| 摘要 |
PROBLEM TO BE SOLVED: To obtain a graft copolymer containing a sulfonate and a phosphate group useful as a dispersant for a pigment-containing ink. SOLUTION: This graft polymer comprises (a) 2-100% of a main chain composed of a hydrophilic main chain having at least 3pKa, completely soluble in water but not in a nonpolar organic solvent and producible from a monomer containing an unneutralized acid and (b) 20-100% of a side chain composed of at least one independent hydrophobic side chain having chain length of at least four carbon atoms, producible from a nonpolar aliphatic or aromatic monomer, in which the side chain is bonded to the main chain at the single end part and at least one independent hydrophobic side chain has 1,000 to 30,000 weight average molecular weight. The graft polymer is useful as a dispersant for an aqueous solution, especially an ink for ink-jet. |
