DOPO-based hybrid flame retardants

Abstract

The invention relates to novel and improved halogen-free flame retardant compounds having the structure of Formula (I): wherein: R1 and R2 are independently hydrogen, C1-C6 alkyl, —P(O)(OR3)2, —P(O)OR3R4, or —P(O)R32, wherein R3 and R4 are independently C1-C4 alkyl, C6-C12 aryl, C7-C15 aralkyl or C7-C15 alkaryl; or R1 and R2 taken together form an unsaturated cyclic ring, which is optionally substituted by an alkyl group; each k is independently an integer from 1 to 2; each X is independently oxygen (O) or sulphur (S); v is 0 or 1; each Y is independently C1-C4 alkylene, C6 arylene, C7-C15 aralkylene, C7-C15 alkarylene, oxygen (O), nitrogen (NR), wherein R is H or C1-C4 alkyl; n is 0, 1 or 2 with the proviso that n is 1 when Y is oxygen (O) or nitrogen (NR); each Z is independently C1-C4 alkylene, C6 arylene, C7-C15 aralkylene or C7-C15 is alkarylene; m is independently 0, 1 or 2; with the proviso that when Y is oxygen (O) or nitrogen (N), m cannot be 0; each Q is independently C1-C4 alkylene; t is an integer from 1 to 2; W is oxygen (O) or sulphur (S). The compounds are particularly suited as flame retardant additives for thermoplastic polyesters.

Dependencies are inferred from the claim text.