Ink for ink-jet recording

Abstract

An ink for ink-jet recording is provided in which C. I. Direct Blue 199 and a thiazole-based compound are used. In this ink, about 1 mol % to about 20 mol % of the total counter ions in C. I. Direct Blue 199 are ammonium ions or organic ammonium ions.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to an ink for ink-jet recording.[0003]2. Description of the Related Art[0004]One of the important characteristics required of an ink for ink-jet recording is that the ink exhibits good light fastness. This is to prevent a reduction in image quality due to fading caused by exposing an ink-jet printed material to light. Therefore, a copper phthalocyanine dye exhibiting better light fastness than magenta and yellow dyes has been employed as a coloring agent of a cyan ink for ink-jet recording.[0005]Another important characteristic required for an ink for ink-jet recording is that the ink resists the growth of mildew. When mildew grows in an ink, the mildew itself acts as a foreign material. Therefore, the ejection stability of an ink containing mildew from nozzles of an ink-jet head decreases, causing clogging of the nozzles. Hence, a thiazole-based compound is added as a mildewproofing agent ...

AI Technical Summary

Benefits of technology

[0013]In the general formula (1), Pc(Cu) represents a copper phthalocyanine nucleus represented by the general formula (2). Each of SO3Y and SO2NH2 groups is present on any of four benzene rings A, B, C and D of the copper phthalocyanine nucleus represented by the general formula (2). Y in the SO3Y group represents a counter ion such as a hydrogen ion, a lithium ion, a sodium ion, a potassium ion, an ammonium ion, an organic ammonium ion and the like.

[0014]C. I. Direct Blue 199 can be produced by a known copper phthalocyanine substitution method having, for example, the following steps (i) and (ii).

[0015]First, copper phthalocyanine is chlorosulfonated with a chlorosulfonating agent. For example, an agent containing a mixture of chlorosulfonic acid and a chlorinating agent (phosphorus oxychloride or phosphorus trichloride) is employed as the chlorosulfonating agent. The molar ratio of the chlorosulfonic acid to the copper phthalocyanine compound (chlorosulfonic acid:copper phthalocyanine compound) is usually within the range of from 5:1 to 200:1. The molar ratio of the chlorinating agent to copper phthalocyanine (chlorinating agent:copper phthalocyanine) is usually within the range of from 0.5:1

Problems solved by technology

Therefore, the ejection stability of an ink containing mildew from nozzles of an ink-jet head decreases, causing clogging of the nozzles.

However, in an ink for ink-jet recording to which a mildewproofing agent composed of a thiazole-based com

Images