JP2002370491A - Cap for ball-point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cap for a ball-point pen which is free from the imperfect sealing, of the apex of a tip part, which is caused by a backlash generated by a creep attributed to a repulsive force of a sealing member between the cap for the ball-point pen and the ball-point pen. SOLUTION: The cap 10 for the ball-point pen 60 is equipped with a cap body 20 formed, in a freely attachable/detachable manner, on the tip 90 side of the ball-point pen 60 and a sealing member 50 installed inside the cap body 20. The sealing member 50 is formed in such a way that it covers the apex of the tip 90 by fitting the cap body 20 to the tip 90 side of the ball-point pen 60. The hardness of the sealing member 50 is set to be Hs5 to Hs35 in terms of a Shore A hardness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ballpoint pen cap, and more particularly to a ballpoint pen cap provided with a sealing member for covering the tip of a chip inside a cap body, and is particularly suitable for use in an aqueous ballpoint pen or an aqueous gel ink ballpoint pen. The present invention relates to a simple ballpoint pen cap.

[0002]

2. Description of the Related Art Conventionally, a ballpoint pen cap has
Various things are provided. For example, a cap body detachably formed on the tip side of a ballpoint pen and a seal member provided inside the cap body are provided. When the cap body is mounted on the tip side of the ballpoint pen, the seal member touches the tip of the tip. A ballpoint pen cap formed to cover is provided.

[0003] This type of ballpoint pen cap is widely used in water-based ballpoint pens and water-based gel ink ballpoint pens. That is, in the aqueous ballpoint pen and the aqueous gel ink ballpoint pen, the tip of the chip is easier to dry and the solvent component in the ink is more likely to evaporate from the tip of the chip than the oil-based ballpoint pen.

For this reason, in a water-based ball-point pen or a water-based gel ink ball-point pen, it is necessary to prevent the tip of the chip from drying and to prevent the solvent component in the ink from volatilizing. In such a case, a ballpoint pen cap formed so that the sealing member covers the tip of the chip is often used.

Hereinafter, an example of this type of conventional ballpoint pen cap will be described with reference to the drawings. FIG. 4 shows a conventional ballpoint pen cap 10 of this type in which the tip of a ballpoint pen 60 is used.
FIG. 4 is a side cross-sectional view showing a state mounted on the 90 side. (Ball Pen 60) First, the ball pen 60 will be briefly described.

As shown in FIG. 4, a ball-point pen 60 includes a cylindrical barrel 70, a conical base 80 fixed to one side of the barrel 70, and a tip 90 protruding from the base 80. Have. (Shaft tube 70) The shaft tube 70 is formed in a cylindrical shape. A conical base 80 is fixed to one side of the shaft cylinder 70. An engagement projection 71 for engaging the ball-point pen cap 10 with the ball-point pen 60 is provided on the outer peripheral surface of the barrel 70 near the base 80. The engaging projection 71 is formed in an annular shape on the outer peripheral surface of the barrel 70 near the base 80.

The barrel 70 is formed integrally by injection molding using a synthetic resin such as AS (acrylonitrile styrene). (Base 80) The base 80 is formed in a conical shape. The base 80 has one side fixed to the barrel 70 and the tip 90 protruding from the other side.

The base 80 is formed by cutting a metal material such as stainless steel. (Chip 90) The chip 90 includes a ball 91 and this ball
A holder 92 for holding 91 is provided. The ball 91 is formed of a cemented carbide. The holder 92 is made of a metal material such as stainless steel,
It is formed by cutting.

The tip 90 projects from the side of the base 80 opposite the barrel 70 so that the ball 91 faces the opposite barrel 70. (Cap for Ballpoint Pen) Next, the cap for ballpoint pen 10 will be described in detail. As shown in FIG. 4, the ballpoint pen cap 10 includes a cylindrical cap body 20, a cylindrical crown 30 fixed to one side of the cap body 20, and a clip formed integrally with the crown 30. 40 and a spherical seal member 50 held by the crown 30.

(Cap body 20) The cap body 20
Is formed in a cylindrical shape. Also, this cap body
An engagement recess 21 for engaging the ballpoint pen cap 10 with the ballpoint pen 60 is provided on the inner peripheral surface on one side of 20. A fitting projection 22 for fixing the crown 30 to the cap body 20 is provided on the inner peripheral surface of the cap body 20 on the side opposite to the engagement recess 21.

The engagement recess 21 is formed in an annular shape on the inner peripheral surface on one side of the cap body 20. The engagement concave portion 21 engages with the engagement convex portion 71 provided on the outer peripheral surface near the base 80 of the barrel 70 when the ballpoint pen cap 10 is mounted on the tip 90 side of the ballpoint pen 60. Is formed. When the engagement concave portion 21 and the engagement convex portion 71 are engaged, the ball-point pen cap 10
It is locked to the side.

The fitting projection 22 is provided on the cap body 20.
Are formed in an annular shape on the inner peripheral surface on the side of the anti-engaging recess 21. The cap body 20 is integrally formed by injection molding using a synthetic resin such as PET (polyethylene terephthalate). (Crest Crown 30) The crown 30 is formed in a cylindrical shape. Further, on one side of the crown 30, a circular holding portion 31 for holding the seal member 50 is provided. In addition, the crown 30 is provided with a circular ventilation hole 32 penetrating from the end on the side opposite to the holding portion 31 to the holding portion 31. A fitting recess 33 for fixing the crown 30 to the cap body 20 is provided on the outer peripheral surface of the crown 30 on the holding portion 31 side. The fitting concave portion 33 is formed in an annular shape on the outer peripheral surface of the crown 30 on the holding portion 31 side. In addition, anti-holding part of crown 30
A clip 40 formed integrally with the crown 30 protrudes from the outer peripheral surface on the 31 side.

The crown 30 is formed integrally with the clip 40 by injection molding using a synthetic resin such as ABS (acrylonitrile butadiene styrene), PC (polycarbonate), or PP (polypropylene). In addition, when the crown 30 is fixed to the cap body 20, the holding portion 31 side of the crown 30 is fitted to the fitting projection of the cap body 20.
Push in from the opening on the 22 side to fit the fitting recess 33 and the fitting protrusion 22
Is performed by fitting.

(Clip 40) The clip 40 is
And are formed integrally with it. Also, this clip 40
The crown 30 protrudes from the outer peripheral surface on the side opposite to the holding portion 31 toward the engaging recess 21 of the cap body 20. The clip 40 is formed integrally with the crown 30 by injection molding using a synthetic resin such as ABS (acrylonitrile butadiene styrene), PC (polycarbonate), or PP (polypropylene).

(Seal Member 50) The seal member 50 is formed in a spherical shape. The seal member 50 is made of rubber such as nitrile rubber, silicon rubber, or EPDM (ethylene propylene diene rubber). The seal member 50 is press-fitted into the holding portion 31 of the crown 30, thereby being held by the crown 30 and positioned inside the cap body 20.

When the ball-point pen cap 10 is mounted on the tip 90 side of the ball-point pen 60, the tip of the tip 90 is buried in the sealing member 50, whereby the sealing member 50 covers the tip of the tip 90. The tip of the tip 90 is prevented from drying, and the solvent component in the ink is prevented from volatilizing.

[0017]

When a cap for a ballpoint pen is mounted on the tip side of a ballpoint pen, the tip of the tip is buried in the seal member, whereby the seal member is elastically deformed. Further, the elastically deformed seal member always tries to return to the original shape. Then, in a state where the cap for the ball-point pen is mounted on the tip side of the ball-point pen, the elastically deformed sealing member always tries to return to the original shape, so that the force in the direction to be separated from the ball-point pen is continuously applied to the cap for the ball-point pen. It will be.

If a force is continuously applied to the ball-point pen cap in a direction in which the ball-point pen is pulled away from the ball-point pen, an engaging concave portion provided on the cap body and an engaging convex portion provided on the shaft cylinder are deformed. When the engaging concave portion or the engaging convex portion is deformed, play occurs due to creep between the ballpoint pen cap and the ballpoint pen, whereby the tip end seal becomes incomplete and the tip end dryness occurs. There is a possibility that the prevention and the volatilization of the solvent component in the ink cannot be sufficiently achieved.

However, if the hardness of the sealing member is reduced, play between the ball-point pen cap and the ball-point pen can be reduced, but the sticky surface of the sealing member increases, and the tip of the chip becomes dirty. In the worst case, the ballpoint pen becomes unwritable.

That is, writability is prevented from occurring between the ball-point pen cap and the ball-point pen while writability is prevented by stickiness on the surface of the seal member, thereby preventing incomplete sealing of the tip of the chip. In this way, it is extremely difficult to sufficiently prevent the tip of the chip from drying and prevent the solvent component in the ink from volatilizing.

According to the first aspect of the present invention, the hardness of the seal member is set within a predetermined range so that writing on the surface of the seal member does not become impossible due to stickiness of the seal member. This also prevents rattling between the ballpoint pen cap and the ballpoint pen, thereby preventing incomplete sealing of the tip of the tip, preventing the tip from drying, and evaporating the solvent component in the ink. It is an object of the present invention to provide a cap for a ballpoint pen capable of sufficiently preventing such a problem.

(Claim 2) A second aspect of the present invention.
According to the invention described in (1), in addition to the object of the invention described in claim 1, by limiting the hardness of the seal member to a predetermined range, the stickiness of the surface of the seal member is reduced. An object of the present invention is to provide a cap for a ballpoint pen that prevents dirt.

(Claim 3) A third aspect of the present invention.
According to the invention described in (1), in addition to the object of the invention described in claim 1, by further restricting the hardness of the seal member within a predetermined range, the stickiness of the surface of the seal member is completely eliminated, thereby, An object of the present invention is to provide a cap for a ballpoint pen that completely prevents the tip from being stained.

(Claim 4) Furthermore, claim 4 of the present invention.
According to the invention described in (1), in addition to the objects of the inventions described in claims (1) to (3), by providing the sealing member with nitrile rubber, there is provided a cap for a ballpoint pen in which the sealing performance at the tip of the tip is further improved. The purpose is to:

[0025]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventor has found that by setting the hardness of the seal member within a predetermined range, it becomes impossible to write due to stickiness of the surface of the seal member. While preventing the backlash from occurring between the ballpoint pen cap and the ballpoint pen, thereby preventing the tip of the tip from drying and
It has been found that the volatilization of the solvent component in the ink can be sufficiently prevented, and the following invention has been completed.

(Claim 1) That is, of the present invention, the invention described in claim 1 is based on a chip (9) of a ballpoint pen (60).
A cap body (20) detachably formed on the 0) side, and a sealing member (50) provided inside the cap body (20).
And the cap body (20) is connected to a ballpoint pen (60).
When mounted on the tip (90) side of the
0) is a ballpoint pen cap (10) formed so as to cover the tip of the chip (90), wherein the seal member (50)
The hardness is Shore A hardness, Hs5 or more and Hs35
It is characterized by the following.

Here, the "cap body (20)" is one of the members constituting the ballpoint pen cap (10), and is detachably formed on the tip (90) side of the ballpoint pen (60). A thing. The “seal member (50)” is provided inside the cap body (20), and when the cap body (20) is mounted on the tip (90) side of the ballpoint pen (60), the tip (90) It covers the tip. That is, when the cap body (20) is mounted on the tip (90) side of the ballpoint pen (60), the seal member (50) seals the vicinity of the ball (91) of the tip (90). .

Specifically, the cap body (20) can be formed, for example, in a cylindrical shape. Also, in this case,
On one side of the cap body (20), a crown (30) formed separately from the cap body (20) can be provided. Then, by holding the sealing member (50) on the crown (30), the sealing member (50) can be provided inside the cap body (20).

The cap body (20) is not limited to the case where it is formed in a cylindrical shape.
3) and a hemispherical crown portion (24) continuously provided on one side of the cylindrical portion (23). Also,
The seal member (50) can be formed, for example, in a spherical shape. In addition, the sealing member (50) includes the cap body (20)
When attached to the tip (90) side of the ballpoint pen (60),
It may be formed so as to cover the tip of the chip (90). Therefore, the chip is not limited to a spherical shape.
It may be formed in a columnar shape, a disk shape, or a cubic shape.

The seal member (50) may be formed of rubber such as natural rubber, isopropylene rubber, butadiene rubber, nitrile rubber, silicon rubber, butyl rubber, ethylene propylene diene rubber, styrene butadiene rubber, and fluoro rubber. Can be. Furthermore, the hardness of the seal member (50) is Shore A hardness, which is Hs5 or more and Hs35 or less.

In the ballpoint pen cap (10) according to the present invention, by setting the hardness of the sealing member (50) to Hs5 or more and Hs35 or less in Shore A hardness, writing on the surface of the sealing member (50) becomes impossible due to stickiness. While avoiding play between the ballpoint pen cap (10) and the ballpoint pen (60),
By preventing the tip (90) from being incompletely sealed, the tip (90) is sufficiently prevented from drying and the solvent component in the ink is prevented from being volatilized.

The hardness of the sealing member (50) is Shore A
If the hardness is over Hs35, the elasticity of the seal member (50) is large, and as a result of use, play is likely to occur between the ballpoint pen cap (10) and the ballpoint pen (60). The seal may be incomplete, and it may not be possible to sufficiently prevent the tip of the tip (90) from drying and prevent the solvent component in the ink from volatilizing.

On the other hand, the hardness of the sealing member (50) is Shore A
If the hardness is less than Hs5, the stickiness of the surface of the seal member (50) increases, and as a result, the tip of the tip (90) becomes dirty, or the ink deteriorates, and the ballpoint pen (60) becomes harder. There is a risk that writing becomes impossible. (Claim 2) In the invention according to claim 2 of the present invention, in addition to the configuration of the invention described in claim 1, the seal member (50) has a hardness of Shore A hardness, Hs20.
It is not less than Hs35 or less.

As described above, the ballpoint pen cap (10) according to the present invention reduces the stickiness of the surface of the seal member (50) by setting the hardness of the seal member (50) to Hs20 or more and Hs35 or less in Shore A hardness. This reduces dirt on the tip of the tip (90). Of course, even if the hardness of the sealing member (50) is less than Hs20 in Shore A hardness, the tip of the tip (90) may become dirty due to the stickiness of the surface of the sealing member (50), but it is sufficiently writable.

(Claim 3) A third aspect of the present invention.
The invention described in (1) is characterized in that, in addition to the configuration of the invention described in claim 1, the hardness of the seal member (50) is Shore A hardness and Hs25 or more and Hs35 or less. As described above, the ballpoint pen cap (10) according to the present invention has a hardness of H (Shore A hardness) of the sealing member (50).
By making s25 or more and Hs35 or less, the stickiness on the surface of the seal member (50) is completely eliminated, and
This completely prevents the tip (90) from becoming dirty.

Of course, even if the hardness of the sealing member (50) is less than Hs25 in Shore A hardness, the tip of the tip (90) may become dirty due to stickiness of the surface of the sealing member (50), but it is possible to write sufficiently. is there. (Claim 4) In the invention according to claim 4 of the present invention, in addition to the structure of the invention described in claims 1 to 3, the seal member (50) is formed of nitrile rubber. It is characterized by.

As described above, in the ballpoint pen cap (10) according to the present invention, the workability and the sealing performance at the tip of the tip (90) are further improved by forming the seal member (50) from nitrile rubber. -ing

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a ballpoint pen cap according to the present invention will be described below with reference to the drawings. FIG.
FIG. 2 is a side sectional view showing a state in which the ballpoint pen cap 10 according to the present embodiment is mounted on the chip 90 side of the ballpoint pen 60, and FIG. 2 is an enlarged view of a main part of the ballpoint pen cap 10.

(Ball Pen 60) First, the ball pen 60 will be briefly described. As shown in FIG.
Is a cylindrical barrel 70, a conical base 80 fixed to one side of the barrel 70, and a tip 90 protruding from the base 80.
And

(Shaft tube 70) The shaft tube 70 is formed in a cylindrical shape. A conical base 80 is fixed to one side of the shaft cylinder 70. A ballpoint pen cap 10 is attached to the outer peripheral surface of the barrel 70 near the base 80.
Is provided with an engaging projection 71 for locking the projection. The engaging projection 71 is formed in an annular shape on the outer peripheral surface of the barrel 70 near the base 80.

The barrel 70 is made of AS (acrylonitrile styrene), PS (polystyrene), or PP.
It is integrally formed by injection molding using a synthetic resin such as (polypropylene). (Base 80) The base 80 is formed in a conical shape. The base 80 has one side fixed to the barrel 70 and the tip 90 protruding from the other side.

The base 80 is formed by cutting a metal material such as brass and then plating the surface. (Chip 90) The chip 90 includes a ball 91 and this ball
A holder 92 for holding 91 is provided. The ball 91 is formed of a cemented carbide. The holder 92 is made of a metal material such as stainless steel,
It is formed by cutting.

The tip 90 protrudes from the side of the base 80 opposite the barrel 70 so that the ball 91 faces the opposite barrel 70. (Cap for Ballpoint Pen) Next, the cap for ballpoint pen 10 will be described in detail. As shown in FIG. 1, a ballpoint pen cap 10 includes a cylindrical cap body 20, a cylindrical crown 30 fixed to one side of the cap body 20, and a clip formed integrally with the crown 30. 40 and a spherical seal member 50 held by the crown 30.

(Cap body 20) The cap body 20
Is formed in a cylindrical shape. Also, this cap body
An engagement recess 21 for engaging the ballpoint pen cap 10 with the ballpoint pen 60 is provided on the inner peripheral surface on one side of 20. A fitting projection 22 for fixing the crown 30 to the cap body 20 is provided on the inner peripheral surface of the cap body 20 on the side opposite to the engagement recess 21.

The engaging recess 21 is formed in an annular shape on the inner peripheral surface on one side of the cap body 20. The engagement concave portion 21 engages with the engagement convex portion 71 provided on the outer peripheral surface near the base 80 of the barrel 70 when the ballpoint pen cap 10 is mounted on the tip 90 side of the ballpoint pen 60. Is formed. When the engagement concave portion 21 and the engagement convex portion 71 are engaged, the ball-point pen cap 10
It is locked to the side.

The fitting projection 22 is provided on the cap body 20.
Are formed in an annular shape on the inner peripheral surface on the side of the anti-engaging recess 21. The cap body 20 is integrally formed by injection molding using a synthetic resin such as PET (polyethylene terephthalate) or PP (polypropylene).

(Crown Crown 30) The crown 30 is formed in a cylindrical shape. In addition, a sealing member is provided on one side of the crown 30.
A circular holding portion 31 for holding 50 is provided. In addition, the crown 30 is provided with a circular ventilation hole 32 penetrating from the end on the side opposite to the holding portion 31 to the holding portion 31. A fitting recess 33 for fixing the crown 30 to the cap body 20 is provided on the outer peripheral surface of the crown 30 on the holding portion 31 side.
Is provided. The fitting concave portion 33 is formed in an annular shape on the outer peripheral surface of the crown 30 on the holding portion 31 side. A clip 40 formed integrally with the crown 30 is protruded from an outer peripheral surface of the crown 30 on the side opposite to the holding portion 31.

The crown 30 is formed integrally with the clip 40 by injection molding using a synthetic resin such as ABS (acrylonitrile butadiene styrene), PC (polycarbonate), or PP (polypropylene). In addition, when the crown 30 is fixed to the cap body 20, the holding portion 31 side of the crown 30 is fitted to the fitting projection of the cap body 20.
Push in from the opening on the 22 side to fit the fitting recess 33 and the fitting protrusion 22
Is performed by fitting.

(Clip 40) The clip 40 is
And are formed integrally with it. Also, this clip 40
The crown 30 protrudes from the outer peripheral surface on the side opposite to the holding portion 31 toward the engaging recess 21 of the cap body 20. The clip 40 is formed integrally with the crown 30 by injection molding using a synthetic resin such as ABS (acrylonitrile butadiene styrene), PC (polycarbonate), or PP (polypropylene).

(Seal Member 50) The seal member 50 is formed in a spherical shape. The seal member 50 is formed of rubber such as nitrile rubber. The seal member 50 is press-fitted into the holding portion 31 of the crown 30, thereby being held by the crown 30 and positioned inside the cap body 20.

When the ball-point pen cap 10 is mounted on the tip 90 side of the ball-point pen 60, the tip of the tip 90 is buried in the seal member 50, whereby the seal member 50 covers the tip of the tip 90. The tip of the tip 90 is prevented from drying, and the solvent component in the ink is prevented from volatilizing. More specifically, as shown in FIG.
When mounted on the side, the ball 91 and the vicinity of the ball 91 of the holder 92 are buried in the seal member 50. Then, the sealing member
Since 50 covers the surface of the protruding portion of the ball 91 and closes the gap between the ball 91 and the holder 92,
The tip of the tip 90 is prevented from drying, and the solvent component in the ink is prevented from volatilizing.

Further, by forming the sealing member 50 from nitrile rubber, the processability and the sealing performance of the tip of the tip 90 can be further improved. That is, nitrile rubber is not only excellent in processability,
It is particularly excellent in airtightness (gas barrier property) among various rubbers. Therefore, by forming the seal member 50 with nitrile rubber, it is possible to more reliably prevent the tip of the chip 90 from drying and prevent the solvent component in the ink from volatilizing.

(Hardness of Seal Member 50)
50 is the Shore A hardness, Hs5 or more, Hs3
5 or less. By setting the hardness of the seal member 50 to be not less than Hs5 and not more than Hs35 in Shore A hardness, it is possible to prevent the writing from becoming impossible due to the stickiness of the surface of the seal member 50, and yet to prevent the backlash between the ballpoint pen cap 10 and the ballpoint pen 60. This prevents the tip 90 from being incompletely sealed, thereby preventing the tip 90 from drying out and preventing the solvent component in the ink from evaporating. It is enough.

If the hardness of the seal member 50 is set to Hs 20 or more in Shore A hardness, the stickiness of the surface of the seal member 50 can be reduced, thereby preventing the tip of the tip 90 from being stained. Of course, the sealing member
Even if the hardness of 50 is less than Hs20 in Shore A hardness and Hs5 or more, the tip of the tip 90 may be stained due to stickiness of the surface of the sealing member 50, but it can be sufficiently written.

Further, if the hardness of the seal member 50 is Hs 25 or more in Shore A hardness, stickiness on the surface of the seal member 50 can be completely eliminated, thereby completely preventing the tip 90 of the tip 90 from being stained. It is. Of course, even if the hardness of the sealing member 50 is less than Hs25 in Shore A hardness,
There is a possibility that the tip of the tip 90 will be stained by stickiness on the surface of the seal member 50, but it is possible to write sufficiently.

If the hardness of the seal member 50 is more than Hs35 in Shore A hardness, the elasticity of the seal member 50 is large, and as a result of use, play is likely to occur between the ballpoint pen cap 10 and the ballpoint pen 60. In addition, the sealing of the tip of the tip 90 may be incomplete, and the tip of the tip 90 may not be sufficiently dried or the solvent component in the ink may not be sufficiently evaporated.

On the other hand, when the hardness of the seal member 50 is less than Hs5 in Shore A hardness, the surface of the seal member 50 becomes sticky, which may cause the tip of the chip 90 to become dirty or the ink to deteriorate. There is a risk that the ballpoint pen 60 will become unable to write. In addition,
The cap body 20 is not limited to a cylindrical shape as shown in FIG.

As shown in FIG. 3, the cap body 20 may be formed so as to have, for example, a cylindrical portion 23 and a crown portion 24 connected to one side of the cylindrical portion 23. . Further, in this case, by providing a large number of ribs 25 radially as viewed from the center of the cylindrical portion 23 on the inner peripheral surface of the cylindrical portion 23 on the crown portion 24 side, by holding the sealing member 50 on these ribs 25, A seal member 50 may be provided inside the cap body 20.

The cap body 20 and the clip 40 may be formed integrally with each other by projecting the clip 40 from the outer peripheral surface of the cap body 20 on the crown portion 24 side. Also,
The seal member 50 is not limited to a spherical shape, and may be, for example, a columnar shape, a disk shape, or a cubic shape.

However, if the seal member 50 is formed in a spherical shape,
The seal member 50 is preferably formed in a spherical shape because the manufacture of the ballpoint pen cap 10 is facilitated. Further, the seal member 50 is not limited to a case formed of nitrile rubber, and may be, for example, rubber such as natural rubber, isopropylene rubber, butadiene rubber, silicon rubber, butyl rubber, ethylene propylene diene rubber, styrene butadiene rubber, and fluoro rubber. Can be formed.

However, since the nitrile rubber is excellent in processability and airtightness (gas barrier property), it is preferable that the seal member 50 is formed of nitrile rubber.

[0062]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. Example 1 A ball-point pen cap 10 having the following configuration was manufactured and mounted on the tip 90 side of a ball-point pen 60 having the following configuration.

The structure of the ballpoint pen cap 10 is as follows: Material of the cap body 20: PET (polyethylene terephthalate) Material of the crown 30: ABS (acrylonitrile butadiene styrene) Material of the seal member 50: Nitrile rubber Shape of the seal member 50: spherical seal Diameter of member 50: 5.0 mm Shore A hardness of seal member 50: Hs20.

The structure of the ballpoint pen 60 is as follows: Material of the barrel 70: AS (acrylonitrile styrene) Material of the cap 80: Brass (plated on the surface) Material of the ball 91: Carbide Alloy Diameter of the ball 91: 1. 00 mm Material of holder 92: stainless steel Ink type: water-based gel ink

In the first embodiment, the amount of burial in the sealing member 50 until the tip of the tip 90 is completely sealed is 0.1 mm.
It was 8 mm. At this time, the repulsive force received by the chip 90 from the seal member 50 was 32 g. (Embodiment 2) In Embodiment 2, only the Shore A hardness of the seal member 50 is changed, and other configurations are the same as those in Embodiment 1.

Specifically, in the second embodiment, the Shore A hardness of the seal member 50 is set to Hs30. In Example 2, the amount of burial in the sealing member 50 until the tip of the tip 90 was completely sealed was 0.9 mm. At this time, the repulsive force received by the chip 90 from the seal member 50 was 55 g.

Example 3 A ball-point pen cap 10 having the following structure was manufactured, and a tip of a ball-point pen 60 having the following structure was manufactured.
Attached to 90 side. The configuration of the ballpoint pen cap 10 is as follows: material of the cap body 20: PET (polyethylene terephthalate) material of the crown 30: PC (polycarbonate) material of the sealing member 50: nitrile rubber shape of the sealing member 50: spherical shape: diameter of the sealing member 50: 3.5 mm Shore A hardness of the seal member 50: Hs20.

The structure of the ballpoint pen 60 is as follows: Material of the barrel 70: AS (acrylonitrile styrene) Material of the cap 80: Brass (plated on the surface) Material of the ball 91: Carbide Alloy Diameter of the ball 91: 1. 00 mm Material of holder 92: stainless steel Ink type: water-based gel ink

In the third embodiment, the amount of burial in the sealing member 50 until the tip of the tip 90 is completely sealed is 0.1 mm.
It was 8 mm. At this time, the repulsive force received by the chip 90 from the seal member 50 was 32 g. (Embodiment 4) In Embodiment 4, only the Shore A hardness of the seal member 50 is changed, and the other configuration is the same as that of Embodiment 3.

Specifically, in the fourth embodiment, the Shore A hardness of the seal member 50 is set to Hs30. In the fourth embodiment, the burial amount in the sealing member 50 until the tip of the tip 90 is completely sealed was 0.9 mm. At this time, the repulsive force received by the chip 90 from the seal member 50 was 55 g.

(Example 5) A ball-point pen cap 10 having the following structure was manufactured, and a tip of a ball-point pen 60 having the following structure was manufactured.
Attached to 90 side. The configuration of the ballpoint pen cap 10 is as follows: material of the cap body 20: PET (polyethylene terephthalate) material of the crown 30: ABS (acrylonitrile butadiene styrene) material of the sealing member 50: nitrile rubber shape of the sealing member 50: spherical shape of the sealing member 50 Diameter: 5.0 mm Shore A hardness of the sealing member 50: Hs20.

The structure of the ballpoint pen 60 is as follows: Material of the barrel 70: AS (acrylonitrile styrene) Material of the cap 80: Brass (plated on the surface) Material of the ball 91: Carbide Alloy Diameter of the ball 91: 0. 38 mm Material of holder 92: stainless steel Ink type: water-based gel ink

In the fifth embodiment, the amount of burial in the sealing member 50 until the tip of the tip 90 is completely sealed is 0.1 mm.
4 mm. At this time, the repulsive force received by the chip 90 from the seal member 50 was 20 g. (Embodiment 6) In Embodiment 6, only the Shore A hardness of the seal member 50 is changed, and the other configuration is the same as that of Embodiment 5.

Specifically, in the sixth embodiment, the Shore A hardness of the seal member 50 is set to Hs30. In Example 6, the amount of burial in the sealing member 50 until the tip of the tip 90 was completely sealed was 0.5 mm. At this time, the repulsive force received by the chip 90 from the seal member 50 was 31 g.

Comparative Example 1 Comparative Example 1 is the same as Example 1 except that only the Shore A hardness of the seal member 50 is changed. Specifically, Comparative Example 1
Is the one in which the Shore A hardness of the seal member 50 is Hs40.

In Comparative Example 1, the amount of burial in the sealing member 50 until the tip of the tip 90 is completely sealed is 1.
2 mm. At this time, the repulsive force received by the chip 90 from the seal member 50 was 190 g. (Comparative Example 2) In Comparative Example 2, only the Shore A hardness of the seal member 50 was changed, and the other configuration was the same as that in Example 1.

Specifically, in Comparative Example 2, the Shore A hardness of the seal member 50 was Hs50. In Comparative Example 2, the buried amount in the sealing member 50 until the tip of the tip 90 was completely sealed was 1.4 mm. At this time, the repulsive force received by the chip 90 from the sealing member 50 was 290 g.

Comparative Example 3 Comparative Example 3 is the same as Example 3 except that only the Shore A hardness of the seal member 50 was changed. Specifically, Comparative Example 3
Is the one in which the Shore A hardness of the seal member 50 is Hs40.

In Comparative Example 3, the amount of burial in the sealing member 50 until the tip of the tip 90 is completely sealed is 1.
2 mm. At this time, the repulsive force received by the chip 90 from the seal member 50 was 190 g. Comparative Example 4 Comparative Example 4 is the same as Example 3 except that only the Shore A hardness of the seal member 50 is changed.

Specifically, in Comparative Example 4, the Shore A hardness of the seal member 50 was Hs50. In Comparative Example 4, the burial amount in the sealing member 50 until the tip of the tip 90 was completely sealed was 1.4 mm. At this time, the repulsive force received by the chip 90 from the sealing member 50 was 290 g.

(Comparative Example 5) In Comparative Example 5, only the Shore A hardness of the seal member 50 was changed, and the other configuration was the same as that in Example 5. Specifically, Comparative Example 5
Is the one in which the Shore A hardness of the seal member 50 is Hs40.

In Comparative Example 5, the amount of burial in the sealing member 50 until the tip of the tip 90 is completely sealed is 0.1 mm.
It was 8 mm. At this time, the repulsive force received by the chip 90 from the sealing member 50 was 120 g. (Comparative Example 6) In Comparative Example 6, only the Shore A hardness of the seal member 50 was changed, and the other configuration was the same as that in Example 5.

Specifically, in Comparative Example 6, the Shore A hardness of the seal member 50 was Hs50. In Comparative Example 6, the amount of burial in the sealing member 50 until the tip of the tip 90 was completely sealed was 1.0 mm. At this time, the repulsive force received by the chip 90 from the seal member 50 was 180 g.

(Evaluation of Ballpoint Pen Cap 10) Each of the ballpoint pen caps 10 of Examples 1 to 6 and Comparative Examples 1 to 6 were evaluated. First, each ball-point pen cap 10 was stored for 90 days in an environment of a temperature of 50 ° C. and a humidity of 60% with the ball-point pen cap 10 attached to the tip 90 side of each ball-point pen 60.

The evaluation of the ballpoint pen cap 10 is as follows.
10 sets of ballpoint pen caps 10 and ballpoint pens 60 each
Was performed by performing the above test. Table 1
The description in the evaluation column shown in (1) shows that (1) rattling occurred between the ball-point pen cap 10 and the ball-point pen 60, and the seal at the tip of the tip 90 was incomplete, and none of the sets was evaluated. → Evaluation “○” (b) One or more sets of looseness occurred between the ball-point pen cap 10 and the ball-point pen 60, and the tip 90 had incompletely sealed the tip 90.

Table 1 below shows the configurations of the ballpoint pen caps 10 of Examples 1 to 6 and Comparative Examples 1 to 6, and the evaluations of these ballpoint pen caps 10, respectively. In Table 1, "amount of burial" means "amount of burial in the sealing member 50 until the tip of the tip 90 is completely sealed".
The “repulsive force” is “the repulsive force that the tip 90 receives from the sealing member 50 when the tip of the tip 90 is completely sealed”.
Are respectively shown.

[0087]

[Table 1]

As described above, in each of the ball-point pen caps 10 of the first to sixth embodiments, no play occurs between the ball-point pen cap 10 and the ball-point pen 60. Was never incomplete. That is, if the ball-point pen cap 10 is formed as shown in Examples 1 to 6,
Specifically, the hardness of the seal member 50 is expressed as Hs in Shore A hardness.
If the distance is set to 20 to Hs30, there will be no play between the ballpoint pen cap 10 and the ballpoint pen 60, and therefore, the sealing of the tip of the tip 90 will not be incomplete.

On the other hand, each of the ballpoint pen caps 10 of Comparative Examples 1 to 6 is a ballpoint pen cap.
A play due to creep occurred between the ballpoint pen 10 and the ballpoint pen 60, which resulted in an incomplete seal at the tip of the tip 90. That is, when the ball-point pen cap 10 is formed as shown in Comparative Examples 1 to 6,
Specifically, the hardness of the seal member 50 is expressed as Hs in Shore A hardness.
If the distance is set to 40 to Hs50, play will occur due to creep between the ballpoint pen cap 10 and the ballpoint pen 60, and this will result in incomplete sealing of the tip of the tip 90.

Further, an experiment was conducted on the numerical value of the hardness of the seal member 50.
If the hardness of the seal member 50 is Hs5 or more and Hs35 or less in Shore A hardness, writing becomes impossible due to stickiness on the surface of the seal member 50, and at the same time, rattling due to creep occurs between the ballpoint pen cap 10 and the ballpoint pen 60. Chip 90
It was confirmed that the seal at the tip of the sample did not become incomplete.

Further, if the hardness of the sealing member 50 is more than Hs 35 in Shore A hardness, a play due to creep occurs between the ballpoint pen cap 10 and the ballpoint pen 60,
As a result, it was confirmed that the seal at the tip of the tip 90 would be incomplete. On the other hand, if the hardness of the seal member 50 is less than Hs5 in Shore A hardness, the surface of the seal member 50 becomes more sticky, thereby causing the tip of the chip 90 to become dirty or the ink to deteriorate. It was confirmed that the ball-point pen 60 would not be able to write.

When the hardness of the seal member 50 is set to Hs 20 or more in Shore A hardness, it is confirmed that the stickiness of the surface of the seal member 50 can be reduced, thereby preventing the tip 90 of the tip 90 from being stained. Was. Of course, even if the hardness of the sealing member 50 is less than Hs20 in Shore A hardness,
The tip of the tip 90 may be stained by the stickiness of the surface of the seal member 50, but it can be sufficiently written.

When the hardness of the seal member 50 is set to Hs25 or more in Shore A hardness, the stickiness of the surface of the seal member 50 can be completely eliminated, thereby completely preventing the tip 90 of the tip 90 from being stained. Was confirmed. Of course, even if the hardness of the sealing member 50 is less than Hs25 in Shore A hardness, the chip 90 may be damaged due to the sticky surface of the sealing member 50.
Although there is a possibility that the tip of the paper may become dirty, it can be sufficiently written.

[0094] In addition, this test is based on the material of the sealing member 50,
The same results as described above were obtained by changing the shape of the seal member 50, the diameter of the seal member 50, the diameter of the ball 91, the material of the cap body 20, the material of the barrel 70, and the like. In the above-described embodiment, an aqueous gel ink was used as the ink. However, a similar tendency was confirmed even when an aqueous ink or an oil-based ink was used.

The present invention is not limited to the above embodiment.

[0096]

As described above, according to the first aspect of the present invention, wobbling occurs between the ball-point pen cap and the ball-point pen while the writing on the surface of the sealing member is prevented from becoming unwieldy. Ballpoint pen, which can prevent the tip of the tip from drying out and prevent the solvent component in the ink from volatilizing. Can be provided.

According to the second aspect of the present invention,
Since stickiness on the surface of the seal member can be reduced, a cap for a ballpoint pen that can prevent the tip of the tip from being stained can be provided. According to the third aspect of the present invention, since stickiness on the surface of the seal member can be completely eliminated, it is possible to provide a ballpoint pen cap that can completely prevent the tip of the chip from being stained.

Further, according to the invention described in claim 4,
It is possible to provide a cap for a ballpoint pen in which the sealing performance at the tip of the tip is further improved.

[Brief description of the drawings]

FIG. 1 is a side cross-sectional view of a ballpoint pen cap according to the present embodiment.

FIG. 2 is an enlarged view of a main part of the ballpoint pen cap according to the embodiment.

FIG. 3 is a side sectional view of a ballpoint pen cap according to another embodiment.

FIG. 4 is a side sectional view of a conventional ballpoint pen cap.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Cap for ball-point pen 20 Cap main body 21 Engagement concave part 22 Fitting convex part 23 Cylindrical part 24 Crown part 25 Rib 30 Crown 31 Holding part 32 Vent hole 33 Fitting concave part 40 Clip 50 Seal member 60 Ball-point pen 70 Shaft barrel 71 Convex part 80 Base 90 Chip 91 Ball 92 Holder

Claims (4)

[Claims] 1. A cap body detachably formed on a tip side of a ballpoint pen, and a seal member provided inside the cap body, wherein the seal member is provided when the cap body is mounted on the tip side of the ballpoint pen. Is a ball-point pen cap formed so as to cover the tip of the chip, wherein the sealing member has a hardness of Shore A hardness and Hs
A ball-point pen cap, which has an Hs of 35 or more and a Hs of 35 or less. 2. The ballpoint pen cap according to claim 1, wherein the hardness of the seal member is Shore A hardness of Hs20 or more and Hs35 or less. 3. The ballpoint pen cap according to claim 1, wherein the hardness of the seal member is in the range of Hs25 to Hs35 in Shore A hardness. 4. The ballpoint pen cap according to claim 1, wherein the seal member is formed of nitrile rubber.