Patent ID: 7918928

Claim:
A pigment ink comprising: a pigment; a modified siloxane compound; water; and a polymer, wherein the modified siloxane compound comprises at least one selected from the group consisting of a modified siloxane compound represented by the following Formula (1) and a modified siloxane compound represented by the following Formula (2), wherein the content (% by mass) of the water is 50.0% by mass or more and 95.0% by mass or less based on the total mass of the ink, and wherein the polymer is at least one selected from the group consisting of a polymer A which has an acid value of from 90 mgKOH/g or more to 150 mgKOH/g or less and in which a hydrogen bond parameter (δh) of the polymer that is obtained by solubility parameters of monomers constituting the polymer is from 1.0 cal 0.5 /cm 1.5 or more to 3.7 cal 0.5 /cm 1.5 or less, and a polymer B which has an acid value of from more than 150 mgKOH/g to 200 mgKOH/g or less and in which a hydrogen bond parameter (δh) of the polymer that is obtained by solubility parameters of monomers constituting the polymer is from 1.0 cal 0.5 /cm 1.5 or more to 1.5 cal 0.5 /cm 1.5 or less: where the modified siloxane compound represented by Formula (1) has a weight average molecular weight of from 8,000 or more to 30,000 or less; in Formula (1), R 1 is an alkylene group having 1 to 20 carbon atom(s), R 2 is a hydrogen atom or an alkyl group having 1 to 20 carbon atom(s), m is from 1 or more to 250 or less, n is from 1 or more to 100 or less, a is from 1 or more to 100 or less, and b is from 0 or more to 100 or less; where the modified siloxane compound represented by Formula (2) has a weight average molecular weight of from 8,000 or more to less than 50,000 and an HLB of from 1 or more to less than 7; in Formula (2), R 5 s are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atom(s), R 6 is an alkylene group having 1 to 20 carbon atom(s), q is from 1 or more to 100 or less, r is from 1 or more to 100 or less, e is from 1 or more to 100 or less, and f is from 0 or more to 100 or less.