| 摘要 |
<p>930,396. Coated fabrics. TIMEFAX CORPORATION. Feb. 8, 1961, No. 4763/61. Drawings to Specification. Class 140. [Also in Group XVI] In an electro-sensitive blank of the kind having a pliable backing with an exposed lithographic surface, the said surface consists mainly of a copolymer of maleic acid and one or more vinyl ethers chosen from the group consisting of vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, and the half methyl and half ethyl esters of the said ethers, and an electrically conductive barrier coat is located between said backing and said surface. A base sheet of paper or other pliable material is supplied with three coatings. The first coating has the correct electrical resistance to render the plate selectively responsive to stylus-applied potentials and is water-impervious, and comprises acetylene black or other electrically conductive carbon black, a binder such as polyvinyl chloride, polyvinyl acetate, acrylonitrile polymers, cellulose ethers or esters, copolymer of vinyl chloride, vinyl acetate, vinylidene chloride polymers, and a solvent, such as methyl ethyl ketone, or methyl isobutyl ketone. The intermediate coating may be hydrophilic or hydrophobic, and may comprise casein, soya protein, gelatine, hydroxyethylcellulose, polyvinyl acetate, polyvinyl alcohol (hydrophilic resins), or methacrylates, styrene, polyvinyl chloride-acetate, polyvinyl chloride, polyvinylidene chloride, urea formaldehyde, cellulose esters and ethers (hydrophobic resins), a solvent, such as methanol or tolusol, and acetylene black or gas black. The third coating forms a lithographic surface, and comprises a copolymer of maleic acid and one or more vinyl ethers, and an insolubilizing agent, e.g. zinc oxide or zinc sulphide. The vinyl ethers are of the group consisting of vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether and the half-methyl and half-ethyl esters thereof.</p> |
