total content of epoxy groups in the entire composition is preferably 0.0150 mol/kg or less, more preferably 0.0145 mol/kg or less, and even more preferably 0.0130 mol/kg or less. More preferably, it is particularly preferably 0.0100 mol/kg or less. By keeping the total content of epoxy groups in the entire flame-retardant polybutylene terephthalate resin composition within this range, the appearance of the molded product obtained from the flame-retardant polybutylene terephthalate resin composition of the present invention can be improved. Therefore, it is possible to suppress the occurrence of deposits on the extruder or the screw of the molding machine during molding, and the contamination of the carbide. Moreover, the mechanical properties of molded articles obtained from the flame-retardant polybutylene terephthalate resin composition of the present invention can be made to have good values.

(Flame retardant aid)
It is preferable that the flame-retardant polybutylene terephthalate resin composition of the present invention further contains a flame-retardant auxiliary agent. The flame retardant aid is not particularly limited, but a flame retardant aid selected from the group consisting of antimony pentoxide, antimony trioxide, and sodium antimonate is preferred, and antimony pentoxide and antimony trioxide are more preferred.

Furthermore, in order to prevent the spread of fire due to dripping of burned resin, it is also preferable to use a dripping prevention agent such as polytetrafluoroethylene.

The range of addition of the above halogenated epoxy flame retardant and flame retardant aid to the resin is preferably 3 to 50 parts by mass of the halogenated epoxy flame retardant to 100 parts by mass of the polybutylene terephthalate resin, and 5 parts by mass of the halogenated epoxy flame retardant. It is more preferably 10 to 30 parts by weight, and even more preferably 10 to 30 parts by weight. In addition, the total content of epoxy groups can be determined by taking into account the content of epoxy compounds (epoxy resins, etc.) added as additives for improving heat shock resistance, which will be described later, in addition to the halogenated epoxy flame retardant. good. Further, the amount of the flame retardant aid is preferably in the range of 1 to 40 parts by mass. If the amount of the halogenated epoxy flame retardant and flame retardant aid added is too small, sufficient flame retardancy cannot be imparted, and if the amount is too large, the mechanical properties of the molded product may deteriorate.

((C) Resin for improving heat shock resistance)
(C) Resin for improving heat shock resistance used in the present invention is required when a molded article made of the flame-retardant polybutylene terephthalate resin composition of the present invention is used in an environment where heating and cooling are repeated. Added to improve heat shock resistance.

(C) As the resin for improving heat shock resistance, an elastic material such as rubber or elastomer is used to impart toughness to the polybutylene terephthalate resin composition, so that it can absorb the distortion that occurs in the molded product. It is preferable to use, and specific examples include olefin elastomer, core-shell elastomer, diene elastomer, polyester elastomer, urethane elastomer, silicone elastomer, styrene elastomer, polyamide elastomer, etc. , or a combination of two or more types.

Examples of the olefin elastomer include ethylene-propylene copolymer (EP copolymer), ethylene-butene copolymer, ethylene-octene copolymer, ethylene-propylene-diene copolymer (EPD copolymer), Copolymer containing at least one unit selected from ethylene-propylene-butene copolymer, ethylene-vinyl acetate copolymer, EP copolymer and EPD copolymer, olefin and (meth)acrylic monomer copolymer with ethylene-ethyl acrylate copolymer, ethylene-glycidyl methacrylate copolymer, α-olefin/α,β-unsaturated carboxylic acid (ester)/α,β-unsaturated carboxylic acid glycidyl ester series Examples include ethylene copolymers obtained by copolymerizing original copolymers and ethylene (co)polymers with maleic anhydride or glycidyl methacrylate. Preferred olefin elastomers include EP copolymers, EPD copolymers, and copolymers of olefin and (meth)acrylic monomers, with ethylene ethyl acrylate being particularly preferred. These olefin elastomers can be used alone or in combination of two or more.

A core-shell elastomer is a polymer in which the core layer is composed of a rubber component (soft component) and the shell layer is composed of a hard component, and acrylic rubber or the like is used as the rubber component of the core layer. The rubber component used in the core layer preferably has a glass transition temperature (Tg) of less than 0°C (for example, -10°C or less), and preferably -20°C or less (for example, -180°C or more and -25°C or less). More preferably, the temperature is −30° C. or lower (for example, −150° C. or higher and −40° C. or lower), particularly preferably.

When using an acrylic rubber as the rubber component, a polymer obtained by polymerizing an acrylic monomer such as an alkyl acrylate as a main component is preferred. The alkyl acrylate used as the monomer of the acrylic rubber is preferably a C1 to C12 alkyl ester of acrylic acid such as butyl acrylate, and more preferably a _C2 to _C6 alkyl ester of acrylic acid.

The acrylic rubber may be a homopolymer or a copolymer of acrylic monomers. When the acrylic rubber is a copolymer of acrylic monomers, it may be a copolymer of acrylic monomers or a copolymer of an acrylic monomer and another unsaturated bond-containing monomer. When the acrylic rubber is a copolymer, the acrylic rubber may be one obtained by copolymerizing a crosslinkable monomer.

A vinyl polymer is preferably used for the shell layer. The vinyl polymer contains, for example, at least one monomer selected from aromatic vinyl monomers, vinyl cyanide monomers, methacrylic acid ester monomers, and acrylic acid ester monomers. Obtained by polymerization or copolymerization. The core layer and shell layer of such a core-shell elastomer may be bonded together by graft copolymerization. This graft copolymerization can be achieved, if necessary, by adding a graft cross-agent that reacts with the shell layer during polymerization of the core layer to provide a reactive group to the core layer and then forming the shell layer. When a silicone rubber is used as the graft cross agent, an organosiloxane having a vinyl bond or an organosiloxane having a thiol is used, and acroxysiloxane, methacryloxysiloxane, and vinylsiloxane are preferably used.

As the polyester elastomer, either an ester-ester type in which both the hard segment and the soft segment have a polyester unit structure, or an ester-ether type in which the soft segment has a polyether unit structure can be preferably used. The former is more preferable in terms of heat resistance, and the latter is more preferable in terms of dimensional accuracy. As the polyester unit structure of the heart segment, aromatic polyester units such as polybutylene terephthalate and polyethylene terephthalate can be preferably used, and as the polyester units of the soft segment, aliphatic polyester units such as polyethylene adipate, polybutylene adipate, and polycaprolactone are preferably used. As the polyether unit of the soft segment, polyethylene glycol and polytetramethylene glycol can be preferably used, but the invention is not limited thereto.

Examples of urethane elastomers include reacting diisocyanates such as 4,4'-diphenylmethane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, tolylene diisocyanate, and hexamethylene diisocyanate with glycols such as ethylene glycol and tetramethylene glycol. Examples include block copolymers in which the hard segment is polyurethane obtained by polyurethane, and the soft segment is polyether such as polyethylene glycol, polypropylene glycol, or polytetramethylene glycol, or aliphatic polyester such as polyethylene adipate, polybutylene adipate, or polycaprolactone. However, it is not limited to this.

Examples of styrenic elastomers include acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-butadiene copolymer, styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, and styrene-ethylene copolymer. -butadiene-styrene copolymer, acrylonitrile-styrene-epoxy group-containing vinyl copolymer, etc., and these can be used alone or in combination of two or more.

Examples of polyamide-based elastomers include, but are not limited to, block copolymers in which nylon 6, nylon 66, nylon 11, nylon 12, etc. are used as hard segments and polyether or aliphatic polyester is used as soft segments. It's not a thing. Although not strictly classified as an elastomer, aliphatic polyamides can also be used as the polyamide elastomer in the present invention.

(C) The amount of the heat shock resistance improving resin added is 5 to 100 parts by weight, and may be 10 to 90 parts by weight or 20 to 80 parts by weight, based on 100 parts by weight of the polybutylene terephthalate resin. However, if a resin with low flame retardancy is added, adding a large amount may worsen the combustibility of the composition, so the content of the alloy resin for improving dimensional accuracy is determined by the flame retardant polybutylene terephthalate of the present invention. It is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the entire resin composition.

(D) As a filler for improving heat shock resistance, it is used within the processing temperature range of resin molded products in the sense of reducing distortion generated in molded products by reducing the shrinkage rate and coefficient of linear expansion of polybutylene terephthalate resin. Inorganic fillers and metal fillers are preferable because they have a small shrinkage coefficient and linear expansion coefficient in the operating temperature range.For molded products used as insulating members combined with metal members, inorganic fillers are used to ensure insulation properties. It is particularly preferable to use

(D) The shape of the filler for improving heat shock resistance may be a fibrous filler, a plate-like filler, a spherical filler, a powder filler, a curved filler, an amorphous filler, or a combination thereof. However, in order to suppress destruction due to heat shock, it is preferable to reduce the anisotropy of contraction and linear expansion, so it is desirable that the filler itself has small anisotropy. It is more preferable to use a filler having an aspect ratio close to 1, such as a plate filler, a spherical filler, or a powder filler. On the other hand, when using a fibrous filler such as glass fiber, the effect of improving mechanical properties such as tensile strength is large, but due to the orientation of the fibrous filler, the anisotropy of the shrinkage rate tends to increase. Therefore, fibrous fillers include short fibers such as milled fibers and whiskers, and flat shapes such as cocoon-shaped, oval, and elliptical cross sections (for example, the ratio of the major axis to the minor axis of the cross section is 1.3 to 10). It is more preferable to use fibers with a relatively small aspect ratio, such as fibers with a relatively small aspect ratio. In particular, it is preferable to use glass fibers with a flat cross section because both heat shock resistance and mechanical properties can be improved.

Specific examples of plate-shaped fillers include plate-shaped talc, mica, glass flakes, metal pieces, and combinations thereof. Specific examples of spherical fillers include glass beads, glass balloons, spherical silica, and the like. Examples of the powder filler include glass powder, talc powder, quartz powder, quartz powder, kaolin, clay, diatomaceous earth, wollastonite, silicon carbide, silicon nitride, metal powder, and inorganic acid metal. Powders of salts (calcium carbonate, zinc borate, calcium borate, zinc stannate, calcium sulfate, barium sulfate, etc.), powders of metal oxides (magnesium oxide, iron oxide, titanium oxide, zinc oxide, alumina, etc.), metals Powders of hydroxides (aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, alumina hydrate (boehmite), etc.), powders of metal sulfides (zinc sulfide, molybdenum sulfide, tungsten sulfide, etc.), and combinations thereof, etc. can be mentioned. In addition, from the viewpoint of metal corrosion resistance, it is preferable that the content of free inorganic acid contained in these fillers for improving heat shock resistance (D) is 0.5% by mass or less, respectively.

(D) The size of the filler for improving heat shock resistance can be appropriately selected in consideration of the balance between the warpage reducing effect, mechanical properties, fluidity, etc. For example, as talc, talc with a volume average particle diameter of 1 to 10 μm or compressed fine powder talc with a bulk specific gravity of 0.4 to 1.5 can be suitably used, and as mica, talc with a volume average particle diameter of 10 to 1.5 can be suitably used. Mica of 60 μm can be suitably used.

These fillers (D) for improving heat shock resistance may be surface-treated (surface-coated) with an inorganic compound and/or an organic compound, and examples of the inorganic compound used for surface treatment include aluminum hydroxide. Preferred examples include inorganic oxides and hydroxides of aluminum, silicon, zirconium, cerium, etc., alumina, silica, zirconia, zirconium hydroxide, zirconia hydrate, cerium oxide, cerium oxide hydrate, cerium hydroxide, etc. . Moreover, these inorganic compounds may be hydrates. Among these, aluminum hydroxide and silica are preferable, and when silica is used, a silica hydrate represented by SiO ₂ ·nH ₂ O is particularly preferable. Further, the organic compound used for surface treatment is not particularly limited, and known compounds such as amine compounds such as monoethanolamine, diethanolamine, triethanolamine, and dichlorohexylamine can be used.

(D) The amount of the filler for improving heat shock resistance is 10 to 200 parts by weight, and may be 20 to 180 parts by weight or 30 to 150 parts by weight, based on 100 parts by weight of the polybutylene terephthalate resin. (D) The amount of the filler for improving heat shock resistance can be appropriately selected in consideration of the balance between the effect of improving heat shock resistance, mechanical properties, fluidity, etc.

(E) Examples of additives for improving heat shock resistance include carbodiimide compounds, epoxy compounds, oxazoline compounds, oxazine compounds, aromatic polycarboxylic acid esters, etc. One type or a combination of two or more of these can be used. Can be used.

As the carbodiimide compound, a compound having at least one carbodiimide group represented by (-N=C=N-) in the molecule can be used. , can be produced by heating organic isocyanate and decarboxylating it.

Examples of carbodiimide compounds include diphenylcarbodiimide, di-cyclohexylcarbodiimide, di-2,6-dimethylphenylcarbodiimide, diisopropylcarbodiimide, dioctyldecylcarbodiimide, di-o-tolylcarbodiimide, di-p-tolylcarbodiimide, di-p- Nitrophenylcarbodiimide, di-p-aminophenylcarbodiimide, di-p-hydroxyphenylcarbodiimide, di-p-chlorophenylcarbodiimide, di-o-chlorophenylcarbodiimide, di-3,4-dichlorophenylcarbodiimide, di-2 , 5-dichlorophenylcarbodiimide, p-phenylene-bis-o-tolylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, p-phenylene-bis-di-p-chlorophenylcarbodiimide, 2,6,2',6 '-tetraisopropyldiphenylcarbodiimide, hexamethylene-bis-cyclohexylcarbodiimide, ethylene-bis-diphenylcarbodiimide, ethylene-bis-di-cyclohexylcarbodiimide, N,N'-di-o-triylcarbodiimide, N,N'-diphenyl Carbodiimide, N,N'-dioctyldecylcarbodiimide, N,N'-di-2,6-dimethylphenylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N,N'-di-2,6-diisopropylphenylcarbodiimide , N,N'-di-2,6-di-tert-butylphenylcarbodiimide, N-tolyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di- p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, N,N'-di-p-tolylcarbodiimide, N,N'-benzylcarbodiimide, N -Octadecyl-N'-phenylcarbodiimide, N-benzyl-N'-phenylcarbodiimide, N-octadecyl-N'-tolylcarbodiimide, N-cyclohexyl-N'-tolylcarbodiimide, N-phenyl-N'-tolylcarbodiimide, N -benzyl-N'-tolylcarbodiimide, N,N'-di-o-ethylphenylcarbodiimide, N,N'-di-p-ethylphenylcarbodiimide, N,N'-di-o-isopropylphenylcarbodiimide, N, N'-di-p-isopropylphenylcarbodiimide, N,N'-di-o-isobutylphenylcarbodiimide, N,N'-di-p-isobutylphenylcarbodiimide, N,N'-di-2,6-diethylphenyl Carbodiimide, N,N'-di-2-ethyl-6-isopropylphenylcarbodiimide, N,N'-di-2-isobutyl-6-isopropylphenylcarbodiimide, N,N'-di-2,4,6-trimethyl Mono- or dicarbodiimide compounds such as phenylcarbodiimide, N,N'-di-2,4,6-triisopropylphenylcarbodiimide, N,N'-di-2,4,6-triisobutylphenylcarbodiimide, poly(1, 6-hexamethylenecarbodiimide), poly(4,4'-methylenebiscyclohexylcarbodiimide), poly(1,3-cyclohexylenecarbodiimide), poly(1,4-cyclohexylenecarbodiimide), poly(4,4'-diphenylmethane) poly(3,3'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(tolylcarbodiimide), Examples include polycarbodiimides such as poly(diisopropylcarbodiimide), poly(methyl-diisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide). Furthermore, xylylene-based polycarbodiimides synthesized from m-xylylene diisocyanate, p-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, p-tetramethylxylylene diisocyanate, etc. can also be used as the polycarbodiimide. Furthermore, a carbodiimide compound obtained by reacting a diisocyanate compound with a diol compound such as a polyether polyol, a polyester polyol, a polycarbonate polyol, a silicone diol, a polyolefin polyol, a polyurethane polyol, or an alkylene (carbon number 21 or more) diol can also be used. Among these, aromatic carbodiimides such as N,N'-di-2,6-diisopropylphenylcarbodiimide and 2,6,2',6'-tetraisopropyldiphenylcarbodiimide are preferred from the viewpoint of heat resistance; Carbodiimides are preferred.

The epoxy compound may be any compound containing an epoxy group in its molecular structure, and preferably glycidyl ether compounds, glycidyl ester compounds, glycidyl amine compounds, glycidylimide compounds, and alicyclic epoxy compounds can be used.

Examples of glycidyl ether compounds include butyl glycidyl ether, stearyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, o-phenylphenyl glycidyl ether, ethylene oxide lauryl alcohol glycidyl ether, ethylene oxide phenol glycidyl ether, ethylene glycol diglycidyl ether, and polyethylene glycol. diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, The combination of bisphenols such as pentaerythritol polyglycidyl ether, 2,2-bis-(4-hydroxyphenyl)propane, 2,2-bis-(4-hydroxyphenyl)methane, and bis(4-hydroxyphenyl)sulfone with epichlorohydrin. Examples include bisphenol A diglycidyl ether type epoxy resin, bisphenol F diglycidyl ether type epoxy resin, bisphenol S diglycidyl ether type epoxy resin, etc. obtained from a condensation reaction. Among these, bisphenol A diglycidyl ether type epoxy resin is preferred.

Examples of glycidyl ester compounds include glycidyl benzoate, glycidyl p-toluate, glycidyl cyclohexanecarboxylate, glycidyl stearate, glycidyl laurate, glycidyl palmitate, glycidyl versatate, and glycidyl oleate. Esters, linoleic acid glycidyl ester, linolenic acid glycidyl ester, terephthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, phthalic acid diglycidyl ester, naphthalene dicarboxylic acid diglycidyl ester, bibenzoic acid diglycidyl ester, methylterephthalic acid diglycidyl ester , hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, cyclohexanedicarboxylic acid diglycidyl ester, adipic acid diglycidyl ester, succinic acid diglycidyl ester, sebacic acid diglycidyl ester, dodecanedioic acid diglycidyl ester, octadecanedicarbone Examples include acid diglycidyl ester, trimellitic acid triglycidyl ester, and pyromellitic acid tetraglycidyl ester. Among these, benzoic acid glycidyl ester and versatile acid glycidyl ester are preferred.

Examples of glycidylamine compounds include tetraglycidyl aminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, diglycidylaniline, diglycidyltoluidine, tetraglycidylmethaxylene diamine, diglycidyltribromoaniline, tetra Examples include glycidyl bisaminomethylcyclohexane, triglycidyl cyanurate, and triglycidyl isocyanurate.

Examples of glycidyl imide compounds include N-glycidyl phthalimide, N-glycidyl-4-methylphthalimide, N-glycidyl-4,5-dimethylphthalimide, N-glycidyl-3-methylphthalimide, N-glycidyl-3,6- Dimethylphthalimide, N-glycidyl-4-ethoxyphthalimide, N-glycidyl-4-chlorophthalimide, N-glycidyl-4,5-dichlorophthalimide, N-glycidyl-3,4,5,6-tetrabromphthalimide, N -Glycidyl-4-n-butyl-5-bromphthalimide, N-glycidylsuccinimide, N-glycidylhexahydrophthalimide, N-glycidyl-1,2,3,6-tetrahydrophthalimide, N-glycidylmaleimide, N- Glycidyl-α,β-dimethylsuccinimide, N-glycidyl-α-ethylsuccinimide, N-glycidyl-α-propylsuccinimide, N-glycidylbenzamide, N-glycidyl-p-methylbenzamide, N-glycidylnaphthamide, Examples include N-glycidyl steramide. Among them, N-glycidyl phthalimide is preferred.

Examples of cycloaliphatic epoxy compounds include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, vinylcyclohexene diepoxide, N-methyl-4, 5-Epoxycyclohexane-1,2-dicarboxylic imide, N-ethyl-4,5-epoxycyclohexane-1,2-dicarboxylic imide, N-phenyl-4,5-epoxycyclohexane-1,2-dicarboxylic imide , N-naphthyl-4,5-epoxycyclohexane-1,2-dicarboxylic acid imide, and N-tolyl-3-methyl-4,5-epoxycyclohexane-1,2-dicarboxylic acid imide.

Further, as other epoxy compounds, epoxy-modified fatty acid glycerides such as epoxidized soybean oil, epoxidized linseed oil, and epoxidized whale oil, phenol novolac type epoxy resins, cresol nosolac type epoxy resins, etc. can be used.

Furthermore, epoxy compounds such as glycidyl esters of α,β-unsaturated acids, such as glycidyl acrylate, glycidyl methacrylate, and glycidyl ethacrylate, can be copolymerized with other monomers by random, block or graft copolymerization. Epoxy-modified resins or epoxy-modified elastomers copolymerized with epoxy-modified resins or epoxy-modified elastomers, specifically, glycidyl group-containing copolymers consisting of α-olefins and glycidyl esters of α,β-unsaturated acids, and epoxy-containing vinyl monomers. A polyorganosiloxane/polyalkyl (meth)acrylate composite rubber graft copolymer obtained by graft polymerization of polymers, a styrene/butadiene copolymer elastomer having an epoxy group in the main chain, and the like can also be used.

Examples of oxazoline compounds include 2-methoxy-2-oxazoline, 2-ethoxy-2-oxazoline, 2-propoxy-2-oxazoline, 2-butoxy-2-oxazoline, 2-pentyloxy-2-oxazoline, 2- Hexyloxy-2-oxazoline, 2-heptyloxy-2-oxazoline, 2-octyloxy-2-oxazoline, 2-nonyloxy-2-oxazoline, 2-decyloxy-2-oxazoline, 2-cyclopentyloxy-2-oxazoline, 2-Cyclohexyloxy-2-oxazoline, 2-allyloxy-2-oxazoline, 2-methallyloxy-2-oxazoline, 2-crotyloxy-2-oxazoline, 2-phenoxy-2-oxazoline, 2-cresyl-2-oxazoline , 2-o-ethylphenoxy-2-oxazoline, 2-o-propylphenoxy-2-oxazoline, 2-o-phenylphenoxy-2-oxazoline, 2-m-ethylphenoxy-2-oxazoline, 2-m-propyl Phenoxy-2-oxazoline, 2-p-phenylphenoxy-2-oxazoline, 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-propyl-2-oxazoline, 2-butyl-2-oxazoline, 2 -Pentyl-2-oxazoline, 2-hexyl-2-oxazoline, 2-heptyl-2-oxazoline, 2-octyl-2-oxazoline, 2-nonyl-2-oxazoline, 2-decyl-2-oxazoline, 2-cyclopentyl -2-oxazoline, 2-cyclohexyl-2-oxazoline, 2-allyl-2-oxazoline, 2-methallyl-2-oxazoline, 2-crotyl-2-oxazoline, 2-phenyl-2-oxazoline, 2-o-ethyl Phenyl-2-oxazoline, 2-o-propylphenyl-2-oxazoline, 2-o-phenylphenyl-2-oxazoline, 2-m-ethylphenyl-2-oxazoline, 2-m-propylphenyl-2-oxazoline, 2-p-phenylphenyl-2-oxazoline, 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(4,4' -dimethyl-2-oxazoline), 2,2'-bis(4-ethyl-2-oxazoline), 2,2'-bis(4,4'-diethyl-2-oxazoline), 2,2'-bis( 4-propyl-2-oxazoline), 2,2'-bis(4-butyl-2-oxazoline), 2,2'-bis(4-hexyl-2-oxazoline), 2,2'-bis(4- phenyl-2-oxazoline), 2,2'-bis(4-cyclohexyl-2-oxazoline), 2,2'-bis(4-benzyl-2-oxazoline), 2,2'-p-phenylenebis(2 -oxazoline), 2,2'-m-phenylenebis(2-oxazoline), 2,2'-o-phenylenebis(2-oxazoline), 2,2'-p-phenylenebis(4-methyl-2- oxazoline), 2,2'-p-phenylenebis(4,4'-dimethyl-2-oxazoline), 2,2'-m-phenylenebis(4-methyl-2-oxazoline), 2,2'-m -phenylenebis(4,4'-dimethyl-2-oxazoline), 2,2'-ethylenebis(2-oxazoline), 2,2'-tetramethylenebis(2-oxazoline), 2,2'-hexamethylene Bis(2-oxazoline), 2,2'-octamethylenebis(2-oxazoline), 2,2'-decamethylenebis(2-oxazoline), 2,2'-ethylenebis(4-methyl-2-oxazoline) ), 2,2'-tetramethylenebis(4,4'-dimethyl-2-oxazoline), 2,2'-9,9'-diphenoxyethanebis(2-oxazoline), 2,2'-cyclohexylene Bis(2-oxazoline), 2,2'-diphenylenebis(2-oxazoline) and the like can be mentioned. Further examples include polyoxazoline compounds containing the above-mentioned compounds as monomer units.

Examples of oxazine compounds include 2-methoxy-5,6-dihydro-4H-1,3-oxazine, 2-ethoxy-5,6-dihydro-4H-1,3-oxazine, 2-propoxy-5,6 -dihydro-4H-1,3-oxazine, 2-butoxy-5,6-dihydro-4H-1,3-oxazine, 2-pentyloxy-5,6-dihydro-4H-1,3-oxazine, 2- Hexyloxy-5,6-dihydro-4H-1,3-oxazine, 2-heptyloxy-5,6-dihydro-4H-1,3-oxazine, 2-octyloxy-5,6-dihydro-4H-1 ,3-oxazine, 2-nonyloxy-5,6-dihydro-4H-1,3-oxazine, 2-decyloxy-5,6-dihydro-4H-1,3-oxazine, 2-cyclopentyloxy-5,6- Dihydro-4H-1,3-oxazine, 2-cyclohexyloxy-5,6-dihydro-4H-1,3-oxazine, 2-allyloxy-5,6-dihydro-4H-1,3-oxazine, 2-meth Examples include allyloxy-5,6-dihydro-4H-1,3-oxazine, 2-crotyloxy-5,6-dihydro-4H-1,3-oxazine, and furthermore, 2,2'-bis(5 , 6-dihydro-4H-1,3-oxazine), 2,2'-methylenebis(5,6-dihydro-4H-1,3-oxazine), 2,2'-ethylenebis(5,6-dihydro- 4H-1,3-oxazine), 2,2'-propylene bis(5,6-dihydro-4H-1,3-oxazine), 2,2'-butylene bis(5,6-dihydro-4H-1,3 -oxazine), 2,2'-hexamethylenebis(5,6-dihydro-4H-1,3-oxazine), 2,2'-p-phenylenebis(5,6-dihydro-4H-1,3- oxazine), 2,2'-m-phenylenebis(5,6-dihydro-4H-1,3-oxazine), 2,2'-naphthylenebis(5,6-dihydro-4H-1,3-oxazine), Examples include 2,2'-P,P'-diphenylenebis(5,6-dihydro-4H-1,3-oxazine). Further examples include polyoxazine compounds containing the above-mentioned compounds as monomer units.

Among the above oxazoline compounds and oxazine compounds, 2,2'-m-phenylenebis(2-oxazoline) and 2,2'-p-phenylenebis(2-oxazoline) are preferred.

Preferred examples of the aromatic polycarboxylic acid ester include trimellitic acid ester and pyromellitic acid ester, with alkyl esters being particularly preferred. Examples of the alkyl group constituting this alkyl ester include a trioctyl group, triisodecyl group, tris(2-ethylhexyl) group, and tributyl group, and any one or a combination of two or more of these may be used. Such aromatic polyhydric carboxylic acid esters can be used alone or in combination of two or more kinds.

(E) The amount of the additive for improving heat shock resistance is 0.1 to 30 parts by weight, preferably 0.2 to 20 parts by weight, per 100 parts by weight of the polybutylene terephthalate resin. More preferably, the amount is .3 to 10 parts by mass.

Furthermore, the amount of the additive for improving heat shock resistance (E) is the total amount of carbodiimide groups, epoxy groups, oxazoline groups, oxazine rings, and ester groups, with the amount of terminal carboxyl groups in the polybutylene terephthalate resin composition being 1. The functional group content may be set to 0.3 to 5 equivalents. The preferred total functional group content is 0.5 to 3 equivalents, more preferably 0.8 to 2 equivalents.

(Additives) Additives are generally added to thermoplastic resins, etc. to improve heat shock resistance, if necessary, in order to impart desired properties other than flame retardancy and heat shock resistance to the composition of the present invention. Known substances other than those that fall under the category of additives can be added and used in combination. For example, antioxidants, ultraviolet absorbers, stabilizers such as light stabilizers, antistatic agents, lubricants, mold release agents, colorants such as dyes and pigments, plasticizers, fluidity improvers, toughness improvers, impact resistance. It is possible to mix any of the following: an improving agent, a resin other than the resin for improving heat shock resistance, a filler other than the filler for improving heat shock resistance, etc.

In addition, when using an inorganic pigment such as carbon black as a coloring agent, it is preferable to use one with an average primary particle diameter of 10 to 100 nm, and use one with an average primary particle size of 25 to 50 nm, in terms of suppressing a decrease in heat shock resistance. It is more preferable. In addition, the average primary particle diameter here is the arithmetic mean particle diameter determined by electron microscopic observation of 1000 colorants before being blended into the resin composition.

In addition, when adding a coloring agent, first melt-knead with (A) polybutylene terephthalate resin or (C) resin used as heat shock resistance improving resin, or other resin that is highly compatible with polybutylene terephthalate resin. It is preferable to add it in the form of a masterbatch because it can further suppress a decrease in heat shock resistance.

[Method for producing flame-retardant polybutylene terephthalate resin composition]
The flame-retardant polybutylene terephthalate resin composition of the present invention may be in the form of a powder mixture or a molten mixture (melt-kneaded product) such as pellets. The method for producing the polybutylene terephthalate resin composition of one embodiment of the present invention is not particularly limited, and can be produced using equipment and methods known in the technical field. For example, the necessary components can be mixed and kneaded using a single-screw or twin-screw extruder or other melt-kneading equipment to prepare pellets for molding. A plurality of extruders or other melt-kneading devices may be used. Furthermore, all the components may be introduced from the hopper at the same time, or some components may be introduced from the side feed port.

Furthermore, the flame-retardant polybutylene terephthalate resin composition of the present invention is vacuum-dried at the stage of each component (raw material) to be supplied to the above-mentioned melt-kneading and/or at the stage of pellets when molded into a molded article. It is preferable to remove water by drying (vacuum drying step). For vacuum drying, a commonly used evaporator, oven, etc. can be used.

[Molded product obtained from flame-retardant polybutylene terephthalate resin composition]
The flame-retardant polybutylene terephthalate resin composition of the present invention can be used for electrical and electronic components such as relays, switches, connectors, actuators, sensors, transformer bobbins, terminal blocks, covers, switches, sockets, coils, and plugs, especially power supplies. It can be preferably used as surrounding parts. Furthermore, it is suitably used as a molding material for automotive parts such as cases for automotive components such as ECU boxes and connector boxes, and automotive electrical components.

There is no particular limitation on the method for obtaining a molded article using this flame-retardant polybutylene terephthalate resin composition, and any known method can be employed. For example, a flame retardant polybutylene terephthalate resin composition is put into an extruder, melted and kneaded to form pellets, and the pellets are put into an injection molding machine equipped with a predetermined mold and injection molded. I can do it.

Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. In addition, the characteristic evaluation was performed by the following method.

(1) Flame retardancy A dry-blended material with the components and composition (parts by mass) shown in Table 1 is supplied to a twin-screw extruder (manufactured by Japan Steel Works, Ltd.) with a 30 mmφ screw and melted at 260°C. After kneading and drying the obtained pellets of the polybutylene terephthalate resin composition at 140°C for 3 hours, injection molding was performed at a cylinder temperature of 250°C and a mold temperature of 70°C, and the resulting pellets conformed to UL94 and had a thickness of 1. /32 inch test pieces were prepared to evaluate flammability. The results are shown in Table 1.

(2) Heat shock resistance A dry-blended material with the ingredients and composition (parts by mass) shown in Table 1 was supplied to a twin-screw extruder (manufactured by Japan Steel Works, Ltd.) with a 30 mmφ screw and heated at 260°C. The pellets of the polybutylene terephthalate resin composition obtained by melt-kneading were dried at 140°C for 3 hours, and then injection molded at a cylinder temperature of 260°C and a mold temperature of 80°C to obtain the test pieces shown in Figures 1 and 2. was insert molded and evaluated for heat shock resistance. FIG. 1 is a diagram showing an insert-molded test piece 10, and FIG. 2 is a diagram showing an insert member 2. As shown in FIG. 1, the test piece 10 has a rectangular prism-shaped insert member 2 made of metal embedded in a rectangular prism-shaped resin member 1 made of a thermoplastic aromatic polyester resin composition. The resin member 1 is molded using the resin composition pellets obtained as described above. As shown in FIG. 2, the insert member 2 has a structure including a square columnar upper part 2a, a square columnar lower part 2b, and a columnar constricted part 2c connecting the two. In the insert member 2, a lower part 2b and a constricted part 2c are embedded in the resin member 1, and an upper part 2a is exposed from the upper surface of the resin member 1 (see FIG. 1(A)). Furthermore, as shown in FIG. 1(B), the corners of the resin member 1 and the corners of the insert member 2 are arranged so as to be located in different directions. That is, the corner portion of the insert member 2 is arranged so as to face the side surface of the resin member 1. The distance between the tip of the corner of the insert member 2 and the side surface of the resin member 1 is about 1 mm. In the resin member 1, the vicinity of the tip of the corner (sharp corner) of the insert member 2 is a thin portion. The above test piece 10 was cooled at -40°C for 1.5 hours and then heated at 180°C for 1.5 hours using a thermal shock tester (manufactured by ESPEC Co., Ltd.) for 20 cycles. The weld part was observed every time. The number of cycles at which cracks occurred in the weld portion was used as an index of heat shock resistance, and evaluation was made as ◎ for 200 cycles or more, ○ for 100 cycles or more, and × for less than 100 cycles. The results are shown in Table 1.

(3) Screw deposits Pellets of the polybutylene terephthalate resin composition obtained in the same manner as in the evaluation of flame retardancy were dried at 140°C for 3 hours, and then melt-kneaded according to the following procedure to determine the amount of black deposits. were visually observed, and those with a significant amount of deposits were rated "x", those with a relatively small amount were rated "○", and those with a small amount were rated "◎". The results are shown in Table 1.
Procedure 1: A polybutylene terephthalate resin composition is extruded for 10 minutes at a cylinder temperature of 275° C. and a screw rotation speed of 20 rpm using a Laboplast Mill manufactured by Toyo Seiki Co., Ltd.
Step 2: Stop the screw while maintaining the cylinder temperature at 275°C, and let the polybutylene terephthalate resin composition in the cylinder stay for 120 minutes.
Step 3: Purge with the polybutylene terephthalate resin composition for 10 minutes at a cylinder temperature of 275° C. and a screw rotation speed of 21 rpm.
Step 4: Purge with polyethylene resin for 5 minutes at a cylinder temperature of 275° C. and a screw rotation speed of 60 rpm.
Step 5: Purge for 5 minutes using the purging material "Rioclean-Z" manufactured by Toyo Color Co., Ltd. at a cylinder temperature of 200° C. and a screw rotation speed of 60 rpm.
Step 6: Pull out the screw, wipe it lightly with cotton flannel to remove the purge material, and then observe the amount of black deposits on the screw.

(4) Flexural modulus After drying the pellets of the polybutylene terephthalate resin composition obtained in the same manner as in the evaluation of flame retardancy at 140°C for 3 hours, at a cylinder temperature of 250°C and a mold temperature of 70°C, A bending test piece of 80 mm x 10 mm x 4 mm was injection molded, and a bending test was performed at a pressing speed of 2.0 mm/min and a distance between fulcrums of 64 mm according to ISO178, and the bending elastic modulus was 8,000 MPa or more. It was evaluated as "○", and those under 8,000 MPa were evaluated as "x". The results are shown in Table 1.

表中の含有量の単位は、質量部である。

The unit of content in the table is parts by mass.

Details of each component listed in Table 1 are as follows.
(A) PBT resin: Polybutylene terephthalate resin manufactured by Wintec Polymer Co., Ltd., terminal carboxyl group concentration 20 meq/kg, intrinsic viscosity 0.7 dL/g (B-1) Brominated epoxy flame retardant 1: Epoxy equivalent 36800 g/ Brominated epoxy compound (B-2) Brominated epoxy flame retardant 2: Brominated epoxy compound with an epoxy equivalent of 43,200 g/eq, an organic solvent amount of 0 ppm, and a weight average molecular weight of about 20,000. Compound (B-3) Brominated epoxy flame retardant 3: Brominated epoxy compound with epoxy equivalent of 28,600 g/eq, organic solvent amount of 60 ppm, weight average molecular weight of about 9,000 (B-4) Brominated epoxy flame retardant 4: Epoxy equivalent Brominated epoxy compound (B'-1) with 19900 g/eq, organic solvent amount 4 ppm, weight average molecular weight about 23000 Brominated polyacrylate flame retardant: ICL JAPAN Co., Ltd., pentabromobenzyl polyacrylate FR-1025 (epoxy equivalent 0 g /eq)
(C) Resin EEA for improving heat shock resistance: manufactured by NUC, ethylene ethyl acrylate copolymer NUC-6570
EEA-g-BAMMA: Modiper A5300, a graft copolymer of ethylene ethyl acrylate and butyl acrylate-methyl methacrylate, manufactured by NOF Corporation
(D) Filler for improving heat shock resistance Circular cross-section GF: manufactured by Nippon Electric Glass Co., Ltd., ECS03T-127 (average fiber diameter 13 μm, average fiber length 3 mm)
Flat cross-section GF: manufactured by Nittobo Co., Ltd., CSG3PA830 (elliptical cross-section glass fiber with major axis 28 μm and minor axis 7 μm (major axis ÷ minor axis ratio = 4), average fiber length 3 mm)
(E) Additive for improving heat shock resistance Carboxylic acid ester: manufactured by ADEKA, pyromellitic acid ester ADEKAISER UL100
Carbodiimide: manufactured by Rhein Chemie Japan, aromatic polycarbodiimide STABAXOL P
Epoxy resin: manufactured by Mitsubishi Chemical Corporation, jER 1004K (epoxy equivalent: 925 g/eq)
Antimony trioxide: manufactured by Nippon Seiko Co., Ltd., PATOX-M
Anti-dripping agent: polytetrafluoroethylene resin

Claims (7)

(A) 100 parts by mass of polybutylene terephthalate resin;
(B) a halogenated epoxy flame retardant having a total organic solvent content of 50 ppm or less;
(C) 5 to 100 parts by mass of a resin for improving heat shock resistance;
(D) 10 to 200 parts by mass of a filler for improving heat shock resistance;
(E) containing 0.1 to 30 parts by mass of an additive for improving heat shock resistance;
A flame-retardant polybutylene terephthalate resin composition in which the total content of epoxy groups in the entire composition is 0.0155 mol/kg or less,
(C) The resin for improving heat shock resistance is one or more selected from olefin elastomer, core-shell elastomer, diene elastomer, polyester elastomer, urethane elastomer, silicone elastomer, styrene elastomer, and polyamide elastomer. including;
(D) the filler for improving heat shock resistance includes one or more selected from inorganic fillers and metal fillers,
(E) the heat shock resistance improving additive contains one or more selected from carbodiimide compounds, epoxy compounds, oxazoline compounds, oxazine compounds, aromatic polycarboxylic acid esters, and combinations thereof;
(B) A flame-retardant polybutylene terephthalate resin composition in which the epoxy equivalent of the halogenated epoxy flame retardant is 30,000 g/eq or more and 43,200 or less. (E) The flame-retardant polyester according to claim 1, wherein the additive for improving heat shock resistance contains an epoxy compound and one or more selected from carbodiimide compounds and aromatic polycarboxylic acid esters. Butylene terephthalate resin composition. The flame-retardant polybutylene terephthalate resin composition according to claim 1 or 2, wherein the content of the halogenated epoxy flame retardant (B) is 3 to 50 parts by mass based on 100 parts by mass of the polybutylene terephthalate resin. The flame-retardant polybutylene terephthalate resin composition according to any one of claims 1 to 3, wherein the halogenated epoxy flame retardant is a brominated epoxy flame retardant. The flame retardant polybutylene terephthalate resin composition according to any one of claims 1 to 4, further comprising a flame retardant aid selected from the group consisting of antimony pentoxide, antimony trioxide, and sodium antimonate. A molded article obtained by injection molding the flame-retardant polybutylene terephthalate resin composition according to any one of claims 1 to 5. The molded article according to claim 6, which is formed by insert molding a metal and/or an inorganic solid.

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