Abstract: A magnet wire insulation designed to withstand voltage wave shapes present in inverter driven motors for a sustained period of time is disclosed. A large surface area inorganic oxide, e.g., fumed silica, may be added into the magnet wire insulation for providing improved resistance to insulation degradation. Alternatively, a mixture of the large surface area inorganic oxide with a low resistivity oxide, e.g., chromium oxide, provides a greater improvement in resistance to insulation degradation. The present invention is particularly useful for extending the life of windings in a motor that is subjected to high voltage, steep wave shapes such as those found in inverter driven motors.

Abstract: A magnet wire insulation designed to withstand voltage wave shapes present in inverter driven motors for a sustained period of time. A large surface area inorganic oxide, e.g., fumed silica, may be added into the magnet wire insulation for providing improved resistance to insulation degradation. Alternatively, a mixture of the large surface area inorganic oxide with a low resistivity oxide, e.g., chromium oxide, provides a greater improvement in resistance to insulation degradation. The present invention is particularly useful for extending the life of windings in a motor that is subjected to high voltage, steep wave shapes such as those found in inverter driven motors.

Abstract: An ultra-high solids content, organic solvent solution of polyester magnet wire enamel is described. The enamel is a tris (2-hydroxy-ethyl) isocyanurate polyester having a ratio of hydroxyl to carboxyl groups of 1.65 to 2.0:1 and a hydroxyl number of 216 to 316. Such enamels are produced with solids contents of greater than 70% by weight and viscosity less than 3,000 cps at 160.degree. C. The method of making such enamel by reacting a glycol, tris (2-hydroxy-ethyl) isocyanurate, and an aromatic diacid or diester, reacting this polymer with modifying phenolic and polyisocyanate and adding an aromatic titanate catalyst is also described.

Abstract: An improved thermally stable, lubricious magnet wire enamel is disclosed which is particularly suitable for use as an outermost insulating, lubricating layer on a magnet wire substrate. The enamel comprises the reaction product of a tri-basic acid anhydride, a diisocyanate and a polyfunctional organosiloxane. The coating has a coefficient of friction, after application to magnet wire, of less than 0.10. It is also substantially all polyfunctional organosiloxane reacted, i.e. substantially no polyfunctional organosiloxane is capable of being extracted from the cured coating with organic solvents.

Abstract: An electron beam curable magnet wire enamel comprises the reaction product of a polyester prepolymer having terminal functional groups reactive with an isocyanate, and a urethane-acrylate prepolymer formed by reacting a diisocyanate and a hydroxyalkylacrylate. The resulting polymer is extrudable at 100% solids onto a magnet wire substrate and electron beam curable.

Abstract: A high solids content, relatively low viscosity, organic solvent solution of polyester magnet wire enamel is described. The enamel is a tris (hydroxy-ethylisocyanurate) polyester having a ratio of hydroxyl to carboxyl groups of 1.65 to 2.0:1 and a hydroxyl number of 216 to 316. Such enamels are produced with solids contents of about 50 to about 70% by weight and viscosity less 1,500 cps at 200.degree. F. The method of making such enamel by reacting a glycol, tris (hydroxy-ethylisocyanurate), and an aromatic diacid or diester in the presence of a titanate catalyst is also described.

Abstract: A water soluble polyimide is described comprising the reaction product of butane tetracarboxylic acid (BTC), a multifunctional amine of the formula: ##STR1## and a diamine, where the multifunctional amine constitutes at least 5% of the total amine equivalents of the reactants and preferably 15% to 40%. An aqueous solution of this polyimide, a method of coating electrical conductors with this polyimide, and the electrical conductors insulated with the polyimide are also described. The polyimide, particularly useful as an insulation coating for magnet wire, is made by reacting the multifunctional amine with the BTC followed by reaction with the diamine, removing the condensed water produced during the reaction.

Abstract: A method of improving the physical and electrical properties of polymer insulation coated electrical conductors is described. A non-ionic surfactant added to an organic solvent solution of insulation polymer followed by coating the solution on the wire, drying and curing, has been found to produce a coated magnet wire with improved concentricity and smoothness, therefore resulting in improvement in other wire properties as well.

Abstract: A water soluble polyimide is described comprising the reaction product of butane tetracarboxylic acid (BTC), a multifunctional amine of the formula: ##STR1## and a diamine, where the multifunctional amine constitutes at least 5% of the total amine equivalents of the reactants and preferably 15% to 40%. An aqueous solution of this polyimide, a method of coating electrical conductors with this polyimide, and the electrical conductors insulated with the polyimide are also described. The polyimide, particularly useful as an insulation coating for magnet wire, is made by reacting the multifunctional amine with the BTC followed by reaction with the diamine, removing the condensed water produced during the reaction.

Abstract: A high solids content, low molecular weight polymer, low viscosity polyamide-imide enamel is described. The enamel is a reaction product of polyisocyanate, trimellitic anhydride, and an isocyanate blocking alcohol having a ratio of free isocyanate to total carboxyl and anhydride groups of 0.99:1 to 0.85:1. The method of making the enamel and the method of coating electrical conductors such as magnet wire with such enamel are also disclosed.

Abstract: A method of making aqueous solutions of polyesterimides and the resulting solutions are disclosed. The disclosed method is particularly adapted to making aqueous solutions of high molecular weight polyesterimides with low acid numbers. The resulting aqueous polymer solutions can also be made with high polymer solids content. Solubilization takes place utilizing a base to open imide bonds in the ester-imide polymer chain. The polymer solution has particular utility as a wire enamel.