FIELD: leather industry, tanning. SUBSTANCE: leather is treated with amphiphilic copolymer (mean molecular mass is 2500-50000). Copolymer is prepared from 10-50 wt. -% at least one hydrophilic monomer that is acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, anhydrides of these acids, acid substituted (meth)acrylate, acid substituted (meth)acrylamide, basic substituted (meth)acrylate, basic substituted (meth)acrylamide or their mixture and 50-90 wt.-% at least one hydrophobic monomer that is alkyl(meth)acrylate, primary alkene, alkylcarboxylic acid vinyl ester, alkylacrylate containing 4-12 carbon atoms in alkyl group, alkylmethacrylate containing 4-12 carbon atoms in alkyl group, alkene-1 containing 4-12 carbon atoms in alkyl group, alkylcarboxylic acid vinyl ester containing 4-12 carbon atoms in alkyl group, styrene, methylstyrene, vinyl acetate, (meth)acrylonitrile, p-alkyl(meth)acrylamide or their mixture. Amphiphilic copolymer is obtained by emulsion polymerization in an aqueous medium that can be used as 20-60% aqueous solution as agent for decrease of leather components volatility. Agent is used for additional upholstering leather tanning. EFFECT: improved method of preparing. 3 cl, 1 tbl
