GB1301023A - Thermoformable laminates made from thermosetting resins - Google Patents

Abstract

1301023 Thermoformable laminates ASHLAND OIL Inc 7 Jan 1970 [16 Jan 1969] 835/70 Heading B5N A laminate produced by a low pressure laminating technique using pressures of up to 1000 p.s.i.g. comprises a sheet of a thermoplastics material laminated to at least one layer of a fibrous material impregnated with a thermosetting resin which has been thermoset during lamination, the resin impregnated material after curing having a thickness of up to 15 mils and the thermoplastic sheet being at least as thick as the resin impregnated material. The fibrous material which may be paper or woven or non-woven fabric, may be impregnated with a solution of the thermosetting resin, e.g. a phenolic or unsaturated polyester resin, in an inert solvent and then dried. Unsaturated polyester resins, e.g. produced from isophthalic acid, maleic acid and propylene glycol, may be used in admixture with copolymerizable monomars, e.g. styrene, diallyl phthalate, vinyl toluene and methyl methacrylate, which if liquid may also act as a solvent, although inert solvents, e.g. acetone, methylene chloride or hydrocarbons, may be used. The impregnating compositions may also contain catalysts, e.g. benzoyl peroxide or cumene hydroperoxide, thickeners, e.g. magnesium oxide, magnesium silicate or silicon dioxide, colouring agents, temporary blocking agents, foam inhibitors and stabilizers, e.g. hydroquinone. The fibrous material may be a decorative paper which may be printed to resemble wood panelling. The assembly may be subjected to heat and pressure in a press, cauls, e.g. of aluminium, which may be etched or anodized being inserted between the platens and the assembly. Release agents, e.g. stearic acid, may be applied to the cauls or included in the impregnated covering material. Resin impregnated overlay sheets, e.g. paper, impregnated with thermosetting resin, may be included between the cauls and sheets of fibrous material. The sheets of thermoplastic material may be of polyvinyl chloride, vinyl chloride/vinyl acetate copolymers, polystyrene or polyethylene. The laminates may subsequently be thermoformed while heating them by the use of an open flame, heated liquids, steam, radiant lamps or a heated press. The laminates may be used as veneers for furniture.