Flame retardant, composition, masterbatch, molded article, and method

Abstract

The purpose of the present invention is to provide a flame retardant that uses a small added amount of flame retardant and imparts excellent flame retardancy to a synthetic resin and to provide a method for achieving flame retardancy.　The present invention is a flame retardant for a synthetic resin, wherein the flame retardant contains component (A): an N-alkoxypiperidine compound having a structure represented by general formula (1) and component (B): a metal hydroxide, and the flame retardant is added so that the total content of component (A) and component (B) to the total amount of synthetic resin, component (A), and component (B) is in the 0.2 to 10 mass% range. [Formula 1] In general formula (1), R11 represents a C1-30 alkyl group or a C5-12 cycloalkyl group, R12, R13, R14, and R15 each independently represent a C1-4 alkyl group, and * represents a bond.

Description

Flame retardant, composition, masterbatch, molded article, and method

[0001] The present invention relates to a flame retardant, a composition, a masterbatch, a molded article, and a method for imparting flame retardancy to synthetic resins.

[0002] Synthetic resins are used in a wide range of applications due to their convenience, but they have the disadvantage of being highly flammable. Various flame retardants have been developed as additives to impart flame retardancy to synthetic resins. For example, metal hydroxides and hindered amine compounds having an N-alkoxy structure are known to be effective as flame retardants for polyolefin-based resins. Patent Document 1 describes a technique for blending inorganic flame retardants such as metal hydroxides with polyethylene-based resins. Patent Document 2 describes a technique for using NOR-HALS compounds having a specific structure to induce flame retardancy in polymers. Patent Document 3 proposes a resin composition containing at least one compound selected from aluminum hydroxide, magnesium hydroxide, and a phosphorus compound, and a NOR-type hindered amine compound.

[0003] JP 61-036343 A International Publication No. 2013 / 136285 US 2022 / 0389196 A1

[0004] When metal hydroxides are used as flame retardants, a large amount must be added to obtain sufficient flame retardancy. Increasing the content of these compounds in a resin in order to obtain sufficient flame retardancy causes problems such as deterioration in the mechanical properties, processability, transparency, and other properties of the resin. When hindered amine compounds having an N-alkoxy structure are used as flame retardants, increasing the content of these compounds in a resin in order to obtain sufficient flame retardancy causes problems such as bleeding onto the resin surface and increased costs.

[0005] The problem to be solved by the present invention is to provide a flame retardant and a method for imparting flame retardancy to synthetic resins using a small amount of flame retardant.

[0006] As a result of investigations by the present inventors, it has been found that excellent flame retardancy is exhibited when an N-alkoxy hindered amine compound and a metal hydroxide are used in amounts smaller than those conventionally considered necessary.

[0007] The present invention provides a flame retardant for synthetic resins, comprising: component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1); and component (B): a metal hydroxide, the flame retardant being added in such a manner that the total content of components (A) and (B) is 0.2 to 10 mass% relative to the total amount of the synthetic resin, components (A), and (B).

[0008] In general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0009] In the flame retardant of the present invention, the component (A) is preferably one or more compounds represented by the following general formula (2), (3) or (4).

[0010] In general formula (2), R ２０ and R ２１ each independently represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R ２２ , R ２３ , R ２４ , R ２５ , R ２６ , R ２７ , R ２８ and R ２９ each independently represents an alkyl group having 1 to 4 carbon atoms.

[0011] In general formula (3), R ３１ , R ３２ and R ３３each independently represents a group represented by the following general formula (3a), and n1, n2, and n3 each independently represent an integer of 1 to 4.

[0012] In general formula (3a), R ３ａ１ and R ３ａ２ each independently represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R ３ａ３ , R ３ａ４ , R ３ａ５ , R ３ａ６ , R ３ａ７ , R ３ａ８ , R ３ａ９ and R ３ａ１０ each independently represents an alkyl group having 1 to 4 carbon atoms; R ３ａ１１ and R ３ａ１２ each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and * represents a bond.

[0013] In general formula (4), R ４１ , R ４２ , R ４３ , R ４４ , R ４５ , R ４６ , R ４７ , R ４８ and R ４９ each independently represents an alkyl group having 1 to 8 carbon atoms; R ４１１ , R ４１２ , R ４１３ , R ４１４ and R ４１５ each independently represents a group represented by the following general formula (4a), n4 and n5 each independently represent an integer of 2 to 12, and n6 represents an integer of 1 to 15.

[0014] In general formula (4a), R ４ａ１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R ４ａ２ , R ４ａ３ , R ４ａ４ and R ４ａ５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0015] In the flame retardant of the present invention, the component (B) is preferably at least one selected from the group consisting of magnesium hydroxide and calcium hydroxide.

[0016] The flame retardant of the present invention is preferably added so that the content of component (B) is in the range of 0.1 to 9.9% by mass relative to the total amount of the synthetic resin, component (A), and component (B).

[0017] The present invention also provides a composition comprising a synthetic resin, component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1), and component (B): a metal hydroxide, wherein the total content of component (A) and component (B) relative to the total amount of the synthetic resin, component (A), and component (B) is 0.2 to 10 mass%.

[0018] In general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0019] The present invention also provides a masterbatch containing a synthetic resin and the flame retardant.

[0020] The present invention also relates to a molded article obtained from the composition.

[0021] The present invention also provides a method for imparting flame retardancy to a synthetic resin by blending component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1) and component (B): a metal hydroxide with the synthetic resin, wherein the total content of components (A) and (B) relative to the total amount of the synthetic resin, component (A), and component (B) is 0.2 to 10 mass%:

[0022] In general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R １２ , R１３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0023] The present invention also provides a method for producing a composition, which comprises blending a synthetic resin with component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1), and component (B): a metal hydroxide, wherein the total content of component (A) and component (B) relative to the total amount of the synthetic resin, component (A), and component (B) is 0.2 to 10 mass%:

[0024] In general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0025] According to the present invention, it is possible to provide a flame retardant that imparts excellent flame retardancy to a synthetic resin, and a composition and a molded article containing the same.

[0026] The present invention relates to a flame retardant, a composition, a masterbatch, a molded article, and a method for imparting flame retardancy to a synthetic resin. Hereinafter, the present invention will be described based on preferred embodiments thereof.

[0027] The flame retardant of the present invention contains component (A): an N-alkoxypiperidine compound having a structure represented by general formula (1), and component (B): a metal hydroxide.

[0028] The flame retardant of the present invention is used in synthetic resins, including those exemplified as synthetic resins contained in the composition described below.

[0029] The flame retardant of the present invention effectively imparts excellent flame retardancy to synthetic resins with the addition of a small amount. The reason for this effect is unclear, but is presumed to be as follows. Compounds with an N-alkoxy structure, such as N-alkoxypiperidine, decompose into alkyl radicals and nitroxy radicals, or N radicals and alkoxy radicals, upon combustion. These radicals are thought to accelerate the decomposition of the resin, resulting in a rapid molecular weight reduction of the resin to a molecular weight range where it is difficult to ignite. This effect moderates combustion and allows the material to drip before the fire spreads, thereby providing a flame-retardant effect. Meanwhile, metal hydroxides exert their flame-retardant effect through the endothermic action of the decomposition of the metal hydroxide during combustion and the dilution of flammable gases with water vapor. However, it is known that the addition of a small amount of metal hydroxide to a resin does not provide sufficient flame-retardant effect. In the flame retardant of the present invention, after combustion is suppressed by the action of the N-alkoxypiperidine compound, the endothermic action and dilution action of the metal hydroxide are exerted, so that the flame retardant effect of the flame retardant is optimally exerted even when the amount of metal hydroxide added is small.

[0030] The component (A) in the flame retardant of the present invention is an N-alkoxypiperidine compound having a structure represented by the following general formula (1).

[0031] In general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0032] The R １１Examples of the alkyl group having 1 to 30 carbon atoms represented by the formula (I) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a hexyl group, an isohexyl group, a tert-hexyl group, a heptyl group, an isoheptyl group, a tert-heptyl group, an octyl group, an isooctyl group, a tert-octyl group, a 2-ethylhexyl group, a nonyl group, an isononyl group, a decyl group, an isopropyl ... Examples of such alkyl groups include linear or branched alkyl groups such as sodecyl, 2-propylheptyl, undecyl, isoundecyl, dodecyl, isododecyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl, octacosyl, nonacosyl, and triacontyl.

[0033] The R １１ Examples of the cycloalkyl group having 5 to 12 carbon atoms represented by the formula (I) include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group.

[0034] The R １１ When is an alkyl group, from the viewpoint of flame retardancy, it is preferably an alkyl group having 1 to 22 carbon atoms, more preferably an alkyl group having 1 to 18 carbon atoms, and even more preferably an alkyl group having 3 to 14 carbon atoms.

[0035] The R １１ When is a cycloalkyl group, from the viewpoint of flame retardancy, it is preferably a cycloalkyl group having 5 to 10 carbon atoms, more preferably a cycloalkyl group having 5 to 8 carbon atoms, and even more preferably a cyclohexyl group.

[0036] The R １２ , R １３ , R １４ and R １５ The alkyl group having 1 to 4 carbon atoms represented by the formula (I) is the same as the above-mentioned R １１Among the groups exemplified as the alkyl group represented by the formula (I), those having 1 to 4 carbon atoms can be mentioned. Among them, from the viewpoint of flame retardancy, a methyl group and an ethyl group are preferred, and a methyl group is more preferred.

[0037] From the viewpoint of flame retardancy, the component (A) is preferably a compound represented by the following general formulas (2) to (4).

[0038] In general formula (2), R ２０ and R ２１ each independently represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R ２２ , R ２３ , R ２４ , R ２５ , R ２６ , R ２７ , R ２８ and R ２９ each independently represents an alkyl group having 1 to 4 carbon atoms.

[0039] In general formula (3), R ３１ , R ３２ and R ３３ each independently represents a group represented by the following general formula (3a), and n1, n2, and n3 each independently represent an integer of 1 to 4.

[0040] In general formula (3a), R ３ａ１ and R ３ａ２ each independently represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R ３ａ３ , R ３ａ４ , R ３ａ５ , R ３ａ６ , R ３ａ７ , R ３ａ８ , R ３ａ９ and R ３ａ１０ each independently represents an alkyl group having 1 to 4 carbon atoms; R ３ａ１１ and R ３ａ１２ each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and * represents a bond.

[0041] In general formula (4), R４１ , R ４２ , R ４３ , R ４４ , R ４５ , R ４６ , R ４７ , R ４８ and R ４９ each independently represents an alkyl group having 1 to 8 carbon atoms; R ４１１ , R ４１２ , R ４１３ , R ４１４ and R ４１５ each independently represents a group represented by the following general formula (4a), n4 and n5 each independently represent an integer of 2 to 12, and n6 represents an integer of 1 to 15.

[0042] In general formula (4a), R ４ａ１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R ４ａ２ , R ４ａ３ , R ４ａ４ and R ４ａ５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0043] R in general formula (2) ２０ and R ２１ , R in general formula (3a) ３ａ１ and R ３ａ２ and R in general formula (4a) ４ａ１ The alkyl group having 1 to 30 carbon atoms or the cycloalkyl group having 5 to 12 carbon atoms represented by the formula (1) above is R １１ Examples include the same alkyl groups having 1 to 30 carbon atoms and cycloalkyl groups having 5 to 12 carbon atoms as represented by the following formula:

[0044] R in general formula (2) ２０ and R ２１ From the viewpoint of flame retardancy, the alkyl group is preferably an alkyl group having 1 to 22 carbon atoms, more preferably an alkyl group having 3 to 18 carbon atoms, even more preferably an alkyl group having 8 to 14 carbon atoms, and particularly preferably an undecyl group.

[0045] R in general formula (3a) ３ａ１and R ３ａ２ From the viewpoint of flame retardancy, the alkyl group is preferably a cycloalkyl group having 5 to 12 carbon atoms, more preferably a cycloalkyl group having 5 to 8 carbon atoms, and even more preferably a cyclohexyl group.

[0046] R in general formula (4a) ４ａ１ From the viewpoint of flame retardancy, the alkyl group is preferably an alkyl group having 1 to 22 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, even more preferably an alkyl group having 2 to 6 carbon atoms, and particularly preferably a propyl group.

[0047] R in general formula (2) ２２ , R ２３ , R ２４ , R ２５ , R ２６ , R ２７ , R ２８ and R ２９ , R in general formula (3a) ３ａ３ , R ３ａ４ , R ３ａ５ , R ３ａ６ , R ３ａ７ , R ３ａ８ , R ３ａ９ and R ３ａ１０ and R in general formula (4a) ４ａ２ , R ４ａ３ , R ４ａ４ and R ４ａ５ The alkyl group having 1 to 4 carbon atoms represented by the formula (I) is the same as the above-mentioned R １１ Among the groups exemplified as the alkyl group represented by the formula (I), those having 1 to 4 carbon atoms can be mentioned. Among them, from the viewpoint of flame retardancy, a methyl group and an ethyl group are preferred, and a methyl group is more preferred.

[0048] In terms of flame retardancy, n1 and n3 in general formula (3) are preferably integers of 2 to 3, and more preferably 3. In terms of flame retardancy, n2 in general formula (3) is preferably an integer of 2 to 3, and more preferably 2.

[0049] R in general formula (4) ４１ , R ４２ , R ４３ , R ４４ , R４５ , R ４６ , R ４７ , R ４８ and R ４９ The alkyl group having 1 to 8 carbon atoms represented by the formula (I) is the same as the above-mentioned R １１ Among the groups exemplified as the alkyl group represented by the formula (I), those having 1 to 8 carbon atoms can be mentioned. Among them, from the viewpoint of flame retardancy, an alkyl group having 2 to 6 carbon atoms is preferred, an alkyl group having 3 to 5 carbon atoms is more preferred, and a butyl group is even more preferred.

[0050] In terms of flame retardancy, n4 and n5 in general formula (4) are preferably integers of 4 to 8, and more preferably 6.

[0051] Specific examples of component (A) include the following compounds No. 1 to No. 3. However, the present invention is not limited in any way by these compounds.

[0052]

[0053]

[0054] In Compound No. 3, n represents an integer of 1 to 15.

[0055] From the viewpoint of flame retardancy, the component (A) is preferably one or more compounds selected from the group consisting of Compounds No. 1 to No. 3, more preferably one or more compounds selected from the group consisting of Compounds No. 1 and No. 2, and even more preferably Compound No. 1.

[0056] The amount of component (A) added to the synthetic resin is preferably 0.1 mass% or more, more preferably 0.15 mass% or more, even more preferably 0.2 mass% or more, and particularly preferably 0.25 mass% or more, based on the total amount of the synthetic resin, component (A), and component (B). This allows sufficient flame retardancy to be imparted to the synthetic resin. The amount of component (A) added to the synthetic resin is preferably 5 mass% or less, more preferably 2.5 mass% or less, even more preferably 1.5 mass% or less, and particularly preferably 1.2 mass% or less, based on the total amount of the synthetic resin, component (A), and component (B). This improves compatibility with the synthetic resin and reduces compounding costs.

[0057] In the flame retardant of the present invention, the N-alkoxypiperidine compound as component (A) may be used alone or in combination of two or more different compounds.

[0058] The component (B) in the flame retardant of the present invention is a metal hydroxide. Examples of the metal hydroxide include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, barium hydroxide, and zinc hydroxide. Among these, magnesium hydroxide and calcium hydroxide are preferred from the viewpoint of flame retardancy, and magnesium hydroxide is more preferred.

[0059] The volume average particle size of component (B) is preferably 0.01 to 100 μm, more preferably 0.05 to 30 μm, and even more preferably 0.1 to 10 μm. This improves the dispersibility of component (B) in the synthetic resin. The volume average particle size is the value at which the volume average is 50% as measured by a laser diffraction / scattering particle size distribution analyzer.

[0060] Component (B) may be surface-treated to improve dispersibility of component (B) in the synthetic resin. Examples of surface treatment agents include silane coupling agents, titanium coupling agents, fatty acids, fatty acid esters, fatty acid amides, and fatty acid metal salts.

[0061] The amount of component (B) added to the synthetic resin is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, based on the total amount of the synthetic resin, component (A), and component (B). This allows for sufficient improvement in flame retardancy. The amount of component (B) added to the synthetic resin is preferably 9.9% by mass or less, more preferably 8% by mass or less, even more preferably 6% by mass or less, and particularly preferably 5% by mass or less, based on the total amount of the synthetic resin, component (A), and component (B). This allows for a good balance between flame retardancy and transparency.

[0062] In the flame retardant of the present invention, the metal hydroxide as component (B) may be used alone or in combination of two or more different compounds.

[0063] The total content of the components (A) and (B) in the flame retardant of the present invention is preferably 50 parts by mass or more, more preferably 80 parts by mass or more, and even more preferably 90 parts by mass or more, per 100 parts by mass of the flame retardant, thereby enabling stable flame retardancy to be exhibited.

[0064] In the flame retardant of the present invention, the content of component (B) per 100 parts by mass of component (A) is preferably 1 part by mass or more, more preferably 20 parts by mass or more, even more preferably 40 parts by mass or more, even more preferably 80 parts by mass or more, and particularly preferably 150 parts by mass or more. This allows the combined use of components (A) and (B) to fully achieve the flame retardancy improvement effect. In the flame retardant of the present invention, the content of component (B) per 100 parts by mass of component (A) is preferably 5,000 parts by mass or less, more preferably 2,500 parts by mass or less, even more preferably 1,500 parts by mass or less, even more preferably 1,000 parts by mass or less, and particularly preferably 500 parts by mass or less. This provides a good balance between flame retardancy and transparency.

[0065] The amount of the flame retardant of the present invention added to a synthetic resin is 0.2% by mass or more, preferably 0.5% by mass or more, more preferably 0.7% by mass or more, and even more preferably 1% by mass or more, as a total content of components (A) and (B) relative to the total amount of the synthetic resin, components (A), and components (B). This allows the flame retardant to fully exhibit its flame retardant performance. The amount of the flame retardant of the present invention added to a synthetic resin is 10% by mass or less, preferably 8.5% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less, as a total content of components (A) and (B) relative to the total amount of the synthetic resin, components (A), and components (B). By being within the above ranges, the compatibility of the flame retardant with the synthetic resin is improved, and the mechanical properties, processability, and transparency inherent to the synthetic resin can be favorably exhibited.

[0066] The flame retardant of the present invention may contain an optional component other than the components (A) and (B). As the optional component, those exemplified as optional components that can be blended in the composition described below can be used.

[0067] The flame retardant of the present invention can be used as a composition by blending it with a synthetic resin, preferably a thermoplastic resin.

[0068] The composition of the present invention contains a synthetic resin, component (A): an N-alkoxypiperidine compound having a structure represented by the general formula (1), and component (B): a metal hydroxide.

[0069] Examples of the synthetic resin include thermoplastic resins such as polyolefin resins, styrene resins, polyester resins, polycarbonate resins, polysulfide resins, polyamide resins, polyether resins, and halogen-containing resins. These may be used alone or in combination of two or more.

[0070] Further examples of the synthetic resin include petroleum resin, coumarone resin, polyvinyl acetate, ethylene-vinyl acetate copolymer, acrylic resin, polymethyl methacrylate, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyurethane, cellulose resin, polyimide resin, polysulfone, liquid crystal polymer, and blends thereof.

[0071] The synthetic resin may be a thermoplastic elastomer such as isoprene rubber, butadiene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, acrylonitrile-butadiene copolymer rubber, styrene-butadiene copolymer rubber, olefin-based elastomer, styrene-based elastomer, polyester-based elastomer, nitrile-based elastomer, vinyl chloride-based elastomer, polyamide-based elastomer, or polyurethane-based elastomer, or these may be used in combination.

[0072] Examples of the polyolefin resin include polyethylene resins such as low-density polyethylene, linear low-density polyethylene, high-density polyethylene, cross-linked polyethylene, and ultra-high molecular weight polyethylene; polypropylene resins such as homopolypropylene, random copolymer polypropylene, block copolymer polypropylene, impact copolymer polypropylene, high-impact copolymer polypropylene, and maleic anhydride-modified polypropylene; α-olefin polymers such as polybutene-1, cycloolefin polymer, poly-3-methyl-1-butene, poly-3-methyl-1-pentene, and poly-4-methyl-1-pentene; and α-olefin copolymers such as ethylene-methyl methacrylate copolymer and ethylene-vinyl acetate copolymer.

[0073] Examples of the styrene resin include syndiotactic polystyrene, acrylonitrile-butadiene-styrene terpolymer, and styrene-ethylene-butylene-styrene block copolymer.

[0074] Examples of the polysulfide resin include polyphenylene sulfide, etc. Examples of the polyamide resin include polyhexamethylene adipamide, etc.

[0075] Examples of the polyester resin include polyalkylene terephthalates such as polyethylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, and polycyclohexanedimethylene terephthalate; polyalkylene naphthalates such as polyethylene naphthalate and polybutylene naphthalate; and degradable aliphatic polyesters such as polyhydroxybutyrate, polycaprolactone, polybutylene succinate, polyethylene succinate, polylactic acid, polymalic acid, polyglycolic acid, polydioxane, and poly(2-oxetanone).

[0076] Among these synthetic resins, from the viewpoint of enabling the flame retardant to exhibit its flame retardant properties more effectively, one or more selected from the group consisting of polyolefin-based resins, styrene-based resins, and copolymers thereof are preferred, polyolefin-based resins are more preferred, polyethylene-based resins and polypropylene-based resins are even more preferred, and polyethylene-based resins are particularly preferred, and these resins are also preferred when used in combination with a thermoplastic elastomer.

[0077] When a polyethylene resin is used as the synthetic resin, from the viewpoint of moldability of the molded article, the melt flow rate of the polyethylene resin at a cylinder temperature of 190°C and a load of 2.16 kg is preferably 40 g / 10 min or less, more preferably 15 g / 10 min or less, and even more preferably 10 g / 10 min or less. Also, the melt flow rate of the polyethylene resin at a cylinder temperature of 190°C and a load of 2.16 kg is preferably 0.1 g / 10 min or more, more preferably 0.5 g / 10 min or more, and even more preferably 0.8 g / 10 min or more.

[0078] When a polypropylene-based resin is used as the synthetic resin, from the viewpoint of moldability of the molded article, the melt flow rate of the polypropylene-based resin at a cylinder temperature of 230°C and a load of 2.16 kg is preferably 40 g / 10 min or less, more preferably 15 g / 10 min or less, and even more preferably 10 g / 10 min or less. Also, the melt flow rate of the polypropylene-based resin at a cylinder temperature of 230°C and a load of 2.16 kg is preferably 0.1 g / 10 min or more, more preferably 0.5 g / 10 min or more, and even more preferably 0.8 g / 10 min or more.

[0079] These synthetic resins can be used regardless of molecular weight, degree of polymerization, polymerization method, density, softening point, proportion of insoluble matter in solvent, degree of stereoregularity, presence or absence of catalyst residue, types and blending ratios of raw material monomers, type of polymerization catalyst, etc. These synthetic resins may be used alone or in combination of two or more. Furthermore, the synthetic resins may be alloyed.

[0080] In the composition of the present invention, the total content of components (A) and (B) relative to the total amount of the synthetic resin, component (A), and component (B) is 0.2% by mass or more, preferably 0.5% by mass or more, more preferably 0.7% by mass or more, and even more preferably 1% by mass or more. This allows the flame retardant to fully exhibit its flame retardant performance. In the composition of the present invention, the total content of components (A) and (B) relative to the total amount of the synthetic resin, component (A), and component (B) is 10% by mass or less, preferably 8.5% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less. By being within the above range, the compatibility of the flame retardant with the synthetic resin is improved, and the mechanical properties, processability, and transparency inherent to the synthetic resin can be favorably exhibited.

[0081] The content of the synthetic resin in the composition of the present invention is preferably 80 parts by mass or more, more preferably 85 parts by mass or more, and even more preferably 90 parts by mass or more, per 100 parts by mass of the composition of the present invention. This allows the inherent mechanical properties, processability, and transparency of the synthetic resin to be exhibited well. The content of the synthetic resin in the composition of the present invention is preferably 99.8 parts by mass or less, more preferably 99.5 parts by mass or less, even more preferably 99.3 parts by mass or less, and particularly preferably 99 parts by mass or less, per 100 parts by mass of the composition of the present invention. This allows the composition of the present invention to contain a flame retardant in an amount necessary to exhibit flame retardant performance.

[0082] The composition of the present invention may contain other optional components together with the flame retardant. The timing of mixing the flame retardant and other optional components with the synthetic resin is not particularly limited. For example, two or more selected from the components other than the synthetic resin may be mixed in advance and then mixed with the synthetic resin, or each component other than the synthetic resin may be mixed sequentially with the synthetic resin. When multiple components are mixed in advance, each component may be pulverized and then mixed, or mixed and then pulverized. When the synthetic resin is an alloy, each component other than the synthetic resin may be added to a compound that is already alloyed, or may be added during the alloying process.

[0083] Other optional components that can be blended into the composition of the present invention are described below. It is preferable to add various additives typically used in each resin to the composition of the present invention as needed to stabilize the composition. Examples of such additives include phenolic antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, ultraviolet absorbers, and hindered amine light stabilizers.

[0084] Examples of the phenolic antioxidants include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, distearyl (3,5-di-tert-butyl-4-hydroxybenzyl) phosphonate, tridecyl-3,5-di-tert-butyl-4-hydroxybenzyl thioacetate, thiodiethylene bis[(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 4,4′-thiobis(6-tert-butyl-m-cresol), ), 2-octylthio-4,6-di(3,5-di-tert-butyl-4-hydroxyphenoxy)-s-triazine, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butylic acid]glycol ester, 4,4'-butylidenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, bis[2-tert-butyl-4-methyl 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)-2,4,6-trimethylbenzene, 1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, pentaerythritol, Examples include thritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2-tert-butyl-4-methyl-6-(2-acroyloxy-3-tert-butyl-5-methylbenzyl)phenol, 3,9-bis[2-(3-tert-butyl-4-hydroxy-5-methylhydrocinnamoyloxy)-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane], and triethylene glycol bis(β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate).

[0085] The amount of the phenolic antioxidant used is 0.001 to 10 parts by mass, preferably 0.01 to 5 parts by mass, per 100 parts by mass of synthetic resin, from the viewpoints of antioxidant effect and compatibility with the synthetic resin.

[0086] Examples of the sulfur-based antioxidant include dialkyl thiodipropionates such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate, and β-alkyl mercaptopropionates of polyols such as pentaerythritol tetra(β-dodecyl mercaptopropionate).

[0087] The amount of the sulfur-based antioxidant used is 0.001 to 10 parts by mass, preferably 0.01 to 5 parts by mass, per 100 parts by mass of synthetic resin, from the viewpoint of antioxidant effect and compatibility with the synthetic resin.

[0088] Examples of the phosphorus-based antioxidant include trisnonylphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris[2-tert-butyl-4-(3-tert-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl] phosphite, tridecyl phosphite, octyl diphenyl phosphite, didecyl monophenyl phosphite, bis(tridecyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)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, tetrakis(tridecyl)isopropylidenediphenol diphosphite, tetrakis(tridecyl)-4 , 4'-n-butylidenebis(2-tert-butyl-5-methylphenol) diphosphite, hexakis(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 sil phosphite, 2,2'-methylenebis(4,6-tert-butylphenyl)-octadecyl phosphite, 2,2'-ethylidenebis(4,6-di-tert-butylphenyl)fluorophosphite, tris(2-[(2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl)amine, and phosphite of 2-ethyl-2-butylpropylene glycol and 2,4,6-tri-tert-butylphenol.

[0089] The amount of the phosphorus-based antioxidant used is 0.001 to 10 parts by mass, preferably 0.01 to 5 parts by mass, per 100 parts by mass of synthetic resin, from the viewpoint of antioxidant effect and compatibility with the synthetic resin.

[0090] In particular, phenol-based antioxidants and phosphorus-based antioxidants are preferably used because they prevent the synthetic resin from being discolored.

[0091] Examples of the ultraviolet absorber include 2-hydroxybenzophenones such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-tert-butyl-4'-(2-methacryloyloxyethoxyethoxy)benzophenone, and 5,5'-methylenebis(2-hydroxy-4-methoxybenzophenone); 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-dodecyl-5'-methylphenyl)benzotriazole, and 2-(2'-hydroxy-3'-tert-butyl-5'-C ７～９2-(2'-hydroxyphenyl)benzotriazoles such as mixed alkoxycarbonylethylphenyl)triazole, 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole, and polyethylene glycol esters of 2-(2'-hydroxy-3'-tert-butyl-5'-carboxyphenyl)benzotriazole; 2-(2-hydroxy-4-hexyloxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-octoxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-acryloyloxyethoxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-(2-ethylhexyloxy ... triaryltriazines such as 2-(2-hydroxy-4-propoxy-5-methylphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-1,3,5-triazine, and 2-(2-hydroxy-4-propoxy-5-methylphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-1,3,5-triazine; phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, and 2,4-di-tert-amylphenyl benzoates such as hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate and hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; and cyanoacrylates such as ethyl-α-cyano-β,β-diphenylacrylate and methyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate.

[0092] The amount of the ultraviolet absorber used is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, per 100 parts by mass of synthetic resin, from the viewpoints of weather resistance and compatibility with the synthetic resin.

[0093] Examples of the hindered amine light stabilizer 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-pentamethyl-4-piperidyl)sebacate, bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, and 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate. tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, bis(2,2,6,6-tetramethyl-4-piperidyl)bis(tridecyl)-1,2,3,4-butanetetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)bis(tridecyl)-1,2,3,4-butanetetracarboxylate carboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)-2-butyl-2-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate, 3,9-bis(1,1-dimethyl-2-[tris(2,2,6,6-tetramethyl-4-piperidyloxycarbonyloxy)butylcarbonyloxy]ethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 3,9-bis(1,1-dimethyl-2-[tris(1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyloxy)butylcarbonyloxy]ethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, ]ethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 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-piperidyl)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-ylamino]undecane, 1 , 6,11-tris[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazin-6-ylamino]undecane, 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol / diethyl succinate polycondensate, 1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane / dibromoethane polycondensate, etc.

[0094] The amount of the hindered amine light stabilizer used is 0.001 to 10 parts by mass, preferably 0.01 to 5 parts by mass, per 100 parts by mass of synthetic resin, from the viewpoints of weather resistance and compatibility with the synthetic resin.

[0095] The composition of the present invention may further contain, as necessary, additives that are commonly used in synthetic resins, such as processing aids, crosslinking agents, antistatic agents, antifogging agents, anti-plate-out agents, surface treatment agents, plasticizers other than those of the present invention, fillers, lubricants, nucleating agents, clarifying agents, reinforcing materials, flame retardants other than the flame retardant of the present invention, fluorescent agents, antifungal agents, bactericides, foaming agents, metal deactivators, release agents, pigments, silicone oils, and silane coupling agents, within limits that do not impair the effects of the present invention.

[0096] Furthermore, when a polyolefin-based resin is used as the synthetic resin, it is preferable to further add a known neutralizing agent, if necessary, to neutralize catalyst residues in the polyolefin-based resin, within a range that does not impair the effects of the present invention.

[0097] Examples of the neutralizing agent include fatty acid metal salts such as calcium stearate, lithium stearate, and sodium stearate; fatty acid amide compounds such as ethylene bis(stearic acid amide), ethylene bis(12-hydroxystearic acid amide), and stearic acid amide; and inorganic compounds such as hydrotalcite. These neutralizing agents may be used in combination.

[0098] The amount of the neutralizing agent used is 0.001 to 3 parts by mass, preferably 0.01 to 1 part by mass, per 100 parts by mass of synthetic resin, from the viewpoints of neutralizing effect and compatibility with the synthetic resin.

[0099] Examples of methods for adding the optional components include adding them to the synthetic resin separately from the flame retardant of the present invention; mixing the flame retardant with a binder, wax, solvent, granulation aid such as silica, etc., which are used as needed, in a desired ratio in advance, granulating the mixture to form a one-pack composite additive, and adding the one-pack composite additive to the synthetic resin; and preparing a masterbatch containing the flame retardant of the present invention and the optional components, and adding the masterbatch to the synthetic resin.

[0100] The timing of blending the flame retardant of the present invention and optional components into the composition of the present invention is not particularly limited. For example, two or more selected from the blending components other than the synthetic resin may be packed together and then blended with the synthetic resin, or each component other than the synthetic resin may be blended sequentially with the synthetic resin. When multiple components are packed together, each component may be pulverized and then mixed, or mixed and then pulverized. When the synthetic resin is a polymer blend, each component other than the synthetic resin may be added to a pre-blended compound, or may be added during the blending process.

[0101] The shape of the composition of the present invention is not particularly limited, and various shapes can be used, such as pellets, granules, powder, lumps, flakes, and strands, and from the viewpoint of handleability, pellets or granules are preferred.

[0102] The method for producing the composition of the present invention is not particularly limited, and known methods can be applied. Specific production methods include a method of mixing using a conventional blender, mixer, etc., a method of melt-kneading using an extruder, etc., and a method of mixing with a solvent and solution-casting. Furthermore, the method for producing the composition of the present invention may also be a method of preparing a masterbatch containing a high concentration of the flame retardant of the present invention and adding this masterbatch to a synthetic resin.

[0103] The masterbatch of the present invention contains a synthetic resin and the flame retardant of the present invention. The masterbatch of the present invention can impart excellent flame retardancy to a molded article even when the amount of the flame retardant of the present invention added to the molded article is small.

[0104] In terms of productivity and dispersibility of the flame retardant, the content of the flame retardant of the present invention in the masterbatch of the present invention is preferably 1 to 90 parts by mass, more preferably 3 to 60 parts by mass, and even more preferably 5 to 50 parts by mass, relative to 100 parts by mass of the synthetic resin.

[0105] Examples of synthetic resins used in the masterbatch of the present invention include those exemplified as synthetic resins contained in the above-mentioned composition. Among them, polyolefin-based resins and styrene-based resins are preferred from the viewpoint of good compatibility with the flame retardant of the present invention, and polyethylene-based resins, polypropylene-based resins, styrene-ethylene-butylene-styrene block copolymers, and ethylene-vinyl acetate copolymers are more preferred. Furthermore, when a polyolefin-based resin is used, it is preferably used in combination with a styrene-ethylene-butylene-styrene block copolymer or an ethylene-vinyl acetate copolymer from the viewpoint of compatibility.

[0106] The masterbatch of the present invention may further contain additives such as phenolic antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, ultraviolet absorbers, hindered amine light stabilizers, processing aids, crosslinking agents, antistatic agents, antifogging agents, antiplateout agents, surface treatment agents, plasticizers other than those of the present invention, fillers, lubricants, nucleating agents, clarifying agents, reinforcing materials, flame retardants other than those of the present invention, fluorescent agents, antifungal agents, bactericides, foaming agents, metal deactivators, mold release agents, pigments, silicone oils, silane coupling agents, and neutralizing agents. This allows the masterbatch of the present invention to impart even more excellent properties to the synthetic resin. These additives may be contained alone or in combination of two or more. The same additives as those described above can be used as these additives.

[0107] The shape of the masterbatch of the present invention is not particularly limited, and various shapes can be used, such as pellets, granules, powder, lumps, flakes, and strands, and from the viewpoint of handleability, pellets or granules are preferred.

[0108] The method for producing the masterbatch of the present invention is not particularly limited, and known methods such as a method of dry-blending a powder or pellet of a synthetic resin with the flame retardant of the present invention, or a method of melt-kneading using an extruder or the like can be used.

[0109] The molded article of the present invention is obtained by molding the composition of the present invention. The molding method of the composition of the present invention is not particularly limited and can be appropriately selected depending on the application, and examples thereof include injection molding, extrusion molding, co-extrusion molding, blow molding, press molding, cast molding, roll molding, vacuum molding, rotational molding, calendar molding, slush molding, dip molding, foam molding, additive manufacturing, T-die casting, inflation molding, thermoforming, etc.

[0110] The use of the molded article of the present invention is not particularly limited, and it can be used for various purposes, such as daily necessities, packaging materials, agricultural materials, electric and electronic parts, machine parts, optical instruments, building materials, and automobile parts.

[0111] The molded article of the present invention can be used in a wide range of industrial fields, such as electricity, electronics, and communications, agriculture, forestry, and fisheries, mining, construction, food, textiles, clothing, medicine, coal, petroleum, rubber, leather, automobiles, precision instruments, wood, building materials, civil engineering, furniture, printing, and musical instruments. Specifically, the composition of the present invention and molded articles thereof can be used for window envelopes, plastic envelopes, twist packaging, printed laminated paper, laminated bags, labels, garbage bags, shopping bags, heavy-duty bags, sanitary materials, general packaging and the like, overwrapping, tableware containers, blister packs, clear cases, trays, boards, cushioning materials, slit yarns, sandbags, flexible container bags, ropes, strings, packing bands, fishing line, woven and knitted fabrics, nets, filters, clothing, industrial materials, braided cords, spun yarns, multi-layered yarns, interior decoration, wadding, staple fiber nonwoven fabrics, agricultural materials, gardening materials, civil engineering materials, bags, carpet backings, bag-making materials, packaging materials, household materials, household goods, electronic and office automation equipment housings, automotive interior materials, bottles, and the like.

[0112] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0113] The present invention includes the following aspects: [1] A flame retardant for synthetic resins, comprising: component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1); and component (B): a metal hydroxide, the flame retardant being added in such a manner that the total content of components (A) and (B) is 0.2 to 10 mass% relative to the total amount of the synthetic resin, components (A), and (B).

[0114] In general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0115] [2] The flame retardant according to [1], wherein the component (A) is one or more compounds represented by the following general formula (2), (3), or (4):

[0116] In general formula (2), R ２０ and R ２１ each independently represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R ２２ , R ２３ , R ２４ , R ２５ , R ２６ , R ２７ , R ２８ and R ２９ each independently represents an alkyl group having 1 to 4 carbon atoms.

[0117] In general formula (3), R ３１ , R ３２ and R ３３ each independently represents a group represented by the following general formula (3a), and n1, n2, and n3 each independently represent an integer of 1 to 4.

[0118] In general formula (3a), R ３ａ１ and R ３ａ２ each independently represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R ３ａ３ , R ３ａ４ , R ３ａ５ , R ３ａ６ , R ３ａ７ , R ３ａ８ , R ３ａ９ and R ３ａ１０ each independently represents an alkyl group having 1 to 4 carbon atoms; R ３ａ１１ and R ３ａ１２ each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and * represents a bond.

[0119] In general formula (4), R ４１ , R ４２ , R ４３ , R ４４ , R ４５ , R ４６ , R ４７, R ４８ and R ４９ each independently represents an alkyl group having 1 to 8 carbon atoms; R ４１１ , R ４１２ , R ４１３ , R ４１４ and R ４１５ each independently represents a group represented by the following general formula (4a), n4 and n5 each independently represent an integer of 2 to 12, and n6 represents an integer of 1 to 15.

[0120] In general formula (4a), R ４ａ１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R ４ａ２ , R ４ａ３ , R ４ａ４ and R ４ａ５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0121] [3] The flame retardant according to [1] or [2], wherein the component (B) is at least one selected from the group consisting of magnesium hydroxide and calcium hydroxide.

[0122] [4] The flame retardant according to any one of [1] to [3], which is added so that the content of the component (B) relative to the total amount of the synthetic resin, the component (A), and the component (B) is 0.1 to 9.9 mass%.

[0123] [5] A composition comprising a synthetic resin, component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1), and component (B): a metal hydroxide, wherein the total content of component (A) and component (B) relative to the total amount of the synthetic resin, component (A), and component (B) is 0.2 to 10 mass%:

[0124] In general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0125] [6] A masterbatch containing a synthetic resin and the flame retardant according to any one of [1] to [4].

[0126] [7] A molded article obtained from the composition according to [5].

[0127] [8] A method for imparting flame retardancy to a synthetic resin, comprising blending component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1) and component (B): a metal hydroxide with the synthetic resin, wherein the total content of components (A) and (B) relative to the total amount of the synthetic resin, component (A), and component (B) is 0.2 to 10 mass%.

[0128] In general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0129] [9] A method for producing a composition, comprising blending a synthetic resin with component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1), and component (B): a metal hydroxide, wherein the total content of component (A) and component (B) relative to the total amount of the synthetic resin, component (A), and component (B) is 0.2 to 10 mass%:

[0130] In general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

[0131] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0132] Production Example 1 Production of Polyethylene Composition 1 Polyethylene composition 1 was prepared by mixing 100 parts by mass of linear low-density polyethylene (melt flow rate [190°C, load 2.16 kg] 1 g / 10 min) with 0.05 part by mass of stearyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate as a phenolic antioxidant and 0.05 part by mass of tris(2,4-di-tert-butylphenyl) phosphite as a phosphorus-based antioxidant.

[0133] Production Example 2 Production of Polyethylene Composition 2 Polyethylene composition 2 was prepared by mixing 100 parts by mass of linear low-density polyethylene (melt flow rate [190°C, load 2.16 kg] 5 g / 10 min) with 0.05 part by mass of stearyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate as a phenolic antioxidant and 0.05 part by mass of tris(2,4-di-tert-butylphenyl) phosphite as a phosphorus-based antioxidant.

[0134] Production Example 3 Production of Polypropylene Composition 1 Polypropylene composition 1 was prepared by mixing 100 parts by mass of homopolypropylene (melt flow rate [230°C, load 2.16 kg] 8 g / 10 min) with 0.05 parts by mass of pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] as a phenolic antioxidant, 0.05 parts by mass of tris(2,4-di-tert-butylphenyl)phosphite as a phosphorus-based antioxidant, and 0.05 parts by mass of calcium stearate as a neutralizing agent.

[0135] Details of each component in Tables 1 to 4 are shown below. Polyethylene composition 1: Produced in the above Production Example 1. Polyethylene composition 2: Produced in the above Production Example 2. Polypropylene composition 1: Produced in the above Production Example 3. (A)-1: Compound No. 1 (A)-2: Compound No. 2 (A)-3: Compound No. 3 (A)-CE1: Bis(2,2,6,6-tetramethylpiperidyl) sebacate (B)-1: Magnesium hydroxide (B)-2: Calcium hydroxide

[0136] Examples 1 to 17, Comparative Examples 1 to 15 <Production of Test Pieces> The components were mixed in the amounts shown in Tables 1 to 3, and melt-kneaded using a Toyo Seiki Seisaku-sho, Ltd., Laboplastomill Micro connected to a twin-screw extruder (product name: 2D15W) at a melt temperature of 200°C and a screw speed of 25 rpm to obtain resin strands. The obtained resin strands were cut using a pelletizer to obtain pelletized compositions. Note that all of the amounts shown in Tables 1 to 3 are based on parts by mass. A cast film having a thickness of 200 μm was produced using the pelletized compositions obtained above. Film production was carried out using a Toyo Seiki Seisakusho Laboplastomill Micro equipped with a single-screw extruder (product name: D1220B) and a T-die (product name: MT60B) under the following conditions: melt temperature 200°C, screw speed 30 rpm, T-die extrusion temperature 200°C, chill roll temperature 60°C, and roll rotation speed 0.40 to 0.45 rpm. 200 mm x 50 mm test pieces, 140 mm x 52 mm test pieces, and 50 mm x 50 mm test pieces were cut out from the obtained film and allowed to stand at 23±2°C and 50±5% RH for 48 hours, after which the following evaluations were carried out.

[0137] <Flame Retardancy Evaluation: UL-94VTM> The 200 mm x 50 mm x 200 μm test specimens obtained above were rolled into a cylindrical shape so that the bottom ends did not overlap, and the bottom end of the specimen was held vertically 10 mm above the burner. A Bunsen burner with an inner diameter of 9.5 mm and a flame length of 20 mm was used as the heat source, and the flame was applied to the bottom end of the specimen for 3 seconds, and the number of seconds it took to burn was measured. After the flame was extinguished, the flame was applied again for 3 seconds, and the number of seconds it took to burn was measured. Flame retardancy was evaluated according to the VTM-0, VTM-1, and VTM-2 evaluation criteria. The resin composition was ranked according to the lowest standard out of the five measurements (n = 5). Test specimens that did not fall into any of the VTM-0 to VTM-2 rankings were designated NR. The results are shown in Tables 1 to 3.

[0138] <Flame Retardancy Evaluation: Oxygen Index> Using the 140 mm x 52 mm x 200 μm test specimens obtained above, the oxygen index of the test specimens was measured in accordance with JIS K7201-2. The oxygen index is the minimum oxygen concentration at which a small vertical test specimen can sustain combustion in a nitrogen and oxygen mixed gas, and a higher value indicates better flame retardancy. The results are shown in Tables 1 to 3.

[0139] <Transparency Evaluation> Using the test pieces of 50 mm × 50 mm × 200 μm obtained above, the transparency (haze value) of the test pieces was measured in accordance with JIS K 7136. The smaller this value, the more excellent the transparency. The results are shown in Tables 1 and 2.

[0140]

[0141]

[0142]

[0143] Tables 1 to 3 show the evaluation results of flame retardancy and transparency for test specimens containing linear low-density polyethylene. Test specimens containing the flame retardant of the present invention (Examples 1 to 17) exhibited superior flame retardancy compared to test specimens not containing a flame retardant (Comparative Examples 1 and 10), test specimens containing only component (A) (Comparative Examples 4, 5, and 15), test specimens containing only component (B) (Comparative Examples 2, 3, 13, and 14), and test specimens in which the total content of components (A) and (B) was outside the range of the present invention (Comparative Examples 6 and 7). Furthermore, when a compound not having the structure of general formula (1) was used instead of component (A) (Comparative Examples 8 to 11), no improvement in flame retardancy was observed even when used in combination with component (B).

[0144] Examples 18-20, Comparative Examples 16-20 <Production of Test Pieces> The components were mixed in the amounts shown in Table 4, and melt-kneaded using a Toyo Seiki Seisaku-sho, Ltd., Laboplastomill Micro connected to a twin-screw extruder (product name: 2D15W) at a melt temperature of 220°C and a screw speed of 25 rpm to obtain resin strands. The obtained resin strands were cut using a pelletizer to obtain pelletized compositions. Note that all of the amounts shown in Table 4 are based on parts by mass. A cast film having a thickness of 200 μm was produced using the pelletized composition obtained above. The film was produced using a Toyo Seiki Seisakusho Laboplastomill Micro equipped with a single-screw extruder (product name: D1220B) and a T-die (product name: MT60B) under the following conditions: melt temperature 220°C, screw speed 30 rpm, T-die extrusion temperature 220°C, chill roll temperature 60°C, and roll rotation speed 0.40 to 0.45 rpm. Test pieces measuring 200 mm x 50 mm were cut from the obtained film and allowed to stand at 23±2°C and 50±5% RH for 48 hours, after which the following evaluations were performed.

[0145] <Flame Retardancy Evaluation: Horizontal Burning Test> The 200 mm x 50 mm test specimen obtained above was held horizontally, and a Bunsen burner with an inner diameter of 9.5 mm and a flame length of 38 mm was used as a heat source. A flame was applied to the center of the short side of the test specimen for 15 seconds, and the burning distance in the long side direction until the flame went out was measured. Measurements were made three times for each test specimen, and the average value was calculated. The shorter the burning distance, the better the flame retardancy. The results are shown in Table 4.

[0146]

[0147] The evaluation results of the flame retardancy of the test specimens containing homopolypropylene are shown in Table 4. The test specimens containing the flame retardant of the present invention (Examples 18 to 20) had shorter burning distances in the horizontal burning test than the test specimen not containing the flame retardant (Comparative Example 16), the test specimens containing only the (A) component (Comparative Examples 18 to 20), and the test specimen containing only the (B) component (Comparative Example 17).

[0148] The above results demonstrate that the flame retardant of the present invention imparts excellent flame retardancy to synthetic resins.

Claims

1. A flame retardant for synthetic resins, comprising: component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1); and component (B): a metal hydroxide, the flame retardant being added in such a range that the total content of components (A) and (B) relative to the total amount of the synthetic resin, components (A), and (B) is 0.2 to 10 mass%. In the general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

2. The flame retardant according to claim 1, wherein component (A) is one or more compounds represented by the following general formula (2), (3) or (4). In the general formula (2), R ２０ and R ２１ each independently represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R ２２ , R ２３ , R ２４ , R ２５ , R ２６ , R ２７ , R ２８ and R ２９ each independently represents an alkyl group having 1 to 4 carbon atoms. In the general formula (3), R ３１ , R ３２ and R ３３ each independently represents a group represented by the following general formula (3a), and n1, n2, and n3 each independently represent an integer of 1 to 4. In the general formula (3a), R ３ａ１ and R ３ａ２ each independently represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R ３ａ３ , R ３ａ４ , R ３ａ５ , R ３ａ６ , R ３ａ７ , R ３ａ８ , R ３ａ９ and R ３ａ１０ each independently represents an alkyl group having 1 to 4 carbon atoms; R ３ａ１１ and R ３ａ１２ each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and * represents a bond. In the general formula (4), R ４１ , R ４２ , R ４３ , R ４４ , R ４５ , R ４６ , R ４７ , R ４８ and R ４９ each independently represents an alkyl group having 1 to 8 carbon atoms; R ４１１ , R ４１２ , R ４１３ , R ４１４ and R ４１５ each independently represents a group represented by the following general formula (4a), n4 and n5 each independently represent an integer of 2 to 12, and n6 represents an integer of 1 to 15. In general formula (4a), R ４ａ１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R ４ａ２ , R ４ａ３ , R ４ａ４ and R ４ａ５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

3. The flame retardant according to claim 1, wherein component (B) is one or more selected from the group consisting of magnesium hydroxide and calcium hydroxide.

4. The flame retardant according to claim 1, which is added so that the content of component (B) is in the range of 0.1 to 9.9 mass% relative to the total amount of the synthetic resin, component (A), and component (B).

5. A composition comprising a synthetic resin, component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1), and component (B): a metal hydroxide, wherein the total content of components (A) and (B) relative to the total amount of the synthetic resin, components (A) and (B) is 0.2 to 10 mass%. In the general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

6. A masterbatch comprising a synthetic resin and the flame retardant according to any one of claims 1 to 4.

7. A molded article obtained from the composition according to claim 5.

8. A method for imparting flame retardancy to a synthetic resin by blending component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1) and component (B): a metal hydroxide with the synthetic resin, wherein the total content of components (A) and (B) relative to the total amount of the synthetic resin, components (A) and (B) is 0.2 to 10 mass%. In the general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

9. A method for producing a composition, which comprises blending a synthetic resin with component (A): an N-alkoxypiperidine compound having a structure represented by the following general formula (1), and component (B): a metal hydroxide, wherein the total content of components (A) and (B) relative to the total amount of the synthetic resin, components (A), and (B) is 0.2 to 10 mass%. In the general formula (1), R １１ represents an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms; R １２ , R １３ , R １４ and R １５ each independently represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

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