Process of Tanning and retanning Leather padding

摘要

The process employs substances with tanning activity comprising 1 to 50% by weight dispersions of a) optionally ionically modified polyisocyanate polyaddition products in b) organic polyhydroxy compounds in the molecular weight range 500 to 12,000, in amounts of 0.5 to 30% by weight, based on polyisocyanate polyaddition products a) on the one hand and pelt weight or shaved weight on the other hand, where appropriate in combination with other substances with tanning activity, and/or with auxiliaries and additives customary in tanning.