JP7439400B2 - Polybutylene terephthalate resin composition, method for producing the same, and two-color molded article - Google Patents

Description

The present invention relates to a polybutylene terephthalate resin composition, and more specifically, it has excellent impact resistance and exhibits excellent resistance in an alkaline environment (hereinafter also referred to as "alkali resistance") and excellent two-color moldability. The present invention relates to a polybutylene terephthalate resin composition, a method for producing the same, and a two-color molded article.

Polybutylene terephthalate resin is easy to process, has excellent mechanical properties, heat resistance, and other physical and chemical properties, so it is used for automobile parts, electrical and electronic equipment parts, construction material parts, and other precision equipment parts. It is widely used in fields such as For example, in the automobile field, parts around the engine such as connectors, distributor parts, ignition coil parts, various control units, various sensors, electrical and electronic equipment parts such as connectors, switch parts, relay parts, coil parts, and construction material parts. Polybutylene terephthalate resin is used in a wide range of fields such as sanitary parts and bolts embedded in concrete.

In such fields, especially in automotive parts, moisture and heat resistance (hydrolysis resistance) has been required. To meet this demand, we have improved hydrolysis resistance by using polybutylene terephthalate resin with a small amount of carboxyl end groups, or by capping the carboxyl end groups by reacting them with a specific compound. can be done.

However, polybutylene terephthalate resin has insufficient alkali resistance, especially its long-term durability, and its use environments and uses are limited. For example, depending on the use of the resin molded product, it may be used in contact with chemicals such as snow melting agents, toilet cleaning agents, bathroom cleaning agents, bleaching agents, and cement. In particular, glass fiber-reinforced products have a significant decrease in strength due to alkali, and deterioration in an alkaline environment is considered a problem.
Furthermore, in the case of parts made of polybutylene terephthalate resin, due to the action of alkaline substances, there is a risk that cracks may occur, especially in thin parts or parts where distortion remains, and eventually breakage may occur.

Furthermore, by using the two-color molding method, a polybutylene terephthalate resin is combined with a resin of a different material and molded together to obtain a molded article with characteristics that cannot be achieved with a single polybutylene terephthalate resin. However, in two-color molding, if the adhesion strength between the polybutylene terephthalate resin and the other resin is not sufficient, the other resin will peel off from the adhesion surface, making it impossible to impart sufficient functionality to the molded product.

Patent Document 1 describes (A) thermoplastic polyester resin, (B) impact resistance imparting agent 1 to 25% by mass, (C) silicone compound and/or fluorine compound 0.1 to 15% by mass, (D ) A thermoplastic polyester resin composition containing 1 to 50% by mass of an inorganic filler and (E) 0.1 to 10% by mass of a polyfunctional compound such as a bisphenol A epoxy resin, an isocyanate compound, and a carboxylic dianhydride, It is disclosed that it has excellent alkali resistance. However, in such a resin composition, the alkali resistance and two-color moldability cannot be said to be at a fully satisfactory level, and the surface appearance tends to deteriorate due to seepage of silicone compounds and fluorine compounds.

Products are rapidly becoming lighter in weight and higher in performance, and even if these molded products are made thinner and smaller, it is necessary for them to exhibit sufficient properties over a long period of time. For this reason, there is currently a need for a polybutylene terephthalate resin composition that does not generate cracks even in thin-walled areas or areas where distortion remains, and has excellent alkali resistance and two-color moldability.

International publication WO00/078867

Particularly in recent years, very high specifications for alkali resistance and two-color moldability have been required. For example, in the alkali resistance test, the details of which will be described later, pass extremely strict standards such as the time required for cracking to occur for more than 300 hours when an insert molded product is immersed in a 10% concentration NaOH aqueous solution. There is also a growing demand for this.
The present invention solves the problems of the prior art described above, and provides a polybutylene terephthalate resin composition that simultaneously improves high alkali resistance and two-color moldability as described above and has excellent impact resistance, and a method for producing the same. , the purpose is to provide a two-color molded body.

As a result of extensive studies to solve the above problems, the present inventors found that (A1) polybutylene terephthalate resin, (A2) polycarbonate resin, (C) epoxy compound, (D) reinforcing filler, and further specific silicone. The resin composition containing the compound has improved alkali resistance and two-color moldability.In particular, by blending the silicone compound as a masterbatch with the thermoplastic resin, the dispersibility of the silicone compound is improved and bleed-out and The present invention has been achieved based on the discovery that the appearance defects are suppressed, and the increase in distortion during heat shock is suppressed, thereby significantly improving heat shock resistance.
The present invention relates to the following polybutylene terephthalate resin composition, method for producing the same, and two-color molded article.

[1] For a total of 100 parts by mass of (A1) and (A2) containing 50 to 95 parts by mass of (A1) polybutylene terephthalate resin and 5 to 50 parts by mass of (A2) polycarbonate resin, 0 to 30 parts by mass of (B) elastomer parts by mass, (C) 0.3 to 4 parts by mass of an epoxy compound, (D) 15 to 80 parts by mass of a reinforcing filler, and (E) a silicone compound having a weight average molecular weight of 10,000 to 80,000, and a thermoplastic resin. A polybutylene terephthalate resin composition containing 1 to 15 parts by mass of a masterbatch.
[2] The polybutylene terephthalate resin composition according to the above [1], wherein the epoxy compound (C) is a novolac type epoxy compound.
[3] (E) The polybutylene terephthalate resin composition for laser welding according to [1] or [2] above, wherein the thermoplastic resin of the masterbatch is incompatible with the polybutylene terephthalate resin.
[4] (E) The polybutylene terephthalate resin composition for laser welding according to any one of [1] to [3] above, wherein the thermoplastic resin of the masterbatch is a polyolefin resin.
[5] (A1) 50 to 95 parts by mass of polybutylene terephthalate resin, 5 to 50 parts by mass of (A2) polycarbonate resin, and 5 to 30 parts by mass of (B) elastomer for a total of 100 parts by mass of (A1) and (A2). (C) 0.3 to 4 parts by mass of an epoxy compound, (D) 15 to 80 parts by mass of a reinforcing filler, and (E) a silicone compound having a weight average molecular weight of 10,000 to 80,000, and a thermoplastic resin. A method for producing a polybutylene terephthalate resin composition, which comprises mixing 1 to 15 parts by mass of a batch, followed by melting and kneading.
[6] Member (I) molded from the polybutylene terephthalate resin composition according to any one of [1] to [4] above, and a resin different from the polybutylene terephthalate resin composition constituting member (I) A two-color molded body comprising a member (II) molded from a composition.
[7] The two-color molded article according to [6] above, wherein the resin composition constituting member (II) is a resin composition containing a polycarbonate resin.

The polybutylene terephthalate resin composition of the present invention has significantly improved alkali resistance and two-color moldability (adhesive strength), and also has excellent impact resistance.
Therefore, the polybutylene terephthalate resin composition of the present invention can be applied to a wide range of fields such as the vehicular field (particularly the automobile field), the electrical and electronic field, and the building materials field. It has excellent alkali resistance, two-color moldability, and impact resistance, especially as molded products for automotive parts such as connectors, distributor parts, ignition coil parts, control unit parts, and sensor parts.
According to the method for producing a polybutylene terephthalate resin composition of the present invention, it is possible to provide a polybutylene terephthalate resin composition that is significantly improved in both alkali resistance and two-color moldability and also has excellent impact resistance.
Moreover, the two-color molded article of the present invention has extremely high alkali resistance and high adhesion strength between resins.

FIG. 2 is a schematic diagram of a rectangular parallelepiped-shaped iron insert used for alkali resistance evaluation in Examples. FIG. 3 is an explanatory cross-sectional view of a mold cavity in which an insert is supported by support pins. FIG. 2 is a schematic diagram of an insert molded product in which two weld lines are formed at the support pin traces.

The content of the present invention will be explained in detail below. In addition, in this specification, "~" is used to include the numerical values described before and after it as a lower limit value and an upper limit value.

The polybutylene terephthalate resin composition of the present invention contains (A1) 50 to 95 parts by mass of polybutylene terephthalate resin and (A2) 5 to 50 parts by mass of polycarbonate resin, based on a total of 100 parts by mass of (A1) and (A2). , (B) 0 to 30 parts by mass of elastomer, (C) 0.3 to 4 parts by mass of epoxy compound, (D) 15 to 80 parts by mass of reinforcing filler, and (E) silicone compound having a weight average molecular weight of 10,000 to 80,000. and a thermoplastic resin in an amount of 1 to 15 parts by mass.

[(A1) Polybutylene terephthalate resin]
The polybutylene terephthalate resin used in the polybutylene terephthalate resin composition of the present invention is a polyester resin having a structure in which terephthalic acid units and 1,4-butanediol units are ester-bonded, and is a polybutylene terephthalate resin (homopolymer). Other examples include polybutylene terephthalate copolymers containing copolymer components other than terephthalic acid units and 1,4-butanediol units, and mixtures of homopolymers and such copolymers.

The polybutylene terephthalate resin may contain dicarboxylic acid units other than terephthalic acid, and specific examples of other dicarboxylic acids include isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, and 2,5-naphthalenedicarboxylic acid. Acid, 2,6-naphthalene dicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis(4,4'-carboxyphenyl) Aromatic dicarboxylic acids such as methane, anthracene dicarboxylic acid and 4,4'-diphenyl ether dicarboxylic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexane dicarboxylic acid and 4,4'-dicyclohexyl dicarboxylic acid, and adipine Examples include aliphatic dicarboxylic acids such as acid, sebacic acid, azelaic acid, and dimer acid.

The diol unit may contain other diol units in addition to 1,4-butanediol, and specific examples of other diol units include aliphatic or alicyclic diols having 2 to 20 carbon atoms. , bisphenol derivatives, and the like. Specific examples include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexane dimethanol, 4,4'-dicyclohexylhydroxymethane, 4 , 4'-dicyclohexylhydroxypropane, ethylene oxide-added diol of bisphenol A, and the like. In addition to the bifunctional monomers mentioned above, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane can be used to introduce a branched structure, and fatty acids can be used to adjust the molecular weight. Small amounts of monofunctional compounds can also be used in combination.

As mentioned above, the polybutylene terephthalate resin is preferably a polybutylene terephthalate homopolymer obtained by polycondensing terephthalic acid and 1,4-butanediol, but it is also preferable to use a dicarboxylic acid other than the above-mentioned terephthalic acid as the carboxylic acid unit. It may be a polybutylene terephthalate copolymer containing one or more diols other than the above-mentioned 1,4-butanediol as one or more types and/or diol units, and the polybutylene terephthalate resin may be a polybutylene modified by copolymerization. In the case of terephthalate resin, specific preferred copolymers include polyester ether resin copolymerized with polyalkylene glycols, particularly polytetramethylene glycol, dimer acid copolymerized polybutylene terephthalate resin, and isophthalic acid copolymerized polybutylene terephthalate resin. Examples include polybutylene terephthalate resin. Among these, it is preferable to use a polyester ether resin copolymerized with polytetramethylene glycol.
Note that these copolymers have a copolymerization amount of 1 mol % or more and less than 50 mol % of the total segment of the polybutylene terephthalate resin. Among these, the amount of copolymerization is preferably 2 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, particularly preferably 5 to 20 mol%. Such a copolymerization ratio tends to improve fluidity, toughness, and tracking resistance, which is preferable.

The terminal carboxyl group content of the polybutylene terephthalate resin may be determined by selecting it as appropriate, but it is usually 60 eq/ton or less, preferably 50 eq/ton or less, and more preferably 30 eq/ton or less. preferable. If it exceeds 50 eq/ton, alkali resistance and hydrolysis resistance will decrease, and gas will be likely to be generated during melt molding of the resin composition. Although the lower limit of the amount of terminal carboxyl groups is not particularly determined, it is usually 10 eq/ton in consideration of productivity in producing polybutylene terephthalate resin.

In addition, the amount of terminal carboxyl groups of polybutylene terephthalate resin is a value measured by dissolving 0.5 g of polyalkylene terephthalate resin in 25 mL of benzyl alcohol and titrating using a 0.01 mol/l benzyl alcohol solution of sodium hydroxide. be. The amount of terminal carboxyl groups can be adjusted by any conventionally known method, such as adjusting polymerization conditions such as raw material charging ratio, polymerization temperature, and pressure reduction method during polymerization, or reacting with a terminal blocking agent. That's fine.

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

Polybutylene terephthalate resin is produced by batchwise or continuous melt polymerization of a dicarboxylic acid component whose main component is terephthalic acid or an ester derivative thereof and a diol component whose main component is 1,4-butanediol. be able to. Further, after producing a low molecular weight polybutylene terectate resin by melt polymerization, the degree of polymerization (or molecular weight) can be increased to a desired value by further performing solid phase polymerization under a nitrogen stream or under reduced pressure.
The polybutylene terephthalate resin is preferably obtained by a manufacturing method in which a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing 1,4-butanediol as a main component are continuously melt-polycondensed.

The catalyst used in carrying out the esterification reaction may be any conventionally known catalyst, and examples thereof include titanium compounds, tin compounds, magnesium compounds, calcium compounds, and the like. Particularly preferred among these are titanium compounds. Specific examples of the titanium compound as an esterification catalyst include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

[(A2) Polycarbonate resin]
The polybutylene terephthalate resin composition of the present invention contains (A2) a polycarbonate resin together with (A1) a polybutylene terephthalate resin.
Polycarbonate resins are optionally branched thermoplastic polymers or copolymers obtained by reacting dihydroxy compounds or small amounts of polyhydroxy compounds with phosgene or carbonic acid diesters. The method for producing polycarbonate resin is not particularly limited, and those produced by the conventionally known phosgene method (interfacial polymerization method) or melting method (ester exchange method) can be used.

The dihydroxy compound as a raw material is substantially free of bromine atoms, and is preferably an aromatic dihydroxy compound. Specifically, 2,2-bis(4-hydroxyphenyl)propane (=bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxy Examples include diphenyl, and preferably bisphenol A. Further, it is also possible to use a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above-mentioned aromatic dihydroxy compound.

Among the polycarbonate resins mentioned above, aromatic polycarbonate resins derived from 2,2-bis(4-hydroxyphenyl)propane, or 2,2-bis(4-hydroxyphenyl)propane and other aromatic dihydroxy An aromatic polycarbonate copolymer derived from the compound is preferred. Alternatively, a copolymer mainly composed of an aromatic polycarbonate resin, such as a copolymer with a polymer or oligomer having a siloxane structure, may be used. Furthermore, two or more of the above-mentioned polycarbonate resins may be used in combination.

To adjust the molecular weight of polycarbonate resins, monovalent aromatic hydroxy compounds may be used, such as m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, p-long chain Examples include alkyl-substituted phenols.

The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 13,000 or more, more preferably 13,500 or more, still more preferably 14,000 or more, and especially preferably 15,000 or more. If a resin having a viscosity average molecular weight lower than 13,000 is used, the resulting resin composition tends to have low mechanical strength such as impact resistance. Moreover, Mv is preferably 60,000 or less, more preferably 40,000 or less, and even more preferably 35,000 or less. If it is higher than 60,000, the fluidity of the resin composition may become poor and moldability may deteriorate.

In the present invention, the viscosity average molecular weight (Mv) of the polycarbonate resin is determined by measuring the viscosity of a methylene chloride solution of the polycarbonate resin at 25°C using an Ubbelohde viscometer, and determining the intrinsic viscosity ([η]). The value calculated from the following Schnell's viscosity formula is shown.
[η]=1.23×10 ⁻⁴ Mv ^0.83

The method for producing polycarbonate resin is not particularly limited, and polycarbonate resin produced by either the phosgene method (interfacial polymerization method) or the melting method (ester exchange method) can be used. It is also preferable to use a polycarbonate resin produced by a melting method and subjected to a post-treatment to adjust the amount of terminal OH groups.

The content of (A2) polycarbonate resin is 5 to 50 parts by mass, preferably 10 parts by mass, based on the total of 100 parts by mass of (A1) polybutylene terephthalate resin and (A2) polycarbonate resin. As mentioned above, it is more preferably 15 parts by mass or more, still more preferably 20 parts by mass or more, and preferably less than 50 parts by mass, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less.
The content of (A1) polybutylene terephthalate resin is preferably 50 to 95 parts by mass based on the total of 100 parts by mass of (A1) polybutylene terephthalate resin and (A2) polycarbonate resin. is more than 50 parts by mass, more preferably 55 parts by mass or more, still more preferably 60 parts by mass or more, and preferably 90 parts by mass or less, more preferably 85 parts by mass or less, even more preferably 80 parts by mass or less. It is.
(A2) If the content of the polycarbonate resin is less than 5 parts by mass, sufficient bonding strength during two-color molding will not be obtained and dimensional stability will also decrease. Moreover, if it exceeds 50 parts by mass, fluidity will deteriorate and alkali resistance will also deteriorate.

[(B) Elastomer]
As the elastomer (B) used in the present invention, a thermoplastic elastomer that is used to improve the impact resistance by blending with a polyester resin may be used. A copolymer of a compound that reacts with can be used.
(B) The glass transition temperature of the elastomer is preferably 0°C or lower, particularly -20°C or lower.

(B) Specific examples of elastomers include copolymers of ethylene and unsaturated carboxylic acid esters (ethylene-methacrylate copolymers, ethylene-butyl acrylate copolymers, etc.), ethylene and aliphatic vinyl compounds, etc. Copolymers, terpolymers of ethylene, propylene, and non-conjugated dienes, acrylic rubbers (polybutyl acrylate, poly(2-ethylhexyl acrylate), butyl acrylate-2-ethylhexyl acrylate copolymers, etc.), polybutadiene, polyisoprene, dienes copolymers (styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, acrylic-butadiene rubber, etc.), copolymers of ethylene and α-olefins having 3 or more carbon atoms (ethylene-propylene copolymers, -butene copolymer, ethylene/octene copolymer, etc.), silicone rubber (polyorganosiloxane rubber, IPN type composite rubber consisting of polyorganosiloxane rubber and polyalkyl (meth)acrylate rubber), and the like. These may be used alone or in combination of two or more.
In addition, in this specification, (meth)acrylate means acrylate and methacrylate, and (meth)acrylic acid means acrylic acid and methacrylic acid.

Another example of the elastomer (B) is a copolymer obtained by polymerizing a rubbery polymer with a monomer compound. Examples of this monomer compound include aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylic acid ester compounds, and (meth)acrylic acid compounds. In addition, epoxy group-containing (meth)acrylic acid ester compounds such as glycidyl (meth)acrylate; maleimide compounds such as maleimide, N-methylmaleimide, and N-phenylmaleimide; α, β- such as maleic acid, phthalic acid, and itaconic acid. Also included are unsaturated carboxylic acid compounds and their anhydrides (eg, maleic anhydride, etc.). These monomer compounds can be used alone or in combination of two or more.

As the elastomer (B), a copolymer of ethylene and an unsaturated carboxylic acid ester is preferred, an ethylene-alkyl acrylate copolymer is preferred, and an ethylene-butyl acrylate copolymer is particularly preferred. From the viewpoint of improving impact resistance and heat shock resistance, the content of butyl acrylate is preferably 10% by mass or more, and more preferably 20% by mass or more. Further, the MFR of the ethylene-butyl acrylate copolymer is preferably 10 g/10 min or more from the viewpoint of improving fluidity, and particularly preferably 20 g/min or more.
By using such an elastomer, impact resistance, fluidity, and heat shock resistance tend to be improved, which is preferable.
These elastomers may be used alone or in combination of two or more.

The content of the elastomer (B) is 0 to 30 parts by weight based on a total of 100 parts by weight of the polybutylene terephthalate resin (A1) and the polycarbonate resin (A2). (B) If the content of the elastomer exceeds 30 parts by mass, heat aging resistance, rigidity, fluidity, and flame retardance will decrease. The content of the elastomer (B) is preferably 25 parts by mass or less, more preferably 20 parts by mass or less.

[(C) Epoxy compound]
The epoxy compound (C) used in the present invention is used to suppress the polybutylene terephthalate resin from undergoing hydrolysis and causing a decrease in molecular weight and at the same time, a decrease in mechanical strength, etc. This promotes the synergistic effect of the masterbatch containing the elastomer (B) and the silicone compound (E) and the thermoplastic resin, thereby further improving the alkali resistance and heat shock resistance.

(C) The epoxy compound may be any compound having one or more epoxy groups in one molecule, and is usually a glycidyl compound which is a reaction product of epichlorohydrin with alcohol, phenol or carboxylic acid, etc. , a compound in which an olefinic double bond is epoxidized may be used.
(C) Epoxy compounds include, for example, novolac type epoxy compounds, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, alicyclic epoxy compounds, glycidyl ethers, glycidyl esters, epoxidized butadiene polymers, resorcin type epoxy Examples include compounds.

Examples of the novolak-type epoxy compound include phenol novolac-type epoxy compounds, cresol novolac-type epoxy compounds, and the like.
Examples of bisphenol A-type epoxy compounds include bisphenol A-diglycidyl ether and hydrogenated bisphenol A-diglycidyl ether, and examples of bisphenol F-type epoxy compounds include bisphenol F-diglycidyl ether and hydrogenated bisphenol F-diglycidyl ether. Examples include ether.

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

Specific examples of glycidyl ethers include monoglycidyl ethers such as methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, phenyl glycidyl ether, butylphenyl glycidyl ether, and allyl glycidyl ether; Examples include diglycidyl ethers such as pentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, propylene glycol diglycidyl ether, and bisphenol A diglycidyl ether.

Examples of the glycidyl esters include monoglycidyl esters such as benzoic acid glycidyl ester and sorbic acid glycidyl ester; diglycidyl esters such as adipic acid diglycidyl ester, terephthalic acid diglycidyl ester, and orthophthalic acid diglycidyl ester.

Examples of the epoxidized butadiene polymer include epoxidized polybutadiene, epoxidized styrene-butadiene copolymer, and epoxidized hydrogenated styrene-butadiene copolymer.
Examples of resorcin type epoxy compounds include resorcin diglycidyl ether.

Moreover, the epoxy compound (C) may be a copolymer containing a glycidyl group-containing compound as one component. Examples include copolymers of glycidyl esters of α,β-unsaturated acids and one or more monomers selected from the group consisting of α-olefins, acrylic acid, acrylic esters, methacrylic acid, and methacrylic esters. It will be done.

The epoxy compound (C) is preferably an epoxy compound having an epoxy equivalent of 50 to 10,000 g/eq and a weight average molecular weight of 8,000 or less. If the epoxy equivalent is less than 50 g/eq, the amount of epoxy groups will be too large, resulting in a high viscosity of the resin composition, and if the epoxy equivalent is more than 10,000 g/eq, the amount of epoxy groups will be small. The effect of improving the alkali resistance, heat shock resistance, and hydrolysis resistance of the polybutylene terephthalate resin composition tends to be difficult to sufficiently exhibit. The epoxy equivalent is more preferably 100 to 7000 g/eq, still more preferably 100 to 5000 g/eq, and most preferably 100 to 3000 g/eq. In addition, those having a weight average molecular weight of more than 8,000 tend to have lower compatibility with polybutylene terephthalate resin and lower mechanical strength of the molded product. The weight average molecular weight is more preferably 7,000 or less, still more preferably 6,000 or less.

As the epoxy compound (C), bisphenol A type epoxy compounds and novolak type epoxy compounds obtained from the reaction of bisphenol A or novolak with epichlorohydrin are preferred. Among these, novolak-type epoxy compounds are particularly preferred from the viewpoints of easy improvement in alkali resistance, hydrolysis resistance, heat shock resistance, and surface appearance of molded products.

The content of the epoxy compound (C) is 0.3 to 4 parts by mass, preferably 0.4 parts by mass or more, based on a total of 100 parts by mass of (A1) polybutylene terephthalate resin and (A2) polycarbonate resin. It is more preferably 0.5 parts by mass or more, and even more preferably 0.6 parts by mass or more. Moreover, it is preferably 3.5 parts by mass or less, more preferably 3 parts by mass or less, still more preferably 2.5 parts by mass or less, particularly preferably 2.2 parts by mass or less. (C) If the content of the epoxy compound is less than 0.3 parts by mass, a decrease in alkali resistance and hydrolysis resistance tends to occur, and if it is more than 4 parts by mass, crosslinking will progress and fluidity during molding will deteriorate. It tends to get worse.

Further, the equivalent ratio of the epoxy group of the epoxy compound (C) to the terminal COOH group of the polybutylene terephthalate resin (A1) (epoxy group/COOH group) is preferably in the range of 0.2 to 2.7. When the equivalent ratio is less than 0.2, hydrolysis resistance tends to deteriorate, and when it exceeds 2.7, moldability tends to become unstable. The ratio of epoxy group/COOH group is more preferably 0.3 or more and 2.5 or less.

[(D) Reinforcing filler]
The polybutylene terephthalate resin composition of the present invention contains (D) a reinforcing filler in a range of 15 to 80 parts by mass based on a total of 100 parts by mass of (A1) polybutylene terephthalate resin and (A2) polycarbonate resin. . (D) The content of the reinforcing filler is preferably 25 parts by mass or more, more preferably 35 parts by mass or more, and preferably 75 parts by mass or less, and more preferably 70 parts by mass or less.
In the present invention, the reinforcing filler refers to a material that is contained in a resin component to improve strength and rigidity, and may be in any form such as fibrous, plate-like, granular, or amorphous.

(D) When the reinforcing filler has a fibrous form, it may be either inorganic or organic. For example, inorganic fibers such as glass fibers, carbon fibers, silica/alumina fibers, zirconia fibers, boron fibers, boron nitride fibers, silicon nitride potassium titanate fibers, metal fibers, wollastonite, and organic fibers such as fluororesin fibers and aramid fibers. Contains fiber. (D) When the reinforcing filler is in the form of fibers, inorganic fibers are preferred, and among these, glass fibers are particularly preferred. (D) The reinforcing filler may be one type or a mixture of two types.

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

In addition to the above-described fibrous reinforcing fillers, other reinforcing fillers in the form of plates, particles, or amorphous shapes may also be contained. The plate-shaped inorganic filler exhibits a function of reducing anisotropy and warpage, and examples include glass flakes, talc, mica, mica, kaolin, and metal foil. Among the plate-shaped inorganic fillers, glass flakes are preferred.

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

In order to improve the adhesion of the interface between the reinforcing filler (D) and the resin component, it is preferable to treat the surface of the reinforcing filler (D) with a surface treatment agent such as a sizing agent. Examples of the surface treatment agent include epoxy resins, acrylic resins, urethane resins, and functional compounds such as isocyanate compounds, silane compounds, and titanate compounds.
In the present invention, it is preferable to use an epoxy resin for surface treatment. As the epoxy resin, novolac type epoxy compounds such as phenol novolac type and cresol novolac type, and bisphenol A type epoxy resins are preferable. Among them, it is preferable to use a novolac type epoxy compound and a bisphenol type epoxy resin in combination, and it is preferable to use a phenol novolac type epoxy compound and a bisphenol A type epoxy resin in combination from the viewpoint of alkali resistance, hydrolysis resistance, and mechanical properties. .

As the functional compound, silane coupling agents such as aminosilane-based, epoxysilane-based, allylsilane-based, vinylsilane-based, etc. are preferable, and among them, aminosilane-based compounds are preferable.
As the aminosilane compound, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-(2-aminoethyl)aminopropyltrimethoxysilane are preferred, and among them, γ-Aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane are preferred.

In the present invention, a novolac type epoxy resin and a bisphenol type epoxy resin are used as a so-called sizing agent, and in addition, a reinforcing filler whose surface is treated with an aminosilane compound is used as a coupling agent. Particularly preferred from the viewpoint of performance. By configuring the surface treatment agent in this way, the inorganic functional group of the aminosilane compound is highly reactive with the surface of the reinforcing filler (D), and the organic functional group of the aminosilane is highly reactive with the glycidyl group of the epoxy resin, and The glycidyl groups of the epoxy resin react appropriately with the polybutylene terephthalate resin (A1), thereby improving the interfacial adhesion between the reinforcing filler (D) and the epoxy resin. As a result, the alkali resistance, hydrolysis resistance, and mechanical properties of the resin composition of the present invention tend to improve.
Furthermore, within the scope of the spirit of the present invention, urethane resins, acrylic resins, antistatic agents, lubricants, water repellents, etc. can be included in the surface treatment agent, and when these other components are included, It is preferable to use urethane resin.

(D) The reinforcing filler can be surface-treated by a conventionally known method, for example, it may be surface-treated in advance with the above-mentioned surface treatment agent, and when preparing the polybutylene terephthalate resin composition of the present invention. A surface treatment agent may be added to the untreated reinforcing filler (D) for surface treatment.
(D) The amount of surface treatment agent adhered to the reinforcing filler is preferably 0.01 to 5% by mass, more preferably 0.05 to 2% by mass. When the content is 0.01% by mass or more, the mechanical strength tends to be improved more effectively, and when the content is 5% by mass or less, the necessary and sufficient effect can be obtained, and the production of the resin composition is improved. This is preferable because it tends to become easier.

[(E) Masterbatch containing silicone compound and thermoplastic resin]
A masterbatch containing (E) a silicone compound having a weight average molecular weight of 10,000 to 80,000 and a thermoplastic resin is blended into the polybutylene terephthalate resin composition of the present invention. Specifically, a masterbatch in the form of pellets in which a silicone compound is dispersed in a thermoplastic resin is blended.
When a silicone compound is blended into a composition in liquid form, it will be uniformly and finely dispersed in the molded product, which will lower the probability of the silicone compound existing on the surface of the molded product, resulting in lower alkali resistance and hydrolysis resistance. In addition, the silicone compound tends to bleed out onto the surface, which tends to cause problems such as deterioration of the surface appearance. In particular, deterioration of the surface appearance and bleed-out of silicone will reduce the bonding strength during two-color molding. On the other hand, by blending the silicone compound into the composition as a masterbatch as in the present invention, bleed-out is suppressed and it becomes possible to uniformly disperse the silicone compound without impairing the surface appearance.

In the present invention, a silicone compound with a weight average molecular weight (Mw) of 10,000 to 80,000 is used. If the Mw is less than 10,000, the alkali resistance will be poor, and if it exceeds 80,000, the heat shock resistance or the surface of the molded product will deteriorate. Appearance deteriorates.
The Mw of the silicone compound is preferably 20,000 or more, more preferably 30,000 or more, even more preferably 40,000 or more, and preferably 75,000 or less, more preferably 70,000 or less, still more preferably 65,000 or less.

The silicone compound used in the masterbatch of the present invention is an organosilicon compound having a skeleton of siloxane bonds and an organic group directly bonded to the silicon. As organic groups directly bonded to silicon, methyl groups, ethyl groups, phenyl groups, vinyl groups, trifluoropropyl groups, and combinations thereof are known, but known siloxane compounds having these groups are particularly restricted. It can be used without any problem. In addition, a part of the organic group is substituted with a substituent having an epoxy group, an amino group, a polyether group, a carboxyl group, a mercapto group, an ester group, a chloroalkyl group, an alkyl group having 3 or more carbon atoms, a hydroxyl group, etc. Siloxane compounds can also be used. The siloxane compounds can be used alone or in combination of two or more.

Siloxane compounds are classified into silicone oils, silicone elastomers, and silicone resins (if necessary, refer to "Silicone Material Handbook" edited by Dow Corning Toray, published August 1993), but in the present invention, any of the above Although silicone resin and silicone oil can also be used, silicone resin and silicone oil are preferred.
Specific examples of silicone oil include dimethyl silicone oil, phenylmethyl silicone oil, alkyl-modified silicone oil, fluorosilicone oil, polyether-modified silicone oil, aliphatic ester-modified silicone oil, amino-modified silicone oil, carboxylic acid-modified silicone oil, Examples include oily silicones such as carbinol-modified silicone oil, epoxy-modified silicone oil, and mercapto-modified silicone oil.

Furthermore, the thermoplastic resin used in the masterbatch of the present invention is preferably a resin that is incompatible with polybutylene terephthalate resin. By using a resin that is incompatible with polybutylene terephthalate as a masterbatch, the presence of a silicone compound at a high concentration in the incompatible resin dispersed in polybutylene terephthalate increases effects such as alkali resistance. It becomes easier to express. Examples of thermoplastic resins that can be used include polyolefin resins, polyamide resins, styrene resins, polyimide resins, polyetherimide resins, polyurethane resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, and polymethacrylate resins. Among the above resins, polyolefin resins are particularly preferred in order to exhibit the various effects of the present invention.

Various polyolefin resins can be used as the polyolefin resin, among which polyethylene resins such as ethylene or propylene homopolymers, ethylene copolymers of ethylene and propylene, butene, hexene, octene, or vinyl acetate; Preferred examples include polypropylene resins such as propylene copolymers of propylene and butene, hexene, or octene. Preferred examples of the polyethylene resin include high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and ethylene-vinyl acetate copolymer (EVA). Preferred examples of the polypropylene resin include polypropylene, propylene-ethylene copolymer, and the like.
Among these, polyethylene resins are preferred, high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE) are more preferred, and low-density polyethylene (LDPE) is particularly preferred.

There are no restrictions on the manufacturing method or polymerization catalyst for polyolefin resin, and various known manufacturing methods such as solution method, bulk method, gas phase method, and high pressure method, as well as radical initiators, Ziegler catalysts, chromium-based catalysts, metallocene-based catalysts, etc. It may be based on

Further, the polyolefin resins may be used alone or in combination of two or more.

The masterbatch can be produced by any conventionally known method, such as mixing using a ribbon blender, Henschel mixer, Banbury mixer, drum tumbler, short-shaft or multi-shaft extruder, etc. Among them, a method using a Henschel mixer, a short-shaft or multi-screw extruder is preferred, and a method of melt-kneading and pelletizing using a short-shaft or multi-screw extruder is particularly preferred. By forming a masterbatch in this way and then melt-kneading it during production, the mechanical properties and slidability of the molded product tend to be better.

(E) A commercially available masterbatch containing a silicone compound and a thermoplastic resin can also be used, for example, one selected from the series manufactured by Dow Corning Toray under the trade name "Silicone Concentrate". You can also use

(E) The preferred content of the silicone compound in the masterbatch containing the silicone compound and the thermoplastic resin is 10 to 80% by mass, more preferably 20 to 70% by mass, even more preferably 20 to 60% by mass, particularly preferably is 20 to 50% by mass.

(E) The content of the masterbatch containing a silicone compound and a thermoplastic resin is 1 to 15 parts by mass, preferably 2 parts by mass, based on a total of 100 parts by mass of (A1) polybutylene terephthalate resin and (A2) polycarbonate resin. ~12 parts by weight, more preferably 3 to 10 parts by weight. If the content is less than 1 part by mass, it is difficult to sufficiently improve the alkali resistance, and if it exceeds 15 parts by mass, the extrudability and molding processability when producing the resin composition by melt-kneading will be poor, Mechanical properties also decrease.

[(F) Mold release agent]
The polybutylene terephthalate resin composition of the present invention preferably contains a mold release agent. As the mold release agent, known mold release agents commonly used for polyester resins can be used, but among them, polyolefin compounds and fatty acid ester compounds are preferable because of their good alkali resistance.In particular, polyolefin compounds and fatty acid ester compounds are preferred. Compounds are preferred.

Examples of the polyolefin compound include compounds selected from paraffin wax and polyethylene wax, and among them, those having a weight average molecular weight of 700 to 10,000, more preferably 900 to 8,000.

Examples of fatty acid ester compounds include fatty acid esters such as saturated or unsaturated monovalent or divalent aliphatic carboxylic acid esters, glycerin fatty acid esters, sorbitan fatty acid esters, and partially saponified products thereof. Among these, mono- or di-fatty acid esters composed of a fatty acid having 11 to 28 carbon atoms, preferably 17 to 21 carbon atoms, and alcohol are preferred.

Examples of fatty acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melisic acid, tetraliacontanoic acid, montanic acid, adipic acid, azelaic acid, etc. It will be done. Furthermore, the fatty acid may be alicyclic.
Alcohols include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, monohydric or polyhydric saturated alcohols having 30 or less carbon atoms are preferred, and aliphatic saturated monohydric or polyhydric alcohols having 30 or less carbon atoms are more preferred. Here, aliphatic also includes alicyclic compounds.
Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, and the like. can be mentioned.
Note that the above ester compound may contain an aliphatic carboxylic acid and/or an alcohol as an impurity, or may be a mixture of a plurality of compounds.

Specific examples of fatty acid ester compounds include glycerin monostearate, glycerin monobehenate, glycerin dibehenate, glycerin-12-hydroxy monostearate, sorbitan monobehenate, pentaerythritol monostearate, and pentaerythritol distear. ester, stearyl stearate, ethylene glycol montanate, and the like.

The content of the mold release agent (F) is preferably 0.1 to 3 parts by mass, but 0.2 to 3 parts by mass, based on a total of 100 parts by mass of (A1) polybutylene terephthalate resin and (A2) polycarbonate resin. It is more preferably 2.5 parts by mass, and even more preferably 0.5 to 2 parts by mass. If it is less than 0.1 part by mass, the surface properties tend to decrease due to poor mold release during melt molding, while if it exceeds 3 parts by mass, the kneading workability of the resin composition tends to decrease, and the molded product The surface tends to become cloudy.

[Stabilizer]
It is preferable that the polybutylene terephthalate resin composition of the present invention contains a stabilizer, since this has the effect of improving thermal stability and preventing deterioration of mechanical strength, transparency, and hue. As the stabilizer, sulfur stabilizers and phenol stabilizers are preferred.

As the sulfur-based stabilizer, any conventionally known sulfur atom-containing compound can be used, and among them, thioethers are preferred. Specifically, for example, didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3-dodecylthiopropionate), thiobis(N-phenyl-β-naphthylamine) ), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyl dithiocarbamate, nickel isopropyl xanthate, and trilauryl trithiophosphite. Among these, pentaerythritol tetrakis (3-dodecylthiopropionate) is preferred.

Examples of phenolic stabilizers include pentaerythritol tetrakis (3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), octadecyl-3-(3,5-di-tert-butyl-4 -hydroxyphenyl)propionate, thiodiethylene bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), pentaerythritol tetrakis(3-(3,5-di-neopentyl-4-hydroxyphenyl) ) propionate), etc. Among these, pentaerythritol tetrakis (3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate is preferred.

One type of stabilizer may be contained, or two or more types may be contained in any combination and ratio.

The content of the stabilizer is preferably 0.001 to 2 parts by mass based on the total of 100 parts by mass of (A1) polybutylene terephthalate resin and (A2) polycarbonate resin. If the content of the stabilizer is less than 0.001 parts by mass, it is difficult to expect improvement in the thermal stability and compatibility of the resin composition, and a decrease in molecular weight and deterioration of hue during molding are likely to occur. If it exceeds the amount, there is a tendency that the amount becomes excessive and silver formation and hue deterioration are more likely to occur. The content of the stabilizer is more preferably 0.01 to 1.5 parts by mass, and even more preferably 0.1 to 1 part by mass.

[Flame retardants]
The polybutylene terephthalate resin composition of the present invention may contain a flame retardant to impart flame retardancy. Examples of the flame retardant include organic halogen compounds, antimony compounds, phosphorus compounds, nitrogen compounds, and other organic and inorganic compounds. Specific examples of the organic halogen compound include brominated polycarbonate, brominated epoxy resin, brominated phenoxy resin, brominated polyphenylene ether resin, brominated polystyrene resin, brominated bisphenol A, pentabromobenzyl polyacrylate, and the like.

Examples of antimony compounds include antimony trioxide, antimony pentoxide, and sodium antimonate. Examples of flame retardants of phosphorus compounds include phosphoric acid ester, polyphosphoric acid, melamine polyphosphate, ammonium polyphosphate, phosphinate metal salt, red phosphorus, and the like. Further, examples of nitrogen-based flame retardants include melamine cyanurate, phosphazene, and the like. Examples of organic flame retardants and inorganic flame retardants other than those mentioned above include inorganic compounds such as aluminum hydroxide, magnesium hydroxide, silicon compounds, and boron compounds.

[Other ingredients]
The polybutylene terephthalate resin composition of the present invention can also contain various conventionally known resin additives, if necessary, within a range that does not impede the effects of the present invention. Various resin additives include antioxidants, ultraviolet absorbers, weather stabilizers, lubricants, colorants such as dyes and pigments, catalyst deactivators, antistatic agents, blowing agents, plasticizers, crystal nucleating agents, and crystallization promoters. agents, etc.

The polybutylene terephthalate resin composition of the present invention may contain other thermoplastic resins, thermosetting resins, etc. other than the above-mentioned essential component resins, if necessary, within a range that does not impede the effects of the present invention. be able to. Other thermoplastic resins include polyamide resin, polyacetal resin, polyphenylene oxide resin, polyphenylene sulfide resin, liquid crystal polyester resin, acrylic resin, etc., and thermosetting resins include phenol resin, melamine resin, silicone resin, Examples include epoxy resin. These may be one type or two or more types.

However, if other resins other than the above-mentioned essential component resins are contained, the content shall be 40 parts by mass or less based on a total of 100 parts by mass of (A1) polybutylene terephthalate resin and (A2) polycarbonate resin. The content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, most preferably 10 parts by mass or less, particularly 5 parts by mass or less, and most preferably 2 parts by mass or less.

The method for producing the polybutylene terephthalate resin composition of the present invention is not limited to a specific method, but includes (A1) 50 to 95 parts by mass of polybutylene terephthalate resin, (A2) 5 to 45 parts by mass of polycarbonate resin. , for a total of 100 parts by mass of (A1) and (A2), (B) 0 to 30 parts by mass of elastomer, (C) 0.3 to 4 parts by mass of epoxy compound, and (D) 15 to 80 parts by mass of reinforcing filler. and (E) a method in which 1 to 15 parts by mass of a masterbatch containing a silicone compound having a weight average molecular weight of 10,000 to 80,000 and a thermoplastic resin are mixed, and then melted and kneaded. The melting and kneading method can be a method commonly employed for thermoplastic resins. Note that as each component (A1), (A2), and (B) to (E), those described above can be used.

The melting/kneading method includes, for example, uniformly mixing the above-mentioned essential components and other components blended as necessary using a Henschel mixer, ribbon blender, V-type blender, tumbler, etc. Examples include a method of melting and kneading using a kneading extruder, roll, Banbury mixer, Laboplast Mill (Brabender), and the like. If necessary, it is preferable to feed the reinforcing filler (D) from the side feeder of the kneading extruder, as this makes it possible to suppress breakage of the reinforcing filler and disperse it. The temperature and kneading time during melting and kneading can be selected depending on the type of components constituting the resin component, the ratio of the components, the type of melting and kneading machine, etc., but the temperature during melting and kneading is 200 to 300. A range of 0.degree. C. is preferred. When the temperature exceeds 300°C, thermal deterioration of each component becomes a problem, and the physical properties of the molded product may deteriorate or the appearance may deteriorate.

The method for producing the desired molded article from the polybutylene terephthalate resin composition of the present invention is not particularly limited, and any conventional molding method for thermoplastic resins can be employed. Examples include injection molding, ultra-high-speed injection molding, injection compression molding, two-color molding, gas-assisted blow molding, molding using an insulated mold, and rapid heating mold. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermoforming method, rotational molding method, lamination molding method, press molding method, Examples include blow molding methods, among which injection molding methods and two-color molding methods are preferred.

The polybutylene terephthalate resin composition of the present invention has particularly high hot melt adhesive strength and low deformation, so even when two-color molding is performed with different resins, two-color molded products with high adhesion strength can be obtained. be able to. That is, two-color molding consisting of a member (I) molded with the polybutylene terephthalate resin composition of the present invention and a member (II) molded with a resin composition different from the polybutylene terephthalate resin composition of member (I). Enables high adhesion strength to the body. In particular, when the resin composition constituting member (II) is a resin composition containing a polycarbonate resin, a two-color molded article having extremely high adhesiveness can be obtained.

In the alkali resistance test using the polybutylene terephthalate resin composition of the present invention, the time until cracks occur when the insert molded product is immersed in a 10% by mass NaOH aqueous solution is preferably 300 hours or more, more preferably 400 hours or more. It is possible to achieve extremely high alkali resistance, more preferably for 500 hours or more, and also has excellent bonding strength, so it has excellent properties particularly for the properties required for automotive parts.

The molded products that can be manufactured include, for example, various storage containers, electrical and electronic parts, OA equipment parts, home appliance parts, mechanical mechanism parts, construction material parts, other precision equipment parts, automobile mechanical parts, sanitary parts, and the like. Particularly suitable for food containers, pharmaceutical containers, oil and fat product containers, vehicle hollow parts, motor parts, various sensor parts, connector parts, switch parts, breaker parts, relay parts, coil parts, transformer parts, lamp parts, etc. Can be used. Among these, it is suitable as a resin material for molded products for in-vehicle parts around an automobile engine, such as various sensors, connectors, distributor parts, ignition coil parts, and cases and casings thereof.

Hereinafter, the present invention will be explained in more detail based on Examples and Comparative Examples, but the present invention should not be interpreted as being limited to the following examples.
The raw material components used in the Examples and Comparative Examples are shown in Table 1 below.

[Examples 1 to 3 and Comparative Examples 1 to 2]
<Production of polybutylene terephthalate resin composition>
Each component other than the glass fiber listed in Table 1 is blended in the proportions (all parts by mass) shown in Table 2 below, and this is mixed using a 30 mm bent type twin screw extruder (manufactured by Japan Steel Works, Ltd., Using a shaft extruder (TEX30α), glass fibers are fed from a side feeder, melted and kneaded at a barrel temperature of 270°C, extruded into strands, and pelletized with a strand cutter to form pellets of polybutylene terephthalate resin composition. Obtained.

<Measurement evaluation method>
Measurement and evaluation of various physical properties and performances in Examples and Comparative Examples were carried out by the following methods.

(a) Charpy impact strength (unit: kJ/m ² )
After drying the obtained pellets at 120°C for 6 hours, they were molded using an injection molding machine "NEX80-9E" manufactured by Nissei Jushi Kogyo Co., Ltd. under the conditions of a cylinder temperature of 250°C and a mold temperature of 80°C for Charpy impact strength measurement. An ISO test piece was molded, and the notched Charpy impact strength was measured in accordance with ISO179.

(b) Hydrolysis resistance evaluation: Tensile strength retention rate (unit: %)
Using an injection molding machine "NEX80-9E" manufactured by Nissei Jushi Kogyo Co., Ltd., an ISO test piece was prepared at a cylinder temperature of 250°C and a mold temperature of 80°C, and a tensile test was conducted in accordance with ISO527.
Furthermore, the above-mentioned ISO test piece was subjected to moist heat treatment for 100 hours at a pressure of 203 kPa in saturated steam at a temperature of 121°C. The tensile strength of the ISO test pieces before and after the moist heat treatment was measured in accordance with ISO527.
The tensile strength retention rate (unit: %) was determined from the following formula.
Tensile strength retention rate (%) = (Tensile strength after treatment/Tensile strength before treatment) x 100

(c) Alkali resistance evaluation After drying the obtained pellets at 120°C for 6 hours, using a vertical injection molding machine "TH60 R5VSE" manufactured by Nissei Jushi Kogyo Co., Ltd., at a cylinder temperature of 250°C and a mold temperature of 80°C, A rectangular parallelepiped-shaped iron (SUS) insert 1 (length 16 mm x width 33 mm x thickness 3 mm) shown in Fig. 1 is inserted into the mold cavity 4 using support pins 2 as shown in Fig. 2. (insert iron piece 3). An insert molded product (18 mm long x 35 mm wide x 5 mm thick) shown in FIG. 3 was produced by insert molding. The thickness of the resin part of this insert molded product is 1 mm.
Two weld lines 6 occur at the support pin marks 5 in the insert molded product.
This insert molded product was immersed in a 10% by mass NaOH aqueous solution at room temperature. After immersion, the presence or absence of cracks was periodically checked visually, and the time (hr) until cracks appeared was measured. The longer this time, the better the alkali resistance.

(d) Surface appearance evaluation Using an injection molding machine "NEX80-9E" manufactured by Nissei Jushi Kogyo Co., Ltd., a flat plate of 100 mm long x 100 mm wide x 3 mm thick was molded at a cylinder temperature of 250°C and a mold temperature of 80°C. The surface appearance was visually observed, and the samples were classified as follows.
○: Good △: Slightly bad ×: Significantly bad

(e) Bonding strength (unit: N)
Manufacture of two-color molded test pieces for joint strength measurement:
An ISO-1A butt type two-color molded test piece was molded using an injection molding machine "J180AD-2M (mold clamping force 180 t, screw diameter cylinder A = 46 mm, B = 40 mm)" manufactured by Japan Steel Works. . The mold temperature was 80°C, and the polycarbonate resin "Iupilon S-3000R" manufactured by Mitsubishi Engineering Plastics Co., Ltd. was molded as the primary material at a cylinder temperature of 300°C, and the secondary materials were obtained in each example and comparative example. The pellets were molded at a cylinder temperature of 260°C.
Measuring bond strength:
The obtained two-color molded test piece was subjected to a tensile test at a room temperature of 23° C. at a speed of 5 mm/min and a distance between chucks of 115 mm to confirm the bonding strength (unit: N) at which it would break.

(f) Comprehensive evaluation Based on the above results, comprehensively evaluate the following three items on a scale of 1 if all are satisfied, 2 if two are satisfied, and 3 if less than one. did.
1) Alkali resistance of 300 hours or more,
2) Good surface appearance is ○
3) Bonding strength is 1000N or more

The results are shown in Table 2 below.

From the results in Table 2 above, it can be seen that the polybutylene terephthalate resin compositions of Examples 1 to 3 achieve impact resistance, hydrolysis resistance, alkali resistance, surface appearance, and two-color moldability in a well-balanced manner.

The polybutylene terephthalate resin composition of the present invention can achieve all of impact resistance, hydrolysis resistance, alkali resistance, surface appearance, and two-color moldability in a well-balanced manner. It is an extremely useful material for manufacturing sensor parts, engine parts, and automobile parts around the suspension. Furthermore, it is useful in a wide range of fields such as electrical and electronic parts, building material parts, and mechanical parts.

1. Insert iron piece 2. Support pin 3. Insert iron piece inserted into the mold 4. Cavity 5. Support pin marks 6. weld line

Claims (6)

(A1) 50 to 95 parts by mass of polybutylene terephthalate resin and (A2) 5 to 50 parts by mass of polycarbonate resin, for a total of 100 parts by mass of (A1) and (A2), (B) 0 to 30 parts by mass of elastomer, (C) 0.3 to 4 parts by mass of an epoxy compound, (D) 15 to 80 parts by mass of a reinforcing filler, and (E) a silicone compound and thermoplastic resin having a weight average molecular weight of 10,000 to 80,000. (E) the thermoplastic resin in the masterbatch is at least one selected from polyolefin resins, polyamide resins, styrene resins, polyphenylene ether resins, and polyphenylene sulfide resins; , a polybutylene terephthalate resin composition characterized in that the content of the silicone compound is 20 to 50% by mass. The polybutylene terephthalate resin composition according to claim 1, wherein the epoxy compound (C) is a novolac type epoxy compound. The polybutylene terephthalate resin composition for laser welding according to claim 1 or 2, wherein the thermoplastic resin of the masterbatch (E) is a polyolefin resin. (A1) 50 to 95 parts by mass of polybutylene terephthalate resin, (A2) 5 to 50 parts by mass of polycarbonate resin, for a total of 100 parts by mass of (A1) and (A2), (B) 0 to 30 parts by mass of elastomer, (C) 0.3 to 4 parts by mass of an epoxy compound, (D) 15 to 80 parts by mass of reinforcing filler, and (E) a silicone compound with a weight average molecular weight of 10,000 to 80,000, polyolefin resin, polyamide resin, styrene resin. , a thermoplastic resin that is at least one selected from polyphenylene ether resin and polyphenylene sulfide resin , and (E) masterbatch 1 to 1, wherein the content of the silicone compound in the masterbatch is 20 to 50% by mass. A method for producing a polybutylene terephthalate resin composition, which comprises mixing 15 parts by mass, followed by melting and kneading. A member (I) molded with the polybutylene terephthalate resin composition according to any one of claims 1 to 3, and a member molded with a resin composition different from the polybutylene terephthalate resin composition constituting member (I). (II) A two-color molded article. The two-color molded article according to claim 5, wherein the resin composition constituting member (II) is a resin composition containing a polycarbonate resin.