Patent ID: 7906606

Claim:
A process for preparing solvent-containing formulations comprising NCO-containing prepolymers based on TDI isocyanurate polyisocyanates and diphenylmethane diisocyanates wherein the formulation has an NCO content of from 1% to 7% by weight, a solids content of from 20% to 70% by weight, a monomeric TDI content of less than 0.2% by weight and a monomeric methylenediphenyl diisocyanate content of less than 2% by weight, the process comprising i) preparing, separate from the prepolymer of step ii), a prepolymer in the presence of organic solvents from isocyanate components A): A) a TDI component comprising TDI isocyanurate polyisocyanates, ii) preparing, separate from the prepolymer of step i), a prepolymer in the presence of organic solvents from isocyanate components B): B) an MDI component comprising diphenylmethane diisocyanates, and iii) mixing the resulting prepolymers to form the solvent containing formulation, wherein at least one of the prepolymers is prepared by reacting the isocyanate component with C) a polyetherdiol having a number-average molecular weight of from 3 000 to 4 500 g/mol and an ethylene oxide content of from 2 to 18% by weight, based on all of the alkylene oxide units present in the diol, and if one of the two prepolymers is not prepared using component C), it is prepared by reacting the isocyanate component with a polyetherpolyol other than component C).