JP4281188B2 - Liquid ejection tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention has a discharge means for the liquid stored inside, such as a marking pen, a sign pen, a ballpoint pen, and a writing tool for storing an ink composition, a cosmetic composition, etc., and is disposed at the interface of the content liquid. In addition, the present invention relates to a liquid ejection tool including a moving plug that moves along with the volume of the content liquid consumed as the content liquid is consumed, and the movement of the interface of the content liquid.
[0002]
[Prior art]
Conventionally, ink that has liquid discharge means such as a pen tip, such as a writing instrument or an applicator, supplies ink to the pen tip, etc., and performs writing, application, drawing, etc., and is stored in an ink tank in a free state In order to prevent ink from leaking at the interface, a movable stopper is known. This stopper follows the movement of the ink interface as the ink volume decreases due to ink consumption, so that the substantial volume of the ink tank is changed, and the inside of the container gradually becomes negative and the ink is supplied to the ejection means. It becomes difficult to be carried out and it can suppress that it becomes a discharge defect. For example, in Japanese Patent Laid-Open No. 62-199492 , the movable stopper is made of silicone rubber, which is an elastic body, and the outer diameter of the movable stopper is slightly larger than the inner diameter of the container, and the ink and air are separated by pressure contact. What is partitioned is disclosed.
[0003]
[Problems to be solved by the invention]
In the case where the elastic body made of silicon rubber as described above is used as a movable stopper, it is arranged in a press-fitted state in the container, so that there is a high possibility that air will be left in the container during assembly. . Since the volume of air left in this way changes greatly due to temperature changes, the volume of air left in the container also expands due to temperature rise, and the movable stopper moves in the direction in which the volume in the container increases. It abuts on the end and cannot move. When the volume expansion accompanying the temperature rise continues, the movable stopper is elastically deformed by the pressure due to the expansion, thereby forming an air flow passage. At this time, if the ink comes out of the container together with the air, it may lead to ink leakage.
[0004]
[Means for Solving the Problems]
That is, the present invention has a liquid discharge means accommodated in a liquid storage container , and is disposed at the interface of the content liquid. The volume of the content liquid consumed and consumed as the content liquid is consumed. In the liquid ejection device having a movable stopper that moves with the movement of the liquid interface, the movable stopper is a hydrogel material that absorbs and swells the liquid to increase the apparent volume, and the movable stopper increases the apparent volume. The gist of the present invention is a liquid ejection tool in which a gap between the liquid storage container and the inner wall of the liquid storage container is filled and both are in contact with each other.
[0005]
[Action]
The moving stopper comes into contact with the liquid surface, absorbs the liquid, and swells to form a liquid-tight state in contact with the inner wall of the container without leaving a space between the moving stopper and the liquid surface. Can be formed.
[0006]
Hereinafter, an example of the liquid ejection tool of the present invention will be described with reference to the drawings.
What is shown in FIG. 1 is an example of a so-called raw ink-type writing instrument that contains ink 1 in a free state therein, and is an example in which a liquid storage container is integrally incorporated in a shaft.
A pen tip holder 3 is joined mainly to the tip of the cylindrical body 2 constituting the ink tank portion, and a fiber tip pen tip 5 is attached to the through hole 4 of the pen tip holder 3 by press fitting. The penetrating hole 4 to which the pen tip 5 is attached is configured such that the rear end ink tank side has a small diameter portion, and the rear portion of the pen core is tightened by press-fitting, and the density of the fibers in the tightened portion is changed. In this part, the ink can be controlled to some extent.
[0007]
The cylindrical body 2 is an injection-molded product of polypropylene resin having a cylindrical shape with an inner diameter of 18 mm, and a tail plug 6 that is also an injection-molded product of polypropylene resin is press-fitted and fixed to the rear part thereof. The tail plug 6 penetrates the center hole 6a toward the ink tank. A movable stopper 7 made of a hydrogel material is disposed at a position in contact with the ink interface inside the cylinder 2. The movable stopper 7 swells by absorbing the content ink and contacts the inner wall of the cylinder 2 to form a liquid-tight state.
[0008]
The movable stopper 7 is about 0.1 mm smaller in diameter than the inner diameter of the cylinder 2 before coming into contact with the ink interface, and is arranged at the ink interface with an appropriate pressure contact force due to swelling. It moves smoothly following the movement of the ink interface. In addition, as a hydrogel material, there exists a water-insoluble polymer by causing a crosslinking reaction by irradiating a polyvinyl alcohol aqueous solution, which is a water-soluble polymer, with γ rays. In addition, as a hydrogel material that is a water-insoluble polymer obtained by copolymerizing a hydrophilic monomer and a hydrophobic macromonomer, a vinyl ester and a copolymer of a styrene copolymer or alkyl methacrylate having a reactive double bond There is a modified polyvinyl alcohol obtained by saponification.
[0009]
【The invention's effect】
As described above, the present invention contacts the inner wall surface of the container and the ink interface without leaving air bubbles in the portion of the liquid storage container where the ink is stored, and forms the storage container in a liquid-tight state. Since the internal pressure of the container can be kept in equilibrium with the atmospheric pressure, it is possible to make it difficult for the content liquid to be discharged and blow out easily with a simple structure. It is possible to suppress leakage as much as possible.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ink 2 Cylinder 3 Pen tip holder 4 Through-hole 5 Pen tip 6 Tail plug 6a Center hole 7 Moving plug

Claims (2)

  It has a means for discharging the liquid stored in the liquid storage container, and is disposed at the interface of the content liquid. With the volume of the content liquid consumed as the content liquid is consumed, along with the movement of the interface of the content liquid In the liquid ejection tool including the movable stopper that moves, the movable stopper is a hydrogel material that absorbs and swells the liquid to increase the apparent volume. By increasing the apparent volume, the movable stopper and the liquid storage container A liquid discharger characterized in that a gap between the inner wall and the inner wall is filled with each other. The hydrogel material is a water-insoluble polymer water-containing material obtained by crosslinking a water-soluble polymer, or a water-insoluble polymer water-containing material obtained by copolymerizing a hydrophobic macromonomer and a hydrophilic monomer. The liquid ejection tool according to claim 1 .

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