Abstract: A process for the treatment of leather comprises the following process steps: (a) Application of at least one cationic or amphoteric aqueous treatment composition to leather by roll coating and/or roll application and/or spray application, and subsequently (b) treatment of the leather with an anionic leather treatment composition in a drum.

Abstract: An automated method for surface monitoring and surface correction of sheet-like materials, for example of leather, especially a method for classifying surfaces of sheet-like materials, comprises the following steps: (a) preparation of a material, (b) optoelectronic recording of the surface of the material, (c) determination of the number of defects, (d) determination of the volume of defects, and subsequent automatic classification of the sheet-like materials according to number and volume of defects.

Abstract: N-Vinyl-containing polymers obtainable by free-radically initiated polymerization of a monomer or monomer mixture of (A) from 5 to 100% by weight of an N-vinylamide or N-vinylamine, (B) from 0 to 95% by weight of monoethylenically unsaturated carboxylic acids having from 3 to 8 carbon atoms or their derivatives, (C) from 0 to 95% by weight of other N-vinyl and/or C-vinyl compounds and (D) from 0 to less than 10% by weight of other copolymerizable monomers, are useful in the form of aqueous solutions or dispersions as tanning materials for self-tanning, pretanning and cotanning of leather pelts and fur pelts and for retanning leather and fur.

Abstract: The invention relates to a process for the production of a multilayered composite element which comprises a layer of leather, a layer of a hard component formed from a polymer, which is bonded to the leather layer in certain areas, and a layer of a soft component, which is arranged between the leather component and the hard component, which comprises laying the leather against one mold surface of a mold, positioning the soft component on the leather, and molding the polymer acting as hard component onto the leather layer and the soft component layer at a pressure of at least 50 bar, preferably greater than 100 bar, in particular greater than 180 bar, and at a temperature of greater than 100° C., preferably from 180 to 280° C., in particular from 200 to 250° C., by bonding the leather and the hard component to one another in certain areas at least, with temperature of the mold surface of the mold being controlled, at least during the bonding.

Abstract: A composition containing (A) one or more aromatic sulfonates, (B) one or more aldehyde resins and (C) a buffer and is prepared and used for treating, in particular neutralizing, leather tanned with mineral compounds or mineral-free compounds.