JP2858264B2 - Flame retardant resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a highly flame-retardant resin composition containing polyphenylene ether as a component and suitable as an electric wire covering material and the like.

Conventional technology and problemsPolyphenylene ether is expected to be used in various fields based on excellent heat resistance, and has improved impact resistance, flame retardancy, chemical resistance, etc. by blending with polyamide and polystyrene. Some have been proposed. However, all of the improved products have poor elongation, flexibility, and resistance to organic solvents, and have a problem that cracks occur at room temperature due to high bending and adhesion of organic solvents. Also, the flame retardancy was not sufficiently satisfactory.

Problems to be Solved by the Invention The present inventors have conducted intensive studies to overcome the above-mentioned problems, and as a result, can achieve the object by adding a special polymer component and a hydrated metal oxide to polyphenylene ether. This has led to the achievement of the present invention.

That is, the present invention relates to a styrene-olefin-styrene block copolymer and 10 parts by weight per 100 parts by weight of the copolymer.
900900 parts by weight of polyphenylene ether, 25-400 parts by weight of an ethylene-based polymer, and 50-300 parts by weight of hydrated metal oxide per 100 parts by weight of the total of the polymer components. It is intended to provide a flame-retardant resin composition.

Action By blending styrene / olefin / styrene block copolymer, elongate while utilizing the excellent properties of polyphenylene ether, and improve the flexibility, flexibility, organic solvent resistance, and especially acetone resistance. Can be. In addition, by blending an ethylene polymer, the stability of the composition can be improved, and a high blending of the hydrated metal oxide becomes possible, and the resin composition has low smoke and high flame retardancy. Can be formed. The composition can be cross-linked by electron beam irradiation or the like, and has excellent extrudability.

Illustrative Components of the Invention The polyphenylene ether used in the present invention is not particularly limited. Various commercial products such as a general grade product, a flame retardant grade product, and a heat resistant grade product can also be used. Those having a higher content of polyphenylene ether are preferably used.

Styrene / olefin / styrene block copolymers include ethylene / butylene, ethylene / propylene,
Those having an olefin rubber polymer such as butadiene or isoprene as an intermediate block are used. Commercially available products include "Clayton G" (trade name, manufactured by Shell Chemical Company, USA),
"Sumitomo TPE-SB" (trade name, manufactured by Sumitomo Chemical Co., Ltd .: Hydrogenated styrene-butadiene-styrene block copolymer to saturate the double bond in the main chain), "Ravalon"
(Trade name, manufactured by Mitsubishi Yuka Co., Ltd.). Preferred styrene-olefin-styrene block copolymer,
Styrene block / olefin block weight ratio of 10/9
0 to 50/50 and a Shore A hardness of 50 to 80.
Those having the same degree of viscosity are preferred from the viewpoint of compatibility with polyphenylene ether. A material having a high molecular weight is more preferable than a material having a high mechanical strength such as tensile properties.

Examples of the ethylene-based polymer include an ethylene / vinyl acetate copolymer, an ethylene / methyl methacrylic acid copolymer, a styrene graft polymer thereof (JP-A-1-131220 and JP-A-1-138214), A propylene copolymer, a composite of an ethylene / propylene / diene terpolymer and a silicone polymer (JP-A-63-72745) and the like are used. The content of vinyl acetate or methyl methacrylic acid in the ethylene-vinyl acetate copolymer, ethylene-methyl methacrylic acid copolymer, or their styrene graft polymers is suitably from 15 to 45% by weight, and the content of grafted styrene is appropriate. Is suitably 10 to 30% by weight. If the content of vinyl acetate or methyl methacrylic acid is too low, the flame retardancy is poor, or the mechanical strength decreases due to the addition of the hydrated metal oxide.If the content is excessive, the electrical properties, heat aging properties, and mechanical strength decrease. I do. On the other hand, if the content of the graft styrene is too low, the effect of enhancing the flame retardancy due to the styrene content is poor, and if the content is too high, the addition properties and mechanical strength of the hydrated metal oxide decrease. Ethylene / methyl methacrylic acid copolymer is commercially available under the trade name of “Aclift” (trade name, manufactured by Sumitomo Chemical Co., Ltd.), and the composite of ethylene / propylene / diene terpolymer and silicone polymer is “JENIX (Trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.).

In the present invention, the compounding amount of the polyphenylene ether is
Styrene / olefin / styrene block copolymer 100
10 to 900 parts by weight per part by weight is suitable, preferably 2 to 900 parts by weight.
5 to 400 parts by weight, especially 30 to 300 parts by weight. If the amount is less than 10 parts by weight, the effect of adding polyphenylene ether is poor, and the irradiated cross-linked product has poor hardness, making it unsuitable as a wire covering material. If the amount exceeds 900 parts by weight, the effect of adding the styrene / olefin / styrene block copolymer becomes poor.

On the other hand, the amount of the ethylene-based polymer is 25 to 4 per 100 parts by weight of the styrene-olefin-styrene block copolymer.
00 parts by weight is suitable, preferably 40 to 250 parts by weight. If the amount is less than 25 parts by weight, the composition is soft and the high-temperature gut-through resistance is low, and the effect of improving the stability of the composition is poor, making it difficult to improve the flame retardancy. When the amount exceeds 400 parts by weight, elongation becomes poor.

As the hydrated metal oxide used in the present invention,
Dehydration metal oxides such as magnesium hydroxide and aluminum hydroxide are exemplified. Of these, magnesium hydroxide, or magnesium hydroxide surface-treated with a fatty acid such as stearic acid, oleic acid, and maleic acid, or a metal salt thereof, is preferred. Magnesium hydroxide having a high purity and a uniform particle size is particularly preferred.

The compounding amount of the hydrated metal oxide is suitably 50 to 300 parts by weight, preferably 100 to 200 parts by weight, per 100 parts by weight of the total of polyphenylene ether, styrene / olefin / styrene block copolymer and ethylene polymer. . The amount is 50
If it is less than 300 parts by weight, the flame retardancy is poor, and if it exceeds 300 parts by weight, the crosslinked product of the composition becomes poor in tensile strength, elongation and low-temperature brittleness resistance.

The flame-retardant resin composition of the present invention can be crosslinked by a crosslinking method using electron beam irradiation, a chemical crosslinking method using a crosslinking agent such as a peroxide, or various other crosslinking methods. A preferred crosslinking method is a method by electron beam irradiation,
The irradiation dose is suitably 10 to 30 Mrad, especially 15 to 20 Mrad. The use of a crosslinking aid is preferred from the viewpoint of improving the properties of the obtained crosslinked product against thermal deformation and the tensile strength.

The crosslinking aid used preferably has two or more ethylenically unsaturated functional groups. Examples include trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, lauryl methacrylate, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, triallyl. Trimellitate, triallyl phosphate, diallyl itaconate, triallyl aconitate, diallyl fumarate,
Diallyl citraconic acid, orthoallylic acid tetraallyl ester, tetraallyloxyethane, N, N'-
Meta-phenylene bismaleimide, phenylmaleimide, triacrylhexahydrotriazine cyanurate, pentaerythritol acrylate, pentaerythritol tetraacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate,
Examples thereof include divinylbenzene, trivinylbenzene, and 1,2-polybutadiene (molecular weight: 1,000 to 5,000). Above all, trimethylolpropane trimethacrylate, triallyl isocyanurate, triallyl trimellitate and the like are preferably used.

An appropriate amount of the crosslinking aid is 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the total of the styrene / olefin / styrene block copolymer, polyphenylene ether and ethylene polymer.

The flame-retardant resin composition of the present invention, if necessary, for example, for the purpose of improving heat resistance, hindered phenols, mercaptobenzimidazoles, aminones, quinones,
Various antioxidants such as phosphorus compounds, copper damage inhibitors, various metal oxides such as zinc oxide, titanium oxide and antimony oxide, boric acid compounds such as zinc borate, acetylene black, thermal black, ketjen black Suitable additives such as carbon black such as furnace black, processing aids such as stearic acid, and appropriate additives such as coloring agents can be added in usual amounts.

The flame retardant resin composition of the present invention can be adjusted by mixing the components. The resulting composition has good extrudability and can be crosslinked by electron beam irradiation or the like. Therefore, it can be used as a coating agent for various articles such as an insulating layer and a jacket layer in an insulated wire.

Effect of the Invention According to the present invention, the use of a hydrated metal oxide provides excellent low smoke properties. In addition, since styrene-olefin-styrene block copolymer and ethylene polymer are used, it takes advantage of the excellent properties of polyphenylene ether to expand, bend, have excellent organic solvent resistance, extrudability, and is stable. The composition can be a composition excellent in flammability, and can be highly blended with a hydrated metal oxide, and can impart high flame retardancy.

Examples Examples 1 to 7, Comparative Examples 1 and 2 Each component was kneaded with a Brabender plast mill (manufactured by Toyo Seiki Co., Ltd.) at the ratios shown in Table 1, and the resulting mixture was press-molded to a thickness of 0.6. mm sheet, and both sides of the sheet were irradiated with an electron beam and crosslinked. The irradiation dose is 15Mrad
/ One side.

Evaluation Test The crosslinked sheets obtained in Examples and Comparative Examples were examined for tensile strength, elongation, oxygen index, flame retardancy, embrittlement temperature, and volume resistivity.

 The results are shown in Table 2.

In the flame retardancy in the table, A means very good, B means good, and C means a little bad.

From Table 2, it can be seen that the crosslinked sheet comprising the flame-retardant resin composition of the present invention has excellent tensile strength, elongation, low-temperature brittleness, excellent volume resistivity, and excellent flame retardancy regardless of the oxygen index. Recognize. The crosslinked sheets of Examples 1 and 5 did not show embrittlement even at -30 ° C.

Claims (1)

(57) [Claims] 1. A styrene / olefin / styrene block copolymer, 10 to 900 parts by weight of polyphenylene ether per 100 parts by weight of the copolymer, 25 to 400 parts by weight of an ethylene polymer, and the polymer component A flame-retardant resin composition comprising 50 to 300 parts by weight of a hydrated metal oxide as a component per 100 parts by weight of the total.