| 摘要 |
<p>PURPOSE:To obtain the titled ink of low viscosity, which does not cause separation of a pigment from a medium, by a process wherein addn. of an aq. soln. of a high-molecular flocculant to a dispersion of a pigment in an aq. medium causes crosslinking between pigment. CONSTITUTION:A pigment such as an org. pigment (e.g., azo dyes), an inorg. pigment (e.g., titanium oxide), or a fluorescent pigment is dispersed homogeneously in an aq. medium using a surfactant (e.g., polyoxyalkylene higher fatty acid esters) and/or a water soluble polymer (e.g., polyacrylic acid) as a dispersant. Then about 0.1-20wt% high-molecular flocculant (e.g., gum arabic, polyvinyl- pyrrolidone), as an aq. soln., is added to said pigment dispersion. The high-molecular flocculant causes crosslinking between pigment particles, with the formation of a coalesced suspension of the pigment, yielding the intended aq. pigment ink for marking pen.</p> |
