JPS647109B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an insulated wire that is obtained using a heat-resistant polymer with excellent solubility in organic solvents and exhibits excellent heat resistance.

It is well known that polyamide-imide resins have high heat resistance, mechanical properties, chemical properties, etc., and are widely used in practical applications as various coatings and adhesives, including those for films and electric wires.

Conventionally, polyamide-imide resins have been synthesized from tribasic acid anhydrides and diisocyanates or tribasic acid anhydride chlorides and diamines. However, when synthesizing using such a method, the organic solvent used as the reaction medium must be kept in a substantially anhydrous state, otherwise the anhydride groups, isocyanate groups, and acid chloride groups will decompose or change in quality, resulting in a sufficient molecular weight. Various precautions must be taken with the synthesis conditions, such as not being able to obtain a polymer and therefore not being able to exhibit the inherent properties of polyamide-imide resin.

There have also been attempts to synthesize polyamideimide resin from tribasic acid anhydride and diamine, but
It has not been possible to obtain one with a sufficient molecular weight and it has not been put into practical use.

On the other hand, as is well known, due to its structure, polyamide-imide resin is extremely poorly soluble in general organic solvents, and therefore, it is difficult to dissolve polyamide-imide resin in general organic solvents. It is put into practical use after being dissolved in a suitable solvent. However, all of these solvents are expensive, so the concentration of resin in the solution is increased as much as possible, and these solvents are simply volatilized into the air during the process of obtaining final products such as coatings and films. It is desired to reduce the amount used. This direction also corresponds to the trend toward resource conservation, which has recently been attracting attention worldwide.

As a result of intensive studies to counter this situation, we found that a heat-resistant polymer with sufficient molecular weight can be obtained by reacting a specific tricarboxylic acid or its functional derivative with a diamine, and that an organic solvent for this heat-resistant polymer can be obtained. They found that the solubility of the compound is excellent, leading to the completion of the present invention.

That is, the present invention uses a polymer obtained by reacting butanetricarboxylic acid or a functional derivative thereof with a diamine in an organic solvent at a monomer concentration of 10 to 90% by weight at 50°C to 300°C, or directly or with other insulators. This invention relates to a method for manufacturing insulated wires by coating and baking them onto conductors.

The polymer used in the present invention is a type of polyamideimide. In the present invention, butanetricarboxylic acid includes 1,2,3-butanetricarboxylic acid, 1,2,4-butanetricarboxylic acid,
1,1,2-butanetricarboxylic acid, 1,3,3
-Butanetricarboxylic acid, 1,4,4-butanetricarboxylic acid, etc. are used, and these are anhydrides,
It is also possible to use them in the form of functional derivatives such as esters and amides. Further, if necessary, tribasic acids or tetrabasic acids such as trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, and functional derivatives of these acids may be used in combination.

The diamine component used in the present invention is a compound represented by the general formula H ₂ N—R ₁ —NH ₂ , where R ₁ is a hydrocarbon group containing at least 2 carbon atoms, and more specifically In other words, aromatic, aliphatic, heterocyclic groups, groups combining these, or divalent groups in which these are bonded with oxygen, nitrogen, sulfur, silicon, phosphorus, etc. are preferable. In addition, these groups include hydroxyl group, alkyl group, cycloalkyl group,
It may be substituted with an allyl group, an alkoxyl group, a cycloalkoxyl group, an allyloxyl group, a halogen, or the like. Specific compounds include metaphenylenediamine, paraphenylenediamine, benzidine, 4,4'-diaminodiphenylmethane, 4,
4'-diaminodiphenyl ethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether,
Para-bis-(4-aminophenoxy)benzene, meta-bis-(4-aminophenoxy)benzene, para-xylylene diamine, metaxylylene diamine, hexamethylene diamine, hebutamethylene diamine, octamethylene diamine, nonamethylene diamine, 1,4 -diaminocyclohexane, bis-(4-amino-phenyl)phosphine oxide, bis-(4-aminophenyl)diethylsilane, etc., and these may be used alone or as a mixture. Depending on the case, a small amount of triamine or tetramine may also be used in combination.

As an organic solvent, N-methylpyrrolidone, N-
Ethylpyrrolidone, N-methylpiperidone, N-
N-alkyl lactams such as methyl caprolactam and N-ethyl caprolactam, phenols such as phenol, cresol, and xylenol, N,
N,N-dialkylcarboxylic acid amides such as N-dimethylacetamide and N,N-dimethylformamide, nitrobenzene, pyridine, quinoline,
Although cyanobenzene, N-alkylaniline, etc. can be used, it is preferable to use N-alkyllactams and phenols as the main components.

In addition to organic solvents as diluents, benzene,
Any of toluene, xylene, high boiling hydrocarbons, etc. can be used.

In the reaction, it is preferable to react butanetricarboxylic acid or a functional derivative thereof with a diamine in approximately equimolar amounts, but if necessary, an excess of either of them may be used.

The monomer concentration of butanetricarboxylic acid or its functional derivative and diamine during the reaction is 10 to 90% by weight, preferably 30 to 80% by weight, and in some cases, it may be diluted during the reaction to continue the reaction. Good too. The reaction temperature is from 50°C to 300°C, preferably from 100°C to the boiling point.

Furthermore, a catalyst can be used to accelerate the reaction, and it is particularly desirable to use a catalyst when the reaction is carried out in a phenolic solvent. Examples of catalysts include triethylamine, tributylamine, dimethylaniline, triethylenediamine,
Tertiary amines such as N-methylmorpholine, 1,8-diazabicyclo(5,4,0)undecane-7,N,,N-dimethylethanolamine, dipropylamine, dibutylamine, diethanolamine, piperidine, morpholine, etc. amines such as secondary amines, dibutyltin dilaurate,
Organometallic compounds such as dibutyltin diacetate,
Examples include metal salts such as zinc naphthenate, zinc octenoate, iron naphthenate, cobalt octenoate, and lead naphthenate.
It is added in an amount of about 10% by weight.

The reaction formula of butanetricarboxylic acid and diamine in the present invention is as follows, for example when 1,2,4-butanetricarboxylic acid is used, and a polyamide-imide resin is produced.

The obtained polymer is coated on an electrical conductor directly or via another insulator under normal conditions and baked to form an insulated wire. Further, another insulating material may be further coated thereon to form an insulated wire. Other insulating materials include general-purpose polyester paint, tris(2-hydroxyethyl) isocyanate-modified polyester paint, polyesterimide paint, tris(2-hydroxyethyl)isocyanate-modified polyesterimide paint, polyurethane paint, oil-based paint, polyvinyl formal paint, In addition to nylon paint, etc.
Epoxy paints, thermoplastic polyester paints, polyvinyl butyral paints, etc., which are mainly used to impart self-bonding properties to insulated wires, are used.

The present invention will be explained below with reference to Examples.

Example 1 356 g of diaminodiphenylmethane (DAM),
174 g of N-methyl-pyrrolidone (NMP) was placed in a flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube and heated. 341 g of 1,2,4-butanetricarboxylic acid (BTRC) was added at 60°C, and the temperature was raised to 200°C.
When kept at this temperature for 14 hours, 84 g of water was distilled out and the viscosity of the contents of the flask became extremely high, so heating was stopped, the flask was cooled, and 726 g of NMP was added to dilute it.
The viscosity of the resulting solution was 32 poise.

A portion of this solution was poured into a large amount of water, and the reduced viscosity (η _sp/c ) of the resulting precipitate was measured (0.5 g/100 ml dimethylacetamide, 30° C.) and found to be 0.36.

In addition, this solution was applied to a copper wire with a diameter of 1 mm by the usual method, and the furnace temperature was 300/350/400°C (inlet/center/
The properties of the enamelled copper wire obtained by repeating the baking process six times in the baking furnace (exit) were as follows.

Finished outer diameter (mm) 1.076 Conductor diameter (mm) 1.000 Film thickness (mm) 0.038 Flexibility (self-diameter winding) Good thermal shock resistance (240°C-1h) 1x diameter Good thermal softening temperature (°C) 380 Resistance Degradability (200℃-6h) 1x diameter good dielectric breakdown voltage (kv) 12.4 Example 2 Diaminodiphenyl ether 357g,
After reacting 339 g of BTRC in 174 g of NMP at 200°C for 15 hours in the same manner as in Example 1, 887 g of NMP was reacted.
and 157 g of xylene were added for dilution. The viscosity of the resulting solution was 28 poise, and the reduced viscosity of the polymer was
It was 0.37.

This solution was applied and baked on a copper wire having a diameter of 1 mm in the same manner as in Example 1, and the properties of the enameled copper wire obtained were as follows.

Finished outer diameter (mm) 1.075 Conductor diameter (mm) 1.000 Film thickness (mm) 0.038 Flexibility (self-diameter winding) Benign thermal shock resistance (240℃-1h) 1x diameter good thermal softening temperature (℃) 370℃ Deterioration resistance (200℃-6h) 1x diameter Good dielectric breakdown voltage (kv) 12.6 The insulated wire obtained by the present invention exhibits good flexibility and dielectric breakdown voltage, and also has good thermal shock resistance,
It has excellent properties as a heat-resistant insulated wire, such as thermal softening temperature and deterioration resistance, and can be used in a wide range of practical applications.

Claims (1)

[Claims] 1. Butanetricarboxylic acid or a functional derivative thereof and a diamine are mixed in an organic solvent at a monomer concentration of 10 to 90%.
A method for producing an insulated wire, which comprises applying and baking a polymer obtained by reacting the polymer at 50°C to 300°C in weight percent onto a conductor directly or through another insulator. 2. The method of manufacturing an insulated wire according to claim 1, which comprises coating the conductor with the polymer directly or via another insulating material, baking the polymer, and then coating the conductor with another insulating material.