Patent ID: 8309851

Claim:
An insulated wire, comprising: a conductor; and an insulating layer of a porous member formed on the conductor by using a water-in-oil type emulsion (W/O emulsion) comprising a thermosetting liquid solventless varnish as the oil and water drops of water-soluble polymer contained in the thermosetting liquid solventless varnish as the water, the thermosetting liquid solventless varnish as the oil consisting of a polymerizable oligomer comprising an urethane acrylate oligomer, a polymerizable monomer comprising a monomer having not less than two of an acryloyl group and a cross-linking initiator comprising a ketal compound, the water-soluble polymer consisting of one selected from hydroxymethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose, wherein the insulating layer of the porous member is formed by that the water-in-oil type emulsion is coated so as to form a thin film as a coated film, the thermosetting liquid solventless varnish as the oil is polymerized and cured after the formation of the thin film, and the water drops as the water is dried and removed after the curing of the thermosetting liquid solventless varnish.