Brother Kogyo Kabushiki-kaisha

Hiromitsu Sago

Shunichi Higashiyama

Kazuma Goto

Narumi Koga

Michiko Aoyama

Masashi Tsuda

Masaya Fujioka

Hideto Yamazaki

Hideo Ohira

Akihiko Taniguchi

Mayuko Umemura

Kazuo Kobayashi

Yoshito Toyoda

Tatsunosuke Hoshi

Yuko Iwamura

Hitomi Sadohara

Mayuko Okada

Akiko Miyajima

An ink set containing a water-based ink for ink jet recording and a treatment liquid. The water-based ink contains a phosphate group-modified self-dispersing pigment, water, and a water-soluble organic solvent. The treatment liquid contains a monovalent metal ion, water, and a water-soluble organic solvent.

Ink set, ink-jet recording apparatus, and ink-jet recording method

An evaluation method for evaluating a pigment ink for ink-jet recording used together with a dye ink and containing a pigment and water includes an aggregation property evaluation method for the pigment in which 10 parts by weight of an aqueous sodium chloride solution is added to 100 parts by weight of the pigment ink; the evaluation method including first aggregation property evaluation adding an X wt % aqueous sodium chloride solution; and second aggregation property evaluation adding a Y wt % aqueous sodium chloride solution; wherein concentrations of the aqueous sodium chloride solutions are set to fulfill the following condition in the first and second aggregation property evaluations: 1.0&#x2266;X&#x3c;Y&#x2266;2.5. The optical density of a printed matter and the dispersion stability of the pigment when the pigment ink is brought in contact with the dye ink can be easily evaluated before the printing.

Method for evaluating pigment ink for ink-jet recording and method for producing pigment ink for ink-jet recording

An ink set containing a water-based ink for ink jet recording and a treatment liquid. The water-based ink contains a phosphate-group modified self-dispersing pigment, water, and a water-soluble organic solvent. The treatment liquid contains an aggregating agent, water, and a water-soluble organic solvent. A dynamic surface tension of the water-based ink, measured under the condition where a life time is about 50 ms, is in the range of 35 mN/m to 45 mN/m. A dynamic surface tension of the treatment liquid, measured under the condition where a life time is about 50 ms, is in the range of 33 mN/m to 45 mN/m.

Ink set and ink-jet recording method

A water-based ink for ink jet recording, containing: a coloring agent; water; and a water-soluble organic solvent. The coloring agent contains a phosphate group-modified self-dispersing pigment. The water-based ink further contains at least one of a reducing sugar and a sugar alcohol and a calcium ion.

Water-based ink for ink jet recording

A water-based ink for ink jet recording, containing: a coloring agent; water; and a water-soluble organic solvent. The coloring agent contains a phosphate group-modified self-dispersing pigment. The water-based ink further contains at least one selected from the group consisting of boric acid, diglycolic acid, and a chelating agent.

An ink set for ink-jet recording contains a yellow ink, a magenta ink, and a cyan ink. Ink sets capable of forming composite black images having good color deterioration properties and ozone resistance may be prepared by selecting an appropriate combination of a yellow ink, a magenta ink, and a cyan ink.

Ink set for ink-jet recording, ink-jet recording apparatus, method of ink-jet recording, method of evaluating ink set for ink-jet recording, and method of manufacturing ink set for ink-jet recording

A water base ink for ink-jet recording is provided, which makes it possible to secure a high recording quality with a sharp image area edge by avoiding any blurring even when recording is performed on regular paper and which has satisfactory purge restoration performance. Therefore, no bubble remains in an ink flow passage, and no discharge failure is caused. Further, the discharge operation never becomes unstable. In the water base ink for ink-jet recording, the surface tension is not less than 40 mN/m, and the amount of dissolved oxygen is not more than 4 mg/L.

Water base ink for ink-jet recording

A fluorescent water base ink for ink-jet recording includes water, a first fluorescent dye, and a second fluorescent dye. The first fluorescent dye absorbs light in a first absorption wavelength region in an ultraviolet region to emit fluorescence, and the first fluorescent dye absorbs light in a second absorption wavelength region to emit no fluorescence. The second fluorescent dye absorbs light in an absorption wavelength region in the ultraviolet region, which is different from the first absorption wavelength region of the first fluorescent dye, to emit fluorescence. A wavelength region of the fluorescence of the second fluorescent dye is not overlapped with the first absorption wavelength region of the first fluorescent dye, but at least a part of the wavelength region of the fluorescence of the second fluorescent dye is overlapped with the second absorption wavelength region. The fluorescence intensity of the ink is increased.

Fluorescent water base ink for ink-jet recording

An ink for ink-jet recording includes a solvent dye in which a xanthene structure and a phthalide structure are spiro bound to each other. When the ink is stored in an ink cartridge containing a polyurethane foam and ink-jet recording is performed, a stable printing density may be achieved and changes in hue may be avoided.

Ink for ink-jet recording

A fluorescent water base ink for ink-jet recording contains a first fluorescent dye and a second fluorescent dye. The first fluorescent dye has a first ultraviolet absorption wavelength region in an absorption spectrum and a first fluorescence emission wavelength region in a fluorescence spectrum. The second fluorescent dye has a second ultraviolet absorption wavelength region which is different from the first ultraviolet absorption wavelength region in an absorption spectrum and a second fluorescence emission wavelength region in a fluorescence spectrum. The first fluorescent dye further has an absorption wavelength region which is different from the first ultraviolet absorption wavelength region and which overlaps at least a part of the second fluorescence emission wavelength region.

Fluorescent water-base ink for ink-jet recording

A fluorescent water base ink for ink-jet recording contains a fluorescent dye having a xanthene skeleton, and a glycol. In the fluorescent dye, the difference in hydrophilic index log P is not less than 2.6 between a substituent bonded to C-9 carbon atom of the xanthene skeleton and other portion of the fluorescent dye than the substituent bonded to the C-9 carbon atom. The glycol has a distance between hydroxyl groups substantially equivalent to or longer than an interatomic distance between atoms directly bonded to C-3 and C-6 carbon atoms of the xanthene skeleton of the fluorescent dye, respectively. It is assumed that the glycol is coordinated with the xanthene skeleton in a bridge form to increase the fluorescence intensity by increasing the electron density of the xanthene skeleton. The ink having high fluorescence intensity and in which the fluorescence intensity is not lowered in a time-dependent manner is provided.

A fluorescent water base ink for ink-jet recording to be used for an ink-jet printer contains water, a pigment, a compound having primary or secondary amide group, and a fluorescent dye represented by the following formula (1): wherein Rrepresents OH or N(R)R, Rrepresents hydrogen atom or halogen atom, and each of Rand Rrepresents hydrogen atom or alkyl group. A sufficient OD value and a fluorescence value are obtained while securing the vivid color development and the excellent water resistance principally in accordance with the interaction of the fluorescent dye and the compound having the amide group.

A water base ink for ink-jet recording contains a surfactant represented by the following formula (1) or (2), dipropylene glycol, a coloring agent, and water:CH&#x2014;(CH)&#x2014;O&#x2014;(CHCHO)&#x2014;H() In the formula (1), R represents alkyl group, and x and y represent integers which satisfy x+y=5 to 15. In the formula (2), z represents an integer of not more than 9. The performance of initial introduction into a recording head is satisfactory, and it is possible to simultaneously reduce the feathering and the color bleed even when the recording is performed on regular paper.

A water base ink for ink-jet recording contains an amine compound selected from the group consisting of N-n-butylethanolamine, 1,4-bis(3-aminopropyl)piperazine, benzylamine, and an amine compound represented by a specified structural formula, a surfactant having a specified structural formula, a coloring agent, and water. It is possible to obtain a satisfactory rub resistance and a high printing quality with a sharp outline without causing any feathering on a recorded image. Further, it is possible to obtain a long term nozzle discharge stability by suppressing any corrosion on a metal member of a discharge head unit of an ink-jet recording apparatus.

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Tokai, Japan

Hiromitsu Sago