Patent GB-592228-A (GB)
Title: Process of making coated fibrous materials and the articles produced
IPC: D21H19/24
Filed: 1944-09-28
Abstract: 592,228. Coated fabrics. SYLVANIA INDUSTRIAL CORPORATION. Sept. 28, 1944, No. 18569. Convention date, Oct. 2, 1943. [Class 140] A waterproof sheet material is produced by sizing a layer of fibrous material with an aqueous alkaline preparation of an alkalisoluble water-insoluble cellulosic material, coagulating, and drying the treated product and thereafter applying a water-resistant intermediate coating and then a moisture-proof top coating. Any textile fabric, which may be knitted, woven or braided, felt or paper, made of natural or artificial fibres or mixtures thereof may be used as the layer of fibrous material. The cellulosic coating liquid may be natural or degraded cellulose in aqueous caustic soda, alkali zincate or stannate, alkali perchlorate, cuprammonia or quarternary ammonium bases, viscose solution may be used, but alkali-soluble water-insoluble cellulose ethers such as alkyl, hydroxyalkyl or carboxyalkyl cellulose ethers are preferred and the coating may be effected by spraying or other specified methods. As coagulant an aqueous acid, acid salt, acid gas or a salt may be used, or, in the case of cellulose ethers, hot water. The sized material may be calendered both before and after the coagulation treatment and it is washed and dried preferably while maintaining a predetermined width. The intermediate coating may include drying oils, drying oil modified resins, thermosetting resins, natural and synthetic rubber and rubber derivatives and other substances such as linseed oil, ferilla oil, soya bean oil, ferilla oil modified alkyd resins, castor oil modified alkyd resins, soya bean oil modified alkyd resins, phenol, urea, or melamine formaldehyde resins, copolymer of butadiene and styrene, polymer of chloroprene, co-polymer of isobutylene and butadiene, polymer of ethylene dichloride and sodium tetrasulphide, halogenated rubber, rubber hydrohalides, cyclised rubber derivatives, cellulose derivatives such as cellulose nitrate and acetate, ethyl or benzyl cellulose, thermoplastic synthetic resins such as the resin resulting from the reaction of polyhydric phenols and aliphatic polyhalides, methacrylate resins or vinyl polymers. The intermediate coating may be applied in the form of an aqueous solution of individual compounds, such as urea and formaldehyde, which will condense to form a resin, or such may be applied in an intermediate form such as dimethylol urea, the final resin being produced on the material with the aid of heat, or an organic solvent solution of the resin or resin forming compounds may be used. A hardening agent, such as ammonium thiocyanate, p-toluene sulphonic acid, maleic acid, salts of chloracetic acid or an alkaline catalyst such as sodium or potassium hydroxide, sodium carbonate or an organic amine may be included in the solution. The intermediate coating composition may include a plasticiser, preferably of the plasticising resin type such as polymerised isobutylene or other polymerised unsaturated hydrocarbons, soft alkyd resin may be used, or organic plasticisers such as dibutyl sebacate, dibutyl phthalate, tricresyl phosphate or cyclohexyl butyl phthalate. The moisture-proof top coating, which is superimposed on the coatings described above may comprise a film-forming base, a moistureproofing agent, a plasticiser and a blending agent dissolved in a solvent or mixture of solvents for all the materials present such as a mixture of xylene and butanol or toluene and butyl acetate. The base may be a cellulose derivative such as the nitrate or acetate or ethyl or benzyl cellulose ; or a thermoplastic synthetic resin such as that resulting from the reaction of polyhydric phenols with aliphatic polyhalides, acrylic and methacrylic acid ester polymers, polyvinyl resins such as a copolymer of vinylidine and vinyl chlorides ; drying oils and drying oil modified resins, and natural and synthetic rubber and rubber like materials such as halogenated rubber, rubber hydrohalides and cyclised rubber derivatives. The plasticiser may be a soft alkyd resin or a non-volatile organic plasticiser such as tricresyl phosphate, dibutyl phthalate, cyclohexyl butyl phthalate and dibutyl sebacate. The moisture-proofing agent may be a wax such as paraffin, ozokerite cerasin or carnauba, and the blending agent for such wax may be ester gum, blown vegetable oil, dammar, japan wax or castor oil phthalate. Two examples specify a cotton fabric coated with various materials as outlined above. Specification 592,225 is referred to.