Abstract: Liquid modified epoxy resins are prepared by reacting a drying oil with a diepoxide in the presence of a metal chelate catalyst. The drying oil may be modified by reacting it with maleic acid, maleic anhydride, or fumaric acid to increase the drying rate. The catalyst may be modified by mixing or reacting it with a borate.

Abstract: A non-pulverulent solid polymeric structure is disclosed which has at least one pendant diaminotriazine ring. The structure is made by immersing a non-pulverulent solid structure which has at least one pendant nitrile group into a basic solution of cyanoguanidine at a temperature which does not dissolve the structure.

Abstract: A stripper composition for thermoset resins is disclosed which comprises about 1 to about 99% of an aromatic compound which has a boiling point over 180.degree. C. and is a phenol or a primary or secondary amine, and about 1 to about 99% of a carboxylic acid compound which has a boiling point over 180.degree. C. and is a rosin acid or a mono- or di-carboxylic fatty acid or an ester thereof. The composition also preferably includes sufficient hydrogen bonding compound to react with any acid present in the composition plus about 20 to about 50% in excess of that amount. A swelling agent is also preferably included.

Abstract: An apparatus and method are disclosed for stripping plastics from articles such as motors by use of a stripping fluid. The apparatus has two heated tanks each having a large lid with a gas exit, a third tank, and means for pumping fluid between any two of the tanks. After the stripping fluid in one heated tank has removed the plastic from articles in that tank, it is pumped to the second heated tank and a washing fluid is pumped from the third tank to the first tank. A fourth tank may also be used to hold excess when a heated tank capacity is not being fully utilized.

Abstract: Thermoset aromatic ethers and other thermoset polymers are stripped from an article by immersing the article in a molten compound of the general formula: ##STR1## WHERE N IS AN INTEGER FROM 5 TO 7. Caprolactam is an especially useful stripping compound.

Abstract: A diglycidyl ether of a diphenol, such as a diglycidyl ether of bisphenol A, is reacted with bisphenol S to form a chain-extended epoxy resin. This chain-extended epoxy resin is then esterified with a fatty acid derived from a drying oil, such as linseed oil fatty acid. The resulting epoxy resin ester is cut with a solvent for use as a rapid drying coating material. A primer using this material is also disclosed.

Abstract: Liquid modified epoxy resins are prepared by reacting a drying oil with a diepoxide in the presence of certain alkali or alkaline earth metal compounds, preferably a lithium soap such as lithium ricinoleate. The drying oil may be modified by reacting it with maleic acid, maleic anhydride, or fumaric acid to increase the drying rate.

Abstract: A solution is prepared of about 30 to about 60 mole percent of a mono-ester of a tricarboxylic anhydride or a diester of a tetracarboxylic acid and about 40 to about 70 mole percent of a dianhydride. An aromatic diisocyanate is added and the solution heated until the viscosity no longer increases. The precursor can be precipitated by the addition of a non-solvent, collected, and re-dissolved in a solvent. The solution of the precursor can be applied to a sheet and cured to form a polyimide or polyamide-imide film, or it can be applied to a wire and cured to form a polyimide or polyamide-imide wire enamel.

Abstract: A composition is disclosed of a dianhydride and a tetracarboxylic acid in the proportions of about 50 to about 70 mole % dianhydride to about 30 to about 50 mole % tetracarboxylic acid, a stoichiometric amount of an aromatic diisocyanate, and a solvent for the dianhydride, the tetracarboxylic acid, and the diisocyanate. A polyimide precursor is prepared by heating the composition at about 30.degree. to 70.degree. C until the evolution of carbon dioxide substantially ceases, and then at about 30.degree. to about 100.degree. C until its viscosity is about Q to about Z6 on the Gardner-Holdt viscosity scale at 18% solids. The polyimide precursor can be spread on a substrate and cured to produce a polyimide film or coated on a wire and cured to produce a polyimide wire enamel.