JPH05339522A - Rapidly curable insulating varnish and insulated wire - Google Patents

Abstract

PURPOSE:To obtain the title varnish with which granulation and foaming can effectively be prevented irrespective of rapid curing by blending a bisphenolic epoxy resin having a specific thermosoftening point with an aromatic polyamide- imide resin. CONSTITUTION:100 pts.wt. aromatic polyamide-imide resin is blended with 1-10 pts.wt. bisphenolic resin having a chemical structure of the formula and having a thermosoftening point of 40-130 deg.C to thereby obtain the title varnish. A polyamide-imide-coated insulated wire produced by applying this varnish to a conductor and baking the same is excellent in any of properties, such as appearance, heat resistance and flexibility, so that it is industrially useful.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating paint and an insulated wire. More specifically, the present invention relates to a polyamide-imide insulating coating having excellent fast-curing properties and a polyamide-imide insulating electric wire formed by coating and baking the coating on a conductor.

[0002]

2. Description of the Related Art Polyamideimide insulated wires have excellent heat resistance, mechanical properties, refrigerant resistance, etc., and are widely used as heat resistant enameled wires having a heat resistant classification of H to C class. For example, polyamide-imide insulated wire is used for electric tool motors, wiper motors, motors for cooling equipment,
It is used as a coil enamel wire for F to H class general-purpose motors and has high reliability.

[0003]

However, the polyamide-imide type insulated electric wire has a drawback that the workability of coating and baking the polyamide-imide type insulating paint on the conductor wire is inferior from the viewpoint of the enamel wire manufacturer.

That is, the polyamide-imide type insulating coating material has a drawback that when it is applied and baked on a conductor at a high temperature, particles and foaming are likely to occur in the baked enamel film. For this reason, in the production of a polyamide-imide insulated wire, the coating amount is reduced at one time so that particles and foaming can be suppressed, the baking temperature is lowered, and the baking is performed at a low speed.

For this reason, it is difficult to improve the productivity per enameled wire coating machine.

The present invention has been made in view of such a point, and its purpose is to solve the above-mentioned drawbacks of the prior art and to effectively suppress particles and foaming even when cured at a high speed. It is an object of the present invention to provide a polyamide-imide insulating coating material capable of achieving the above, and a polyamide-imide insulating electric wire formed by applying and baking the insulating coating material on a conductor.

[0007]

The gist of the present invention is that 100 parts by weight of an aromatic polyamide-imide resin has the chemical structural formula of the following chemical formula 1 and has a heat softening point of 40 to 130.
And 1-10 parts by weight of a bisphenol-based epoxy resin blended at high temperature,

[0008]

[Chemical 1]

An insulated wire is obtained by coating and baking the above-mentioned fast-curing insulating coating material on a conductor directly or through another insulating layer.

In the present invention, as the aromatic polyamideimide resin, a polyamideimide insulating coating formed by reacting an aromatic tribasic acid anhydride and an aromatic diisocyanate in a polar solvent is suitable.

Examples of this type of polyamide-imide insulating paint include DAI-500 manufactured by Nitto Denko Corporation, HI-406 manufactured by Hitachi Chemical Co., Ltd., and NH-AI manufactured by Tokoku Paint Co., Ltd.
Etc. can be used.

In the present invention, the epoxy resin to be blended with 100 parts by weight of the aromatic polyamide-imide resin is limited to the bisphenol type epoxy resin having a heat softening point of 40 to 130 ° C. because the bisphenol having a heat softening point of 40 ° C. or lower is used. Since the epoxy resin is too low, it is likely to be decomposed by heat during baking at high temperature, resulting in the generation of particles and foaming. On the contrary, the bisphenol epoxy resin having a softening point of 130 ° C or higher has an excessively high molecular weight. This is because the compatibility with the polyamide-imide resin is lowered, the cloudiness of the paint is promoted, and the paint stability is deteriorated.

Here, as the bisphenol-based epoxy resin having a thermal softening point of 40 to 130 ° C., Epicoat 1001, Epicoat 1002, and Epicoat 10 manufactured by Ciel Co., Ltd.
03, Epicoat 1004, Epicoat 1007 and the like.

Further, here, the heat softening point is 40 to 13
The blending amount of bisphenol-based epoxy resin at 0 ° C is 1 to 1
The limitation to 0 parts by weight is that when the compounding amount of the bisphenol epoxy resin is 1 part by weight or less, there is no effect of suppressing particles and foaming, and conversely, when it is 10 parts by weight or more, the heat resistance of the obtained insulated wire is sharply reduced. This is because

[0015]

The fast-curing insulating coating material and insulated wire of the present invention contain 1 part by weight of a bisphenol epoxy resin having a heat softening point of 40 to 130 ° C. in 100 parts by weight of an aromatic polyamideimide resin.
By using 10 parts by weight of the fast-curing insulating coating composition, the abnormal curing reaction that leads to the particles and foaming of the aromatic polyamideimide resin itself during the baking and curing process can be effectively suppressed and the curing speed can be remarkably improved. This rapid-curing insulating paint can be applied and baked on a conductor at a high speed, thereby producing an insulated wire with significantly improved productivity and quality.

[0016]

EXAMPLES Next, examples of the fast curing insulating coating material and the insulated wire of the present invention will be described together with comparative examples.

[Comparative Example 1] DAI-5 manufactured by Nitto Denko Corporation with a resin content of 30% on a conductor wire having a conductor diameter of 1.0 mmφ.
00 insulating paint is applied, excess insulating paint is squeezed out with a die, and then baked by passing through an enamel wire coating machine with an effective furnace length of 6 m and a furnace temperature of 480 ° C. at a speed of 20 m / min. The insulated wire of Comparative Example 1 was obtained by repeating the coating and baking operations a plurality of times so that the enamel coating thickness became 39 μm.

[Comparative Example 2] The baking speed of the enamel wire was set to 3
An insulated electric wire of Comparative Example 2 was obtained in the same manner as Comparative Example 1 except that it was set to 0 m / min.

[Comparative Example 3] HI of Hitachi Chemical Co., Ltd.
An insulated wire of Comparative Example 3 was obtained in the same manner as Comparative Example 1 except that -406 insulating coating was used.

[Comparative Example 4] HI of Hitachi Chemical Co., Ltd.
An insulated wire of Comparative Example 4 was obtained in the same manner as in Comparative Example 1 except that -406 insulating coating was used and the baking speed of the enamel wire was changed to 30 m / min.

[Comparative Example 5] DAI-5 manufactured by Nitto Denko Corporation having a resin concentration of 30% is provided on a conductor wire having a conductor diameter of 1.0 mmφ.
An insulating paint of Comparative Example 5 was obtained by adding 0.5 part by weight of Epicoat 1007 to 100 parts by weight of the resin content of 00 insulating paint.

Next, after applying the insulating paint of Comparative Example 5 on a conductor wire having a conductor diameter of 1.0 mmφ, excess insulating paint was squeezed out with a die, and then the effective furnace length was 6 m and the furnace temperature was 48.
The enamel coating thickness is 39 μm by baking by passing it through a 0 ° C. enamel wire coating machine at a speed of 30 m / min, and then repeating this insulating coating application and baking operations several times.
Thus, an insulated wire of Comparative Example 5 was obtained.

[Comparative Example 6] An insulated wire of Comparative Example 5 was obtained in the same manner as Comparative Example 5 except that the blending amount of Epicoat 1007 was 12.0 parts by weight.

[Comparative Example 7] In Comparative Example 7, 10.0 parts by weight of Epicoat 1009 was added to 100 parts by weight of the resin component of DAI-500 insulating paint of Nitto Denko Corporation having a resin concentration of 30%. An insulating paint was obtained, but the resulting insulating paint became cloudy within 24 hours when left at room temperature, making the enamel coating and baking work difficult.

[Example 1] DAI-5 manufactured by Nitto Denko Corporation with a resin concentration of 30% on a conductor wire having a conductor diameter of 1.0 mmφ.
The rapid-curing insulating coating material of Example 1 was obtained by mixing 1 part by weight of Epicoat 1007 with 100 parts by weight of the resin content of 00 insulating coating material.

Next, after applying the fast-curing insulating coating material of this Example 1 on a conductor wire having a conductor diameter of 1.0 mmφ, excess insulating coating material was squeezed out with a die, and then an effective furnace length of 6 m and a furnace temperature of 480 ° C. Baking by passing through the enamel wire coating machine at a speed of 30 m / min, and then applying this insulating coating,
The enamel film thickness is 3 by repeating the baking operation several times.
An insulated wire of Example 1 was obtained with a thickness of 9 μm.

Example 2 An insulated wire of Example 2 was obtained in the same manner as in Example 1 except that the blending amount of Epicoat 1007 was 2.5 parts by weight.

[Example 3] An insulated wire of Example 3 was obtained in the same manner as in Example 1 except that the blending amount of Epicoat 1007 was 5.0 parts by weight.

[Example 4] An insulated wire of Example 4 was obtained in the same manner as in Example 1 except that the amount of Epicoat 1007 was 7.5 parts by weight.

[Example 5] An insulated wire of Example 4 was obtained in the same manner as in Example 1 except that the compounding amount of Epicoat 1007 was 10.0 parts by weight.

[Embodiment 6] DAI of Nitto Denko Corporation
HI of Hitachi Chemical Co., Ltd. instead of 500 insulating paint
An insulated wire of Example 6 was obtained in the same manner as Example 3 except that 406 was used. [Example 7] An insulated wire of Example 7 was obtained in the same manner as in Example 5 except that HI-406 of Hitachi Chemical Co., Ltd. was used instead of the DAI-500 insulating paint of Nitto Denko Corporation. [Example 8] An insulated wire of Example 8 was obtained in the same manner as in Example 3 except that the bisphenol-based epoxy resin to be blended was Epicoat 1001.

[Example 9] Example 5 except that the bisphenol-based epoxy resin to be blended was Epicoat 1001.
An insulated wire of Example 9 was obtained in the same manner as in.

[Example 10] An insulated wire of Example 10 was obtained in the same manner as in Example 3 except that the bisphenol type epoxy resin to be blended was Epicoat 1004.

[Example 11] An insulated wire of Example 11 was obtained in the same manner as in Example 5 except that the bisphenol type epoxy resin to be blended was Epicoat 1004.

Next, a characteristic test was conducted on the polyamide-imide insulated wires of Comparative Examples 1 to 6 and Examples 1 to 11 thus obtained.

The test method of the characteristic test is JIS-C3003.
Went according to.

Table 1 shows the results of these tests.

Appearance The appearance inspection judges the appearance of the insulated wire under test,
Good ones are indicated by ◯, and bad ones are indicated by x.

Flexibility The flexibility test first takes the insulated wires under test and then
It was stretched by 0% and then wound around a winding rod having a conductor diameter n times. The results are shown by the minimum double diameter with no cracks on the surface coating.

Heat softening resistance results are shown in terms of heat softening temperature.

Resistance to heat deterioration Regarding the resistance to heat deterioration, first, the insulated wires to be tested were taken, then these were twisted and twisted, and then these were thermally deteriorated at 220 ° C. for 7 days,
Finally, the dielectric breakdown voltage was measured for each of the sample not thermally deteriorated and the sample thermally deteriorated. The results are shown by the residual ratio of the dielectric breakdown voltage of the sample that was thermally deteriorated when the dielectric breakdown voltage of the sample that was not thermally deteriorated was set to 100.

[0042]

[Table 1]

As can be seen from Table 1, by baking the polyamide-imide insulating coating composition of Comparative Example 1 at a speed of 20 m / min, a polyamide-imide insulated electric wire of Comparative Example 1 having excellent appearance and various properties can be obtained. However, the baking speed of the polyamide-imide insulating coating composition of Comparative Example 1 is as low as 20 m / min.

On the other hand, the polyamide-imide insulated wire of Comparative Example 2 was obtained by baking the polyamide-imide insulating coating composition of Comparative Example 1 at a speed of 30 m / min. However, the obtained polyamide-imide insulated electric wire of Comparative Example 2 has a drawback that the appearance, heat softening resistance, wear resistance, and heat deterioration resistance are deteriorated.

The same tendency can be seen in Comparative Examples 3 and 4 having different brands of polyamide-imide insulating coatings.

An insulated wire prepared by coating and baking the insulating paint of Comparative Example 5 prepared by mixing 0.5 part by weight of a bisphenol epoxy resin with 100 parts by weight of an aromatic polyamide-imide resin is the insulated wire of Comparative Example 2. Like the above, there is a drawback that the appearance is deteriorated.

The aromatic polyamideimide resin 100
The insulated wire formed by applying and baking the insulating paint of Comparative Example 6 in which 1 part by weight of the bisphenol-based epoxy resin is blended in an amount of 12.0 parts by weight has a drawback in that the heat softening resistance, the wear resistance, and the heat deterioration resistance are deteriorated. There is.

On the other hand, the polyamide-imide insulated wires of Examples 1 to 11 are conventional insulating paints, Comparative Example 1
Despite being baked at 30 m / min, which is 50% faster than the appropriate baking speed, the various properties showed excellent results.

[0049]

EFFECT OF THE INVENTION The insulating coating material of the present invention has excellent coating stability and exhibits remarkable rapid curing property, and a polyamide-imide insulated wire formed by coating and baking the insulating coating material on a conductor has Both heat resistance and flexibility can exhibit various excellent properties and are industrially useful.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akio Mitsuoka 4-10-1, Kawajiri-cho, Hitachi-shi, Ibaraki Hitachi Cable Electric Co., Ltd. Toyoura factory (72) Inventor Yoshiyuki 4-10 Kawajiri-cho, Hitachi-shi, Ibaraki No. 1 Hitachi Cable Co., Ltd. Toyoura Plant (72) Inventor Shinichi Oda 1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Electric Works Co., Ltd. (72) Teruhiko Akimoto 1-1, Shimohozumi, Ibaraki City, Osaka Prefecture No. 2 Nitto Denko Corporation

Claims (3)

[Claims] 1. 100 parts by weight of an aromatic polyamide-imide resin has a chemical structural formula of the following chemical formula 1 and has a thermal softening point of 40 to 40.
A fast-curing insulating coating material comprising 1 to 10 parts by weight of a bisphenol-based epoxy resin at 130 ° C. [Chemical 1] 2. An insulated wire comprising a polyamide-imide insulating layer provided on a conductor directly or via another insulating layer,
The polyamide-imide insulating layer is a resin composition comprising 100 parts by weight of an aromatic polyamide-imide resin and 1-10 parts by weight of a bisphenol-based epoxy resin having a thermal softening point of 40-130 ° C. Insulated wire. 3. The fast-curing insulating coating material according to claim 1, wherein the aromatic polyamide-imide resin is obtained by reacting an aromatic tribasic acid anhydride with an aromatic diisocyanate.