Abstract: Acicular ferromagnetic metal particles consisting essentially of iron are prepared by a process wherein acicular iron(III) oxide hydroxide provided with a shape-stabilizing surface coating, or iron(III) oxide obtained therefrom by dehydration, is reduced by means of a decomposable organic compound and hydrogen.

Abstract: A polyimide powder particularly suitable for the production of moldings by high pressure sintering is prepared by mixing a solution of an aromatic polyimido-acid, obtained by a conventional process and having an intrinsic viscosity of 1.5 to 2.5 dl/g, in an aprotic dipolar organic solvent, with a water-entraining agent, heating the mixture to the boiling point of the entraining agent, azeotropically distilling off the water formed, filtering off the polyimide powder which precipitates, washing it if appropriate, and drying it.

Abstract: The invention relates to polyurethane coatings prepared from the reaction products of a polyester or polyether, a hydroxyl compound containing acetylenic or ethylenic unsaturation and an organic polyisocyanate.

Abstract: A process for the electrical insulation of wire by enamelling, using aqueous dispersions which are applied thereto by means of applicator rollers. The thickness of the dispersion coating on the wire can be varied by merely suitably selecting the circumferential speed of the applicator rollers.

Abstract: A polyamide-imide precondensate which is solid at room temperature, but is fusible and soluble in polar solvents. It is manufactured by first condensing 1 mole of diamine with 2 moles of tricarboxylic acid anhydride in a diol as the solvent, to give a diimide-dicarboxylic acid, then esterifying the diimide-dicarboxylic acid with the diol and finally effecting the polycondensation by adding 1 mole of diamine per mole of diester. The precondensate may be used, as a melt, as a solution in organic solvents or as an aqueous dispersion, for coating electrical conductors.

Abstract: The manufacture of paper-like and textile-like sheet materials by the use of fibrids which have been obtained by dissolving poly(amide-imide) resins in an organic solvent, mixing the resulting solution with a liquid which is a non-solvent for the polymer and introducing the resulting solution into a liquid precipitation medium while exposing it to shearing forces.The present invention relates to the use, for the manufacture of paper-like and textile-like sheet materials, of novel fibrids, which have been obtained by dissolving poly(amide-imide) resins in an organic solvent, mixing the resulting solution with a liquid which is a non-solvent for the polymer and introducing the resulting solution into a liquid precipitation medium while exposing it to shearing forces.

Abstract: A process for the electrical insulation of metallic conductors by coating wires with aqueous dispersions of coating materials, comprising the following steps which are carried out in a single cycle: introducing the starting dispersion into a storage zone A; continuously withdrawing part of the dispersion from the storage zone and feeding said part to a dispersing zone, where it is homogenized and comminuted; if necessary, cooling the dispersion to below 40.degree. C in a cooling zone; feeding the dispersion to a fractionating zone D, where it is separated into a coarse fraction and a fine fraction; and finally, passing the fine fraction through coating zones E, through which wires are drawn so as to receive a coating.

Abstract: A process for the manufacture of finely divided polyester-imide powders wherein solutions of polyester-imides in organic solvents are solidified by cooling, the solvent is removed by sublimation and the solid product is pulverized. The powders may be used, as aqueous dispersions, to produce heat-resistant coatings on metallic conductors.

Abstract: Process for the manufacture of polyester imides. Melamine, an at least tribasic carboxylic acid, a polyhydric alcohol and, optionally, an aromatic dicarboxylic acid are condensed at elevated temperature. The polyester imides are suitable, in the form of solutions, aqueous dispersions or melts, for use as baking enamels for metallic conductors.

Abstract: The present invention relates to thermostable coating, impregnating and bonding agents. They are suspensions of finely divided water-insoluble or at most only slightly water-swellable thermostable organic binders or mixtures based on these binders in aqueous solutions of high molecular weight organic substances. They are used particularly for coating wire, for the production of thermostable coatings and for the production of laminates.

Abstract: Aqueous polyester imide dispersions are prepared by allowing molten polyester imide to solidify and then comminuting it in the dry state to a particle size of 100 .mu.m or less, whereupon the particles are milled in water to a particle size of less than 5 .mu.um. The dispersions may be used for the manufacture of heat-resistant bonds and impregnations and for electrical insulation of metallic conductors. m.