GB250398A - Manufacture of tanning substances - Google Patents

Abstract

250,398. Farbwerke vorm. Meister, Lucius, & Br³ning, Krõnzlein, G., Voss, A., and Gõrtner, H. April 24, 1925. Addition to 211,145 and 240,003. Sulphonated ethers of phenolic resins.-The processes of the parent Specifications are modified by using aromatic or aliphatic compounds containing one or more sulpho groups capable of being easily exchanged instead of compounds containing halogen atoms which are easily exchanged. Thus a phenolic resin of high molecular weight may be condensed with such a compound containing a replaceable sulpho group, or a phenolic body of lower molecular weight may be condensed with the sulphonic acid and the product treated with a substance capable of converting a phenol into a phenolic resin; in the latter case the treatment with a resinifying agent may be dispensed with if the initial condensation product is subjected to a heating operation so as to effect further condensation. The products must be sulphonated if they do not already contain a sulpho group. They precipitate gelatine and convert animal hides into light coloured leather of good mechanical properties. According to examples, (1) the sodium salt of 1-#-sulphomethyl-2-oxynaphthalene-6-sulphonic acid (obtained by condensing sodium 2-oxynaphthalene-6-sulpho acid with sulphite and formaldehyde) is condensed in aqueous alkaline solution with the resin from phenol and formaldehyde; after acidifying, the sulphur dioxide is expelled by boiling and the product evaporated to a syrup; (2) the solution of sodium 1-oxybenzene-2-#-methylsulphonate obtained from phenol, formaldehyde and sulphite is mixed with disodium p-phenol sulphonate and condensed by heating at 140-150‹ C.; (3) sodium- 2-oxynaphthalene-1-#-sulphonic acid is condensed with m-cresol and the resulting m-cresylether of 2-oxy-1-oxymethylnaphthalene further simultaneously condensed and sulphonated by heating with formaldehyde and sulphite; (4) sodium 1-#- sulphomethyl-2-oxynaphthalene-6-sulphonate its heated with p : p'-dioxydiphenylsulphone at 140-160‹ C.