| 摘要 |
1,121,721. Antistatic floor covering. MARLEY TILE CO. Ltd. 28 March, 1967 [30 March, 1966], No. 14175/66. Addition to 998,745. Heading B5A. An antistatic or conductive floor covering is manufactured by (i) preparing a granulate of a vinyl chloride homopolymer or copolymer, (ii) coating the granules with an aqueous polymeric emulsion containing a conductive powder, (iii) evaporating water from the emulsion, (iv) compressing the coated granulate into a sheet or slab and (v) dividing the sheet or slab into one or more laminµ, at least one surface of which consists of uncoated faces of split granules. The granulate preferably has the same composition and is formed by the same method as the granulate used in Specification 998,745. The emulsion is preferably formed by emulsion polymerization of vinyl chloride or mixtures of vinyl chloride with vinyl acetate or vinylidene chloride and may contain phthalate or phosphate plasticizers, stabilizers such as lead compounds, organotin compounds and mixtures of barium and cadmium salts of fatty acids and emulsifying agents such as alkyl aryl polyethylene glycol ethers. The conductive powder may be carbon black, graphite, aluminium or copper. The latex coating preferably comprises 5 to 25% by weight of the granules and contains up to 40% of carbon or graphite for an antistatic covering and up to 70% for a conductive covering. The dividing of the slabs into laminae which are preferably 0.04 to 0À5 inches thick may be effected by a slicing machine with a horizontal revolving knife. Unevenness in the laminae may be ironed out with a hot hydraulic press. |
