Abstract

A method of forming a composite board is disclosed, comprising steps of providing a mould, preparing pouring and spreading a layer of facing composition having at least 59wt% magnesium oxide powder and optional components in an aqueous solution of MgCl2/ with at least one woven cloth reinforcing sheet layer contained in the layer; preparing, pouring and spreading a main body composition comprising a pourable and spreadable slurry of a solid component including 7% to 40% by volume magnesium oxide, 10% to 85% by volume of a particulate ceiiulosic material, and from 5% to 40% by volume of a non-celllulosic lightening filler, in an aqueous solution of MgCl2; and placing and containing said mould in a controlled atmosphere to cure and dry.

IPC Classes  ?

• B32B 13/02 - Layered products essentially comprising a water-setting substance, e.g. concrete, plaster, asbestos cement, or like builders' material with fibres or particles embedded in it or bonded with it
• C09K 21/02 - Inorganic materials
• E04B 1/62 - Insulation or other protectionElements or use of specified material therefor
• C04B 9/02 - Magnesium cements containing chlorides, e.g. Sorel cement
• C04B 28/32 - Magnesium oxychloride cements, e.g. Sorel cement
• C04B 103/63 - Flame-proofing agents
• C04B 111/28 - Fire resistance