JPH02304808A - Insulated wire - Google Patents

Abstract

PURPOSE:To acquire a solderable insulated wire simultaneously with the maintenance of the excellent heat. resistance of a polyamido-imide resin by spreading and baking an insulating coating prepared through the process of blending a proper quantity of specific stabilizing polyisocyanate with the polyamido-imide resin, on a conductor. CONSTITUTION:An insulating coating prepared through the process of adding 75 pts.wt. to 400 pts.wt. of a stabilizing polyisocyanate compound derived from diphenylmethane diisocyanate to 100 pts.wt. of a polyamido-imide resin whose molecular weight ranges from 0.1 to 1.0 in reduced specific-viscosity is spread and baked on a conductor. Namely, the application of less than 0.1 in the molecular weight of the polyamido-imide resin causes the insufficient flexibility of an insulated wire, while the application of not less than 0.1 in the molecular weight thereof causes the generation of many foams in the coating for the insulated wire under manufacture and therefore causes poor productivity to the wire. Also the application of less than 75 pts.wt. of the polyisocyanate compound makes the insulated wire not solderable, while the application of not less than 400 pts.wt. thereof brings the wire little improvement in its heat-resistance and therefore brings the degree of flexibility as we the insulating coating of the wire to a drop. Such an insulated wire as it uses the polyamido-imide resin whose molecular weight is specified may be excellent both in its external appearance and in its characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an insulated wire with excellent solderability and good heat resistance.

(Conventional technology and its problems) Polyurethane insulated wire can be used without removing the insulation film.
Since it can be soldered as is, it is widely used as winding wire for electronic devices.

Recently, equipment has become smaller and more sophisticated, the ambient temperature in which the equipment is used has increased, and there has been a demand for improved heat resistance of the parts used.

Therefore, there are some applications in which conventional polyurethane insulated wires cannot satisfy the heat resistance requirements, and polyester insulated wires and esterimide insulated wires have begun to be used in some cases.

Although heat resistance is satisfactory when using polyester or esterimide insulated wires mentioned above, there is a problem that soldering is not possible, and the user has to choose whether to prioritize heat resistance or ease of terminal processing. I'm worried,
There is a strong demand for insulated wires that have both heat resistance and solderability.

As a result of intensive study on the above-mentioned problems, the present inventor maintained the excellent heat resistance of polyamide-imide resin by applying and baking an insulating paint containing polyamide-imide resin and an appropriate amount of a specific stabilized polyisocyanate onto the conductor. However, we succeeded in obtaining an insulated wire that can be soldered.

(Japanese Patent Application No. 63-251558) As a result of further detailed study of the above-mentioned technique, the present inventor found that the use of polyamideimide having a predetermined molecular weight and structure is particularly effective, and thus arrived at the present invention.

(Structure of the Invention) The present invention uses 75 parts by weight to 400 parts by weight of a stabilized polyisocyanate compound obtained from diphenylmethane diisocyanate to 100 parts by weight of a polyamideimide resin having a molecular weight of 0.1 to 1.0 in reduced specific viscosity. This insulated wire is characterized by having an added insulating paint applied and baked onto the conductor.

According to the present invention, polyamide-imide resin has an amide bond and an imide bond in its molecule, and there are two specific examples of manufacturing methods as follows.

One method involves reacting at least one acid chloride of tricarboxylic acid anhydride with at least one diamine. Further, a part of the acid chloride of the tricarboxylic anhydride may be replaced with at least one dicarboxylic dichloride, at least one tetracarboxylic dianhydride, or at least one dicarboxylic dichloride and at least one tetracarboxylic dianhydride. It may be replaced with carboxylic dianhydride.

Further, a part of the above diamine may be replaced with at least one kind of triamine,
Alternatively, at least one type of tetramine may be replaced with at least one triamine and at least one type of tetramine.

Examples of the acid chloride of tricarboxylic anhydride include 4-acid chloride of trimellitic anhydride.

Examples of dicarboxylic acid dichloride include terephthalic acid dichloride, isophthalic acid dichloride, adipic acid dichloride, and the like.

Examples of diamines include 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether m-phenylenediamine, and the like. An example of triamine is
8.4.4'-)riaminodiphenyl ether and the like. An example of tetramine is 3.3'.

4.4'-tetraaminodiphenyl ether and the like.

Another example of a typical manufacturing method involves reacting at least one tricarboxylic acid anhydride with at least one diisocyanate.

Further, a part of the above tricarboxylic anhydride may be at least one dicarboxylic acid, or at least one tetracarboxylic dianhydride, or at least one dicarboxylic acid and at least one tetracarboxylic dianhydride. You can replace it with

Further, a part of the above diisocyanate may be replaced with at least one type of trivalent or higher polyisocyanate.

Examples of tricarboxylic anhydrides include trimellitic anhydride.

Examples of dicarboxylic acids include isophthalic acid, terephthalic acid, adipic acid, and the like.

Examples of tetracarboxylic dianhydride include pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, and the like. Examples of diisocyanates include diphenylmethane-4,4'-diisocyanate, diphenyl ether-4,z-diisocyanate, tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and the like.

Examples of polyisocyanates include polymethylene polyphenylene polyisocyanate.

Among these, it is preferable to use a polyamide-imide resin obtained by reacting an aromatic tricarboxylic acid anhydride or its derivative with an aromatic diisocyanate because it can better exhibit the heat resistance characteristic of polyamide-imide resins. In the present invention, the molecular weight is determined by the reduced specific viscosity 0.1 to 1.
It is necessary to use a polyamideimide resin having a

If the molecular weight is less than 0.1 in terms of reduced specific viscosity, the obtained insulated wire will have poor flexibility, and if it is more than 1.0, a large number of bubbles will occur in the film during the production of the insulated wire, resulting in poor productivity. Further, it is preferable to use a polyamideimide resin having a reduced specific viscosity of 0.2 to 0.5 because the properties of the resulting insulated wire are good and the workability during production of the insulated wire is also good.

In particular, those having a reduced specific viscosity of 0.3 have the best properties and workability.

The reduced specific viscosity shown in the present invention is based on DMAC or NM in the solvent.
2 Using P, the concentration of polyamideimide resin was adjusted to 100% as a solvent.
It is shown as a measured value at a temperature of 30°C when the weight is 0.5g per m1.

Stabilized polyisocyanate obtained from diphenylmethane diisocyanate is diphenylmethane diisocyanate alone, or polyisocyanate obtained by reacting diphenylmethane diisocyanate with polyols, polyamines, polycarboxylic acids, etc. The isocyanate groups are combined with phenols, alcohols, cabrolaccum, etc. Any compound blocked with a known blocking agent such as the following can be used.

Specific examples include Coronate 2508 manufactured by Nippon Polyurethane Co., Ltd., which is a polyisocyanate obtained from diphenylmethane diisocyanate and a polyol blocked with a phenol, and Millionate MS-50°, manufactured by Nippon Polyurethane Co., Ltd., which is a polyisocyanate obtained from diphenylmethane diisocyanate and a polyol blocked with a phenol. .

The present invention is not effective with stabilized polyisocyanates other than those obtained from diphenylmethane diisocyanate.

For example, when using a stabilized polyisocyanate obtained from a polyol and tolylene diisocyanate, the solderability is good, but the flexibility of the insulating film is poor; When a stabilized polyisocyanate containing an isocyanuric ring is used, the insulating film has good flexibility but cannot be soldered.

In the present invention, 75 to 400 parts by weight of a stabilized polyisocyanate compound obtained from diphenylmethane diisocyanate is added to 100 parts by weight of the polyamide-imide resin.
It is necessary to add parts by weight. If it is less than 75 parts by weight, the obtained insulated wire will not be solderable, and if it is more than 400 parts by weight, the heat resistance of the obtained insulated wire will be little improved and the flexibility of the insulating film will also be reduced.

The solvent used in the insulating paint of the present invention is NM 2 P, which is used as a solvent for polyamideimide resin.
A combination of , DMAC, DMF, etc. and a diluent such as solvent naphtha, toluene, xylene, etc. is preferred, but phenol, cresols, cellosolve, phenyl cellosolve, methyl cellosolve, glycosolve, methyl cellosolve, phenyl, which are used in ordinary baking paints, are preferred. Glycol ethers such as cellosolve, cellosolve acetate, cyclohexanone, methylethyletone, ethyl acetate, tetrahydrofuran, nitrobenzene, dioxane, furfural, sulfolane, DMSol, pyridine, aniline, diethyl carbonate, ethanol, methanol, butanol, cyclohexanol, etc. are used. You may also add some.

If necessary, amines such as naphthenic acid, metal salts of octenoic acid, alkylamines, and imidazoles can be used as curing catalysts in the insulating coating of the present invention.

When manufacturing insulated wires, it is preferable to add an appropriate amount of the above-mentioned catalyst because manufacturing is easier and products with better heat resistance can be obtained.

The insulating paint of the present invention includes thermoplastic resins such as polyvinyl formal, polyamide, polyester, polyurethane, polyether, polysulfone, polyether sulfone, and polyetherimide, melamine resin, and phenol resin, to an extent that does not impair the characteristics of the present invention. It is also possible to add thermosetting resins such as polyester, polyurethane, polyesterimide, polyamideimide, polyesteramideimide, polyimide, hydantoin, fillers, pigments, dyes, surfactants, lubricants, antioxidants, etc. .

The present invention will be explained in detail in the following examples, but the present invention is not limited to these examples.

The following reference examples show insulating paints used in comparative examples and examples.

(Reference Example 1) (Polyamide-imide insulation coating) 192.1 g (1.0 mol) of trimellitic anhydride and 250.3 g (1.0 mol) of diphenylmethane-4,4'-diisocyanate
,0 mol) and N-methyl-2- and 770 g of lolidon.
and solvent naphtha (Maruzen Petrochemical Swazol #11
000) 380 and reacted at 80°C for 3 hours, the temperature was raised to 165°C in 6 hours, and at this temperature 2
A polyamide-imide insulating paint was obtained by a time reaction. The reduced specific viscosity of the resin was 0.51.

(Reference Examples 2 to 6) By using the same raw materials as in Reference Example 1 and changing the reaction temperature and reaction time, the reduced specific viscosity of the resin was 0.07 (Reference Example 2
), 0.13' (Reference Example 3), 0.31 (Reference Example 4),
Polyamideimide having a weight of 0.85 (Reference Example 5) and 1.15 (Reference Example 6) was obtained.

(Example 1) Coronate 2503 (hereinafter referred to as Coronet) 2503 manufactured by Nippon Polyurethane Co., Ltd., which is a stabilized polyisocyanate obtained from a polyol and diphenylmethane diisocyanate, was used for 100 parts by weight of the resin content of the polyamide-imide insulation paint prepared in Reference Example 1. 200 parts by weight of (abbreviated) as a catalyst, 1 part by weight of dibutyltin laurate, dissolved and mixed, and the insulating paint was coated on a 0.3mm diameter copper conductor with a film thickness of 0.02mm.
It was coated and baked to a thickness of 0 mm. Table 1 shows the results of evaluating the characteristics of the obtained insulated wire.

(Comparative Example 1) An insulated wire was produced in the same manner as in Example 1 except that the polyamide-imide insulating paint was used as that produced in Reference Example 2,
Characteristics were evaluated. The results are shown in Table 1.

(Examples 2 to 4) Example 1 except that the polyamide-imide insulating paint was prepared in Reference Example 3 (Example 2), Reference Example 4 (Example 3), and Reference Example 5 (Example 4), respectively. Insulated wires were prepared and their characteristics were evaluated in the same manner as above. The results are shown in Table 1.

(Comparative Example 2) When an attempt was made to produce an insulated wire in the same manner as in Example 1, except that the polyamide-imide insulating paint was used as the one produced in Reference Example 6, many bubbles occurred, the wire broke, and an insulated wire was not obtained. There wasn't.

(Effects of the Invention) As explained above, the insulated wire using the polyamide-imide resin of the present invention with a defined molecular weight has good appearance and properties, and has great industrial value.

Claims (6)

[Claims] (1) An insulating paint prepared by adding 75 parts by weight to 400 parts by weight of a stabilized polyisocyanate compound obtained from diphenylmethane diisocyanate to 100 parts by weight of a polyamideimide resin having a molecular weight of 0.1 to 1.0 in reduced specific viscosity. An insulated wire characterized by coating and baking on the conductor. (2) The molecular weight of polyamide-imide resin is 0 in terms of reduced specific viscosity.
．． The insulated wire according to claim 1, wherein the insulated wire has a molecular weight of 2 to 0.5. (3) The molecular weight of polyamide-imide resin is 0 in terms of reduced specific viscosity.
．． 3. The insulated wire according to claim 1. (4) The insulated wire according to claim 1, wherein the polyamide-imide resin is a compound obtained by reacting an aromatic tricarboxylic acid anhydride or a derivative thereof with an aromatic diisocyanate. (5) The insulated wire according to claim 1, wherein the stabilized polyisocyanate compound obtained from diphenylmethane diisocyanate is a polyisocyanate compound obtained by stabilizing the isocyanate groups of diphenylmethane diisocyanate with a blocking agent. (6) The insulated wire according to claim 1, wherein the stabilized polyisocyanate compound obtained from diphenylmethane diisocyanate is a stabilized polyisocyanate compound obtained by stabilizing the polyisocyanate obtained from a polyol and diphenylmethane diisocyanate with a blocking agent.