Glyoxal mono( alpha - or beta -formylalkyl) acetals as tanning agents in the production of leather and skin pelts

摘要

Process for the tanning of leather and skin pelts, in which, as tanning agents, glyoxal mono( alpha - or beta -formylalkyl) acetals I or II <IMAGE> in which R<1> is C1- to C24-alkyl, C2- to C24-alkenyl, a group of the formula -(AO)m-R<4> in which A is a 1,2-alkylene group of 2 to 4 carbon atoms and m may adopt a value from 1 to 20, C5- to C8-cycloalkyl, C7- to C18-aralkyl, C6- to C18-aryl, where aromatic rings may in addition comprise from one to three C1- to C12-alkyl groups, C1- to C12-alkoxy groups, halogen atoms, cyano groups, hydroxyl groups, carboxyl groups, C1- to C12-alkoxycarbonyl groups or sulpho groups as substituents, or is a five- or six-membered unsaturated or saturated heterocyclic ring comprising up to three heteroatoms from the group consisting of nitrogen, oxygen and sulphur, which ring may in addition be benzo fused and can be substituted by from one to three C1- to C12-alkyl groups, C1- to C12-alkoxy groups, halogen atoms, cyano groups, hydroxyl groups, phenyl groups, phenoxy groups or C1- to C12-alkoxycarbonyl groups, R<2> is the group -CH2OR<4>, -CO-OR<5> or -CHO, R<3> is hydrogen, the radical R<1> or a group of the formula <IMAGE> , R<4> is hydrogen or the radical R<1>, and R<5> is hydrogen, alkali metal, ammonium or the radical R<1>, and n is a number from 1 to 30, or, from the compounds I and/or II, by intra- or ... Original abstract incomplete.