JP2001180179A - Liquid discharging implement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid storage container capable of scarcely bringing about discharging fault or ejection of a content liquid with a simple structure and suppressing external leakage of the liquid from a moving plug as much as possible. SOLUTION: The moving plug is constituted of a hydrogel material making liquidtight contact with the inner wall of the container by bulging by the content liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marking pen and a felt-tip pen for accommodating an ink composition, a cosmetic composition and the like.
A writing instrument such as a ballpoint pen or an applicator, having means for discharging liquid contained therein, disposed at the interface of the content liquid, and the volume and content of the content liquid consumed as the content liquid is consumed The present invention relates to a liquid ejection device including a moving stopper that moves with movement of a liquid interface.

[0002]

2. Description of the Related Art Conventionally, there has been provided a liquid discharging means such as a pen tip such as a writing instrument or an applicator, and ink is supplied to the pen tip or the like so that writing, coating and drawing can be freely performed in an ink tank. 2. Description of the Related Art There is known an arrangement in which a moving stopper is disposed at an interface between inks stored in a state so as to cover the ink so that the ink does not leak. This moving stopper follows the movement of the ink interface as the ink volume decreases due to ink consumption, so the actual volume inside the ink tank changes, and the pressure inside the container gradually becomes negative, and ink is supplied to the discharge means. And the occurrence of ejection failure can be suppressed. For example, Japanese Patent Application Laid-Open No. Sho 62-199192 discloses that the moving stopper is made of silicone rubber which is an elastic body, the outer diameter of the moving stopper is slightly larger than the inner diameter of the container, and the ink and the air are contacted by pressing. What compartments are disclosed.

[0003]

In the case where the elastic member made of silicone rubber is used as a movable stopper as described above, the movable stopper is disposed in a press-fit state in the container, so that air is left in the container during assembly. It was highly likely that Since the volume of the air left in this manner changes greatly due to a temperature change, the air left in the container also expands in volume due to a rise in temperature, and the moving stopper moves in the direction in which the volume in the container increases, and finally the container It abuts on the end and cannot move. Further, when the volume expansion accompanying the temperature rise continues, the moving stopper is elastically deformed by the pressure due to the expansion to form an air passage. At this time, if the ink comes out of the container together with the air, the ink sometimes leaks.

[0004]

That is, the present invention has means for discharging liquid contained therein, which is disposed at the interface of the content liquid, and the content consumed as the content liquid is consumed. In a liquid ejector provided with a moving stopper that moves with the volume of the liquid and the movement of the interface of the content liquid, the moving stopper absorbs and swells the liquid to increase the apparent volume and increase the apparent volume. The gist of the present invention is that the gap between the moving stopper and the inner wall of the liquid storage container is filled with the liquid stopper so that both are in contact with each other.

[0005]

The moving stopper comes in contact with the liquid surface, absorbs the liquid, and swells, and forms a liquid-tight state by contacting the inner wall of the container without leaving a space between the moving stopper and the liquid surface. A press contact state can be formed.

Hereinafter, an example of the liquid ejection device of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a so-called raw ink type writing instrument in which the ink 1 is stored in a free state, in which a liquid storage container is integrally incorporated in a shaft. A pen tip holder 3 is joined to a tip end of a cylinder 2 mainly constituting an ink tank part, and a pen tip 5 made of a fiber bundle is attached to a through hole 4 of the pen tip holder 3 by press-fitting. The penetrating hole 4 in which the pen tip 5 is attached has a small diameter portion at the rear end of the ink tank, and the rear portion of the pen core is tightened by press-fitting to reduce the fiber density of the tightened portion. Is higher than the portion, so that the ink discharge can be controlled to some extent in this portion.

The cylindrical body 2 is an injection molded product of a polypropylene resin having a cylindrical shape with an inner diameter of 18 mm, and a tail plug 6, which is also an injection molded product of a polypropylene resin, is press-fitted and fixed to a rear portion thereof. The tail plug 6 penetrates the center hole 6a toward the inside of the ink tank. A moving stopper 7 made of a hydrogel material is disposed at a position in contact with the ink interface inside the cylinder 2. The moving stopper 7 absorbs the ink and swells, and comes into contact with the inner wall of the cylinder 2 to form a liquid-tight state.

Before the moving stopper 7 comes into contact with the ink interface,
It is smaller than the inner diameter of the cylindrical body 2 by about 0.1 mm, and is arranged at the ink interface with an appropriate pressing force due to swelling, and moves smoothly following the movement of the ink interface accompanying ink consumption. It is. As the hydrogel material, there is a water-insoluble polymer which is subjected to a crosslinking reaction by irradiating an aqueous solution of polyvinyl alcohol, which is a water-soluble polymer, with gamma rays. Further, as a hydrogel material which is a water-insoluble polymer obtained by copolymerizing a hydrophilic monomer and a hydrophobic macromonomer, a copolymer of a vinyl ester, a styrene copolymer having a reactive double bond or an alkyl methacrylate is used. There is a modified polyvinyl alcohol obtained by saponifying

[0009]

As described above, according to the present invention, the liquid storage container is formed in a liquid-tight manner by contacting the inner wall surface and the ink interface without leaving air bubbles in the portion where the ink is stored. Because the volume of ink consumed has been moved and the internal pressure of the container can be kept at the same level as the atmospheric pressure, it is possible to make it difficult for defective ejection and ejection of the content liquid to occur with a simple structure. Leakage of the liquid from the moving stopper to the outside can be suppressed 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 Cylindrical body 3 Pen tip holder 4 Through hole 5 Pen tip 6 Tail plug 6a Center hole 7 Moving tap

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuo Kato 4-1-8 Yoshimachi, Soka-shi, Saitama Prefecture Pentel Co., Ltd. Grass Processing Plant (72) Inventor Masashi Hiroki 4-1 Yoshimachi, Soka-shi, Saitama Prefecture 8 Pentel Corporation Grass Processing Plant (72) Inventor Masayuki Kawasaki 4-1-8 Yoshimachi, Soka City, Saitama Prefecture Pentel Corporation Grass Processing Plant (72) Inventor Masamitsu Nagahama 4-1 Yoshimachi, Soka City, Saitama Prefecture 8 Pentel Co., Ltd. Grass processing plant F-term (reference) 2C350 GA03 GA04 KC00 NA10 NC04 NC23

Claims (4)

[Claims] A discharge means for discharging the liquid contained therein;
A liquid ejector provided with a moving stopper that is disposed at an interface of the content liquid and that moves with the volume of the content liquid consumed as the content liquid is consumed, and the movement of the interface of the content liquid; Absorbs the liquid and swells to increase the apparent volume, and the increase in the apparent volume fills the gap between the movable stopper and the inner wall of the liquid storage container, and both are brought into contact. Liquid ejector. 2. The moving plug according to claim 1, wherein the apparent volume increase rate is 150.
2. The liquid ejection device according to claim 1, wherein the amount is from about 300% to about 300%. 3. The liquid ejection device according to claim 1, wherein the moving stopper is a hydrogel material. 4. The hydrogel material according to claim 1, wherein the hydrogel material is a water-insoluble polymer hydrate containing a water-soluble polymer cross-linked and / or a water-insoluble polymer hydrate containing a hydrophobic macromonomer and a hydrophilic monomer. The liquid discharging device of the liquid discharging device according to claim 3, wherein: