Water-based inks for ink-jet printing

A water dispersion for ink-jet printing, comprising colorant-containing water-insoluble vinyl polymer particles in which the water-insoluble vinyl polymer is a polymer containing constitutional units represented by the following formulae (1) and (2):

• wherein R1 is a hydrogen atom or a methyl group;
• and R2 is a substituted or unsubstituted arylalkyl group having 7 to 22 carbon atoms or a substituted or unsubstituted aryl group having 6 to 22 carbon atoms;
• and
• wherein R3 is a hydrogen atom or a methyl group;
• R4O is an oxypropylene group;
• R5O is an oxyalkylene group having 2 or 4 carbon atoms;
• R6 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a phenyl group which may be substituted with an alkyl group having 1 to 9 carbon atoms in which R4O and R5O are random-added or block-added, and when block-added, the structure may be in the form of either —COO—(R4O)x—(R5O)y—R6 or —COO—(R5O)y—(R4O)x—R6;
• and x and y represent average molar numbers of addition where x is a number from 1 to 30 and y is a number from 0 to 30, and if y is 2 or more, a plurality of the R5O groups may be the same or different, with the proviso that a weight ratio of the constitutional unit represented by the formula (1) to the constitutional unit represented by the formula (2) in the polymer is in the range of from 1/2 to 10/1.