Toyo Ink Manufacturing Company

Yasuharu Iida

Seiji Sawada

Sunao Satake

Seiji Aida

Hisashi Uraki

Tsutomu Fujigamori

Ichiro Toyoda

Akio Sato

Toshiyuki Uemura

Shinya Fujimatsu

Shigeyuki Ehashi

Yoshimitsu Ueno

Motonori Ando

Tsukasa Iguchi

A water-dispersed inkjet recording liquid excellent in water resistance and transparency and also excellent in the property of ejection from a nozzle, containing, as a colorant, a water-based dispersion of an organic pigment (A) which is at least one member selected from the group consisting of a quinacridone pigment, a benzimidazolone pigment, an insoluble azo pigment, a fuzed azo pigment, a quinophthalone pigment, a naphthol pigment, a perylene pigment and an isoindolinone pigment and has an average particle diameter of 10 to 150 nm (measured by laser scattering), the water-based dispersion of the organic pigment (A) being obtained by mechanically kneading a mixture containing at least three components of the organic pigment (A), a water-soluble inorganic salt (B) in an amount by weight at least three times as large as the amount of the organic pigment (A) and a water-soluble solvent (C) to finely mill the organic pigment (A), and then removing the water-soluble inorganic salt (B) and the water-soluble solvent (C) by washing the kneaded mixture with water, and a process for the production thereof.

Inkjet recording liquid and process for the production thereof

An inkjet recording ink having excellent water resistance and having excellent ejection stability through a nozzle, which ink is obtained by dispersing colorant particles in a water-based liquid, the colorant particles being a product formed by coating each of resin particles having an average particle diameter of 50 to 300 nm with an organic pigment.

Water-based ink-jet recording fluid

A surface-treated organic pigment excellent in initial dispersibility and long-term dispersion stability in water and an organic solvent and free from the coagulation of pigment particles, obtained by reacting a sulfonating agent with an organic pigment dispersed in a solvent in which the organic pigment is insoluble or sparingly soluble, and thereby introducing a sulfonic acid group to the surface of each particle of the organic pigment.

Surface-treated organic pigment and process for the production thereof

An inkjet ink having sufficient water resistance on a recording sheet but having excellent re-solubility in an ink in a head portion and excellent ejection stability through a nozzle, the inkject ink comprising an aqueous liquid, a pigment and a water-soluble resin, the water-soluble resin being a terpolymer obtained from acrylic acid, styrene and .alpha.-methyl styrene and having a weight average molecular weight of 2,000 to 8,000 and an acid value of 90 to 130, and a process for the production of the inkjet ink, which comprises preparing a concentrated aqueous dispersion of a pigment and a terpolymer obtained from acrylic acid, styrene and .alpha.-methylstyrene, adding water and an additive to the concentrated dispersion to dilute the concentrated dispersion and maintaining the diluted dispersion at a temperature between 60.degree. C. and 80.degree. C. for 5 to 48 hours.

Inkjet ink and process for the production thereof

The present invention relates to an aqueous ink jet recording liquid of a pigment type, which liquid has excellent stability and printing characteristics; and also to a process for the preparation of said liquid. The ink jet recording liquid of the present invention is obtained by dispersing a pigment and a resin in an aqueous medium. Said resin is an aqueous dispersion-type resin comprising a shell composed of a polymer having a glass transition point in the range of 50.degree. C. to 150.degree. C. and a core composed of a polymer having a glass transition point in the range of -100.degree. C. to 40.degree. C.

Ink jet recording liquid

The present invention relates to an ink jet recording liquid obtained by dispersing a pigment in an aqueous medium, said aqueous medium comprising glycerol and 1,3-propanediol. The ink jet recording liquid of the present invention is capable of sustaining prolonged stable discharge onto the recording surface without clogging the nozzle of an ink jet printer and exhibits excellent storage stability.

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Tokyo, Japan

Yasuharu Iida