Patent ID: 6936678

Claim:
Process for preparing solvent-containing and/or diluent-containing polyisocyanates based on 2,4- and/or 2,6-diisocyanato-toluene which contain isocyanurate groups and <0.1% by weight of monomeric disocyanate comprising a) carrying out a catalytic trimerization of a diisocyanate component in the presence of a solvent component and a catalyst component; combined to form a mixture, wherein the mixture comprises from 20 to 80% by weight diisocyanate component, wherein the dilsocyanate component contains a mixture of 2,4-diisocyanatotoluene and 2,6-diisocyanatotoluen at a weight ratio of from 3:2 to 9:1, wherein the mixture comprises from 20 to 80% by weight of solvents and/or diluents, wherein the mixture comprises phenolic catalysts contaning dialkylaminomethyl groups, and wherein the catalytic trimerization is carried out at a temperature from 70°C. and 120°C. in the absence of aliphatic hydroxyl groups and urethane groups, and b) ending the reaction subsequently, by stopping with catalyst poisons.