Water-soluble dye composition and recording liquid containing the same

摘要

A black recording liquid suitable for use in ink-jet recording or as an ink for writing instruments comprises at least two water-soluble dyes and a liquid medium. Each of the dyes satisfies the condition defined by the following expression [I], and a mixture of these dyes satisfies the condition defined by the following expression [II]. <IMAGE> [I] <IMAGE> [II] In these expressions, a* and b* are chromaticness indices defined in the CIE 1976 (L*, a*, b*) space, i indicates the ith dye of the dyes used together, and n is an integer of 2 or more.