Patent GB-1412261-A (GB)
Title: Simulated leathers
IPC: D06N3/14
Filed: 1972-10-25
Abstract: 1412261 Simulated leathers TORAY INDUSTRIES Inc 25 Oct 1972 49205/72 Heading B2E A simulated leather comprises: a fibrous substrate having a thickness of 0.3 to 3.0 mm which comprises fabric impregnated with a polymer; a coating layer (III) adhering to the fibrous substrate and having a thickness of 0.1 to 3.0 mm, which comprises a wet coagulated polymer composition containing from 50 to 300 parts by weight of inorganic particles per 100 parts by weight of the polymer in its composition the inorganic particles having a mean particle diameter of from 0.03 to 5.0Á and being insoluble in water, and the polymer in that composition comprising at least 60% by wt. of polyurethane; a coating layer (II) adhering to layer (III) and having a thickness of 0.01 to 0.3 mm, which comprises a wet coagulated polymer composition which contains from 0 to 50 parts by weight of inorganic particles per 100 parts by weight of polymer, the inorganic particles having a mean particle diameter of from 0.03 to 5.0Á and being insoluble in water, and the polymer of this composition comprising at least 80% by wt. of polyurethane; and a coating layer (I), adhering to the layer (II), having a thickness of from 0.001 to 0.1 mm and having a 20% elongation modulus of from 5 to 100 kg/cm<SP>2</SP>, which comprises a dry coagulated polymer composition comprising at least 80% by wt of polyurethane. The fibrous substrate may comprise polymer fibres of 0.01 to 1.0 denier in a non-woven, woven or knitted web. In examples, the polymer is nylon-6 or polyethylene terephthalate. The polyurethane contained in the coating layers (I), (II) and (III) and the impregnating polymer, is preferably the reaction product of a polymer diol, diisocyanate and diamine and/or a lower M.W. diol, the polymer diol comprising polyetherdiol, polyesterdiol, and/or polyetheresterdiol. The other polymer contained in the coating layer (I), (II) or (III) may be p.v.c., polyvinyl acetate, polyvinylidene chloride, poly (meth) acrylic acid, alkyl poly (meth) acrylate or copolymers thereof, and these layers and the impregnating composition may contain additives such as pigments (e.g. carbon black) dyes, antioxidants, pulp powders or fibre powders. The inorganic compounds contained in coating layers (II) and (I) may be kaolinite, carbonates (e.g. ZnCO 3 , CdCO 3 , CuCO 3 , CaCO 3 , BaCO 3 ), oxides (e.g. ZnO, TiO 2 , Cr 2 O 3 , Al 2 O 3 , antimony, cobalt, tin or iron oxide), sulphates (e.g. BaSO 4 , CaSO 4 ), phosphates (e.g. zinc, aluminium, ferrous, barium phosphate, or calcium monohydrogen phosphate), silicates (e.g. cobalt, magnesium, potassium alumino silicate) or mixtures thereof. In a preferred method of making the simulated leather, (1) coating layer (II) is coated e.g. by reverse roll coater, on a release layer, then coating (III) is coated e.g. by doctor knife, on coating layer (II), (2) the fabric, is impregnated, then dipped in non- solvent to coagulate the impregnating composition, then (3) pressed onto the coatings on the release layer (4) the assembly is then dipped in coagulating liquid to coagulate layers (III) and (II) and unite them with the impregnated fibrous substrate and (5) the release layer is then stripped from the release layer before, during or after extracting solvents from the layers, washing and drying and (6) the coating layer (I) is applied e.g. by gravure roll, to layer (II).