JP2014162820A - Polybutylene terephthalate-based resin composition molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polybutylene terephthalate-based resin composition molded article excellent in jet-blackness and impact resistance.SOLUTION: A molded article is obtained by molding a polybutylene terephthalate-based resin composition including 2 to 22 pts. mass of an elastomer (B) and 0.01 pt.mass or more of carbon black (C) based on 100 pts.mass of polybutylene terephthalate (A). In the polybutylene terephthalate-based resin composition molded article excellent in jet-blackness, a phase of the elastomer (B) disperses at a surface layer part of the molded article, and the dispersed phases have R/r of 8 or less on average when a maximum diameter of each dispersed phase is defined as R and a maximum diameter out of diameters perpendicular to the maximum diameter R is defined as r.

Description

  The present invention relates to a molded article of a polybutylene terephthalate resin composition, and more particularly to a molded article of a polybutylene terephthalate resin composition excellent in jet blackness and impact resistance.

Polybutylene terephthalate is excellent in mechanical properties, heat resistance, chemical resistance, weather resistance, and electrical properties, and is widely used in fields such as automobile materials and electrical / electronic parts.
In particular, in the fields of electrical and electronic devices, such as housings of various portable terminal devices and automobile interior parts, in order to give a high-class feeling from the viewpoint of design and design, depth and clarity are particularly important. There is also a strong demand for the appearance of an excellent jetness (also called piano black) equivalent to lacquering, with a feeling and a calm atmosphere.

  Conventionally, black coloration of polybutylene terephthalate has been performed with a black pigment typified by carbon black. Examples thereof include a black polyester colorant (Patent Document 1) in which carbon black is dispersed in a mixed resin of polyethylene terephthalate and polybutylene terephthalate, polybutylene terephthalate, aromatic polycarbonate or polyethylene terephthalate, and an acrylic compound. Examples thereof include a reinforced polybutylene terephthalate resin composition (Patent Document 2) containing a colorant composed of an inorganic filler, carbon black, and the like.

Moreover, the impact resistance of the molded article made of polybutylene terephthalate is not always sufficient, which is an obstacle to the development of practical applications.
As a method for improving the impact resistance of the polyester resin, various methods have been proposed so far, for example, a composition containing an ethylene-glycidyl methacrylate copolymer (Patent Document 3), ethylene-glycidyl methacrylate-methyl acrylate, etc. It has been proposed to blend various elastomers such as a composition (Patent Document 4) blended with the above terpolymer.

However, when an elastomer is blended with polybutylene terephthalate containing carbon black, the jetness is likely to deteriorate, and the compatibility of impact resistance and high jetness is a major issue in developing a jet black polybutylene terephthalate resin grade. It has become.
Furthermore, in the case of electrical and electronic equipment casings, automotive interior and exterior parts, etc., in recent years, the thickness of molded products (parts) has been reduced, and it has been required to have flame retardancy. Therefore, there is a demand for a polybutylene terephthalate-based resin composition molded article having impact resistance and high jetness even when a flame retardant is formulated.

Japanese Patent Laid-Open No. 5-194825 JP-A-9-104812 Japanese Patent Publication No. 58-47419 Japanese Patent Publication No.59-28223

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a polybutylene terephthalate-based resin composition molded article excellent in jetness and impact resistance. There is.

In order to solve the above-mentioned problems, the present inventors have intensively studied the composition of the polybutylene terephthalate resin composition and the morphology of the molded product, and as a result, the morphology of the resin composition molded product has a jet black effect. In other words, in the molded body obtained by molding a polybutylene terephthalate-based resin composition containing a specific amount of elastomer and carbon black with respect to polybutylene terephthalate, an elastomer (B The present invention has been completed by finding that a molded body in which the phase of) satisfies a specific condition and is dispersed solves the above problems and exhibits excellent impact resistance and high jetness.
According to the present invention, the following polybutylene terephthalate-based resin composition molded article is provided.

[1] A polybutylene terephthalate resin composition containing 2 to 22 parts by mass of elastomer (B) and 0.01 parts by mass or more of carbon black (C) with respect to 100 parts by mass of polybutylene terephthalate (A) is molded. A molded body comprising
In the surface layer portion of the molded body, the phase of the elastomer (B) is dispersed, and the dispersed phase has a maximum diameter of R in the direction perpendicular to the maximum diameter R and the maximum diameter of each dispersed phase. A polybutylene terephthalate-based resin composition molded article having excellent jetness, wherein R / r is 8 or less on average when r.
[2] The polybutylene terephthalate (A) further includes a polycarbonate resin (D), and the polybutylene terephthalate (A) is 50 to 85 on the basis of a total of 100% by mass of the polybutylene terephthalate (A) and the polycarbonate resin (D). The polybutylene terephthalate-based resin composition molded article according to the above [1], containing 15% by mass and 15 to 50% by mass of the polycarbonate resin (B).

[3] The polybutylene terephthalate-based resin composition further contains the flame retardant (E) in an amount of 7 to 35 parts by mass with respect to 100 parts by mass of the total amount of the polybutylene terephthalate (A) and the polycarbonate resin (D). 1] or [2] molded polybutylene terephthalate resin composition [4] The polybutylene terephthalate resin composition further comprises an antimony compound (F), polybutylene terephthalate (A) and polycarbonate resin (D). The polybutylene terephthalate-based resin composition molded article according to any one of the above [1] to [3], which is contained in an amount of 1 to 15 parts by mass with respect to 100 parts by mass of the total amount.
[5] The polybutylene terephthalate-based resin composition molded article according to [3] or [4], wherein the flame retardant (E) is a brominated polycarbonate.
[6] The polybutylene terephthalate-based resin composition molded body according to any one of the above [1] to [5], wherein the molded body has an L ^* value of 40 or less.

The molded body of the polybutylene terephthalate resin composition of the present invention has good jet blackness and impact resistance.
For this reason, the polybutylene terephthalate-based resin composition molded body of the present invention is used as an insulating part for electrical and electronic equipment, for example, a housing, a connector, a relay, a switch, a sensor, an actuator, a terminal switch, etc. It can be preferably used.

It is a figure which shows the shape of the rectangular parallelepiped box shape molded article used for evaluation of the curvature in an Example. 4 is a scanning electron micrograph of the surface layer portion of the molded body obtained in Example 4. FIG. 4 is a scanning electron micrograph of the surface layer portion of the molded body obtained in Example 4. FIG.

[Summary of Invention]
The molded body of polybutylene terephthalate resin composition of the present invention contains 2 to 22 parts by mass of elastomer (B) and 0.01 parts by mass or more of carbon black (C) with respect to 100 parts by mass of polybutylene terephthalate (A). A molded body formed by molding a polybutylene terephthalate-based resin composition, wherein the phase of the elastomer (B) is dispersed in the surface layer portion of the molded body (the surface layer portion is defined from the surface of the molded piece to 20 μm inside). In addition, the dispersed phase has an average R / r of 8 or less, where R is the maximum diameter of each dispersed phase and r is the maximum diameter in the direction perpendicular to the maximum diameter R. It is characterized by that.
The molded article of the polybutylene terephthalate resin composition of the present invention has excellent impact resistance by forming a morphology in which the phase of the elastomer (B) is thus dispersed in the surface layer portion of the molded article. It is presumed that the high jetness is expressed.

Hereinafter, the contents of the present invention will be described in detail.
The description of each constituent element described below may be made based on typical embodiments and specific examples of the present invention, but the present invention is interpreted to be limited to such embodiments and specific examples. It is not a thing. In the present specification, “to” is used to mean that the numerical values described before and after it are used as the lower limit and the upper limit, and “ppm” means “mass ppm”.

[Polybutylene terephthalate (A)]
The polybutylene terephthalate (A), which is the main component of the polybutylene terephthalate-based resin composition molded article of the present invention, is a polycondensation of a dicarboxylic acid compound and a dihydroxy compound, a polycondensation of an oxycarboxylic acid compound or a polycondensation of these compounds. Etc., which may be either a homopolyester or a copolyester.

As the dicarboxylic acid compound constituting the polybutylene terephthalate (A), an aromatic dicarboxylic acid or an ester-forming derivative thereof is preferably used.
Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2′-dicarboxylic acid, Biphenyl-3,3′-dicarboxylic acid, biphenyl-4,4′-dicarboxylic acid, 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. Terephthalic acid can be preferably used.

These aromatic dicarboxylic acids may be used as a mixture of two or more. As is well known, these can be used in polycondensation reactions as ester-forming derivatives such as dimethyl esters in addition to free acids.
If the amount is small, together with these aromatic dicarboxylic acids, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid, sebacic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and 1 One or more alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid can be mixed and used.

Examples of the dihydroxy compound constituting the polybutylene terephthalate (A) include fats such as ethylene glycol, propylene glycol, butanediol, hexylene glycol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol, and triethylene glycol. Group diol, cycloaliphatic-1,4-dimethanol and other alicyclic diols, and mixtures thereof. If the amount is small, one or more kinds of long-chain diols having a molecular weight of 400 to 6,000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, and the like may be copolymerized.
In addition, aromatic diols such as hydroquinone, resorcin, naphthalenediol, 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 are introduced to introduce a branched structure, and fatty acids are used for molecular weight adjustment. A small amount of a monofunctional compound can be used in combination.

  As the polybutylene terephthalate (A), usually, a polycondensation product of a dicarboxylic acid and a diol, that is, 50% by mass of the entire resin, preferably 70% by mass or more of this polycondensate is used. The dicarboxylic acid is preferably an aromatic carboxylic acid, and the diol is preferably an aliphatic diol.

Of these, polyalkylene terephthalate, in which 95 mol% or more of the acidic component is terephthalic acid and 95 mass% or more of the alcohol component is an aliphatic diol, is preferred. Typical examples are polybutylene terephthalate and polyethylene terephthalate. These are preferably close to homopolyester, that is, 95% by mass or more of the total resin is composed of a terephthalic acid component and a 1,4-butanediol or ethylene glycol component.
In the present invention, the main component of the polybutylene terephthalate resin composition is preferably polybutylene terephthalate, but polyalkylene glycol such as isophthalic acid, dimer acid, polytetramethylene glycol (PTMG), etc. Those that are polymerized are also preferred. These copolymers are those having a copolymerization amount of 1 mol% or more and less than 50 mol% in all segments of polybutylene terephthalate. Among them, the copolymerization amount is preferably 2 to 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 30 mol%.

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

[Elastomer (B)]
As the elastomer (B) used in the present invention, a thermoplastic elastomer used for improving impact resistance by blending with a polyester resin or a polycarbonate resin may be used. For example, a rubber polymer or rubber heavy polymer is used. A compound obtained by copolymerizing a compound that reacts with the compound is used. The glass transition temperature of the elastomer (B) is preferably 0 ° C. or lower, particularly preferably −20 ° C. or lower.

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

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

The elastomer (B) is preferably an elastomer containing an acrylic and / or butadiene component, and is preferably a copolymer obtained by copolymerizing a butadiene-based or acrylic rubbery polymer with a monomer compound that reacts therewith. Further, it may be a composite rubber with silicone.
Specific examples of the elastomer containing an acrylic and / or butadiene component include, for example, acrylonitrile-butadiene copolymer, acrylic-butadiene rubber, acrylic-silicone rubber, and a copolymer obtained by polymerizing a monomer compound with these rubbery polymers. A polymer is mentioned. Examples of the monomer compound include aromatic vinyl compounds, vinyl cyanide compounds, (meth) acrylic acid ester compounds, (meth) acrylic acid compounds, and the like. In addition, epoxy group-containing (meth) acrylic acid ester compounds such as glycidyl (meth) acrylate; maleimide compounds such as maleimide, N-methylmaleimide and N-phenylmaleimide; α, β- such as maleic acid, phthalic acid and itaconic acid Examples thereof also include unsaturated carboxylic acid compounds and anhydrides thereof (for example, maleic anhydride). These monomers can be used alone or in combination of two or more.

  The elastomer containing the acrylic and / or butadiene component is preferably of the core / shell type graft copolymer type from the viewpoint of improving impact resistance, and the butadiene component-containing rubber and / or the acrylic component-containing rubber polymer is used as the core. A core / shell type graft copolymer comprising a shell layer formed by copolymerizing a monomer selected from an acrylic ester, a methacrylic ester and an aromatic vinyl compound around the layer is particularly preferred.

  Examples of the core / shell type graft copolymer include butyl acrylate-methyl methacrylate copolymer, butadiene-methyl methacrylate / styrene copolymer, silicone / acryl-methyl methacrylate copolymer, methyl methacrylate-butadiene-styrene polymer. (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene polymer (MABS), methyl methacrylate-butadiene polymer (MB), methyl methacrylate-acryl-butadiene rubber copolymer, methyl methacrylate-acryl-butadiene rubber-styrene copolymer Examples include coalescence. These core / shell type graft copolymers may be used alone or in combination of two or more. Among these, acrylic core / shell type elastomers in which both the core and the shell are acrylic acid esters are preferable from the viewpoint of jet blackness, impact resistance, heat aging resistance, and light resistance.

  The content of the acrylic and / or butadiene component in the elastomer containing the acrylic and / or butadiene component is preferably 50 to 95% by mass, more preferably 60 to 90% by mass, and even more preferably 70 to 85% by mass. . If the content of the acrylic and / or butadiene component is less than 50% by mass, the impact resistance tends to be inferior, and if it exceeds 95% by mass, the flame retardancy and weather resistance tend to deteriorate, such being undesirable.

The average primary particle diameter of the elastomer (B) used as a raw material is usually 2 μm or less, preferably 1 μm or less, more preferably 700 nm or less, further preferably 500 nm or less, and particularly preferably 350 nm or less. Moreover, a minimum is 20 nm normally, Preferably it is 50 nm, More preferably, it is 80 nm, More preferably, it is 100 nm.
The average secondary particle size of the elastomer (B) used as a raw material is preferably 400 μm or less, more preferably 350 μm or less, and even more preferably 300 μm or less. The lower limit is usually 10 μm, preferably 30 μm, more preferably 50 μm.
The average primary particle diameter of the elastomer (B) used as a raw material is a value obtained by measuring 200 or more maximum diameters R of the elastomer dispersed phase and arithmetically averaging them with respect to the morphology observation result of the resin composition. Say. The average secondary particle diameter of the raw material elastomer (B) refers to the particle diameter of the peak top of the maximum peak in the volume frequency distribution of the particle diameter obtained by the laser diffraction / scattering method for the elastomer (B) powder used as the raw material. Say.

  In the present invention, the half-width of the maximum peak in the secondary particle diameter volume frequency distribution of the elastomer (B) used as a raw material is preferably 700 μm or less, more preferably 600 μm or less, and 500 μm or less. More preferably, it is more preferably 300 μm or less. Further, the lower limit of the full width at half maximum is usually 20 μm, preferably 40 μm, more preferably 80 μm, and further preferably 100 μm.

  Further, in the elastomer (B) used as a raw material, the ratio of secondary particles having a particle diameter of 800 μm or more is preferably 5% by mass or less, more preferably 3% by mass or less, and 1% by mass or less. Is more preferable. The ratio of secondary particles having a particle diameter of 700 μm or more is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 3% by mass or less.

  The apparent density of the elastomer (B) used as a raw material is preferably 0.3 g / ml or more, more preferably 0.35 g / ml or more, and further preferably 0.4 g / ml or more.

  By adopting an elastomer having the above particle diameter and apparent density, jet blackness tends to be good, which is preferable.

  Content of an elastomer (B) is 2-22 mass parts with respect to 100 mass parts of polybutylene terephthalate (A). When the content of the elastomer (B) is less than 2 parts by mass, the effect of improving the impact resistance is small, and when it exceeds 22 parts by mass, the heat resistance and rigidity are lowered. The content of the preferred elastomer (B) is 5 parts by mass or more, 15 parts by mass or less, and further 12 parts by mass or less.

In the present invention, the elastomer (B) constitutes a morphological structure existing in a dispersed state in the polybutylene terephthalate (A) phase in the surface layer portion of the molded body. When the polybutylene terephthalate (A) further contains a polycarbonate resin (D), the elastomer (B) is preferably present in the polycarbonate resin (D) phase.
In the dispersed elastomer (B), when the maximum diameter of the dispersed phase is R and the maximum diameter in the direction perpendicular to the maximum diameter is r, R / r is an average of 8 or less, preferably 7. It is 5 or less, more preferably 7 or less, preferably 1.1 or more, more preferably 1.5 or more, and further preferably 2 or more.
When the elastomer (B) is monodispersed, R / r is calculated as described above. However, when the elastomer (B) is in a daisy chain due to aggregation, one aggregate is converted into one elastomer. Considering it as a dispersed phase, R and r of one aggregate are obtained, and the R / r ratio is calculated.
When the elastomer (B) is aggregated, the number of elastomers in one aggregate is preferably 10 or less, more preferably 7 or less, still more preferably 4 or less, and particularly preferably 2. By taking such a morphology, the balance between impact resistance and jetness tends to be more excellent.
Details of a specific method for observing the morphology of the molded body and how to obtain the R / r ratio will be described later.

In the present invention, the elastomer is preferably monodispersed. However, when the elastomer aggregate is present, the area ratio of the elastomer aggregate in the morphology observation result is 40% or less of the total area of the elastomer. Preferably, it is 30% or less, more preferably 20%, and particularly preferably 10% or less.
In the present invention, the surface layer portion of the molded product refers to a region from the surface of the molded product to the inside of 20 μm, and the morphology observation is performed by the method described in Examples and Examples below.

[Carbon black (C)]
The carbon black (C) in the present invention is not limited in its production method, raw material type and the like, and any conventionally known one can be used. Specific examples include oil furnace black, channel black, acetylene black, and ketjen black. Among these, oil furnace black is preferable from the viewpoint of colorability and cost.

  The average particle diameter of the carbon black (C) may be selected and determined as appropriate, but is preferably 5 to 60 nm, more preferably 7 to 55 nm, and particularly preferably 10 to 50 nm. By setting the average particle diameter in the above range, aggregation of carbon black is suppressed, jet blackness is improved, and the appearance tends to be improved. The average particle size of carbon black is obtained by obtaining an enlarged aggregate image according to the procedure described in ASTM D3849 standard (standard test method of carbon black-morphological characterization by electron microscopy). The particle diameter of 3,000 particles can be measured and calculated by arithmetic averaging.

Nitrogen adsorption specific surface area of the carbon black (C) used in the present invention is preferably usually less than 1000 m ² / g, is preferably Among them 50 to 400 m ² / g. It is preferable that the nitrogen adsorption specific surface area be less than 1000 m ² / g because the fluidity of the polybutylene terephthalate resin composition and the appearance of the molded body tend to be improved. The nitrogen adsorption specific surface area is JIS
It can be measured according to K6217 (unit: m ² / g).

Further, DBP absorption amount of the carbon black (C) ^is preferably less than 300 cm 3/100 g, is preferably Among them 30~200cm ³ / 100g. The DBP absorption amount by less than 300 cm ^3/100 g, there is a tendency that appearance of fluidity and molding of polybutylene terephthalate resin composition is improved preferably.
Incidentally, DBP absorption amount can be measured according to JIS K6217 (unit ^cm 3 / 100g).
Carbon black (C) is not particularly limited with respect to its pH, but it is usually 2 to 10, preferably 3 to 9, and more preferably 4 to 8.

  The content of carbon black (C) is 0.01 parts by mass or more, preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more with respect to 100 parts by mass of polybutylene terephthalate (A). Yes, preferably 4 parts by mass or less, more preferably 3.5 parts by mass or less, and still more preferably 1 part by mass or less. If the carbon black content is too large, the surface properties and molding shrinkage of the molded product may be deteriorated, and mold contamination may occur in the production process.

  Carbon black (C) can be used alone or in combination of two or more. Furthermore, carbon black can be granulated using a binder, and can also be used in a master batch that is melt-kneaded at a high concentration in a resin. By using a melt-kneaded master batch, the handling property at the time of extrusion and the dispersibility in the resin composition tend to be good. Examples of the resin include polybutylene terephthalate, polystyrene-based resin, polycarbonate-based resin, and acrylic resin. In particular, polybutylene terephthalate and acrylonitrile-styrene-based resin are preferably used.

  The content of carbon black (C) in the master batch is preferably 5 to 80% by mass, more preferably 10 to 70% by mass, further preferably 15 to 60% by mass, and particularly preferably 18 to 40% by mass. . If the carbon black content in the masterbatch exceeds 80% by mass, poor dispersion of the carbon black may occur, which is not preferable. The amount of carbon black masterbatch used may be appropriately selected and determined. Usually, it is 0.5 to 10 parts by mass with respect to 100 parts by mass of polybutylene terephthalate (A), and in particular 1 to 8 parts by mass. In particular, the amount is preferably 1.5 to 5 parts by mass.

[Polycarbonate resin (D)]
The polybutylene terephthalate (A) used in the present invention preferably contains a polycarbonate resin (D).
The polycarbonate resin is an optionally branched thermoplastic polymer or copolymer obtained by reacting a dihydroxy compound or a small amount thereof with phosgene or a carbonic acid diester. The production method of the polycarbonate resin is not particularly limited, and a polycarbonate resin produced by a conventionally known phosgene method (interfacial polymerization method) or a melting method (transesterification method) can be used.

  As the raw material dihydroxy compound, an aromatic dihydroxy compound is preferable, 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A), tetramethylbisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, Hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, etc. are mentioned, Preferably bisphenol A is mentioned. In addition, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can also be used.

  As the polycarbonate resin, among the above-mentioned, aromatic polycarbonate resin derived from 2,2-bis (4-hydroxyphenyl) propane, or 2,2-bis (4-hydroxyphenyl) propane and other aromatic dihydroxy Aromatic polycarbonate copolymers derived from the compounds are preferred. Further, it may be a copolymer mainly composed of an aromatic polycarbonate resin, such as a copolymer with a polymer or oligomer having a siloxane structure. Furthermore, you may mix and use 2 or more types of the polycarbonate resin mentioned above.

  In order 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 And alkyl-substituted phenols.

  The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 20000 or more, more preferably 23000 or more and 25000 or more. If the viscosity average molecular weight is lower than 20000, the resulting resin composition tends to have a low mechanical strength. Moreover, it is preferable that it is 60000 or less, It is more preferable that it is 40000 or less, It is further more preferable that it is 35000 or less. If it is higher than 60000, 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 determined by measuring the viscosity of the methylene chloride solution of the polycarbonate resin at 20 ° C. using an Ubbelohde viscometer, and determining the intrinsic viscosity ([η]). The value calculated from the following Schnell viscosity equation 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 the phosgene method (interfacial polymerization method) and the melting method (transesterification method) can also be used. Moreover, the polycarbonate resin which performed the post-process which adjusts the amount of terminal OH groups to the polycarbonate resin manufactured by the melting method is also preferable.

  The content of the polycarbonate resin (D) is 50 to 85% by mass of the polybutylene terephthalate (A) and 15% of the polycarbonate resin (B) based on a total of 100% by mass of the polybutylene terephthalate (A) and the polycarbonate resin (D). The polybutylene terephthalate (A) is preferably 55 to 80% by mass, the polycarbonate resin (B) is 20 to 45% by mass, and more preferably the polybutylene terephthalate (A) is 60% by mass. -75 mass% and polycarbonate resin (B) are 25-40 mass%. If the content of the polycarbonate resin (D) is below the lower limit, the impact resistance and toughness improving effect of the polybutylene terephthalate resin composition tends to be small, and if the content exceeds the upper limit, the fluidity tends to deteriorate. is there.

[Flame Retardant (E)]
It is also preferable that the polybutylene terephthalate resin composition used in the present invention contains a flame retardant (E).
As the flame retardant (E), known flame retardants for plastics can be used. Specifically, halogen flame retardants, phosphorus flame retardants (such as melamine polyphosphate), nitrogen flame retardants (such as melamine cyanurate) ), Metal hydroxides (magnesium hydroxide, etc.).
As the halogen-based flame retardant, a brominated flame retardant is more preferable.

Bromine-based flame retardant As the brominated flame retardant, any conventionally known brominated flame retardant used in thermoplastic resins can be used. Examples of such brominated flame retardants include aromatic compounds such as brominated epoxy compounds such as tetrabromobisphenol A epoxy oligomers and polybrominated benzyls such as pentabromobenzyl polyacrylate). Brominated epoxy compounds such as (meth) acrylate, polybromophenyl ether, brominated polystyrene, epoxy oligomer of tetrabromobisphenol A, brominated imide compounds such as N, N′-ethylenebis (tetrabromophthalimide) (EBTPI), Examples thereof include brominated polycarbonate.

  Among them, from the viewpoint of good thermal stability, polybrominated benzyl (meth) acrylates such as pentabromobenzyl polyacrylate, brominated epoxy compounds such as epoxy oligomers of tetrabromobisphenol A, brominated polycarbonate, and brominated polystyrene are preferable. Is preferably a brominated polycarbonate.

  As a polybrominated benzyl (meth) acrylate, a polymer obtained by polymerizing benzyl (meth) acrylate containing a bromine atom alone, copolymerizing two or more kinds, or copolymerizing with other vinyl monomers It is preferable that the bromine atom is added to the benzene ring, and the number of addition is preferably 1 to 5, more preferably 4 to 5 per benzene ring.

  Examples of the benzyl acrylate containing a bromine atom include pentabromobenzyl acrylate, tetrabromobenzyl acrylate, tribromobenzyl acrylate, and mixtures thereof. Examples of benzyl methacrylate containing a bromine atom include methacrylates corresponding to the acrylates described above.

  Specific examples of other vinyl monomers used for copolymerization with benzyl (meth) acrylates containing bromine atoms include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and benzyl acrylate. Acrylic acid esters; Methacrylic acid esters such as methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, benzyl methacrylate; Unsaturated carboxylic acids such as styrene, acrylonitrile, fumaric acid, maleic acid or anhydrides thereof; Vinyl acetate And vinyl chloride.

  These are usually preferably used in an equimolar amount or less, particularly 0.5 times the molar amount or less with respect to the benzyl (meth) acrylate containing a bromine atom.

  In addition, as vinyl monomers, xylene diacrylate, xylene dimethacrylate, tetrabromoxylene diacrylate, tetrabromoxylene dimethacrylate, butadiene, isoprene, divinylbenzene, etc. can be used, and these usually contain bromine atoms. 0.5 mol or less of benzyl acrylate or benzyl methacrylate can be used.

  As the polybrominated benzyl (meth) acrylate, pentabromobenzyl polyacrylate is preferable from the viewpoint of high bromine content and high electrical insulation characteristics (tracking resistance).

  Specific examples of brominated epoxy compounds include bisphenol A brominated epoxy compounds represented by tetrabromobisphenol A epoxy compounds.

The molecular weight of the brominated epoxy compound is arbitrary and may be appropriately selected and determined, but is preferably 10,000 to 100,000 in terms of mass average molecular weight (Mw), and among them, the higher molecular weight is preferable, specifically Mw 15000 to 80000, particularly 18000 to 78000 (Mw), more preferably 20000 to 75000 (Mw), particularly 22000 to 70000, and those having a high molecular weight are also preferable within this range.
The epoxy equivalent of the brominated epoxy compound is preferably 4000 to 40000 g / eq, particularly 4500 to 35000 g / eq, and particularly preferably 10,000 to 30000 g / eq.
Although the bromine atom content in the brominated epoxy compound is arbitrary, it is usually 10% by mass or more, preferably 20% by mass or more, particularly preferably 30% by mass or more, in order to impart sufficient flame retardancy. The upper limit is 60% by mass, preferably 55% by mass or less.

  Moreover, a brominated epoxy oligomer can also be used together as a brominated epoxy compound. In this case, for example, by using about 1 to 50% by mass of an oligomer having an Mw of 5000 or less, flame retardancy, releasability and fluidity can be appropriately adjusted.

  The brominated polycarbonate is preferably a brominated polycarbonate obtained from brominated bisphenol A, particularly tetrabromobisphenol A. Examples of the terminal structure include a 4-t-butylphenyl group and a 2,4,6-tribromophenyl group, and those having a 2,4,6-tribromophenyl group in the terminal group structure are particularly preferable.

  The average number of carbonate repeating units in the brominated polycarbonate may be appropriately selected and determined, but is usually 2 to 30. If the average number of carbonate repeating units is small, the molecular weight of polybutylene terephthalate may be lowered during melting. On the other hand, if it is too large, the melt viscosity of the polycarbonate becomes high, causing a dispersion failure in the molded body, and the appearance of the molded body, particularly the glossiness may be lowered. Therefore, the average number of repeating units is preferably 3 to 15, particularly 3 to 10.

  The brominated polycarbonate obtained from the brominated bisphenol A can be obtained, for example, by an ordinary method in which brominated bisphenol and phosgene are reacted. Examples of the end-capping agent include aromatic monohydroxy compounds, which may be substituted with a halogen or an organic group.

The brominated polystyrene preferably includes brominated polystyrene containing a repeating unit represented by the following general formula (1).
(In formula (1), t is an integer of 1 to 5, and n is the number of repeating units.)

The brominated polystyrene may be either brominated polystyrene or produced by polymerizing a brominated styrene monomer, but the polymerized brominated styrene is free bromine (atom) This is preferable because of the small amount.
In the general formula (1), the CH group to which brominated benzene is bonded may be substituted with a methyl group. The brominated polystyrene may be a copolymer obtained by copolymerizing another vinyl monomer. Examples of the vinyl monomer in this case include styrene, α-methylstyrene, acrylonitrile, methyl acrylate, butadiene, and vinyl acetate. Moreover, brominated polystyrene may be used as a single substance or a mixture of two or more different structures, and may contain units derived from styrene monomers having different numbers of bromines in a single molecular chain.

  Specific examples of brominated polystyrene include, for example, poly (4-bromostyrene), poly (2-bromostyrene), poly (3-bromostyrene), poly (2,4-dibromostyrene), poly (2,6 -Dibromostyrene), poly (2,5-dibromostyrene), poly (3,5-dibromostyrene), poly (2,4,6-tribromostyrene), poly (2,4,5-tribromostyrene) , Poly (2,3,5-tribromostyrene), poly (4-bromo-α-methylstyrene), poly (2,4-dibromo-α-methylstyrene), poly (2,5-dibromo-α- Methyl (styrene), poly (2,4,6-tribromo-α-methylstyrene), poly (2,4,5-tribromo-α-methylstyrene) and the like, and poly (2,4,6-tribromostyrene). And poly (2,4,5-tribromostyrene) and polydibromostyrene and polytribromostyrene containing an average of 2 to 3 bromine groups in the benzene ring are particularly preferably used.

In the brominated polystyrene, the number n (average polymerization degree) of the repeating units in the general formula (1) is preferably 30 to 1,500, more preferably 150 to 1,000, particularly 300 to 800. Is preferred. If the average degree of polymerization is less than 30, blooming tends to occur. On the other hand, if it exceeds 1,500, poor dispersion tends to occur and the mechanical properties tend to deteriorate. The mass average molecular weight (Mw) of brominated polystyrene is preferably 5,000 to 500,000, more preferably 10,000 to 500,000, and 10,000 to 300,000. More preferably, it is preferably 10,000 to 70,000.
In particular, in the case of the brominated product of polystyrene described above, the mass average molecular weight (Mw) is preferably 50,000 to 70,000, and in the case of brominated polystyrene by a polymerization method, the mass average molecular weight (Mw) is 10 It is preferable that it is about 3,000-30,000. In addition, a mass average molecular weight (Mw) can be calculated | required as a value of standard polystyrene conversion by GPC measurement.

  The brominated polystyrene preferably has a bromine concentration of 52 to 75% by mass, more preferably 56 to 70% by mass, and even more preferably 57 to 70% by mass. By setting the bromine concentration in such a range, it is easy to keep good flame retardancy.

  Further, the content of free bromine in the brominated polystyrene is preferably 0.5% by mass or less, more preferably 0.45% by mass or less, and further preferably 0.4% by mass or less. preferable. When the content of free bromine exceeds 0.5% by mass, the amount of free bromine in the resin composition finally obtained increases, and is desorbed when the resin composition is at a high temperature during processing or molding. In some cases, the heat discoloration resistance, color tone, and light discoloration stability of the resin composition may be deteriorated, or metal corrosion of a mold or the like may be caused during molding. Also, removing the free bromine content up to 0% by mass requires purification so as not to be economical, so the lower limit of the content is usually 0.001% by mass and 0.005% by mass. %, And more preferably 0.01% by mass.

  The content of chlorine in the brominated polystyrene is preferably 0.2% by mass or less, more preferably 0.15% by mass or less, and further preferably 0.08% by mass or less. 0.03% by mass or less is particularly preferable. If the chlorine content in the brominated polystyrene exceeds 0.2% by mass, the chlorine content in the finally obtained resin composition is excessively increased, and the tracking resistance and toughness tend to deteriorate.

  Furthermore, the sulfur content in the brominated polystyrene is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, and further preferably 0.02% by mass or less. . If the sulfur content in brominated polystyrene exceeds 0.1% by mass, the sulfur content in the final resin composition will increase too much, and the tracking resistance and mold corrosion resistance will tend to deteriorate. It is in.

  The content of free bromine, chlorine and sulfur in brominated polystyrene can be measured by a combustion ion chromatography method. Specifically, brominated polystyrene was heated under conditions of 270 ° C. and 10 minutes in an argon atmosphere using an automatic sample combustion apparatus of “AQF-100 type” manufactured by Mitsubishi Chemical Analytech Co., and bromine, chlorine and sulfur generated The amount of can be determined by quantifying using “ICS-90” manufactured by Nippon Dionex.

  The preferable content when including the flame retardant (E) is 7 to 35 parts by mass, more preferably 9 parts by mass with respect to a total of 100 parts by mass of the polybutylene terephthalate resin (A) and the polycarbonate resin (D). More preferably, it is 10 parts by mass or more, more preferably 15 parts by mass or more, preferably 34 parts by mass or less, more preferably 32 parts by mass or less, and further preferably 28 parts by mass or less. It is. If the content of the flame retardant (E) is too small, the flame retardancy of the resin composition used in the present invention becomes insufficient. On the other hand, if the content is too large, problems such as deterioration of mechanical properties and bleeding out of the flame retardant occur.

[Antimony compound (F)]
The polybutylene terephthalate resin composition used in the present invention preferably contains an antimony compound (F) which is a flame retardant aid.
Examples of the antimony compound (F) include antimony trioxide (Sb ₂ O ₃ ) and antimony pentoxide (Sb ₂ O ₅ ). In terms of flame retardancy, it is preferable to use antimony trioxide. When a polycarbonate resin is blended, antimony pentoxide is preferable from the viewpoint of inhibiting transesterification.

  In the present invention, it is preferable to use a double salt of antimony pentoxide and another metal oxide as antimony pentoxide. Specifically, the double salt of antimony pentoxide and another metal oxide is preferably, for example, a double salt represented by the following general formulas (2) to (4). These may be used in combination at any ratio.

n (X ₂ O) · Sb ₂ O ₅ · m (H ₂ O) (2)
n (YO) · Sb ₂ O ₅ · m (H ₂ O) (3)
n (Na ₂ O) · Sb ₂ O ₅ (4)
(In these formulas, X represents a monovalent alkali metal element, Y represents a divalent alkaline earth metal element, n represents 0 to 1.5, and m represents 0 to 4. m and n represent formula (2). And in Formula (3), each is determined independently)

In the above formulas (2) to (4), X includes lithium, sodium, potassium, cesium and the like, and Y includes calcium, magnesium, barium and the like. n is larger than 0, usually 0.3 or more, particularly preferably 0.65 to 1.5. If n is too small, the desorption rate of adsorbed water is small, so that the melt viscosity tends to change. Conversely, if n is too large, the amount of antimony will be relatively lowered, and as a flame retardant aid. The effect is reduced.
m is 0-4, preferably 0-2. If m is too large, hydrolysis of the polybutylene terephthalate resin becomes remarkable, which is not preferable.

  The preferable content of the antimony compound (F) is 1 to 15 parts by mass, more preferably 1.2 parts by mass or more, with respect to 100 parts by mass in total of the polybutylene terephthalate (A) and the polycarbonate resin (D). More preferably, it is 1.5 mass parts or more, More preferably, it is 13 mass parts or less, More preferably, it is 10 mass parts or less.

[Morphology of molded resin composition]
As described above, in the polybutylene terephthalate-based resin composition molded body of the present invention, the phase of the elastomer (B) is dispersed in the surface layer portion of the molded body, and the maximum diameter of the dispersed phase is R and the maximum diameter. When the maximum diameter of the diameters in the vertical direction is r, the ratio R / r between them is an average of 8 or less. Here, the surface layer portion refers to a region from the surface of the molded body to the inside of 20 μm.
As described above, the R / r ratio of the dispersed elastomer (B) is preferably 7.5 or less, more preferably 7 or less, preferably 1.1 or more, more preferably 1.5 or more. is there.
As described above, when the elastomer is monodispersed, R / r is calculated as described above. However, when the elastomer is in a daisy chain shape due to aggregation, one aggregate is regarded as one elastomer. Considering R and r of one aggregate, the R / r ratio is calculated. In the present invention, when the elastomer is aggregated, the number of elastomers in one aggregate is preferably 10 or less, more preferably 7 or less, still more preferably 4 or less, and particularly preferably 2. By taking such a morphology, the balance between impact resistance and jetness tends to be more excellent.

  Further, the elastomer is preferably monodispersed, but when the elastomer aggregate is present, the area ratio of the elastomer aggregate in the morphology observation result is preferably 40% or less of the total area of the elastomer, and 30 % Or less is more preferable, 20% is more preferable, and 10% or less is particularly preferable.

The morphology of the molded body of the polybutylene terephthalate resin composition of the present invention can be measured by observing the cross section of the molded body with an optical microscope, SEM (scanning electron microscope), TEM (transmission electron microscope), etc. Is observed with a scanning electron microscope (SEM). The cross section in the direction parallel to the resin flow direction is observed in the region from the surface of the center of the molded body (not near the gate) to the inside of 20 μm.
Specifically, using a SEM, the surface layer portion of the cross section of the molded body is observed with a STEM image having a magnification of 3,000 to 30,000 under an acceleration voltage of 25 kV.

Such morphology of the surface layer portion of the molded body can be confirmed by observing FIGS. 2 and 3, for example. 2 and 3 are photographs of STEM images of the surface layer portion of the molded body obtained in Example 4 of the present invention (magnification 10,000 times and 30,000 times).
2 and 3, the flow direction of the resin during molding is from left to right in FIGS. 2 and 3, and it is polybutylene terephthalate (A) that constitutes the continuous phase (matrix phase). A phase stretched into a dark layer existing therein is a polycarbonate resin (D) phase. Further, the darkest part is considered to be an antimony compound. And since white island-shaped thing is a dispersed phase of an elastomer (B), and many exist in a dark polycarbonate resin (D) phase, an elastomer (B) is in a polycarbonate resin (D) phase. It can be seen that the particle size is finely dispersed at 100 to 300 nm, and the ratio of aggregates in which the elastomers (B) are linked in a bead shape is small. In other examples, a similar morphology was observed for the dispersion of elastomer (B).
Thus, the molded product of the present invention has a unique morphology.

  On the other hand, when the surface layer part of the molded body obtained in Comparative Examples 1, 2, and 4 of the present invention was observed by STEM under the same conditions as described above, the elastomer (B) was not finely dispersed as in the examples. Many of the elastomers connected in a bead shape were observed.

  When the morphological structure as in the comparative example is obtained, it is considered that the blackness of the molded body is lowered and the white color is likely to appear white. As in the example, the elastomer (B) phase is finely dispersed, and the ratio (R / r) of the maximum diameter R to the maximum diameter r of the diameters perpendicular to the maximum diameter is 8 or less. In some cases, it is considered that high jetness can be exhibited.

  The R / r ratio is regarded as an average value, and is calculated from a value obtained by measuring 200 or more maximum diameters R of the elastomer (B) dispersed phase and a maximum diameter r of the diameters perpendicular to the maximum diameter. They are obtained by arithmetically averaging them. When the elastomer is in a daisy chain, one aggregate is regarded as one elastomer, R and r of one aggregate are obtained, and the R / r ratio is similarly calculated.

The molded product of the present invention can achieve a level of L ^{* that} cannot be achieved when an elastomer is used in combination with carbon black, and the preferred L ^* value is 40 or less, more preferably 38 or less, and even more preferably 37 or less. Is possible.

[Preferable control method of molded body morphology]
By having such a morphological structure, the molded article of the present invention becomes a molded article excellent in jet blackness and impact resistance.
The polybutylene terephthalate resin composition used for the production of the resin composition molded body of the present invention is preferably produced by a melt kneading method using a melt kneader such as an extruder, but the polybutylene terephthalate resin composition It is difficult to stably form the morphological structure defined in the present invention by simply mixing and kneading each component of the raw materials, and it is recommended to knead by a special method. Below, the preferable manufacturing method for forming the morphological structure prescribed | regulated by this invention stably is demonstrated.

Polybutylene terephthalate (A), elastomer (B), and carbon black (C) are mixed at a predetermined ratio, then supplied to a single-screw or twin-screw extruder provided with a die nozzle, melt-kneaded, and resin from the die nozzle After extruding the composition into a strand, it is cut to produce pellets.
At this time, it is preferable to use a twin screw extruder as the melt kneader. Especially, it is preferable that L / D which is the ratio of the screw length L (mm) to the screw diameter D (mm) satisfies the relationship of 20 <(L / D) <100, and 30 <(L / D) It is more preferable to satisfy <70. When the ratio is 20 or less, the elastomer (B) is difficult to finely disperse. On the other hand, even if it exceeds 100, thermal degradation of the elastomer (B) tends to be remarkable, and it is difficult to finely disperse.
The shape of the die nozzle is not particularly limited, but a circular nozzle having a diameter of 1 to 10 mm is preferable, and a circular nozzle having a diameter of 2 to 7 mm is more preferable in terms of pellet shape.

  Moreover, it is preferable that it is 200-300 degreeC, and, as for the melting temperature of the resin composition at the time of melt-kneading, it is more preferable that it is 210-295 degreeC. When the melting temperature is less than 200 ° C., melting is insufficient and unmelted gel is likely to occur frequently. On the other hand, when it exceeds 300 ° C., the resin composition is thermally deteriorated and easily colored.

  The screw rotation speed during melt kneading is preferably 100 to 1,000 rpm, and more preferably 50 to 800 rpm. If the screw rotation speed is less than 100 rpm, the elastomer (B) tends to hardly disperse, and conversely if it exceeds 1,000 rpm, the elastomer (B) tends to aggregate and not disperse finely. The discharge rate is preferably 5 to 1,000 kg / hr, and more preferably 10 to 900 kg / hr. When the discharge amount is less than 5 kg / hr, the dispersibility of the elastomer (B) tends to be lowered, and when it exceeds 1,000 kg / hr, the dispersibility of the elastomer (B) tends to be lowered.

Shear rate of the resin composition in the die nozzle is preferably 10～10,000Sec ^-1, more preferably 50～5,000Sec ^-1, more preferably from 70～1,000Sec ^-1 . By setting the shear rate within the above range, the morphology defined in the present invention tends to be stably formed, which is preferable. Such shear rate is generally determined from the discharge amount of the resin composition and the shape of the cross section of the die nozzle. For example, when the cross section of the die nozzle is circular, it can be calculated by γ = 4Q / πr ^3. it can. Here, γ represents the shear rate (sec ⁻¹ ), Q represents the discharge amount (cc / sec) of the resin composition per die nozzle, and r represents the radius (cm) of the die nozzle cross section.

  The resin composition extruded from the die nozzle in a strand shape is cut into a pellet shape by a pelletizer or the like. In the present invention, the surface temperature of the strand at the time of cutting is 60 to 150 ° C., particularly 70 to 150 ° C. It is preferable to cool the strands. Usually, it is cooled by a method such as air cooling or water cooling, but water cooling is preferable in terms of cooling efficiency. In such water cooling, the strand may be cooled in a water tank containing water, and a desired strand surface temperature can be obtained by adjusting the water temperature and the cooling time. The shape of the pellets thus produced is preferably 1 to 8 mm in diameter, more preferably 2 to 6 mm, more preferably 3 to 5 mm, and more preferably 1 to 10 mm in length in the case of a columnar shape. Is 2 to 6 mm, more preferably 3 to 5 mm.

In the present invention, the relationship between the shear rate γ (sec ⁻¹ ) in the die nozzle and the surface temperature T (° C.) of the strand at the time of strand cutting is as follows:
1 × 10 ³ <(γ · T) <9.9 × 10 ⁵
If the relationship is satisfied, the morphological structure defined in the present invention tends to be formed stably. In addition, it is easy to suppress rough skin phenomenon and toughness deterioration due to poor dispersion of each component of the resin composition, and it is easy to keep good mechanical properties, flame retardancy, insulation properties, etc. . The lower limit of (γ · T) is more preferably 1 × 10 ⁴ , and the upper limit is more preferably 8.5 × 10 ⁵ .
In order to adjust the value of (γ · T) within the above range, the shear rate and the surface temperature of the strand may be adjusted.

  In the present invention, a polybutylene terephthalate-based resin composition having a morphological structure defined in the present invention can be produced by applying the above preferable conditions alone or in combination of a plurality thereof. It is effective to employ production conditions such that the speed or the value of (γ · T) satisfies the above formula.

  By adopting such a method for producing a polybutylene terephthalate resin composition, a polyester composition molded article having a morphological structure defined in the present invention can be produced stably. However, the production of the polybutylene terephthalate resin composition of the present invention is not limited to such a method, and other methods may be used as long as the morphology structure defined by the present invention is obtained.

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

  Examples of the phosphorus-based stabilizer include phosphorous acid, phosphoric acid, phosphite ester, and phosphate ester. Among them, organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds are preferable.

The organic phosphate compound is preferably the following general formula:
(R ¹ O) _3-n P (═O) OH _n
(Wherein, 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).
More preferably, R ¹ is a long-chain alkyl acid phosphate compound having 8 to 30 carbon atoms. Specific examples of the alkyl group having 8 to 30 carbon atoms include octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, A hexadecyl group, an octadecyl group, an eicosyl group, a triacontyl group, etc. are mentioned.

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

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

  Examples of the organic phosphite compound include triphenyl phosphite, tris (nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris (2-ethylhexyl) phosphite, and tris (tridecyl). ) Phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite Hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4′-butylidene-bis (3-methyl-6-t rt-butylphenyldi (tridecyl) phosphite), tetra (tridecyl) 4,4′-isopropylidenediphenyldiphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, di Lauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris (4-tert-butylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite Phytopolymer, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite Phosphite, 2,2'-methylenebis (4,6-di -tert- butylphenyl) octyl phosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite and the like.

The organic phosphonite compound is preferably 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 at least one of R ⁵ , R ⁶ and R ⁷ ) One is an aryl group having 6 to 30 carbon atoms.).

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

One type of phosphorous stabilizer may be contained, or two or more types may be contained in any combination and ratio.
As described above, octadecyl acid phosphate is particularly preferable as the phosphorus-based stabilizer, which exhibits excellent compatibility and exhibits a remarkable transesterification inhibitory effect.

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

  The content of the stabilizer is preferably 0.001 to 1 part by mass with respect to 100 parts by mass in total of the polybutylene terephthalate (A) and the polycarbonate resin (D). When the content of the stabilizer is less than 0.001 part by mass, it is difficult to expect an improvement in the thermal stability and compatibility of the resin composition, and a decrease in molecular weight and a deterioration in hue during molding are likely to occur. When it exceeds, it will become excess amount and there exists a tendency for generation | occurrence | production of silver and a hue deterioration to occur further easily. The content of the stabilizer is more preferably 0.001 to 0.7 parts by mass, and still more preferably 0.005 to 0.5 parts by mass.

[Inorganic filler]
The polybutylene terephthalate resin composition can contain an inorganic filler to improve its mechanical properties. Any conventional inorganic filler can be used. Specific examples include fibrous inorganic fillers such as glass fibers, carbon fibers, and mineral fibers. Among these, glass fibers are preferably used. In this invention, it is preferable that an inorganic filler is 100 mass parts or less with respect to a total of 100 mass parts of a polybutylene terephthalate (A) and a polycarbonate resin (D), especially 20-80 mass parts.

[Anti-drip agent]
It is also preferable that the polybutylene terephthalate resin composition contains an anti-dripping agent. As the anti-drip agent, polytetrafluoroethylene (PTFE) is preferable, has a fibril-forming ability, easily disperses in the resin composition, and shows a tendency to form a fibrous material by bonding the resins together. is there. Specific examples of polytetrafluoroethylene include, for example, trade names “Teflon (registered trademark) 6J” or “Teflon (registered trademark) 30J” commercially available from Mitsui DuPont Fluorochemical Co., Ltd., Daikin Industries, Ltd. Examples include the commercially available product name “Polyflon” or the product name “Fullon” marketed by Asahi Glass Co., Ltd.
The content ratio of the dripping inhibitor is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass in total of the polybutylene terephthalate (A) and the polycarbonate resin (D). If the anti-dripping agent is less than 0.1 parts by mass, the flame retardancy tends to be insufficient, and if it exceeds 20 parts by mass, the appearance tends to deteriorate. The content ratio of the anti-dripping agent is more preferably 0.1 to 10 parts by mass, preferably 0.2 to 5 parts per 100 parts by mass in total of the polybutylene terephthalate (A) and the polycarbonate resin (D). Part by mass.

[Release agent]
The polybutylene terephthalate resin composition preferably further contains a release agent. As the mold release agent, known mold release agents usually used for polyester resins can be used. Among them, polyolefin compounds, fatty acid ester compounds, and silicone systems are particularly difficult in that they do not hinder metal film adhesion. One or more mold release agents selected from compounds are preferred.

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

  Examples of the fatty acid ester compounds include fatty acid esters such as glycerin fatty acid esters and sorbitan fatty acid esters, and partially saponified products thereof. Preferred are mono- or di-fatty acid esters. Specifically, glycerol monostearate, glycerol monobehenate, glycerol dibehenate, glycerol-12-hydroxy monostearate, sorbitan monobehenate, etc. are mentioned.

  Moreover, as a silicone type compound, the compound modified | denatured from points, such as compatibility with a polyester resin, is preferable. Examples of the modified silicone oil include silicone oil in which an organic group is introduced into the side chain of polysiloxane, silicone oil in which an organic group is introduced into both ends and / or one end of polysiloxane, and the like. Examples of the organic group to be introduced include an epoxy group, an amino group, a carboxyl group, a carbinol group, a methacryl group, a mercapto group, and a phenol group, and preferably an epoxy group. As the modified silicone oil, a silicone oil in which an epoxy group is introduced into the side chain of polysiloxane is particularly preferable.

  It is preferable that content of a mold release agent is 0.05-2 mass parts with respect to a total of 100 mass parts of polybutylene terephthalate (A) and polycarbonate resin (D). If the amount is less than 0.05 parts by mass, the surface property tends to be lowered due to defective mold release at the time of melt molding. Cloudiness may be seen on the body surface. The content of the release agent is preferably 0.07 to 1.5 parts by mass, more preferably 0.1 to 1.0 parts by mass.

[Other ingredients]
The polybutylene terephthalate resin composition may further contain various additives as long as the effects of the present invention are not impaired. Such additives include UV absorbers, dyes and pigments other than carbon black, fluorescent brighteners, antistatic agents, antifogging agents, lubricants, antiblocking agents, fluidity improvers, plasticizers, dispersants, antibacterial agents Agents and the like.

  Further, the polybutylene terephthalate resin composition may contain a thermoplastic resin other than the polybutylene terephthalate (A) and the polycarbonate resin (D) as long as the effects of the present invention are not impaired. Specific examples of the other thermoplastic resins include polyethylene terephthalate, polyacetal resin, polyamide resin, polyphenylene oxide resin, polystyrene resin, polyphenylene sulfide ethylene resin, polysulfone resin, polyethersulfone resin, and polyetherimide resin. , Polyether ketone resin, polyolefin resin and the like.

[Molded body]
The polybutylene terephthalate-based resin composition molded body of the present invention is not limited in its shape, pattern, color, size, etc., and may be arbitrarily set according to the use of the molded body.
The molding method itself of the molded body is not particularly limited, and a molding method generally employed for the polybutylene terephthalate resin composition can be arbitrarily adopted. For example, injection molding method, ultra-high speed injection molding method, injection compression molding method, two-color molding method, hollow molding method such as gas assist, molding method using heat insulating mold, rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermoforming method, rotational molding method, laminate molding method, press molding method, Examples thereof include blow molding methods, and in particular, injection molding methods such as injection molding methods, ultra-high speed injection molding methods, and injection compression molding methods are preferably applied.

  In injection molding, in order to obtain a molded article having a morphological structure defined in the present invention, for example, selection of molding machine conditions such as screw configuration of an injection molding machine, processing of an inner wall of a screw or cylinder, nozzle diameter, mold structure, etc. Various methods such as plasticization, measurement, adjustment of molding conditions during injection, addition of other components to the molding material, and the like can be mentioned. In particular, it is preferable to adjust, for example, cylinder temperature, back pressure, screw rotation speed, injection speed, and the like as conditions during plasticization, measurement, and injection. For example, when adjusting the cylinder temperature, it is preferably set to 230 to 280 ° C, more preferably 240 to 270 ° C. When adjusting the back pressure, it is preferably set to 2 to 15 MPa, more preferably 4 to 10 MPa. When adjusting a screw rotation speed, Preferably it sets to 20-300 rpm, More preferably, it sets to 20-250 rpm. When adjusting the injection speed, it is preferably set to 10 to 500 mm / sec, more preferably 20 to 400 m / sec.

  As described above, the molded article of the present invention is excellent in jet blackness and impact resistance, and can be widely used in applications that require a high-class feeling and impact resistance. It is particularly suitable for automobile interior and exterior parts.

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

(Examples 1 to 10)
Engagement type co-directional twin-screw extruder (“TEX30α” manufactured by Nippon Steel Works Co., Ltd.), screw so that each component and dye / pigment described in Table 1 have the mixing ratio (parts by mass) described in Table 2 The diameter was 32 mm) and L / D = 54.2) at 25 kg / hr. Extruder barrel set temperature is C1 to C15, die is 250 ° C., screw rotational speed is 200 rpm, nozzle number is 4 holes (circular (φ4 mm), length is 1.5 cm), shear rate (γ) is 211 sec ⁻¹ Extruded as a strand below. The strand temperature immediately after extrusion was 270 ° C.
The extruded strand was introduced into a water bath whose temperature was adjusted to 30 to 50 ° C. and cooled. The strand surface temperature (T) is cooled to 65 ° C. at a temperature measured with an infrared thermometer (γ · T = 1.4 × 10 ⁴ ), inserted into a pelletizer and cut, and pellets of the resin composition are obtained. Manufactured.
The obtained pellets were dried by heating at 120 ° C. for 7 hours, and using an injection molding machine (“NEX80-9E” manufactured by Nissei Plastic Industry Co., Ltd.), cylinder temperature 250 ° C., mold temperature 80 ° C., injection pressure 150 MPa, injection holding. 60mm x 60mm x 3mm thickness flat plate for morphological observation, jet blackness and hue (L ^* value) evaluation under conditions of pressure time 15sec, cooling time 15sec, injection speed 120mm / sec, back pressure 4MPa, screw rotation speed 80rpm And other test specimens for evaluation were injection molded.

(Comparative Examples 1-7)
Engagement type same-direction twin screw extruder (“TEX44αII” manufactured by Nippon Steel Works, Ltd.), screw so that each component and dye / pigment described in Table 1 have the mixing ratio (parts by mass) described in Table 3 A diameter of 47 mm, L / D = 55.2) was supplied at 300 kg / hr. The barrel set temperature of the extruder is C1 to C15, the die is 250 ° C., the screw speed is 230 rpm, the number of nozzles is 10 holes (circular (φ4 mm), length 1.5 cm), and the shear rate (γ) is 1012 sec ⁻¹ . Extruded as a strand below. The strand temperature immediately after extrusion was 290 ° C.
The extruded strand was introduced into a water bath whose temperature was adjusted to 30 to 50 ° C. and cooled. The strand surface temperature (T) is cooled to 125 ° C. at a temperature measured with an infrared thermometer (γ · T = 1.3 × 10 ⁵ ), inserted into a pelletizer and cut, and pellets of the resin composition are obtained. Manufactured.
The obtained pellets were dried by heating at 120 ° C. for 7 hours, and using an injection molding machine (“NEX80-9E” manufactured by Nissei Plastic Industry Co., Ltd.), cylinder temperature 250 ° C., mold temperature 80 ° C., injection pressure 150 MPa, injection holding. 60mm x 60mm x 3mm thickness flat plate for morphological observation, jet blackness and hue (L ^* value) evaluation under conditions of pressure time 15sec, cooling time 15sec, injection speed 120mm / sec, back pressure 4MPa, screw rotation speed 80rpm And other test specimens for evaluation were injection molded.

(1) Morphological observation [preparation of ultrathin sections]
From a plane parallel to the resin flow direction at the center of the flat test piece obtained by the above method, a section including the surface layer portion (portion from the surface to a depth of 20 μm) of the cross section was cut out. Using this slice, an ultrathin slice having the parallel surface as a surface was prepared with an ultramicrotome (Leica “UC7”) equipped with a sample cooling device (cryo unit) using a diamond knife. The set cutting conditions are a sample chamber temperature of −105 ° C., a cutting speed of 0.2 mm / s, and a sample thickness of 100 nm.

[staining]
After loading the ultrathin sections on a copper grid, the surface of the sections was exposed to ruthenium tetroxide vapor at 15 ° C. for 40 minutes and stained with ruthenium tetroxide. By this dyeing, the polybutylene terephthalate resin is observed in STEM as a gray matrix, the polycarbonate resin is dark, and the elastomer is white.

[STEM conditions]
The stained ultrathin section is a surface layer portion having a cross section parallel to the resin flow direction under the conditions of a high-resolution field emission scanning electron microscope “S-4800” manufactured by Hitachi High-Tech, Inc., an acceleration voltage of 25 kV, a signal STEM, and an emission current of 10 μA. (A portion from the surface to a depth of 20 μm) was observed with a STEM image having a magnification of 3,000 to 30,000. The values of R and r of the elastomer (B) were calculated by measuring 200 particle diameters of each elastomer or an aggregate in which they were connected in a bead shape, and calculating the arithmetic average.

  The dispersion state of the elastomer in the surface layer portion of the molded body of Examples 1 to 10 having an R / r value of 8 or less is the same as that shown in FIGS. 2 and 3, respectively. As described above, polybutylene terephthalate. It was confirmed that the elastomer (B) was finely dispersed in the matrix of (A) or the polybutylene terephthalate (A) and the polycarbonate resin (D).

  On the other hand, in the surface layer part of the molded body of Comparative Examples 1, 2, and 4, it can be confirmed that there are many R / r exceeding 8 and the elastomer (B) being connected in a bead shape in the resin flow direction. It was.

Further, jet blackness, warpage, flame retardancy, releasability, and impact resistance were evaluated as follows.
(2) Jetness and hue (L ^* value)
About the flat test piece obtained above, L ^* value (SCE) was measured. For the measurement, a spectrocolorimetric color difference meter (Konica Minolta Optics, CM-3600d, compliant with ISO 7724/1) is used, D65 / 10 (reflective illumination, 10 ° direction light reception), SCE (regular reflected light removal) colorimetry. Was measured using a target mask CM-A (φ8 mm).
Moreover, the jetness of the test piece was visually determined in the following two stages.
○: Clear black color ×: Black surface where white turbidity is not conspicuous

(3) Flame retardancy (UL94)
In accordance with the method of Subject 94 (UL94) of Underwriters Laboratories, flame retardancy was tested using five test pieces (thickness: 0.75 mm). Flame retardancy was classified into V-0, V-1 and V-2 according to the evaluation method described in UL94. V-0 has the highest flame retardancy.

(4) Warpage Using the Nissei Plastic Industries injection molding machine “NEX80-9E”, the resulting pellets were retained at a cylinder temperature of 250 ° C., a mold temperature of 80 ° C. for 20 minutes in the cylinder, and then FIG. 1 is a perspective view as viewed from the outside of a rectangular parallelepiped box-shaped molded product, and the right diagram in FIG. 1 is a perspective view showing a state in which the bottom face is up. A rectangular parallelepiped box-shaped product having a width of 33 mm, a depth of 17 mm, and a thickness of 1.5 mm was formed. The gate is the two-point gate shown in the center of the bottom surface.

Fix the bottom of the box to the top, measure the length of the short side of the bottom along the line from the center of 1 mm from the short side of the bottom and the line from the center of 24 mm from the other short side. The internal warpage rate was evaluated according to the criteria.
Inner curvature ratio (%) = (length in the short side direction at a position 1 mm from the end of the box) / (length in the short side direction at a position 24 mm from the end of the box) × 100

  A case where the warpage rate was 1 to 2% was judged as “◯”. Those having an internal warpage rate of 1 to 2% are preferable because the amount of internal warpage of the molded product is small and the dimensional accuracy is good.

(5) Releasability Using the obtained pellet molding machine “NEX80-9E”, the cylinder temperature is 250 ° C., the mold temperature is 80 ° C., the molding cycle is 23 seconds, and the cooling time is 20 seconds. Under the conditions, the box-shaped molded product described in the evaluation of the warp was injection molded. The releasability at that time was evaluated in the following two stages.
○: The ejector pin mark remains on the molded product and the appearance is good. △: The ejector pin mark remains slightly on the molded product. To obtain a molded product with a good appearance by continuous molding, the ejector pin mark remains. However, “Δ” in the present invention is a level at which there is no problem as an actual molded product.

(6) Impact resistance An ISO tensile test piece (thickness: 4.0 mm) was injection molded under the above conditions. Based on ISO 179, a test piece with a thickness of 4.0 mm was produced from this test piece, and a notched Charpy impact strength (unit: kJ / m ² ) was measured in an environment of 23 ° C.
The above evaluation results are shown in Tables 2 and 3.

  From Table 2 and Table 3, the following becomes clear. That is, it can be seen that the polybutylene terephthalate-based resin composition molded article of the present invention is a molded article having excellent impact resistance and high jetness. On the other hand, it can be seen that the comparative example not having the morphology of the present invention and the molded article of the comparative example not satisfying the composition of claim 1 do not satisfy the effects of the present invention.

  The molded article of the polybutylene terephthalate resin composition of the present invention is a molded article having excellent jet blackness and impact resistance, and can be used particularly suitably as an electric / electronic equipment part, a casing, an interior / exterior part for automobiles, etc. The availability of is very high.

Claims (6)

Molding formed by molding a polybutylene terephthalate resin composition containing 2 to 22 parts by mass of elastomer (B) and 0.01 parts by mass or more of carbon black (C) with respect to 100 parts by mass of polybutylene terephthalate (A). Body,
In the surface layer portion of the molded body, the phase of the elastomer (B) is dispersed, and the dispersed phase has a maximum diameter of R in the direction perpendicular to the maximum diameter R and the maximum diameter of each dispersed phase. A polybutylene terephthalate-based resin composition molded article having excellent jetness, wherein R / r is 8 or less on average when r.   The polybutylene terephthalate (A) further includes a polycarbonate resin (D), and the polybutylene terephthalate (A) is 50 to 85% by mass based on a total of 100% by mass of the polybutylene terephthalate (A) and the polycarbonate resin (D). The polybutylene terephthalate-based resin composition molded article according to claim 1, comprising 15 to 50 mass% of the polycarbonate resin (B).   The polybutylene terephthalate-based resin composition further contains 7 to 35 parts by mass of the flame retardant (E) with respect to 100 parts by mass of the total amount of the polybutylene terephthalate (A) and the polycarbonate resin (D). 2. A molded article of polybutylene terephthalate resin composition according to 1.   The polybutylene terephthalate resin composition further contains 1 to 15 parts by mass of the antimony compound (F) with respect to 100 parts by mass of the total amount of the polybutylene terephthalate (A) and the polycarbonate resin (D). The polybutylene terephthalate-based resin composition molded article according to any one of the above.   The polybutylene terephthalate-based resin composition molded article according to claim 3 or 4, wherein the flame retardant (E) is a brominated polycarbonate. L ^* value of a molded object is 40 or less, The polybutylene terephthalate-type resin composition molded object of any one of Claims 1-5.