Patent ID: 7291659

Claim:
A water dispersion for ink-jet printing comprising particles of a water-insoluble graft polymer which contain a colorant, said graft polymer having a main chain which is a polymer chain containing a constitutional unit derived from a salt-forming group-containing monomer (a) and a constitutional unit derived from an aromatic ring-containing (meth)acrylate monomer and represented by the formula (1) (b) in which a weight ratio of the constitutional unit derived from the salt-forming group-containing monomer (a) to the constitutional unit derived from the aromatic ring-containing (meth)acrylate monomer and represented by the formula (1) (b) in the main chain is 1/1 to 1/20 wherein R 1 is a hydrogen atom or a methyl group; and R 2 is a substituted or unsubstituted aralkyl group having 7 to 22 carbon atoms or a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and a side chain which is a polymer chain containing a constitutional unit derived from one or more kinds of hydrophobic monomers (c) selected from the group consisting of a styrene-based monomer, a (meth)acrylic ester, and an aromatic ring-containing (meth)acrylate wherein a weight ratio of the main chain to the side chain is 1/1 to 20/1.