Patent ID: 8759411

Claim:
A method for enhancing flame retardance of a polyurethane material, the method comprising: incorporating a diphosphine compound as a flame retardant into the polyurethane material, wherein the polyurethane material comprises a polyurethane component, a diphosphine compound, optionally a further polymer, and optionally a further additive, wherein the diphosphine compound is a diphosphine compound of the formula (I): wherein X is S or O; n is 0 or 1; R 1 , R 2 , R 3 , and R 4 are each independently C 1 -C 10 -alkyl, C 1 -C 10 -hydroxyalkyl, C 1 -C 10 -alkoxy, C 1 -C 10 -hydroxyalkoxy, C 3 -C 10 -cycloalkyl, C 3 -C 10 -cycloalkoxy, C 6 -C 10 -aryl, C 6 -C 10 -aryloxy, C 6 -C 10 -aryl-C 1 -C 4 -alkyl, C 6 -C 10 -aryl-C 1 -C 4 -alkoxy, C 6 -C 10 -hydroxy-aryl, C 6 -C 10 -hydroxy-aryloxy, C 1 -C 10 -thioalkyl, C 6 -C 10 -thioaryl or C 1 -C 4 -thioalkyl-C 6 -C 10 -aryl, NR 5 R 6 , COR 2 , COOR 5 , or CONR 5 R 6 ; and R 5 and R 6 are each independently H, C 1 -C 10 -alkyl, C 3 -C 10 -cycloalkyl, C 6 -C 10 -aryl, or C 6 -C 10 -aryl-C 1 -C 4 -alkyl, wherein a total amount of the diphosphine compound of the formula (I) is from 2 to 15 parts by weight, based on 100 parts by weight of the polyurethane component.