Waterfast ink formulations for thermal ink-jet using organic amines

摘要

A print which has superior waterfastness can be made on paper from an ink-jet printer using an ink comprising a water soluble dye, water with or without a water soluble organic solvent, and sufficient polyalkylene polyamine to provide the ink with a pH of at least 10. About 2 to 10% urea may be added to the ink to reduce crusting of the ink.