Dainichiseika Color & Chemicals Mfg. Co., Ltd.

Yoshiyuki Zama

Michiei Nakamura

Hisao Okamoto

Yoshio Abe

Atsushi Nogami

Naoyuki Sakai

Hiroyuki Shimanaka

Hiromitsu Yanagimoto

Kazuo Kanou

Hideyuki Koiso

Tohru Hosoda

Kenji Ogawa

Dai Watanabe

Shojiro Horiguchi

Hiroaki Saikatsu

Yutaka Nakagawa

Naoki Hirata

Shotoku Takami

Koji Tsuchiya

Masaru Hasegawa

Shiro Yamamiya

Kimihide Kawamura

Seishichi Sasaki

Shirou Yamamiya

Michiel Nakamura

Tetsuya Yanagimoto

Hiroaki Yamada

Katsuhiko Kitabayashi

Masahiro Tsuchiya

Shozo Ohira

This present invention can provide a novel pigment useful in color image displays to form blue pixels capable of providing high-level brightness and saturation, especially a finely-divided pigment which has bright hue and is excellent in pigment physical properties such as light fastness, solvent resistance and heat resistance, and a process for producing the same, a pigment dispersion making use of the pigment, and an ink for a color filters. The novel pigment is produced by forming into a pigment a subphthalocyanine represented by the following formula (1): wherein X is a halogen atom, presents diffraction peaks at diffraction angles (2&#x3b8;) 7.0&#xb0;, 12.3&#xb0;, 20.4&#xb0; and 23.4&#xb0; in x-ray diffraction, and has an average particle size of 120 to 20 nm.

Pigment

A water-based pigment ink contains a pigment, a hydrophilic dispersant, an aqueous medium, an alkali agent for solubilizing the hydrophilic dispersant in the aqueous medium, and a hydrophilic compound having at least one structural unit of 'hydrophobic molecular chain-hydrophilic molecular chain-hydrophobic molecular chain' in a structure thereof. The water-based pigment ink is suited especially as an ink for ink-jet printers.

Water-based pigment inks, image recording method, and image recording system

Image-recording, hydrophilic colorants having an organic pigment linked to a hydrophilic compound through a linking group and which are capable of forming images excellent in print quality such as chroma, gloss, density, light fastness and abrasion fastness, and also as hydrophilic colorants capable of affording inks excellent in physical properties such as long-term storability and press stability are described.

Hydrophilic coloring matter for recording image, aqueous coloring agent for recording image, method and device for recording image

A process produces a sulfonated solid particle by burning sulfur to yield gaseous sulfur dioxide, subjecting the gaseous sulfur dioxide to catalytic oxidation to yield gaseous sulfur trioxide, and sulfonating a dry powdery or granular solid particle with the gaseous sulfur trioxide in a gas phase-solid phase reaction.

Process for producing sulfonated solid particles

A finely divided pigment is formed of an aggregate of primary particles. A number of primary particles of not greater than 0.1 &mgr;m in particle size is at least 95% of an entire number of the primary particles, and a number of primary particles of greater than 0.1 &mgr;m in particle size is at most 5% of the entire number of the primary particles. The finely divided pigment can be produced by grinding a parent pigment (pre-division pigment) together with a water-soluble inorganic salt and a water-soluble organic solvent in a grinding machine at a temperature of from 30 to 90&deg; C. for 2 to 6 hours under a load, and then removing the water-soluble inorganic salt and the water-soluble organic solvent. A coloring composition comprises a dispersing medium and the finely divided pigment dispersed in the dispersing medium. The coloring composition is, for example, an image recording agent for the ink-jet recording system, an image recording agent for the electronic printing or electrostatic recording system, or a coloring agent for forming color filter pixels.

Finely divided pigments and coloring compositions

Near-infrared transmitting black azo pigments

A near-infrared reflecting composite pigment comprises a near-infrared non-absorbing colorant and a white pigment coated with the near-infrared non-absorbing pigment. The near-infrared reflecting composite pigment can be produced by mixing a colorant dispersion, in which the near-infrared non-absorbing colorant is dispersed in a liquid medium, with the white pigment in a form selected from powder or a dispersion and then drying the resultant mixture. A near-infrared reflecting coating agent comprises as a coloring agent the near-infrared reflecting composite pigment. A near-infrared reflecting material comprises a base material coated on a surface thereof with the near-infrared reflecting coating agent.

Near-infrared reflecting composite pigments

A print is produced by printing or coating an infrared reflective coloring agent and another printing ink containing an infrared absorptive coloring agent in combination on a base material. The print therefore contains visually-recognizable information along with other information which is recognizable by infrared rays.

Prints and production method thereof

Growing community of inventors

Tokyo, Japan

Yoshiyuki Zama