JPS6246583B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel electrically insulating polyester resin mixture that can be coated in a heated and molten state. Normally, when a synthetic resin is heated and melted in a solvent-free state without adding a solvent to it for coating, the higher the molecular weight of the resin, the higher the melting temperature. Conventionally, when manufacturing insulated wires by simply heating and melting a melt-type coating resin, coating it on a conductor, and then baking it, the resin usually has a high molecular weight, so it is necessary to make it have a viscosity suitable for coating. It was necessary to heat the material to a high temperature, such as 200°C or higher. However, when a resin such as a polyester resin is heated at such a high temperature, the reaction of the resin proceeds in the melting tank, and over a long period of time, a portion of the resin gels, making it impossible to apply the coating. At the same time, performing melt coating at a high temperature of 200°C or higher caused various difficulties in the operation, making it impossible to operate smoothly. In order to avoid this, when insulated wires are manufactured using a melt coating method using low molecular weight polyester resin, the curing reaction speed of the coating film is inferior and the resulting insulated wires have poor performance, especially heat resistance. The softening temperature was low. The present invention has been made in view of the current situation, and as a result of intensive research, it has been found that 100 parts by weight of a polyester resin containing a crosslinkable hydroxyl group in the molecule is added to N-alkyl-N'-phenyl-p-phenylenediamine or N-aryl-N By adding 0.05 to 5.0 parts by weight of '-phenyl-p-phenylenediamine and using a mixture, melt coating can be carried out at a relatively low temperature such as 100 to 200°C. It has been found that the coating surface of the obtained insulated wire can be smoothed and a baked coating can be provided which has significantly improved heat resistance and softening temperature. That is, the polyester resin used in the present invention includes polyethylene terephthalate having an -OH group in the side chain, a polyester resin alone or other resins such as phenol aldehyde resin,
It is a mixture with melamine resin, alkyd resin, and oil-based enamel. Also, N-alkyl-N'-phenyl-p-phenylene-diamine is N-isopropyl-N'-phenyl-p-phenylenediamine, and N-aryl-N'-phenyl-p-phenylenediamine is It is a chemical mixture of N.N'-diphenyl-p-phenylenediamine and diaryl-p-phenylenediamine. Polyethylene terephthalate and polyester resins include terephthalic acid, isophthalic acid and its alkyl ester compounds, ethylene glycol,
It can be synthesized from aliphatic polyhydric alcohols such as glycerin and trimethylolpropane, tris(2-hydroxyethyl)isocyanurate, trimellitic acid, and diaminodiphenylmethane. In the present invention, N-alkyl-N'-phenyl-p-phenylene diamine or N-aryl-N'-phenyl-p-phenylene is added to 100 parts by weight of the polyester resin or a mixture of this and other resins. The amount of diamine etc. added is 0.05
The reason for limiting the amount to ~5.0 parts by weight is that if the amount of these compounds is less than 0.05 parts by weight, the effects shown above cannot be obtained sufficiently, and if it exceeds 5.0 parts by weight, the insulated wire This is because the flexibility of the baked film obtained in this case is poor. Next, examples of the present invention and comparative examples will be shown. Comparative example 0.9 mol of dimethyl terephthalate, 0.1 mol of dimethyl isophthalate, 1.6 mol of ethylene glycol, 0.4 mol of glycerin, and 1 g of lead acetate at 140 ~
After a heating reaction was carried out at 220°C to distill off methanol, a reduced compression combination was carried out at 160 to 220°C to distill off excess ethylene glycol. Next, 0.1 mol of ethylene glycol was added to the reaction mixture, and the reaction mixture was heated at 200° C. for 3 hours to obtain a polyester resin (A). The viscosity of this resin (A) is
It was 1200 centipoise at 160°C. Example 1 Polyester resin (A) synthesized in the above comparative example
500g and N-isopropyl-N'-phenyl-p-
5 g of phenylenediamine was heated and stirred at 180° C. for 2 hours to obtain a uniform resin mixture (B). The viscosity of this resin (B) was 1700 centipoise at 160°C. Example 2 500 g of the polyester resin (A) obtained in Comparative Example and 8 g of N-N'-diphenyl-p-phenylenediamine were stirred at 180°C for 2 hours to obtain a uniform resin mixture (C). The viscosity of this resin is 160℃
It was 1700 centipoise. Then, the resin (B) and resin (C) as the resin mixture of the present invention and the resin (A) as the comparative resin were melt-coated on a copper wire with an outer diameter of 1 mm at 160°C, and the length was 4.5 mm. The wire was passed through a baking furnace with a furnace temperature of 450° C. and baked three times to obtain an insulated wire with a coating thickness of 37 μm. The characteristics of each of the insulated wires thus obtained were measured. The results are shown in Table 1.

[Table] As is clear from the above table, using the mixture of the present invention,
The insulated wire obtained by melt-coating this on a conductor uses conventional polyester resin, and has significantly superior heat softening properties and other properties compared to insulated wire obtained by the same melt-coating method. It is extremely useful when applied to electric wires.

Claims (1)

[Claims] 1 Add 0.05 to 100 parts by weight of a polyester resin containing a crosslinkable hydroxyl group in the molecule to N-alkyl-N'-phenyl-P-phenylenediamine or N-aryl-N'-phenyl-P-phenylenediamine. A polyester resin mixture for melt coating, characterized in that 5.0 parts by weight is added and mixed.