JPS6113611A - Manufacture of insulated coil - Google Patents

Abstract

PURPOSE:To obtain an insulated coil having excellent dielectric loss tangent-voltage characteristics by a method wherein an insulating sheet lined by a porous insulating material is wound around a coil conductor, the resin in which prescribed quantity of multifunctional vinyl monomer and phenoxy resin is contained in an epoxy compound is used as an impregnating resin when the insulated coil is formed by applying heat and pressure by impregnating low viscosity resin into the insulating sheet. CONSTITUTION:An insulating sheet is wound around a coil conductor, low viscosity resin is impregnated therein, a molding work is performed by applying heat and pressure, and an insulated coil is formed. According to this constitution, the resin consisting of an epoxy compound containing at least two epoxy groups in a molecule, 5-300pts.wt. of multifunctional vinyl monomer having two or more acrylic groups or a methacrylic group or an allyl group in a molecule for 100pts.wt. of the mixture of said epoxy compound and a hardening agent, is used as a low viscosity impregnating resin. Through these procedures, a crosslinking reticulation can be made uniform and, at the same time, the flexibility and the dimensional stability of the insulated coil can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing an insulated coil using a novel low-viscosity impregnated resin. More specifically, the present invention relates to a method of manufacturing an insulated coil suitable for use in rotating machines that use high voltage, such as turbine generators, water turbine generators, and motors.

[Prior art]

For turbine generators, water turbine generators, etc.

As the demand for electric power increases, there is a growing tendency to increase the capacity of each unit and raise the operating voltage, and recently, products with operating voltages as high as JOkV have appeared.

Due to this increase in working voltage, insulated coils are required to have stricter performance in many respects, including heat cycle resistance against repeated startup and stoppages, heat deterioration resistance due to rising hot water temperature, and mechanical properties against vibrations and short circuits. It looks like this.

Insulated coils built into rotating machines are generally placed in a gas phase, but under high voltage, corona discharge occurs due to air breakdown of the gas present in the coil, and the insulating layer of the coil is destroyed. Therefore, insulating sheets (including tape-shaped ones, hereinafter the same) using mica foil, which has excellent heat resistance, corona resistance, voltage resistance, etc., have been used as an insulating material for a long time.

A normal insulated coil is made by winding the above-mentioned insulating sheet around a coil conductor formed into a predetermined shape, and impregnating this wound layer with epoxy-impregnated resin to form an insulating layer. Many impregnating resins have high viscosity at room temperature;
Moreover, many have short pot lives.

Adding diluents is a common method for reducing the viscosity of resins, but regular diluents are highly irritating to the skin.
In addition, there are many cases in which the properties deteriorate sharply, and there is a drawback that sufficient properties cannot be obtained.

[Summary of the invention]

In order to overcome the above-mentioned drawbacks, the inventors of the present invention made extensive research and found that they obtained 100 parts by weight (hereinafter simply "parts") of a mixture of an epoxy compound containing at least one epoxy group in the molecule and a curing agent for this epoxy compound. ), polyfunctional vinyl monomers having one or more acrylic, methacrylic, or allyl groups in one molecule. By blending 300 parts and 0.7 to 70 parts of fenoki resin, a new low viscosity impregnated resin with low viscosity and a long pot life can be obtained, and in the production of insulated coils using this low viscosity impregnated resin. The present inventors have discovered that impregnation at room temperature is sufficiently possible and impregnation failure does not occur at all, leading to an improvement in the initial breakdown voltage, and that the electrical properties after thermal deterioration are also extremely stable, leading to the completion of the present invention.

(J) That is, the present invention provides insulation J-, which is obtained by winding an insulating sheet with a porous insulating material as a backing material around a coil conductor, impregnating this wound layer with a low-viscosity impregnated resin, and molding it under heat and pressure. In the method for manufacturing an insulated coil having ``a mixture of an epoxy compound containing at least one epoxy group in one molecule and a curing agent for this epoxy compound as the low-viscosity impregnated resin, and 10θ parts by weight of the mixture, It is characterized by using a low-viscosity impregnating resin produced by blending 300 parts by weight of a polyfunctional vinyl monomer jA-, which has one or more acrylic groups, methacrylic groups, or allyl groups, and o, t-1oxx parts of a phenoxy resin. This is a method of manufacturing an insulated coil.

The features of the present invention are that the epoxy compound is blended with low-viscosity acrylic (methacrylic) or allyl monomer to lower the viscosity of the impregnated resin, and that the epoxy cured network and vinyl crosslinked network are compatible with each other so that they do not react with each other. By homogenizing well.

Epoxy resin has the advantages of flexibility and dimensional stability.

Achieves the effect of increasing heat deformation temperature of vinyl resin (4') The purpose is to make a well-balanced cured product.

Furthermore, by adding phenoxy resin as a high molecular weight component, flexibility can be imparted to the impregnated resin by intervening the phenoxy resin as a non-crosslinking linear component in the crosslinked network. This is also one of the features of the present invention.

Hereinafter, a method for manufacturing an insulated coil according to the present invention will be explained.

First, the epoxy compound that can be used in the present invention may be any compound having at least one epoxy group in one molecule, such as bisphenol A type D
ER-332 (Dow Company product name).

Epicote txt<Shell store product name), GY-aSZ(
Novolac type DEN-4 such as Ciba (product name)!
3t (Dow Company product name), alicyclic type CY-/RI9
(trade name of Chipa Co., Ltd.), and these can be used alone or in combination.

In addition, the epoxy curing agent that can be used in the present invention may be any cyclic acid anhydride, such as methyltetrahydrophthalic anhydride [HN-co100, and as a curing accelerator, tricresyl borate, Metal clays such as triethanolamine titanate, cobalt acetylacetonate, zinc octylate, metal chelate compounds, BF,
Lewis acids such as y, BCJ-a, PFs, and AsFy, and their amine complexes can be used, and these may be mixed and used if necessary.

Furthermore, examples of polyfunctional vinyl monomers having an acrylic (methacrylic) group or an allyl group in one molecule that can be used in the present invention include diallyl phthalate, diallyl isophthalate, triallyl trimellitate, triallyl isocyanurate, and bisphenol group. Examples include diglycidyl ether di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and trihydroxyethyl isocyanurate tri(meth)acrylate.

The curing agent for the epoxy compound is desirably blended in a ratio of 50 to ISO parts to loO parts of the epoxy compound.

If the blending amount is out of this range, the cross-linking between the epoxy component and the curing agent component will not be sufficient, and the heat distortion temperature and mechanical
Electrical properties deteriorate, which is not desirable. The polyfunctional vinyl monomer having an acrylic (methacrylic) group or an allyl group in one molecule is desirably blended in an amount of 5 to 300 parts based on io parts of the mixture of the epoxy compound and the curing agent. If the amount is less than 3 parts, the effect of adding the vinyl compound (lower viscosity, etc.) cannot be obtained, and if it exceeds 300 parts, the curing shrinkage rate will be too large and the properties as an impregnated resin will deteriorate, both of which are not preferred.

Furthermore, the phenoxy resin has a molecular weight of ooo to 60. θ
00 for 100 parts of epoxy compound.

It is desirable to mix 0./-10 parts, and the blending amount is 0./-10 parts.
If the amount is less than 1 part, the effect of imparting flexibility will not be sufficient, and the io
If the amount exceeds 1.0 parts, the viscosity of the impregnated resin will increase too much, which is not practical.

Furthermore, for the purpose of promoting the reaction of the impregnated resin used in the present invention, it is effective to add a catalyst. Examples of the catalyst include vinyl polymerization initiation catalysts such as dicumyl peroxide, benzoyl peroxide, di-t-butyl hydroperoxide, and azobisisobutyronitrile.

In addition, in order to further lower the viscosity of the resin impregnated with -functional vinyl monomers such as styrene, vinyltoluene, α
- Methylstyrene, acrylonitrile, N-vinylpyrrolidone, etc. can be added in an amount not exceeding -00 parts to the lθθ part of a sweat-containing resin, but since these will lead to a decrease in the properties, it is necessary to keep the amount to the minimum necessary. be.

The insulated coil of the present invention is produced by winding an insulating sheet around a coil conductor, impregnating this wound layer with the above-mentioned novel low-viscosity impregnated resin under vacuum and pressure under known conditions, and then inserting it into a mold and forming it under heat and pressure. At the very least, an insulated coil is manufactured. The heating and pressure molding conditions are: heating temperature / 00-1, t 0°C,
A pressurization pressure of 5-io parts and a heating time of v to koda hours are used, thereby obtaining an insulated coil with excellent electrical and thermal properties.

If the molding conditions are out of the above range, the resulting insulating (f) coil will have weak interlayer adhesion, resulting in a significant decrease in electrical properties during thermal deterioration, and undesirable flaking or peeling of the insulating layer.

As described above, according to the present invention, the electrical properties, especially the dielectric contact-voltage properties (hereinafter simply referred to as ΔtaOδ) after thermal deterioration, are better than the imaging coil formed using the conventional Evogishi impregnated resin.
It has become possible to manufacture Yuen coils with excellent quality.

[Embodiments of the invention]

The method for manufacturing an insulated coil of the present invention will be described in detail below with reference to Examples and Comparative Examples.

Example 1 As an epoxy compound, 65 parts of IN-Coco 00 (Hitachi Chemical product name), 2 parts of triphthyrolpropane triacrylate per part of Epicoat t-za (product name of Shell Co., Ltd.) gO
0 parts, molecular weight approximately 30. θoo pheno-+ ShiW fat 0.
2 parts of dicumyl peroxidide as a catalyst, 3 parts of dicumyl peroxidide, and 0.2 parts of substituent octylic acid were added.

A low viscosity impregnated resin was obtained.

The initial viscosity of the impregnated resin was /θθCp5 (centivoids) at 23°C.

Next, a glass cloth (manufactured by Arisawa Seisakusho, thickness θ, Oxtsog) was placed on a coil conductor with a cross section of <IO x 10 m, which was made by combining double glass-wrapped rectangular copper wires of 2 ooo cod in 2 rows and 20 stages. The laminated mica tape obtained as a backing material is wound 71 times in a half-overlap manner.

In addition, as a protective layer, Tetron tape (manufactured in large quantities, thickness o,
tazwm) is wound once, and the pressure is 0. /1mHy or less, vacuum impregnation was carried out for 7 hours, and then pressure impregnation was carried out for V hours at pressure 3, and then inserted into a mold and heated and pressure molded at temperature t, 3z℃, and pressure car 〇t''c' for 6 hours. After that, polymerization was further carried out at 730°C for 76 hours to obtain an insulated coil.In order to understand the characteristics of this insulated coil, initial Δ-δ and breakdown voltage, 1
Δ-δ was measured after 16 days at 70°C. These results are shown in Table 1. The pot life (pot life) of the above-mentioned low-viscosity impregnated resin was tracked by leaving the resin in a constant temperature and humidity chamber at a temperature of 10°C and a relative humidity of 35%, and periodically measuring the viscosity. That is, in this measurement, the number of days until the viscosity at 25° C. do not have.

As a result, the viscosity of the above-mentioned impregnated resin did not exceed 0.0 cps even after 6 months at 10° C. and was very good.

Next, after curing this low viscosity impregnated resin at 770°C for 6 hours,
Further, it was cured at 730° C. for 76 hours to obtain a cured product. The bending strength of this cured product was measured based on II8 (7X) JK. As a result, a very good result was obtained, takg/d at 3°C. Also.

The heating weight loss was measured based on JIS C, ztOy.

As a result, the weight loss after heating at 110℃ for 16 days was
%, which was a good value.

The results of the above initial viscosity, pot life bending strength, heating weight loss are summarized in Table 2.

Example GY-:Lsg (Ciba brand name) as a coepoxy compound
For 100 parts, HN-ssoθ (Hitachi Chemical brand name) t
b part, trihydroxyethyl isocyanu L/-) J
0 parts, phenoxy resin with a molecular weight of approximately 70,000 0.3
parts, IO parts of styrene, 0.02 parts of benzoyl peroxide and 0.0 parts of cobalt acetylacetonate as catalysts.
．． ! was added to obtain a low viscosity impregnated resin. The initial viscosity of this impregnated resin was 0 cps at ℃.

Next, an insulated coil was manufactured under the same conditions as in Example 1, and the -1 and initial breakdown voltages were measured.
It was also very good. These results are shown in Table 1.

Further, the pot life of the above-mentioned impregnated resin was very good and did not exceed y o o cpg even after 6 months at 5°C.

Furthermore, the bending strength and weight loss after heating at 00°C for 14 days were 9/- and 1.1%, respectively.
A good value of 7% was obtained. These results are shown in Table 2.

Example 3 2.0 parts of phenoxy resin with a molecular weight of about 30,000 and 9 parts of methylhimic anhydride (Hitachi Chemical product name) were added to 100 parts of GY-Co5 (product name, Ciba Co., Ltd. (l2)) as an epoxy compound. -2 parts, 70 parts of trimethylolpropane triacrylate, 70 parts of trihydroxyethyl isocyanurate trimethacrylate.

di-t-butyl hydroperoxide Q as a catalyst,
A low-viscosity impregnated resin was produced in the same manner as in Example 1, except that 0.3 parts of zinc octylate was added to a portion.

The initial viscosity of this impregnated resin was /00 Cps at 5°C.

Furthermore, an insulated coil was manufactured in the same manner as in Example 1.

When the ΔS and δ and the initial breakdown voltage were measured, it was found that Example 1
The emergency pressure was also good. These results are shown in Table 7.

Further, the pot life of the above-mentioned impregnated resin did not exceed po cps even after 6 months at z°C and was excellent under extreme pressure. These results are shown in Table 1.

Example DwR-33x (trade name of Dow Company) as a Hiro epoxy compound
100 copies, Ebiko) 1009 (Shell company product name)
To 10 parts, add 1 part of phenoxy resin with a molecular weight of about 30.000, 0 part, θ part of trihydroxyethyl isocyanurate triacrylate, IO part of styrene, and tS part of HN-2-〇〇 (trade name of Hitachi Chemical) as a catalyst. A low-viscosity impregnated resin was produced in the same manner as in Example, except that 0.1 part of dicumyl peroxide and 06.2 parts of zinc octylate were added. The initial viscosity of this impregnated resin is 2 parts at °C/, 20
It was Cps.

Furthermore, an insulated coil was manufactured in the same manner as in Example 1.

When ΔIAIIδ and initial breakdown voltage were measured, they were very good as in Example 1. These results are the first
Shown in the table.

Moreover, the pot life of the impregnated resin described in -H was very good and did not exceed tlo o cps even after 6 months at 2 parts C. These results are shown in Table 1.

Comparative example l GY-, 2 parts g (Ciba brand name) as an epoxy compound
Approximately 5 molecular weight per 100 parts? 0,000 phenoxy resin lj part, HN-co2OO (Hitachi Chemical brand name) go
@, trihydroxyethyl isocyanurate triacrylate 3! A low-viscosity impregnated resin was produced in the same manner as in Example 1, except that part rO, 100 parts of styrene, part of dicumyl peroxide O0 as a catalyst, and 0.3 parts of zinc octylate were added.

When the properties of this impregnated resin and the properties of the insulated coil were measured, the initial viscosity of the impregnated resin was 25°C / j Ocp
However, the pot life characteristics were extremely poor (exceeded θOcps after 30 days) because it exceeded the usage range of the phenoxy resin used for the impregnating resin.

In addition, the curing properties and properties of the insulated coil exceed the range of use for polyfunctional vinyl monomers.

The bending strength, heating weight loss, and electrical properties of the insulated coil were all very poor.

These results are shown in Tables 1 and 2. Comparative Example Coepoxy compound: Gy-, 2 parts g (Ciba brand name)
For 100 parts, HN-koλθO (Hitachi Chemical brand name)g
A low viscosity impregnated @j fat was produced in the same manner as in Example 1, except that part s was added and a part of coethyl and SuCI ly-methylimidazole (Shikoku Kasei brand name) Ol were added as catalysts.

When the properties of this impregnated resin and the properties of the insulated coil were measured, the initial viscosity was already BS at 2 parts °C.

cps, it was unsuitable as a room temperature impregnating resin.

In addition, since the initial viscosity is high even at the manufacturing stage of insulated coils,
Poor impregnation occurred and the electrical properties were very poor.

These results are shown in Tables 1 and 4. ＠/Table Characteristic thermal deterioration of insulated coils, 3)/kV/sheet? - Redundancy I:P-Measurement using a BL type viscosity needle at 25°C By using the The target is extremely large.

Claims (4)

[Claims] (1) A method for producing an insulated coil having an insulating layer formed by winding an insulating sheet with a porous insulating material as a backing material on a coil conductor, impregnating the wound layer with a low-viscosity impregnated resin, and forming the insulating layer under heat and pressure. , the low-viscosity impregnating resin is an epoxy compound containing at least two epoxy groups in one molecule;
For 100 parts by weight of this mixture of epoxy compound and curing agent, 5 parts of a polyfunctional vinyl monomer having two or more acrylic groups, methacrylic groups, or allyl groups in one molecule
A method for producing an insulated coil, characterized by using a low-viscosity impregnating resin produced by blending ~300 parts by weight and 0.1 to 10 parts by weight of a phenoxy resin. (2) The low-viscosity impregnating resin contains a vinyl monomer having one vinyl group in one molecule in an amount not exceeding 200 parts by weight per 100 parts by weight of a mixture of an epoxy compound and a curing agent for the epoxy compound. A method for manufacturing an insulated coil according to claim 1. (3) As a phenoxy resin, the molecular weight is 15,000~
The method of manufacturing an insulated coil according to claim 1, using a phenoxy resin in the range of 60,000. (4) Heating pressure molding conditions are heating temperature 100-250℃
, Pressure: 5-100kg/cm^2, Heating time: 4-2
The method for manufacturing an insulated coil according to claim 1 or 3, wherein the heating time is 4 hours.