Patent GB-1516920-A (GB)
Title: Simulated granite and its preparation
IPC: C08L33/00
Filed: 1976-06-17
Abstract: 1516920 Simulated granite articles E I DU PONT DE NEMOURS & CO 17 June 1976 [18 June 1975] 25113/76 Heading C1H Simulated granite articles comprise (A) 35-95% by volume (based on total granite volume) of a matrix comprising (1) at least 34% by volume (based on total granite volume) of polymer having a refractive index n D  according to ASTM (D542)27 between 1À4 and 1À65 and (2) 1-50% by volume (based on total granite volume) of filler having a maximum particle size less than 100 microns and an amorphous or mean crystalline axial refractive index (n D ) between 1À4 and 1À65 in such a ratio of (1) to (2) that the optical density to visible light of a 0À01 inch thick film of the matrix is less than 1À5, (B) 0À1 to 50% by volume (based on total granite volume) of randomly distributed opaque particles having a minimum particle size greater than 200 microns and an optical density to visible light greater than 2À0 and (C) 0À1 to 50% by volume (based on total granite volume) of randomly distributed translucent particles, transparent particles or both having a minimum particle size greater than 200 microns and an optical density to visible light less than 2À0 in such a ratio of (A) to (B) to (C) that the optical density to visible light of 0À05 inch thick wafer of the article is less than 3À0. The matrix polymers may be acrylic (many listed and exemplified). Other polymers are referred to. In castable compositions for making the simulated granite articles, the polymer for forming the matrix may be present as a polymerizable syrup comprising fluid polymerizable constituent and a polymeric viscosity control constituent. The matrix filler may be talc, quartz, fine silica, wood flour, diatomaceous earth, gypsum, glass, clays, chalk, marble, limestone, asbestos, aluminium silicate, aluminium stearate, mullite, calcium silicate, anhydrite, boracite, borax and alumina trihydrate. The opaque particles may be calcined talc, magnetite, siderite, ilmenite, goethite, galena, graphite, coal, chalcopyrite, pyrite, hematite, limonite, pyroxenes, amphiboles, biotite, sphalerite, anatase, corundum, diamond, carborundum, anhydrite, chalk, diurite, rutile, sandstone, shale, slate, sparite, vermiculite, natural granite, peat, basalt, brick, charcoal, concrete, plaster, porcelain, sawdust, seashells, slag, wood, or various filled or pigmented chips of insoluble or crosslinked polymers such as ABS resins, cellulose esters, cellulose ethers, epoxy resins, polyethylene, ethylene copolymers, melamine resins, phenolic resins, polyacetals, polyacrylics, polydienes, polyesters, polyisobutylenes, polypropylenes, polystyrenes, urea/formaldehyde resins, polyureas, polyurethanes, polyvinyl chloride, polyvinylidene chloride and polyvinyl esters. The translucent or transparent particles may be agate, alabaster, albite, calcite, chalcedony, chert, feldspar, flint quartz, glass, malachite, marble, mica, obsidian, opal, quartz, quartzite, rock gypsum, sand, silica, travertine, wollastonite and moderately filled or unfilled, pigmented or dyed, insoluble or crosslinked chips of polymers given as examples above of opaque particles. The simulated granite articles may contain dyes, pigments, metallic fibres, dusts, flakes, chips or shavings, non-metallic chips or flakes (e.g. titanium nitride, nickel sulphide, cobalt sulphide, anhydrous chromic chloride, magnesium sulphide), natural or coloured flocks or chopped fibres e.g. asbestos, rayon, cotton, nylon, flax, polyester, glass, hair, hemp, paper pulp, polyacrylonitrile, polyethylene, polypropylene, protein, rock wool, wood fibre and wool, ultra-violet light stabilizers, fire retardant agents, e.g. polyvinyl chloride, polyvinylidene chloride and copolymers), fire retardant monomers (e.g. bis-[#-chloroethyl] vinyl phosphonate). inorganic chemicals e.g. zinc phosphate, cross linking agents. flow agents and anti-stick or release agents.