Abstract: There is disclosed an insulated wire comprising a conductor, a primer layer coating the conductor, and an insulating layer coating the primer layer. The primer layer is formed by curing an epoxy resin.

Abstract: Provided is an insulated electrical wire having an insulating coating that is relatively inexpensive, has good mechanical strengths such as hardness and good thermosoftening resistance, and exhibits a high corona discharge inception voltage. The insulated electrical wire comprises a conductor and an insulating coating which covers the conductor, and the insulating coating includes an insulating layer formed by applying and baking a mixed resin of a polyetherimide and a polyesterimide. In particular, the mixing ratio (weight ratio) of the polyesterimide to the polyetherimide is 75:25 to 10:90. An electrical coil produced by winding the insulated electrical wire and a motor comprising the electrical coil are also provided.

Abstract: A heat-resistant resin varnish characterized by comprising a polyamideimide resin whose terminal isocyanate group is blocked with a blocking agent and a polyamic acid, which is freed from viscosity increase even without employing any complicated step such as heating or cooling and which is easily applicable to a substrate and can form, through curing, films having excellent strength and elongation (toughness) equivalent to those of polyimide resin; heat-resistant resin films which are made of a heat-resistant resin formed by baking the varnish and have excellent toughness; heat-resistant composites having the heat-resistant resin films; and insulated wire which is covered with an insulating coating film made from the varnish through curing and having excellent toughness and which can be easily manufactured at a low cost.

Abstract: An insulated electrical wire coated with a polyamide-imide insulating material which is a copolymer of anhydrotrimellitic acid, aliphatic and aromatic dicarboxylic acids and a diisocyanate, with a molar ratio of the acids to the diisocyanate of from about 0.9:1.0 to about 1.1:1.0 and optionally further containing from about 1 part wt. to about 30 parts wt. of an epoxy resin per each 100 parts of the copolymer. Optionally the aforementioned insulation can be an interior, first coating, coated by a second coating of a polyamide, polyamide-imide, and when the first coat does not contain an epoxy, then a polyimide.