process for the production of hexabrom, tetrabrom, tetrabromdichlor or dibromdichlordiphenylsulfiden

摘要

A synthetic polymer composition having fire-retardant properties comprises a synthetic organic polymer e.g. polyethylene polypropylene, polystyrene, polyvinyl acetate, polyvinyl chloride, polyethylene terephthalate, nylon, polyurethanes, epoxy resins, having dispersed therein up to 10% based on the weight of the polymer of a halogenated diphenylsulphide of the formula FORM:1015028/C3/1 in which x is 0 or 1 and n is 2 or 3 when x is 0 and is 1 or 2 and x is 1. Specified compounds are tetrabromo - diphenylsulphide and hexabromo-diphenylsulphide.ALSO:The invention relates to halogenated diphenylsulphides of the general formula FORM:1015028/C2/1 in which x is 0 or 1 and n is 2 or 3 when x is 0 and is 1 or 2 and x is 1 and to brominated diphenyl sulphides of the general formula FORM:1015028/C2/2 where m and n are 1, 2 or 3 and are such that the sum of m and n is 4 or 6. Compounds claimed per se are tetrabromo-diphenylsulphide; hexabromo - diphenylsulphide and tetrabromo - dichlorodiphenylsulphide. Compounds in which x = 1 and n = 1 or 2 may be obtained by effecting simultaneous nuclear bromination and chlorination of diphenylsulphide in order to introduce two chlorine constituents and at least two bromine substituents into the starting material. The compounds in which x = 0 and n = 2 or 3 may be obtained by effecting nuclear bromination of diphenylsulphide to introduce 4 or 6 bromine substituents, preferably in an inert solvent and in the presence of a nuclear bromination catalyst e.g. iron powder with a small molar excess of bromine at an elevated temperature. Sufficient chlorine to oxidize the hydrogen bromide formed by bromination to bromine may also be present, the reaction mixture always containing an excess of bromine over chlorine. Examples are given of the preparation of the compounds claimed per se.