Disappearance-style notebook

Abstract

To provide an extendable / retractable writing instrument comprising a follower (tracking body), in which the follower enables a residual amount of ink to be visually recognized, and which can suppress ink ejection due to pressure fluctuation while preventing direct current of ink by capillary force.SOLUTION: In a state that a pen tip 60 is attached to a front part of a refill 20 serving as an ink tank in a barrel 10 and that there are arranged an ink 25 accommodated in the refill 20, and a follower 30 at a rear part of the ink 25, an extendable / retractable writing instrument A is arranged, between a rear part of the follower 30 and a rear end side of the refill 20, with: a substitution liquid 40 insoluble or poorly soluble with respect to the ink 25 and the follower 30; and at least one capillary porous body 50 to which capillary force is applied through impregnation of the substitution liquid 40. Furthermore, the pen tip 60 is extendable from / retractable into the barrel 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a writing instrument equipped with a follower that allows the remaining ink level to be visually confirmed, and to a retractable writing instrument in which the pen tip can be retracted from the barrel, preventing direct flow of ink through capillary force while suppressing ink spray due to pressure fluctuations. [Background technology]

[0002] Generally, writing instruments have excellent display properties and make it easy to see the remaining ink level. They consist of a writing instrument body such as an ink container, ink, and a follower (follower) filled at the rear end of the ink. Many of them have a structure that includes a ballpoint pen tip or a minutely movable valve system to prevent direct flow of ink.

[0003] Writing instruments that use ballpoint pen tips like the former to prevent direct flow of ink often have ink designed to prevent direct flow of ink from the tip even when the tip is kept facing downwards and in contact with a non-writing surface during storage, etc., which narrows the range of ink design options. In addition, the valve-type writing implements used in the latter case have a problem in that they have a rattle when writing, making for a poor writing feel, and the ink flow rate changes depending on how long the valve is open, which can lead to differences in the density of lines drawn when writing letters and straight lines.

[0004] Known examples of retractable (knock-type) writing instruments that attempt to solve these problems include a retractable writing instrument equipped with a suppression mechanism at the rear of the main body of the writing instrument that suppresses direct current of ink filled in an ink tank, a pen tip attached to the front of the main body of the writing instrument, and a flexible pressure reducing member at the rear of the main body of the writing instrument that reduces the pressure inside the ink tank when the writing instrument is knocked (see, for example, Patent Document 1).

[0005] However, the writing instrument of Patent Document 1 mentioned above has an excellent function of preventing the direct current phenomenon of ink and controlling the internal pressure by using a capillary porous body (head valve) which acts as a flexible pressure reducing member, but a space is formed between the rear of the follower and the rear end of the ink tank, and the capillary porous body is arranged in this space. If the internal sealing is not sufficient, the ink may evaporate, and in the case of a retractable writing instrument which does not seal the nib, it may not be able to withstand long-term storage. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2014-131870 A (claims, Figures 13 to 17, etc.) Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above-mentioned conventional problems and aims to solve them, and aims to provide a retractable writing instrument equipped with a follower that allows the remaining ink level to be visually checked, which does not affect use even when the barrel and other parts are not sufficiently sealed, a so-called knock-type writing instrument. [Means for solving the problem]

[0008] As a result of extensive research into solving the above-mentioned conventional problems, the inventors discovered that a retractable writing instrument meeting the above-mentioned objectives could be obtained by configuring the pen tip to be attached to the front of an ink tank, with ink contained in the ink tank and a follower arranged at the rear of the ink, and by arranging a replacement liquid with specific physical properties and at least one capillary porous body impregnated with the replacement liquid with specific physical properties and imparted with capillary force between the rear of the follower and the rear end of the ink tank, and thus completed the present invention.

[0009] In other words, the retractable writing instrument of the present invention is characterized in that a pen tip is attached to the front of an ink tank, ink is contained in the ink tank, a follower is arranged behind the ink, and between the rear of the follower and the rear end of the ink tank, a replacement liquid that is insoluble or poorly soluble in the ink and the follower, and at least one capillary porous body that has been impregnated with the replacement liquid to impart capillary force, are arranged, and the pen tip can be retracted from the barrel. The displacement liquid is preferably at least one selected from mineral oil, petroleum oil, hydrocarbon oil, paraffin wax, silicone oil, fluorine-based oil, and mixtures thereof. The follower preferably comprises a follower rod or a follower float. The displacement liquid is preferably held by the capillary force of the capillary porous body and supplied to the displacement liquid at the rear of the follower via a relay wick. [Effects of the Invention]

[0010] According to the present invention, a retractable writing instrument is provided that has a follower that allows the remaining ink level to be visually confirmed, and that has a pen tip that is less likely to volatilize. [Brief explanation of the drawings]

[0011] [Figure 1] 1A and 1B show an example of an embodiment of a retractable writing instrument of the present invention, in which FIG. 1A is a plan view and FIG. 1B is a central longitudinal cross-sectional view. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, please note that the technical scope of the present invention is not limited to the respective embodiments described in detail below, but extends to the inventions set forth in the claims and their equivalents. Furthermore, the present invention can be implemented based on the contents disclosed in this specification and common general technical knowledge in the relevant field (including design matters and obvious matters). FIG. 1 shows an example of an embodiment of a retractable writing instrument of the present invention, where (a) is a plan view and (b) is a central vertical cross-sectional view.

[0013] As shown in Figures 1(a) and (b), the retractable writing instrument A of this embodiment comprises at least a barrel 10, a refill 20 serving as an ink tank housed within the barrel 10, ink 25, a follower 30, an oily replacement liquid 40, a capillary porous body 50, a nib (writing part: pen core) 60, and a clip member 70 that provides a retraction mechanism (knock mechanism), and is characterized in that the nib 60 is retractable from the barrel 10. As shown in Figure 1(a), in this specification, the tip of the writing instrument, i.e., the side of the pen tip 60, is defined as the "front" side of the writing instrument, and the side opposite the pen tip 60 of the writing instrument along the axial direction (longitudinal direction) of the writing instrument is defined as the "rear" side of the writing instrument.

[0014] The barrel 10 is made up of a front barrel 11 and a rear barrel 12. The refill 20 is constructed by attaching a pen tip 60 to the front end of an ink reservoir 21 that contains ink 25. The refill 20 is composed of a cylindrical front barrel 21 and a cylindrical rear barrel 22, with the front barrel 21 fitted into the rear barrel 22. The front barrel 21 and rear barrel 22 that make up the refill 20, which serves as an ink tank, are formed using, for example, a thermoplastic resin, a thermosetting resin, or the like, and are molded entirely or partially to be opaque or transparent (and translucent), although either may be adopted from the standpoint of appearance and practicality. In this embodiment, the ink storage locations of the front barrel 21 and rear barrel 22 are made visible to make it easier to read the remaining amount.

[0015] This refill 20 directly contains ink 25, and a follower 30 is placed in contact with the rear side of the ink 25. Between the rear of the follower 30 and the rear end side of the refill 20, an oily replacement liquid 40 consisting of a liquid that is insoluble or poorly soluble in the ink 25 and follower 30 is placed, and at least one capillary porous body 50 that has been impregnated with the oily replacement liquid 40 to impart capillary force is placed, and a pen tip 60 is attached to the front of the refill 20 via a tip shaft 65.

[0016] Front barrel 65 is made of a cylindrical body and has a flange portion 66 on its outer periphery, and is attached between front barrel 21 and rear barrel 22 on the front opening side of refill 20, and is fixed by fitting via a cylindrical interposing member 67, with nib 60 fixed inside front barrel 65. Refill 20, front barrel 65, and interposing member 67 are molded from a resin such as polypropylene (PP).

[0017] The ink 25 contained in the refill 20 is not particularly limited as long as it is a liquid ink such as a water-based ink or an oil-based ink. Depending on the application (water-based ink, oil-based ink, etc.), the ink composition used may include pigments (including resin pigments), colorants such as dyes, main solvents, resins, thickeners, and optional components contained in inks for writing instruments. Optional components may include, for example, anti-rust agents, anti-fungal agents, surfactants, lubricants, and humectants that are compatible with the ink and do not adversely affect the ink. Additionally, non-volatile solvents that are compatible with the main solvent and do not adversely affect the product characteristics may also be included as drying suppression additives. In this embodiment, the ink 25 is composed of a low-viscosity aqueous ink composition.

[0018] The follower 30 has no fluidity, is insoluble in the ink 25 and the oily replacement liquid 40, and is inserted near the boundary between the ink 25 and the oily replacement liquid 40, and is made of an oily gel-like material. The follower 30 made of this oily gel-like material can be made of at least one selected from mineral oil, petroleum oil, hydrocarbon oil, paraffin wax, silicone oil, and fluorine-based oil, as well as a thickener or gelling agent. Examples of thickeners and gelling agents include metal soaps, bentonites, fatty acid amides, hydrogenated castor oil, metal particles including titanium oxide, silica, and alumina, celluloses, and elastomers. Furthermore, a surfactant such as a silicone surfactant may be appropriately added.

[0019] This follower 30 is inserted near the boundary between the ink 25 and the oily replacement liquid 40 in the refill 20, in this embodiment, into both the ink 25 and the oily replacement liquid 40, and is able to follow well as the ink 25 is consumed.

[0020] The oily replacement liquid 40 is a liquid that is insoluble or poorly soluble in the ink 25 and follower 30, is composed of a non-volatile material, and follows along with the follower 30 as the ink is consumed during writing, and examples thereof include at least one type selected from mineral oil, petroleum-based oil, hydrocarbon-based oil, paraffin wax, silicone oil, and fluorine-based oil (each alone or a mixture of two or more of these, the same applies below). Examples of mineral oils include polybutene and process oil, and commercially available products include Nissan Polybutene N (manufactured by NOF Corporation), LV-7, LV-10, LV-25, LX-50, LV-100, HV-15, HV-35, HV-50, HV-100, HV-300, HV-1900, and HV-3000 (all manufactured by Nippon Petrochemical Co., Ltd.), 35R (manufactured by Idemitsu Kosan Co., Ltd.), Diana Process Oil MC-W90, PS-430, and PS-90 (all manufactured by Idemitsu Kosan Co., Ltd.), and refined mineral oil Dyna Fresia W380 (manufactured by Idemitsu Kosan Co., Ltd.). Examples of petroleum oils include polybutene. Examples of hydrocarbon oils include liquid paraffin and heavy isoparaffin. Examples of silicone oils include dimethylpolysiloxane, methylphenylpolysiloxane, and dimethylcyclopolysiloxane. Fluorine-based oils include substances that are liquid or grease-like at room temperature, in which some or all of the hydrogen atoms in a polyalkyl ether compound have been substituted with fluorine, and may contain halogens such as chlorine and bromine, phosphorus, sulfur, nitrogen, etc. Examples include fluoropolyethers such as perfluoropolyethers (perfluoroalkyl polyethers, etc.), and hydrofluoroethers, and products such as the Demnum series manufactured by Daikin Industries, Ltd. are commercially available. As the oily displacement liquid 40, process oil or silicone oil is preferable from the viewpoints of safety, volatility, etc. Furthermore, even if the diameter of the refill 20 that serves as the ink tank is increased, it is desirable to set the difference in specific gravity between the follower 30 and the oily replacement liquid 40 [(specific gravity of follower 30) - (specific gravity of replacement liquid 40)] to 0 to 0.2 in order to further improve tracking, ensure stable ink supply, and efficiently follow as ink is consumed. In this embodiment, the follower 30 is made of a gelled mineral oil, and the oily replacement liquid 40 is made of protease oil.

[0021] The capillary porous body 50 is housed in the rear barrel 22 of the refill 20, and may be made of any material as long as it is a porous body to which capillary force has been imparted, including, for example, a fiber bundle made of one or a combination of two or more types of natural fibers, animal fibers, resin fibers, etc., a sintered body, a fiber core obtained by processing a fiber bundle such as felt or by resin-processing such a fiber bundle, and a foam material such as sponge. The capillary porous body 50 is impregnated with the oily displacement liquid 40 and is connected to the oily displacement liquid 40 at the rear of the ink 25 via a relay wick 55, which is a capillary porous body to which capillary force has been imparted and has the same properties as the capillary porous body 50. Like the porous capillary body 50, the relay core 55 is made of a porous material selected from among fiber bundles, sintered bodies, fiber cores made by processing fiber bundles such as felt or resin-processing these fiber bundles, and foam materials such as sponge, and the connecting portion of the porous capillary body 50 has a hemispherical tapered portion 56 to ensure a secure connection. The relay core 55 is fixed by fitting into the fitting portion of the rear end of the front barrel 21 and the rear barrel 22 of the refill 20. As a result, the oily replacement liquid 40 at the rear of the ink 25 is held by the capillary force of the porous capillary body 50, via the relay core 55.

[0022] The pen tip 60 is a rod-shaped member, the tip of which serves as the writing part 61. Examples of materials that can be used include a porous body having air holes, such as a sponge, a sintered body, a fiber bundle, a foam, a spongy body, a felt body, and a porous body. Porous materials include natural fibers, animal hair fibers, polyacetal resins, polyethylene resins, acrylic resins, polyester resins, polyamide resins, polyurethane resins, polyolefin resins, polyvinyl resins, polycarbonate resins, polyether resins, and polyphenylene resins. In this embodiment, the pen tip 60 is made of a sintered body obtained by sintering various types of plastic powder.

[0023] The clip member 70 is equipped with a retractable mechanism (knock mechanism), and as shown in Figure 1(b), comprises a first spring 71 arranged in front of the refill 20, a slider 72 arranged behind the refill 20 and against which the rear end of the refill 20 abuts, a clip 75 connected to the slider 72, a metal member 80 attached to the clip 75, a second spring 73 arranged within the slider 72, and a crown 90 fitted to the rear end of the barrel 10. The first spring 71 biases the refill 20 rearward. The second spring 73 biases the clip 90 so that the front end of the clip 80 approaches the barrel 10. In Figures 1(a) and (b), the pen tip 60 is recessed in the front end of the barrel 10.

[0024] When the clip member 70, which has this protruding / retracting mechanism (knocking mechanism), is operated by moving the clip 75 forward from the state shown in Figure 1(b), the clip 75, slider 72, and refill 20 move forward together against the biasing force of the first spring 71. At this time, the pen tip 60 at the tip of the refill 20 protrudes from the front end of the barrel 10, and the writing instrument A enters a writing state. On the other hand, when the rear end of the clip 75 is pushed toward the barrel 10, the front end of the clip 75 moves away from the barrel 10 against the biasing force of the second spring 73. When this operation is performed, the clip 75, slider 72, and refill 20 move backward together due to the biasing force of the first spring 71. At this time, the nib 60 at the tip of the refill 20 sinks into the front end of the barrel 10, and the writing instrument A enters a non-writing state.

[0025] In writing instrument A configured in this manner, nib 60 is fixed to the tip of refill 20, which serves as an ink tank, via tip barrel 65, refill 20 is filled with ink 25 and follower 30, and the top of follower 30 is filled with oily replacement liquid 40, which is held by capillary porous body 50 and supplied via relay core 55. When writing with writing part 61 of nib 60, as ink 25 is consumed through writing, follower 30 moves toward nib 60 until the end of the stroke, and the space above follower 30 is replaced with oily replacement liquid 40 rather than air. This oily substitution liquid 40 does not expand easily, so it is possible to prevent ink from spurting out until the end of the stroke. Furthermore, even in a retractable writing instrument that does not seal the nib, the tip side of the ink 25 in the refill 20 is held by the nib 60, and the rear end side is held by the oily substitution liquid 40, which is in turn held by the capillary porous body 50, so that evaporation of the ink is suppressed, resulting in a retractable writing instrument with a nib that is less likely to evaporate, and which can withstand long-term storage.

[0026] As described above, the oily replacement liquid 40 is held in place by the capillary force of the capillary porous body 50, which prevents direct flow of ink and prevents ink from spraying out and flowing in a straight line. This mechanism is characterized by reduced flow resistance because the ink 25 passes only through the refill 20 and the pen tip 60, and is configured to allow for a wider range of ink design tolerances (ink type, low viscosity, etc.). In the retractable writing implement A shown in Figures 1(a) and (b), when writing, the ink is discharged, allowing writing to continue as normal. On the other hand, once writing is finished, the capillary force of the capillary porous body 50 is able to support the weight of the ink 25. This cycle controls the ink flow pressure applied to the pen tip to a constant pressure, resulting in a retractable writing implement that prevents the direct current and backflow phenomena of ink. Furthermore, in this retractable writing instrument, there are no or very few air bubbles inside the refill 20, so the internal pressure does not change when heated, etc., and ink is prevented from gushing out from the pen tip 60 even during storage. The amount of ink 25 used (filled amount) and the amount of oil-based replacement liquid 40 used (filled amount) vary depending on the type of ink and its viscosity, the capillary force of the capillary porous body, the size of the ink tank, etc., and an appropriate amount is used (filled) to achieve the above-mentioned effects.

[0027] The retractable writing instrument of the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the technical concept of the present invention. For example, in the retractable writing instruments of the above embodiments, the follower 30 is made of an oily gel-like material, but it may also be made of a follower made of a follower rod, a follower float, or at least one type of oil selected from mineral oil, petroleum oil, hydrocarbon oil, paraffin wax, silicone oil, and fluorine-based oil. The follower rod also has no fluidity, is insoluble in the ink 25 and the oily replacement liquid 40, and is inserted near the boundary between the ink 25 and the oily replacement liquid 40. For example, the follower rod has an overall cylindrical shape and is integrally composed of a front pillar that faces the pen tip, a recessed pillar that is recessed in the center, and a rear pillar.

[0028] The material of the follower rod can be, for example, polypropylene, ethylene-vinyl alcohol copolymer resin, polyacrylonitrile, nylon, polyethylene terephthalate, polycarbonate, polystyrene, polyvinylidene chloride, polyvinyl chloride, various rubbers, etc. Preferably, a solid body made of these materials, or a hollow structure or porous body thereof can be used. The shape of this follower consisting of a follower rod can be cylindrical, rectangular, triangular, or similar to the cross section of the ink tank 10, and its overall length (height) varies depending on the type of writing instrument, the inner diameter of the refill 20, the liquid properties of the ink 25, etc., and an appropriate length is set. Alternatively, the follower may be made of a follower float. Examples of follower floats include those made of resin such as polypropylene (PP), which are cylindrical bodies with a predetermined diameter and length, with the lengths of the front column, recessed column, and rear column divided into three equal parts, and the recessed part recessed 1 mm deep inside.

[0029] In the above embodiment, an oil-based substitute liquid is used as the substitute liquid 40, but a water-based substitute liquid may also be used depending on the type of ink used. Examples of aqueous replacement liquids include at least one selected from water (purified water, pure water, ultrapure water, distilled water, etc.), hydrophilic alcohols, and hydrophilic glycols, and aqueous solutions of the above hydrophilic alcohols and hydrophilic glycols can also be used. Examples of hydrophilic alcohols include monohydric alcohols such as methanol, ethanol, 2-propanol, and butyl alcohol, and polyhydric alcohols such as glycerin, diglycerin, triglycerin, polyglycerin, and trimethylolpropane. The hydrophilic glycols include at least one of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, and the like. Preferably, the aqueous replacement liquid has a low vapor pressure from the standpoints of volatility and safety, and glycerin or an aqueous solution thereof is preferably used.

[0030] Furthermore, in each of the above embodiments, the capillary porous body 50 and the relay wick 55 are configured as different members (two components), but they may be configured as one integral member, with the replacement liquid being held by the capillary force of one capillary porous body and supplied to the oil-based or aqueous replacement liquid at the rear of the follower 30. In this case, the capillary force may be increased by making the portion that will become the relay wick a high-density portion. Furthermore, the capillary porous body 50 may be divided into two members, with the replacement liquid being held by the capillary force of the two capillary porous bodies via the relay wick 55.

[0031] Furthermore, although the above embodiments have been described with reference to ink for writing instruments (water-based ink, oil-based ink), the pen tip may be used in combination with a liquid such as liquid cosmetics, liquid medicine, coating liquid, or correction fluid, and may be used as a suitable coating member. The writing instrument of the present invention can also be used as a marking pen such as a felt-tip pen, underline pen, or paint marker, or as a writing instrument for use on writing boards such as whiteboards and blackboards. [Example]

[0032] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0033] Example 1 The following configuration and retractable writing implement conforming to Figures 1(a) and (b) were used, along with the following ink. The dimensions of the pen tip, follower, replacement liquid, capillary porous body, relay core, etc. were as follows:

[0034] (30 followers) Mineral oil gel, specific gravity: 0.95 (40% oil-based replacement fluid) Process oil, specific gravity: 0.85 (Configuration of porous body 50) Polyester fiber bundle, diameter φ8mm, length 30mm (Configuration of relay core 55) Polyester fiber bundle core, maximum diameter φ6mm, minimum (reduced diameter) diameter φ3mm, length 10mm (Pen tip 60 configuration) PE sintered core, 60% porosity

[0035] (Ink composition) The ink used had the following composition (total 100% by mass): Moisturizer: Trimethylglycine (glycine betaine) 7.5% by mass Pentaerythritol 4.5% by mass Colorant: NKW-4805 Yellow (manufactured by Nippon Fluorescent Co., Ltd.) 40.0% by mass Preservative: BioAce (Keikai Kasei Co., Ltd.) 0.3% by mass pH adjuster: Triethanolamine 1.0% by mass Fluorine-based surfactant: Surflon 8111N (AGC Seimi Chemical Co., Ltd.) 0.2% by mass Water-soluble organic solvent: ethylene glycol 3.0% by mass Water (solvent): ion-exchanged water 43.5% by mass

[0036] In the retractable writing instrument A of Example 1 configured as described above, the pen tip 60 is attached to the tip of the refill 20, which serves as an ink tank, via the tip barrel 65. The refill 20 is filled with a follower 30 consisting of an aqueous ink composition 25 and an oily gel-like substance. The upper part of the follower 30 is filled with a replacement liquid 40. The replacement liquid 40 is held by a capillary porous body 50 and supplied via a relay core 55. The replacement liquid 40 and the ink (aqueous ink composition) 25 are blocked by the follower 30 so that they do not mix. As a result, the follower 30 moves as ink is consumed through writing, and because the space above the follower 30 is filled not with air but with replacement liquid 40, which does not expand easily, it has been confirmed that ink spurting and direct currents can be prevented until the end of the stroke. With this retractable writing instrument A, the ink is discharged during writing, allowing normal writing. On the other hand, once writing is finished, the weight of the ink 25 can be supported by the capillary force of the porous capillary body 50. This cycle controls the ink flow pressure on the pen tip to a constant pressure, preventing ink direct current and backflow, as well as ink spurting. Even in a retractable writing instrument without a sealed pen tip, the leading end of the ink 25 in the refill 20 is held by the pen tip 60, and the trailing end by the oily replacement liquid 40, which is held by the porous capillary body 50. This prevents ink evaporation, making the pen tip less likely to evaporate, and confirming that the retractable writing instrument can withstand long-term storage. Furthermore, when writing on paper using the writing instrument of Example 1, it was confirmed that ink could be reliably supplied to the pen tip 60, the flow rate was stable, and writing could be done without smearing. Furthermore, the highly visible refill 20 made it easy to read the remaining ink level, allowing for reliable writing, and that a retractable writing instrument with many advantages could be obtained, such as the ease of designing an ultra-thin shaft. In this retractable writing instrument A, the refill 20 is stably filled with the aqueous ink composition 25, follower 30, replacement liquid 40, capillary porous body 50, and relay core 55, and the effects of the present invention can be achieved without impairing the above-mentioned tracking function or the function of preventing ink spray and direct current until the end of the stroke even when subjected to impacts such as retraction and retraction operations. [Industrial Applicability]

[0037] The retractable writing implement of the present invention can be used as a so-called marking pen such as a felt-tip pen, an underline pen, or a paint marker, or as a writing implement for writing boards such as a whiteboard or a blackboard. [Explanation of symbols]

[0038] A writing instrument 10 shaft cylinder 20 Refill (ink tank) 21 Front axle 22 rear axle 30 followers 40 Displacement liquid 50 Capillary porous body 60 nibs

Claims

[Claim 1] A retractable writing instrument characterized in that a pen tip is attached to the front of an ink tank, ink is contained in the ink tank, and a follower is arranged behind the ink, and between the rear of the follower and the rear end of the ink tank, a replacement liquid that is insoluble or poorly soluble in the ink and the follower, and at least one porous capillary body that has been impregnated with the replacement liquid to impart capillary force, are arranged, and the replacement liquid is arranged between the follower and the porous capillary body, and the pen tip is retractable from the barrel.

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