JPH0648683Y2 - Varnish resistant insulated wire - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric wire, and more particularly to a varnish-resistant insulated electric wire.

[Prior art]

An insulated electric wire in which a copper conductor is covered with a rubber / plastic insulating composition is a general-purpose electric wire, and one of its uses is a lead-out electric wire for a motor. Since this motor output wire is usually attached for output before the motor varnish impregnation step, the varnish also adheres to the electric wire insulator at the same time when the motor varnish is impregnated, and is cured as it is. Therefore, there is a problem that the insulator and the varnish are firmly adhered to each other and the flexibility is lost, and the insulator is co-cracked together with the varnish that bends the electric wire.

As a conventional means for solving this difficulty, there is known a means for forming a layer containing a fluorine-based surface treatment agent further on the outer periphery of a coated insulated wire provided with an insulating layer. This fluorine-based surface treatment agent is excellent in releasability and can considerably prevent varnish adhesion and co-cracking based on it, but in this conventional technique, this treatment agent layer is easily separated from the insulated wire, For a long period of time, it was difficult for the treating agent layer to adhere stably and uniformly, and there was a great difficulty in its durability.

[Problems to be solved by the invention]

The problem to be solved by the present invention is to solve the above-mentioned drawbacks of the conventional varnish-resistant insulated electric wire. More specifically, it is an insulated electric wire excellent in varnish resistance that does not break together with varnish by varnish treatment. The goal is to develop an insulated wire that is extremely durable.

[Means for solving problems]

This problem can be achieved by forming a curable silicone rubber layer on the outer periphery of the coated insulated wire formed on the surface of the insulating coating layer and curing it to provide a cured layer. That is, the present invention relates to a varnish-resistant insulated wire characterized in that a silicone rubber cured layer is provided on the outer periphery of the covered insulated wire.

[Function of device]

In the present invention, since a cured silicone rubber layer having excellent releasability is formed on the surface of the insulated wire, the varnish adheres to the insulation of the wire when the varnish of the motor is impregnated and is cured as it is. However, since the interface between the insulator and the varnish does not adhere, the insulator does not co-crack together with the varnish, which makes the wire extremely suitable as a lead wire for a motor.

Further, it should be particularly noted in the present invention that the above-mentioned silicone rubber cured layer is formed by forming a curable silicone rubber layer on the covered insulated wire and then curing and curing it by an appropriate means. The cured silicone rubber layer is firmly formed on the insulating layer, so that its durability is significantly improved as compared with the case where a conventional fluorine-based treating agent or the like is formed.

[Constitution of device]

As shown in FIG. 1, the electric wire of the present invention comprises a copper conductor (1) coated with an insulating coating layer (2), and a silicone rubber cured layer (3) formed on the surface of the insulating coating layer (2). It is a thing.

The copper conductor (1) itself, which has been conventionally used for this type of electric wire, can be used in a wide range.

Further, as the rubber / plastic composition used for the rubber / plastic insulating coating layer (2), any of those conventionally used as this type of insulating composition for electric wires can be used, and a typical composition thereof is used. Is as follows. That is, natural rubber, butyl rubber, styrene-butadiene rubber,
Butadiene rubber, styrene-butadiene-block copolymer, ethylene-propylene copolymer, ethylene-propylene-diene terpolymer, urethane rubber, silicone rubber, chlorosulfonated polyethylene, chlorinated polyethylene, ethylene-vinyl acetate copolymer Polymer, polyethylene, polypropylene, polyvinyl chloride, ethylene-ethyl acrylate copolymer, poly-4-methylpentene-
1 type or a mixture of 2 or more types, such as 1 and the like, and a filler which is usually compounded with rubber or plastic as necessary,
Flame retardant, plasticizer, process oil, vulcanizing agent, vulcanization accelerator,
Stabilizers, antioxidants, colorants, lubricants and the like are blended, and if necessary, they are vulcanized (crosslinked) before use.

As the thickness of the rubber / plastic insulating coating layer (2), the conventional thickness is sufficient.

As the silicone rubber cured layer (3) formed on the insulating coating layer (2), a layer obtained by curing a composition mainly composed of a curable silicone rubber and curing it by an appropriate means is used. As a means for forming the silicone rubber cured layer (3), the composition layer is formed on the coating insulation layer (2) of the insulation-coated electric wire, and then this is applied by an appropriate means such as electron beam, ultraviolet ray, or heating. It is cured by such means as to cure it.

The means for providing the silicone rubber composition on the insulating coating layer (2) of the coated insulated wire is not particularly limited, and the point is that the composition layer is formed on the insulating coating layer (2). As a representative example, means such as coating, spraying, extrusion coating, mixing with an insulating material and bleeding on the surface of the insulating layer after extrusion molding can be exemplified.

The curable silicone rubber composition used at this time is mainly composed of room temperature curable silicone rubber or (and) low temperature curable silicone rubber which cures at a relatively low temperature, usually about 60 to 100 ° C. The above composition may further contain other usual additives such as a filler if necessary.
In some cases, it may be further diluted with an appropriate solvent. A preferable composition is a composition containing a low temperature curable type silicone rubber, which is usually a two-component type of a silicone rubber and a curing agent.

The thickness of the silicone rubber cured layer (3) is usually 0.01
It is not less than μm, preferably about 0.1 to 100 μm.

[Brief description of drawings]

 FIG. 1 shows a sectional view of an example of the drawing of the present invention. (1) …… Copper conductor (2) …… Insulation coating layer (3) …… Silicone rubber cured layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliographic references Sho 54-48383 (JP, U)

Claims (3)

[Scope of utility model registration request] 1. A varnish-resistant insulated electric wire, characterized in that a cured silicone rubber layer is provided on the outer circumference of the covered insulated electric wire. 2. The insulated wire according to claim 1, wherein the silicone rubber cured layer is a cured product of room temperature cured silicone rubber. 3. The insulated wire according to claim 1, wherein the cured product of silicone rubber is a cured product of low temperature curing type silicone rubber.