GB704870A - Improvements in and relating to building boards - Google Patents

Abstract

704,870. Fibre board; coated fibreboard. HJELTE, S. M. Nov. 24, 1950 [Nov. 25, 1949], No, 28823/50. Classes 96 and 140 A building and roofing board comprises a hard pressed fibre board completely impregnated with bituminous material and heated until carbonization has commenced. The bituminous material may be asphalt, tar (wood or coal) heavy distillation products of tar, pitch, talloil pitch or stearine pitch, and it may be stabilized, e.g., by an alkaline material. If impregnating at room temperatures, emulsions, dispersions or solutions are used, but preferably heating and/or vacuum and pressure are used, and the boards themselves may also be heated. An inorganic filler, e.g. mesaa waste calcium carbonate-may be added to the fibres before making the board, or the board may be impregnated with a mixture of bituminous material and mesa. Heating and impregnation may be effected in an inert atmosphere. For roofing one or both sides of the board may have a bituminous coating containing an inorganic filler or an artificial resin or mixtures of these, and water repellant stone chips may be embedded in the coating. To improve the fireproof qualities the coating may have a covering of a waterproof binder with or without stone chips. The binder may be protein plastics, cellulose plastics, e.g. ethyl cellulose, synthetic resins, e.g. vinyl-, alkyd-,or urea compounds, e.g. polyvinyl acetate animal or casein glue hardened by formaldehyde. A binder softener, e.g. a polyhydric alcohol, glycerine, e.g. or an aliphatic ester may also be present, and if the binder is sprayed diluents, e.g. acetone are added. The binder may contain a pigment, and it may also be applied to chips embedded in the coating. Cement mixed with waterglass may be sprayed over the covering. One or both surfaces of the board may be metallized, by spraying with metal, by applying a metal plate, or by admixing dispersed metal with the covering.