JP3336221B2 - Insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated electric wire having a polyester resin coating excellent in heat resistance and wet heat resistance.

[0002]

2. Description of the Related Art In recent years, with the miniaturization, high performance, and sealing of electric equipment, the operating temperature of the electric equipment has often increased in an atmosphere in which moisture has been confined inside the electric equipment. In order to improve the reliability of the insulated wire, it is strongly desired that the insulated wire used as the material be made heat resistant and moist heat resistant.

Conventionally, insulated wires are polyvinyl formal insulated wires (meaning insulated wires using an insulating paint containing polyvinyl formal; the same applies to insulated wires using other insulating paints) and polyurethane insulation. Electric wires, polyester insulated wires, polyester imide insulated wires, polyamide imide insulated wires, and the like have been put to practical use.
Among them, polyester insulated wires and polyester imide insulated wires are the most used because they combine productivity and economy in addition to excellent properties such as heat resistance, but the moisture and heat resistance of these insulated wires is The above demands are not yet at a satisfactory level and improvements are desired.

[0004]

As a method for improving the moisture and heat resistance of polyester insulated wires and polyester imide insulated wires, Japanese Patent Application Laid-Open No. 5-339540 discloses a method in which a polyester resin or a polyesterimide resin has a heat softening point of 40 ° C. or more. The use of an insulating paint obtained by dissolving an epoxy resin having a benzene nucleus in an organic solvent is disclosed.
An insulated wire using this insulating paint has improved wet heat resistance, but is inferior in flexibility, low in heat softening point and heat deterioration, and does not satisfy required performance.

Accordingly, an object of the present invention is to provide an insulated wire having excellent heat resistance and heat and humidity resistance overcoming the drawbacks of the conventional polyester insulated wire and polyesterimide insulated wire. The present inventor has focused on the above-disclosed technology, and as a result of intensive studies, without mixing with the polyester resin or polyesterimide resin that has produced the epoxy resin, the epoxy resin is another component as one component for synthesizing these resins. The present inventors have found that an insulated wire suitable for the purpose can be obtained by using an insulating paint containing a polyester resin or a polyesterimide resin obtained by reacting with a component, and completed the present invention.

[0006]

The above object is achieved by the present invention described below. That is, the present invention, on the conductor,
(A) a divalent carboxylic acid having a five-membered imide group,
At least one other aromatic polycarboxylic acid,
Insulation containing (B) at least one kind of dihydric alcohol, (C) at least one kind of trihydric or higher polyhydric alcohol and (D) a polyester resin obtained by reacting an epoxy resin having a softening point of 60 ° C. or higher. An insulated wire characterized by being coated and baked with a paint.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to embodiments of the present invention. A feature of the present invention is that a polyester resin obtained by reacting an aromatic polycarboxylic acid, a polyhydric alcohol, and an epoxy resin is used as the polyester resin used for the insulating coating.

As the aromatic polycarboxylic acid (A) used in the present invention, any of those conventionally used for the synthesis of polyesters and polyesterimides for insulating coatings can be used. For example, terephthalic acid, isophthalic acid Aromatic carboxylic acids such as phthalic anhydride, dimethyl terephthalic acid, dimethyl isophthalic acid, trimellitic anhydride, 5-membered carboxylic anhydrides, anhydrides thereof, and lower alkyls having 1 to 6 carbon atoms Derivatives such as esters)
Besides these, aromatic carboxylic anhydrides containing one carboxyl group, such as trimellitic anhydride, hemi-mellitic anhydride, naphthalenetricarboxylic anhydride, diphenyltricarboxylic anhydride, benzophenonetricarboxylic anhydride And an aromatic diamine consisting of a primary amino group, such as 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether,
Examples thereof include dicarboxylic acids having a 5-membered ring diimide group obtained by reacting 4 '-(or 3,3'-) diaminodiphenylsulfone, p- (or m-) phenylenediamine and the like. These aromatic polycarboxylic acids can be used alone or in combination of two or more.

Particularly preferred aromatic polycarboxylic acids are terephthalic acid or dimethyl terephthalic acid, and furthermore, for example, 2 moles of trimellitic anhydride and 1 mole of 4,4'-diaminodiphenylmethane By mixing a dicarboxylic acid having a five-membered imide group synthesized from imide and modifying the imide, that is, by producing a polyesterimide resin, the heat resistance of an insulated wire using an insulating paint containing the resin is significantly improved. . The five-membered diimidedicarboxylic acid can be synthesized by a method other than those described above, and the synthesis method is not particularly limited.

As the divalent alcohol (B) used in the present invention, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propylene glycol, 1,3-propanediol- And 1,3- (or 1,4-) butanediol, 1,5-pentanediol, 1,6-hexanediol, and cyclic glycols such as 1,4-cyclohexanedimethanol and trimethylene glycol. Can be These can be used alone or in combination of two or more. Particularly preferred is ethylene glyco-
It is.

Examples of the trivalent or higher polyhydric alcohol (C) in the present invention include, for example, glycerin, 1,1,1
-Trimethylolethane, 1,1,1, -trimethylo-
Examples thereof include aliphatic alcohols such as lupropane and pentaerythritol, and tris- (2-hydroxyethyl) isocyanurate. These can be used alone or in combination of two or more. Particularly preferred is glycerin.

The epoxy resin (D) used in the present invention comprises:
Any epoxy resin having a thermal softening point of 60 ° C. or higher can be used. For example, a bisphenol A type epoxy resin (for example, YD-001, 011, 014, 01 manufactured by Toto Kasei Co., Ltd.)
7,019, etc. and Epicoat 10 manufactured by Yuka Shell Epoxy Co., Ltd.
01, 1004, 1007, 1009, etc.), novolak type epoxy resin (for example, ECN-26 manufactured by Asahi Kasei Corporation)
8, 273, 278, 285, 292, 299, etc.). Particularly preferred is a bisphenol A type epoxy resin.

The epoxy resin having a heat softening point of 60 ° C. or higher is used when the heat softening point is lower than 60 ° C., because the epoxy resin has a low molecular weight and a small epoxy equivalent. This is because the property is extremely low and cannot be put to practical use.

In the present invention, as the polyester resin,
Component (A) aromatic polycarboxylic acids described above
(D) An epoxy resin is used, and a polyester resin synthesized by reacting these in an organic solvent at the following ratio in an organic solvent or without using an organic solvent according to a conventional method is used. In the present invention, (A) an aromatic polycarboxylic acid, (B) a dihydric alcohol and (C) a trihydric or higher polyhydric alcohol, the proportion of the component (A) in the total thereof is 25 to 60 equivalents. %, The ratio of the component (B) is 30 to 60 equivalent%, and the component (C)
) Is 10 to 30 equivalent% (provided that the component (A) + the component (B) + the component (C) = 100 equivalent%), and the total alcohol equivalent is 20 to 80%
Use in excess. Also, (D) epoxy resin
Polyester resin 1 theoretically obtained by reacting components (A) to (C) at the above ratio without using an epoxy resin
It is used in an amount of 15 to 50 parts by weight with respect to 00 parts by weight. When each component is used outside the above range, gelation occurs during the reaction to form a solvent-insoluble resin, or heat resistance, moisture resistance, and flexibility are required for insulated wire coatings. It is difficult to obtain a polyester resin having balanced properties.

Using these components, 14
A polyester resin is obtained by performing a polyesterification reaction at 0 to 240 ° C. for about 3 to 10 hours. The reaction can be carried out without using an organic solvent or by adding an organic solvent. When an organic solvent is added, phenol, which is usually used as a solvent for insulating paint,
Solvents having a phenolic hydroxyl group such as cresol and xylenol are used.

When a divalent carboxylic acid having a 5-membered imide group is used in combination with another aromatic polycarboxylic acid as the reaction component (A), the previously synthesized divalent carboxylic acid is used. In a polyester resin synthesis reaction system, for example, trimellitic anhydride and 4,4'-diaminodiphenylmethane are charged at a molar ratio of 2: 1 and a five-membered diimidedicarboxylic acid is charged in the system. An acid may be generated to carry out the resin synthesis reaction.
Further, in order to accelerate the synthesis reaction of the resin, a catalyst such as tetrabutyl titanate, lead acetate, lead oxide and dibutyltin oxide can be added.

In the present invention, when a divalent carboxylic acid having a five-membered imide group is not used as the component (A), a polyester resin is obtained. When the divalent carboxylic acid is used in combination, a polyester resin is obtained. An imide resin is formed.
These are collectively referred to as polyester resins in the present invention.

The insulated wire of the present invention is manufactured by applying and baking an insulating coating obtained by dissolving the polyester resin obtained above in an organic solvent on a conductor.
As the solvent for the paint used in the present invention, for example, pheno-
It is preferable to combine a solvent having a phenolic hydroxyl group such as toluene, cresol or xylenol with a diluent such as xylene or solvent naphtha, but N-methyl-2-
Solvents used for baking paints such as pyrrolidone, dimethylacetamide, dimethylformamide, glycol ethers, alcohols and ketones may be used, or some of them may be added.

When the paint used in the present invention is applied to a conductor and baked on the conductor to form an insulated wire, the use of a small amount of a metal desiccant or a compound of titanic acid increases the production take-up speed of the insulated wire and the surface of the insulated wire. It is preferable because the smoothness is further improved. Examples of the metal desiccant include zinc octenoate and lead naphthenate, and examples of the titanate compound include tetrabutyl titanate and tetraisopropyl titanate. 0.1 to 8.0 with respect to 100 parts by weight of the solid content of the insulating paint.
Parts by weight, preferably 1.0 to 5.0 parts by weight.

In the coating material used in the present invention, there may be used a stabilized isocyanate or a polyamide, in which the isocyanate group of the polyisocyanate is blocked with phenol or the like, as long as the characteristics of the present invention are not impaired. Thermoplastic resins such as polyester and polysulfone, thermosetting resins such as melamine resin and phenol resin, dyes, pigments, lubricants, and other paint additives can be appropriately added.

An insulated wire using the insulating paint of the present invention is prepared by adjusting the above paint to a viscosity suitable for work with an appropriate solvent.
It is manufactured by applying and baking on a conductor such as a soft copper wire according to a conventional method to form an insulating layer. The conductor used at this time is, for example, a copper wire, a silver wire, a stainless steel wire, etc., and the applicable conductor diameter may be any diameter from a very fine wire to a thick wire, and is limited to a specific conductor diameter. It is not something to be done. Generally, the conductor diameter is 0.05 to 2.0
It is mainly applied to copper wires of about mm.

The method of forming an insulating film on the conductor is as follows.
The method may be based on a conventionally known method, and is not limited at all.
For example, the above-mentioned insulating paint is applied to a conductor by a method such as a felt drawing method or a die drawing method, and continuously passed through a baking furnace at a temperature of about 350 to 550 ° C. several times or tens of times. An insulating coating is formed. The thickness of the insulating film is a thickness specified in a standard such as JIS, NEMA or IEC.

In the insulated wire of the present invention, a lubricant such as liquid paraffin or solid paraffin is further applied on the insulating coating layer formed on the conductor by the above-mentioned insulating paint to improve the winding property. Can be. Further, as generally used for imparting other properties to the insulated wire, another insulating paint can be applied and baked to laminate the insulating layer. For example, when a higher heat resistance is required, a polyimide-based insulating coating or a polyamide-imide insulating coating is used. When a higher winding property is required, a polyamide-based insulating coating such as 6,6-nylon is used. If the paint is required to be coil self-supporting,
For example, self-fusing paints such as polyvinyl butyral paints, phenoxy paints, polyamide paints, and polysulfone paints are used.

[0024]

EXAMPLES The present invention will be specifically described below with reference to Reference Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples.

Reference Example 1 970 g of dimethyl terephthalic acid was placed in a 5-liter flask equipped with a stirrer, a nitrogen inlet tube, a condenser and a thermometer.
(5 moles), 326 g (5.25 moles) of ethylene glycol, 138 g (1.5 moles) of glycerin, 4 parts of Epicoat 1007 (epoxy resin manufactured by Yuka Shell Epoxy Co.)
When 46 g and 1 g of lead oxide were charged and heated while blowing nitrogen, at 150 ° C., distillation of methanol started and the reaction started. After the temperature was raised to 220 ° C. over 10 hours, the heating was stopped to synthesize a polyester resin. The content was diluted with 1,845 g of cresol, cooled to 100 ° C., and further mixed with 62 g of tetrabutyl titanate.
A polyester resin paint having a resin content of 45% was obtained.

Reference Example 2 A polyester resin was synthesized in the same manner as in Reference Example 1. However, 970 g (5 mol) of dimethyl terephthalic acid, 326 g (5.25 mol) of ethylene glycol, and trimethylo-
201 g (1.5 mol) of lupropane, Epicoat 100
7 was reacted as 471 g and 1 g of lead oxide.
Diluted with 1,948 g of tetrabutyl titanate 66
g of a polyester resin paint having a resin content of 45%.

Reference Example 3 A polyesterimide resin was synthesized in the same manner as in Reference Example 1. However, 873 g (4.5 mol) of dimethyl terephthalic acid, 255 g (0.5 g) of a five-membered diimide dicarboxylic acid
Mol), 310 g (5.0 mol) of ethylene glycol,
Glycerin (154 g, 1.7 mol), Epicoat 100
7 was reacted as 380 g and 1 g of lead oxide.
Diluted with 2,119 g of tetrabutyl titanate 66
g of a polyesterimide resin paint having a resin content of 45%. The 5-membered diimidedicarboxylic acid was obtained by reacting trimellitic anhydride with 4,4'-diaminodiphenylmethane in cresol at a molar ratio of 2: 1 and separating and purifying it. It was used.

Reference Example 4 A polyesterimide resin was synthesized in the same manner as in Reference Example 1. However, 873 g (4.5 mol) of dimethyl terephthalic acid, 255 g (0.5 g) of a five-membered diimide dicarboxylic acid
Mol), 310 g (5.0 mol) of ethylene glycol,
Glycerin (154 g, 1.7 mol), Epicoat 100
7 was reacted as 254 g and 1 g of lead oxide.
Diluted with 1,956 g of toluene, tetrabutyl titanate 61
g of a polyesterimide resin paint having a resin content of 45%. The diimide dicarboxylic acid used was previously synthesized in the same manner as in Reference Example 3.

Reference Example 5 A polyesterimide resin was synthesized in the same manner as in Reference Example 1. However, 873 g (4.5 mol) of dimethyl terephthalic acid, 255 g (0.5 g) of a five-membered diimide dicarboxylic acid
Mol), 310 g (5.0 mol) of ethylene glycol,
Glycerin (154 g, 1.7 mol), Epicoat 100
7 was reacted as 571 g and 1 g of lead oxide.
Diluted with 2,363 g of toluene, tetrabutyl titanate 74
g of a polyesterimide resin paint having a resin content of 45%. As the diimidedicarboxylic acid, one synthesized in the same manner as in Reference Example 3 was used.

Reference Example 6 A polyester was obtained in the same manner as in Reference Example 1. However, 970 g (5 mol) of dimethyl terephthalic acid, 326 g (5.25 mol) of ethylene glycol, and 138 g of glycerin
(1.5 mol) and 1 g of lead oxide, diluted with 1,317 g of cresol, tetrabutyl titanate 4
5 g of a polyester resin paint having a resin content of 45% was obtained.

Reference Example 7 A polyester resin was obtained in the same manner as in Reference Example 1. However,
Dimethyl terephthalic acid 970 g (5 mol), ethylene glycol 326 g (5.25 mol), glycerin 138
g (1.5 mol) and 1 g of lead oxide, diluted with 1,845 g of cresol, blended and dissolved with 446 g of Epicoat 1007, and then mixed with tetrabutyl titanate.
And a polyester resin paint having a resin content of 45% was obtained.

Reference Example 8 A polyester resin was synthesized in the same manner as in Reference Example 1. However, 970 g (5 mol) of dimethyl terephthalic acid, 326 g (5.25 mol) of ethylene glycol, and trimethylo-
The reaction was carried out with 201 g (1.5 mol) of lupropane and 1 g of lead oxide, diluted with 1,392 g of cresol, and mixed with 47 g of tetrabutyl titanate to obtain a polyester resin paint having a resin content of 45%.

Reference Example 9 A polyester resin was synthesized in the same manner as in Reference Example 1. However, 970 g (5 mol) of dimethyl terephthalic acid, 326 g (5.25 mol) of ethylene glycol, and trimethylo-
After reacting with 201 g (1.5 mol) of lepropane and 1 g of lead oxide, diluting with 1,948 g of cresol, mixing and dissolving 471 g of Epicoat 1007, and then mixing 66 g of tetrabutyl titanate Thus, a polyester resin paint having a resin content of 45% was obtained.

Reference Example 10 A polyesterimide resin was synthesized in the same manner as in Reference Example 1. However, 873 g (4.5 mol) of dimethyl terephthalic acid, 255 g (0.5 g) of a five-membered diimide dicarboxylic acid
Mol), 310 g (5.0 mol) of ethylene glycol,
The reaction was carried out with 154 g (1.7 mol) of glycerin and 1 g of lead oxide, diluted with 1,630 g of cresol, and blended with 51 g of tetrabutyl titanate to obtain a polyesterimide resin paint having a resin content of 45%. Here, as the diimide dicarboxylic acid, one synthesized in the same manner as in Reference Example 3 was used.

Reference Example 11 A polyesterimide resin was obtained in the same manner as in Reference Example 1.
However, 873 g (4.5 mol) of dimethyl terephthalic acid,
The reaction was carried out as 255 g (0.5 mol) of 5-membered diimide dicarboxylic acid, 310 g (5.0 mol) of ethylene glycol, 154 g (1.7 mol) of glycerin and 1 g of lead oxide to give 2,119 g of cresol. After dilution, 380 g of Epicoat 1007 was blended and dissolved, and then 66 g of tetrabutyl titanate was blended to obtain a polyesterimide resin paint having a resin content of 45%. Here, as the diimide dicarboxylic acid, one synthesized in the same manner as in Reference Example 3 was used.

Reference Example 12 A polyesterimide resin was obtained in the same manner as in Reference Example 1.
However, 873 g (4.5 mol) of dimethyl terephthalic acid,
255 g (0.5 mol) of a five-membered ring diimide dicarboxylic acid, 310 g (5.0 mol) of ethylene glycol, 154 g (1.7 mol) of glycerin, epicoat 1007
Was reacted as 127 g and 1 g of lead oxide, diluted with 1,793 g of cresol, and 56 g of tetrabutyl titanate was reacted.
Was blended to obtain a polyesterimide resin paint having a resin content of 45%. In addition, what was synthesized in the same manner as in Reference Example 3 was used as the diimide dicarboxylic acid.

Reference Example 13 A polyesterimide resin was obtained in the same manner as in Reference Example 1.
However, 873 g (4.5 mol) of dimethyl terephthalic acid,
255 g (0.5 mol) of a five-membered ring diimide dicarboxylic acid, 310 g (5.0 mol) of ethylene glycol, 154 g (1.7 mol) of glycerin, epicoat 1007
Was reacted as 761 g and 1 g of lead oxide, diluted with 2,609 g of cresol, and 81 g of tetrabutyl titanate was reacted.
Was blended to obtain a polyesterimide resin paint having a resin content of 45%. Here, as the diimide dicarboxylic acid, one synthesized in the same manner as in Reference Example 3 was used.

Examples 1 to 3 , Comparative Examples 1 to 4, and Reference Examples 14 to 19 Each of the paints of Reference Examples 1 to 13 was coated with a copper wire having a conductor diameter of 0.32 mm in a horizontal baking furnace having a furnace length of 2.5 m. And furnace temperature 500
The coating and baking were performed at a temperature of 6 ° C., 6 dies, and a take-up speed of 22 m / min to produce an insulated wire having a film thickness of 0.018 mm. The properties of the obtained insulated wire were evaluated by the following test methods. Tables 1 and 2 show the component compositions at the time of synthesis of the polyester resin, and Tables 3 and 4 show the evaluation results of the insulated wires.

The test was performed according to JIS C 3003 (Testing method for enameled copper wire and enameled aluminum wire).

(1) Dielectric breakdown voltage after thermal degradation A two-twisted sample was subjected to 20 in the dielectric breakdown voltage test of JIS C 3003.
After standing in a constant temperature bath at 0 ° C. for 168 hours, the test was carried out in accordance with the dielectric breakdown voltage test of JIS C 3003, and the holding ratio to the initial value was measured.

(2) Moisture / heat resistance A two-twisted sample from a JIS C 3003 dielectric breakdown voltage test was sealed in a 700 ml autoclave together with 0.2 vol% of water and left in a thermostat at 120 ° C. for 168 hours. Rear JIS 3003 C
Was carried out in accordance with the dielectric breakdown voltage test, and the retention ratio with respect to the initial value was measured.

[0042]

[Table 1] Polyester resin synthetic component composition (Part 1) (Note) PE: represents a polyester resin. PEI: represents a polyesterimide resin.

[0043]

[Table 2] Table 2. Polyester resin synthetic component composition (Part 2) (Note) PE: represents a polyester resin. PEI: represents a polyesterimide resin.

[0044]

[Table 3] Table 3. Insulated wire characteristics (1)

[0045]

[Table 4] Table 4. Insulated wire characteristics (Part 2)

The results in Tables 3 and 4 show that the insulating paint of the present invention has excellent heat resistance and wet heat resistance while overcoming the drawbacks of the insulated wire using the conventional insulating paint. .

[0047]

The insulated wire according to the present invention has both excellent heat resistance and moist heat resistance, and can sufficiently meet the demand for insulated wires used for electric equipment in recent years.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Yagida 1-7-6 Bakurocho, Nihonbashi, Nihonbashi, Tokyo Dai-Nisseika Kogyo Co., Ltd. (56) References JP 50-55700 (JP, A) JP 5-159630 (JP, A) JP-A-3-237170 (JP, A) JP-A-55-112216 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01B 3/16 -3/56 C09D 163/00 C09D 167/02 C08G 63/00-63/76

Claims (2)

(57) [Claims] Claims: 1. A (A) five-membered imide group is provided on a conductor.
Divalent carboxylic acids and at least one other aromatic polycarboxylic acids which, (B) divalent least one alcohol, (C) at least one trihydric or higher polyhydric alcohol and (D) An insulated wire characterized by applying and baking an insulating paint containing a polyester resin obtained by reacting an epoxy resin having a softening point of 60 ° C. or higher. 2. The above components (A), (B) and (C)
Is an amount in which the proportion of the component (A) is 25 to 60 equivalent%, the proportion of the component (B) is 30 to 60 equivalent%, and the proportion of the component (C) is 10 to 30 equivalent%. In addition, the total alcohol equivalent is an amount that causes an excess of 20 to 80% of the total acid equivalent, and the component (D) is obtained by reacting the components (A), (B) and (C) in the above ratio without the presence of the same. 15 to 100 parts by weight of the resulting polyester resin
The insulated wire according to claim 1, wherein the amount is 50 parts by weight.