JP2019151810A - Polybutylene terephthalate resin composition - Google Patents

Abstract

To provide a polybutylene terephthalate resin composition which has low warpage and low specific gravity, has a small amount of gas generation, and is excellent in mechanical properties at high temperatures.SOLUTION: A polybutylene terephthalate resin composition contains 45-100 pts.mass of an acrylonitrile-styrene copolymer (B), 0.2-3 pts.mass of an epoxy modified acrylic polymer (C) and 10-100 pts.mass of a glass fiber (D) based on 100 pts.mass of a polybutylene terephthalate resin (A).SELECTED DRAWING: None

Description

  The present invention relates to a polybutylene terephthalate resin composition, and more particularly to a polybutylene terephthalate resin composition having low warpage and low specific gravity, a small amount of gas generation, and excellent mechanical properties at high temperatures.

  Thermoplastic polyester resin represented by polybutylene terephthalate resin has excellent mechanical and electrical properties as well as chemical resistance and heat resistance. It is 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 automobiles, specifically, for example, indoor inner mirror stays, door handles, and the like, are required to have light weight, high strength, high rigidity, and excellent appearance. A reinforced thermoplastic resin, especially a 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 with the thermoplastic polyester resin as the base. However, if the amount of reinforcing material is increased, the moldability (fluidity) of the fiber reinforced polyester resin composition will decrease, and the blended fibrous reinforcing material will be easily raised on the surface of the molded product, resulting in surface roughness and gloss reduction. However, the shrinkage anisotropy (molding shrinkage ratio) of the molded product such as deterioration of the appearance of the product and warpage of the molded product becomes a problem.

For the purpose of improving the strength by adding these fibrous reinforcements and not damaging the surface properties such as appearance, surface treatment of fibrous reinforcements and the use of epoxy resins and silane coupling agents have been proposed. (For example, refer to Patent Documents 1 and 2).
However, just by applying a special treatment to the fibrous reinforcement as in these patent documents, the surface properties such as the appearance of the obtained molded product are not satisfactory, and the shrinkage anisotropy of the molded product is also a problem. It becomes.

As parts for vehicles, parts that require high strength are mixed with a large amount of fibrous reinforcing material of 50% by mass or more. In this case, the fluidity of the resin composition is further reduced, and the fibrous reinforcement The material appearance becomes severe and the surface appearance is significantly deteriorated.
On the other hand, if the amount of the fibrous reinforcing material added is small, warping tends to occur.

An invention in which ABS resin and polyethylene terephthalate resin in which the dispersed particle diameter of the butadiene component is refined to 1 μm or less are added to 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, it is not easy to maintain a good balance between appearance and low warpage in this invention.

  In particular, in the case of use in the interior of a car, there are regulations on VOC (volatile organic compounds), which is a strict guideline for the organic matter released, and vehicle interior parts are strongly required to clear this. It's getting on.

Japanese Patent Publication No.51-7702 JP 2006-16557 A Japanese Patent No. 3098308

  An object (problem) of the present invention is to provide a polybutylene terephthalate resin composition having low warpage and low specific gravity, a small amount of gas generation, and excellent mechanical properties at high temperatures.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a glass comprising a polybutylene terephthalate resin and a specific amount of acrylonitrile-styrene copolymer and a specific amount of epoxy-modified acrylic polymer. The present inventors have found that a fiber-reinforced polybutylene terephthalate resin composition can solve the above-described problems, and have reached the present invention.
The present invention relates to the following polybutylene terephthalate resin composition.

[1] With respect to 100 parts by mass of the polybutylene terephthalate resin (A), 45 to 100 parts by mass of an acrylonitrile-styrene copolymer (B), 0.2 to 3 parts by mass of an epoxy-modified acrylic polymer (C), And a polybutylene terephthalate resin composition, comprising 10 to 100 parts by mass of glass fiber (D).
[2] In the above [1], the amount of the styrene monomer detected when the gas generated by heat-treating the polybutylene terephthalate resin composition at 270 ° C. for 10 minutes is analyzed by gas chromatography is 45 ppm or less. The polybutylene terephthalate resin composition described.
[3] The polybutylene terephthalate resin composition according to the above [1] or [2], wherein the acrylonitrile-styrene copolymer (B) is a bulk polymer.

  The polybutylene terephthalate resin composition of the present invention has less warpage, less gas generation, can satisfy VOC regulations, has low specific gravity, and is excellent in mechanical properties such as mechanical strength in an environment assuming high temperature inside the vehicle. Therefore, it can be suitably used particularly as a vehicle interior part.

Hereinafter, embodiments of the present invention will be described in detail. The following description may be made based on embodiments and specific examples, but the present invention is not construed as being limited to such embodiments and specific examples.
In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

  The polybutylene terephthalate resin composition of the present invention has an acrylonitrile-styrene copolymer (B) of 45 to 100 parts by mass and an epoxy-modified acrylic polymer (C) with respect to 100 parts by mass of the polybutylene terephthalate resin (A). It contains 0.2 to 3 parts by mass and 10 to 100 parts by mass of glass fiber (D).

[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, the polybutylene terephthalate copolymer containing other copolymerization components other than a terephthalic acid unit and a 1, 4- butanediol unit, and the mixture of a homopolymer and the said copolymer are included.

  The polybutylene terephthalate resin (A) may contain dicarboxylic acid units other than terephthalic acid. 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) methane, anthracene dicarboxylic acid, aromatic dicarboxylic acids such as 4,4′-diphenyl ether dicarboxylic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 4,4′-dicyclohexyldicarboxylic acid, And aliphatic diacids such as adipic acid, sebacic acid, azelaic acid, dimer acid, etc. Carboxylic acids, and the like.

  The diol unit may contain other diol units in addition to 1,4-butanediol. 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 4,4'-dicyclohexylhydroxypropane, ethylene oxide addition diol of bisphenol A, and the like. In addition to the above-mentioned bifunctional monomers, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane are introduced to introduce a branched structure, and fatty acids are used for molecular weight control. A small amount of a monofunctional compound can be used in combination.

As described above, the polybutylene terephthalate resin (A) is preferably a polybutylene terephthalate homopolymer obtained by polycondensation of terephthalic acid and 1,4-butanediol, but as the carboxylic acid unit, other than the above terephthalic acid. It may be a polybutylene terephthalate copolymer containing one or more dicarboxylic acids and / or one or more diols other than 1,4-butanediol as the diol unit, and the polybutylene terephthalate resin (A) is a co-polymer. In the case of a polybutylene terephthalate resin modified by polymerization, specific preferred copolymers thereof include polyalkylene glycols, particularly polyester ether resins copolymerized with polytetramethylene glycol, and dimer acid copolymerized polybutylene terephthalate. Resin, isophthalic acid It includes polymer polybutylene terephthalate resin. Among these, it is preferable to use a polyester ether resin copolymerized with polytetramethylene glycol.
These copolymers are those having a copolymerization amount of 1 mol% or more and less than 50 mol% in all segments of the polybutylene terephthalate resin. Among them, the copolymerization amount is preferably 2 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%. By setting it as such a copolymerization ratio, it exists in the tendency for fluidity | liquidity, toughness, and tracking resistance to improve easily, and is preferable.

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

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

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

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

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

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

  Examples of the styrene monomer constituting the acrylonitrile-styrene copolymer (B) include styrene, α-methyl styrene, p-methyl styrene, vinyl xylene, ethyl styrene, dimethyl styrene, p-tert-butyl styrene, vinyl. Naphthalene, methoxystyrene, monobromostyrene, dibromostyrene, fluorostyrene, tribromostyrene and the like can be mentioned, styrene and α-methylstyrene are more preferable, and styrene is particularly preferable.

Other copolymerizable monomers other than styrene monomers and acrylonitrile include (meth) acrylic acid ester monomers and maleimide monomers such as maleimide, N-methylmaleimide, N-phenylmaleimide , Α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, phthalic acid, itaconic acid, and anhydrides thereof.
Among these, (meth) acrylic acid ester monomers are preferably exemplified. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, Amyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, phenyl (meth) acrylate, Examples include benzyl (meth) acrylate, and particularly methyl methacrylate.
The notation of (meth) acrylate indicates that both methacrylate and acrylate are included, and the notation of (meth) acrylic acid ester indicates that both methacrylic acid ester and acrylic acid ester are included.

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

Further, acrylonitrile - as a melt volume rate of the styrene copolymer (B) (MVR), preferably in the range 220 ° C., under a load 10kg of 5 to 100 cm ^3/10 min, 10~80cm ^3/10 min 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, and 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 a GPC (gel permeation chromatography) method.

  The acrylonitrile-styrene copolymer (B) is preferably an acrylonitrile-styrene copolymer (AS resin) or an acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), and particularly an acrylonitrile-styrene copolymer (AS resin). Is preferred.

The method for producing the acrylonitrile-styrene 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 can be used. Of these, bulk polymerization is preferred because it uses less solvent or emulsifier and has less impurities and less gas generated from the polybutylene terephthalate resin composition of the present invention.
The acrylonitrile-styrene copolymer (B) is commercially available, and bulk polymer products, emulsion polymer products, solution polymer products, suspension polymer products, etc. are commercially available. Among these, the bulk polymer product is a solvent. Since no emulsifier or emulsifier is used, there are few impurities, which is preferable because the amount of gas generated from the polybutylene terephthalate resin composition of the present invention is reduced.

In the present invention, as the acrylonitrile-styrene copolymer (B), the gas generated by heat treatment at 270 ° C. for 10 minutes is analyzed by gas chromatography, whereby the amount of styrene monomer and the amount of ethylbenzene are determined. Although it can be measured, it is preferable to use a styrene monomer having an amount of 600 (mass) ppm or less. When the amount of styrene-based monomer gas is 600 ppm or less, the amount of gas generated during molding is reduced, and the amount of gas generated from the molded body when molded is small. The VOC problem is solved, and the appearance of the molded body is improved because of a small amount of gas during molding. On the other hand, when it exceeds 600 ppm, it becomes difficult to solve the VOC problem in the case of an interior part for a vehicle, and the appearance tends to be poor. The amount of the styrenic monomer is more preferably 550 ppm or less, further preferably 300 ppm or less, particularly preferably 200 ppm or less, and the lower limit thereof is usually 50 ppm. If it is less than 50 ppm, it is not preferable because it requires refining so as not to be economical. In the case of using a plurality of types as the acrylonitrile-styrene copolymer (B), the total amount calculated from the amount of styrene monomer gas from each polymer and the respective mass ratio to be used. is there.
The amount of the styrene monomer can be obtained by analyzing the gas generated by heat treatment at 270 ° C. for 10 minutes by gas chromatography, but the measured value is converted into a value per mass of the copolymer. The amount to be obtained (unit: mass ppm), and the specific conditions are as detailed in the examples.

The total of the styrene monomer and ethylbenzene when the gas generated by heat treatment at 270 ° C. for 10 minutes is analyzed by gas chromatography is preferably 650 (mass) ppm or less. Since the total gas amount of both is 650 ppm or less, the amount of gas generated at the time of molding is reduced, and the amount of gas generated from the molded body when formed into a molded body is small. The problem of VOC is solved, and the appearance of the molded body is improved because of less gas during molding. The total gas amount of both is more preferably 500 ppm or less, still more preferably 400 ppm or less, and its lower limit is usually 150 ppm. If it is less than 150 ppm, it is not preferable because it requires refining so as not to be economical.
In addition, when using multiple types as an acrylonitrile-styrene-type copolymer (B), the generation amount of the styrene-type monomer and ethylbenzene from each polymer as well as the above, and each mass ratio to be used, Is the total amount calculated.

In order to make the amount of styrene monomer and ethylbenzene in the acrylonitrile-styrene copolymer within the above range, the constitution of the devolatilization process after polymerization of the acrylonitrile-styrene copolymer and the operating conditions of the devolatilization process are changed. It becomes possible by strengthening. In the case of suspension polymerization, the copolymer latex obtained at an appropriate temperature and vacuum is stripped, coagulated with high-temperature steam, or stripped under reduced pressure using high-temperature steam. And the coagulated copolymer is washed with hot water and further dried under vacuum. In bulk polymerization, it is possible to adjust the degree of vacuum, supply speed or heating temperature in a vacuum devolatilizer.
It is also possible to select a commercially available product satisfying the conditions or to further dry the commercially available product to obtain the desired amount of styrene monomer or ethylbenzene.

  The content of the acrylonitrile-styrene copolymer (B) is 45 to 100 parts by mass with respect to 100 parts by mass of the polybutylene terephthalate resin (A). If the content is less than 45 parts by mass, the ratio of the amorphous resin is low and the shrinkage ratio is large, which causes warping of the molded product. If the content exceeds 100 parts by mass, the ratio of the amorphous resin is high and the heat resistance is high. In addition to the decrease, the 85 ° C. atmosphere bending strength and weld strength decrease. The content of the acrylonitrile-styrene copolymer (B) is preferably 50 parts by mass or more, more preferably 55 parts by mass or more, still more preferably 60 parts by mass or more, and particularly preferably 65 parts by mass or more. Is 95 parts by mass or less, more preferably 90 parts by mass or less.

[Epoxy-modified acrylic polymer (C)]
The polybutylene terephthalate resin composition of the present invention contains an epoxy-modified acrylic polymer (C). The epoxy-modified acrylic polymer (C) is not particularly limited, but an acrylic polymer composed of a (meth) acrylic acid alkyl ester and an unsaturated glycidyl compound is preferable.

Examples of (meth) acrylic acid alkyl esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid. Isobutyl, s-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, (Meth) acrylic acid alkyl esters having a linear or branched alkyl group such as (meth) acrylic acid decyl and (meth) acrylic acid dodecyl are preferred, and in particular, (meth) acrylic acid having 1 to 12 carbon atoms. Alkyl esters are more preferred, such as methyl (meth) acrylate, ethyl (meth) acrylate, (meth ) Acrylate, propyl (meth) acrylate, butyl 2-ethylhexyl (meth) acrylic acid.
In the present specification, “(meth) acryl” means “acryl” and / or “methacryl”.

  As the unsaturated glycidyl compound, an epoxy group-containing polymerizable unsaturated compound is preferable. Unsaturated glycidyl ester such as glycidyl (meth) acrylate and glycidyl itaconate, or vinyl glycidyl ether, allyl glycidyl ether, 2-methyl, etc. Preferable examples include unsaturated glycidyl ethers such as allyl glycidyl ether and styrene-p-glycidyl ether. Among them, unsaturated glycidyl esters, particularly epoxy group-containing (meth) acrylic acid esters are preferable, more preferably glycidyl (meth) acrylate, that is, glycidyl acrylate, glycidyl methacrylate (GMA), particularly glycidyl methacrylate (GMA). preferable.

The epoxy-modified acrylic polymer (C) is preferably a copolymer obtained by copolymerizing another monomer other than those described above, and is particularly preferably a copolymer obtained by copolymerizing a styrene monomer.
Examples of the styrene monomer include styrene, α-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, methoxystyrene, monobromostyrene, dibromostyrene, Examples thereof include fluorostyrene and tribromostyrene, and styrene and α-methylstyrene are more preferable, and styrene is particularly preferable.

  The epoxy-modified acrylic polymer (C) is a structural unit derived from a (meth) acrylic acid alkyl ester (C1), an epoxy group-containing (meth) acrylic acid ester (C2), or a styrene monomer (C3). When it contains, as for preferable content of each structural unit, when the mass of an epoxy-modified acrylic polymer (C) is 100 mass%, C1 component becomes like this. Preferably it is 50-99 mass%, More preferably, it is 55-95. The C2 component is preferably 0.05 to 20% by mass, more preferably 0.1 to 18% by mass, and the C3 component is preferably 0 to 49.5% by mass, more preferably 0 to 45%. It is preferable that it is mass%, Furthermore, it is 5-45 mass%.

  The epoxy equivalent of the epoxy-modified acrylic polymer (C) is preferably 100 to 1000 g / mol, more preferably 200 to 800 g / mol. When the epoxy equivalent exceeds 1000 g / mol, the dispersion of the acrylonitrile-styrene copolymer in the composition may be insufficient. On the other hand, when the epoxy equivalent is less than 100 g / mol, the viscosity is remarkably increased and the moldability is impaired. There is a case.

  The weight average molecular weight (Mw) of the epoxy-modified acrylic polymer (C) is preferably 4000 to 13000, and more preferably 5000 to 12000.

  Content of an epoxy-modified acrylic polymer (C) is 0.2-3 mass parts with respect to 100 mass parts of polybutylene terephthalate resins (A). If the amount is less than 0.2 parts by mass, the cross-linkage between the polybutylene terephthalate molecules becomes insufficient, and the mechanical strength tends to decrease. If the amount exceeds 3 parts by mass, the cross-linkage between the polybutylene terephthalate molecules excessively proceeds to increase the viscosity. It raises remarkably and moldability will be impaired. The content of the copolymer (C) is preferably 0.25 parts by mass or more, preferably 2.8 parts by mass or less, more preferably 2 with respect to 100 parts by mass of the thermoplastic polyester resin (A). 0.0 part by mass or less, more preferably 1.0 part by mass or less.

[Glass fiber (D)]
The polybutylene terephthalate resin composition of the present invention contains 10 to 100 parts by mass of the glass fiber (D) with respect to 100 parts by mass of the polybutylene terephthalate resin (A). When the content is less than 10 parts by mass, the reinforcing effect may not be sufficient, and when it exceeds 100 parts by mass, the appearance and impact resistance may be inferior and the fluidity may not be sufficient. The preferable content of the glass fiber (D) is 45 parts by mass or more, more preferably 55 parts by mass or more, further preferably 65 parts by mass or more, particularly 100 parts by mass of the polybutylene terephthalate resin (A). 70 parts by mass or more is preferable, preferably 95 parts by mass or less, and more preferably 90 parts by mass or less. Thus, by containing glass fiber (D), the strength, rigidity, and dimensional stability of the polybutylene terephthalate resin composition of the present invention can be improved.

  There is no restriction | limiting in particular in the kind of glass fiber (D), For example, glass fibers, such as E glass, C glass, A glass, and S glass, can be mentioned. Among these, E glass fibers are preferred in that they do not adversely affect the thermal stability of the polybutylene terephthalate resin.

  The average fiber diameter of the glass fiber (D) 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. Glass fibers having an average fiber diameter of less than 1 μm are not easy to produce and may increase costs, whereas if they exceed 100 μm, the tensile strength of the glass fibers may decrease. The fiber cross section may be circular or flat.

The glass fiber (D) may be a round fiber or a flat fiber cross section, but is a glass fiber having a substantially circular cross section with a flatness ratio (major axis / minor axis) of 1 to 1.5. Preferably there is. 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 obtained by observing 2000 glass fibers of filler residue collected by processing such as high-temperature ashing of a molded product, dissolution with a solvent, and decomposition with a chemical with an optical microscope. It is a calculated average value.

Although the average fiber length of glass fiber (D) is not specifically limited, For example, it is preferable that it is 1-10 mm, It is more preferable that it is 1.5-6 mm, It is further more preferable that it is 2-5 mm. If the average fiber length of the glass fiber (D) 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 resulting resin composition.
The average fiber length is determined by using an image analyzer from an image obtained by observing 2000 glass fibers of a filler residue collected by processing such as high-temperature ashing of a molded product, dissolution with a solvent, and decomposition with a chemical using an optical microscope. It is a value of the calculated number average fiber length. Further, when calculating such a value, the fiber diameter is used as a guide and the length is less than that.

The glass fiber (D) 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 coupling agents include chlorosilane compounds such as vinyltrichlorosilane and methylvinyldichlorosilane, alkoxysilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, and γ-methacryloxypropyltrimethoxysilane. Compounds, epoxy silane compounds such as β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, acrylic compounds, isocyanate compounds, titanate compounds, epoxy compounds, etc. Can be mentioned.

In addition, the glass fiber (D) used in the present invention is usually preferably used as a chopped strand (chopped glass fiber) obtained by cutting a number of these fibers into a predetermined length. It is preferable to add a sizing agent to the fiber. In addition to the advantage that the production stability of the polybutylene terephthalate resin composition of the present invention is increased by blending the sizing agent, good mechanical properties can be obtained.
There is no restriction | limiting in particular as a sizing agent of glass fiber (D), For example, resin emulsions, such as a vinyl acetate resin, an ethylene-vinyl acetate copolymer, an acrylic resin, an epoxy resin, a polyurethane resin, a polyester resin, etc. can be mentioned. Preferably, acrylic resin, epoxy resin, and polyurethane resin are used.

[Other ingredients]
The polybutylene terephthalate resin composition of the present invention can contain a thermoplastic resin other than essential components within a range not impairing the effects of the present invention. As other thermoplastic resins, specifically, for example, polyethylene terephthalate resin, polycarbonate resin, polyacetal resin, polyamide resin, polyphenylene oxide resin, polyphenylene sulfide resin, polysulfone resin, polyethersulfone resin, polyetherimide resin, Examples include polyether ketone resins and polyolefin resins.
However, when the resin other than the essential components is contained, the content is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts with respect to 100 parts by mass of the polybutylene terephthalate resin (A). It is preferable that the amount be 3 parts by mass or less, particularly 3 parts by mass or less.

  In addition, various additives other than those described above may be contained. Examples of such additives include stabilizers, carbon black, mold release agents, flame retardants, flame retardant aids, anti-dripping agents, and ultraviolet absorption. 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 in that it has effects of improving thermal stability and preventing deterioration of mechanical strength and hue. As the stabilizer, a phosphorus stabilizer, a sulfur stabilizer, and a phenol stabilizer are preferable, and a phenol stabilizer is particularly preferable.

  Phosphorous stabilizers include phosphorous acid, phosphoric acid, phosphite ester (phosphite), trivalent phosphate ester (phosphonite), and pentavalent phosphate ester (phosphate). Phyto, phosphonite and phosphate compounds are preferred.

The organic phosphate compound is preferably 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, and may be the same or different. N represents an integer of 0 to 2.)
It is a compound represented by these. More preferably, R ¹ is a long-chain alkyl acid phosphate compound having 8 to 30 carbon atoms. Specific examples of the alkyl group having 8 to 30 carbon atoms include octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, A hexadecyl group, an octadecyl group, an eicosyl group, a triacontyl group, etc. are mentioned.

  Examples of the long-chain alkyl acid phosphate 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, nonyl phenyl acid phosphate Acid phosphate, phenoxyethyl acid phosphate, alkoxy polyethylene glycol acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, geo Chill acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, and a bis-nonylphenyl acid phosphate, or the like. Among these, octadecyl acid phosphate is preferable, and this is marketed under the trade name “ADEKA STAB AX-71” of ADEKA.

As the organic phosphite compound, preferably, the following general formula:
^{R 2 O-P (OR 3} ) (OR 4)
(Wherein R ² , R ³ and R ⁴ are each a hydrogen atom, an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, and among R ² , R ³ and R ⁴ ) At least one of them is an aryl group having 6 to 30 carbon atoms.)
The compound represented by these is mentioned.

  Examples of the organic phosphite compound include triphenyl phosphite, tris (nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris (2-ethylhexyl) phosphite, and tris (tridecyl). ) Phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite Hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4′-butylidene-bis (3-methyl-6-t rt-butylphenyldi (tridecyl) phosphite), tetra (tridecyl) 4,4′-isopropylidenediphenyldiphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, di Lauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris (4-tert-butylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite Phytopolymer, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite Phosphite, 2,2'-methylenebis (4,6-di -tert- butylphenyl) octyl phosphite, 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 the following general formula:
R ⁵ -P (OR ⁶ ) (OR ⁷ )
(In the formula, R ⁵ , R ⁶ and R ⁷ are each a hydrogen atom, an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, and among R ⁵ , R ⁶ and R ⁷ , At least one of them is an aryl group having 6 to 30 carbon atoms.)
The compound represented by these is mentioned.

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

  As the sulfur stabilizer, any conventionally known sulfur atom-containing compound can be used, and among these, 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 dibutyldithiocarbamate, nickel isopropylxanthate, trilauryltrithiophosphite. Among these, pentaerythritol tetrakis (3-dodecylthiopropionate) is preferable.

  Examples of the phenol-based stabilizer include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4). -Hydroxyphenyl) propionate, thiodiethylenebis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), 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], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate is preferred.

  Among them, it is preferable to use a hindered phenol 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 is increased, so that the stabilizer is altered and loses its stabilizing effect, or during the production of a resin composition such as melt kneading or in a high temperature environment such as injection molding. But it becomes difficult to produce gas. 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, more preferably 280 ° C. or lower.

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 1.5 parts by mass with respect to 100 parts by mass of the polybutylene terephthalate resin (A). When the content of the stabilizer is less than 0.001 part by mass, it is difficult to expect an improvement in the thermal stability and compatibility of the resin composition, and a decrease in molecular weight and hue deterioration during molding are likely to occur. When it exceeds the part, it becomes an excessive amount, and there is a tendency that silver streak and hue deterioration are more likely to occur. The content of the stabilizer is more preferably 0.005 to 1.2 parts by mass, and still more preferably 0.01 to 1.0 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.
There are no restrictions on the type, raw material type, and manufacturing method of carbon black, and any of furnace black, channel black, acetylene black, ketjen black, and the like can be used. The number average particle diameter is not particularly limited, but is preferably 5 to 60 nm. As described above, by using carbon black having a number average particle diameter in a predetermined range, a composition in which blisters are hardly generated at a high temperature can be obtained.
In addition, the number average particle diameter is obtained as a unit constituent particle from an aggregate enlarged image obtained by the procedure described in ASTM D3849 standard (standard test method of carbon black—morphological characterization by electron microscopy). 3,000 particle diameters can be measured and arithmetically averaged.

Nitrogen adsorption specific surface area of the carbon black ^{(unit: m} 2 / g) is preferably normally 1,000m less than ² / g, is preferably Among them, 50 to 400 m ² / g. Setting the nitrogen adsorption specific surface area to less than 1,000 m ² / g is preferred 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.

Further, the carbon black DBP (dibutyl phthalate) absorption ^is preferably less than 300 cm 3/100 g, is preferably Among them 30~200cm ³ / 100g. The DBP absorption amount by less than 300 cm ^3/100 g, preferably tends to increase the appearance of fluidity and a molded article of polybutylene terephthalate resin composition of the present invention. Incidentally, DBP absorption ^(unit: cm 3 / 100g) can be measured according to JIS K6217.
The carbon black to be used is not particularly limited in terms of pH, but is usually 2 to 10, preferably 3 to 9, and more preferably 4 to 8.

Carbon black can be used alone or in combination of two or more. Furthermore, carbon black can be granulated using a binder, and can also be used in a masterbatch that is melt-kneaded at a high concentration in another resin. By using the melt-kneaded master batch, the handling property during extrusion and the dispersibility improvement in the resin composition can be achieved. Examples of the resin include polystyrene resin, polyester resin, and acrylic resin.
The content of carbon black in the master batch is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, and further 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). As mentioned above, it is 0.1 mass part or more especially, More preferably, it is 2 mass parts or less, More preferably, it is 1.5 mass parts or less, Most preferably, it is 1.0 mass part or less. When the content is less than 0.01 parts by mass, the weather resistance may be insufficient. When the content exceeds 5 parts by mass, mechanical properties such as moldability and impact resistance tend to be deteriorated.

[Release agent]
The polybutylene terephthalate resin composition of the present invention preferably contains a release agent.
Examples of the release agent include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds, polysiloxane silicone oils, and the like.

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

  As aliphatic carboxylic acid in ester of aliphatic carboxylic acid and alcohol, the same thing as the said aliphatic carboxylic acid can be used, for example. 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, monovalent or polyvalent 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. In addition, an aliphatic includes an alicyclic compound here.

  Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, and the like. Is mentioned.

  In addition, said ester may contain aliphatic carboxylic acid and / or alcohol as an impurity. Moreover, although said ester may be a pure substance, it may be a mixture of a plurality of compounds. Furthermore, the aliphatic carboxylic acid and alcohol which combine to form one ester may be used alone or in combination of two or more in any combination and ratio.

  Specific examples of esters of aliphatic carboxylic acids and alcohols include montanic acid ester wax, beeswax (mixture based on myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmi Tate, glycerol monostearate, glycerol distearate, glycerol tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, etc. .

  Examples of the aliphatic hydrocarbon compound include polyolefin wax such as liquid paraffin, paraffin wax, microcrystalline wax and polyethylene wax, Fischer-Tropsch wax, α-olefin oligomer having 3 to 12 carbon atoms, and the like. Here, the aliphatic hydrocarbon includes alicyclic hydrocarbons. Further, these hydrocarbons may be partially oxidized. The number average molecular weight is preferably 200 to 30000, more preferably 1000 to 15000, still more preferably 1500 to 10000, and particularly preferably 2000 to 5000. The aliphatic hydrocarbon compound may be a single substance, but even a mixture of various constituent components and molecular weights can be used as long as the main component is within the above range.

  In the present invention, the mold release agent is preferably a polyolefin wax from the viewpoint of heat resistance. As the polyolefin wax, any conventionally known wax can be used. For example, it preferably has 2 to 30 carbon atoms, more preferably 2 to 12 carbon atoms, and still more preferably 2 to 10 carbon atoms, or an arbitrary ratio of two. (Co) polymers (meaning polymerization or copolymerization; the same shall apply hereinafter) containing at least species.

  Examples of the olefin having 2 to 30 carbon atoms include ethylene, propylene, an α-olefin having 4 to 30 carbon atoms (preferably 4 to 12 and more preferably 4 to 10), and 4 to 30 carbon atoms (preferably 4). -18, more preferably 4-8) dienes. 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 releasability and heat resistance.
The manufacturing method of polyethylene wax is arbitrary, for example, can be manufactured by polymerization of ethylene or thermal decomposition of polyethylene.

  As the mold release agent, those having an acid value of 10 to 40 mgKOH / g are preferable from the viewpoint that the mold release resistance is small, the effect of improving the mold release is remarkable, and the volatile content is small. The acid value is more preferably 11 to 35 mgKOH / g, still more preferably 12 to 32 mgKOH / g. As long as the acid value is in the range of 10 to 40 mgKOH / g, those having an acid value of less than 10 mgKOH / g and those exceeding 40 mgKOH / g may be used in combination. What is necessary is just to become 10-40 mgKOH / g.

  As the release agent having an acid value of 10 to 40 mgKOH / g, an ester of an aliphatic carboxylic acid and an alcohol as described above and having an acid value of 10 to 40 mgKOH / g, an aliphatic hydrocarbon compound described above, Represents a carboxyl group (a carboxylic acid (anhydride) group, that is, a carboxylic acid group and / or a carboxylic anhydride group), a haloformyl group, an ester group, a carboxylic acid metal base, a hydroxyl group, and an alcohol. A modified polyolefin wax provided with a functional group having an affinity for a polyester resin such as a group, an epoxy group, an amino group, or an amide group is preferred.

Examples of the carboxyl group used for modifying the polyolefin wax include low molecular weight compounds containing carboxylic acid groups such as maleic acid, maleic anhydride, acrylic acid, and methacrylic acid, low molecular weight compounds containing sulfo groups such as sulfonic acid, and phosphones. Examples thereof include a low molecular weight compound 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 in any proportion.
The addition amount of the acid in the modified polyolefin wax is usually 0.01 to 10% by mass, preferably 0.05 to 5% by mass with respect to the modified polyolefin wax.

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

The type of functional group is preferably a carboxyl group because it has a moderate 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 matter is reduced, and the mold release effect is reduced. There is. On the other hand, if the concentration is too high, for example, the polymer main chain constituting the polyolefin wax is excessively cleaved during modification, and the molecular weight of the modified polyolefin wax is excessively reduced, resulting in increased generation of volatile matter, and polyester resin. Cloudiness may occur on the surface of the molded body.
As the modified polyolefin wax, an oxidized polyethylene wax is preferable.

In addition, 1 type may contain the mold release agent and 2 or more types may contain it by arbitrary combinations and a ratio.
The content of the release agent is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and usually 2 parts by mass or less, preferably 100 parts by mass of the polybutylene terephthalate resin (A). 1.5 parts by mass or less. When the content of the release agent is less than the lower limit of the above range, the effect of releasability may not be sufficient, and when the content of the release agent exceeds the upper limit of the above range, hydrolysis resistance And mold contamination during injection molding may occur.

[Method for Producing Resin Composition]
The method for producing the polybutylene terephthalate resin composition of the present invention can be carried out in accordance with a conventional method for preparing a polybutylene terephthalate resin composition. That is, the polybutylene terephthalate resin (A), the styrene copolymer (B), the epoxy-modified acrylic polymer (C), and other resin components and various additives that are optionally added may be mixed together. Then, the mixture is melt kneaded with a single or twin screw extruder. The glass fiber (D) is preferably side fed. Further, a part of which is made into a master batch may be blended and melt-kneaded. Furthermore, it is also possible to produce various molded products by supplying a mixture obtained by mixing each component in advance to a molding machine such as an injection molding machine without melt-kneading.

  The heating temperature at the time of 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 poor appearance. Therefore, it is desirable to select a screw configuration in consideration of shear heat generation. In order to suppress decomposition during kneading or molding in the subsequent process, it is desirable to use an antioxidant or a heat stabilizer.

Since the polybutylene terephthalate resin composition of the present invention is low outgas, the amount of styrene monomer detected when a gas generated by heat treatment at 270 ° C. for 10 minutes is analyzed by gas chromatography is preferably 45. It becomes possible to make (mass) ppm or less. When the amount of the styrene monomer gas in the resin composition is 45 ppm or less, the VOC problem is solved even when used as a vehicle interior part, and the appearance at the time of molding is also improved. On the other hand, if it exceeds 45 ppm, cleanliness as an interior part for a vehicle is deteriorated, 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 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 styrenic monomer gas in the resin composition can be obtained by analyzing a gas generated by heat treatment at 270 ° C. for 10 minutes using a gas chromatograph. The amount (unit: ppm by mass) obtained by converting to the value of, and the specific conditions are as detailed in the examples.

In the polybutylene terephthalate resin composition of the present invention, the amount of ethylbenzene detected when a gas generated by heat treatment at 270 ° C. for 10 minutes is analyzed by gas chromatography is preferably 3 (mass) ppm or less. It becomes possible. By doing in this way, the VOC problem is solved even when used as a vehicle interior part, and the appearance at the time of molding is also improved.
The amount of ethylbenzene gas in the resin composition can be obtained by analyzing a gas generated by heat treatment at 270 ° C. for 10 minutes using a gas chromatograph, but the measured value is converted into a value per mass of the resin composition. The specific conditions are as detailed in the examples.

  The polybutylene terephthalate resin composition of the present invention preferably has a total amount of styrene monomer and ethylbenzene detected when a gas generated by heat treatment at 270 ° C. for 10 minutes is analyzed by gas chromatography, preferably 45 It becomes possible to make (mass) ppm or less. By doing in this way, the VOC problem is solved even when used as a vehicle interior part, and the appearance at the time of molding is also improved. The total amount of the styrene monomer and ethylbenzene in the resin composition is preferably 30 ppm or less, more preferably 20 ppm or less, and the lower limit is usually 3 ppm.

In order to make the amount of styrene monomer gas in the resin composition 45 ppm or less, the above acrylonitrile-styrene copolymer (B) has a styrene monomer gas amount of 600 ppm or less, preferably 550 ppm or less. It is possible to use them, or further by blending the above-mentioned phosphite stabilizers, hindered phenol stabilizers and the like.
The amount of ethylbenzene gas in the resin composition can be reduced to 3 ppm or less by, for example, blending the above-described phosphite stabilizer, hindered phenol stabilizer, or the like.

[Molding]
The method for producing a molded product using the above-described polybutylene terephthalate resin composition is not particularly limited, and any molding method generally employed for the polybutylene terephthalate resin composition can be arbitrarily adopted. For example, injection molding method, ultra-high speed injection molding method, injection compression molding method, two-color molding method, hollow molding method such as gas assist, molding method using heat insulating mold, rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermoforming method, rotational molding method, laminate molding method, press molding method, Examples thereof include a blow molding method. Among these, the injection molding method is preferable because the effects of the present invention are remarkable, such as the productivity and the surface property of the obtained molded article.

The amount of the volatile organic compound (TVOC amount) in the molded body molded from the composition of the present invention is preferably 30 μg C / g or less, more preferably 20 μg C / g or less. In order to make the TVOC amount of the molded body as described above, a styrene monomer gas amount of 600 ppm or less, preferably 550 ppm or less is used as the acrylonitrile-styrene copolymer (B). Is possible by blending a phosphite stabilizer or a hindered phenol stabilizer.
In addition, the specific measuring method of the amount of volatile organic compounds (TVOC) of a molded object is as having described in detail in the Example.

  Molded products molded from the above polybutylene terephthalate resin composition by injection molding, etc. have low warpage, low gas generation, excellent mechanical properties at high temperatures, and low specific gravity. It can be particularly preferably used as a vehicle interior part.

  As vehicle interior parts, interior parts for vehicles such as automobiles, trains, trains, etc., for example, inner mirror stays, wave louvers for air conditioners, door handles, handles, doors, sunroofs, seat belts, register blades, Preferred examples include a washer lever, a window regulator handle, a knob of the window regulator handle, a passing light lever, a sun visor bracket, various housings, a switch, and a clip.

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

[Production Example of Acrylonitrile-Styrene Copolymer (B1)]
Connect the first reactor, which is a complete mixing tank, and the second reactor, which is a tower-type plug flow reactor with a stirrer, and connect two devolatilizer tanks with preheaters in series. Configured. 15 parts by mass of ethylbenzene, 0.01 parts 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. A raw material solution was prepared. This raw material solution was introduced into a first reactor controlled at 130 ° C. at 6.0 kg per hour. The reaction solution was continuously extracted from the first reactor and introduced into the second reactor. Next, after heating to 160 ° C. with a preheater, it was introduced into the first devolatilization tank reduced to 65 kPa, and further heated to 220 ° C. with a preheater and then introduced into the second devolatilization tank reduced to 1.0 kPa. Residual monomer and solvent were removed. This was extruded and cut into strands to obtain pellet-shaped acrylonitrile-styrene copolymer (B1). As shown in Table 1, the composition of the copolymer (B1) (mass ratio of monomer units) was 30% by mass of acrylonitrile units and 70% by mass of styrene units.

The mass average molecular weight (Mw) and acrylonitrile copolymerization amount (% by mass, “PAN ratio”) of the acrylonitrile-styrene copolymer in Table 1 were measured by the methods described above. MVR was measured using a melt indexer manufactured by Takara Industries Co., Ltd., and the melt flow volume MVR per unit time (unit: cm ³ / unit) measured on the pellets obtained above at 220 ° C. under a load of 2.16 kgf. 10 min).

[Measurement of styrene content and ethylbenzene content]
The amount of styrene and the amount of ethylbenzene in the acrylonitrile-styrene copolymer used was measured by placing 0.002 g of a sample in a glass collecting tube having an outer diameter of 6.35 mm and a length of 90 mm and heat-treating at 270 ° C. for 10 minutes (Thermal The gas generated by the Desorption method was performed by the following chromatograph.
Measuring instrument: GCMS-QP2010 (manufactured by Shimadzu Corporation)
Column: UA-1701 ID 0.25mm
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 multiplier with conversion dynode Ion source temperature: 250 ° C

(Examples 1-12, Comparative Examples 1-7)
After uniformly mixing the components shown in Table 1 above in the proportions (all parts by mass) shown in Table 2 using a tumbler mixer, a twin screw extruder (“TEX30α” manufactured by Nippon Steel Works) was used, The resin composition melt-kneaded under conditions of a cylinder 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.

<Evaluation of resin composition>
[Measurement of styrene content and ethylbenzene content]
Measurement of the amount of styrene and the amount of ethylbenzene in the obtained polybutylene terephthalate resin composition was carried out by placing 0.02 g of a sample in a glass collecting tube having an outer diameter of 6.35 mm and a length of 90 mm, and heat treatment at 270 ° C. for 10 minutes ( The gas generated by the Thermal Desorption method was measured by the following chromatograph. The measured value was converted to a value per copolymer or resin composition amount, and the amount of styrene and ethylbenzene generated (unit: mass ppm) was used.
Measuring instrument: GCMS-QP2010 (manufactured by Shimadzu Corporation)
Column: UA-1701 ID 0.25mm
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 multiplier with conversion dynode Ion source temperature: 250 ° C

[Retention thickening (appearance evaluation of staying strand)]
Using a capillograph (Capillograph 1C manufactured by Toyo Seiki Co., Ltd.), using a flat capillary with a measurement temperature of 270 ° C. and 1φ × 30 mm, the pellets obtained above were charged and retained for 30 minutes, at a shear rate of 91.2 sec ⁻¹ . Strands produced by extrusion (retaining strands) were obtained, and the quality of the appearance was judged in the following four stages A to D.
A: Gloss is observed on the strand surface and appearance is good B: Gloss is slightly observed on the strand surface and appearance is slightly poor C: No gloss is found on the strand surface and appearance is poor D: Strand cannot be produced and appearance Impossible to evaluate

<Evaluation of molded body>
[Measurement of TVOC]
The obtained pellets were dried at 120 ° C. for 5 hours, and then 100 mm × 100 mm × 2 mm in an injection molding machine (“NEX80” manufactured by Nissei Plastic Industry Co., Ltd.) under conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. Thick molded bodies were injection molded. Volatile organic compound amount As a measurement of TVOC (total volatile organic compounds) amount, the obtained molded product was cut into 10 to 25 mg, about 2 g of each sample was put in a 22 ml vial, sealed, and HS-GC ( Heat treatment was performed at 120 ° C. for 5 hours using a headspace gas chromatograph mass spectrometer. And the peak integration area of the volatile organic substance component detected with the gas chromatograph was calculated, weight-converted into acetone as a standard, and TVOC (unit: microgram C / g) per 1g of compacts was calculated.
Note that Comparative Example 3 could not be molded because the viscosity was too high.

[85 ℃ ambient bending strength]
The obtained pellets were dried at 120 ° C. for 5 hours, and then an ISO multipurpose test piece (4 mm) with an injection molding machine (“NEX80” manufactured by Nissei Plastic Industry Co., Ltd.) under conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. Thickness) was injection molded.
The bending strength (maximum bending stress, unit: MPa) was measured at a temperature of 85 ° C. in accordance with ISO 178 using an ISO multipurpose test piece (4 mm thickness).

[Warpage amount]
Using an injection molding machine (“NEX80” manufactured by Nissei Plastic Industry Co., Ltd.), a circular plate having a diameter of 100 mm and a thickness of 1.6 mm was molded with a side gate mold under conditions of a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C. The amount of warpage (unit: mm) of the plate was determined.

[Comprehensive evaluation]
Judgment is made based on the following criteria.
A: Evaluation of molded product “warping amount is 5.0 mm or less”, “85 ° C. atmosphere bending strength is 120 MPa or more”, evaluation of resin composition “generation amount of styrene and ethylbenzene is 55 ppm or less”, “residual thickening is All conditions of “A or B” are satisfied.
B: None of A and C below.
C: Evaluation of molded product “warping amount is 6.0 mm or more”, “85 ° C. atmosphere bending strength is less than 120 MPa”, evaluation of resin composition “generation amount of styrene and ethylbenzene exceeds 55 ppm”, “retention thickening is D ”.
The above evaluation results are shown in Table 2-3 below.

  The polybutylene terephthalate resin composition of the present invention is less warped, has less gas generation, can satisfy VOC regulations, and has excellent bending strength at high temperatures, so it can be used for various molded products, especially for automobiles, etc. It can be suitably used as an interior part for vehicles.

Claims (3)

  45-100 parts by mass of acrylonitrile-styrene copolymer (B), 0.2-3 parts by mass of epoxy-modified acrylic polymer (C), and glass fiber with respect to 100 parts by mass of polybutylene terephthalate resin (A) (D) The polybutylene terephthalate resin composition characterized by containing 10-100 mass parts.   2. The polybutylene according to claim 1, wherein the amount of styrene monomer detected when a gas generated by heat-treating the polybutylene terephthalate resin composition at 270 ° C. for 10 minutes is analyzed by gas chromatography is 45 ppm or less. A terephthalate resin composition.   The polybutylene terephthalate resin composition according to claim 1 or 2, wherein the acrylonitrile-styrene copolymer (B) is a bulk polymer.