LAMINATES

摘要

1477658 Laminates IMPERIAL CHEMICAL INDUSTRIES Ltd 31 July 1975 [8 Oct 1974] 43511/74 Addition to 1470066 Heading B5N A laminated panel comprises a core of rigid isocyanurate based foam sandwiched between two facing sheets embedded within the foam core a binding material which is permeable to isocyanurate foam forming ingredients and is capable of improving the coherence of the foam on exposure to fire, at least one of the facing sheets having an adherent layer of intumescent material applied to its inner surface. The intumescent material may be a sodium silicate having the formula Na 2 O(SiO 2 )x(H 2 O)y in which x -is 0À5-5 and y is the number of molecules of water present, and may have incorporated therein a reinforcing material, e.g. -alumina or zirconia fibres or glass matting in the form of chapped roving, random mat or continuous strand mat. The foam used is prepared by .reacting in the presence of a blowing agent and a catalyst -capable of polymerizing isocyanate groups to isocyanurate groups, an excess of an organic polyisocyanate with a polymeric polyol. The foam-forming mixture may be formed and cured between the facing sheets. The facing sheets may be made from wood, paper, cardboard, metal, e.g. steel, asbestos, plasterboard, fibre glass,: fibre glass/polyester mixtures or rubber or plastics materials, e.g. polyvinyl chloride or acrylonitrile/butadiene/ styrene copolymers. The outer surface of the facing sheets may be smooth or embossed or indented to provide functional or decorative effects. The binding material, e.g. metal wires, filaments or -meshes, such as chicken wire, and glass, or plastics fibres, strands, filaments, strips or extrusions in single, random, woven or meshed form, may be embedded within the foam core preferably not deeper than 1 inch from one or both outer surfaces of the core, suitably in one or both outer surfaces of the foam core such that it touches one or both inner surfaces of the facing sheets. The laminate may be made in a horizontal or vertical batch mould, jig or press or a continous laminating machine. Edging members which become part of the finished laminate -may be inserted in the mould before the foam is introduced.