GB997127A - Resin-impregnated sheets for laminates - Google Patents

Abstract

997,127. Laminates. CASSELLA FARBWERKE MAINKUR A.G. April 4, 1963 [April 4, 1962], No. 13401/63. Heading B5N. Paper and fabrics made from natural or regenerated cellulose fibres which are used in the production of thermosetting laminates, are impregnated with a mixture containing 15-90% of an aminotriazinÚ- or urea-formaldehyde condensation product and 85-10% of a hydroxymethyl compound of a tetrahydros-triazine-2(lH)-one, to a resin content of 20-75%, referred to the total weight of the dried paper or fabric. The hydroxymethyl compounds of the tetrahydro-s-triazine-2(1H)- ones used may be those produced by the condensation of 1 mol. of urea and 2 mols. of formaldehyde together either with 1 mol. of ammonia, an alkylamine or a hydroxyalkylamine or with ¢ mol. of an alkylene diamine, the alkyl and alkylene radicals containing not more than 6 carbon atoms. Unmodified or modified, unetherified or etherified urea- or aminotriazine-formaldehyde resins, e.g. melamine-formaldehyde resins modified with polyalcohols or sugars, may be used. The impregnated paper or fabrics may serve as decorative print sheets, core sheets, balancing sheets, over-lay or underlay sheets or as filler or primer foils in the production of low- or high-pressure laminates. They may be used for coating moulded fibre and chip-boards and may be coated prior to the pressing operation with quick-curing melamine resins. The laminates produced may be coated with a polyester varnish.