| abstract |
PURPOSE: To enable the stabilization of printing operation after prolonged stoppage of the printing particularly with an ink jet printer, by incorporating a specified quaternary phosphonium ion into a water-base ink composition used as, e.g., a writing ink, a printing ink or a stamping ink. n CONSTITUTION: This water-based ink composition contains a quaternary phosphonium ion of formula I (wherein R 1 WR 4 are each a substituted or unsubstituted alkyl group, or a substituted or unsubstituted phenyl group). Examples of the quaternary phosphonium ions include those of formulas II, III, and IV. It is most desirable that a phosphonium ion be incorporated into this ink composition as a pH modifier comprising phosphonium hydroxide or phosphonium carbonate, or as a counter ion of a dye containing acid groups of, e.g., a sulfonic acid or a carboxylic acid. n COPYRIGHT: (C)1988,JPO&Japio |