Refill body and ink dispenser

Abstract

To provide a refill body and an ink applicator that can suppress the generation of air bubbles.SOLUTION: A refill body 1 according to the present invention includes: a chip member 10 that holds a ball body 12 at a front end; an ink storage tube 30 that stores ink 33 inside; a joint 20 that has a connecting cylinder portion 22 which is provided with a joint body portion 21 with a through hole 24 which is provided inside and a connecting hole 22a extending rearward from the joint body portion 21, has a larger diameter than the through hole 24, and into which the ink storage tube 30 is press-fitted, and connects the tip member 10 and the ink storage tube 30; a storage tube front surface 32 of the ink storage tube 30; and an air residual suppressant 40 that is disposed between the storage tube front surface 32 and an opposing surface 23 opposed to the storage tube front surface 32 in the connecting hole 22a.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a refill body and an ink applicator.

Background Art

[0002] For example, as a refill body which is a ball pen refill as an ink applicator, there is provided a refill body including a chip member that holds a ball body at the front end, an ink storage tube that stores ink inside, and a joint that connects the chip member and the ink storage tube. As a method of connecting the joint and the ink storage tube, there is a method of press-fitting and fitting the ink storage tube into the inner diameter side of a connecting cylinder portion provided on the rear side of the joint (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, according to this method, as a method of connecting the joint and the ink storage tube, compared with the method of press-fitting and fitting the outer diameter side of the connecting cylinder portion provided on the rear side of the joint into the inner diameter side of the ink storage tube, in a high-temperature environment or when stored for a long time, bubbles are likely to occur in the ink of the ink storage tube of the ball pen refill. Then, due to these bubbles, the ink may spurt out from the rear end of the ink storage tube or the ink discharge amount may become unstable.

[0005] An object of the present invention is to provide a refill body and an ink applicator in which the generation of bubbles is suppressed.

Means for Solving the Problems

[0006] To achieve the above objective, the present invention provides a refill body comprising: a tip member that holds a ball body at its front end; an ink storage tube containing ink inside; a joint body having a through hole inside; and a connecting cylinder portion extending rearward from the joint body portion, having a larger diameter than the through hole and a connecting hole into which the ink storage tube is press-fitted; and an air residue suppressant disposed between the front surface of the ink storage tube and the opposing surface in the connecting hole that faces the front surface of the storage tube.

[0007] The air residue suppressant preferably contains at least one selected from silicone oil, grease, lubricating oil, or vegetable oil.

[0008] The aforementioned ink may be a water-based ink.

[0009] Furthermore, in order to achieve the above objective, the present invention provides an ink applicator equipped with the above-mentioned refill body. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a refill body and an ink applicator that can suppress the generation of bubbles in high-temperature environments or when stored for long periods of time. [Brief explanation of the drawing]

[0011] [Figure 1] This is a side view of the refill body 1 of the embodiment, with the outline of the cursive writing 100 indicated by a dashed line. [Figure 2] This is a cross-sectional view of the front side of the refill body 1 of the embodiment. [Figure 3] This diagram illustrates an example of the manufacturing process for the refill body 1 of the embodiment, where (a) is the air residue suppressant application process, (b) is the ink storage tube-fitting press-fitting process, (c) is the ink filling process, and (d) is the grease filling process. [Figure 4] This table shows the results of verifying the bubble generation state between the refill body 1 of the embodiment and the refill body of the comparative form. [Figure 5]This table summarizes the types of air residue suppressants 40 used in the embodiments and the fluids applied to the front surface 32 of the containment pipe in the comparative configuration. [Modes for carrying out the invention]

[0012] This section describes a refill body 1 for a writing instrument, or cursive body 100, according to an embodiment of the present invention. In this embodiment, a ballpoint pen is used as the writing instrument, or cursive body 100, and a ballpoint pen refill is used as the refill body 1. Figure 1 is a side view of the refill body 1, with the outline of the writing instrument, or cursive body 100, indicated by a dashed line. Figure 2 is a front cross-sectional view of the refill body 1. The refill body 1 comprises a tip member 10, an ink storage tube 30, and a connector 20 connecting the tip member 10 and the ink storage tube 30. Hereinafter, the side with the tip member 10 will be referred to as the front, and the side with the ink storage tube 30 as the rear.

[0013] (Chip member 10) The tip member 10 comprises a tip body 11 and a ball body 12 held in front of the tip body 11. In this embodiment, a so-called needle-type tip member 10 is used as the tip member 10, but it is not limited to this. The tip body 11 comprises a cylindrical central portion 11a, a cylindrical front end portion 11b provided in front of the central portion 11a and having a smaller outer diameter than the central portion 11a, a tapered portion 11c provided in front of the front end portion 11b and having a tapered outer diameter that decreases as it moves forward from the front end portion 11b, and a cylindrical connecting portion 11d provided behind the central portion 11a and having a smaller outer diameter than the central portion 11a.

[0014] The chip body 11 is provided with a ball-holding chamber 14 for holding a ball body 12 and a back hole 15 extending from the rear to the front of the chip body 11. The ball-holding chamber 14 and the back hole 15 are in communication. The front of the ball-holding chamber 14 is crimped inward, and the ball body 12 is rotatably held within the ball-holding chamber 14 with its front side protruding from the front edge of the ball-holding chamber 14. The diameter of the back hole 15 decreases in stages towards the front. A crimped portion 16 is formed on the rear side of the connecting portion 11d.

[0015] (Joint 20) The joint 20 includes a joint body portion 21 and a connecting cylinder portion 22 provided on the rear side of the joint body portion 21 and having an outer diameter larger than that of the joint body portion 21. The material of the joint 20 in the embodiment is PP (polypropylene), but it is not limited thereto. For example, it may be a resin material such as PBT (polybutylene terephthalate) or ABS, or metal.

[0016] A through hole 24 extending in the front-rear direction is provided inside the joint body portion 21. The through hole 24 has, in order from the front side, a chip fixing hole 24a, a valve seat portion 24b, a small-diameter hole 24c, and a large-diameter hole 24d, and these are in communication with each other. The connecting portion 11d of the chip member 10 is press-fitted into the chip fixing hole 24a of the joint 20. Thereby, an ink flow path for ink to flow from the ink storage tube 30 through the through hole 24 and the back hole 15 to the ball body 12 during writing is formed.

[0017] A check valve ball 28 is disposed inside the valve seat portion 24b. FIG. 2 shows the position of the check valve ball 28 when the front side of the refill body 1 is upward. The check valve ball 28 closes most of the small-diameter hole 24c by its own weight, thereby preventing the backflow of ink.

[0018] On the other hand, when the front side of the refill body 1 is downward, the check valve ball 28 falls to the front side of the refill body 1 by its own weight. Thereby, the check valve ball 28 separates from the valve seat portion 24b, the ink flow path in the valve seat portion 24b is opened, and the ink can flow into the valve seat portion 24b.

[0019] The connecting cylinder portion 22 is provided with a connecting hole 22a that communicates with the large-diameter hole 24d of the through hole 24, extends in the front-rear direction, and has a larger diameter than the large-diameter hole 24d. The ink storage tube 30 is press-fitted into the connecting hole 22a. The surface facing the rear on the inner surface of the connecting hole 22a is an opposing surface 23 that opposes the storage tube front surface 32, which is the surface of the front end of the ink storage tube 30.

[0020] (Ink storage tube 30) The ink storage tube 30 is a cylindrical member for storing ink, and an ink storage hole 31 for storing ink 33 is provided inside the ink storage tube 30. The ink storage tube 30 of the embodiment is a transparent polypropylene round pipe, but is not limited thereto, and may be other resin pipes such as PE or ABS, metal pipes, paper tubes, etc. When the ink storage tube 30 is a resin pipe, it may be manufactured by being cut into a predetermined length after being formed by extrusion molding, or may be manufactured by being formed into a predetermined length by injection molding.

[0021] (Ink 33) In the embodiment, the ink 33 is an aqueous ink, and more specifically, an aqueous gel ink. The aqueous gel ink has a lower boiling point than, for example, an oil-based ink, so there is a high possibility of generating bubbles. However, the ink 33 is not limited thereto and may be an oil-based ink. Note that the ink used in the refill body of the present invention is not limited to the writing ink as in the embodiment, and also includes correction ink (correction fluid), glue, etc.

[0022] (Air residue inhibitor 40) An air residue inhibitor 40 is disposed between the front surface 32 of the storage tube of the ink storage tube 30 and the opposing surface 23 of the connection hole 22a facing the front surface 32 of the storage tube. The air residue inhibitor 40 is a liquid substance, and for example, is any one of silicone oil, grease, lubricating oil, or vegetable oil. These air residue inhibitors 40 may be used alone, in combination of two or more, or mixed. The air residue inhibitor 40 is not limited to silicone oil, grease, lubricating oil, or vegetable oil as long as it is a fluid with good wettability to the front surface 32 of the storage tube and low volatility. The air residue inhibitor 40 preferably has a viscosity of 8 mm 2 / s or more at 25°C. Furthermore, "good wettability" means that when applied to the front surface 32 of the storage tube during the manufacturing of the refill body 1 described below, it can be spread and adhere well to the front surface 32 of the storage tube. Also, "low volatility" means that when applied to the front surface 32 of the storage tube 30 of the ink storage tube 30 during the manufacturing of the refill body 1 described below, the ink storage tube 30 is pressed into the connecting cylinder portion 22 of the fitting 20, and the ink does not vaporize during the manufacturing of the refill body 1, or its boiling point is higher than that of the ink used.

[0023] (Manufacturing method) Figure 3 is a diagram illustrating an example of the manufacturing process of the refill body 1 of the embodiment. The manufacturing process of the refill body 1 includes (a) an air residue suppressant application step, (b) an ink storage tube-fitting press-fitting step, (c) an ink filling step, (d) a grease filling step, and (e) a centrifugal degassing step (not shown).

[0024] (a) Air residue suppressant application process Figure 3(a) shows the process of applying an air residue inhibitor to the front surface 32 of the ink storage tube 30. For example, the front surface 32 of the ink storage tube 30 is brought into contact with the air residue inhibitor 40 placed on a stand, thereby applying the air residue inhibitor 40 to the front surface 32 of the ink storage tube.

[0025] (b) Ink container tube-fitting press-fit process Figure 3(b) shows the ink storage tube-fitting press-fitting process, which follows the air residue suppressant application process. In the ink storage tube-fitting press-fitting process, the front part of the ink storage tube 30, to which the air residue suppressant 40 has been applied to the front surface 32 of the storage tube, is press-fitted into the connecting cylindrical portion 22 of the fitting 20 to which the tip member 10 is attached.

[0026] (c) Ink filling process Figure 3(c) shows the ink filling process, which follows the ink storage tube-fitting press-fitting process. In the ink filling process, the ink injector 71 is inserted into the ink storage hole 31, and the ink 33 is injected from the front of the ink storage hole 31.

[0027] (d) Grease filling process Figure 3(d) shows the grease filling process, which follows the ink filling process. Grease 50 is injected behind the ink in the ink storage hole 31 into which the ink 33 has been injected, using a grease injector 72. The grease 50 prevents the ink 33 from leaking out from the rear end of the ink storage tube 30 when the refill body 1 is stored or transported with its front side facing upward or on its side.

[0028] (e) Centrifugal defoaming process (b) In the ink storage tube-fitting press-fitting process, (c) ink filling process, and (d) grease filling process, air bubbles may be mixed into the ink and grease. In the centrifugal degassing process, these air bubbles are removed using a centrifuge. Specifically, the refill body 1 is held in a centrifuge with its tip (the tip member 10 side) facing outwards from the rotation axis and rotated to remove the air bubbles. The refill body 1 of this embodiment is manufactured through the above process. Furthermore, the order of the manufacturing process for refill body 1 is not limited to this. For example, it may be manufactured in the following order: (a) air residue suppressant application process, (c) ink filling process, (b) ink storage tube-fitting press-fitting process, (d) grease filling process, and (e) centrifugal degassing process. Also, if grease 50 is not filled, the (d) grease filling process may be omitted.

[0029] Generally, the ink capacity of an ink reservoir tube may be adjusted depending on the size of the ballpoint pen and the type of ink used. In this case, by appropriately changing the inner diameter of the ink storage tube (the diameter of the ink storage hole), it is possible to adjust the position of the rear end of the ink in the front-to-back direction within the ink storage tube to be the same, even if the amount of ink stored in the ink storage tube differs. In this case, the ink reservoir tube has a simpler shape compared to the fittings and can be manufactured by extrusion molding, so even if multiple types of ink reservoir tubes with different inner diameters are manufactured, the cost will not be significantly higher.

[0030] On the other hand, the connectors that connect to the ink reservoir tube include (1) those in which the outer diameter side of the connecting cylinder is press-fitted into the ink reservoir hole of the ink reservoir tube, and (2) those in which the inner diameter side of the connecting cylinder is press-fitted to the outside of the ink reservoir tube.

[0031] In case (1), changing the inner diameter of the ink reservoir tube necessitates changing the outer diameter of the connecting cylinder. This means that a corresponding fitting must be manufactured for each ink reservoir tube with a different inner diameter. Fittings are more complex in shape than ink reservoir tubes and are generally manufactured by injection molding, so they are more expensive to manufacture than ink reservoir tubes. Therefore, if a corresponding fitting is to be manufactured, an injection molding die is required for each fitting, which increases the overall manufacturing cost of the refill unit.

[0032] In case (2), if the inner diameter of the ink storage tube is changed while keeping the outer diameter constant, the same type of fitting can be used, and the overall manufacturing cost of the refill can be reduced. However, in this case, conventionally, a phenomenon occurred where bubbles formed in the ink inside the ink reservoir tube under high-temperature conditions or after long-term storage. As a result, ink would spray out from the rear end of the ink reservoir tube or the ink discharge volume would become unstable.

[0033] The inventors of this invention believe that the factors causing the generation of these bubbles are as follows: The front surface of the ink reservoir tube and the opposing surface of the connecting hole facing the front surface of the reservoir tube are both manufactured to be flat and parallel to each other. However, since the ink reservoir tube is manufactured by extrusion molding and then cut to a predetermined length, the accuracy of the flatness of the front surface of the reservoir tube is not very high. Therefore, when the ink reservoir tube is pressed into the connecting cylinder of the fitting, even if the front surface of the reservoir tube contacts the opposing surface of the connecting hole, a gap may remain between the front surface of the reservoir tube and the opposing surface of the connecting hole, and air may remain in that gap. Because the air remaining between the front surface of the reservoir tube and the opposing surface of the connecting hole is oriented in a direction that intersects the centrifugal direction (the front-to-back direction of the refill body), it is difficult to degass it by the centrifugal degassing process. As a result, even after the centrifugal degassing process, air remains between the front surface of the containment tube and the opposite surface of the connecting hole, and this remaining air acts as a starting point for the generation of bubbles in the ink.

[0034] However, in the embodiment of the refill body 1, an air residue suppressant 40 is placed between the front surface 32 of the ink storage tube 30 and the opposing surface 23 of the connecting hole 22a. Therefore, when the ink storage tube 30 is pressed into the connecting cylindrical portion 22 of the joint 20, the gap between the front surface 32 of the storage tube and the opposing surface 23 of the connecting hole 22a is filled with the air retention suppressant 40, thereby suppressing the retention of air in that gap. Thus, the generation of air bubbles in the ink 33, which may be caused by residual air, can be reduced. Thus, even in the form of (2) in which the overall manufacturing cost of the refill body of the present invention can be reduced, the generation of air bubbles in the ink of the ink storage tube can be suppressed.

[0035] (Experimental results) Next, we will describe the experimental results verifying the bubble generation reduction effect of the refill body 1 of the embodiment. Figure 4 is a table showing the results of verifying the bubble generation state of the refill body 1 of the embodiment and the refill body of the comparative form.

[0036] A total of 28 types of refill bodies 1 were prepared, 10 of each, for Examples 1 to 18 and Comparative Examples 1 to 10. For Examples 1 to 10 and Comparative Examples 1 to 6, the refill bodies 1 were left standing horizontally in an 80°C environment, and the bubble generation rate was checked after 24 hours. For Examples 11 to 18 and Comparative Examples 7 to 10, the refill bodies were left standing horizontally in a 60°C, 80%RH environment, and the bubble generation rate was checked after 4 weeks. RH represents relative humidity. The "bubble generation rate" is the percentage of refill bodies 1 in each example and comparative example in which bubbles were observed in the ink 33 inside the ink storage tube 30 as seen by visual inspection, out of 10 refill bodies 1.

[0037] Examples 1 to 18 are refill bodies 1 in which the air residue suppressant 40 is placed between the front surface 32 of the housing tube and the opposing surface 23 of the connecting cylindrical portion 22. Comparative Examples 1 to 10 are refill bodies 1 in which the air residue suppressant 40 is not placed between the front surface 32 of the housing tube and the opposing surface 23 of the connecting cylindrical portion 22. In the following description, the same reference numerals as in the embodiments will be used for the comparative examples.

[0038] (Joint 20) The material of fitting 20 is PP (polypropylene).

[0039] (Air residue suppressant 40) Figure 5 is a table summarizing the types of air residue inhibitors 40 used in the embodiments and the fluids applied to the front surface 32 of the containment tube in the comparative embodiment. For the air residue inhibitors 40, silicone oils 1-7, grease, lubricating oil, and vegetable oil were used. For the fluids in the comparative embodiment, water, alcohols 1-3, or red aqueous gel ink were used. Of these, the red aqueous gel ink used in Comparative Example 6 is the same as the red aqueous gel ink filled into the ink containment tube in that comparative example. The "viscosity" in Figure 5 is the value measured using an E-type viscometer at 25°C and 50 rpm. Furthermore, the "coating state" in Figure 4 represents the state when these were applied to the front surface 32 of the housing tube during the manufacturing of the refill body 1, and was evaluated visually as follows. ○: It could be applied to the entire surface of the housing tube front 32 and could be retained between the housing tube front 32 and the opposing surface 23 of the connecting cylinder portion 22 without volatilizing. △: After application, it evaporated and could not be retained between the front surface 32 of the housing tube and the opposing surface 23 of the connecting cylinder portion 22. ×: Due to its low wettability, it could not be applied to the entire surface of the front surface 32 of the housing tube.

[0040] (Ink storage tube 30) The material of the ink storage tubes 30 is transparent PP (polypropylene). All of the ink storage tubes 30 in the examples and comparative examples were round pipes with an outer diameter of φ4.5 mm and an inner diameter of φ3.3 mm, manufactured by extruding and then cutting to a predetermined length.

[0041] The ink 33 filled into the ink storage tube 30 is red aqueous gel ink in Examples 1 to 10 and Comparative Examples 1 to 6. In Examples 11 to 18 and Comparative Examples 7 to 10, the inks are black, red, blue, and blue-black aqueous gel inks. The boiling points of the aqueous gel inks are all around 100°C. In all cases, grease was filled behind the ink.

[0042] (Examples 1 to 10) Examples 1 to 10 were conducted under identical conditions except for the type of air residue inhibitor 40, which was either silicone oil 1 to 7, grease, lubricating oil, or vegetable oil. In all 1 to 10, the bubble generation rate was 0%. This result indicates that the air residue inhibitor 40 is effective in preventing bubble generation during storage in high-temperature environments.

[0043] (Comparative Examples 1 to 6) Comparative Example 1 is an example in which the air residue suppressant 40 is not placed. Comparative Examples 2 to 6 are examples in which water or alcohol 1 to 3, which is a fluid, and red aqueous gel ink filled in the ink storage tube 30 are placed between the front surface 32 of the storage tube and the opposing surface 23 of the connecting cylinder portion 22. Comparative Examples 1 to 6 are the same as Examples 1 to 10 except for the presence or type of the air residue suppressant 40. Comparative Example 1 had a bubble generation rate of 60%. The water in Comparative Example 2, the alcohol 3 (glycerin) in Comparative Example 5, and the red aqueous gel ink in Comparative Example 6 had low wettability to the ink storage tube 30 and were hydrophobic, preventing them from being applied to the entire surface of the front surface 32 of the storage tube. Alcohol 1 (ethanol) in Comparative Example 3 and Alcohol 2 (1-propanol) in Comparative Example 4 were highly volatile and could not be retained between the front surface 32 of the containment tube and the opposing surface 23 of the connecting cylinder portion 22. Therefore, Comparative Examples 2 to 6 were equivalent to Comparative Example 1, in which the air residue suppressant 40 was not placed between the front surface 32 of the containment tube and the opposing surface 23 of the connecting cylinder portion 22, and the bubble generation rate was high in all cases.

[0044] (Examples 11 to 18) Examples 11 to 18 are experiments to verify whether the bubble formation state changes depending on the ink color. Examples 11 to 14 differed only in ink color, with all other conditions being constant, and silicone oil 1 (KF-410) was used as the air residue inhibitor 40. Examples 15 to 18 differed only in ink color, with all other conditions being constant, and silicone oil 4 (KF-96-100cs) was used as the air residue inhibitor 40. The inks used were black, red, blue, and blue-black. In Examples 11 to 18, the samples were left standing horizontally at 60°C and 80% RH, and the rate of bubble formation was confirmed after 4 weeks. In Examples 11 to 18, the bubble generation rate was 0% in all cases, confirming that, regardless of the type (color) of ink, the refill body 1 of the embodiment can suppress the generation of bubbles even during long-term storage.

[0045] (Comparative Examples 7 to 10) Comparative Examples 7 to 10 are examples where the air residue suppressant 40 was not present. Comparative Examples 7 to 10 differ only in ink color; all other conditions are the same. Comparative Examples 7 to 10 are identical to Examples 11 to 18 with the same ink color, except for the presence or absence of the air residue suppressant 40. In all cases, the bubble generation rate in Comparative Examples 7 to 10 was 30%, which was high.

[0046] As described above, in Examples 1 to 18, which are refill bodies 1 in which the air residue suppressant 40 is placed between the front surface 32 of the housing tube and the opposing surface 23 of the connecting cylinder portion 22, the bubble generation rate was 0% in all cases. On the other hand, in Comparative Examples 1 to 10, which are refill bodies 1 in which the air residue suppressant 40 is not placed between the front surface 32 of the housing tube and the opposing surface 23 of the connecting cylinder portion 22, bubbles were generated in all cases.

[0047] Based on the above results, as in this embodiment, by placing the air residue suppressant 40 between the front surface 32 of the storage tube and the opposing surface 23 of the connecting hole 22a facing the front surface 32 of the storage tube, when the ink storage tube 30 is pressed into the connecting cylinder portion of the joint 20, the gap between the front surface 32 of the storage tube and the opposing surface 23 of the connecting hole 22a is filled by the air residue suppressant 40, reducing the possibility of air remaining in that gap. Therefore, it is considered that the increase in air bubbles in the ink, which originates from residual air, was suppressed. [Explanation of symbols]

[0048] 1 Refill 10 Chip components 11. Chip body 12 balls 20 fittings 21 Joint body 22 Connecting cylinder part 22a Connection hole 23 Opposing surfaces 24 Through holes 30 ink reservoir tubes 31 Ink reservoir holes 32 Front of the housing tube 33 Ink 40 Air residue suppressant 100 Cursive

Claims

1. A tip member that holds a ball at its front end, An ink reservoir tube containing ink inside, A joint comprising a joint body portion having a through hole inside, and a connecting cylinder portion extending rearward from the joint body portion, having a connecting hole larger in diameter than the through hole and into which the ink storage tube is press-fitted, the joint connecting the tip member and the ink storage tube, A liquid air residue suppressant is disposed between the front surface of the ink storage tube and the opposing surface of the connecting hole that faces the front surface of the storage tube. A refill body equipped with this feature.

2. The air residue suppressant comprises at least one selected from silicone oil, grease, lubricating oil, or vegetable oil. The refill body according to claim 1.

3. The aforementioned ink is a water-based ink. The refill body according to claim 1 or claim 2.

4. An ink applicator comprising the refill body according to claim 1 or claim 2.

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