JPH07256814A - Curing accelerator treated insulating sheet and production thereof - Google Patents

Abstract

PURPOSE:To provide a curing accelerator treated insulating sheet capable of holding a binder and a curing accelerator without mixing them and holding good preservability, taping workability and resin impregnation properties. CONSTITUTION:In a curing accelerator treated insulating sheet 1 composed of a composite material wherein a mica sheet and a fibrous base material are laminated by a binder layer and containing a curing accelerator of an epoxy resin, the fibrous base material 2 containing an epoxy resin as a binder and the mica sheet 3 containing zinc naphthanate dissolved in mineral oil being a solvent as the curing accelerator are laminated by an epoxy resin layer 4 being a binder layer. A method for producing the curing accelerator treated insulating sheet contains a process sprinkling a curing accelerator treatment soln. prepared by diluting zinc naphthanate dissolved in mineral oil with an org. solvent over the surface of the mica sheet 3 and a process blowing heated air to the surface of the fibrous base material 2 to evaporate the org. solvent in the mica sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hardening accelerator which is taped to a coil conductor of a high-voltage rotating electric machine as an insulating tape cut into a predetermined width, and is vacuum impregnated with an epoxy resin and heat-cured to form a main ground insulating layer The present invention relates to an agent-treated insulating sheet and a method for manufacturing the same.

[0002]

2. Description of the Related Art For impregnating an epoxy resin containing a curing agent composed of an acid anhydride into an impregnating resin, impregnating an insulating tape layer with vacuum pressure and heating and curing the same, for main insulation of a stator coil of a high voltage rotating electric machine. Is an insulating tape made of laminated mica sheet or peeled mica sheet (hereinafter referred to as mica sheet together) as a backing material on glass fiber sheet base material or polyester fleece base material with epoxy resin as a binder. A sheet cut into a predetermined width is used. This kind of insulating tape
There is known a curing accelerator-treated insulating tape (sheet) in which an organic acid metal salt, for example, zinc naphthenate, is preliminarily included in the insulating tape as a curing accelerator in order to accelerate the curing reaction of the impregnated resin. As a method of including a curing accelerator in the insulating tape, a solution of zinc naphthenate dissolved in an organic solvent such as cyclohexane is used as the accelerator treatment liquid, and the insulating tape is dipped in this, or the curing accelerator is applied to the epoxy resin. A method of manufacturing an insulating sheet using a binder mixed uniformly is known.

[0003]

In an insulating tape containing zinc naphthenate as a curing accelerator, the solubility of zinc naphthenate in cyclohexane as an organic solvent is poor, and a large amount of cyclohexane is required when preparing the accelerator treatment liquid. However, there is a problem in that it requires a long time for its preparation. In addition, in the method of immersing the insulating tape in the accelerator treatment liquid prepared in this way, the epoxy resin as a binder dissolves in a large amount of cyclohexane and flows out. And the mica pieces fall off during taping, or the insulating tape gradually hardens and the taping workability of the insulating tape deteriorates.For example, when using a taping machine, the taping machine There are inconveniences such as the number of revolutions of the head being limited to 80 rpm or less. Furthermore, when the curing accelerator is uniformly mixed with the epoxy resin to form a binder, the curing accelerator in the mixed state and the epoxy resin gradually react to cure the insulating tape, so that the usable life of the insulating tape ( (Storing period) becomes shorter, the tape does not fit well during taping work, and wrinkles occur, and the impregnated resin is impeded by the hardened binder to impregnate the impregnated resin, and impregnation is likely to occur. However, there is a need for improvement.

An object of the present invention is to provide a curing accelerator-treated insulating sheet which can retain a binder and a curing accelerator without being mixed with each other, and thus retains good storability, taping workability and resin impregnation property. Especially.

[0005]

In order to solve the above problems, according to the present invention, a mica sheet and a fibrous base material are bonded together by a binder, and a curing accelerator for an epoxy resin is used. In a curing accelerator treated insulating sheet containing, a fibrous base material containing an epoxy resin as a binder,
A mica sheet containing zinc naphthenate as a curing accelerator using a mineral oil as a solvent is bonded with an epoxy resin as a binder.

In the method for producing the curing accelerator-treated insulating sheet, the mica sheet is attached to the epoxy resin-coated side of the fibrous base material coated with the epoxy resin from one side, and then dissolved in mineral oil. A step of spraying a curing accelerator treatment liquid prepared by diluting a zinc naphthenate solution with an organic solvent from the surface side of the mica sheet, and blowing heated air from the surface side of the fibrous base material to evaporate the organic solvent in the mica sheet. And a step of performing.

It is assumed that a fibrous base material containing an epoxy resin as a binder is laminated on both sides of a mica sheet containing zinc naphthenate as a curing accelerator using mineral oil as a solvent. The method for producing a curing accelerator-treated insulating sheet, a mica sheet is attached to the epoxy resin-coated surface side of a fibrous base material coated with an epoxy resin from one surface, and then zinc naphthenate dissolved in mineral oil. A step of spraying a curing accelerator treatment liquid obtained by diluting the solution with an organic solvent from the surface side of the mica sheet, and a step of blowing heated air from the surface side of the fibrous base material to evaporate the organic solvent in the mica sheet. And a step of laminating a fibrous base material obtained by coating an epoxy resin on the surface of a mica sheet obtained by evaporating an organic solvent with the surface coated with the epoxy resin on the mica sheet side.

[0008]

In the present invention, a fibrous base material containing an epoxy resin as a binder and a mica sheet containing zinc naphthenate as a curing accelerator using mineral oil as a solvent are bonded together with an epoxy resin as a binder. Because
The resulting curing accelerator treated insulating sheet separates the portion containing zinc naphthenate as a curing accelerator and the portion containing an epoxy resin as a binder, and suppresses the curing reaction of the binder caused by mixing them. Therefore, it is possible to obtain a function of preventing deterioration of taping workability and deterioration of resin impregnation property due to curing of the tape and extending a usable period (storability).

In addition, the method for producing the curing accelerator-treated insulating sheet is such that a mica sheet is attached to the epoxy resin-coated side of a fibrous base material coated with epoxy resin from one side, and then the mineral oil is added. A step of spraying a curing accelerator treatment liquid prepared by diluting a dissolved zinc naphthenate solution with an organic solvent from the surface side of the mica sheet, and blowing heated air from the surface side of the fibrous base material to the organic solvent in the mica sheet. By including the step of evaporating, the amount of organic solvent for dilution can be greatly reduced by utilizing the property of zinc naphthenate that is easily dissolved in mineral oil, so that the curing applied from the surface side of the mica sheet The amount of accelerator processing liquid can be reduced to suppress the permeation to the side of the fibrous base material containing the binder, and heated air can be blown from the surface side of the fibrous base material to remove organic matter from the surface of the mica sheet By promoting evaporation of the agent, the ability to positionally separate the portion containing the epoxy resin as a partial and binder comprising zinc naphthenate is obtained.

Further, if a fibrous base material containing an epoxy resin as a binder is laminated on both sides of a mica sheet containing zinc naphthenate as a curing accelerator using mineral oil as a solvent, the mica pieces will come off. And a curing accelerator-treated insulating sheet excellent in taping workability can be obtained.
Further, the manufacturing method, the surface of the mica sheet evaporated organic solvent, by adding the step of bonding the epoxy resin-coated fibrous base material with the epoxy resin-coated surface on the mica sheet side. Can be easily achieved.

[0011]

EXAMPLES The present invention will be described below based on examples. FIG. 1 is a sectional view schematically showing a curing accelerator-treated insulating sheet according to an embodiment of the present invention. In the figure, a curing accelerator treated insulating sheet 1 comprises a fibrous base material 2 containing an epoxy resin as a binder, and a mica sheet 3 containing zinc naphthenate as a curing accelerator using mineral oil as a solvent.
The epoxy resin layer 4 as a binder is used as a composite material bonded together. In the curing accelerator-treated insulating sheet 1 thus configured, the binder containing zinc naphthenate as a curing accelerator and the epoxy resin as a binder are separated from each other, and the binder is generated by mixing them. Since the curing reaction of the tape is suppressed, deterioration of taping workability and resin impregnation due to the curing of the tape is prevented, and the usable life (storing period) of the tape is maintained from the conventional 3 months to 6 months. The effect of extending to one year is obtained.

FIG. 2 is an explanatory view schematically showing a method for producing a curing accelerator-treated insulating sheet according to an embodiment of the present invention, in which epoxy resin is applied from one surface to form a binder layer 4. The quality base material 2 is a zinc naphthenate solution dissolved in mineral oil (for example, machine oil) in a state where the step of attaching an untreated mica sheet 13, for example, an assembled mica sheet to the surface side coated with the epoxy resin is completed. An appropriate amount of the curing accelerator treatment liquid 15 diluted with an organic solvent (for example, cyclohexane) is sprayed from the front surface side of the untreated mica sheet 13 using the spraying device 16. Further, when the spraying step of the curing accelerator treatment liquid is completed, heated air 17 is blown from the hot air dryer 18 arranged on the surface side of the fibrous base material, and the untreated mica sheet 13 is in the process of permeating. The organic solvent in the curing accelerator treatment liquid 15 is evaporated. Therefore, when this step is completed, the fibrous base material 2 containing the epoxy resin as the binder, and the mica sheet 3 holding zinc naphthenate containing the mineral oil as the solvent as the curing accelerator,
A curing accelerator-treated insulating sheet 1 as a composite material obtained by pasting together with an epoxy resin layer 4 as a binder is obtained, and zinc naphthenate and the binder are mixed during the manufacturing process, and the curing reaction gradually progresses. It is possible to eliminate the conventional problem that the curing of the tape is accelerated, and improve the storability and taping processability.

According to the production method of the embodiment, the hardening accelerator whose content of cyclohexane for dilution is greatly reduced to about 1/4 of that of the conventional one by utilizing the property of zinc naphthenate which is easily dissolved in mineral oil. The treatment liquid can be easily prepared in a short time, and the amount of the curing accelerator treatment liquid sprayed from the surface side of the mica sheet is reduced to suppress the permeation of the treatment liquid into the binder 4 and the fibrous base material 2 side. At the same time, by blowing heated air from the surface side of the fibrous base material to promote the evaporation of the organic solvent from the surface of the mica sheet, the part 3 containing zinc naphthenate and the part containing epoxy resin as a binder are formed. It is possible to obtain the function of suppressing the curing reaction of the binder caused by mixing the two with each other and mixing them.

FIG. 3 is an explanatory view schematically showing a curing accelerator-treated insulating sheet and a manufacturing method thereof according to another embodiment of the present invention. The curing accelerator after the hot air drying step in the manufacturing method shown in FIG. 2 is completed. As described above, the step of attaching the fibrous base material 2 coated with the epoxy resin to the surface of the mica sheet 3 containing the curing accelerator of the treated insulating sheet 1 with the epoxy resin layer 4 side facing the mica sheet 3 side is added. Is different from the embodiment described above. The curing accelerator-treated insulating sheet 10 thus obtained covers both sides of the mica sheet 3 containing the curing accelerator with the fibrous base material 2 containing the binder to maintain its flexibility and at the time of taping work. In order to prevent the scattered mica pieces and peeled mica pieces from scattering, a curing accelerator-treated insulating sheet with excellent taping workability can be obtained. For example, the rotation speed of the taping head by a taping machine can be changed from the conventional 80 rpm to 280 rpm.
And the effect of improving taping work efficiency is obtained, and the stator coil of the high-voltage rotating electric machine obtained by impregnating the taping layer with epoxy resin under vacuum pressure and heating and curing has less occurrence of partial discharge. It was demonstrated that the taping layer has excellent resin impregnation property. The obtained stator coil of the high-voltage rotating electric machine contains a small amount of mechanical oil added as a solvent for zinc naphthenate therein,
It was also confirmed that the amount thereof is small and does not adversely affect the curing reaction of the impregnated resin.

[0015]

As described above, the present invention provides a curing accelerator-treated insulating sheet comprising a bonding material of a mica sheet and a fibrous base material, wherein zinc naphthenate as a curing accelerator is added to mineral oil on the mica sheet side. It was configured to be contained in a dissolved state and to contain an epoxy resin as a binder on the fibrous base material side.
As a result, it is possible to suppress the hardening of the tape caused by the mixture of zinc naphthenate and the epoxy resin, prevent the deterioration of taping workability and resin impregnation property, and maintain the flexibility of the tape during the useful life ( It is possible to provide a curing accelerator-treated insulating sheet having a long-term storage property in which the storage period) is extended from the conventional three months to six months to one year.

Further, by dissolving zinc naphthenate in mineral oil and then diluting it with an organic solvent, the amount of the organic solvent in the accelerator treatment liquid is reduced to about 1/4 of the conventional amount, and this is sprayed from the mica sheet side. The curing accelerator-treated insulating sheet is configured to promote the evaporation of the organic solvent by blowing heated air from the fibrous base material side while permeating the mica sheet with a curing accelerator in the manufacturing process. It is possible to avoid mixing with a binder, and it is possible to provide a curing accelerator-treated insulating sheet having a long usable life period and excellent in taping workability and resin impregnation property.

Further, if the curing accelerator-treated insulating sheet and the manufacturing method thereof are configured so that the binder-treated fibrous base material is bonded to both sides of the curing accelerator-treated mica sheet, the flexibility is maintained for a long period of time. , Since it can prevent the mica pieces from peeling off during the taping work, for example, it provides a curing accelerator-treated insulating sheet that can accelerate the rotating speed of the taping head to about 3.5 times that of the conventional type and improve the taping efficiency of the rotating electric machine coil. can do.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a curing accelerator-treated insulating sheet according to an embodiment of the present invention.

FIG. 2 is an explanatory view schematically showing a method for producing a curing accelerator-treated insulating sheet according to an embodiment of the present invention.

FIG. 3 is an explanatory view schematically showing a curing accelerator-treated insulating sheet according to another embodiment of the present invention and a manufacturing method thereof.

[Explanation of symbols]

1 Curing Accelerator Treated Insulation Sheet 2 Fibrous Base Material (Binder Retaining Section) 3 Mica Sheet (Curing Accelerator Retaining Section) 4 Binder Layer (Epoxy Resin Layer) 10 Curing Accelerator Treated Insulation Sheet 13 Untreated Mica Sheet 15 Curing accelerator treatment liquid (zinc naphthenate, mineral oil,
Cyclohexane) 16 Spraying device 17 Heated air 18 Hot air dryer

Claims (4)

[Claims] 1. A composite material comprising a mica sheet and a fibrous base material bonded together with a binder, which contains a curing accelerator for an epoxy resin, and a fibrous base material containing an epoxy resin as a binder. A curing accelerator-treated insulating sheet, which is obtained by bonding a mica sheet containing zinc naphthenate as a curing accelerator using mineral oil as a solvent with an epoxy resin as the binder. 2. A fibrous base material coated with an epoxy resin from one surface thereof is pasted with a mica sheet on the epoxy resin coated surface side, and then a zinc naphthenate solution dissolved in mineral oil is diluted with an organic solvent. Characterized in that it includes a step of spraying the curing accelerator treatment liquid from the surface side of the mica sheet, and a step of blowing heated air from the surface side of the fibrous base material to evaporate the organic solvent in the mica sheet. A method for producing the curing accelerator-treated insulating sheet according to claim 1. 3. A fibrous base material containing an epoxy resin as a binder, which is laminated on both sides of a mica sheet containing zinc naphthenate as a curing accelerator using mineral oil as a solvent. The curing accelerator-treated insulating sheet according to 1. 4. A mica sheet is attached to the epoxy resin-coated surface side of a fibrous base material coated with epoxy resin from one surface, and then a zinc naphthenate solution dissolved in mineral oil is diluted with an organic solvent. A step of spraying the curing accelerator treatment liquid from the surface side of the mica sheet, a step of blowing heated air from the surface side of the fibrous base material to evaporate the organic solvent in the mica sheet, and evaporating the organic solvent. 4. A curing accelerator-treated insulating sheet according to claim 3, further comprising a step of laminating a fibrous base material having an epoxy resin applied on the surface of the mica sheet with the epoxy resin applied surface facing the mica sheet. Manufacturing method.