Patent ID: 7147700

Claim:
A water base ink for ink-jet recording comprising: water; self-dispersing type carbon black; at least one anionic surfactant which is selected from a surfactant represented by the following formula (1) and a surfactant represented by the following formula (2); and at least one nonionic surfactant which is selected from a surfactant represented by the following formula (3) and a mixture of a surfactant represented by the following formula (4) and a surfactant represented by the following formula (5): R 1 —O(CH 2 CH 2 O) x —SO 3 M (1) wherein R 1 represents an alkyl group having carbon atoms of a number of 12 to 15, X is 0 to 4, and M represents Na or organic amine in the formula (1); wherein R 2 represents an alkyl group having carbon atoms of a number of 12 in the formula (2); wherein each of R 3 to R 8 represents hydrogen or an alkyl group of C=18, and a+b+c+d+e+f represents an integer of 30 to 80 in the formula (3); wherein R 9 represents an alkyl group having carbon atoms of a number of 16 to 18, and l+m+n=10 to 30 is satisfied in the formula (4); wherein R 10 represents an alkyl group having carbon atoms of a number of 16 to 18, and o+p+q=10 to 30 is satisfied in the formula (5).