摘要 |
1427647 Microspheres/resin compositions FIRET BV 19 July 1974 [20 July 1973] 32053/74 Heading C3C [Also in Division D1] Microspheres, e.g. comprising a polymer of vinylidine chloride or a copolymer thereof with acrylonitrile, having a diameter of 4-20 microns, a bulk density of 0�65-0�75 g./cm.<SP>3</SP> and containing isobutane as blowing agent, are applied to a non-woven fibric in aqueous dispersion, e.g. with polyacrylonitrile binder. The impregnated fabric may be dried and heated to 118� C. to expand the microspheres to 10-100 microns diameter, 0�01-0�02 g./cm.<SP>3</SP> density and cross-link the binder. An unsaturated polyester binder may then be applied with a curing agent and cured. |