| 摘要 |
<p>A thin, pressure-sensitive, ink-releasing transfer element such as a ribbon capable of releasing a substantially uniform and intense amount of smudge-resistant ink at least about four times from overlapping impressed areas of the ink layer corresponding to each double image width during high speed printing use on "hammer-impression" high speed typewriters. The thinness of the ribbon is important not only to accommodate a maximum amount of ribbon on the feed spool, but primarily in order to provide a ribbon which is operative in such typewriters to produce images having excellent sharpness, uniform intensity, edge profile and freedom from pick-over, which properties also result from the cooperative nature of the ink and undercoating used on such ribbons. The present method involves applying an ink layer comprising a microporous resinous binder containing pressure-exudable, substantially-solid, thixotropic ink having a viscosity of at least about 100,000 centipoises and containing a hydrophilic pigment and a wetting agent having both hydrophilic and oleophilic radicals, by means of a volatile coating vehicle comprising a miscible mixture of (a) a volatile liquid solvent which is a solvent for the resinous binder and for the ink vehicle but is a non-solvent for the wetting agent and (b) another less volatile liquid which is a solvent for the wetting agent and for the ink vehicle but is a non-solvent for the resinous binder.</p> |
