Thermoplastic polyester resin composition

Abstract

A thermoplastic polyester resin composition characterized by comprising 100 parts by mass of a thermoplastic polyester resin (A) having an intrinsic viscosity of 0.60 dl / g or higher but lower than 0.85 dl / g, 5-30 parts by mass of a maleic-anhydride-modified olefin polymer (B), 0.2-4.5 parts by mass of a hydrolysis inhibitor (C), and 10-80 parts by mass of a reinforcing filler (D) and by either containing no thermoplastic resin (E) which has a water absorption, as determined by the ISO 62A method, of 0.28 mass% or greater or containing the thermoplastic resin (E) in an amount less than 9 parts by mass per 100 parts by mass of the thermoplastic polyester resin (A).

Description

Technical Field

[0001] The present invention relates to a thermoplastic polyester resin composition, and more particularly, to a thermoplastic polyester resin composition that has high-level balanced properties of mechanical strength, heat resistance, and dimensional stability, is excellent in tracking resistance, heat shock resistance, and hydrolysis resistance, and is further excellent in fluidity during injection molding.

Background Art

[0002] Thermoplastic polyester resins typified by polybutylene terephthalate and polyethylene terephthalate are excellent in mechanical strength, chemical resistance, electrical insulation, etc., and also have excellent heat resistance, moldability, and recyclability. Therefore, they are widely used in electrical and electronic equipment parts, automotive parts, other electrical components, mechanical parts, etc.

[0003] In the field of electrical and electronic equipment, in order to ensure safety against ignition due to electrical load, it is necessary to be excellent in tracking resistance, which is one of the electrical properties. In recent years, electrical and electronic equipment parts and electrical components have been rapidly miniaturized and densified, resulting in a smaller insulation distance. As a result, the required specifications for the tracking resistance and the like of these parts (molded products) have become increasingly strict.

[0004] Insulating materials tend to dry and become charged due to heat generated from the device during energization, so dust tends to adhere to the surface of the insulating material. Therefore, parts formed from the insulating material tend to have dust adhering to their surfaces during device shutdown, and the dust absorbs moisture in the air, and the absorbed moisture reduces the surface resistance of the material and increases the leakage current. Generally, electrical components are more or less exposed to such a situation, and the tracking resistance characteristics of insulating materials are highly regarded. In the case of electrical and electronic equipment parts, requirements such as the Comparative Tracking Index (CTI) of Underwriters Laboratories in the United States must be met, and recently, it has been required that the CTI satisfies the PLC0 level (600V ≤ CTI).

[0005] As materials that have tried to improve the tracking resistance, for example, Patent Document 1 discloses a resin composition containing a thermoplastic polyester resin and an olefin copolymer composed of an α-olefin and a glycidyl ester of an α,β-unsaturated acid. If necessary, it is described that conventional flame retardants, fillers such as talc, kaolin, and silica, and fibrous fillers such as glass fibers may be added. However, simply adding an olefin copolymer composed of an α-olefin and a glycidyl ester of an α,β-unsaturated acid to a thermoplastic polyester resin can improve the tracking resistance, but there is a problem that the high fluidity during injection molding originally possessed by the thermoplastic polyester resin is impaired, and the molding characteristics of the resulting resin composition deteriorate. Patent Document 2 describes a resin composition composed of a polybutylene terephthalate resin, a bromine-based flame retardant, an antimony-based flame retardant aid, a fluorinated ethylene-based polymer, a polyolefin, and a metal silicate-based filler and glass fiber. Further, Patent Document 3 discloses a resin composition composed of a thermoplastic polyester resin, compressed fine powder talc, and a benzyl (meth) acrylate-based halogenated flame retardant, and it is described that a fibrous reinforcing agent may be added if necessary.

[0006] On the other hand, when used as electrical parts or mechanical parts, they may be colored for easy distinction from other parts. Although it is common to add carbon black to make it black, since carbon black has conductivity, there is a problem that the tracking resistance decreases due to the addition. Therefore, there is a demand for materials that can be used for electrical and electronic equipment parts that are black and have excellent tracking resistance, but in reality, no satisfactory materials have been obtained.

[0007] In addition, electrical and electronic equipment parts and automotive electrical parts are often combined with metal members to form parts. However, as miniaturization progresses, the wall thickness of molded products is decreasing rapidly and the shapes of parts are becoming more complex, and a high level of heat shock resistance is also required.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] In view of the above circumstances, an object of the present invention is to provide a thermoplastic polyester resin material that has a high level of balance in the mechanical strength, heat resistance, and dimensional stability characteristics originally possessed by the thermoplastic polyester resin, and is also excellent in tracking resistance, hydrolysis resistance, heat shock resistance, and fluidity during injection molding.

Means for Solving the Problems

[0010] As a result of intensive studies to solve the above problems, the present inventor has found that by containing a maleic anhydride-modified olefin polymer, a hydrolysis inhibitor, and a reinforcing filler in a specific amount in a thermoplastic polyester resin having a specific intrinsic viscosity, the characteristics of mechanical strength, heat resistance, and dimensional stability are well balanced at a high level, and the material is also excellent in tracking resistance, hydrolysis resistance, heat shock resistance, and fluidity during injection molding, thus completing the present invention. The present invention relates to the following thermoplastic polyester resin compositions and molded articles.

[0011] [1] For 100 parts by mass of a thermoplastic polyester resin (A) having an intrinsic viscosity of 0.60 dl / g or more and less than 0.85 dl / g, 5 to 30 parts by mass of a maleic anhydride-modified olefin polymer (B), 0.2 to 4.5 parts by mass of a hydrolysis inhibitor (C), and 10 to 80 parts by mass of a reinforcing filler (D) are contained, and it does not contain a thermoplastic resin (E) having a water absorption rate of 0.28% by mass or more measured by the ISO 62A method, or even if it contains it, the content is less than 9 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). A thermoplastic polyester resin composition characterized by that. [2] Furthermore, the thermoplastic polyester resin composition according to [1] above, which contains carbon black (F). [3] The thermoplastic polyester resin composition according to [2] above, wherein the carbon black (F) is compounded as a carbon black masterbatch having a carbon black concentration of 30 to 80% by mass. [4] The thermoplastic polyester resin composition according to [2] or [3] above, wherein the carbon black (F) is contained in an amount of 0.02 to 1.0 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A) as a polyolefin-based carbon black masterbatch. [5] The thermoplastic polyester resin composition according to any one of [1] to [4] above, wherein the maleic anhydride-modified olefin polymer (B) is a maleic anhydride-modified ethylene-propylene copolymer. [6] The thermoplastic polyester resin composition according to any one of [1] to [5] above, wherein the intrinsic viscosity of the thermoplastic polyester resin (A) is 0.60 dl / g or more and less than 0.75 dl / g. [7] The thermoplastic polyester resin composition according to any one of [1] to [6] above, wherein the thermoplastic polyester resin (A) is a polybutylene terephthalate-based resin. [8] The thermoplastic polyester resin composition according to any one of [1] to [7] above, wherein the hydrolysis inhibitor (C) is an epoxy compound. [9] The thermoplastic polyester resin composition according to [8] above, wherein the epoxy equivalent of the epoxy compound is 100 to 2000 g / eq.

[10] Furthermore, a thermoplastic polyester resin composition according to any one of [1] to [9] above, containing a flame retardant.

[11] Furthermore, a thermoplastic polyester resin composition according to any one of [1] to

[10] above, containing a colorant.

[12] A molded article obtained by molding the thermoplastic polyester resin composition according to any one of [1] to

[11] above.

[13] The molded article according to

[12] above, which is a fitting member.

[14] The molded article according to

[12] above, which is an insert molded article. [Advantages of the Invention]

[0012] The thermoplastic polyester resin composition of the present invention has high-level balanced properties of mechanical strength, heat resistance, and dimensional stability, and is excellent in tracking resistance, heat shock resistance, and hydrolysis resistance. Furthermore, it also has excellent fluidity during injection molding. Therefore, the thermoplastic polyester resin composition of the present invention can be particularly preferably used as insulating parts for electric and electronic equipment parts and electrical components, such as housings, connectors, relays, switches, circuit breakers, electromagnetic switches, terminal blocks, sensors, actuators, terminal switches, etc. of electric and electronic equipment parts. As molded articles, for example, as fitting members having a fitting structure, and also as insert molded articles, etc., it can be particularly preferably used. [Brief Description of the Drawings]

[0013]

Figure 1

[0014] The thermoplastic polyester resin composition of the present invention contains, per 100 parts by mass of a thermoplastic polyester resin (A) having an intrinsic viscosity of 0.60 dl / g or more and less than 0.85 dl / g, 5 to 30 parts by mass of a maleic anhydride-modified olefin polymer (B), 0.2 to 4.5 parts by mass of a hydrolysis inhibitor (C), and 10 to 80 parts by mass of a reinforcing filler (D), and does not contain a thermoplastic resin (E) having a water absorption rate of 0.28% by mass or more measured by the ISO62A method, or even if it contains the thermoplastic resin (E), the content thereof is less than 9 parts by mass per 100 parts by mass of the thermoplastic polyester resin (A).

[0015] Hereinafter, embodiments of the present invention will be described in detail. The explanations described below may be based on embodiments and specific examples, but the present invention is not to be construed as being limited to such embodiments and specific examples. In this specification, "~" is used to mean including the numerical values described before and after it as a lower limit value and an upper limit value.

[0016] [Thermoplastic polyester resin (A)] The thermoplastic polyester resin composition of the present invention contains a thermoplastic polyester resin (A). The thermoplastic polyester resin (A) is a polyester obtained by polycondensation of a dicarboxylic acid compound and a dihydroxy compound, polycondensation of an oxycarboxylic acid compound, or polycondensation of these compounds, and may be either a homopolyester or a copolyester.

[0017] As the dicarboxylic acid compound constituting the thermoplastic polyester resin (A), an aromatic dicarboxylic acid or its ester-forming derivative is preferably used. Examples of the aromatic dicarboxylic acid 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, diphenyl sulfone-4,4'-dicarboxylic acid, diphenyl isopropylidene-4,4'-dicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid, anthracene-2,5-dicarboxylic acid, anthracene-2,6-dicarboxylic acid, p-terphenylen-4,4'-dicarboxylic acid, pyridine-2,5-dicarboxylic acid, etc., and terephthalic acid can be preferably used.

[0018] These aromatic dicarboxylic acids may be used as a mixture of two or more. As is well known, in addition to the free acid, dimethyl ester or the like can be used as an ester-forming derivative in the polycondensation reaction. In addition, if the amount is small, one or more aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid, sebacic acid, etc., and alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid can be mixed and used together with these aromatic dicarboxylic acids.

[0019] Examples of the dihydroxy compound constituting the thermoplastic polyester resin (A) include aliphatic diols such as ethylene glycol, propylene glycol, butanediol, hexylene glycol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol, triethylene glycol, etc., alicyclic diols such as cyclohexane-1,4-dimethanol, etc., and mixtures thereof. In addition, if the amount is small, one or more long-chain diols having a molecular weight of 400 to 6,000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, etc. may be copolymerized. In addition, aromatic diols such as hydroquinone, resorcinol, naphthalenediol, dihydroxydiphenyl ether, and 2,2-bis(4-hydroxyphenyl)propane can also be used.

[0020] In addition to the bifunctional monomers as described above, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane for introducing a branched structure, and monofunctional compounds such as fatty acids for molecular weight adjustment can also be used in a small amount in combination.

[0021] As the thermoplastic polyester resin (A), those mainly composed of polycondensation of dicarboxylic acid and diol are usually used, that is, those in which 50% by mass or more, preferably 70% by mass or more of the whole resin is composed of this polycondensate. As the dicarboxylic acid, aromatic carboxylic acid is preferable, and as the diol, aliphatic diol is preferable.

[0022] Among them, polyalkylene terephthalate in which 95 mol% or more of the acid component is terephthalic acid and 95% by mass or more of the alcohol component is aliphatic diol is preferable. Typical examples thereof are polybutylene terephthalate and polyethylene terephthalate. These are preferably those close to homopolyester, that is, those in which 95% by mass or more of the whole resin is composed of terephthalic acid component and 1,4-butanediol or ethylene glycol component.

[0023] In the resin composition of the present invention, as the thermoplastic polyester resin (A), it is preferable that the main component (that is, 50% by mass or more) is polybutylene terephthalate resin or polyethylene terephthalate resin, and polybutylene terephthalate resin is particularly preferable.

[0024] As the thermoplastic polyester resin (A), those having an intrinsic viscosity of 0.60 dl / g or more and less than 0.85 dl / g, preferably 0.60 dl / g or more and less than 0.75 dl / g, more preferably 0.65 dl / g or more and less than 0.75 dl / g are used. When a resin having an intrinsic viscosity lower than 0.60 dl / g is used, the mechanical strength of the resulting resin composition may be lowered, the hydrolysis resistance may be deteriorated, or the heat shock resistance may be lowered. When the intrinsic viscosity becomes 0.85 dl / g or more, the fluidity is poor, and it becomes difficult to obtain good fluidity when combined with the maleic anhydride-modified olefin polymer (B). The intrinsic viscosity is preferably 0.62 dl / g or more, particularly 0.64 dl / g or more, 0.66 dl / g or more, and particularly preferably 0.67 dl / g or more, and preferably 0.83 dl / g or less, particularly 0.81 dl / g or less, 0.80 dl / g or less, 0.79 dl / g or less, 0.78 dl / g or less, 0.77 dl / g or less, 0.76 dl / g or less, 0.75 dl / g or less, 0.74 dl / g or less, 0.73 dl / g or less, 0.72 dl / g or less, and particularly preferably 0.71 dl / g or less.

[0025] The intrinsic viscosity of the thermoplastic polyester resin is measured at 30 °C in a mixed solvent of 1,1,2,2-tetrachloroethane and phenol at a mass ratio of 1:1.

[0026] In addition, the amount of terminal carboxyl groups of the thermoplastic polyester resin (A) may be appropriately selected and determined. Usually, it is 60 eq / ton or less, preferably 50 eq / ton or less, and more preferably 30 eq / ton or less. When it exceeds 60 eq / ton, gas is likely to be generated during the melt molding of the resin composition. The lower limit of the amount of terminal carboxyl groups is not particularly defined, but considering the productivity of the production of the thermoplastic polyester resin, it is usually 10 eq / ton.

[0027] The amount of terminal carboxyl groups in the polyester resin refers to the value obtained by dissolving 0.5 g of the polyalkylene terephthalate resin in 25 mL of benzyl alcohol and measuring it by titration using a 0.01 mol / L benzyl alcohol solution of sodium hydroxide. As a method for adjusting the amount of terminal carboxyl groups, any conventionally known method may be used, such as a method of adjusting polymerization conditions such as the raw material charging ratio, polymerization temperature, and decompression method during polymerization, or a method of reacting a terminal blocking agent.

[0028] [Maleic anhydride-modified olefin polymer (B)] As the maleic anhydride-modified olefin polymer (B), one obtained by modifying, preferably graft-modifying, an olefin polymer with maleic anhydride can be used. By combining the maleic anhydride-modified olefin polymer (B) with each component, both tracking resistance and heat shock resistance can be improved.

[0029] Here, the "graft modification" includes not only the case where maleic anhydride is introduced as a long side chain with respect to the skeleton of the olefin polymer, but also any case where it is chemically bonded to the olefin polymer. The graft modification can be carried out by various conventionally known methods. The modification method is not limited, but examples include (i) a melt modification method in which maleic anhydride is added to a molten olefin polymer for graft copolymerization, and (ii) a solution modification method in which maleic anhydride is added to an olefin polymer dissolved in a solvent for graft copolymerization. Among these, the melt modification method that does not require the use of a solvent is preferred, and graft modification using an extruder is more preferred. In addition, in order to perform graft modification efficiently, it is preferably carried out in the presence of a radical initiator.

[0030] As the olefin polymer in the maleic anhydride-modified olefin polymer (B), homopolymers or copolymers of α-olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, octene-1, etc. can be mentioned, and two or more of these can be used in combination. As the maleic anhydride-modified olefin polymer (B), a maleic anhydride-modified olefin copolymer is preferable, and in particular, a maleic anhydride-modified ethylene-propylene copolymer, a maleic anhydride-modified ethylene-butene copolymer, a maleic anhydride-modified ethylene-hexene copolymer, a maleic anhydride-modified ethylene-octene copolymer are preferable, and among them, a maleic anhydride-modified ethylene-propylene copolymer is preferable.

[0031] The acid modification rate (content) of the maleic anhydride-modified olefin polymer (B) is preferably 0.05 to 10% by mass, more preferably 0.1 to 5% by mass.

[0032] Also, the melt flow rate (MFR) of the maleic anhydride-modified olefin polymer (B) is not particularly limited, but is preferably 0.05 to 10 g / 10 min, more preferably 0.1 to 5 g / 10 min, and particularly preferably 0.1 to 3 g / 10 min. Note that MFR means the value at 190 °C and a load of 2.16 kg.

[0033] The content of the maleic anhydride-modified olefin polymer (B) is 5 to 30 parts by mass, preferably 5 to 25 parts by mass, based on 100 parts by mass of the thermoplastic polyester resin (A). By containing in such an amount in combination with other components, a high level of tracking resistance, specifically, a 0 level (CTI: 600 V or more) with PLC can be achieved. If the content exceeds 30 parts by mass, the elastic modulus of the resin composition will decrease. The content is preferably 6 parts by mass or more, more preferably 7 parts by mass or more, preferably 25 parts by mass or less, more preferably 23 parts by mass or less, and even more preferably 20 parts by mass or less, based on 100 parts by mass of the thermoplastic polyester resin (A).

[0034] [Hydrolysis inhibitor (C)] As the hydrolysis inhibitor, compounds having reactivity with the carboxylic acid and hydroxyl group which are terminal functional groups of the thermoplastic polyester resin (A), such as epoxy compounds, carbodiimide compounds, isocyanate compounds, oxazoline-based compounds, etc. are applicable. Among these, epoxy compounds are preferable.

[0035] As the epoxy compound, any compound having one or more epoxy groups in one molecule may be used. Usually, glycidyl compounds which are reaction products of alcohols, phenols, carboxylic acids, etc. and epichlorohydrin, or compounds obtained by epoxidizing olefinic double bonds may be used. Examples of the epoxy compound include novolak type epoxy compounds, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, alicyclic epoxy compounds, glycidyl ethers, glycidyl esters, epoxidized butadiene polymers, resorcin type epoxy compounds, etc.

[0036] Examples of the novolak type epoxy compounds include phenol novolak type epoxy compounds, cresol novolak type epoxy compounds, etc. Examples of the bisphenol A type epoxy compounds include bisphenol A - diglycidyl ether, hydrogenated bisphenol A - diglycidyl ether, etc. Examples of the bisphenol F type epoxy compounds include bisphenol F - diglycidyl ether, hydrogenated bisphenol F - diglycidyl ether, etc.

[0037] Examples of the alicyclic epoxy compounds include vinylcyclohexene dioxide, dicyclopentadiene monoxide, 3,4 - epoxycyclohexyl - 3,4 - cyclohexyl carboxylate, bis(3,4 - epoxycyclohexylmethyl) adipate, vinylcyclohexene diepoxide, 3,4 - epoxycyclohexyl glycidyl ether, etc.

[0038] Specific examples of glycidyl ethers include monoglycidyl ethers such as methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, phenyl glycidyl ether, butylphenyl glycidyl ether, allyl glycidyl ether, etc.; diglycidyl ethers such as neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, propylene glycol diglycidyl ether, bisphenol A diglycidyl ether, etc. Examples of glycidyl esters include monoglycidyl esters such as glycidyl benzoate, glycidyl sorbate, etc.; diglycidyl esters such as adipic acid diglycidyl ester, terephthalic acid diglycidyl ester, orthophthalic acid diglycidyl ester, etc.

[0039] Examples of epoxidized butadiene polymers include epoxidized polybutadiene, epoxidized styrene-butadiene copolymer, epoxidized hydrogenated styrene-butadiene copolymer, etc. Examples of resorcinol-type epoxy compounds include resorcinol diglycidyl ether, etc.

[0040] In addition, the epoxy compound may be a copolymer having a glycidyl group-containing compound as one component. For example, a copolymer of a glycidyl ester of an α,β-unsaturated acid and one or more monomers selected from the group consisting of α-olefins, acrylic acid, acrylic acid esters, methacrylic acid, and methacrylic acid esters can be mentioned.

[0041] Moreover, as the epoxy compound, an epoxy compound having an epoxy equivalent of 100 to 2000 g / eq is preferred. When the epoxy equivalent is less than 100 g / eq, the amount of epoxy groups is too large, resulting in a high viscosity of the resin composition. Conversely, when the epoxy equivalent exceeds 2000 g / eq, the amount of epoxy groups is small, and thus the effects of improving the alkali resistance, heat shock resistance, and hydrolysis resistance of the resin composition tend to be insufficiently manifested. The epoxy equivalent is more preferably 100 to 1500 g / eq. In addition, the molecular weight of the epoxy compound preferably has a weight average molecular weight of 8000 or less. When the weight average molecular weight exceeds 8000, the compatibility with the thermoplastic polyester resin (A) decreases, and the mechanical strength of the molded product tends to decrease. The weight average molecular weight is more preferably 7000 or less, and even more preferably 6000 or less.

[0042] As the epoxy compound, bisphenol A-type epoxy compounds and novolak-type epoxy compounds obtained from the reaction of bisphenol A or novolak with epichlorohydrin are preferred. Among them, novolak-type epoxy compounds are particularly preferred in terms of easily improving alkali resistance, hydrolysis resistance, heat shock resistance, and the surface appearance of the molded product.

[0043] The content of the hydrolysis inhibitor (C) is 0.2 to 4.5 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). By setting the content within such a range, the hydrolysis resistance of the resin composition can be improved, a decrease in mechanical strength and the like can be suppressed, and furthermore, the synergistic effect with the maleic anhydride-modified olefin polymer (B) can be promoted, and the alkali resistance and heat shock resistance can be further improved. When the content of the hydrolysis inhibitor (C) is less than 0.2 part by mass, a decrease in alkali resistance and hydrolysis resistance is likely to occur. When it is more than 4.5 parts by mass, crosslinking progresses and the fluidity during molding tends to deteriorate. The content of the hydrolysis inhibitor (C) is preferably 0.3 parts by mass or more, more preferably 0.4 parts by mass or more, still more preferably 0.5 parts by mass or more, and preferably 4 parts by mass or less, more preferably 3 parts by mass or less, still more preferably preferably 2.5 parts by mass or less, particularly preferably 2 parts by mass or less.

[0044] Furthermore, in the present invention, it is preferable that the ratio (B) / (C) of the content of the maleic anhydride-modified olefin polymer (B) to the hydrolysis inhibitor (C) is 99 to 80 / 1 to 20. When (B) / (C) is within such a range, hydrolysis resistance and moldability can be balanced well. When the amount of the hydrolysis inhibitor (C) is less than this range, the hydrolysis resistance tends to deteriorate, and when it exceeds this range and becomes large, the viscosity increases during molding and the moldability tends to become unstable. (B) / (C) is more preferably 98 to 80 / 2 to 20, and still more preferably 97 to 90 / 3 to 10.

[0045] [Reinforcing filler (D)] The thermoplastic polyester resin composition of the present invention contains a reinforcing filler (D). The reinforcing filler refers to a material that is incorporated into the resin component to improve strength and rigidity, and may be in any form such as fibrous, plate-like, granular, amorphous, etc.

[0046] When the form of the reinforcing filler (D) is fibrous, it may be either inorganic or organic. For example, it includes inorganic fibers such as glass fiber, carbon fiber, silica-alumina fiber, zirconia fiber, boron fiber, boron nitride fiber, potassium titanate silicon nitride fiber, metal fiber, wollastonite, and organic fibers such as fluororesin fiber, aramid fiber. When the reinforcing filler (D) is fibrous, inorganic fibers are preferred, and among them, glass fiber is particularly preferred. The reinforcing filler (D) may be of one type or a mixture of two types.

[0047] When the form of the reinforcing filler (D) is fibrous, its average fiber diameter, average fiber length, and cross-sectional shape are not particularly limited. However, the average fiber diameter is preferably selected in the range of, for example, 1 to 100 μm, and the average fiber length is preferably selected in the range of, for example, 0.1 to 20 mm. The average fiber diameter is more preferably 1 to 50 μm, and even more preferably about 5 to 20 μm. Also, the average fiber length is preferably about 0.12 to 10 mm. Further, when the fiber cross-section has a flat shape such as an oval, elliptical, or cocoon shape, the flatness ratio (ratio of major axis to minor axis) is preferably 1.4 to 10, more preferably 2 to 6, and even more preferably 2.5 to 5. By using such glass fibers with a deformed cross-section, it is preferable because the dimensional stability such as warping of the molded product and anisotropy of the shrinkage rate is easily improved.

[0048] In addition to the fibrous reinforcing filler described above, other reinforcing fillers in the form of plates, granules, or amorphous can also be contained. The plate-like inorganic filler exhibits a function of reducing anisotropy and warpage, and examples include glass flakes, talc, mica, muscovite, kaolin, etc. Among the plate-like inorganic fillers, glass flakes are preferred.

[0049] Examples of other granular or amorphous inorganic fillers include ceramic beads, asbestos, clay, zeolite, potassium titanate, barium sulfate, titanium oxide, silicon oxide, aluminum oxide, magnesium hydroxide, etc.

[0050] In order to improve the adhesion at the interface between the reinforcing filler (D) and the resin component, it is preferable to treat the surface of the reinforcing filler (D) with a surface treatment agent such as a sizing agent. Examples of the surface treatment agent include epoxy resins, acrylic resins, urethane resins, and functional compounds such as isocyanate-based compounds, silane-based compounds, and titanate-based compounds. In the present invention, it is preferable to use an epoxy resin for surface treatment. As the epoxy resin, novolac-type epoxy compounds such as phenol novolac type and cresol novolac type, and bisphenol A type epoxy resin are preferable. Among them, it is preferable to use a combination of a novolac-type epoxy compound and a bisphenol A type epoxy resin, and it is preferable to use a combination of a phenol novolac type epoxy compound and a bisphenol A type epoxy resin from the viewpoints of alkali resistance, hydrolysis resistance and mechanical properties.

[0051] As the functional compound, silane coupling agents such as aminosilane-based, epoxysilane-based, allylsilane-based, and vinylsilane-based are preferable, and among them, aminosilane-based compounds are preferable. As the aminosilane-based compound, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane are preferable, and among them, γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane are preferable.

[0052] In the present invention, it is particularly preferable to use a novolac-type epoxy resin and a bisphenol-type epoxy resin as so-called sizing agents, and in addition, a reinforcing filler surface-treated with an aminosilane-based compound as a coupling agent from the viewpoints of alkali resistance and hydrolysis resistance. By configuring the surface treatment agent in such a manner, the inorganic functional group of the aminosilane-based compound is highly reactive with the surface of the reinforcing filler (D), and the organic functional group of the aminosilane is highly reactive with the glycidyl group of the epoxy resin. Further, the glycidyl group of the epoxy resin reacts moderately with the thermoplastic polyester resin (A) respectively, so that the interfacial adhesion between the reinforcing filler (D) and the epoxy resin is improved. As a result, the alkali resistance, hydrolysis resistance, and mechanical properties of the resin composition of the present invention are likely to be improved. Also, within a range not departing from the gist of the present invention, a urethane resin, an acrylic resin, an antistatic agent, a lubricant, a water repellent, etc. can be included in the surface treatment agent. When including these other components, it is preferable to use a urethane resin.

[0053] The surface treatment of the reinforcing filler (D) can be carried out by a conventionally known method. For example, it may be surface-treated in advance with the above surface treatment agent, or when preparing the resin composition of the present invention, the surface treatment agent may be added separately from the untreated reinforcing filler (D) for surface treatment. The adhesion amount of the surface treatment agent to the reinforcing filler (D) is preferably 0.01 to 5% by mass, and more preferably 0.05 to 2% by mass. By setting it to 0.01% by mass or more, the mechanical strength tends to be more effectively improved, and by setting it to 5% by mass or less, the necessary and sufficient effects can be obtained, and the production of the resin composition tends to be facilitated, which is preferable.

[0054] The content of the reinforcing filler (D) is 10 to 80 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). By being in such a range, the strength and rigidity can be improved. The content is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, further preferably 40 parts by mass or more, and preferably 75 parts by mass or less, more preferably 70 parts by mass or less.

[0055] [Thermoplastic resin (E) with a water absorption rate of 0.28% by mass or more] The thermoplastic polyester resin composition of the present invention does not contain a thermoplastic resin (E) having a water absorption rate measured by the ISO62A method of 0.28% by mass or more, or even if it contains it, the content is less than 9 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). By not containing a thermoplastic resin (E) other than the thermoplastic resin (E) or, even if it contains it, being less than the above amount, significant dimensional changes due to water absorption can be suppressed. The water absorption rate of the thermoplastic resin (E) is preferably 0.25% by mass or more, more preferably 0.20% by mass or more. The upper limit of the water absorption rate of the thermoplastic resin (E) is not limited, but is usually 7% by mass or less, preferably 6% by mass or less, more preferably 5% by mass or less.

[0056] Here, the water absorption rate of the resin is a value obtained by measuring the moisture content after immersion in water at 23°C for 24 hours in accordance with the ISO62A method. It is carried out using a flat test piece with a length and width of 60 mm and a thickness of 3.0 mm, and is the mass % obtained from the percentage of the mass increase before and after water absorption with respect to the original mass (100%) of the test piece.

[0057] The water supply rate of thermoplastic resins is, for example, polyamide resin: 0.4 - 4%, polyimide resin: 0.3%, polyamideimide resin: 0.28%, polymethyl methacrylate resin: 0.3%, ABS resin: 0.3%. The polycarbonate resin is 0.24%, and the polyoxymethylene resin is 0.25%. Incidentally, the water absorption rate of polybutylene terephthalate resin is about 0.09%, and that of polyethylene terephthalate resin is about 0.10%. As the thermoplastic resin (E), a polyamide resin is preferable. In the present invention, within a range that does not impair the effects of the present invention, it is also possible to contain a thermoplastic resin having a water supply rate of less than 0.28% other than the thermoplastic polyester resin (A). As such a thermoplastic resin having a water absorption rate of less than 0.28% other than the thermoplastic polyester resin (A), a polycarbonate resin is preferable because it can suppress warping during molding. When containing a thermoplastic resin having a water absorption rate of less than 0.28% other than the thermoplastic polyester resin (A), the content thereof is preferably less than 9 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). Even when containing a polycarbonate resin, the content thereof is preferably less than 9 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A).

[0058] [Carbon black (F)] The resin composition of the present invention preferably contains carbon black (F) for the purpose of imparting black coloring and enhancing weather (light) resistance such as ultraviolet resistance.

[0059] There are no restrictions on the production method or raw material type of carbon black itself, and any conventionally known one can be used. Specifically, for example, oil furnace black, channel black, acetylene black, ketjen black, etc. can be mentioned. The average particle diameter of the carbon black is preferably 30 to 300 nm, more preferably 50 nm or more, still more preferably 80 nm or more, particularly preferably 100 nm or more. Also, 200 nm or less is more preferable, 170 nm or less is still more preferable, 150 nm or less is particularly preferable, and most preferably 140 nm or less. The average particle diameter of the carbon black is a value obtained by acquiring an aggregate enlarged image according to the procedure described in ASTM D3849, measuring the particle diameters of 3,000 particles as unit constituent particles from this aggregate image, and calculating the arithmetic mean.

[0060] Also, the DBP oil absorption amount of the carbon black is preferably less than 100 ml / 100 g, more preferably less than 70 ml / 100 g, and still more preferably less than 50 ml / 100 g. By making the DBP oil absorption amount less than 100 ml / 100 g, the fluidity of the resin composition tends to improve, which is preferable. The lower limit is usually 5 ml / 100 g, preferably 10 ml / 100 g. The DBP oil absorption amount is a value measured in accordance with JIS K6217-4:2008. Also, the iodine adsorption amount (mg / g) per unit mass of the carbon black is preferably less than 60 mg / g, and more preferably less than 40 mg / g. The lower limit is usually 1 mg / g, preferably 3 mg / g. By making the iodine adsorption amount less than 60 mg / g, the fluidity of the resin composition tends to improve, which is preferable. The iodine adsorption amount is a value measured in accordance with JIS K6217-1:2008.

[0061] The nitrogen adsorption specific surface area of the carbon black is usually 100 m2 Less than / g is preferable, and among them, 80 m 2 / g or less, and among them, 50 m 2 / g or less, particularly 30 m 2 / g or less is preferable. By making the nitrogen adsorption specific surface area 100 m 2 / g or less, the fluidity of the resin composition tends to improve, which is preferable. The lower limit is usually 1 m 2 / g, preferably 3 m 2 / g. The nitrogen adsorption specific surface area is a value measured in accordance with JIS K6217-2:2001. Also, there is no particular limitation on the pH of the carbon black, but it is usually 2 to 10, preferably 3 to 9, and more preferably 4 to 8.

[0062] The content of carbon black (F) is preferably 0.01 to 0.5 parts by mass, more preferably 0.05 parts by mass or more, further preferably 0.1 parts by mass or more, more preferably 0.4 parts by mass or less, and further preferably 0.3 parts by mass or less with respect to 100 parts by mass of the thermoplastic polyester resin (A).

[0063] Carbon black (F) is preferably compounded as a masterbatch. By using the masterbatch, the handleability during melt-kneading of the thermoplastic polyester resin composition and the dispersibility in the resin composition become good, and a resin composition excellent in tracking resistance can be obtained. As the masterbatch, a carbon black masterbatch having a carbon black concentration of 30 to 80% by mass is preferable.

[0064] As carbon black (F), a polyolefin resin-based carbon black masterbatch is preferable. By using a masterbatch melt-kneaded at a high concentration in a polyolefin resin base, the handleability during melt-kneading of the thermoplastic polyester resin composition and the dispersibility in the resin composition become good, and a resin composition excellent in tracking resistance can be obtained.

[0065] As the polyolefin resin used as the base resin of the masterbatch, a homopolymer or copolymer composed of at least one α-olefin having 2 to 8 carbon atoms or a modified product thereof is preferable. Among them, a polyethylene resin, a polypropylene resin, etc. are particularly preferable. As the base resin of the carbon black masterbatch, resins such as polybutylene terephthalate resin can be considered. However, for example, when using a polybutylene terephthalate resin, the effect of improving the tracking resistance tends to be inferior to that of polyolefin resins. As the polyolefin resin, a polyethylene resin is particularly preferable.

[0066] The content of carbon black in the masterbatch is preferably 30 to 80% by mass, more preferably 30 to 70% by mass, and still more preferably 35 to 65% by mass. If the content of carbon black in the masterbatch is less than 30% by mass, the addition amount of the masterbatch will increase in order to obtain a sufficient blackness, and a good black appearance may not be obtained. On the other hand, if it exceeds 80% by mass, poor dispersion of carbon black may occur, which is not preferable.

[0067] The content of the carbon black masterbatch is preferably 0.2 to 4.5 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). If it exceeds 4.5 parts by mass, the tracking resistance tends to deteriorate. The content is more preferably 0.5 part by mass or more, still more preferably 1 part by mass or more, more preferably 4 parts by mass or less, and still more preferably 3.5 parts by mass or less.

[0068] [Flame retardant] The polyester resin composition of the present invention preferably contains a flame retardant. As the flame retardant, for example, a halogen-based flame retardant, a phosphorus-based flame retardant, or a silicone-based flame retardant can be contained. Among them, it is preferable to contain a halogen-based flame retardant or a phosphorus-based flame retardant. Preferable specific examples of the halogen-based flame retardants include brominated polycarbonate resin, brominated epoxy resin, brominated phenoxy resin, brominated polyphenylene ether resin, brominated polystyrene resin, brominated bisphenol A, glycidyl brominated bisphenol A, pentabromobenzyl polyacrylate, brominated imide (such as brominated phthalimide), etc. Among them, bromine-based flame retardants are preferable, and brominated polycarbonate resin, brominated polystyrene resin, glycidyl brominated bisphenol A, and pentabromobenzyl polyacrylate tend to be likely to suppress the decrease in impact resistance and are more preferable.

[0069] Examples of the phosphorus-based flame retardants include metal (di)phosphinates such as aluminum ethylphosphinate, aluminum diethylphosphinate, aluminum ethylmethylphosphinate, zinc diethylphosphinate, reaction products of melamine and phosphoric acid typified by melamine polyphosphate, phosphate esters, phosphazenes such as cyclic phenoxyphosphazene, linear phenoxyphosphazene, and crosslinked phenoxyphosphazene. Among them, metal (di)phosphinates, melamine polyphosphate, and phosphazenes are preferable in terms of excellent thermal stability.

[0070] The content of the flame retardant is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). If the flame retardant is less than 5 parts by mass, it is difficult to obtain sufficient flame retardancy, and if it exceeds 100 parts by mass, the improvement in tracking resistance may not be recognized in some cases. A more preferable content of the flame retardant is 10 parts by mass or more, more preferably 15 parts by mass or more, particularly preferably 20 parts by mass or more with respect to 100 parts by mass of the thermoplastic polyester resin (A), and also more preferably 80 parts by mass or less, more preferably 70 parts by mass or less, among which 60 parts by mass or less, particularly preferably 50 parts by mass or less.

[0071] Furthermore, the polyester resin composition of the present invention preferably contains a flame retardant aid together with the flame retardant. Examples of the flame retardant aid include antimony compounds, zinc borate, copper oxide, magnesium oxide, zinc oxide, molybdenum oxide, zirconium oxide, tin oxide, iron oxide, titanium oxide, aluminum oxide, etc., and two or more of them may be used in combination. Among these, antimony compounds and zinc borate are preferred in terms of better flame retardancy. Examples of the antimony compound include antimony trioxide (Sb2O3), antimony pentoxide (Sb2O5), sodium antimonate, etc. In particular, when a halogen-based flame retardant is used, it is preferable to use antimony trioxide in combination due to the synergistic effect with the flame retardant. When a halogen-based flame retardant and an antimony compound are used in combination, the mass concentration of the halogen atom derived from the halogen-based flame retardant and the antimony atom derived from the antimony compound in the polyester resin composition is preferably 5 to 16% by mass in total, and more preferably 6 to 15% by mass. If it is less than 5% by mass, the flame retardancy tends to decrease, and if it exceeds 16% by mass, the mechanical strength and tracking resistance characteristics may decrease. Also, the mass ratio of the halogen atom to the antimony atom (halogen atom / antimony atom) is preferably 0.3 to 5, and more preferably 0.3 to 4.

[0072] The content of the flame retardant aid is preferably 1 to 30 parts by mass, more preferably 5 to 25 parts by mass, and still more preferably 10 to 20 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A).

[0073] [Colorant] The polyester resin composition of the present invention may contain a colorant. By containing a colorant, the molded article can be given a color tone. The colorant may be a colored colorant or an achromatic colorant. The colorant may be a pigment or a dye.

[0074] Examples of the colored colorants include a red colorant, a blue colorant, a yellow colorant, a green colorant, and an orange colorant. Alternatively, a red colorant composition or the like obtained by mixing two or more colorants to make it red may be used. The colorant preferably includes an orange colorant and / or an orange colorant composition.

[0075] When a colored colorant is included, its content is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, based on 100 parts by mass of the thermoplastic polyester resin (A). By setting the content to be at least the above lower limit value, the colorability tends to be further improved. Also, the upper limit value of the content of the colored colorant is preferably 1 part by mass or less, more preferably 0.8 part by mass or less, based on 100 parts by mass of the thermoplastic polyester resin (A). By setting the content to be at most the above upper limit value, the mechanical strength tends to be further improved.

[0076] [Release agent] The thermoplastic polyester resin composition of the present invention preferably contains a release agent. As the release agent, known release agents commonly used for polyester resins can be used. Among them, polyolefin-based compounds and fatty acid ester-based compounds are preferable in terms of good alkali resistance, and particularly, polyolefin-based compounds are preferable.

[0077] Examples of the polyolefin-based compounds include paraffin wax, Fischer-Tropsch wax, polyethylene wax, etc. Among them, those having a weight average molecular weight of 700 to 10,000, and further preferably 900 to 8,000 are preferable.

[0078] Examples of the fatty acid ester-based compounds include saturated or unsaturated monovalent or divalent aliphatic carboxylic acid esters, glycerin fatty acid esters, sorbitan fatty acid esters, and other fatty acid esters and their partial saponified products. Among them, mono- or di-fatty acid esters composed of fatty acids having 11 to 28 carbon atoms, preferably 17 to 21 carbon atoms, and alcohols are preferable.

[0079] Examples of the fatty acid include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetratetracontanoic acid, montanic acid, adipic acid, azelaic acid and the like. The fatty acid may be alicyclic. Examples of the alcohol include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have substituents such as fluorine atoms and aryl groups. Among these, monohydric or polyhydric saturated alcohols having 30 or less carbon atoms are preferable, and aliphatic saturated monohydric or polyhydric alcohols having 30 or less carbon atoms are more preferable. Here, the aliphatic includes alicyclic compounds. Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol and the like. The above ester compound may contain aliphatic carboxylic acid and / or alcohol as impurities, and may be a mixture of a plurality of compounds.

[0080] Specific examples of the fatty acid ester-based compound include glycerin monostearate, glycerin monobehenate, glycerin dibehenate, glycerin-12-hydroxymonostearate, sorbitan monobehenate, pentaerythritol monostearate, pentaerythritol distearate, stearyl stearate, ethylene glycol montanate and the like.

[0081] The content of the mold release agent is preferably 0.1 to 3 parts by mass, more preferably 0.2 to 2.5 parts by mass, and still more preferably 0.3 to 2 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). If it is less than 0.1 part by mass, the surface property is likely to deteriorate due to poor mold release during melt molding. On the other hand, if it exceeds 3 parts by mass, the kneading workability of the resin composition is likely to deteriorate, and cloudiness is likely to occur on the surface of the molded body.

[0082] [Stabilizer] It is preferable that the thermoplastic polyester resin composition of the present invention contains a stabilizer in that it has the effects of improving thermal stability and preventing deterioration of mechanical strength, transparency, and hue. As the stabilizer, sulfur-based stabilizers and phenolic stabilizers are preferable.

[0083] As the sulfur-based stabilizer, any conventionally known sulfur atom-containing compound can be used, and among them, thioethers are preferable. Specifically, for example, didodecyl thiodipropionate, ditetradecyl thiodipropionate, dioctadecyl thiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropylxanthate, trilauryl trithiophosphite can be mentioned. Among these, pentaerythritol tetrakis(3-dodecylthiopropionate) is preferable.

[0084] Examples of the phenolic stabilizer include pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylene bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), pentaerythritol tetrakis(3-(3,5-dineopentyl-4-hydroxyphenyl)propionate), etc. Among these, pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferable.

[0085] The stabilizer may contain one kind, or may contain two or more kinds in any combination and ratio.

[0086] The content of the stabilizer is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). If the content of the stabilizer is less than 0.001 part by mass, it is difficult to expect improvement in the thermal stability and compatibility of the resin composition, and a decrease in molecular weight and deterioration of hue are likely to occur during molding. If it exceeds 2 parts by mass, it tends to be an excessive amount and silver generation and further deterioration of hue are more likely to occur. The content of the stabilizer is more preferably 0.01 to 1.5 parts by mass, and still more preferably 0.1 to 1 part by mass.

[0087] [Other contained components] The thermoplastic polyester resin composition of the present invention can contain other thermoplastic resins other than the above-mentioned thermoplastic polyester resin (A) and thermoplastic resin (E) within a range that does not impair the effects of the present invention. However, when containing other resins other than the thermoplastic polyester resin (A) and thermoplastic resin (E), the content is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 8 parts by mass or less, particularly preferably 5 parts by mass or less, and especially preferably 3 parts by mass or less with respect to 100 parts by mass of the thermoplastic polyester resin (A).

[0088] Further, the thermoplastic polyester resin composition of the present invention may contain various additives other than those described above. Examples of such additives include anti-dripping agents (such as fluororesins), ultraviolet absorbers, antistatic agents, antifogging agents, antiblocking agents, plasticizers, dispersants, antibacterial agents, and the like. Examples of the plasticizer include various plasticizers such as ester plasticizers (aromatic polycarboxylic acid esters, alicyclic polycarboxylic acid esters, polyesters, sucrose fatty acid esters, etc.), phosphate ester plasticizers (tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, etc.), acrylic polymers, and the like. These plasticizers can be used alone or in combination of two or more. Among these plasticizers, plasticizers with high boiling points (for example, plasticizers having a boiling point of 250 to 400°C, preferably 270 to 400°C, more preferably about 300 to 400°C) are preferred. When a plasticizer is included, effects such as improvement in fluidity can be obtained, for example.

[0089] [Production of Thermoplastic Polyester Resin Composition] To produce the thermoplastic polyester resin composition of the present invention, it can be carried out according to a conventional method for preparing a resin composition. That is, the above-described essential components, as well as other components and additives added as desired, are mixed well together, and then melt-kneaded with a single-screw or twin-screw extruder. Also, without pre-mixing all the components, or only a part of them is pre-mixed, and they are supplied to the extruder using a feeder and melt-kneaded to prepare a resin composition. Further, a resin composition may be prepared by blending a part made into a masterbatch and melt-kneading. Note that it is preferable to side-feed the reinforcing filler (D) by a side feeder. Furthermore, it is also possible to directly supply a mixture in which each component has been pre-mixed to a molding machine such as an injection molding machine without melt-kneading to produce various molded articles.

[0090] [Molded Article] The method for manufacturing a molded article using the thermoplastic polyester resin composition of the present invention is not particularly limited, and any molding method generally adopted for thermoplastic polyester resin compositions can be arbitrarily adopted. For example, injection molding, ultra-high-speed injection molding, injection compression molding, two-color molding, hollow molding methods such as gas assist, molding methods using heat-insulating molds, molding methods using rapidly heated molds, foam molding (including supercritical fluids), insert molding, IMC (in-mold coating molding) molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, blow molding, etc. Among them, injection molding and insert molding are preferred because the effects of the present invention are remarkable, such as good productivity and surface properties of the obtained molded article.

[0091] The obtained molded article has high-level and well-balanced mechanical strength, heat resistance, and dimensional stability characteristics, and is excellent in tracking resistance, heat shock resistance, and hydrolysis resistance. Therefore, as an insulating member for electrical and electronic equipment parts and electrical components where these characteristics are strictly required, for example, it can be particularly preferably used for housings, connectors, relays, switches, breakers, electromagnetic switches, terminal blocks, sensors, actuators, terminal switches, etc. As a molded article, for example, it can be particularly preferably used as a fitting member having a fitting structure or as an insert molded article.

Examples

[0092] Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not to be 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.

[0093]

Table 1

[0094] (Examples 1 to 17, Comparative Examples 1 to 6) After uniformly mixing each component other than the glass fiber shown in Table 1 above at the ratios (all in parts by mass) shown in Table 2 below using a tumbler mixer, the mixture was charged into the hopper of a twin-screw extruder ("TEX30α" manufactured by Nippon Steel Works, Ltd., L / D = 42), and the glass fiber was side-fed. The resin composition was melt-kneaded under the conditions of a cylinder set temperature of 260°C, a discharge rate of 40 Kg / h, and a screw rotation speed of 200 rpm, quenched in a water tank, and pelletized using a pelletizer to obtain pellets of the thermoplastic polyester resin composition.

[0095] <Tracking resistance (CTI: V)> After drying the pellets obtained above at 120°C for 6 hours until just before use, using an injection molding machine ("NEX-80" manufactured by Nissei Plastic Industrial Co., Ltd.), at a cylinder temperature of 260°C, a square flat test piece with a thickness of 3.0 mm and a side length of 100 mm was molded, and a tracking resistance test defined in Test Method UL746A, Item 23 was conducted and measured in accordance with ASTM D3638. An electrolytic solution (0.1% aqueous solution of ammonium chloride, resistivity 385 Ω·cm at 23°C) was dropped from the nozzle of the apparatus at 30-second intervals, a voltage of 600 V or less (25 V step) was applied between both platinum electrodes, the number of drops of the electrolytic solution until tracking occurred was measured, and the voltage (unit: V) at which the average value of 5 times was less than 50 drops was determined. The CTI is preferably 400 V or more, more preferably 450 V or more, and most preferably 600 V or more.

[0096] <Flowability (injection molding peak pressure: MPa)> As an evaluation of the flowability, the peak pressure during injection molding was measured as follows. After drying the pellets obtained by the above manufacturing method at 120°C for 5 hours, using an injection molding machine ("NEX-80" manufactured by Nissei Plastic Industrial Co., Ltd.), the injection molding peak pressure (unit: MPa) when molding a test piece of 100×100×2 mmt was measured under the conditions of a cylinder temperature of 260°C and a mold temperature of 80°C. The peak pressure during molding is preferably 55 MPa or less.

[0097] <Hydrolysis resistance (strength retention rate after wet heat treatment:%)> After drying the pellets obtained by the above manufacturing method at 120°C for 5 hours, using an injection molding machine (J85AD manufactured by Japan Steel Works, Ltd.), an ISO multipurpose test piece (thickness 4.0 mm) was molded under the conditions of a cylinder temperature of 250°C and a mold temperature of 80°C. Using an ISO multipurpose test piece (thickness 4.0 mm), in accordance with ISO 527, under the condition of a tensile speed of 5 mm / min, the tensile strength (before treatment, unit: MPa) was measured. Also, an ISO multipurpose test piece (thickness 4.0 mm) was processed for 100 hours using a pressure cooker tester (manufactured by Hirayama Seisakusho) under the conditions of a temperature of 121°C, a relative humidity of 100%, and a pressure of 2 atm, and similarly, the tensile strength (after hydrothermal treatment, unit: MPa) was measured. From the following formula, the strength retention rate (%) after hydrothermal treatment was determined. Tensile strength after hydrothermal treatment / Tensile strength before hydrothermal treatment × 100% It is preferable that the strength retention rate after hydrothermal treatment is 50% or more.

[0098] <Heat shock resistance (number of cycles)> After drying the obtained pellets at 120°C for 6 hours, using an injection molding machine (J50ADS manufactured by Japan Steel Works, Ltd.), at a cylinder temperature of 250°C and a mold temperature of 80°C, an insert 1 made of iron (SUS) in a substantially rectangular parallelepiped shape shown in FIG. 1 (length 10 mm × width 80 mm × thickness 8.2 mm) was charged into the mold cavity, and an insert molded product 2 having a resin part with a wall thickness of 1 mm on the outer periphery of the insert 1 was manufactured. Using this insert molded product 2, a heat shock test was conducted with a heat shock test apparatus TSA-102ES manufactured by ESPEC. The conditions of the heat shock test were cycles of -40°C for 60 minutes → 150°C for 60 minutes. The insert molded product 2 was subjected to the heat shock test, taken out every 10 cycles, and the presence or absence of crack x on the surface of the molded product 2 was observed, and the number of cycles at which cracks began to appear was determined and evaluated. It is preferable that the number of cycles is 200 cycles or more.

[0099] <Tensile modulus (MPa)> Using the ISO multi-purpose test specimens (4 mm thick) obtained above, the tensile modulus (unit: MPa) was measured in accordance with ISO 527. The tensile modulus is preferably 7500 MPa or more.

[0100] <Water absorption rate (%) of molded product> The test specimens of 100×100×2 mm t molded during the fluidity evaluation were placed in a desiccator to cool to room temperature without absorbing water after molding, and then their weights were measured to the 0.1 mg digit (let the weight be m). After the test specimens were immersed in water at 23 °C for 24 hours, the test specimens were taken out of the water, and all the moisture on the surface was wiped off using a dry cloth, and then their weights were measured to the 0.1 mg digit (let the weight be M). The water absorption rate (%) was calculated from the following formula. (M - m) ÷ m × 100

[0101] <Comprehensive evaluation> For the following items 1 to 6, the following levels a to c were set. 1: CTI a: 350 V or more b: 450 V or more c: 600 V or more 2: Peak pressure a: 80 MPa or less b: 55 MPa or less c: 50 MPa or less 3: Strength retention rate a: 50% or more b: 60% or more c: 70% or more 4: Number of cycles a: 100 or more b: 200 or more c: 300 or more 5: Tensile modulus a: 6500 MPa or more b: 7500 MPa or more c: 8000 MPa or more 6: Water absorption rate a: 0.15% or less b: 0.10% or less c: 0.05% or less In the results of the above items 1 to 6, for each level achieved, a: 1 point, b: 2 points, c: 3 points, and those that did not reach level a were set to 0 points, and the total score was obtained. As the comprehensive evaluation, based on the total score, the following criteria were used for judgment. A (the best): 18 points B (very good): 14 points or more C (good): 12 points or more D (bad): 10 points or more E (Very Bad): Less than 10 points The above results are shown in Table 2 below. In the table, "Ex. n" represents Example n, and "Comp. n" represents Comparative Example n.

[0102]

Table 2

[0103]

Table 3

[0104]

Table 4

Industrial Applicability

[0105] The thermoplastic polyester resin composition of the present invention has excellent mechanical strength, heat resistance, and dimensional stability in a well-balanced manner at a high level. It is also excellent in tracking resistance, heat shock resistance, and hydrolysis resistance, and further has excellent fluidity during injection molding. Therefore, it can be particularly preferably used as an insulating member for electrical and electronic equipment parts and electrical components.

Claims

1. Based on 100 parts by mass of a thermoplastic polyester resin (A) having an intrinsic viscosity of 0.60 dl / g or more and less than 0.85 dl / g, 5 to 30 parts by mass of a maleic anhydride-modified olefin polymer (B), 0.2 to 4.5 parts by mass of a hydrolysis inhibitor (C), 10 to 80 parts by mass of a reinforcing filler (D), and 0.01 to 0.5 parts by mass of carbon black (F) are contained. It does not contain a thermoplastic resin (E) having a water absorption rate of 0.28% by mass or more measured by the ISO62A method, or even if it contains it, the content is less than 9 parts by mass based on 100 parts by mass of the thermoplastic polyester resin (A), and the ratio (B) / (C) of the content of the maleic anhydride-modified olefin polymer (B) to the hydrolysis inhibitor (C) is 99 to 80 / 1 to 20. A thermoplastic polyester resin composition characterized by this.

2. The thermoplastic polyester resin composition according to claim 1, wherein the carbon black (F) is blended as a carbon black masterbatch having a carbon black concentration of 30 to 80% by mass.

3. The thermoplastic polyester resin composition according to claim 2, wherein the carbon black (F) is contained in an amount of 0.01 to 1.0 parts by mass based on 100 parts by mass of the thermoplastic polyester resin (A) as a polyolefin-based carbon black masterbatch.

4. The thermoplastic polyester resin composition according to any one of claims 1 to 3, wherein the maleic anhydride-modified olefin polymer (B) is a maleic anhydride-modified ethylene-propylene copolymer.

5. The thermoplastic polyester resin composition according to any one of claims 1 to 4, wherein the intrinsic viscosity of the thermoplastic polyester resin (A) is 0.60 dl / g or more and less than 0.75 dl / g.

6. The thermoplastic polyester resin composition according to any one of claims 1 to 5, wherein the thermoplastic polyester resin (A) is a polybutylene terephthalate-based resin.

7. The thermoplastic polyester resin composition according to any one of claims 1 to 6, wherein the hydrolysis inhibitor (C) is an epoxy compound.

8. The thermoplastic polyester resin composition according to claim 7, wherein the epoxy equivalent of the epoxy compound is 100 to 2000 g / eq.

9. The thermoplastic polyester resin composition according to any one of claims 1 to 8, further containing a flame retardant.

10. The thermoplastic polyester resin composition according to any one of claims 1 to 9, further containing a colorant.

11. A molded article formed from the thermoplastic polyester resin composition according to any one of claims 1 to 10.

12. The molded article according to claim 11, which is an alignment member.

13. The molded article according to claim 11, which is an insert molded article.

Images