Abstract: The invention provides a discolorable ink composition which is irreversibly erasable by heating to about 40° C. to 120° C. A discolorable ink composition, where an electron-donating color-forming organic compound and an electron-accepting compound are incorporated in wax particles, whereby the electron-donating color-forming compound in a state color-developed by the electron-accepting compound is separated from a decolorizer and kept in the color-developed state, while when the wax is liquefied by heating, the decolorizer reacts with the electron-accepting compound to convert the electron-donating color-forming organic compound into a decolorized state.

Abstract: In a water-based ink composition of the present invention, 2.5 to 50 wt % of white-colored resin particles and 2.5 to 50 wt % of film-forming resin emulsions in a solid content are contained with respect to the total amount of the ink, the ratio of said white-colored resin particles to film-forming resin emulsions is 1:0.2 to 1:3, and not less than 20 wt % of said white-colored resin particles and film-forming resin emulsions in a solid content are contained in total.

Abstract: A tip unit (1) incorporated in a liquid applicator such as a ball-point pen, the tip unit being capable of an increased rate of liquid discharge with no leaking or clogging problem. To achieve it, the tip unit (1) is accommodated in a tip body (11) having a ball housing (15), a ball (10), a capillary hole (16), and a proximal bore, the ball housing (15) being a passage for allowing liquid to flow therethrough, the ball (10) being rotatively held in the ball housing (15). The ball housing (15) is provided with at least one ink channel (47) adapted to communicate the ball housing (15) with the capillary hole (16) or the proximal bore. The ball housing (15) has a ball resting seat (45) and a side wall (41) that are connected by a connecting surface (71) having a shape of a truncated conical surface with its apex toward the distal end of the tip unit (1).

Abstract: The invention provides a discolorable ink composition which is irreversibly erasable by heating to about 40° C. to 120° C. A discolorable ink composition, where an electron-donating color-forming organic compound and an electron-accepting compound are incorporated in wax particles, whereby the electron-donating color-forming compound in a state color-developed by the electron-accepting compound is separated from a decolorizer and kept in the color-developed state, while when the wax is liquefied by heating, the decolorizer reacts with the electron-accepting compound to convert the electron-donating color-forming organic compound into a decolorized state.

Abstract: A method for producing a tip unit for a liquid applicator including: a first process of shaping the contour of a tip body in the form of a truncated conical surface; a second process of forming a ball housing having an open end at its distal end in the tip body; a third process of placing a ball into the ball housing; a fourth process of scraping the peripheral side of the distal end portion of the tip body to form a peripherally scraped portion after the first process; and a fifth process of deforming the peripherally scraped distal end portion of the tip body toward the ball.

Abstract: The ink of the present invention comprises at least a three-dimensional film-forming component and water, comprises an adhesive synthetic resin emulsion as said three-dimensional film-forming component, and comprises at least 30% by weight of said adhesive synthetic resin emulsion on the basis of the solid content with respect to the total amount of the ink, and minimum film-forming temperature (MFT) of said adhesive synthetic resin emulsion is not greater than 25° C. and further, said ink comprises 1 to 3% by weight of a film-forming assistant with respect to the total amount of the ink.

Abstract: An erasable ink composition comprising water, a water-soluble organic solvent, and the following colorant, colorless resin particles and shear-thinning, viscosity-adjustment agent, characterized in that the colorless resin particles have a mean particle diameter smaller than that of the colorant and are contained in an amount larger than that of the colorant: (a) 3 to wt % (based on the whole ink) of colorless resin particles which are made of at least one resin selected from among acrylic resins, urethane resins, silicone resins and melamine resins and have a mean particle diameter of 0.10 to 10 ?m, (b) 1 to 40 wt % (based on the whole ink) of a colorant having a mean particle diameter of 2 ?m or above, and (c) 0.01 to 4 wt % (based on the whole ink) of a shear thinning, viscosity-adjustment agent.

Abstract: In a water-based ink composition of the present invention, 2.5 to 50 wt % of white-colored resin particles and 2.5 to 50 wt % of film-forming resin emulsions in a solid content are contained with respect to the total amount of the ink, the ratio of said white-colored resin particles to film-forming resin emulsions is 1:0.2 to 1:3, and not less than 20 wt % of said white-colored resin particles and film-forming resin emulsions in a solid content are contained in total.

Abstract: A tip unit (1) incorporated in a liquid applicator such as a ball-point pen, the tip unit being capable of an increased rate of liquid discharge with no leaking or clogging problem. To achieve it, the tip unit (1) is accommodated in a tip body (11) having a ball housing (15), a ball (10), a capillary hole (16), and a proximal bore, the ball housing (15) being a passage for allowing liquid to flow therethrough, the ball (10) being rotatively held in the ball housing (15). The ball housing (15) is provided with at least one ink channel (47) adapted to communicate the ball housing (15) with the capillary hole (16) or the proximal bore. The ball housing (15) has a ball resting seat (45) and a side wall (41) that are connected by a connecting surface (71) having a shape of a truncated conical surface with its apex toward the distal end of the tip unit (1).

Abstract: A method for producing a tip unit (1) for a liquid applicator in a stable and easy process, the tip unit (1) being capable of increasing the rate of liquid discharge is provided. The method includes at least five processes; that is, a first process of shaping the contour of a tip body (11) in the form of a truncated conical surface; a second process of forming a ball housing (15) having an open end at its distal end in the tip body (11); a third process of placing a ball (10) into the ball housing (15); a fourth process of scraping the peripheral side of the distal end portion of the tip body (11) to form a peripherally scraped portion (55) after the first process; and a fifth process of deforming the peripherally scraped distal end portion of the tip body (11) toward the ball (10).

Abstract: The ink of the present invention comprises at least a three-dimensional film-forming component and water, comprises an adhesive synthetic resin emulsion as said three-dimensional film-forming component, and comprises at least 30% by weight of said adhesive synthetic resin emulsion on the basis of the solid content with respect to the total amount of the ink, and minimum film-forming temperature (MFT) of said adhesive synthetic resin emulsion is not greater than 25° C. and further, said ink comprises 1 to 3% by weight of a film-forming assistant with respect to the total amount of the ink.

Abstract: The present invention provides erasable aqueous color material composition for scratching off comprising pigment particles with opacifying property and aqueous emulsions of resins with lump coagulation property, wherein said pigment particles with opacifying property are scaly aluminum particles or synthetic resin particles, and said aqueous emulsions of resins with lump coagulation property are aqueous emulsions of styrene butadiene rubber or carboxy modified styrene butadiene rubber.

Abstract: An erasable ink composition comprising water, a water-soluble organic solvent, and the following colorant, colorless resin particles and shear-thinning, viscosity-adjustment agent, characterized in that the colorless resin particles have a mean particle diameter smaller than that of the colorant and are contained in an amount larger than that of the colorant: (a) 3 to wt % (based on the whole ink) of colorless resin particles which are made of at least one resin selected from among acrylic resins, urethane resins, silicone resins and melamine resins and have a mean particle diameter of 0.10 to 10 ?m, (b) 1 to 40 wt % (based on the whole ink) of a colorant having a mean particle diameter of 2 ?m or above, and (c) 0.01 to 4 wt % (based on the whole ink) of a shear thinning, viscosity-adjustment agent.

Abstract: The main object is to provide a water-based ink composition which is not only superior in hiding power but also has satisfactory writing properties. This invention relates to a water-based ink composition comprising a powder consisting of inorganic particles comprising at least one of aluminum oxide, titanium dioxide and boron nitride and water.

Abstract: The main object is to provide a water-based ink composition which is not only superior in hiding power but also has satisfactory writing properties. This invention relates to a water-based ink composition comprising a powder consisting of inorganic particles comprising at least one of aluminum oxide, titanium dioxide and boron nitride and water.

Abstract: The present invention relates to an aqueous ink for ball point pens comprising a coloring pigment, a water-soluble organic solvent, water and a polysaccharide, wherein pigment particles of said coloring pigment gather and form a spotted agglomerate phase. The present invention also relates to an aqueous ink with a coloring pigment and a metallic powder pigment comprising a water-soluble organic solvent, water and a polysaccharide, wherein pigment particles of both the coloring pigment and the metallic powder pigment gather to the same pigment phase and form a complex agglomerate phase.