| 摘要 |
<p>This invention is directed to improved aqueous pigment-based ink compositions for use in ink jets and methods of enhancing and/or controlling the optical density and print sharpness of both pigment-based and dye-based inks. The improved ink composition includes a class of organic quaternary ammonium compounds which improve the optical density and print sharpness of the inks. Other improvements include the use of a polyalkylene oxide to impedence match the ink with the drop formation rate to provide drop formation rates as high as 8,000 drops per second. These high drop rates permit higher writing speeds and enhanced printer resolution. Yet another improvement to ink jet ink composition is the addition of urea, urea derivatives and thiol compounds. These compounds prevent the ink jet from accumulating dried ink thus preventing clogging of the ink jet.</p> |
