Brother Kogyo Kabushiki-Kaisha

Mayuko Umemura

Shunichi Higashiyama

Hideto Yamazaki

Masashi Tsuda

Michiko Aoyama

Hiromitsu Sago

Ryuji Kato

Noriaki Satoh

The ink-jet recording apparatus has an ink passage into which a water based ink or a preservation solution is filled. The ink passage employs a rubber member formed from a rubber which is formed of a butyl rubber polymer, a rubber polymer vulcanizable with an organic peroxide, and an organic peroxide. The water-based ink has a dynamic surface tension at a lifetime of 100 ms of about 35 mN/m to about 45 mN/m as measured by means of a maximum bubble pressure method at a measurement temperature of 25&#xb0; C. The preservation solution has a dynamic surface tension at a lifetime of 100 ms of about 30 mN/m to about 35 mN/m as measured by means of the maximum bubble pressure method at a measurement temperature of 25&#xb0; C.

Ink-jet recording apparatus

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

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.

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Chiryu, Japan

Mayuko Umemura