JPH0196258A - Electrical insulating composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electrically insulating composition with excellent dispersibility, 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-based materials such as chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, and polyvinyl chloride. Polymer etc. 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 powder surface of the metal oxide used for this purpose is very active, and it tends to aggregate during kneading processing (there are problems with 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 includes a resin or rubber, a metal oxide having an average particle size of 100 μm or less, and a powder having an average particle size of 1/10 or less of the metal oxide. It is characterized by being made by admixing a resin or powdered rubber that has been fixed.

In the present invention, immobilization treatment refers to stirring the metal oxide and powdered resin or powdered rubber using a mill, thereby attaching the powdered resin or powdered rubber to the surface of the metal oxide using a mechanochemical method, and then using a pulverizer or the like. This refers to the process of driving powdered resin or powdered rubber into a metal oxide and fixing it using the impact force and frictional force of the metal oxide. At this time, microencapsulation is also possible by raising the temperature above the melting point of the powdered resin or powdered rubber. Such immobilization treatment can suppress aggregation of metal oxides, and furthermore, by immobilizing them with a hydrophobic resin or rubber, water resistance can be significantly improved.

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 100 μm or less, and if it exceeds this, immobilization becomes difficult.

Powdered resins 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, and nylon. 12. Polyamide resin such as nylon 610, polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene hexafluoropropylene copolymer, tetrafluoroethylene perfluorovinylether copolymer, ethylene fluoroethylene copolymer, polybutsu Examples include fluororesins such as vinyl chloride and polyvinylidene fluoride, vinyl chloride resins, vinylidene chloride resins, chlorinated polyethylene resins, polystyrene resins, polymethyl methacrylate resins, phenol resins, acrylonitrile butadiene styrene resins, and the like. Furthermore, polycarbonate, acetal resin,
Epoxy resin, polyester, polyphenylene oxide, polyimide, polyamideimide, polyarylate,
Engineering plastics such as 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.

These powdered resins or powdered rubbers must have an average particle size of one-tenth or less of that of the metal oxide, and if it is larger than this, immobilization 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 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.

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.
The mixture was put into a 6-inch roll kept at ~150°C for roll kneading, and after mixing, a 40 m/m extruder (L/D = 25) kept at 120 ~ 160°C was used to create a mixture with an outer diameter of 2.0
Thickness 1.mm on copper wire. An insulated wire was manufactured by extrusion coating to a thickness of 0 mm. In Examples 1 to 4 and Comparative Examples 1 and 2, crosslinked insulated wires were produced by holding in a steam atmosphere of 13 kg/cm'' for 3 minutes following extrusion coating.

For immobilization treatment, 0M Dizer 1 from Nara Kikai Seisakusho Co., Ltd.
Using Hybridizer 1 and Hybridizer 1, the metal oxide and powdered resin or powdered rubber were stirred for 10 minutes using OM Dizer 1O to adhere the powdered resin or powdered rubber to the surface of the metal oxide, and then treated with Hybridizer 1 for 6 minutes. Fixed.

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.
The case where there were 10 pieces/10 cm or more of aggregates with a size exceeding 10 cm was judged as poor, and the case with less than that was judged as good.

*l Mouni viscosity ML, +4 (100°C) 40, ethylene content 70 mo1%, propylene content 29 mo1%, ethylidenenorbornene fi1 mo1% *2 Mouni viscosity ML. , (100°C) 55, chlorine content 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 Average particle size 10 μm Lead monoxide/average particle size 0.5μm
Powdered polyethylene = immobilization treatment at a ratio of 80/20 *6 Trilead tetraoxide with an average particle size of 15 μm / average particle size of 0°5 μm
Immobilization treatment at a ratio of m powder polyethylene = 70730 *7 Molybdenum oxide with an average particle size of 5 μm / average particle size of 0.3
Powdered polyethylene of μm = immobilization treatment at a ratio of 90/10 *8 Magnesium oxide with an average particle size of 2 μm/average particle size of 0.
1 μm powder polyethylene = immobilization treatment at a ratio of 80/20 * 9 No treatment * 1 O trilead tetroxide with an average particle size of 15 μm/average particle size I μm
As is clear from Table 1, no agglomeration was observed in any of Examples 1 to 6 according to the present invention, which showed good dispersibility. 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 case of 3, there is severe aggregation and poor dispersibility.

[Effects of the Invention] As explained above, the present invention involves mixing a metal oxide with powdered resin or powdered rubber that has been immobilized with the resin or rubber, which eliminates agglomeration of the metal oxide,
Good dispersibility can be achieved.

Claims (1)

[Claims] (1) A resin or rubber is mixed with a metal oxide with an average particle size of 100 μm or less, and a powder resin or powder rubber with an average particle size of 1/10 or less of the metal oxide is fixed. An electrically insulating composition characterized by: