| 摘要 |
<p>1,179,197. Colour-reactive copy sheets; paper. NATIONAL CASH REGISTER CO. 15 Feb., 1968 [21 March; 1967], No. 7442/68. Heading D2B. A copy-receiving paper sheet has a discontinuous sub-surface stratum of acidic polymeric material. It may be made by applying a solution of the polymer to the surface of the paper, and then applying a solvent for the polymer to drive it down below the surface and evaporating the solvent. Suitable polymers are phenol-aldehyde polymers, phenolacetylene polymers, maleic acid-rosin resins, partially or wholly hydrolysed copolymers of maleic anhydride with styrene, ethylene or vinyl methyl ether, and mixtures of these. A coreactant referred to is 3, 3'-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide. The coating may also contain microcapsules of chromogenic ink.</p> |
