Patent GB-1055872-A (GB)
Title: Improvements in and relating to porous articles
Inventor: MARSH MICHAEL SALISBURY
IPC: D06N3/04
Filed: 1962-04-11
Abstract: Artificial leather-like material in the form of a laminate having a flesh side and a grain side consists of a nonwoven fibrous base, a porous non-fibrous film and a wear-resistant layer which is thinner than the porous film, the porous film being between the wear-resistant layer and the grain side of the non-woven fibrous base.  The porous film may be a copolymer of acrylonitrile with butadiene or styrene, a natural or synthetic isoprene, a chlorosulphonphonated polyethylene, plasticized polyvinyl chloride, a plasticized copolymer of vinyl chloride and vinyl acetate or vinylidene chloride, polyvinyl acetate, or a polyurethane prepared by reacting a di- or poly-isocyanate with a polyester, polyether or polyesteramide.  The wear-resistant layer may be discontinuous and of synthetic polymeric material e.g. an acrylic resin, a polychloroprene, a copolymer of butadiene and acrylonitrile, a copolymer of vinylidene chloride and vinyl chloride, or a polyurethane prepared by reacting a di-or polyisocyanate with a polyester, polyether, or polyesteramide, or may be continuous and of material modified so that it is water-vapour-permeable e.g. casein-permaldehyde methoxy methylated nylon.  The porous film may be at least 5%, but not more than 100% of the thickness of the non-woven base.  The wear-resistant layer may be less than 5/1000 inch thick. The non woven fibrous base may be composed of fibres at least 30% of which are cellulose fibres.  The material may be produced by applying to the grain side of a non-woven fibrous base having a flesh side and a grain side, a polymeric film forming material capable of forming a flexible film, the film forming material containing finely divided particles of a substance which can subsequently be removed from the film, mechanically smoothing the surfaces of the film, removing the particles from the film to form a porous film, and applying to the surface of the film a wear-resistant layer which is thinner than the porous film.  The non-woven fibrous base may be of natural or synthetic fibres e.g. nylon and cellulosic fibres such as a cotton, regenerated cellulose, viscose ravon, and cellulose acetate, which may be bonded together by means of a thermoplastic bonding agent, e.g. polyethylacrylate, felting or needle punching and which has been pressed whilst heated on one side.  The uncoated flesh side of the material may be shaved just sufficient to level the surface and then buffed to raise the fibres.  The shaving and buffing may be effected before coating.  The grain side of the non-woven base may be shaved and/or buffed before coating.  The finely divided particles may be water-soluble and are removed by leaching with water.  There may be a plurality of separate porous films and each can be made from any polymeric material capable of forming a flexible film.  The film may be applied by extrusion or knife coating and the wear resistant layer by spraying.  The material may be moulded by hot pressing, embossed, and flock fibres may be p  applied by means of an electrostatic field and fixed by an adhesive.