Method for increasing the stability of non-ionic surfactant-containing ink compositions

摘要

A method for increasing the cloud point and stability of an ink. An ink is provided which includes a solvent, a coloring agent, and an ethoxylated non-ionic surfactant to increase print quality. To increase the cloud point of the ink (which is affected by the surfactant), the ink is placed in contact with a polymeric foam (e.g. polyurethane foam) which reacts with the surfactant to produce an ink product having a higher cloud point. The treated ink product is then removed from the foam. Treatment may be accomplished by passing the ink through the foam before placing the ink in an ink cartridge. Removal of the treated ink product from the foam may be achieved by compressing the foam. Alternatively, the ink may be placed within an ink cartridge containing the polymeric foam in which the ink will be treated in situ inside the cartridge.