JPS58140910A - Insulated wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulated wire with excellent mechanical windability and heat resistance.

Insulated wire coated with polyimide resin has excellent heat resistance, and
Although it has been widely used as a 20°C class enamelled wire, it has the disadvantage that the mechanical strength of the coating is poor.

The present invention aims to improve the mechanical strength of polyimide resin-coated insulated wires and to provide inexpensive insulated wires.

That is, the gist of the present invention is an incyanurate ring-containing polyinsyanate, an aromatic diisocyanate, a lactam,
and a polyamide-imide resin obtained by reacting a polycarboxylic acid containing an acid anhydride group in a cresol solvent, or a resin composition mainly composed of polyamide-imide resin as an outer layer and a polyimide resin as an inner layer, and coated on the conductor circumference. The thickness of the outer layer is 1, and the thickness of the inner layer is 0.
5 to 20.

The incyanurate ring-containing polyisocyanate, which is the raw material for the polyamide-imide resin used in the present invention, is obtained by trimerizing a polyisocyanate compound, and this reaction is carried out in the presence of a solvent that does not react with incyanate groups.
It is desirable to use a trimerization catalyst of a polyisocyanate compound in order to carry out the reaction efficiently without adding a component that reacts with isocyanate groups such as phenol or lactams.

Examples of solvents include aliphatic and aromatic hydrocarbons, halogenated aromatic hydrocarbons, ester-based, ketone-based, ether-based, and ethylene glycol monoalkyl monoacetate-based solvents as long as they dissolve the polyisocyanate compound as a raw material. , dimethyl sulfide, and the like.

Trimerization catalysts for polyisocyanate compounds include alkali metal acetates, metal salts and organic metal compounds such as iron, magnesium, esters, zinc, tin, lead, copper, titanium, N-methylmorpholine, 1,8-diazabicyclo( 5,4,0)Undecane-7,2-(dimethylaminomethyl)-4゜6-dimethylphenol and other phenol Mannifhi bases, tertiary amines such as 2-dimethylaminoethanol, etc. can be used, and there are no particular restrictions. There is no Qo.

The reaction temperature for trimerizing the polyisocyanate compound is, for example, in the range of 50 to 160°C.

The raw material for the incyanurate ring-containing polyisocyanate may be any aliphatic, alicyclic, or aromatic diisocyanate compound, but aromatic diisocyanates, especially 4,4'-diphenylmethane diisocyanate, tolylene diinocyanate, xylylene diisocyanate, etc. Isocyanate, 4
, 4'-diphenyl ether diisocyanate and the like are preferred.

In terms of heat resistance and flexibility, the isocyanurate ring-containing polyisocyanate has a residual incyanate group content of 10
The range is preferably 70% (assuming the incyanate group content in the raw incyanate is 100).

It is preferable to use the isocyanurate ring-containing polyinsyanate in an amount of 0.01 to 0.60 equivalents based on the total isocyanate components in terms of heat resistance and flexibility.

Lactam, which is an important raw material for cresol solvent solubilization, can generally be anything that reacts with incyanate groups or acid anhydride groups in cresol solvents and is soluble in cresol solvents. However, considering solubility, reactivity, and cost, ε-caprolactam is better.

The amount of lactam used is preferably 0.30 to 0.90 equivalents of the total isocyanate equivalents (epsilon-cabrolactum is considered to be bifunctional) from the viewpoint of heat resistance, flexibility and solubility.

Examples of the aromatic diisocyanate include 4,4'-diphenylmethane diisocyanate), 4,4'-diphenyl ether diisocyanate, tolylene diisocyanate,
Xylylene diisocyanate and the like are preferred.

As a polycarboxylic acid having an acid anhydride group, heat resistance,
Trinolift acid anhydride is preferred in terms of cost.

The amount of isocyanate component and acid component used is such that the ratio of isocyanate group to carboxyl group and acid anhydride group is 1.
．． From the viewpoint of heat resistance, it is preferable to select the range from 5 to 0.8.

In order to obtain a resin with a high molecular weight that is preferable in terms of the characteristics of an insulated wire, it is particularly preferable that the ratio of isocyanate groups to carboxyl groups and acid anhydride groups is around 1.0.

In addition to cresol, phenol,
Xynol, etc. can be used, and even a mixed solvent can be used.For synthesis, all isocyanate components, lactam and cresol solvent are charged and reacted at 160 to 190°C for 1 to 3 hours, and then the acid anhydride group-containing polycarboxylic acid is Mind, 20
Continue the reaction at 0-220°C for 10-20 hours.

The polyamide-imide resin thus obtained has particularly good properties as an insulated wire if it has a reduced specific viscosity of 0.15 or more when measured in dimethylformamide.

This polyamide-imide resin is then mixed with a cresol solvent to a resin content of 20 to 400 to 40 parts by weight and used as a varnish for insulated wires.

The polyamide-imide resin used in the present invention forms a long-length mel film with excellent heat resistance, mechanical properties, and splatter resistance even when used alone. Significant improvements can be made by adding one or more secondary resins such as amino resins, epoxy resins, polyisocyanate resins, and phenoxy resins. The amount of the secondary resin added is 01 to 60 parts by weight per 100 parts by weight of the polyamide-imide resin, and if it exceeds this range, the flexibility of the enameled wire will decrease.

In particular, when using a resin composition in which 0.1 to 15 parts by weight of an amine resin and a phenol resin are added to 100 parts by weight of a polyamide-imide resin, an insulating film with excellent appearance and flexibility can be obtained. .

The polyimide resin used in the present invention is Trenise #2000. #3000 (manufactured by Toshi Co., Ltd.) and Pyre-ML varnish (manufactured by Du-Pont, USA)
), but is not limited to kneading.

In addition, in the present invention, the outer layer coating thickness is 1, and the inner layer coating thickness is 05 to 20. This is because, although it improves, the heat resistance decreases significantly, and when it is 20 or more, heat resistance is good but sufficient mechanical strength cannot be obtained.

In order to balance mechanical strength and heat resistance, it is preferable that when the outer layer has a thickness of 1, the inner layer has a thickness of 2 to 6.

Hereinafter, specific examples of the present invention will be described while comparing them with comparative examples.

Comparative Example 1 An enamelled wire was obtained by applying and baking a 1.0 mm y5 conductor of Trenine #20DO varnish.

Comparative Example Z (1) Synthetic acid of aromatic diisocyanate trimer
Minutes grams tolylene diisocyanate 600 xylene
6002-dimethylaminoethanol (catalyst) 1.8 The above ingredients were placed in a four-bottle flask equipped with a thermometer and a stirrer, and the temperature was raised to 140'CF in a nitrogen stream.At the same temperature, the content of isocyanate groups (initial concentration The reaction was continued until the weight (48 weight) became 25 weight.

Q) Diisocyanate trimer synthesized in polyamide-imide resin synthesis (1) (50% solution) 37.0
0.114.4'-diphenylmethane diincyanate 113.3
0.91 Trinolyphic anhydride 9
6.0 1.0ε-cabu-lactam 3
6.60.65 Cresol 300 The above ingredients except trimeltic anhydride were placed in a four-bottle flask equipped with a thermometer, a stirrer, and a fractionating tube, and the temperature was raised to 180°C in a nitrogen stream and the reaction was continued for 1.90 minutes. conduct. Next, trimellitic anhydride was added, the temperature was raised to 210°C, and the reaction was continued at this temperature for 15 hours.

Next, the resin concentration was adjusted to 60% by weight with cresol to obtain one varnish. The viscosity of this varnish is 250 pores.1.
0, measured in dimethylformamide of 47C resin,
y = reduced viscosity was 023.

One piece of polyamide-imide tree and eleven pieces of varnish obtained as described above was applied and baked on a 10-diameter conductor to obtain one enamelled wire.

Comparative Example 6 5 parts by weight each of PR-1501 (phenol formaldehyde resin manufactured by Hitachi Chemical ■) and Melan-20 (alkoxy-modified amino resin manufactured by Hitachi Chemical ■) were added to 100 parts by weight of the polyamide-imide resin in Comparative Example 2 Vc, A polyamideimide resin composition was prepared by adjusting the resin concentration to 30% with cresol, and this was made into a polyamideimide resin composition with a concentration of 1.0 + nm S.
An enamelled wire was obtained by coating and baking it on a conductor.

Comparative Examples 4 and 5 and Examples 1 to 5 The polyamide-imide resin composition in Comparative Example B was used as an outer layer,
The polyimide resin in Comparative Example 1 was used as an inner layer and coated and baked on a 1.0 mm conductor so that the film thicknesses of the inner and outer layers were as shown in the table below to obtain a double-coated airmel wire.

The characteristics of the various enamelled wires in the above comparative examples and examples are shown in the table below.

The mechanical strength was evaluated by a reciprocating abrasion test in accordance with JIS-C3003, and the heat resistance was evaluated by measuring the residual dielectric breakdown voltage after thermal deterioration of the twisted pair samples at high temperatures.

(1) Load 70J9 (21 Judgment Criteria ◎: Insulation failure rate after deterioration for 30 days at 280℃ 60
% or more ○:
40~60chi△:
20~40×:
Section 20 and below (11) As explained above, the present invention provides an insulated wire with an outer layer made of a cresol solvent-soluble polyamideimide resin and an inner layer made of a polyimide resin, which has excellent mechanical strength and heat resistance, and is inexpensive. This results in a highly insulated wire.

(12)

Claims (1)

[Claims] 1. A polyamide-imide resin obtained by reacting an isocyanurate ring-containing polyisocyanate, an aromatic diisocyanate, a lactam, and a polycarboxylic acid containing an acid anhydride group in a cresol solvent, or The outer layer is made of a resin composition mainly composed of a resin composition, and the inner layer is made of a polyimide resin.
An insulated wire characterized in that the inner layer has a coating thickness of 0.5 to 20. Z The above polyamide-imide resin contains 1,00 equivalents of polycarboxylic acid containing an acid anhydride group, 0.01 to 0.30 equivalents of incyanurate ring-containing polyisocyanate, aromatic diisocyanate and isocyanurate ring-containing polyisocyanate. Claim 1, characterized in that it is obtained by reacting in a cresol solvent with a sum of equivalents of 0.80 to 1.50 equivalents and a lactam of 0.3 to 0 g equivalents. Insulated wire. 3 0.1 to 15 parts of amino resin and phenol resin are each added to 100 parts by weight of the above polyamide-imide resin.
An insulated wire according to claim 1 or 2, characterized in that the inner layer is made of a resin composition added in parts by weight.