JP2000011763A - Insulated wire and manufacture of coil using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulated wire, having self-lubricating properties, excelling in the ability to be worked into a coil, high in impregnation varnish coatability, capable of being worked into a coil under strict conditions if an insulation film is thinned down, and capable of being treated with an impregnation varnish satisfactorily, and a manufacturing method of a coil capable of being treated with an impregnation varnish satisfactorily by using the self- lubricating insulated wire. SOLUTION: This insulated wire has at least one insulating layer formed by applying/baking an insulation coating material on a conductor, and an anti- friction material layer formed by applying/baking thereon an anti-friction material including wax and a thermosetting resin, and the anti-friction material to be applied includes a rosin resin and/or a maleic resin of 3 to 20 wt. portions per 100 wt. portions of solid content of the anti-friction material, and this method is for manufacturing a coil by winding the insulated wire into a coil and treating it with an impregnation varnish.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated wire used as a coil for a motor or a generator. More specifically, the present invention relates to an insulated electric wire having both good coil workability and good impregnating varnish coatability, and a method for manufacturing a coil using the same.

[0002]

2. Description of the Related Art Insulated wires covered with an electrical insulator are used in large quantities for applications in coils incorporated in various electric devices. In recent years, the speed and rationalization of this insulated wire coil winding process have been promoted, and the coil winding operation has been shifted from conventional manual winding to processing by an automatic coil winding machine. However, when performing this automatic coil winding processing,
Since a large tension is applied to the insulated wire and the work is performed at a high speed, the stress of the coating is large, and the insulated wire is inevitably easily damaged. For this reason, layer shorts,
Insufficient insulation of the coil, such as ground failure, is likely to occur.

Further, when forming the coil, increasing the space factor of the insulated wire in the status lot in the coil as much as possible results in downsizing of the entire device and cost reduction. There is a demand for diameter reduction. In recent years, as the diameter has been reduced, the diameter of the conductor has been required to be fixed or increased for the purpose of further increasing the power of equipment, and the thickness of the insulating film has been required to be reduced. However, reducing the thickness of the insulating coating increases the frequency of coating damage during the coil processing (coil winding operation and insertion into the status lot), thereby increasing the rate of occurrence of coil insulation failure. In order to solve the above-mentioned problems, objects that come into contact with each other, or objects that come into contact with the wires (metal rods, phase paper, etc.)
It is conceivable that the friction coefficient of the film decreases and the film strength improves.
The lower the coefficient of friction, the easier the coil winding operation, and the higher the coating strength, the less the damage during coil processing.

As a means for reducing the friction coefficient, a method of applying a lubricant to the surface of an electric wire or a method of adding a lubricant to an insulating paint and baking the same is known. As a method of improving the coating strength, an insulated wire coated with a polyamide-imide paint and baked is usually used. This wire has higher mechanical strength and better wear resistance than other resins (polyester, polyurethane, polyester imide, polyester amide imide, polyimide), so it is often used when coil processing conditions are severe. Was.

[0005] Therefore, when coil winding is performed under severe conditions, enameled wires having a coating obtained by applying and baking the above-mentioned polyamide-imide paint as an insulating layer and further lubricating the surface layer are widely used. . In recent years, since a significant decrease in friction coefficient and improvement in wear resistance can be expected for this lubrication treatment, lubricating paints (lubricants) in which wax and a thermosetting resin are dispersed in water have been used. Have been.

However, since the enameled wire using this lubricant has a wax and a thermosetting resin baked on the surface of the electric wire, it is impregnated with a varnish treatment (after winding the enameled wire in a coil shape, filling the space between the wires). When the enameled wire is unified with a varnish, the surface of the electric wire repels the varnish depending on the type of the varnish. When impregnated varnish treatment is performed, the wire will not be separated by the vibration of the motor, etc.Also, the wound of the enamel wire generated by coil processing can be sealed, but if the wire surface repels the varnish, the adhesion to the enamel wire will decrease. This makes the wire easier to separate, and makes it harder to seal the wound of the enameled wire, so that insulation failure is more likely to occur. In the manufacture of motors and generators, the wire is damaged during the process of pushing the wire into the slot, but if the varnish is not firmly adhered to the surface, the wire will not be sealed and many pinholes will occur. Becomes The fact that the surface of the electric wire repels varnish is a problem in the manufacture of motors and generators. This problem occurs when either a solvent-type varnish or a solvent-free varnish is used. Particularly, a solvent-free powder epoxy resin-based varnish is easily repelled. It has been found that this phenomenon also changes depending on the conditions for baking the lubricant on the enameled wire. In general, as the baking is performed at a high temperature and a high speed, the electric wire surface is more likely to repel varnish. Therefore, it has been difficult to apply a lubricating treatment by a method with high productivity and to provide an electric wire surface that does not repel varnish.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a self-lubricating property, excellent coil workability, high impregnating varnish coating property, and coil processing under severe conditions even if the insulating film is thinned. It is an object of the present invention to provide an insulated electric wire which can perform the varnish treatment favorably and can perform the immersion varnish treatment favorably. Further, an object of the present invention relates to a method for manufacturing a coil in which an impregnating varnish treatment can be favorably performed using a self-lubricating insulated wire.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above-mentioned problems, and as a result, by adding a predetermined amount of a rosin resin and / or a maleic acid resin to a lubricant used for lubricating a surface. The inventor has found that an insulated wire having a surface that does not repel varnish with improved impregnating varnish coatability can be obtained, and the present invention has been accomplished based on this finding. That is, the present invention provides (1) at least one insulating layer formed by applying and baking an insulating paint on a conductor, and a lubricating agent formed by applying and baking a lubricant containing a wax and a thermosetting resin. An insulated wire having a lubricant layer, wherein the applied lubricant comprises 3 to 20 parts by weight of a rosin-based resin and / or a maleic acid-based resin per 100 parts by weight of a lubricant solid content. (2) The insulated wire according to (1), wherein the insulating paint for forming the insulating layer comprises a polyamideimide resin, and (3) the insulated wire according to (1). It is intended to provide a method for manufacturing a coil, comprising winding an insulated wire into a coil and performing an impregnating varnish treatment.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The insulated wire of the present invention has at least one insulating layer and a lubricant layer on a conductor. The conductor is not particularly limited, and may be a commonly used conductor. In the present invention, the insulating layer can be formed by applying and baking an insulating paint by an ordinary method. As the insulating paint, a commonly used one can be used, and specifically, for example, comprises one or more kinds selected from polyvinyl formal, polyurethane, polyester, polyesterimide, polyesteramideimide, polyamideimide, polyimide and the like. The insulating layer may be a single layer,
Two or more layers may be formed by combining two or more kinds of paints.

In the present invention, it is preferable to use a polyamideimide resin paint as the insulating paint in order to improve the strength of the insulating layer. The base resin of the polyamide-imide resin paint at this time is not particularly limited, and may be obtained by a conventional method, for example, by directly reacting a tricarboxylic anhydride and a diisocyanate in a polar solvent, or
A product obtained by first reacting a diamine with a tricarboxylic anhydride in a polar solvent, introducing an imide bond, and then amidating with a diisocyanate can be used.

As the tricarboxylic anhydride used for preparing the resin, trimellitic anhydride is usually used.
In this case, the reaction may be carried out by replacing a part of the tricarboxylic anhydride with a tetracarboxylic anhydride. As the tetracarboxylic anhydride at this time, for example, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride or the like is used. Further, a part of the tricarboxylic anhydride may be replaced with another acid or an acid anhydride such as trimellitic acid, isophthalic acid, terephthalic acid and the like. On the other hand, diisocyanates to be reacted with tricarboxylic anhydride include, for example, 4,4 ′
-Diphenylmethane diisocyanate, aromatic diisocyanates such as tolylene diisocyanate,
As diamines, m-phenylenediamine, 4,4 ′
Aromatic diamines such as -diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, and 4,4'-diaminobenzophenone. Further, N-methyl-2-pyrrolidone can be preferably used as the polar solvent.

Further, in order to improve the adhesion between the insulating layer and the conductor, the polyamideimide-based resin coating may contain a trialkylamine or an alkoxylated melamine resin. As the trialkylamine, lower alkyl trialkylamines such as trimethylamine, triethylamine, tripropylamine and tributylamine can be preferably used. Of these, trimethylamine and triethylamine are most preferable in terms of flexibility and adhesion. Further, as the alkoxylated melamine resin, for example, a melamine resin substituted with a lower alkoxy group such as a butoxylated melamine resin and a methoxylated melamine resin can be used, and a methoxylated melamine resin is preferable in terms of resin compatibility. The insulating layer with high adhesion to such a conductor is used as the lowermost layer, and an insulating layer of another composition is formed, or an intermediate layer is formed to prevent external stress from being transmitted to the lowermost layer. A layer may be provided.

In the insulated wire of the present invention, the thickness of the insulating layer is not particularly limited, but is usually 20 to 40 μm, preferably 25 to 35 μm. Further, the baking treatment of the insulating paint is a process obvious to those skilled in the art, and conditions such as temperature can be appropriately determined according to the type of the insulating paint to be used, the thickness of the insulating layer, and the like. When used, a baking temperature of 400 to 500 ° C. can be adopted as a preferable condition.

The insulated wire of the present invention has a lubricant layer on the surface layer of the above-mentioned coating layer having at least one insulating layer. This lubricant layer can be formed by applying and baking a lubricant containing a rosin-based resin and / or a maleic acid-based resin together with a wax, a thermosetting resin or the like. The lubricant is usually prepared by mixing an aqueous dispersion of a wax and an aqueous alkali solution of a thermosetting resin. In the present invention, the rosin-based resin and / or the maleic acid-based resin are further mixed with, for example, an alcohol solution or an alkali solution. Mix as an aqueous solution.

In this lubricant, waxes commonly used in lubricants can be used without any particular limitation, for example, natural waxes such as carnauba wax, beeswax, cadelilla wax, rice wax, paraffin wax,
Synthetic waxes such as polyethylene wax and montan wax are exemplified. From the viewpoint of abrasion resistance and slipperiness of the insulated wire, it is preferable to use wax as hard as possible. The ratio of the wax and the thermosetting resin in the lubricant is not particularly limited, but the weight ratio of the wax / resin is 30 / 70-
It is preferably 70/30. The thermosetting resin has a function of fixing the wax when the lubricant is baked. In the present invention, a thermosetting resin usually used for a lubricant can be used, and for example, a shellac resin and a phenol resin can be suitably used.

In the present invention, a rosin-based resin and / or a maleic acid-based resin are further contained in the lubricant. Examples of the rosin-based resin and / or maleic acid-based resin that can be used in the present invention include rosin, rosin-modified maleic resin, and styrene-maleic acid resin. The rosin resin and the maleic acid resin preferably have an acid value of 80 or more. If the acid value is too low, the resin becomes insoluble in the alcohol and the aqueous alkali solution cannot be prepared, so that it may be difficult to mix the resin with the lubricant. In the present invention, the addition amount of the rosin-based resin and / or the maleic acid-based resin is usually 3 to 20 parts by weight based on 100 parts by weight of the solid content of a normal lubricant except for the rosin-based resin and / or the maleic acid-based resin. Parts, preferably 5-1
5 parts by weight. If the rosin-based resin and / or the maleic acid-based resin is less than 3 parts by weight, the coatability of the impregnated varnish will not be sufficiently improved, and if it exceeds 20 parts by weight, the paint stability of the lubricant will be impaired. In the present invention, by adding a predetermined amount of the rosin-based resin and / or the maleic acid-based resin to the lubricant layer, the curing of the thermosetting resin of the lubricant itself is suppressed, and the fixation of the lubricant layer is appropriately performed. It is thought to weaken, and the impregnating varnish coatability is high,
In the impregnating varnish treatment, a powder type varnish can be formed into an insulated electric wire having a smooth surface which can be applied well.

In the insulated wire of the present invention, the thickness of the lubricant layer is not particularly limited, but is preferably 1 to 2 μm. Also,
The total coating thickness is also not particularly limited, but is preferably 25 to 35 μm. The baking treatment of the lubricant coating is also obvious to those skilled in the art, and the conditions such as the temperature are appropriately determined according to the linear velocity and the like, but are preferably performed at a temperature in the range of 300 to 500 ° C.

In the method of manufacturing a coil according to the present invention, the method of winding the coil is not particularly limited, and the coil can be wound by ordinary automatic coil winding. Since the insulated wire of the present invention used in the method of the present invention is excellent in coil workability, it is possible to perform automatic coil winding work under severe conditions. The shape and type of the coil are not particularly limited. When the insulated varnish treatment of the insulated wire of the present invention is carried out, it can be carried out well by a method using a liquid varnish or a method using a powder type varnish. For example, even if a powder epoxy resin-based varnish, which has conventionally been easily repelled by lubricated electric wires, is used, the electric wires are sufficiently fixed and there is no problem such as the wires being separated.

[0019]

Next, the present invention will be described in more detail with reference to examples. In each of the examples and comparative examples, the baking of the insulating paint was performed at 500 ° C., and the baking of the lubricant paint was performed at 500 ° C.
C. was performed. Example 1 Commercially available lubricant paint TEC9601 (trade name, manufactured by Toshiba Chemical Corporation, consisting of carnauba wax and shellac resin)
Rosin-modified maleic acid resin (acid value 300, Marquid 33 (trade name, manufactured by Arakawa Chemical Industry Co., Ltd.))
5 parts by weight with respect to 100 parts by weight of the total solid content of No. 1 were stirred at room temperature to obtain a lubricant coating No. 1. Commercially available polyamide-imide resin paint HI406 on a 1.0 mmφ copper wire
(Trade name, manufactured by Hitachi Chemical Co., Ltd.) is applied and baked a plurality of times using a vertical hot air baking machine with a furnace length of 8 m, and the coating thickness is 30 μm.
Was formed. A lubricant coating No. 1 was applied and baked once thereon to form a lubricant layer having a coating thickness of 2.0 μm, and an insulated wire having a total coating thickness of 32 μm was obtained.

Example 2 A lubricant coating No. 1 'was obtained in the same manner as in Example 1 except that the amount of the rosin-modified maleic resin was changed to 10 parts by weight based on 100 parts by weight of the total solid content of TEC9601. Was. An insulating layer was formed on a copper wire in the same manner as in Example 1, and an anti-friction paint No.
An insulated wire of 2 μm (insulating layer 30 μm, lubricant layer 2.0 μm) was obtained.

Example 3 Instead of rosin-modified maleic resin, styrene maleic resin (acid value 200, Alastar 700 (trade name, manufactured by Arakawa Chemical Industries, Ltd.)) was added in an amount of 5 parts by weight based on 100 parts by weight of the total solid content of TEC9601. A lubricant coating No. 2 was obtained in exactly the same manner as in Example 1 except that the above parts were used. An insulating layer was formed on a copper wire in the same manner as in Example 1, and a lubricant coating No. 2 was applied on top of this.
Apply and bake once to obtain a total coating thickness of 32 μm (insulating layer 30 μm).
m, lubricant layer 2.0 μm).

Example 4 The same styrene-maleic acid resin as in Example 3 was used in place of the rosin-modified maleic resin, and the total solid content of TEC9601 was 10%.
A lubricant coating No. 2 'was obtained in exactly the same manner as in Example 1, except that 10 parts by weight was used per 0 parts by weight. An insulating layer was formed on a copper wire in the same manner as in Example 1, and a lubricant paint N was formed thereon.
o.2 'was applied once and baked to obtain an insulated wire having a total coating thickness of 32 µm (insulating layer 30 µm, lubricant layer 2.0 µm).

Example 5 A rosin resin (China rosin (trade name, manufactured by Arakawa Chemical Industry Co., Ltd.)) was used instead of the rosin-modified maleic acid resin, using TEC960.
A lubricant coating No. 3 was obtained in exactly the same manner as in Example 1 except that 5 parts by weight was used per 100 parts by weight of the total solids. An insulating layer was formed on a copper wire in the same manner as in Example 1, and an anti-friction paint No. 3 was applied and baked once on the copper wire to obtain a total coating thickness of 32.
An insulated wire having a thickness of 30 μm (insulating layer 30 μm, lubricant layer 2.0 μm) was obtained.

Example 6 Lubrication was performed in exactly the same manner as in Example 1 except that the same rosin resin as in Example 5 was used instead of the rosin-modified maleic resin and 10 parts by weight based on 100 parts by weight of the total solid content of TEC9601. A paint No. 3 'was obtained. An insulating layer was formed on a copper wire in the same manner as in Example 1, and a lubricant coating No. 3 'was applied and baked once thereon to form a total coating thickness of 32 µm (insulating layer 30 µm,
An insulated wire having a lubricant layer (2.0 μm) was obtained.

Example 7 A commercially available adhesive-made improved polyamideimide resin paint HI406A (trade name, manufactured by Hitachi Chemical Co., Ltd.) was applied and baked on a 1.0 mmφ copper wire a plurality of times using a vertical hot-air baking machine having a furnace length of 8 m. Then, a lower insulating layer having a thickness of 30 μm was formed. The same lubricant coating No. 1 as in Example 1 was applied thereon and baked once to form a lubricant layer having a coating thickness of 2.0 μm.
An insulated wire having a total coating thickness of 32 μm was obtained.

COMPARATIVE EXAMPLE 1 An insulating layer was formed on a copper wire in the same manner as in Example 1, and a commercially available lubricant paint TEC9601 was applied once and baked to obtain a total coating thickness of 32 μm (insulating layer 30 μm, reduced 1. Lubricant layer
0 μm). Comparative Example 2 The same rosin-modified maleic resin as used in Example 1 was used for a commercially available lubricant paint TEC9601.
2 parts by weight based on 100 parts by weight of the total solids, and stirred at room temperature to obtain a lubricant coating No. 4. An insulating layer was formed on a copper wire in the same manner as in Example 1, and a lubricant coating No. 4 was formed thereon.
Is applied once and baked to give a total coating thickness of 32 μm (insulating layer 30).
.mu.m, lubricant layer 2.0 .mu.m).

Comparative Example 3 The same rosin-modified maleic resin as used in Example 1 was used in a commercially available lubricant paint TEC9601.
Was added to 100 parts by weight of the total solid content, and stirred at room temperature to obtain a lubricant coating No. 5. An insulating layer was formed on a copper wire in the same manner as in Example 1, and a lubricant coating No.
5 is applied once and baked to form a total coating thickness of 32 μm (insulating layer 3
0 μm, a lubricant layer 2.0 μm) was obtained.

Example 8 The following tests were performed on the insulated wires obtained in Examples 1 to 7 and Comparative Examples 1 to 3. The results are shown in Table 1. Paint Stability Each of the lubricant paints used in Examples 1 to 7 and Comparative Examples 1 to 3 was left at room temperature for 7 days, and evaluated by the presence or absence of precipitation. ：: No precipitation occurred ×: Precipitation occurred Static friction coefficient Measured according to the test method of JIS K 7125. Abrasion resistance (reciprocating type) Measured by the test method of the former JIS C 3003. Impregnating varnish coatability An insulated wire is tightly wound around a 6.5 mm mandrel to produce a 75 mm long helical coil, which is then 190
After preheating at ℃, it was immersed in an epoxy resin-based powder varnish (Epiform F290 (trade name, manufactured by Somar)), pulled up, and thermally cured at 180 ° C. The appearance of the coil was visually observed and evaluated as follows. ：: The varnish adhered uniformly and the surface was smooth. Δ: There is a portion where varnish has been repelled, and a portion having unevenness and a portion having a smooth surface are mixed. ×: The varnish was repelled, and the entire surface was uneven. Varnish coating adhesive strength A helical coil was prepared in the same manner as above, and
After preheating at 90 ° C., it was immersed in an epoxy resin powder varnish, pulled up, and thermally cured at 180 ° C. For this coil, the adhesive force of the varnish coating film at room temperature was measured by a method according to ASTM-D-2519.

[0029]

[Table 1]

As is clear from the results in Table 1, Example 1
The insulated wires obtained in Steps 7 to 7 have good abrasion resistance and excellent coil workability, and the varnish is uniformly adhered to the surface when the coil is treated with a powder epoxy resin varnish. Had high adhesion. The coil obtained by the method of the present invention had little coating damage due to coil winding, and the wires were sufficiently fixed with varnish. On the other hand, in the insulated wires of Comparative Examples 1 and 2, the phenomenon of repelling the varnish on the surface in the coil impregnation varnish treatment was observed, and the adhesion of the varnish coating film was low. In the insulated wire of Comparative Example 3, the varnish adhered without being partially repelled, but the adhesive strength was lower than that of the example and was not sufficient. Further, the lubricant paint No. 5 used in Comparative Example 3 was poor in stability, and a precipitate was formed 7 days after the preparation.

[0031]

The insulated wire according to the present invention has a self-lubricating property that can withstand severe coil processing conditions and has excellent impregnating varnish coating properties. Therefore, the insulated wire of the present invention enables the impregnating varnish treatment of a self-lubricating enameled wire, which was conventionally insufficient or difficult to impregnate varnish treatment. Therefore, if a coil is formed by performing an impregnation varnish treatment after winding the coil using such an insulated wire, a coil having excellent wear resistance, coil workability, and excellent varnish fixability can be obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5G305 AA02 AA11 AB18 AB34 AB36 BA09 BA25 CA06 CA24 CA27 CA41 CA46 CB28 CB29 CD15 DA11 DA22 5G309 CA05 MA03 MA16 5G313 AB03 AC02 AC03 AD04 AE01 AE05

Claims (3)

[Claims] An at least one insulating layer formed by applying and baking an insulating paint on a conductor, and a lubricating agent layer formed by applying and baking a lubricant containing wax and a thermosetting resin. Wherein the lubricant to be applied comprises 3 to 20 parts by weight of a rosin-based resin and / or a maleic acid-based resin per 100 parts by weight of a lubricant solid content. Insulated wires. 2. The insulated wire according to claim 1, wherein the insulating coating for forming the insulating layer contains a polyamideimide resin. 3. A method for manufacturing a coil, comprising: winding the insulated wire according to claim 1 in a coil and performing an impregnation varnish treatment.