Process for preparing liquid polyisocyanate compositions, and their use.

摘要

A method for the preparation of a liquid polyisocyanate composition which comprises reacting one molar proportion of diphenylmethane diisocyanate containing at least 15% by weight of the 2,4 min -isomer with from 0.01 to 0.8 molar proportions of a monohydric alcohol of the formula: A - OH wherein A represents an alkyl radical containing from 9 to 16 carbon atoms or a radical of the formula: <CHEM> wherein R represents an alkyl group containing from 1 to 12 carbon atoms, R<1> represents hydrogen or an alkyl group containing from 1 to 3 carbon atoms and x is an integer of from 1 to 58, the reaction being performed at a temperature of from 100 to 250 DEG C and in the presence of a catalyst for the NCO/OH reaction. The liquid diisocyanate compositions are useful in the manufacture of polyurethanes, especially elastomers and flexible foams.