JPS5829701B2 - Denchiyakuzetsuenhouhou - Google Patents

Description

Detailed Description of the Invention This invention uses an aqueous dispersion containing an inorganic powder such as mica powder and an aqueous dispersion type varnish, and uses an electrophoresis method to coat an electrical conductor with an inorganic powder content of 80% (weight φ or less). Similarly) above strand insulating layer (first electrodeposited layer) and a ground insulating layer (second electrodeposited layer) having an inorganic content of 70 to 99φ are formed, and furthermore, an organic The present invention relates to an electrodeposition insulation method for, for example, rotating machine coils, in which wire insulation and ground insulation are simultaneously performed by impregnating an insulating paint or an inorganic insulating paint.

A method is known in which a tape or sleeve made of woven fabric or non-woven fabric made of inorganic or organic aggregate is provided on the conductor to be coated, and then electrodeposition is applied in water-dispersed varnish. However, in this method, the properties of the insulating film depend on the properties of the water-dispersed varnish, so there are concerns about heat resistance, mechanical properties, and electrical insulation, especially when used at high temperatures.

Furthermore, in the conventional method, taping work is essential for forming the insulating layer, which requires a lot of manpower, resulting in poor work efficiency and high cost.

This invention solves all of the various drawbacks associated with conventional insulating layer formation, improves the heat resistance, mechanical properties, electrical properties, etc. of the insulating film, and creates an electrodeposited insulated conductor with high reliability in electrical insulation performance. The present invention provides an easily obtainable electrodeposition insulation method.

That is, the present invention uses an aqueous dispersion of inorganic powder to coat a conductor with a high inorganic content (80% or more) by electrophoresis.
After forming a first electrodeposited layer and removing water by heating, a second electrodeposited layer having an inorganic content of 70 to 99% is applied to the coated object by bundling or polymerizing the first electrodeposited layer and applying an electrophoretic method. A deposited layer is formed, and after heating, an organic insulating paint or an inorganic insulating paint is impregnated into all the voids of the electrodeposited layer formed by this electrophoresis method, so that the whole is integrated. It forms a strong insulating film.

The necessary conditions for the first electrodeposited layer are that it can be electrodeposited when immersed in the electrodeposition paint again after heating, and that it has at least the mechanical strength necessary for handling in the subsequent process. This is largely determined by the mineral content in the electrodeposited layer.

Although it is related to the thickness of the electrodeposited layer, the inorganic content is 80%.
If it is less than 75, it becomes necessary to extremely increase the electrodeposition voltage during post-electrodeposition, and if it is less than 75, electrodeposition becomes impossible.

The thickness of the electrodeposited layer is determined by the withstand voltage characteristics between the bare edges, but it is required to be at least 2 to 7 or more, so it should be 80 to 1.
20μ is adopted.

A necessary condition for the second electrodeposited layer is that the organic or inorganic insulating paint can be impregnated up to the wire insulation.

When the inorganic content is 70% or less, there are fewer voids in the inorganic powder layer, making it difficult for the insulating paint to impregnate.

In addition, if the inorganic content in the electrodeposited layer exceeds 99, the mechanical strength of the electrodeposited layer becomes weak, so the inorganic content in the ground insulating layer should be 70 to 99, particularly preferably 75 to 98.
The excellent range is appropriate.

Mica powder is particularly preferably used as an inorganic substance in electrodeposition baths used for rotating machine coils, heat-resistant electric wires, and fire-resistant electric wires, since not only insulating performance but also mechanical strength and flexibility of the deposited layer are required. For rotating machine coils and structural insulators that do not require flexibility, inorganic powders other than mica powder, or a mixture of mica powder and inorganic powders, may be used.

Examples of the inorganic powder include inorganic powders such as chopped glass fiber, glass powder, silica powder, and alumina powder.

When mica powder is used as the inorganic powder, the wire insulation part,
The size of the mica powder scales in the electrodeposited layer in both the ground insulation part and the electrodeposited layer is as follows:
The selection is made taking into consideration the mechanical strength of the electrodeposited layer, the impregnability of the insulating paint, the electrodepositivity, etc., but if the mica powder scales exceed a certain size (20 mesh or less), the electrodeposit will fail. Mica powder scales having a size of 20 mesh or more are used because the mica scales electrically block electrically and a thick film cannot be obtained.

Regarding electrodeposition voltage, a voltage of 10 V to 100 V is used for the primary electrodeposition coating, and a considerably higher voltage for the secondary electrodeposition coating compared to the first electrodeposition coating, i.e. 50V
300V is applied.

The reason for this is that the first electrodeposited layer becomes an electrically blocking layer and mica powder scales do not electrophoresis at low voltage.

Conventional electrodeposition insulation methods using only water-dispersed varnish have various properties that depend on the performance of the water-dispersed varnish used for electrodeposition, so there is an urgent need to develop varnishes with good properties. At present, a desirable water-dispersed varnish with good heat resistance that can be applied to the insulation of child coils has not yet appeared.

In the method of the present invention, the performance of the insulating film is determined by the insulating paint used to impregnate the insulating film, but by selecting an insulating paint suitable for the purpose, an insulating film having excellent properties can be easily formed.

Furthermore, as described above, no taping work is required to form the insulating layer, which greatly improves productivity.

Furthermore, while conventional electrodeposition insulation methods require an organic solvent as a coagulant during film formation, this invention uses mica powder as the main ingredient, eliminating the need for organic solvents. The step curing step can be omitted, and the drying time can be reduced to about 1/10 to 115 times.

As the water-dispersed varnish used in this invention, the following various synthetic resin water-dispersed varnishes can be used.

For example, polyurethane resin varnish, polyester resin varnish, epoxy resin varnish, epoxy ester resin varnish, polyimide resin varnish, polyamideimide resin varnish, polyesterimide resin varnish, acrylic resin varnish, etc. can be used as appropriate for this electrodeposition insulation. It is used as an electrodeposition coating method.

In addition, the organic insulating paint for impregnation used in this invention includes epoxy resin varnish, polyamideimide resin varnish, silicone resin varnish, polyimide resin varnish, etc., which have good heat resistance, and the inorganic insulating paint includes For example, phosphoric acid-based paints such as an aqueous solution of primary phosphates of metals (At, Mg, Zn, etc.), silica-based paints such as colloidal silica (for example, ``Snowtechs'' manufactured by Nirasan Chemical Co., Ltd.) are electrodeposited in this electrodeposition insulation method. Used as an insulating coating to be impregnated into layers.

Also, since the impregnating property is a question, the viscosity of the insulating paint to be impregnated should be approximately 1000 cp (centimeter, poise) and 50 to 50.
800 cp is most commonly used.

There are no particular restrictions on the material of the electrodeposited object, that is, the conductor, as long as it is an electrical conductor, and there are no particular restrictions on the shape of the conductor; for example, it may be a linear object, a rod-like object, a plate-like object, etc. There may be.

The insulation method of the present invention will be described below with reference to Examples.

Note that parts and parts in Examples are parts by weight.

[Example 1] Water-dispersed acrylic-epoxy resin varnish (■-550
-20 varnish (manufactured by Ryoden Kasei) was mixed with mica powder of 100 meshes or more thoroughly washed with water at a ratio of 9 parts to 1 part of the resin content of the water-dispersed varnish, stirred well, and electrodeposited uniformly. Adjusted the paint.

A rotating machine armature coil shaped into a hexagonal shape was used as an anode, and a stainless steel plate was immersed as a cathode in this adjusted electrocoating paint, and a DC voltage of 50V was applied to 8
A first electrodeposited layer (
A layer (hereinafter referred to as "mica layer") was precipitated.

Next, this coil was taken out from the electrodeposition paint and heated at 230°C for 15 minutes to remove moisture and reduce the film thickness to 0.
．． A film of 10 fi was obtained.

Next, six coils that had been subjected to the above heat treatment were bundled together and immersed in the electrodeposition paint as an anode, and the distance between the electrodes was 15 (15 in m).
A DC voltage of 0 V was applied for 10 seconds to electrophoretically form a second electrodeposited layer on the coil.

Next, take this coil out of the electrodeposition paint and heat it to 230℃.
After heat treatment for 30 minutes at
-590-15 varnish (trade name, manufactured by Ryoden Kasei, epoxy resin) was vacuum impregnated for 1 hour and taken out, and then heat treated at 150°C for 15 hours to a film thickness of 0.45711I.
An electrodeposited insulating film having a substantially uniform coating of Il was obtained.

The wire dielectric breakdown voltage of the electrodeposited insulating film was 9.5 (■), and the dielectric breakdown voltage to ground was 23 KV or higher.

[Example 2] The same water-dispersed varnish as in Example 1 above was prepared by washing thoroughly with water.
Electrodeposition paint with a total non-volatile content of 13%, which is made by adding ion-exchanged water to a solution in which 8 to 80 meshes of mica powder is mixed in a ratio of 9 parts to 1 part of water-dispersed varnish resin and thoroughly stirring to uniformly disperse the mixture. adjusted.

An armature coil for a rotating machine shaped into a hexagonal shape was immersed in the adjusted electrodeposition paint as an anode, and the distance between the electrodes was 15Cr.
A first mica layer was deposited on the coil by applying current for 15 seconds at IL170.

This coil was then heat-treated at 230° C. for 15 minutes to obtain a film with a film thickness of o and osm.

Furthermore, four coils subjected to the above electrodeposition treatment were bundled and dipped in the electrodeposition paint as an anode, and the distance between the electrodes was 15 (1'1).
A second electrodeposited layer was provided on the coil by applying current at lloOV for 55 seconds.

After heat-treating this coil, it is impregnated with Hl-400 varnish (trade name, manufactured by Hitachi Chemical, polyamide-imide-imide resin) and heat-treated to form an electrodeposited insulation film with a nearly uniform coating thickness of 1 m. A film was obtained.

The wire dielectric breakdown voltage of the electrodeposited insulating film was 9 KV, and the dielectric breakdown voltage to ground was 7 in 50 or more.

[Example 3] A water-dispersed varnish containing 77 parts of bisphenol-type epoxy resin, 3 parts of ethylene glycol, and 20 parts of tetrahydrophthalic anhydride as a resin of a water-dispersed varnish was mixed with thoroughly washed mica powder having a mesh size of 35 or more. 9 for 1 part
Ion-exchanged water was added to the mixed solution at a ratio of 1.5 parts, and the mixture was thoroughly stirred to prepare an electrodeposition paint having a total non-volatile content of 15 φ and uniformly dispersed.

An armature coil for a rotating machine shaped into a hexagonal shape was immersed in the adjusted electrodeposition paint as an anode, and the distance between the electrodes was 15Cr.
A first mica layer was deposited on the coil by applying current at rL, 20V for 25 seconds.

This coil was then heat-treated at 230° C. for 15 seconds to obtain a film with a thickness of 0.11M.

Further, six coils subjected to the above electrodeposition treatment were bundled and dipped in the electrodeposition paint as an anode, and the distance between the electrodes was 15 CIrL.
A second mica layer was deposited on the coil by applying current at 200V for 60 seconds.

Next, after heat-treating this coil, the electrodeposited layer was coated with Norimide 102 varnish (trade name, Nippon Ropeia Clothing).
The electrodeposited insulating film was impregnated with a polyimide resin (polyimide resin) and heat-treated to obtain an electrodeposited insulating film having a substantially uniform coating film with three film thicknesses.

The wire dielectric breakdown voltage of the electrodeposited insulating film was 8 KV, and the dielectric breakdown voltage to ground was 7 in 80 or more.

[Example 4] Mica powder of 100 mesh or more was mixed in at a ratio of 9 parts to 1 part of the resin content of Lefton RK-6308, an acrylic water-dispersible varnish manufactured by Du Pont, and thoroughly stirred to uniformly disperse the mixture. An electrodeposition paint with a total non-volatile content of 30% was prepared.

A rotating machine armature coil formed in a hexagonal shape was immersed in the adjusted electrodeposition paint as an anode, and the distance between the electrodes was 15Cr.
A first mica layer was deposited on the coil by applying current at 50 V IL for 9 seconds.

This electrodeposited material was then heat-treated at 230° C. for 15 minutes to obtain a film having a thickness of 0.1M.

Further, six coils subjected to the above electrodeposition treatment were bundled and dipped in the electrodeposition paint as an anode, and the distance between the electrodes was 15 crIL.
A second mica layer was deposited on the coil by applying current at 1300 μm for 25 seconds.

Then, after heat-treating this electrodeposited material, V is applied to the electrodeposited body.
-590-15 varnish (trade name, manufactured by Ryoden Kabo Co., Ltd., epoxy resin) was impregnated and heat treated to obtain an electrodeposited insulating film having a thickness of 2M and having a substantially uniform coating.

The strand dielectric breakdown voltage of the electrodeposited insulating film was 10.1, and the dielectric breakdown voltage to ground was 65 KV or more.

[Example 5] An armature coil for a rotating machine having a hexagonal bottom shape was immersed as an anode in the same electrodeposition bath as in Example 1, and the distance between the poles was 15 cIrL1.
A first mica layer was deposited on the coil by applying current for 4 seconds at 100 μm.

This electrodeposited material was then heat-treated at 230° C. for 15 minutes to obtain a film having a thickness of 0.1 M.

Furthermore, four tortoiseshell-shaped coils subjected to the above electrodeposition treatment were bundled together and immersed in the electrodeposition paint as an anode, and the distance between the electrodes was 15.
A second mica layer was deposited on the coil by applying current at 1Z77Z1150V for 45 seconds.

After heat-treating this coil, the electrodeposited body is impregnated with colloidal silica (trade name: "Snowtex 30J, manufactured by Nissan Chemical Co., Ltd."), which is an inorganic insulating coating, and heat-treated to form a film with a thickness of 2 cm. An electrodeposited insulating film with a nearly uniform coating was obtained.

The wire dielectric breakdown voltage of the electrodeposited insulating film was 8 KV, and the dielectric breakdown voltage to ground was 60 mm or higher.

Furthermore, according to the method of this embodiment, all water-dispersed varnishes such as polyurethane resin varnish, polyester resin varnish, and polyimide resin varnish can be applied.
These also showed almost the same characteristics as the examples.

As described above, according to the present invention, a first electrodeposited layer having an inorganic powder content of 80% or more is formed on a conductor, and a plurality of the above electrodeposited materials are bundled and the inorganic powder content is After forming the second electrodeposited layer of 70 to 99 mm, the electrodeposited film is impregnated with an insulating coating, which greatly improves productivity and improves thermal, mechanical, and electrical properties. The present invention provides an electrodeposited insulation method for forming an electrodeposited insulation film of any thickness with good physical properties.

Claims (1)

[Claims] 1. Using an aqueous dispersion containing an inorganic powder and a water-dispersed varnish as an electrodeposition paint, forming a first electrodeposition layer having an inorganic content of 80% by weight or more on a conductor using an electrophoresis method, After heating this to remove moisture, a plurality of conductors having the first electrodeposited layer are polymerized and further immersed in electrodeposition paint, so that the inorganic content is 70 to 99% by weight on the conductor. An electrodeposited insulation method, which comprises forming a second electrodeposited layer, heating it to remove moisture, and then impregnating the electrodeposited layer with an organic or inorganic insulating paint.