METHOD FOR LEATHER TANNAGE Russian patent published in 1998 - IPC

FIELD: production of leathers of mineral tannage. SUBSTANCE: after pickling of skin, concurrent tannage with chrome tanning agent and neutralization with alkali agent are carried out at one step. Alkali agent is used in the form of mixture of sodium hydrocarbonate with carbamide-formaldehyde resin in ratio of 85:15-88:12%. Preliminarily prepared from this mixture are tablets weighing 1-2 g. These tablets are dried at temperature of 50-70 C and coated with nitrocellulose in the amount of 1.0-1.5% of dry tablet weight, and dried again at the same temperature. EFFECT: provision for continuity of process and its simplification, saving of tanning materials and higher quality of leathers.