Improvements in leather-like sheet material

摘要

783,020. Agglutinated fibrous sheet materials; laminates. DU PONT DE NEMOURS & CO., E. 1. Aug. 12, 1955, No. 23351/55. Class 140. Leather-like sheet material comprises, by weight, 20 to 85 per cent of matted, undrawn but orientable fibres of a synthetic linear polymer and 80 to 15 per cent of an expensible polymeric binder. The sheet material may be prepared by bringing the fibres, in the form of an unwoven mat, web or felt, into intimate contact with the binder by impregnation with a solution or dispersion of the binder or by mixing in those cases wherein a fibrous or particulate form of binder is used. The product is then consolidated by thermal or solvent means ; pressure may be used. Non-permeable sheet material may be formed by uniting an unwoven mat of fibres with the binder in the form of a continuous sheet. Specified polymers for use as binders are polyethylene, polypropylene, polyisobutylene, polybutene-2 polyisoprene, vinyl chloride, 2 - 3 - dichlorobutadiene, vinyl acetate, butadiene/styrene, tetrafluoro - ethy - lene/ethylene, vinyl chloride/vinyl acetate, vinylidene polymers and copolymers including both the monoene and diene types, cellulose acetate and cyanoethylene cellulose. Specified polymers for use as the fibre component are high molecular weight vinylidene type addition polymers, polymers and copolymers of the alpha - methylenecarboxylic acids including copolymers with acrylonitrile ; polyamides, polyesters, polyesterarnides, dibasic acid/ diamine or amino acid polyamides, dibasic acid/diol or hydroxy acid/polyesters, intermixed polyester/polyamides, polytetramethylene - sebacamide, polyethylene - terephthalamide, polydodecamethylene adipamide, poly- D- or L- or DL-alamine, poly-D or L- or DL- leucine, polyepsilonaminocaproic acid, polydodecamethylene adipate, polyethylene adipate, polyethylene sebacate, polyhexamethylene oxalate, poly-D or L- or DL-lactic acid, poly-D or L- or DL-mandelic acid and poly-epsilonhydroxycaproic acid. Structural fibres ranging in length from 0.01 inch to 8 inches may be used. In examples : (i) two non-woven mats of polyhexamethyleneadipamide fibres are plied together, impregnated with a solution of polyvinyl chloride/dioctyl phthalate in a tetrahydrofuran/ dimethylformamide solvent mixture, dried, pressed for 10 minutes at 160‹ C. and then split ; and (ii) non-woven mats of polyhexamethyleneadipamide fibres are laminated with polyethylene films and pressed at 140‹ C. for 4 minutes.