Abstract: A tail plug to be attached to a tail end of a shaft part of a writing instrument includes an inner plug that is fitted into the shaft part and an outer plug that is coupled with the inner plug. The inner plug has a first opening through which a fluid can flow in an axial direction of the shaft part; the outer plug has a second opening through which a fluid can flow in the axial direction of the shaft part, and at least one of the first opening and the second opening are configured to be closed when the outer plug and the inner plug are coupled with each other.

Abstract: A is a pen including: an ink reservoir that stores an ink including decorative particles and a pen tip section. The ink reservoir includes a tubular casing member having liquid blocking properties and an ink occlusion material disposed inside the casing member. The casing member has a first opening end and a second opening end. The ink occlusion material includes multiple fibers disposed in the casing member and the multiple fibers respectively having one ends and other ends each disposed at a position corresponding to the first opening end or the second opening end of the casing member.

Abstract: Provided is a writing instrument which includes a pen tip part; a coating liquid storage section; a cylindrical part so as to cover the coating liquid storage section, and fixed to the pen tip part; a valve mechanism disposed at a tip end portion of the coating liquid storage section; an operation member configured to open the valve mechanism and allow the coating liquid flowing out from the coating liquid storage section to flow toward a pen tip side via the valve mechanism; and a cylindrical elastic member connecting the valve mechanism with the operation member. The coating liquid storage section is relatively movable to the pen tip part in the axial direction, and the operation member is configured to open the valve mechanism in association with the relative movement of the coating liquid storage section to the pen tip part.

Abstract: A pen includes: an ink reservoir configured to store an ink; and a pen tip section including an ink application part configured to apply the ink to an ink application object. The ink application part of the pen tip section includes: a rigid tip made of a rigid material and having a hemispherical outer surface, an inner surface facing toward the ink reservoir, and a penetration part penetrating from the inner surface side to the outer surface side of the rigid tip; and at least one foam body filled in the penetration part at least on the side of the penetration part close to the outer surface side of the rigid tip, and provided with at least one air bubble formed to communicate from the outer surface side of the foam body to the inner surface side of the foam body.

Abstract: A pen has an ink reservoir configured to store an ink containing decorative particles and a pen tip configured to apply the ink to an ink coating target. The pen tip includes a proximal end to which the ink is supplied from the ink reservoir, a distal end opposite to the proximal end and configured to contact the ink coating target, and a groove opening on the outer circumferential surface of the pen tip and extending from the proximal end to the distal end.

Abstract: A pen including an ink reservoir to store an ink; a pen tip which has a proximal end and a distal end opposite to the proximal end and applies an ink to a coating target; an ink guide to guide the ink in the reservoir toward the pen tip; and a holder part which has a through hole through which the pen tip is inserted and holds at least the proximal end of the pen tip while exposing the distal end of the pen tip with the pen tip inserted through the through hole. The holder part includes: an ink holding part capable of holding the ink from the ink guide and formed at least partially around a circumference of the through hole; and a first opening opening on an inner circumferential surface that defines the through hole and communicating with the ink holding part.

Abstract: The present invention provides an ink filling tool including: an ink tank having an internal space configured to store a liquid ink; and a cylindrical nozzle having an inner hole communicating with the internal space of the ink tank, the nozzle being insertable into the through hole. The nozzle is configured to be capable of pressing the valve mechanism which is present inside a pen in a state of being inserted into the through hole, and the nozzle has an ink circulating part configured to communicate the inner hole with an outside in a direction orthogonal to the axis of the nozzle.

Abstract: A method for manufacturing a colored aluminum product or a colored aluminum alloy product includes the following steps of (i) subjecting a substrate made of aluminum or aluminum alloy to an anodic oxidation in a treatment solution containing phosphoric acid to form an anodic oxidation film having a plurality of pores on a surface of the substrate, (ii) treating the substrate with warm water having a temperature between 40 and 100° C., and (iii) immersing the substrate in a pigment composition for coloration includes pigment particles, a dispersing agent and water to fill the pigment particles into a plurality of the pores in the anodic oxidation film on the surface of the substrate, thereby performing coloration.

Abstract: A plurality of inlets are defined in a circulation path between an ink reservoir and an ink absorbing member by an inlet forming part formed in the circulation path.

Abstract: A method for manufacturing a colored aluminum product or a colored aluminum alloy product includes the following steps of (i) subjecting a substrate made of aluminum or aluminum alloy to an anodic oxidation in a treatment solution containing phosphoric acid to form an anodic oxidation film having a plurality of pores on a surface of the substrate, (ii) treating the substrate with warm water having a temperature between 40 and 100° C., and (iii) immersing the substrate in a pigment composition for coloration includes pigment particles, a dispersing agent and water to fill the pigment particles into a plurality of the pores in the anodic oxidation film on the surface of the substrate, thereby performing coloration.