JP6381014B2 - Writing instrument using batting to prevent ink ejection - Google Patents

Description

  The present invention relates to a writing instrument using a cotton pad that prevents air from being ejected from a pen tip during writing by forming an air escape path in the cotton pad.

In some conventional writing instruments, a batting filled with ink is accommodated in a shaft cylinder, and one end of a pen tip is brought into contact with the batting and the other end is exposed from the shaft cylinder. And it was possible to write by the ink penetrating from the batting into the pen tip by capillary action.
At this time, when thin fibers were used for the batting, the ink could be held between the thin fibers by the capillary phenomenon generated between the fibers.
However, if air bubbles enter the inside of the batting, for example, when ink is filled, or if air enters for some reason during use, the air cannot escape to the outside through the space between the thin fibers. After that, the retained air expands due to a change in atmospheric pressure or a change in temperature, and ink may be ejected from the pen tip.

Patent Document 1 below discloses an aqueous writing instrument in which an ink occlusion body (corresponding to the batting) filled with aqueous ink is housed in a shaft tube. An air circulation body such as metal or resin having a C-shaped cross section subjected to water repellent treatment is inserted into the ink occlusion body. The air circulation body is opened at both ends of the ink occlusion body, thereby eliminating the difference in air pressure between the front and rear shafts.
In the following Patent Document 2, in the core for a marking pen (corresponding to the above-described batting) filled with ink using crimped fibers, the thickness of the fiber at the center is 1.5 to 4 denier (of the fiber). The unit of thickness is expressed by the weight (g) of 9,000 m of fibers)), the thickness of the fiber in the peripheral part is 1.5 to 3 times that of the central part, and the occupation of the central part There is disclosed a core having a cross-sectional area that is not smaller than a cross-sectional area of a base portion of the tip (corresponding to a portion where the pen tip contacts the pad).

Here, although the ink is held in both the fibers in the central portion and the fibers in the peripheral portion, only the central portion is in contact with the tip, so the ink required for writing is The ink held by the fibers in the central part is used, and when the ink in the central part becomes insufficient, the ink in the peripheral part is supplied to the central part.
Further, as described above, since the ink required for writing uses ink held by the fiber in the central portion having a large holding force due to capillary action, the ink does not fall off during writing.

Japanese Utility Model Publication No. 60-58386 JP-A-53-104318

As described above, in the conventional technique of inserting a different configuration into the batting or configuring with a fiber having a different thickness, if air stays in the batting for some reason, it is effective for discharging it. The configuration is not disclosed. Therefore, the above-described prior art cannot solve the problem of ink ejection and blurring caused by the expansion of the air.
Therefore, in view of the above problems, the present invention has an object to provide a writing instrument that can solve the problem of ink ejection and dripping caused by expansion of air staying in the batting by forming an air escape path in the batting. To do.

In order to solve the above problems, the present invention is composed of the shaft tube 11, the small-diameter fiber 36, and the large-diameter fiber 35 having a large gap between the fibers compared to the small-diameter fiber 36, and the shaft In the writing instrument 10 provided with the batting 33 accommodated in the cylinder 11, the nib 24 with one end contacting the batting 33 and the other end exposed from the shaft cylinder 11,
The large-diameter fibers 35 occupy 5 to 30% of the entire batting 33.
Here, the “large diameter fiber 35” refers to a fiber having a larger cross-sectional area than the “small diameter fiber 36”, specifically, a fiber having a large numerical value represented by denier.
In addition, since the gap between the narrow fibers 36 is narrow, a capillary phenomenon occurs and the fine fibers 36 can hold ink between the thin fibers 36. On the other hand, since the gap between the large diameter fibers 35 is large, the capillary force is weaker than that between the small diameter fibers 36. Therefore, the ink is sucked between the fine fibers 36 having a stronger capillary force, so that the ink is not held between the large fibers 35 and an air escape path is formed.

At this time, the large-diameter fibers 35 occupy a ratio of 5% or more of the entire batting 33. If the large-diameter fiber 35 is less than 5% of the ratio of the batting 33, a sufficiently wide air escape passage cannot be formed between the large-diameter fibers 35. This is because if the air staying in the air expands, ink may be ejected from the pen tip 24.
The large-diameter fiber 35 occupies a ratio of 30% or less of the entire batting 33. When the large-diameter fiber 35 exceeds 30% of the ratio of the batting 33, the ratio of the small-diameter fiber 36 that can hold ink decreases, and the large-diameter fiber 35 has a large gap so that the ink is held. This is because the amount of ink retained in the batting 33 is reduced because it is not possible.

  The thickness of the large diameter fiber 35 is preferably 1.5 to 8 times the thickness of the small diameter fiber 36. Here, when the thickness of the large-diameter fiber 35 is less than 1.5 times the thickness of the small-diameter fiber 36, the thickness is almost the same as the small-diameter fiber 36. The effect of forming an air escape route cannot be expected. On the other hand, if the thickness of the large-diameter fiber 35 exceeds 8 times the thickness of the small-diameter fiber 36, the large-diameter fiber 35 is too thick and narrower than a certain thickness when trying to converge into a cylindrical shape. Also, it is difficult to converge because it is too stiff to make it thinner. The thickness of the large diameter fiber 35 is more desirably 3 to 5 times the thickness of the small diameter fiber 36.

Further, the thickness of the large diameter fiber 35 is desirably 5 denier or more. That is, the thickness of the conventionally used batting fiber is about 3 denier, and in order to form an air escape path between the fibers, the large diameter fiber 35 needs to have this thickness. Because it does. At this time, the thickness of the large-diameter fiber 35 is more preferably 10 denier or more. The large-diameter fibers 35 are desirably arranged together on one side of the entire batting 33.
Here, since the portion where the capillary force is weak is formed between the large-diameter fibers 35, if the small-diameter fiber 36 and the large-diameter fiber 35 are mixed, a region where the capillary force is weak is sufficiently obtained. It cannot be secured. Therefore, in order to form a region having a sufficient area and a weak capillary force, it is desirable that the large-diameter fibers 35 are unevenly distributed in the batting 33.

Note that the pen tip 24 or a member interposed between the pen tip 24 and the pen tip 24 is inserted into the axial center portion of the batting 33. At this time, if the region of the large diameter fiber 35 exists in this axial center portion, the air escape path between the fibers of the large diameter fiber 35 is blocked by the pen tip 24. Then, the intended purpose of discharging the air in the batting 33 cannot be achieved. Therefore, also in this sense, it is desirable that the large-diameter fibers 35 are unevenly distributed near the outer periphery of the batting 33.
Hereinafter, how the problem is solved by the operation of the present invention will be described.
When ink is filled into the batting 33, there is a large gap between the large-diameter fibers 35, so that the air passage 34 is a space for escaping air staying in the batting 33 without holding ink, and the small-diameter fibers The 36 will hold ink. If the air passage 34 is formed, even if air enters the small-diameter fiber 36, air does not accumulate in the filling 33 because the air goes to the air passage 34.

  Further, when the air reaches the air passage 34, even if the air expands due to a change in pressure or temperature, the expanded air does not act on the extrusion of the ink, and as a result, the ejection of ink does not occur. It has become.

In the batting of the present invention, since the gap between the large-diameter fibers is large, the air passage is formed without holding ink, and air is exhausted from the inside of the batting, so that even when the pressure changes or the temperature changes Ink no longer squirts from the nib.
Moreover, since the said large diameter fiber is only used for a part of said fiber of the said batting, it can produce without a normal manufacturing process and a big change.

It is a front view of the writing instrument which concerns on embodiment of this invention. It is the front view which removed the cap of the writing instrument which concerns on embodiment of this invention. It is front sectional drawing of the state which removed the cap of the writing instrument which concerns on embodiment of this invention. It is the schematic diagram which expanded the cross section of the batting 33 of this invention.

(overall structure)
As shown in FIG. 1, the writing instrument 10 according to the present embodiment has an appearance in which two caps 21 are attached to both ends of the shaft tube 11. In the following description, of the pen tips 24 provided at both ends, the tip provided with the thick pen tip 25 is referred to as the leading end side, while the tip provided with the thin pen tip 26 is referred to as the rear end. Let it be the side.
When the caps 21 are removed, the pen tips 24 for writing are exposed from both ends of the barrel 11 as shown in FIG.
The shaft cylinder 11 is fitted into a cylindrical central portion 12, a fine pen tip accommodating portion 13 integrally formed on the rear end side of the central portion 12, and an opening portion on the front end side of the central portion 12. And a thick pen nib accommodating portion 14 connected with each other.

The central portion 12 accommodates a batting 33 filled with ink (see FIG. 3). The batting 33 is molded into a substantially cylindrical shape, and has a diameter that is the same as the inner diameter of the central portion 12 and a length that is the same as the length of the central portion 12.
Further, the fibers of the batting 33 extend in the longitudinal direction and are provided with a small diameter fiber 36 and a large diameter fiber 35. The large-diameter fiber 35 is a fiber having a larger cross-sectional area than the small-diameter fiber 36. The small diameter fiber 36 and the large diameter fiber 35 are wrapped by a wound film 37. At this time, the large-diameter fibers 35 are collectively arranged on one side of the batting 33.
The ink filled in the batting 33 is held between the thin fibers 36 by a capillary phenomenon. On the other hand, since the gap between the large diameter fibers 35 is large, the capillary force is weaker than that between the small diameter fibers 36. Therefore, the ink is sucked between the small diameter fibers 36 having a stronger capillary force, so that the ink is not held between the large diameter fibers 35, and this is an air passage 34 (see FIG. 4).

The two nibs 24 are inserted so that one end of each nib 24 comes into contact with the thin fiber 36, and ink penetrates the other end of the two nibs 24 by capillary action. To do.
(Detailed configuration)
The center portion 12, the fine pen tip accommodating portion 13, the thick pen tip accommodating portion 14, and the cap 21 shown in FIG. 2 are formed by injection molding of polypropylene.
The fine pen tip accommodating portion 13 has a thin pen tip accommodating portion large diameter portion 18 formed integrally with the central portion 12 on the front end side, and a thin pen tip accommodating portion small diameter portion 20 on the rear end side, There is a fine pen tip accommodating portion middle diameter portion 19 with the fine pen tip accommodating portion large diameter portion 18 and the thin pen tip accommodating portion small diameter portion 20 interposed therebetween. Further, the outer peripheral surface of the fine pen tip accommodating portion large diameter portion 18 is a surface to be fitted with the thin cap 23.

The thick pen nib accommodating part 14 has a thick pen nib accommodating part connecting part 17 connected to the central part 12 on the rear end side, and a thick nib accommodating part small diameter part 16 on the front end side. A large nib accommodating portion large diameter portion 15 is interposed between the accommodating portion connecting portion 17 and the thick nib accommodating portion small diameter portion 16. An outer peripheral surface of the thick pen tip accommodating portion connecting portion 17 is formed so as to be inserted into and fixed to the inner peripheral surface of the central portion 12. Further, the outer peripheral surface of the large-diameter portion 15 of the thick nib accommodating portion is a surface that fits into the thick cap 22.
As shown in FIG. 3, the fine pen tip 26 includes a fine relay core 32 that contacts the fine fiber 36 on the front end side, and a fine tip lead 29 exposed from the fine pen tip accommodating portion 13 to the rear end side. Have The narrow core 29 is tapered in the rear end direction.

The thick pen tip 25 has a thick relay core 31 that contacts the thin fiber 36 on the rear end side, and a thick tip core 28 that is exposed from the thick pen tip accommodating portion 14 to the front end side. The tip of the thick tip 28 is cut obliquely.
The thick nib 25 and the thin nib 26 shown in FIG. 3 are formed of hardened fiber bundles.
As shown in FIG. 4A, the cross section of the batting 33 has a small-diameter fiber region 39 occupying a relatively large region and a large-diameter fiber region 38 that is unevenly distributed on one side. The small-diameter fiber region 39 is a bundle of a plurality of bundles of fibers having relatively small denier values, and the gap between the fibers is relatively small as shown in FIG. It is narrow and a capillary force for holding ink is generated here. On the other hand, the large-diameter fiber region 38 is a collection of a plurality of fibers having a relatively large denier value, and the gap between the fibers is relatively wide as shown in FIG. Capillary force sufficient to hold ink is not generated, and the air passage 34 is formed.

The batting 33 is formed by bundling the small-diameter fibers 36 and the large-diameter fibers 35 in a cylindrical shape and is wrapped by the wound film 37. At this time, as the wound film 37, a method of wrapping the batting 33 with a film of resin or the like, a method of coating the outer peripheral portion of the batting 33, and the like can be considered.
As for the occupation range of the said large diameter fiber area | region 38, it is desirable to occupy the ratio of about 5 to 30% of the whole cross section of the said batting 33. FIG.
The thickness of the small-diameter fiber 36 is less than 5 denier, preferably about 3 denier.
The thickness of the large diameter fiber 35 is preferably 1.5 to 8 times the thickness of the small diameter fiber 36. Further, the thickness of the large-diameter fiber 35 is preferably 5 denier or more, preferably 10 denier or more, and if it is 15 denier or more, the function and effect are further improved.

(Function)
When the batting 33 is filled with ink, the gap between the large diameter fibers 35 is large, so that the ink is held between the small diameter fibers 36 without holding the ink. Therefore, the air passage 34 is formed between the large-diameter fibers 35 and is a space through which the air in the batting 33 is released.
(effect)
When one end of the nib 24 is brought into contact with the small-diameter fiber 36, the ink in the small-diameter fiber 36 permeates the other end of the nib 24 by capillary action. Then, the ink that has penetrated into the other end of the nib 24 is transmitted to the paper surface and writing is possible.

At this time, even if the air infiltrate and stays in the batting 33 for some reason, and then the air in the batting 33 expands due to atmospheric pressure change or temperature change, between the large diameter fibers 35 Through the formed air passage 34, the accumulated air is discharged from the air passage 34. Therefore, ink is not ejected by the expansion of the staying air.
Further, even if the large-diameter fibers 35 are mixed with the batting 33, the small-diameter fibers 36 occupy most of the ratio. Therefore, it is not necessary to reduce the ink filling amount so much.
Further, the writing instrument 10 according to the present embodiment is a marker pen having a pen tip at both ends, but is not limited to this, and can be realized as a sign pen or a ballpoint pen of a type in which ink is dipped and held in the batting 33 It is.

About the writing instrument of the shape shown in the following FIGS. 1-4, the batting which concerns on Examples 1-7 of the characteristic shown in following Table 1 and Comparative Examples 1-3 was adjusted, and this was filled. The dimensions of the batting were 6.5 mm in diameter, 80 mm in length, 89% porosity, and 17% crimp rate. For each of these examples and comparative examples, an experiment of the following procedure was tried as an ink ejection test.
1. Leave the writing instrument at 0 ° C for 6 hours.
2. Thereafter, the temperature is gradually raised to 40 ° C. over 6 hours.
3. When 40 ° C is reached, leave it for 6 hours.
4). Thereafter, the temperature is gradually lowered to 0 ° C. over 6 hours.

Experiments were conducted by changing the thickness of the large-diameter fiber and the occupation ratio of the large-diameter fiber with respect to the entire batting, with the steps 1 to 4 as one cycle. The evaluation criteria for the experimental results were as follows.
A: Ink leakage and movement were not recognized at all.
B: Although ink movement was recognized, there was no leakage.
C: Ink leakage occurred.
The experimental results are shown in Table 1 below.

In addition, 註 1 in the table represents that the fiber of the large diameter fiber was too thick and could not be converged into a cylindrical shape. In addition, ridge 2 indicates that the ink filling could not be performed because the occupation ratio of the fine fiber was too low.

As a result, no ink leakage occurred in Examples 1 to 7.
On the other hand, in the case of the comparative example 1, the fiber of the large diameter fiber was too thick and could not be converged into a cylindrical shape.
Moreover, the difference between Examples 1-6 and Comparative Examples 2 and 3 is only the occupation ratio of the large-diameter fiber with respect to the whole batting.

In Comparative Example 2, the occupation ratio of the large diameter fiber is lower than those in Examples 1 to 6, and in Comparative Example 3, the occupation ratio of the large diameter fiber is higher than those in Examples 1 to 6.
In the case of Comparative Example 2, the occupation ratio of the large-diameter fibers was too low to form an air passage serving as an air escape path in the batting, and ink leakage occurred.
In the case of Comparative Example 3, since the occupation ratio of the large-diameter fibers was too high, the portion of the small-diameter fibers was too small, and ink ejection occurred without being able to store the ink.
From the above results, it was found that the occupation ratio of the large diameter fiber to the entire batting is preferably about 5 to 30%, and the thickness of the large diameter fiber is preferably about 1.5 to 8 times that of the small diameter fiber.

  Further, when paying attention to the thickness of the large-diameter fiber, it has been found that it is desirable to exceed 5 denier of Example 7, and if possible, it is more desirable to be 10 denier or more as in Examples 1-6.

10 Writing instruments 11 Shaft cylinder
12 Central part 13 Thin nib receiving part
14 Thick nib housing 15 Thick nib housing large diameter
16 Thick nib receiving part small diameter part 17 Thick nib receiving part connecting part
18 Fine pen tip storage section large diameter portion 19 Thin pen tip storage section medium diameter portion
20 Thin nib holder small diameter part 21 Cap
22 thick cap 23 thin cap
24 nib 25 thick nib
26 Fine pen tip 27 Tip
28 Thick tip 29 Thin tip
30 Relay core 31 Thick relay core
32 Fine relay core 33 Filling
34 Air passage 35 Large diameter fiber
36 Thin fiber 37 Rolled film
38 Large fiber region 39 Small fiber region

Claims (5)

A barrel,
Constituted by a small diameter fiber and a large diameter fiber having a large gap between the fibers compared to the small diameter fiber, and a batting accommodated in the shaft tube,
In a writing instrument provided with a nib that contacts one end to the batting and the other end exposed from the shaft tube,
While the said large diameter fiber accounts for 5 to 30% of the whole cross section of the said batting ,
The region occupied by the large-diameter fibers is unevenly distributed on one side of the cross section,
A writing instrument, wherein an air passage is formed between the large-diameter fibers .   The writing instrument according to claim 1, wherein the thickness of the large-diameter fiber is 1.5 to 8 times the thickness of the small-diameter fiber.   The writing instrument according to claim 2, wherein the thickness of the large-diameter fiber is 3 to 5 times the thickness of the small-diameter fiber.   The writing instrument according to claim 1, 2, or 3, wherein the thickness of the large-diameter fiber is 5 denier or more.   The writing instrument according to claim 4, wherein a thickness of the large-diameter fiber constituting the batting is 10 denier or more.