ARTIFICIAL LEATHERS

摘要

1,273,729. Coated fabrics. KANEGAFUCHI BOSEKI K.K. 14 Aug., 1970 [14 Aug., 1969; 27 March, 1970], No. 39329/70. Heading B2E. [Also in Division D1] Artificial leather is prepared by applying an organic solvent solution of a linear polyurethane to a non-woven fabric to form an adhesive layer, superimposing a woven fabric thereon, applying an organic solvent solution of polyurethane to the woven fabric as and when a part of the adhesive layer solution exudes onto the surface of the woven fabric. without coagulation of the adhesive layer and contacting the product with a coagulating liquid which is a non-solvent for the polyurethanes but miscible with the organic solvents so as to simultaneously coagulate the two polyurethane layers. The fabrics may be of polyamide, polyester, polyacrylonitrile, cotton or viscose rayon fibres and the non-woven fabric may be bonded with a synthetic resin or natural or synthetic rubber latex such as styrene/butadiene or acrylonitrile/butadiene copolymer. The coagulation bath may be water, an aqueous solution of an inorganic salt, or an organic solvent and may optionally also contain urea or thiourea. The polyurethane layers usually have a microporous structure and the adhesive layer may comprise a hydroxyl terminated polyurethane containing at least one ether linkage whereas the outer coating may comprise an alcoholic residue terminated polyurethane free from ether linkages, the modulus of elasticity of the two layers normally differing by at least 1.0 x 108 dyne/ cm2. The adhesive polyurethane may also contain urea, thiourea, talc, inorganic salts, pigments and dyes and the outer polyurethane layer may also contain minor amounts of PVC, polyacrylonitrile, polyacrylic acid and copolymers thereof. The polyurethane solutions may be applied by dip coater or by various types of knife, gravure and direct and reverse roll coaters.