Polyurethane prepolymers based on oleochemical polyols, their production and use

摘要

The invention relates to isocyanate-terminated polyurethane prepolymers containing a stoichiometric excess of an isocyanate component comprised of one or more aromatic isocyanates containing on average from 2 to 4 isocyanate groups per molecule and a polyol component comprised of an oleochemical polyol prepared by epoxidation of a triglyceride containing olefinic unsaturation and subsequent ring opening with an alcohol. In use, accelerators, flameproofing agents, blowing agents and, optionally, liquefying agents, dyes and/or stabilizers, are included. The oleochemical polyol does not contain any free epoxide groups and is obtained by complete ring opening of epoxidized triglycerides of a fatty acid mixture containing at least partly olefinically unsaturated fatty acids with one or more C1-C12 alcohols and partial conversion by alcoholysis or transesterification of the triglyceride derivatives to alkyl ester polyols containing from 1 to 12 carbon atoms in the alkyl radical. A process for the production of these polyurethane prepolymers and to their use as starting materials for the production of polyurethane foams is included.