JP7288752B2 - Thermoplastic resin composition and molded article - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition and a molded article, and more particularly to a thermoplastic resin composition having high heat resistance and excellent warpage resistance, and a molded article comprising the same.

Thermoplastic polyester resins represented by polybutylene terephthalate and polyethylene terephthalate are excellent in mechanical strength, chemical resistance, electrical insulation, etc. etc. is widely used.

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

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

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

JP 2006-16559 A JP 2007-314619 A

An object (problem) of the present invention is to provide a thermoplastic resin composition having high heat resistance and excellent warpage resistance, and a molded article made of the same.

As a result of intensive studies to solve the above-described problems, the present inventors have found that when combining a low-molecular-weight polyalkylene terephthalate resin with a high-molecular-weight polystyrene resin or rubber-reinforced polystyrene resin (HIPS), the amount of the polyalkylene terephthalate resin is reduced. The amount of polystyrene resin or HIPS is large, and the resin composition further blended with polycarbonate resin and / or styrene-maleic acid copolymer has a low molecular weight polyalkylene terephthalate resin. The present inventors have found that a resin composition exhibiting high heat resistance, which is a characteristic of polyalkylene terephthalate, and excellent in warp resistance, have arrived at the present invention.
The present invention relates to the following thermoplastic resin composition and molded article.

[1] Based on a total of 100 parts by mass of (A) and (B) below, (A) 20 parts by mass or more and less than 50 parts by mass of polyalkylene terephthalate resin, and (B) 50 parts by mass of polystyrene resin or rubber-reinforced polystyrene resin Contains more than 80 parts by mass or less, and further contains 1 to 25 parts by mass of (C) a polycarbonate resin and / or a styrene-maleic acid copolymer with respect to a total of 100 parts by mass of (A) and (B),
(A) The weight average molecular weight (Mw _A ) of the polyalkylene terephthalate resin is 20,000 to 65,000, (B) The weight average molecular weight (Mw _B ) of the polystyrene resin or rubber-reinforced polystyrene resin is 150,000 to 500,000,
(C) A polycarbonate resin and/or a styrene-maleic acid copolymer and (A) a polyalkylene terephthalate resin having a mass ratio (C)/(A) of 0.1 to 0.7. A thermoplastic resin composition.
[2] (A) the weight average molecular weight (Mw _A ) of the polyalkylene terephthalate resin, the amount ratio of (A) to the total content of (A) and (B), and (B) polystyrene resin or rubber-reinforced polystyrene The thermoplastic according to [1] above, wherein the weight average molecular weight (Mw _B ) of the resin and the ratio of (B) to the total content of (A) and (B) satisfy the following relational expression (I): Resin composition.
0.1≦[quantity ratio of (B)/Mw _B ]/[quantity ratio of (A)/Mw _A ]≦0.7 (I)
[3] Further, the above [1] or The thermoplastic resin composition according to [2].
[4] The thermoplastic resin composition according to any one of [1] to [3] above, wherein (A) the polyalkylene terephthalate resin is polybutylene terephthalate and/or polyethylene terephthalate.
[5] A molded article made of the thermoplastic resin composition according to any one of [1] to [4] above.
[6] The molded article according to [5] above, which is a housing for a head-up display or an engine control unit.

The thermoplastic resin composition of the present invention has a low content of polyalkylene terephthalate resin and conversely a high content of polystyrene resin or rubber-reinforced polystyrene resin. (matrix) or becomes a sea of co-continuous structure, so it is excellent in high heat resistance and low warpage property, and is also excellent in mechanical strength and chemical resistance derived from polyalkylene terephthalate resin.
Therefore, the thermoplastic resin composition of the present invention can be suitably used for parts of various electrical and electronic devices, interior or exterior parts for automobiles, and the like.

The thermoplastic resin composition of the present invention is based on a total of 100 parts by mass of (A) and (B), (A) polyalkylene terephthalate resin of 20 parts by mass or more and less than 50 parts by mass, (B) polystyrene resin or rubber reinforcement Contains more than 50 parts by mass of polystyrene resin and 80 parts by mass or less, and (C) a polycarbonate resin and / or a styrene-maleic acid copolymer, with respect to a total of 100 parts by mass of (A) and (B) 1 to 25 parts Contains parts by mass,
(A) The weight average molecular weight (Mw _A ) of the polyalkylene terephthalate resin is 20,000 to 65,000, (B) The weight average molecular weight (Mw _B ) of the polystyrene resin or rubber-reinforced polystyrene resin is 150,000 to 500,000,
(C) A polycarbonate resin and/or a styrene-maleic acid copolymer and (A) a polyalkylene terephthalate resin having a mass ratio (C)/(A) of 0.1 to 0.7. do.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. Although the explanations described below may be made based on embodiments and specific examples, the present invention should not be construed as being limited to such embodiments and specific examples.
In this specification, the term "~" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.

[(A) Polyalkylene terephthalate resin]
The thermoplastic resin composition of the present invention contains (A) a polyalkylene terephthalate resin having a weight average molecular weight (Mw _A ) of 20,000 to 65,000.
By using those having a mass average molecular weight (Mw _A ) in the range of 20000 to 65000, the characteristics of polyalkylene terephthalate resin are strongly manifested, excellent in high heat resistance and low warpage, and also in mechanical strength and chemical resistance. is also an excellent resin composition.
If the weight average molecular weight (Mw _A ) is less than 20000, the mechanical strength tends to be low. On the other hand, if it is larger than 65,000, it becomes difficult to form the above-mentioned sea-island structure, and the polystyrene resin or rubber-reinforced polystyrene resin tends to form a sea, and the flowability of the resin composition is deteriorated, resulting in poor moldability. The weight average molecular weight (Mw _A ) is preferably 25,000 or more, more preferably 30,000 or more, and preferably 60,000 or less.

In the present invention, the weight average molecular weight (Mw _A ) of the (A) polyalkylene terephthalate resin is the weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography).

The polyalkylene terephthalate resin (A) used in the present invention can be produced by a known polycondensation method or the like. The production method may be either batch polymerization or continuous polymerization, and both transesterification and direct polymerization can be applied, but continuous polymerization is preferred from the viewpoint of productivity.

As a melt polymerization method by a continuous method, for example, a dicarboxylic acid component and a diol component are heated in one or more esterification reactors in the presence of an esterification reaction catalyst, preferably at 150 to 280° C., more preferably. is continuously esterified under reduced pressure at a temperature of 180-265°C. Next, the obtained oligomer, which is the esterification reaction product, is transferred to a polycondensation reaction tank, and in one or more polycondensation reaction tanks, in the presence of a polycondensation reaction catalyst, preferably 210 to 280°C
, more preferably at a temperature of 220 to 265° C. under reduced pressure.

The mass average molecular weight (Mw _A ) of the polyalkylene terephthalate resin (A) obtained by polycondensation can be adjusted mainly by the polycondensation reaction time. The shorter the polycondensation time, the lower the weight average molecular weight (Mw _A ). However, under conditions where the amount of polymerization catalyst is large, the molecular weight shows a rapid increase from the initial stage of polymerization, making it difficult to stably obtain the weight average molecular weight suitable for the present invention. It is preferable to adjust the amount of catalyst according to the average molecular weight.

(A) Polyalkylene terephthalate resin is a polyester obtained by polycondensation of terephthalic acid as a dicarboxylic acid compound and a dihydroxy compound, and may be homopolyester or copolyester.

(A) As the dicarboxylic acid compound constituting the polyalkylene terephthalate resin, a terphthalic acid compound or an ester-forming derivative thereof is preferably used.
Aromatic dicarboxylic acids other than terephthalic acid can also be used in combination. 2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4 ,4′-dicarboxylic acid, diphenylisopropylidene-4,4′-dicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4′-dicarboxylic acid, anthracene-2,5-dicarboxylic acid, anthracene-2, 6-dicarboxylic acid, p-terphenylene-4,4′-dicarboxylic acid, pyridine-2,5-dicarboxylic acid, etc., and these are ester-forming derivatives such as dimethyl esters in addition to free acids in the polycondensation reaction. can be used.
Among the above, isophthalic acid or its ester-forming derivative can be preferably used.

If the amount is small, together with terephthalic acid and the above aromatic dicarboxylic acids, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid, and sebacic acid, 1,2-cyclohexanedicarboxylic acid, and 1,3-cyclohexanedicarboxylic acid Acids and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid can be used in combination of one or more.

(A) Dihydroxy compounds constituting the polyalkylene terephthalate resin include ethylene glycol, propylene glycol, butanediol, hexylene glycol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol, triethylene glycol, and the like. Examples include aliphatic diols, alicyclic diols such as cyclohexane-1,4-dimethanol, and mixtures thereof. Among these, butanediol and ethylene glycol are particularly preferred.

One or more long-chain diols having a molecular weight of 400 to 6,000, ie, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, etc. may be copolymerized.
Aromatic diols such as hydroquinone, resorcinol, naphthalene diol, dihydroxydiphenyl ether, and 2,2-bis(4-hydroxyphenyl)propane can also be used.

In addition to the above bifunctional monomers, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane for introducing a branched structure, and fatty acids for molecular weight adjustment. A small amount of monofunctional compound can also be used together.

(A) The polyalkylene terephthalate resin is mainly composed of polycondensation of terephthalic acid and a diol, that is, the amount exceeding 50% by mass, preferably 70% by mass or more, more preferably 80% by mass or more of the total resin. It is preferred to use those consisting of polycondensates. Aliphatic diols are preferred as diols.

(A) The amount of terminal carboxyl groups of the polyalkylene terephthalate resin may be appropriately selected and determined, but it is usually 60 eq/ton or less, preferably 50 eq/ton or less, and 30 eq/ton or less. is more preferred. If it exceeds 60 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 generally 3 eq/ton, preferably 5 eq/ton, more preferably generally 10 eq/ton.

The amount of terminal carboxyl groups of the (A) polyalkylene terephthalate resin is a value measured by dissolving 0.5 g of the resin in 25 ml of benzyl alcohol and titrating with a 0.01 mol/l benzyl alcohol solution of sodium hydroxide. . As a method for adjusting the amount of terminal carboxyl groups, any conventionally known method may be used, such as a method of adjusting polymerization conditions such as the raw material charge ratio during polymerization, the polymerization temperature, and a decompression method, or a method of reacting a terminal blocking agent. You can do it.

(A) The polyalkylene terephthalate resin is preferably a polyalkylene terephthalate resin in which 95 mol% or more of the acid component is terephthalic acid and 95 mol% or more of the alcohol component is an aliphatic diol. are polybutylene terephthalate resins and polyethylene terephthalate resins. These are preferably similar to homopolyesters, that is, 95 mol % or more of the entire resin is preferably composed of a terephthalic acid component and a 1,4-butanediol or ethylene glycol component.
(A) Polyalkylene terephthalate resin is preferably polybutylene terephthalate resin and/or polyethylene terephthalate resin.
Among them, the (A) polyalkylene terephthalate resin preferably contains a polybutylene terephthalate resin as a main component, and the polybutylene terephthalate resin accounts for more than 50% by mass in the (A) polyalkylene terephthalate resin. At that time, it is also preferable to contain the polyethylene terephthalate resin in an amount of less than 50% by mass.

Polybutylene terephthalate resin is produced by melt-polymerizing a dicarboxylic acid component or ester derivative thereof containing terephthalic acid as a main component and a diol component containing 1,4-butanediol as a main component in a batch or continuous process. can do. Further, after producing a low-molecular-weight polybutylene terephthalate resin by melt polymerization, the degree of polymerization (or molecular weight) can be increased to a desired value by solid-phase polymerization under a nitrogen stream or under reduced pressure.

The polybutylene terephthalate resin is preferably produced by continuous melt polycondensation of a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of 1,4-butanediol.

Catalysts used in carrying out the esterification reaction may be those conventionally known, such as titanium compounds, tin compounds, magnesium compounds, calcium compounds, and the like. Particularly suitable among these are titanium compounds. 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.

The polybutylene terephthalate resin may be a polybutylene terephthalate resin modified by copolymerization (hereinafter sometimes referred to as "modified polybutylene terephthalate resin"). Polyester ether resins obtained by copolymerizing alkylene glycols (especially polytetramethylene glycol), dimer acid-copolymerized polybutylene terephthalate resins, and isophthalic acid-copolymerized polybutylene terephthalate resins can be used.

When a polyester ether resin obtained by copolymerizing polytetramethylene glycol is used as the modified polybutylene terephthalate resin, the proportion of the tetramethylene glycol component in the copolymer is preferably 3 to 40% by mass, more preferably 5 to 30% by mass. % is more preferred, and 10 to 25% by mass is even more preferred.
When a dimer acid-copolymerized polybutylene terephthalate resin is used as the modified polybutylene terephthalate resin, the ratio of the dimer acid component to the total carboxylic acid component is preferably 0.5 to 30 mol% as carboxylic acid groups. 1 to 20 mol % is more preferable, and 3 to 15 mol % is even more preferable.
When an isophthalic acid-copolymerized polybutylene terephthalate resin is used as the modified polybutylene terephthalate resin, the ratio of the isophthalic acid component to the total carboxylic acid component is preferably 1 to 30 mol % in terms of carboxylic acid groups. 20 mol % is more preferred, and 3 to 15 mol % is even more preferred.
Among the modified polybutylene terephthalate resins, a polyester ether resin obtained by copolymerizing polytetramethylene glycol and an isophthalic acid copolymerized polybutylene terephthalate resin are preferable.

The amount of terminal carboxyl groups of the polybutylene terephthalate resin may be appropriately selected and determined, but is usually 60 eq/ton or less, preferably 50 eq/ton or less, more preferably 40 eq/ton or less. , 30 eq/ton or less. If it exceeds 60 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 productivity in the production of polybutylene terephthalate resin.

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

(A) As the polyalkylene terephthalate resin, one containing a polybutylene terephthalate homopolymer and the modified polybutylene terephthalate resin is also preferable. By containing a specific amount of modified polybutylene terephthalate resin, weld strength and alkali resistance are likely to be improved, which is preferable.
When the polybutylene terephthalate homopolymer and the modified polybutylene terephthalate resin are contained, the content of the modified polybutylene terephthalate resin is preferably 100% by mass in total of the polybutylene terephthalate homopolymer and the modified polybutylene terephthalate resin. It is 5 to 50% by mass, more preferably 10 to 40% by mass, still more preferably 15 to 30% by mass.

Furthermore, (A) polyalkylene terephthalate resin preferably contains polybutylene terephthalate resin and polyethylene terephthalate resin. By containing a specific amount of polyethylene terephthalate resin, low warpage, appearance, and weld strength are likely to be improved, which is preferable.
When polybutylene terephthalate resin and polyethylene terephthalate resin are contained, the content of polyethylene terephthalate resin is preferably 5% by mass or more and less than 50% by mass with respect to the total 100% by mass of polybutylene terephthalate resin and polyethylene terephthalate resin. , more preferably 10 to 45% by mass, more preferably 15 to 40% by mass.

Polyethylene terephthalate resin is a resin having oxyethyleneoxyterephthaloyl units composed of terephthalic acid and ethylene glycol as main structural units for all structural repeating units, and contains structural repeating units other than oxyethyleneoxyterephthaloyl units. good too. Polyethylene terephthalate resin is produced using terephthalic acid or its lower alkyl ester and ethylene glycol as main raw materials, but other acid components and/or other glycol components may be used together as raw materials.

Acid components other than terephthalic acid include phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3- Examples include phenylenedioxydiacetic acid and structural isomers thereof, dicarboxylic acids such as malonic acid, succinic acid and adipic acid and derivatives thereof, and oxy acids such as p-hydroxybenzoic acid and glycolic acid or derivatives thereof.

Diol components other than ethylene glycol include aliphatic glycols such as 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, pentamethylene glycol, hexamethylene glycol and neopentyl glycol, and cyclohexane. Alicyclic glycols such as dimethanol, aromatic dihydroxy compound derivatives such as bisphenol A and bisphenol S, and the like are included.

Furthermore, the polyethylene terephthalate resin has a branching component such as a trifunctional acid such as tricarballylic acid, trimellitic acid, trimellitic acid, etc., or a tetrafunctional acid such as pyromellitic acid, or an acid having ester type performance, or glycerin, trimethylolpropane, A copolymer obtained by copolymerizing 1.0 mol % or less, preferably 0.5 mol % or less, more preferably 0.3 mol % or less of an alcohol having a trifunctional or tetrafunctional ester-forming ability such as pentaerythritol. may be

(A) When both a polybutylene terephthalate resin and a polyethylene terephthalate resin are contained as the polyalkylene terephthalate resin, the weight average molecular weight (Mw _A ) of the (A) polyalkylene terephthalate resin is 20,000 to 65,000, but the polybutylene Either a terephthalate resin and a polyethylene terephthalate resin, or a combination of resins each exceeding 20,000 to 65,000 is also possible, and it is possible by setting the weight average molecular weight (Mw _A ) within the above range as (A) the polyalkylene terephthalate resin. is.

The terminal carboxyl group concentration of the polyethylene terephthalate resin is preferably 3 to 50 eq/ton, more preferably 5 to 40 eq/ton, more preferably 10 to 30 eq/ton.
The terminal carboxyl group concentration of polyethylene terephthalate resin is a value obtained by dissolving 0.5 g of polyethylene terephthalate resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol/l benzyl alcohol solution of sodium hydroxide. be.
As a method for adjusting the amount of terminal carboxyl groups, any conventionally known method may be used, such as a method of adjusting polymerization conditions such as the raw material charge ratio during polymerization, the polymerization temperature, and a decompression method, or a method of reacting a terminal blocking agent. You can do it.

[(B) Polystyrene resin or rubber-reinforced polystyrene resin]
The thermoplastic resin composition of the present invention contains (B) a polystyrene resin and/or a rubber-reinforced polystyrene resin.
The polystyrene resin may be a homopolymer of styrene or a copolymer obtained by copolymerizing other aromatic vinyl monomers such as α-methylstyrene, paramethylstyrene, vinyltoluene, vinylxylene, etc., in a range of 50% by mass or less. There may be.

The rubber-reinforced polystyrene resin is preferably copolymerized or blended with 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, more preferably 5 to 20% by mass.
High impact polystyrene (HIPS) is particularly preferred as the rubber-reinforced polystyrene resin.

In the present invention, the polystyrene resin or rubber-reinforced polystyrene resin (B) having a weight average molecular weight (Mw _B ) of 150,000 to 500,000 is used. A polystyrene resin or a rubber-reinforced polystyrene resin having such a mass average molecular weight (Mw _B ), based on a total of 100 parts by mass of (A) and (B), and 20 parts by mass or more and 50 parts by mass of (A) a polyalkylene terephthalate resin (B) polystyrene resin or rubber-reinforced polystyrene resin in an amount of more than 50 parts by mass and not more than 80 parts by mass, and (A) the polyalkylene terephthalate resin becomes dominant in terms of physical properties, resulting in a high Heat resistance and low warpage can be achieved. If the weight average molecular weight (Mw _B ) is less than 150000, the heat resistance will be insufficient.
The weight average molecular weight (Mw _B ) is preferably 155,000 or more, more preferably 160,000 or more, still more preferably 175,000 or more, and preferably 450,000 or less, more preferably 430,000 or less, still more preferably 400,000 or less.

The weight average molecular weight (Mw _B ) of the (B) polystyrene resin or rubber-reinforced polystyrene resin is the weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography).

As described above, the content of (A) polyalkylene terephthalate resin is 20 parts by mass or more and less than 50 parts by mass based on a total of 100 parts by mass of (A) and (B), (B) polystyrene resin or rubber-reinforced polystyrene resin is more than 50 parts by mass and 80 parts by mass or less, preferably (A) is 25 parts by mass or more and less than 50 parts by mass, more preferably 30 parts by mass or more and less than 50 parts by mass, still more preferably 30 to 48 parts by mass , (B) is preferably more than 50 parts by mass and 75 parts by mass or less, more preferably more than 50 parts by mass and 70 parts by mass or less, still more preferably 52 to 70 parts by mass.

Further, in the present invention, (A) the mass average molecular weight (Mw _A ) of the polyalkylene terephthalate resin, the amount ratio of (A) to the total content of (A) and (B), and (B) the polystyrene resin Alternatively, the mass average molecular weight (Mw _B ) of the rubber-reinforced polystyrene resin and the ratio of (B) to the total content of (A) and (B) preferably satisfy the following relational expression (I).
0.1≦[quantity ratio of (B)/Mw _B ]/[quantity ratio of (A)/Mw _A ]≦0.7 (I)

The definition of the above formula (I) is explained below.
As described above, in the present invention, the polyalkylene terephthalate resin (A) forms a co-continuous structure, preferably a sea of a sea-island structure, although the amount of the polyalkylene terephthalate resin is small. _A ] represents the ease with which (A) the polyalkylene terephthalate resin becomes a sea. The larger the amount ratio of (A), the more easily the sea becomes, and the better the fluidity of (A), the more likely the sea becomes, and the smaller the _MwA , the better the fluidity.
On the other hand, the [quantity ratio of (B)/Mw _B ] in formula (I) represents the ease with which (B) polystyrene resin or rubber-reinforced polystyrene resin becomes a sea. Naturally, the larger the amount ratio of (B), the more easily the sea becomes, and the better the fluidity of (B), the more likely the sea becomes, and the smaller the _MwB , the better the fluidity.
The formula (I) is the ratio of the tendency of the component (B) to form the sea and the tendency of the component (A) to form the sea, and the value of the formula (I) is preferably 0.1 to 0.7. If it is in the range of (A), even if the amount ratio of (A) is small, the characteristics of (A) the polyalkylene terephthalate resin are predominantly manifested, and high heat resistance can be obtained.
Further, the reason why the resin composition satisfying the relational expression (I) of this quantitative ratio exhibits high heat resistance is that (A) the polyalkylene terephthalate resin and the (B) polystyrene resin and the rubber-reinforced polystyrene This is true only for resins, and acrylonitrile-styrene copolymers, which have similar compositions, cannot exhibit excellent properties even if they satisfy the above formula (I), and are peculiar. be.

By satisfying the formula (I), the (A) polyalkylene terephthalate resin is more likely to become the sea (matrix), and the resulting thermoplastic resin composition exhibits higher heat resistance and a higher degree of low warpage. Also, the chemical resistance of polyalkylene terephthalate can be maintained.
The value of formula (I) is more preferably 0.15 or more, still more preferably 0.18 or more, more preferably 0.6 or less, still more preferably 0.55 or less, and particularly preferably 0.5 or less. be.

[(C) Polycarbonate resin or styrene-maleic acid copolymer]
The polybutylene terephthalate resin composition of the present invention contains (C) a polycarbonate resin or a styrene-maleic acid copolymer. (C) By containing a polycarbonate resin or a styrene-maleic acid copolymer, compatibility between the polyalkylene terephthalate phase and the polystyrene resin or rubber-reinforced polystyrene resin can be reinforced, and high strength can be expressed.

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

The raw material dihydroxy compound does not substantially contain a bromine atom, and is preferably an aromatic dihydroxy compound. Specifically, 2,2-bis(4-hydroxyphenyl)propane (that is, bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4- Examples include dihydroxydiphenyl and the like, preferably bisphenol A. A compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can also be used.

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

Monohydric aromatic hydroxy compounds may be used to control the molecular weight of polycarbonate resins, such as m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, p-long chain Alkyl-substituted phenols and the like can be mentioned.

The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 15,000 or more, more preferably 20,000 or more, still more preferably 23,000 or more, particularly preferably 25,000 or more, and most preferably more than 28,000. preferable. If the viscosity-average molecular weight is lower than 20,000, the resulting resin composition tends to have low mechanical strength such as impact resistance. Also, Mv is preferably 60,000 or less, more preferably 40,000 or less, and even more preferably 35,000 or less. If it is higher than 60,000, the fluidity of the resin composition may deteriorate and the moldability may deteriorate.

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

The method for producing the polycarbonate resin is not particularly limited, and polycarbonate resins produced by either the phosgene method (interfacial polymerization method) or the melt method (transesterification method) can be used. Also preferred is a polycarbonate resin prepared by subjecting a polycarbonate resin produced by a melting method to a post-treatment for adjusting the amount of terminal OH groups.

The styrene-maleic acid copolymer is preferably a styrene-maleic anhydride copolymer (SMA resin), which is a copolymer of a styrene monomer and a maleic anhydride monomer. Known polymerization methods are possible.

The molecular weight and the like of the styrene-maleic acid copolymer are not particularly limited. Preferably it is 80,000 or more and 350,000. Here, the weight average molecular weight is the polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent.

Other monomer components can be copolymerized with the styrene-maleic acid copolymer as long as the characteristics of the present invention are not impaired. vinyl cyanide-based monomers, unsaturated carboxylic acid alkyl ester-based monomers such as methyl methacrylate and methyl acrylate, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, etc. and the like, and these can be used alone or in combination of two or more.

The content of (C) polycarbonate resin and styrene-maleic acid copolymer is, with respect to a total of 100 parts by mass of (A) polyalkylene terephthalate resin and (B) polystyrene resin or rubber-reinforced polystyrene resin, both alone or in total is 1 to 25 parts by mass, preferably 3 to 20 parts by mass, more preferably 3 to 18 parts by mass.

In the thermoplastic resin composition of the present invention, the mass ratio (C)/(A) of the contents of (C) polycarbonate resin and/or styrene-maleic acid copolymer and (A) polyalkylene terephthalate resin is 0 .1 to 0.7. By setting (C)/(A) in such a range, excellent strength can be exhibited while maintaining high heat resistance. (C)/(A) is preferably 0.1 to 0.5, more preferably 0.1 to 0.4.

[(D) glass fiber]
The thermoplastic resin composition of the present invention preferably contains (D) glass fiber.
As the glass fiber, if it is usually used for thermoplastic polyester resin, A glass, E glass, alkali resistant glass composition containing zirconia component, chopped strand, 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 blending the masterbatch or the like. Among them, as the glass fiber used in the present invention, alkali-free 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 fibers may be treated with a sizing agent or surface treatment agent. In addition to the untreated (D) glass fibers, a sizing agent or a surface treatment agent may be added for surface treatment during the production of the resin composition of the present invention.

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

(D) Glass fibers may be used in combination of two or more depending on the properties required, and the total content of (A) polyalkylene terephthalate resin and (B) polystyrene resin or rubber-reinforced polystyrene resin is 100. Based on parts by mass, preferably 5 to 150 parts by mass, more preferably 10 to 120 parts by mass, among them 15 to 100 parts by mass, particularly preferably 20 to 90 parts by mass, most preferably 30 to 80 parts by mass. . By containing in such a range, the strength and heat resistance of the obtained molded article can be improved, and the shrinkage reduction effect can be enhanced. When the content exceeds 150 parts by mass, the surface appearance of the molded article deteriorates. If it is less than 5 parts by mass, the effect of improving the strength is reduced.

The thermoplastic resin composition of the present invention preferably contains other inorganic fillers in the form of plates, granules, or amorphous, in addition to the above-described (D) glass fiber. The plate-like inorganic filler exhibits the function of reducing anisotropy and warpage, and examples thereof include talc, glass flakes, mica, mica, kaolin, and metal foil. Glass flakes are preferred among the plate-like inorganic fillers.
Other particulate or amorphous inorganic fillers include ceramic beads, clays, zeolites, barium sulfate, titanium oxide, silicon oxide, aluminum oxide, magnesium hydroxide, zinc sulfide, and the like.
Talc, titanium oxide, and zinc sulfide are particularly preferred as other inorganic fillers.

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

[Stabilizer]
It is preferable that the thermoplastic resin composition of the present invention contain a stabilizer because it has effects of improving thermal stability and preventing deterioration of mechanical strength, transparency and hue. Phosphorus-based stabilizers, sulfur-based stabilizers and phenol-based stabilizers are preferred as stabilizers.

Phosphorus-based stabilizers include phosphorous acid, phosphoric acid, phosphites (phosphites), trivalent phosphates (phosphonites), pentavalent phosphates (phosphates) and the like, among which phosphites , phosphonites and phosphates are preferred.

The organic phosphate compound preferably has 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, R ¹ is a long-chain alkyl acid phosphate compound having 8 to 30 carbon atoms. Specific examples of alkyl groups 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 and the like can be mentioned.

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, 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 phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, bisnonylphenyl acid phosphate and the like. Among these, octadecyl acid phosphate is preferred, and this product is commercially available from ADEKA under the trade name "ADEKA STAB AX-71".

The organic phosphite compound preferably has the following general formula:
R ² OP(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 is an aryl group having 6 to 30 carbon atoms.)
The compound represented by is mentioned.

Examples of organic phosphite compounds include triphenylphosphite, tris(nonylphenyl)phosphite, dilauryl hydrogen phosphite, triethylphosphite, tridecylphosphite, tris(2-ethylhexyl)phosphite, tris(tridecyl ) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyl dipropylene glycol diphosphite, tetraphenyl tetra (tridecyl) pentaerythritol tetraphosphite , hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4′-butylidene-bis(3-methyl-6-tert-butylphenyl di(tridecyl)phosphite), tetra(tridecyl) 4,4 '-isopropylidene 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)pentaerythritol di Phosphites, 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 preferred.

The organic phosphonite compound preferably has the following general formula:
R ⁵ -P(OR ⁶ )(OR ⁷ )
(wherein 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 is an aryl group having 6 to 30 carbon atoms.)
The compound represented by is mentioned.

Examples of organic phosphonite compounds include tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'-biphenyl diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite night, tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite, tetrakis(2,6-di-iso-propylphenyl)-4,4'-biphenylene diphosphonite, Tetrakis (2,6-di-n-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis (2,6-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis ( 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 thioethers are particularly preferable. Specific examples include 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 preferred.

Phenolic stabilizers include, for example, pentaerythritol tetrakis (3-(3,5-di-t-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-letetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl ) propionate is preferred.

One stabilizer may be contained, or two or more stabilizers 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 a total of 100 parts by mass of (A) polyalkylene terephthalate resin and (B) polystyrene resin or rubber-reinforced polystyrene resin. If 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 deterioration in color during molding are likely to occur. If it exceeds, the amount becomes excessive, and the generation of silver and the deterioration of the hue tend to occur more easily. The stabilizer content is more preferably 0.01 to 1.5 parts by mass, and still more preferably 0.1 to 1 part by mass.

[Release agent]
The thermoplastic resin composition of the present invention preferably contains a release agent. As the release agent, known release agents that are commonly used for polyester resins can be used. Among them, polyolefin compounds and fatty acid ester compounds are preferable in terms of good alkali resistance, and particularly polyolefin compounds. Compounds are preferred.

Examples of polyolefin compounds include compounds selected from paraffin waxes and polyethylene waxes. Among them, those having a weight average molecular weight of 700 to 10,000, more preferably 900 to 8,000 are preferred.

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

Examples of fatty acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melicic acid, tetralyacontanoic acid, montanic acid, adipic acid, and azelaic acid. be done. Fatty acids may also be cycloaliphatic.
Alcohols may include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have substituents such as fluorine atoms and aryl groups. Among these, monohydric or polyhydric saturated alcohols having 30 or less carbon atoms are preferred, and saturated monohydric or polyhydric alcohols having 30 or less carbon atoms are more preferred. Here, the term "aliphatic" also includes alicyclic compounds.
Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, and the like. is mentioned.
The above ester compound may contain aliphatic carboxylic acid and/or alcohol as impurities, or may be a mixture of a plurality of compounds.

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

The content of the release agent is preferably 0.1 to 3 parts by mass with respect to a total of 100 parts by mass of (A) polyalkylene terephthalate resin and (B) polystyrene resin or rubber-reinforced polystyrene resin. It is more preferably 2 to 2.5 parts by mass, still more preferably 0.3 to 2 parts by mass. If the amount is less than 0.1 parts by mass, the surface property tends to be deteriorated due to poor mold release during melt molding. The surface tends to become cloudy.

[Carbon black]
The thermoplastic resin composition of the present invention preferably contains carbon black.
Carbon black is not limited in its type, raw material type, and production method, and any of furnace black, channel black, acetylene black, ketjen black, etc. can be used. Although the number average particle diameter is not particularly limited, it is preferably about 5 to 60 nm.

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 100 parts by mass in total of (A) polyalkylene terephthalate resin and (B) polystyrene resin or rubber-reinforced polystyrene resin. 3 parts by mass. If it is less than 0.1 part by mass, the desired color may not be obtained or the effect of improving weather resistance may not be sufficient, and if it exceeds 4 parts by mass, mechanical properties may deteriorate.

[Other ingredients]
The thermoplastic resin composition of the present invention includes the above-described (A) polyalkylene terephthalate resin, (B) polystyrene resin or rubber-reinforced polystyrene resin, (C) polycarbonate resin and styrene-maleic acid copolymer other thermoplastic A resin can be contained within a range that does not impair the effects of the present invention. Specific examples of other thermoplastic resins include polyacetal resins, polyamide resins, polyphenylene oxide resins, polyphenylene sulfide resins, polysulfone resins, polyethersulfone resins, polyetherimide resins, polyetherketone resins, and polyolefin resins. etc.
However, when other resins are contained, the content is preferably 20 parts by mass or less with respect to a total of 100 parts by mass of (A) polyalkylene terephthalate resin and (B) polystyrene resin or rubber-reinforced polystyrene resin. It is more preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less.

In addition, the thermoplastic resin composition of the present invention may contain various additives other than those described above. agents, antistatic agents, antifogging agents, antiblocking agents, plasticizers, dispersants, antibacterial agents, coloring agents, dyes and pigments, and the like.

[Production 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, (A) a polyalkylene terephthalate resin and (B) a polystyrene resin or rubber-reinforced polystyrene resin, other resin components added as desired, and various additives are thoroughly mixed together, and then extruded by a single-screw or twin-screw extruder. Melt and knead. The resin composition can also be prepared without premixing the respective components, or premixing only a part of them, feeding them to an extruder using a feeder and melt-kneading them. Alternatively, a masterbatch of a part thereof may be blended and melt-kneaded. Furthermore, it is also possible to supply a mixture obtained by mixing each component in advance to a molding machine such as an injection molding machine as it is without melt-kneading to produce various moldings.

The heating temperature for melt-kneading can be appropriately selected from the range of 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 structure in consideration of shear heat generation and the like. In order to suppress decomposition during kneading and subsequent molding, it is desirable to use antioxidants and heat stabilizers.

[Molded body]
The method for producing a molded article using the thermoplastic resin composition of the present invention is not particularly limited, and any molding method generally employed for thermoplastic resin compositions can be employed. Examples include injection molding, ultra-high speed injection molding, injection compression molding, two-color molding, hollow molding such as gas assist, molding using heat insulating molds, and rapid heating molds. 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, A blow molding method and the like can be mentioned. Among them, the injection molding method is preferable because the effects of the present invention, such as improved productivity and improved surface properties of the resulting molded article, are remarkable.

The resulting molded article is excellent in heat resistance, low warpage, and chemical resistance, and is therefore suitable for electrical and electronic equipment parts, interior and exterior parts for automobiles, and other electric parts that require these properties strictly. In particular, it can be suitably used as interior and exterior parts for automobiles, such as housings for head-up displays installed in automobiles, housings for engine control units (ECUs), and the like.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention should not be construed as being limited to the following examples.
The components used in the following examples and comparative examples are shown in Table 1 below.

(Examples 1 to 6, Comparative Examples 1 to 6)
After uniformly mixing each component shown in Table 1 in the ratio shown in Table 2 below (all parts by mass) in a tumbler mixer, a twin-screw extruder (“TEX30α” manufactured by Japan Steel Works, Ltd., L / D = 42), the resin composition melted and kneaded under the conditions of a cylinder set temperature of 260 ° C., a discharge rate of 40 kg / h, and a screw rotation speed of 200 rpm is rapidly cooled in a water tank, pelletized using a pelletizer, and a thermoplastic resin composition. I got a pellet of stuff.

[MVR]
MVR is the melt flow volume MVR per unit time (unit: cm ³ /10 min) of the pellets obtained above under the conditions of 265 ° C. and a load of 5 kgf using a melt indexer manufactured by Takara Industry Co., Ltd. was measured.

[Tensile breaking strength, tensile breaking elongation]
After drying the pellets obtained above at 120 ° C. for 5 hours, using an injection molding machine manufactured by Nippon Steel Corporation (clamping force 85 T), under the conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C., ISO multi-purpose Specimens (4 mm thick) were injection molded.
Based on ISO527, tensile strength at break (unit: MPa) and tensile elongation at break (unit: %) were measured using the above ISO multi-purpose test piece (4 mm thick).
[Maximum flexural strength, flexural modulus]
Using the ISO multi-purpose test piece (4 mm thick), the maximum flexural strength (unit: MPa) and flexural modulus (unit: MPa) were measured at a temperature of 23° C. in accordance with ISO178.
[Notched Charpy impact strength]
Notched Charpy impact strength (unit: kJ/m ² ) was measured at a temperature of 23° C. for a notched test piece obtained by notching the above ISO multipurpose test piece (4 mm thick) according to ISO179.

[Deformation temperature under load and judgment of heat resistance]
Using the above ISO multi-purpose test piece (4 mm thick), the load deflection temperature was measured under the condition of a load of 1.80 MPa in accordance with ISO75-1 and ISO75-2.
Heat resistance was determined according to the following criteria.
○: Deflection temperature under load is 150°C or more △: Deflection temperature under load is 130°C or more and less than 150°C ×: Deflection temperature under load is less than 130°C

[Warpage amount and warpage determination]
Using an injection molding machine ("NEX80" manufactured by Nissei Plastic Industry Co., Ltd.), a cylinder temperature of 260 ° C and a mold temperature of 80 ° C are used to mold a circular plate with a diameter of 100 mm and a thickness of 1.6 mm using a side gate mold. The warp amount (unit: mm) of the plate was determined.
Evaluation of warpage was performed according to the following criteria.
○: The amount of warp is less than 1 mm △: The amount of warp is 1 mm or more and less than 3 mm ×: The amount of warp is 3 mm or more The results are shown in Table 2 below.

Since the thermoplastic resin composition of the present invention is excellent in heat resistance and low warpage properties, it can be particularly suitably used as electrical and electronic equipment parts, interior and exterior parts for automobiles, and other electric parts that require these properties strictly.

Claims (6)

Based on a total of 100 parts by mass of the following (A) and (B), (A) 20 parts by mass or more and less than 50 parts by mass of a polyalkylene terephthalate resin, (B) a polystyrene resin or a rubber-reinforced polystyrene resin (with a syndiotactic structure (excluding polystyrene resins.) is more than 50 parts by mass and 80 parts by mass or less, and (C) a polycarbonate resin and / or a styrene-maleic acid copolymer is added to a total of 100 parts by mass of (A) and (B). On the other hand, it contains 1 to 25 parts by mass,
(A) The weight average molecular weight (Mw _A ) of the polyalkylene terephthalate resin is 20,000 to 65,000, (B) The weight average molecular weight (Mw _B ) of the polystyrene resin or rubber-reinforced polystyrene resin is 150,000 to 500,000, and (A) the polyalkylene An amount exceeding 50% by mass in the terephthalate resin is polybutylene terephthalate resin,
(C) A polycarbonate resin and/or a styrene-maleic acid copolymer and (A) a polyalkylene terephthalate resin having a mass ratio (C)/(A) of 0.1 to 0.7. A thermoplastic resin composition. (A) the mass-average molecular weight (Mw _A ) of the polyalkylene terephthalate resin, the ratio of (A) to the total content of (A) and (B), and the mass of (B) the polystyrene resin or the rubber-reinforced polystyrene resin 2. The thermoplastic resin composition according to claim 1, wherein the average molecular weight (Mw _B ) and the ratio of (B) to the total content of (A) and (B) satisfy the following relational expression (I).
0.1≦[quantity ratio of (B)/Mw _B ]/[quantity ratio of (A)/Mw _A ]≦0.7 (I) Further, (D) glass fiber, (A) polyalkylene terephthalate resin and (B) polystyrene resin or rubber-reinforced polystyrene resin of 5 to 150 parts by weight with respect to a total of 100 parts by weight containing. A thermoplastic resin composition. (A) The thermoplastic resin composition according to any one of claims 1 to 3, wherein the polyalkylene terephthalate resin is polybutylene terephthalate. A molded article made of the thermoplastic resin composition according to any one of claims 1 to 4. 6. The molded article according to claim 5, which is a housing for a head-up display or an engine control unit.