| 摘要 |
1348390 Pressure-sensitive record sheets NATIONAL CASH REGISTER CO 15 Dec 1971 [6 Jan 1971] 58253/71 Heading D2B A pressure-sensitive record sheet comprises a substrate having a coating of polymeric film material which includes minute, encased droplets of marking liquid and binder material for binding the encased droplets to each other and the substrate, free spaces being left in the binder material such that the coating may be compressed on application of pressure to a first stage without release of marking liquid and then to a second stage with release of marking liquid. The droplets may or may not be encapsulated. The voids in the binder material may be caused by the addition of hollow spherical particles, polymeric foam, or by forcing gas e.g. air into the material. The coating may include fillers such as siliceous materials, asbestos fibres, polymeric fibres, starch granules, expanded or unexpanded polymeric micro-beads, and cellulosic fibres. Conventional binder materials may be used. The marking liquid may be an ink, chromogenic dye e.g. CVL containing liquid, or chromogenic dye developer e.g. phenolic resin containing liquid. The latter two liquids may be encapsulated and incorporated in the same coating to provide a "self-contained" sheet. Alternatively, the chromogenic dye and its developer may be coreacted using separate sheets. The developer may be applied only to portions of sheets where it is desired to have an image appear. The coating may be multi-layered, one layer containing an ink of a different colour from that of another layer. An intermediate layer of ink-resistant material, e.g. polyvinyl alcohol for oil-based inks, may be provided between the two layers. In this way, it is possible to obtain one colour on the uncoated surface of the coated sheet through migration of ink through the substrate, and a different colour on a separate copy sheet. An opaque overcoat may be applied to the coating on the substrate for masking purposes. The marking fluid may contain a magnetic or fluorescent substance. The substrate may be made of paper, polyethylene terephthalate film, a glass fibre felted sheet, or polystyrene synthetic paper. |
