Organic antimony complexes

A flame retardant additive for resins, particularly polyvinyl chloride and polyurethane resins, comprises an antimony complex prepared by reacting an antimony trialkoxide with an ester of a hydroxy carboxylic acid (the carboxylic group being that which is esterified), each mole of alkoxide being reacted with 1 to 3 moles of ester. The esters may be mixed esters and may be derived from lactic, malic, tartaric, citric or salicylic acids, while the esterifying alcohol may be a C1-12 saturated or unsaturated alcohol or benzyl alcohol or their halogenated derivatives. The alkoxide may be derived from a C1-5 alkanol. In examples: "antimony dibutyl tartrate" is incorporated in (1) a P.V.C., allyl phthalate, "Epikote" (Registered Trade Mark) 834 mix and (2) a polyester, diisocyanate, dibromopropyl tartrate mix which is processed into a foam. The second Provisional Specification refers to the use of bromine-containing compounds, particularly esters of bromo alcohols with hydroxy acids and also high ...