Patent ID: 7276113

Claim:
A surface-modified pigment having at least two surface-active agents each of which is chemically immobilized onto the surface of the pigment, wherein the first surface-active agent has a hydrophilic-lipophilic balance of about 10 or higher and contains at least one functional group selected from the group consisting of a carboxyl group, the salt of a carboxyl group, a phosphorous group, a sulfur group, and a silane group; the second surface-active agent has a hydrophilic-lipophilic balance of about 9 or lower and contains at least one functional group selected from the group consisting of a carboxyl group, the salt of a carboxyl group, a phosphorous group, and a silane group; and the difference in the hydrophilic-lipophilic balance values between the first and the second surface-active agent is at least about 5.