Patent ID: 8367794

Claim:
A polyisocyanate mixture which is liquid at temperatures above −5° C. and is based on diphenylmethane 2,4′-diisocyanate, wherein A) the NCO content of said polyisocyanate mixture is 14.5 to 24% by weight; B) the content of isocyanate groups bonded in the 2 position of said polyisocyanate mixture is greater than 50%; and C) the content of allophanate groups (calculated as C 2 HN 2 O 3 having a molecular weight of 101) of said polyisocyanate mixture is 7.7 to 17.6% by weight wherein said diphenylmethane 2,4′-diisocyanate is pure 2,4′- isomer or a mixture of 2,4′- isomer with up to 2.0% by weight of diphenylmethane 4,4′-diisocyanate and/or up to 1.0% by weight of diphenylmethane 2,2′-diisocyanate, based on the total weight of said polyisocyanate mixture and wherein said polyisocyanate mixture comprises reaction products prepared with intermediate urethane formation from A) diphenylmethane 2,4′-diisocyanate with B) monohydric alcohols having 3 to 18 carbon atoms per molecule while maintaining an NCO/OH ratio of 4:1 to 8.5:1.