Resin composition, pellet, and molded article

Abstract

To provide a resin composition obtained by compounding a polyalkylene terephthalate resin with an A glass fiber and / or a C glass fiber and giving a molded article having excellent strength retention after a wet heat test and to provide a pellet and a molded article.SOLUTION: The resin composition according to the present disclosure comprises a polyalkylene terephthalate resin, an epoxy compound, and at least one of C-glass fiber and / or A-glass fiber.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a pellet, and a molded article, and more particularly to a resin composition containing a polyalkylene terephthalate resin as a main component. [Background technology]

[0002] Polyalkylene terephthalate resins, typified by polybutylene terephthalate resin and polyethylene terephthalate resin, are widely used in electrical and electronic equipment parts, automotive interior and exterior parts, other electrical parts, machine parts, etc., because of their excellent mechanical strength, chemical resistance, electrical insulation properties, etc. Here, in order to improve the mechanical strength of the polyalkylene terephthalate resin, glass fibers (usually E-glass fibers) are sometimes blended into the polyalkylene terephthalate resin (Patent Document 1, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-087234 [Patent Document 2] Japanese Patent Publication No. 2022-8175 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, recycling of glass fibers has been considered from the viewpoint of effective utilization of resources, and therefore, it is considered to blend recycled glass fibers into polyalkylene terephthalate resins. Here, recycled glass fibers are often made from inexpensive glass used for glass bottles and building materials. Therefore, recycled glass fibers are often A-glass fibers or C-glass fibers. However, the inventors' investigations revealed that when a molded product is produced by blending A-glass fibers or C-glass fibers with a polyalkylene terephthalate resin, the strength decreases after a wet heat test. The present invention aims to solve these problems and to provide a resin composition comprising a polyalkylene terephthalate resin blended with A-glass fiber and / or C-glass fiber, which, when molded into a molded article, has excellent strength retention after a wet heat test, as well as pellets and molded articles. [Means for solving the problem]

[0005] In view of the above-mentioned problems, the present inventors have conducted research and found that the above-mentioned problems can be solved by blending an epoxy compound into a resin composition in which A-glass fiber and / or C-glass fiber are blended with a polyalkylene terephthalate resin. Specifically, the above problems were solved by the following means. [1] A polyalkylene terephthalate resin, an epoxy compound; Contains at least one of C glass fiber and / or A glass fiber, Resin composition. [2] The resin composition according to [1], wherein the polyalkylene terephthalate resin contains a polybutylene terephthalate resin. [3] The resin composition according to [1] or [2], wherein the epoxy compound comprises an epoxidized fatty acid ester. [4] The resin composition according to [1] or [2], wherein the epoxy compound comprises epoxidized vegetable oil, soybean oil, and / or linseed oil. [5] The resin composition according to [1] or [2], wherein the epoxy compound contains linseed oil. [6] The resin composition according to any one of [1] to [5], wherein the C glass fiber and / or the A glass fiber contains recycled glass fiber. [7] The resin composition according to any one of [1] to [6], wherein the C glass fiber and / or the A glass fiber contains sodium oxide and / or potassium oxide in a total amount of 1 part by mass or more per 100 parts by mass of the C glass fiber and / or the A glass fiber. [8] The polyalkylene terephthalate resin includes a polybutylene terephthalate resin, The epoxy compound contains linseed oil. the C-glass fibers and / or A-glass fibers comprise recycled glass fibers; [1] to [7]. The resin composition according to any one of [1] to [7], wherein the C glass fiber and / or the A glass fiber contain sodium oxide and / or potassium oxide in a total amount of 1 part by mass or more per 100 parts by mass of the C glass fiber and / or the A glass fiber. [9] Pellets of the resin composition according to any one of [1] to [8].

[10] A molded article molded from the resin composition according to any one of [1] to [8].

[11] A molded article molded from the pellets described in [9]. [Effects of the Invention]

[0006] The present invention makes it possible to provide a resin composition comprising a polyalkylene terephthalate resin blended with A-glass fiber and / or C-glass fiber, which, when molded into a molded article, has excellent strength retention after a wet heat test, as well as pellets and molded articles. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to only this embodiment. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as upper and lower limits. "A to B" means that the range is A or more and B or less. In addition, any combination of the upper and lower limit values ​​of the numerical values ​​in this specification is an example of this embodiment. In this specification, various physical properties and characteristic values ​​are those at 23°C unless otherwise specified. If the measurement methods, etc. described in the standards shown in this specification change from year to year, they will be based on the standards in effect as of January 1, 2024, unless otherwise specified. If the measurement methods, etc. described in the standards shown in this specification are abolished as of January 1, 2024, they will be based on the standards in effect at the time of abolition.

[0008] The resin composition of the present embodiment is characterized by containing a polyalkylene terephthalate resin, an epoxy compound, and at least one of C-glass fiber and / or A-glass fiber. By adopting such a constitution, it is possible to provide a resin composition that, when formed into a molded article, has an excellent strength retention rate after a wet heat test. In other words, because C-glass fiber and / or A-glass fiber contain a large amount of alkaline components, it is presumed that when molded articles containing them in polyalkylene terephthalate resin are subjected to moist heat treatment, the alkaline decomposition of the polyalkylene terephthalate resin is accelerated, resulting in poor mechanical strength of the molded articles. Under these circumstances, it is presumed that the resin composition of the present embodiment contains an epoxy compound, which allows the strength retention rate after wet heat treatment to be increased.

[0009] Hereinafter, the embodiments of the present invention will be described in detail. However, the explanation of the constituent elements described below is an example of an embodiment of the present invention, and the present invention is not limited to these contents.

[0010] <Polyalkylene terephthalate resin> The resin composition of the present embodiment contains a polyalkylene terephthalate resin. In this embodiment, the polyalkylene terephthalate resin preferably contains a polyethylene terephthalate resin and / or a polybutylene terephthalate resin, and more preferably contains at least a polybutylene terephthalate resin.

[0011] More specifically, the polyalkylene terephthalate resin is a polyester obtained by polycondensation of terephthalic acid as a dicarboxylic acid compound and a diol, and may be either a homopolyester or a copolyester.

[0012] As the dicarboxylic acid compound constituting the polyalkylene terephthalate resin, a terphthalic acid compound or an ester-forming derivative thereof is preferably used. Aromatic dicarboxylic acids other than terephthalic acid can also be used in combination. Examples include 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, diphenylether-4,4'-dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, diphenylisopropylidene-4,4'-dicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid, anthracene-2,5-dicarboxylic acid, anthracene-2,6-dicarboxylic acid, p-terphenylene-4,4'-dicarboxylic acid, and pyridine-2,5-dicarboxylic acid. These can be used in the polycondensation reaction as ester-forming derivatives such as dimethyl esters in addition to free acids. Of the above, isophthalic acid or its ester-forming derivatives are particularly preferred.

[0013] In addition, a small amount of terephthalic acid or the above-mentioned aromatic dicarboxylic acid may be used in combination with one or more aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid, and sebacic acid, or alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.

[0014] Examples of dihydroxy compounds constituting the polyalkylene terephthalate resin include aliphatic diols such as ethylene glycol, propylene glycol, butanediol, hexylene glycol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol, and triethylene glycol, alicyclic diols such as cyclohexane-1,4-dimethanol, and mixtures thereof. Among these, butanediol and ethylene glycol are particularly preferred.

[0015] It is also possible to copolymerize one or more long-chain diols having a molecular weight of 400 to 6,000, such as polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, etc. Also usable are aromatic diols such as hydroquinone, resorcinol, naphthalenediol, dihydroxydiphenyl ether, and 2,2-bis(4-hydroxyphenyl)propane.

[0016] In addition to the above-mentioned bifunctional monomers, a small amount of a trifunctional monomer such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, or trimethylolpropane can be used in combination to introduce a branched structure, or a monofunctional compound such as a fatty acid can be used in combination to adjust the molecular weight.

[0017] The polyalkylene terephthalate resin is preferably one formed by polycondensation of terephthalic acid and a diol, i.e., one in which the polycondensate accounts for more than 50% by mass of the entire resin, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and even more preferably 99% by mass or more. The diol is preferably an aliphatic diol, preferably 1,4-butanediol or ethylene glycol, and more preferably 1,4-butanediol.

[0018] The amount of terminal carboxyl groups in the polyalkylene terephthalate resin (preferably polybutylene terephthalate resin) may be appropriately selected and determined, but is typically 80 eq / ton or less, preferably 50 eq / ton or less, more preferably 30 eq / ton or less, even more preferably 20 eq / ton or less, and even more preferably 15 eq / ton or less. By setting the amount below the upper limit, the hydrolysis resistance of the resin composition tends to be improved. There is no particular lower limit for the amount of terminal carboxyl groups, but it is preferably 1 eq / ton or more, more preferably 5 eq / ton or more, and even more preferably typically 10 eq / ton or more.

[0019] The amount of terminal carboxyl groups in a polyalkylene terephthalate resin is determined by dissolving 0.5 g of the resin in 25 mL of benzyl alcohol and titrating the solution with a 0.01 mol / L benzyl alcohol solution of sodium hydroxide. The amount of terminal carboxyl groups can be adjusted by any conventional method, such as adjusting the polymerization conditions, such as the raw material charge ratio, polymerization temperature, and pressure reduction, or by reacting a terminal blocking agent.

[0020] The intrinsic viscosity of the polyalkylene terephthalate resin (preferably polybutylene terephthalate resin) is preferably 0.50 dL / g or more, more preferably 0.60 dL / g or more, even more preferably 0.70 dL / g or more, even more preferably 0.80 dL / g or more, even more preferably 0.85 dL / g or more, and even more preferably 0.90 dL / g or more. By setting the intrinsic viscosity at or above the lower limit, deterioration of physical properties such as strength tends to be effectively suppressed. Furthermore, the intrinsic viscosity of the polyalkylene terephthalate resin (preferably polybutylene terephthalate resin) is preferably 1.30 dL / g or less, more preferably 1.15 dL / g or less. By setting the intrinsic viscosity at or below the upper limit, deterioration of the fluidity of the resin composition tends to be effectively suppressed.

[0021] The intrinsic viscosity is measured by the following method. Polyalkylene terephthalate resin pellets are dissolved in a phenol / 1,1,2,2-tetrachloroethane (1 / 1 mass ratio) mixed solvent by stirring at 110°C for 1 hour to a concentration of 1.00 g / dL. The solution is then cooled to 30°C. Using a fully automatic solution viscometer, the time it takes for the sample solution and the solvent alone to fall at 30°C is measured, and the intrinsic viscosity is calculated using the formula: Intrinsic viscosity=((1+4K H η sp ) 0.5 -1) / (2K H C) where η sp =η / η0-1, where η is the time it takes for the sample solution to fall, η0 is the time it takes for the solvent alone to fall, C is the concentration of the sample solution (g / dL), and K H is Huggins' constant. K H was set to 0.33. The fully automatic solution viscometer used is manufactured by Shibayama Scientific Co., Ltd. When the resin composition of the present embodiment contains two or more polyalkylene terephthalate resins, the intrinsic viscosity is the intrinsic viscosity of the mixture.

[0022] Preferred polyalkylene terephthalate resins are those in which 95 mol % or more of the acid component is terephthalic acid and 95 mol % or more of the alcohol component is an aliphatic diol, and representative examples thereof are polybutylene terephthalate resin and polyethylene terephthalate resin. These are preferably similar to homopolyesters, i.e., 95 mol % or more of the resin as a whole is composed of terephthalic acid and 1,4-butanediol or ethylene glycol components. The polyalkylene terephthalate resin is preferably a polybutylene terephthalate resin and / or a polyethylene terephthalate resin. Among these, the polyalkylene terephthalate resin preferably contains polybutylene terephthalate resin as a main component, and more than 50% by mass of the polyalkylene terephthalate resin is preferably polybutylene terephthalate resin. In this case, it is also preferable that the polyalkylene terephthalate resin contains less than 50% by mass of polyethylene terephthalate resin.

[0023] Polybutylene terephthalate resin can be produced by batch or continuous melt polymerization of a dicarboxylic acid component containing terephthalic acid as the main component or an ester derivative thereof with a diol component containing 1,4-butanediol as the main component. After producing a low-molecular-weight polybutylene terephthalate resin by melt polymerization, the degree of polymerization (or molecular weight) can be increased to a desired value by further solid-state polymerization under a nitrogen gas flow or reduced pressure.

[0024] The polybutylene terephthalate resin is preferably produced by a continuous melt polycondensation method of a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of 1,4-butanediol.

[0025] The catalyst used in carrying out the esterification reaction may be a conventionally known catalyst, such as a titanium compound, a tin compound, a magnesium compound, or a calcium compound. Among these, titanium compounds are particularly preferred. Specific examples of titanium compounds used as esterification catalysts include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

[0026] The polybutylene terephthalate resin may be a polybutylene terephthalate resin modified by copolymerization (hereinafter, also referred to as a "modified polybutylene terephthalate resin"), and specific preferred copolymers thereof include polyester ether resins copolymerized with polyalkylene glycols (particularly polytetramethylene glycol), dimer acid copolymerized polybutylene terephthalate resins, and isophthalic acid copolymerized polybutylene terephthalate resins.

[0027] When a polyester ether resin copolymerized with polytetramethylene glycol is used as the modified polybutylene terephthalate resin, the proportion of the tetramethylene glycol component in the copolymer is preferably 3 to 40 mass%, more preferably 5 to 30 mass%, and even more preferably 10 to 25 mass%. When a dimer acid copolymerized polybutylene terephthalate resin is used as the modified polybutylene terephthalate resin, the proportion of the dimer acid component in all carboxylic acid components is preferably 0.5 to 30 mol %, more preferably 1 to 20 mol %, and even more preferably 3 to 15 mol %, in terms of carboxylic acid groups. When an isophthalic acid copolymerized polybutylene terephthalate resin is used as the modified polybutylene terephthalate resin, the proportion of isophthalic acid components in all carboxylic acid components is preferably 1 to 30 mol %, more preferably 1 to 20 mol %, and even more preferably 3 to 15 mol %, in terms of carboxylic acid groups. Among the modified polybutylene terephthalate resins, polyester ether resins copolymerized with polytetramethylene glycol and isophthalic acid copolymerized polybutylene terephthalate resins are preferred.

[0028] The content of the polyalkylene terephthalate resin (preferably polybutylene terephthalate resin) in the resin composition of this embodiment is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more, based on 100% by mass of the resin composition. Depending on the application, etc., it may be 45% by mass or more or 50% by mass or less. Furthermore, the content of the polyalkylene terephthalate resin (preferably polybutylene terephthalate resin) is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less, and may be 60% by mass or less depending on the application, etc. The resin composition of the present embodiment may contain only one type of polyalkylene terephthalate resin (preferably polybutylene terephthalate resin), or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0029] <Styrene-based resin>> The resin composition of the present embodiment may contain a styrene-based resin, which can further improve the mechanical strength (e.g., tensile properties, bending properties, etc.) of the resulting molded article. The styrene-based resin used in this embodiment is not particularly limited, and any known styrene-based resin can be used. The styrene-based resin may be a polymer of a styrene-based monomer, or may be a resin obtained by polymerizing a styrene-based monomer and, if necessary, one or more other vinyl monomers copolymerizable therewith.

[0030] Examples of the styrene-based monomer include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, and other styrene derivatives, with styrene being particularly preferred. These may be used alone or in combination of two or more.

[0031] Other vinyl monomers copolymerizable with styrene-based monomers include α,β-unsaturated carboxylic acids and their anhydrides, such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, phthalic acid, and itaconic acid; methacrylic acid alkyl esters, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, cyclohexyl methacrylate, and dodecyl methacrylate; methyl acrylate, ethyl acrylate, and the like. Examples of the acrylic acid ester include alkyl esters of acrylic acid such as butyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, cyclohexyl acrylate, and dodecyl acrylate; aryl esters of acrylic acid such as phenyl acrylate and benzyl acrylate; aryl methacrylate esters such as phenyl methacrylate and benzyl methacrylate; maleimide-based monomers such as maleimide, N-methylmaleimide, and N-phenylmaleimide; and acrylonitrile.

[0032] As the styrene-based resin, a copolymer of a styrene-based monomer and an acrylonitrile monomer (acrylonitrile-styrene resin) is preferred. In the acrylonitrile-styrene resin, the proportion of styrene-based monomers in the total of 100% by mass of the monomers constituting the resin is preferably 20% by mass or more, more preferably 30% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. The acrylonitrile-styrene resin may be a copolymer of a styrene-based monomer, acrylonitrile, and another monomer copolymerizable with either of them. The proportion of the other monomer is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, particularly preferably 5% by mass or less, 3% by mass or less, 2% by mass or less, and particularly preferably 1% by mass or less, based on 100% by mass of the total monomers constituting the acrylonitrile-styrene resin. There are no limitations on the method for producing the acrylonitrile-styrene resin, and known methods can be used, such as bulk polymerization, emulsion polymerization, solution polymerization, and suspension polymerization.

[0033] When the resin composition of the present embodiment contains a styrene-based resin in addition to a polyalkylene terephthalate resin, the mass ratio of the polyalkylene terephthalate resin to the styrene-based resin is preferably 10:90 to 90:10.Furthermore, the proportion of the polyalkylene terephthalate resin relative to 100 parts by mass of the total of the polyalkylene terephthalate resin and the styrene-based resin is preferably 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, more preferably 40 parts by mass or more, even more preferably 50 parts by mass or more, still more preferably 60 parts by mass or more, and preferably 90 parts by mass or less, more preferably 80 parts by mass or less, and still more preferably 70 parts by mass or less.

[0034] The total amount of the polyalkylene terephthalate resin and the styrene-based resin blended as necessary in the resin composition of this embodiment is preferably 70 mass% or more, more preferably 75 mass% or more, even more preferably 80 mass% or more, and preferably 90 mass% or less, based on 100 mass% of the resin composition. The resin composition of the present embodiment may contain only one type of styrene-based resin, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0035] <C glass fiber and / or A glass fiber> The resin composition of this embodiment contains C glass fiber and / or A glass fiber. C glass fiber and / or A glass fiber is a glass fiber containing more alkali metal components (usually sodium oxide and / or potassium oxide) than E glass fiber, and the total of sodium oxide and / or potassium oxide is preferably 1 part by mass or more (preferably 2 parts by mass or more, more preferably 5 parts by mass or more, and preferably 20 parts by mass or less) with respect to 100 parts by mass of the total of the C glass fiber and / or A glass fiber. In this embodiment, the appearance of the molded product obtained even when using such glass fiber can be made good.

[0036] C glass fiber and / or A glass fiber may be recycled glass fiber, and is preferably mechanical recycled glass fiber. A glass is the most widely used glass and is excellent as a recycled resource. Recycled glass fiber is contrasted with virgin glass fiber, and it means including defective products and edge materials that occurred during the production of glass fiber in addition to glass fiber that has once been put on the market. In the resin composition of this embodiment, it is preferable to contain 1% by mass or more of recycled glass fiber with respect to 100% by mass of the total amount of C glass fiber and A glass fiber contained in the resin composition, and it may be 10% by mass or more, 30% by mass or more, 50% by mass or more, 70% by mass or more, 90% by mass or more, and is also 100% by mass or less.

[0037] The C glass fiber and / or A glass fiber preferably has a number-average fiber length of 0.5 to 10 mm, more preferably 1 to 5 mm. The use of glass fibers with such a number-average fiber length can further improve mechanical strength. The number-average fiber length is calculated from the measured values ​​obtained by randomly selecting glass fibers to be measured for fiber length from an image obtained by observation with an optical microscope and measuring the long sides of the fibers. The observation is performed at a magnification of 20x, and the number of fibers measured is 1,000 or more. This roughly corresponds to the cut length. The cross section of the C glass fiber and / or A glass fiber may be any shape, such as a circle, an ellipse, an oval, a rectangle, a rectangle with semicircles on both short sides, or a cocoon shape, but a circle is preferred. Here, the circle includes not only a circle in the geometric sense but also what is generally called a circle in the technical field of this embodiment. The number-average fiber diameter of the C-glass fiber and / or A-glass fiber is preferably 4.0 μm or more, more preferably 4.5 μm or more, and even more preferably 5.0 μm or more. The upper limit of the number-average fiber diameter of the glass fiber is preferably 15.0 μm or less, more preferably 14.0 μm or less. The use of glass fibers having a number-average fiber diameter within this range tends to produce molded products with superior mechanical strength. The number-average fiber diameter of the glass fiber is calculated from the measured values ​​obtained by randomly selecting glass fibers to be measured for fiber diameter from an image obtained by observation with an electron microscope, measuring the fiber diameter near the center, and then measuring the measured fiber diameter. The observation is performed at a magnification of 1,000x, and the number of fibers measured is 1,000 or more. The number-average fiber diameter of glass fibers having a cross section other than a circle is the number-average fiber diameter when converted into a circle with the same area as the cross section. The glass fibers used in this embodiment may be treated with a surface treatment agent or a sizing agent. When the glass fibers are treated with a surface treatment agent or a sizing agent, the content of the surface treatment agent and the sizing agent is preferably 0.01 to 1% by mass of the glass fibers.

[0038] In this embodiment, the total content of C glass fiber and / or A glass fiber in the resin composition is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, even more preferably 7% by mass or more, still more preferably 10% by mass or more, and is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, still more preferably 25% by mass or less, and still more preferably 20% by mass or less. By setting the content at or above the lower limit, mechanical strength tends to be further improved. Meanwhile, by setting the content at or below the upper limit, strength retention after wet heat resistance tends to be further improved. The resin composition of the present embodiment may contain only one type of C glass fiber and / or A glass fiber, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0039] The resin composition of the present embodiment may or may not contain glass fibers other than the C glass fibers and the A glass fibers. The resin composition of this embodiment may be configured to be substantially free of glass fibers other than C-glass fiber and A-glass fiber. "Substantially free of glass fibers other than C-glass fiber and A-glass fiber" means that the content of glass fibers other than C-glass fiber and A-glass fiber in the resin composition of this embodiment is less than 10% by mass of the resin composition, preferably less than 5% by mass, and more preferably less than 1% by mass.

[0040] In particular, the resin composition of this embodiment may or may not contain E-glass fibers. The E-glass fiber may be virgin glass fiber or recycled glass fiber. When the resin composition of the present embodiment contains E-glass fibers, the content thereof is preferably 10 to 20% by mass of the resin composition. Furthermore, when the resin composition of the present embodiment contains E glass fiber, the amount is preferably 1 to 50 parts by mass, and more preferably 1 to 30 parts by mass, per 100 parts by mass of the total amount of glass fiber and / or A glass fiber contained in the resin composition. The resin composition of this embodiment may be configured to be substantially free of E-glass fibers. "Substantially free of E-glass fibers" means that the content of E-glass fibers in the resin composition of this embodiment is less than 10% by mass, preferably less than 5% by mass, and more preferably less than 1% by mass.

[0041] <Epoxy compounds> The resin composition of the present embodiment contains an epoxy compound. By containing an epoxy compound, the hydrolysis resistance of the obtained molded article tends to be improved. The epoxy compound may be a monofunctional epoxy compound or a polyfunctional epoxy compound, but a polyfunctional epoxy compound is preferred. Examples of polyfunctional epoxy compounds include bisphenol A epoxy compounds, bisphenol F epoxy compounds, resorcinol epoxy compounds, novolac epoxy compounds, alicyclic compound diepoxy compounds, glycidyl ethers, and epoxidized polybutadienes. More specifically, alicyclic compound epoxy compounds such as bisphenol A epoxy compounds, bisphenol F epoxy compounds, resorcinol epoxy compounds, novolac epoxy compounds, vinylcyclohexene dioxide, and dicyclopentadiene oxide can all be preferably used. Among these, bisphenol A epoxy compounds and novolac epoxy compounds are more preferred. The epoxy compound may also be a copolymer containing a glycidyl group-containing compound as a constituent component, such as a copolymer of a glycidyl ester of an α,β-unsaturated acid with one or more monomers selected from the group consisting of an α-olefin, acrylic acid, an acrylic acid ester, methacrylic acid, a methacrylic acid ester, and styrene. Furthermore, the epoxy compound is preferably a copolymer of an epoxy group-containing monomer and a styrene-based monomer, and may also be a copolymer with other copolymerizable monomers. Examples of the styrene-based monomer constituting the copolymer of an epoxy group-containing monomer and a styrene-based monomer include glycidyl (meth)acrylate and glycidyl itaconate, with glycidyl methacrylate and glycidyl acrylate being preferred, and glycidyl methacrylate being particularly preferred. Examples of the styrene-based monomer include styrene, α-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, methoxystyrene, monobromostyrene, dibromostyrene, fluorostyrene, and tribromostyrene, with styrene and α-methylstyrene being more preferred, and styrene being particularly preferred. Specific examples of copolymers of epoxy group-containing monomers and styrene-based monomers include glycidyl (meth)acrylate-styrene copolymers and glycidyl (meth)acrylate-styrene-methyl (meth)acrylate, which tend to improve adhesion to epoxy-based adhesives and are therefore particularly preferred.

[0042] In addition to the above, the epoxy compounds can be found in paragraphs 0038 to 0050 of JP-A-2020-199755 and paragraph 0043 of JP-A-2020-125468, the contents of which are incorporated herein by reference.

[0043] The epoxy compound used in this embodiment is preferably an epoxidized fatty acid ester. By using an epoxidized fatty acid ester, thickening of the resin composition can be effectively suppressed, and a significantly high strength retention rate can be achieved even after a moist heat treatment test. This is presumably because the epoxy groups in the epoxidized fatty acid ester are unevenly distributed in the side chains, making them less reactive than terminal epoxy groups. Epoxidized fatty acid esters are compounds obtained by epoxidizing fatty acid esters. The fatty acid ester is preferably a fatty acid ester having one or more (preferably 2 to 10) unsaturated bonds in the molecule. The fatty acid ester is preferably an epoxidized natural fat or oil. As epoxidized natural fats and oils, epoxidized animal fats or epoxidized vegetable fats, soybean oil and / or linseed oil can be used. Examples of animal fats and oils include beef tallow, lard, chicken fat, milk fat, and fish oil. Examples of vegetable fats and oils include soybean oil, rapeseed oil, linseed oil, corn oil, palm oil, sunflower oil, grape oil, cottonseed oil, sesame oil, rice bran oil, peanut oil, castor oil, tung oil, safflower oil, olive oil, and grapeseed oil. At least one selected from the group consisting of soybean oil, rapeseed oil, linseed oil, corn oil, and palm oil is preferred, soybean oil and / or linseed oil is more preferred, and linseed oil is even more preferred.

[0044] The epoxy equivalent of the epoxidized fatty acid ester is preferably 1500 g / eq or less, more preferably 1000 g / eq or less, even more preferably 800 g / eq or less, even more preferably 500 g / eq or less, still more preferably 300 g / eq or less, and preferably 50 g / eq or more, more preferably 75 g / eq or more, even more preferably 100 g / eq or more, still more preferably 150 g / eq or more. By setting it to the upper limit or less, hydrolysis resistance tends to be improved. Furthermore, by setting it to the lower limit or more, thickening of the resin composition tends to be suppressed. When the resin composition of the present embodiment contains two or more epoxy compounds, the epoxy equivalent weight is the weighted average value of the epoxy equivalent weights of the respective epoxy compounds.

[0045] For details of the epoxidized fatty acid ester, in addition to the above, the descriptions in paragraphs 0046 to 0070 of JP-A-2019-026727 and the descriptions in paragraphs 0016 to 0025 of JP-A-2023-136871 can be referred to, the contents of which are incorporated herein by reference. Commercially available epoxidized fatty acid esters can also be used. For example, Chemicizer SE-100 (epoxidized soybean oil, ESBO, general-purpose grade), Chemicizer SE-100ST (epoxidized soybean oil, high-grade), and Chemicizer ELS-100 (epoxidized linseed oil), all manufactured by Sanwa Synthetic Chemical Industry Co., Ltd.; and Sanso Cizer E-2000H (epoxidized soybean oil), Sanso Cizer E-9000H (epoxidized linseed oil), all manufactured by Shin-Nihon Rikagaku Co., Ltd. Examples of such epoxidized fatty acids include SANSO CIZER E-4030 (epoxidized fatty acid isobutyl ester), SANSO CIZER E-6000 (epoxidized fatty acid 2-ethylhexyl ester), manufactured by ADEKA Corporation, ADEKA CIZER O-130P (epoxidized soybean oil), ADEKA CIZER O-180A (epoxidized linseed oil), ADEKA CIZER D-32 (epoxidized fatty acid octyl ester), and ADEKA CIZER D-55 (epoxidized fatty acid alkyl ester).

[0046] When the resin composition of the present embodiment contains an epoxy compound, the content thereof is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, and even more preferably 0.5 parts by mass or more, relative to 100 parts by mass of the polyalkylene terephthalate resin. The upper limit of the content of the epoxy compound is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 7.0 parts by mass or less, and even more preferably 5.0 parts by mass or less, relative to 100 parts by mass of the polyalkylene terephthalate resin. In particular, when the resin composition of this embodiment contains an epoxidized fatty acid ester, the content of the epoxidized fatty acid ester is preferably 0.8 parts by mass or more, more preferably 1.1 parts by mass or more, and preferably 15 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 7.0 parts by mass or less, and even more preferably 5.0 parts by mass or less, relative to 100 parts by mass of the polyalkylene terephthalate resin. Even when the epoxidized fatty acid ester is blended with the polyalkylene terephthalate resin, thickening of the resin composition can be suppressed, so the blending amount can be increased. The resin composition of the present embodiment may contain only one type of epoxy compound, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0047] <Stabilizer> The resin composition of the present embodiment may contain a stabilizer (a light stabilizer and / or a heat stabilizer). The stabilizer preferably contains one or more compounds selected from the group consisting of thioether compounds, hindered phenol compounds, and phosphite compounds, and more preferably a hindered phenol compound. In this embodiment, it is also preferable to use two or more of the thioether-based compounds, hindered phenol-based compounds, and phosphite-based compounds in combination as needed.

[0048] The thioether-based compound may be any conventionally known sulfur-containing compound, and among these, thioethers are preferred. By including the thioether-based compound in the resin composition of the present embodiment, the appearance of the molded article tends to be improved and the thermal stability tends to be improved. Specific examples include didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate], thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropyl xanthate, and trilauryl trithiophosphite. Among these, 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate] is preferred. Commercially available products include Shipro Chemicals' product name "Seenox 412S" and ADEKA's product name "Adekastab AO-412S."

[0049] Examples of hindered phenol compounds include pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylenebis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), pentaerythritol tetrakis(3-(3,5-di-neopentyl-4-hydroxyphenyl)propionate), and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene. 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 preferred. Commercially available products include those manufactured by ADEKA under the trade names "ADK STAB AO-60" and "ADK STAB AO-330," and those manufactured by BASF under the trade name "IRGANOX NOX 1010."

[0050] The phosphite compound is preferably a compound represented by the formula: R 2 OP(OR 3 )(OR 4 ) (In the formula, R 2 , R 3 and R 4 are each a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms, and R 2 , R 3 and R 4 At least one of the groups is an aryl group having 6 to 30 carbon atoms.) Examples of the compound include compounds represented by the following formula: Examples of the phosphite compound include triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris(2-ethylhexyl) phosphite, tris(tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono(tridecyl) phosphite, tetraphenyl dipropylene glycol diphosphite, tetraphenyl tetra(tridecyl) pentaerythritol tetraphosphite, hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl di(tridecyl) phosphite), tetra(tridecyl) 4,4'-isopropyl phosphate, tetra(tridecyl) ... propylidenediphenyl diphosphite, bis(tridecyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris(4-tert-butylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, and the like. Among these, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is preferred. An example of a commercially available product is "ADEKA STAB PEP-36" manufactured by ADEKA Corporation.

[0051] Other examples of stabilizers include the descriptions in paragraphs 0067 to 0075 of JP 2021-063196 A, paragraphs 0046 to 0057 of JP 2018-070722 A, paragraphs 0030 to 0037 of JP 2019-056035 A, and paragraphs 0066 to 0078 of WO 2017 / 038949 A. The contents of these descriptions are incorporated herein by reference.

[0052] The content of the stabilizer in the resin composition of this embodiment is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the polyalkylene terephthalate resin. By ensuring that the content is above the lower limit, the effect of suppressing thermal and oxidative degradation of the resin during melt-kneading, molding, and use as a molded product tends to be more improved, and heat resistance tends to be improved. Furthermore, the upper limit of the stabilizer content is preferably 1.0 parts by mass or less, more preferably 0.8 parts by mass or less, more preferably 0.6 parts by mass or less, even more preferably 0.5 parts by mass or less, and even more preferably 0.4 parts by mass or less, relative to 100 parts by mass of the polyalkylene terephthalate resin. By ensuring that the content is below the upper limit, adverse effects on appearance and physical properties due to aggregation of additives such as stabilizers tend to be effectively suppressed, and discoloration of the resin composition tends to be suppressed. The resin composition of the present embodiment may contain only one stabilizer, or may contain two or more stabilizers. When two or more stabilizers are contained, the total amount is preferably in the above range.

[0053] <Other ingredients> The resin composition of the present embodiment may contain other components in addition to those described above, as necessary, as long as the desired physical properties are not significantly impaired. The other components may be contained alone or in any combination and ratio of two or more. Examples of other components include resin additives, fillers other than the above-mentioned glass fibers, and the like. Specific examples of resin additives include flame retardants, flame retardant auxiliaries, anti-dripping agents, transesterification inhibitors, ultraviolet absorbers, release agents, colorants (pigments, dyes), nucleating agents, antistatic agents, anti-fogging agents, anti-blocking agents, flow improvers, plasticizers, and dispersants. The total amount of these other components is preferably 0% by mass or more and less than 10% by mass, more preferably 0% by mass or more and less than 5% by mass, and even more preferably 0% by mass or more and less than 3% by mass, based on 100% by mass of the resin composition. In the resin composition of this embodiment, the total of the polyalkylene terephthalate resin, the epoxy compound, the C glass fiber and / or the A glass fiber, and any other components blended as required is 100% by mass. In the resin composition of the present embodiment, the polyalkylene terephthalate resin, the styrene-based resin blended as needed, the epoxy compound, the C-glass fiber and / or the A-glass fiber, and the stabilizer preferably account for 90% by mass or more of the resin composition in total, more preferably 95% by mass or more, and may even account for 100% by mass.

[0054] <Method of manufacturing resin composition> The resin composition of this embodiment can be produced by a conventional method for preparing a resin composition (e.g., pellets). Typically, the components and various optional additives are thoroughly mixed together and then melt-kneaded in a single-screw or twin-screw extruder. Alternatively, the resin composition of this embodiment can be prepared without premixing the components, or by premixing only a portion of the components, feeding the mixture into an extruder using a feeder and melt-kneading the mixture. For example, glass fibers are preferably fed into an extruder using a side feeder and melt-kneaded. Alternatively, a masterbatch may be prepared by melt-kneading some of the components with a thermoplastic resin, followed by blending the remaining components with the masterbatch and melt-kneading the resulting mixture. The thermoplastic resin to be used for the masterbatch is preferably a polyalkylene terephthalate resin, more preferably a polybutylene terephthalate resin and / or a polyethylene terephthalate resin, and even more preferably a polybutylene terephthalate resin.

[0055] <Method of manufacturing molded products> The resin composition or pellets of this embodiment are molded according to a known method. The method for producing the molded article is not particularly limited, and any molding method generally used for resin compositions can be used. Examples thereof include injection molding, ultra-high speed injection molding, injection compression molding, two-color molding, gas-assisted or other hollow molding, molding using a heat-insulating mold, molding using a rapid heating mold, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding), extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, blow molding, etc., among which injection molding is preferred. For details of the injection molding method, please refer to the description in paragraphs 0113 to 0116 of Japanese Patent No. 6183822, the contents of which are incorporated herein by reference. Furthermore, the mold temperature during molding such as injection molding is preferably 40 to 150°C.

[0056] <Application> The resin composition of the present embodiment is used as a molded article formed from the resin composition or pellets. The resin composition and pellets can be used for a wide range of known applications. For example, they can be used indoors or outdoors as materials for electrical and electronic devices, automobiles, housing, and parts manufacturing in other industrial fields. More specifically, examples of the material include breakers, electromagnetic switches, various relay parts, transformer parts, sensor parts, switch parts, connector parts, terminal parts, actuator parts, outlet parts, socket parts, plug parts, capacitor parts, resistor parts, charging parts, battery parts, housing parts, structural parts, insulating parts, etc. In particular, the material can be suitably used as a material for parts located near electrical contacts. Automotive materials include lamp housings, reflectors, bezels, extensions, connectors, ECU cases, housings for in-vehicle cameras and millimeter-wave radars, battery cases, and sensor housings. Electrical and electronic components include various housings, display devices for personal computers, game consoles, televisions, etc., printers, copiers, scanners, fax machines, electronic organizers and PDAs, electronic desk calculators, electronic dictionaries, cameras, video cameras, mobile phones, battery packs, recording medium drives and readers, mice, numeric keypads, CD players, MD players, portable radios and audio players, housings, covers, keyboards, buttons, switch components, power meter casings, battery cases, battery transport trays, relays, sensors, actuators, terminal switches, and grill cooking equipment parts. [Example]

[0057] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0058] 1.Raw materials The following raw materials were used: [Table 1]

[0059] 2. Examples 1 to 6, Comparative Examples 1 and 2, Reference Examples 1 and 2 <Compound> The components shown in Table 1 were mixed uniformly in a tumbler mixer in the proportions shown in Table 2 or Table 3 (each component in Table 2 and Table 3 is expressed in mass %), with the exception of the glass fiber. The resulting mixture was fed into a twin-screw extruder ("TEX30α" manufactured by The Japan Steel Works, Ltd.) through the main feed port. The cylinder temperature of the first kneading section was set to 260°C, and the glass fiber was fed through a side feeder. The resin composition was melt-kneaded under conditions of a cylinder temperature setting of 220°C and a screw rotation speed of 200 rpm after the addition of the glass fiber, and then quenched in a water bath and pelletized using a pelletizer to obtain pellets of the resin composition.

[0060] <Melt Volume Rate (MVR)> The melt volume rate (MVR) of the obtained resin composition was measured in accordance with ISO 1133 at a measurement temperature of 250°C and a measurement load of 5 kgf. The unit is cm. 3 / 10min.

[0061] <Tensile strength and its retention rate after wet heat treatment> The resin composition pellets obtained above were dried at 120°C for 5 hours, and then injection-molded into JIS K7139 multipurpose test pieces (4 mm thick) using an injection molding machine (J-85AD-60H) under conditions of a cylinder temperature of 265°C and a mold temperature of 80°C. The obtained multipurpose test piece (4 mm thick) was treated for 50 hours using a pressure cooker tester under conditions of a temperature of 121°C, a relative humidity of 100%, and a pressure of 2 atm. The pressure cooker tester used was ESPEC EH8-221M.

[0062] For the test specimens before and after the moist heat treatment, the tensile strength (unit: MPa) and its retention rate (unit: %) were measured at a temperature of 23°C using the above ISO multipurpose test specimens (4 mm thick) in accordance with ISO527-1 and 2. Flexural strength retention rate (%) = (tensile strength after PCT treatment / tensile strength without PCT treatment) x 100

[0063] [Table 2]

[0064] [Table 3]

[0065] As is clear from the above results, by blending an epoxy compound in the resin composition of this embodiment, molded articles having excellent strength even after wet heat treatment were obtained (Examples 1 to 6). In addition, the MVR of the resin composition was low, and thickening was effectively suppressed. In particular, by using an epoxidized fatty acid ester as the epoxy compound, thickening of the resin composition was more effectively suppressed (Examples 3, 4, 5, and 6) than when E-glass fiber was used (Reference Examples 1 and 2). In contrast, when no epoxy compound was blended, the strength of the molded article after the moist heat treatment test was poor (Comparative Examples 1 and 2).

[0066] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.

Claims

1. a polyalkylene terephthalate resin; an epoxy compound; Contains at least one of C-glass fiber and / or A-glass fiber, Resin composition.

2. The resin composition according to claim 1 , wherein the polyalkylene terephthalate resin comprises a polybutylene terephthalate resin.

3. The resin composition according to claim 1 or 2, wherein the epoxy compound comprises an epoxidized fatty acid ester.

4. The resin composition according to claim 1 or 2, wherein the epoxy compound comprises epoxidized vegetable oil, soybean oil and / or linseed oil.

5. The resin composition according to claim 1 or 2, wherein the epoxy compound comprises linseed oil.

6. The resin composition according to claim 1 or 2, wherein the C-glass fiber and / or the A-glass fiber comprises recycled glass fiber.

7. 3. The resin composition according to claim 1, wherein the C glass fiber and / or the A glass fiber contains sodium oxide and / or potassium oxide in a total amount of 1 part by mass or more per 100 parts by mass of the C glass fiber and / or the A glass fiber.

8. the polyalkylene terephthalate resin comprises a polybutylene terephthalate resin, The epoxy compound contains linseed oil. the C-glass fibers and / or A-glass fibers comprise recycled glass fibers; 2. The resin composition according to claim 1, wherein the C glass fiber and / or the A glass fiber contains sodium oxide and / or potassium oxide in a total amount of 1 part by mass or more per 100 parts by mass of the C glass fiber and / or the A glass fiber.

9. Pellets of the resin composition according to claim 1, 2 or 8.

10. A molded article molded from the resin composition according to claim 1, 2 or 8.

11. A molded article formed from the pellets according to claim 9.