Sulphonane derivs of aromatic carboxylic acids,converting s - groups to sulphonanes and keeping free carboxylic groups

摘要

Sulphonanes are produced by treating sulphonic acids (SOH3H)-Ar- (COOH)x (where x is 1-3) and acidity of sulphonic group is pKSO3H, and carboxylic group pK(COOH)2) with salts of acids, of pK values between pKSO3H and pK(COOH)x, or, by partial neutralisation of the sulphonic acids using strong bases, esp. alkali or alkaline earth metal hydroxides. Strongly acid sulphonic groups are harmful when used for example in modification of polyethylene fibres and only sulphonanes are usable.