Abstract: Stable solutions of diisocyanate polyaddition products in a solvent mixture containing: a) inert organic solvents, b) primary and/or secondary alcohols and c) semiacetals of formaldehyde and the process of preparing such solutions. Methods of dressing leather with said solutions are also disclosed.

Abstract: Comparatively low viscosity biuret containing polyisocyanates are produced by reacting diisocyanates and biuretizing agents in proportions corresponding to a molar ratio of diisocyanate to monofunctional biuretizing agent of at least 11 : 1.

Abstract: A process is provided for the production of synthetic polyurethane plastics, particularly foam plastics, containing biuret groups by reacting polyisocyanates, polyhydroxyl and/or polycarboxyl compounds, flame inhibitors and, if desired, blowing agents, emulsifiers, activators and other additives which is characterized by using as the polyisocyanate solutions in monomeric polyisocyanates of from about 1 per cent to 85 per cent of polyisocyanates containing biuret groups and having the formula: ##EQU1## in which R is an aromatic, araliphatic or cycloaliphatic radical which may, if desired, be substituted andn is an integer from 0 to 5, wherein the proportion of biuret-polyisocyanates having more than three isocyanate groups is at least 20 per cent by weight based on the total quantity of biuret-polyisocyanates, and the solutions contain from about 0.03 per cent to about 5 per cent by weight of chemically combined emulsifiers.

Abstract: Adducts useful as solvents are prepared from lactams and an aliphatic, cycloaliphatic or araliphatic alcohol or thioalcohol. Solutions of the adducts in the lactam, alcohol or thioalcohol are also disclosed as well as a process for preparing the adducts and solutions thereof.

Abstract: Stable, concentrated solutions, miscible with water in any ratio, of azo and anthraquinone dyestuffs containing sulphonic acid groups are obtained by means of association compounds of lactams with polyalcohols, optionally with water and optionally with further water-miscible organic solvents.

Abstract: A substrate to be used as a support for a release coating is provided with a powdery release support with a release agent which is substantially non-tacky by applying on the support an aqueous solution, dispersion or paste containing a lactam compound which is water soluble, swells in water or forms a paste with water, drying the resulting coating. The process comprises treating the release agent, drying the release agent, applying a polyurethane coating over the release support and then removing the polyurethane coating from the release support. The release agent is selected from lactams and addition compounds of lactams with water, oximes, amines, monofunctional or polyfunctional alcohol or thioalcohols and mixture thereof.

Abstract: The present invention relates to stable solutions of urea diisocyanates in diisocyanates which are free from urea groups which solutions are prepared by a process which comprises reacting in the absence of a solvent at a temperature from about -20.degree.C to about 80.degree.C an organic diisocyanate with a bis-secondary diamine such that the NCO/NH-ratio is from 2.5 : 1 to 20 : 1. The solutions of the invention are well-suited for use as isocyanate component for the preparation of polyurethane resins by the isocyanate polyaddition process.

Abstract: An improved process for the preparation of isocyanate group containing telomers of reduced viscosity by conducting the telomerization of an ethylenically unsaturated monomer with an organic isocyanate in the presence of an organic compound containing at least one sulfhydryl group.

Abstract: Isocyanate polyaddition products which are cross-linked via allophanate, biuret, or uretdione imine groups are linearized by reacting them in the presence of polar solvents with low molecular weight polyisocyanates at temperatures between 90.degree. and 200.degree.C and then preferably reacting the linearized product with amino alkyl silane derivatives to prepare products which are easily cross-linked by atmospheric moisture to form soft highly elastic films.

Abstract: Formaldehyde and a polyaddition product of an organic diisocyanate and an organic compound having hydrogen atoms determinable by the Zerewitinoff method are reacted in a mixture of a tertiary alcohol and an inert organic solvent to form N-methylolated diisocyanate polyaddition products for use, inter alia, as coatings, lacquers and the like.