Resin composition and molded article

Abstract

The present invention provides a resin composition with excellent heat shock resistance and a molded product using the same. [Solution] (A) Polybutylene terephthalate resin, (B) Carbodiimide compounds, (C) Elastomer and, (D) Fibrous inorganic filler and A resin composition containing, The (B) carbodiimide compound comprises (b1) a cyclic carbodiimide compound and (b2) an aromatic carbodiimide compound. The total content of the (b1) cyclic carbodiimide compound and the (b2) aromatic carbodiimide compound is 0.6 to 2.0 parts by mass per 100 parts by mass of the (A) polybutylene terephthalate resin. The resin composition is one in which the mass ratio [(b1) / (b2)] of the cyclic carbodiimide compound (b1) to the aromatic carbodiimide compound (b2) is 0.2 to 1.6.

Description

[Technical Field]

[0001] This disclosure relates to resin compositions and molded articles. [Background technology]

[0002] Polybutylene terephthalate (PBT) resin has excellent mechanical, electrical, and moldability properties and is used in a wide range of applications, including automotive parts and electrical / electronic components. In particular, in the automotive field, it is used as a housing material for sensors and connectors used in electrical control, actuators, and ECUs. Since automotive parts are used in environments with large temperature fluctuations, composite molded products of metal and resin (insert molded products) are prone to cracking due to strain caused by the difference in linear expansion between metal and resin. To prevent cracking, it has been proposed to improve the toughness of the resin by adding various additives and elastomers.

[0003] Patent Document 1 describes a composition mainly composed of polybutylene terephthalate resin having a terminal carboxyl group content of 30 meq / kg or less, combined with a specific amount of carbodiimide compound, fibrous filler, and elastomer, which exhibits extremely excellent resistance to heat shock and hydrolysis without a significant decrease in mechanical properties. Patent Document 2 describes how to prepare a polybutylene terephthalate resin composition by blending a benzyl acrylate halogenate compound, an antimony oxide compound, a carbodiimide compound, and glass fibers as a filler with polybutylene terephthalate resin, thereby providing a polybutylene terephthalate resin composition with excellent heat shock resistance, flame retardancy, and hydrolysis resistance. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2009 / 150831 [Patent Document 2] International Publication No. 2011 / 058992 [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of this disclosure is to provide a resin composition with excellent heat shock resistance and a molded article using the same. [Means for solving the problem]

[0006] This disclosure includes the following aspects: (A) Polybutylene terephthalate resin and (B) Carbodiimide compounds, (C) Elastomer and, (D) Fibrous inorganic filler and A resin composition containing, The (B) carbodiimide compound comprises (b1) a cyclic carbodiimide compound and (b2) an aromatic carbodiimide compound. The total content of the (b1) cyclic carbodiimide compound and the (b2) aromatic carbodiimide compound is 0.6 to 2.0 parts by mass per 100 parts by mass of the (A) polybutylene terephthalate resin. A resin composition in which the mass ratio [(b1) / (b2)] of the (b1) cyclic carbodiimide compound to the (b2) aromatic carbodiimide compound is 0.2 to 1.6. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a resin composition with excellent heat shock resistance and a molded article using the same. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows the shape and dimensions of the test specimens used in the thermal shock resistance test of the example. [Modes for carrying out the invention]

[0009] Hereinafter, an embodiment of the present disclosure will be described in detail. However, the scope of the present disclosure is not limited to the embodiment described herein, and various modifications can be made without departing from the spirit of the present disclosure. Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification. Further, when a plurality of upper limit values and lower limit values are described for a specific parameter, any upper limit value and lower limit value can be combined to form a suitable numerical range. Further, the lower limit value and / or upper limit value of the numerical range described in the present disclosure can be replaced with a numerical value within that numerical range and shown in the examples. When a plurality of numerical ranges are described for a plurality of parameters, any numerical range can be adopted for each parameter and they can be arbitrarily combined. The expression "X to Y" indicating a numerical range means "X or more and Y or less". When a specific description described for one embodiment is applicable to other embodiments, the description may be omitted in other embodiments.

[0010] <Resin composition> The resin composition according to this embodiment is (A) Polybutylene terephthalate resin, (B) Carbodiimide compound, (C) Elastomer, (D) Fibrous inorganic filler and is a resin composition containing the (B) carbodiimide compound contains (b1) cyclic carbodiimide compound and (b2) aromatic carbodiimide compound, the total content of the (b1) cyclic carbodiimide compound and the (b2) aromatic carbodiimide compound is 0.6 to 2.0 parts by mass with respect to 100 parts by mass of the (A) polybutylene terephthalate resin, the mass ratio [(b1) / (b2)] of the (b1) cyclic carbodiimide compound to the (b2) aromatic carbodiimide compound is 0.2 to 1.6.

[0011] Conventionally, as described in Patent Documents 1 and 2, it is known that carbodiimide compounds are added to resin compositions mainly composed of polybutylene terephthalate resin in order to improve heat shock resistance and hydrolysis resistance. The carbodiimide compounds added to resin compositions mainly composed of polybutylene terephthalate resin have mainly been aliphatic carbodiimide compounds, alicyclic carbodiimide compounds, and aromatic carbodiimide compounds. When these carbodiimide compounds are added to polymers and melt-kneaded, or when the polymers are remelted and processed, isocyanate gases, known to be highly irritating and sensitizing, are generated, requiring measures to improve the working environment, such as exhaust systems. As carbodiimides that do not release isocyanate compounds, cyclic carbodiimide compounds with a carbodiimide ring containing one carbodiimide group within a single ring are also known, but cyclic carbodiimide compounds are particularly affected by the increase in viscosity due to crosslinking reactions with polybutylene terephthalate, which significantly deteriorates the moldability of the resin composition. The inventors have diligently conducted research and have found that by using aromatic carbodiimide compounds and cyclic carbodiimides in a specific ratio and blending them in a specific total amount with polybutylene terephthalate resin, it is possible to provide a resin composition and molded articles using the same that have superior heat shock resistance while suppressing viscosity increase compared to blending aromatic carbodiimide compounds or cyclic carbodiimides alone. This led to the completion of this disclosure. The reason for these unique effects has not been identified, but it is presumed that the reason for the improved heat shock resistance is that aromatic carbodiimide compounds and cyclic carbodiimides have different reactivity with the terminal groups of polybutylene terephthalate, as well as different adhesion to fillers, which alleviates localized stress that may occur within the molded product obtained from the resin composition. Furthermore, it is presumed that the reason for the suppression of viscosity increase is that by using aromatic carbodiimide compounds and cyclic carbodiimides in combination, the amount of cyclic carbodiimide compounds used can be reduced, thereby suppressing the effects of the crosslinking reaction between the cyclic carbodiimide compounds and polybutylene terephthalate.

[0012] [(A) Polybutylene terephthalate resin] The resin composition according to this embodiment includes (A) polybutylene terephthalate resin. In this specification, "(A) polybutylene terephthalate resin (hereinafter sometimes referred to as PBT resin)" means at least terephthalic acid or its ester-forming derivative (C 1-6 This refers to a polybutylene terephthalate resin obtained by polycondensation of a dicarboxylic acid component (such as alkyl esters or acid halides) and a glycol component (such as alkylene glycol (1,4-butanediol) having at least four carbon atoms or its ester-forming derivative (such as acetylated compounds)). In this embodiment, (A) polybutylene terephthalate resin is not limited to homopolybutylene terephthalate resin, but may be a copolymer containing 60 mol% or more of butylene terephthalate units.

[0013] (A) The amount of terminal carboxyl groups in the polybutylene terephthalate resin is not particularly limited as long as it does not hinder the purpose of this disclosure, but is preferably 30 meq / kg or less, and more preferably 25 meq / kg or less.

[0014] (A) The intrinsic viscosity of the polybutylene terephthalate resin is not particularly limited as long as it does not hinder the purpose of this disclosure, but is preferably 0.60 dL / g or more and 1.5 dL / g or less, and more preferably 0.65 dL / g or more and 1.2 dL / g or less. When a polybutylene terephthalate resin with an intrinsic viscosity in this range is used, the resulting polybutylene terephthalate resin composition will have particularly good moldability. Furthermore, the intrinsic viscosity can 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 can be 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. The intrinsic viscosity of the polybutylene terephthalate resin can be measured, for example, in o-chlorophenol at a temperature of 35°C.

[0015] (A) In the preparation of polybutylene terephthalate resin, when using an aromatic dicarboxylic acid other than terephthalic acid or its ester-forming derivative as a comonomer component, for example, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-dicarboxydiphenyl ether, etc. 8-14 Aromatic dicarboxylic acids; such as succinic acid, adipic acid, azelaic acid, sebacic acid, etc. 4-16 C alkanedicarboxylic acids; cyclohexanedicarboxylic acids, etc. 5-10 Cycloalkane dicarboxylic acids; ester-forming derivatives of these dicarboxylic acid components (C 1-6 Alkyl ester derivatives and acid halides (such as those mentioned above) can be used. These dicarboxylic acid components can be used individually or in combination of two or more.

[0016] Among these dicarboxylic acid components, C isophthalic acid and others 8-12 Aromatic dicarboxylic acids, and C such as adipic acid, azelaic acid, and sebacic acid. 6-12 Alkane dicarboxylic acids are more preferred.

[0017] (A) In the preparation of polybutylene terephthalate resin, when using a glycol component other than 1,4-butanediol as a comonomer component, for example, C2-10 alkylene glycols such as ethylene glycol, propylene glycol, trimethylene glycol, 1,3-butylene glycol, hexamethylene glycol, neopentyl glycol, 1,3-octanediol; polyoxyalkylene glycols such as diethylene glycol, triethylene glycol, dipropylene glycol; alicyclic diols such as cyclohexanedimethanol, hydrogenated bisphenol A; aromatic diols such as bisphenol A, 4,4'-dihydroxybiphenyl; C2-4 alkylene oxide adducts of bisphenol A such as bisphenol A ethylene oxide 2 mol adduct, bisphenol A propylene oxide 3 mol adduct; or ester-forming derivatives (such as acetylated products) of these glycols can be used. These glycol components can be used alone or in combination of two or more.

[0018] Among these glycol components, C2-6 alkylene glycols such as ethylene glycol, trimethylene glycol, polyoxyalkylene glycols such as diethylene glycol, or alicyclic diols such as cyclohexanedimethanol are more preferred.

[0019] Comonomer components that can be used in addition to the dicarboxylic acid component and the glycol component include, for example, aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 4-carboxy-4'-hydroxybiphenyl; aliphatic hydroxycarboxylic acids such as glycolic acid, hydroxycaproic acid; C 3-12 lactones such as propiolactone, butyrolactone, valerolactone, caprolactone (ε-caprolactone, etc.); ester-forming derivatives (C 1-6 alkyl ester derivatives, acid halides, acetylated products, etc.) of these comonomer components.

[0020] In one embodiment, the content of (A) polybutylene terephthalate resin is preferably 10 to 85% by mass, more preferably 20 to 80% by mass, and even more preferably 30 to 70% by mass, based on 100% by mass of the total amount of the resin composition.

[0021] [(B) Carbodiimide compounds] The resin composition according to this embodiment comprises (B) a carbodiimide compound, wherein (B) the carbodiimide compound comprises (b1) a cyclic carbodiimide compound and (b2) an aromatic carbodiimide compound. By using (b1) the cyclic carbodiimide compound and (b2) the aromatic carbodiimide compound in combination and blending them with a polybutylene terephthalate resin in specific ratios and amounts described later, it is possible to provide a resin composition and molded articles using the same that have superior heat shock resistance while suppressing viscosity increase compared to blending the aromatic carbodiimide compound or the cyclic carbodiimide alone.

[0022] ((b1) Cyclic carbodiimide compounds) In this specification, "(b1) cyclic carbodiimide compound" means a carbodiimide compound having a carbodiimide group in a cyclic structure. A cyclic carbodiimide compound may have multiple cyclic structures. One cyclic structure has one carbodiimide group (-N=C=N-), and its primary and secondary nitrogens are bonded by a bonding group. One cyclic structure has only one carbodiimide group. The number of atoms in the cyclic structure is preferably 8 to 50, more preferably 10 to 30, even more preferably 10 to 20, and particularly preferably 10 to 15. Here, the number of atoms in the cyclic structure means the number of atoms that directly constitute the ring structure; for example, 8 for an 8-membered ring, and 50 for a 50-membered ring. The number of atoms in the cyclic structure is preferably selected from the range of 10 to 30, more preferably 10 to 20, and particularly preferably 10 to 15.

[0023] The molecular weight of the (b1) cyclic carbodiimide compound is preferably 100 to 1,000. If the molecular weight is 100 or more, the (b1) cyclic carbodiimide compound has advantages in terms of structural stability and volatility. If the molecular weight is 1,000 or less, the synthesis in a dilution system is not required in the production of the cyclic carbodiimide, and the yield does not decrease easily, which is advantageous in terms of cost. From this viewpoint, it is more preferably 100 to 750, and even more preferably 250 to 750. Here, the molecular weight of the (b1) cyclic carbodiimide compound refers to the weight-average molecular weight if the (b1) cyclic carbodiimide compound has a molecular weight distribution.

[0024] In one embodiment, the (b1) cyclic carbodiimide compound is preferably a compound having a cyclic structure represented by the following general formula (I).

[0025] [ka] (wherein Q is a 2-4 valent bonded group which may contain a heteroatom and / or substituents, is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof).

[0026] In one embodiment, Q is -Ar a -OXO-Ar b - Preferably, the group is represented by Ar a and Ar b Each of these may independently be a phenylene group or a naphthalene-diyl group, which may have substituents, and may be a monocyclic or condensed polycyclic alicyclic group, an aromatic group, or a heterocyclic group, preferably with substituents. In this case, examples of substituents include C1-C20 alkyl groups, C6-C15 aryl groups, halogen atoms, nitro groups, amide groups, hydroxyl groups, ester groups, ether groups, aldehyde groups, etc., and preferably C1-C6 alkyl groups or phenyl groups. If X has two cyclic structures, it is preferably an alkanediyl group. If X has four cyclic structures, it is preferably an alkanetetrayl group.

[0027] In one embodiment, the cyclic carbodiimide compound (b1) is preferably a compound represented by formula (II).

[0028] [ka]

[0029] In the formula, X is a tetravalent group represented by the following formula (i). In the formula, Ar 1 ~Ar 4 Each of these may independently be a substituted divalent monocyclic or fused polycyclic alicyclic group, aromatic group, or heterocyclic group, preferably a substituted orthophenylene group or 1,2-naphthalene-diyl group. Examples of substituents include C1-C20 alkyl groups, C6-C15 aryl groups, halogen atoms, nitro groups, amide groups, hydroxyl groups, ester groups, ether groups, aldehyde groups, etc. Also, Ar 1 ~Ar 4 If it is a heterocyclic group, then that heterocyclic group contains a heteroatom selected from the group consisting of O, N, S, and P.

[0030] [ka]

[0031] In one embodiment, the following compounds are examples of (b1) cyclic carbodiimide compounds that can be suitably used.

[0032] [ka]

[0033] (This is the case where a cyclic carbodiimide compound is attached to the main chain of the polymer, and n is the number of repeating units of the polymer.)

[0034] [ka]

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] [(b2) Aromatic carbodiimide compounds] In this specification, "(b2) Aromatic carbodiimide compound" means a carbodiimide compound whose main chain is aromatic. In other words, it means an aromatic compound having a carbodiimide group as a substituent. In this embodiment, the aromatic carbodiimide compounds include diphenylcarbodiimide, di-2,6-dimethylphenylcarbodiimide, N-triyl-N'-phenylcarbodiimide, di-p-nitrophenylcarbodiimide, di-p-aminophenylcarbodiimide, di-p-hydroxyphenylcarbodiimide, di-p-chlorophenylcarbodiimide, di-p-methoxyphenylcarbodiimide, di-3,4-dichlorophenylcarbodiimide, di-2,5-dichlorophenylcarbodiimide, di-o-chlorophenylcarbodiimide, p-phenylene-bis-di-o-triylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, p-phenylene-bis-di-p-chlorophenylcarbodiimide, and ethylene-bis-diphenylcarbodiimide. Examples include mono or dicarbodiimide compounds such as poly(2,4'-diphenylmethanecarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(3,5'-dimethyl-4,4'-biphenylmethanecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(3,5'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(1,3-diisopropylphenylenecarbodiimide), poly(1-methyl-3,5-diisopropylphenylenecarbodiimide), poly(1,3,5-triethylphenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide), and two or more of these can be used in combination. Among these, di-2,6-dimethylphenylcarbodiimide, poly(4,4'-diphenylmethanecarbodiimide), poly(phenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide) are particularly preferred. (B) The carbodiimide compound may include other carbodiimide compounds other than (b1) the cyclic carbodiimide compound and (b2) the aromatic carbodiimide compound, but preferably (B) the carbodiimide compound consists only of (b1) the cyclic carbodiimide compound and (b2) the aromatic carbodiimide compound.

[0039] [(B) Total content of carbodiimide compounds] In the resin composition according to this embodiment, the total content of (b1) cyclic carbodiimide compound and (b2) aromatic carbodiimide compound is 0.6 to 2.0 parts by mass per 100 parts by mass of (A) polybutylene terephthalate resin. In one embodiment, the total content of (b1) cyclic carbodiimide compound and (b2) aromatic carbodiimide compound is preferably 0.7 to 2.0 parts by mass, more preferably 0.7 to 1.8 parts by mass, even more preferably 0.7 to 1.8 parts by mass, and particularly preferably 0.8 to 1.6 parts by mass of (B) carbodiimide compound per 100 parts by mass of (A) polybutylene terephthalate resin. By having the total content of (b1) cyclic carbodiimide compound and (b2) aromatic carbodiimide compound within the above range, it is easier to obtain a resin composition with superior heat shock resistance while suppressing viscosity increase. In one embodiment, the total content of (b1) cyclic carbodiimide compound and (b2) aromatic carbodiimide compound is preferably 0.1 to 5% by mass, more preferably 0.2 to 1% by mass, and even more preferably 0.3 to 1% by mass, based on 100% by mass of the total amount of the resin composition.

[0040] [(b1) Mass ratio of the cyclic carbodiimide compound to the (b2) aromatic carbodiimide compound [(b1) / (b2)]] In the resin composition according to this embodiment, the mass ratio [(b1) / (b2)] of the cyclic carbodiimide compound (b1) to the aromatic carbodiimide compound (b2) is 0.2 to 1.6. In one embodiment, the mass ratio [(b1) / (b2)] of the (b1) cyclic carbodiimide compound to the (b2) aromatic carbodiimide compound is preferably 0.22 to 1.6, more preferably 0.22 to 1.5, even more preferably 0.24 to 1.5, and particularly preferably 0.24 to 1.4. By having the mass ratio [(b1) / (b2)] of the (b1) cyclic carbodiimide compound to the (b2) aromatic carbodiimide compound within the above range, it is easier to obtain a resin composition with superior heat shock resistance while suppressing viscosity increase.

[0041] [(C) Elastomer] The resin composition according to this embodiment includes (C) an elastomer. (C) Elastomers, when combined with (D) fibrous inorganic fillers described later, impart elasticity to the resin composition and improve the balance between strength and toughness of molded articles obtained from the resin composition according to this embodiment, thereby further enhancing heat shock resistance. Examples of (C) elastomers include olefin-based elastomers, core-shell-based elastomers, diene-based elastomers, polyester-based elastomers, urethane-based elastomers, silicone-based elastomers, styrene-based elastomers, polyamide-based elastomers, etc., and one or more of these can be used in combination.

[0042] Examples of olefin-based elastomers include ethylene-propylene copolymers (EP copolymers), ethylene-butene copolymers, ethylene-octene copolymers, ethylene-propylene-diene copolymers (EPD copolymers), ethylene-propylene-butene copolymers, ethylene-vinyl acetate copolymers, copolymers containing at least one unit selected from EP copolymers and EPD copolymers, copolymers of olefins and (meth)acrylic monomers, ethylene-ethyl acrylate copolymers, ethylene-glycidyl methacrylate copolymers, α-olefin·α,β-unsaturated carboxylic acid (ester)·α,β-unsaturated carboxylic acid glycidyl ester ternary copolymers, and ethylene copolymers obtained by copolymerizing an ethylene (co)polymer with maleic anhydride or glycidyl methacrylate. Preferred olefin-based elastomers include EP copolymers, EPD copolymers, and copolymers of olefins and (meth)acrylic monomers, with ethylene ethyl acrylate being particularly preferred from the viewpoint of fluidity and release properties. These olefin-based elastomers can be used alone or in combination of two or more types.

[0043] Core-shell elastomers are polymers composed of a core layer made of rubber (soft component) and a shell layer made of hard component, with acrylic rubber being used as the rubber component of the core layer. The rubber component used in the core layer has a glass transition temperature (T g The temperature is preferably below 0°C (for example, -10°C or below), more preferably below -20°C (for example, -180°C or higher and -25°C or below), and particularly preferably below -30°C (for example, -150°C or higher and -40°C or below).

[0044] When using acrylic rubber as the rubber component, polymers obtained by polymerizing acrylic monomers such as alkyl acrylates as the main component are preferred. The alkyl acrylates used as monomers for acrylic rubber include butyl acrylate and other acrylic acid C110 1-12 Alkyl esters of acrylic acid are preferred, and C 2-6 Alkyl esters are more preferred.

[0045] Acrylic rubber may be a homopolymer or copolymer of acrylic monomers. If the acrylic rubber is a copolymer of acrylic monomers, it may be a copolymer of acrylic monomers with other acrylic monomers, or a copolymer of acrylic monomers with other unsaturated bond-containing monomers. If the acrylic rubber is a copolymer, it may also be a copolymer of crosslinkable monomers.

[0046] Vinyl polymers are preferably used for the shell layer. Vinyl polymers are obtained by polymerizing or copolymerizing at least one monomer selected from, for example, aromatic vinyl monomers, vinyl cyanide monomers, methacrylate monomers, and acrylic acid monomers. The core layer and shell layer of such a core-shell elastomer may be bonded together by graft copolymerization. This graft copolymerization is obtained, if necessary, by adding a graft cross-agent that reacts with the shell layer during polymerization of the core layer, thereby providing reactive groups to the core layer, and then forming the shell layer. When silicone rubber is used as the graft cross-agent, organosiloxanes having vinyl bonds or organosiloxanes having thiols are used, and acronoxysiloxane, methacryloxysiloxane, and vinylsiloxane are preferably used.

[0047] As polyester elastomers, both ester-ester type elastomers having polyester unit structures in both the hard and soft segments, and ester-ether type elastomers having polyether unit structures in the soft segments, are preferably used. However, the former is more preferable in terms of heat resistance, and the latter in terms of dimensional accuracy. Aromatic polyester units such as polybutylene terephthalate and polyethylene terephthalate can preferably be used as the polyester unit structure of the hard segment, aliphatic polyester units such as polyethylene adipate, polybutylene adipate, and polycaprolactone can preferably be used as the polyester unit structure of the soft segment, and polyethylene glycol and polytetramethylene glycol can preferably be used as the polyether unit structure of the soft segment, but are not limited to these.

[0048] Examples of urethane-based elastomers include, but are not limited to, block copolymers in which polyurethane obtained by 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 forms the hard segment, and polyethers such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, or aliphatic polyesters such as polyethylene adipate, polybutylene adipate, and polycaprolactone form the soft segment.

[0049] Examples of styrene-based elastomers include acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-butadiene copolymer, styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, styrene-ethylene-butadiene-styrene copolymer, and acrylonitrile-styrene-epoxy group-containing vinyl copolymer, which can be used individually or in combination of two or more.

[0050] Examples of polyamide 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 polyethers or aliphatic polyesters are used as soft segments. Furthermore, although not strictly classified as elastomers, aliphatic polyamides can also be used as polyamide elastomers.

[0051] In one embodiment, the content of (C) elastomer is preferably 1.0 part by mass or more and 50 parts by mass or less, more preferably 5 parts by mass or more and 40 parts by mass or less, even more preferably 10 parts by mass or more and 35 parts by mass or less, and particularly preferably 10 parts by mass or more and 30 parts by mass or less, per 100 parts by mass of (A) (polybutylene terephthalate resin). By having the content of (C) elastomer in the resin composition within the above range, the balance between strength and toughness of the molded article obtained from the resin composition can be improved, thereby further enhancing the resistance to heat shock. In one embodiment, the content of (C) elastomer is preferably 1 to 25% by mass, more preferably 2 to 20% by mass, and even more preferably 6 to 10% by mass, based on 100% by mass of the total amount of the resin composition.

[0052] [(D) Fibrous inorganic filler] The resin composition according to this embodiment includes (D) a fibrous inorganic filler. By combining it with the (C) elastomer described above, the balance between strength and toughness of the molded article obtained from the resin composition according to this embodiment can be improved, thereby further enhancing its resistance to thermal shock. (D) Examples of fibrous inorganic fillers include glass fibers, asbestos fibers, carbon fibers, silica fibers, silica-alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, potassium titanate fibers, and also metallic fibrous materials such as stainless steel, aluminum, titanium, copper, and brass. When using these fibrous fillers, it is desirable to use a consolidating agent or surface treatment agent if necessary. In one embodiment, (D) the fibrous inorganic filler is preferably glass fiber. Any known glass fiber is preferably used as the glass fiber, regardless of the glass fiber diameter, shape such as cylindrical, cocoon-shaped, or oval cross-section, or the length or glass cutting method used when manufacturing chopped strands or roving. The type of glass is not limited, but E glass or corrosion-resistant glass containing zirconium in its composition is preferably used.

[0053] In one embodiment, the length of (D) fibrous inorganic filler is not particularly limited, but is preferably 0.2 mm or more, more preferably 2.0 mm or less, and even more preferably 0.3 mm or more and 1.5 mm or less. The cross-section of (D) fibrous inorganic filler may be circular or elliptical. From the viewpoint of filling performance with respect to the thickness of the molded product and the gate diameter, the diameter of a circular cross-section is preferably 5 μm or more and 20 μm or less, and preferably 10 μm or more and 15 μm or less. In the case of an elliptical cross-section, the major axis and minor axis are not particularly limited, but the major axis is preferably 10 μm or more and 26 μm or less, more preferably 12 μm or more and 20 μm or less, and the minor axis is preferably 5 μm or more and 13 μm or less, and even more preferably 6 μm or more and 10 μm or less. (D) The length, cross-sectional diameter, or major and minor axes of the fibrous inorganic filler can be calculated using a scanning electron microscope and image processing software, and the arithmetic mean measured for 1000 (C) fibrous inorganic fillers is used. (D) The length, cross-sectional diameter, or major and minor axes of the fibrous inorganic filler can also be taken from the manufacturer's catalog values. If the fibrous inorganic filler is circular, the resin composition can be ashed at approximately 600°C, the ashed residue can be dispersed in a 5% by mass polyethylene glycol aqueous solution, and then transferred to a petri dish. Images of 1000 fibrous inorganic fillers in the ashed residue can be captured from a CCD camera to a PC, and the arithmetic mean can be obtained using an image processing method with an image measuring instrument ("LUZEX AP" manufactured by Nireco Corporation).

[0054] In one embodiment, the content of (D) fibrous inorganic filler is preferably 20 parts by mass or more and 150 parts by mass or less, more preferably 30 parts by mass or more and 130 parts by mass or less, and more preferably 40 parts by mass or more and 110 parts by mass or less, per 100 parts by mass of polybutylene terephthalate resin. By having the content of (D) fibrous inorganic filler within the above range, the balance between strength and toughness of the molded article obtained from the resin composition can be improved, thereby further enhancing the resistance to heat shock. In one embodiment, the content of (D) fibrous inorganic filler is preferably 10 to 60% by mass, more preferably 15 to 40% by mass, and even more preferably 25 to 30% by mass, based on 100% by mass of the total amount of the resin composition.

[0055] [Other ingredients] The resin compositions of this disclosure may also contain other polymers, other fillers, and known substances commonly added to synthetic resins, such as flame retardants, flame retardant additives, epoxy resins, anti-dripping agents, lubricants, plasticizers, stabilizers, colorants, antioxidants, ultraviolet absorbers, antistatic agents, dyes, pigments, etc., as appropriate, insofar as they do not impair the effects of this disclosure, depending on the required performance.

[0056] Other polymers refer to polymers other than (A) polybutylene terephthalate resin, (B) carbodiimide compounds, and (C) polymers that constitute elastomers, for example, epoxy group-containing copolymers. Other fillers refer to fillers other than (D) fibrous inorganic fillers, for example, organic fillers, carbon black, etc.

[0057] ((E) Flame retardants and (F) Flame retardant enhancers) In one embodiment, the resin composition preferably contains (E) a flame retardant and (F) a flame retardant aid. By including (E) a flame retardant and (F) a flame retardant aid, a resin composition with superior flame retardancy can be obtained.

[0058] (E) As for flame retardants, those commonly used as flame retardants can be used. Specifically, halogen-based flame retardants include brominated epoxy flame retardants, brominated polyacrylate flame retardants, brominated polystyrene flame retardants, brominated polyphenylene ether flame retardants, brominated polycarbonate flame retardants, brominated biphenyl ether flame retardants, and brominated diphthalimide flame retardants. Non-halogen-based flame retardants include phosphate ester flame retardants, calcium or aluminum salts of phosphinates or diphosphinic acid, and red phosphorus. Among these, brominated epoxy flame retardants and brominated polyacrylate flame retardants are particularly preferred from the viewpoint of heat shock resistance.

[0059] In one embodiment, (E) the flame retardant is preferably one or more flame retardants selected from brominated epoxy flame retardants and brominated acrylate flame retardants. As a brominated epoxy flame retardant, for example, brominated versions of aromatic epoxy compounds (such as biphenyl-type epoxy compounds, bisphenol A-type epoxy compounds, phenol novolac-type epoxy compounds, and cresol novolac-type epoxy compounds) containing one or more epoxy groups in one molecule can be used. Brominated epoxy flame retardants can be used individually or in combination of two or more types.

[0060] As a brominated acrylate-based flame retardant, for example, one can be used that has a structure obtained by copolymerizing benzyl acrylate containing bromine with benzyl methacrylate or the like, which has a similar structure. Examples of bromine-containing benzyl acrylates include pentabromobenzyl acrylate, tetrabromobenzyl acrylate, tribromobenzyl acrylate, or mixtures thereof. Among these, pentabromobenzyl acrylate is preferred. Examples of benzyl methacrylate copolymerizable with bromine-containing benzyl acrylate include methacrylates corresponding to the acrylates mentioned above. Furthermore, copolymerization with vinyl monomers is also possible. Examples of vinyl monomers include acrylic acid esters such as acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and benzyl acrylate; methacrylic acid esters such as methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and benzyl methacrylate; unsaturated carboxylic acids or their anhydrides such as styrene, acrylonitrile, fumaric acid, and maleic acid; vinyl acetate; vinyl chloride; and crosslinkable vinyl monomers, xylylenediacrylate, xylylenedimethacrylate, tetrabrom xylylenediacrylate, tetrabrom xylylenedimethacrylate, butadiene, isoprene, and divinylbenzene can also be used. These are preferably used in amounts equal to or less than equimolar, and more preferably 0.5 times the molar amount, relative to benzyl acrylate or benzyl methacrylate. Brominated acrylate flame retardants can be used individually or in combination of two or more types.

[0061] (F) Examples of flame retardants include antimony-based flame retardants, metal borate salt-based flame retardants, and nitrogen-based flame retardants. Typically, antimony-based or metal borate salt-based flame retardants are used with halogen-based flame retardants, and nitrogen-based flame retardants are used with non-halogen-based flame retardants.

[0062] Examples of antimony-based flame retardants include antimony trioxide, antimony pentoxide, or sodium antimonate. Examples of metal borate salt-based flame retardant additives include calcium borate, sodium borate, and zinc borate. Examples of nitrogen-based flame retardant additives include salts of triazine compounds with cyanuric acid or isocyanuric acid (e.g., melamine cyanurate).

[0063] In one embodiment, (F) the flame retardant is preferably an antimony oxide compound. From the viewpoint of heat shock resistance, antimony pentoxide is particularly preferred as the antimony oxide compound.

[0064] In one embodiment, the content of (E) flame retardant is preferably 1 to 50 parts by mass, more preferably 10 to 40 parts by mass, preferably 20 to 35 parts by mass, and most preferably 25 to 35 parts by mass, with respect to 100 parts by mass of (A) polybutylene terephthalate resin.

[0065] In one embodiment, the content of (F) flame retardant aid is preferably 1 to 50 parts by mass, more preferably 5 to 40 parts by mass, preferably 5 to 30 parts by mass, and most preferably 10 to 20 parts by mass, per 100 parts by mass of (A) polybutylene terephthalate resin.

[0066] ((G) Epoxy resin) In one embodiment, the resin composition preferably contains an epoxy resin. Including an epoxy resin makes it easier to obtain a resin composition with superior heat shock resistance. Examples of epoxy resins include biphenyl-type epoxy resins, bisphenol A-type epoxy resins, phenol novolac-type epoxy resins, and cresol novolac-type epoxy resins. It is preferable to use one or more selected from these. The epoxy resin may be used alone or in any combination of two or more types. The epoxy equivalent of the epoxy resin is preferably 600 to 1500 g / equivalent (g / eq). The epoxy equivalent can be measured by potentiometric titration with glacial acetic acid and cetyltrimethylammonium bromide, in accordance with JIS K-7236.

[0067] In one embodiment, the epoxy resin content is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 5 parts by mass or less, even more preferably 1 part by mass or more and 5 parts by mass or less, and particularly preferably 1 part by mass or more and 2 parts by mass or less, per 100 parts by mass of (A) polybutylene terephthalate resin.

[0068] ((H) Anti-dripping agent) In one embodiment, the resin composition may contain (H) an anti-dripping agent. Including (H) an anti-dripping agent can prevent dripping during combustion, and the flame retardancy of the resin composition is more easily improved. Examples of anti-dripping agents include fluorine-containing monomers (tetrafluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, hexafluoropropylene, perfluoroalkyl vinyl ether, etc.) alone or copolymers thereof, or copolymers of the fluorine-containing monomer with other copolymerizable monomers (olefin monomers such as ethylene and propylene, acrylic monomers such as (meth)acrylate, etc.). Polytetrafluoroethylene is preferred due to its availability, high effectiveness, and ease of handling. In one embodiment, the content of the anti-dripping agent is preferably 0.1 parts by mass or more and 5 parts by mass or less, and more preferably 1 part by mass or more and 2 parts by mass or less, per 100 parts by mass of (A) polybutylene terephthalate resin.

[0069] (Lubricant) In one embodiment, the resin composition may contain a lubricant. Including a lubricant makes it easier to improve the moldability of the resin composition. A fatty acid-based lubricant is preferred. In one embodiment, the lubricant content is preferably 0.1 parts by mass or more and 1 part by mass or less, and more preferably 0.5 parts by mass or more and 1 part by mass or less, per 100 parts by mass of (A) polybutylene terephthalate resin.

[0070] (Plasticizer) In one embodiment, the resin composition may contain a plasticizer. Including a plasticizer makes it easier to improve the moldability of the resin composition. A pyromellitic acid mixed linear alkyl ester is preferred as the plasticizer. In one embodiment, the content of the plasticizer is preferably 1 to 20 parts by mass, and more preferably 5 to 10 parts by mass, per 100 parts by mass of (A) polybutylene terephthalate resin.

[0071] (Stabilizer) In one embodiment, the resin composition may contain a stabilizer. Including a stabilizer makes it easier to improve the durability and stability of the molded article containing the resin composition. Examples of stabilizers include organic acid salts, inorganic acid salts, oxides, and hydroxides of alkali metals and alkaline earth metals. Specifically, examples of alkali metal compounds include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium acetate, potassium acetate, lithium acetate, sodium stearate, potassium stearate, lithium stearate, sodium borohydride, lithium borohydride, sodium phenylborohydrate, sodium benzoate, potassium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium salt, dipotassium salt, dilithium salt of bisphenol A, sodium salt, potassium salt, lithium salt of phenol, and the like. Furthermore, examples of alkaline earth compounds include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium bicarbonate, barium bicarbonate, magnesium bicarbonate, strontium bicarbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, and strontium stearate. Among these compounds, potassium acetate and calcium acetate are preferred. In one embodiment, the content of the stabilizer is preferably 0.001 parts by mass or more and 0.1 parts by mass or less, and more preferably 0.05 parts by mass or more and 0.015 parts by mass or less, per 100 parts by mass of (A) polybutylene terephthalate resin.

[0072] (Coloring agent) In one embodiment, the resin composition may contain a colorant. Examples of colorants include inorganic pigments [black pigments such as carbon black (e.g., acetylene black, lamp black, thermal black, furnace black, channel black, Ketjen black, etc.), red pigments such as iron oxide red, orange pigments such as molybdate orange, white pigments such as titanium dioxide, etc.], and organic pigments (yellow pigment, orange pigment, red pigment, blue pigment, green pigment, etc.). In one embodiment, the content of the colorant is preferably 0.1 parts by mass or more and 5 parts by mass or less, and more preferably 1 part by mass or more and 1.5 parts by mass or less, per 100 parts by mass of (A) polybutylene terephthalate resin.

[0073] (Antioxidant) In one embodiment, the resin composition may contain an antioxidant. Including an antioxidant makes it easier to improve the durability and stability of the molded article containing the resin composition. Examples of antioxidants include hindered phenol antioxidants, thioether antioxidants, and hindered amine antioxidants, and it is preferable to include a hindered phenol antioxidant. In one embodiment, the content of the antioxidant is preferably 0.1 parts by mass or more and 5 parts by mass or less, and more preferably 0.1 parts by mass or more and 1 part by mass or less, per 100 parts by mass of (A) polybutylene terephthalate resin.

[0074] (Method for manufacturing resin compositions) The resin composition according to this embodiment can be manufactured by various methods conventionally known as methods for manufacturing thermoplastic resin compositions. A suitable method for manufacturing the resin composition is, for example, a method in which each component is melt-kneaded using a melt-kneading device such as a single-screw or twin-screw extruder to form extruded pellets.

[0075] Furthermore, the (B) carbodiimide compound can also be incorporated as a masterbatch with a thermoplastic resin as the matrix. While a masterbatch of the (B) carbodiimide compound is preferably made with polybutylene terephthalate resin as the matrix, masterbatches using other thermoplastic resins as the matrix can also be used.

[0076] The resin composition according to this embodiment is measured in accordance with ISO 11443 at a temperature of 260°C and a shear rate of 1000 sec. -1 The melt viscosity can be 0.4 kPa·s or less, more preferably 0.38 kPa·s or less, and even more preferably 0.36 kPa·s or less. Because the resin composition according to this embodiment exhibits such a melt viscosity, it shows excellent fluidity during molding and can be suitably used in injection molding such as insert molding, resulting in fewer molding defects such as short shots.

[0077] The resin composition obtained according to this embodiment has excellent resistance to thermal shock and is therefore suitable for use in various applications such as insert parts. In particular, it is suitable for use as a material for insert molded products such as busbars for automotive applications because it is less prone to cracking due to thermal shock even when subjected to drastic temperature changes.

[0078] <Molded products> The molded article according to this embodiment contains the above-mentioned resin composition. By containing the above-mentioned resin composition, the molded article according to this embodiment exhibits excellent heat shock resistance and excellent long-term reliability as a material. In one embodiment, the molded product is preferably an insert molded product. Because the expansion and contraction rates (so-called linear expansion coefficients) due to temperature changes differ significantly between polybutylene terephthalate resin and conductive members such as metal, cracks are prone to occur due to temperature changes during use. In particular, when the conductive member embedded in the polybutylene terephthalate resin is a thin insert part (for example, a plate-shaped member with an average thickness of 3 mm or less), it has been difficult to obtain an insert molded product that is practical and resistant to thermal shock. The molded product of this embodiment, which has excellent thermal shock resistance, is an insert molded product, making it less susceptible to cracks due to thermal shock even when subjected to drastic temperature changes, and therefore is suitable for use as an automotive part.

[0079] (Application) The molded product according to this embodiment is suitable for general home appliances, electrical and electronic components incorporated into office automation equipment, mechanical components, automobile parts, and the like, as it enables the production of molded products with excellent heat shock resistance.

[0080] Furthermore, it is suitably used as a component for electric vehicles, where durability and flame retardancy as electrical and electronic components are required. For example, although not particularly limited, it is suitable as a material for cases housing components for electric vehicles such as busbars, power modules, boost DC / DC converters, buck DC / DC converters, capacitors, insulators, motor terminal blocks, batteries, electric compressors, battery current sensors, and junction blocks.

[0081] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of this disclosure are disclosed below. [1](A) Polybutylene terephthalate resin and (B) Carbodiimide compounds, (C) Elastomer and, (D) Fibrous inorganic filler and A resin composition containing, The (B) carbodiimide compound comprises (b1) a cyclic carbodiimide compound and (b2) an aromatic carbodiimide compound. The total content of the (b1) cyclic carbodiimide compound and the (b2) aromatic carbodiimide compound is 0.6 to 2.0 parts by mass per 100 parts by mass of the (A) polybutylene terephthalate resin. A resin composition in which the mass ratio [(b1) / (b2)] of the (b1) cyclic carbodiimide compound to the (b2) aromatic carbodiimide compound is 0.2 to 1.6. [2] The resin composition according to [1], wherein the amount of (B) carbodiimide compound is 0.8 to 1.8 parts by mass per 100 parts by mass of (A) polybutylene terephthalate resin. [3] The resin composition according to [1] or [2], wherein the mass ratio [(b1) / (b2)] of the (b1) cyclic carbodiimide compound to the (b2) aromatic carbodiimide compound is 0.22 to 1.5. [4](D) The resin composition according to any one of [1] to [3], wherein the fibrous inorganic filler is glass fiber. [5] The resin composition according to any one of [1] to [4], further comprising a flame retardant and a flame retardant aid. [6] The resin composition according to any one of [1] to [5], further comprising an epoxy resin. A molded article comprising any of the resin compositions described in [7], [1], to [6]. [8] The molded product described in [7], which is an insert molded product. [Examples]

[0082] The present disclosure will be further illustrated by the following examples, but these examples will not limit the interpretation of the present disclosure.

[0083] <Preparation of resin composition> The raw materials were mixed in the proportions shown in Tables 1-3, and extruded using a twin-screw extruder (TEX 30, manufactured by Japan Steel Works) at a cylinder temperature of 260°C and screw rotation of 130 rpm to produce pellets of each resin composition for the examples and comparative examples. A blank space in Tables 1-3 indicates that the component was not present.

[0084] [(A): Polybutylene terephthalate (PBT) resin] • Polybutylene terephthalate (manufactured by Polyplastics Co., Ltd., intrinsic viscosity 0.68 dL / g, carboxylic acid terminal group content 13 meq / kg) [(B): Carbodiimide compounds] • (b1): Cyclic carbodiimide (manufactured by Teijin Limited, "Carbodista TCC-NP") • (b2): Aromatic carbodiimide (manufactured by LANXESS K.K., "STABAXOL P100") [(C): Elastomer] • Olefin-based elastomer (manufactured by NOF Corporation, "Modiper A5300") [(D): Fibrous inorganic filler] • Glass fiber (manufactured by Nippon Electric Glass Co., Ltd., "ECS03T-127") [(E) Flame retardant] (1): Benzyl acrylate brominated resin (manufactured by ICL JAPAN Co., Ltd., "FR-1025") (2): Brominated epoxy resin (manufactured by Ushin Polymer Co., Ltd., "CXB-1500C") [(F) Flame retardant additive] (1): Antimony trioxide (manufactured by Nippon Seikou Co., Ltd., "PATOX-M") (2): Antimony pentoxide (manufactured by Nissan Chemical Corporation, "Sun Epoch NA1030") [(G) Epoxy resin] • Bisphenol A type epoxy resin (manufactured by Tomoe Engineering Co., Ltd., "YD014C"), epoxy equivalent weight 938g / equivalent [(H) Anti-dripping agent] • Polytetrafluoroethylene resin (manufactured by AGC Inc., "Fluon CD097E") [Lubricant] • Special fatty acid ester (manufactured by Riken Vitamin Co., Ltd., "Rikemar B-74") [Plasticizer] • Pyromellitic acid mixed alcohol ester (manufactured by ADEKA Corporation, "ADEKA Sizer UL-100") [Stabilizer] • Potassium acetate (manufactured by Fujifilm Wako Pure Chemical Corporation) [Coloring agents] • Carbon black (manufactured by Mitsubishi Chemical Corporation, "MA600B") [Antioxidant] • Hindered phenol antioxidant (BASF Japan Ltd., "IRGANOX1010")

[0085] <Melting viscosity> After drying each pellet prepared as described above at 140°C for 3 hours, the pellets were then processed in accordance with ISO 11443 using a Capillograph 1B (manufactured by Toyo Seiki Seisakusho Co., Ltd.) with a barrel temperature of 260°C, a capillary tube diameter of φ1 mm × 20 mm L, and a shearing rate of 1000 sec. -1 The melt viscosity was measured.

[0086] <Tensile strength retention rate (hydrolysis resistance)> After drying each pellet prepared as described above at 140°C for 3 hours, tensile test specimens were injection molded using an injection molding machine (Sumitomo Heavy Industries, Ltd., "SE100EV-A") at a resin temperature of 260°C and a mold temperature of 80°C to conform to ISO 3167 standards. The tensile strength was then measured in accordance with ISO 527-1 and 527-2. Furthermore, injection-molded test specimens were treated for 100 hours at 121°C and 100% RH using a high-accelerated life testing apparatus (Hirayama Seisakusho, "PC-R8D"). The tensile strength after treatment was measured, and the retention rate of tensile strength before and after treatment [(tensile strength after treatment) / (tensile strength before treatment)] was calculated. A higher retention rate before and after treatment indicates superior hydrolysis resistance.

[0087] <Heat shock resistance> Using the pellets prepared above and L-shaped metal insert parts, test specimens as shown in Figure 1 were insert-molded by injection molding. The resulting molded specimens were then subjected to a thermal shock resistance test using a thermal shock tester (Hitachi Appliances, "ES-107LH"), in which the process of heating at 140°C for 1 hour and 30 minutes, then cooling to -40°C for 1 hour and 30 minutes, and finally heating back up to 140°C constituted one cycle. The number of cycles until cracks appeared in the molded product (shown as "Number of Cycles" in Tables 1-3) was measured. A higher number of cycles until cracks appear in the molded product indicates superior thermal shock resistance. The results are shown in Tables 1-3.

[0088] [Table 1]

[0089] [Table 2]

[0090] [Table 3]

[0091] As shown in Tables 1-3, molded articles using the resin compositions of the embodiments satisfying the configuration of this embodiment required approximately twice as many cycles to develop cracks compared to molded articles using the resin compositions of comparative examples that did not satisfy the configuration of this embodiment. In other words, the resin composition of this embodiment yielded molded articles with superior heat shock resistance. Furthermore, despite containing a cyclic carbodiimide compound (b1), which is known to increase melt viscosity, the polybutylene terephthalate resin composition of the example showed suppressed increases in melt viscosity. Furthermore, the resin compositions of the examples generally exhibited higher tensile strength retention compared to the resin compositions of the comparative examples. In other words, molded articles using the resin compositions of the examples generally showed superior hydrolysis resistance.

Claims

1. (A) Polybutylene terephthalate resin, (B) Carbodiimide compounds, (C) Elastomer and (D) Fibrous inorganic filler and A resin composition containing, The carbodiimide compound (B) is It has a cyclic structure represented by the following general formula (I), and the number of atoms in one cyclic structure is 8-5. (b1) Cyclic carbodiimide compound, which is 0. (wherein Q is a divalent to tetravalent bond group which is an aliphatic group, alicyclic group, aromatic group, or combination thereof, which may contain a heteroatom and / or substituents), and Diphenylcarbodiimide, di-2,6-dimethylphenylcarbodiimide, N-triyl-N'-phenylcarbodiimide, di-p-nitrophenylcarbodiimide, di-p-aminophenylcarbodiimide, di-p-hydroxyphenylcarbodiimide, di-p-chlorophenylcarbodiimide, di-p-methoxyphenylcarbodiimide, di-3,4-dichlorophenylcarbodiimide, di-2,5-dichlorophenylcarbodiimide, di-o-chlorophenylcarbodiimide, p-phenylene-bis-di-o-triylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, p-phenylene-bis-di-p-chlorophenylcarbodiimide, ethylene-bis-diphenylcarbodiimide ; comprising one or more (b2) aromatic carbodiimide compounds selected from poly(2,4'-diphenylmethanecarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(3,5'-dimethyl-4,4'-biphenylmethanecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(3,5'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(1,3-diisopropylphenylenecarbodiimide), poly(1-methyl-3,5-diisopropylphenylenecarbodiimide), poly(1,3,5-triethylphenylenecarbodiimide) and poly(triisopropylphenylenecarbodiimide), The total content of the (b1) cyclic carbodiimide compound and the (b2) aromatic carbodiimide compound is 0.6 to 2.0 parts by mass per 100 parts by mass of the (A) polybutylene terephthalate resin. A resin composition in which the mass ratio [(b1) / (b2)] of the cyclic carbodiimide compound (b1) to the aromatic carbodiimide compound (b2) is 0.2 to 1.

6.

2. The resin composition according to claim 1, wherein the amount of (B) carbodiimide compound is 0.8 to 1.8 parts by mass per 100 parts by mass of (A) polybutylene terephthalate resin.

3. The resin composition according to claim 1 or 2, wherein the mass ratio [(b1) / (b2)] of the (b1) cyclic carbodiimide compound to the (b2) aromatic carbodiimide compound is 0.22 to 1.

5.

4. (D) The resin composition according to claim 1 or 2, wherein the fibrous inorganic filler is glass fiber.

5. Furthermore, the resin composition according to claim 1 or 2, comprising (E) a flame retardant and (F) a flame retardant aid.

6. Furthermore, the resin composition according to claim 1 or 2, further comprising (G) epoxy resin.

7. A molded article comprising the resin composition according to claim 1 or 2.

8. The molded article according to claim 7, which is an insert molded article.

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