Resin compositions, pellets, and molded articles

Abstract

To provide a resin composition, pellets, and molded articles that are excellent in flame retardancy and heat resistance, and that have a high dielectric breakdown strength retention rate. The resin composition according to this disclosure comprises 100 parts by mass of a resin component consisting of (a) 80 to 100 parts by mass of a polyphenylene ether resin and (b) 0 to 20 parts by mass of a styrene resin, (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group, and (d) a condensed phosphate ester flame retardant, wherein the total content of (c) the phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) the condensed phosphate ester flame retardant is 10 to 25 parts by mass per 100 parts by mass of the resin component, and the mass ratio (c) / (d) of the content of (c) the phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) the condensed phosphate ester flame retardant is 18 / 82 to 90 / 10.

Description

[Technical Field]

[0001] The present invention relates to resin compositions, pellets, and molded articles. In particular, it relates to resin compositions containing a polyphenylene ether resin as a main component. [Background technology]

[0002] Resin compositions based on polyphenylene ether resins possess characteristics such as heat resistance, electrical properties, dimensional stability, impact resistance, and low specific gravity. Furthermore, because polyphenylene ether resin compositions can achieve flame retardancy without using halogenated compounds or antimony compounds, which have a significant environmental impact, they are widely used in various applications such as electrical and electronic components, office equipment parts, automotive parts, building materials, and various other exterior materials and industrial products.

[0003] Furthermore, in recent years, the miniaturization and increased performance of components have led to a demand for a wider range of performance characteristics. For example, Patent Document 1 discloses a polyphenylene ether resin composition that is excellent in flame retardancy and long-term flame retardancy, comprising a polyphenylene ether resin, a phosphorus-based flame retardant, and a phosphorus-based antioxidant. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2017 / 077683 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, the inventors' investigations revealed that while the resin composition described in Patent Document 1 exhibits excellent flame retardancy, it may have poor heat resistance. In particular, it was found that it is difficult to achieve both flame retardancy and heat resistance (load deflection temperature) while maintaining high dielectric breakdown strength after heating. The present invention aims to solve the aforementioned problems and to provide a resin composition, pellets, and molded articles that are excellent in flame retardancy and heat resistance, and that have a high dielectric breakdown strength retention rate after heating. [Means for solving the problem]

[0006] Based on the above problems, the inventors conducted research and found that the above problems can be solved by blending a phosphate compound having an aromatic ring substituted with a hydrocarbon group with a condensed phosphate ester flame retardant in a predetermined ratio. Specifically, the above problem was solved by the following means. [1] A resin component comprising 100 parts by mass of (a) 80 to 100 parts by mass of polyphenylene ether resin and (b) 0 to 20 parts by mass of styrene resin, (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group, and (d) a condensed phosphate ester flame retardant, The total content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant is 10 to 25 parts by mass per 100 parts by mass of the resin component. A resin composition wherein the mass ratio (c) / (d) of the content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant is 18 / 82 to 90 / 10. [2] The resin composition according to [1], wherein the mass ratio (c) / (d) of the content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant is 30 / 70 to 90 / 10. [3] The resin composition according to [1] or [2], further comprising (e) an inorganic filler. [4] The resin composition according to any one of [1] to [3], wherein the phosphate compound having an aromatic ring substituted with a hydrocarbon group (c) comprises a phosphate compound having an aromatic ring substituted with an alkyl group having 1 to 3 carbon atoms. [5] The resin composition according to any one of [1] to [4], wherein the phosphate compound having an aromatic ring substituted with a hydrocarbon group (c) comprises a compound represented by formula (P1). [ka] (In formula (P1), each R is an alkyl group having 1 to 3 carbon atoms, and each n is an integer from 0 to 5, provided that at least one of the three n is an integer from 1 to 5.) [6] The resin composition according to any one of [1] to [5], wherein the (d) condensed phosphate ester flame retardant comprises a compound represented by formula (P2). [ka] (In formula (P2), X is a divalent organic group, X 2 Each of the elements is an alkyl group having 1 to 3 carbon atoms, and each of the elements n2 is an integer from 0 to 5. [7] The mass ratio of the content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant, (c) / (d), is 30 / 70 to 90 / 10, and further, (e) an inorganic filler is included. The phosphate compound having an aromatic ring substituted with a hydrocarbon group (c) includes the compound represented by formula (P1), The resin composition according to any one of [1] to [6], wherein the (d) condensed phosphate ester flame retardant comprises a compound represented by formula (P2). [ka] (In formula (P1), each R is an alkyl group having 1 to 3 carbon atoms, and each n is an integer from 0 to 5, provided that at least one of the three n is an integer from 1 to 5.) [ka] (In formula (P2), X is a divalent organic group, X 2is each independently an alkyl group having 1 to 3 carbon atoms, and n2 is each independently an integer of 0 to 5.) The pellet of the resin composition according to any one of [1] to [7]. A molded article formed from the resin composition according to any one of [1] to [7]. A molded article formed from the pellet according to [8]. [Effect of the Invention]

[0007] According to the present invention, a resin composition, a pellet, and a molded article capable of providing a molded article excellent in flame retardancy and heat resistance and having a high insulation breakdown strength retention rate after heating have been provided. [Mode for Carrying Out the Invention]

[0008] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an exemplification for explaining the present invention, and the present invention is not limited only to the present embodiment. In this specification, "~" is used to mean including the numerical values described before and after it as lower and upper limits. Further, any combination of the upper and lower limits of the numerical values in this specification can be cited as an example of the present embodiment. In this specification, a combination of preferred embodiments is a more preferred embodiment. In this specification, unless otherwise specified, various physical property values and characteristic values are those at 23°C. When the measurement methods and the like described according to the standards shown in this specification differ depending on the year, unless otherwise specified, they are based on the standards as of January 1, 2025. When the measurement methods and the like described according to the standards shown in this specification have been abolished as of January 1, 2025, they are based on the standards at the time of abolition.

[0009] The resin composition of this embodiment is characterized in that, with respect to 100 parts by mass of a resin component consisting of (a) 80 to 100 parts by mass of a polyphenylene ether resin and (b) 0 to 20 parts by mass of a styrene resin, it contains (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant, the total content of (c) the phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) the condensed phosphate ester flame retardant is 10 to 25 parts by mass per 100 parts by mass of the resin component, and the mass ratio (c) / (d) of the content of (c) the phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) the condensed phosphate ester flame retardant is 18 / 82 to 90 / 10. By adopting this configuration, a resin composition can be obtained that provides molded products with excellent flame retardancy and heat resistance, as well as a high retention rate of dielectric breakdown strength after heating.

[0010] In other words, to improve the flame retardancy of polyphenylene ether resins, it is conceivable to incorporate phosphorus-based flame retardants. Therefore, the inventors considered incorporating (d) condensed phosphate ester flame retardants, which are commonly used in polyphenylene ether resins. However, it was found that when the content of (d) condensed phosphate ester flame retardants was high, the retention rate of dielectric breakdown strength of the resulting molded articles deteriorated. Therefore, it was decided to use (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group in combination with (d) the condensed phosphate ester flame retardant. It is presumed that the phosphate compound having an aromatic ring substituted with a hydrocarbon group improved the stability between the phosphorus and oxygen atoms due to steric hindrance by the hydrocarbon group, thereby improving flame retardancy while maintaining high dielectric breakdown strength. On the other hand, it was found that when the amount of phosphate compound having an aromatic ring substituted with a hydrocarbon group was high, the temperature of deflection under load became low. Under these circumstances, it is presumed that by adjusting the ratio of (c) / (d), excellent flame retardancy and heat resistance (high DTUL) and a high dielectric breakdown strength retention rate could be achieved.

[0011] The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is merely one example of an embodiment of the present invention and is not limited to these.

[0012] <(a) Polyphenylene ether resin> The resin composition of this embodiment includes (a) a polyphenylene ether resin. The (a) polyphenylene ether resin used in the resin composition of this embodiment can be a known polyphenylene ether resin, for example, a polymer having a main chain of structural units represented by the following formula is exemplified. The (a) polyphenylene ether resin may be either a homopolymer or a copolymer. The (a) polyphenylene ether resin may also contain a group having -X(=O)- (where X is a carbon atom, a sulfur atom, or a phosphorus atom), but it is preferable that it is substantially free of such groups. Substantially free means that 90% or more by mass, more preferably 95% or more by mass, and even more preferably 99% or more by mass of the structural units constituting the (a) polyphenylene ether resin are structural units that do not contain a group having -X(=O)-. Examples of groups having -X(=O)- include carbonyl groups, ester groups, phosphate ester groups, phosphite ester groups, hypophosphite ester groups, sulfoxyoxide groups, sulfone groups, etc.

[0013] [ka] (In the formula, two R a Each of these independently represents a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, an aminoalkyl group, a halogenated alkyl group, a hydrocarbon oxy group, or a halogenated hydrocarbon oxy group, and the two R b Each of these independently represents a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, a halogenated alkyl group, a hydrocarbon oxy group, or a halogenated hydrocarbon oxy group. However, two R a (They cannot both become hydrogen atoms.)

[0014] Ra and R b are each independently preferably a hydrogen atom, a primary or secondary alkyl group, or an aryl group. Preferred examples of the primary alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-amyl group, an isoamyl group, a 2-methylbutyl group, a 2,3-dimethylbutyl group, a 2-, 3- or 4-methylpentyl group, or a heptyl group. Preferred examples of the secondary alkyl group include, for example, an isopropyl group, a sec-butyl group, or a 1-ethylpropyl group. In particular, R a is preferably a primary or secondary alkyl group having 1 to 4 carbon atoms or a phenyl group. R b is preferably a hydrogen atom.

[0015] Preferred homopolymers of the (a) polyphenylene ether-based resin include, for example, polymers of 2,6-dialkylphenylene ethers such as poly(2,6-dimethyl-1,4-phenylene ether), poly(2,6-diethyl-1,4-phenylene ether), poly(2,6-dipropyl-1,4-phenylene ether), poly(2-ethyl-6-methyl-1,4-phenylene ether), poly(2-methyl-6-propyl-1,4-phenylene ether). Examples of the copolymer include 2,6-dialkylphenol / 2,3,6-trialkylphenol copolymers such as 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dimethylphenol / 2,3,6-triethylphenol copolymer, 2,6-diethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dipropylphenol / 2,3,6-trimethylphenol copolymer; graft copolymers obtained by graft-polymerizing styrene onto poly(2,6-dimethyl-1,4-phenylene ether); graft copolymers obtained by graft-polymerizing styrene onto 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, and the like.

[0016] In this embodiment, (a) the polyphenylene ether resin is particularly preferably poly(2,6-dimethyl-1,4-phenylene ether) and 2,6-dimethylphenol / 2,3,6-trimethylphenol random copolymer. In addition, polyphenylene ether resins with specified terminal group numbers and copper content, as described in Japanese Patent Application Publication No. 2005-344065, can also be suitably used.

[0017] (a) The polyphenylene ether resin is preferably one with an intrinsic viscosity of 0.2 to 0.8 dL / g, and more preferably 0.3 to 0.6 dL / g, measured in chloroform at 30°C. A viscosity of 0.2 dL / g or higher tends to improve the mechanical strength of the resin composition, while a viscosity of 0.8 dL / g or lower tends to improve fluidity and facilitate molding. Alternatively, two or more (a) polyphenylene ether resins with different intrinsic viscosities may be used in combination to achieve this viscosity range.

[0018] The (a) polyphenylene ether resin used in this embodiment may be recycled polyphenylene ether resin (including recovered products, material recycled products, chemical recycled products, etc.), rejected products, or scraps generated when molding molded products from a polyphenylene ether resin composition.

[0019] The method for producing the polyphenylene ether resin (a) used in this embodiment is not particularly limited, and a known method can be employed, for example, by oxidative polymerization of a monomer such as 2,6-dimethylphenol in the presence of an amine copper catalyst. In this case, the intrinsic viscosity can be controlled to a desired range by selecting the reaction conditions. Control of the intrinsic viscosity can be achieved by selecting conditions such as polymerization temperature, polymerization time, and catalyst amount.

[0020] (b) Styrene resin The resin composition of this embodiment may also contain (b) a styrene-based resin. Examples of styrene-based resins used in this embodiment include polystyrene resin (PS), rubber-modified styrene resin (also known as high-impact polystyrene, HIPS), acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-ethylene propylene-rubber-styrene copolymer (AES resin), styrene-IPN (Inter Penetration Network) type rubber copolymer, styrene-olefin block copolymer, or mixtures thereof. In this embodiment, rubber-modified styrene resin is preferred.

[0021] Rubber-modified styrene resins refer to all rubber-modified styrene resins that contain rubber particles including rubber polymers, and one or more types of styrene resins. Specifically, the resin is obtained by dispersing rubber particles containing a rubbery polymer in a matrix of styrene-based resin, either by polymerizing a styrene-based compound alone, or a styrene-based compound with a compound copolymerizable with the styrene-based compound, in the presence of a rubbery polymer. Rubber particles containing a rubbery polymer may have a styrene-based resin encapsulated inside the rubbery polymer and / or have a styrene-based resin grafted onto the outside of the rubbery polymer.

[0022] The rubbery polymer in the rubber-modified styrene resin is not particularly limited, but diene rubbers such as polybutadiene, styrene-butadiene copolymer rubber, butadiene-butyl acrylate copolymer rubber, and acrylonitrile-butadiene copolymer rubber, acrylic rubbers such as polybutyl acrylate, silicone-acrylic composite rubber, polyisoprene, polychloroprene, ethylene-propylene rubber, ethylene-propylene-diene ternary copolymer rubber, styrene-butadiene block copolymer rubber, styrene-isoprene block copolymer rubber, and other block copolymers, as well as hydrogenated versions thereof, can be used. Among these rubbery polymers, polybutadiene, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, and polybutyl acrylate are preferred. These rubbery polymers may be used individually or in combination of two or more types.

[0023] The content of the rubbery polymer in the rubber-modified styrene resin is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, and even more preferably 5% by mass or more. The content of the rubbery polymer in the rubber-modified styrene resin is preferably 50% by mass or less, and from the viewpoint of the impact resistance and moldability of the resin composition, it is preferably 45% by mass or less, even more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0024] Examples of styrene resins included in rubber-modified styrene resins include polystyrene (PS), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-ethylene propylene-rubber-styrene copolymer (AES resin), and styrene-IPN type rubber copolymer. These may be used individually or in combination of two or more types.

[0025] The styrene resin used in this embodiment may be recycled styrene resin (including recovered products, material recycled products, chemical recycled products, etc.), rejected products, or scraps generated when molding molded products from styrene resin compositions.

[0026] <(a) blend ratio of polyphenylene ether resin and (b) styrene resin> The resin composition of this embodiment contains (a) a polyphenylene ether resin in a ratio of 80 to 100 parts by mass and (b) a styrene resin in a ratio of 0 to 20 parts by mass. In the resin composition of this embodiment, when the total of (a) the polyphenylene ether resin and (b) the styrene resin is 100 parts by mass, the proportion of (a) the polyphenylene ether resin is preferably 81 parts by mass or more, more preferably 82 parts by mass or more, even more preferably 83 parts by mass or more, even more preferably 84 parts by mass or more, and also preferably 100 parts by mass or less, preferably 99 parts by mass or less, more preferably 98 parts by mass or less, even more preferably 97 parts by mass or less, and even more preferably 96 parts by mass or less. Setting the proportion above the lower limit tends to further improve the short-term heat resistance and flame retardancy of the resulting molded product. Setting the proportion below the upper limit tends to further improve the moldability of the resin composition and the impact resistance of the resulting molded product. The resin composition of this embodiment may contain only one type each of (a) polyphenylene ether resin and (b) styrene resin, or it may contain two or more types of either or both. When two or more types of (a) polyphenylene ether resin and / or (b) styrene resin are included, it is preferable that the total amount is within the above range.

[0027] The total amount of (a) polyphenylene ether resin and (b) styrene resin in the resin composition of this embodiment is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, even more preferably 45% by mass or more, even more preferably 50% by mass or more, even more preferably 55% by mass or more, and especially most preferably 57% by mass or more. Setting it above the lower limit tends to effectively exhibit the inherent properties of the polyphenylene ether resin and styrene resin, such as heat resistance, electrical properties, dimensional stability, impact resistance, and low specific gravity. Furthermore, the total amount of (a) polyphenylene ether resin and (b) styrene resin in the resin composition of this embodiment is preferably 83% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, even more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less. Setting it below the upper limit allows the modifying effect of the additive components that impart the desired properties to the resin composition to be effectively exhibited.

[0028] <(c) Phosphate compounds having aromatic rings substituted with hydrocarbon groups> The resin composition of this embodiment contains a phosphate compound having an aromatic ring substituted with a hydrocarbon group. By including a phosphate compound having an aromatic ring substituted with a hydrocarbon group, the dielectric breakdown strength can be maintained at a high level even after moist heat treatment, and the mechanical properties can also be further improved. (c) In phosphate compounds having an aromatic ring substituted with a hydrocarbon group, the hydrocarbon group is preferably a phenyl group, a C6-C12 alkylphenyl group, a C1-C6 alkyl group, more preferably a C1-C3 alkyl group, and even more preferably a methyl group. (c) The number of hydrocarbon groups that are substituents in a single molecule of a phosphate compound having an aromatic ring substituted with hydrocarbon groups is preferably 1 to 10, and more preferably 2 to 9. (c) Phosphate compounds having an aromatic ring substituted with a hydrocarbon group preferably include compounds represented by formula (P1). [ka] (In formula (P1), each R is an alkyl group having 1 to 3 carbon atoms, and each n is an integer from 0 to 5, provided that at least one of the three n is an integer from 1 to 5.)

[0029] In formula (P1), each R is independently an alkyl group having 1 to 3 carbon atoms, and a methyl group is preferred. In formula (P1), n ​​is an independent integer between 0 and 5, and is preferably 1 or greater, and also preferably 3 or less. In equation (P1), it is preferable that at least one of the three n is an integer between 1 and 5, at least two of the three n are independently integers between 1 and 5, and it is preferable that all three n are independently integers between 1 and 5.

[0030] Examples of compounds represented by formula (P1) are shown below. It goes without saying that the present invention is not limited to these. [ka]

[0031] The content of the phosphate compound having an aromatic ring substituted with a hydrocarbon group in the resin composition of this embodiment is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, even more preferably 9 parts by mass or more, even more preferably 11 parts by mass or more, and also preferably 22 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 17 parts by mass or less, even more preferably 15 parts by mass or less, and even more preferably 13 parts by mass or less. Setting the content above the lower limit tends to further improve the flame retardancy and moldability of the resulting molded article. Setting the content below the upper limit tends to further improve the short-term heat resistance and mechanical strength of the resulting molded article. The resin composition of this embodiment may contain only one phosphate compound having an aromatic ring substituted with a hydrocarbon group, or it may contain two or more. When it contains two or more, it is preferable that the total amount is within the above range.

[0032] The resin composition of this embodiment may or may not contain triphenyl phosphate (TPP). The resin composition of this embodiment can be substantially TPP-free. Substantially TPP-free means that the TPP content is less than 15% by mass of the content of the phosphate compound having an aromatic ring substituted with a (c) hydrocarbon group contained in the resin composition, preferably less than 10% by mass, more preferably less than 7% by mass, even more preferably less than 5% by mass, even more preferably less than 3% by mass, and even more preferably less than 1% by mass, less than 0.1% by mass, or less than 0.01% by mass. [ka]

[0033] <(d) Condensed phosphate flame retardant> The resin composition of this embodiment contains (d) a condensed phosphate ester flame retardant. By including (d) the condensed phosphate ester flame retardant, the flame retardancy of the resulting molded article can be further improved. (d) As a condensed phosphate ester flame retardant, a compound represented by formula (P) is preferred. Formula (P) [ka] (In formula (P), R1, R2, R3, and R4 each independently represent a hydrogen atom or an organic group, except when R1, R2, R3, and R4 are all hydrogen atoms. X represents a divalent organic group, and r represents an integer from 1 to 3.)

[0034] In formula (P), the organic group is, for example, an alkyl group (e.g., an alkyl group having 1 to 5 carbon atoms), a cycloalkyl group (e.g., a cycloalkyl group having 6 to 12 carbon atoms), or an aryl group (e.g., an aryl group having 6 to 12 carbon atoms), with or without substituents, and an aryl group is preferred. Examples of substituents include alkyl groups, alkoxy groups, alkylthio groups, aryl groups, aryloxy groups, arylthio groups, halogen atoms, aryl halides, etc., and alkyl groups are preferred. Groups are also possible combinations of these substituents, or groups obtained by bonding these substituents with oxygen atoms, sulfur atoms, nitrogen atoms, etc. A divalent organic group is a group with two or more valents that can be obtained by removing one hydrogen atom from the above organic group. Examples include alkylene groups (e.g., alkylene groups having 1 to 5 carbon atoms), phenylene groups, substituted phenylene groups (e.g., phenylene groups which may be substituted with an alkyl group having 1 to 5 carbon atoms), and polynuclear phenylene groups derived from bisphenols. In this embodiment, in formula (P), R1, R2, R3, and R4 are preferably phenyl groups which may each be independently substituted with an alkyl group having 1 to 5 carbon atoms (preferably a methyl group). In formula (P), X is preferably a phenylene group or a group consisting of a combination of a phenylene group and an alkylene group, and more preferably a phenylene group. In formula (P), r is preferably 1 or 2, and more preferably 1. The compound represented by formula (P) may be a mixture of compounds in which r is 1 to 3.

[0035] In this embodiment, (d) the condensed phosphate ester flame retardant is more preferably a compound represented by formula (P2). [ka] (In formula (P2), X is a divalent organic group, X 2 Each of the elements is an alkyl group having 1 to 3 carbon atoms, and each of the elements n2 is an integer from 0 to 5.

[0036] In formula (P2), X is a divalent organic group and is equivalent to X in formula (P), and the preferred range is also the same. In formula (P2), X 2 Each of these is independently an alkyl group having 1 to 3 carbon atoms, and a methyl group is preferred. Each n2 is an independent integer between 0 and 5, preferably an independent integer greater than or equal to 1, and preferably an independent integer less than or equal to 3. When n2 is 1 or greater, and preferably 2, the dielectric breakdown strength retention rate of the resulting molded product after heating tends to be significantly higher.

[0037] Examples of compounds represented by formula (P) and / or formula (P2) are shown below. It goes without saying that the present invention is not limited to these. [ka]

[0038] In this embodiment, it is particularly preferable to include the following compound as the compound represented by formula (P2). By using the following compound, the dielectric breakdown strength retention rate after heating of the resulting molded article tends to be significantly higher. [ka]

[0039] The content of (d) condensed phosphate ester flame retardant in the resin composition of this embodiment is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, preferably 22 parts by mass or less, more preferably 17 parts by mass or less, even more preferably 15 parts by mass or less, even more preferably 19 parts by mass or less, and even more preferably 5 parts by mass or less, based on 100 parts by mass of the resin component consisting of (a) polyphenylene ether resin and (b) styrene resin. Setting the content above the lower limit tends to further improve the flame retardancy and moldability of the resulting molded article. Also, setting the content below the upper limit tends to further improve the short-term heat resistance of the resulting molded article. The resin composition of this embodiment may contain only one type of (d) condensed phosphate ester flame retardant, or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0040] <(c) Total content and blend ratio of phosphate compounds having aromatic rings substituted with hydrocarbon groups and (d) condensed phosphate ester flame retardants> In the resin composition of this embodiment, the total content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant is preferably 10 parts by mass or more, 12 parts by mass or more, 25 parts by mass or less, 20 parts by mass or less, and more preferably 17 parts by mass or less, per 100 parts by mass of the resin component consisting of (a) a polyphenylene ether resin and (b) a styrene resin. Setting the content above the lower limit tends to further improve the flame retardancy and moldability of the resulting molded article. Setting the content below the upper limit tends to further improve the short-term heat resistance of the resulting molded article.

[0041] Also, in the resin composition of the present embodiment, the mass ratio (c) / (d) of the content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group to (d) a condensed phosphate ester flame retardant is 18 / 82 to 90 / 10, preferably 30 / 70 to 90 / 10. By setting it to be not less than the lower limit value, the obtained molded product tends to have a higher insulation breakdown strength retention rate and better long-term heat resistance. Also, by setting it to be not more than the upper limit value, the obtained molded product tends to have a higher insulation breakdown strength retention rate and better short-term heat resistance. Further, with respect to 100 parts by mass of the total amount of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant, the content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group is preferably 40 parts by mass or more, more preferably 45 parts by mass or more, in order to further increase the insulation breakdown strength of the molded product in some cases. Also, in order to further increase the insulation breakdown strength retention rate, it is preferably 85 parts by mass or less, more preferably 80 parts by mass or less, further preferably 75 parts by mass or less, still more preferably 70 parts by mass or less, and even more preferably 65 parts by mass or less.

[0042] <(e) Inorganic filler> The resin composition of the present embodiment preferably contains (e) an inorganic filler. By containing (e) an inorganic filler, the mechanical strength of the obtained molded product can be increased.

[0043] The inorganic fillers that can be included in the resin composition of this embodiment are those that have the effect of improving the mechanical properties of the resin composition obtained by blending them with the resin, and commonly used inorganic fillers for plastics can be used. Preferably, fibrous inorganic fillers such as glass fibers, carbon fibers, basalt fibers, wollastonite, and potassium titanate fibers can be used. In addition, granular or amorphous fillers such as calcium carbonate, titanium oxide, feldspar minerals, clay, organic clay, and glass beads; plate-like fillers such as talc; and flake-like inorganic fillers such as glass flakes, mica, and graphite can also be used. Among these, fibrous fillers, especially glass fibers, are preferred from the viewpoint of mechanical strength and heat resistance. As for glass fibers, either a round cross-sectional shape or an irregular cross-sectional shape can be used. It is more preferable to use inorganic fillers that have been surface-treated with a coupling agent or other surface treatment agent to improve adhesion with the resin. Glass fibers to which a surface treatment agent has been applied tend to have excellent durability, resistance to humid heat, resistance to hydrolysis, and resistance to thermal shock.

[0044] Any conventionally known surface treatment agent can be used. Specifically, various coupling agents such as aminosilanes, epoxysilanes, allylsilanes, vinylsilanes, and titanates are preferred. Among these, aminosilanes, epoxysilanes, and vinylsilanes are preferred. Specifically, preferred examples include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, and γ-methacryloxypropyltrimethoxysilane. The silane compounds may be used individually or in combination. Furthermore, if necessary, surfaces treated with fatty acid amide compounds, lubricants such as silicone oil, antistatic agents such as quaternary ammonium salts, resins with film-forming ability such as epoxy resins and urethane resins, or mixtures of resins with film-forming ability with heat stabilizers and flame retardants can also be used.

[0045] In this embodiment, glass fibers refer to fibrous inorganic materials, and more specifically, chopped glass fibers are preferred, which are formed by bundling 1,000 to 10,000 glass fibers together and cutting them to a predetermined length. In this embodiment, the glass fibers have a number-average fiber length of 0.5 to 10 mm, and more preferably 1 to 5 mm. By using glass fibers with such a number-average fiber length, the mechanical strength can be further improved. The number-average fiber length is calculated by randomly selecting glass fibers to be measured from an image obtained by observation with an optical microscope, measuring their longest side, and then calculating the number-average fiber length from the obtained measurement values. The observation magnification is set to 20x, and the number of measured fibers is 1,000 or more. The number-average fiber length generally corresponds to the cut length. Furthermore, the cross-section of the glass fiber may be circular, elliptical, oblong, rectangular, a rectangle with semicircles attached to both short sides, or cocoon-shaped, but a circular shape is preferred. Here, "circular" includes not only a circular shape in the geometric sense, but also what is commonly referred to as circular in the technical field of this embodiment. The number-average fiber diameter of glass fibers is preferably 4.0 μm or more at the lower limit, 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 glass fibers is preferably 15.0 μm or less, and more preferably 14.0 μm or less. Using glass fibers having a number-average fiber diameter within this range tends to yield molded products with superior mechanical strength. The number-average fiber diameter of glass fibers is calculated by randomly selecting glass fibers to be measured from an image obtained by observing with an electron microscope, measuring the fiber diameter near the center, and obtaining the measured values. The observation magnification is 1,000x, and the number of measurements is 1,000 or more. For glass fibers with a cross-section other than circular, the number-average fiber diameter is calculated as the number-average fiber diameter when converted to a circle with the same area as the cross-sectional area.

[0046] Glass fibers are generally obtained by melt-spinning supplied glass such as E glass (Electrical glass), C glass (Chemical glass), A glass (Alkali glass), S glass (High strength glass), D glass, and alkali-resistant glass, but any material that can be made into glass fibers can be used and is not particularly limited. In this embodiment, it is preferable to include E glass.

[0047] Glass fibers are available commercially. Examples of commercially available products include T-286H, T-756H, T-127, T-289H, T-852H from Nippon Electric Glass Co., Ltd., DEFT2A from Owens Corning, HP3540 from PPG, and CSG3PA820 from Nitto Boseki Co., Ltd.

[0048] If the resin composition of this embodiment contains (e) an inorganic filler, its content is 10 parts by mass or more, preferably 30 parts by mass or more, more preferably 35 parts by mass or more, even more preferably 40 parts by mass or more, and even more preferably 45 parts by mass or more, per 100 parts by mass of the resin component consisting of (a) a polyphenylene ether resin and (b) a styrene resin. Setting the content above the lower limit tends to further improve the mechanical strength of the resulting molded product. Furthermore, the upper limit of the inorganic filler content is 100 parts by mass or less, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, even more preferably 65 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of the resin component consisting of (a) a polyphenylene ether resin and (b) a styrene resin. Setting the content below the upper limit allows the effects of adding an inorganic filler to be exerted while maintaining moldability without impairing the fluidity of the resin. The resin composition of this embodiment may contain (e) only one type of inorganic filler, or it may contain two or more types. If it contains two or more types, it is preferable that the total amount is within the above range.

[0049] <(f) Stabilizers> The resin composition of this embodiment may contain stabilizers such as heat stabilizers and antioxidants. Examples of stabilizers include organic stabilizers such as phenolic stabilizers, amine stabilizers, phosphorus stabilizers, and thioether stabilizers, as well as inorganic thermal stabilizers such as zinc oxide. In this embodiment, phenolic stabilizers and zinc oxide are preferred, and zinc oxide is more preferred. The resin composition of this embodiment may contain stabilizers such as heat stabilizers and antioxidants. Examples of stabilizers include organic stabilizers such as phenolic stabilizers, amine stabilizers, phosphorus stabilizers, and thioether stabilizers, as well as inorganic thermal stabilizers such as zinc oxide. In this embodiment, inorganic stabilizers are more preferred, and zinc oxide is particularly preferred, as it can effectively improve the dielectric breakdown strength retention rate of the molded article after heating. In this embodiment, an organic stabilizer (preferably a phenolic stabilizer) and an inorganic stabilizer (preferably zinc oxide) may be used in combination. With regard to stabilizers, please refer to paragraph 0036 of International Publication No. 2019 / 026689 and paragraphs 0044-0046 of Japanese Patent Publication No. 2022-001624, which are incorporated herein by reference.

[0050] As a phenolic stabilizer, a hindered phenolic stabilizer is preferably used. Specific examples of hindered phenol stabilizers 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], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphate, and 3,3',3'',5,5',5''-hexa-tert-butyl-a,a',a''-(methylpentadecyl) (2,4,6-triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl) Examples include -4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazine-2-ylamino)phenol, and 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate.

[0051] 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. Specific examples of such hindered phenol-based stabilizers include, for example, BASF's "Irganox (registered trademark; hereinafter the same) 1010" and "Irganox 1076," and ADEKA's "ADEKA Stab AO-50" and "ADEKA Stab AO-60."

[0052] The stabilizer content in the resin composition of this embodiment is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, even more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of the resin composition. It may also be preferably less than 5 parts by mass, more preferably 4 parts by mass or less, and even more preferably 3 parts by mass or less, 2 parts by mass or less, or 1 part by mass or less. By setting the stabilizer content within the above range, the effect of adding the stabilizer is more effectively exerted. The resin composition of this embodiment may contain only one stabilizer or two or more stabilizers. When two or more stabilizers are included, it is preferable that the total amount is within the above range.

[0053] <(g) Coloring agent> The resin composition of this embodiment may contain a coloring agent. Including a coloring agent can give the resulting molded product a color, which tends to improve its aesthetic appeal. The coloring agent may be a pigment or a dye, but a pigment is preferred. Examples of pigments include inorganic pigments (black pigments such as carbon black, red pigments such as iron oxide red, orange pigments such as molybdate orange, and white pigments such as titanium dioxide) and organic pigments (yellow pigments, orange pigments, red pigments, blue pigments, green pigments, etc.). Inorganic pigments are preferred, black pigments are more preferred, and carbon black is even more preferred. When a colorant is incorporated into the resin composition of this embodiment, it may be incorporated in the form of a masterbatch. As the thermoplastic resin for masterbatch formation, (b) a styrene-based resin is preferred. If the resin composition in this embodiment contains a coloring agent, the content is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.4 parts by mass or more, per 100 parts by mass of the resin composition. Furthermore, the content of the coloring agent is preferably 10.0 parts by mass or less, more preferably 5.0 parts by mass or less, and even more preferably 3.0 parts by mass or less, per 100 parts by mass of the resin composition. When preparing a masterbatch of a coloring agent, it is preferable that the actual amount of coloring agent used is within the above range. The resin composition of this embodiment may contain only one coloring agent or two or more. When two or more coloring agents are included, it is preferable that the total amount is within the above range.

[0054] <Other ingredients> The resin composition of this embodiment may contain other components besides those mentioned above. Specifically, examples include thermoplastic resins other than (a) polyphenylene ether-based resins and (b) styrene-based resins, such as polyamide resins, polyester resins, polyphenylene sulfide resins, liquid crystal polyester resins, polycarbonate resins, polyacetal resins, polyacrylonitrile resins, acrylic resins, and polyethylene resins, as well as thermosetting resins such as epoxy resins, melamine resins, and silicone resins. Two or more of these thermoplastic and thermosetting resins can also be used in combination. Furthermore, the resin composition of this embodiment may also contain resin additives. Specifically, it may contain internal lubricants (such as fatty acid metal salts and polyethylene wax), mold release agents (such as silicone oil, fatty acids, and fatty acid esters), weather resistance modifiers, nucleating agents, impact resistance modifiers, plasticizers, flowability modifiers, and the like. If the above-mentioned other components are included, their content is preferably less than 5% by mass of the resin composition, more preferably less than 3% by mass, and may be less than 1% by mass.

[0055] The resin composition of this embodiment is prepared so that the total of (a) a polyphenylene ether resin, (b) a styrene resin, (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group, and (d) a condensed phosphate ester flame retardant, and other components added as needed, amounts to 100% by mass. Furthermore, the resin composition of this embodiment preferably contains 95% by mass or more of the total of (a) a polyphenylene ether resin, (b) a styrene resin, (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group, and (d) a condensed phosphate ester flame retardant, and (e) an inorganic filler, (f) a stabilizer, and (g) a pigment, which is more preferably 97% by mass or more, and even more preferably 99% by mass or more.

[0056] <Method for producing resin compositions> Any method can be used to manufacture the resin composition of this embodiment. For example, one method involves mixing each component, such as (a) a polyphenylene ether resin, (b) a styrene resin, (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group, and (d) a condensed phosphate ester flame retardant, using a mixing means such as a V-type blender to prepare a single blended product, which is then melt-kneaded in a vented extruder to form pellets. Alternatively, as a two-stage mixing method, some components are first thoroughly mixed and then melt-kneaded in a vented extruder to produce pellets, which are then mixed with the other components and melt-kneaded in a vented extruder. (e) When inorganic fillers are included, side feeding is permitted.

[0057] <Properties of resin compositions> The resin composition of this embodiment can satisfy the following characteristics in particular. The resin composition of this embodiment preferably has a temperature of deflection under load (DTUL) of 129°C or higher, more preferably 130°C or higher, and even more preferably 135°C or higher, when molded into an ISO 3167:93A type test specimen, in accordance with ISO 75-1. There is no upper limit to the temperature of deflection under load, but 170°C or lower is practical, and it may also be 160°C or lower. Such a temperature of deflection under load is achieved by precisely adjusting the mass ratio of the content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant. The resin composition of this embodiment preferably satisfies V-0 in flame retardancy based on a vertical flammability test (UL94V test: 1.5 mmt) of 5 tubes in accordance with the UL94 standard. Such excellent flame retardancy is achieved by precisely adjusting the mass ratio of the content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant. The resin composition of this embodiment preferably has a dielectric breakdown strength retention rate of 60% or more after being molded to a thickness of 1 mm and heated at 180°C for 600 hours, more preferably 65% ​​or more, and even more preferably 70% or more. There is no upper limit, but it is usually 110% or less.

[0058] <Uses of resin compositions> One form of the resin composition of this embodiment is a pellet. The resin composition of this embodiment is widely used in applications where polyphenylene ether resins, particularly blends of polyphenylene ether resins and styrene resins, are commonly used. Examples include automotive exterior and body panels, automotive interior parts, and automotive underbody parts. Specifically, it is suitable for exterior and body panels such as bumpers, fenders, door panels, moldings, emblems, engine hoods, wheel covers, roofs, spoilers, and engine covers, as well as underbody parts and interior parts such as instrument panels and console box trims. Furthermore, it can be used as a cabinet or chassis for various computers and their peripherals, other office automation equipment, televisions, video players, various disc players, refrigerators, air conditioners, LCD projectors, etc. Furthermore, it can be used as fuel cases for solid methanol batteries, secondary battery cells, fuel cell water distribution pipes, water cooling tanks, boiler casings, ink-related parts and components and chassis for inkjet printers, and molded products such as water pipes and fittings.

[0059] The molded article of this embodiment is formed from the resin composition or pellets of this embodiment. The method for manufacturing the molded product in this embodiment is not particularly limited, and any molding method commonly used for resin compositions can be arbitrarily employed. Examples include injection molding, ultra-high-speed injection molding, injection compression molding, two-color molding, hollow molding methods such as gas-assisted molding, molding using a heat-insulating mold, molding using a rapidly heated mold, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating) molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, and blow molding. Molding methods using a hot runner system can also be used. [Examples]

[0060] The present invention will be described in more detail below with reference to examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate, as long as they do not depart 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 other reasons, measurements can be taken using other instruments with equivalent performance.

[0061] The following ingredients were used. [Table 1] [Table 2]

[0062] The structures of components (c) and (d) used in the examples are as follows. (c-1) [ka] (c-2) [ka] (d-1) [ka] (d-2) [ka] (x-1) [ka]

[0063] Examples 1-5, Comparative Examples 1-9 The components shown in Tables 1 and 2 were mixed in the proportions (by mass) shown in Tables 3 to 6. A twin-screw extruder (Shibaura Machine Co., Ltd.: TEM18SS) was used to melt-knead the mixture at a cylinder temperature of 290°C, a die head temperature of 300°C, and a screw rotation speed of 300 rpm to obtain a resin composition (pellets). The following evaluations were performed using the obtained resin composition (pellets). The results are shown in Tables 3 to 6.

[0064] <Flame retardancy (combustion test V)> After drying the pellets obtained by the above manufacturing method at 120°C for 2 hours, test pieces for flammability testing with dimensions of length × width × thickness = 125 mm × 13 mm × 1.5 mm were molded using an injection molding machine (Shibaura Machine Co., Ltd., "EC75SX") under conditions of cylinder temperature 300°C and mold temperature 100°C. The obtained flammability test specimens were subjected to two vertical flammability tests (UL94V test: 1.5mm thick) in sets of five specimens, in accordance with the UL94 standard. The grades are classified as V-0, V-1, and V-2, from best to worst. Each set was graded based on the vertical flammability test, and the results are shown in Tables 3 to 6. If the results of the two tests differed, the result for the low flame retardancy grade was adopted.

[0065] <Temperature of deflection under load (DTUL) (°C)> After drying the pellets obtained by the above manufacturing method at 120°C for 2 hours, ISO3167:93A type test specimens (hereinafter referred to as "ISO test specimens") were injection molded in accordance with ISO-15103 under conditions of cylinder temperature 300°C and mold temperature 100°C using an injection molding machine (Shibaura Machine Co., Ltd., "EC75SX"). In accordance with ISO-75-2, the load deflection temperature (in °C) at a load of 1.80 MPa was measured using a strip-shaped test specimen measuring 80 mm × 10 mm × 4 mmt, which was prepared by machining the parallel section of the above ISO test specimen.

[0066] <Tensile strength (MPa)> In accordance with ISO-527, the tensile strength (in MPa) was measured using the ISO test specimens obtained above under conditions of 23°C and 50% humidity.

[0067] <Bending strength (MPa)> Using a strip-shaped test specimen measuring 80 mm × 10 mm × 4 mm (thickness) prepared by machining the parallel section of the above ISO test specimen, the bending strength (unit: MPa) was measured in accordance with ISO-178 under conditions of 23°C and 50% humidity.

[0068] <Dielectric breakdown strength (MV / m)> After drying the pellets obtained by the above manufacturing method at 120°C for 2 hours, flat test pieces with dimensions of 100mm x 100mm x 1mm were molded using an injection molding machine (Shibaura Machine Co., Ltd., "EC75SX") under conditions of cylinder temperature of 300°C and mold temperature of 100°C. The dielectric breakdown strength of the obtained flat plate-shaped test specimens was measured using the short-time method in oil at 23°C, in accordance with JIS C2110, with electrodes shaped as a 20 mm diameter sphere and a 25 mm diameter cylindrical shape.

[0069] <Dielectric breakdown strength retention rate (%)> A flat test specimen was placed in a hot air circulating oven at 180°C and subjected to heat treatment for 600 hours. After that, the dielectric breakdown strength was measured using the same method as described above. The retention rate (%) of the dielectric breakdown strength after heat treatment was calculated based on the dielectric breakdown strength before heat treatment.

[0070] [Table 3]

[0071] [Table 4]

[0072] [Table 5]

[0073] [Table 6]

[0074] As is clear from the results above, the molded articles formed from the resin composition of this embodiment exhibited excellent flame retardancy, heat resistance, and dielectric breakdown strength retention (Examples 1-5). Furthermore, they also exhibited excellent mechanical strength. In contrast, when (c) a triphenyl phosphate without substituents was used instead of a phosphate compound having an aromatic ring substituted with a hydrocarbon group (Comparative Example 1), the dielectric breakdown strength retention rate was significantly worse. Furthermore, the mechanical strength also decreased. Furthermore, (c) when a phosphate compound having an aromatic ring substituted with a hydrocarbon group is not included (Comparative Example) 2) Furthermore, the dielectric breakdown strength retention rate deteriorated even more significantly. Mechanical strength also decreased.Alternatively, in the cases of Comparative Examples 8 and 9, the flame retardancy was inferior. Furthermore, when a phosphazene compound was used instead of the phosphate compound having an aromatic ring substituted with a hydrocarbon group (Comparative Example 3), the dielectric breakdown strength retention rate became even more significantly worse. Mechanical strength also decreased. Furthermore, even when (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant were combined, if the ratio was below the lower limit of the present invention (Comparative Example 4), the dielectric breakdown strength retention rate deteriorated even more significantly. Mechanical strength also decreased. Moreover, if the ratio exceeded the upper limit of the present invention (Comparative Example 5), the dielectric breakdown strength retention rate deteriorated even more significantly. Mechanical strength also decreased. (b) When the proportion of styrene resin was high (Comparative Example 6), flame retardancy and mechanical strength were inferior. When the total amount of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant was small (Comparative Example 7), the dielectric breakdown strength retention rate was even more significantly worse.

[0075] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications are possible without departing from the intent and scope of the invention.

Claims

1. (a) 80 to 100 parts by mass of polyphenylene ether resin and (b) 0 to 20 parts by mass of styrene resin, 100 parts by mass of resin component, (c) phosphate compound having an aromatic ring substituted with a hydrocarbon group, and (d) condensed phosphate ester flame retardant, The total content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant is 10 to 25 parts by mass per 100 parts by mass of the resin component. The mass ratio of the content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant, (c) / (d), is 18 / 82 to 90 / 10. The phosphate compound having an aromatic ring substituted with a hydrocarbon group is the compound represented by formula (P1), A resin composition wherein the (d) condensed phosphate ester flame retardant is a compound represented by formula (P2). 【Chemistry 1】 (In formula (P1), each R is an alkyl group having 1 to 3 carbon atoms, and each n is an integer from 0 to 5, provided that at least one of the three n is an integer from 1 to 5.) 【Chemistry 2】 (In formula (P2), X is a divalent organic group, X ２ Each of the elements is an alkyl group having 1 to 3 carbon atoms, and each of the elements n2 is an integer from 0 to 5.

2. The resin composition according to claim 1, wherein the mass ratio of the content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant, (c) / (d), is 30 / 70 to 90 / 10.

3. Furthermore, (e) the resin composition according to claim 1 or 2, comprising an inorganic filler.

4. The mass ratio of the content of (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) a condensed phosphate ester flame retardant, (c) / (d), is 30 / 70 to 90 / 10, and further, (e) an inorganic filler is included. The phosphate compound having an aromatic ring substituted with a hydrocarbon group is the compound represented by formula (P1), The resin composition according to claim 1, wherein the (d) condensed phosphate ester flame retardant is a compound represented by formula (P2). 【Transformation 3】 (In formula (P1), each R is an alkyl group having 1 to 3 carbon atoms, and each n is an integer from 0 to 5, provided that at least one of the three n is an integer from 1 to 5.) 【Chemistry 4】 (In formula (P2), X is a divalent organic group, X ２ Each of the elements is an alkyl group having 1 to 3 carbon atoms, and each of the elements n2 is an integer from 0 to 5.

5. Pellets of the resin composition according to claim 1, 2, or 4.

6. A molded article formed from the resin composition according to claim 1, 2, or 4.

7. A molded article formed from the pellets described in claim 5.

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