JPH11111059A - Solderable enameled wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve both solderability and heat resistance by constituting a solderable enameled wire by applying/baking enamel paint mainly composed of a compound formed by partially polymerizing a polyurethane structure having a urethane bond in a polyamide structure, on a conductor. SOLUTION: A chemical structure of this compound is expressed by a formula, and desirably, when the composition ratio of a polyamide imide structure and a polyurethane structure in this is (10/90 to 90/10), sufficient heat resistance and solderability are obtained. In the formula, R is an aliphatic chain. When this is used as enamel paint, polyamide imide almost maintains original heat resistance, and an enamel coating film decomposes/melts at about 400 to 450 deg.C in a short time, and soldering can be easily performed. This compound is obtained in such a way that after trimellitic acid anhydride and excessive 4.4'- diphenyl methane isocyanate dissolve in a solvent, it is agitated at a high temperature, a prescribed quantity of bivalent fatty acid alcohol is added thereafter, and is agitated at a high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solderable enameled wire, and more particularly to a solderable enameled wire for high heat resistance.

[0002]

2. Description of the Related Art In recent years, in the connection of enameled wire terminals, solderable enamelled wires which can be directly soldered without removing the coating of the enameled wire are widely used in order to rationalize electrical work. ing.

As this solderable enameled wire, a polyurethane enameled wire is often used, and particularly widely used for a small-diameter enameled wire in which it is difficult to mechanically remove the coating.

[0004] With the recent demand for miniaturization, high performance, or high reliability of equipment, higher heat resistance is required for solderable enameled wires.

For this reason, a modified polyurethane enameled wire in which a part of polyurethane is modified with polyesterimide to improve heat resistance, a modified polyesterimide enameled wire in which a urethane group is introduced into polyesterimide to impart solderability, and the like. Have been studied in various ways and have been put to practical use.

[0006]

However, in the case of these modified polyurethane enameled wires and modified polyesterimide enameled wires, if the heat resistance is emphasized, the solderability becomes insufficient. On the contrary, if the solderability is emphasized, the heat resistance becomes insufficient. Performance becomes insufficient.

That is, since the solderability and the heat resistance are contradictory properties, it is very difficult to make them compatible.
Conventional modified polyurethane enameled wires and modified polyesterimide enameled wires have not sufficiently satisfied the properties required in recent years.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a solderable enameled wire having good solderability and excellent heat resistance.

[0009]

According to a first aspect of the present invention, a polyurethane structure having a urethane bond in a polyamideimide structure is partially polymerized.

[0010]

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An enamel paint mainly composed of a paint having the chemical structure described above is applied and baked on a conductor.

The invention according to claim 2 is the solderable enameled wire according to claim 1, wherein the composition ratio of the polyamide imide structure and the polyurethane structure in the coating material is 10/90 to 90/10.

The reasons for limiting the above numerical range will be described below.

The reason that the composition ratio between the polyamideimide structure and the polyurethane structure is 10/90 to 90/10 is that if the composition ratio is smaller than 10/90, the heat resistance is insufficient.
If the composition ratio is larger than 90/10, the solderability deteriorates.

According to the above construction, a polyurethane structure having a urethane bond in a polyamideimide structure is partially polymerized.

[0016]

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Since the enamel paint mainly composed of the paint having the chemical structure described above is applied and baked on the conductor, a solderable enamel wire having good solderability and excellent heat resistance is obtained. be able to.

[0018]

Embodiments of the present invention will be described below.

The solderable enameled wire of the present invention focuses on polyamideimide which does not have solderability but is excellent in heat resistance. In order to impart solderability to polyamideimide, urethane bond to polyamideimide structure is used. Is prepared by partially polymerizing a polyurethane structure having the following formula, and applying and baking this paint on a conductor as an enamel paint.

Next, a method for producing a solderable enameled wire of the present invention will be described.

In the method for producing an enamel paint used for a solderable enamel wire according to the present invention, first, trimellitic anhydride and excess 4,4'-diphenylmethane diisocyanate are dissolved in a solvent and the solvent is heated to a high temperature. To stir to prepare a solution of a polyamideimide oligomer having an isocyanate terminal.

Thereafter, a dihydric aliphatic alcohol whose molar ratio to trimellitic anhydride is adjusted to a predetermined value is added to the polyamideimide oligomer solution, and the polyamideimide oligomer solution is further heated to a high temperature. To obtain an enamel paint.

The enamel paint is baked and applied on a conductor using a general technique to obtain a solderable enamel wire.

The dihydric aliphatic alcohol is not particularly limited, but when importance is placed on heat resistance, it is preferable to use those having 6 or less carbon atoms. And these may be used alone or in combination of two or more.

The solvent is not particularly limited, and examples thereof include N-methyl-2-pyrrolidone.

According to the solderable enameled wire of the present invention,
Since a coating obtained by partially polymerizing a polyurethane structure having a urethane bond in a polyamideimide structure is used as an enamel coating, the excellent heat resistance inherent in polyamideimide is substantially unchanged and soldering is usually performed. In a temperature range of about 400 to 450 ° C., the enamel coating is decomposed and dissolved in a short time, and soldering can be easily performed.

[0027]

【Example】

(Example 1) 1 mol of 4,4'-diphenylmethane diisocyanate and 0.5 mol of trimellitic anhydride are dissolved in 900 ml of N-methyl-2-pyrrolidone, and this solution is stirred at 140 ° C for 2 hours.

Next, 0.5 mol of butanediol is added to this stirring liquid, and this solution is again stirred at 140 ° C. for 2 hours to produce an enamel paint.

After applying this enamel paint on a copper conductor having a diameter of 0.2 mm so as to have a single coating thickness, the copper conductor is baked to produce a solderable enamel wire.

Example 2 Trimellitic anhydride was added in an amount of 0.1%.
Except that 8 mol and 0.2 mol of butanediol are used, a solderable enameled wire is produced in the same manner as in Example 1.

(Example 3) Trimellitic anhydride was added to 0.1%.
A solderable enameled wire is prepared in the same manner as in Example 1 except that 2 mol and butanediol are changed to 0.8 mol.

Example 4 A solderable enameled wire is produced in the same manner as in Example 1 except that 0.5 mol of ethylene glycol is used instead of 0.5 mol of butanediol.

Example 5 A solderable enameled wire is prepared in the same manner as in Example 1 except that 0.5 mol of hexanediol is used instead of 0.5 mol of butanediol.

Comparative Example 1 As an enamel paint, a polyamide-imide paint (HI-406-30) manufactured by Hitachi Chemical Co., Ltd.
After applying this enamel paint on a copper conductor having a diameter of 0.2 mm so as to have a single coating thickness, the copper conductor is subjected to a baking treatment to produce an enameled wire.

(Comparative Example 2) As an enamel paint, a solderable polyesterimide paint (FS-
Using 2), this enamel paint is applied on a copper conductor having a diameter of 0.2 mm so as to have one thickness, and then the copper conductor is subjected to a baking treatment to produce an enameled wire.

(Comparative Example 3) Trimellitic anhydride was added to 0.1%.
An enameled wire is produced in the same manner as in Example 1, except that 95 mol and 0.05 mol of butanediol are used.

(Comparative Example 4) Trimellitic anhydride was added in 0.1 ml.
An enameled wire is prepared in the same manner as in Example 1 except that the amount of the enamel wire is changed to 05 mol and the butanediol to 0.95 mol.

In each of Examples 1 to 5 and Comparative Examples 1 to 4, the dielectric breakdown voltage (kV), flexibility, adhesion, heat shock after 220 ° C. × 1 hour, softening temperature (kV) of the enameled wire or the enameled wire were used. ℃) 、 240 ℃ × 7days
Thermal Degradability (Dielectric Breakdown Voltage Residual Rate (%); (Dielectric Breakdown Voltage After Thermal Degradation Test × 100) / (Dielectric Breakdown Voltage Before Thermal Degradation Test)) Solderability at 440 ° C.
The test was performed for c). The above tests were conducted according to JIS
-Performed in accordance with C3003.

Table 1 shows the specifications of the solderable enameled wires or enameled wires of Examples 1 to 5 and Comparative Examples 1 to 4, and the results of various tests.

[0040]

[Table 1]

As shown in Table 1, the flexibility, adhesion, and heat shock were good in all the solderable enameled or enameled wires of Examples 1 to 5 and Comparative Examples 1 to 4. . The dielectric breakdown voltages were 9.0 kV, 9.2 kV, 8.7 kV, and 8.8 k, respectively.
V, 9.0 kV, 9.0 kV, 8.8 kV, 8.6 k
V, 9.0 kV.

In the solderable enameled wires of Examples 1 to 5, the composition ratio between trimellitic anhydride and butanediol (or ethylene glycol or hexanediol) was determined by changing the composition ratio between the polyamideimide structure and the polyurethane structure. Each is adjusted so as to be within the specified range (10/90 to 90/10).

For this reason, the softening temperatures of the solderable enameled wires of Examples 1 to 5 were 370 ° C. and 390 ° C., respectively.
340 ° C., 380 ° C., 360 ° C., and the dielectric breakdown voltage residual ratios indicating the thermal degradation are 90%, 92%, and 82%, respectively.
%, 92% and 87%, and has excellent heat resistance. Furthermore, the time required for soldering in the solderable enameled wires of Examples 1 to 5 was 6 seconds, 12 seconds, and 3 seconds, respectively.
Seconds, 10 seconds and 3 seconds, all of which were solderable.

On the other hand, in the enameled wire of Comparative Example 1, since the enamel paint was made of a 100 mol% polyamide-imide paint, the softening temperature was 420 ° C., the residual breakdown voltage was 95%, and the heat resistance was poor. Although excellent, soldering was not possible.

In the enameled wire of Comparative Example 2, since the enamel paint is composed of 100 mol% of a solderable polyesterimide paint, soldering is possible (the time required for soldering is 6 seconds), but the softening temperature is low. 330
° C, the residual breakdown voltage was 80%, and the heat resistance was poor.

In the enameled wire of Comparative Example 3, the composition ratio between trimellitic anhydride and butanediol was 47.
5: 2.5, and the composition ratio between the polyamide-imide structure and the polyurethane structure is within the specified range (10/90 to 90/1).
0) Since it was outside, the softening temperature was 400 ° C., and the residual breakdown voltage was 93%, which was excellent in heat resistance, but soldering was impossible.

In the enameled wire of Comparative Example 4, the composition ratio of trimellitic anhydride to butanediol was 2.5:
47.5, and the composition ratio between the polyamide-imide structure and the polyurethane structure is within a specified range (10/90 to 90/10).
Therefore, although soldering was possible (the time required for soldering was 2 seconds), the softening temperature was 310 ° C., the residual breakdown voltage was 78%, and the heat resistance was poor.

[0048]

In summary, according to the present invention, the use of a coating obtained by partially polymerizing a polyurethane structure having a urethane bond in the polyamideimide structure as the enamel coating for the solderable enameled wire allows the polyamideimide to be originally used. While having excellent heat resistance, it has an excellent effect that a solderable enameled wire that can be easily soldered can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C08G 18/34 C08G 18/34 Z

Claims (2)

[Claims] 1. Polyurethane structure having a urethane bond in a polyamideimide structure is partially polymerized. Enamel paint mainly composed of paint with the chemical structure of
A solderable enameled wire characterized by being coated and baked on a conductor. 2. The composition wherein the composition ratio of the polyamide imide structure and the polyurethane structure in the coating material is 10/90.
2. The solderable enameled wire according to claim 1, wherein the number is from 90 to 90/10.