Mitigation of dye crystallization in images on transparencies and glossy media
US5609674A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1995 |
| Grant date | Mar 11, 1997 |
| Priority date | — |
| Expiry date | Dec 1, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D11/328
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method and ink-jet ink composition are provided for reducing crystallization of Acid Yellow 23 anionic dye in ink-jet ink compositions printed on transparencies and glossy media, both film- and paper-based. The method comprises formulating the yellow ink-jet ink composition in accordance with at least one of the following three conditions: (a) a first condition, wherein the yellow ink-jet ink composition includes about 6 to 9 wt % ethylhydroxypropanediol, about 3 to 9 wt % 2-pyrrolidone, and about 3 to 9 wt % diethylene glycol; (b) a second condition, wherein the vehicle of the yellow ink-jet ink includes a buffer in amount sufficient to maintain the pH of the ink-jet ink within the range of about 5 to 7; and (c) a third condition, wherein the cation of the inorganic salt component of the ink-jet ink comprises calcium ions to the substantial exclusion of magnesium ions. While any or all of the foregoing conditions may be implemented to reduce crystallization in the yellow ink, a combination of the three is particularly efficacious. A narrower embodiment also incorporates two alternative techniques, namely reducing the dye load of the yellow ink to no more than about 3.5 wt % and …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.