阅读说明：本技术 聚对苯二甲酸丁二醇酯树脂组合物 (Polybutylene terephthalate resin composition ) 是由 神谷元畅 藤井泰人 清水隆浩 古川香织 于 2020-03-24 设计创作，主要内容包括：本发明为一种聚对苯二甲酸丁二醇酯树脂组合物,其含有特性粘度为0.60～1.0dl/g的聚对苯二甲酸丁二醇酯树脂(A)20～50质量％、纤维状填充材料(B)20～45质量％、熔体体积流动速率(MVR)为30cm～(3)/10min以上的聚碳酸酯树脂(C)1～20质量％、共聚聚对苯二甲酸丁二醇酯树脂(D)3～20质量％及纤维状填充材料(B)以外的无机填充材料(E)0～20质量％,该聚对苯二甲酸丁二醇酯树脂组合物可以获得改善缩痕,同时维持高负荷挠曲温度,并且具有优异的外观的成型品。(The invention provides a polybutylene terephthalate resin composition comprising 20-50 mass% of a polybutylene terephthalate resin (A) having an intrinsic viscosity of 0.60-1.0 dl/g, 20-45 mass% of a fibrous filler (B), and a melt volume flow rate (MVR) of 30cm 3 1 to 20% by mass of a polycarbonate resin (C) for 10min or more, 3 to 20% by mass of a copolymerized polybutylene terephthalate resin (D), and an inorganic filler (E) other than the fibrous filler (B)0 to 20% by mass, and a molded article having an excellent appearance, which is improved in sink marks while maintaining a high deflection temperature under load, can be obtained.)

1. A polybutylene terephthalate resin composition characterized by comprising 20 to 50 mass% of a polybutylene terephthalate resin (A) having an intrinsic viscosity of 0.60 to 1.0dl/g, 20 to 45 mass% of a fibrous filler (B), and a melt volume flow rate MVR of 30cm³1 to 20% by mass of a polycarbonate resin (C) for 10min or more, 3 to 20% by mass of a copolymerized polybutylene terephthalate resin (D), and 0 to 20% by mass of an inorganic filler (E) other than the fibrous filler (B).

2. The polybutylene terephthalate resin composition according to claim 1, further comprising 0 to 25% by mass of a polyethylene terephthalate resin (F).

3. The polybutylene terephthalate resin composition according to claim 1 or 2, wherein the polybutylene terephthalate resin composition has a deflection temperature under load of 190 ℃ or higher.

Technical Field

The present invention relates to a polybutylene terephthalate resin composition which can reduce the occurrence of sink marks during molding and can maintain a high deflection temperature under load.

Background

Generally, a polybutylene terephthalate resin is widely used for automobile parts, electric and/or electronic parts, household sundries, and the like because of its excellent mechanical properties, heat resistance, chemical resistance, and the like. From the viewpoint of weight reduction and cost reduction, thinning of these components is progressing. In order to satisfy practical strength even when the molded article is thin, a method of reinforcing the molded article by arranging a plurality of rib portions, boss portions, and the like with a resin composition reinforced with glass fibers or the like has been studied.

However, when the rib portion or the boss portion is disposed in the molded article, sink marks become conspicuous and the appearance may be impaired.

In order to solve such a problem, patent documents 1 and 2 propose a method of adding an amorphous polyamide or a polyamide that is difficult to crystallize to a crystalline polyamide or a glass fiber to suppress crystallinity, and further adding a spherical filler to suppress shrinkage in the thickness direction to improve sink marks. However, the addition of an amorphous component has a problem that the deflection temperature under load is lowered and the toughness is insufficient. In addition, in patent document 3, a bromine-based flame retardant and an antimony compound are dispersed in a polybutylene terephthalate resin composition, whereby sink marks can be suppressed, but the deflection temperature under load is not mentioned. Patent document 4 proposes a polybutylene terephthalate resin composition in which an impact resistance improving material of butadiene rubber is mixed in a combination of a polybutylene terephthalate resin and an aromatic polycarbonate resin, and which can suppress sink marks, but does not mention the deflection temperature under load, and has problems that the deflection temperature under load is lowered by the butadiene rubber, and incompatible rubber components bleed out of the surface of a molded article to deteriorate the appearance.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2009-7482

Patent document 2: japanese patent laid-open publication No. 2013-203869

Patent document 3: japanese patent laid-open publication No. 2013-173822

Patent document 4: japanese laid-open patent publication No. 11-106624

Disclosure of Invention

Problems to be solved by the invention

The purpose of the present invention is to provide a polybutylene terephthalate resin composition that can provide a molded article that has improved sink marks, maintains a high load deflection temperature, and has an excellent appearance.

Means for solving the problems

The present inventors have conducted intensive studies on the structure and properties of a polybutylene terephthalate resin composition in order to solve the above problems, and as a result, have completed the present invention.

That is, the present invention has the following configuration.

[1]A polybutylene terephthalate resin composition characterized by comprising 20-40 mass% of a polybutylene terephthalate resin (A) having an intrinsic viscosity of 0.60-1.0 dl/g, 20-45 mass% of a fibrous filler (B), and a melt volume flow rate (MVR) of 30cm³1 to 20% by mass of a polycarbonate resin (C) for 10min or more, 3 to 20% by mass of a copolymerized polybutylene terephthalate resin (D), and 0 to 20% by mass of an inorganic filler (E) other than the fibrous filler (B).

[2] The polybutylene terephthalate resin composition according to [1], which further comprises 0 to 25% by mass of a polyethylene terephthalate resin (F)

[3] The polybutylene terephthalate resin composition according to any one of [1] and [2], wherein the polybutylene terephthalate resin composition has a deflection temperature under load of 190 ℃ or higher.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a polybutylene terephthalate resin composition which can provide a molded article improved in sink marks and maintained at a high deflection temperature under load can be provided.

Detailed Description

The present invention will be specifically described below. The content (mixing amount) of each component described below represents an amount (mass%) of the polybutylene terephthalate resin composition taken as 100 mass%. The amount of each component mixed is the content in the polybutylene terephthalate resin composition, and therefore the amount of each component mixed corresponds to the content.

[ polybutylene terephthalate resin (A) ]

The polybutylene terephthalate resin is a polymer obtained by a conventional polymerization method such as a polycondensation reaction of a dicarboxylic acid containing terephthalic acid or an ester-forming derivative thereof as a main component and a diol containing 1, 4-butanediol or an ester-forming derivative thereof as a main component. The repeating unit of the polybutylene terephthalate in the polybutylene terephthalate resin (a) is preferably 85 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, and particularly preferably 100 mol%.

The Intrinsic Viscosity (IV) of the polybutylene terephthalate resin (A) is preferably 0.60 to 1.0dl/g, more preferably 0.60 to 0.90dl/g, and still more preferably 0.65 to 0.88 dl/g. When the Intrinsic Viscosity (IV) of the polybutylene terephthalate resin composition produced by the present invention exceeds 1.0dl/g, the deflection temperature under load is lowered; on the other hand, if the amount is less than 0.60dl/g, mechanical properties and chemical properties are remarkably deteriorated, which is not preferable. The Intrinsic Viscosity (IV) of the polybutylene terephthalate resin (A) is a value (unit: dl/g) measured at 30 ℃ using a Ubbelohde viscometer by dissolving 0.1g of the resin in 25ml of a mixed solvent of phenol/tetrachloroethane (mass ratio 6/4).

The polybutylene terephthalate resin composition contains the polybutylene terephthalate resin (A) in an amount of 0 to 40 mass%, preferably 0 to 38 mass%, and more preferably 15 to 35 mass%. By blending the polybutylene terephthalate resin (a) within this range, various properties can be satisfied. The polybutylene terephthalate resin (a) in the present invention is a main component in all resins of the polybutylene terephthalate resin composition of the present invention. Preferably, the content is at most in all resins.

[ fibrous Filler (B) ]

The polybutylene terephthalate resin composition of the present invention may be mixed with a fibrous filler (B) in an amount within a range that does not impair the effects of the present invention, for the purpose of improving heat resistance and rigidity. Examples of the fibrous filler (B) include glass fibers, carbon fibers, potassium titanate fibers, silica/alumina fibers, zirconia fibers, metal fibers, and the like, and glass fibers are preferred.

As the glass fiber, any known glass fiber can be preferably used, and the glass fiber is not limited to the diameter of the glass fiber, the cross-sectional shape such as a circular, cocoon-shaped cross-section, or an elliptical cross-section, or the length and glass cutting method used for producing chopped strands, rovings, or the like. In the present invention, the kind of glass is not limited, and E glass and corrosion-resistant glass containing zirconium element in the composition are preferably used from the viewpoint of quality.

In the present invention, for the purpose of improving the interfacial properties between the fibrous filler (B) and the resin matrix, it is preferable to use a fibrous filler surface-treated with an organic treating agent such as an aminosilane compound or an epoxy compound. As the aminosilane compound or epoxy compound used for the fibrous filler, any known one can be preferably used, and the kind of the aminosilane compound or epoxy compound is not limited.

The content of the fibrous filler (B) in the polybutylene terephthalate resin composition is 20 to 45 mass%, preferably 22 to 43 mass%, and more preferably 25 to 40 mass%. By mixing the fibrous filler (B) within this range, a polybutylene terephthalate resin composition having improved heat resistance and rigidity can be obtained.

[ polycarbonate resin (C) ]

The polycarbonate in the polycarbonate resin (C) in the present invention can be produced by a solvent method, that is, by a reaction of a dihydric phenol with a carbonate precursor such as phosgene or an ester interchange reaction of a dihydric phenol with a carbonate precursor such as diphenyl carbonate in a solvent such as methylene chloride in the presence of a known acid acceptor or a known molecular weight modifier. Here, as the dihydric phenol preferably used, there are bisphenols, particularly 2, 2-bis (4-hydroxyphenyl) propane, that is, bisphenol a. In addition, a part or all of bisphenol A may be replaced with other dihydric phenol. Examples of the dihydric phenol other than bisphenol a include compounds such as hydroquinone, 4-dihydroxybiphenyl, and bis (4-hydroxyphenyl) alkane, and halogenated bisphenols such as bis (3, 5-dibromo-4-hydroxyphenyl) propane and bis (3, 5-dichloro-4-hydroxyphenyl) propane. The polycarbonate may be a homopolymer using 1 dihydric phenol or a copolymer using 2 or more dihydric phenols. The polycarbonate resin (C) is preferably a resin formed of only polycarbonate. The polycarbonate resin (C) may be a resin obtained by copolymerizing a component other than polycarbonate (for example, a polyester component) within a range (20% by mass or less) not impairing the effects of the present invention.

The polycarbonate resin (C) used in the present invention is particularly preferably a high-fluidity material having a melt volume flow rate (MVR) (unit: cm: measured under a load of 1.2kg at 300 DEG C³A/10 min) of 30 or more is preferable. The MVR of the polycarbonate resin (C) is preferably 100 or less. The MVR of the polycarbonate resin (C) is preferably 40 to 100, more preferably 40 to 90, and still more preferably 40 to 80. When a material having an MVR of less than 30 is used, the flowability is greatly reduced, the deflection temperature under load is reduced, and the moldability is deteriorated. When the MVR exceeds 100, the molecular weight is too low, and the physical properties are deteriorated, and the problem of gas generation due to decomposition is likely to occur.

The content of the polycarbonate resin (C) used in the present invention is 1 to 20% by mass. The inclusion of the polycarbonate resin (C) further reduces sink marks. The polycarbonate resin (C) is preferably 1 to 18% by mass. If the amount exceeds 20 mass%, deterioration of the molding cycle due to reduction in crystallinity, appearance defects due to reduction in fluidity, and the like are likely to occur, and thus it is not preferable.

[ copolymerized polybutylene terephthalate resin (D) ]

The copolymerized polybutylene terephthalate resin (D) in the present invention is a resin in which 1, 4-butanediol accounts for 80 mol% or more and the total of terephthalic acid and 1, 4-butanediol accounts for 120 to 180 mol% when the total acid component and the total diol component are taken as 100 mol% and 100 mol%, respectively. The copolymerization component may contain at least 1 or more selected from the group consisting of isophthalic acid, sebacic acid, adipic acid, trimellitic acid, 2, 6-naphthalenedicarboxylic acid, ethylene glycol, diethylene glycol, neopentyl glycol, 1, 4-cyclohexanedimethanol, 1, 2-propanediol, 1, 3-propanediol and 2-methyl-1, 3-propanediol. Among these, isophthalic acid is preferable as the copolymerization component, and the copolymerization ratio is preferably 20 to 80 mol%, more preferably 20 to 60 mol%, and further preferably 20 to 40 mol% with respect to 100 mol% of the total acid components constituting the copolymerized polybutylene terephthalate resin (D). When the copolymerization ratio is less than 20 mol%, transferability to a mold tends to be poor, and it is difficult to obtain a sufficient appearance; if the copolymerization amount exceeds 80 mol%, the molding cycle may be reduced and the releasability may be reduced.

The molecular weight of the copolymerized polybutylene terephthalate resin (D) varies depending on the specific copolymerization composition, but the reduced viscosity (measured by dissolving 0.1g of a sample in 25ml of a mixed solvent of phenol/tetrachloroethane (mass ratio: 6/4) and measuring at 30 ℃ with a Ubbelohde tube) is preferably 0.4 to 1.5dl/g, more preferably 0.4 to 1.3 dl/g. If it is less than 0.4dl/g, toughness may be reduced; if it exceeds 1.5dl/g, the flowability may be lowered.

The content of the copolymerized polybutylene terephthalate resin (D) is 3 to 20 mass%. By containing the copolymerized polybutylene terephthalate resin (D), the appearance of the molded article is improved. The copolymerized polybutylene terephthalate resin (D) is preferably 4 to 15% by mass, more preferably 5 to 15% by mass, and still more preferably 5 to 13% by mass.

[ inorganic Filler (E) ]

The inorganic filler (E) in the present invention is an inorganic filler different from the fibrous filler (B). The inorganic filler (E) in the present invention is preferably an inorganic filler having a spherical and/or amorphous shape, rather than a fibrous or plate-like shape. The spherical and/or amorphous shape is preferably 3.0 in all of the major axis and minor axis (major axis/minor axis), the flatness (minor axis/thickness), and the aspect ratio (projected area diameter/thickness), and more preferably 2.0 or less. If these values exceed 3.0, the Weld strength (Weld strength) tends to decrease.

Specific examples include, but are not limited to, glass beads, silica, calcium carbonate, wollastonite, barium sulfate, acicular wollastonite, and particulate aluminum borate. In addition, materials treated with generally known silane coupling agents can also be used without any problem. The particle size of the inorganic filler (E) is not particularly limited, and any particle size may be used, but for example, a particle size of 1 to 80 μm is preferable, and a particle size of 2 to 30 μm is more preferable.

The content of the inorganic filler (E) is 0 to 20% by mass. The inorganic filler (E) may be absent (mixed), but the load deflection temperature can be further increased by the inclusion. The content of the inorganic filler (E) is preferably 3 to 18% by mass.

[ polyethylene terephthalate resin (F) ]

The polyethylene terephthalate resin (F) in the present invention is basically a homopolymer of ethylene terephthalate units. In addition, in the range in which various properties are not impaired, when the total acid component constituting the polyethylene terephthalate resin (F) is 100 mol% and the total diol component is 100 mol%, other components may be copolymerized at most by about 5 mol%. As other components, diethylene glycol formed by condensation of ethylene glycol during polymerization is also included.

The molecular weight of the polyethylene terephthalate resin (F) is preferably measured at a reduced viscosity (measured by dissolving 0.1g of a sample in 25ml of a mixed solvent of phenol/tetrachloroethane (mass ratio 6/4) and measuring the solution at 30 ℃ C. using an Ubbelohde viscometer) of 0.4 to 1.0dl/g, more preferably 0.5 to 0.9 dl/g. If it is less than 0.4dl/g, the strength of the resin may be reduced; if it exceeds 1.0dl/g, the flowability of the resin may be lowered.

The content of the polyethylene terephthalate resin (F) is preferably 0 to 25% by mass, more preferably 0 to 22% by mass. By containing (mixing) the polyethylene terephthalate resin (F) within this range, various properties can be satisfied. By containing the polyethylene terephthalate resin (F), a high load deflection temperature can be achieved. When the polyethylene terephthalate resin (F) is contained, the content thereof is preferably 10 to 25% by mass, more preferably 13 to 22% by mass.

[ other additives ]

The polybutylene terephthalate resin composition of the present invention may contain various known additives as needed within a range not impairing the characteristics of the present invention. Examples of the known additives include colorants such as pigments, mold release agents, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, modifiers, antistatic agents, flame retardants, dyes, and ester interchange inhibitors.

Examples of the release agent include long-chain fatty acids, esters thereof, or metal salts thereof, amide compounds, polyethylene wax, silicone, polyethylene oxide, and the like. The long-chain fatty acid is particularly preferably one having 12 or more carbon atoms, and examples thereof include stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, and the like, and a part or all of the carboxylic acid may be esterified with a mono-diol or a poly-diol (Polyglycol), or may form a metal salt. Examples of the amide compound include ethylene bis-terephthalamide and methylene bis-stearamide. These mold release agents may be used alone or in the form of a mixture.

The ester interchange inhibitor is a stabilizer for preventing the ester interchange reaction of the polyester resin as the name implies. In the alloy between polyester resins, and the like, many transesterification reactions occur due to the application of heat regardless of optimization of the conditions at the time of production. If the degree of this is very large, the desired alloy characteristics cannot be obtained. In particular, since the transesterification reaction of polybutylene terephthalate and polycarbonate often occurs, in this case, the crystallinity of polybutylene terephthalate is greatly reduced, which is not preferable. In the present invention, the addition of the transesterification inhibitor can prevent the transesterification reaction between the polybutylene terephthalate resin (a) and the polycarbonate resin (C), and thus can maintain proper crystallinity. As the ester exchange inhibitor, a phosphorus compound having a catalytic deactivation effect of the polyester resin can be preferably used, and for example, "ADEKA STAB AX-71" manufactured by ADEKA Co., Ltd. The content of the ester exchange inhibitor is preferably 0.05 to 2% by mass, more preferably 0.1 to 0.5% by mass.

The total content of these various additives may be 5% by mass or more, assuming that the polybutylene terephthalate resin composition is 100% by mass. That is, the total of the components (A), (B), (C), (D), (E) and (F) is preferably 95 to 100% by mass based on 100% by mass of the polybutylene terephthalate resin composition. The above (F) is an optional component.

The polybutylene terephthalate resin composition of the present invention, having the above-described configuration, can satisfy a deflection temperature under load of 190 ℃ or higher as measured by a method described later. The deflection temperature under load is more preferably 192 ℃ or higher.

Examples

The present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited thereto. The measurement values described in the examples were obtained by the following methods. The test piece used for the measurement was made of a material molded as follows: the obtained polybutylene terephthalate resin composition pellets were dried at 130 ℃ for 4 hours, and then molded into a shape conforming to ISO3167 using an injection molding machine (J110 AD-110H, manufactured by Japan Steel works) under conditions of a cylinder temperature of 270 ℃ and a mold temperature of 80 ℃.

(1) Flexural strength, flexural modulus, and flexural modulus

The measurement was carried out in accordance with ISO-178.

(2) Charpy impact strength

Measured according to JIS K7111.

(3) Deflection temperature under load

According to JIS K7191-2: 2007, measurement was carried out. The load was 1.80 MPa.

(4) Appearance of molded article

The obtained polybutylene terephthalate resin composition pellets were dried at 130 ℃ for 4 hours, and then molded into a 100mm × 100mm × 2mm (thick) molded article using an injection molding machine (J110 AD-110H, manufactured by Japan Steel works) under conditions of a cylinder temperature of 270 ℃ and a mold temperature of 80 ℃, and at this time, the appearance of the molded article molded at an injection speed range in which the filling time was 1 second was visually observed.

O: the surface had a glossy feeling, had no appearance defects and was good

And (delta): some appearance defects occur in portions (particularly, in the end portions of the molded body or in the vicinity of the gate, etc.)

X: appearance defects occurred in the entire molded article

(5) Evaluation of sink marks

The obtained polybutylene terephthalate resin composition pellets were dried at 130 ℃ for 4 hours, and then molded into injection molded test pieces 100mm × 100mm × 4mm (thickness) by using an injection molding machine (J110 AD-110H manufactured by Japan Steel works) under conditions of a cylinder temperature of 270 ℃, a mold temperature of 80 ℃, an injection molding time of 8 seconds, a filling time of 1 second, a pressure holding of 60MPa, and a cooling time of 15 seconds, and the test pieces were visually observed and evaluated according to the following criteria.

O: no sink mark was observed

X: sink marks were observed

The components used in examples and comparative examples are as follows.

A polybutylene terephthalate resin (A);

(A-1) polybutylene terephthalate resin: manufactured by Toyobo Co., Ltd., intrinsic viscosity of 0.83dl/g

(A-2) polybutylene terephthalate resin: manufactured by Toyobo Co., Ltd., intrinsic viscosity of 0.75dl/g

(A-3) polybutylene terephthalate resin: manufactured by Toyobo Co., Ltd., intrinsic viscosity of 0.68dl/g

(A-4) polybutylene terephthalate resin: manufactured by Toyobo Co., Ltd., intrinsic viscosity of 1.10dl/g

A fibrous filler (B);

(B) glass fiber (average fiber length 3mm, average fiber diameter 11 μm): T-120H (manufactured by Ridong textile Co., Ltd.)

A polycarbonate resin (C);

(C-1): "Calibre 301-40" manufactured by Sumika Styron Polycarbonate, Inc., melt volume flow rate (300 ℃, load 1.2kg)40cm³/10min

(C-2): "Calibre 200-80" manufactured by Sumika Styron Polycarbonate, Inc., melt volume flow rate (300 ℃, load 1.2kg)80cm³/10min

(C-3): "Calibre 301-6" manufactured by Sumika Styron Polycarbonate, Inc., melt volume flow rate (300 ℃, load 1.2kg)6cm³/10min

A copolymerized polybutylene terephthalate resin (D);

(D) The method comprises the following steps TPA/IPA//1,4-BD 70/30//100 mol% copolymer, Toyobo Byron (registered trademark) sample, Toyo Co., Ltd., reduced viscosity of 0.73dl/g (TPA is terephthalic acid, IPA is isophthalic acid, 1,4-BD is 1, 4-butanediol)

An inorganic filler (E);

(E-1): calcium carbonate: amorphous filler "white stone P-30" available from Baishi calcium Co Ltd

(E-2): glass beads: spherical Filler "EGB 731B" manufactured by Potters-Ballotini K.K.)

A polyethylene terephthalate resin (F);

(F) the method comprises the following steps Polyethylene terephthalate resin: reduced viscosity 0.63dl/g manufactured by Toyobo Co

A transesterification inhibitor; ADK STAB AX-71, manufactured by ADEKA Inc "

< examples 1 to 10, comparative examples 1 to 6 >

The respective components were blended with a tumbler so as to have the compositions shown in table 1, and then melt-kneaded with a twin-screw extruder (STS 35 manufactured by Coperion corporation) to obtain pellets of the compositions.

The obtained composition particles were dried and then evaluated by the above-mentioned method. The results are shown in Table 1.

From Table 1, it is understood from examples 1 to 10 that the load deflection temperature, the appearance and the sink marks can be balanced by adjusting the ratio of the fibrous filler to the polycarbonate resin and by mixing and adjusting the copolymerized polybutylene terephthalate resin to improve the appearance.

As is clear from examples 4 and 5, the polybutylene terephthalate resin can be used while maintaining the properties if it has a predetermined intrinsic viscosity range; if the intrinsic viscosity exceeds the predetermined value, the deflection temperature under load is lowered as in comparative example 1. Further, as is clear from example 9, when the polycarbonate resin had a predetermined MVR range, it could be used while maintaining the properties; if the MVR is outside the specification, the deflection temperature under load is lowered as shown in comparative examples 2 and 3. From this, it is found that, when the viscosities of the polybutylene terephthalate resin and the polycarbonate resin are within the predetermined range, both improvement of sink marks and suppression of load deflection temperature can be achieved.

From example 8, it is understood that even if the glass fiber is increased, the appearance, sink marks, and deflection temperature under load can be balanced by adjusting the blend of the polycarbonate resin and the copolymerized polybutylene terephthalate resin.

From comparative examples 4 to 6, it is clear that when all the conditions of whether or not each component is added, the amount added, and the viscosity are not satisfied, the balance among the appearance, sink marks, and deflection temperature under load is not achieved.

As described above, by using the polybutylene terephthalate resin composition in the combination ratio according to the present invention, it is possible to provide a polybutylene terephthalate resin composition that satisfies all the requirements in terms of appearance, sink marks, and suppression of a decrease in deflection temperature under load.

Industrial applicability of the invention

The resin composition of the present invention can suppress sink marks while maintaining a load deflection temperature as compared with a conventional polybutylene terephthalate resin composition, and is useful as a material for a molded article having a complicated shape such as a boss portion or a rib portion.