Insulated wire and resin dispersion

1. An insulated wire consisting of one thin insulating layer composed of a resin dispersion, coated on a conductor, wherein the thickness of the thin insulating layer is 20 to 60 μm, and wherein the resin dispersion consists of:

a polyester-series resin (A) in a continuous phase; and

a resin (B) having a glycidyl ester compound of an unsaturated carboxylic acid represented by formula (1) and dispersed with an average particle diameter of 0.05 to 3 μm in the resin (A);

wherein R represents an alkenyl group having 2 to 18 carbon atoms and X represents a carbonyloxy group;

wherein the resin dispersion is a compound in which resin (B) is uniformly and finely dispersed in resin (A);

wherein the resin dispersion contains 1 to 10 mass parts of the resin (B), to 100 mass parts of the polyester-series resin (A); and

wherein the insulated wire has a dielectric breakdown voltage of from 6.7 to 7.8 kV after being left for 1 hour at 100° C.

2. The insulated wire according to claim 1 , wherein the resin (B) is at least one selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, and itaconic acid glycidyl ester.

3. The insulated wire according to claim 1 , wherein the resin (B) is at least one selected from the group consisting of an ethylene/glycidyl methacrylate copolymer, an ethylene/glycidyl methacrylate/methyl acrylate terpolymer, an ethylene/glycidyl methacrylate/vinyl acetate terpolymer, and an ethylene/glycidyl methacrylate/methyl acrylate/vinyl acetate quarterpolymer.

4. The insulated wire according to claim 1 , wherein the resin (B) is an ethylene/glycidyl methacrylate/methyl acrylate terpolymer.

5. The insulated wire according to claim 1 , wherein the insulated wire has a softening temperature of 250° C. or more.

6. An insulated wire consisting of one thin insulating layer composed of a resin dispersion, coated on a conductor, wherein the thickness of the thin insulating layer is 20 to 60 μm, and wherein the resin dispersion consists of:

a polyester-series resin (A) in a continuous phase; and

a resin (B) having a glycidyl ester compound of an unsaturated carboxylic acid represented by formula (1),

wherein R represents an alkenyl group having 2 to 18 carbon atoms and X represents a carbonyloxy group, and an olefin-series resin (C), each of which is dispersed with an average particle diameter of 0.05 to 3 μm in the resin (A);

wherein the olefin-series resin (C) is a copolymer composed of at least one component selected from the group consisting of an acrylic component and a vinyl component; and an olefin component;

wherein the resin dispersion is a compound in which resin (B) is uniformly and finely dispersed in resin (A);

wherein the resin dispersion contains 1 to 10 mass parts of the resin (B), and 5 to 10 mass parts of the olefin-series resin (C), to 100 mass parts of the polyester-series resin (A); and

wherein the insulated wire has a dielectric breakdown voltage of from 6.7 to 7.8 kV after being left for 1 hour at 100° C.

7. The insulated wire according to claim 6 , wherein the insulated wire has a softening temperature of 250° C. or more.

8. The insulated wire according to claim 1 or 6 , wherein the polyester-series resin (A) is a polymer obtained by condensation reaction of a dicarboxylic acid with a diol.

9. The insulated wire according to claim 1 or 6 , wherein the resin (B) is a copolymer composed of an olefin component and an epoxy group-containing compound-component.

10. The insulated wire according to claim 1 or 6 , wherein the resin (B) is a copolymer composed of an olefin component and an unsaturated carboxylic acid glycidyl ester component.

11. The insulated wire according to claim 1 or 6 , wherein the resin (B) is a copolymer composed of at least one component selected from the group consisting of an acrylic component and a vinyl component; an olefin component, and an epoxy group-containing compound component.

12. The insulated wire according to claim 1 or 6 , wherein the resin (B) is a copolymer composed of at least one component selected from the group consisting of an acrylic component and a vinyl component; an olefin component, and an unsaturated carboxylic acid glycidyl ester component.