JPH10130479A - Electrical insulating resin composition and enameled wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical insulating resin compsn. which has a good chemical peelability and characteristics not degradable and to provided an enameled wire obtd. by using the same. SOLUTION: This compsn. contains a polyester resin obtd. by reacting a polyhydric alcohol component contg. 5-10 equivalent % cyclohexanedimethanol and 50-60 equivalent % triol with a polybasic acid component contg. 8-100 equivalent % terephthalic acid and/or its alkyl ester in an excess ratio of alcohol of 30-60%. The compsn. is applied to a conductor and baked to give an enameled wire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition for electrical insulation and an enameled wire.

[0002]

2. Description of the Related Art Conventionally, as a resin composition for electrical insulation, especially a resin composition for enameled wire, various properties such as mechanical properties, electrical properties, heat resistance and the like are relatively well balanced. It is used. However, from the viewpoint of recent rationalization and productivity improvement, terminal processing,
That is, there is a demand for a polyester varnish that has good chemical release and does not decrease the above-mentioned various properties. Conventionally, in order to improve the chemical releasability, techniques such as reducing the molecular weight, reducing the amount of the curing agent, and introducing a long-chain methylene structure into the resin structure have been adopted. Inferior properties such as heat resistance.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and provides a resin composition for electrical insulation which has good chemical releasability and does not degrade various properties. It is. The invention according to claim 2 provides an enameled wire coated with the above-mentioned resin composition for electrical insulation.

[0004]

According to the present invention, (A) cyclohexane dimethanol is used as a polyhydric alcohol component in an amount of 5 to 10%.
The polyhydric alcohol component containing 50 to 60 equivalent% of triol and the polybasic acid component containing 80 to 100 equivalent% of (B) terephthalic acid and / or its alkyl ester are mixed with an alcohol excess ratio of 30 to 60%. The present invention relates to a resin composition for electrical insulation containing a polyester resin obtained by reacting within a range, and an enameled wire obtained by applying and baking this resin composition on a conductor.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the resin composition for electrical insulation of the present invention, cyclohexanedimethanol is used as a polyhydric alcohol component of the component (A) in an amount of 5 to 10 equivalent% of the polyhydric alcohol component. It is more preferable to use 6 to 8 equivalent% of cyclohexanedimethanol. When the amount of cyclohexanedimethanol used is less than 5 equivalent% with respect to the total amount of the polyhydric alcohol component, there is no effect on the chemical releasability, while when it exceeds 10 equivalent%, the heat resistance tends to decrease.

As the polyhydric alcohol component, triol is further used in the range of 50 to 60 equivalent%, preferably in the range of 53 to 58 equivalent% of the polyhydric alcohol component. Examples of the triol include glycerin, tris-2-hydroxyethyl isocyanurate, trimethylolpropane, hexanetriol and the like, and these can be used alone or in combination of two or more. If the proportion of the triol is too small, the curability and heat resistance are inferior. If the proportion is too large, the chemical releasability, adhesion and flexibility may be reduced. Polyhydric alcohol components include triol, ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, 1,4-
Diols such as butanediol and 1,6-hexanediol are used, and the total is 100 equivalent%.

As the polybasic acid component (B), terephthalic acid and / or an alkyl terephthalate is used as an essential component in an amount of 80 to 100 equivalent%. Examples of the alkyl terephthalate include dimethyl terephthalate, monomethyl terephthalate, and diethyl terephthalate. As the polybasic acid component, one or more of terephthalic acid and its alkyl ester can be used. If the amount of terephthalic acid and / or terephthalic acid alkyl ester is less than the above range, the balance between chemical releasability and other properties is reduced. Further, as the polybasic acid component, for example, isophthalic acid, adipic acid, sebacic acid, etc., which are commonly used in polyester varnish for enameled copper wire, may be used.

Further, in order to improve heat resistance, the compound represented by the general formula (I)

Embedded image [Wherein R ¹ represents a trivalent organic group such as a residue of a tricarboxylic acid, and R ² represents a divalent organic group such as a residue of a diamine]. Examples of the imidic acid include imidodicarboxylic acid obtained by reacting 2 mol of trimellitic anhydride with 1 mol of diamine (see Japanese Patent Publication No. 51-40113). Instead of reacting the diamine with trimellitic anhydride in advance and using it as imidodicarboxylic acid, the diamine and trimellitic anhydride may be added during the production of the hydroxyl group-containing polyester. As a diamine,
4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether and the like.

The amount of imidic acid used is from 0 to 0 of the polybasic acid component.
It is preferably in the range of 20 equivalent%, more preferably in the range of 5 to 15 equivalent%. If the amount of imidic acid is too small, the heat resistance tends to be poor, and if it is too large, the chemical releasability and the appearance of the enameled wire may be reduced.

The mixing ratio of the polyhydric alcohol component to the polybasic acid component is preferably such that the equivalent ratio of the hydroxyl group to the carboxyl group is 1.3 to 1.6 from the viewpoint of flexibility and heat resistance. More preferably, it is set to 0.4 to 1.5. If the equivalent ratio of the hydroxyl group to the carboxyl group is large, the chemical releasability decreases, and if it is small, the heat resistance decreases.

The synthesis of the polyester resin used in the present invention is carried out by heating and reacting the above-mentioned acid component and alcohol component at a temperature of 170 to 250 ° C. in the presence of an esterification catalyst. At this time, as the esterification catalyst used, for example, tetrabutyl titanate, lead acetate,
Examples include dibutyltin laurate and zinc naphthenate. The imidodicarboxylic acid may be a previously synthesized one, or a mixture of a diamine and a component to be an imide acid of trimellitic anhydride with another acid component and an alcohol component at the same time and heating to perform imidization and esterification. It may be performed simultaneously. At this time, the compounding amount of the diamine and trimellitic anhydride is an amount corresponding to the compounding amount of the imidodicarboxylic acid. In addition, since the viscosity at the time of synthesis is high, it is preferable to perform synthesis in the coexistence of a phenol-based solvent such as phenol, cresol, and xylenol.

[0012] If necessary, a curing agent such as tetrabutoxytitanate and a metal salt of an organic acid (zinc salt, lead salt, manganese salt, etc.) may be added to the electrically insulating resin composition of the present invention as an appearance improving agent. can do. The amount of the curing agent is preferably 3 to 10% by weight based on the polyester resin, and the amount of the metal salt of the organic acid is preferably 0.1 to 1% by weight based on the polyester resin.

The electrical insulating resin composition of the present invention can be used after being dissolved in a solvent and adjusted to an appropriate viscosity.
In this case, as a solvent to be used, for example, phenol, cresol, xylenol, cellosolves, xylene, or the like, that is, a solvent having good solubility with a polyester resin is used.

The resin composition for electrical insulation of the present invention is coated on a conductor such as a copper wire and baked to form an enameled wire having excellent chemical releasability, but has various properties such as heat resistance and abrasion resistance. The characteristics do not deteriorate.

[0015]

Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the present invention. In the examples, “%” means “% by weight” unless otherwise specified.

Example 1 In a four-necked flask equipped with a thermometer, a stirrer and a condenser,
39.6 g of 4,4'-diaminodiphenylmethane (0.
4 equivalents), 76.8 g (0.8 equivalents) of trimellitic anhydride, 349.2 g (3.6 equivalents) of dimethyl terephthalate, 83.4 g (2.72 equivalents) of glycerin, 71.9 g of ethylene glycol (2. 32 equivalents), 20.2 g (0.28 equivalents) of cyclohexanedimethanol, 114 g of cresol, and 0.64 g of tetrabutyl titanate were added, and the temperature was raised from room temperature to 170 ° C. for 1 hour in a nitrogen stream, followed by a reaction for 3 hours. . Then, the obtained solution was heated at 215 ° C.
And reacted for 6 hours to synthesize a polyester.
580 g of cresol was added to the obtained resin solution, and 26.5 g of tetrabutyl titanate and 25.4 g of zinc naphthenate (metal content: 6%) were added to obtain a polyester resin liquid having a nonvolatile content of 40%.

Example 2 In a four-necked flask equipped with a thermometer, a stirrer and a condenser,
39.6 g of 4,4'-diaminodiphenylmethane (0.
4 eq), 76.8 g (0.8 eq) of trimellitic anhydride, 349.2 g (3.6 eq) of dimethyl terephthalate, 81.6 g (2.66 eq) of glycerin, 73.8 g (2. 38 eq.), 20.2 g (0.28 eq.) Of cyclohexanedimethanol, 114 g of cresol and 0.64 g of tetrabutyl titanate were heated in a nitrogen stream from room temperature to 170 ° C. for 1 hour and reacted for 3 hours. . Then, the obtained solution was heated at 215 ° C.
And reacted for 6 hours to synthesize a polyester.
580 g of cresol was added to the obtained resin solution, and 26.4 g of tetrabutyl titanate and 25.3 g of zinc naphthenate (metal content: 6%) were added to obtain a polyester resin liquid having a nonvolatile content of 40%.

Comparative Example 1 In a four-necked flask equipped with a thermometer, a stirrer and a condenser,
39.6 g of 4,4'-diaminodiphenylmethane (0.
4 equivalents), 76.8 g (0.8 equivalents) of trimellitic anhydride, 349.2 g (3.6 equivalents) of dimethyl terephthalate, 73.0 g (2.38 equivalents) of glycerin, 99.8 g (3. 22 eq.), 114 g of cresol and 0.64 g of tetrabutyl titanate were added, and the temperature was raised from room temperature to 170 ° C. for 1 hour in a nitrogen stream, followed by a reaction for 3 hours. Next, the resulting solution was heated to 215 ° C. and reacted for 6 hours to synthesize a polyester. 583 g of cresol was added to the obtained resin solution, and 26.4 g of tetrabutoxytitanate and 25.3 g of zinc naphthenate (metal content: 6%) were added to obtain a polyester resin liquid having a nonvolatile content of 40%.

Comparative Example 2 In a four-necked flask equipped with a thermometer, a stirrer and a condenser,
39.6 g of 4,4'-diaminodiphenylmethane (0.
4 eq), 76.8 g (0.8 eq) of trimellitic anhydride, 349.2 g (3.6 eq) of dimethyl terephthalate, 73.0 g (2.38 eq) of glycerin, 96.4 g (3. 11 eq.), 7.9 g of cyclohexanedimethanol (0.11 eq.), 114 g of cresol and 0.64 g of tetrabutyl titanate were heated in a nitrogen stream from room temperature to 170 ° C. for 1 hour and reacted for 3 hours. . Next, the resulting solution was heated to 215 ° C. and reacted for 6 hours to synthesize a polyester. 580 g of cresol was added to the obtained resin solution, and 26.5 g of tetrabutyl titanate and 25.4 g of zinc naphthenate (metal content: 6%) were added to obtain a polyester resin liquid having a nonvolatile content of 40%.

The polyester resin liquids obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were applied to a copper wire having a diameter of 1.0 mm according to the following baking conditions and baked at a wire speed of 15 m / min. And enameled wires. [Baking conditions] Baking furnace: Hot-air vertical furnace (furnace length: 5.5 m) Furnace temperature: Inlet / outlet = 320 ° C / 430 ° C Coating method: 6 dies The general characteristics of the obtained enameled wire are JIS C 3003.
The results were shown in Table 1.

[0021]

[Table 1]

[0022]

According to the resin composition for electrical insulation of the first aspect, a coating film having good chemical peelability and excellent in various properties such as heat resistance and softening resistance is produced. The enameled wire according to claim 2 has a coating having the above-mentioned properties, and there is no deterioration in properties as compared with a conventional polyester wire.

Claims (2)

[Claims] (A) cyclohexanedimethanol is 5 to 10 equivalent% of a polyhydric alcohol component, and triol is 50%.
80 to 100 equivalents of a polyhydric alcohol component containing Ｂ60 equivalent% and (B) terephthalic acid and / or an alkyl ester thereof.
And a polybasic acid component containing an equivalent%, an alcohol excess of 30 to
An electrically insulating resin composition containing a polyester resin obtained by reacting in a range of 60%. 2. An enameled wire obtained by applying and baking the resin composition for electrical insulation according to claim 1 on a conductor.