JP7075450B2 - Polybutylene terephthalate resin composition for vehicle interior parts - Google Patents

Description

The present invention relates to a polybutylene terephthalate resin composition for vehicle interior parts, and more particularly to a polybutylene terephthalate resin composition for vehicle interior parts having low warpage, low specific density, and low gas generation.

Thermoplastic polyester resin represented by polybutylene terephthalate resin itself has excellent mechanical properties, electrical properties, etc., as well as chemical resistance, heat resistance, etc., so various electrical and electronic equipment parts, It is also widely used as a material for manufacturing interior and exterior parts for vehicles such as automobiles and other general industrial products.

In particular, interior parts for vehicles such as those for automobiles, specifically, for example, indoor inner mirror stays and door handles, are required to be lightweight, have high strength and high rigidity, and have an excellent appearance. Reinforced thermoplastic resin, especially fiber-reinforced polyester resin, is used as a material for manufacturing these parts.

In order to improve the strength and rigidity of the molded product obtained from the fiber-reinforced polyester resin, it is necessary to increase the amount of the fibrous reinforcing material to be blended in the thermoplastic polyester resin as the substrate. However, if the blending amount of the reinforcing material is increased, the moldability (fluidity) of the fiber-reinforced polyester resin composition is lowered, and the blended fibrous reinforcing material is likely to emerge on the surface of the molded product, resulting in surface roughness and deterioration of gloss. However, there are problems such as deterioration of the appearance of the product and shrinkage anisotropy (molding shrinkage rate) of the molded product such as warpage of the molded product.

For the purpose of improving the strength by adding these fibrous reinforcing materials and not impairing the surface properties such as appearance, surface treatment of the fibrous reinforcing materials and the use of epoxy resin and silane coupling agent have been proposed. (See, for example, Patent Documents 1 and 2).
However, the surface properties such as the appearance of the obtained molded product are not sufficiently satisfactory by simply applying a special treatment to the fibrous reinforcing material as in these patent documents, and the shrinkage anisotropy of the molded product is also a problem. It becomes.

As vehicle parts, parts that require high strength will be blended with a fibrous reinforcing material in a large amount of 50% by mass or more. In this case, the fluidity of the resin composition is further reduced and the fibrous reinforcing material is strengthened. The embossment of the material becomes severe and the surface appearance is significantly deteriorated.
On the other hand, if the amount of the fibrous reinforcing material added is small, warpage is likely to occur.

Invention to add ABS resin and polyethylene terephthalate resin in which the dispersed particle size of the butadiene component is reduced to 1 μm or less to the polybutylene terephthalate resin reinforced with a fibrous reinforcing material in order to improve the appearance and warpage of the molded product (Patent Document). 3) has been reported.
However, even in this invention, it is not easy to maintain a good balance between appearance and low warpage.

In addition, especially in the case of use in the interior of an automobile, there is a regulation on VOC (volatile organic compounds) emissions, which is a strict guideline for released organic substances, and it is strongly required to clear this for vehicle interior parts. It's starting.

Special Publication No. 51-7702 Japanese Unexamined Patent Publication No. 2006-16557 Japanese Patent No. 3098308

An object (problem) of the present invention is to provide a polybutylene terephthalate resin composition for vehicle interior parts having low warpage property, low specific density, and low gas generation amount.

As a result of diligent studies to solve the above-mentioned problems, the present inventors have added acrylonitrile-styrene-based copolymer having a specific amount of styrene gas generation and a specific amount of glass fiber to the polybutylene terephthalate resin. The present invention has been achieved by finding that the above-mentioned problems can be solved and a polybutylene terephthalate resin composition for vehicle interior parts having low warpage property, low specific gravity, and a small amount of gas generation can be obtained.
The present invention relates to the following polybutylene terephthalate resin compositions for vehicle interior parts.

[1] With respect to 100 parts by mass of the polybutylene terephthalate resin (A), 5 to 100 parts by mass of the acrylonitrile-styrene copolymer (B) and 10 to 100 parts by mass of the glass fiber (C) are contained.
The acrylonitrile-styrene copolymer (B) is characterized in that the amount of the styrene monomer is 500 ppm or less when the gas generated by heat treatment at 270 ° C. for 10 minutes is analyzed by a gas chromatograph. Polybutylene terephthalate resin composition for parts.
[2] In the above [1], the amount of styrene-based monomer detected when the gas generated by heat-treating the polybutylene terephthalate resin composition at 120 ° C. for 30 minutes is analyzed by a gas chromatograph. The polybutylene terephthalate resin composition for vehicle interior parts described.

The polybutylene terephthalate resin composition of the present invention has less warpage, low specific density, less gas generation, and can clear VOC regulations, so that it can be suitably used as a vehicle interior component.

Hereinafter, embodiments of the present invention will be described in detail. Although the description described below may be based on embodiments and specific examples, the present invention is not construed as being limited to such embodiments and specific examples.
In addition, in this specification, "-" is used in the meaning which includes the numerical values described before and after it as the lower limit value and the upper limit value.

The polybutylene terephthalate resin composition of the present invention has 5 to 100 parts by mass of an acrylonitrile-styrene copolymer (B) and 10 to 100 parts by mass of a glass fiber (C) with respect to 100 parts by mass of the polybutylene terephthalate resin (A). Containing parts,
The acrylonitrile-styrene copolymer (B) is characterized in that the amount of the styrene monomer is 500 ppm or less when the gas generated by heat treatment at 270 ° C. for 10 minutes is analyzed by gas chromatography.

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

The polybutylene terephthalate resin (A) may contain a dicarboxylic acid unit other than terephthalic acid, but specific examples of other dicarboxylic acids include isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2, 5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis (4,4') -Carboxyphenyl) Aromatic dicarboxylic acids such as methane, anthracendicarboxylic acid and 4,4'-diphenylether dicarboxylic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and 4,4'-dicyclohexyldicarboxylic acid. , And aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, and dimer acid.

The diol unit may contain other diol units in addition to 1,4-butanediol, but specific examples of the 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, cyclohexanedimethanol, 4,4'-dicyclohexylhydroxymethane, 4 , 4'-Dicyclohexylhydroxypropane, ethylene oxide-added diol of bisphenol A, and the like. In addition to the above-mentioned bifunctional monomers, trimellitic acids such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane for introducing a branched structure, and fatty acids for adjusting the molecular weight can be used. A small amount of the monofunctional compound can also be used in combination.
When other diol units are contained in addition to these 1,4-butanediol, the copolymerization amount is preferably 1 mol% or more and less than 50 mol% in all the polybutylene terephthalate resin segments. .. Among them, the copolymerization amount is preferably 2 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%.

The polybutylene terephthalate resin (A) is preferably a polybutylene terephthalate homopolymer obtained by polycondensing terephthalic acid and 1,4-butanediol, but the carboxylic acid unit is a dicarboxylic acid 1 other than the above-mentioned terephthalic acid. It may be a polybutylene terephthalate copolymer containing one or more diols other than the 1,4-butanediol as the seed or more and / or the diol unit. In the polybutylene terephthalate resin (A), the ratio of terephthalic acid in the dicarboxylic acid unit is preferably 70 mol% or more, more preferably 90 mol% or more, from the viewpoint of mechanical properties and heat resistance. Similarly, the proportion of 1,4-butanediol in the diol unit is preferably 70 mol% or more, more preferably 90 mol% or more.

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

The catalyst used in carrying out the esterification reaction may be a conventionally known one, and examples thereof include titanium compounds, tin compounds, magnesium compounds, calcium compounds and the like. Of these, a titanium compound is particularly suitable. 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.

The polybutylene terephthalate resin (A) may be a polybutylene terephthalate resin modified by copolymerization, and as a specific preferable copolymer thereof, polyalkylene glycols, particularly polytetramethylene glycol, are copolymerized. Examples thereof include the polyester ether resin obtained from the above, a dimer acid copolymer polybutylene terephthalate resin, and an isophthalic acid copolymer polybutylene terephthalate resin. In addition, these copolymers have a copolymerization amount of 1 mol% or more and less than 50 mol% in all segments of a polybutylene terephthalate resin. Among them, the copolymerization amount is preferably 2 to 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%.
When a copolymer is used as the polybutylene terephthalate resin (A), it is particularly preferable to use a polyester ether resin copolymerized with polytetramethylene glycol. The proportion of the tetramethylene glycol component in the copolymer is preferably 3 to 40% by mass, more preferably 5 to 30% by mass, still more preferably 10 to 25% by mass. Such a copolymerization ratio tends to improve fluidity, toughness, and tracking resistance, which is preferable.

The amount of the terminal carboxyl group of the polybutylene terephthalate resin (A) may be appropriately selected and determined, but is usually 60 eq / ton or less, preferably 50 eq / ton or less, and 30 eq / ton or less. Is even more preferable. If it exceeds 50 eq / ton, gas is likely to be generated during melt molding of the resin composition. The lower limit of the amount of the terminal carboxyl group is not particularly determined, but is usually 10 eq / ton in consideration of the productivity of producing the polybutylene terephthalate resin.

The amount of terminal carboxyl groups in the polybutylene terephthalate resin is a value measured by dissolving 0.5 g of the polyalkylene terephthalate resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / l benzyl alcohol solution of sodium hydroxide. be. As a method for adjusting the amount of the terminal carboxyl group, a conventionally known arbitrary method such as a method of adjusting the polymerization conditions such as the raw material charging ratio at the time of polymerization, the polymerization temperature, the depressurization method, and the method of reacting the terminal blocking agent can be used. Just do it.

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

[Acrylonitrile-styrene copolymer (B)]
The polybutylene terephthalate resin composition of the present invention contains an acrylonitrile-styrene copolymer (B). The acrylonitrile-styrene-based copolymer (B) is a copolymer of acrylonitrile and a styrene-based monomer, and may be a copolymer of another copolymerizable monomer.

Examples of the styrene-based monomer constituting the acrylonitrile-styrene-based copolymer (B) include styrene, α-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene and vinyl. Examples thereof include naphthalene, methoxystyrene, monobromstyrene, dibromstyrene, fluorostyrene, tribromstyrene, etc., with styrene and α-methylstyrene being more preferable, and styrene being particularly preferable.

Examples of copolymerizable monomers other than the styrene-based monomer and acrylonitrile include (meth) acrylic acid ester-based monomers and maleimide-based single amounts such as maleimide, N-methylmaleimide, and N-phenylmaleimide. Examples thereof include α, β-unsaturated carboxylic acids such as body, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, phthalic acid, and itaconic acid, and their anhydrides.
Among these, (meth) acrylic acid ester-based monomers are preferably mentioned, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and the like. Amil (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, phenyl (meth) acrylate, Benzyl (meth) acrylate and the like can be mentioned, and methyl methacrylate and the like can be mentioned in particular.
The notation of (meth) acrylate indicates that it contains both methacrylate and acrylate, and the notation of (meth) acrylic acid ester indicates that it contains both methacrylic acid ester and acrylic acid ester.

In the acrylonitrile-styrene copolymer (B), the acrylonitrile monomer is preferably 15 to 45% by mass, more preferably 20 to 40% by mass.

The method for producing the acrylonitrile-styrene-based copolymer (B) is not limited and a known method can be adopted. For example, bulk polymerization, emulsion polymerization, solution polymerization, suspension polymerization and the like are used. Of these, bulk polymerization is preferable because it does not use a solvent or emulsifier and has few impurities.

The acrylonitrile monomer in the acrylonitrile-styrene copolymer (B) is preferably 5 to 95% by mass, more preferably 8 to 35% by mass. The content of the unit derived from the styrene-based monomer is preferably 50 to 95% by mass, more preferably 65 to 92% by mass.
In the present invention, the amount of acrylonitrile in the acrylonitrile-styrene copolymer (B) is measured by the Kjeldahl method.

The melt volume rate (MVR) of the acrylonitrile-styrene copolymer (B) is preferably in the range of 5 to 100 cm ^3/10 minutes at 220 ° C. and a load of 10 kg, and is preferably 10 to 80 cm ^3/10 minutes. Is more preferable.
The mass average molecular weight (Mw) of the acrylonitrile-styrene copolymer (B) is preferably in the range of 60,000 to 220,000, more preferably 80,000 to 200,000.
In the present invention, the mass average molecular weight (Mw) of the acrylonitrile-styrene copolymer (B) is measured by the GPC (gel permeation chromatography) method.

Examples of the acrylonitrile-styrene copolymer include an acrylonitrile-styrene copolymer (AS resin) and an acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), and an acrylonitrile-styrene copolymer (AS resin) is particularly preferable. ..

In the present invention, the amount of the styrene-based monomer as the acrylonitrile-styrene-based copolymer (B) when the gas generated by heat treatment at 270 ° C. for 10 minutes is analyzed by gas chromatography is 500 (mass) ppm or less. Use what is. When the amount of styrene-based monomer gas is 500 ppm or less, the problem of VOC for vehicle interior parts is solved, and the appearance is also improved because the amount of gas is small at the time of molding. On the other hand, if it exceeds 500 ppm, it becomes difficult to solve the VOC problem as an interior component for a vehicle, and the appearance tends to be poor.
The amount of the styrene-based monomer is preferably 300 ppm or less, more preferably 240 ppm or less, and the lower limit thereof is usually 150 ppm. It is not preferable to make it less than 150 ppm because it has purification that disregards economic efficiency.
The amount of the styrene-based monomer can be determined by analyzing the gas generated by heat treatment at 270 ° C. for 10 minutes with a gas chromatograph, and the specific conditions thereof are as described in detail in Examples. be.

In order to keep the amount of the styrene-based monomer in the acrylonitrile-styrene-based copolymer within the above range, the composition of the devolatilization step after the polymerization of the acrylonitrile-styrene-based copolymer and the operating conditions of the devolatilization step are strengthened. This makes it possible. In the case of suspension polymerization, stripping of the copolymer latex obtained at an appropriate temperature and in vacuum, coagulation with high-temperature steam, or stripping under reduced pressure using high-temperature steam. Or, the solidified copolymer is washed with high-temperature water and further dried under vacuum. Further, bulk polymerization is possible by adjusting the degree of vacuum, the supply rate or the heating temperature in the vacuum devolatilizer.
It is also possible to select a commercially available product that satisfies the conditions, or to further dry the commercially available product to obtain a desired styrene-based monomer amount.

The content of the acrylonitrile-styrene copolymer (B) is 5 to 100 parts by mass with respect to 100 parts by mass of the polybutylene terephthalate resin (A). If the content is less than 5 parts by mass, the shrinkage rate becomes large, which causes warpage of the molded product, and if it exceeds 100 parts by mass, the heat resistance is lowered and the weld strength is lowered. The content of the acrylonitrile-styrene copolymer (B) is preferably 10 parts by mass or more, more preferably more than 50 parts by mass, preferably 95 parts by mass or less, and more preferably 90 parts by mass. It is as follows.

[Glass fiber (C)]
The polybutylene terephthalate resin composition of the present invention contains glass fiber (C) in an amount of 10 to 100 parts by mass with respect to 100 parts by mass of the polybutylene terephthalate resin (A). If the content is less than 10 parts by mass, the reinforcing effect may not be sufficient, and if it exceeds 100 parts by mass, the appearance and impact resistance may be poor and the fluidity may not be sufficient. The preferable content of the glass fiber (C) is 15 parts by mass or more, more preferably 20 parts by mass or more, still more preferably 25 parts by mass or more with respect to 100 parts by mass of the polybutylene terephthalate resin (A). Further, it is preferably 95 parts by mass or less, and more preferably 90 parts by mass or less. By containing the glass fiber (C) in this way, the strength, rigidity and dimensional stability of the polybutylene terephthalate resin composition of the present invention can be improved.

The type of the glass fiber (C) is not particularly limited, and examples thereof include glass fibers such as E glass, C glass, A glass, and S glass. Among these, the fiber of E glass is preferable in that it does not adversely affect the thermal stability of the polybutylene terephthalate resin.

The average fiber diameter of the glass fiber (C) is not particularly limited, but is preferably selected in the range of 1 to 100 μm, more preferably 2 to 50 μm, still more preferably 3 to 30 μm, and particularly preferably 5 to 20 μm. A glass fiber having an average fiber diameter of less than 1 μm is not easy to manufacture and may increase in cost, while if it exceeds 100 μm, the tensile strength of the glass fiber may decrease. The cross section of the fiber may be circular or flat.

The glass fiber (C) may have a perfect circular or flat fiber cross section, but is a glass fiber having a flatness (major axis / minor axis) of 1 to 1.5 in the fiber cross section and a substantially circular cross section. It is preferable to have. The flatness is preferably 1 to 1.4, more preferably 1 to 1.2, and particularly preferably 1 to 1.1.
The flatness value is determined by an image analyzer from an image of 2000 glass fibers of filler residue collected by high-temperature ashing of the molded product, dissolution with a solvent, decomposition with chemicals, etc., observed with an optical microscope. It is a calculated average value.

The average fiber length of the glass fiber (C) is not particularly limited, but is preferably, for example, 1 to 10 mm, more preferably 1.5 to 6 mm, and even more preferably 2 to 5 mm. If the average fiber length of the glass fiber (C) is less than 1 mm, the reinforcing effect may not be sufficiently exhibited, and if it exceeds 10 mm, it may be difficult to mold the obtained resin composition.
The average fiber length is determined by an image analyzer from an image of 2000 glass fibers of the filler residue collected by high-temperature ashing of the molded product, dissolution with a solvent, decomposition with chemicals, etc., observed with an optical microscope. It is the value of the calculated number average fiber length. Further, when calculating such a value, the value is based on a method in which the fiber diameter is used as a guide and the length shorter than that is not counted.

The glass fiber (C) used in the present invention can be surface-treated with a coupling agent such as aminosilane or epoxysilane for the purpose of improving the adhesion with the polybutylene terephthalate resin (A).
Examples of the coupling agent include chlorosilane compounds such as vinyltrichlorosilane and methylvinyldichlorosilane, and alkoxysilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, and γ-methacryloxypropyltrimethoxysilane. Compounds, epoxysilane compounds such as β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, acrylic compounds, isocyanate compounds, titanate compounds, epoxy compounds, etc. Can be mentioned.

Further, as the glass fiber (C) used in the present invention, it is usually preferable to use a bundle of a large number of these fibers as a chopped strand (chopped glass fiber) cut to a predetermined length, and at this time, glass. It is preferable to add a converging agent to the fiber. By blending the converging agent, in addition to the advantage of increasing the production stability of the polybutylene terephthalate resin composition of the present invention, good mechanical properties can be obtained.
The sizing agent for the glass fiber (C) is not particularly limited, and examples thereof include resin emulsions such as vinyl acetate resin, ethylene-vinyl acetate copolymer, acrylic resin, epoxy resin, polyurethane resin, and polyester resin. , Preferably acrylic resin, epoxy resin, polyurethane resin.

[Other ingredients]
The polybutylene terephthalate resin composition of the present invention can contain a thermoplastic resin other than the above, as long as the effect of the present invention is not impaired. Specific examples of other thermoplastic resins include polyethylene terephthalate resin, polycarbonate resin, polyacetal resin, polyamide resin, polyphenylene oxide resin, polyphenylene sulfide resin, polysulfone resin, polyether sulfone resin, and polyetherimide resin. Examples thereof include polyether ketone resins and polyolefin resins.

In addition, various additives other than those described above may be contained, and such additives include stabilizers, carbon blacks, mold release agents, flame retardants, flame retardants, anti-dripping agents, and ultraviolet absorbers. Examples thereof include agents, antistatic agents, antifogging agents, antiblocking agents, plasticizers, dispersants, antibacterial agents, colorants and the like.

[Stabilizer]
It is preferable that the polybutylene terephthalate resin composition of the present invention contains a stabilizer because it has an effect of improving thermal stability and preventing deterioration of mechanical strength and hue. As the stabilizer, a phosphorus-based stabilizer, a sulfur-based stabilizer and a phenol-based stabilizer are preferable, and a phenol-based stabilizer is particularly preferable.

Examples of the phosphorus-based stabilizer include phosphoric acid, phosphoric acid, phosphite, trivalent phosphoric acid ester (phosphonite), pentavalent phosphoric acid ester (phosphate), and the like, among which phosphite is used. , Phosphoronite and phosphate are preferred.

The organic phosphate compound is preferably given the following general formula:
(R ¹ O) _3-n P (= O) OH _n
(In the formula, R ¹ is an alkyl group or an aryl group, which may be the same or different. N represents an integer of 0 to 2.)
It is a compound represented by. More preferably, a long-chain alkyl acid phosphate compound in which R ¹ has 8 to 30 carbon atoms can be mentioned. Specific examples of the alkyl group having 8 to 30 carbon atoms include an octyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group, an isononyl group, a decyl group, an isodecyl group, a dodecyl group, a tridecyl group, an isotridecyl group and a tetradecyl group. Examples thereof include a hexadecyl group, an octadecyl group, an eicosyl group, and a triacontyl group.

Examples of long-chain alkyl acid phosphates include octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, lauryl acid phosphate, octadecyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonylphenyl acid phosphate and cyclohexyl. Acid phosphate, phenoxyethyl acid phosphate, alkoxypolyethylene glycol acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl acid phosphate, di-2-ethylhexyl acid. Examples thereof include phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distealyl acid phosphate, diphenyl acid phosphate, bisnonylphenyl acid phosphate and the like. Among these, octadecyl acid phosphate is preferable, and this product is commercially available under the trade name "ADEKA STAB AX-71" of ADEKA.

The organic phosphite compound is preferably preferably the following general formula:
R ² OP (OR ³ ) (OR ⁴ )
(In the formula, R ² , R ³ and R ⁴ are hydrogen atoms, alkyl groups having 1 to 30 carbon atoms or aryl groups having 6 to 30 carbon atoms, respectively, and among R ² , R ³ and R ⁴ , respectively. At least one of them is an aryl group having 6 to 30 carbon atoms.)
Examples thereof include compounds represented by.

Examples of the organic phosphite compound include triphenylphosphite, tris (nonylphenyl) phosphite, dilaurylhydrogenphosphite, triethylphosphite, tridecylphosphite, tris (2-ethylhexyl) phosphite, and tris (tridecyl). ) Phenylphosphite, tristearylphosphite, diphenylmonodecylphosphite, monophenyldidecylphosphite, diphenylmono (tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite , Hydrogenated Bisphenol A Phenol Phenylphosphite Polymer, Diphenylhydrogenphosphite, 4,4'-Butylidene-bis (3-methyl-6-tert-butylphenyldi (tridecyl) phosphite), Tetra (tridecyl) 4,4 '-Isopropyridene diphenyl diphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris (4- tert-butylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, bis (2,4-di-tert-butylphenyl) pentaerythritoldi Phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2'-methylenebis (4,6-di-tert-butylphenyl) octylphosphite, bis ( 2,4-Dicumylphenyl) pentaerythritol diphosphite and the like. Among these, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is preferable.

The organic phosphonite compound is preferably given the following general formula:
R5 ^- P (OR ⁶ ) (OR ⁷ )
(In the formula, R ⁵ , R ⁶ and R ⁷ are hydrogen atoms, alkyl groups having 1 to 30 carbon atoms or aryl groups having 6 to 30 carbon atoms, respectively, and among R ⁵ , R ⁶ and R ⁷ , respectively. At least one of them is an aryl group having 6 to 30 carbon atoms.)
Examples thereof include compounds represented by.

Examples of the organic phosphonite compound include tetrakis (2,4-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite and tetrakis (2,4-di-n-butylphenyl) -4,4'-bipheni. Range phosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3'-biphenylenediphospho Nite, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite, Tetrakiss (2,6-di-n-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di-n-butylphenyl) -4,4'-biphenylenediphosphonite 2,6-Di-tert-butylphenyl) -4,3'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite and the like. ..

As the sulfur-based stabilizer, any conventionally known sulfur atom-containing compound can be used, and among them, thioethers are preferable. Specifically, for example, didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3-dodecylthiopropionate), thiobis (N-phenyl-β-naphthylamine). ), 2-Mercaptobenzothiazole, 2-Mercaptobenzimidazole, Tetramethylthium monosulfide, Tetramethylthiuram disulfide, Nickeldibutyldithiocarbamate, Nickelisopropylxantate, Trilauryltrithiophosphite. Among these, pentaerythritol tetrakis (3-dodecylthiopropionate) is preferable.

Examples of the phenolic stabilizer include pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3,5-di-tert-butyl-4). -Hydroxyphenyl) propionate, thiodiethylenebis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), pentaerythritol tetrakis (3- (3,5-di-neopentyl-4-hydroxyphenyl) ) Propionate) and the like. Among these, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) ) Propionate is preferred.

Above all, it is preferable to use a hindered phenolic stabilizer having a melting point of 150 ° C. or higher. When the melting point is 150 ° C. or higher, the thermal stability of the stabilizer itself becomes high, so that the stabilizer itself loses its stabilizing effect due to deterioration, or during the production of a resin composition such as melt kneading or in a high temperature environment such as injection molding. However, it becomes difficult to generate gas. Further, even if the light reflector provided with the metal thin film on the obtained molded product is exposed to a high temperature atmosphere, the surface of the metal thin film is violated and the light reflector is suppressed from becoming cloudy. The melting point is more preferably 180 ° C. or higher, further preferably 200 ° C. or higher, and particularly preferably 220 ° C. or higher. The upper limit of the melting point is usually 350 ° C. or lower, preferably 300 ° C. or lower, and more preferably 280 ° C. or lower.

As the stabilizer, one type 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 1 part by mass with respect to 100 parts by mass of the polybutylene terephthalate resin (A). If the content of the stabilizer is less than 0.001 part by mass, it is difficult to expect improvement in thermal stability and compatibility of the resin composition, and a decrease in molecular weight and deterioration of hue during molding are likely to occur, and 1 part by mass is used. If it exceeds the amount, the amount becomes excessive, and there is a tendency that silver streak occurs and hue deterioration is more likely to occur. The content of the stabilizer is more preferably 0.005 to 0.9 parts by mass, still more preferably 0.01 to 0.8 parts by mass.

[Carbon black]
The polybutylene terephthalate resin composition of the present invention preferably contains carbon black. By containing carbon black, the weather resistance and appearance of the polybutylene terephthalate resin composition and the molded product are improved.
The type, raw material type, and manufacturing method of carbon black are not limited, and any of furnace black, channel black, acetylene black, ketjen black, and the like can be used. The number average particle size is not particularly limited, but is preferably 5 to 60 nm. By using carbon black having a number average particle diameter in a predetermined range as described above, it is possible to obtain a composition in which blister is unlikely to occur at high temperatures.
For the number average particle size, an aggregate magnified image is obtained according to the procedure described in the ATM D3849 standard (standard test method for carbon black-morphological characterization by electron microscopy), and the aggregate image is used as a unit constituent particle. The diameter of 3,000 particles can be measured and calculated by arithmetic averaging.

The nitrogen adsorption specific surface area (unit: m ² / g) of carbon black is usually preferably less than 1,000 m ² / g, and more preferably 50 to 400 m ² / g. It is preferable that the nitrogen adsorption specific surface area is less than 1,000 m ² / g because the fluidity of the polybutylene terephthalate resin composition and the appearance of the molded product tend to be improved. The nitrogen adsorption specific surface area can be measured according to JIS K6217.

The amount of DBP (dibutyl phthalate) absorbed by carbon black is preferably less than 300 cm ^3/100 g, and more preferably 30 to 200 cm ^3/100 g. It is preferable that the amount of DBP absorbed is less than 300 cm ^3/100 g because the fluidity of the polybutylene terephthalate resin composition of the present invention and the appearance of the molded product tend to be improved. The amount of DBP absorbed (unit: cm ^3/100 g) can be measured according to JIS K6217.
The pH of the carbon black used is not particularly limited, but is usually 2 to 10, preferably 3 to 9, and even more preferably 4 to 8.

Carbon black can be used alone or in combination of two or more. Further, carbon black can be granulated using a binder, and can also be used in a masterbatch in which a high concentration of carbon black is melt-kneaded in another resin. By using the melt-kneaded masterbatch, it is possible to improve the handleability at the time of extrusion and the dispersibility in the resin composition. Examples of the resin include polystyrene-based resins, polyester-based resins, and acrylic-based resins.
The content of carbon black in the masterbatch is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, still more preferably 30 to 60% by mass.

The content of carbon black is preferably 0.01 to 5 parts by mass, more preferably 0.05 parts by mass or more, and further preferably 0.08 parts by mass with respect to 100 parts by mass of the polybutylene terephthalate resin (A). The above is particularly 0.1 parts by mass or more, more preferably 2 parts by mass or less, still more preferably 1.5 parts by mass or less, and particularly preferably 1.0 part by mass or less. If the content is less than 0.01 parts by mass, the weather resistance may be insufficient, and if it exceeds 5 parts by mass, mechanical properties such as moldability and impact resistance tend to deteriorate.

[Release agent]
The polybutylene terephthalate resin composition of the present invention preferably contains a mold release agent.
Examples of the release agent include an aliphatic carboxylic acid, an ester of an aliphatic carboxylic acid and an alcohol, an aliphatic hydrocarbon compound, and a polysiloxane-based silicone oil.

Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acids. Here, the aliphatic carboxylic acid also includes an alicyclic carboxylic acid. Among these, the preferred aliphatic carboxylic acid is a monovalent or divalent carboxylic acid having 6 to 36 carbon atoms, and an aliphatic saturated monovalent carboxylic acid having 6 to 36 carbon atoms is more preferable. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, araquinic acid, bechenic acid, lignoseric acid, cellotic acid, melissic acid, tetrariacontanic acid, montanic acid and adipine. Acids, azelaic acid and the like can be mentioned.

As the aliphatic carboxylic acid in the ester of the aliphatic carboxylic acid and the alcohol, for example, the same one as the above-mentioned aliphatic carboxylic acid can be used. On the other hand, examples of the alcohol 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 preferable, and aliphatic saturated monohydric alcohols or aliphatic saturated polyhydric alcohols having 30 or less carbon atoms are more preferable. Here, the aliphatic term also contains an alicyclic compound.

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.

The above ester may contain an aliphatic carboxylic acid and / or an alcohol as impurities. Further, the above ester may be a pure substance or a mixture of a plurality of compounds. Further, as the aliphatic carboxylic acid and the alcohol which are combined to form one ester, one kind may be used, or two or more kinds may be used in any combination and ratio.

Specific examples of esters of aliphatic carboxylic acid and alcohol include montanic acid ester wax, beeswax (a mixture containing myricyl palmitate as a main component), stearyl stearate, behenyl behenate, stearyl behenate, and glycerin monopalmi. Examples thereof include tate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate and the like. ..

Examples of the aliphatic hydrocarbon compound include polyolefin waxes such as liquid paraffin, paraffin wax, microcrystalline wax and polyethylene wax, fisher-tropus wax, and α-olefin oligomers having 3 to 12 carbon atoms. Here, the aliphatic hydrocarbon also includes an alicyclic hydrocarbon. Further, these hydrocarbons may be partially oxidized. The number average molecular weight is preferably 200 to 30,000, more preferably 1000 to 15,000, still more preferably 1500 to 10000, and particularly preferably 2000 to 5000. The aliphatic hydrocarbon compound may be a single substance, but a mixture of various constituents and molecular weights can be used as long as the main component is within the above range.

In the present invention, as the mold release agent, polyolefin wax is preferable from the viewpoint of suppressing fogging. As the polyolefin wax, any known conventionally known wax can be used, for example, preferably a type of olefin having 2 to 30 carbon atoms, more preferably 2 to 12 carbon atoms, still more preferably 2 to 10 carbon atoms, or an arbitrary ratio of two. Examples thereof include (co) polymers containing more than one species (meaning polymerization or copolymerization; the same shall apply hereinafter).

Examples of the olefin having 2 to 30 carbon atoms include ethylene, propylene, α-olefin having 4 to 30 carbon atoms (preferably 4 to 12, more preferably 4 to 10), and 4 to 30 carbon atoms (preferably 4). -18, more preferably 4-8) diene. Examples of the α-olefin include 1-butene, 4-methyl-1-pentene, 1-pentene, 1-octene, 1-decene and 1-dodecene. Examples of the diene include butadiene, isoprene, cyclopentadiene, 11-dodecadiene and the like.

As the polyolefin wax, polyethylene wax is preferable from the viewpoint of fogging property, mold release property and heat resistance.
The method for producing polyethylene wax is arbitrary, and for example, it can be produced by polymerization of ethylene or thermal decomposition of polyethylene.

As the mold release agent, one having an acid value of 10 to 40 mgKOH / g is preferable because it has a small mold release resistance, a remarkable effect of improving the mold release property, and a small amount of volatile matter. The acid value is more preferably 11 to 35 mgKOH / g, still more preferably 12 to 32 mgKOH / g. If the acid value is in the range of 10 to 40 mgKOH / g, the acid value of less than 10 mgKOH / g and the acid value of more than 40 mgKOH / g may be used in combination, and the acid value of the plurality of types of releasing agents as a whole may be determined. It may be 10 to 40 mgKOH / g.

As the mold release agent having an acid value of 10 to 40 mgKOH / g, an ester of the above-mentioned aliphatic carboxylic acid and an alcohol having an acid value of 10 to 40 mgKOH / g, or the above-mentioned aliphatic hydrocarbon compound is preferable. In the polyolefin wax, a carboxyl group (carboxylic acid (anhydrous) group, that is, a carboxylic acid group and / or a carboxylic acid anhydride group; the same applies hereinafter), a haloformyl group, an ester group, a metal carboxylate base, a hydroxyl group, and an alcoholic acid. A modified polyolefin wax having a functional group compatible with the polyester resin, such as a group, an epoxy group, an amino group, and an amide group, is preferable.

As the carboxyl group used for the modification of the polyolefin wax, a low molecular weight compound containing a carboxylic acid group such as maleic acid, maleic anhydride, acrylic acid, and methacrylic acid, a low molecular weight compound containing a sulfo group such as sulfonic acid, and phosphon. Examples thereof include low molecular weight compounds containing a phospho group such as an acid. Among these, low molecular weight compounds containing a carboxylic acid group are preferable, and maleic acid, maleic anhydride, acrylic acid, methacrylic acid and the like are particularly preferable. These carboxylic acids may be used alone or in combination of two or more at any ratio.
The amount of acid added to the modified polyolefin wax is usually 0.01 to 10% by mass, preferably 0.05 to 5% by mass, based on the modified polyolefin wax.

Specific examples of the haloformyl group include a chloroformyl group and a bromoformyl group. The means for imparting these functional groups to the polyolefin wax may be any conventionally known method, and specifically, for example, copolymerization with a compound having a functional group, post-processing such as oxidation, or the like. Method may be used.

As the type of the functional group, a carboxyl group is preferable because it has an appropriate affinity with the polyester resin. The concentration of the carboxyl group in the modified polyolefin wax may be appropriately selected and determined, but if it is too low, the affinity with the polyester resin is small, the effect of suppressing volatile components is small, and the release effect is reduced. There is. On the contrary, if the concentration is too high, for example, the polymer main chain constituting the polyolefin wax is excessively cut at the time of modification, and the molecular weight of the modified polyolefin wax is excessively lowered, so that volatile components are generated and the polyester resin is generated. Cloudiness may occur on the surface of the molded body.
As the modified polyolefin wax, polyethylene oxide wax is preferable.

In addition, 1 type may be contained in the mold release agent, and 2 or more types may be contained in arbitrary combinations and ratios.
The content of the release agent is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, and usually 2 parts by mass or less, preferably 2 parts by mass, based on 100 parts by mass of the polybutylene terephthalate resin (A). It is 1.5 parts by mass or less. If the content of the release agent is less than the lower limit of the above range, the effect of the release property may not be sufficient, and if the content of the release agent exceeds the upper limit of the above range, the hydrolysis resistance There is a possibility that the mold will be reduced and the mold will be contaminated during injection molding.

[Manufacturing method of resin composition]
The method for producing the polybutylene terephthalate resin composition of the present invention can be carried out according to a conventional method for preparing a polybutylene terephthalate resin composition. That is, the polybutylene terephthalate resin (A), the acrylonitrile-styrene copolymer (B), other resin components to be added if desired, and various additives are mixed well together, and then a single-screw or twin-screw extruder is used. Melt and knead. The glass fiber (C) is preferably side-fed. Further, a masterbatch of a part thereof may be blended and melt-kneaded. Further, it is also possible to supply a mixture in which each component is mixed in advance to a molding machine such as an injection molding machine as it is without melt-kneading to manufacture various molded products.

The heating temperature for melt-kneading can be appropriately selected from the range of usually 220 to 300 ° C. If the temperature is too high, decomposition gas is likely to be generated, which may cause a poor appearance. Therefore, it is desirable to select a screw configuration in consideration of shear heat generation and the like. It is desirable to use an antioxidant or a heat stabilizer in order to suppress decomposition during kneading and molding in the subsequent process.

Since the polybutylene terephthalate resin composition of the present invention has a low outgas, the amount of the styrene-based monomer detected when the gas generated by heat treatment at 120 ° C. for 30 minutes is analyzed by a gas chromatograph is preferably 30. (Mass) can be up to ppm or less. When the amount of the styrene-based monomer gas in the resin composition is 30 ppm or less, the problem of VOC for vehicle interior parts is solved, and the appearance at the time of molding is also improved. On the other hand, if it exceeds 30 ppm, the cleanliness as an interior component for a vehicle deteriorates, it becomes difficult to solve the VOC problem, and the appearance at the time of molding tends to be poor. The amount of the styrene-based monomer gas in the resin composition is preferably 30 ppm or less, more preferably 20 ppm or less, and the lower limit thereof is usually 2 ppm.
The amount of the styrene-based monomer gas in the resin composition can be determined by analyzing the gas generated by heat treatment at 120 ° C. for 30 minutes with a gas chromatograph, and the specific conditions thereof are described in Examples. As detailed.

Further, the amount of volatile organic compounds (TVOC, Total Volatile Organic Compounds) of the polybutylene terephthalate resin composition of the present invention can be preferably 30 μg C / g or less, more preferably 20 μg C / g or less.
The specific method for measuring the amount of volatile organic compounds (TVOC) in the polybutylene terephthalate resin composition is as described in detail in Examples.

In order to reduce the amount of styrene-based monomer gas in the resin composition to 30 ppm or less, use the above-mentioned acrylonitrile-styrene-based copolymer (B) having a styrene-based monomer gas amount of 500 ppm or less, or further. This is possible by blending the above-mentioned phosphite-based stabilizer, hindered phenol-based stabilizer, or the like.

[Molding]
The method for manufacturing a vehicle interior component using the above-mentioned polybutylene terephthalate resin composition is not particularly limited, and a molding method generally adopted for the polybutylene terephthalate resin composition can be arbitrarily adopted. For example, an injection molding method, an ultra-high speed injection molding method, an injection compression molding method, a two-color molding method, a hollow molding method such as gas assist, a molding method using a heat insulating mold, and a rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermal molding method, rotary molding method, laminated molding method, press molding method, Blow molding method and the like can be mentioned. Among them, the injection molding method is preferable because the effects of the present invention are remarkable, such as good productivity and surface properties of the obtained molded product.

Molded products obtained by molding the above polybutylene terephthalate resin composition by injection molding or the like are particularly preferably used as vehicle interior parts in which these characteristics are strictly required because they have low warpage, low specific gravity, and a small amount of gas generated. ..

Vehicle interior parts include interior parts for vehicles such as automobiles, trains, and trains, such as inner mirror stays, wave louvers for air conditioners, door handles, handles, doors, sun roofs, seat belts, and register blades. Preferred examples include washer levers, wind regulator handles, wind regulator handle knobs, passing light levers, sun visor brackets, various housings, switches, clips and the like.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not construed as being limited to the following examples.
The components used in the following Examples and Comparative Examples are as shown in Table 1 below.

[Production example of acrylonitrile-styrene copolymer (B1)]
The first reactor, which is a complete mixing type stirring tank, and the second reactor, which is a tower type plug-flow type reactor with a stirrer, are connected in series, and two devolatilization tanks with preheaters are connected in series. Configured. 15 parts by mass of ethylbenzene, 0.01 part by mass of t-butylperoxyisopropyl monocarbonate, and 0.25 parts by mass of t-dodecyl mercaptan are mixed with 85 parts by mass of a monomer solution containing 30% by mass of acrylonitrile and 70% by mass of styrene. The raw material solution was used. This raw material solution was introduced into a first reactor controlled at 130 ° C. at 6.0 kg / h. The reaction solution was continuously withdrawn from the first reactor and introduced into the second reactor. Next, it was introduced into the first devolatilization tank which was heated to 160 ° C. with a preheater and then reduced to 65 kPa, and further introduced into the second devolatilization tank which was heated to 220 ° C. with a preheater and then reduced to 1.0 kPa. Residual monomers and solvent were removed. This was extruded into a strand and cut to obtain a pellet-shaped acrylonitrile-styrene copolymer. As shown in Table 1, the composition of this copolymer (mass ratio of monomer unit) was 30% by mass of acrylonitrile unit and 70% by mass of styrene unit.

[Production example of acrylonitrile-styrene copolymer (B2)]
In the production example of the acrylonitrile-styrene copolymer (B1), the acrylonitrile-styrene copolymer (B2) is similarly modified except that the acrylonitrile in the monomer solution is changed to 33% by mass and the styrene is changed to 67% by mass. Manufactured.

[Production example of acrylonitrile-styrene copolymer (B3)]
In the production example of the acrylonitrile-styrene copolymer (B1), the acrylonitrile-styrene copolymer (B3) is similarly modified except that the acrylonitrile in the monomer solution is changed to 25% by mass and the styrene is changed to 75% by mass. Manufactured.

The mass average molecular weight (Mw) and the acrylonitrile copolymer amount (“PAN ratio”) of the acrylonitrile-styrene copolymer in the above table were measured by the methods as described above. The MVR is a melt indexer manufactured by Takara Kogyo Co., Ltd., and the pellets obtained above are measured at 220 ° C. and a load of 2.16 kgf, and the melt flow volume per unit time is MVR (unit: cm ³ /). 10 min) was measured.

(Examples 1 to 3 , 9, Reference Examples 4 to 8 , 10, Comparative Examples 1 to 3)
After each component shown in Table 1 above is uniformly mixed with a tumbler mixer at the ratio shown in Table 2 or less (all by mass), a twin-screw extruder (“TEX30α” manufactured by Japan Steel Works, Ltd. is used to form a cylinder. The resin composition melt-kneaded under the conditions of a set temperature of 260 ° C. and a screw rotation speed of 200 rpm was rapidly cooled in a water tank and pelletized using a pelletizer to obtain pellets of a polybutylene terephthalate resin composition.

[Measurement of styrene amount and ethylbenzene amount]
To measure the amount of styrene and ethylbenzene in the acrylonitrile-styrene copolymer used, 0.002 g of the sample was placed in a glass collection tube with an outer diameter of 6.35 mm and a length of 90 mm, and heat-treated at 270 ° C. for 10 minutes (Thermal). The gas generated by the Desolution method) was measured by the following chromatograph.
To measure the amount of styrene and the amount of ethylbenzene in the obtained polybutylene terephthalate resin composition, 0.02 g of the sample was placed in a glass collecting tube having an outer diameter of 6.35 mm and a length of 90 mm, and heat-treated at 120 ° C. for 30 minutes. The gas generated by the Thermal Desolution method) was measured by the following chromatograph. The measured value was converted into a value per amount of copolymer or resin composition substance and used as the content (in ppm unit) of the amount of styrene and ethylbenzene.
Measuring equipment: GCMS-QP2010 (manufactured by Shimadzu Corporation)
Column: UA-1701 Inner diameter 0.25 mm
Carrier gas: He
Pressure: 80kPa
Column flow rate: 1.4 mL / min
Column oven temperature: 50 ° C
Vaporization chamber temperature: 25 ° C
Detector: Secondary electron double tube with conversion dynode Ion source temperature: 250 ° C

[Measurement of TVOC]
The obtained pellets are dried at 120 ° C. for 5 hours, and then 100 mm × 100 mm × 2 mm thick in an injection molding machine (“NEX80” manufactured by Nissei Resin Industry Co., Ltd.) under the conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. The test piece was injection molded. Amount of volatile organic compounds As a measurement of the amount of TVOC (total volatile compounds), the obtained molded product is cut into 10 to 25 mg, and about 2 g of the sample is placed in a 22 ml vial, sealed and sealed with HS-GC. The heat treatment was carried out at 120 ° C. for 5 hours. Then, the peak integrated area of the volatile organic compound detected by gas chromatography was calculated, and acetone was converted into a standard weight to determine the amount of volatile organic compound (μgC / g) per 1 g of pellets.

[Evaluation of hydrolysis resistance: tensile strength retention after 50 hours of treatment]
The obtained pellets are dried at 120 ° C. for 5 hours, and then an ISO multipurpose test piece (4 mm) is used in an injection molding machine (“NEX80” manufactured by Nissei Plastic Industry Co., Ltd.) under the conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. Thickness) was injection molded.
Using an ISO multipurpose test piece, the tensile strength (before treatment) was measured under the condition of a tensile speed of 5 mm / min in accordance with ISO527 (unit: MPa).
Further, the ISO multipurpose test piece is treated with a pressure cooker (PCT) tester (manufactured by Hirayama Seisakusho Co., Ltd.) at a temperature of 121 ° C., a relative humidity of 100%, and a pressure of 2 atm for 50 hours to obtain the same tensile strength. The measurement was performed, and the strength retention rate (unit:%) after the treatment with respect to that before the treatment was calculated.

[Amount of warp]
A disk with a diameter of 100 mm and a thickness of 1.6 mm is molded with a side gate mold under the conditions of a cylinder temperature of 260 ° C and a mold temperature of 80 ° C using an injection molding machine (“NEX80” manufactured by Nissei Resin Industry Co., Ltd.) and warped. The amount (unit: mm) was determined.

[Mold deposit evaluation]
The molding machines and conditions used for the evaluation are as follows.
Injection molding machine SE50 manufactured by Sumitomo Heavy Industries, Ltd.
Injection pressure 50MPa Injection speed 80mm / sec
Cylinder temperature 260 ° C
Injection time 3 sec
Cooling 8 sec
Mold temperature 80 ℃
Sackback 3mm
Molded product Length 35 mm Width 14 mm, Thickness 2 mm
Mold Pingate Mold Continuously injection-molded under the above conditions, and after 1000 shots, visually observe the state of the mold deposit (mold contamination) adhering to the mold and evaluate according to the following criteria. did.
◎; Mold deposit is hardly recognized.
○; Mold deposit is slightly recognized.
×; Mold deposit is clearly recognized.
The above evaluation results are shown in Table 2 below.

The polybutylene terephthalate resin composition of the present invention has a low warp property, a low specific density, and a small amount of gas generated, so that it can be suitably used as an interior part for a vehicle such as an automobile, and has very high industrial utility. be.

Claims (2)

More than 50 parts by mass of a bulk polymer of acrylonitrile-styrene copolymer (AS resin) or acrylonitrile-styrene-acrylic rubber copolymer (ASA resin) with respect to 100 parts by mass of polybutylene terephthalate resin (A) A method for producing a polybutylene terephthalate resin composition for vehicle interior parts, which comprises blending 10 to 100 parts by mass of glass fiber (C) and melt-kneading at a heating temperature of 220 to 300 ° C. The method for producing a polybutylene terephthalate resin composition for vehicle interior parts according to claim 1, wherein the glass fiber (C) is blended in an amount of 25 to 90 parts by mass with respect to 100 parts by mass of the polybutylene terephthalate resin (A).