INK, INK JET RECORDING BY USING IT, AND MACHINERY USING THE INK

摘要

PURPOSE:To obtain a magenta ink excellent in water resistance, stability and long-term shelf stability and free from the clogging of a delivery port by using a recording agent containing both a specified compound and a specified amount of alkali metal ions for an ink consisting of a recording agent and a liquid medium. CONSTITUTION:An ink consisting of a recording agent and a liquid medium that serves to dissolve or disperse it and contains at least water and a water-soluble organic solvent (e.g. glycerin, N-methyl-2-pyrrolidone or isopropyl alcohol), wherein the recording agent contains at least one compound of the formula (wherein X is SO2, O or S; R1 to R9 are each H, a 1-5C alkyl, amino, OH, halogen or nitro; S1 and S2 are each SO3<-> or COO<->; and a and b are each 1 or 2) and alkali metal ions in an amount of N mol per mol of the anionic groups S1 and S2 in the formula, wherein the N satisfies the equation 0.3XB<=N<=0.95XB [wherein B = (the number of mol of the compound of the formula)X(a+b--1)].