g compound having a P--OH linkage in the molecular and being selected from the group consisting of organic acid phosphates of the general formulas: ##STR8## wherein R3 and R4 are an organic group, m is 0 or 1, and x and y are 0, 1 or 2 provided that the sum of x and y is 1 or 2; organic acid phosphites of the general formulas: (R3 O)x (R4 O)y P(OH)2-m and Rx 3 Ry 4 P(OH)2-m wherein R3, R4, m, x an