JP2001202824A - Resin composition for electrical insulation and enamel wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for electrical insulation generating a film which maintains a mechanical property, heatproof property, flexibility and electrical insulation property of enamel wire, and particularly has close adhesion property with conductor, abrasion proof property and an excellent close adhesion property after thermal degradation, and an enamel wire using the composition. SOLUTION: A resin composition for electrical insulation which is formed containing (A) polyester imido resin having isocyanurate ring in its molecular, and (B) aminothiazole expressed in the general formula (1) below, and an enamel wire which is made by applying the resin composition for electrical insulation on a conductor and attaching it using heat. Formula 1 Formula 2 [A and B in the formula forms 5 five membered rings with radical, and A is N, NR or CR, B is CR or CR2 (each R is alkyl radical being the number of hydrogen atom or carbon atom 1-4), or A and B both form a part of an aromatic ring].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Hitherto, as an insulated wire having heat resistance, a polyimide wire, a polyamideimide wire and a polyesterimide wire have been known. Among these, for example, from the viewpoint of the balance between properties and price, a polyesterimide resin having an imide bond and an isocyanurate ring in the molecular chain using tris (2-hydroxyethyl) isocyanurate (hereinafter abbreviated as THEIC) is used. A relatively large amount of baked polyester imide wire is used.

On the other hand, in the recent assembly process of electric equipment, high-speed winding work by a machine is performed, and severe stress such as elongation, abrasion and bending is applied to the enameled wire. It is getting stricter year by year. Therefore, the enameled wire is required to have high adhesion between the conductor and the coating and abrasion resistance.
The adhesiveness of the polyesterimide varnish using satisfies the requirements.

As means for improving the adhesion between a polyesterimide varnish and a conductor using THEIC, JP-A-2-58567 and JP-A-7-316425 disclose a method for improving the adhesion.
Discloses that a thiol compound is incorporated into a polyesterimide varnish. However, when this method is used, although the adhesion between the conductor and the coating is improved, there is a problem that the adhesion between the conductor and the coating after the enameled wire is thermally deteriorated is extremely reduced.

[0005]

SUMMARY OF THE INVENTION The present invention provides an enameled wire having various properties such as mechanical properties, heat resistance, flexibility, and electrical insulation properties, while maintaining adhesion and abrasion resistance with a conductor. An object of the present invention is to provide a resin composition for electrical insulation capable of forming a film having excellent adhesion after thermal deterioration, and an enameled wire using the composition.

[0006]

The present invention provides (A) a polyesterimide resin having an isocyanurate ring in the molecule, and (B) a general formula (1)

Embedded image Wherein A and B are groups

Embedded image A is N, NR or CR, B is CR or CR ₂ (each R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), or A and B together form a part of one aromatic ring].

[0007] The present invention also relates to a resin composition for electrical insulation, comprising 0.01 to 1 part by weight of the component (B) based on 100 parts by weight of the component (A). Furthermore, the present invention
The present invention relates to an enameled wire obtained by applying the resin composition for electrical insulation on a conductor and baking the conductor.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The polyesterimide resin having an isocyanurate ring in the molecule in the present invention is obtained by reacting an acid component with an alcohol component. Here, the isocyanurate ring has the following structure.

Embedded image

The polyesterimide resin used in the present invention has a general formula (2) as a part of the acid component.

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]. .

As the imidodicarboxylic acid represented by the general formula (2), for example, imidodicarboxylic acid obtained by reacting 2 moles of tricarboxylic anhydride with 1 mole of diamine (see Japanese Patent Publication No. 51-40113) )
Is mentioned. Instead of reacting the diamine with the tricarboxylic anhydride in advance and using it as the imidodicarboxylic acid, the diamine and the tricarboxylic anhydride may be added during the production of the polyesterimide to form a residue of the imidodicarboxylic acid.

Examples of the tricarboxylic anhydride include trimellitic anhydride, 3,4,4'-benzophenone tricarboxylic anhydride, and 3,4,4'-biphenyltricarboxylic anhydride. Is preferred.
As the diamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, m-phenylenediamine, p-phenylenediamine, 1,4-diaminonaphthalene, hexamethylenediamine, diaminodiphenylsulfone and the like are used.

The amount of imidodicarboxylic acid to be used is preferably in the range of 15 to 65 equivalent% of the total acid component.
It is more preferable that the content be in the range of ６０60 equivalent%. If the amount of the imidodicarboxylic acid is too small, the heat resistance tends to be inferior, and if it is too large, the flexibility and the appearance of the enameled wire may decrease.

The acid component other than the above-mentioned imidodicarboxylic acid includes terephthalic acid or its lower alkyl ester,
For example, dimethyl terephthalate, monomethyl terephthalate, diester terephthalate and the like are used. Also,
Compounds commonly used in polyester varnish for enameled wire,
For example, isophthalic acid, adipic acid, phthalic acid, sebacic acid and the like can be used.

As the alcohol component used for the production of the polyesterimide resin having an isocyanurate ring in the molecule, those having an isocyanurate ring are preferably used, and tris- (hydroxymethyl) isocyanurate and tris- (2 Isocyanurate compounds having three hydroxyl groups, such as -hydroxyethyl) isocyanurate and tris- (3-hydroxypropyl) isocyanurate, are more preferred.
(2-Hydroxyethyl) isocyanurate is the 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 is too small, the heat resistance tends to be poor, and if it is too large, the flexibility tends to decrease.

Examples of the alcohol component other than the alcohol component having an isocyanurate ring include diols such as ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, 1,3-butanediol, and 1,4-butanediol. , Glycerin, trimethylolpropane, hexanetriol, tris such as tris- (2-hydroxyethyl) isocyanurate and the like. These acid components and alcohol components are used alone or in combination of two or more.

The mixing ratio of the alcohol component and the acid component is as follows:
From the viewpoint of flexibility and heat resistance, the equivalent ratio of the hydroxyl group to the carboxyl group is preferably from 1.3 to 2.5, and more preferably from 1.5 to 2.2. When the equivalent ratio of the hydroxyl group to the carboxyl group is large, the flexibility tends to decrease, and when it is small, the heat resistance tends to decrease.

The synthesis of the polyesterimide resin used in the present invention is carried out, for example, 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, examples of the esterification catalyst used include tetrabutyl titanate, lead acetate, dibutyltin laurate, zinc naphthenate and the like. The imidodicarboxylic acid may be one synthesized in advance, or the imidization and esterification by mixing and heating the diamine and trimellitic anhydride imide acid components simultaneously with other acid components and alcohol components. May be performed simultaneously. At this time, the amount of the diamine and trimellitic anhydride is preferably an amount corresponding to the amount of the imidodicarboxylic acid. Also,
Since the viscosity at the time of the synthesis is high, it is preferable to perform the synthesis in the coexistence of a phenol-based solvent such as phenol, cresol, and xylenol.

The aminothiazole used in the present invention is
It is represented by the general formula (1). In particular,
The following compounds are included:

[0019]

Embedded image (In each formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

More specifically preferred compounds include
2-aminothiazole, 2-aminobenzothiazole,
2-amino-1,3,4-thiadiazole and the like.

The resin composition for electrical insulation of the present invention is used in an amount of 100 parts by weight of the polyesterimide resin as described above.
Preferably, 0.01 to 1 part by weight of aminothiazole is blended, more preferably 0.05 to 0.8 part by weight. When the amount of the aminothiazole is less than 0.01 part by weight, the effect of improving the adhesiveness is small, and when the amount of the aminothiazole exceeds 1 part by weight, the adhesiveness after thermally degrading the enamel wire tends to decrease. .

If necessary, a curing agent such as tetrabutyl titanate and a metal salt of an organic acid, for example, a zinc salt, a lead salt, and a manganese salt, may be added to the electrical insulating resin composition of the present invention. can do. The amount of curing agent used is
The amount is preferably 3 to 10% by weight based on the polyesterimide resin, and the amount of the metal salt of the organic acid is preferably 0.1 to 1% by weight based on the polyesterimide resin.

The resin composition for electrical insulation of the present invention can be used after being dissolved in a solvent and adjusted to an appropriate viscosity.
As the solvent used at this time, for example, phenol,
A solvent having good solubility with the polyesterimide resin, such as cresol, xylenol, cellosolves, and xylene, is used.

The thus obtained resin composition for electrical insulation of the present invention is coated on a conductor such as a copper wire and baked to give an enameled wire having excellent wear resistance, adhesion and adhesion after thermal deterioration. It can be. Except for using the composition of the present invention, the method for producing an enameled wire is not particularly limited, and can be according to a conventional method. The obtained enameled wire of the present invention does not deteriorate in various properties such as flexibility.

[0025]

Next, the present invention will be described in more detail with reference to examples. In the examples, “%” means “% by weight” unless otherwise specified.

Example 1 (1) Preparation of Polyesterimide Resin Solution A four-necked flask equipped with a thermometer, a stirrer and a condenser was charged with
158.4 g of 4,4'-diaminodiphenylmethane
(1.6 equivalents), 307.2 g of trimellitic anhydride
(3.2 equivalents), 232.8 g of dimethyl terephthalate
(2.4 equivalents), 375.8 g (4.32 equivalents) of tris- (2-hydroxyethyl) isocyanurate, 89.3 g (2.88 equivalents) of ethylene glycol, 385 g of cresol, and 1.16 g of tetrabutyl titanate. Then, the temperature was raised from room temperature to 170 ° C. for 1 hour in a nitrogen stream to carry out a reaction for 3 hours. Next, the obtained solution was heated to 215 ° C. and reacted for 6 hours to synthesize a polyesterimide. 920 g of cresol was added to the obtained resin solution, and 41.2 g of tetrabutyl titanate was added to obtain a nonvolatile matter 4
A 2% polyesterimide resin solution was obtained.

(2) Preparation of Resin Composition for Electrical Insulation Polyesterimide resin liquid 100 obtained in (1) above
Then, 0.084 g of 2-aminothiazole (0.2% based on the solid content of the resin solution) was added to g, to obtain a resin composition for electrical insulation.

Example 2 In Example 1 (2), except that 0.084 g (0.2% based on the solid content of the resin solution) of 2-aminobenzothiazole was added instead of 2-aminothiazole, Performed according to Example 1.

Example 3 In Example 1 (2), 2-amino-1,3,4-thiadiazole 0.0 was used instead of 2-aminothiazole.
The procedure was performed in the same manner as in Example 1 except that 84 g (0.2% based on the solid content of the resin solution) was added.

Comparative Example 1 The polyesterimide resin liquid of Example 1 (1) was used as it was.

Comparative Example 2 In Example 1 (2), instead of 2-aminothiazole, 5-amino-1,3,4-thiadiazole-2- was used.
0.084 g of thiol (0.2% based on the solid content of the resin solution)
%) Was carried out in the same manner as in Example 1 except that% was added.

<Test Examples> Examples 1-3 and Comparative Examples 1-2
The resin composition obtained in the above was 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 14 m / min.
An enameled wire was prepared. [Coating and baking conditions] Baking furnace: Hot-air vertical furnace (furnace length: 5.5 m) Furnace temperature: Inlet / outlet = 320 ° C / 430 ° C Coating method: Enamel wire through which resin composition is passed is drawn by a die and baked The procedure of passing through the furnace is performed seven times. The diameter of the first to seventh dies is 1.05mm, 1.06m
m, 1.07mm, 1.08mm, 1.09mm, 1.10m
m, 1.11 mm.

The adhesion test of the obtained enameled wire was evaluated according to the following method, and other general characteristics (flexibility, thermal shock resistance, dielectric breakdown voltage, softening resistance) were measured according to JIS.
The measurement was performed according to C3003, and the results are shown in Table 1. [Adhesion test] The adhesion is evaluated by a rapid cutting method. That is, both ends of an enameled wire having an appropriate length are fixed, and the cutting is performed at a tensile speed of about 4 m / s with a mark length of 250 mm. The length (mm) of the exposed portion (two locations) of the conductor at the cut location is represented as, for example, 1.0 + 1.0. Similarly, the length of the part where the film is separated from the conductor (floating part of the film) is expressed as 5.0 + 5.0. This is performed at the initial stage of the enameled wire and after deterioration at 200 ° C. for 6 hours. In the measurement results of the adhesion, the smaller the value, the better the adhesion between the film and the conductor.

[0034]

[Table 1]

From the results shown in Table 1, the enameled wires prepared by using the resin compositions obtained in Examples 1 to 3 showed abrasion resistance and adhesion (compared to those obtained in Comparative Example). It can be seen that the characteristics were excellent at the initial stage and after 200 ° C./6 hours), and were the same in other characteristics such as flexibility.

[0036]

The polyesterimide resin composition having an isocyanurate bond in the molecular chain according to the present invention is excellent in abrasion resistance and adhesiveness (initial and after 200 ° C./6 hours) and has flexibility and the like. The enameled wire which does not decrease the various characteristics is obtained.

Claims (3)

[Claims] 1. A polyesterimide resin having (A) an isocyanurate ring in the molecule, and (B) a general formula (1) [Wherein A and B are groups represented by the formula: A is N, NR or CR, B is CR or CR ₂ (each R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), or A and B both form a part of one aromatic ring]. 2. Component (A): 100 parts by weight of component
The resin composition for electrical insulation according to claim 1, comprising (B) component 0.01 to 1 part by weight. 3. An enameled wire obtained by applying the resin composition for electrical insulation according to claim 1 on a conductor and baking the conductor.