MANUFACTURE OF RESIN-INPREGNATED PAPER

摘要

1350668 Resin impregnated paper laminates OTSUKA KAGAKU YAKUHIN KK 9 July 1971 [10 July 1970] 32262/71 Heading B5N [Also in Divisions D2 and C3] A process for producing resin impregnated paper products by impregnating paper with a polymerizable substance, a free-radical initiator and a polymerization accelerator and heating or irradiating with ionizing radiation to produce polymerization, is characterized by the fact that the paper is impregnated with the three components prior to polymerization, in two or three stages in each of which one or two of the components are present separately from the other component or components, the polymerizable substance being a vinyl or vinylidene monomer or an oligomer thereof, or an unsaturated polyester dissolved in a vinyl or vinylidene monomer. The amount of accelerator present is sufficient to ensure complete polymerization. In the examples, corrugated paper comprising a sheet of corrugated paper sandwiched between two flat sheets of paper is used. In Example (2) an impregnated laminate of 5 sheets of such paper was produced by (a) impregnating each with a solution of cumene hydroperoxide and cyclohexanone peroxide (initiators) in methanol (the methanol then being evaporated), (b) superposing the sheets and impregnating with a mixture of styrene, methyl methacrylate and azodiisobutyronitrile (monomers and foaming agent) and (c) impregnating with cobalt naphthenate (accelerator) dissolved in styrene. The assembly was then cured with heat, to produce a foamed structure. In Example (3) a laminate of two sheets of the same corrugated paper impregnated with a vinyl acetate/methmethacrylate copolymer was produced in a similar manner, except that it was not foamed.