METHOD OF LEATHER MAKING Russian patent published in 1998 - IPC

FIELD: leather industry. SUBSTANCE: semifinished product of cattle hides is tanned additionally with chrome tanning agent and neutralized at liquid coefficient 0.4-0.8 simultaneously with treatment with hydroxyethylated fat at amount 1.5-2.5% of semifinished product mass (as measured for 100% fat). Material is treated with saponification product of polyacrylonitrile an aqueous dispersion (content of carboxyl-groups is 10-14% of polymer mass) taken at amount 3-4% of semifinished product (as measured for dry matter). Then material is stained, greased and tanned additionally with organic tanning agents. EFFECT: improved quality of leather due to their increased strength property. 1 tbl