JPS6055931B2 - colored insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rubber or plastic insulated wire having a colored coating.

Traditionally, rubber and plastic insulated wires were identified using (1)
) Mix the coloring agent into the insulation.

(2) Apply a paint containing a colorant made by dissolving synthetic rubber in an organic solvent. Two methods have been adopted.

In (1), it is necessary to manufacture a large number of formulations with different colorants, which makes material management complicated. Furthermore, in the case of short products, there is a lot of loss time such as cleaning and setup of the extruder. In the case of (2), the organic solvent is scattered, which causes material loss, and also poses the problem of environmental pollution. Liquid polymers such as acrylic ester oligomers can be used to overcome this problem.

However, in general, materials with a high curing speed have poor flexibility.

2. Materials with excellent flexibility have a slow curing speed.

As a result, it has rarely been applied to coatings on insulated wires. Therefore, there is a need for a material that has low material loss, a high curing speed, excellent flexibility of the cured product, good adhesion to the insulator, and does not adversely affect the properties of the insulator.

The purpose of the present invention is to eliminate the drawbacks of the prior art described above,
An object of the present invention is to provide a new colored insulated wire that can economically and technically easily identify rubber and plastic insulated wires. The gist of the present invention resides in a colored insulated wire characterized by coating a rubber or plastic insulator on the circumference of a conductor with a colored paint mainly composed of acrylic urethane oligomer and curing the coated paint.

Here, acrylic urethane oligomer has at least one acrylic ester group CH2CH-C-O at the end.
- or methacrylic acid ester group C-C-O- and at least one urethane group -COO- in the molecule
An oligomer containing NH- with a molecular weight of 200 to 500 degrees. Urethane bonds are produced by the reaction of polyols and isocyanates. For example, caprolactone polyol/isoborone diisocyanate/hydroxyacrylate oligomer, adipic acid polyol/tolylene diisocyanate/hydroxyacrylate oligomer, trimethylolpropane polyol/
tolylene diisocyanate/hydroxyacrylate, etc., and Uvitha, which is commercially available from Thiokol.
Examples include, but are not limited to, ne782 (a product made by acrylating a urethane oligomer made from polyester and an aromatic diisocyanate) and Uvithane783 (a product made by acrylating a urethane oligomer made from a polyester and an aliphatic diisocyanate). do not have.

In order to reduce the viscosity of acrylic urethane oligomer,
Reactive diluents such as ethylhexyl acrylate, benzyl acrylate, vinyl-pyrrolidone, ethoxyethyl acrylate, and ethoxyethoxyethyl acrylate may be added alone or in combination of two or more.

Of course, conventionally used organic solvents may also be used. Even in this case, the amount of solvent can be significantly reduced compared to the conventional method. A colorant is added to this system.

Colorants may be the same as those used in the prior art.
Further, there is no problem in mixing an antioxidant, a crosslinking agent, a photosensitizer, a wax, a thixotropic agent that imparts thixotropic properties, etc., if necessary.

As a curing method, any of ultraviolet irradiation, infrared heating, electron beam irradiation, etc. may be employed.

Here, the insulator on the circumference of the conductor is a cross-linked polyolefin (polyolefin refers to polyethylene, a copolymer mainly composed of ethylene, or a terpolymer; polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer) , ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, etc.), natural rubber, synthetic rubber, (ethylene-propylene rubber, phthyl rubber, chlorosulfonated polyethylene, chlorinated polyethylene, styrene-phtadiene rubber, chloroprene) rubber,
Nitrile rubber, acrylic rubber, etc.) can be used. Refers to those used alone or in combination. Next, examples of the present invention will be described. Example 1 3 parts by weight of titanium oxide, 1 part by weight of phthalocyanine blue, and 5 parts by weight of photosensitizer benzophenone were mixed with a mixture of 50 parts by weight of Uvithane 782 (manufactured by Thiokol) and 5 parts by weight of ethylhexyl acrylate. The blue paint obtained was thinly coated on the natural rubber insulator on the circumference of the conductor to a thickness of about 100 μm, and irradiated with a 2 KW high-pressure mercury lamp from a height of 15 ann.

The irradiation time was 2 seconds. The coating was sufficiently cured and no cracks occurred even when bent to its own diameter. No difference was observed in physical properties or electrical properties between the cases with and without the colored coating layer. Example 2 A paint containing 70 parts by weight of UviU1ane 783 (manufactured by Thiokol), 3 parts by weight of vinyl-pyrrolidone, 3 parts by weight of methyl ethyl ketone, 5 parts by weight of carbon black, and 2 parts by weight of benzoyl peroxide was applied around the conductor. It was coated on a cross-linked polyethylene insulator, and after the solvent was volatilized, it was irradiated with an electron beam (1 molar σ Mrad).

The irradiation time was 1 second. The results were similar to Example 1.

Comparative Example 1 5 parts by weight of trimethylolpropane triacrylate,
A coating material was prepared in the same manner as in Example 1 by adding 3 parts by weight of titanium oxide, 1 part by weight of phthalocyanine blue, and 5 parts by weight of photosensitizer benzophenone to 5 parts by weight of ethylhexyl acrylate.

Although it was sufficiently cured, cracks occurred due to self-diameter winding. Comparative Example 2 Example of a paint containing 7 parts by weight of 2-hydroxy dodecyl acrylate, 3 parts by weight of vinylpyrrolidone, 3 parts by weight of titanium oxide, 1 part by weight of phthalocyanine blue, and 5 parts by weight of photosensitizer benzophenone. It was carried out in the same manner as in 1.

The surface was not hardened at all. It took at least 1 minute to completely cure. A semiconductive layer is sometimes formed on the insulator of rubber or plastic insulated wire for use as an electrode.

In this case, by mixing carbon black or graphite alone or in combination with the coating composition of the present invention, it is possible to adjust a paint that maintains volume resistivity according to the type and amount of these conductive substances. The semiconducting layer can be formed by the curing method described above. According to the colored insulated wire of the present invention, by employing a specific coating composition, organic solvents that cause material loss can be removed or greatly reduced, and environmental pollution can also be significantly reduced.

Further, compared to conventional heat curing, it can be cured in an extremely short time (about 1 second) by ultraviolet ray or electron beam irradiation.
In particular, when ultraviolet curing is used, equipment costs and operating costs are significantly reduced.

Of course, in the case of heat curing, material loss can be expected to be reduced by reducing the amount of organic solvent used. Of course, the flexibility is also comparable to electric wires without colored coatings.

Claims (1)

[Claims] 1. A rubber or plastic insulator is provided on the circumference of the conductor, and a coating layer of a colored paint mainly composed of acrylic urethane oligomer is formed as the outermost layer on the outer circumference, and the coating layer is configured by curing. Colored insulated wire.