Patent ID: 7335249
Filing Date: 2008-02-26
Classification: C09D

Abstract:
1. A water base ink set for ink-jet recording including: a black ink containing a self-dispersing black pigment, which is dispersed in a solvent by having a negative charge, and a water-soluble polyvalent alcohol alkyl ether; and a yellow ink containing a water-soluble anionic yellow dye in which a number of counter ion or ions per one molecule is not more than 3, a surfactant based on amine represented by the following general formula (1), and a water-soluble polyvalent alcohol alkyl ether; wherein an amount of the self-dispersing black pigment contained in the black ink is 0.1 to 20% by weight; an amount of the water-soluble anionic yellow dye contained in the yellow ink is 1 to 5% by weight, and an amount of the water-soluble polyvalent alcohol alkyl ether contained in the yellow ink is 2 to 5% by weight; and the water-soluble polyvalent alcohol alkyl ether is at least one selected from the group consisting of dipropylene glycol-n-propyl ether, triethylene glycol-n-butyl ether and tripropylene glycol-n-butyl ether; wherein R represents an alkyl group or an alkenyl group having a number of carbons of 8 to 18, and x+y is 5 to 15.