JPH0196250A - Flame-retardant electrical insulating composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition effective in suppressing the lowering of electrical properties caused by absorption of water and moisture, having excellent flame-retardance and suitable as an insulating material for wire and cable, etc., by fixing red phosphorus to powdery resin or powdery rubber and compounding the product and a metal hydroxide to a resin or a rubber. CONSTITUTION:A powdery red phosphorus is fixed to a powdery resin (e.g. polyethylene) or a powdery rubber (e.g. ethylene propylene rubber) having an average particle diameter of <=1,000mum. The average particle diameter of the red phosphorus powder is <=1/10 of that of the powdery resin, etc. A resin or a rubber is compounded with a (A) >=0.5pts.wt. (in terms of red phosphorus) of the fixed red phosphorus and (B) >=50pts.wt. of a metal hydroxide (e.g. aluminum hydroxide).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a flame-retardant electrical insulation composition that can suppress deterioration of electrical properties due to water absorption and moisture absorption, particularly for use in insulation materials and sheath materials for electric wires and cables. The present invention relates to flame retardant electrical insulation compositions suitable for application. .

[Prior Art] Resins or rubbers such as polyethylene, ethylene propylene rubber, polyvinyl chloride, and chloroprene rubber are often used as insulation materials and sheath materials for electric wires and cables.

As a recent trend, strong flame retardancy has become required for electric wires and cables for nuclear power plants, as well as electric wires for wiring inside panels and inside machines.

As one method of making resin or rubber flame retardant, a technique of mixing metal hydroxide and red phosphorus has been attracting attention.

[Problems to be Solved by the Invention] However, red phosphorus easily absorbs water and moisture, leading to a decrease in electrical characteristics.

An object of the present invention is to provide a flame-retardant electrical insulating composition that can prevent deterioration of electrical properties by suppressing water absorption and moisture absorption of red phosphorus.

[Means for solving the problems] The flame-retardant electrical insulation composition of the present invention comprises resin or rubber,
Powdered resin or powdered rubber with an average particle size of 1000 μm or less, with an average particle size of 1/io of the powdered resin or powdered rubber.
It is characterized by being made by fixing the following red phosphorus and by mixing it with metal hydroxide.

In the present invention, immobilization treatment refers to stirring the powdered resin or powdered rubber and red phosphorus in a mill, thereby mechanochemically adhering the red phosphorus to the surface of the powdered resin or powdered rubber, and then applying impact force using a pulverizer or the like. , refers to the use of frictional force to drive and fix red phosphorus into powdered resin or powdered rubber.

In this way, by immobilizing with hydrophobic resin or rubber, water absorption and moisture absorption can be suppressed. In addition, the fixation treatment can suppress the aggregation of red phosphorus,
It also improves dispersibility.

Powder resins used in the immobilization treatment include polyolefins such as polyethylene, polypropylene, polybutene-11 ethylene-vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene methyl acrylate copolymer, ethylene butene-1 copolymer, ethylene butene-1 terpolymer, Nylon 6, nylon 11. Nylon 1
2. Polyamide resin such as nylon 610, polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene hexafluoropropylene copolymer, tetrafluoroethylene perfluorovinyl ether copolymer, ethylene fluoroethylene copolymer, polybutylene Fluororesins such as vinyl, polyvinylidene butt,
Examples include vinyl chloride resin, vinylidene chloride resin, chlorinated polyethylene resin, polystyrene resin, polymethyl methacrylate resin, phenol resin, acrylonitrile butadiene styrene resin, and the like. Furthermore, polycarbonate, acetal resin, epoxy resin, polyester,
Engineering plastics such as polyphenylene oxide, polyimide, polyamideimide, polyarylate, and polyetheretherketone can also be used.

Powdered rubbers include ethylene propylene rubber, styrene butadiene rubber, butyl rubber, natural rubber, chloroprene rubber, chlorosulfonated polyethylene, nitrile rubber, evichlorohydrin rubber, silicone rubber, fluoro rubber, urethane rubber, norbornene rubber, etc. can be given. Further examples include olefin-based, styrene-based, fluorine thread, urethane-based, ester-based, amide-based, and vinyl chloride-based thermoplastic elastomers.

Note that it is preferable to use polyolefin, which has excellent electrical properties, as the insulating material.

These powdered resins or powdered rubbers have an average particle size of 1000
It is necessary to use a material with a diameter of .mu.m or less; if it is larger than this, the immobilization process becomes difficult.

The average particle size of the red phosphorus used in the immobilization process must be less than I/10 of the average particle size of the above-mentioned powdered resin or powdered rubber, and if it exceeds this, the immobilization process becomes difficult.

The immobilized product obtained as described above is mixed with a metal hydroxide into a resin or rubber, and examples of this resin or rubber include those similar to the above-mentioned powdered resin or powdered rubber. They can be used alone or in combination of two or more. In this case, the resin or rubber into which the immobilized material is mixed does not necessarily have to be of the same type as the powdered resin or powdered rubber, and may be in the form of powder, liquid, pellet, bulk, or block. But that's fine.

Examples of metal hydroxides include aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, calcium hydroxide, barium hydroxide, hydrotalcite, etc., and these can be used alone or in combination of two or more types. .

The amount of metal hydroxide and immobilized material mixed into the resin or rubber is not particularly limited, but in order to have a significant effect on improving flame retardancy, 50 parts by weight or more of the metal hydroxide must be immobilized. It is desirable to mix 0.5 part by weight or more in terms of red phosphorus.

In the present invention, in addition to the above components, crosslinking agents, antioxidants, lubricants, softeners, dispersants, etc. may be used as appropriate.

[Example of the invention] Various ingredients were mixed in 100% according to the blending ratios shown in Table 1.
The material was put into a 6-inch roll kept at °C, mixed with rolls, and after kneaded, it was put on a copper wire with an outer diameter of 2.0 mm using a 40 m/m extruder (L/D = 25) kept at 120 °C. An insulated wire was manufactured by extrusion coating to a thickness of 1 and 0 mm. In addition, for Examples 1 to 4 and Comparative Examples 1 to 3, following extrusion coating, 3 kg/cm' of water vapor atmosphere was applied.
A cross-linked insulated wire was produced by holding for a minute.

For immobilization treatment of various metal hydroxides, Nara Kikai Seisakusho (
Using 0M Dizer 10 and Hybridizer 1 from Co., Ltd.,
The powdered resin or powdered rubber and red phosphorus were stirred for 10 minutes using a 0M dizer 10 to adhere red phosphorus to the surface of the powdered resin, and then treated using a hybridizer 1 for 6 minutes to fix it.

The results of evaluating the insulation resistance and flame retardance of the insulated wires of Examples and Comparative Examples are shown in the lower column of Table 1.

The evaluation was based on the following.

Flame retardancy: Based on JISC3004, if the insulated wire held horizontally is burned in a burner, it passes if it disappears within 1 minute, and if it burns for more than 1 minute, it is rejected.

Insulation resistance: JIS
Measured based on C3004.

*1 Mouni viscosity ML, (100°C) 40, ethylene amount 70 mo1%, propylene amount 30 mo1% *2 Mouni viscosity ML, (100 °C) 35, ethylene amount 70 mo1%, propylene amount 29 mo1%, Ethylidene norbornene content 1 mo1% *3 Melt index (190'C) 1.5, vinyl acetate content 12% by weight *4 Melt index (1900C) 1.5, ethyl acrylate content 19% by weight *5 Average particle size 50 μm Powdered polyethylene/average particle size 4
Red phosphorus in μm = Fixed treatment at a ratio of 60/40 *6 Powdered polyethylene with an average particle size of 100 μm / Red phosphorus with an average particle size of 9 μm = Fixed treatment at a ratio of 50150 *7 Average particle size 20 μm 1 No treatment * 8 Average Powdered polyethylene with a particle size of 100 μm / Red phosphorus with an average particle size of 9 μm = 70730 As is clear from Table 1 of Blen, all Examples 1 to 6 according to the present invention passed the flame retardancy test and It shows good insulation resistance even after being submerged in water for months. On the other hand, in Comparative Example 1, in which no red phosphorus was mixed, the flame retardance was rejected, and in Comparative Examples 2 and 3, in which red phosphorus was not immobilized, the insulation resistance decreased significantly.

[Effects of the Invention] As explained above, the present invention mixes red phosphorus in powdered resin or powdered rubber and metal hydroxide into a resin or rubber, which has excellent flame retardancy. Furthermore, it is possible to suppress deterioration of electrical characteristics due to water absorption and moisture absorption.

Claims (1)

[Claims] (1) A product obtained by immobilizing red phosphorus with an average particle size of 1/10 or less of the powdered resin or powdered rubber on a resin or rubber with an average particle size of 1000 μm or less, and metal water. A flame-retardant electrical insulating composition comprising an oxide.