| 摘要 |
1505109 Coated stencil sheet GESTETNER Ltd 23 June 1976 [25 June 1975] 26981/75 Heading B2E [Also in Division B6] A duplicating stencil comprises an oleophobic tissue having on one face an imageable, ink-impervious, smooth-surfaced coating penetrating into but not through the tissue and which in use contacts the surface receiving the duplicated image, and on the other face an ink-impervious coating, the weight ratio of the second to the first coating being not more than 1:2¢ and preferably more than 1:7. The tissue may be of abaca fibres, optionally with jute or viscose fibres, and may be wet-strengthened; oleophobic, and optionally hydrophobic, properties are imparted by impregnating with a solution of a perfluorocomplex or an acrylic acid-fluorinated alkyl acrylate copolymer, which solution may contain urea, by roller or dip coating. The inkimpervious coatings may be the same or may differ, and may be applied from solution. Specified coating materials are plasticised nitrocellulose for pressure-sensitive stencils and cellulose acetate butyrate mixed with partially compatible oils, and optionally vinylchloridevinyl acetate copolymer and coumaroneindene resin, for heat-sensitive stencils. |
