Resin composition and molded article

Abstract

To provide a resin composition in which phosphorus-based flame retardants are well dispersed, and which exhibits excellent flame retardancy while fully maintaining the inherent physical properties of the polyolefin resin. [Solution] A resin composition according to one aspect of the present invention comprises a thermoplastic resin (A), a phosphorus-based flame retardant (B), and a copolymer (C) of an α-olefin and an unsaturated carboxylic acid, wherein the ratio of the phosphorus-based flame retardant (B) to the thermoplastic resin (A) is 5% by mass or more and 400% by mass or less, and the ratio of the copolymer (C) to the phosphorus-based flame retardant (B) is 10% by mass or less.

Description

[Technical Field]

[0001] The present invention relates to resin compositions and molded articles. This application claims priority based on Japanese Patent Application No. 2020-93089, filed in Japan on 28 May 2020, and Japanese Patent Application No. 2021-44430, filed in Japan on 18 March 2021, and the contents thereof are incorporated herein by reference. [Background technology]

[0002] Polyolefin resins have excellent mechanical properties (bending properties, tensile properties, etc.), chemical resistance, and moldability, and because they are low in specific gravity and inexpensive, their molded products are used in a wide range of applications, including machinery, electrical and electronic equipment, office automation equipment, automotive interior and exterior materials, and electric vehicles. In these applications, molded articles may require flame retardancy. For example, molded articles used in housings (frames, enclosures, exteriors, covers, etc.) and cables for electrical and electronic equipment and office automation equipment require high flame retardancy.

[0003] Because polyolefin resins are highly flammable, flame retardants are added to their molded products to impart flame retardancy. Traditionally, flame retardants used were systems combining bromine-based flame retardants and antimony compounds because they were inexpensive and highly flame-retardant. However, these systems had problems with bioavailability, and in recent years, phosphorus-based flame retardants have come into use. Patent Document 1 proposes a polyolefin resin composition containing two specific phosphorus-based flame retardants.

[0004] On the other hand, Patent Document 2 proposes the use of an alkyl methacrylate polymer mainly composed of alkyl methacrylate units having an alkyl group with two or more carbon atoms as a dispersant for polyolefin additives such as flame retardants and crystal nucleating agents, and a resin composition containing this dispersant, a polyolefin additive, and a polyolefin resin.

[0005] Furthermore, Patent Document 3 proposes a flame-retardant resin composition comprising an olefin polymer, an ethylene polymer containing maleic anhydride, and a flame retardant. In addition, Patent Document 4 proposes a non-halogen flame-retardant resin composition containing a specific amount of ethylene, a ternary polymer of polar group-containing α-olefin and maleic anhydride, and a specific amount of 180 to 250 parts by mass of a non-halogen flame retardant. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2013-119575 [Patent Document 2] International Publication No. 2011 / 96596 [Patent Document 3] Japanese Patent Application Publication No. 5-117452 [Patent Document 4] Japanese Patent Application Publication No. 2014-91753 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the resin composition described in Patent Document 1 has poor dispersibility of phosphorus-based flame retardants, resulting in poorly dispersed phosphorus-based flame retardants in the molded product and causing an appearance defect. The resin composition described in Patent Document 2 contains a large amount of dispersant, which can impair the excellent physical properties of the polyolefin resin, such as its mechanical properties.

[0008] Furthermore, it has been found that the compositions described in Patent Documents 3 and 4 may not be able to provide molded articles that have sufficient mechanical strength and flexural modulus while also possessing high flame retardancy.

[0009] The present invention aims to provide a resin composition and a molded article thereof in which a phosphorus-based flame retardant is well dispersed and which exhibits excellent flame retardancy while fully maintaining the inherent physical properties of the polyolefin resin. [Means for solving the problem]

[0010] The present invention has the following aspects. [1] A resin composition comprising a thermoplastic resin (A), a phosphorus-based flame retardant (B), and a copolymer (C) of an α-olefin and an unsaturated carboxylic acid, wherein the ratio of the phosphorus-based flame retardant (B) to the thermoplastic resin (A) is 5% by mass or more and 400% by mass or less, and the ratio of the copolymer (C) to the phosphorus-based flame retardant (B) is 10% by mass or less. [2] The resin composition according to [1], wherein the proportion of the thermoplastic resin (A) to the total mass of the resin composition is 20% by mass or more and 85% by mass or less. [3] The resin composition according to [1] or [2], wherein the copolymer (C) is a copolymer of α-olefin and maleic anhydride. [4] The resin composition according to any one of [1] to [3], wherein the thermoplastic resin (A) is a polyolefin resin. A molded article comprising any of the resin compositions described in [5], [1], to [4]. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a resin composition and a molded article thereof in which a phosphorus-based flame retardant is well dispersed and excellent flame retardancy is exhibited while fully maintaining the inherent physical properties of the polyolefin resin. [Modes for carrying out the invention]

[0012] [Resin composition] A resin composition according to one aspect of the present invention (hereinafter also referred to as "this resin composition") comprises a thermoplastic resin (A), a phosphorus-based flame retardant (B), and a copolymer (C) of α-olefin and an unsaturated carboxylic acid, wherein the ratio of the phosphorus-based flame retardant (B) to the thermoplastic resin (A) (100% by mass) is 5% by mass or more and 400% by mass or less, and the ratio of the copolymer (C) to the flame retardant (B) (100% by mass) is 10% by mass or less.

[0013] By incorporating this resin composition, it is possible to obtain a molded article with minimal reduction in mechanical properties and high flame retardancy. Since the copolymer (C) of an α-olefin and an unsaturated carboxylic acid has portions with high affinity for the thermoplastic resin (A) and the phosphorus-based flame retardant (B) respectively, when an appropriate amount of the copolymer (C) is contained, the phosphorus-based flame retardant (B) is well dispersed in the thermoplastic resin (A). Therefore, it is possible to prevent a decrease in mechanical properties due to aggregation of the phosphorus-based flame retardant (B). On the other hand, although an improvement in flame retardancy due to the dispersion effect of the phosphorus-based flame retardant (B) can be expected, since the copolymer (C) of an α-olefin and an unsaturated carboxylic acid has a tendency to be easily combustible, if there is too much of the copolymer (C), a large amount of the copolymer (C) is arranged on the surface of the molded body, and conversely, the flame retardancy of the molded body decreases. Therefore, by containing the thermoplastic resin (A), the phosphorus-based flame retardant (B), and the copolymer (C) of an α-olefin and an unsaturated carboxylic acid within an appropriate amount range, it is possible to provide a resin composition capable of obtaining a molded body having high flame retardancy with little decrease in mechanical properties.

[0014] This resin composition may further contain other flame retardants or flame retardant aids other than the phosphorus-based flame retardant (B). This resin composition may further contain other components other than the above, as necessary, within a range not impairing the effects of the present invention.

[0015] [Thermoplastic resin (A)] There is no particular limitation on the thermoplastic resin, and examples thereof include polyolefin resins, polycarbonate resins, polyester resins, acrylonitrile styrene resins, ABS resins, polyamide resins, modified polyphenylene oxides, etc. These may be used alone or in combination of two or more. For example, the thermoplastic resin (A) may be a composite resin of two or more of the above thermoplastic resins.

[0016] There is no particular limitation on the polyolefin resin, and examples thereof include the resins described below. There is no particular limitation on the polyester resin, and for example, polybutylene terephthalate can be mentioned. There is no particular limitation on the polyamide resin, and for example, nylon 66 and nylon 6 can be mentioned. In particular, the present invention is especially useful when the thermoplastic resin (A) is a polyolefin resin. In this invention, "polyolefin resin" means a resin in which the proportion of olefin units or cycloolefin units is 90 mol% or more of the total constituent units of the resin. The proportion of olefin units or cycloolefin units relative to 100 mol% of all constituent units of the polyolefin resin is preferably 95 mol% or more, and particularly preferably 98 mol% or more.

[0017] Examples of polyolefin resins include α-olefin polymers such as polyethylene, polypropylene, polybutene, poly(3-methyl-1-butene), poly(3-methyl-1-pentene), and poly(4-methyl-1-pentene); α-olefin copolymers such as ethylene-propylene blocks or random copolymers, α-olefin-propylene blocks or random copolymers having 4 or more carbon atoms, ethylene-methyl methacrylate copolymers, and ethylene-vinyl acetate copolymers; and cycloolefin polymers such as polycyclohexene and polycyclopentene. Examples of polyethylene include low-density polyethylene, linear low-density polyethylene, and high-density polyethylene. Examples of polypropylene include isotactic polypropylene, syndiotactic polypropylene, hemiisotactic polypropylene, and stereoblock polypropylene. In α-olefin-propylene blocks or random copolymers having 4 or more carbon atoms, examples of α-olefins having 4 or more carbon atoms include butene, 3-methyl-1-butene, 3-methyl-1-pentene, and 4-methyl-1-pentene. These polyolefin resins may be used individually or in combination of two or more types.

[0018] The polyolefin resin preferably contains polypropylene. Polypropylene may be used in combination with other polyolefin resins. For example, as the polyolefin resin, a mixture of polypropylene and other α-olefin polymers such as ethylene-propylene blocks or random copolymers, or α-olefin-propylene blocks or random copolymers having 4 or more carbon atoms may be used. The polyolefin resin is preferably composed mainly of polypropylene. The proportion of polypropylene relative to 100% by mass of the polyolefin resin is preferably 50% by mass or more, and more preferably 60% by mass or more. Polyolefin resin is particularly preferred to be polypropylene from the viewpoint of flame retardancy.

[0019] The melt mass flow rate (MFR) of the thermoplastic resin (A) is preferably 0.1 g / 10 min or more, more preferably 0.5 g / 10 min or more, while preferably 80 g / 10 min or less, and more preferably 60 g / 10 min or less. If the MFR of the thermoplastic resin (A) is above the lower limit, the moldability is better, and if it is below the upper limit, the bending properties, tensile properties, chemical resistance properties, etc. are better. The preferred lower and upper limits can be combined as appropriate (the same applies hereinafter). The MFR of thermoplastic resin (A) may be, for example, 0.1 g / 10 min to 80 g / 10 min, or 0.5 g / 10 min to 60 g / 10 min or more. The melt mass flow rate of thermoplastic resin (A) is measured in accordance with JIS K7210, under conditions of a temperature of 230°C and a load of 2.16 kg.

[0020] The ratio of thermoplastic resin (A) to the total mass of the resin composition is preferably 20% by mass or more, more preferably 30% by mass or more, more preferably 40% by mass or more, more preferably 50% by mass or more, more preferably 55% by mass or more, and still more preferably 60% by mass or more. On the other hand, it is preferably 85% by mass or less, more preferably 83% by mass or less, and still more preferably 80% by mass or less. If the ratio of thermoplastic resin (A) is above the lower limit, the inherent physical properties of thermoplastic resin (A) are more likely to be expressed, and if it is below the upper limit, the flame retardancy is better. The ratio of thermoplastic resin (A) to the total mass of the resin composition may be, for example, 20% by mass or more and 85% by mass or less, 30% by mass or more and 85% by mass or less, 40% by mass or more and 85% by mass or less, 50% by mass or more and 85% by mass or less, 55% by mass or more and 83% by mass or less, or 60% by mass or more and 80% by mass or less.

[0021] [Phosphorus-based flame retardant (B)] Phosphorus-based flame retardants (B) are phosphorus compounds, that is, compounds that contain a phosphorus atom in their molecule. The phosphorus-based flame retardant (B) exerts its flame-retardant effect by forming char during the combustion of the resin composition. The phosphorus-based flame retardant (B) may be any known substance, such as (poly)phosphate or (poly)phosphate ester. "(Poly)phosphate" refers to a phosphate or polyphosphate. "(Poly)phosphate ester" refers to a phosphate ester or polyphosphate ester. The phosphorus-based flame retardant (B) is preferably solid at 80°C.

[0022] As for the phosphorus-based flame retardant (B), (poly)phosphate is preferred in terms of flame retardancy. Examples of (poly)phosphates include ammonium polyphosphate, melamine polyphosphate, piperazine polyphosphate, piperazine orthophosphate, melamine pyrophosphate, piperazine pyrophosphate, melamine polyphosphate, melamine orthophosphate, calcium phosphate, and magnesium phosphate. Compounds in which melamine or piperazine is replaced with other nitrogen compounds can also be used in the same manner. Examples of other nitrogen compounds include N,N,N',N'-tetramethyldiaminomethane, ethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, N,N-dimethylethylenediamine, N,N'-diethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-diethylethylenediamine, 1,2-propanediamine, 1,3-propanediamine, and tetramethylethylenediamine. Diamine, pentamethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, trans-2,5-dimethylpiperazine, 1,4-bis(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, acetoguanamine, benzoguanamine, acrylicguanamine, 2,4-diamino-6-nonyl-1,3,5-tri Azine, 2,4-diamino-6-hydroxy-1,3,5-triazine, 2-amino-4,6-dihydroxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-ethoxy-1,3,5-triazine, 2,4-diamino-6-propoxy-1,3,5-triazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-mercapto-1 Examples include 3,5-triazine, 2-amino-4,6-dimercapto-1,3,5-triazine, ammeline, benzguanamine, acetoguanamine, phthalodiguanamine, melamine cyanurate, melamine pyrophosphate, butylenediguanamine, norbornenediguanamine, methylenediguanamine, ethylenedimelamine, trimethylenedimelamine, tetramethylenedimelamine, hexamethylenedimelamine, and 1,3-hexylenedimelamine.These (poly)phosphates may be used individually or in combination of two or more.

[0023] Among the phosphorus-based flame retardants (B), a salt of (poly)phosphoric acid and a nitrogen compound (hereinafter also referred to as "compound (B1)") is preferred. "(Poly)phosphoric acid" refers to phosphoric acid or polyphosphoric acid. Compound (B1) is an intomessent flame retardant that forms a foamed char surface expansion layer (intomescent) when the resin composition is burned. The formation of the surface expansion layer suppresses the diffusion of decomposition products and heat transfer, resulting in excellent flame retardancy. Examples of nitrogen compounds in compound (B1) include ammonia, melamine, piperazine, and the other nitrogen compounds mentioned above.

[0024] Examples of commercially available phosphorus-based flame retardants (B) include ADEKA FP-2100J, FP-2200, and FP-2500S (manufactured by ADEKA Corporation).

[0025] As described above, the ratio of phosphorus-based flame retardant (B) to thermoplastic resin (A) (100% by mass) is between 5% by mass and 400% by mass. By keeping the ratio of phosphorus-based flame retardant (B) to thermoplastic resin (A) within this range, when used in combination with the copolymer (C) of α-olefin and carboxylic anhydride described later, a significant decrease in mechanical properties and flexural modulus can be prevented while obtaining high flame retardancy.

[0026] Among the above, the ratio of phosphorus-based flame retardant (B) to thermoplastic resin (A) is preferably 10% by mass or more, more preferably 15% by mass or more, and particularly preferably 20% by mass or more. On the other hand, it is preferably 300% by mass or less, more preferably 250% by mass or less, more preferably 200% by mass or less, more preferably 150% by mass or less, more preferably 100% by mass or less, more preferably 80% by mass or less, more preferably 50% by mass or less, and particularly preferably 40% by mass or less. The ratio of phosphorus-based flame retardant (B) to thermoplastic resin (A) may be, for example, 5% by mass or more and 300% by mass or less, 5% by mass or more and 250% by mass or less, 5% by mass or more and 200% by mass or less, 5% by mass or more and 150% by mass or less, 5% by mass or more and 100% by mass or less, 10% by mass or more and 80% by mass or less, 15% by mass or more and 50% by mass or less, or 20% by mass or more and 40% by mass or less.

[0027] The ratio of the phosphorus-based flame retardant (B) to the total mass of the resin composition is preferably 15% by mass or more, more preferably 17% by mass or more, and even more preferably 20% by mass or more, while preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. If the ratio of the phosphorus-based flame retardant (B) is above the lower limit, the flame retardancy is better, and if it is below the upper limit, the inherent physical properties of the thermoplastic resin (A) are more likely to be exhibited. The proportion of the phosphorus-based flame retardant (B) to the total mass of the resin composition may be, for example, 15% by mass or more and 50% by mass or less, 17% by mass or more and 45% by mass or less, or 20% by mass or more and 40% by mass or less.

[0028] [Copolymer of α-olefin and unsaturated carboxylic acid (C)] The copolymer (C) enhances the dispersibility of the phosphorus-based flame retardant (B) in the thermoplastic resin (A). In the present invention, "(C) copolymer of α-olefin and unsaturated carboxylic acid" means a copolymer in which the proportion of α-olefin units is 20 mol% or more and 80 mol% or less relative to 100 mol% of the total of α-olefin units and unsaturated carboxylic acid units. In copolymer (C), the ratio of α-olefin units to the total of 100 mol% of α-olefin units and unsaturated carboxylic acid units is preferably 30 mol% or more, while preferably 70 mol% or less. If the ratio of α-olefin units is above the lower limit, compatibility with polyolefin resins is particularly excellent, and if it is below the upper limit, compatibility with phosphorus-based flame retardants (B) is better.

[0029] In copolymer (C), α-olefins having 10 to 80 carbon atoms are preferred. If the α-olefin has 10 or more carbon atoms, compatibility with polyolefin resins tends to be better, and if it has 80 or fewer carbon atoms, raw material costs tend to be better. More preferably, the α-olefin has 12 to 70 carbon atoms, and even more preferably, 18 to 60 carbon atoms.

[0030] In copolymer (C), examples of unsaturated carboxylic acids include (meth)acrylic acid, maleic acid, methylmaleic acid, fumaric acid, methylfumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, glutaconic acid, norbornane-5-ene-2,3-dicarboxylic acid, and esters, anhydrides, and imides of these unsaturated carboxylic acids. "(meth)acrylic acid" refers to acrylic acid or methacrylic acid. Specific examples of esters, anhydrides, or imides of unsaturated carboxylic acids include (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and glycidyl (meth)acrylate; dicarboxylic acid anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, and 5-norbornene-2,3-dicarboxylic acid anhydride; and maleimide compounds such as maleimide, N-ethylmaleimide, and N-phenylmaleimide. These may be used individually or in combination of two or more. Among the above, esters and dicarboxylic anhydrides are preferred in terms of copolymerization reactivity. In particular, dicarboxylic anhydrides are preferred in terms of compatibility with phosphorus-based flame retardants (B), and maleic anhydride is especially preferred.

[0031] The weight-average molecular weight of copolymer (C) is preferably 2,000 or more, more preferably 3,000 or more, while it is preferably 50,000 or less, and more preferably 30,000 or less. If the weight-average molecular weight of copolymer (C) is within the above upper and lower limit range, the dispersibility of the phosphorus-based flame retardant (B) is better. The weight-average molecular weight of copolymer (C) may be, for example, 2,000 to 50,000, or 3,000 to 30,000. The weight-average molecular weight of copolymer (C) is a value on a standard polystyrene basis, measured by gel permeation chromatography after dissolving copolymer (C) in tetrahydrofuran (THF).

[0032] Examples of commercially available copolymers (C) include Recolb CE2 (manufactured by Clariant Japan Co., Ltd.) and Diacarna 30M (manufactured by Mitsubishi Chemical Corporation).

[0033] As described above, this resin composition contains copolymer (C), while the ratio of copolymer (C) to phosphorus-based flame retardant (B) is 10% by mass or less. In particular, the ratio of copolymer (C) to phosphorus-based flame retardant (B) (100% by mass) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and especially preferably 0.3% by mass or more. On the other hand, it is preferably 8% by mass or less, even more preferably 6% by mass or less, and especially preferably 5% by mass or less. By having the ratio of copolymer (C) to phosphorus-based flame retardant (B) (100% by mass) within the above range, a molded article with high flame retardancy can be obtained while maintaining high mechanical strength and high flexural modulus. The ratio of copolymer (C) to phosphorus-based flame retardant (B) (100% by mass) may be, for example, 0.01% by mass or more and 8% by mass or less, 0.05% by mass or more and 8% by mass or less, 0.1% by mass or more and 6% by mass or less, or 0.3% by mass or more and 5% by mass.

[0034] The ratio of copolymer (C) to the total mass of the resin composition is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, even more preferably 0.1% by mass or more, while preferably 1.2% by mass or less, more preferably 1.1% by mass or less, and even more preferably 1.0% by mass or less. If the ratio of copolymer (C) is above the lower limit, the phosphorus-based flame retardant (B) is well dispersed, resulting in good flame retardancy and physical properties of the resin composition, as well as good appearance of the resulting molded article. If the ratio of copolymer (C) is below the upper limit, the influence of copolymer (C) on the flame retardancy of the resin composition can be suppressed. The ratio of copolymer (C) to the total mass of the resin composition may be, for example, 0.01% by mass or more and 1.2% by mass or less, 0.03% by mass or more and 1.1% by mass or less, or 0.1% by mass or more and 1.0% by mass or less.

[0035] Furthermore, the ratio of copolymer (C) to the total mass of thermoplastic resin (A) and phosphorus-based flame retardant (B) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and still preferably 0.1% by mass or more, while preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and still preferably 1.0% by mass or less. If the ratio of copolymer (C) is above the lower limit, the phosphorus-based flame retardant (B) will be dispersed more well, resulting in better flame retardancy and physical properties of the resin composition and better appearance of the resulting molded article. If the ratio of copolymer (C) is below the upper limit, the influence of copolymer (C) on the flame retardancy of the resin composition can be further suppressed. The ratio of copolymer (C) to the total mass of thermoplastic resin (A) and phosphorus-based flame retardant (B) may be, for example, 0.01% by mass or more and 2.0% by mass or less, 0.05% by mass or more and 1.5% by mass or less, or 0.1% by mass or more and 1.0% by mass or less. The total mass ratio of the thermoplastic resin (A), phosphorus-based flame retardant (B), and copolymer (C) to the total mass of the resin composition is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, particularly preferably 40% by mass or more, and may also be 100% by mass.

[0036] [Other flame retardants or flame retardant enhancers] Other preferred flame retardants or flame retardant additives include organic or inorganic flame retardants or flame retardant additives that do not contain halogens. Examples of such flame retardants or flame retardant additives include triazine ring-containing compounds, silicone-based flame retardants, metal hydroxides, metal oxides, boric acid compounds, and expandable graphite.

[0037] Examples of triazine ring-containing compounds include melamine, ammeline, benzguanamine, acetoguanamine, phthalodiguanamine, melamine cyanurate, butylenediguanamine, norbornenediguanamine, methylenediguanamine, ethylenedimelamine, trimethylenedimelamine, tetramethylenedimelamine, hexamethylenedimelamine, and 1,3-hexylenedimelamine. Examples of silicone-based flame retardants include silicone oil, silicone rubber, and silicone resin. Examples of metal hydroxides include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, barium hydroxide, zinc hydroxide, and Kissmer 5A (a trademark for magnesium hydroxide manufactured by Kyowa Chemical Industry Co., Ltd.). Examples of metal oxides include inorganic compounds such as zinc oxide, titanium oxide, aluminum oxide, magnesium oxide, titanium dioxide, and hydrotalcite, as well as surface-treated products thereof. Specific examples of metal oxides include TIPAQUE R-680 (trademark for titanium oxide manufactured by Ishihara Sangyo Co., Ltd.), Kyowa Mag 150 (trademark for magnesium oxide manufactured by Kyowa Chemical Industry Co., Ltd.), DHT-4A (hydrotalcite: manufactured by Kyowa Chemical Industry Co., Ltd.), and Alkamizer 4 (trademark for zinc-modified hydrotalcite manufactured by Kyowa Chemical Industry Co., Ltd.). Examples of boric acid compounds include zinc borate. These flame retardants or flame retardant aids may be used individually or in combination of two or more.

[0038] [Other ingredients] This resin composition may contain at least one inorganic fiber filler (D) selected from the group consisting of glass fibers and carbon fibers. One inorganic fiber filler (D) may be used alone, or two or more may be used in combination.

[0039] The type of glass fiber is not particularly limited; any type of glass fiber, such as E-glass, C-glass, S-glass, or D-glass, can be used. The form of the glass fibers is not particularly limited, and any type of glass fiber such as chopped strands, roving, yarn, or glass wool can be used, however, chopped strands and glass wool are preferred in terms of workability.

[0040] The type of carbon fiber is not particularly limited; any carbon fiber such as polyacrylonitrile (PAN) carbon fiber, pitch carbon fiber, or graphite fiber can be used. The form of the carbon fiber is not particularly limited, and any carbon fiber such as filament, regular tow, large tow, stable yarn, or chopped strand can be used, but chopped strand is preferred in terms of workability.

[0041] When the resin composition contains inorganic fiber filler (D), the ratio of inorganic fiber filler (D) to the total mass of the resin composition is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, while preferably 50% by mass or less, more preferably 40% by mass or less, more preferably 30% by mass or less, more preferably 25% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less. If the ratio of inorganic fiber filler (D) is above the lower limit, lip prevention effect and smoke suppression effect are easily obtained, and if it is below the upper limit, the original physical properties of the thermoplastic resin (A) are less likely to be impaired.

[0042] If the resin composition contains an inorganic fiber filler (D), it may further contain an interfacial strength enhancer (E) for the inorganic fiber filler (D). As the interfacial strength improving agent (E), polymers having an olefin skeleton (excluding polyolefin resins and copolymers (C)) are preferred, particularly in terms of compatibility with thermoplastic resins (A) such as polyolefin resins. The interfacial strength is further improved by the compatibility of the olefin skeleton with the polyolefin resin.

[0043] The interfacial strength enhancer (E) preferably has an acidic group. The reaction between the inorganic fibrous filler (D) and the acidic group further improves the interfacial strength. Examples of acidic groups include carboxyl groups, carboxylic acid anhydride groups, sulfonic acid groups, sulfinic acid groups, phosphonic acid groups, and phosphinic acid groups. Preferably, at least one selected from the group consisting of carboxyl groups, carboxylic acid anhydride groups, sulfonic acid groups, sulfinic acid groups, phosphonic acid groups, and phosphinic acid groups is preferred, more preferably at least one selected from the group consisting of carboxyl groups, carboxylic acid anhydride groups, and phosphonic acid groups is preferred, and particularly preferably at least one selected from the group consisting of carboxyl groups and carboxylic acid anhydride groups.

[0044] Methods for producing an interfacial strength improver (E) having an olefin skeleton and acidic groups include: (1) a method of reducing the molecular weight of an olefin resin by thermal decomposition at high temperature, followed by the addition of a compound or monomer having an acidic group; (2) a method of polymerizing a low molecular weight olefin resin, followed by the addition of a compound or monomer having an acidic group; and (3) a method of copolymerizing α-olefin with a compound or monomer having an acidic group. Polymerization methods can include radical polymerization methods such as solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization, as well as living polymerization. Furthermore, a method of forming macromonomers first and then polymerizing them is also possible. Examples of compounds or monomers having an acidic group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, maleic anhydride, and citraconic anhydride, with maleic anhydride being particularly preferred.

[0045] Examples of commercially available interfacial strength improvers (E) include Yumex 1001 and 1010 (manufactured by Sanyo Chemical Industries, Ltd.), and Kayabrid 002PP and 003PP (manufactured by Kayaku Nurion Co., Ltd.).

[0046] This resin composition may contain at least one selected from the group consisting of antioxidants, ultraviolet absorbers, light stabilizers, and anti-aging agents.

[0047] Examples of antioxidants include phenolic antioxidants, phosphorus-based antioxidants, and thioether-based antioxidants. Examples of phenolic antioxidants include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, distearyl(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate, 1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 4,4'-thiobis(6-tert-butyl-m-cresol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), and 4,4'- Tylidenebis(6-tertiary butyl-m-cresol), 2,2'-ethylidenebis(4,6-ditertiary butylphenol), 2,2'-ethylidenebis(4-secondary butyl-6-tertiary butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tertiary butylphenyl)butane, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tertiary butylbenzyl) isocyanurate, 1,3,5-tris(3,5-ditertiary butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris(3,5-ditertiary butyl-4-hydroxybenzyl) isocyanurate Zyl)-2,4,6-trimethylbenzene, 2-tert-butyl-4-methyl-6-(2-acryloyloxy-3-tert-butyl-5-methylbenzyl)phenol, stearyl(3,5-ditert-butyl-4-hydroxyphenyl)propionate, tetrakis[3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate methyl]methane, thiodiethylene glycol bis[(3,5-ditert-butyl-4-hydroxyphenyl)propionate], 1,6-hexamethylene bis[(3,5-ditert-butyl-4-hydroxyphenyl)propionate] ], bis[3,3-bis(4-hydroxy-3-tertiary butylphenyl)butyric acid] glycol ester, bis[2-tertiary butyl-4-methyl-6-(2-hydroxy-3-tertiary butyl-5-methylbenzyl)phenyl] terephthalate, 1,3,5-tris[(3,5-ditertiary butyl-4-hydroxyphenyl)propionyloxyethyl] isocyanurate, 3,9-bis[1,1-dimethyl-2-{(3-tertiary butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5) Examples include undecane, triethylene glycol bis[(3-tertiary butyl-4-hydroxy-5-methylphenyl)propionate], etc. The content of the phenolic antioxidant is preferably 0.001 parts by mass or more, more preferably 0.05 parts by mass or more, and more preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of the synthetic resin component in the resin composition.

[0048] Examples of phosphorus-based antioxidants include trisnonylphenyl phosphite, tris[2-tertiary butyl-4-(3-tertiary butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl] phosphite, tridecyl phosphite, octyl diphenyl phosphite, di(decyl)monophenyl phosphite, di(tridecyl)pentaerythritol diphosphite, di(nonylphenyl)pentaerythritol diphosphite, and bis(2,4-ditertiary butylphenyl Penyl) Pentaerythritol Diphosphite, Bis(2,6-Diter-butyl-4-methylphenyl) Pentaerythritol Diphosphite, Bis(2,4,6-Triter-butylphenyl) Pentaerythritol Diphosphite, Bis(2,4-Dicumylphenyl) Pentaerythritol Diphosphite, Tetra(tridecyl) Isopropylidene Diphenol Diphosphite, Tetra(tridecyl)-4,4'-n-Butylidene Bis(2-Terter-butyl-5-methylphenyl) (Tri-Tri-Butyl) Diphosphite, Hexa(tridecyl)-1,1,3-Tris(2-methyl-4-hydroxy-5-tertiary butylphenyl)butane triphosphite, Tetrakis(2,4-ditertiary butylphenyl)biphenylenediphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,2'-methylenebis(4,6-tertiary butylphenyl)-2-ethylhexyl phosphite, 2,2'-methylenebis(4,6-tertiary butylphenyl) Examples include phenyl)-octadecyl phosphite, 2,2'-ethylidenebis(4,6-diter-butylphenyl)fluorophosphite, tris(2-[(2,4,8,10-tetrakister-butyldibenzo[d,f][1,3,2]dioxaphosphine-6-yl)oxy]ethyl)amine, phosphite of 2-ethyl-2-butylpropylene glycol and 2,4,6-triter-butylphenol, and tris(2,4-di-ter-butylphenyl) phosphite. The content of the phosphorus-based antioxidant is preferably 0.001 parts by mass or more, more preferably 0.05 parts by mass or more, and more preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of the synthetic resin component in the resin composition.

[0049] Examples of thioethyl antioxidants include dialkylthiodipropionates such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate, as well as pentaerythritol tetra(β-alkylthiopropionate esters). The content of the thioether-based antioxidant is preferably 0.001 parts by mass or more, more preferably 0.05 parts by mass or more, and more preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of the synthetic resin component in the resin composition.

[0050] Examples of UV absorbers include 2-hydroxybenzophenones such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis(2-hydroxy-4-methoxybenzophenone); 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-diter-butylphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-3'- 2-(2'-hydroxyphenyl)benzotriazoles such as tertiary butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tertiary octylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole, 2,2'-methylenebis(4-tertiary octyl-6-(benzotriazolyl)phenol), and 2-(2'-hydroxy-3'-tertiary butyl-5'-carboxyphenyl)benzotriazole; phenyl Benzoates such as lysilate, resorcinol monobenzoate, 2,4-diter-butylphenyl-3,5-diter-butyl-4-hydroxybenzoate, 2,4-diter-amylphenyl-3,5-diter-butyl-4-hydroxybenzoate, hexadecyl-3,5-diter-butyl-4-hydroxybenzoate; substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; ethyl-α-cyano-β,β-diphenylacrylate, methyl Examples include cyanoacrylates such as 2-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate; and triaryltriazines such as 2-(2-hydroxy-4-octoxyphenyl)-4,6-bis(2,4-diter-butylphenyl)-s-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-s-triazine, and 2-(2-hydroxy-4-propoxy-5-methylphenyl)-4,6-bis(2,4-diter-butylphenyl)-s-triazine. The amount of ultraviolet absorber is preferably 0.001 parts by mass or more, more preferably 0.05 parts by mass or more, per 100 parts by mass of the synthetic resin component in the resin composition, while preferably 30 parts by mass or less, and more preferably 10 parts by mass or less.

[0051] Examples of light stabilizers include 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6,6-tetramethyl-4-piperidyl benzoate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, and tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-buta Butanetetracarboxylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, bis(2,2,6,6-tetramethyl-4-piperidyl)·di(tridecyl)-1,2,3,4-butanetetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)·di(tridecyl)-1,2,3,4-butanetetracarboxylate, bis(1,2,2,4,4-pentamethyl-4-piperidyl)-2-butyl-2-(3,5-diter-butyl-4-hydroxybenzyl Malonate, 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol / diethyl succinate polycondensate, 1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate, 1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane / 2,4-dichloro-6-tertiary octylamino-s-triazine polycondensate, 1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidylamino) Lysyl)amino)-s-triazine-6-yl]-1,5,8,12-tetraazadodecane, 1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazine-6-yl]-1,5,8-12-tetraazadodecane, 1,6,11-tris[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazine-6-yl]aminoundecane, 1,6,11-tris[2,4-bis(N-butyl-N-(1,2,2,6,Examples of hindered amine compounds include 6-pentamethyl-4-piperidyl)amino)-s-triazine-6-yl]aminoundecane. The amount of light stabilizer is preferably 0.001 parts by mass or more, more preferably 0.05 parts by mass or more, per 100 parts by mass of the synthetic resin component in the resin composition, while preferably 30 parts by mass or less, and more preferably 10 parts by mass or less.

[0052] This resin composition may contain other fillers besides the inorganic fiber filler (D). Other fillers that can be used include fibrous, plate-like, granular, and powder-like materials. Specifically, these include asbestos fibers, metal fibers, potassium titanate whiskers, aluminum borate whiskers, magnesium-based whiskers, silicon-based whiskers, warlastenite, sepiolite, asbestos, slag fibers, zonolite, elestadite, gypsum fibers, silica fibers, silica-alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers and other inorganic fibrous reinforcing materials such as boron fibers, polyester fibers, nylon fibers, acrylic fibers, regenerated cellulose fibers, acetate fibers, kenaf, ramie, cotton, jute, hemp, sisal, flax, and linen. Examples of reinforcing materials include organic fibrous reinforcing materials such as silk, Manila hemp, sugarcane, wood pulp, paper waste, recycled paper and wool, glass flakes, non-swelling mica, graphite, metal foil, ceramic beads, clay, mica, sericite, zeolite, bentonite, dolomite, kaolin, fine silicic acid powder, feldspar powder, potassium titanate, shirasu balloons, calcium carbonate, magnesium carbonate, barium sulfate, calcium oxide, aluminum oxide, titanium oxide, titanium dioxide, aluminum silicate, gypsum, novaculite, dawsonite and white clay, in the form of plates or granules. These fillers may be coated or bundled with thermoplastic resins such as ethylene-vinyl acetate copolymers or thermosetting resins such as epoxy resins, or treated with coupling agents such as aminosilanes and epoxysilanes. The content of other fillers is preferably 10 parts by mass or more, preferably 20 parts by mass or more, and more preferably 60 parts by mass or less, and more preferably 50 parts by mass or less, per 100 parts by mass of the synthetic resin component in the resin composition.

[0053] This resin composition may contain a nucleating agent. As nucleating agents, those commonly used as nucleating agents for polyolefin resins can be used as appropriate, such as inorganic nucleating agents and organic nucleating agents.

[0054] Specific examples of inorganic nucleating agents include kaolinite, synthetic mica, clay, zeolite, graphite, carbon black, magnesium oxide, titanium oxide, calcium sulfide, boron nitride, calcium carbonate, barium sulfate, aluminum oxide, neodymium oxide, and metal salts such as phenylphosphonate. These inorganic nucleating agents may be modified with organic substances to improve their dispersibility in the composition.

[0055] Specific examples of organic crystal nucleating agents include sodium benzoate, potassium benzoate, lithium benzoate, calcium benzoate, magnesium benzoate, barium benzoate, lithium terephthalate, sodium terephthalate, potassium terephthalate, calcium oxalate, sodium laurate, potassium laurate, sodium myristate, potassium myristate, calcium myristate, sodium octacosanoate, calcium octacosanoate, sodium stearate, potassium stearate, lithium stearate, calcium stearate, magnesium stearate, barium stearate, sodium montanaate, calcium montanaate, sodium tolulate, sodium salicylate, potassium salicylate, and salicylic acid. Examples include metal salts of organic carboxylic acids such as zinc, aluminum dibenzoate, potassium dibenzoate, lithium dibenzoate, sodium β-naphthalate, and sodium cyclohexanecarboxylate; organic sulfonates such as sodium p-toluenesulfonate and sodium sulfisophthalate; carboxylic acid amides such as stearic acid amide, ethylenebislauric acid amide, palmitic acid amide, hydroxystearic acid amide, erucic acid amide, and tris(t-butylamide) trimesinate; benzylidene sorbitol and its derivatives; metal salts of phosphorus compounds such as sodium-2,2'-methylenebis(4,6-di-t-butylphenyl)phosphate; and sodium 2,2-methylbis(4,6-di-t-butylphenyl).

[0056] This resin composition may contain a plasticizer. As plasticizers, those commonly used as plasticizers for polyolefin resins can be used as appropriate, such as polyester-based plasticizers, glycerin-based plasticizers, polycarboxylic acid ester-based plasticizers, polyalkylene glycol-based plasticizers, and epoxy-based plasticizers. These plasticizers may be used individually or in combination of two or more.

[0057] Specific examples of polyester plasticizers include polyesters composed of acid components such as adipic acid, sebatic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, and rosin, and diol components such as propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, ethylene glycol, and diethylene glycol, as well as polyesters composed of hydroxycarboxylic acids such as polycaprolactone. These polyesters may have their ends sealed with monofunctional carboxylic acids or monofunctional alcohols, or with epoxy compounds, etc.

[0058] Specific examples of glycerin-based plasticizers include glycerin monoacetomolaurate, glycerin diacetomolaurate, glycerin monoacetomostearate, glycerin diacetomooleate, and glycerin monoacetomomonomonate.

[0059] Specific examples of polycarboxylic acid ester plasticizers include phthalate esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diheptyl phthalate, dibenzyl phthalate, and butyl benzyl phthalate; trimellitic acid esters such as tributyl trimellitic acid, trioctyl trimellitic acid, and trihexyl trimellitic acid; adipic acid esters such as diisodecyl adipate, n-octyl-n-decyl adipate, methyl diglycol-butyl diglycol adipate, benzyl methyl diglycol adipate, and benzyl butyl diglycol adipate; citrate esters such as triethyl acetyl citrate and tributyl acetyl citrate; azelaic acid esters such as di-2-ethylhexyl azelaic acid; dibutyl sebacate; and sebacate esters such as di-2-ethylhexyl sebacate.

[0060] Specific examples of polyalkylene glycol-based plasticizers include polyethylene glycol, polypropylene glycol, poly(ethylene oxide-propylene oxide) block and / or random copolymer, polytetramethylene glycol, ethylene oxide addition polymers of bisphenols, propylene oxide addition polymers of bisphenols, tetrahydrofuran addition polymers of bisphenols, and other polyalkylene glycols, or end-binding compounds such as their terminal epoxy-modified compounds, terminal ester-modified compounds, and terminal ether-modified compounds.

[0061] Epoxy plasticizers generally refer to epoxy triglycerides, which consist of alkyl epoxy stearate and soybean oil, but other types of epoxy resins, such as those mainly made from bisphenol A and epichlorohydrin, can also be used.

[0062] Other specific examples of plasticizers include benzoic acid esters of aliphatic polyols such as neopentyl glycol dibenzoate, diethylene glycol dibenzoate, and triethylene glycol di-2-ethyl butyrate; fatty acid amides such as stearic acid amide; aliphatic carboxylic acid esters such as butyl oleate; oxy acid esters such as methyl acetylricinoleate and butyl acetylricinoleate; pentaerythritol; various sorbitols; polyacrylic acid esters; and paraffins.

[0063] This resin composition may contain a fluorine-containing anti-dripping agent. Examples of fluorine-containing anti-dropping agents include fluorine-containing polymers having fibril-forming ability. Examples of such fluorine-containing polymers include polytetrafluoroethylene (hereinafter also referred to as "PTFE"), tetrafluoroethylene copolymers (e.g., tetrafluoroethylene / hexafluoropropylene copolymers), partially fluorinated polymers as described in U.S. Patent No. 4,379,910, and polycarbonate resins produced from fluorinated diphenols. Among these, PTFE is preferred.

[0064] PTFE with fibril-forming ability has an extremely high molecular weight and tends to bond with other PTFE materials to form fibers when subjected to external forces such as shear force. The molecular weight is preferably 1 million or more, more preferably 2 million or more, based on the number average molecular weight determined from the standard specific gravity, while preferably 10 million or less, and more preferably 9 million or less. PTFE with fibril-forming ability can be used not only in solid form but also in aqueous dispersion form.

[0065] Examples of commercially available PTFE products with fibril-forming ability include Teflon® 6J from Mitsui DuPont Fluorochemicals Co., Ltd., and Polyflon® MPA FA500 and F-201L from Daikin Industries, Ltd. Examples of commercially available aqueous dispersions of PTFE include Fluon AD-939E from Asahi ICI Fluoropolymers Co., Ltd., Fluon D-310 and D-210C from Daikin Industries, Ltd., and Teflon 31JR from Mitsui DuPont Fluorochemicals Co., Ltd.

[0066] To improve the dispersibility of fibril-forming PTFE in resin compositions and to obtain even better flame retardancy, mechanical properties, and flexural modulus, it is also possible to use a PTFE mixture in the form of a mixture of fibril-forming PTFE and other resins. The proportion of PTFE to the total mass of the PTFE mixture is preferably 1% by mass or more, more preferably 5% by mass or more, while preferably 60% by mass or less, and more preferably 55% by mass or less. When the proportion of PTFE is within this range, good dispersibility of PTFE can be achieved.

[0067] PTFE mixtures can be obtained, for example, by (1) mixing an aqueous dispersion of PTFE with an aqueous dispersion or solution of another resin and co-precipitating to obtain a co-aggregated mixture (methods described in Japanese Patent Publication No. 60-258263, Japanese Patent Publication No. 63-154744, etc.), (2) mixing an aqueous dispersion of PTFE with dried particles of another resin (method described in Japanese Patent Publication No. 4-272957), or (3) uniformly mixing an aqueous dispersion of PTFE with a solution of another resin and simultaneously obtaining each medium from such mixture. (1) A method of removal (as described in Japanese Patent Publication No. 06-220210, Japanese Patent Publication No. 08-188653, etc.), (2) a method of polymerizing monomers that form other resins in an aqueous dispersion of PTFE (as described in Japanese Patent Publication No. 9-95583), or (3) a method of uniformly mixing an aqueous dispersion of PTFE and a dispersion of other resins, polymerizing vinyl monomers in the resulting mixed dispersion, and then obtaining a mixture (as described in Japanese Patent Publication No. 11-29679, etc.) can be used. Commercially available PTFE mixtures include Mitsubishi Chemical's "Metablen A3000" and GE Specialty Chemicals' "BLENDEX B449."

[0068] The content of the fluorine-containing anti-dropping agent is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and still more preferably 0.1 parts by mass or more, as PTFE, per 100 parts by mass of the resin composition, while preferably 1 part by mass or less, more preferably 0.8 parts by mass or less, and still more preferably 0.5 parts by mass or less.

[0069] In addition to the above, this resin composition may contain additives commonly used in synthetic resins, such as crosslinking agents, antistatic agents, metal soaps, spot fillers, antifogging agents, plate-out inhibitors, surface treatment agents, fluorescent agents, antifungal agents, disinfectants, foaming agents, metal deactivators, mold release agents, pigments, processing aids, etc., to the extent that they do not impair the effects of the present invention.

[0070] [Method for producing resin composition] Any method can be used to manufacture this resin composition. For example, a thermoplastic resin (A), a phosphorus-based flame retardant (B), a copolymer (C), and optionally other flame retardants, flame retardant aids, and other components may be thoroughly mixed using premixing means such as a V-type blender, Henschel mixer, mechanochemical device, or extruder mixer, and if necessary, granulated using an extruder or briquetting machine, and then melt-kneaded and extruded in a melt-kneader. Examples of melting and mixing machines include twin-screw extruders such as vented twin-screw extruders, Banbury mixers, mixing rolls, single-screw extruders, and multi-screw extruders with three or more shafts. The temperature during melting and mixing is, for example, 170-260°C. As described above, the extruded resin composition is either directly cut and pelletized using equipment such as a pelletizer, or cooled to form strands, and then these strands are cut and pelletized using equipment such as a pelletizer.

[0071] In the resin composition described above, since it contains a copolymer (C) along with a thermoplastic resin (A) and a phosphorus-based flame retardant (B), it can exhibit excellent flame retardancy while sufficiently maintaining the inherent physical properties of the polyolefin resin (A) (for example, mechanical strength and flexural modulus). The copolymer (C) improves the dispersibility of the phosphorus-based flame retardant (B) in thermoplastic resins (A), such as polyolefin resins. Improved dispersibility of the phosphorus-based flame retardant (B) is thought to facilitate char formation during combustion, thereby improving flame retardancy. While the exact mechanism is unclear, the following is a possible explanation. In particular, when the thermoplastic resin (A) is a polyolefin resin, polyolefin resins are classified as low-polarity resins among thermoplastic resins, making it difficult to disperse polar additives such as phosphorus-based flame retardants (B). On the other hand, copolymer (C) has excellent compatibility with polyolefin resins due to its low-polarity α-olefin moiety, and excellent compatibility with phosphorus-based flame retardants (B) due to its polar unsaturated carboxylic acid moiety. It is thought that the presence of copolymer (C) between the polyolefin resin and the phosphorus-based flame retardant (B) during the melt-kneading of the resin composition improves the dispersibility of the phosphorus-based flame retardant (B) in the polyolefin resin.

[0072] The effects of copolymer (C) include (1) improved dispersibility of phosphorus-based flame retardant (B) (fine dispersion), (2) promotion of char formation during combustion, and (3) improvement of physical properties (tensile fracture point strain). Specifically, regarding the effects during combustion, when a flat test piece obtained by molding a resin composition containing a thermoplastic resin (A) and a phosphorus-based flame retardant (B) is heated with a burner, if the resin composition does not contain copolymer (C), small and numerous chars are formed on the surface. However, if the resin composition contains copolymer (C), the size of the chars increases, and the heat transfer suppression effect improves. Furthermore, in a cone calorimeter test, when a 3 mm thick flat plate obtained by molding a resin composition containing a thermoplastic resin (A) and a phosphorus-based flame retardant (B) is burned by radiant heat, if the resin composition does not contain copolymer (C), many gaps in the chars are generated and the molded body burns. However, if the resin composition contains copolymer (C), the gaps in the chars decrease, and chars are formed by combustion on the sides, resulting in a dome shape. Although the mechanism is unclear, the addition of copolymer (C) forms a stronger char, suppressing heat transfer and enabling a V-0 rating in the UL94 test. The copolymer (C) can produce the above effects even in small amounts (for example, 1.2% by mass or less relative to the total mass of the resin composition).

[0073] According to this resin composition, the phosphorus-based flame retardant (B) is well dispersed, making it possible to obtain a molded article in which the dispersibility calculated by the following formula is, for example, 22% or less, and even 21% or less. Dispersibility [%]=4,000μm 2 The sum of the area values ​​of particles of the above size [μm 2 ]÷flame retardant area (threshold 3%, 136,331)[μm 2 ]×100 Here, 4,000 μm 2 The sum of the area values ​​of the particles of the above sizes and the flame retardant area are determined by image processing of the optical microscope image of the molded body. For details, please refer to the examples described below.

[0074] [Molded body] A molded article according to one aspect of the present invention is made of this resin composition. The shape of the molded product is not particularly limited and can take various forms such as resin plates, sheets, films, cables, and irregularly shaped products.

[0075] The molded article is obtained by molding this resin composition. The molding method is not particularly limited and can include extrusion, calendering, injection molding, roll molding, compression molding, blow molding, etc. The temperature at which this resin composition is molded is, for example, 170 to 260°C. [Examples]

[0076] The present invention will be described in detail below with reference to examples. However, the present invention is not limited in any way by the following examples. In the following examples, percentages are based on mass unless otherwise specified. The following items were evaluated.

[0077] (1) Flame retardant (UL94) The resulting molded material (1 / 16-inch test rod) was used to determine its flame retardancy in accordance with the UL94 standard.

[0078] (2) Evaluation of the dispersibility of flame retardants 1 The number of undispersed flame retardants present in the obtained molded body (sheet with a thickness of 0.5 mm) was evaluated. As the evaluation procedure, the sheet was observed at a magnification of 50 times (eyepiece 10 times, objective 5 times) by irradiating transmitted light using an optical microscope (manufactured by Nikon, product name: ECLIPSE E600W POL). From this optical microscope image, 5 images of 640×480 pixels were randomly selected and captured using image processing software (Image J, Ver 1.52a) and converted to 8-bit format. When observed at 50 times magnification, 1,000 μm is 260 pixels, so 640×480 pixels is 4,454,379 μm 2 which is equivalent to. Subsequently, by Bandpass filter processing, the flame retardant in the sheet was emphasized and density measurement was carried out. Since the flame retardant has the darkest contrast in the image, the area value where the binarized area from the minimum value (0) becomes 3% was used as the threshold value and extracted as the flame retardant area. Subsequently, among the particles in the binarized image, particles with a size of 4,000 μm 2 or more, the total area of the particles was calculated, and the dispersibility [%] was calculated by the following formula, and the average value of the dispersibility of each of the 5 images was obtained. Dispersibility [%] = 4,000 μm 2 Total area value of particles with a size of or more [μm 2 ÷Flame retardant area (threshold 3%, 136,331) [μm 2 ×100

[0079] (3) Evaluation of flame retardant dispersibility 2 From the images observed by the same operation as in the above (2) Evaluation of flame retardant dispersibility 1, the dispersibility was compared according to the following criteria. A: 100 or more flame retardant particles are observed in the photo. B: The number of flame retardant particles in the photo is 50 or more and less than 100. C: The number of flame retardant particles in the photo is less than 50. D: The number of flame retardant particles in the photo is less than 30. In this evaluation, it is shown that the dispersibility is better as it goes from A to D. (4) Flexural properties The resulting molded body (JIS K7139-A1 dumbbell test piece) was cut to a length of 80 mm, and its flexural modulus (GPa) was measured in accordance with JIS K7171.

[0080] (5) Tensile properties Using the obtained molded body (JIS K7139-A1 dumbbell test specimen), the tensile yield strength (MPa) and tensile fracture strain (%) were measured in accordance with JIS K7161-1.

[0081] (6) Combustion calorific value (corn calorimeter) For a test specimen measuring 100mm x 100mm x 3mm thick, using a Toyo Seiki Co., Ltd. Model: C3 Cone Calorimeter III, in accordance with ISO 5660-1 (2002), the radiant heat was measured at 50 kW / m². 2 Under these conditions, the maximum heat generation rate (kW / m 2 ), total heat output (MJ / m 2 ) was measured.

[0082] The following ingredients will be used: <Polyolefin resin> A-1: Polypropylene resin (manufactured by Nippon Polypropylene Co., Ltd., Novatec PP FY-4, melt mass flow rate 5g / 10 min). A-2: Polypropylene resin (manufactured by Nippon Polypropylene Co., Ltd., Novatec PP SA06GA, melt mass flow rate 60g / 10 min). <Flame retardant> B: Phosphorus-based flame retardant composition (manufactured by ADEKA Corporation, ADEKA Stab FP-2200, containing 50-60% piberazine pyrophosphate, 35-45% melamine pyrophosphate, and 3-6% zinc oxide based on the total mass of the phosphorus-based flame retardant composition).

[0083] <Dispersant> C-1: α-olefin / maleic anhydride copolymer (manufactured by Mitsubishi Chemical Corporation, Diacarna 30M, weight-average molecular weight 7,800). C-2: α-olefin / maleic anhydride copolymer (manufactured by Clariant Japan Co., Ltd., Recolb CE2, weight-average molecular weight 13,500). C-3: Maleic anhydride-modified polyethylene (manufactured by Mitsui Chemicals, Inc., High Wax 1105A). C-4: Acid-modified polyethylene (manufactured by Clariant Japan Co., Ltd., Recolb H12).

[0084] [Examples 1-7, Comparative Examples 1-4] The raw materials shown in Table 1 were blended in the proportions indicated in Table 1 and mixed by hand. Then, a resin composition was obtained by melt-kneading using a φ30 mm co-screw extruder (model name "BT-30", manufactured by Plastics Engineering Laboratory Co., Ltd., L / D=30) under the conditions of a screw rotation speed of 250 rpm and a cylinder temperature of 200°C. "L / D" indicates the ratio of screw length (L) to diameter (D).

[0085] The obtained resin composition was injection molded using a 100t injection molding machine (model name "SE-100DU", manufactured by Sumitomo Heavy Industries, Ltd.) at a molding temperature of 200°C to obtain a molded body (1 / 16 inch test rod). This molded body (1 / 16 inch test rod) was used as a test specimen for evaluation under UL94. Furthermore, the obtained resin composition was injection molded using a 100t injection molding machine (model name "SE-100DU", manufactured by Sumitomo Heavy Industries, Ltd.) at a molding temperature of 200°C to obtain a molded body (JIS K7139-A1 dumbbell test piece). This molded body (JIS K7139-A1 dumbbell test piece) was used as a test piece for evaluating bending and tensile properties.

[0086] Furthermore, the obtained resin composition was injection molded using a 100t injection molding machine (model name "SE-100DU", manufactured by Sumitomo Heavy Industries, Ltd.) at a molding temperature of 200°C to obtain a molded body (100 × 100 × 3 mm square plate). This molded body (100 × 100 × 3 mm square plate) was then pressed using a hydraulic molding machine (manufactured by Shoji Iron Works Co., Ltd.) at a molding temperature of 200°C and a molding pressure of 10 MPa, following a procedure of preheating for 5 minutes, pressurizing for 5 minutes, and cooling for 5 minutes to obtain a molded body (sheet) with a thickness of 0.5 mm. This molded body (sheet) was used as a test piece for evaluating the dispersibility of the flame retardant.

[0087] Each of these molded articles was measured for its respective properties. The results are shown in Table 1. Regarding dispersibility, Dispersibility Evaluation 1 was evaluated for Examples 1-7 and Comparative Examples 1-3, while Dispersibility Evaluation 2 was evaluated for Example 4 and Comparative Examples 1 and 4. Furthermore, the percentages (%) of the dispersibility (value obtained in Dispersibility Evaluation 1), flexural modulus, and tensile fracture strain for each example and comparative example were calculated for Comparative Example 1. These values ​​are shown in Table 1 as the dispersibility ratio, flexural modulus ratio, and tensile fracture strain, respectively.

[0088] [Example 8] A flame retardant masterbatch-1 was prepared by melt-kneading a φ30 mm co-directional twin-screw extruder (model name "BT-30", manufactured by Plastics Engineering Laboratory Co., Ltd., L / D=30) at a screw rotation speed of 250 rpm and a cylinder temperature of 200°C. The composition consisted of 39.18 mass% of polypropylene resin A-2: Novatec PP, SA06GA, 58.78 mass% of phosphorus-based flame retardant composition B: Adeka Stab FP-2200, 1.96 mass% of dispersant C-1: Diacarna 30M, 0.04 mass% each of antioxidants C-1: Diacarna 30M, 0.04 mass% each. Masterbatch-1 was mixed with polypropylene resin A-1 Novatec PP FY4 in a composition of 50% by mass. The mixture was then injection molded using a 100t injection molding machine (model name "SE-100DU", manufactured by Sumitomo Heavy Industries, Ltd.) at a molding temperature of 200°C, and evaluated in the same manner as in Example 1. The results obtained are shown in Table 1.

[0089] [Example 9] Masterbatch-2 was obtained under the same conditions as in Example 8, except that the composition was 29.31% by mass of A-2: Novatec PP, SA06GA as the polypropylene resin, 68.39% by mass of B: Adeka Stab FP-2200 as the phosphorus-based flame retardant composition, 2.25% by mass of C: Diacarna 30M as the dispersant, and 0.03% by mass each of Adeka Stab AO-60, 2112 as antioxidants. The obtained masterbatch-2 was mixed with polypropylene resin A-1 Novatec PP FY4 at a composition of 47% by mass and 53% by mass, and then injection molded under the same conditions as in Example 8, and evaluated in the same way as in Example 1. The results obtained are shown in Table 1.

[0090] [Table 1]

[0091] In Table 1, B / A represents the ratio (%) of phosphorus-based flame retardant (B) to thermoplastic resin (A) (100%). C / B represents the ratio (%) of copolymer (C) to phosphorus-based flame retardant (B) (100%) (the same applies hereafter).

[0092] Molded articles of the resin compositions of Examples 1 to 9, which included a copolymer (C) (C-1 or C-2) of α-olefin and an unsaturated carboxylic acid, exhibited superior flame retardancy and flame retardant dispersibility compared to molded articles of the resin composition of Comparative Example 1, which did not contain copolymer (C). Furthermore, sufficient flexural modulus and tensile yield strength were achieved, and the tensile fracture strain was improved due to the improved dispersibility of the flame retardant. Furthermore, since the UL94 standard test results for Examples 1 to 9 were all V-0, it can be seen that the resin compositions of Examples 1 to 9 are resin compositions that suppress dripping during combustion.

[0093] On the other hand, the molded article of the resin composition of Comparative Example 2, which contained maleic anhydride-modified polyethylene instead of copolymer (C), exhibited excellent flame retardancy but poor dispersibility of the flame retardant. Furthermore, it was found to have a small tensile fracture strain ratio and inferior mechanical strength. The molded article of the resin composition in Comparative Example 3, in which acid-modified polyethylene was used instead of copolymer (C), exhibited poor flame retardancy and dispersibility of the flame retardant. Furthermore, it was found to have a low tensile fracture strain ratio and inferior mechanical strength. Comparative Example 4, in which the ratio of copolymer (C) to phosphorus-based flame retardant (B) was too high, showed better dispersion of the flame retardant compared to Example 4, but the flexural modulus was significantly reduced, indicating that the inherent properties of polypropylene were greatly impaired.

[0094] [Comparison test of combustion calorific value using a cone calorimeter] The raw materials shown in Table 2 were blended in the proportions indicated in Table 2 and mixed by hand. Then, a resin composition was obtained by melt-kneading using a φ30 mm co-screw extruder (model name "BT-30", manufactured by Plastics Engineering Laboratory Co., Ltd., L / D=30) under the conditions of a screw rotation speed of 250 rpm and a cylinder temperature of 200°C. Using the obtained resin composition, test specimens for evaluating the dispersibility of the flame retardant were prepared in the same manner as in Example 1, and dispersibility evaluation 1 was performed to determine the dispersibility and dispersibility ratio. The results are shown in Table 2. Furthermore, the obtained resin composition was injection molded using a 100t injection molding machine (model name "SE-100DU," manufactured by Sumitomo Heavy Industries, Ltd.) at a molding temperature of 200°C to obtain a molded body (a 100 × 100 × 3 mm rectangular plate). The calorific value of the obtained molded body was evaluated using a cone calorimeter. The results are shown in Table 2.

[0095] [Table 2]

[0096] In the comparison of combustion calorific value using a cone calorimeter shown in Table 2, Examples 3, 10, and 11, which included the copolymer (C) (C-1 or C-2) of α-olefin and unsaturated carboxylic acid, had lower total calorific value and maximum heat generation rate, and exhibited superior flame retardancy compared to Comparative Examples 1 and 5, which did not contain copolymer (C). [Industrial applicability]

[0097] According to the resin composition of the present invention, a molded article can be obtained in which the phosphorus-based flame retardant is well dispersed, exhibiting excellent flame retardancy, mechanical strength, and flexural modulus. Since the molded article obtained using the resin composition of the present invention exhibits excellent flame retardancy, mechanical strength, and flexural modulus, it can be suitably used as a molding material, cable, etc., in fields such as automobiles, office automation equipment such as printers, and electrical and electronic equipment such as mobile phones.

Claims

1. It comprises a thermoplastic resin (A), a phosphorus-based flame retardant (B), and a copolymer of α-olefin and an unsaturated carboxylic acid (C), The ratio of the phosphorus-based flame retardant (B) to the thermoplastic resin (A) is 5% by mass or more and 400% by mass or less. A resin composition in which the ratio of the copolymer (C) to the phosphorus-based flame retardant (B) is 10% by mass or less.

2. The resin composition according to claim 1, wherein the proportion of the thermoplastic resin (A) to the total mass of the resin composition is 20% by mass or more and 85% by mass or less.

3. The resin composition according to claim 1 or 2, wherein the copolymer (C) is a copolymer of α-olefin and maleic anhydride.

4. The resin composition according to any one of claims 1 to 3, wherein the thermoplastic resin (A) is a polyolefin resin.

5. A molded article comprising the resin composition according to any one of claims 1 to 4.

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