GB597099A - Improvements in or relating to the manufacture of water soluble condensation products - Google Patents

Abstract

Water-soluble products useful in the tanning industry as tanning, dispersing or bleaching agents, in the textile industry, for dyeing, printing and dressing, as dispersing or reserving agents, and, in certain cases, as fungicides, are manufactured by the action of alkali bisulphites, in an aqueous medium and with gradual addition of a strong acid, on methylol derivatives obtainable by the action of formaldehyde on phenols of the general formula <FORM:0597099/IV/1> wherein R represents an alkyl, aryl, hydroxy-aryl, aralkyl, hydroxyaralkyl or cycloalkyl radical and -X- represents a simple linkage or -SO2-, and wherein the aryl nuclei may contain substituents such as halogen atoms or the methyl group, e.g. p-phenylphenol, 4 : 41-dihydroxydiphenylmethane, 4 : 41 - dihydroxy - diphenylpropane, 4 : 41-dihydroxydiphenyl sulphone and their homologues and halogen derivatives, or mixtures of phenols consisting wholly or mainly of those of the above formula. The process may be carried out at temperatures not exceeding the boiling point of the reaction medium under atmospheric pressure (i.e. 100-110 DEG C.), and the addition of acid is stopped when a sample diluted with water is stable at pH 1.5-2.5. The pH is then adjusted to a value appropriate to the use for which the product is intended. In examples: (1) 4 : 41-dihydroxydiphenyl sulphone is boiled with formaldehyde and caustic soda in water, and the resulting solution is boiled with sodium bisulphite solution with gradual addition of sulphuric acid; (2) 4 : 41-dihydroxydiphenylpropane is similarly treated; (3) as in (1) with slight modifications in quantities and concentrations of reagents; (4) the sulphuric acid in (2) is replaced by hydrochloric acid; (5) a mixture of 4 : 41-dihydroxydiphenyl sulphone and 4 : 41-dihydroxydiphenylpropane is treated as in (3). Samples have been furnished under Sect. 2 (5) of products prepared similarly from: (A) p-cyclohexylphenol; (B) 4 : 41 - m - dicresylolsul - phone; (C) 4-o-cresylolpropane.