JPS5856403A - Process for insulating electrical machinery and apparatus - Google Patents

Abstract

PURPOSE:To improve the storage stability of resin for use in an impregnating process and the heat resistance of an insulating layer after the layer has been formed by a method wherein, after an insulating base material processed with cyanate resin is applied to a conductor, the conductor is impregnated with sensory impregnating resin, before being heated to harden. CONSTITUTION:An insulating base material 1 is coated with a layer 2 of bismurrey imidotoliadin. The base material thus processed is not sticky and readily handled, so that workability is greately improved. After the insulating base material 4 thus processed is wound on a metal conductor 3 the preset number of times, the assembly is placed in a container for impregnation, wherein the assembly is impregnated with epoxy resin without containing a hardening agent nor a hardening accelerator under vacuum and pressure. The processed material is taken out and heated at 150-180 deg.C for several hours. Subsequently, the material is cooled to obtain a hardened insulating layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for insulating windings or layered insulation parts of electrical equipment, particularly rotating machines, stationary machines, etc.

In general, impregnated resins used for insulating electrical equipment such as rotating machines are required to have excellent pot life or storage stability, and to be cured quickly by heating after impregnation. Furthermore, it is desired that the storage stability after being used for impregnation treatment is not impaired.

Epoxy resins, polyimide resins, polyester resins, etc. are known as impregnating resins used to form insulation layers using the conventional resin impregnation method, but all require the use of a curing agent or curing accelerator to cure them. It is. Curing agents and curing accelerators are generally premixed into the impregnating resin or pretreated on the insulating substrate. In the former case, it is well known that the pot life or storage stability of the resin deteriorates due to the presence of the admixture agent and curing accelerator mixed in advance. The latter method also has the disadvantage that the curing agent or curing accelerator that has been applied to the insulating substrate in advance mixes into the resin during the impregnation process, impairing the storage stability of the impregnated resin.

Therefore, the present invention provides an electrically conductive solution that eliminates the drawbacks of the prior art as described above, improves the storage stability of the resin used in the impregnation process, and makes it possible to improve the heat resistance of the insulating layer after formation. The purpose of this invention is to provide a method for processing equipment insulation.

Here, the insulating base material is pretreated with a cyanate-based resin that can be cured only by heating when mixed with other functional resins without the need for curing agents or curing accelerators, and this treated insulation By applying the substrate to the conductor and then impregnating it with a functional impregnating resin and heat curing, an improved method of processing electrical equipment has been found that has many advantages. According to this method, there is no need to mix a curing agent or a curing accelerator into the impregnated resin, and therefore the pot life or storage stability of the impregnated resin is significantly improved. Furthermore, since bismaleimide triazine resin, which is a cyanate resin, is solid at room temperature, an insulating base material treated with this resin has the advantage that it does not become sticky when applied, such as winding, and has good workability. Furthermore, even if cyanate-based resin is mixed into the resin used for impregnation, it has almost no effect on the pot life of the impregnated resin at room temperature, and the cyanate-based resin provides heat resistance to the insulating layer after it is heated and cured. I also found out that it will happen.

Therefore, according to the present invention, an insulating base material is pretreated with a cyanate-based resin, this insulating base material is applied to a conductor, the assembled conductor is impregnated with a solvent-free impregnated resin under vacuum pressure, and then heated and cured. A method of forming an insulating layer on a conductor is provided.

The cyanate resin used in the present invention does not require a curing agent or a curing accelerator, has good reactivity with other impregnating resins at high temperatures, and is easily cured simply by heating the mixture. Particularly preferred cyanate resins are bismaleimide triazine resins. This is solid at room temperature, and 5
It has a melting point of 0-60°C.

The treatment of the insulating base material is carried out by impregnating or coating the cyanate resin by making it into a liquid state by heating or by making it into a face shape with an organic solvent such as methyl ethyl ketone or methyl imbutyl ketone. The solvent is then evaporated off. Insulating base materials include mica, glass cloth, glass paper,
Inorganic materials such as glass tape, paper, heat-resistant polyamide paper, polyester cloth, polyester film,
Tapes, sheets, etc. made of polymer fiber sheets such as polyimide films, films, various mixed papers, etc. can be applied.

Insulating substrates treated with cyanate-based resins can be applied to conductors in a variety of ways. For example, it can be wound a predetermined number of times onto a metal conductor, or it can be laminated to form a layered insulation. The conductor to which the insulating substrate has been applied in this way is then subjected to vacuum pressure impregnation.

The impregnation treatment can be carried out by methods and conditions commonly used in this type of technology.

The impregnating resin used in the impregnation treatment of the present invention may be any one commonly used in this type of technology, but one that can be cured by reacting with the cyanate resin at high temperatures is particularly preferred. Such impregnating resins include: epoxy resins, acrylic resins, acrylic-epoxy resins, alkyd resins, polyurethane resins, phenolic resins, polyester resins, melamine resins, urea resins, xylene resins, polyimide resins, polybutadiene resins, and rubbery polymers. , thermoplastic resins, etc. Further, since the above-mentioned cyanate resin has high heat resistance, the heat resistance of the insulating layer formed by subsequent heat curing with these impregnated resins is improved.

The assembled conductor impregnated as described above is then heated and cured by a conventional method to form a cured insulating layer on the conductor. Generally 100°C or higher, preferably 150°C
Heated to a temperature of ~180°C.

When heated, the cyanate resin treated on the insulating base material melts and mixes with the impregnating resin in the insulating layer, reacts and hardens,
A more heat-resistant insulating layer is formed.

As described above, according to the method of the present invention, the impregnating resin can be cured simply by heating to a high temperature without adding a curing agent or a curing accelerator to the impregnating resin.

The method of the present invention is particularly suitable for forming an insulating layer for the windings of rotating machines, but can also be used for insulating the windings of stationary devices such as transformers and reactors other than rotating machines, and also for other electrical equipment. It can be widely applied to insulation treatment of layered insulation parts in.

Embodiments of the present invention will be described below with reference to the drawings. 3. Embodiment FIG. 1 illustrates an insulating base material (sheet or tape) treated with a cyanate resin according to the present invention. this is,
A layer 2 of bismaleimide triazine resin (manufactured by Mitsubishi Gas Chemical Co., Ltd., melting point 50-60°C) is applied on an insulating base material 1 by a coating method. This treated base material is non-sticky and has very good handling and workability. FIG. 2 shows a state in which the thus treated insulating base material is wound around a metal conductor.

Here, 3 is a conductor, and 4 is a treated insulating base material. After the treated insulating base material was wound a predetermined number of times, the assembly was placed in an impregnating container and impregnated with an epoxy resin (manufactured by Shell Chemical Co., Ltd., EP828) containing no curing agent or curing accelerator under vacuum pressure. It was observed that a hardened insulating layer was formed when the impregnated body was taken out, heated to 150 to 180°C for several hours, and then cooled.

[Brief explanation of drawings]

FIG. 1 shows the construction of one embodiment of an insulating substrate treated with a shear+-super resin according to the present invention. FIG. 2 shows an application example of an insulating substrate treated with a cyanate resin.

Claims (1)

[Claims] (1) An insulating base material is pre-treated with a resin having a cyanate group, this insulating base material is applied to a conductor, the assembled conductor is impregnated with a solvent-free impregnated resin under vacuum pressure, and then heated. A method of forming an insulating layer on a conductor by curing it. (2. The method according to claim 1, wherein the insulating base material is an insulating tape or sheet impregnated with or impregnated with a resin having a cyanate group. (3) Scope of claims 3. The method according to item 1 or 2, wherein the resin having a cyanate group is a bismaleimide triazine resin.