JP2001080262A - Ball for ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball for a ballpoint pen, the wear of which is reduced and which ensures a smooth writability. SOLUTION: In this ball for a ballpoint pen, a rigid coating layer 21 is formed on the surface of a spherical body made of a ceramic sintered body. As a result, ceramic particles as matrix can be prevented from falling off. Further, the surface strength of the ball is improved, resulting in realizing a favorable wear resistance. Furthermore, the lowering of a writing touch on paper due to the sinking of the ball in a pen point main body is retarded, resulting in keeping a favorable writing run on paper over a long period of term.

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. 5, 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. 6, 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 super-hard alloy in which hard intermetallic compound particles such as WC are sintered via a bonding metal such as Co is conventionally used.

In recent years, inks using titanium oxide, aluminum powder, or the like as a pigment have been frequently used. In the ink containing titanium oxide, it is necessary to increase the blending amount of titanium oxide in order to secure the shielding property. Further, in the ink containing the aluminum powder, it is necessary to use a powder having a very large particle diameter in order to give a metallic luster.

With the spread of such inks containing titanium oxide and aluminum powder, in recent years, balls 11 made of ceramic sintered bodies such as alumina and zirconia, which have higher hardness and excellent corrosion resistance, have been used. Is coming.

[0008]

However, in the ink using titanium oxide or aluminum powder as described above, even if a ball made of a ceramic sintered body such as alumina or zirconia is used, The fact is that the ceramic particles on the surface fall off and are worn, and the dropped off pieces act as an abrasive to quickly wear 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.

Also, when a conventional ball is used for an ink using titanium oxide or aluminum powder, the lubricity of the ink deteriorates due to the presence of the titanium oxide or aluminum powder, and the ball rotates smoothly when writing continuously. And the handwriting is interrupted. Also, since titanium oxide and aluminum powder have a large specific gravity, the pigment is uniformly dispersed to prevent sedimentation,
High-viscosity ink is used, the adhesion to the ball is low, and line skipping due to the formation of a portion of the ball surface that is not wet with the ink is likely to occur.

[0010] As described above, the conventional ball has a problem that the ink used tends to cause abrasion and line skipping of the ball, which tends to hinder smooth writing.

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 can reduce abrasion of the ball and ensure smooth writing.

[0012]

Means for Solving the Problems To achieve the above object, the ball for a ballpoint pen of the present invention is characterized in that a hard coating layer is formed on the surface of a spherical body made of a ceramic sintered body. I do.

That is, in the ballpoint pen ball of the present invention, a hard coating layer is formed on the surface of a spherical body made of a ceramic sintered body. For this reason, the presence of the hard coating layer can prevent the ceramic particles as the base material from falling off. Moreover, the coating layer improves the surface strength of the ball and improves the abrasion resistance, delaying the writing taste due to sinking of the ball into the pen tip body,
Good writing taste is maintained over a long period of time. Moreover,
Since the abrasion of the pen tip body is suppressed, even if the ball diameter is reduced, the abrasion is small, so that it is possible to cope with fine characters.

In the ball for a ballpoint pen of the present invention, when a hole having an average hole diameter of 15 μm or less is formed on at least the surface of the spherical body, the ball is filled with pigment or ink in the hole. The rotation facilitates the rotation of the ball, increases the pumping of ink, and increases the adhesion of the ink to the ball.
Therefore, line skipping unlike the related art is unlikely to occur, and smooth writing performance can be secured.

In the ball-point pen ball of the present invention, when at least the surface of the spherical body has a first hole and a second hole having different average hole diameters, the first hole is formed.
Among the second holes, the ball is rotated in a state where the pigment or the ink is contained in the hole having the larger average hole diameter among the second holes, so that the ball is easily rotated and the pumping of the ink is increased. 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 not less than 1 μm and not more than 5 μm;
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 ceramic sintered body is a silicon carbide sintered body, it has excellent wear resistance and good corrosion resistance, and maintains a good writing quality for a long period of time.

In the ball-point pen ball of the present invention, when the above-mentioned coating layer is a layer containing one or more of the following substances A as a main component, the presence of the above-mentioned coating layer causes the formation of the ball. The surface strength is sufficiently improved, and the ceramic particles as the base material can be effectively prevented from falling off. A: boride, nitride, carbide, aluminum oxide, aluminum nitride, silicon carbide, silicon nitride, silicon oxide, zirconium oxide, titanium oxide, titanium carbonitride, titanium carbonitride, cubic boron nitride, tungsten of the 4A / 5A / 6A transition metal , Tungsten carbide, diamond

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 ball-point pen for pigmented ink, wear of the ball and the pen tip body is prevented. The effect of maintaining the writing taste is more remarkable,
It is effective. That is, high-viscosity inks have been used frequently recently because pigments having a high specific gravity can be sufficiently dispersed. Examples of the above-mentioned pigments include, for example, titanium oxide and aluminum powder, and when an ink containing such a pigment is used,
Conventional balls are severely worn, causing the ball and the pen tip body to be greatly worn. In the ball of the present invention, since the surface strength of the ball is improved by the coating layer and the wear resistance is improved, even when the ink containing the pigment as described above is used, the wear of the ball or the pen tip body is reduced. It is greatly reduced.

[0021]

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

FIG. 1 is an enlarged sectional view showing an embodiment of a ballpoint pen ball of the present invention. The ball has a first hole A and a second hole B having different average hole diameters formed on a surface 20 of a spherical body made of a ceramic sintered body.

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 provided on the surface of the spherical body made of the ceramic sintered body.
Are formed. 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, due to the presence of the first hole A having a small average hole diameter, the adhesion of the ink to the ball is increased, and the outflow amount of the ink is increased.

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 holes 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 by, for example, using a photograph obtained by observing the surface of a 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.

A hard coating layer 21 is formed on the surface 20 of the ball. Preferred as the coating layer 21 is a layer containing one or more of the following substances A as a main component. Such a coating layer 21
This is because the ball is sufficiently hard, the surface strength of the ball is improved, and the ceramic particles as the base material can be effectively prevented from falling off. Note that the coating layer 21 may be used as a single layer or a plurality of layers may be combined. A: 4A / 5A
• Group 6A transition metal borides, nitrides, carbides, aluminum oxide, aluminum nitride, silicon carbide, silicon nitride, silicon oxide, zirconium oxide, titanium oxide, titanium carbonitride, cubic boron nitride, tungsten, tungsten carbide, diamond

Specific examples of the material for forming the coating layer 21 include, for example, TiC, Ti ₂ N, TiN, Ti
B, TiB ₂ , TiO ₂ , TiCN, W ₂ C, WC,
W, AlN, Al ₂ O ₃ , SiC, Si ₃ N ₄ , SiO
_{2, c-BN, CrN,} ZrN, ZrO 2, NbC, T
aC, HfC, HfN, HfB ₂ , diamond (including diamond-like carbon) and the like.

The coating layer 21 has a thickness of 0.01
The thickness is preferably from 3 μm to 3 μm. The upper limit of the thickness is more preferably 1.5 μm, and the lower limit is more preferably 0.1 μm. The above thickness is 0.01
If it is less than μm, the abrasion resistance will not be improved, and if it exceeds 3 μm, the cost will increase, and the diameter of the ball will be too large and may fall out of tolerance.
Further, a method of forming a coating layer by making the ball smaller is also conceivable, but it is difficult to manufacture the ball within a dimensional tolerance. Furthermore, there is a possibility that the relatively small first hole A may be filled.

The presence of the coating layer 21 can prevent the ceramic particles serving as the base material from falling off. In addition, the coating layer 21 improves the surface strength of the ball and improves abrasion resistance, delays a decrease in writing quality due to sinking of the ball into the pen tip body, and maintains a good writing quality for a long period of time. Is done. In addition, since the abrasion of the pen tip main body is suppressed, even if the ball diameter is reduced, the abrasion is small.

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 hole A is 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.

Then, various physical vapor deposition methods such as vacuum vapor deposition, sputtering, and ion plating, and heat C are applied to the ball having the first and second holes A and B formed on the surface 20.
By applying various chemical vapor deposition methods such as VD, MOCVD, optical CVD, and plasma CVD, and ion implantation methods,
By forming the coating layer 21 as described above, the ball of the present invention is obtained.

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. 4, 5 and 7).

The ink used for the ballpoint pen is not particularly limited, and various inks such as oil-based inks, water-based inks, and gel inks are used. In particular, high-viscosity inks having a viscosity of 100 mPa.s to 20,000 mPa.s 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, pigments such as titanium oxide and aluminum powder can be sufficiently dispersed in high-viscosity inks having the above-mentioned viscosity range, and thus have recently been used frequently. In the ball, since the coating layer 21 improves the surface strength of the ball and improves wear resistance, even when the ink containing the pigment as described above is used, the abrasion of the ball and the pen tip body is large. It is alleviated.

Further, titanium oxide and aluminum powder tend to lower the rotation of the ball, and the conventional ball tends to cause line skipping. In addition, the high viscosity ink is inferior in 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 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. Generation can be effectively prevented.

As the pigment used in the above ink, acid
Not limited to titanium oxide and aluminum powder
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 pigment include various azo pigments such as monoazo lake, monoazo, disazo, condensed azo, and metal complex salt azo; dyeing of phthalocyanines, acid dye lakes, basic dye lakes, etc .; , 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.

FIG. 2 shows a ball-point pen ball according to a second embodiment of the present invention. In this ball, the second hole B is not formed on the surface 20, and only the first hole A is formed. Also in this case, the presence of the first hole A improves the adhesion of the ink to the ball. Other than that,
The same operation and effect as those of the first embodiment are provided.

FIG. 3 shows a ball-point pen ball according to a third embodiment of the present invention. In this ball, the first hole A is not formed on the surface 20, and only the second hole B is formed. Also in this case, the effect of pumping out ink is improved due to the presence of the second hole B. Otherwise, the first
The same operation and effect as those of the embodiment can be obtained.

In each of the above embodiments, the ball was polished by barrel polishing and grinding wheel grinding. However, the present invention is not limited to this.
Various methods such as electrolytic grinding and chemical polishing are used. Also,
Although a spherical ball is illustrated as the ball, the present invention is not limited to this, and is applicable to a columnar ball and the like. Further, in each of the above embodiments, the first hole A is formed on the surface of the ball by polishing, and then the coating layer 21 is formed. However, after the coating layer 21 is formed on the surface of the ball, polishing or the like is performed. May be used to form the first hole A.

[0047]

As described above, according to the ballpoint pen ball of the present invention, the presence of the hard coating layer can prevent the ceramic particles as the base material from falling off. In addition, the coating layer improves the surface strength of the ball and improves the abrasion resistance, slows down the writing taste due to the ball sinking into the pen tip body, and maintains a good writing taste for a long period of time. You. In addition, since the abrasion of the pen tip main body is suppressed, even if the ball diameter is reduced, the abrasion is small.

[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 according to a second embodiment of the present invention.

FIG. 3 is an enlarged sectional view showing a ballpoint pen ball according to a third embodiment of the present invention.

FIG. 4 is a sectional view showing a pen tip of a ballpoint pen.

FIG. 5 is an enlarged sectional view of a main part of the pen tip.

FIG. 6 is a sectional view of the pen point main body taken along line AA.

FIG. 7 is a sectional view showing a use state of the pen tip.

[Explanation of symbols]

 20 surface 21 coating layer

Claims (9)

[Claims] 1. A ball for a ballpoint pen, wherein a hard coating layer is formed on a surface of a spherical body made of a ceramic sintered body. 2. The ball for a ballpoint pen according to claim 1, wherein a hole having an average hole diameter of 15 μm or less is formed on at least the surface of the spherical body. 3. The ball for a ballpoint pen according to claim 1, wherein a first hole and a second hole having different average hole diameters are formed on at least a surface of the spherical body. 4. 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 3, wherein 5. The ballpoint pen ball according to claim 4, wherein the average distance between the first holes is shorter than the average distance between the second holes. 6. The ball for a ballpoint pen according to claim 1, wherein the ceramic sintered body is a silicon carbide sintered body. 7. The coating layer according to claim 1, wherein the coating layer is mainly composed of one or more of the following substances A.
The ball for a ball-point pen according to any one of claims 1 to 6. A: boride, nitride, carbide, aluminum oxide, aluminum nitride, silicon carbide, silicon nitride, silicon oxide, zirconium oxide, titanium oxide, titanium carbonitride, titanium carbonitride, cubic boron nitride, tungsten of the 4A / 5A / 6A transition metal , Tungsten carbide, diamond 8. The ball for a ballpoint pen according to claim 1, which is used for a ballpoint pen for high viscosity ink. 9. The ball-point pen ball according to claim 1, which is used for a pigment-containing ink ball-point pen.