Abstract: A method for selecting a resin or rubber material to construct an ink flow passage of an ink-jet recording apparatus includes immersing the resin or rubber material in water at 60° C. for 2 weeks in a tightly closed vessel, and determining an amount of eluted fatty acid derivative. If the amount of fatty acid derivative is not more than 20 ppm with respect to a total amount of the resin or rubber material, it is judged that the resin or rubber material is appropriate as the material for the ink flow passage. It is possible to select, by the convenient method, the material which is most suitable for the actual condition of use, without examining components and compositions of respective materials.

Abstract: An ink for ink-jet recording includes water, a basic dye, and a specified pH-adjusting agent. Those usable as the pH-adjusting agent include, for example, monoethanolamine, diethanolamine, ammonium hydrogencarbonate, and sodium carbonate. An image, which is excellent in chromaticness and color feature, can be formed. Further, metal portions, especially an ink tank, a head, and ink flow passages thereof are prevented from corrosion which would be otherwise caused by the ink.

Abstract: An ink cartridge for ink-jet recording apparatus includes an ink tank usable in an ink-jet recording apparatus and a water base ink filled in the ink tank. In the ink cartridge, the ink tank is formed of polyolefin containing a sorbitol derivative as a crystal-nucleating agent, and the pH of the water base ink filled in the tank has been adjusted to be not less than 4.0 to less than 8.0. This makes it is possible to prevent the sorbitol derivative, contained in the polyolefin as the crystal-nucleating agent, from depositing in the water base ink filled in the ink tank.

Abstract: A method for selecting a resin or rubber material to construct an ink flow passage of an ink-jet recording apparatus includes immersing the resin or rubber material in water at 60° C. for 2 weeks in a tightly closed vessel, and determining an amount of eluted fatty acid derivative. If the amount of fatty acid derivative is not more than 20 ppm with respect to a total amount of the resin or rubber material, it is judged that the resin or rubber material is appropriate as the material for the ink flow passage. It is possible to select, by the convenient method, the material which is most suitable for the actual condition of use, without examining components and compositions of respective materials.

Abstract: A water base ink set for ink-jet recording includes a water base ink which contains an acid dye, and a water base ink which contains a basic dye. The water base ink contains a polymer which has an average molecular weight of 3,000 to 20,000 and which is represented by the following formula (1): wherein X represents H or COONa, and Y represents H, COONa, SO3Na, or CH2OR in the formula (1). R represents a substituted group having SO3Na with carbon atom or atoms of a number of 1 to 5. When the ink containing the acid dye and the ink containing the basic dye are mixed with each other, then the head discharge section is prevented from any clog-up, and it is possible to perform the stable jetting operation.

Abstract: An ink for ink-jet recording comprises a pigment, an anionic surfactant, and a cationic surfactant. The cationic surfactant interacts with the anionic surfactant which does not contribute to the dispersion of the pigment in the ink to avoid any excessive permeation of the anionic surfactant into paper. It is possible to obtain a sharp image in which the printing concentration is high and the feathering and the bleeding are scarcely caused.

Abstract: An ink for ink-jet recording comprises water, a basic dye, and a specified pH-adjusting agent. Those usable as the pH-adjusting agent include, for example, monoethanolamine, diethanolamine, ammonium hydrogencarbonate, and sodium carbonate. An image, which is excellent in chromaticness and color feature, can be formed. Further, metal portions, especially an ink tank, a head, and ink flow passages thereof are prevented from corrosion which would be otherwise caused by the ink.

Abstract: An ink for ink-jet recording comprises a pigment, an anionic surfactant, and a cationic surfactant. The cationic surfactant interacts with the anionic surfactant which does not contribute to the dispersion of the pigment in the ink to avoid any excessive permeation of the anionic surfactant into paper. It is possible to obtain a sharp image in which the printing concentration is high and the feathering and the bleeding are scarcely caused.

Abstract: In a toner for an image-forming apparatus having a toner flow control means for controlling the flow of a charged toner and a toner feeding means for feeding the charged toner to the toner flow control means, the toner feeding means and the toner flow control means being so provided as to come into contact with each other through the charged toner, the toner comprises a core material constituted of at least a binder resin, and a fine-powdered abrasive adhering to the surface of the core material.

Abstract: A developer for developing an electrostatic latent image formed on an photosensitive body, including a toner, a fluidity improving material, a cleaning material, and hydrophobic fine particles obtained by treating surfaces of the fine particles with silicone, the treated fine particles containing not less than 5% of the silicone.

Abstract: An electrostatic latent image developer containing a carrier, a toner, and an electric field adjusting agent. The electric field adjusting agent is formed as particles having an average particle size smaller than that of the carrier, and contains a magnetic powder in a specific amount less than that of a magnetic powder contained in the carrier and greater than that of a magnetic powder contained in the toner. The magnetic powder may be deposited on the surface of each particle of the electric field adjusting agent to form a conductive layer capable of smoothly taking or imparting charges away from or to the toner. Accordingly, an electric field formed in a gap between a developing sleeve and a photosensitive member can be intensified to thereby prevent an edge effect and enhance a permittivity in this gap. Accordingly, the electrostatic latent image formed on the photosensitive member can be faithfully developed.

Abstract: An electrostatic latent image developer is composed of 10 to 70 parts by weight of a magnetic toner including at least a magnetic powder and a resin, the toner having an average particle size of 5 to 10 .mu.m, a bulk density of at least 0.4 g/cm, a coherence of not larger than 20%, and a volume resistivity of at least 10.sup.9 .OMEGA. cm at an AC electric field of 1 kHz, and 30 to 90 parts by weight of a carrier made of a transition oxide, the carrier having an average particle size of 30 to 70 .mu.m. The toner is uniformly charged so that quick rising-up of the charge is possible. The developer provides high quality, uniform images without blurring.