JP2011082020A - Resin composition for electrical insulation and enameled wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for electrical insulation which can form a coating excellent in flexibility, while maintaining a mechanical characteristics, heat resistance and electrical insulating characteristics required for an enameled wire, and to provide an enameled wire using the same. <P>SOLUTION: The resin composition for electrical insulation is formed by containing (A) polyester imide resin having an isocyanurate ring in a molecule chain and (B) antioxidant. The resin composition for electrical insulation is applied and baked onto a conductor to form the enameled wire. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

Conventionally, polyimide wires, polyamideimide wires, and polyesterimide wires are known as insulated wires having heat resistance. Among these, for example, polyester imide resin in which imide bond and isocyanurate ring are introduced into a molecular chain using tris (2-hydroxyethyl) isocyanurate (hereinafter abbreviated as THEIC) from the viewpoint of balance between characteristics and price. A polyesterimide wire and a polyesterimide / polyamideimide wire (double-coated wire) baked with a relatively large amount are used.
On the other hand, in the recent assembly process of electrical equipment, high-speed winding work is carried out by machines, and severe stress such as expansion and bending is applied to the enameled wire, and the degree is getting severe year by year. . Therefore, a high degree of flexibility is required for the enameled wire, but the enameled wire characteristics of the polyesterimide varnish using the conventional THEIC are insufficient for the requirement.
As means for improving the flexibility of the polyesterimide varnish using THEIC, it is conceivable to reduce the amount of THEIC or the amount of the imide component.
However, when this method is used, the flexibility is improved, but the heat resistance of the enameled wire is lowered. Moreover, as means for improving the adhesion between the polyesterimide varnish and the conductor using THEIC, Patent Document 1 discloses that a melamine resin is blended in the polyesterimide varnish, and Patent Document 2 and Patent Document 3 disclose. It is disclosed that a thiol compound is added to a polyesterimide varnish. However, when the methods of Patent Documents 2 and 3 are used, the initial adhesion between the conductor and the film is improved, but there is a problem that the adhesion between the conductor and the film after the enamel wire is thermally deteriorated is extremely lowered. there were.

Japanese Patent Publication No. 04-056864 JP-A-2-58567 JP 7-316425 A

  The present invention relates to a resin composition for electrical insulation capable of producing a film having particularly excellent flexibility while maintaining various properties such as mechanical properties, heat resistance and electrical insulation properties of the enamel wire, and an enamel wire using the same The purpose is to provide.

The present invention provides an electrically insulating resin composition comprising (A) a polyesterimide resin having an isocyanurate ring in a molecular chain and (B) an antioxidant.
Moreover, this invention provides the said resin composition for electrical insulation containing 0.1-10 mass parts of antioxidant (B) with respect to 100 mass parts of said polyesterimide resin (A). .
The present invention also provides an enameled wire obtained by applying the above resin composition for electrical insulation on a conductor and baking it.

  If the fat composition for electrical insulation containing a polyesterimide having an isocyanurate ring in the molecular chain according to the present invention is used, an enameled wire that has excellent flexibility and does not deteriorate various properties such as heat resistance can be obtained.

  The polyesterimide resin having an isocyanurate ring in the molecule in the present invention is obtained by a reaction between an acid component and an alcohol component. Here, the isocyanurate ring is represented by the following structure.

The polyesterimide resin used in the present invention is represented by the general formula (2) as a part of the acid component.
[In general formula (2), R ¹ represents a trivalent organic group such as a tricarboxylic acid residue, and R ² represents a divalent organic group of a diamine residue]. Is preferred.

一般式（２）で表されるイミドジカルボン酸としては、例えばジアミン１モルに対してトリカルボン酸無水物２モルを反応させることにより得られるイミドジカルボン酸（特公昭５１−４０１１３号公報参照）が挙げられる。
また、あらかじめジアミンとトリカルボン酸無水物とを反応させてイミドジカルボン酸として用いないで、ジアミンとトリカルボン酸無水物をポリエステルイミドの製造時に加えて、イミドジカルボン酸の残基を形成してもよい。

Examples of the imide dicarboxylic acid represented by the general formula (2) include imide dicarboxylic acid (see Japanese Patent Publication No. 51-40113) obtained by reacting 2 mol of tricarboxylic anhydride with 1 mol of diamine. It is done.
Alternatively, a diamine and a tricarboxylic acid anhydride may be reacted in advance and not used as an imide dicarboxylic acid, but a diamine and a tricarboxylic acid anhydride may be added during the production of a polyesterimide to form an imide dicarboxylic acid residue.

  Examples of the tricarboxylic acid anhydride include trimellitic acid anhydride, 3,4,4'-benzophenone tricarboxylic acid anhydride, 3,4,4'-biphenyltricarboxylic acid anhydride, and trimellitic acid anhydride is preferable.

  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 used is preferably in the range of 15 to 65 equivalent% of the total acid component, and more preferably in the range of 20 to 60 equivalent%. If the amount of imide dicarboxylic acid used is too small, the heat resistance tends to be inferior. If it is too large, the flexibility and the appearance of the enameled wire may be deteriorated.
As the acid component other than the imide dicarboxylic acid, terephthalic acid or a lower alkyl ester thereof, for example, terephthalic acid diesters such as monomethyl terephthalate, lower alkyl diesters of terephthalic acid, for example, dimethyl terephthalate, and the like are used. In addition, compounds commonly used in polyesterimide varnishes for enameled wires, such as isophthalic acid, adipic acid, phthalic acid, sebacic acid and the like can also be used.

  Moreover, it is preferable to use what has an isocyanurate ring as an alcohol component used for manufacture of the polyesterimide resin which has an isocyanurate ring in a molecular chain, Tris (hydroxymethyl) isocyanurate, Tris (2-hydroxyethyl) Isocyanurate compounds having three hydroxyl groups such as isocyanurate and tris (3-hydroxypropyl) isocyanurate are more preferred, and tris (2-hydroxyethyl) isocyanurate is most preferred. The amount of the isocyanurate compound used is preferably in the range of 30 to 90 equivalent%, more preferably in the range of 40 to 80 equivalent% of the total alcohol component. When the amount of the isocyanurate compound used is too small, the heat resistance tends to be inferior, and when it is too much, the flexibility tends to decrease.

  Examples of alcohol components 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, Triols such as 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, and the equivalent ratio of the hydroxyl group to the carboxyl group is 1.5 to 2.2. More preferably. 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 less than 1.3, the heat resistance tends to decrease.
The synthesis of the polyesterimide resin used in the present invention is, for example, the above-mentioned acid component and alcohol component in the presence of an esterification catalyst at a temperature of 160 to 250 ° C., preferably 170 to 250 ° C. for 3 to 15 hours, preferably Is carried out by heating reaction for 5 to 10 hours. In this case, examples of the esterification catalyst used include tetrabutyl titanate, lead acetate, dibutyltin laurate, and zinc naphthenate. The reaction is preferably performed in an inert atmosphere such as nitrogen gas. The imide dicarboxylic acid may be synthesized in advance, and the components that become imide acid of a tricarboxylic acid anhydride such as diamine and trimellitic anhydride are mixed and heated simultaneously with other acid components and alcohol components. The imidization and esterification may be performed simultaneously. At this time, the blending amount of the diamine and the tricarboxylic acid anhydride is preferably set to an amount corresponding to the blending amount of the imide dicarboxylic acid.
Moreover, since the viscosity at the time of synthesis is high, for example, the synthesis is preferably performed in the presence of a phenolic solvent such as phenol, cresol, or xylenol.

  Examples of the antioxidant used in the present invention include hydroquinone, 2,5-di-t-butylhydroquinone, 2-t-butyl-4-methylphenol, 2,6-di-t-butylphenol, bisphenol A, 2, 6-di-t-butyl-4-methylphenol, butylhydroxyanisole, 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, IRGANOX 245, IRGANOX 259, IRGANOX 1010, IRGANOX 1035, IRGANOX 1076, IRGANOX 1098, IRGANOX 1330 (above, manufactured by Ciba Specialty Chemicals, Inc., trade name), phenolic antioxidants, distearyl thiodipropionate, 4,4′-thiobis (3 -Methyl-6-tert-butylphenol ), Sulfur-based antioxidants such as 2-mercaptobenzimidazole, phosphorus-based antioxidants such as triphenyl phosphite and trilauryl trithiophosphite, Nn-butyl-p-aminophenol, octylated diphenylamine, Amine-based antioxidants such as N, N′-di-sec-butyl-p-phenylenediamine and N, N′-di-β-naphthyl-p-phenylenediamine are used.

The resin composition for electrical insulation of the present invention is obtained by blending an antioxidant with the polyesterimide resin as described above.
It is preferable to set it as 0.1-10 mass parts with respect to 100 mass parts of polyesterimide resins, and, as for the compounding quantity of antioxidant, it is more preferable to set it as 0.3-8 mass parts. When the amount of the antioxidant is less than 0.1 parts by mass, the improvement in the flexibility of the enameled wire is hardly exhibited, and when it exceeds 10 parts by mass, the heat resistance of the enameled wire tends to decrease.

If necessary, the resin composition for electrical insulation according to the present invention may further contain a curing agent such as tetrabutyl titanate or a metal salt of an organic acid such as a zinc salt, a lead salt, or a manganese salt. Can do. The use amount of the curing agent is preferably 3 to 10% by mass with respect to the polyesterimide resin, and the use amount of the organic acid metal salt is preferably 0.1 to 1% by mass with respect to 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 a solvent used in this case, for example, a solvent having good solubility with a polyesterimide resin, such as phenol, cresol, xylenol, cellosolves, and xylene is used.

  The resin composition for electrical insulation of the present invention thus obtained is applied to a conductor such as a copper wire and baked to obtain an enameled wire excellent in wear resistance, adhesion and adhesion after heat deterioration. Can do. Except for using the resin composition for electrical insulation of the present invention, the method for producing the enameled wire is not particularly limited and can follow conventional methods. For example, a plurality of steps of applying the resin composition for electrical insulation of the present invention on a conductor and baking it by heating at 350 to 550 ° C., preferably 400 to 500 ° C. for 1 minute to 5 minutes, preferably 2 to 4 minutes. A method in which a film having a desired thickness is formed on a conductor by repeating the process once. Although the thickness of the film finally formed is not particularly limited, it is usually preferably 0.02 to 0.08 mm, and more preferably 0.03 to 0.06 mm. The enameled wire of the present invention thus obtained does not deteriorate various properties such as flexibility.

The present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In the examples, “%” means “% by mass” unless otherwise specified.
Example 1
Preparation of polyesterimide resin liquid To a four-necked flask equipped with a thermometer, a stirrer and a condenser, 158.4 g (1.6 equivalents) of 4,4′-diaminodiphenylmethane, 307.2 g (3.2 equivalents) of trimellitic anhydride, 232.8 g (2.4 eq) dimethyl terephthalate, 375.8 g (4.32 eq) tris (2-hydroxyethyl) isocyanurate, 89.3 g (2.88 eq) ethylene glycol, 385 g cresol and tetrabutyl titanate 1.16 g was added, the temperature was raised from room temperature (25 ° C.) to 170 ° C. in 1 hour in a nitrogen stream, and the reaction was allowed to proceed for 3 hours.
Next, the obtained solution was heated to 215 ° C. and reacted for 6 hours to synthesize a polyesterimide having an isocyanurate ring in the molecular chain. To the obtained resin solution, 920 g of cresol was added, and 41.2 g of tetrabutyl titanate was added to obtain a polyesterimide resin liquid having a nonvolatile content of 42%.

Preparation of Resin Composition for Electrical Insulation To 100 g of the polyesterimide resin liquid obtained in (1) above, IRGANOX 1010 [pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl)] 1.26 g of propionate] (3% with respect to the solid content of the resin liquid) was added to obtain a resin composition for electrical insulation. The content of tetrabutyl titanate (curing agent) in this resin composition for electrical insulation was 4% with respect to the solid content in the polyesterimide resin liquid.

(Example 2)
In Example 1 (2), instead of IRGANOX 1010, IRGANOX 1098 [N, N′-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide)] 1.26 g ( Example 3 was performed except that 3%) of the solid content of the resin liquid was added.

(Example 3)
In Example 1 (2), instead of IRGANOX 1010, 0.42 g (1% with respect to the solid content of the resin liquid) of N, N′-di-β-naphthyl-p-phenylenediamine was added. It carried out according to Example 1.

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

(Comparative Example 2)
The same procedure as in Example 1 was performed except that 0.021 g of IRGANOX 1010 (0.05% based on the solid content of the resin liquid) was added in Example 1 (2).
[Test example]
The resin compositions obtained in Examples 1 to 3 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 14 m / min to produce an enameled wire.
[Coating / baking conditions]
・ Baking furnace: Hot air type furnace (furnace length 5.5m)
-Furnace temperature: Inlet / Outlet = 320 ° C / 430 ° C
-Coating method: The enameled wire through which the resin composition is passed is squeezed with a die and passed through a baking furnace seven times. The diameters of the dice from the first time to the seventh time were changed to 1.05 mm, 1.06 mm, 1.07 mm, 1.08 mm, 1.09 mm, 1.10 mm, and 1.11 mm.
Moreover, the general characteristics (flexibility, thermal shock resistance, dielectric breakdown voltage, softening resistance) of the obtained enameled wire were measured according to JIS C3003 (enameled wire test method), and the results are shown in Table 1. .

  From the results shown in Table 1, the enameled wire produced using the resin composition obtained by blending the antioxidant in Examples 1 to 3 is a comparative example in which the antioxidant is not blended or the blending amount is small. It can be seen that the flexibility is improved as compared with that obtained in the above, and the characteristics such as heat resistance are also equivalent.

Claims (3)

(A) A resin composition for electrical insulation comprising a polyesterimide resin having an isocyanurate ring in a molecular chain and (B) an antioxidant. The resin composition for electrical insulation according to claim 1, comprising 0.1 to 10 parts by mass of (B) an antioxidant with respect to 100 parts by mass of the polyesterimide resin (A). An enameled wire obtained by applying the resin composition for electrical insulation according to claim 1 or 2 onto a conductor and baking it.