Patent GB-1008283-A (GB)
Title: Non-woven fabrics
IPC: D04H1/64
Filed: 1962-11-06
Abstract: A non-woven bonded fibrous fabric comprises a main body of non-woven synthetic hydrophobic fibres having at least one surface thereof covered with a non-woven web of cellulose fibre.  Suitable hydrophobic fibres include nylon, polyvinylidene chloride, polyethylene glycol terephthalate and acrylonitrile fibres including polyacrylonitrile and copolymers of at least 70% by weight of acrylonitrile with vinyl acetate, acrylic acid esters, vinyl pyridene and mixtures thereof.  The hydrophobic fibres may be a carded web, may be random laid or deposited in an air stream.  The web is at least 1/4 mil and preferably from 2 to 1,000 mils in thickness and the fibres preferably have a length of at least 1/2 inch and a denier between 1 and 20.  The cellulose fibres may be cotton or regenerated cellulose rayon and have a denier of from 1 to 10 and upwards.  The minimum thickness of the web is from 1/4 to 2 mils.  The cellulose fibre web may be formed separately and then applied to the hydrophic fibre web or the cellulose fibres may be deposited by an air stream on the hydrophobic web passing over a suction box or screen.  One or more cellulose fibre webs may be applied to one or more superimposed hydrophobic webs.  Cellulose webs may be applied to both surfaces of the hydrophobic webs.  After assembly, the composite web is bonded, preferably with a polymeric binder which can be cross-linked to render the fabric resistant to laundering and dry-cleaning.  Suitable binders include copolymers containing from 0.5 to 20% by weight of units containing such functional groups as glycidyl, carboxyl (in free acid or salt form), amide, N-methylolamide, amine or hydroxyl. Monomers suitable for the preparation of such copolymers include glycidyl methacrylate, acrylic acid, itaconic acid, acrylamide, N-methylolacrylamide, dimethylaminoethyl methacrylate and b -hydroxypropyl methacrylate.  These functional monomers may be copolymerized with other monoethylenically unsaturated comonomers particularly those of such character as to produce water insoluble copolymers.  Examples of such comonomers include esters of acrylic acid with saturated aliphatic alcohols having 1 to 18 carbon atoms, esters of methacrylic acid with saturated aliphatic alcohols having 1 to 18 carbon atoms, acrylonitrile, methacrylonitrile, styrene, vinyltoluene, vinyl acetate, vinyl chloride and vinylidene chloride. The binder may also include from 0.5 to 10% by weight, based on the weight of the copolymer, of an aminoplast or a poly (vic-epoxide). Examples of the aminoplast are the water-soluble condensates of formaldehyde with urea, N,N1-ethyleneurea, and aminotriazines such as melamine or dialkyl-substituted melamines, as well as the water-soluble alkylated methylol condensates obtained from such alcohols as methanol, ethanol and isopropanol.  Examples of the polyepoxides are those described in Specification 868,335.  The binder is applied by spraying, by immersion or by rolls. Excess binder is removed by squeezing and the web is dried and th binder cured by heating to a temperature between 105 DEG C. and 300 DEG C. Preferably between 5 and 150% by weight of dry binder based on weight of dry fibre is applied.  The fabric in the form having only one surface covered with cellulose fibres may be laminated with polyethylene film, transparent cellulosic sheet material, foamed polyurethane or polystyrene, paper or a veneer of wood, adhered to the hydrophobic fibrous layer.