JP2000351936A - Insulating coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulating coating capable of being baked at a temperature lower than a common working baking temperature in the production of an insulated electric wire having a heat resistance equal to or higher than F-rank, and enabling the production of an insulated electric wire having excellent heat resistance and soldering property. SOLUTION: This insulating coating is obtained by compounding (A) 100 pts.wt. of a polyesterimide resin having an OH group at a terminal obtained by reacting (a) a dicarboxylic acid having a pentacyclic imide group or its derivative, or their mixture with (b) an aromatic polycarboxylic acid or its derivative, (c) an aliphatic dihydroxy alcohol and (d) a polyhydroxy alcohol higher than trivalent in the presence of an organic solvent with (B) 50-300 pts.wt. of a mixture of stabilized polyisocyanates containing 10-60 equivalent % of a stabilized polyisocyanate having cyanuric rings based on the amount of effective NCO group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating paint excellent in workability and capable of obtaining a heat-resistant insulated wire having solderability.

[0002]

2. Description of the Related Art In recent years, the size and weight of electric devices such as motors and transformers and the performance thereof have been remarkably increased. Along with this, in order to improve the reliability of electrical equipment, the heat resistance of insulated wires, which are used materials, has been increasing.
W), a polyesterimide insulated wire (EIW) using a polyesterimide insulating paint, a polyamideimide insulated wire (AIW) using a polyamideimide insulating paint, and the like have been developed and put into practical use.

[0003] On the other hand, insulated wire manufacturers have been developing and improving insulated wire manufacturing equipment in order to increase productivity by raising the work baking temperature, mainly for the purpose of improving productivity. It would be more convenient if the work baking temperature could be lowered. In the manufacture of the above-mentioned heat-resistant insulated wires such as PEW, EIW, and AIW,
The working baking temperature usually needs to be 450 ° C. or higher, whereas the production of polyurethane insulated wire (UEW) usually requires 3 ° C.
It is possible at 00 ° C or higher. However, the heat resistance of this UEW is class E, and does not reach the heat resistance required by electric appliance manufacturers.

[0004] Under these circumstances, insulated wire manufacturers require an insulating paint that has heat resistance at least equal to or higher than PEW and can be manufactured at a work baking temperature lower than that at the time of manufacturing PEW or the like. On the other hand, electrical equipment manufacturers that use insulated wires have been trying to streamline processes such as labor-saving automation mainly to reduce costs, and as a result, insulated wires will lead to not only the above-mentioned heat resistance but also labor-saving automation. They have been demanding ones with various characteristics.

As one of the various characteristics that lead to labor-saving automation, there is a demand for solderability in which the insulating coating of the insulated wire is simultaneously peeled off and soldered in the terminal treatment.
The method of terminal stripping of insulated wires includes (1) mechanical stripping,
There are methods such as (2) thermal decomposition peeling, (3) chemical peeling, and (4) solder peeling, but in consideration of working time, conductor intactness, continuous processing, etc., removal of the terminal insulation film and soldering Is considered most preferable. For this reason, insulated wires that can be soldered at the same time as the insulation coating is peeled off are strongly demanded from electrical equipment manufacturers, in addition to heat resistance.

[0006]

As an insulated wire that can be soldered, there is a polyurethane insulated wire (UEW). However, as described above, the heat resistance is as low as Class E. In addition, heat-resistant F-class polyesterimide urethane insulated wires have been developed and put to practical use as a heat-resistant product of UEW, but those having excellent heat resistance have poor solderability, and those having excellent solderability have heat resistance. There are still many unsatisfactory points such as poor sex. As a result, the glass transition temperature (hereinafter abbreviated as Tg) of the insulating film is emphasized as a measure of heat resistance, and at least 1
An insulating coating material having a Tg of 80 ° C. or higher and capable of forming an insulating film having a solderability of 400 seconds or less for 2 seconds has been required.

[0007] Accordingly, an object of the present invention is to enable baking of an insulated wire having a heat resistance of class F or higher at a temperature lower than the normal working baking temperature, and the heat resistance of the insulating film of the formed insulated wire. However, an object of the present invention is to provide an insulating paint which enables production of an insulated wire having a Tg of 180 ° C. or more and a solderability of 400 ° C. for 2 seconds or less. The present inventors have conducted various studies on a stabilized polyisocyanate as a crosslinking agent in order to achieve the above object, and as a result, a stabilized polyisocyanate having a cyanuric ring and a stabilized polyisocyanate having no cyanuric ring have been specified. By using them together in proportions, it became possible to manufacture insulated wires at a lower working baking temperature than during the manufacture of PEW, etc., and found that the manufactured insulated wires had excellent heat resistance and solderability, and completed the present invention. I came to.

[0008]

The above object is achieved by the present invention described below. That is, the present invention relates to (A) (a)
(B) an aromatic polycarboxylic acid or a derivative thereof, (c) an aliphatic dihydric alcohol, and (d) a trivalent carboxylic acid or a derivative thereof containing a 5-membered imide group. Based on 100 parts by weight of a polyesterimide resin having an OH group at the terminal obtained by reacting the above polyhydric alcohol with an organic solvent in the presence of an organic solvent, (B) a stabilized polyisocyanate having a cyanuric ring is used as an effective NCO
An insulating coating material comprising 50 to 300 parts by weight of a stabilized polyisocyanate mixture containing 10 to 60 equivalent% as a base.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to embodiments of the invention. The polyesterimide resin (A) used in the present invention is known, and an insulating coating containing the resin and a stabilized polyisocyanate is also disclosed in JP-A-3-190.
917 and the like. A feature of the present invention is to use a mixture of a polyesterimide resin (A) and a stabilized polyisocyanate having no cyanuric ring, which contains a stabilized polyisocyanate having a cyanuric ring as a crosslinking agent in a specific ratio. is there. Although the above publication discloses the use of a stabilized polyisocyanate having a cyanuric ring alone, the use of this and a stabilized polyisocyanate having no cyanuric ring in a specific ratio leads to an improvement in solderability. There is no suggestion that the heat resistance can be improved without deteriorating the heat resistance.

The polyesterimide resin (A) containing a five-membered imide group used in the present invention comprises (a)
(B) an aromatic polycarboxylic acid or a derivative thereof, (c) an aliphatic dihydric alcohol, and (d) a trivalent carboxylic acid or a derivative thereof containing a 5-membered imide group. It can be obtained by reacting the above polyhydric alcohol with an organic solvent.

From the viewpoint of the flexibility, heat resistance and solderability of the insulating coating, (a) is 5 to 20 equivalent%, and (b) is 10 to
30 equivalent%, (c) 25 to 60 equivalent%, (d) 10
The reaction is preferably performed at a ratio of 40 equivalent%. or,
In order to produce a polyesterimide resin having a terminal OH group, all the acid components comprising (a) and (b) and (c)
And the total alcohol component consisting of (d) are reacted so that the ratio of total acid component / total alcohol component is 1 / 1.4 to 2.5 (equivalent ratio).

The components used for producing the polyesterimide resin (A) containing a five-membered imide group will be described below. A divalent carboxylic acid containing a five-membered imide group or a derivative (a) thereof is prepared by, for example, reacting the following (a) and (b) or (a) with (c) by a conventionally known method. It is obtained by doing. (A) A carboxylic anhydride containing at least one other reactive group (carboxyl group, carboxylic anhydride group, hydroxyl group, etc.) in addition to the five-membered carboxylic anhydride group. (B) A primary amine containing at least one other reactive group (carboxyl group, hydroxyl group, primary amino group, etc.) in addition to the primary amino group. (C) Polyisocyanate.

Examples of the carboxylic anhydride (a) containing at least one other reactive group in addition to the five-membered carboxylic anhydride group include tricarboxylic anhydrides, for example, trimellitic anhydride, Hemimellitic anhydride, naphthalene tricarboxylic anhydride, diphenyltricarboxylic anhydride, benzophenone tricarboxylic anhydride, and the like. Examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, naphthalene tetracarboxylic dianhydride, diphenylmethane tetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, and the like.

Examples of primary amines (b) containing at least one other reactive group in addition to the primary amino group include, for example, ethylenediamine, hexamethylenediamine, dimethylheptamethylenediamine, dimethylhexamethylene Aliphatic diamines such as diamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenylether, dimethylbisphenyldiamine,
Aromatic diamines such as diaminonaphthalene, phenylenediamine, and xylylenediamine, and further, for example, amino alcohols such as monoethanolamine and dimethylethanolamine, and aminocarboxylic acids such as aminopropionic acid can be given.

Examples of the polyisocyanate (c) include phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, diphenyl ether diisocyanate, diphenyl sulfone diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, and the like.

The divalent carboxylic acid containing a 5-membered imide group is preferably a divalent carboxylic acid obtained from 2 moles of trimellitic anhydride and 1 mole of an aromatic diamine in view of the heat resistance of the insulated wire obtained. Is an acid. Economically, 2 moles of trimellitic anhydride and diaminodiphenylmethane 1
Preference is given to divalent carboxylic acids obtained in moles. These divalent carboxylic acids containing a five-membered imide group are usually obtained by reacting (a) with (b) or (c) in a solvent.

Examples of the solvent used in the above reaction include polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, phenol, cresol, xylenoleic acid, xylene, solvent naphtha, methyl ethyl ketone, ethyl acetate and the like. Hydrocarbon solvents. These solvents can be used alone or as a mixed solvent.

Examples of the aromatic polycarboxylic acid or its derivative (b) include terephthalic acid, isophthalic acid, phthalic anhydride, dimethyl terephthalic acid, dimethyl isophthalic acid, trimellitic anhydride, naphthalene tricarboxylic anhydride, diphenyl Examples include tricarboxylic anhydride, benzophenone tricarboxylic anhydride, pyromellitic dianhydride, naphthalene tetracarboxylic dianhydride, diphenylmethane tetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, and the like. These can be used alone or as a mixture of two or more.

Examples of the aliphatic dihydric alcohol (c) include ethylene glycol, diethylene glycol,
1,3-propanediol, 1,4-butanediol,
Examples thereof include 1,5-pentanediol, 1,6-hexanediol, 1,2-propylene glycol, and 1,3-butanediol. These can be used alone or as a mixture of two or more.

Examples of the trihydric or higher polyhydric alcohol (d) include glycerin, pentaerythritol,
Examples thereof include 1,1-trimethylolethane, 1,1,1-trimethylolpropane, and tris- (2-hydroxyethyl) isocyanunate. These can be used alone or as a mixture of two or more.

In the production of the polyesterimide resin having an OH group at the terminal used in the present invention, it is preferable to use each component in the above-mentioned ratio, and to use a divalent carboxylic acid containing a five-membered imide group or a divalent carboxylic acid containing the same. When the derivative or the mixture (a) thereof is less than 5 equivalent%, when the aliphatic dihydric alcohol (c) exceeds 60 equivalent% and the trihydric or higher polyhydric alcohol (d) is less than 10 equivalent%, it is obtained. The heat resistance of the insulated wire becomes insufficient.

The polyesterimide resin (A) having a terminal OH group used in the present invention can be produced by a known method, and the production method is not particularly limited. For example, the following conventionally known methods can be used. (1) After forming a divalent carboxylic acid containing a 5-membered imide group in the above-mentioned (a), (b) or (c) in a solvent, the aliphatic dihydric alcohol is added to the system. A method of adding a trihydric or higher polyhydric alcohol, an aromatic polycarboxylic acid or a derivative thereof, and reacting at 200 to 250 ° C. for 3 to 15 hours. (2) A divalent carboxylic acid containing a 5-membered imide group is formed in a solvent according to (a), (b) or (c) above. Separately, a polyester intermediate comprising an aliphatic dihydric alcohol, a trihydric or higher polyhydric alcohol, an aromatic polyhydric carboxylic acid or a derivative thereof is formed. Then, a method of reacting these reaction products at 200 to 250 ° C. for 3 to 15 hours. (3) A polyester intermediate comprising an aliphatic dihydric alcohol, a trihydric or higher polyhydric alcohol, an aromatic polyhydric carboxylic acid or a derivative thereof is formed. In this system, a solvent and the above-mentioned (a), (b) or (c) are added to form a divalent carboxylic acid containing a 5-membered imide group, followed by 2
A method of reacting at 00 to 250 ° C for 3 to 15 hours. (4) The above-mentioned (a), (b) or (c), an aliphatic dihydric alcohol, a trihydric or higher polyhydric alcohol, an aromatic polycarboxylic acid or a derivative thereof are added all at once to a solvent. To produce a divalent carboxylic acid containing a 5-membered imide group at 120-180 ° C, followed by 200-250 ° C
For 3 to 15 hours.

As the solvent used for the above reaction and dilution, for example, phenol, cresol, xylenol,
Polar solvents such as dimethylformamide and N-methyl-2-pyrrolidone can be used. Further, as the auxiliary solvent at the time of dilution, for example, a hydrocarbon solvent such as toluene, xylene, solvent naphtha, methyl ethyl ketone, and cyclohexanone can be used.

The insulating coating of the present invention can be obtained by dissolving the polyesterimide resin having an OH group at the terminal obtained above in a solvent and adjusting the concentration to an appropriate concentration. Normally,
The solution of the polyesterimide resin obtained above is used. As the solvent, a solvent having a phenolic hydroxyl group is usually used, and the most useful solvent is cresylic acid. Cresolic acid includes phenol, cresol, and xylenol, and has a boiling range of 180 to 230 ° C.

The insulating coating composition of the present invention contains a stabilized polyisocyanate as a crosslinking agent. The stabilized polyisocyanate used in the present invention is a mixture of a stabilized polyisocyanate having a cyanuric ring and a stabilized polyisocyanate having no cyanuric ring. The stabilized polyisocyanate having a cyanuric ring is a compound obtained by trimerizing an organic polyisocyanate into a cyclic compound.
Desmodur CT-Stable (manufactured by Bayer), a stabilized polyisocyanate obtained from tolylene diisocyanate, Desmodur P, a stabilized polyisocyanate obtained from isophorone diisocyanate
L340, Desmodur BL4265 (manufactured by Sumitomo Bayer Urethane Co., Ltd.), Desmodur TPLS2759, which is a stabilized polyisocyanate obtained from hexamethylene diisocyanate, and Sumidur BL3175 (manufactured by Sumitomo Bayer Urethane Co., Ltd.). These can be used alone or as a mixture.

Examples of the stabilized polyisocyanate having no cyanuric ring to be used in combination include, for example, Millionate MS-50 (manufactured by Nippon Polyurethane Industry), which is a stabilized polyisocyanate obtained from 4,4'-diphenylmethane diisocyanate. Coronate 2503 (manufactured by Nippon Polyurethane Industry), Desmodur AP-Stable (manufactured by Bayer), which is a stabilized polyisocyanate obtained from tolylene diisocyanate, and the like.
These can be used alone or as a mixture.

In the stabilized polyisocyanate mixture, the proportion of the stabilized polyisocyanate having a cyanuric ring depends on the amount of effective NCO groups in the total effective NCO in the mixture.
10 to 60 equivalent%, preferably 20 to 50 equivalent% of the base amount
Is the amount Here, the effective amount of NCO groups means the amount of isocyanate groups regenerated by dissociation of the blocking agent in the stabilized polyisocyanate. If the effective NCO group content of the stabilized polyisocyanate having a cyanuric ring is less than 10 equivalent%, the heat resistance of an insulated wire obtained at a lower work baking temperature than the insulating paint for PEW is insufficient, and
If it exceeds the equivalent%, the solderability of the obtained insulated wire will deteriorate, and further, elongate pinholes will occur over time, making practical use difficult.

The proportion of the stabilized polyisocyanate mixture (B) used in the insulating coating of the present invention is determined by the polyesterimide resin (A) having a terminal OH group used in the present invention.
The proportion is 50 to 300 parts by weight, preferably 75 to 200 parts by weight, per 100 parts by weight. If the amount is less than 50 parts by weight, it is difficult to produce an insulated wire satisfying the required heat resistance and solderability, and if it exceeds 300 parts by weight, the heat resistance deteriorates.

Stabilized polyisocyanate mixture (B)
Is dissolved in a solvent or directly mixed with the solution of the polyesterimide resin (A) and mixed and dissolved. If necessary, a solvent is further added to dissolve uniformly. As the solvent at the time of dissolution and dilution, the above-mentioned solvent used for the synthesis of the polyesterimide resin is used.

The addition of an organometallic compound to the insulating paint thus obtained, if necessary, can further increase the speed at which the insulated wire can be taken in and improve the surface smoothness of the insulated wire. preferable. Examples of the organic metal compound include metal salts such as zinc and lead of aliphatic or alicyclic carboxylic acids such as zinc octenoate and lead naphthenate, and tin compounds such as dibutyltin laurate and dibutyltin diacetate. . Further, the insulating coating of the present invention, thermoplastic resin such as polyamide, polyester, polysulfone, as long as the characteristics of the present invention are not impaired,
It is also possible to add thermosetting resins such as melamine resins and phenol resins, dyes, pigments, lubricants, and other additives for paints.

If the insulating paint of the present invention is adjusted to a viscosity suitable for work with an appropriate solvent, and then applied on a conductor such as an annealed copper wire according to a conventional method, it is baked at a work baking temperature lower than that of the paint for PEW. To make an insulated wire. And the obtained insulated wire is excellent in heat resistance and solderability.
Further, the upper layer of the insulated wire manufactured by the insulating paint of the present invention can be coated with lubricant such as liquid paraffin or solid paraffin for winding property, and is generally used to impart other properties. It is also possible to provide an insulating layer which has been coated with another insulating paint and baked. For example, if further heat resistance is required, polyimide-based insulation paint or polyamide-imide insulation paint,
Polyamide coating such as nylon 6,6 when winding property is required, self-fusing coating when coil self-support is required, for example, polyvinyl butyral, phenoxy, polyester, polyamide, polysulfone coating Can be applied.

[0032]

Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.

Reference Example 1 Dimethyl terephthalate 680 was placed in a 5-liter flask equipped with a stirrer, a nitrogen gas inlet tube, a condenser and a thermometer.
g (3.5 mol), ethylene glycol 260 g (4.
2 mol), 260 g (2.8 mol) of glycerin and 3 g of tetrabutyl titanate.
At 0 ° C., demethanol accompanying the transesterification reaction started. After the temperature was gradually raised to 200 ° C. over 10 hours, 1,170 g of cresol was charged to stop the reaction. 10
After cooling to 0 ° C, trimellitic anhydride 580 was added to the system.
g (3.0 mol) and 300 g (1.5 mol) of 4,4'-diaminodiphenylmethane were charged and heated again while blowing in nitrogen gas. Dehydration started and the formation of diimidedicarboxylic acid started. After keeping at 150 ° C. for 5 hours, the mixture was further heated and kept at 200 ° C. for 5 hours to cause an esterification reaction, and then diluted with 580 g of cresylic acid to stop the reaction. A resin solution was obtained.

Reference Example 2 Dimethyl terephthalate 3 was prepared in the same apparatus as in Reference Example 1.
90 g (2.0 mol), trimellitic anhydride 190 g
(1.0 mol), 310 g of ethylene glycol (3.4
Mol), 310 g (5.0 mol) of glycerin and 3 g of tetrabutyl titanate, and reacted in the same manner as in Reference Example 1. Thereafter, 1,200 g of cresol was charged to stop the reaction. After cooling to 100 ° C., 580 g (3.0 mol) of trimellitic anhydride and 300 g (1.5 mol) of 4,4′-diaminodiphenylmethane were charged into the system and reacted again in the same manner as in Reference Example 1. The reaction was stopped by diluting with 600 g of cresylic acid to obtain a polyesterimide resin solution having a resin content of 50% by weight.

Reference Example 3 In the same apparatus as in Reference Example 1, dimethyl terephthalate 6
80 g (3.5 mol), 310 g ethylene glycol
(5.0 mol), 450 g of trimethylolpropane
(3.4 mol) and 3 g of tetrabutyl titanate, and reacted in the same manner as in Reference Example 1.
20 g was charged to stop the reaction. After cooling to 100 ° C., 580 g (3.0 mol) of trimellitic anhydride and 300 g of 4,4′-diaminodiphenylmethane were added to the system.
(1.5 mol), and reacted again in the same manner as in Reference Example 1. The reaction was stopped by diluting with 660 g of cresylic acid to obtain a polyesterimide resin solution having a resin content of 50% by weight.

Example 1 In a 5 liter flask equipped with a stirrer and a thermometer, 1,000 g of the polyesterimide resin solution of Reference Example 1 and Desmodur CT-Stable (manufactured by Bayer AG; effective NCO1)
(4% by weight), 240 g, Coronate 2503 (manufactured by Nippon Polyurethane Industry Co., Ltd .; effective NCO weight: 10%), 510 g, 1,250 g of cresylic acid, 1,160 g of xylene, and 10 g of zinc naphthenate, and uniformly dissolved at 80 ° C. 30% by weight of an insulating paint was obtained.

Example 2 In the same manner as in Example 1, 1,000 g of the polyesterimide resin solution of Reference Example 2, 195 g of Desmodur CT-Stable (manufactured by Bayer), 805 g of Coronate 2503 (manufactured by Nippon Polyurethane Industry), Cresylic acid 1,
590 g, xylene 1,400 g and zinc naphthenate 1
5 g were dissolved to obtain an insulating paint having a resin content of 30% by weight.

Example 3 In the same manner as in Example 1, 1,000 g of the polyesterimide resin solution of Reference Example 2 and Desmodur BL4265
(Sumitomo Bayer Urethane Co .; effective NCO weight 8%) 3
95 g, Coronate 2503 (manufactured by Nippon Polyurethane Industry Co., Ltd.) 740 g, 1,590 g of cresylic acid, 1,260 g of xylene, and 15 g of zinc naphthenate were dissolved to obtain an insulating paint having a resin content of 30% by weight.

Example 4 In the same manner as in Example 1, 1,000 g of the polyesterimide resin solution of Reference Example 3, 195 g of Desmodur CT-Stable (manufactured by Bayer), 805 g of Coronate 2503 (manufactured by Nippon Polyurethane Industry), Cresylic acid 1,
590 g, xylene 1,410 g and zinc naphthenate 1
5 g were dissolved to obtain an insulating paint having a resin content of 30% by weight.

Comparative Example 1 In the same manner as in Example 1, 1,000 g of the polyesterimide resin solution of Reference Example 2, 1,000 g of Coronate 2503 (manufactured by Nippon Polyurethane Industry Co., Ltd.), 1,5 g of cresylic acid
90 g, xylene 1,395 g and zinc naphthenate 15
g was dissolved to obtain an insulating paint having a resin content of 30% by weight.

Comparative Example 2 In the same manner as in Example 1, 1,000 g of the polyesterimide resin solution of Reference Example 1, 470 g of Desmodur CT-Stable (manufactured by Bayer), 280 g of Coronate 2503 (manufactured by Nippon Polyurethane Industry), Cresylic acid 1,
250 g, xylene 1,160 g and zinc naphthenate 1
0 g was dissolved to obtain an insulating paint having a resin content of 30% by weight.

The insulating paints obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were applied to a copper wire having a conductor diameter of 0.20 mm in a horizontal baking furnace having a furnace length of 2.5 m and a furnace temperature of 400 ° C. and a felt. Eight times,
It was applied and baked under the condition of a take-up speed of 50 m / min to produce an insulated wire having a coating thickness of 0.015 mm. These baking conditions are usually conditions in which the working baking temperature is too low and not suitable for the production of PEW, EIW, and AIW. The appearance, solderability, heat resistance and the like of the obtained insulated wire were tested. The appearance, adhesion, flexibility, softening resistance, dielectric breakdown voltage, and solderability were measured in accordance with JIS C 3003 (Test method for enameled copper wire and enameled aluminum wire). Tg, which is a measure of heat resistance, was measured at 10 ° C. by a compression load method (a load of 20 g) using a thermomechanical measuring device manufactured by Rigaku Corporation.
/ Min. Table 1 shows the test results of these electric wire characteristics.

Table 1 (Insulated wire characteristics) (Note) Impossible: Does not peel even after soaking for 10 seconds

The results in Table 1 show that the insulated wire obtained by using the insulating paint of the present invention has excellent heat resistance and solder peeling properties, which overcome the drawbacks of the conventional solderable insulated wire. It indicates that.

[0045]

According to the present invention described above, an insulating paint capable of producing an insulated wire having excellent heat resistance and solder peelability at a work baking temperature in the production of UEW lower than a work baking temperature in the production of EIW. Is provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01B 3/30 H01B 3/30 M // C08G 18/42 C08G 18/42 Z (72) Inventor Kazuhiro Sunouchi 1-7-6, Nihonbashi-cho, Nihonbashi, Chuo-ku, Tokyo Dai-Nisseika Kogyo Co., Ltd. (72) Inventor Setsuo Terada 1-7-6, Nihonbashi-bakurocho, Nihonbashi, Chuo-ku, Tokyo Dai-Ni Seika Kogyo Co., Ltd. F-term (reference) DB03 DC02 DC03 DF01 DF04 DF32 HC35 HD00 JA02 QB06 RA07 4J038 DG262 DG292 DJ051 NA21 5G305 AA02 AA11 AB24 BA09 CA18 CA22 CA32 CA51 CA55

Claims (1)

[Claims] (A) (a) a divalent carboxylic acid containing a five-membered imide group or a derivative or a mixture thereof, (b) an aromatic polycarboxylic acid or a derivative thereof, and (c) a fat Imide group-terminated polyesterimide resin 1 obtained by reacting a group 2 dihydric alcohol with (d) a trihydric or higher polyhydric alcohol in the presence of an organic solvent
50 to 30 parts by weight of a mixture of a stabilized polyisocyanate containing 10 to 60 equivalent% of (B) a stabilized polyisocyanate having a cyanuric ring in an effective NCO group amount.
An insulating paint characterized by comprising 0 parts by weight.