Dry cleaning baths contg. fluorinated surfactants - as cleaning builders, give better solvent recovery on distillation

摘要

Solid materials are cleaned in organic solvent baths contg. 0.01-0.2 g/l, esp. 0.05-0.1 g/l of solvent-soluble or -emulsifyable fluorine contg. surface active agents. Typical fluorine-contg. cpds. are e.g. Y(CF2)COOM (I); CnF2n+1(CH2)COOM; CnF2n+1SO3M; Y(CF2)n(CH2)m-O-CH2CH2COOM; (CnF2n+1)mPO(OM)3-m, etc., where Y is H or F; M is H, monovalent metal ion, NH4+, R3NH+, NR4+ in which R is 1-3C alkyl or alkylol gp.; n is 6-12 and m is 1-4. The process is esp. useful in the prodn. of dry cleaning baths for textiles based e.g. on perchloroethylene and contg. a soluble or emulsifyable fluorine cpd. as stated. The baths have excellent dirt removal characteristics and the presence of the fluorine cpd. gives improved recoverey of the solvent in known distillative purification units used for regenerating the spent cleaning bath, compared with baths contg. known cleaning builder formulations.