JP2022092143A - Thermoplastic resin composition - Google Patents

Abstract

To provide a thermoplastic resin composition achieving all of low warpage, heat resistance and heat shock resistance at a high-level and excellent also in mechanical strength, appearance and chemical resistance.SOLUTION: A thermoplastic resin composition containing (C) 12 to 35 pts.mass of an elastomer and (D) 5 to 150 pts.mass of glass fiber relative to a total 100 pts.mass of (A) 15 to 50 pts.mass of a polybutylene terephthalate resin having intrinsic viscosity of 0.3 to 0.8 dl/g and (B) 50 to 85 pts.mass of rubber-reinforced polystyrene or polystyrene, in which (C) the elastomer contains (C-1) an epoxy group-containing olefin-based elastomer or an epoxy group-containing acryl-based elastomer, and (B) melt viscosity at 250°C, 912 sec.-1 of the rubber-reinforced polystyrene or polystyrene is in a range of 70 to 300 Pa s.SELECTED DRAWING: None

Description

The present invention relates to a thermoplastic resin composition, and more particularly to a thermoplastic resin composition that achieves low warpage, heat resistance, and heat shock resistance at a high level in a well-balanced manner.

Thermoplastic polyester resins typified by polybutylene terephthalate and polyethylene terephthalate are excellent in mechanical strength, chemical resistance, electrical insulation, etc., and therefore are excellent in electrical and electronic equipment parts, interior and exterior parts for automobiles, other electrical parts, and mechanical parts. It is widely used for such purposes.

However, since polybutylene terephthalate resin is a crystalline resin, it has a large molding shrinkage rate, and in particular, when a reinforcing filler such as glass fiber is blended, the anisotropy tends to increase, and the molded product warps. In some cases. Therefore, in order to reduce the warp, a method of mixing various amorphous resins has been proposed.

Patent Document 1 describes (a) 50 to 96% by weight of polyester resin, (b) 35 to 3% by weight of rubber-modified polystyrene resin, (c) aromatic polycarbonate resin and / or styrene-maleic anhydride copolymer 15. A polyester resin composition obtained by blending a glass fiber in which a sizing agent containing (B) an amino-based silane coupling agent and a novolak type epoxy resin is attached to a resin (A) consisting of about 1% by weight and (C) an epoxy compound. The invention described is excellent in fluidity, dimensional accuracy and heat resistance. However, such a polyester resin composition is required to be further improved in terms of heat resistance and low warpage.

Further, Patent Document 2 describes (A) 10 to 80% by weight of a thermoplastic polyester resin, (B) 1 to 15% by weight of an epoxy group-containing vinyl-based copolymer, and (C) 1 to 15% by weight of an ABS resin. D) Two or more kinds of resins from (d-1) maleic anhydride-modified polystyrene resin, (d-2) rubber-modified polystyrene resin and (d-3) polycarbonate resin 1 to 20% by weight, (E) glass fiber 0 A thermoplastic polyester resin composition containing up to 50% by weight, (F) a halogenated epoxy bromine-based flame retardant of 3 to 20% by weight, and (G) an antimony compound of 1 to 10% by weight is flame-retardant and has high impact resistance. In addition to high strength and low warpage, it is described that it is excellent in heat cycle property, dimensional stability after annealing treatment, and heat resistance rigidity. However, recently, heat resistance and low warpage are required at extremely high levels, and the thermoplastic polyester resin composition described in Patent Document 2 is still insufficient in terms of heat resistance and low warpage.

According to Patent Document 3, the present inventor has made polystyrene resin rich by combining a low molecular weight polyalkylene terephthalate resin and a high molecular weight polystyrene resin with a small amount of polyalkylene terephthalate resin and a large amount of polystyrene resin. Nevertheless, it has been proposed that the resin composition exhibits high heat resistance, which is a characteristic of polyalkylene terephthalate, and has excellent low warpage. However, although this resin composition is excellent in the above points, it has been found that there is a problem in heat shock resistance.

Japanese Unexamined Patent Publication No. 2006-16559 Japanese Unexamined Patent Publication No. 2007-314619 International release WO2020 / 111011

An object (problem) of the present invention is to provide a thermoplastic resin composition having excellent low warpage resistance, heat resistance and heat shock resistance, and excellent mechanical strength and chemical resistance.

As a result of diligent studies to solve the above-mentioned problems, the present inventor has combined a small amount of low molecular weight polybutylene terephthalate resin, a large amount of polystyrene-based resin, and further combined with an epoxy group-containing elastomer. We have found that this can be solved and arrived at the present invention.
The present invention relates to the following thermoplastic resin compositions and molded articles.

1. 1. (A) 15 to 50 parts by mass of a polybutylene terephthalate resin having an intrinsic viscosity of 0.3 to 0.8 dl / g and (B) 50 to 85 parts by mass of rubber-reinforced polystyrene or polystyrene, with respect to (C) a total of 100 parts by mass. It contains 12 to 35 parts by mass of an elastomer and 5 to 150 parts by mass of (D) glass fiber, and (C) the elastomer contains (C-1) an epoxy group-containing olefin-based elastomer or an epoxy group-containing acrylic-based elastomer. B) A thermoplastic resin composition characterized in that the melt viscosity of rubber-reinforced polystyrene or polystyrene at 250 ° C. and 912 sec ^-1 is in the range of 70 to 300 Pa · s.
2. 2. The thermoplastic resin composition according to 1 above, wherein the elastomer (C) further contains (C-2) a styrene-based elastomer.
3. 3. (C-2) The thermoplastic resin composition according to 2 above, wherein the styrene-based elastomer has a mass average molecular weight of 150,000 to 500,000.
4. The thermoplastic resin composition according to 2 or 3 above, wherein the mass ratio (C-1) / (C-2) of the contents of (C-1) and (C-2) is 0.2 or more.

5. The thermoplastic resin composition according to any one of 1 to 4 above, further comprising (E) a polycarbonate resin in an amount of 1 to 30 parts by mass with respect to a total of 100 parts by mass of (A) and (B).
6. (C-1) The epoxy group-containing olefin-based elastomer or the epoxy group-containing acrylic elastomer is copolymerized with glycidyl methacrylate and contains 3 to 15% by mass of a constituent unit derived from glycidyl methacrylate. The thermoplastic resin composition according to the above.
7. A molded product comprising the thermoplastic resin composition according to any one of 1 to 6 above.
8. The molded product according to 7 above, which is a molded product obtained by inserting a metal.
9. The molded product according to 7 or 8 above, which is an in-vehicle housing component.

In the thermoplastic resin composition of the present invention, the low molecular weight (A) polybutylene terephthalate resin has a sea-island structure despite the fact that (A) the polybutylene terephthalate resin is low and (B) the rubber-reinforced polystyrene or polystyrene is rich. Sea (matrix) or sea of co-continuous structure, (B) rubber-reinforced polystyrene or polystyrene with high melt viscosity becomes islands, and (C) epoxy group-containing olefin-based elastomer or epoxy group-containing acrylic-based elastomer exists. Due to its thickening effect, (B) rubber-reinforced polystyrene or the islands of polystyrene are more aggregated, resulting in higher heat shock resistance, lower warpage resistance, excellent heat resistance, and mechanical strength. It also has excellent appearance and chemical resistance. Further, by containing (D) glass fiber, the resin phase of (A) polybutylene terephthalate resin becomes continuous via the glass fiber, so that it becomes easy to form a matrix (sea), and as a result, low warpage is achieved. It has excellent heat shock resistance and heat resistance. Further, when the polycarbonate resin is further contained, the strength and appearance can be further improved.
Therefore, the thermoplastic resin composition of the present invention is also suitable for insert molded products into which a metal is inserted. Further, the thermoplastic resin composition of the present invention can be suitably used as parts of various electric and electronic devices, interior / exterior parts for automobiles, housing parts for automobiles, and the like.

It is a schematic diagram of the rectangular parallelepiped shape iron insert used for the evaluation of heat shock resistance in an Example. It is sectional drawing of the mold cavity in which the insert object was supported by a support pin. It is a schematic diagram of the insert molded product in which two weld lines are generated in the support pin trace.

The thermoplastic resin composition of the present invention comprises (A) 15 to 50 parts by mass of a polybutylene terephthalate resin having an intrinsic viscosity of 0.3 to 0.8 dl / g and (B) 50 to 85 parts by mass of rubber-reinforced polystyrene or polystyrene. A total of 100 parts by mass contains 12 to 35 parts by mass of (C) elastomer and 5 to 150 parts by mass of (D) glass fiber, and (C) elastomer is (C-1) epoxy group-containing olefin-based elastomer or It contains an epoxy group-containing acrylic elastomer, and is characterized in that (B) the melt viscosity of (B) rubber-reinforced polystyrene or polystyrene at 250 ° C. and 912 sec ^-1 is in the range of 70 to 300 Pa · s.

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.

[(A) Polybutylene terephthalate resin]
The thermoplastic resin composition of the present invention contains (A) polybutylene terephthalate resin having an intrinsic viscosity (IV) of 0.3 to 0.8 dl / g.
By using a product having an intrinsic viscosity (IV) as low as 0.3 to 0.8 dl / g in combination with (B) rubber-reinforced polystyrene or polystyrene, it is excellent in heat shock resistance, low warpage and heat resistance, and also. It is a resin composition having excellent mechanical strength and chemical resistance. The polybutylene terephthalate resin (A) preferably has high rigidity. The polybutylene terephthalate resin having high rigidity is characterized by having a rigidity of 1500 MPa or more in a flexural modulus according to ISO 178.
If the intrinsic viscosity (IV) is lower than 0.3 dl / g, the heat resistance of polybutylene terephthalate is not exhibited and the mechanical strength tends to be low. Further, when the content is higher than 0.8 dl / g, the above-mentioned sea-island structure is difficult to form, (B) rubber-reinforced polystyrene or polystyrene tends to form the sea, and heat shock resistance and low warpage resistance deteriorate, and the resin composition Poor fluidity and moldability tend to deteriorate. The intrinsic viscosity (IV) is preferably 0.4 dl / g or more, more preferably 0.5 dl / g or more, further 0.55 dl / g or more, and particularly preferably 0.6 dl / g or more, and preferably 0. It is .75 dl / g or less.

In the present invention, 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.

(A) The polybutylene terephthalate resin is a polyester resin having a structure in which a terephthalic acid unit and a 1,4-butanediol unit are ester-bonded. In addition to the polybutylene terephthalate resin (homopolymer), a terephthalic acid unit and 1 , A polybutylene terephthalate copolymer containing other copolymerization components other than 4-butanediol units, and a mixture of a homopolymer and the copolymer.

(A) The polybutylene terephthalate resin may contain a dicarboxylic acid unit other than terephthalic acid, and specific examples of other dicarboxylic acids include isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, and 2,5. -Naphthalenedicarboxylic acid, 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, 4,4'-diphenylether dicarboxylic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 4,4'-dicyclohexyldicarboxylic acid, Examples thereof include 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, and 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 can be mentioned. 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.

As described above, the polybutylene terephthalate resin (A) is preferably a polybutylene terephthalate homopolymer obtained by polycondensing terephthalic acid and 1,4-butanediol, but the (A) polybutylene terephthalate resin is also crystalline. Polybutylene terephthalate copolymer containing one or more dicarboxylic acids other than the above-mentioned terephthalic acid as a carboxylic acid unit and / or one or more diols other than the above 1,4-butanediol as a diol unit, as long as the above is not impaired. When the (A) polybutylene terephthalate resin is a polybutylene terephthalate resin modified by copolymerization, specific preferred copolymers thereof include polyalkylene glycols, particularly polytetramethylene glycol. Examples thereof include a polyester ether resin obtained by copolymerizing 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 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%. With such a copolymerization ratio, fluidity and toughness tend to be improved, which is preferable.

The polybutylene terephthalate resin (A) preferably has a terminal carboxyl group amount of 0.1 to 30 eq / ton. If it exceeds 30 eq / ton, the hydrolysis resistance and the alkali resistance tend to decrease, and gas tends to be generated during melt molding of the resin composition. The amount of the terminal carboxyl group is more preferably 3 eq / ton or more, further preferably 5 eq / ton or more, more preferably 25 eq / ton or less, still more preferably 20 eq / ton or less.

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

(A) The polybutylene terephthalate resin 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 continuous 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.
(A) Polybutylene terephthalate resin is obtained by a manufacturing method in which a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing 1,4-butanediol as a main component are continuously melt-polycondensed. 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.

[(B) Rubber-reinforced polystyrene or polystyrene]
The thermoplastic resin composition of the present invention contains (B) rubber-reinforced polystyrene or polystyrene, and uses rubber-reinforced polystyrene or polystyrene having a melt viscosity in the range of 70 to 300 Pa · s at 250 ° C. and 912 sec ^-1 .

(B) Rubber-reinforced polystyrene or polystyrene is preferably amorphous. Here, amorphous refers to a characteristic in which a clear melting point and melting peak are not detected when a sample is measured using a differential scanning calorimeter (DSC) or the like. On the contrary, the crystallinity means a property that a crystal structure in which molecules are regularly arranged is likely to be obtained and has a melting point and a melting peak as measured by a differential scanning calorimeter (DSC) or the like. Syndiotactic polystyrene or the like in which benzene rings are regularly arranged alternately with respect to the polymer backbone is crystalline, and is preferably excluded as (B) rubber-reinforced polystyrene or polystyrene.

The polystyrene resin is a homopolymer of styrene or a copolymer of other aromatic vinyl monomers such as α-methylstyrene, paramethylstyrene, vinyltoluene, vinylxylene and the like in a range of, for example, 50% by mass or less. There may be.

The rubber-reinforced polystyrene resin is preferably obtained by copolymerizing or blending a butadiene-based rubber component, and the amount of the butadiene-based rubber component is usually 1% by mass or more and less than 50% by mass, preferably 3 to 40% by mass. , More preferably 5 to 30% by mass, still more preferably 5 to 20% by mass. As the rubber reinforced polystyrene resin, high impact polystyrene (HIPS) is particularly preferable.

In the present invention, (B) rubber-reinforced polystyrene or polystyrene having a melt viscosity of 70 to 300 Pa · s at 250 ° C. and 912 sec ^-1 is used. (B) rubber-reinforced polystyrene or polystyrene having such a melt viscosity (η _B ) is used in an amount of 15 to 50 parts by mass of (A) polybutylene terephthalate resin, (B) rubber-reinforced polystyrene or polystyrene by 50 to 85 parts by mass [(A). And (B) based on 100 parts by mass in total], and by further blending (C) elastomer, (A) polybutylene terephthalate resin becomes dominant in physical properties, and as a result, high heat resistance. And low warpage resistance and heat shock resistance can be achieved. If the melt viscosity is 70 Pa · s or more, the heat resistance can be improved. Further, when the melt viscosity is 300 Pa · s or less, excellent production stability and fluidity can be provided.

(B) The melt viscosity (η _B ) of rubber-reinforced polystyrene or polystyrene is preferably 80 Pa · s or more, more preferably 90 Pa · s or more, still more preferably 100 Pa · s or more, especially 110 Pa · s or more, particularly 120 Pa · s. It is preferably s or more. The upper limit thereof is preferably 250 Pa · s or less, more preferably 220 Pa · s or less, further 200 Pa · s or less, particularly preferably 180 Pa · s or less, and particularly preferably 160 Pa · s or less.
The melt viscosity conforms to ISO 11443 and can be measured by using a capillary reometer and a slit direometer. Specifically, using an orifice with a capillary diameter of 1 mm and a capillary length of 30 mm, the piston melts from the stress when the piston is pushed into a furnace body with an inner diameter of 9.5 mm heated to 250 ° C. at a piston speed of 75 mm / min. The viscosity can be calculated.

As described above, the content of (A) polybutylene terephthalate resin is 15 to 50 parts by mass based on the total of 100 parts by mass of (A) and (B), and (B) rubber-reinforced polystyrene or polystyrene is 50 to 50 parts by mass. Although it is 85 parts by mass, (A) is preferably 20 parts by mass or more, more preferably 25 parts by mass or more, further preferably 30 parts by mass or more, preferably 47 parts by mass or less, and more preferably 45 parts by mass or less. Is. (B) is preferably 80 parts by mass or less, more preferably 75 parts by mass or less, further preferably 70 parts by mass or less, preferably 53 parts by mass or more, and more preferably 55 parts by mass or more.
(B) When the content of rubber-reinforced polystyrene or polystyrene is in such a range, heat shock resistance and low warpage resistance can be further improved.

[(C) Elastomer]
The thermoplastic resin composition of the present invention contains (C) an elastomer, and the (C) elastomer contains (C-1) an epoxy group-containing olefin-based elastomer or an epoxy group-containing acrylic-based elastomer. (C-1) High heat shock resistance is possible by containing an olefin-based or acrylic-based elastomer containing an epoxy group, and heat shock resistance is insufficient with an elastomer containing no epoxy group.

[(C-1) Epoxy group-containing olefin-based elastomer or epoxy group-containing acrylic-based elastomer]
The component (C-1) is an olefin-based elastomer or an acrylic-based elastomer containing an epoxy group, and is an elastomer in which a glycidyl group is introduced into the olefin-based elastomer or the acrylic-based elastomer. The method for introducing the glycidyl group is not limited, and any known method can be adopted. Specifically, for example, a vinyl-based monomer having an epoxy group such as an α, β-unsaturated acid glycidyl ester compound such as glycidyl acrylate, glycidyl methacrylate, glycidyl etacrilate, and glycidyl itaconate is used as an elastomer raw material. Examples thereof include a method of copolymerizing with a certain olefin-based or acrylic-based monomer, a method of polymerizing an elastomer polymer using a polymerization initiator or a chain transfer agent having an epoxy group, a method of grafting an epoxy compound to an elastomer, and the like.

The content of the glycidyl group is usually 1 to 20% by mass, particularly preferably 3 to 15% by mass, more preferably 3 to 12% by mass, and particularly preferably 4 to 8% by mass in the case of the glycidyl methacrylate group. ..

Examples of the olefin-based elastomer include polybutadiene, polyisoprene, a random copolymer and a block copolymer of styrene-butadiene, a hydrogenated additive of the block copolymer, a diene-based elastomer such as a butadiene-isoprene copolymer, and ethylene. -Random copolymers and block polymers of propylene, random copolymers and block copolymers of ethylene-butene, copolymers of ethylene and α-olefins, ethylene such as ethylene-propylene-hexadiene copolymers- Preferable examples include a propylene non-conjugated diene ternary copolymer and a butylene-isoprene copolymer.

The acrylate-based elastomer is a rubber-like elastic body obtained by polymerizing an acrylic acid ester or copolymerization containing the same as a main component. For example, an acrylic acid ester such as butyl acrylate and a cross-linking property such as a small amount of butylene acrylate. Examples of the polymer obtained by polymerizing the monomer include a rubber-like polymer obtained by graft-polymerizing a graft-polymerizable monomer such as methyl methacrylate.

Examples of the acrylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, hexyl acrylate, 2-ethyl hexyl acrylate and the like, in addition to butyl acrylate. In addition to butylene acrylate, crosslinkable monomers include polyols such as butylene acrylate and trimethylolpropane trimethacrylate and esters of acrylic acid or methacrylic acid, vinyl acrylates, vinyl compounds such as vinyl methacrylate, and allyl. Examples thereof include acrylate, allyl methacrylate, diallyl malate, diallyl fumarate, diallyl itaconate, monoallyl malate, and monoallyl fumarate.

In addition to methyl methacrylate, examples of the graft-polymerizable monomer include methacrylic acid esters such as ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, and lauryl methacrylate, styrene, and acrylonitrile. Further, acrylates having a glycidyl group, for example, glycidyl methacrylate and the like can be mentioned. A part of the graft-polymerizable monomer may be coexisted and copolymerized when the above acrylic acid ester and the crosslinkable monomer are polymerized to produce a polymer.

As the olefin-based elastomer or the acrylic-based elastomer, a copolymer or the like in which the above-mentioned olefin-based monomer and the above-mentioned acrylate-based monomer are combined is also preferable.

(C-1) The epoxy group-containing olefin-based elastomer or the epoxy group-containing acrylic elastomer is preferably a copolymer of glycidyl methacrylate, and particularly preferably contains 3 to 15% by mass of a constituent unit derived from glycidyl methacrylate.

[(C-2) Styrene-based elastomer]
The (C) elastomer preferably further contains (C-2) a styrene-based elastomer.
(C-2) As the styrene-based elastomer, a block copolymer composed of a polymer block containing a vinyl aromatic compound as a polymerization component and a polymer block containing a conjugated diene as a polymerization component, and a hydrogenated product thereof are preferable.

Examples of the vinyl aromatic compound constituting the polymer block of the vinyl aromatic hydrocarbon include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, pt-butylstyrene, 1,3-dimethylstyrene, and the like. Examples thereof include styrene such as lower alkyl substituted styrene, vinylnaphthalene and vinylanthracene, or derivatives thereof. These can be used alone or in combination of two or more.

Examples of the conjugated diene constituting the conjugated diene block include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like.

(C-2) The styrene-based elastomer comprises at least two polymer blocks P mainly composed of a vinyl aromatic compound and at least one polymer block Q mainly composed of butadiene and / or isoprene. , A block copolymer represented by (PQ) n-P (n represents an integer of 1 or more), a block copolymer of triblock or more is preferable, and the polymer block P is A block copolymer occupying 20 to 60% by mass or a hydrogenated block copolymer obtained by hydrogenating the block copolymer is preferable.
In the above, the subject means that it is more than 50% by mass, preferably 55% by mass or more, more preferably 60% by mass or more, further 70% by mass or more, and particularly 80% by mass or more. Is 90% by mass or more.

A block copolymer such as triblock represented by the formula (PQ) n-P has a high molecular weight-matching thickening effect and becomes an island portion in the sea-island structure formed by the obtained resin composition (B). ) It is preferable because the rubber-reinforced polystyrene or the island portion of the polystyrene is more aggregated and the effect of improving the heat shock resistance is higher. In the case of PQ-type diblock copolymers, the fluidity is too good and the thickening effect tends to be small, and the effect of improving heat shock resistance tends to be small.

(C-2) Preferred specific examples of the styrene-based elastomer include styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), and styrene-isoprene-styrene block. Polymers (SIS), hydrogenated styrene-isoprene-styrene block copolymers (SEPS) and the like can be mentioned.

(C-2) Styrene-based elastomers having a high molecular weight have a high thickening effect, and (B) rubber-reinforced polystyrene or the islands of polystyrene are more likely to aggregate, and the effect of improving heat shock resistance is enhanced, which is preferable. When the mass average molecular weight is in the range of 150,000 to 500,000, the above effect becomes remarkable, which is preferable. The mass average molecular weight is more preferably 200,000 or more, further preferably 250,000 or more, particularly preferably 300,000 or more, more preferably 450,000 or less, still more preferably 400,000 or less.

The content of (C) elastomer is 12 to 35 parts by mass, preferably 14 parts by mass with respect to 15 to 50 parts by mass of (A) polybutylene terephthalate resin and 100 parts by mass of (B) rubber-reinforced polystyrene or polystyrene in total. By mass or more, more preferably 15 parts by mass or more, further preferably 16 parts by mass or more, preferably 30 parts by mass or less, more preferably 27 parts by mass or less, still more preferably 25 parts by mass or less, particularly 23 parts by mass. The following is preferable. (C) When the content of the elastomer is in such a range, the heat shock resistance can be further improved.

The content of the (C-2) styrene-based elastomer is preferably 0 to 25 parts by mass, more preferably 2 parts by mass or more, still more preferably 2 parts by mass, based on 100 parts by mass of the total of (A) and (B). Is 5 parts by mass or more, preferably 23 parts by mass or less, more preferably 20 parts by mass or less, and further preferably 18 parts by mass or less. (C-2) By containing the styrene-based elastomer in such an amount, a higher degree of heat shock resistance can be exhibited.

The mass ratio (C-1) / (C-2) of the content of the (C-1) epoxy group-containing olefin-based or acrylic-based elastomer and the (C-2) styrene-based elastomer shall be 0.2 or more. Is more preferable, more preferably 0.3 or more, still more preferably 0.5 or more, still more preferably 5 or less, still more preferably 3 or less. With such a mass ratio, it is possible to impart particularly high heat shock resistance and excellent fluidity.

[(D) Glass fiber]
The thermoplastic resin composition of the present invention contains (D) glass fiber.
As the glass fiber, if it is usually used for thermoplastic polyester resin, it has an alkali-resistant glass composition containing A glass, E glass, and zirconia components, chopped strant, roving glass, thermoplastic resin and glass fiber. Any known glass fiber can be used regardless of the form of the glass fiber at the time of compounding such as the master batch of. Among them, as the glass fiber used in the present invention, non-alkali glass (E glass) is preferable for the purpose of improving the thermal stability of the thermoplastic resin composition of the present invention.

(D) The glass fiber may have a round cross section in the length direction, and a glass fiber having an irregular shape ratio of 2 to 6 in the length direction cross section is also preferable. The irregular shape ratio of the cross section in the length direction assumes a rectangle with the minimum area circumscribing the cross section perpendicular to the length direction of the glass fiber, and the length of the long side of this rectangle is the major axis, and the length of the short side. It is the ratio of the major axis / the minor axis when the minor axis is defined as. By containing glass fibers having a variant ratio of 2 to 6, the glass fibers are oriented (A) to exhibit the function of bridging between the phases of the polybutylene terephthalate resin, and the polybutylene terephthalate resin is a matrix (sea). Therefore, it is possible to specifically improve the heat resistance and to have excellent low warpage and appearance.
Furthermore, when the glass fiber exists in a state of being surrounded by the phase of the (A) polybutylene terephthalate resin, the bridging effect between the (A) polybutylene terephthalate resin phase by the glass fiber is higher. In addition, since the bulky glass fiber acts as a bulking agent for the (A) polybutylene terephthalate resin, the heat resistance is likely to be further improved.

In the case of a glass fiber having a modified cross section, the irregular shape ratio is more preferably 2.5 or more, further preferably 3 or more, still more preferably 5.5 or less, still more preferably 5 or less. It is particularly preferable that the shape of the cross section in the length direction is substantially rectangular.
The cross-sectional area of the glass fiber in the length direction is preferably 180 μm ² or more and 300 μm ² or less, and such a cross-sectional area makes it easy for the polybutylene terephthalate resin to form a matrix, resulting in improved heat resistance. easy. The cross-sectional area is more preferably 180 μm ² or more and 250 μm ² or less, and further preferably 180 μm ² or more and 200 μm ² or less.
The thickness of the glass fiber is not particularly limited, but it is preferable that the minor axis is about 2 to 20 μm and the major axis is about 5 to 50 μm.

(D) The glass fiber may be treated with a sizing agent or a surface treating agent. Further, at the time of producing the resin composition of the present invention, a sizing agent or a surface treating agent may be added separately from the untreated glass fiber for surface treatment.

Examples of the sizing agent include resin emulsions such as vinyl acetate resin, ethylene / vinyl acetate copolymer, acrylic resin, epoxy resin, polyurethane resin, and polyester resin.
Examples of the surface treatment agent include aminosilane compounds such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ- (2-aminoethyl) aminopropyltrimethoxysilane, vinyltrichlorosilane, and methylvinyldi. Chlorosilane compounds such as chlorosilane, alkoxysilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxy Examples thereof include epoxysilane-based compounds such as silane and γ-glycidoxypropyltrimethoxysilane, acrylic-based compounds, isocyanate-based compounds, titanate-based compounds, and epoxy-based compounds.
Two or more of these sizing agents and surface treatment agents may be used in combination, and the amount (adhesion amount) used thereof is usually 10% by mass or less, preferably 0.05 to 0, based on the mass of the glass fiber (D). It is 5% by mass. By setting the adhesion amount to 10% by mass or less, a necessary and sufficient effect can be obtained.

Two or more kinds of (D) glass fibers may be used in combination depending on the required characteristics, and the content thereof is 100 parts by mass in total of (A) polybutylene terephthalate resin and (B) rubber-reinforced polystyrene or polystyrene. On the other hand, it is 5 to 150 parts by mass, preferably 10 parts by mass or more, more preferably 20 parts by mass or more, further preferably 30 parts by mass or more, particularly preferably 40 parts by mass or more, and preferably 120 parts by mass or less. , More preferably 100 parts by mass or less, particularly preferably 80 parts by mass or less, and particularly preferably 60 parts by mass or less. By containing it in such a range, high heat resistance can be achieved, and the effect of reducing the strength and shrinkage rate of the obtained molded body can be enhanced.

The resin composition of the present invention exists in a state in which (D) glass fibers are surrounded by a phase of (A) polybutylene terephthalate resin in the cross-sectional structure of the molded body of the resin composition observed with an electron microscope. Is preferable. Further, it is preferable that (A) the polybutylene terephthalate resin forms a co-continuous phase with the sea (matrix) having a sea-island structure, or (B) rubber-reinforced polystyrene or polystyrene. By having such a morphology structure, the heat resistance is specifically improved, the warp resistance is excellent, and the appearance is likely to be excellent.

The thermoplastic resin composition of the present invention preferably contains carbon fibers or other plate-shaped, granular or amorphous fillers in addition to the above-mentioned (D) glass fibers. The plate-shaped inorganic filler exhibits a function of reducing anisotropy and warpage, and examples thereof include talc, glass flakes, mica, mica, kaolin, and metal leaf. Among the plate-shaped inorganic fillers, glass flakes are preferable.
Examples of the granular or amorphous filler include ceramic beads, clay, zeolite, barium sulfate, titanium oxide, silicon oxide, aluminum oxide, magnesium hydroxide, zinc sulfide and the like.
As other inorganic fillers, talc, titanium oxide and zinc sulfide are preferable, and talc is particularly preferable.

The content of the other inorganic filler is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass in total of (A) polybutylene terephthalate resin and (B) rubber-reinforced polystyrene or polystyrene. , More preferably 0.5 parts by mass or more, further preferably 1 part by mass or more, and even more preferably 20 parts by mass or less.

[(E) Polycarbonate resin]
The resin composition of the present invention preferably further contains (E) a polycarbonate resin. By containing (E) a polycarbonate resin, (A) polybutylene terephthalate resin and (B) rubber-reinforced polystyrene or polystyrene are promoted to be compatible with each other, thereby being dispersed in (A) polybutylene terephthalate resin phase (B). ) By reducing the dispersed particle size of rubber-reinforced polystyrene or polystyrene and increasing the interfacial strength, the mechanical strength can be further improved and an excellent appearance can be easily obtained.

The polycarbonate resin is a optionally branched thermoplastic polymer or copolymer obtained by reacting a dihydroxy compound or a small amount of a polyhydroxy compound with a phosgene or a carbonic acid diester. The method for producing the polycarbonate resin is not particularly limited, and those produced by a conventionally known phosgene method (interfacial polymerization method) or melting method (transesterification method) can be used.

The raw material dihydroxy compound is substantially free of bromine atoms, and aromatic dihydroxy compounds are preferable. Specifically, 2,2-bis (4-hydroxyphenyl) propane (ie, bisphenol A), tetramethylbisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, resorcinol, 4,4- Examples thereof include dihydroxydiphenyl, and preferably bisphenol A. Further, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can also be used.

Among the above-mentioned polycarbonate resins, the aromatic polycarbonate resin derived from 2,2-bis (4-hydroxyphenyl) propane (that is, bisphenol A) or 2,2-bis (4-hydroxyphenyl) propane is used as the polycarbonate resin. And aromatic polycarbonate copolymers derived from other aromatic dihydroxy compounds are preferred. Further, it may be a copolymer mainly composed of an aromatic polycarbonate resin, such as a polymer having a siloxane structure or a copolymer with an oligomer. Further, two or more of the above-mentioned polycarbonate resins may be mixed and used.

To adjust the molecular weight of the polycarbonate resin, a monovalent aromatic hydroxy compound may be used, for example, m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, p-long chain. Examples thereof include alkyl-substituted phenols.

The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 14,000 or more, more preferably 15,000 or more, further preferably 15500 or more, preferably 60,000 or less, and preferably 40,000 or less. Is more preferable, and 35,000 or less is further preferable. By using a resin composition having a viscosity average molecular weight in the above range, the obtained resin composition does not have a decrease in mechanical strength such as impact resistance, and the fluidity of the resin composition does not decrease or the moldability does not deteriorate. preferable.

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

The method for producing the polycarbonate resin is not particularly limited, and a polycarbonate resin produced by any of a phosgene method (interfacial polymerization method) and a melting method (transesterification method) can be used. Further, a polycarbonate resin produced by a melting method and subjected to post-treatment for adjusting the amount of OH groups at the ends is also preferable.

The content of (E) the polycarbonate resin is preferably 1 to 30 parts by mass, more preferably 3 parts by mass, based on 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) rubber-reinforced polystyrene or polystyrene. More than parts, more preferably 5 parts by mass or more, especially 8 parts by mass or more, particularly preferably 10 parts by mass or more, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, especially 17 parts by mass or less. It is preferably 15 parts by mass or less.

[Stabilizer]
It is preferable that the thermoplastic resin composition of the present invention contains a stabilizer because it has an effect of improving thermal stability and preventing deterioration of mechanical strength, transparency and hue. As the stabilizer, a phosphorus-based stabilizer, a sulfur-based stabilizer and a phenol-based stabilizer are 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, 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 given 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-tert-butyl-4-hydroxyphenyl) propionate Is preferable.

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 2 parts by mass with respect to 100 parts by mass in total of (A) polybutylene terephthalate resin and (B) rubber-reinforced polystyrene or polystyrene. 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 2 parts by mass is used. If it exceeds the amount, the amount becomes excessive and the generation of silver and the deterioration of hue tend to occur more easily. The content of the stabilizer is more preferably 0.01 to 1.5 parts by mass, still more preferably 0.1 to 1 part by mass.

[Release agent]
The thermoplastic resin composition of the present invention preferably contains a mold release agent. As the mold release agent, known mold release agents usually used for polyester resins can be used, but among them, polyolefin-based compounds and fatty acid ester-based compounds are preferable in terms of good alkali resistance, and especially polyolefin-based ones. Compounds are preferred.

Examples of the polyolefin compound include compounds selected from paraffin wax and polyethylene wax, and among them, those having a weight average molecular weight of 700 to 10000, more preferably 900 to 8000 are preferable.

Examples of the fatty acid ester compound include saturated or unsaturated monovalent or divalent aliphatic carboxylic acid esters, glycerin fatty acid esters, fatty acid esters such as sorbitan fatty acid esters, and partial saponified products thereof. Among them, mono or difatty acid esters composed of fatty acids having 11 to 28 carbon atoms, preferably 17 to 21 carbon atoms and alcohols are preferable.

Examples of the fatty acid include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, araquinic acid, behenic acid, lignoseric acid, cellotic acid, melissic acid, tetrariacontanic acid, montanic acid, adipic acid, azelaic acid and the like. Be done. Further, the fatty acid may be an alicyclic type.
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 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 compound may contain an aliphatic carboxylic acid and / or an alcohol as an impurity, or may be a mixture of a plurality of compounds.

Specific examples of the fatty acid ester compound include glycerin monostearate, glycerin monobehenate, glycerin dibehenate, glycerin-12-hydroxymonostearate, sorbitan monostearate, pentaerythritol monostearate, and pentaeristoldi. Examples thereof include stearate, stearyl stearate, and ethylene glycol montanic acid ester.

The content of the release agent is preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) rubber-reinforced polystyrene or polystyrene, but 0.2 to 0.2 to It is more preferably 2.5 parts by mass, still more preferably 0.3 to 2 parts by mass. If it is less than 0.1 part by mass, the surface property is likely to be deteriorated due to poor mold release during melt molding, while if it is more than 3 parts by mass, the kneading workability of the resin composition is likely to be deteriorated, and the molded product is formed. The surface tends to be cloudy.

[Carbon black]
The thermoplastic resin composition of the present invention preferably contains carbon black.
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 about 5 to 60 nm.

The carbon black is preferably blended as a masterbatch premixed with a thermoplastic resin, preferably a polyalkylene terephthalate resin, particularly a polybutylene terephthalate resin.

The content of carbon black is preferably 0.1 to 4 parts by mass, more preferably 0.2 to 3 parts by mass, based on 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) rubber-reinforced polystyrene or polystyrene. It is a department. If it is 0.1 part by mass or more, the effect of obtaining a desired color is enhanced, and the effect of improving weather resistance can be expected. If it is 4 parts by mass or less, it can be expected to suppress deterioration of mechanical properties.

[Other ingredients]
The thermoplastic resin composition of the present invention does not impair the effects of the present invention by using other thermoplastic resins other than the above-mentioned (A) polybutylene terephthalate resin, (B) rubber-reinforced polystyrene or polystyrene, and (E) polycarbonate resin. It can be contained in a range. Specific examples of other thermoplastic resins include polyacetal resin, polyamide resin, polyphenylene oxide resin, polyphenylene sulfide resin, polysulfone resin, polyether sulfone resin, polyetherimide resin, polyether ketone resin, and polyolefin resin. And so on.
However, when other resins are contained, the content is preferably 20 parts by mass or less with respect to 100 parts by mass in total of (A) polybutylene terephthalate resin and (B) rubber-reinforced polystyrene or polystyrene. More preferably, it is 5 parts by mass or less, and more preferably 3 parts by mass or less.

Further, the thermoplastic resin composition of the present invention may contain various additives other than those described above, and such additives include a flame retardant, a flame retardant aid, a drip inhibitor, and ultraviolet absorption. Examples thereof include agents, antistatic agents, antifogging agents, antiblocking agents, plasticizers, dispersants, antibacterial agents, colorants, dyes and pigments.

[Manufacturing of thermoplastic resin composition]
The thermoplastic resin composition of the present invention can be produced according to a conventional method for preparing a resin composition. That is, (D) polybutylene terephthalate resin excluding glass fiber, (B) rubber-reinforced polystyrene or polystyrene, and (C) elastomer, and other resin components and various additives added as desired together. Mix well and then melt and knead in a single-screw or twin-screw extruder. Further, it is also possible to prepare a resin composition without mixing each component in advance or by mixing only a part thereof in advance and supplying it to an extruder using a feeder to melt-knead it. 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 produce various molded bodies. The glass fiber (D) is preferably side-fed using a side feeder.

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.

[Molded product]
The method for producing a molded product using the thermoplastic resin composition of the present invention is not particularly limited, and any molding method generally used for the thermoplastic 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 these, injection molding and insert molding are particularly preferable, and insert molding for inserting a metal member is particularly suitable.

The obtained molded body has excellent low warpage resistance, heat shock resistance and heat resistance, and also has excellent mechanical strength and chemical resistance. Therefore, electrical and electronic equipment parts, interior / exterior parts for automobiles, etc., whose characteristics are strictly required. It is suitably used as an electrical component of. Electrical and electronic equipment parts include IH cooker housing parts, button cases, grill handles, coil peripheral members, rice cooker protection frames, relay cases, smart meter housings, industrial breaker housings, inverter cases, and mobile phone housings. Specific examples thereof include a body, a housing for warm equipment, a separator for a battery, a case for a battery, a tray for transporting electronic parts, a tray for transporting a battery, and a charging facility for an automobile.
For interior and exterior parts for automobiles, in-vehicle housing parts, in-vehicle battery cases, in-vehicle battery covers, in-vehicle battery separators, various motor cases, sensor cases, camera cases, holder parts, air conditioner wind direction control plates, door mirror stays. It can be particularly preferably used for a housing of a head-up display installed in an automobile, a housing for an engine control unit (ECU), and a connector component for electrical components of an automobile.
In particular, since the polyester resin composition of the present invention has a high degree of heat shock resistance, as a molded product into which a metal member is inserted, for example, an insert molded product such as an electric appliance part, an in-vehicle electrical component, an in-vehicle housing component, etc. Etc. are suitable.

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.

(Examples 1 to 4, comparative examples 1 to 5)
The components used are as shown in Table 1 below.

Of the components shown in Table 1 above, the components excluding (D) glass fiber are uniformly mixed with a tumbler mixer at the ratio (all by mass) shown in Table 2 below, and then a twin-screw extruder (Japan). Using "TEX30α" manufactured by Japan Steel Works, L / D = 42), (D) glass fiber is charged using a side feeder, cylinder set temperature 260 ° C, discharge rate 40 kg / h, screw rotation speed 200 rpm. The resin composition melt-kneaded under the above conditions was rapidly cooled in a water tank and pelletized using a pelletizer to obtain pellets of the thermoplastic resin composition.

[Tension breaking strength, tensile breaking elongation rate]
After the pellets obtained above are dried at 120 ° C. for 5 hours, ISO is used under the conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. using an injection molding machine (mold clamping force 85T) manufactured by Japan Steel Works, Ltd. A multipurpose test piece (4 mm thick) was injection molded.
In accordance with ISO527, the tensile breaking strength (unit: MPa) and the tensile breaking elongation (unit:%) were measured using the ISO multipurpose test piece (4 mm thickness).
[Maximum bending strength, flexural modulus]
In accordance with ISO178, the maximum bending strength (unit: MPa) and flexural modulus (unit: MPa) were measured at a temperature of 23 ° C. using the above ISO multipurpose test piece (thickness of 4 mm).
[Charpy impact strength with notch]
In accordance with ISO179, the notched Charpy impact strength (unit: kJ / m ² ) of the notched test piece obtained by notching the ISO multipurpose test piece (4 mm thickness) was measured at a temperature of 23 ° C.

[Heat shock resistance]
The obtained pellets are dried at 120 ° C. for 6 hours, and then using a TH60 R5VSE vertical injection molding machine manufactured by Nissei Plastic Industries Co., Ltd., the iron having a rectangular parallelepiped shape shown in FIG. 1 at a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. As shown in FIG. 2, the insert 1 (length 16 mm × width 33 mm × thickness 3 mm) of SUS) was charged into the mold cavity 4 with the support pin 2 and inserted (insert iron piece 3). The insert-molded product (length 18 mm × width 35 mm × thickness 5 mm) shown in FIG. 3 was produced by insert molding. The wall thickness of the resin portion of this insert molded product is 1 mm. In the insert molded product, two weld lines 6 are generated in the support pin marks 5. Using this insert-molded product, a heat shock test was performed using a heat shock test device TSA-102ES manufactured by ESPEC.
The condition of the heat shock test is a cycle of -40 ° C for 60 minutes → 150 ° C for 60 minutes, and the minimum number of cycles in which cracks occur in a total of 10 weld lines of 5 molded products in the heat shock test. And the average value (number of cycles).
From the minimum and average values of the number of cycles obtained above, the heat shock resistance was evaluated and judged according to the following criteria.
⊚: The minimum number of cycles is 200 cycles or more 〇: The minimum number of cycles is 50 cycles or more and less than 200 cycles, and the average value is 200 cycles or more ×: None of the above criteria is satisfied.

[Degree of deflection temperature under load and heat resistance]
Using the above ISO multipurpose test piece (thickness 4 mm), the deflection temperature under load was measured under the condition of load 1.80 MPa in accordance with ISO75-1 and ISO75-2.
The heat resistance was judged according to the following criteria.
〇: Deflection temperature under load is 150 ° C or higher ×: Deflection temperature under load is less than 150 ° C

[Warp amount and warp property judgment]
With an injection molding machine (“NEX80” manufactured by Nissei Resin Industry Co., Ltd.), a disk with a diameter of 100 mm and a thickness of 1.6 mm is used as a side gate metal under the conditions of a cylinder temperature of 260 ° C., a mold temperature of 80 ° C., and an injection time of 0.5 sec. It was molded by a mold, and the amount of warpage (unit: mm) of the disk was determined.
Warpage was evaluated and judged according to the following criteria.
⊚: Warpage amount is less than 1.0 mm 〇: Warpage amount is 1.0 mm or more and 1.5 mm or less ×: Warpage amount is more than 1.5 mm or more The results are shown in Table 2 below.

The thermoplastic resin composition of the present invention is excellent in low warpage resistance, heat shock resistance and heat resistance, and is also excellent in mechanical strength, chemical resistance and flame retardancy. It can be suitably used for in-vehicle electrical components, in-vehicle housing parts, and the like.

Claims (9)

(A) 15 to 50 parts by mass of a polybutylene terephthalate resin having an intrinsic viscosity of 0.3 to 0.8 dl / g and (B) 50 to 85 parts by mass of rubber-reinforced polystyrene or polystyrene, with respect to (C) a total of 100 parts by mass. It contains 12 to 35 parts by mass of an elastomer and 5 to 150 parts by mass of (D) glass fiber, and (C) the elastomer contains (C-1) an epoxy group-containing olefin-based elastomer or an epoxy group-containing acrylic-based elastomer. B) A thermoplastic resin composition characterized in that the melt viscosity of rubber-reinforced polystyrene or polystyrene at 250 ° C. and 912 sec ^-1 is in the range of 70 to 300 Pa · s. The thermoplastic resin composition according to claim 1, wherein (C) the elastomer further comprises (C-2) a styrene-based elastomer. (C-2) The thermoplastic resin composition according to claim 2, wherein the styrene-based elastomer has a mass average molecular weight of 150,000 to 500,000. The thermoplastic resin composition according to claim 2 or 3, wherein the mass ratio (C-1) / (C-2) of the contents of (C-1) and (C-2) is 0.2 or more. The thermoplastic resin composition according to any one of claims 1 to 4, further comprising (E) a polycarbonate resin in an amount of 1 to 30 parts by mass with respect to a total of 100 parts by mass of (A) and (B). (C-1) Any of claims 1 to 5, wherein the epoxy group-containing olefin-based elastomer or the epoxy group-containing acrylic elastomer is copolymerized with glycidyl methacrylate and contains 3 to 15% by mass of a structural unit derived from glycidyl methacrylate. The thermoplastic resin composition according to. A molded product comprising the thermoplastic resin composition according to any one of claims 1 to 6. The molded product according to claim 7, which is a molded product obtained by inserting a metal. The molded product according to claim 7 or 8, which is an in-vehicle housing component.

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