| abstract |
The invention relates to novel and improved halogen-free flame retardant compounds having the structure of Formula I:n nwherein: nR 1 and R 2 are independently hydrogen, C 1 -C 6 alkyl, -P(O)(OR 3 ) 2 , -P(O)OR 3 R 4 , or -P(O)R 3 2 , nwherein R 3 and R 4 are independently C 1 -C 4 alkyl, C 6 -C 12 aryl, C 7 -C 15 aralkyl or C 7 -C 15 alkaryl; or R 1 and R 2 taken together form an unsaturated cyclic ring, which is optionally substituted by an alkyl group; neach k is independently an integer from 1 to 2; neach X is independently oxygen (O) or sulphur (S); nv is 0 or 1; neach Y is independently C 1 -C 4 alkylene, C 6 arylene, C 7 -C 15 aralkylene, C 7 -C 15 alkarylene, oxygen (O), nitrogen (NR), wherein R is H or C 1 -C 4 alkyl; nn is 0, 1 or 2 with the proviso that n is 1 when Y is oxygen (O) or nitrogen (NR); neach Z is independently C 1 -C 4 alkylene, C 6 arylene, C 7 -C 15 aralkylene or C 7 -C 15 alkarylene; m is independently 0, 1 or 2; with the proviso that when Y is oxygen (O) or nitrogen (N), m cannot be 0; neach Q is independently C 1 -C 4 alkylene; nt is an integer from 1 to 2; nW is oxygen (O) or sulphur (S). n The compounds are particularly suited as flame retardant additives for thermoplastic polyesters. |