JPH0196249A - Electrical insulating composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having improved dispersibility of metal oxide and suitable as an insulating material for wire and cable, by fixing a metal oxide to powdery resin or powdery rubber and compounding the product to a resin or a rubber. CONSTITUTION:A powdery metal oxide (e.g. magnesium oxide or lead monoxide) 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 metal oxide powder is <=1/10 of that of the powdery resin, etc. The fixed product is compounded and kneaded to a resin or a rubber in an amount of 0.5pts.wt. in terms of metal oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electrically insulating composition with excellent dispersibility and suitable for application to insulating materials and sheath materials for electric wires and cables.

[Prior art] Insulating materials and sheath materials for electric wires and cables include polyolefins such as polyethylene and ethylene propylene rubber, or chlorine rubbers such as chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, and polyvinyl chloride. type polymers are used. In order to improve the processing stability, vulcanization acceleration, heat aging resistance, etc. of resins or rubbers, metal oxides have been conventionally blended into resins or rubbers.

[Problems to be Solved by the Invention] However, the metal oxide used for such purposes has a very active powder surface and tends to aggregate during kneading processing, resulting in problems in dispersibility.

An object of the present invention is to provide an electrical insulating composition that can improve the dispersibility of metal oxides.

[Means for Solving the Problems] The electrical insulating composition of the present invention has a powder resin or powder rubber having an average particle size of 1000 μm or less, and a powder resin or powder rubber having an average particle size of 10 times smaller than that of the powder resin or powder rubber. It is characterized in that it is made by admixing one or less metal oxides that have been subjected to immobilization treatment.

In the present invention, immobilization treatment refers to stirring the powdered resin or powdered rubber and the metal oxide using a mill, thereby mechanochemically adhering the metal oxide to the surface of the powdered resin or powdered rubber, and then using a pulverizer or the like. This refers to the process of injecting and fixing metal oxides into powdered resin or powdered rubber using the impact force and frictional force. Such immobilization treatment can suppress aggregation of metal oxides and significantly improve dispersibility.

Powdered resins used for immobilization 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-terpolymer, Nylon 6, nylon 11. Nylon 1
2. Polyamide resins such as nylon 610, polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene hexafluoropropylene copolymer, tetrafluoroethylene perfluorovinyl ether copolymer, ethylene fluoroethylene copolymer, polybutsu Fluororesins such as vinyl chloride, polyvinylidene fluoride,
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.

Powder rubbers include ethylene propylene rubber, styrene butadiene rubber, butyl rubber, natural comb, chloroprene rubber, chlorosulfonated polyethylene, nitrile rubber, shrimp chloride rubber, silicone rubber, fluoro rubber, urethane rubber, norhonen 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.

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.

Metal oxides used for immobilization include magnesium oxide, -lead oxide, trilead tetroxide, zinc oxide, antimony oxide, molybdenum oxide, niobium oxide, titanium oxide, zirconium oxide, iron oxide, tin oxide, and tin oxide. Examples include vanadium. The average particle size of the metal oxide must be one-tenth or less 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 resin or rubber, but as this resin or rubber,
The same materials as the above-mentioned powdered resins and powdered rubbers can be mentioned, and they can be used alone or in combination of two or more kinds. In this case, the resin or rubber with which the immobilized material is mixed does not necessarily have to be of the same type as the powdered resin or powdered rubber (and the properties may be powder, liquid, pellet, bulk, or block). Either is fine.

There is no particular limit to the amount of the immobilized material mixed into the resin or rubber, but in order to obtain the desired effect,
It is desirable that the amount is 0.5 part by weight or more in terms of metal oxide.

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

[Example of the invention] Various ingredients were mixed into 100% according to the blending ratios shown in Table 1.
It was put into a 6-inch roll kept at ~150°C and roll-kneaded, and after kneading, the 4-inch mixture was kept at 120-160°C.
Using a 0m/m extruder (L/D=25), outer diameter 2.0m
Thickness 1.m on copper wire. An insulated wire was manufactured by extrusion coating the OMM. In Examples 1 to 4 and Comparative Examples 1.2, crosslinked insulated wires were manufactured by holding the wires in a steam atmosphere of 13 kg/cm'' for 3 minutes following extrusion coating.

For the immobilization treatment of various metal oxides, OM Daiza 1O and Hybridizer 1 from Nara Kikai Seisakusho Co., Ltd. were used.
The powdered resin or powdered rubber and the metal oxide were stirred for 10 minutes using an M dizer 10 to adhere the metal oxide to the surface of the powdered resin or powdered rubber, and then treated with a hybridizer 1 for 6 minutes to fix it.

The results of evaluating the dispersibility of the resin composition on each side were evaluated in the first
It is shown in the bottom column of the table. The dispersibility was evaluated by observing the appearance of the manufactured insulated wire (10 cm) using a microscope with a magnification of 20 times.
A case where 10 aggregates/10 cm or more of aggregates with a size exceeding 10 cm or more were present was judged as poor, and a case smaller than that was judged as good.

*l Mu viscosity ML, 4i (100°C) 40, ethylene volume 70 mo1%, propylene amount 29 mo1%, ethylidene norbornene amount 1 mo1% *2 Moo viscosity ML, (100'C) 55, chlorine amount 35% by weight, sulfur content 1% by weight *3 Degree of polymerization 1200 *4 Melt index (190°C) 1.5, vinyl acetate content 12% by weight *5 Powdered polyethylene with an average particle size of 20 μm/average particle size 1
Immobilization treatment with a ratio of lead monoxide in μm = 60/40 *6 Powdered polyethylene with an average particle size of 30 μm/average particle size 2
Immobilization treatment at a ratio of trilead tetroxide in μm = 50150 *7 Immobilization treatment at a ratio of powdered polyvinyl chloride with an average particle size of 100 μm/molybdenum oxide with an average particle size of 5 μm = 70/30 *8 Immobilization treatment at a ratio of 70/30 with an average particle size of 10 μm Powdered polyethylene/average particle size 0
．． 5 μm magnesium oxide = 40/60 ratio of immobilization treatment * 9 no treatment * lO Powdered polyethylene with average particle size of 30 μm / Trilead tetraoxide with average particle size of 2 μm = blend in the ratio of 50150 As is clear from Table 1 In Examples 1 to 6 according to the present invention, no aggregation was observed and good dispersibility was exhibited. Comparative Example 1, in which untreated metal oxide was mixed, had poor dispersibility;
Comparative example 2 where metal powder was simply blended with powdered resin
．． In No. 3, aggregation was severe and dispersibility was poor.

[Effects of the Invention] As explained above, the present invention involves fixing metal oxides in powdered resin or powdered rubber and mixing them into resin or rubber, which eliminates agglomeration of metal oxides,
Good dispersibility can be achieved.

Claims (1)

[Claims] (1) Mix a resin or rubber with a powdered resin or powdered rubber with an average particle size of 1000 μm or less and a metal oxide with an average particle size of 1/10 or less of that of the powdered resin or powdered rubber. An electrical insulating composition characterized by comprising: