Abstract: Zinc chelates of terephthaloyl-terephthalic/oxalic copolyhydrazides, the oxalic dihydrazide and terephthalic dihydrazide units having a molar ratio in the range of 19:6 to 6:19, as well as the products aftertreated with an oxalic acid solution.

Abstract: Mixtures hardenable under the influence of air moisture are provided. They comprise at least one organic polyisocyanate or an polyepoxide and as a moisture activated hardener an N,N'-substituted imidazolidine derivative or an N,N'-substituted hexahydropyrimidine derivative, which show at no nitrogen atom a --CO--NH-- grouping and which are present in sufficient amount to provide for cross-linking. The mixtures for example provide lacquers and adhesives having various touch dry times.

Abstract: Flame retardant films and fibers of zinc chelates of terephthaloyl-terephthalic/oxalic copolyhydrazides, the oxalic dihydrazide and terephthalic dihydrazide units having a molar ratio in the range of 19:6 to 6:19. The products aftertreated with an oxalic acid solution are colorless.

Abstract: A process for the production of high molecular weight, fiber- and film-trimming polyterephthaloyl oxalamidrazone and polydiphenylether-4,4'-dicarboxylic acid oxalamidrazone where a solution of pure terephtaloyl chloride or diphenyl-ether-4,4'-dicarboxylic acid dichloride in an inert solvent free from amines and water is slowly added, at a temperature between 10.degree. C. and 35.degree. C., to a solution of pure oxalic acid bisamidrazone in dimethyl acetamide and/or N-methyl pyrrolidone, free from amines and water, containing 4 to 6 percent by weight of anhydrous lithium chloride, the total quantity of the solvents used amounting to 1.25 to 3.30 liters per mole of oxalic acid bisamidrazone.

Abstract: A process for the stabilization of a polymer which is a barium, strontium and/or calcium complex of polyterephthaloyl oxalamidrazone or polydiphenylether-dicarboxylic acid-4,4'-oxalamidrazone wherein the polymer is treated in an acidic to neutral aqueous solution, e.g. at pH of 1 to 7, containing an acid or salt compound selected from the group consisting of oxalic acid, alkali oxalate, alkali sulfite, alkali hydrogen sulfite, alkali dithionite and alkali hydrogen sulfate. The resulting product has a much improved resistance to UV, oxidation and hydrolysis. Such polymers are especially useful in the form of flame-retardant threads, yarns, filaments, fibers, felts, fabrics and the like.

Abstract: A metal compound of a polyacyl-2,4-dihydrazino-s-triazine in which the metal is chemically bound in complex form to the polymer to provide dimensionally stable and heat-resistant polymeric compounds which are useful as pigments, catalysts and synthetic fibers.