JP2001080261A - Ball for ball point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball for a ball point pen, with which broken lines are hard to develop during continuous writing and a smooth writability can be ensured. SOLUTION: In this ball for a ball pen, first holes A and second holes B, the average hole diameters of which are different from each other, are formed on at least the surface of a spherical body made of rigid material. Since the ball is rotated under the state that pigment and ink are held in the holes B, the average hole diameter of which is larger than that of the hole A, between the first and the second holes A and B, the ball easily rotates, resulting in dipping out much ink. In addition, due to the presence of the hole A, the average hole diameter of which is smaller than that of the other hole, the adhesion of the ink to the ball becomes higher and simultaneously the dipping-out effect of the ink is improved. Thus, the rotatability of the ball and the adhesion of the ink are improved and the efflux of the ink becomes larger, resulting in making the conventional development of broken lines difficult and allowing to ensure a smooth writability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ballpoint pen ball used for a pen point of a ballpoint pen.

[0002]

2. Description of the Related Art Conventionally, the tip of a ballpoint pen for gel ink has a structure as shown in FIG. In the figure, reference numeral 10 denotes a pen tip body formed in a hollow shape, the tip side of which is tapered, and a ballpoint pen ball (hereinafter referred to as “ball”) 11 is rotatably attached to the tip. And the pen tip body 1
0 is connected to an ink cylinder (not shown), and ink supplied from the ink cylinder to the hollow portion is supplied to the ink flow path 12.
Through the ball 11.

[0003] The tip of the pen tip will be described in detail.
As shown in FIG. 6, a ball accommodating recess 13 communicating with the ink flow path 12 is formed at the tip, and a caulking portion 14 is formed at an opening of the ball accommodating recess 13 in a state where the ball 11 is accommodated. It is designed to be rotatably held. The inner surface of the ball accommodating recess 13 is formed in a mortar-shaped tapered surface 15.
As shown in FIG. 7, five ink grooves 16 are radially formed in order to secure an outflow amount of ink.

When writing with the above-mentioned pen tip, FIG.
As shown in the figure, the ball 11 at the tip of the pen
It is pressed against 2. At this time, the ball 11 is displaced obliquely upward in the ball housing recess 13 (arrow B in the drawing). Next, the ink is guided from the hollow portion of the pen tip body 10 through the ink flow path 12 and the ink groove 16 into the ball accommodating recess 13, and as the ball 11 rotates, the ink travels on the surface of the ball 11 and 22 and the handwriting is performed (arrow C in the figure).

As a material of the pen tip body 10, a metal material such as stainless steel or the like is generally used. On the other hand, as the ball 11, a superhard alloy obtained by sintering hard intermetallic compound particles such as WC via a bonding metal such as Co is generally used, and the superhard alloy is spherically polished. Is used.

[0006]

Recently, inks using aluminum powder, titanium oxide or the like as a pigment have been frequently used. In the ink containing the aluminum powder, it is necessary to use a powder having a very large particle diameter (for example, 5 μm or more) in order to give metallic luster. On the other hand, in the case of the ink containing titanium oxide, it is necessary to increase the blending amount of titanium oxide in order to secure the shielding property.
Furthermore, since aluminum powder and titanium oxide have a large specific gravity, it is necessary to use a high-viscosity ink to uniformly disperse the pigment and prevent sedimentation.

[0007] When a conventional ball is used for an ink using aluminum powder or titanium oxide as a pigment as described above, the lubricity of the ink is deteriorated due to the presence of aluminum powder having a large particle size and a large amount of titanium oxide. When writing continuously, it is difficult for the ball to rotate smoothly, and the "line skipping" phenomenon in which the handwriting is interrupted is likely to occur. In addition, since the ink has a high viscosity, the ink has a low adhesive force to the ball, and a line jump due to a portion of the ball surface that is not wet with the ink is likely to occur.

As described above, the conventional ball has a problem that line skipping is apt to occur depending on the type of ink used, and trouble is likely to occur in smooth writing.

Further, when a conventional super-hard alloy ball is used for an ink using titanium oxide or the like as a pigment as described above, the bonding metal on the surface is worn away during use, and the existing metal is present in this portion. Small particles of the hard intermetallic compound particles fall off and act as an abrasive, causing abrasion of the pen tip body. As a result, there has been a problem that the ball sinks into the pen tip main body, making it difficult to write or faint, and the writing taste deteriorates early.

Further, in the ink in which the pigment such as the aluminum powder is dispersed, a conductive substance is often added in order to increase the affinity between the aluminum powder and another pigment. When a conventional ball is used for such ink, there is a problem that a potential difference is generated between the ball and the pen tip main body, and the ball or the pen tip main body is likely to be corroded during long-term use or storage.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a ballpoint pen ball which is unlikely to cause line skipping during continuous writing and can ensure smooth writing.

[0012]

In order to achieve the above object, a ballpoint pen ball according to the present invention has a first hole and a second hole having different average hole diameters on at least the surface of a spherical body made of a hard material. The gist is that a hole is formed.

That is, in the ballpoint pen ball of the present invention, a first hole and a second hole having different average hole diameters are formed on at least the surface of a spherical body made of a hard material. For this reason, since the ball is rotated in the state where the pigment or the ink is contained in the hole having the larger average hole diameter among the first and second holes, the ball is easily rotated and the pumping of the ink is often performed. Become. In addition, the presence of the holes having a small average hole diameter increases the adhesion of the ink to the ball, and also improves the ink pumping effect.
Therefore, according to the ballpoint pen ball of the present invention, the rotation property of the ball and the adhesion of the ink are improved, and the outflow of the ink is increased. it can.

In the ball-point pen ball of the present invention, the first hole has an average hole diameter of 1 μm or more and 5 μm or less, and
When the average hole diameter of the holes is 7 μm or more and 15 μm or less, the existence of the relatively large second hole and the relatively small first hole effectively improves the ball rotation and ink adhesion. As a result, the outflow of ink is improved, and line skipping can be effectively prevented.

In the ball-point pen ball of the present invention, when the average distance between the first holes is shorter than the average distance between the second holes, the average distance between the first holes is relatively small. By shortening the distance, the ink adhesion can be effectively improved.

In the ballpoint pen ball of the present invention, when the hard material is a ceramic sintered body or when the hard material is a silicon carbide sintered body, small pieces due to abrasion of a bonding metal such as a conventional ball. No shedding occurs. Therefore, abrasion of the pen tip main body is suppressed, deterioration of writing taste due to sinking of the ball into the pen tip main body is delayed, and good writing taste is maintained for a long period of time. In addition, since the abrasion of the pen tip main body is suppressed, even if the ball diameter is reduced, the abrasion is small. Furthermore, even when used for highly conductive ink, the ceramic sintered body ball hardly corrodes, and there is no potential difference between the ball and the pen tip body. Can be reduced.

In the ball-point pen ball of the present invention, when it is used for a ballpoint pen for high-viscosity ink or when it is used for a ballpoint pen for pigment-containing ink, the line skipping is suppressed to ensure writing performance. The effect is particularly remarkable and effective. In other words, high-viscosity inks have been widely used recently because pigments having a large specific gravity and large particle sizes can be sufficiently dispersed. Among such pigments, there are, for example, those that easily lower the rotation of the ball, such as aluminum powder and titanium oxide, and when ink containing such a pigment is used, line skipping is likely to occur in a conventional ball. . Also,
The high-viscosity ink has poor adhesion to the ball, so that line skipping is also likely to occur, which tends to hinder smooth writing. In the ball of the present invention, the presence of the first and second holes facilitates the smooth rotation of the ball, improves the adhesion of the ink to the ball, promotes the outflow of the ink, and effectively prevents the occurrence of line skipping. Can be prevented.

[0018]

Next, embodiments of the present invention will be described in detail.

FIG. 1 is an enlarged sectional view showing one embodiment of the ballpoint pen ball of the present invention. In the ball, a first hole A and a second hole B having different average hole diameters are formed on a surface 20 of a spherical body made of a hard material.

Examples of the hard material include alloy tool steel, bearing steel, high-speed tool steel, powder high-speed tool steel, dispersion-type sintered high-speed tool steel, super-hard alloy, ceramic sintered body,
Various hard materials such as cermet can be used. Among the hard materials described above, ceramic sintered bodies are particularly preferably used because they reduce the wear of the pen tip body and also have excellent corrosion resistance. That is, the ceramic sintered body does not have a bonding metal such as a super hard alloy or a cermet,
Since the small pieces do not fall off due to wear of the bonding metal during use, wear of the pen tip body is suppressed, and deterioration of writing quality due to sinking of the ball into the pen tip body is delayed. Also, even when used for highly conductive inks, the ceramic sintered balls hardly corrode,
Since no potential difference occurs between the pen tip body and the pen tip body, corrosion of the pen tip body can be reduced.

The ceramic sintered body is not particularly limited, and various types can be used. For example, WC, TiC, VC, Cr ₃ C ₂ , Ta
Including carbides such as C, NbC, Mo ₂ C, B ₄ C, ZrC, SiC, Al ₂ O ₃ , CrO ₃ , MgO, SiO
_{2, BeO, ThO 2, TiO} 2, CaO, TiO, Z
Various oxides such as rO ₂ , TiN, c-BN, Si
₃ N _4, various nitrides such as _AlN, ZrB _{2, CrB,} T
Various borides such as iB ₂ , MoSi ₂ , TiSi ₂ , C
Various silicides such as rSi _{2 and the} like can be mentioned. These are used alone or in combination.

Among these, in particular, the SiC sintered body is
It is preferably used because of its excellent properties such as wear resistance and corrosion resistance.

A first hole A and a second hole B having different hole diameters are formed on the surface of the spherical body of the hard material. Of the first and second holes A and B, the ball is rotated in a state where the pigment or the ink is contained in the second hole B having a large average hole diameter. Ink pumping increases. In addition, the presence of the first hole A having a small average hole diameter increases the ink adhesion to the ball and also improves the ink pumping effect.

The average diameter of the first holes A is preferably 1 μm or more and 5 μm or less. 4 μm is more preferable as the upper limit value of the average hole diameter of the first hole A, and 3 μm is more preferable. When the average hole diameter of the first hole A is less than 1 μm, the ink adhesion is insufficient and the ink outflow tends to be insufficient. When the average hole diameter exceeds 5 μm, the ball surface becomes rough and the pen tip body may be worn. Because there is.

The average diameter of the second hole B is preferably 7 μm or more and 15 μm or less. 8 μm is more preferable as the lower limit of the average hole diameter of the second hole B. The second
13 μm is more preferable as the upper limit value of the average hole diameter of the hole B.
m, and 10 μm is more preferable. When the average hole diameter of the second hole B exceeds 15 μm, the pen tip body is more likely to be worn, and ink tends to leak from between the pen tip body and the ball. When the average hole diameter is less than 7 μm, the effect of pumping out the pigment is reduced. This is because line shortage is likely to occur due to a shortage.

The average hole diameter of the first and second holes A and B can be determined, for example, by using a photograph obtained by observing the surface of the ball with a scanning electron microscope and photographing at a magnification of about 1000 to 5000 times. Can be measured.

The average distance between the first holes A is preferably shorter than the average distance between the second holes B. The reason for this is that by shortening the average distance between the relatively small first holes A, the ink adhesion can be effectively improved.

The ball of the present invention can be manufactured, for example, as follows. That is, first, an auxiliary agent is added to a predetermined ceramic powder such as SiC or the like to reduce the average particle diameter to 1%.
It is adjusted so as to be not more than μm to obtain a raw material powder. Next, a binder or the like is added to the raw material powder to form a cubic or columnar compact, and the compact is sintered under predetermined sintering conditions to obtain a sintered compact. Then, the sintered body is formed into a substantially spherical shape by barrel polishing or the like, and the spherical body is rolled together with diamond powder between two whetstones held at a constant interval, and polished into fine diamond powder. To obtain a spherical body by polishing the surface to a mirror surface.

At this time, a void B '(see FIG. 1) is formed in the sintered body by adjusting the molding density, sintering time, and sintering temperature of the green compact. Then, the sintered body is spheroidized and polished so that the void B '
To be formed. The hole diameter of the second hole B (in other words, the diameter of the void B ') is determined by the molding density, sintering time, and sintering temperature of the green compact. That is, the lower the molding density, the larger the hole diameter of the second hole B, the longer the sintering time, and the higher the sintering temperature, the smaller the hole diameter of the second hole B.

The first holes A are formed by adjusting a grindstone or abrasive grains when polishing the sintered body. That is, after the sintered body is formed into a substantially spherical shape by performing barrel polishing or the like, first, coarse marks are formed by coarse polishing with a coarse grindstone or abrasive grains. Then, by performing finish polishing without intermediate polishing, the above-mentioned trace of polishing is left on the surface 20 as the first hole A, and the other surface 20 is mirror-finished to form the first hole A. Therefore, the hole diameter of the first hole A becomes larger as the grindstone or the abrasive grain in the coarse polishing becomes coarser, and the hole diameter of the first hole A becomes smaller if a fine grindstone or the abrasive grain is used in the rough polishing.

The ball is attached to a predetermined pen tip main body, and is used as a part of the pen tip of a ballpoint pen (see FIGS. 5, 6, and 8).

The ink used in the ballpoint pen is not particularly limited, and various inks such as oil-based inks, water-based inks, and gel inks can be used. In particular, high-viscosity inks having a viscosity of 100 mPa · s to 20,000 mPa · s are used. Ink is preferably used. EL made by Tokimec
P type viscometer 3 ° (R14) cone, 0.5 rpm (20
° C). The lower limit of the ink viscosity is 500 m
More preferably, it is Pa · s or more.

That is, among the high viscosity inks in the above viscosity range, pigments having a high specific gravity or large particle diameters can be sufficiently dispersed in the high viscosity inks, and therefore, these inks have recently been used frequently. . Such pigments include:
For example, there are materials such as aluminum powder and titanium oxide which tend to lower the rotation of the ball. When ink containing such a pigment is used, line skipping is likely to occur in a conventional ball. Further, in the case of the high-viscosity ink, since the adhesion to the ball is inferior, line skipping is also likely to occur, and trouble occurs in smooth writing. In the ball of the present invention, the presence of the first and second holes A and B facilitates the smooth rotation of the ball, improves the adhesion of ink to the ball, promotes the outflow of ink, and reduces the risk of line skipping. The occurrence can be effectively prevented.

As the pigment used in the above ink, a
Not limited to luminium powder or titanium oxide
And various types are used. For example, as an inorganic pigment
, Zinc white, red iron oxide, chromium oxide, iron black, titanium yellow
(TiO₂・ BaO ・ NiO 、 TiO₂・ NiO ・ Sb
₂O₃, TiO₂・ Sb₂O₃・ NiO, ZnO ・ Fe
₂O ₃, ZnO • Fe₂O₃・ Cr₂O₃, TiO₂・
CoO / NiO / ZnO, CoO / Al₂O₃・ Cr₂
O₃Etc.), cobalt blue, cellulia
Various oxides such as blue and cobalt green, and alumina
Various hydroxides such as white, yellow iron oxide, viridian,
Cadmium yellow, cadmium red, vermilion, lithopone, etc.
Various sulfides, graphite, molybdate orange, zinc
Various chromate such as chromate, gypsum, barium sulfate etc.
Seed sulfate, calcium carbonate, various carbonates such as lead white, ultramarine
Such as silicate, manganese violet, cobalt violet
Various phosphates such as citrate, arsenate such as emerald green,
Ferrocyanide such as navy blue, carbon black, ocher,
Various metal powders such as barium yellow, bronze powder and zinc powder, natural
Pearl essence, basic lead carbonate, bismuth oxychloride, cloud
Various pearl pigments such as mother titanium and the like can be mentioned.

Examples of the organic pigments include various azo pigments such as monoazo lake, monoazo, disazo, condensed azo and metal complex azo, dyeing of phthalocyanines, acid dye lakes, basic dye lakes, etc., anthraquinone, thioindigo, perinone. , Perylene, quinacridone, dioxazine, isoindolinone, quinophthalone, isoindoline and various condensed polycyclic pigments, nitroso, alizarin lake,
Metal complex salts such as azomethine, aniline black, alkali blue, and daylight fluorescent pigments.

In the above-described embodiment, the ball is polished by barrel polishing and grinding wheel grinding. However, the present invention is not limited to this, and various types of polishing such as magnetic fluid polishing, electrolytic polishing, electrolytic grinding, and chemical polishing can be used. A technique is used. In addition, the ball is illustrated as a sphere, but the present invention is not limited to this, and is applicable to a column-shaped ball and the like.

Next, examples will be described together with comparative examples.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment
Is 2 μm, and the average hole diameter of the second hole B is 10 μm.
The ball of the present invention was obtained with a μm (see FIG. 1).

[0039]

Comparative Example 1 A ball having a mirror surface 20 having neither the first hole A nor the second hole B was obtained using ZrO ₂ as a hard material (see FIG. 2).

[0040]

Comparative Example 2 A ball having only the first hole A on the surface 20 was obtained using Al ₂ O ₃ as a hard material (see FIG. 3).

[0041]

[Comparative Example 3] SiC was used as a hard material and the surface 20 was used.
Then, a ball having only the second hole B was obtained (see FIG. 4).

FIG. 5 shows the above embodiment and each comparative example.
And a writing test was performed under the following conditions to evaluate the writing properties. The results are shown in Table 1 below. [Writing test conditions] Writing angle: 65 ° Load: 100 g Writing speed: 5 cm / sec Writing distance: 300 m Pen tip body: Stainless steel [Ink used] Aluminum powder pigment: 5.0 wt% pH adjuster: 0.04 wt % Thickener: 0.3% by weight Blue organic pigment: 6.0% by weight Humectant: 18% by weight Pigment dispersion resin: 1.0% by weight Deionized water: 69.66% by weight

[0043]

[Table 1]

As is clear from Table 1 above, it is found that the balls of the examples have better writability than the comparative examples.

[0045]

As described above, according to the ballpoint pen ball of the present invention, the ball is rotated in a state where the pigment or ink is contained in the hole having the larger average hole diameter among the first and second holes. This makes the ball easier to rotate,
Ink pumping increases. In addition, the presence of the holes having a small average hole diameter increases the adhesion of the ink to the ball, and also improves the ink pumping effect. Therefore, according to the ballpoint pen ball of the present invention, the rotation property of the ball and the adhesion of the ink are improved, and the outflow of the ink is increased. it can.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing one embodiment of a ballpoint pen ball of the present invention.

FIG. 2 is an enlarged sectional view showing a ballpoint pen ball of Comparative Example 1.

FIG. 3 is an enlarged cross-sectional view showing a ballpoint pen ball of Comparative Example 2.

FIG. 4 is an enlarged sectional view illustrating a ballpoint pen ball of Comparative Example 3.

FIG. 5 is a cross-sectional view showing a pen tip of a ball-point pen.

FIG. 6 is an enlarged sectional view of a main part of the pen tip.

FIG. 7 is a sectional view taken along the line AA of the pen tip main body.

FIG. 8 is a sectional view showing a use state of the pen tip.

[Explanation of symbols]

 20 Surface A First hole B Second hole

Claims (7)

[Claims] 1. A ball-point pen ball wherein a first hole and a second hole having different average hole diameters are formed on at least the surface of a spherical body made of a hard material. 2. An average hole diameter of the first hole is 1 μm or more and 5 μm.
The average hole diameter of the second hole is 7 μm or more and 15 μm or less.
The ball for a ball-point pen according to claim 1, wherein 3. The ball-point pen ball according to claim 2, wherein the average distance between the first holes is shorter than the average distance between the second holes. 4. The ball for a ballpoint pen according to claim 1, wherein the hard material is a ceramic sintered body. 5. The ball for a ballpoint pen according to claim 4, wherein the hard material is a silicon carbide sintered body. 6. The ball for a ballpoint pen according to claim 1, which is used for a ballpoint pen for high viscosity ink. 7. The ballpoint pen ball according to claim 1, which is used for a pigmented ink ballpoint pen.