GB1377526A - Photopolymerised glass-fibre-reinforced plastics material - Google Patents

Abstract

1377526 Glass fibre laminates REICHHOLD-ALBERT-CHEMIE AG 2 Feb 1972 [3 Feb 1971] 4823/72 Heading B5N [Also in Divisions D1 and B2] Laminates comprise an unsaturated polyester resin containing as photoinitiator 0À1 to 5À1. by weight of benzoin etherified with a primary or secondary alcohol or with a phenol is reinforced by glass fibres and crosslinked by light irradiation. The resin comprises 55 to 60% of the total wt. of the product. The glass fibres may comprise a roving, non-woven mat a woven fabric with a linen or twill weave or a mock lens fabric. One resin-fibre layer may be laminated to a second with the resin and/or coated on one or both sides with a pigmented or unpigmented lacquer comprising unsaturated polyester, alkyd alkyd-melamine or acid curable urea resin or one or two component polyurethane. In one example 67 parts of resin produced from 2 moles maleic anhydride, 1 mole phthalic anhydride and 3À08 moles propane-diol is mixed with 38 parts by weight of styrene, stabilized with 0À014% hydroquinone and mixed with 1À5 parts by weight of benzoinethyl ether. In a second example tetrachlorophthalic anhydride is used. Lists of polyhydric alcohols, saturated and unsaturated dicarboxylic acids, copolymerizable vinyl compounds, benzoin ethers, hydroquinone stabilizers, #-γ-unsaturated ether alcohols such as trimethylolpropane-diallyl ether for rendering the resin air drying accelerators, e.g. cobalt octoate, and perbenzoate, peroxide or azobis-isobutyronitrile catalysts are given. Preferably the resin is pre-gelled by irradiation with super-actinic fluorescent lumps for 60 to 280 seconds followed by brief irradiation under high pressure mercury vapour lamps for 20 to 80 seconds per mm. thickness. Tungsten and Xenon lamps and sunlight are mentioned. The photo-curable liquid resin may be spread uniformly upon a release coated sheet, the glass fibre reinforcement place on top, a release coated plastic film added, air squeezed out with a roller and the resin photo-cured. Alternatively two glass fibre mats bound with polyester resin are placed upon a release coated polished aluminium sheet, the photo-curable resin added, the laminate covered by a release coated transparent film and U.V. light applied for 250 seconds from high pressure mercuy lamps. The products may be laminated to chipboard, blackboard or pywood on both sides.