Patent ID: 7553963

Claim:
A process for the preparation of a storage-stable, liquid, partially trimerized and allophanized polyisocyanate composition containing isocyanurate groups and having an NCO group content of about 15 to about 41% by weight, comprising: (1) partially trimerizing and allophanizing: (A) from 5 to 85% by weight of toluene diisocyanate having an isomer distribution of: (1) from 60 to 100% by weight of the 2,4-isomer, and (2) from 0 to 40% by weight of the 2,6-isomer, with the sum of the %'s by weight of (A)(1) and (A)(2) totaling 100% by weight of (A); and (B) from 5 to 85% by weight of a polyisocyanate of the diphenylmethane series comprising: (1) from 0 to 50% by weight of polyisocyanates of the diphenylmethane series having an isocyanate functionality greater than 2, (2) from 40 to 100% by weight of 4,4′-diphenylmethane diisocyanate, (3) from 0 to 20% by weight of 2,4′-diphenylmethane diisocyanate, and (4) from 0 to 6% by weight of 2,2′-diphenylmethane diisocyanate, with the sum of the %'s by weight of (B)(1), (B)(2), (B)(3) and (B)(4) totaling 100% by weight of (B); and (C) from 0.1 to 10% by weight of an organic compound or mixture thereof containing from 1 to 4 hydroxyl groups capable of reacting with NCO groups and having a molecular weight of from 32 to 6000; wherein the sum of the %'s by weight of (A), (B) and (C) total 100% by weight, in the presence of: (D) at least one trimerization catalyst and optionally at least one allophanation catalyst, followed by addition of: (E) an acidic stopper.