JP2003151353A - Electrically insulating resin composition and enameled wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrically insulating resin composition having a better baked-wire appearance than conventional and non-deteriorating characteristics, while solving problems on conventional technology, and an enameled wire using the same. SOLUTION: The electrically insulating resin composition formed by incorporating benzyl alcohol of 10-70 pts.wt. as a solvent in a polyester imide resin of 100 pts.wt. using imide dicarboxylic acid for a 15-65 equivalence % of acidic component and tris-(2-hydroxyethyl) isocyanurate for a 30-90 equivalence % alcohol component, is applied to a conductor and then baked thereto to form the enameled wire.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin composition for electrical insulation and an enamel wire using the same.

[0002]

2. Description of the Related Art Conventionally, polyimid wire, polyamidimid wire and polyesterimid wire are known as insulated wires having heat resistance. Among these, for example, from the viewpoint of balance between characteristics and price, a polyester imid resin in which an imid bond and an isocyanurate ring are introduced into a molecular chain by using tris (2-human oxyethyl) isocyanurate (hereinafter abbreviated as THEIC). A relatively large amount of polyester imidized wire that has been baked is used.

However, the polyester imid wire baked with the polyester imid resin is apt to cause wrinkles and corrugations on the appearance of the baking line, and a leveling agent such as a metal salt is used to improve the wrinkles and corrugations. However, when a leveling agent is added, the wrinkle surface of the baking line appearance is reduced, but foaming is likely to occur.Generally, the leveling agent is not used. It is not possible, and the thickness of the insulating film is non-uniform, and the insulation reliability is poor.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and does not cause wrinkles, corrugation, or foaming in the appearance even when a conductor is baked into an enamel wire. Therefore, the present invention provides a resin composition for electrical insulation in which the film becomes uniform and the reliability of the insulation is improved, and an enamel wire using the same.

[0005]

SUMMARY OF THE INVENTION The present invention provides 15-
Imidocacarbonic acid is used in 65 equivalent% and the alcohol content is 40 to 90%.
100 parts by weight of a polyester imid resin using tris- (2-humanoxyloxyethyl) isocyanurate in an equivalent ratio of 100% by weight, and as a solvent, benzyl alcohol 10 to 70
The present invention provides a resin composition for electrical insulation in which parts by weight are blended, and an enamel wire obtained by applying the resin composition onto a conductor and baking it.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester imid resin having an isocyanurate ring in its molecular chain according to the present invention is obtained by the reaction of an acid component and an alcohol component. Here, the isocyanurate ring has the following structure. The polyester imid resin used in the present invention is represented by the general formula (1) as a part of the acid component.

[0007]

[Chemical 1] [Wherein R 1 is a trivalent organic group such as a residue of tricarbonic acid, R 2
Means a divalent organic group such as a diamine residue, etc.] is preferable. Examples of the imidodicarbonic acid represented by the general formula (1) include imidodicarbonic acid (see Japanese Patent Publication No. 51-40113) obtained by reacting 2 mols of tricarbonic anhydride with 1 mol of diamine. To be Instead of reacting diamine and tricarboic acid anhydride in advance to use as imidodicarboic acid, diamine and tricarboic acid anhydride may be added at the time of production of polyester imid to form a residue of imidodicarboic acid.

Examples of the tricarbonic anhydride include trimellitic anhydride, 3,4,4'-benzophenone tricarbonic anhydride, and 3,4,4'-biphenyltricarbonic anhydride. Is preferred. As diamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, m-phenylene diamine, p-phenylene diamine, 1,4-diaminonaphthalene, hexamethylene diamine, diamino diphenyl sulfone and the like are used.

The amount of imidodicarboic acid used is 15
It is preferable to be in the range of to 65 equivalent%, and 20 to 60 equivalent%
It is more preferable to set to the range. If the amount of imidodicarboic acid used is too small, the heat resistance tends to be poor, and if it is too large, the flexibility and the appearance of the enamel wire may deteriorate. As the acid component other than the above imidodicarboic acid, terephthalic acid or a lower alkyl ester thereof, for example, terephthalic acid diester such as monomethyl terephthalate or lower alkyl diester of terephthalic acid, for example, dimethyl terephthalate is used. In addition, compounds commonly used in polyester iminish varnish for enameled wire, for example, isophthalic acid, adipic acid,
It is also possible to use phthalic acid, sebacic acid, or the like.

Further, as the alcohol component used in the production of a polyester imidate resin having an isocyanurate ring in the molecule, it is preferable to use one having an isocyanurate ring, such as tris (human "oxymethyl) isocyanurate or tris (2-human oxy). More preferred are isocyanurate compounds having three hydroxyl groups, such as ethyl) isocyanurate and tris (3-human oxypropyl) isocyanurate, and tris (2-human oxyethyl) isocyanurate is most preferred. The amount of the isocyanurate compound used is preferably in the range of 30 to 90 equivalent% of the total alcohol component, and more preferably in the range of 40 to 80 equivalent%. If the amount of the isocyanurate compound used is too small, the heat resistance tends to deteriorate, and if it is too large, the flexibility tends to decrease.

Examples of the alcohol component other than the above-mentioned alcohol component having an isocyanurate ring include ethylene glycol, propylene glycol, polyethylene glycol, neopentyl glycol, 1,3-butanediol,
Diols such as 1,4-butanediol and triols such as glycerin, trimethylolpropane and hexanetriol are used. These acid components and alcohol components may be used alone or in combination of two or more.

From the viewpoint of flexibility and heat resistance, the mixing ratio of the alcohol component and the acid component is preferably 1.3 to 2.5, more preferably 1.5 to 2.2, in terms of the equivalent ratio of the hydroxyl group to the carboxyl group. . If the equivalent ratio of the hydroxyl group to the carboxyl group is larger than 2.5, the flexibility tends to decrease, and if it is smaller than 1.3, the heat resistance tends to decrease. The polyester imid resin used in the present invention can be synthesized, for example, by mixing the above acid component and alcohol component in the presence of an esterification catalyst in an amount of 160 to 25.
The reaction is carried out at a temperature of 0 ° C, preferably 170 to 250 ° C for 3 to 15 hours, preferably 5 to 10 hours.
In this case, examples of the esterification catalyst used include tetrabutyl titanate, lead acetate, dibutylsulaurate, zinc naphthenate, and the like. Further, the reaction is preferably carried out under an inert atmosphere such as nitrogen gas. The imidodicarboic acid may be pre-synthesized, or the imidic acid component of diamine and trimellitic anhydride may be mixed and heated simultaneously with other acid components and alcohol components to effect imidation and esterification. May be performed at the same time. At this time, the blending amount of diamine and trimellitic anhydride is preferably an amount corresponding to the blending amount of the imidodicarbonic acid.

Since the viscosity at the time of synthesis is high, for example,
The synthesis is preferably performed in the coexistence of a phenolic solvent such as phenol, cresol, xylenol. As the benzyl alcohol used in the present invention, those which are usually sold can be used. The resin composition for electrical insulation of the present invention comprises the above polyester imid resin and benzyl alcohol. The blending amount of benzyl alcohol is preferably 10 to 70 parts by weight, and more preferably 20 to 40 parts by weight, based on 100 parts by weight of the polyester imid resin. When the amount of benzyl alcohol is less than 10 parts by weight, the effect of making the appearance of the baking line uniform is less effective, and the polyester imid resin exceeding 70 parts by weight tends not to dissolve.

If necessary, a curing agent such as tetrabutyl titanate may be added to the resin composition for electrical insulation of the present invention. The amount of curing agent used is 3 with respect to polyester imid resin.
The amount of the organic acid metal salt used is preferably 0.1 to 1% by weight based on the polyester imid resin.

The resin composition for electrical insulation of the present invention can be used in combination with a solvent other than benzyl alcohol as a solvent. Examples of the solvent used at this time include:
Solvents having good solubility with the polyester imid resin such as phenol, cresol, xylenol, cellosolves, and xylene are used.

The resin composition for electrical insulation of the present invention thus obtained is coated on a conductor such as a copper wire and baked to have an excellent appearance of the baked wire and excellent properties such as flexibility and heat resistance. Enamel wire can be obtained. There is no particular limitation on the method for producing the enameled wire, except that the composition of the present invention is used, and a conventional method can be used. For example, the resin composition for electrical insulation of the present invention is applied onto a conductor, and the temperature is 350 to 550 ° C, preferably 400 to 500.
A method of forming a coating having a desired thickness on the conductor by repeating the step of heating at 1 ° C. for 1 to 5 minutes, preferably 2 to 4 minutes and baking a plurality of times. The thickness of the film finally formed is not particularly limited, but is usually preferably 0.02 to 0.08 mm, and more preferably 0.03 to 0.06 mm. The enamel wire of the present invention thus obtained does not deteriorate in various properties such as flexibility.

[0017]

EXAMPLES Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these. In addition, "%" in the examples means "% by weight" unless otherwise specified. Example 1 (1) Preparation of Polyester Imidide Resin Liquid In a four-necked flask equipped with a thermometer, a stirrer and a condenser, 15,4 g (1.6 equivalents) of 4,4′-diaminodiphenylmethane and 307.2 g of trimellitic anhydride were prepared.
(3.2 equivalents), dimethyl terephthalate 232.8g (2.4 equivalents), tris (2-human ethyloxyethyl) isocyanurate 375.8g (4.32 equivalents), ethylene glycol 89.3g
(2.88 eq.), 385 g of cresol and 1.16 g of tetrabutyl titanate were added, and the temperature was raised from room temperature to 170 ° C. in 1 hour in a nitrogen stream.
Reacted for hours. Next, the obtained solution was heated to 215 ° C. and reacted for 6 hours to synthesize a polyester ester. To the obtained resin solution, 200 g of benzyl alcohol, 720 g of cresol, and 41.2 g of tetrabutyl titanate were added to obtain a polyester imid resin solution having a nonvolatile content of 42%.

Example 2 Polyester imide as shown in Example 1 was mixed with benzyl alcohol 500.
420 g of cresol and 41.2 g of tetrabutyl titanate were added to obtain a polyester imid resin solution having a nonvolatile content of 42%.

Example 3 Polyester imide as shown in Example 1 was mixed with benzyl alcohol 700.
220 g of g cresol and 41.2 g of tetrabutyl titanate were added to obtain a polyester imid resin solution having a nonvolatile content of 42%.

Comparative Example 1 In a four-necked flask equipped with a thermometer, a stirrer and a condenser, 79.2 g (0.8 equivalent) of 4,4'-diaminodiphenylmethane and 153.6 g of trimellitic anhydride (1.
(6 equivalents), dimethyl terephthalate 310.4 g (3.2 equivalents), tris (2-human ethyloxyethyl) isocyanurate 375.8 g (4.32 equivalents), ethylene glycol 89.3 g (2.
88 equivalents), 385 g of cresol and 1.16 g of tetrabutyl titanate,
In a nitrogen stream, the temperature was raised from room temperature to 170 ° C. in 1 hour and the reaction was carried out for 3 hours. Then, the temperature of the obtained solution was raised to 215 ° C.
The reaction was allowed to proceed for a period of time to synthesize polyester imido. To the obtained resin solution, 920 g of cresol and 41.2 g of tetrabutyl titanate were added to obtain a polyester imid resin solution having a nonvolatile content of 42% and a number average molecular weight of 5000.

[0021]

[Test Example] The resin compositions obtained in Examples 1 to 3 and Comparative Example 1 were applied to a copper wire having a diameter of 1.0 mm according to the following baking conditions and baked at linear speeds of 14 and 16 m / min to form an enamel wire. It was made.

[0022]

[Coating / baking conditions]

Baking furnace: Hot air type vertical furnace (furnace length 5.5 m) Furnace temperature: Inlet / outlet = 320 ° C / 430 ° C Coating method: Squeeze the enamel wire that has passed through the resin composition with a gyro and pass through the baking furnace 7 Do it once. The diameter of the 1st to 7th dice is 1.05mm, 1.06mm, 1.07mm, 1.08
mm, 1.09mm, 1.10mm, 1.11mm. The general properties (appearance, flexibility, thermal shock resistance, dielectric breakdown voltage, softening resistance) of the obtained enamel wire were measured according to JIS C3003, and the results are shown in Table 1. From the results shown in Table 1, the enameled wire produced by using the resin compositions obtained in Examples 1 to 3 has a baked wire appearance, compared to those obtained in Comparative Examples.
It is shown that the general properties are excellent.

[0023]

[Table 1]

[0024]

EFFECTS OF THE INVENTION By using the resin composition for electrical insulation according to the present invention, it is possible to produce an enameled wire which has a better appearance of a baked wire than conventional and has excellent insulation reliability.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J002 CM041 FD140 GQ01                 4J043 PA08 QB21 RA24 SA71 SB01                       TA12 UA391 UA432 UB222                       VA102 YA28 ZA46 ZB03                       ZB48                 5G305 AA11 AB02 AB36 BA05 CA22                       CD12                 5G309 MA04 MA17

Claims (2)

[Claims] 1. Imidodicarbonic acid is used in 15 to 65 equivalent% of the acid component, and tris- (2-human oxyethyl) is used in 30 to 90 equivalent% of the alcohol component.
An electrically insulating resin composition comprising 100 parts by weight of a polyester imid resin using isocyanurate and 10 to 70 parts by weight of benzyl alcohol as a solvent. 2. An enameled wire obtained by applying the resin composition for electrical insulation according to claim 1 onto a conductor and baking the conductor.