| 摘要 |
<p>PURPOSE:To amine or alkali metal salt of anionic polymer is added to an aqueous suspension of an organic pigment, further an acid is added thereto to allow the anionic polymeric molecule to stick to the surface of the organic pigment whereby a pigment which is used in aqueous pigment ink for writing is obtained. CONSTITUTION:An amine or alkali metal salt of anionic polymer such as styrene-maleic acid copolymer, styrene-acrylic acid copolymer is added to an aqueous suspension of an organic pigment, then, an acid is added to the mixture under stirring to obtain the objective pigment where the anionic polymer sticks to the surface of the organic pigment. The amount of the anionic polymer is 0.5-20wt% based on the organic pigment.</p> |
