Patent ID: 7740697

Claim:
An aqueous ink comprising micromicelles comprised of: two or more surfactants forming micelles in an opaque or translucent dispersed state in water when used in conjunction, wherein the two or more surfactants comprise a first surfactant having an HLB equal to or greater than 6 and less than 10 and a second surfactant having an HLB of 10 to 15, wherein the first and second surfactants have the structurally same hydrophobic group unit, and wherein each of the first and second surfactants has an ethylene oxide unit or propylene oxide unit; and a compound having an alkyl group which is different from the hydrophobic group unit of the first and second surfactants and is less hydrophobic than the hydrophobic group unit of the first and second surfactants, wherein the compound has only a hydroxyl group as a water-soluble group, wherein the first surfactant comprises a compound represented by formula (I) and the second surfactant comprises a compound represented by formula (I), wherein formula (I) is as follows: A—C≡C—B (I) wherein A and B are each independently selected from the group consisting of a hydrogen atom, and groups expressed by the following general formulae (II A ) and (II B ) wherein X A represents C n H 2n+1 (n is an integer number of 1 to 10), X B represents C m H 2m+1 (m is an integer number of 1 to 10), Y A and Y B represent a ring-opened ethylene oxide unit and/or a ring-opened propylene oxide unit, and a and b are each independently an integer number, and wherein the compound having an alkyl group is a compound represented by formula (III) wherein R 1 , R 2 , and R 3 each independently represent a hydrogen atom or an alkyl group having 1 to 16 carbon atoms, (X), (Y) and (Z) each independently represent OH or D-OH, and D represents a ring-opened ethylene oxide and/or a ring-opened propylene oxide.