Patent ID: 8722137

Claim:
A method of making an insulated wire, said method comprising: coating a perimeter of a conductor with a liquid crosslink-curable resin composition containing an aqueous absorbent polymer dispersed therein to provide an insulating layer around the conductor, the aqueous absorbent polymer comprising a pre-absorbed water-swollen absorbent polymer; cross-linking the aqueous absorbent polymer-containing liquid crosslink-curable resin composition to provide a cured insulating layer; and heating the cured insulating layer to remove moisture in the aqueous absorbent polymer to faint voids in the insulating layer, wherein the aqueous absorbent polymer has an average particle diameter of 10 μm or less before swelling, an amount of water absorption of the aqueous absorbent polymer after swelling in a range from 10 g/g to 100 g/g, and the aqueous absorbent polymer-containing liquid crosslink-curable resin composition has a moisture content in a range from 25% to 65%, thereby a size and a shape of the voids in the insulated layer are controlled.