摘要 |
The present invention provides a process for preparing a solid pigment composition for pigment ink comprising the steps of (a) dissolving polyvinyl alcohol in water, and dispersing pigments in the resulting solution; (b) adding aldehyde derivatives to the resulting pigment dispersion and allowing the polyvinyl alcohol to react with the aldehyde derivatives to prepare polyvinyl acetal; and (c) drying the acetalated pigment dispersion. The pigment ink resulted from the process, employs water-soluble solvents (for example, alcohol solvent, glycol solvent or other non-toxic solvents), contains sufficient amount of pigments, has low concentration with good pigment dispersion and storage stability, and shows good writing or recording ability with improved color-development.
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