Inkjet recording ink and ink cartridge using the ink, inkjet recording apparatus, inkjet recording method and ink recorded matter

An ink cartridge, comprising:

• a vessel;
• and
• an inkjet recording ink housed in the vessel,
• wherein the inkjet recording ink comprises:
• water;
• a water-soluble solvent;
• a pigment;
• and
• a phosphate group-containing copolymer,
• wherein the phosphate group-containing copolymer comprises a structural unit represented by the following general formula (1) and a structural unit represented by the following structural formula (1):
• wherein, in the general formula (1), R1 represents either of a hydrogen atom and a methyl group;
• and M+ represents any of an alkali metal ion, an organic ammonium ion, an organic amine ion and a hydrogen ion, one-half or more of the M+ in the copolymer is an alkali metal ion, an organic ammonium ion or an organic amine, and the remainder is a hydrogen ion:

An inkjet recording apparatus, comprising:

• an inkjet recording ink;
• and
• an ink flying unit configured to record an image by applying a stimulus to the inkjet recording ink to allow the inkjet recording ink to fly,
• wherein the inkjet recording ink comprises:
• water;
• a water-soluble solvent;
• a pigment;
• and
• a phosphate group-containing copolymer,
• wherein the phosphate group-containing copolymer comprises a structural unit represented by the following general formula (1) and a structural unit represented by the following structural formula (1):
• wherein, in the general formula (1), R1 represents either of a hydrogen atom and a methyl group;
• and M+ represents any of an alkali metal ion, an organic ammonium ion, an organic amine ion and a hydrogen ion, one-half or more of the M+ in the copolymer is an alkali metal ion, an organic ammonium ion or an organic amine, and the remainder is a hydrogen ion: