JP3103089B2 - Heat resistant coil - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to improvements in heat-resistant coils, and more particularly, to heat-resistant coils having improved heat resistance and insulation properties.

(Prior art) Conventionally, as a wire having excellent heat resistance, a conductor having a heat-resistant insulating film formed by applying a paint mainly composed of an organometallic polymer such as a polyborosiloxane resin on a conductor and baking it. in use. When such a heat-resistant electric wire is used for a coil, an electric wire obtained by baking the above paint in an undercured state so as to have excellent flexibility is formed into a coil shape by coil winding or the like, and then heated. Is impregnated with the same paint as the paint for forming an insulating coating film (see Japanese Patent Application Laid-Open No. 58-212114).

However, in such a coil according to the conventional method, the solvent in the varnish acts on the insulating layer in the process of impregnation with the varnish for impregnating treatment. However, there is a problem that the melting and blistering of the coil cannot be avoided, so that the insulation of the coil is significantly reduced. Further, in order to minimize the dissolution and blistering of the insulating layer, a method of heating the entire coil before the impregnation treatment and curing the insulating coating film has been proposed, but the process is complicated, The disadvantage is that production takes time.

(Problems to be Solved by the Invention) In view of the above points, the present invention significantly improves the insulation performance by preventing the insulation coating from dissolving and blistering while maintaining good heat resistance of the coil. An object is to provide a small number of heat-resistant coils having excellent productivity.

(Means for Solving the Problems) The present invention provides, on a conductor, a polyborosiloxane resin,
Heat-resistant electrical insulation in which one or more resins selected from the group consisting of polycarbosilane resin, polysilastyrene resin, polytitanocarbosilane resin, and polysilazane resin and an inorganic filler are dissolved or dispersed in a solvent. An insulated wire made by coating and baking paint on a conductor is formed into a coil shape,
In a heat-resistant coil obtained by impregnating the whole with an impregnating paint, the impregnating paint has a weight loss of 100% by weight or less when heated at 400 ° C. for 24 hours, and 100% by weight or less of mica 100 to 100% by weight. The present invention relates to a heat-resistant coil having 600 parts by weight as a main component.

The insulated wire used for the heat-resistant coil of the present invention is produced by applying and baking a conductor with a heat-resistant electric insulating paint obtained by dissolving or dispersing the following components in a solvent.

That is, a polyborosiloxane resin, a polycarbosilane resin, a polysilastyrene resin, a polytitanocarbosilane resin, and a polysilazane resin each have a metal element such as silane, titanium, or boron in a main chain and a methyl group in a side chain. A polymer having excellent heat resistance to which an organic group such as a phenyl group is bonded may be used. These resins can be used alone or in combination of two or more.

In addition, an insulating inorganic filler is added to this paint for the purpose of improving the heat resistance and insulation properties of the obtained electric wire. These insulating inorganic fillers include magnesium oxide, alumina, zirconium oxide, calcium oxide, iron oxide, boron oxide, chromium oxide, titanium oxide, silica, mica,
Oxide ceramics such as talc, potassium titanate, thorium oxide, uranium oxide, zirconium silicate, silicon carbide, titanium carbide, zirconium carbide, titanium boride, zirconium boride, titanium nitride, boron nitride, aluminum nitride, silicon nitride And non-oxide ceramics such as molybdenum silicide, various glass powders, etc., and these can be used alone or as a mixture. When these insulating inorganic fillers are added to the coating material, the amount is preferably 5 to 300 parts by weight based on 100 parts by weight of the resin.

The heat-resistant electric insulating coating of the present invention is obtained by dissolving or dispersing the above components in an organic solvent such as xylene, toluene, N-methyl-2-pyrrolidone, or dimethylformamide or silicone oil, and stirring, or It is manufactured by mixing or dissolving or dissolving in a solvent of the above to form a liquid. The heat-resistant electric insulating paint thus obtained has the same properties as an organic paint at room temperature, and is easy to handle and easy to impregnate and apply. Then, if the firing is completed after the impregnation or the application, the organic group of the side chain is eliminated, and finally, it becomes semi-ceramic and exhibits excellent heat resistance.

The heat-resistant electric insulating coating of the present invention may contain, in addition to the above-mentioned components, other known additives as long as the effects of the present invention are not impaired.

The heat-resistant electric wire according to the present invention is produced by applying the heat-resistant electric insulating paint directly on the conductor or via another insulating layer, and firing the coating to have a flexibility capable of forming a coil.

Also, at this time, an inorganic fiber or tape such as glass or ceramic is wound on the insulating coating film made of the heat-resistant electric insulating paint, or these are impregnated with the heat-resistant electric insulating paint or the like before winding. For example, an inorganic fiber winding may be used.

The heat-resistant coil of the present invention is formed into a coil shape by winding the flexible heat-resistant electric wire manufactured as described above on the coil core, and then the whole is formed in the impregnating paint described below. It is manufactured by impregnating and heating appropriately to cure the layer of impregnating paint.

The impregnating coating material of the present invention contains an organopolysiloxane composition whose weight loss upon heating at 400 ° C. for 24 hours is 10% by weight or less and mica as main components, and is used by appropriately dissolving or dispersing them in a solvent. This organopolysiloxane composition has a low decomposition and volatile content even when heated at a temperature of 400 ° C. for 24 hours. In the case of a silicone varnish (paint), the solidified content of the paint excluding the solvent is as described above. Any silicone varnish can be used as long as the silicone varnish is of a solvent type or a non-solvent type. Specifically, a silicone varnish having 100% methyl groups in the side chain of organopolysiloxane (TSR127B, manufactured by Toshiba Silicone Co., 9.8% by weight after heating at 400 ° C. for 24 hours) or an alkenyl-group-containing organo-organic liquid at room temperature Silicone varnish made by mixing polysiloxane and organohydrogenpolysiloxane (weight ratio about 100: 5) and an inorganic filler (for example, silica, talc, metal hydrate, etc.) (manufactured by Dow Corning Toray Silicone Co., Ltd.) AY49-208, weight loss after heating at 400 ° C. for 24 hours 8.4% by weight). The latter (AY49-208) is 20
When heated at a temperature of 0 ° C. or less, first, the alkenyl group-containing organopolysiloxane and the organohydrogen polysiloxane react with each other to proceed with crosslinking to form a rubber-like cured product, which is further heated at a temperature of 350 ° C. or more. Due to this, the thermal decomposition reaction of the crosslinked silicone polymer, the bonding reaction between the thermal decomposition product and the inorganic filler progresses, and finally a hard ceramic-like cured product is obtained. is there.

In the impregnating paint of the present invention, 150 to 300 parts by weight of mica is added to 100 parts by weight of such a specific organopolysiloxane composition. By adding a predetermined amount of mica, it is possible to significantly prevent the occurrence of cracks in the cured portion of the impregnating paint after coil production, and it has good adhesion to the insulated wire and reduces the occurrence of peeling. . On the other hand, if the addition amount exceeds 300 parts by weight, the varnish viscosity becomes high, and it becomes difficult to perform the impregnation treatment.

(Action) Since the heat-resistant coil of the present invention uses an insulated wire provided with an insulating coating film made of the above-mentioned heat-resistant electric insulating paint, the wire itself has extremely excellent heat resistance and impregnation. The weight loss of the paint for treatment when heated at 400 ° C for 24 hours is 10
Since it is composed of the organopolysiloxane composition of not more than weight% and mica, the heat resistance of the electric wire itself does not decrease. In addition, this impregnating coating does not adversely affect the insulation coating of the insulated wire, such as swelling or dissolution, even if the heating step conventionally performed before the impregnation is omitted. Has been improved. Further, foaming does not occur after the coating material for impregnation treatment is cured by heating.

(Example) An example of the present invention will be described.

Example 1 A heat-resistant electric insulating coating obtained by dissolving a polyborosiloxane resin and an inorganic filler in N-methyl-2-pyrrolidone was applied on a nickel-copper conductor and baked in a flexible state (finished heat-resistant electric wire). (1 mm in diameter) was wound on a coil core. Next, this was mixed with the above-mentioned AY49-208 (resin content of 400 ° C).
The resin was impregnated with 100 parts by weight of a resin component (weight loss after heating for 24 hours and 8.4% by weight) and 100 parts by weight of mica, and then dried by heating at 50 ° C. for 8 hours to produce a heat-resistant coil.

The insulation resistance value and the breakdown voltage value of the obtained heat-resistant coil were measured at the initial stage and after heating at 400 ° C. for 72 hours, respectively. The results are shown in the table together with the coil appearance after heating at 400 ° C for 72 hours.

Examples 2 to 4 Using the impregnating paint in which each component was blended in the proportions shown in the table,
Otherwise, a heat-resistant coil was manufactured in the same manner as in Example 1.
The obtained heat-resistant coil was tested in the same manner as in Example 1.
The results are shown in the table.

Comparative Examples 1 to 3 As a comparison, a resin using a silicone varnish (trade name: TSR116, manufactured by Toshiba Silicone Co., Ltd.) having a weight loss of 43.0% by weight after heating at 400 ° C. for 24 hours (Comparative Example 1). In addition, examples were shown in which the amount of mica in the impregnating paint was too small (Comparative Example 2), and in which the glass powder was mixed instead of mica in the impregnating paint (Comparative Example 3). The obtained coil was tested in the same manner as in Example 1. The results are shown in the table.

(Effects of the Invention) As described above, the heat-resistant coil of the present invention, while maintaining good heat resistance, prevents dissolution and blistering of the insulating coating film of the insulated wire, greatly improves the insulating performance, and improves the impregnated coating film. Cracks and peeling can be prevented from occurring.

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Claims (1)

(57) [Claims] An inorganic filler comprising one or more resins selected from the group consisting of a polyborosiloxane resin, a polycarbosilane resin, a polysilastyrene resin, a polytitanocarbosilane resin, and a polysilazane resin, on a conductor. Insulated wire formed by applying and baking a conductor with a heat-resistant electrical insulating paint obtained by dissolving or dispersing the agent in a solvent and forming a coil, and the entire heat-resistant coil impregnated with the paint for impregnation,
The above-mentioned impregnating paint has an organopolysiloxane composition having a weight loss of 10% by weight or less after heating at a temperature of 400 ° C. for 24 hours.
A heat-resistant coil mainly comprising 0 parts by weight and 100 to 600 parts by weight of mica.