Resin composition and molded article

Abstract

To provide a resin composition which satisfactorily disperses a phosphorus-based flame retardant and can exhibit excellent flame retardancy while sufficiently maintaining the physical properties inherent in a polyolefin resin.SOLUTION: There is provided a resin composition which 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 thermoplastic resin (A) is a polyolefin resin, the phosphorus-based flame retardant (B) is a salt of phosphoric acid and a nitrogen compound and contains melamine or piperazine as the nitrogen compound, the ratio of the phosphorus-based flame retardant (B) to the thermoplastic resin (A) is 5 mass% or more and 400 mass% or less and the ratio of the copolymer (C) to the phosphorus-based flame retardant (B) is 10 mass% or less.SELECTED DRAWING: None

Description

[Technical Field]

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

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

[0003] Since polyolefin resins are highly flammable, flame retardants are blended into molded articles of the resins to impart flame retardancy to the resins. Conventionally, a combination of bromine-based flame retardants and antimony compounds has been used as a flame retardant because it is inexpensive and has high flame retardancy. However, due to the problem of biopersistence, phosphorus-based flame retardants have come to be used in recent years. 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, the main component of which is an alkyl methacrylate unit having an alkyl group having 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] Patent Document 3 proposes a flame-retardant resin composition comprising an olefin polymer, an ethylene polymer containing a maleic anhydride component, and a flame retardant. Patent Document 4 proposes a halogen-free flame-retardant resin composition containing a specific amount of a terpolymer of ethylene, an α-olefin having a polar group, and maleic anhydride, and a specific amount of a halogen-free flame retardant in the range of 180 to 250 parts by mass. [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 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the resin composition described in Patent Document 1 has a problem in that the dispersibility of the phosphorus-based flame retardant is poor, and poorly dispersed phosphorus-based flame retardant is generated in the molded product, resulting in a poor appearance. The resin composition described in Patent Document 2 contains a large amount of dispersant added, which may impair the excellent physical properties, such as mechanical properties, of the polyolefin resin.

[0008] It has also 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 having high flame retardancy.

[0009] An object of the present invention is to provide a resin composition in which a phosphorus-based flame retardant is well dispersed and which can exhibit excellent flame retardancy while adequately maintaining the inherent physical properties of polyolefin resin, and a molded article thereof. [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) relative 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 an 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. [5] A molded article made of the resin composition according to any one of [1] to [4]. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a resin composition in which a phosphorus-based flame retardant is well dispersed and which can exhibit excellent flame retardancy while sufficiently maintaining the inherent physical properties of the polyolefin resin, and a molded article thereof. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Resin composition] A resin composition according to one embodiment of the present invention (hereinafter also referred to as "the resin composition") comprises a thermoplastic resin (A), a phosphorus-based flame retardant (B), and a copolymer (C) of an α-olefin and an unsaturated carboxylic acid, in which 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] When the present resin composition has the above-described structure, it is possible to obtain a molded article having high flame retardancy with little deterioration in mechanical properties. The α-olefin / unsaturated carboxylic acid copolymer (C) has a high affinity with both the thermoplastic resin (A) and the phosphorus-based flame retardant (B). Therefore, the inclusion of an appropriate amount of copolymer (C) allows the phosphorus-based flame retardant (B) to be well dispersed in the thermoplastic resin (A). This prevents the degradation of mechanical properties due to aggregation of the phosphorus-based flame retardant (B). While the dispersion effect of the phosphorus-based flame retardant (B) is expected to improve flame retardancy, the α-olefin / unsaturated carboxylic acid copolymer (C) tends to be highly flammable. However, excessive copolymer (C) results in excessive copolymer (C) being distributed on the surface of the molded article, thereby reducing the flame retardancy of the molded article. Therefore, by incorporating appropriate amounts of the thermoplastic resin (A), the phosphorus-based flame retardant (B), and the α-olefin / unsaturated carboxylic acid copolymer (C), a resin composition can be provided that can produce molded articles with high flame retardancy and minimal degradation of mechanical properties.

[0014] The present resin composition may further contain a flame retardant or a flame retardant aid other than the phosphorus-based flame retardant (B). The present resin composition may further contain other components in addition to those described above, as necessary, within the scope of not impairing the effects of the present invention.

[0015] [Thermoplastic resin (A)] The thermoplastic resin is not particularly limited, but examples thereof include polyolefin resin, polycarbonate resin, polyester resin, acrylonitrile-styrene resin, ABS resin, polyamide resin, modified polyphenylene oxide, 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] The polyolefin resin is not particularly limited and includes the resins described below. The polyester resin is not particularly limited and includes, for example, polybutylene terephthalate. The polyamide resin is not particularly limited and includes, for example, nylon 66 and nylon 6. In particular, the present invention is particularly useful when the thermoplastic resin (A) is a polyolefin resin. In the present invention, the term "polyolefin resin" refers to a resin in which olefin units or cycloolefin units account for 90 mol % or more of all structural units constituting the resin (100 mol %). The proportion of olefin units or cycloolefin units relative to 100 mol % of all structural units constituting the polyolefin resin is preferably 95 mol % or more, 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 block or random copolymers, α-olefin-propylene block 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 the α-olefin-propylene block or random copolymers having 4 or more carbon atoms, examples of the 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 alone or in combination of two or more.

[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 with other α-olefin polymers such as an ethylene-propylene block or random copolymer, or an α-olefin-propylene block or random copolymer having 4 or more carbon atoms may be used. The polyolefin resin preferably contains polypropylene as a main component, and 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. The polyolefin resin is particularly preferably 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, and is preferably 80 g / 10 min or less, more preferably 60 g / 10 min or less. If the MFR of the thermoplastic resin (A) is not less than the lower limit, the molding processability is superior, and if it is not more than the upper limit, the bending properties, tensile properties, chemical resistance, etc. are superior. The preferable lower limit and upper limit can be combined as appropriate (the same applies hereinafter). The MFR of the thermoplastic resin (A) may be, for example, 0.1 g / 10 min or more and 80 g / 10 min or less, or 0.5 g / 10 min or more and 60 g / 10 min or more. The melt mass flow rate of the 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 proportion of the thermoplastic resin (A) relative 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 even more preferably 60% by mass or more, while it is preferably 85% by mass or less, more preferably 83% by mass or less, and even more preferably 80% by mass or less. If the proportion of the thermoplastic resin (A) is equal to or greater than the lower limit, the inherent physical properties of the thermoplastic resin (A) are easily exhibited, and if it is equal to or less than the upper limit, the flame retardancy is better. The proportion of the thermoplastic resin (A) relative to the total mass of the present 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 retardants (B)] The phosphorus-based flame retardant (B) is a phosphorus compound, ie, a compound containing a phosphorus atom in the molecule. The phosphorus-based flame retardant (B) exerts a flame retardant effect by forming char when the resin composition is burned. The phosphorus-based flame retardant (B) may be a known one, and examples thereof include (poly)phosphates, (poly)phosphate esters, etc. "(Poly)phosphates" refers to phosphates or polyphosphates. "(Poly)phosphate esters" refers to phosphate esters or polyphosphate esters. The phosphorus-based flame retardant (B) is preferably a solid at 80°C.

[0022] As the phosphorus-based flame retardant (B), a (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. Furthermore, compounds in which melamine or piperazine is replaced with other nitrogen compounds can also be used in the above examples. 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, tetramethylethylene ... Ethylenediamine, 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, acrylguanamine, 2,4-diamino-6-nonyl-1,3,5-trimethyl-1 ... 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 ,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 alone or in combination of two or more.

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

[0024] Commercially available phosphorus-based flame retardants (B) include, for example, Adeka STAB FP-2100J, FP-2200, and FP-2500S (manufactured by ADEKA Corporation).

[0025] As described above, 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. When the ratio of the phosphorus-based flame retardant (B) to the thermoplastic resin (A) is in this range, when the thermoplastic resin (A) is used in combination with the copolymer (C) of an α-olefin and a carboxylic anhydride described below, a significant decrease in mechanical properties and flexural modulus can be prevented and high flame retardancy can be obtained.

[0026] Among the above, the ratio of the phosphorus-based flame retardant (B) to the 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, while 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 the phosphorus-based flame retardant (B) to the 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 proportion of the phosphorus-based flame retardant (B) relative 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 it is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. If the proportion of the phosphorus-based flame retardant (B) is equal to or greater than the lower limit, the flame retardancy is superior, and if it is equal to or less than 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) relative 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, "copolymer (C) 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 the copolymer (C), the proportion of α-olefin units relative to the total of α-olefin units and unsaturated carboxylic acid units (100 mol%) is preferably 30 mol% or more, and 70 mol% or less. When the proportion of α-olefin units is equal to or more than the lower limit, the compatibility with polyolefin resins is particularly excellent, and when it is equal to or less than the upper limit, the compatibility with the phosphorus-based flame retardant (B) is excellent.

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

[0030] In the copolymer (C), examples of the unsaturated carboxylic acid 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, imides, etc. of these unsaturated carboxylic acids. "(Meth)acrylic acid" refers to acrylic acid or methacrylic acid. Specific examples of the ester, anhydride, or imide of unsaturated carboxylic acid 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 alone or in combination of two or more. Among these, esters and dicarboxylic acid anhydrides are preferred from the viewpoint of copolymerization reactivity, and among these, dicarboxylic acid anhydrides are preferred, with maleic anhydride being particularly preferred, from the viewpoint of compatibility with the phosphorus-based flame retardant (B).

[0031] The weight average molecular weight of the copolymer (C) is preferably at least 2,000, more preferably at least 3,000, and is preferably at most 50,000, more preferably at most 30,000. When the weight average molecular weight of the copolymer (C) is within the above upper and lower limit ranges, the dispersibility of the phosphorus-based flame retardant (B) is better. The weight average molecular weight of the copolymer (C) may be, for example, 2,000 or more and 50,000 or less, or 3,000 or more and 30,000 or less. The weight average molecular weight of the copolymer (C) is a value calculated as a standard polystyrene equivalent, measured by dissolving the copolymer (C) in tetrahydrofuran (THF) and subjecting it to gel permeation chromatography.

[0032] Commercially available copolymers (C) include, for example, Ricorb CE2 (manufactured by Clariant Japan KK) and Diacarna 30M (manufactured by Mitsubishi Chemical Corporation).

[0033] As described above, the resin composition contains the copolymer (C), and the ratio of the copolymer (C) to the 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, particularly preferably 0.3% by mass or more, while it is preferably 8% by mass or less, more preferably 6% by mass or less, particularly 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, it is possible to obtain a molded product having high flame retardancy while maintaining high mechanical strength and high flexural modulus. The ratio of the copolymer (C) to the 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 proportion of copolymer (C) relative to the total mass of the resin composition is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.1% by mass or more, while it is 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. When the proportion of copolymer (C) is above the lower limit, the phosphorus-based flame retardant (B) is well dispersed, improving the flame retardancy and physical properties of the resin composition and the appearance of the resulting molded article. When the proportion 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 proportion of copolymer (C) relative to the total mass of the present resin composition may be, for example, 0.01 mass% or more and 1.2 mass% or less, 0.03 mass% or more and 1.1 mass% or less, or 0.1 mass% or more and 1.0 mass% or less.

[0035] Furthermore, the proportion of copolymer (C) relative 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 even more preferably 0.1% by mass or more, while it is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less. When the proportion of copolymer (C) is above the lower limit, the phosphorus-based flame retardant (B) is more dispersed, improving the flame retardancy and physical properties of the resin composition and the appearance of the resulting molded article. When the proportion of copolymer (C) is below the upper limit, the effect of copolymer (C) on the flame retardancy of the resin composition can be further suppressed. The proportion of the copolymer (C) relative to the total mass of the thermoplastic resin (A) and the phosphorus-based flame retardant (B) may be, for example, 0.01 mass% or more and 2.0 mass% or less, 0.05 mass% or more and 1.5 mass% or less, or 0.1 mass% or more and 1.0 mass% or less. The proportion of the total mass of the thermoplastic resin (A), the phosphorus-based flame retardant (B), and the copolymer (C) relative 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 be 100% by mass.

[0036] [Other flame retardants or flame retardant synergists] The other flame retardants or flame retardant aids are preferably halogen-free organic or inorganic flame retardants or flame retardant aids, such as triazine ring-containing compounds, silicone flame retardants, metal hydroxides, metal oxides, boric acid compounds, and expandable graphite.

[0037] Examples of the triazine ring-containing compound include melamine, ammeline, benzguanamine, acetoguanamine, phthalodiguanamine, melamine cyanurate, butylenediguanamine, norbornenediguanamine, methylenediguanamine, ethylenedimelamine, trimethylenedimelamine, tetramethylenedimelamine, hexamethylenedimelamine, and 1,3-hexylenedimelamine. Examples of silicone 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 Kismer 5A (a trademark of 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 (a trademark of titanium oxide manufactured by Ishihara Sangyo Kaisha, Ltd.), Kyowamag 150 (a trademark of magnesium oxide manufactured by Kyowa Chemical Industry Co., Ltd.), DHT-4A (hydrotalcite manufactured by Kyowa Chemical Industry Co., Ltd.), and Alkamiser 4 (a trademark of zinc-modified hydrotalcite manufactured by Kyowa Chemical Industry Co., Ltd.). Examples of boric acid compounds include zinc borate. These flame retardants or flame retardant auxiliaries may be used alone or in combination of two or more.

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

[0039] The type of glass fiber is not particularly limited, and any glass fiber such as E-glass, C-glass, S-glass, or D-glass can be used. The form of the glass fiber is not particularly limited, and any glass fiber such as chopped strand, roving, yarn, or glass wool can be used, but chopped strand and glass wool are preferred from the viewpoint of workability.

[0040] The type of carbon fiber is not particularly limited, and any carbon fiber such as polyacrylonitrile (PAN)-based carbon fiber, pitch-based carbon fiber, graphite fiber, etc. 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, chopped strand, etc. can be used, but chopped strand is preferred from the viewpoint of workability.

[0041] When the resin composition contains an inorganic fiber filler (D), the proportion of the inorganic fiber filler (D) relative to the total mass of the resin composition is preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and is preferably 50 mass% or less, more preferably 40 mass% or less, more preferably 30 mass% or less, more preferably 25 mass% or less, more preferably 10 mass% or less, even more preferably 5 mass% or less, and particularly preferably 3 mass% or less. If the proportion of the inorganic fiber filler (D) is at least the lower limit, anti-rip and smoke-suppressing effects are easily obtained, while if it is at most the upper limit, the inherent physical properties of the thermoplastic resin (A) are less likely to be impaired.

[0042] When the present resin composition contains an inorganic fiber filler (D), it may further contain an interfacial strength improver (E) for the inorganic fiber filler (D). As the interfacial strength improver (E), a polymer having an olefin skeleton (excluding polyolefin resins and copolymers (C)) is preferred, particularly from the viewpoint of compatibility with the thermoplastic resin (A) such as a polyolefin resin. The compatibility of the olefin skeleton with the polyolefin resin further improves the interfacial strength.

[0043] The interfacial strength improver (E) preferably has an acidic group, which reacts with the inorganic fibrous filler (D) to further improve the interfacial strength. Examples of the acidic group include a carboxyl group, a carboxylic acid anhydride group, a sulfonic acid group, a sulfinic acid group, a phosphonic acid group, and a phosphinic acid group. At least one selected from the group consisting of a carboxyl group, a carboxylic acid anhydride group, a sulfonic acid group, a sulfinic acid group, a phosphonic acid group, and a phosphinic acid group is preferred, at least one selected from the group consisting of a carboxyl group, a carboxylic acid anhydride group, and a phosphonic acid group is more preferred, and at least one selected from the group consisting of a carboxyl group and a carboxylic acid anhydride group is particularly preferred.

[0044] Examples of methods for producing the interfacial strength improver (E) having an olefin skeleton and an acidic group include (1) a method in which an olefin resin is thermally decomposed at high temperature to reduce its molecular weight, and then a compound or monomer having an acidic group is added to the resulting resin; (2) a method in which a low-molecular-weight olefin resin is polymerized, and then a compound or monomer having an acidic group is added to the resulting resin; and (3) a method in which an α-olefin and a compound or monomer having an acidic group are copolymerized. Examples of polymerization methods that can be used include radical polymerization methods such as solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization, as well as living polymerization methods. Furthermore, a method in which a macromonomer is first formed and then polymerized can also be used. 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] Commercially available interfacial strength improvers (E) include, for example, Eumex 1001 and 1010 (manufactured by Sanyo Chemical Industries, Ltd.), and Kayabrid 002PP and 003PP (manufactured by Kayaku Nouryon Co., Ltd.).

[0046] The present resin composition may contain at least one selected from the group consisting of antioxidants, ultraviolet absorbers, light stabilizers, and antiaging agents.

[0047] Examples of the antioxidant include phenol-based 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)propionic acid amide], 4,4'-thiobis(6-tert-butyl-m-cresol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-butyl- Ethylidenebis(6-tert-butyl-m-cresol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4-sec-butyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate diethyl)-2,4,6-trimethylbenzene, 2-tert-butyl-4-methyl-6-(2-acryloyloxy-3-tert-butyl-5-methylbenzyl)phenol, stearyl (3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)methylpropionate]methane, thiodiethylene glycol bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,6-hexamethylene bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] ], bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butyric acid] glycol ester, bis[2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl] terephthalate, 1,3,5-tris[(3,5-ditert-butyl-4-hydroxyphenyl)propionyloxyethyl] isocyanurate, 3,9-bis[1,1-dimethyl-2-{(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5] undecane, triethylene glycol bis[(3-tert-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, per 100 parts by mass of the synthetic resin component in the resin composition, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less.

[0048] Examples of phosphorus-based antioxidants include trisnonylphenyl phosphite, tris[2-tert-butyl-4-(3-tert-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite, tridecyl phosphite, octyldiphenyl phosphite, di(decyl)monophenyl phosphite, di(tridecyl)pentaerythritol diphosphite, di(nonylphenyl)pentaerythritol diphosphite, bis(2,4-ditert-butylphenyl)phosphite, phenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, tetra(tridecyl)isopropylidenediphenol diphosphite, tetra(tridecyl)-4,4'-n-butylidenebis(2-tert-butyl-5-methylphenol) Hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane triphosphite, Tetrakis(2,4-ditert-butylphenyl)biphenylene diphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,2'-methylenebis(4,6-tert-butylphenyl)-2-ethylhexyl phosphite, 2,2'-methylenebis(4,6-tert-butylphenyl)-2-ethylhexyl phosphite phenyl)-octadecyl phosphite, 2,2'-ethylidenebis(4,6-di-tert-butylphenyl)fluorophosphite, tris(2-[(2,4,8,10-tetrakis-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl)amine, phosphite of 2-ethyl-2-butylpropylene glycol and 2,4,6-tri-tert-butylphenol, tris(2,4-di-tert-butylphenyl)phosphite, etc. 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, per 100 parts by mass of the synthetic resin component in the resin composition, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less.

[0049] Examples of thioether antioxidants include dialkylthiodipropionates such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate, and pentaerythritol tetra(β-alkylthiopropionate)s. 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, relative to 100 parts by mass of the synthetic resin component in the resin composition, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less.

[0050] Examples of the ultraviolet absorber 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'-di-tert-butylphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-3'- 2-(2'-hydroxyphenyl)benzotriazoles such as 2-(tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole, 2,2'-methylenebis(4-tert-octyl-6-(benzotriazolyl)phenol), and 2-(2'-hydroxy-3'-tert-butyl-5'-carboxyphenyl)benzotriazole; phenyl Benzoates such as ricinate, resorcinol monobenzoate, 2,4-ditert-butylphenyl-3,5-ditert-butyl-4-hydroxybenzoate, 2,4-ditert-amylphenyl-3,5-ditert-butyl-4-hydroxybenzoate, hexadecyl-3,5-ditert-butyl-4-hydroxybenzoate; substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide, 2-ethoxy-4'-dodecyloxanilide; ethyl-α-cyano-β,β-diphenylacrylate, methyl 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-di-tert-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-di-tert-butylphenyl)-s-triazine. The content of the 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, and is preferably 30 parts by mass or less, 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-butadiene. 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-di-tert-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-tert-octylamino-s-triazine polycondensate, 1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidinol)] lysyl)amino)-s-triazin-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-triazin-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-triazin-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-triazin-6-yl)aminoundecane. The content of the 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, and is preferably 30 parts by mass or less, more preferably 10 parts by mass or less.

[0052] The present resin composition may contain fillers other than the inorganic fiber filler (D). As other fillers, fibrous, plate-like, granular, and powder-like fillers can be used. Specific examples include inorganic fibrous reinforcing materials such as asbestos fiber, metal fiber, potassium titanate whisker, aluminum borate whisker, magnesium whisker, silicon whisker, wollastonite, sepiolite, asbestos, slag fiber, zonolite, elestadite, gypsum fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, and boron fiber, polyester fiber, nylon fiber, acrylic fiber, regenerated cellulose fiber, acetate fiber, kenaf, ramie, cotton, jute, hemp, sisal, flax, linen, Examples of suitable fillers include organic fibrous reinforcing materials such as silk, Manila hemp, sugarcane, wood pulp, waste paper, recycled paper, and wool, as well as plate-like or granular reinforcing materials such as glass flakes, non-swelling mica, graphite, metal foil, ceramic beads, clay, mica, sericite, zeolite, bentonite, dolomite, kaolin, finely powdered silicic acid, 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 clay. These fillers may be coated or bundled with a thermoplastic resin such as ethylene-vinyl acetate copolymer or a thermosetting resin such as epoxy resin, or may be treated with a coupling agent such as aminosilane or epoxysilane. The content of the other filler is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, per 100 parts by mass of the synthetic resin component in the resin composition, and is preferably 60 parts by mass or less, more preferably 50 parts by mass or less.

[0053] The resin composition may contain a crystal nucleating agent. As the crystal nucleating agent, any of those generally used as crystal nucleating agents for polyolefin resins can be used as appropriate, including, for example, inorganic crystal nucleating agents and organic crystal nucleating agents.

[0054] Specific examples of inorganic crystal 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, etc. These inorganic crystal nucleating agents may be modified with an organic substance to enhance 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 montanate, calcium montanate, sodium toluate, sodium salicylate, potassium salicylate, and salicylic acid. Examples of the organic carboxylic acid metal salts include zinc dibenzoate, aluminum dibenzoate, potassium dibenzoate, lithium dibenzoate, sodium β-naphthalate, and sodium cyclohexanecarboxylate; organic sulfonates such as sodium p-toluenesulfonate and sodium sulfoisophthalate; carboxylic acid amides such as stearic acid amide, ethylene bislauric acid amide, palmitic acid amide, hydroxystearic acid amide, erucic acid amide, and trimesic acid tris(t-butylamide); benzylidene sorbitol and derivatives thereof; phosphorus compound metal salts such as sodium 2,2'-methylenebis(4,6-di-t-butylphenyl)phosphate; and 2,2-methylbis(4,6-di-t-butylphenyl)sodium.

[0056] The resin composition may contain a plasticizer. As the plasticizer, any plasticizer generally used as a plasticizer 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 alone or in combination of two or more.

[0057] Specific examples of polyester-based plasticizers include polyesters composed of an acid component such as adipic acid, sebacic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, or rosin, and a diol component such as propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, ethylene glycol, or diethylene glycol, and polyesters composed of hydroxycarboxylic acids such as polycaprolactone. These polyesters may be end-capped with a monofunctional carboxylic acid or a monofunctional alcohol, or may be end-capped with an epoxy compound or the like.

[0058] Specific examples of glycerin-based plasticizers include glycerin monoacetomonolaurate, glycerin diacetomonolaurate, glycerin monoacetomonostearate, glycerin diacetomonooleate, and glycerin monoacetomonomonoacetate.

[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; trimellitate esters such as tributyl trimellitate, trioctyl trimellitate, and trihexyl trimellitate; 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; citric acid esters such as triethyl acetyl citrate and tributyl acetyl citrate; azelaic acid esters such as di-2-ethylhexyl azelaate; and sebacate esters such as dibutyl sebacate and di-2-ethylhexyl sebacate.

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

[0061] Epoxy plasticizers generally refer to epoxy triglycerides made from alkyl epoxy stearate and soybean oil, but other so-called epoxy resins, such as those made primarily from bisphenol A and epichlorohydrin, can also be used.

[0062] Specific examples of other 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; oxyacid esters such as methyl acetylricinoleate and butyl acetylricinoleate; pentaerythritol, various sorbitols, polyacrylic acid esters, and paraffins.

[0063] The present resin composition may contain a fluorine-containing anti-dripping agent. Examples of fluorine-containing anti-dripping 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 such as those disclosed in U.S. Pat. No. 4,379,910, and polycarbonate resins produced from fluorinated diphenols. Among these, PTFE is preferred.

[0064] PTFE having fibril-forming ability has an extremely high molecular weight and tends to bond with other PTFE molecules to form fibers under external action such as shear force. Its molecular weight, in terms of number average molecular weight determined from standard specific gravity, is preferably 1 million or more, more preferably 2 million or more, and is preferably 10 million or less, more preferably 9 million or less. PTFE having fibril-forming ability can be used in the form of an aqueous dispersion as well as in a solid form.

[0065] Commercially available PTFE products capable of forming fibrils include Teflon (registered trademark) 6J manufactured by DuPont-Mitsui Fluorochemicals Co., Ltd. and Polyflon (registered trademark) MPA FA500 and F-201L manufactured by Daikin Industries, Ltd. Commercially available aqueous dispersions of PTFE include Fluon AD-939E manufactured by Asahi ICI Fluoropolymers Co., Ltd., Fluon D-310 and D-210C manufactured by Daikin Industries, Ltd., and Teflon 31JR manufactured by DuPont-Mitsui Fluorochemicals Co., Ltd.

[0066] In order to improve the dispersibility of fibril-forming PTFE in the resin composition and 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 relative to the total mass of the PTFE mixture is preferably 1% by mass or more, more preferably 5% by mass or more, and is preferably 60% by mass or less, 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 prepared by, for example, (1) a method of 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 Application Laid-Open Nos. 60-258263 and 63-154744, etc.), (2) a method of mixing an aqueous dispersion of PTFE with dried particles of another resin (method described in Japanese Patent Application Laid-Open No. 4-272957), or (3) a method of uniformly mixing an aqueous dispersion of PTFE with a solution of another resin and simultaneously extracting each medium from the mixture. (4) a method of polymerizing a monomer that forms another resin in an aqueous dispersion of PTFE (the method described in JP-A-06-220210, JP-A-08-188653, etc.), or (5) a method of uniformly mixing an aqueous dispersion of PTFE and a dispersion of another resin, polymerizing a vinyl monomer in the resulting mixed dispersion, and then obtaining a mixture (the method described in JP-A-11-29679, etc.). Commercially available PTFE mixtures include "Metablen A3000" from Mitsubishi Chemical Corporation and "BLENDEX B449" from GE Specialty Chemicals.

[0068] The content of the fluorine-containing anti-dripping agent is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, in terms of the amount of PTFE per 100 parts by mass of the resin composition, and is preferably 1 part by mass or less, more preferably 0.8 parts by mass or less, and even more preferably 0.5 parts by mass or less.

[0069] In addition to the above, the resin composition may contain additives commonly used in synthetic resins, such as crosslinking agents, antistatic agents, metal soaps, fillers, antifogging agents, anti-plateout agents, surface treatment agents, fluorescent agents, antifungal agents, bactericides, foaming agents, metal deactivators, release agents, pigments, and processing aids, within ranges that do not impair the effects of the present invention.

[0070] [Method of producing resin composition] Any method can be used to produce the resin composition, for example, by thoroughly mixing the thermoplastic resin (A), the phosphorus-based flame retardant (B), the copolymer (C), and, if necessary, other flame retardants, flame retardant auxiliaries, and other components using a premixing means such as a V-type blender, a Henschel mixer, a mechanochemical device, or an extrusion mixer, optionally granulating the mixture using an extrusion granulator or a briquetting machine, and then melt-kneading and extruding the mixture in a melt kneader. Examples of the melt kneader include a twin-screw extruder such as a vented twin-screw extruder, a Banbury mixer, a kneading roll, a single-screw extruder, and a multi-screw extruder having three or more screws. The temperature during melt-kneading is, for example, 170 to 260°C. The resin composition extruded as described above is directly cut into pellets by a machine such as a pelletizer, or is cooled to form strands, and then the strands are cut into pellets by a machine such as a pelletizer.

[0071] The resin composition described above contains the copolymer (C) in addition to the thermoplastic resin (A) and the phosphorus-based flame retardant (B), and therefore can exhibit excellent flame retardancy while fully maintaining the inherent physical properties of the polyolefin resin (A) (e.g., mechanical strength and flexural modulus). The copolymer (C) improves the dispersibility of the phosphorus-based flame retardant (B) in the thermoplastic resin (A), such as a polyolefin resin. It is believed that the improved dispersibility of the phosphorus-based flame retardant (B) facilitates the formation of char during combustion, improving flame retardancy. While the mechanism behind this is unclear, the following is thought to be the cause. In particular, when the thermoplastic resin (A) is a polyolefin-based 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, the copolymer (C) has low-polarity α-olefin moieties that are highly compatible with polyolefin resins, and polar unsaturated carboxylic acid moieties that are highly compatible with phosphorus-based flame retardants (B). It is believed that the presence of copolymer (C) between the polyolefin resin and the phosphorus-based flame retardant (B) during melt-kneading of the resin composition improves the dispersibility of the phosphorus-based flame retardant (B) in the polyolefin resin.

[0072] The effects of the copolymer (C) include (1) improving the dispersibility of the phosphorus-based flame retardant (B) (fine dispersion), (2) promoting char generation during combustion, and (3) improving physical properties (tensile strain at break). Specifically, 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, but if the resin composition contains copolymer (C), the size of the chars increases, improving the heat transfer suppression effect. Furthermore, in a cone calorimeter test, when a 3 mm thick flat test piece 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 for the char are generated and the molded body burns, but if the resin composition contains copolymer (C), the gaps for the char are reduced, and char is formed by burning on the sides, forming a dome-like shape. Although the mechanism is unknown, adding copolymer (C) forms a stronger char, suppressing heat transfer and enabling the material to achieve a V-0 rating in the UL94 test. The copolymer (C) can exert the above effects even in a small amount (for example, 1.2 mass % or less based on the total mass of the resin composition).

[0073] According to the present resin composition, the phosphorus-based flame retardant (B) is well dispersed, and therefore it is possible to obtain a molded article having a dispersibility calculated by the following formula of, for example, 22% or less, or even 21% or less. Dispersibility [%]=4,000μm 2 The sum of the area values ​​of particles of size ≥ 100 μm 2 ] ÷ flame retardant area (threshold 3%, 136,331) [μm 2 ] x 100 Here, 4,000 μm 2 The total area of ​​particles of the above sizes and the area of ​​the flame retardant can be determined by image processing of an optical microscope image of the molded article, as described in detail in the Examples below.

[0074] [Molded body] A molded article according to one aspect of the present invention is made from the resin composition. The shape of the molded product is not particularly limited, and may take various forms such as a resin plate, sheet, film, cable, or irregularly shaped product.

[0075] The molded article can be obtained by molding the present resin composition. The molding method is not particularly limited, and examples thereof include extrusion, calendaring, injection molding, rolling, compression molding, and blow molding. The temperature at which the present resin composition is molded is, for example, 170 to 260°C. [Example]

[0076] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the following examples. In the following examples, % is by mass unless otherwise specified. Evaluations were carried out on the following items.

[0077] (1) Flame retardant (UL94) The resulting molded articles (1 / 16 inch test bars) were used to judge the flame retardancy in accordance with the UL94 standard.

[0078] (2) Flame retardant dispersibility evaluation 1 The number of undispersed flame retardants present in the obtained molded product (0.5 mm thick sheet) was evaluated. The evaluation procedure involved observing the sheet using an optical microscope (Nikon, product name: ECLIPSE E600W POL) at 50x magnification (10x eyepiece, 5x objective) with transmitted light. Five 640 x 480 pixel images were randomly selected from the optical microscope images and captured using image processing software (Image J, Ver. 1.52a), and converted to 8-bit format. When observed at 50x magnification, 1,000 μm is 260 pixels, so 640 x 480 pixels is 4,454,379 μm. 2 After that, the flame retardant in the sheet was emphasized by bandpass filtering, and the concentration was measured. Because the flame retardant has the strongest contrast in the image, the area where the binarized area value is 3% from the minimum value (0) was set as the threshold, and the flame retardant area was extracted. Next, particles in the binarized image with a size of 4,000 μm were extracted. 2 The particle areas of the above sizes were summed up, and the dispersibility [%] was calculated using the formula below, and the average dispersibility for each of the five images was determined. Dispersibility [%]=4,000μm 2 The sum of the area values ​​of particles of size ≥ 100 μm 2 ] ÷ flame retardant area (threshold 3%, 136,331) [μm 2 ] x 100

[0079] (3) Flame retardant dispersibility evaluation 2 The dispersibility was compared based on the images observed in the same manner as in (2) Evaluation of Dispersibility of Flame Retardant 1 above, according to the following criteria. A: More than 100 flame retardant particles are observed in the photograph. B: There are 50 or more but less than 100 flame retardant particles in the photograph. C: There are less than 50 flame retardant particles in the photograph. D: There are less than 30 flame retardant particles in the photograph. In this evaluation, the dispersibility increases from A to D. (4) Bending properties The obtained molded article (JIS K7139-A1 dumbbell test piece) was cut into a length of 80 mm, and the flexural modulus (GPa) was measured in accordance with JIS K7171.

[0080] (5) Tensile properties The obtained molded body (JIS K7139-A1 dumbbell test piece) was used to measure the tensile strength at yield (MPa) and the tensile strain at break (%) in accordance with JIS K7161-1.

[0081] (6) Combustion calorific value (cone calorie meter) A 100mm x 100mm x 3mm thick test piece was measured using a Toyo Seiki Co., Ltd. Model: C3 Cone Calorimeter III in accordance with ISO5660-1 (2002) at a radiant heat of 50kW / m 2 Under the condition, the maximum heat generation rate (kW / m 2 ), total calorific value (MJ / m 2 ) was measured.

[0082] The following raw materials were used: <Polyolefin resin> A-1: Polypropylene resin (Novatec PP FY-4, manufactured by Japan Polypropylene Corporation, melt mass flow rate 5 g / 10 min). A-2: Polypropylene resin (Novatec PP SA06GA, manufactured by Japan Polypropylene Corporation, melt mass flow rate 60 g / 10 min). <Flame retardant> B: Phosphorus-based flame retardant composition (ADEKA CORPORATION, ADK STAB FP-2200, containing 50 to 60% piperazine pyrophosphate, 35 to 45% melamine pyrophosphate, and 3 to 6% zinc oxide based on the total mass of the phosphorus-based flame retardant composition).

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

[0084] [Examples 1 to 7, Comparative Examples 1 to 4] The raw materials shown in Table 1 were blended in the ratios shown in Table 1 and mixed by hand blending. Then, using a φ30 mm co-rotating twin-screw extruder (model name "BT-30", manufactured by Plastics Technology Research Institute Co., Ltd., L / D=30), the mixture was melt-kneaded at a screw rotation speed of 250 rpm and a cylinder temperature of 200°C to obtain a resin composition. "L / D" indicates the ratio of the screw length (L) to the 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 article (1 / 16 inch test bar). This molded article (1 / 16 inch test bar) was used as a test piece for UL94 evaluation. The obtained resin composition was injection molded using a 100 ton injection molding machine (model name "SE-100DU", manufactured by Sumitomo Heavy Industries, Ltd.) at a molding temperature of 200°C to obtain a molded article (JIS K7139-A1 dumbbell test piece). This molded article (JIS K7139-A1 dumbbell test piece) was used as a test piece for evaluating bending properties and tensile properties.

[0086] The resin composition was injection molded at 200°C using a 100-ton injection molding machine (SE-100DU, manufactured by Sumitomo Heavy Industries, Ltd.) to obtain a molded body (100 x 100 x 3 mm square plate). This molded body (100 x 100 x 3 mm square plate) was then pressed at 200°C and 10 MPa using a hydraulic molding machine (manufactured by Shoji Iron Works Co., Ltd.) with a procedure of 5 minutes of preheating, 5 minutes of pressure application, and 5 minutes of cooling, 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] The properties of these molded products were measured, and the results are shown in Table 1. With regard to dispersibility, Examples 1 to 7 and Comparative Examples 1 to 3 were evaluated as Dispersibility Evaluation 1, and Example 4 and Comparative Examples 1 and 4 were evaluated as Dispersibility Evaluation 2. Furthermore, the ratios (%) of the dispersibility (values ​​obtained in Dispersibility Evaluation 1), flexural modulus, and tensile strain at break of each Example and Comparative Example to the dispersibility (values ​​obtained in Dispersibility Evaluation 1), flexural modulus, and tensile strain at break of Comparative Example 1 were calculated. These values ​​are shown in Table 1 as dispersibility ratio, flexural modulus ratio, and tensile strain at break.

[0088] [Example 8] Flame retardant masterbatch-1 was produced by melt-kneading the following composition: A-2: Novatec PP, SA06GA as polypropylene resin, 58.78 mass% B: ADK STAB FP-2200 as phosphorus-based flame retardant composition, 1.96 mass% C-1: Diakarna 30M as dispersant, and 0.04 mass% each of ADK STAB AO-60 and 2112 as antioxidants using a φ30 mm co-rotating twin-screw extruder (model name "BT-30", manufactured by Plastics Engineering Research Institute Co., Ltd., L / D=30) at a screw rotation speed of 250 rpm and a cylinder temperature of 200°C. This Masterbatch-1 was mixed with 50% by mass of polypropylene resin A-1 Novatec PP FY4 at a composition of 50% by mass, and the mixture was injection molded using a 100 ton 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 obtained results are shown in Table 1.

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

[0090] [Table 1]

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

[0092] The molded articles of the resin compositions of Examples 1 to 9 containing the copolymer (C) (C-1 or C-2) of an α-olefin and an unsaturated carboxylic acid were superior in flame retardancy and dispersibility of the flame retardant compared to the molded article of the resin composition of Comparative Example 1 not containing the copolymer (C). In addition, sufficient flexural modulus and tensile strength at yield point were exhibited, and further, the tensile strain at break was improved due to the improved dispersibility of the flame retardant. Furthermore, in Examples 1 to 9, the test results according to the UL94 standard were all V-0, which indicates that the resin compositions of Examples 1 to 9 are resin compositions that are inhibited from 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), had excellent flame retardancy but poor dispersibility of the flame retardant.Furthermore, it was found that the tensile strain ratio at break was small and the mechanical strength was poor. The molded article of the resin composition of Comparative Example 3, in which acid-modified polyethylene was blended instead of copolymer (C), was inferior in flame retardancy and dispersibility of the flame retardant. It is also clear that the tensile strain ratio at break was small and the mechanical strength was poor. In Comparative Example 4, in which the ratio of copolymer (C) to phosphorus-based flame retardant (B) was too high, the dispersion of the flame retardant was better than in Example 4, but the flexural modulus was significantly reduced, indicating that the inherent properties of polypropylene were significantly impaired.

[0094] [Comparative combustion heat generation test using a cone calorimeter] The raw materials shown in Table 2 were blended in the ratios shown in Table 2 and mixed by hand blending. Then, using a φ30 mm co-rotating twin-screw extruder (model name "BT-30", manufactured by Plastics Technology Research Institute Co., Ltd., L / D=30), the mixture was melt-kneaded at a screw rotation speed of 250 rpm and a cylinder temperature of 200°C to obtain a resin composition. For the obtained resin composition, a test piece for evaluating the dispersibility of the flame retardant was 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. The resin composition was injection molded at a molding temperature of 200°C using a 100-ton injection molding machine (SE-100DU, manufactured by Sumitomo Heavy Industries, Ltd.) to obtain a molded product (a square plate measuring 100 x 100 x 3 mm). The combustion heat value of the molded product was evaluated using a cone calorimeter. The results are shown in Table 2.

[0095] [Table 2]

[0096] In comparison of the combustion heat release values ​​using a cone calorimeter as shown in Table 2, Examples 3, 10, and 11, which contained a copolymer (C) (C-1 or C-2) of an α-olefin and an unsaturated carboxylic acid, had lower total heat release values ​​and maximum heat release rates and were more flame retardant than Comparative Examples 1 and 5, which did not contain the copolymer (C). [Industrial Applicability]

[0097] According to the resin composition of the present invention, a phosphorus-based flame retardant is well dispersed, and a molded article having excellent flame retardancy, mechanical strength, and flexural modulus can be obtained. The molded article obtained using the resin composition of the present invention has excellent flame retardancy, mechanical strength, and flexural modulus, and is therefore suitable for use as a molding material, cable, etc. in the automotive field, the office automation equipment field such as printers, the electrical and electronic field such as mobile phones, etc.

Claims

1. The flame retardant comprises a thermoplastic resin (A), a phosphorus-based flame retardant (B), and a copolymer (C) of an α-olefin and an unsaturated carboxylic acid, the thermoplastic resin (A) is a polyolefin resin, the phosphorus-based flame retardant (B) is a salt of (poly)phosphoric acid and a nitrogen compound, and the nitrogen compound contains melamine or piperazine; 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, wherein the ratio of the copolymer (C) to the phosphorus-based flame retardant (B) is 10 mass % or less.

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

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

4. The resin composition according to any one of claims 1 to 3, wherein the α-olefin in the copolymer (C) has 10 or more and 80 or less carbon atoms.

5. The resin composition according to any one of claims 1 to 4, wherein in the copolymer (C), the proportion of the α-olefin units relative to a total of 100 mol% of the α-olefin units and the unsaturated carboxylic acid units is 30 mol% or more and 70 mol% or less.

6. The resin composition according to any one of claims 1 to 5, wherein the weight average molecular weight of the copolymer (C) is 2,000 or more and 50,000 or less.

7. The resin composition according to any one of claims 1 to 6, which contains a metal oxide.

8. The resin composition according to claim 7 , wherein the metal oxide comprises zinc oxide.

9. A molded article made of the resin composition according to any one of claims 1 to 8.

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