| 摘要 |
<p>1420624 Coated flexible sheet materials IMPERIAL CHEMICAL INDUSTRIES Ltd 27 July 1973 [8 Aug 1972 (2)] 36940/72 and 36942/72 Heading B2E Polyethylene and/or ethylene copolymer backings are applied to carpets, rugs or mats by (1) sprinkling on the reverse side thereof a powder comprising a mixture of (a) from 2 to 12% by weight of a foaming agent composition which begins to decompose at 120 to 200‹C, (b) at least 10% by weight of a polymeric component consisting of polyethylene and/or one or more polymers of ethylene with up to 20% by weight (on the copolymer) of one or more of vinyl acetate, and methyl, ethyl or butyl esters of acrylic or methacrylic acid, the polymeric component having a melt flow index of from 5 to 30 and (c) 0 to 88% by weight of one or more ingredients chosen to modify the physical properties of the backing or reduce the cost thereof, (2) heating the product to a temperature at which the mixture fuses and the foaming agent decomposes and (3) cooling the mixture so as to cause it to re-solidify and form an adhesive bond. The preferred foaming agents are benzene-1, 3-disulphohydrazide, diphenyl sulphone-3, 3'-disulphohydrazide and diphenyl oxide-4, 4'-disulphohydrazide and a mixture of azodicarbonamide and an activator such as a metal soap, e.g. zinc stearate, or metal oxides such as zinc oxide or alumina or inert oxides of non-metals such as silica. Fillers may be present such as clay, talc, silica, alumina, whiting, barium sulphate or wood flour. Other additives such as petroleum waxes and tack resins such as fully or partially hydrogenated wood rosin esters, coumarone-indene resins, petroleum derived hydrocarbon resins, permanently fusible phenolic resins, copolymers of alpha-methyl styrene with vinyl toluene, "formolite" resins and polydiene resins. Preferably, the powder should be able to pass through a mesh of aperture size 1200 Ám.</p> |
