JP2010254762A - Resin composition for electric insulation and enameled wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for electric insulation which forms a coating film having excellent adhesion with a conductor, wear resistance and adhesion after heat deterioration while maintaining mechanical properties, heat resistance, flexibility, electric insulating property or the like required for an enameled wire, and to provide an enameled wire. <P>SOLUTION: The resin composition for electric insulation includes (A) a polyester imide resin having an isocyanurate ring in the molecular chain, (B) a melamine resin, and (C) an antioxidant. The enameled wire is obtained by applying the resin composition for electric insulation on a conductor and fixing the applied composition to the conductor by baking. <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 the molecular chain using tris (2-hydroxyethyl) isocyanurate (hereinafter abbreviated as THEIC) from the viewpoint of balance between characteristics and price. A relatively large amount of polyester imide wire is used.
On the other hand, in the recent assembly process of electrical equipment, high-speed winding work is performed by machines, and severe stress such as elongation, wear, and bending is applied to the enamel wire, and the degree becomes severe year by year. ing. Therefore, a high degree of adhesion between the conductor and the film and wear resistance are required for the enameled wire, but the adhesion of the polyesterimide varnish using the conventional THEIC is insufficient for the requirement. there were.
As means for improving the adhesion between the polyesterimide varnish using the THEIC and the conductor, Japanese Patent Publication No. 04-056864 discloses blending a melamine resin into the polyesterimide varnish. However, when this method is 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.

Japanese Patent Publication No. 04-056864

  The present invention is particularly excellent in adhesion to conductors, wear resistance and adhesion after thermal deterioration while maintaining various properties such as mechanical properties, heat resistance, flexibility and electrical insulation properties of enameled wire. It aims at providing the resin composition for electrical insulation which can produce a film | membrane, and an enamel wire using the same.

The present invention provides a resin composition for electrical insulation comprising [1] (A) a polyesterimide resin having an isocyanurate ring in a molecular chain, (B) a melamine resin, and (C) an antioxidant. Is.
Moreover, this invention contains (B) melamine resin 0.01-5 mass part and (C) antioxidant 0.1-10 mass part with respect to 100 mass parts of [2] (A) polyesterimide resin. The resin composition for electrical insulation according to the above [1] is provided.
The present invention also provides an enameled wire obtained by applying [3] the resin composition for electrical insulation according to [1] or [2] above on a conductor and baking it.

  If the fat composition for electrical insulation obtained by combining a polyesterimide resin having an isocyanurate ring (bond) in the molecular chain according to the present invention in combination with a melamine resin and an antioxidant is used, wear resistance and adhesion It is possible to obtain an enameled wire that is excellent in properties (initially and after thermal degradation of 200 ° C./6 h) and does not deteriorate various properties such as flexibility.

  The polyesterimide resin having an isocyanurate ring in the molecule used 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.

  As a polyesterimide resin used for this invention, what uses the imide dicarboxylic acid represented by General formula (2) as a part of acid component is preferable.

〔一般式（２）中、Ｒ^１は、トリカルボン酸の残基である３価の有機基、Ｒ^２は、ジアミン残基の２価の有機基を表す〕
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。

[In General Formula (2), R ¹ represents a trivalent organic group that is a residue of a tricarboxylic acid, and R ² represents a divalent organic group of a diamine residue]
As the imide dicarboxylic acid represented by the general formula (2), for example, imide dicarboxylic acid obtained by reacting 2 mol of tricarboxylic acid anhydride with 1 mol of diamine (see Japanese Patent Publication No. 51-40113). Can be mentioned.
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 aromatic tricarboxylic acid anhydrides represented by the general formulas (3) and (4), such as trimellitic acid anhydride, 3,4,4′-benzophenone tricarboxylic acid anhydride, Examples include 3,4,4′-biphenyltricarboxylic acid anhydride, and trimellitic acid anhydride is preferable.

（但し、一般式（３）、(４)中、Ｒ^’は、水素、炭素数１〜１０のアルキル基又はフェニル基を示し、Ｙは、単結合、−ＣＨ_２−、−ＣＯ−、−ＳＯ_２−、又は−Ｏ−を示す。）

(In the general formulas (3) and (4), R ^′ represents hydrogen, an alkyl group having 1 to 10 carbon atoms or a phenyl group, and Y represents a single bond, —CH ₂ —, —CO—, — SO _2- or -O- is shown.)

  As the diamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, m-phenylenediamine, p-phenylenediamine, 1,4-diaminonaphthalene, hexamethylenediamine, diaminodiphenylsulfone and the like are used. Examples of the diisocyanate include those obtained by changing the amino group to an isocyanate group.

  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. Further, compounds commonly used for polyester imide varnishes for enameled wires, such as isophthalic acid, adipic acid, phthalic acid, sebacic acid and the like can also be used.

As the alcohol component used for the production of the polyesterimide resin having an isocyanurate ring in the molecular chain, those having an isocyanurate ring are preferably used. Tris (hydroxymethyl) isocyanurate, tris (2-hydroxyethyl) isocyanurate An isocyanurate compound having three hydroxyl groups, such as tris (3-hydroxypropyl) isocyanurate, is preferable, and tris (2-hydroxyethyl) isocyanurate is most preferable.
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 dilaurate, and zinc naphthenate. The reaction is preferably performed in an inert atmosphere such as nitrogen gas. The above-mentioned imide dicarboxylic acid may be synthesized in advance, or imidation and esterification by mixing and heating components that become imide and imide acid of trimellitic anhydride simultaneously with other acid components and alcohol components. May be performed simultaneously. At this time, the blending amount of diamine and trimellitic 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.

  There is no restriction | limiting in particular in the melamine resin of (B) component used for this invention. Commercially available methylated melamine and butylated melamine are used.

  Examples of the antioxidant of component (C) 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, trade name, manufactured by Ciba Specialty Chemicals), distearyl thiodipropionate, 4,4 '-Thiobis (3-methyl- 6-t-butylphenol), sulfur-based antioxidants such as 2-mercaptobenzimidazole, phosphorus-based antioxidants such as triphenyl phosphite and trilauryltrithiophosphite, Nn-butyl-p-aminophenol, octyl Amine-based antioxidants such as diphenylamine, N, N′-di-sec-butyl-p-phenylenediamine, and N, N′-di-β-naphthyl-p-phenylenediamine are used. A phenolic antioxidant having a large effect on the adhesion after heat deterioration is preferably used.

The resin composition for electrical insulation of the present invention is obtained by blending (B) melamine resin and (C) antioxidant in (A) polyesterimide resin as described above.
The blending amount of the melamine resin is preferably 0.01 to 5 parts by mass and more preferably 0.05 to 3 parts by mass with respect to 100 parts by mass of the (A) polyesterimide resin. When the amount of the melamine resin is less than 0.01 parts by mass, the effect of improving the adhesion is small, and when the amount of the melamine resin exceeds 5 parts by mass, the heat resistance of the enamel wire tends to decrease.

  Moreover, it is preferable to set it as 0.1-10 mass parts with respect to 100 mass parts of polyesterimide resin, and, as for the compounding quantity of (C) 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 effect of suppressing the decrease in adhesion after heat deterioration of the enamel wire is hardly exhibited, and when it exceeds 10 parts by mass, the heat resistance of the enamel wire tends to be reduced. .

  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, the step of applying the resin composition for electrical insulation of the present invention on a conductor and heating and baking 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.

EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not restrict | limited to these. In the examples, “%” means “% by mass” unless otherwise specified.
Example 1
Preparation of polyesterimide resin solution In a four-necked flask equipped with a thermometer, stirrer and condenser, 158.4 g (1.6 equivalents) of 4,4′-diaminodiphenylmethane, 307.2 g (3.2 equivalents) of trimellitic anhydride, Dimethyl terephthalate 232.8 g (2.4 eq), tris (2-hydroxyethyl) isocyanurate 375.8 g (4.32 eq), ethylene glycol 89.3 g (2.88 eq), cresol 385 g and tetrabutyl titanate 1.16 g was added, and the temperature was raised from room temperature (25 ° C.) to 170 ° C. in 1 hour in a nitrogen stream, and the reaction was performed for 3 hours.
Next, the obtained solution was heated to 215 ° C. and reacted for 6 hours to synthesize polyesterimide. 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, 0.126 g of ML-20 (Melamine resin manufactured by Hitachi Chemical Co., Ltd.) as the component (B) (solid content of the resin liquid) 0.36%) and 1.26 g (3% based on the solid content of the resin liquid) of IRGANOX 1010 as component (C) were 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), ML-28 (Melamine resin manufactured by Hitachi Chemical Co., Ltd.) 0.21 g (0.5% based on the solid content of the resin liquid) was added instead of ML-20. This was carried out according to Example 1.

(Example 3)
In Example 1 (2), instead of IRGANOX 1010, IRGANOX 1098 0.42 g (1% with respect to the solid content of the resin liquid) 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), it carried out according to Example 1 except not adding IRGANOX 1010.

<Test example>
The resin compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 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
Application 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 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 C3003, The results are summarized in Table 1.

[Adhesion test]
The evaluation of adhesion was performed by a rapid cutting method. The both ends of the enameled wire having an appropriate length are fixed, and the marked line distance is 250 mm, and the enameled wire is cut at a tensile speed of 4 m / s. The total of the length (mm) of the exposed portion of the conductor and the length of the portion where the film is peeled from the conductor (floating of the film) at the cut portion is measured. This was performed for the initial stage of the enameled wire, 200 ° C., and after 6 hours of degradation, with the film floating.
In the adhesion measurement results, a smaller value indicates better adhesion between the film and the conductor.

From the results shown in Table 1, when only the (A) polyesterimide resin of Comparative Example 1 was used, the adhesion was poor both in the normal state and after the heat deterioration test, and (B) a melamine resin was blended (C) an antioxidant. In Comparative Example 2 in which no is added, the adhesion is good even in a normal state, but the adhesion after the heat deterioration test is greatly deteriorated. On the other hand, the enameled wire produced using the resin compositions obtained in Examples 1 to 3 in which (B) a melamine resin and (C) an antioxidant are blended with (A) a polyesterimide resin is a comparative example. It can be seen that it is excellent in wear resistance and adhesion (initial and after 200 ° C./6 h) as well as in the properties such as flexibility as compared with those obtained in the above.
If the fat composition for electrical insulation containing a polyesterimide having an isocyanurate ring (bond) in the molecular chain according to the present invention is used, it has excellent wear resistance and adhesion (initial and after 200 ° C / 6h heat deterioration). Thus, an enameled wire in which various properties such as flexibility are not deteriorated can be obtained.

Claims (3)

(A) A resin composition for electrical insulation comprising a polyesterimide resin having an isocyanurate ring in a molecular chain, (B) a melamine resin, and (C) an antioxidant. (A) The electrical insulation of Claim 1 which contains 0.01-5 mass parts of (B) melamine resin and 0.1-10 mass parts of antioxidant with respect to 100 mass parts of polyesterimide resin. Resin composition. An enameled wire obtained by applying the resin composition for electrical insulation according to claim 1 or 2 onto a conductor and baking it.