JPH03115478A - Insulating coating material and insulated wire - Google Patents

Abstract

PURPOSE:To obtain an insulating coating material having good heat resistance and processability and capable of forming a film excellent in surface lubricity by mixing a coating material composed mainly of a polyamide-imide resin soluble in a phenolic solvent with a specified polyimide resin soluble in a phenolic solvent at a specified ratio. CONSTITUTION:An insulating coating material formed by mixing a coating material (A) composed mainly of a polyamide-imide resin soluble in a phenolic solvent with a polyimide resin (B) soluble in a phenolic solvent, obtained by reacting an aromatic tetracarboxylic acid and/or its derivative, a higher fatty acid and/or its derivative, and an aromatic diamine so as to provide a weight ratio of A to B of (95:5) to (70:3). In addition to components A and B, a theic- modified polyester-imide resin (C) may be incorporated in an amount sufficient to provide a weight ratio of A:B:C of (90:5:5) to (50:30:20).

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention relates to an insulating paint that can form a coating film with good heat resistance, process resistance, etc. and excellent lubricity, and the like. This invention relates to an insulated wire made by applying and baking an insulating paint directly onto a conductor or through another insulating layer.

(Prior Art) Polyamide-imide wires, polyesterimide/polyamide-imide double-coated wires, and the like have been used as insulated wires with little processing deterioration and good heat resistance.

Incidentally, in recent years, electrical equipment manufacturers have been using high-speed automatic wire winding machines to speed up the manufacturing of equipment, but all of the above insulated wires have poor surface lubricity, and during the winding process, Due to mechanical damage to the insulating coating,
It was not possible to use such a high-speed automatic winding machine. Therefore, it is desired to improve the surface lubricity of such electric wires.

Conventionally, in order to improve the surface lubricity of insulated wires,
A liquid lubricant such as liquid paraffin or refrigerating machine oil, or a solid lubricant such as solid paraffin or carnauba wax is applied onto the outermost insulating coating.

(Problem to be solved by the invention) However, in the method of applying liquid lubricant, it is difficult to apply the lubricant uniformly, and it is easy for dust etc. to adhere to the surface. The problem was that it did not improve much.

Furthermore, although the method of applying solid lubricants improves lubricity and slipperiness compared to liquid lubricants, it is difficult to apply uniformly, and the solvent that dissolves the lubricant may cause crazing on the insulating coating. was there. Furthermore, when insulated wires coated with solid lubricant are used in refrigerator motors, etc., the lubricant is extracted by the refrigerant, resulting in a decrease in lubricity and the extracted lubricant being transferred to the compressor valve and refrigerant outlet. There was a risk that it would get stuck in the mouth, etc. and reduce the refrigeration ability.

In recent years, as a method of imparting lubricity to the surface of insulated wires, an insulating paint containing powder of synthetic resin with excellent lubricity such as polyethylene, polypropylene, or polytetrafluoroethylene is applied and baked onto the conductor. A method is proposed.

However, with this method, the synthetic resin powder used is poorly soluble in solvents, making it difficult to uniformly disperse it in the insulating paint, lacking stability as a paint, and making it difficult to obtain electric wires with a good appearance. The problem is that there is no.

In addition, an insulating paint whose main component is polyamide-imide resin, which contains polyamide-imide modified by bonding a straight-chain alkyl group to the end of the molecular chain, has been developed.By applying this paint to the outermost layer and baking it, the surface Insulated wires with improved lubricity have been developed.

However, in such insulated wires, it is not possible to increase the degree of polymerization of the modified polyamide-imide base resin very much, it is difficult to increase the blending ratio of linear alkyl groups, and the flexibility of the coating film is not sufficient. There is a problem.

The present invention was made to solve these conventional problems, and provides an insulating paint that can form a coating film that has good heat resistance, process resistance, etc. and excellent lubricity, and an insulating paint that can form a film that has excellent heat resistance, process resistance, etc. The object of the present invention is to provide an insulated wire coated and baked with heat resistance, process resistance, and lubricity significantly improved.

[Structure of the Invention] (Means for Solving the Problems) The insulating paint of the present invention comprises (A) a paint whose main component is a phenolic solvent-soluble polyamideimide resin, and (B) (
a) aromatic tetracarboxylic acid and/or its derivative; (b) higher fatty acid and/or its derivative;
C) A phenolic solvent-soluble polyimide resin obtained by reacting it with an aromatic diamine, the ratio of the polyamide-imide resin (A) to the polyimide resin (B) is 95:5 to 70:30 by weight. Alternatively, these (A) and (B) components may be further mixed with (C).
) Saic modified polyesterimide resin, (A) polyamideimide resin, (B) polyimide resin and (C)
It is characterized by being mixed with Saic-modified polyesterimide resin in a weight ratio of 90:5:5 to 50:30:20.

Further, the insulated wire of the present invention is characterized in that such an insulating paint is baked onto the conductor either directly or via another insulating layer.

In the present invention, the coating material (A) mainly composed of a phenolic solvent-soluble polyamideimide resin may contain at least 5 mol% of dicarboxylic acid as disclosed in JP-A-81-1.30322, for example. or a tricarboxylic acid anhydride or a derivative thereof, and one or two of polyisocyanates or derivatives thereof.
The product obtained by heating and reacting at least 1:1 equivalent ratio in a phenolic solvent such as phenol, cresol, xylenol, or petroleum naphtha in the coexistence of a polyamide resin is used. Ru.

Further, as the polyimide resin soluble in the phenolic solvent (B), for example, (a) at least 30 mol% of 3.3'', 4,4-benzophenonetetracarboxylic acid (BT) or its derivatives (anhydrides and Contains lower alkyl ester.The same applies to the acid components below.

) containing an aromatic tetracarboxylic acid or its derivative;
(b) a higher fatty acid or a derivative thereof; and (C) at least 30 mol % of the following general formula (wherein X 1icI12 , O1, SO2, C(CH3
) 2 or S, and R is a monovalent organic group selected from a lower alkyl group, a lower alkoxyl group, a COOH group, an OH group, a 5O31 (group, or a halogen. The same applies hereinafter) A resin obtained by subjecting an aromatic diamine including a diamine represented by .) to a heating reaction is used.

Here, the aromatic tetracarboxylic acids other than BT in (a) include pyromellitic acid, 3.3-. 4.4-diphenyltetracarboxylic acid, 3.3-. 4.4--Diphenyl ether tetracarboxylic acid, bicyclooctene-2,3,
Examples include 5,8-tetracarboxylic acid and naphthalenetetracarboxylic acid.

Further, the higher fatty acids (b) include tocosanoic acid, tricosanoic acid, tetracosanoic acid, pentacosanoic acid, hexacosanoic acid, etc., and especially monk's wax acid (carbon number 28 to
Hoechst wax (manufactured by Hoechst Javan Co., Ltd.) based on 32) or its derivatives is preferably used.

Further, (c) of the above-mentioned general formula [N[IIco[II
An example of a diamine with a special structure represented by [ ] is 3
．． V-diaminodiphenylmethane, 3.3'-diaminodiphenyl ether, 3.3-diaminodiphenylsulfone, 3.3=-diaminodiphenylpropane, 3.
3"-diaminodiphenyl sulfide, 3.3"-dimethyl-4,4-diaminodiphenyl ether, 3. F
'-dimethyl4.4'-diaminodiphenylmethane, 2
．． 4-diaminotoluene, 2.6diaminotoluene,
l-isopropyl-2,4-metaphenylenediamine,
1-dioxy-2,4-diaminobenzene, 2.4-
Diaminobenzoic acid, 2.6-diaminobenzoic acid, 2.4
-diaminophenol, 2,6-diaminophenol,
1-sulfo-264-diaminobenzene, ■-sulfo 2,6-diaminobenzene, ■-chloro2.4-
Examples include diaminobenzene.

In addition, aromatic diamines other than these special diamines include 4.4-diaminodiphenylmethane, 4.4'-
Diaminodiphenylpropane, 4.4-diaminodiphenyl sulfide, 4.4-diaminodiphenylsulfone, 4.4=-diaminodiphenyl ether, 1.
Examples include 5-diaminonaphthalene.

In order to obtain the polyimide resin soluble in the phenolic solvent (B) by reacting these components, the acid component and the diamine component are blended in an equivalent ratio of approximately 1:1, and the
1. At a temperature of 80°C. -Heat for several hours.

This reaction is suitable for phenol, cresol, xylenol, etc. because it is easy to control and because the reaction product can be directly added to the paint containing the polyamideimide resin (A) as a main component. It is preferable to carry out the process in a phenolic solvent.

In the insulating paint of the present invention, the mixing ratio of (A) the polyamide-imide resin paint and (B) the polyimide resin soluble in a phenolic solvent is 95:5 to 7 in weight ratio of the resin components.
The range is 0:30.

If the blending ratio of the resin (B) is less than 5% by weight (hereinafter simply referred to as %), the effect of improving the lubricity of the insulating coating film will not be obtained, and the heat resistance will also be insufficient. On the other hand, if the blending ratio of the resin (B) exceeds 30%, one resin component in the coating material will separate, resulting in poor stability and reduced flexibility of the insulating coating film.

In the insulating paint of the present invention, in addition to the same components (A) and (B), the Saic-modified polyesterimide resin (C), which is blended as a third component, has THEr in its molecular structure.
It is a polyesterimide containing C [tris-(2-hydroxyethyl)isocyanurate], which is usually produced by the method shown below and is commercially available as an insulating coating.

In other words, an imide group is added to a part of the Saic-modified polyester (trade name: Isonel, manufactured by Schenectady, USA), which is obtained by introducing a cyanuric ring into Alcanex (manufactured by GE, USA), which is a glycerin crosslinked polyester resin paint. or polyesterimide resin paint obtained by introducing imide groups into Alkanex (
It can be obtained by a method such as further introducing a cyanuric ring into Dr. Beck Co., Ltd. (trade name: Telebeck Pl+).

In the present invention, among such saic-modified polyesterimide resins, for example, Isomid 40SH (
(manufactured by Solar Eclipse Schenectady Chemical Co., Ltd.), TVE 5385
(manufactured by Toshiba Chemical Corporation), TI (E I
It is suitable to use one in which the content of C is in the range of 5 to 80 mol % based on the total resin content.

In addition, the mixing ratio of the same components of (A) and (B) above and such saic modified polyesterimide resin should be in the range of 90:5:5 to 50:30:20 in weight ratio of resin components. is desirable.

If the blending ratio of these components is out of the above range, the resin components will separate and the paint will become unstable.

Furthermore, it is not possible to obtain an insulated wire that is well-balanced and excellent in various properties such as surface lubricity, heat resistance, flexibility, workability, and refrigerant resistance.

In order to manufacture an insulated wire from the insulating paint of the present invention, the insulating paint is coated on the conductor directly or via another insulating layer and baked to form a lubricating insulating layer at least on the outermost side.

In particular, when a saic modified polyesterimide resin paint or a normal polyesterimide resin paint is applied and baked on a conductor to form a lower insulating layer, and the insulating paint of the present invention is applied and baked on top of that, more excellent properties are obtained. An insulated wire is obtained.

That is, it has good adhesion, further excellent heat resistance and insulation properties, and has significantly improved refrigerant resistance.

(Function) In the insulating paint of the present invention, (A,) a paint whose main component is a phenolic solvent-soluble polyamideimide resin, (B) (a) aromatic tetracarboxylic acid and/or its derivative, and ( b) A phenolic solvent-soluble polyimide resin obtained by reacting a higher fatty acid and/or its derivative with (C) an aromatic diamine, or further mixed with (C) a saic-modified polyesterimide resin at a predetermined ratio. Because of this, it has excellent stability as a paint, and the resin content does not separate even after long-term storage.

In addition, the insulated wire of the present invention, which is made by applying and baking such an insulating paint directly onto the conductor or through another insulating layer, has excellent surface lubricity and can be coil-wound using a high-speed automatic winding machine. This will not cause any damage to the paint film. Furthermore, it has excellent heat resistance, process resistance, flexibility, refrigerant resistance, electrical and mechanical properties, etc.

(Example) Examples of the present invention will be described below.

Example 1 Trimellitic anhydride 9.6 g (0.05 mol) Isophthalic acid 8.3 g (0.05 mol), diphenylmethane diisocyanate 25.0 g (0.1 mol), Nylon 66 (Amilan CMIO07 East) company product name) 4.0g,
30 g of cresol was reacted at 200 to 210° C. for 10 hours while removing generated carbon dioxide gas, and then 80 g of cresol was added to stop the reaction. After returning to room temperature, 5 g of block MDI (Millionate MS-50, trade name of Nippon Polyurethane Co., Ltd.) was added, and further diluted with cresol to obtain a mixture with a non-volatile content of 30.0% and a viscosity of 49.0 Poise (30').
A polyamideimide resin solution (A) of C) was obtained.

Also, 30.6 g of 3.3-4.4=-benzophenonetetracarphonic dianhydride (BTDA)
(0,095 mol), 5.0 g of montan wax acid, and 22.8 g (0.10 mol) of 3,3-dimethyl-4,4'-diaminodiphenylmethane were reacted in 145 g of m-cresol with distilled water. 1.60℃ while removing
The reaction was carried out for 3 hours at a temperature of 0.42 (0.5
A polyimide resin solution (B) of %m by weight in cresol was obtained.

Next, these polyamide-imide resin solution (A) and polyimide resin solution (B) were mixed at a resin solid content ratio of 80:20.
The resin content is 29.3% and the viscosity is 58P.
oise (30°C) insulation paint was obtained.

The resulting insulating paint had good stability, and the resin component did not separate even after being left at room temperature for two months.

Also, apply this insulating paint on a conductor with a diameter of 1.000 mm.
Saic modified polyesterimide resin TVE5385 is coated and baked using a conventional method at a viscosity of 58 Poisc (30°C) to form a lower insulating layer, and then coated on top of the lower insulating layer. Speed 12.
Baked under conditions of 0m7 minutes, finished outer diameter 1.084mm
An insulated wire with a ratio of upper layer/lower layer of 3/7 was obtained.

Example 2 Polyamideimide resin solution (A) used in Example 1,
! ：、、Ho IJ Garbage Fm Fat-soluble M (B) ト、TVE
5385 at a resin solid content ratio of 70:20:10, the resin concentration was 30.1%, and the viscosity was 55 Poi.
se (30°C) insulation paint was obtained.

The resin component of the obtained insulating paint did not separate even after being left at room temperature for two months.

Next, apply this insulating paint to a diameter of 1 in the same manner as in Example 1.
．． Coated and baked on the two-digit TvE5385 coated and baked layer on the 000II11 conductor, resulting in a finished outer diameter of 1.084 mm.
An insulated wire was obtained.

The characteristics of the insulated wires of Example 1 and Example 2 thus obtained were as shown in the following table.

The surface slipperiness was expressed as a coefficient of static friction.

For comparison, a coated and baked layer of TVE 5385 was provided on the conductor, and a polyamide-imide resin solution (A
) and an insulated wire formed by coating and baking only a layer of TVE 5385 (Comparative Example 2), and an insulated wire having only a coating and baking layer of TVE 5385 on the conductor (Comparative Example 2), and the results were the same. Shown in the table.

(hereinafter referred to as "Kinpaku") [Effects of the Invention] As is clear from the above examples, the insulating paint of the present invention has good stability, and the resin component does not separate even after long-term storage.

In addition, by applying and baking this insulating paint, it improves heat resistance, processing resistance, electrical insulation, mechanical properties, flexibility,
It is possible to form an insulating coating film with good abrasion resistance, good refrigerant resistance, etc., and very good lubricity.

An insulated wire coated with such an insulating paint and baked has significantly improved lubricity as well as heat resistance and processing resistance.

Claims (4)

[Claims] (1) (A) A paint whose main component is a phenolic solvent-soluble polyamideimide resin, (B) (a) an aromatic tetracarboxylic acid and/or its derivative, and (b) a higher fatty acid and/or its derivative. and (c) an aromatic diamine, and a phenolic solvent-soluble polyimide resin obtained by reacting the polyimide resin (A) and the polyimide resin (B) in a weight ratio of 95:5 to 95:5.
An insulating paint characterized by being mixed in a ratio of 70:30. (2) (A) A paint whose main component is a phenolic solvent-soluble polyamideimide resin, (B) (a) an aromatic tetracarboxylic acid and/or its derivative, and (b) a higher fatty acid and/or its derivative. and (c) a phenolic solvent-soluble polyimide resin obtained by reacting with an aromatic diamine, and (C) a saic-modified polyesterimide resin, and a polyamide-imide resin of (A) and a polyimide resin of (B). The ratio of (C) to Saic modified polyesterimide resin is 90:5:5 to 5 by weight.
An insulating paint characterized by being mixed in a ratio of 0:30:20. (3) An insulated wire characterized in that the insulating paint according to item 1 is applied and baked onto a conductor directly or via another insulating layer. (4) An insulated wire characterized in that the insulating paint according to item 2 is applied and baked onto a conductor directly or via another insulating layer.