| 摘要 |
818,830. Flexible laminates; coating webs. LONZA ELECTRIC & CHEMICAL WORKS Ltd. July 29, 1957 [July 28, 1956], No. 23978/57. Class 140. Laminates comprising foamed thermoplastic materials, for example foamed polyvinyl chloride, polystyrene, cellulose acetate, or isocyanate resins, united to flexible supporting webs of textile, paper, felt, thermoplastic resin or other material, are made by applying a thermoplastic powder to a travelling supporting web, heating the web, for example by infra-red radiation, sufficiently to soften the powder, and applying to it, with light pressure, a web of the foamed material. The powder may comprise a plasticized or unplasticized polymer or copolymer of vinyl chloride, vinyl acetate, styrene, methyl methacrylate, acrylonitrile or butadiene, or a cellulose ester, and may be applied by brushes, by dusting, or by a rotating unpolished roller, but preferably by such a roller in contact with a powder container and rotating in a direction opposite to, and at a peripheral speed 3-8 times that of, the travelling web. The grain size of the powder should not exceed 0.2 mm. and is preferably 0.06 mm. or less. The thickness of the foam layer is preferably of the order 2-10 mm. Examples are given of the lamination of foamed plasticized polyvinyl chloride to calico, to a web of plasticized polyvinyl chloride, to produce a floor covering, and between two webs of tricot respectively, using a powdered copolymer of 75 per cent polyvinyl chloride and 25 per cent polyvinyl acetate of substantially 0.06 mm. mesh size. Specifications 694,964 . and 716,388, [both in Group IV (a)], are referred to. |
