| 摘要 |
1,171,927. Coated substrates. H. R. DALTON. 20 Oct., 1966 [22 Oct., 1965; 15 Sept., 1966], No. 47033/66. Heading B2E. [Also in Divisions B5, Cl and C3] An electric signal-responsive film having a resinous film body and carbon black particles dispersed within said body and which when examined under adequate magnification and in a thickness low enough for examination, shows individual resin particles in a size range of from 1 to 50Á surrounded by a cloud of carbon black particles is made by casting and drying a layer of a multi-phase resin suspension and drying, the suspension being made by jointly or sequentially conducting the steps of (a) making a multi-phase-resin-complex comprising a film-forming resin and a volatile organic solvent wherein said film-forming resin is only partially dissolved to provide in said complex from 20 to 80% by weight of the resin content in the form of (i) solid particles thereof or particles thereof swollen by imbibed solvent, or (ii) a mixture of said solid particles or swollen particles, said particles in the dry state free of solvent being from 1 to 50Á in size; and (b) dispersing carbon black particles in said complex. The film may be left on the substrate to form a composite material or stripped therefrom. The carbon black particles may have been previously coated with a monolayer of an organic adsorbate soluble in an organic solvent compatible with that used in the formation of the complex. Specified filmforming resins are vinyl chloride-vinyl acetate copolymers, vinylidene chloride-acrylonitrile copolymers, styrene-butadiene copolymers and polyvinyl chloride. The substrate may comprise paper or cardboard previously coated with a copolymer of vinyl-chloride and vinyl acetate. A masking coating e.g. of nitrocellulose and ethyl cellulose may be applied to the film. The substrate may comprise an electrically conducting paper or film or a metallic foil. |
