THERMALLY STABLE CYCLIC PHOSPHONATE ESTERS THEIR PREPARATION AND POLYMERS CONTAINING THEM AS FLAME RETARDANT ADDITIVES

摘要

1418497 Cyclic phosphonates MOBIL OIL CORP 10 Oct 1972 [15 Nov 1971] 46604/72 Heading C2P [Also in Division C3] The invention comprises compounds of Formula (A) and (B) wherein a is 0 or 1; b is 0, 1 or 2; c is 1, 2 or 3; a+b+c is 3; d is 0, 1 or 2; e is 1,2 or 3; d+e is 1, 2 or 3; R, RSP1/SP and each RSP4/SP (independently) are alkyl, phenyl, halophenyl, hydroxyphenyl, tolyl, xylyl, benzyl, phenethyl, hydroxyalkyl, phenoxyethyl or dibromophenoxyethyl; RSP2/SP is alkyl; RSP3/SP is C 1 -C 4 alkyl or C 1 -C 4 hydroxyalkyl; when d = 0 and e = 1, RSP5/SP is alkyl, phenyl, chlorophenyl, bromophenyl, dibromophenyl, tribromophenyl, hydroxyphenyl, naphthyl, tolyl, xylyl, benzyl or phenethyl; when d+e = 2, RSP5/SP is a direct bond, alkylene, vinylene, phenylene, tetrachlorophenylene or tetrabromophenylene; and when d+e = 3, RSP5/SP is benzenetriyl. Preparation of the above is from compounds of formulµ by the reactions effected at elevated temp. (up to 300‹ C.) optionally in the presence of a catalyst. The values of b, c, d and e in the products may vary in dependence on the relative proportions of the reactants. In Examples Ic and Id, the XI reactant dimethyl methylphosphonate is prepared in situ from trimethyl phosphite. The above reactions are also said to yield "various polycondensed products". Compounds (A) and (B) are used as flameretardants for polymeric materials (bulk, foam or fibrous).