| 摘要 |
1297551 Phenolic foam laminate DYNAMIT NOBEL AG 22 June 1970 [23 June 1969] 30279/70 Heading B5N [Also in Division D1] A phenolic resin is adhered to a fibrous layer by foaming in contact therewith and the fibrous layer is subsequently impregnated with either (1) tarry or bituminous material, (2) a thermoplastic polymer or copolymer of ethylenically unsaturated monomers, or (3) a phenol-aldehyde condensate, the foam and impregnant then being dried. The surface layer may be pasteboard, soda paper, or a woven or non-woven fabric. The phenolic foam can be introduced as a foamable mixture containing blowing agent and hardener, between two surface webs and foamed and hardened in a double belt press at 60-80‹ C. Alternatively, it can be foamed in a mould lined with a surface layer. The impregnant is a solution, dispersion, emulsion, or melt. It may be applied by dipping, coating, or spraying at 20-100‹ C. The tarry material may be obtained by the dry distillation of coal, lignite, peat or wood. The bituminous material may be obtained by refining petroleum having a molecular weight of from 300 to 3000. The polymer may be a vinyl, acrylic, methacrylic, or ethacrylic polymer of molecular weight 10,000 to 60,000. The phenolic resin impregnant may be obtained by the alkaline condensation of a phenol, optionally alkylated, and an aldehyde (as may the phenolic foam). |
