Aqueous ink, ink cartridge and ink jet recording method
Provided is an aqueous ink for ink jet, containing a resin particle, and a cyclic amide-based, water-soluble organic solvent. The resin particle has a core portion that contains a cyano group-containing unit, and a shell portion that contains an aromatic group-containing unit, an anionic group-containing unit and a unit derived from a crosslinking agent, but free of cyano group-containing unit. Ink jet recording using the aqueous ink can record images that excel in abrasion resistance and gloss clarity.
1. An aqueous ink for ink jet comprising:
a resin particle; and
a water-soluble organic solvent,
wherein the resin particle has a core portion that comprises a cyano group-containing unit, and a shell portion that comprises an aromatic group-containing unit, an anionic group-containing unit, and a unit derived from a crosslinking agent, but free of cyano group-containing unit, and
wherein the water-soluble organic solvent comprises a cyclic amide.
2. The aqueous ink according to claim 1 , wherein the resin particle has a glass transition temperature of 95° C. or more, and a minimum film forming temperature of 30° C. or less.
3. The aqueous ink according to claim 1 , wherein a percentage (% by mass) of the cyano group-containing unit in the core portion is 10% by mass or more to 60% by mass or less.
4. The aqueous ink according to claim 1 , wherein the cyano group-containing unit is a unit derived from at least one of acrylonitrile or methacrylonitrile.
5. The aqueous ink according to claim 1 , wherein the cyclic amide is at least one selected from the group consisting of 2-pyrrolidone, N-methyl-2-pyrrolidone, 1-(2-hydroxyethyl)-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and 1,3-bis(2-hydroxyethyl)-5,5-dimethylhydantoin.
6. The aqueous ink according to claim 1 , wherein the content (% by mass) of the cyclic amide, when expressed in mass ratio relative to the content (% by mass) of the resin particle, is 0.5 times or more to 2.5 times or less.
7. The aqueous ink according to claim 1 , further comprising a water-soluble resin having an acid value of 100 mgKOH/g or more to 180 mgKOH/g or less.
8. The aqueous ink according to claim 1 , further comprising a coloring material.
9. An ink cartridge comprising an ink, and an ink storage portion that stores the ink,
the ink being the aqueous ink as defined in claim 1 .
10. An ink jet recording method by which an image is recorded on a recording medium with an ink ejected from a recording head of an ink jet system,
the ink being the aqueous ink as defined in claim 1 .