| 摘要 |
Polymeric sulphochlorides of the type described in Specification 776,043 are prepared by reacting polymers of the form (-A-)n, where A is a divalent radical containing an aromatic group and n is an integer at least equal to 3 in solution in organic solvents with sufficient excess of chlorosulphonic acid to keep the product in solution in at least the early stages of the reaction. Exemplified polymers are polystyrene, polyvinylnaphthalene and copolymers of styrene with maleic anhydride, diethyl maleate and ethyl vinylsulphonate. Suitable solvents are halogenated or unhalogenated saturated aliphatic hydrocarbons, e.g. carbon tetrachloride, trichloroethane, ethylene chloride and heptane. Preferably at least two equivalents of chlorosulphonic acid are used and the products precipitated by adding excess solvent. In examples the sulphochloride solution is filtered before precipitation and the precipitate purified by dissolving in acetone or benzene and reprecipitating with benzene or isopropanolmethanol mixtures. The products may be used as intermediates in the preparation of colour couplers in colour photography. German Specification 503,923 and 580,366 and U.S.A. Specification 2,445,569 also are referred to. |
