Inorganic structural materials have many desirable properties for a wide range of applications especially in the building industry. However improvements in surface finish and appearance are often desirable and in some cases such as glass reinforced cement (GRC) a measure of protection from long term weathering is required.
Water penetration into structural inorganic materials could be reduced by using a plastics or metal facing. However bonding between the facing material and the inorganic layer is a problem, especially from the cost point of view, if the inorganic structural materials are to be wet laid up directly on the facing.
GB 1065053 discloses a polyester modified cement useful for making concrete and said to be useful for covering metals, hardwood and other wet or dry surfaces and to adhere strongly to such surfaces. However the cement does not appear to have been previously used as an adhesive for bonding a facing to structural materials.
GB 2092950A describes a method of providing a glass reinforced plastics (GRP) laminate with a metal facing, which method includes coating the metal facing with an adhesive, laying the facing in a mould, and, after allowing the adhesive to cure, laying uncured thermosetting resin and reinforcement on the adhesive (see also copending U.S. Pat. application No. 340,405). However, at that time the cladding of an inorganic material with a protective facing still presented a problem to the building industry.