Improvement in structural material unitario, and process for the production of a structural material unitario

摘要

1512084 Laminates FORMICA INTERNATIONAL Ltd 17 June 1976 [19 June 1975] 26121/75 Heading B5N A unitary structural material comprises a preformed thermoset plastics laminate sheet secured to a water-set cementitous composition through an intermediate porous fibrous sheet of high wet strength, the intermediate porous fibrous sheet being bonded to the preformed thermoset plastics laminate sheet by an adhesive and being keyed to the cementitious material as a result of having been embedded in the cementitious compositions before watersetting thereof. The thermoset plastics laminate, which may have a decorative appearance, is produced by assembling a stack of a plurality of thermosettable resin impregnated organic fibrous sheets and then applying heat and pressure to effect consolidation. A preferred laminate comprises an alpha cellulose paper overlay and a printed paper decorative layer each impregnated with a thermoset melamine formaldehyde resin and a core layer comprising a plurality of Kraft-paper sheets impregnated with a thermoset phenol-formaldehyde resin. The fibrous sheet which may be made of synthetic polymer, cellulosic, glass or asbestos fibres, has a tensile strength when completely wetted by water which is 20% or more of its dry tensile strngth, and may be woven or non- woven. The adhesive which may be applied either to the laminate and/or to the fibrous sheet may be a phenol-formaldhyde, ureaformaldehyde, epoxy or polyvinyl alcohol resin. The cementitious. composition may comprise plaster, inorganic particle/sodium silicate mixtures, lime or cement mortar or concrete, and may contain reinforcing materials, e.g. chopped glass fibre strands, reticulate or rod reinforcements. The cementitious composition may be foamed and/or include light-weight aggregate, e.g. vermiculite, expanded perlite, powdered fly-ash or expanded synthetic polymer beads, the surface of the laminate bonded to the fibrous sheet may be roughened by mechanical abrasion or sand-blasting prior to bonding. A discontinous primer layer, e.g. of a polymeric latex or epoxy resin, may be provided between the fibrous sheet and cementitious compositions. The fluid cementitious composition may be applied to the surface of the fibrous sheet adhesively bonded to the laminate positioned decorative surface downwards on or in a mould or jig, or the fluid cementitious layer may be poured into a mould and the laminate having bonded thereto the fibrous sheet, positioned thereon. Alternatively two composite boards each comprising a laminate with a fibrous sheet adhesively bonded thereto may be positioned in spaced apart relationship with their fibrous sheet surfaces facing towards each other and fluid cementitious composition introduced between them.