JPS62247739A - Manufacture of electric insulated coil - Google Patents

Abstract

PURPOSE:To prevent resin from flowing out and from lowering electrical, mechanical and thermal characteristics, by impregnating and hardening the resin after the outflow preventive tape, which is provided with a latent hardening agent for epoxy resin as a hardening accelerator, is wound around the outside circumference of the raw insulating layer. CONSTITUTION:The latent hardening agent for epoxy resin obtained by the reaction upon a multifunctional epoxy resin compound, a compound having at least one functional group and a tertiary amino acid group of OH-group, SH-group, COOH-group, and CONH NH2-group in its molecule and an organic compound having two and more active hydrogen in the molecule are dissolved and dispersed uniformly into the solution with the solvent such as methyl ethyl ketone as nonreactive binder where the phenoxy resin and the like solid under the normal temperature is dissolved. The material for tape is immersed into this solution and made into the outflow preventive tape, which is wound around and then impregnated with resin and hardened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the production of electrically insulated coils such as high-voltage motor coils, and in particular, to prevent the resin impregnated in the insulating layer from flowing out during the curing of the resin. This paper relates to a devised manufacturing method and the leakage prevention tape used therein.

[Prior art and its problems]

In the resin impregnation treatment of insulated wire rings for electrical equipment, it is essential that the impregnated resin be retained without flowing out during curing in order to ensure its insulation performance.

However, since impregnated resins are generally used repeatedly, those with a long shelf life (pot life) are used.
It often takes a long time to cure, and has the disadvantage that the resin flows out during this time.

Various methods have been used in the past to compensate for the drawbacks of impregnated resin and to prevent resin from flowing out. One of these methods is to hold the curing accelerator of impregnated resin in various tape materials. There is a method of wrapping a leak-preventing tape around the outermost circumference of the insulating layer, and then impregnating and curing the resin.

Although this method has good economic efficiency and workability, its leakage prevention performance is greatly influenced by the curing accelerator retained in the tape.

The curing accelerator retained in the spill prevention tape must have the following properties:

(1) High curing accelerating ability for i-containing resin.

Q) Preliminary drying performed before impregnating the resin will not volatilize it.

In order to meet these conditions, there are examples of using imidazole compounds with a high melting point, such as 2 PH2CN C (trade name, manufactured by Shikoku Kasei Kogyo Co., Ltd.), but such imidazole compounds with a high melting point do not have the ability to accelerate curing. not enough.

[Failure to solve the problem]

Therefore, the inventors of the present invention have conducted various experiments and researches in order to obtain a sufficient resin leakage prevention effect using the above-mentioned method of manufacturing electrically insulated coils. This solves the problem.

That is, the present invention uses a polyfunctional epoxy compound disclosed in JP-A-60-4524 and an OH group, an S
A compound having at least one functional group among H group, C0OH group, and C0NHNH snow group and a tertiary amino group, and an organic compound having two or more active hydrogens in the molecule (
However, a latent curing agent for epoxy obtained by reacting an epoxy group and a compound having a tertiary amino group is
Various tape materials are immersed in a solution in which a phenoxy resin, a highly viscous alicyclic epoxy resin, etc., which is solid at room temperature and a non-reactive binder, is uniformly dispersed in a solvent such as methyl ethyl ketone or toluene. All of the above-mentioned problems have been solved by using the leakage prevention tape manufactured by the above-mentioned method.

The amount of the curing accelerator retained in the insulating layer is 1-1 to 100 parts of the impregnated resin consisting of an epoxy resin and an acid anhydride.
The range of 3 parts is desirable.

The reason for this is that if the amount is less than 1 part, a sufficient outflow prevention effect cannot be obtained, and if it is more than 3 parts, there is a risk of deteriorating the physical properties of the cured epoxy resin.

The tape material used here is selected from tapes such as glass tape, polyester spun tape, and polyester film, polyester nonwoven fabric, and aromatic polyamide paper.

As the phenoxy resin used together with the curing accelerator, commonly manufactured and sold phenoxy resins can be used as appropriate depending on the workability required for the spill prevention tape. As the alicyclic epoxy resin, a high viscosity or low melting point solid obtained by modifying a polyolefin epoxy resin synthesized by a peroxidation method is preferably used.

The epoxy resin and arsenic anhydride that are blended into the impregnated resin are not particularly limited, and examples of epoxy resins include polyglycidyl ether obtained from polyhydric phenol, polyhydric alcohol, and epichlorohydrin, Nozerak-type phenol, epichlorohydrin, etc. Epoxy resins such as epoxy nozelac obtained from P1, polyolefin-based epoxy resin synthesized by peroxidation method, and polyglycidyl ester obtained from cyclohexene oxide or hexahydrophthalic acid and epichlorohydrin can be used alone or Two or more types are used in combination, and the acid anhydrides used include maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, dodecenylsuccinic anhydride, methylendomethylenetetrahyphthalic anhydride, and anhydride. Methyltetrahydrophthalic acid, methylhexahydrophthalic anhydride, etc. are used.

〔Example〕

EXAMPLES The present invention will be specifically explained below using examples.

First, the leakage prevention tape according to the present invention is produced in the following manner.

Finerex 310 (manufactured by Fine Bolmers Co., Ltd.) dissolved in a mixed solvent of methyl ethyl ketone and toluene:
Amicure MY-24 [trade name: latent curing agent for epoxy manufactured by Ajinomoto Co., Inc.] 5f'i was uniformly dispersed in a 2% solution 5002 of [alicyclic epoxy resin], and 0.13
After immersing the glass tape for 10 minutes in X19■, it was taken out and air-dried to obtain a spill prevention tape according to the present invention (hereinafter referred to as q-present invention tape 1).

Next, instead of a 2% solution of Finerex 310 dissolved in a mixed solvent of methyl ethyl ketone and toluene, a 40% methyl ethyl ketone solution of phenoxy resin (YP-50EK-4QC (product name: C) manufactured by Tobu Kasei Co., Ltd.) was diluted. A spill prevention tape (hereinafter referred to as "invention tape 2") was obtained in the same manner as above except that a 1% solution was used.

[Comparative Example 1] 2 dissolved in a mixed solvent of methyl ethyl ketone and toluene
Part 4MZ (Product name = 2-ethyl-1 manufactured by Shikoku Kasei Co., Ltd.
-Methylimidazole] A glass tape was immersed in the same manner as described above to obtain a spill prevention tape.

[Comparative Example 2] 2 P HZ -CN (Product name =
1-Cyanethyl-2-phenyl-4 manufactured by Shikoku Kasei Co., Ltd.
A spill prevention tape was obtained in the same manner as in Comparative Ratio 1 except that 5-di(cyanoethoxymethyl)imidazole was used.

[Example 1] The above-mentioned present invention tapes 1 and 2 and Comparative Example 1. The spill prevention tape obtained in Comparative Example 2 was cut into 2 m lengths, the shredded tape was heated at 120°C for 10 hours, and the untreated glass tape was cut into 2 m lengths. DER, 332 [:Product name: 3100 parts of bisphenol A epoxy resin manufactured by Dow Chemical Company, I(N
It was immersed for 5 minutes in an impregnated resin consisting of 80 parts of Tetrahydrophthalic anhydride (manufactured by Hitachi Chemical Co., Ltd.) and 0.2 parts of K61 B (modified amino acid manufactured by Certilny Co., Ltd.) for 5 minutes, and immediately after being pulled out, it was kept at a constant temperature of 150°C. They were placed in a bath and cured for 10 hours, and the amount of resin adhered was compared.

The results are shown in Table 1. In the case of the tape of Comparative Example 1, the tape without heat treatment showed the same amount of adhesion as the tape of the present invention, but when heated, 2 parts of 4MZ evaporated and the amount of adhesion decreased. extremely low.

In the case of the tape of Comparative Example 2, the decrease in adhesion amount due to heat treatment was small, but the increase was small compared to the untreated tape, indicating that the curing accelerating ability of 2PH2-CN is low. In contrast to the examples, it is clear that inventive tape 1 and inventive tape 2 have a large amount of resin attached, are not affected by heat treatment, and are excellent outflow prevention tapes.

[Example 2] A coil in which the above-described tape 1 of the present invention was wound once in a 1/2 wrap around a coil in which the main insulating layer was formed by winding a laminated mica tape lined with glass cloth three times in a 1/2 wrap. and spill prevention tape according to Comparative Example 2 at 172 lamps.
After drying the entire wound coil at 120°C for 10 hours, the impregnation resin used in Example 1 was impregnated with vacuum pressure.
:: Insulated coils were prepared by curing them for 1θ time, and the applied voltage-dielectric loss tangent (tan δ) characteristics were compared.

As shown in the attached drawings, the coil using all the tapes of the present invention has a tan δ of 1% or less even when the applied voltage is high (shown by the solid line), and the tan δ is 1% in the high voltage region.
It is clearly superior to the coil using the tape according to Comparative Example 2, which exceeds .

〔Effect of the invention〕

As described above, according to the method for manufacturing an electrical insulating wire in which the tape of the present invention is wound around the outermost circumference of an electrical wire, impregnated with resin, and cured, the resin impregnated into the spill prevention tape layer is quickly cured. This prevents the resin impregnated inside from flowing out and deteriorating electrical, mechanical, and thermal properties, and ensures insulation performance.

[Brief explanation of drawings]

The drawings show the dielectric loss tangent according to the embodiment of the present invention and comparatively.
It is a voltage characteristic diagram. Applied voltage (KV) -1

Claims (2)

[Claims] (1) A method for manufacturing an electrically insulating coil, in which a main insulating layer is formed around a conductor, and the main insulating layer is impregnated with a resin whose main components are a polyfunctional epoxy resin and a polyfunctional acid anhydride curing agent, Polyfunctional epoxy compound with OH group, SH group, C in the molecule
Compounds that have at least one functional group among the OOH group and CONHNH_2 group and a tertiary amino group, and organic compounds that have two or more active hydrogens in the molecule (however, compounds that have an epoxy group and a tertiary amino group) A leak-prevention tape containing a latent curing agent for epoxy obtained by reacting the resin (excluding compounds) as a curing accelerator for the resin is wound around the outer periphery of the main insulating layer, and then impregnated with the resin and cured. A method of manufacturing an electrically insulated coil, characterized by: (2) A polyfunctional epoxy compound and a compound that has at least one functional group among OH group, SH group, COOH group, and CONHNH_2 group and a tertiary amino group in the molecule and two or more active groups in the molecule. A resin spill prevention tape characterized in that the tape retains a latent curing agent for epoxy obtained by reacting an organic compound having hydrogen (excluding compounds having an epoxy group and a tertiary amino group).