Toyo Ink Mfg. Co., Ltd.

Jun Kaneda

Seiji Aida

Toshiyuki Uemura

Kenshiro Shimada

Atsushi Katsuya

Takashi Negishi

Norifumi Watanabe

Yoshiyuki Onai

Eriko Suzuki

The present invention relates to recording material having a laser coloring layer, wherein the laser coloring layer comprises one or more materials selected from among pigments, dyes and inorganic materials, and the laser coloring layer exhibits absorption at a wavelength within a range from 700 to 12,000 nm. The recording material of the present invention has a laser coloring layer of a desired hue, such as yellow, cyan, magenta, orange, white or black, and by conducting printing by laser irradiation, a recorded item with excellent color tone can be obtained.

Recording material and method of recording

A water-based pigment dispersion comprising 100 parts by weight of a pigment, 3 to 30 parts by weight of a sulfonic acid group-containing pigment derivative and water, wherein the sulfonic acid group-containing pigment derivative has only one sulfonic acid group in a molecule of a pigment of which the type is the same as the type of the pigment to be dispersed, the sulfonic acid group forms at least one salt selected from the group consisting of ammonia salt, an organic amine salt and a salt in which at least 15% of the sulfonic acid group is liberated and the rest is a salt with monovalent metal, the content of metal ion having a valence of at least 2 in a solid matter of the above water-based pigment dispersion is 500 ppm or less, and the above pigment is dispersed in water according to electrostatic repulsion due to the sulfonic acid group-containing pigment derivative adsorbed on the particle surface of the pigment, an inkjet recording liquid containing the same and process for the production thereof.

Water-based pigment dispersion, use thereof and process for the production thereof

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Chuo-ku, Japan

Jun Kaneda