GB1118221A - Composite materials - Google Patents

Abstract

A composite material comprises particles of a foamed thermoplastic synthetic resin dispersed through and embedded in a fibrous matrix. It may be made by mixing foamable particles of a thermoplastic synthetic resin with fibre in the form of a wet pulp, removing the excess moisture and heating to foam the particles. An adhesive binder may also be present in the pulp, and may be coagulated, e.g. by alum, before the excess moisture is removed. The particles may be distributed between thin interconnected flakes of matted fibres, with void spaces between the particles. The material may be further heated to collapse the foamed particles. The foamable particles may be of a polymer or copolymer of ethylene, propylene, butadiene, styrene, vinyltoluene, or alpha-methylstyrene, acrylonitrile, vinyl chloride, vinyl acetate, methyl acrylate, methyl methacrylate or ethyl acrylate. The foamable particles contain a blowing agent, e.g. butane, pentane, sodium bicarbonate, ammonium bicarbonate, dinitrosopentamethylenediamine or barium azodicarboxylate, and may also contain a nucleating agent, e.g. finely divided silica. The fibres may be natural or artificial, e.g. of wood, straw, bagasse, rags or paper pulp, regenerated cellulose, cellulose acetate, glass, polyethylene, polypropylene, nylon, poly(ethylene terephthalate) or polyacrylonitrile. The adhesive binder, if used, may be starch, casein, water glass, bitumen or a polymer latex, e.g. of natural rubber, styrene/butadiene copolymer, poly(vinyl acetate) or an acrylic resin. The fibres or the foamed particles or both may be coloured, the fibres and particles may be of different colours. The composite material may be in board form which can be made into cartons or used in laminated constructions or for thermal and sound insulation, or cut into pellets for use as a loose-fill insulating medium. A pigmet referred to is red iron oxide.ALSO:A composite material comprises particles of a foamed thermoplastic synthetic resin dispersed through and embedded in a fibrous matrix. It may be made by mixing foamable particles of a thermoplastic synthetic resin with fibre in the form of a wet pulp, removing the excess moisture and heating to foam the particles. An adhesive binder may also be present in the pulp, and may be coagulated, e.g. by alum, before the excess moisture is removed. The particles may be distributed between thin interconnected flakes of matted fibres, with void spaces between the particles. The material may be further heated to collapse the foamed particles. The foamable particles may be of a polymer or copolymer of ethylene, propylene, butadiene, styrene vinyltoluene, or alpha-methylstyrene, acrylonitrile, vinyl chloride, vinyl acetate, methyl acrylate, methyl methacrylate or ethyl acrylate. The foamable particles contain a blowing agent, e.g. butane, pentane, sodium bicarbonate, ammonium bicarbonate, dinitrosopentamethylenediamine or barium azodicarboxylate, and may also contain a nucleating agent, e.g. finely divided silica. The fibres may be natural or artificial, e.g. of wood, straw, bagasse, rags or paper pulp, regenerated cellulose, cellulose acetate, glass, polyethylene, polypropylene, nylon, poly(ethylene terephthalate) or polyacrylonitrile. The adhesive binder, if used, may be starch, casein, water glass, bitumen or a polymer latex, e.g. of natural rubber, styrene/butadiene copolymer, poly(vinyl acetate) or an acrylic resin. The fibres or the foamed particles or both may be coloured, the fibres and particles may be of different colours. The composite material may be in board form which can be made into cartons or used in laminated constructions or for thermal and sound insulation, or cut into pellets for use as a loose-fill insulating medium. A pigment referred to is red iron oxide.