MULTILAYER LEATHER Russian patent published in 2000 - IPC

FIELD: light industry, particularly, production of leather with polymer coating. SUBSTANCE: multilayer artificial leather has multilayer fibrous base which consists of natural and artificial, synthetic fibers or threads impregnated with polymer binder and face polymer layer made on base of flexible polymers including special-purpose additives. Fibrous base is formed of 2-4 layers of stitched laps. Each lap is fastened with sewing thread with linear density of 22-32 tex from polyamide or from polyester. Number of loops for 50 mm length of lap amounts to 35-50 units along lap and 20-30 units across lap with total surface density of laps of 400-700 g/sq.cm. Each lap is impregnated with solution or dispersions of polymer binder. Face polymer layer is applied in the form of solutions or dispersions and formed so that depth of penetration into impregnated base amounts up to 0.15-0.7 of base thickness. Treatment, crowing and formation of face surface of leather are carried out with formation of salient pattern whose length of its projections is 0.3-0.9 mm and 10 sq.cm of lap carry 150-350 projections. Ratio of layers of artificial leather in thickness is the following, correspondingly: 1: (0.1-0.5): (0.2-0.5). EFFECT: improved steam permeability, increased durability and wear resistance of leather in wide range of temperatures. 1 tbl, 9 ex