. . . . "R1 R2 NR3 wherein R1 and R2 are each hydrogen or a C1 to C6 and preferably a C2 to C4 alkyl, linear or branched, and R3 is an alkyl, linear or branched, having from 3 to 20 and preferably 4 to 12, or R3 is --R4 NH2 wherein R4 is a C2 to C18 alkyl, linear or branched, and preferably 3 to 11, the sum of carbon atoms in R1, R2 and R3 being from 3 to 20 and preferably from 7 to 13." .