| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a water-dispersion of a colored polyester having recording capability with superior recording integrity, resolution, etc., by dispersing a dispersoid mainly composed of colored particles of a polyester resin into a dispersion medium mainly composed of water at a specified concentration and viscosity. SOLUTION: A polycarboxylic acid (e.g. terephthalic acid) and a polyhydric alcohol (e.g. ethylene glycol) are subjected to polycondensation reaction to produce a polyester resin, which, after granulated, is colored with a dye and/or a pigment. A dipersoid mainly composed of the colored particles of the obtained polyester resin is dispersed into a dispersion medium mainly composed of water to obtain a water dispersion of the colored polyester in a way that the concentration of the dispersoid and the viscosity of the dispersing medium satisfy the conditions given by formula I and formula II [ηi is a viscosity of the water dispersion in cPs at 20 deg.C;ηo is a viscosity of the water dispersion medium at 20 deg.C; S is a concentration of the dispersoid (effective volume ratio)]. The obtained water dispersion of the colored polyester can suitably be used for writing instruments, various types of non-impact printers, etc.</p> |
