Abstract: Disclosed is a combination of a water-based ink and a wetting solution for ink-jet recording, which enables smooth introduction of the water-based ink into an ink-jet head. One end of a capillary having an inner diameter of from about 0.1 to about 1 mm is dipped in the water-based ink so that the water-based ink rises inside the capillary. A combination of a water-based ink and a wetting solution that satisfy the following formula (1) is selected: Vi/Vs?about 2??(1) wherein Vs indicates a rising speed of the water-based ink at an intermediate position before and after the water-based ink rising when an inner wall of the capillary is in a dry state, and Vi indicates a rising speed of the water-based ink when an inner wall of the capillary is wetted with the wetting solution.

Abstract: 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.

Abstract: A water base ink set for ink-jet recording includes a black ink containing a negatively charged self-dispersing black pigment and a water-soluble polyvalent alcohol alkyl ether; and a yellow ink containing a water-soluble anionic yellow dye in which a number of counter ion or ions per one molecule is not more than 3, a surfactant based on amine represented by the following general formula (1), and a water-soluble polyvalent alcohol alkyl ether; R—N—(CH2CH2O)xH(CH2CH2O)yH??(1) wherein R represents an alkyl group or an alkenyl group having a number of carbons of 8 to 18, and x+y is 5 to 15. Accordingly, the water ink set in which no bleeding or no coagulation of the pigment occur is provided.

Abstract: A water base pigment ink for ink-jet recording contains a pigment, water, and at least one of polyethylene glycol and diglycerol. The ink is solidified into a solid matter when the water is evaporated. Further, the solid matter is redissolved in the unsolidified water base pigment ink for ink-jet recording. When the ink is used, then neither clog-up of a nozzle nor discharge failure is caused, no load is imposed by the solidified ink on the maintenance system such as the wiping equipment, and the sticking performance on the paper is satisfactory.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed is a combination of a water-based ink and a wetting solution for ink-jet recording, which enables smooth introduction of the water-based ink into an ink-jet head. One end of a capillary having an inner diameter of from about 0.1 to about 1 mm is dipped in the water-based ink so that the water-based ink rises inside the capillary. A combination of a water-based ink and a wetting solution that satisfy the following formula (1) is selected: Vi/Vs?about 2??(1) wherein Vs indicates a rising speed of the water-based ink at an intermediate position before and after the water-based ink rising when an inner wall of the capillary is in a dry state, and Vi indicates a rising speed of the water-based ink when an inner wall of the capillary is wetted with the wetting solution.

Abstract: 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 R1 represents OH or N(R3)R4, R2 represents hydrogen atom or halogen atom, and each of R3 and R4 represents 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.

Abstract: 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.

Abstract: An ink set for ink-jet recording includes two or more inks each of which contains water, a coloring agent, and a water-soluble organic solvent. The ink set is prepared so that a ratio (Vmin/Vmax) between a maximum permeation velocity Vmax of the ink and a minimum permeation velocity Vmin of the ink is not less than 0.6 when the respective inks are developed by means of paper chromatography on a certain paper. It is possible to suppress the bleeding of a formed image.

Abstract: A water base ink set for ink-jet recording includes a black ink containing a negatively charged self-dispersing black pigment and a water-soluble polyvalent alcohol alkyl ether; and a yellow ink containing a water-soluble anionic yellow dye in which a number of counter ion or ions per one molecule is not more than 3, a surfactant based on amine represented by the following general formula (1), and a water-soluble polyvalent alcohol alkyl ether; R—N—(CH2CH2O)xH(CH2CH2O)yH??(1) wherein R represents an alkyl group or an alkenyl group having a number of carbons of 8 to 18, and x+y is 5 to 15. Accordingly, the water ink set in which no bleeding or no coagulation of the pigment occur is provided.

Abstract: 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.

Abstract: 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.

Abstract: A water base ink for ink-jet recording contains a self-dispersing type pigment, glycol ether, and water. In the glycol ether, the number of carbon atoms of an ethylene oxide moiety is not less than 8, and the solubility in water at 25° C. is not less than 1%. The ink reduces the blurring of a recorded image which would be otherwise caused by the feathering on the paper surface. The ink is excellent in drying performance on the paper surface, and the ink makes it possible to stably disperse the pigment.

Abstract: 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 R1 represents OH or N(R3)R4, R2 represents hydrogen atom or halogen atom, and each of R3 and R4 represents 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.

Abstract: An X-ray image reader including a plurality of read heads and a scan drive device for scanning an X-ray image-storing member by moving the read heads is disclosed. The X-ray image reader has a multi head mode in which a read processing of an X-ray image held on the X-ray image storing member is performed by using at least two of the read heads, and a single head mode in which a read processing of an X-ray image held on the X-ray image storing member is performed by using only one of the read heads. The multi head mode is selected when a high-speed measurement is requested and the single head mode is selected when precise measurement is requested.

Abstract: A water base pigment ink for ink-jet recording contains a pigment, water, and at least one of polyethylene glycol and diglycerol. The ink is solidified into a solid matter when the water is evaporated. Further, the solid matter is redissolved in the unsolidified water base pigment ink for ink-jet recording. When the ink is used, then neither clog-up of a nozzle nor discharge failure is caused, no load is imposed by the solidified ink on the maintenance system such as the wiping equipment, and the sticking performance on the paper is satisfactory.

Abstract: A water base ink for ink-jet recording, which is usable for an ink-jet recording apparatus having an ink-jet head provided therein with an ink flow passage formed of nickel or nickel alloy, includes a coloring agent, water, and a water-soluble organic solvent. The ink is blended so that a current density, which is obtained within an electric potential range of −600 to +300 mV, is not more than 100 &mgr;A/cm2 when anodic polarization measurement is performed by using a reference electrode of silver/silver chloride, a counter electrode of platinum, and a working electrode of nickel or nickel alloy. The ink does not corrode any part for constituting the flow passage in the ink-jet head.

Abstract: An ink for ink-jet recording consisting essentially of a water-soluble solvent, a pigment, and a compound represented by the following general formula (1): wherein AO represents oxyalkylene group, R represents alkyl group, and m and n represent natural numbers, respectively. It is possible to effectively suppress the feathering and the bleeding.

Abstract: A water base ink for ink-jet recording contains a self-dispersing type pigment, glycol ether, and water. In the glycol ether, the number of carbon atoms of an ethylene oxide moiety is not less than 8, and the solubility in water at 25° C. is not less than 1%. The ink reduces the blurring of a recorded image which would be otherwise caused by the feathering on the paper surface. The ink is excellent in drying performance on the paper surface, and the ink makes it possible to stably disperse the pigment.