Relay core and liquid applicator including the relay core

Abstract

To provide a relay core capable of suppressing or preventing an ink from being abnormally discharged to safely feed the ink to an application part such as a pen point, and a liquid applicator including the relay core.SOLUTION: A relay core 1 consists of a long bar-shaped relay core main body 2. The relay core main body 2 is constituted so as to have a tip connection part 2a for connecting a pen point and the like at a tip side thereof and have a small diameter part 2b formed so as to have a smaller diameter than an outer diameter of the relay core main body 2 at a rear end side of the tip connection part 2a. A cross-section of the relay core main body 2 is constituted so as to have an outer peripheral part constituting a peripheral wall of the relay core main body 2 and one or a plurality of ribs extending toward the inside in a radial direction from the outer peripheral part, and the ribs are formed so as to extend from a tip of the relay core main body 2 up to a rear end thereof along an axial direction to thereby form spaces for ink channels.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a relay core and a liquid applicator including the relay core. More specifically, the present invention relates to an ink relay core that can prevent or suppress with a very high probability abnormal ejection of ink, particularly ink containing large-diameter particles or ink having a high viscosity, and can stably supply ink to an application part such as a nib or a pen tip, and a liquid applicator including the ink relay core and usable for applications such as writing instruments and cosmetic tools.

Background Art

[0002] Conventionally, a liquid applicator having an ink storage part for storing ink built in a shaft cylinder and having a pen tip as an application part or a writing part at the tip of the shaft cylinder has been used for applications such as writing instruments such as marking pens, signature pens, and fountain pens, and cosmetic tools such as eyeliners. In such a liquid applicator, in order to supply ink from the ink storage part to the pen tip, a relay core is disposed so as to be connected between the ink storage part and the pen tip.

[0003] Regarding the relay core, its material and shape are appropriately selected according to the application of the liquid applicator, the type of ink (particularly the viscosity of the ink and the particle diameter of the pigment contained in the ink), the structure of the shaft cylinder, and the like. Generally, as the relay core, there are those formed by binding a synthetic fiber bundle made of acrylic fiber, polyester fiber, nylon fiber, etc. with an adhesive resin such as urethane resin, and those made of a plastic molded body. Examples of such relay cores are disclosed in Patent Documents 1 and 2.

[0004] In the specification of Chinese Utility Model No. 207544588 (Patent Document 1), a cosmetic pen ink guiding core that can smoothly supply a liquid containing a liquid or a powder substance has been proposed.

[0005] This makeup brush ink guiding core is provided with an ink guiding groove on its outer peripheral wall surface, which extends from one axial end surface of the makeup brush ink guiding core to the other axial end surface.

[0006] Furthermore, in International Publication No. 2020 / 116604 (Patent Document 2), a relay core has been proposed that can supply a liquid containing particles to a pen tip for application in a certain amount without clogging within the relay core while the relay core has capillary force and liquid holding force.

[0007] This relay core is a relay core for supplying a liquid containing particles to the pen tip, The relay core has a flow path extending along the axial direction, The longitudinal section of the flow path is substantially linear from the rear end portion to the front end portion of the relay core, The cross section of the flow path has a shape including a portion having a shape capable of holding the liquid by capillary force and a portion having a shape through which the particles can pass.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Disclosure of the Invention

Problems to be Solved by the Invention

[0009] In a conventional relay core composed of a fiber bundle, when the ink used contains large-diameter particles such as lame pigments or pearl pigments, when supplying ink to the pen tip through the ink flow path in the relay core, the particles clog in the intertwined fiber bundle, and there is a problem that the ink cannot be stably supplied to the pen tip.

[0010] In the makeup pen ink guiding core disclosed in Patent Document 1, the ink guiding groove is formed by forming irregularities on the outer peripheral portion. Therefore, since the outer peripheral portion has irregularities, there are problems such as difficulty in accurately adjusting the outer diameter and difficulty in measuring the outer diameter. Furthermore, when processing into a predetermined shape, there is also a problem that delicate processing is difficult.

[0011] In the relay core disclosed in Patent Document 2, in the cross section of the central portion of the relay core, all flow paths are surrounded by the outer contour portion of the relay core and are arranged inside the outer contour portion. Therefore, if it is such a thing, the manufacture of the relay core is easy and it is possible to accurately adjust the outer diameter of the relay core. However, when this relay core is used, the internal pressure of the ink storage portion may increase. In that case, ink ejection abnormalities such as ink leaking from the tip together with the expanded air are likely to occur.

[0012] In view of such a situation, the present invention aims to provide an ink relay core that does not cause ink ejection abnormalities, particularly for inks containing large-diameter particles or inks having a high viscosity, or suppresses them with an extremely high probability, and stably supplies ink to the application portion such as the nib or pen tip, and a liquid applicator including this ink relay core.

Means for Solving the Problems

[0013] That is, the invention according to claim 1 of the present invention is a relay core composed of a long rod-shaped relay core body, wherein the relay core body has a tip connection portion for connecting the nib or pen tip on the tip side thereof, and has a small-diameter portion formed to have a smaller diameter than the outer diameter of the relay core body on the rear end side of the tip connection portion, the cross section of the relay core body is configured to have an outer peripheral portion constituting the peripheral wall of the relay core main body and one or a plurality of ribs extending radially inward from the outer peripheral portion, By forming the rib to extend along the axial direction from the tip to the rear end of the relay core main body, one or a plurality of spaces of a required size are formed between the peripheral wall and each rib, and between each rib 、 The relay core body is configured such that, at least in the portion where its outer diameter is maximum, in a cross-sectional view, the porosity of the portion within the range extending from the center to the position at 65% of the radius is 20 to 70%, and the porosity of the annular portion formed circumferentially from the position at 65% of the radius to the outer peripheral surface is 0 to 20%. which is a relay core characterized by this.

[0014] The invention according to claim 2 of this invention is in the relay core according to claim 1, the small diameter portion is continuously formed along the axial direction of the relay core main body to the rear end edge which is characterized by this.

[0015] The invention according to claim 3 of this invention is in the relay core according to claim 1 or 2, the space is present radially inside the peripheral wall at least in the small diameter portion, and thus not exposed to the external space in the radial direction which is characterized by this.

[0016] The invention according to claim 4 of this invention is in the relay core according to any one of claims 1 to 3, the thickness from the outer peripheral surface of the small diameter portion to the inner wall constituting the outermost portion in the radial direction of the space is 0.1 mm or more which is characterized by this.

[0017] The invention according to claim 5 of this invention is in the relay core according to any one of claims 1 to 4, the relay core main body is configured such that its tip has a pointed shape that tapers toward the tip side is characterized thereby.

[0018] The invention according to claim 6 of this invention is in the relay core according to any one of claims 1 to 5, wherein the rib is configured such that in a cross-sectional view, the inner ends thereof are connected to each other at the radial center is characterized thereby.

[0019] The invention according to claim 7 of this invention is in the relay core according to any one of claims 1 to 5, wherein the rib is configured such that in a cross-sectional view, the inner ends thereof are not connected to each other is characterized thereby.

[0020] The invention according to claim 8 of this invention is in the relay core according to any one of claims 1 to 7 wherein the relay core main body is provided with a nib or pen tip that can be fitted and detached from the tip connection portion, and is configured such that the length between the tip of the nib or pen tip and the tip of the relay core main body is within the range of 2 to 6 mm is characterized thereby.

[0021] The invention according to claim 9 of this invention is in the relay core according to any one of claims 1 to 8 wherein the relay core main body is adjusted in its bendability such that when a vertical load is applied to the tip portion so that the tip portion is crushed by 2 mm in a state inclined at an angle of 45°, the repulsive force generated is 20 gf or less is characterized thereby.

[0022] ​​The claims of the present invention 10 The invention described in any one of claims 1 to 9 in the relay core described in any of the above, the relay core main body is composed of an elastomer and is characterized by this.

[0023] The claims of the present invention 11 The invention described in any one of claims 1 to 10 in the relay core described in any of the above, the relay core main body is provided with an ink temporary holding member composed of a cylindrical body that surrounds the relay core main body and abuts on the outer peripheral surface, the ink temporary holding member is provided with one or a plurality of through holes formed radially through on its outer peripheral surface, the through holes are configured to communicate with the external space and also communicate with a gap formed between the inner surface of the ink temporary holding member and the small-diameter portion of the relay core main body and are characterized by this.

[0024] The claims of the present invention 12 The invention described in any one of claims 1 to 11 comprises a relay core described in any of the above and is a liquid applicator characterized by this.

Advantages of the Invention

[0025] The relay core (ink relay core) of the present invention is composed of a long rod-shaped relay core body. The relay core body has a tip connection portion at its tip end for connecting a nib or pen tip, and has a small-diameter portion formed to have a smaller diameter than the outer diameter of the relay core body on the rear end side of the tip connection portion. The cross section of the relay core body is configured to have an outer peripheral portion constituting the peripheral wall of the relay core body and one or a plurality of ribs extending radially inward from the outer peripheral portion. By forming the ribs to extend along the axial direction from the tip to the rear end of the relay core body, one or a plurality of spaces of required sizes are formed between the peripheral wall and each rib, and between each rib. Therefore, in the relay core, a gap is formed on the outer peripheral surface of the small-diameter portion, and thus air can be discharged and introduced using this gap. Thus, in the relay core, an air-exchange gap is formed inside it separately from the ink flow path constituted by the space. When the temperature inside the liquid applicator rises due to the body temperature when the liquid applicator is held by hand, and the air in the ink reservoir expands and the internal pressure rises, or when an end cap or a tail plug is fitted to the ink reservoir, and thus a change in air pressure occurs during the manufacture of the liquid applicator while ensuring airtightness, the air extruded from the ink reservoir is discharged through the gap, and it is possible to stably supply and discharge ink while suppressing or preventing ink leakage and abnormal ink ejection. Furthermore, by suppressing or preventing the occurrence of abnormal ink ejection, waste of ink is suppressed or prevented, and thus it is also possible to extend the usable period of the product (liquid applicator). It should be noted that this effect is remarkable when the ink flow path is configured to be larger so that ink containing large-diameter particles or ink having a high viscosity can pass through. Also, in this invention, the relay core body is configured such that, at least in the portion where its outer diameter is maximum, in a cross-sectional view, the porosity of the portion within the range extending from the center to the position at 65% of the radius is 20 to 70%, and the porosity of the annular portion formed circumferentially from the position at 65% of the radius to the outer peripheral surface is 0 to 20%.

[0026] Furthermore, in the relay core, the small-diameter portion can be continuously formed along the axial direction of the relay core body to the rear end edge. With such a configuration, the gap formed on the outer peripheral surface of the small-diameter portion extends to the rear end edge along the axial direction of the relay core main body. Therefore, air can be mainly discharged and introduced from the rear end side of the relay core main body. In addition, as will be described later, when the small-diameter portion is configured to include a rear end connection portion for connecting to an ink storage body that stores ink on the rear end side thereof, it can be configured to have a continuously decreasing diameter up to the rear end edge of the rear end connection portion.

[0027] In the relay core, by forming the space so as to exist radially inside the peripheral wall at least in the small-diameter portion, the space can be configured not to be exposed to the external space in the radial direction. With such a configuration, in the relay core, malfunction of the ink flow path caused by deformation or torsion of the ink flow path formed by the space due to stress applied during processing or burrs that may occur during processing is suppressed or prevented, and stable supply and discharge of ink can be achieved.

[0028] In the relay core, the thickness from the outer peripheral surface of the small-diameter portion to the inner wall constituting the outermost part in the radial direction of the space can be set to 0.1 mm or more. With such a configuration, since the strength of the small-diameter portion is improved, deformation or torsion of the ink flow path due to stress applied during processing or burrs that may occur during processing is prevented with a higher probability. As a result, malfunction of the ink flow path that may occur due to the deformation or torsion is also prevented with a higher probability, so that the supply and discharge of ink can be performed more stably without being inhibited.

[0029] In the relay core, the relay core main body can be configured to have a sharp shape in which its tip portion tapers toward the tip side. With such a configuration, it is possible to impart flexibility to the tip of the relay core.

[0030] In the relay core, the ribs can be configured such that the inner ends in a cross-sectional view are connected to each other at the radial center. Even when the relay core body is configured to have a pointed shape in which its tip end becomes tapered toward the tip side with such a configuration, the tip end of the relay core body does not come apart, and it becomes possible to perform high-precision machining on the relay core body, particularly its tip end.

[0031] On the other hand, in the relay core, the ribs can also be configured such that the inner ends in a cross-sectional view are not connected to each other. According to such a configuration, each rib has a free end at the inner end in a cross-sectional view and protrudes in a branched state toward the radial center. Therefore, even when the tip end of the relay core is configured to have a pointed shape, each rib forms a rod-like body and comes apart toward the tip side. Furthermore, when the tip or pen tip connected to the tip side of the relay core is composed of a fiber bundle or a hair bundle, each hair constituting the tip or pen tip is intertwined with the rod-like body, and a more appropriate firmness and an optimal application feeling can be obtained at the tip end of the relay core.

[0032] In the relay core, the relay core body can be configured such that the porosity of the portion within the range extending from the center to the position of 65% of the radius in a cross-sectional view is 20 to 70% at least in the portion where its outer diameter is the largest. With such a configuration, even if the ink contains large-diameter particles, it becomes possible to stably supply and discharge the ink. Furthermore, the relay core body can be configured such that the porosity of the annular portion formed in the circumferential direction from the position of 65% of the radius to the outer peripheral surface in a cross-sectional view is 0% to 20%. According to such a configuration, since the strength of the peripheral wall constituting the small-diameter portion is improved, even when the small-diameter portion is processed, ink clogging that may occur due to deformation or twisting of the space as the ink flow path is less likely to occur. As a result, even when the ink contains large-diameter particles, it is possible to stably supply and discharge the ink.

[0033] In the relay core, a nib or pen tip that can be fitted and detached from the tip connection portion of the relay core main body is provided, and the length between the tip portion of the nib or pen tip and the tip portion of the relay core main body can be set within the range of 2 to 6 mm. With such a configuration, to a certain extent, the inherent hardness of the tip of the relay core can be added to the degree of bending of the nib or pen tip. Therefore, an appropriate hardness is imparted to the coating feeling, and an appropriate firmness is obtained in the nib or pen tip. When a liquid applicator is configured, it becomes easier to perform coating, writing, drawing, etc. (hereinafter referred to as "coating, etc.") on objects such as paper and skin. Furthermore, since the tip portion of the relay core is located at a position close to the coating surface, it becomes easier to increase the amount of pigment or ink adhering to the object of coating, etc. As a result, it becomes possible to enhance the color development property. Note that, as the form of the nib or pen tip, a fiber bundle core, a hair bundle core, or a rubber core (particularly, a porous rubber core) can be selected.

[0034] In the relay core, when a vertical load is applied to the tip portion so that the tip portion is crushed by 2 mm in a state where the relay core main body is inclined at an angle of 45°, the repulsive force generated can be configured to be 20 gf or less. With such a configuration, it is possible to impart an appropriate firmness and an optimal coating feeling or writing feeling to the liquid applicator by the synergistic effect of the relay core and the nib or pen tip without impairing the inherent elasticity of the nib or pen tip.

[0035] In the relay core, the relay core main body can be made of an elastomer. With such a configuration, when the liquid applicator is configured, it is possible to obtain more appropriate firmness, flexibility, and resilience, and to obtain an optimal application feeling or writing texture.

[0036] Furthermore, in the relay core, an ink temporary holding member composed of a cylindrical body that surrounds the relay core main body and abuts against the outer peripheral surface can be provided on the relay core main body. At that time, one or a plurality of through holes formed to penetrate in the radial direction are provided on the outer peripheral surface of the ink temporary holding member, and the through holes are configured to communicate with the external space and also communicate with a gap formed between the inner surface of the ink temporary holding member and the small diameter portion of the relay core main body. With such a configuration, even when the ink contains large-diameter particles, it is possible to more reliably prevent abnormal ink discharge and stably supply and discharge the ink.

[0037] Note that the relay core can be used as a relay core of various liquid supply tools for performing applications or the like on objects such as paper or skin.

Brief Description of the Drawings

[0038]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0039] Hereinafter, embodiments of the relay core according to the present invention will be specifically described based on the attached drawings. Note that the relay core of the present invention is not limited to the illustrated embodiments, and improvements can be made within the scope that does not change the gist of the invention.

[0040] The ink relay core 1 according to the present invention (hereinafter referred to as "relay core 1") is composed of a long rod-shaped relay core main body 2 as shown in FIGS. 1 and 2, and as shown in FIG. 6, it is combined with a pen tip 3, an ink storage body 4, and a shaft cylinder 5 to form a liquid applicator 7. Note that as will be described later, the relay core main body 2 has one or more ink flow paths 23 formed along the axial direction and consisting of spaces of required sizes, extending from the tip to the rear end.

[0041] As shown in FIGS. 1 and 2, a rear end connection portion 2c for connecting to an ink storage body 4 for storing ink is provided at the rear end portion of the relay core main body 2. In FIG. 1, the rear end connection portion 2c is continuously formed so as to have a reduced diameter from the rear end edge of the small diameter portion 2b toward the rear end side.

[0042] In FIGS. 1 and 2, reference numeral 2d is a stepped portion formed along the circumferential direction due to the difference in outer diameter between the relay core main body 2 and the tip portion formed with a smaller diameter than the relay core main body 2. By abutting the stepped portion 2d against the outer edge (opening portion) of the fitting portion 3a formed at the rear end portion of the nib (pen tip) or the pen tip 3, the relay core main body 2 and the nib (pen tip) or the pen tip 3 are axially fitted at an appropriate position.

[0043] As shown in FIGS. 1 and 2, the relay core main body 2 has a tip connection portion 2a for connecting the nib or the pen tip 3 as an application portion (the portion where application etc. is performed) on its tip side, and a small diameter portion 2b formed with a smaller diameter than the outer diameter of the relay core main body 2 on the rear end side of the tip connection portion 2a.

[0044] The small-diameter portion 2b is formed to have a smaller diameter than the outer diameter of the large-diameter portion of the relay core main body 2. When forming the liquid applicator, in the small-diameter portion 2b, a gap G is formed between its outer peripheral surface and the shaft cylinder 5 (when the ink temporary holding member 6 is disposed in the small-diameter portion 2b, between the outer peripheral surface and the inner peripheral surface of the ink temporary holding member 6 to be described later). The gap G is configured to communicate with the external space and constitutes an air flow path. Therefore, air can be discharged and introduced using this gap G. Therefore, in the present invention, since an air-exchange gap G is formed separately from the ink flow path 23 inside the relay core 1, more specifically, on the outer periphery of the small-diameter portion 2b, when the liquid applicator is held by hand, if the air in the ink storage body 4 expands due to a temperature rise in the liquid applicator caused by body temperature or the like and the internal pressure increases, or when an end cap or a tail plug is fitted to the ink storage body, even when a change in air pressure occurs due to ensuring airtightness during the manufacture of the liquid applicator, the air extruded from the ink storage body 4 is discharged through the gap G formed on the outer periphery of the small-diameter portion 2b as a flow path. As a result, since the air extruded from the ink storage body 4 does not pass through the ink flow path 23 in the relay core 1 and ink is not discharged from the tip of the relay core 1, the occurrence of ink leakage or abnormal ink discharge is suppressed or prevented. Moreover, the occurrence of defects in the product (liquid applicator) is not present or is suppressed, and the wasteful use of ink is suppressed or prevented, so it is also possible to extend the usable period of the product. This effect is particularly remarkable when the capillary force is intentionally reduced by enlarging the ink flow path so that ink containing large-diameter particles or ink having a high viscosity can pass through the ink flow path. This is because, in order to allow ink containing large-diameter particles or ink having a high viscosity to pass through, it is necessary to widen the space constituting the ink flow path. However, the wider this space is, the lower the capillary force contributing to ink holding becomes. As a result, the ink is less likely to remain in the ink flow path and is more likely to flow out toward the tip. In addition, in this embodiment, although the small-diameter portion 2b is formed coaxially with the large-diameter portion of the relay core main body 2, the small-diameter portion 2b may be formed so that its cross-sectional area is smaller than the cross-sectional area of the relay core main body 2 as long as it does not affect the supply of ink in the ink flow path 23.

[0045] Regarding the small-diameter portion 2b, as long as the air discharge and inflow are configured to be possible by configuring the gap G formed on its outer periphery (the gap formed between the outer peripheral surface of the small-diameter portion 2b and the inner peripheral surface of the shaft cylinder 5 or the ink temporary holding member 6 described later) to communicate with the external space, it can be formed at any position other than the tip end portion of the relay core main body 2.

[0046] For example, in the relay core main body 2, the small-diameter portion 2b can be formed with a predetermined length between the central portion in the axial direction and the rear end edge.

[0047] In FIG. 1, the small-diameter portion 2b is continuously formed along the axial direction of the relay core main body 2 to the rear end edge. Therefore, the gap G is formed so as to extend to the rear end edge along the axial direction of the relay core main body 2. In this case, in a state where the ink reservoir 4 is filled with ink, it is possible to mainly perform only the discharge and inflow of air from the rear end side of the relay core main body 2.

[0048] Also, as shown in FIG. 2, the small-diameter portion 2b can be formed near the central portion in the axial direction of the relay core main body 2 so that air can be discharged and flowed in. In this case, the gap G formed on the small-diameter portion 2b and the through-hole 6c of the ink temporary holding member 6 described later may be communicated so that, in addition to the gap G, the through-hole 6c is used for air discharge and inflow. At that time, regarding the gap G, the through hole 6c inside the ink temporary holding member 6 made of a cylindrical body may be enlarged, the through hole 6c inside may be formed into a non-circular shape instead of a circular cylindrical shape, or a groove having a required depth extending along the axial direction may be formed inside, so that the gap G, the through hole 6c, and the ink storage body 4 are configured to communicate with each other.

[0049] Regarding the radial size of the small diameter portion 2b, it is only necessary to be set so that a gap G through which air can pass is formed on the outer periphery of the small diameter portion 2b, and there is no particular limitation. However, the small diameter portion 2b can be configured such that, for example, its diameter is 50% to 85% of the outer diameter (diameter) of the relay core main body 2.

[0050] In this invention, the relay core main body 2 is configured to have a peripheral wall with a required thickness. In FIGS. 3 and 4, the cross section (a section in a direction orthogonal to the axial direction) of the relay core main body 2 is supposed to have an annular outer peripheral portion 21 with a required radial length. Therefore, the ink flow path 23 formed inside the relay core main body 2 exists inside the radial direction of the peripheral wall (outer wall portion) having the predetermined thickness (radial length). With such a configuration, in the relay core main body 2, the ink flow path 23 is surrounded by the peripheral wall (outer peripheral portion 21) and does not protrude radially outward (is not exposed to the external space in the radial direction). Therefore, it is possible to suppress or prevent the ink flow path from being deformed or twisted due to stress applied during processing or burrs that may be generated during processing. As a result, ink clogging is also suppressed or prevented, so that it is possible to stably supply and discharge ink. Note that the outer peripheral portion (peripheral wall) can be formed at least in the small diameter portion 2b.

[0051] At that time, the thickness (radial length) L from the outer peripheral surface of the small diameter portion 2b to the inner wall constituting the outermost portion in the radial direction of the ink flow path 23 is preferably set to be 0.1 mm or more, more preferably 0.13 mm or more. With such a configuration, in the relay core body 2, the strength of the small-diameter portion 2b is improved, so that it is possible to prevent, with a higher probability, the ink flow path from being deformed or twisted by stress applied during processing or burrs that may occur during processing. As a result, ink clogging is also suppressed or prevented, so that ink supply and discharge can be performed more stably without being hindered.

[0052] As shown in FIGS. 3 and 4, the relay core body 2 is configured such that its cross section (a cross section in a direction orthogonal to the axial direction) has an annular outer peripheral portion 21 that constitutes the peripheral wall of the relay core body 2, and one or a plurality of ribs 22 extending radially inward (preferably radially) from this outer peripheral portion 21. Each of the ribs 22 is formed to extend along the axial direction from the tip end to the rear end of the relay core body 2. Further, when a plurality of the ribs 22 are provided, the ribs 22 are provided at a predetermined interval from each other. With such a configuration, in the relay core body 2, one or a plurality of spaces of a required size are formed between the peripheral wall (outer peripheral portion 21) and each rib 22, and between each rib 22, and the spaces constitute an ink flow path 23 for allowing ink to pass through. Note that the size of the space, that is, the ink flow path 23, may be selected according to the relay core body 2, its small-diameter portion 2b, the maximum diameter of particles contained in the ink to be used, etc., and there is no particular limitation. For example, the radial length of the ink flow path 23 is set to be within the range of 0.1 to 0.7 mm in diameter.

[0053] As shown in FIG. 3, each rib 22 may be configured such that its inner end portions are connected to each other particularly at the radial center, or as shown in FIG. 4, the inner end portions may be configured not to be connected to each other.

[0054] In FIG. 3, each rib 22 in the relay core body 2 is configured such that its inner end portions are connected to each other at the radial center in a cross-sectional view. With such a configuration, even when the relay core body 2 is configured such that its tip portion has a pointed shape that tapers toward the tip side, the tip portion of the relay core body 2 does not break apart, and it is possible to perform precise machining on the relay core body 2, particularly on its tip portion.

[0055] On the other hand, in FIG. 4, each rib 22 inside the relay core body 2 is configured such that its inner ends are not connected to each other in a cross-sectional view. When configured in this way, since the tip portion (the end portion on the radially inner side) of each rib 22 is a free end, each rib 22 protrudes in a branched state toward the central portion in the radial direction. Therefore, when the nib or pen tip 3 connected to the tip side of the relay core 1 is composed of a fiber bundle or a hair bundle, each individual hair constituting the nib or pen tip 3 is intertwined with each rib 22, so that a more appropriate firmness and an optimal application feeling can be obtained. It should be noted that this effect is particularly remarkable when the relay core body 2 is configured to have a pointed shape that tapers toward the tip side. This is because each free end of the tip portion (the end portion on the radially inner side) of each rib 22 protrudes in a rod shape toward the tip side.

[0056] As the material constituting the relay core body 2, any material can be used as long as it can at least exhibit capillary action, that is, enable the supply of ink from the ink storage body 4 disposed on the rear end side of the relay core body 2 to the nib (pen tip) or pen tip 3 disposed on the tip side of the relay core body 2, and it can be appropriately selected according to desired characteristics and qualities such as writing feeling, strength, durability, and abrasion resistance.

[0057] Preferably, a thermoplastic resin such as a polyoxymethylene-based resin is selected as the material constituting the relay core body 2. The material may be in the form of an elastomer, and it can be used alone or in an appropriate combination of two or more kinds. With such a configuration, the relay core body 2 can be easily molded into a predetermined shape, for example, by extrusion molding, etc., and a good appearance can be obtained. Even when the inner ends of the respective ribs 22 are not connected to each other, good ribs are formed. Therefore, even when the ink contains large-diameter particles (for example, particles having a particle diameter of about 10 μm to 200 μm), it is possible to prevent or suppress with a very high probability the occurrence of abnormal ink ejection, and stably supply and discharge the ink.

[0058] When the relay core 1 is used as a relay core for a cosmetic tool, it is preferable to select a material that does not generate formaldehyde or the like as the material constituting the relay core body 2. As such a material, more preferably, it is selected from polyolefin resins such as polypropylene, polyester resins, nylon resins, and those in the form of elastomers thereof, and still more preferably, it is selected from polyester elastomers. Note that these materials can be used alone or in appropriate combination of two or more.

[0059] The relay core body 2 is preferably configured such that, at least in the portion where its outer diameter is maximum, the porosity of the portion other than the outer peripheral portion 21, particularly the portion within the range extending from the center to the position of 65% of the radius in the cross section, is preferably 20 to 70%, more preferably 25 to 55%, and still more preferably 30 to 50%. With such a configuration, even when the ink contains large-diameter particles, it is possible to stably supply and discharge the ink. Furthermore, as will be described later, when the tip of the relay core body 2 is configured to have a tapered shape that tapers toward the tip side, the repulsive force can be appropriately weakened, and this repulsive force can also be adjusted by adjusting the porosity or the like. Note that this effect is particularly remarkable when the respective ribs 22 are configured such that their inner ends are connected to each other at the central portion in the radial direction.

[0060] Further, the relay core body 2 is preferably configured such that the porosity of an annular portion formed circumferentially from a position at 65% of the radius to the outer peripheral surface in the outer peripheral portion 21, particularly in the cross section, is preferably 0% to 20% (no air permeability or the porosity is greater than 0 and 20% or less), more preferably 0 to 10%. With such a configuration, the strength of the peripheral wall (outer peripheral portion 21) constituting the small-diameter portion 2b is improved. Therefore, even when the small-diameter portion 2b is processed, deformation or torsion of the ink flow path 23 is less likely to occur, and ink clogging caused by such deformation or torsion is also less likely to occur. As a result, even when the ink contains large-diameter particles, it is possible to stably supply and discharge the ink. It should be noted that this effect is particularly remarkable when each of the ribs 22 is configured such that the inner ends thereof are connected to each other at the radial center portion.

[0061] In the cross-sectional shape shown in FIG. 3(A), the porosity of the portion within the range from the center to the position at 65% of the radius is about 40.9%, and the porosity of the annular portion formed circumferentially from the position at 65% of the radius to the outer peripheral surface is about 0.3%. In the cross-sectional shape shown in FIG. 3(B), the porosity of the portion within the range from the center to the position at 65% of the radius is about 36.6%, and the porosity of the annular portion formed circumferentially from the position at 65% of the radius to the outer peripheral surface is about 0.3%. Furthermore, in the cross-sectional shape shown in FIG. 3(C), the porosity of the portion within the range from the center to the position at 65% of the radius is about 44.4%, and the porosity of the annular portion formed circumferentially from the position at 65% of the radius to the outer peripheral surface is about 6.1%.

[0062] The relay core body 2 is preferably configured such that its tip end has a sharp shape that tapers toward the tip end side. With such a configuration, it is possible to impart flexibility to the tip end of the relay core. Furthermore, when attaching the tip to the tip portion of the relay core body 2, since the fibers constituting the tip are along the tip portion having a sharp shape, the tip of the tip is likely to be gathered and is less likely to come apart, and thus the operational effect can also be obtained.

[0063] The relay core body 2 is preferably configured to have a predetermined degree of flexibility, at least at its tip portion. Regarding the degree of flexibility, for example, the relay core body 2 is placed on a weighing device such as a mass meter in a state where it is tilted at an angle of 45°, and a vertical load is applied to the tip portion so that the tip portion of the relay core body 2 is crushed by 2 mm. It can be evaluated by obtaining the repulsive force from the mass measured at this time. Preferably, the repulsive force is 20 gf or less. When it exceeds 20 gf, the writing feeling during use tends to be hard. With such a configuration, when a liquid applicator is configured, without impairing the original elasticity of the tip or pen tip, due to the synergistic effect between the relay core and the tip or pen tip, an appropriate firmness and an optimal application feeling or writing feeling can be obtained. This operational effect is more remarkable because when the relay core body 2 (at least its tip portion) is made of a material in the form of an elastomer, the tip of the relay core body 2 becomes flexible, its resilience increases, and appropriate adjustment can be made so that it has desired quality or characteristics.

[0064] Regarding the relay core body 2, depending on the application, it can be formed so that the length in the axial direction becomes a predetermined value.

[0065] As shown in FIG. 5, an ink temporary holding member 6 composed of a cylindrical body that surrounds the relay core body 2 and abuts on the outer peripheral surface can be disposed on the relay core body 2. The ink temporary holding member 6 can be composed of, for example, ABS resin or the like. When a large amount of ink is supplied to the outside of the relay core body 2, even if the ink overflows, the ink is temporarily held and the held ink is supplied (returned) to the ink storage body 4.

[0066] In FIG. 5, the ink temporary holding member 6 is formed in a bellows shape and has a comb-tooth portion 6a composed of a plurality of grooves on its outer peripheral portion. The comb-tooth portion 6a (particularly its groove portion 6b) holds the ink that overflows from the ink storage body 4.

[0067] In FIG. 5, the ink temporary holding member 6 is provided with a through hole 6c formed to penetrate in the radial direction on its outer peripheral surface. The through hole 6c is formed to communicate with the external space and also with a gap G formed between the inner surface of the ink temporary holding member 6 and the small-diameter portion 2a of the relay core main body 2. Therefore, air can flow or be exchanged through the gap G and the through hole 6c. So, when the liquid applicator is held by hand and the temperature inside the liquid applicator rises due to body temperature or the like, and the air in the ink storage body 4 expands and the internal pressure rises, or when an end cap or a tail plug is fitted to the ink storage body and a change in air pressure occurs due to ensuring airtightness during the manufacture of the liquid applicator, the air pushed out from the ink storage body 4 is discharged through the comb-tooth portion 6a and the through hole 6c as flow paths. Furthermore, the ink pushed out together with the air is stored in the comb-tooth portion 6a of the ink temporary holding member 6. As a result, even when the capillary force is low by enlarging the ink flow path of the relay core so that ink containing large-diameter particles or ink having a high viscosity can pass through, it is possible to more reliably prevent ink ejection abnormalities.

[0068] Regarding the through hole 6c, one or a plurality of them can be provided continuously and / or intermittently along the axial direction and / or the circumferential direction, but preferably, it is formed so as to be located directly above the small-diameter portion 2b.

[0069] As shown in Fig. 6, the relay core 1 of such a configuration is combined with a tip or pen tip 3 that contacts an object such as paper or skin and is connected (arranged) on the tip side thereof, an ink reservoir 4 filled with a desired ink and connected (arranged) on the rear end side, and a shaft portion (shaft cylinder) 5 made of plastic or metal, and can be used as a liquid supply tool 7. Therefore, such a liquid supply tool is also included in the present invention. Regarding the relay core 1, it can be used as a relay core for various liquid supply tools that perform writing, drawing, coating, etc. on objects such as paper and skin, such as writing liquid supply tools such as marking pens, signature pens, and fountain pens, and cosmetic liquid supply tools such as eyeliners.

[0070] There is no particular limitation on the method of arranging the tip or pen tip 3 on the tip side of the relay core 1. In Fig. 6, a fitting portion 3a formed by a recess or hole having a required depth that is detachably formed with the tip connection portion 2a of the relay core 1 is formed at the rear end portion of the tip or pen tip 3. Therefore, by inserting the tip connection portion 2a of the relay core main body 2 into the fitting portion 3a, the pen tip 3 and the relay core 1 are fitted in the axial direction.

[0071] When fitting the tip or pen tip 3 and the relay core 1 in the axial direction, the length (distance) M between the tip portion of the tip or pen tip 3 and the tip portion of the relay core main body 2 is preferably set to be in the range of about 2 to 6 mm, more preferably about 3 to 5 mm. With such a configuration, an appropriate hardness is imparted to the bending condition of the tip or pen tip 3 attached to the tip side of the relay core main body 2, and an appropriate stiffness is obtained, so that coating and the like become easier. This effect is more remarkable when the relay core main body 2 (at least its tip portion) is made of a material in the form of an elastomer, because the tip of the relay core main body 2 becomes flexible and its resilience also increases. Also, when the length M is less than 2 mm, if the tip of the pen tip (coating part) 3 is a brush tip, the hairs at the tip of the brush tip tend to break easily. When it exceeds 6 mm, the coating feeling becomes indistinguishable from that of a normal makeup brush. Note that the shorter the distance M between the tip of the brush tip or pen tip 3 and the tip of the relay core body 2, the easier it is for the ink supplied from the ink storage body 4 to reach the tip of the brush tip or pen tip 3. As a result, the amount of pigment or ink adhering to the object to be coated or the like increases, enhancing the color development property, and the pigment or ink tends to be discharged with a good discharge amount. Also, when the distance M is short, the tip of the brush tip tends to break. However, by configuring the relay core body 2 to have a sharp shape that tapers as its tip approaches the tip side, it is possible to make the tip of the brush tip less likely to break. In FIG. 6, the length between the tip of the pen tip 3 and the tip of the relay core body 2 is set to be about 4 mm.

[0072] There is no particular limitation on the method of configuring the length M between the tip of the brush tip or pen tip 3 and the tip of the relay core body 2 to be within the predetermined range. For example, by controlling the position of the step portion 2d formed on the tip side of the relay core body 2 so as to abut against the opening of the inserted portion 3a formed at the rear end portion of the brush tip or pen tip 3, the length between the tip of the brush tip or pen tip 3 and the tip of the relay core body 2 can be configured to be within the predetermined range.

[0073] Note that there is no particular limitation on the form of the brush tip or pen tip 3. For example, various cores such as fiber or fiber bundle core, hair bundle core, sintered core, and plastic core can be appropriately selected according to the application. As the form of the brush tip or pen tip 3, preferably a fiber bundle core, a hair bundle core, or a rubber core is selected. Conventionally, when a rubber core composed of a porous rubber (porous rubber core) was selected as the rubber core, since the strength of the porous rubber core tended to be weak, if a relatively hard tip was used as the relay core, there was a risk that the relay core would pierce through the rubber core when the rubber core deformed during coating or the like. However, according to the relay core of the present invention, since its tip is configured to be flexible, the relay core does not pierce through the rubber core.

Example

[0074] Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited by these examples.

[0075] <Example 1> A relay core was manufactured by the following manufacturing method.

[0076] <Manufacturing method> (1) A polyester elastomer was extrusion-molded to obtain a long rod-shaped synthetic resin molded body with an outer diameter of φ1.5 mm. At that time, the synthetic resin molded body was formed such that its cross-sectional shape had a plurality of ribs 22 and ink flow paths 23 as shown in Fig. 3(C), and the thickness L from the ink flow path 23 to the outer peripheral portion (peripheral wall) was 0.2 mm. (2) The synthetic resin molded body obtained in (1) was cut to a predetermined length and ground to form the shape shown in Fig. 1, such that the outer diameter of its small-diameter portion 2b was φ1.3 mm, thereby obtaining the target relay core. Note that, in the small-diameter portion 2b of the obtained relay core, the thickness L from the inner wall constituting the outermost portion in the radial direction of the ink flow path 23 to the outer peripheral surface of the small-diameter portion 2b was 0.1 mm.

[0077] <Example 2> A relay core was manufactured in the same manner as in Example 1, except that the outer diameter of the small-diameter portion 2b was φ1.1 mm and the ink flow path 23 was exposed on the outer side in the radial direction in the small-diameter portion 2b.

[0078] <Comparative Example 1> A relay core was manufactured in the same manner as in Example 1, except that the small-diameter portion 2b was not formed and the relay core was formed into a shape similar to that shown in FIG. 2. In the obtained relay core, the thickness L from the inner wall constituting the outermost diameter in the radial direction of the ink flow path 23 to the outer peripheral surface of the small-diameter portion 2b was 0.2 mm.

[0079] <Comparative Example 2> A relay core was manufactured by the following manufacturing method.

[0080] <Manufacturing method> (1) Polyester fibers with a fiber fineness of 5.5 dtex were bundled to form a bundled body. (2) The bundled body obtained in (1) was compression-molded by heating to obtain a columnar fiber bundle with an outer diameter of φ1.5 mm. (3) The fiber bundle obtained in (2) was impregnated with a urethane resin solution and dried with hot air to cure the resin, obtaining a long rod-shaped relay core substrate. (4) The relay core substrate obtained in (3) was cut to a predetermined length and ground to form the shape shown in FIG. 1, with the outer diameter of the small-diameter portion 2b being φ1.3 mm, thereby obtaining the target relay core.

[0081] <Example 3> A liquid applicator (pen) was manufactured by the following manufacturing method.

[0082] <Manufacturing method> (1) The relay core 1 obtained in Example 1 above was assembled to the ink temporary holding member 6. Regarding the assembly of the relay core 1 to the ink temporary holding member 6, the relay core 1 was inserted through a through-hole formed along the axial direction provided in the ink temporary holding member 6. (2) The tip connection portion 2a of the relay core 1 of the assembled product obtained in (1) was inserted and fixed into a hole (insertion portion) 3a formed at the rear end portion of the spike 3 so that the length M between the tip end portion of the relay core 1 and the tip end portion of the spike 3 was 4.0 mm. (3) Insert and fix the assembled product obtained in (2) from the rear end of the shaft portion (shaft cylinder) 5 so that the tip portion thereof protrudes by a required length, attach the ink storage body 4 to the rear end portion of the assembled product, and obtain a liquid applicator having the same configuration as the liquid applicator shown in Fig. 6, which is the intended one.

[0083] <Example 4 and Comparative Example 3> Liquid applicators were produced in the same manner as in Example 3, except that the relay core obtained in Example 2 or Comparative Example 1 was used instead of the relay core obtained in Example 1.

[0084] [Test Example 1] Evaluation of the dischargeability of large-diameter pigments Regarding the liquid applicators obtained in the above Examples 3 and 4 and Comparative Example 3, using ink containing large-diameter pigments (particle diameter: 40 μm), based on the following evaluation method, the appearance of the lines during writing was visually observed to evaluate the dischargeability (ease of discharge or ejection of large-diameter pigments) of the large-diameter pigments (large-diameter pigments). Furthermore, regarding the liquid applicators obtained in the above Examples 3 and 4 and Comparative Example 3, based on the following evaluation method, the presence or absence of ink leakage was evaluated. The results are shown in Tables 1 and 2.

[0085] <Evaluation method> After filling the ink storage body 4 of the liquid applicator with ink containing large-diameter metallic pigments (pigments that reflect light) having a particle diameter of 40 μm, writing was performed so that a line was drawn with the tip of the nib in contact with the paper surface, and the appearance of this line was visually confirmed, and the appearance was evaluated according to the following evaluation criteria. Furthermore, the liquid applicator was held by hand, and it was visually confirmed whether ink leakage occurred with the nib facing downward, and the presence or absence of ink leakage was evaluated according to the following evaluation criteria.

[0086] <Evaluation criteria for the dischargeability of large-diameter pigments> 〇: The discharge of metallic pigments is smooth. △: The discharge of metallic pigments occurs. ×: Glitter pigment is not sufficiently discharged

[0087] <Evaluation Criteria for Ink Leakage> 〇: No ink leakage occurs ×: Ink leakage occurs

[0088]

Table 1

[0089]

Table 2

[0090] <Results> From Tables 1 and 2, in the liquid applicators obtained in Examples 3 and 4, since the relay cores constituting these liquid applicators, that is, the relay cores obtained in Examples 1 and 2, both have small-diameter portions, the ink used contains large-diameter pigments, and even when the capillary force is low due to increasing the size of the ink flow path of the relay core so that the large-diameter pigments are discharged, it can be seen that ink leakage does not occur and ink is discharged normally. In particular, in the liquid applicator obtained in Example 3, since the relay core obtained in Example 1 is configured to have an outer peripheral portion with a predetermined thickness in a cross-sectional view at its small-diameter portion, even though the ink used contains large-diameter pigments and the capillary force is low due to increasing the size of the ink flow path so that the large-diameter pigments are discharged, it can be seen that ink leakage does not occur and the discharge of glitter pigment is good, and thus the discharge of ink is extremely smooth. On the other hand, in the liquid applicator obtained in Comparative Example 3, although the discharge of glitter pigment is appropriately performed, ink leakage occurs, and there is also a possibility that ink ejection abnormalities may occur in the future. From the above, according to the relay core of the present invention, since air can flow or be exchanged through the void formed on the outer periphery of the small-diameter portion, when constructing a liquid applicator, the ink used contains large-diameter pigments, and the size of the ink flow path is increased so that the large-diameter pigments are discharged. Even when the capillary force is low, or even when the ink used contains large-diameter pigments, it is obvious that ink leakage does not occur and the discharge of ink or pigments is carried out normally.

[0091] <Example 5> A liquid applicator was manufactured in the same manner as in Example 3, except that the tip connection portion 2a of the relay core 1 was inserted and fixed into the hole (insertion portion) 3a formed at the rear end portion of the nib 3 so that the length M between the tip end portion of the relay core 1 and the tip end portion of the nib 3 was 1.9 mm.

[0092] <Example 6> A liquid applicator was manufactured in the same manner as in Example 3, except that the tip connection portion 2a of the relay core 1 was inserted and fixed into the hole 3a formed at the rear end portion of the nib 3 so that the length M between the tip end portion of the relay core 1 and the tip end portion of the nib 3 was 6.1 mm.

[0093] <Comparative Example 4> A liquid applicator was manufactured in the same manner as in Example 3, except that the relay core obtained in Comparative Example 2 was used instead of the relay core obtained in Example 1.

[0094] [Test Example 2] Evaluation of writing quality Regarding the liquid applicators obtained in the above Examples 3, 5, and 6 and Comparative Example 4, an evaluation of the writing quality was performed based on the following evaluation method. Regarding the liquid applicators obtained in the above Examples 3, 5, and 6 and Comparative Example 4, the relay core constituting the liquid applicator was placed on a mass scale in a state inclined at an angle of 45°, and a repulsive force was measured from the mass measured when a vertical load was applied to the tip end portion so that the tip end portion was crushed by 2 mm. These results are shown in Table 3.

[0095] <Evaluation method> Regarding the liquid applicator, the writing feel was evaluated by applying it to human skin and having the feel at that time judged.

[0096]

Table 3

[0097] <Results> From Table 3, it can be seen that the relay cores constituting the liquid applicators obtained in Examples 3, 5, and 6 are all the relay cores obtained in Example 1 above, that is, the relay cores according to this invention, and as a result of the evaluation according to this Test Example 2, the repulsive force was 20 gf or less. The fact that the repulsive force is 20 gf or less indicates that when a liquid applicator is configured using this relay core, the liquid applicator has an appropriate writing feel. The liquid applicator obtained in Example 5 has a relatively short length from the tip of the relay core constituting the liquid applicator to the tip of the nib. Although partial splitting of the nib was observed, it had an appropriate writing feel. The liquid applicator obtained in Example 6 has a relatively long length from the tip of the relay core constituting the liquid applicator to the tip of the nib, but had a writing feel equivalent to that of a general pen. This is because the distance between the tip of the relay core and the tip of the application part (nib) is long, and it is configured such that the influence of the tip of the relay core on the application surface is difficult to reach. In particular, the pen obtained in Example 3 had no splitting and had an optimal writing feel. In contrast, in the liquid applicator obtained in Comparative Example 4, the length from the tip of the relay core constituting the liquid applicator to the tip of the nib is the same as that of the liquid applicator obtained in Example 3. However, the repulsive force of the relay core made of a fiber bundle was greater than 20 gf as a result of the evaluation according to this Test Example 2, and the writing feeling of the liquid applicator was hard. In particular, when applying with a depression of 4 mm or more so that the entire tip of the relay core hits the application target, the writing feeling becomes hard. When applying only with the tip so that the entire tip of the relay core does not hit the application target, a writing feeling equivalent to that of a general pen was obtained. In this case, however, only the nib bends while the relay core is hard and does not bend, so the tip of the nib and the tip of the relay core tend to separate and the tip of the nib tends to break apart. Therefore, in the liquid applicator obtained in Example 3, the relay core is configured so that its repulsive force is 20 gf or less, and the length between the tip of the nib and the tip of the relay core is set within a range of about 2 to 6 mm. It can be seen that the tip of the nib does not break apart and has an optimal writing feeling. From the above, it is clear that the liquid applicator using the relay core according to this invention has an excellent writing feeling.

Industrial Applicability

[0098] The relay core of this invention consists of a long rod-shaped relay core body. The relay core body is provided with a small-diameter portion formed to have a smaller diameter than its outer diameter. The small-diameter portion is configured such that the void formed on its outer circumference communicates with the external space. Therefore, in this relay core, since air can be discharged and introduced (air exchange) using the air flow path formed by the void, even if air is pushed out from the ink storage body, this air is discharged through the void. As a result, even if the ink contains large-diameter particles or has a high viscosity, it is possible to stably supply and discharge the ink while suppressing or preventing ink leakage and abnormal ink ejection. Therefore, this relay core can be used as a relay core for a liquid applicator for the purpose of writing, drawing, etc., and can be used in a wide range of applications.

Explanation of symbols

[0099] 1 Relay core 2 Relay core body 2a Tip connection part 2b Small-diameter part 2c Rear-end connection part 2d Step part 21 Outer peripheral part 22 Rib 23 Ink flow path 3 Tip or pen tip 3a Inserted part 4 Ink reservoir 5 Shaft part (shaft cylinder) 6 Ink temporary holding member 6a Comb teeth part 6b Groove part 6c Through hole 7 Liquid applicator G Gap L Thickness (radial length) from the outer peripheral surface of the small-diameter part to the inner wall constituting the outermost part in the radial direction of the ink flow path M Length between the tip of the tip or pen tip and the tip of the relay core (relay core body)

Claims

1. A relay core composed of a long rod-shaped relay core body, wherein the relay core body, has a tip connection portion for connecting a spike tip or a pen tip on its tip side, and is configured to have a small diameter portion formed to have a smaller diameter than the outer diameter of the relay core body on the rear end side of the tip connection portion, the cross section of the relay core body, is configured to have an outer peripheral portion constituting the peripheral wall of the relay core body and one or more ribs extending radially inward from the outer peripheral portion, by forming the ribs to extend along the axial direction from the tip to the rear end of the relay core body, one or more spaces of a required size are formed between the peripheral wall and each rib, and between each rib, the relay core body, is configured such that at least in the portion where its outer diameter is the largest, the porosity of the portion within the range extending from the center to the position of 65% of the radius in a cross-sectional view is 20 to 70%, and the porosity of the annular portion formed circumferentially from the position of 65% of the radius to the outer peripheral surface is 0% to 20%, characterized relay core.

2. The small diameter portion, is continuously formed along the axial direction of the relay core body to the rear end edge, characterized relay core according to claim 1.

3. The space, exists radially inward of the peripheral wall at least in the small diameter portion, so that it is not exposed to the external space in the radial direction, characterized relay core according to claim 1 or 2.

4. The thickness from the outer peripheral surface of the small diameter portion to the inner wall constituting the outermost portion in the radial direction of the space, is 0.1 mm or more, characterized relay core according to any one of claims 1 to 3.

5. The relay core body, is configured such that its tip portion has a sharp shape that tapers toward the tip side, characterized relay core according to any one of claims 1 to 4.

6. The rib, is configured such that in a cross-sectional view, the inner ends thereof are connected to each other at the radial center, characterized relay core according to any one of claims 1 to 5.

7. The rib, is configured such that in a cross-sectional view, the inner ends thereof are not connected to each other, characterized relay core according to any one of claims 1 to 5.

8. The relay core body, is provided with a spike tip or a pen tip that can be fitted and detached from the tip connection portion, and is configured such that the length between the tip portion of the spike tip or pen tip and the tip portion of the relay core body is within the range of 2 to 6 mm. The relay core according to any one of claims 1 to 7, characterized in that...

9. The relay core main body is... When a vertical load is applied to the tip end thereof such that the tip end is crushed by 2 mm while being inclined at an angle of 45° obliquely, the resilience force generated is adjusted so as to be 20 gf or less. The relay core according to any one of claims 1 to 8, characterized in that...

10. The relay core main body is... Composed of an elastomer. The relay core according to any one of claims 1 to 9, characterized in that...

11. The relay core main body is... Provided with an ink temporary holding member composed of a cylindrical body that surrounds the relay core main body and abuts against the outer peripheral surface. The ink temporary holding member is... On its outer peripheral surface, provided with one or a plurality of through-holes formed to penetrate in the radial direction. The through-hole is... Configured to communicate with the external space and also with a gap formed between the inner surface of the ink temporary holding member and the small-diameter portion of the relay core main body. The relay core according to any one of claims 1 to 10, characterized in that...

12. Comprising the relay core according to any one of claims 1 to 11. The liquid applicator, characterized in that...

Images