JP4831590B2 - Ballpoint pen and ballpoint pen tip - Google Patents

Description

【００４４】
鱗片状の粒子からなる顔料の詳細は下表のとおりである。ここで、Ｌ50とは、扁平形顔料粒子の長径の分布の中央値である。
【００４５】
【表２】

【００４６】
比較対照用に、球状の粒子からなる顔料を含むインキを調製した。その組成は下表のとおりである。
【００４７】
【表３】

【００４８】
球状の粒子からなる顔料の詳細は下表のとおりである。ここで、Ｌavとは、球状粒子の直径の平均値である。
【００４９】
【表４】

【００５０】
これらのインキをボールペンのインキタンクに充填し、筆記性を連続筆記試験及び手書きによる官能試験により評価した。
実験に用いたチップの詳細を下表に示す。ソケットは快削ステンレス鋼製、ボールはブラックサファリン製である。
なお、扁平形顔料粒子の短径は１μｍ程度であるので、どのチップにおいても最小隙間（ａ）は扁平形顔料粒子の短径の最大値(Ｔmax)より十分に大きい。
【００５１】
【表５】

【００５２】
ここで、ボールペンチップの正面視においてボール又はボールハウジングと交差しないように引いた最長の線分の長さ（ｂ）は、図１の関係から、次式によって算出したものである。
【００５３】
【数１】

【００５４】
チップとして、「２９−４」チップを用い、インキの種類を変えて筆記性評価を行った。その結果を下表に示す。○は筆記可能、×は筆記不能である。このとき、ボールペンチップの最小隙間（ａ）は５１．２μｍ、ボールペンチップの正面視においてボール又はボールハウジングと交差しないように引いた最長の線分の長さ（ｂ）は４５０μｍである。
【００５５】
【表６】

【００５６】
この結果から見られるように、扁平形顔料粒子の長径の最大値Ｌmaxが８０μｍと、ボールペンチップの最小隙間ａ（５１．２μｍ）より大きくても筆記は可能である。一方、Ｌmaxが１５０μｍとなると筆記不能となっている。ボールペンチップの正面視においてボール又はボールハウジングと交差しないように引いた最長の線分の長さｂは４５０μｍなので、単純に考えると筆記可能なようであるが、実際には顔料粒子相互の絡み合いによって詰まりを生ずると考えられる。ここで、ｂ／Ｌmax＝３．０のときは詰まり、ｂ／Ｌmax＝５．６３のときは詰まらない。
【００５７】
上記の実験結果では、Ｌmaxが８０μｍと１５０μｍの間にしきい値があったので、Ｌmaxを８０μｍ及び１５０μｍとしてボール直径を変えずにボールペンチップの寸法を変えて同様の筆記性評価を行った。その結果を下表に示す。なお、球状粒子を含むインキについても筆記性評価を行った。
【００５８】
【表７】

【００５９】
上表より明らかなように、扁平状粒子を含むインキについて、Ｌmax＝８０μｍでもチップの開口が小さくなると詰まり、Ｌmax＝１５０μｍでもチップの開口が大きくなると詰まらなくなる。具体的には、Ｌmax＝８０μｍについては、ｂ＝３５０μｍ（ｂ／Ｌmax＝４．３８）のときに詰まり、ｂ＝３８０μｍ（ｂ／Ｌmax＝４．７５）のときには詰まらない。Ｌmax＝１５０μｍについては、ｂ＝４５０μｍ（ｂ／Ｌmax＝３．００）のときに詰まり、ｂ＝４７０μｍ（ｂ／Ｌmax＝３．１３）のときには詰まらない。
球状粒子を含むインキについては、Ｌmaxがボールペンチップの最小隙間ａより大きければ詰まり、小さければ詰まらない。
【００６０】
チップとして、ボール直径０．８ｍｍの「０．８」チップを用い、扁平形粒子を含有するインキの種類を変えて同様の筆記性評価を行った。その結果を下表に示す。このとき、ボールペンチップの最小隙間（ａ）は３４．７μｍ、ボールペンチップの正面視においてボール又はボールハウジングと交差しないように引いた最長の線分の長さ（ｂ）は３３０μｍである。
【００６１】
【表８】

【００６２】
この結果においても、扁平形顔料粒子の長径の最大値Ｌmaxが８０μｍと、ボールペンチップの最小隙間ａ（３４．７μｍ）より大きくても筆記は可能である。一方、Ｌmaxが１５０μｍとなると筆記不能となっている。上記線分の長さｂは３３０μｍなので、単純に考えると筆記可能なようであるが、実際には顔料粒子相互の絡み合いによって詰まりを生ずると考えられる。ここで、ｂ／Ｌmax＝２．２０のときは詰まり、ｂ／Ｌmax＝４．１３のときは詰まらない。
【００６３】
球状粒子を含有するインキについて、チップとして、同じく「０．８」チップを用い、インキの種類を変えて同様の筆記性評価を行った。その結果を下表に示す。
【００６４】
【表９】

【００６５】
この結果において、球状顔料粒子の直径の最大値Ｌmaxが４０．３μｍと、ボールペンチップの最小隙間ａ（３４．７μｍ）より大きくなると筆記不能となっている。扁平形粒子においてＬmaxが８０μｍでも筆記可能であるのと対照的である。
【００６６】
顔料粒子の径の分布と筆記性との関連を調べるために実験を行った。インキ用顔料として、比較的小粒径の「ＷＸＭ０６５０」顔料と比較的大粒径の「ＷＸＭ７４９３」顔料を用いた。それぞれの顔料における粒子の長径の分布を図５，６に示す。「ＷＸＭ０６５０」顔料を４％含有するインキ（Ａ）、「ＷＸＭ７４９３」顔料を４％含有するインキ（Ｂ）、「ＷＸＭ０６５０」顔料と「ＷＸＭ７４９３」顔料を２％ずつ含有するインキ（Ｃ）、「ＷＸＭ７４９３」顔料を２％含有するインキ（Ｄ）を調製した。インキ（Ｃ）における粒子の長径の分布を図７に示す。これらのインキについて「２９−４」チップを用いて筆記を行った。その結果を下表に示す。
【００６７】
【表１０】

【００６８】
上表におけるインキ（Ｂ）とインキ（Ｃ）、インキ（Ｂ）とインキ（Ｄ）の比較からわかるように、Ｌmax及びｂ／Ｌmaxの値が同じであっても、大径粒子の存在割合が減少すれば流出可能となる。
【００６９】
これは、大径粒子の顔料の間に小径粒子が入り込み、大径粒子間にすき間ができるためであると考えられる。
【００７０】
上記のごとく、扁平形顔料粒子を含有するインキを用いたときは、顔料粒子の長径の最大値Ｌmaxがボールペンチップの最小隙間ａより大きくてもボールペンチップは詰まらず、筆記は可能である。
ボールペンチップが筆記時に詰まるか否かは、ボールペンチップの各部寸法と顔料粒子の径の分布との関係によると考えられる。そのしきい値の定量的な算出法については未だ不明なところがあるが、ｂ／Ｌmaxの値が重要なファクターとなるようである。
実験データから帰納すれば、詰まりのおそれを十分に低減するには、ボールペンチップの正面視においてボール又はボールハウジングと交差しないように引いた最長の線分の長さ（ｂ）は、扁平形顔料粒子の長径の最大値（Ｌmax）の３倍より大きいことが好ましく、詰まりのおそれを確実に除くには、扁平形顔料粒子の長径の最大値（Ｌmax）の５倍より大きいことが好ましいと考えられる。
【００７１】
以下の樹脂系フレーク顔料を用い、アルミニウムフレーク顔料と同様に筆記性評価を行った。使用した樹脂系フレーク顔料と評価結果を下表に示す。なお、インクの配合は、表１の組成において、アルミニウムペーストを添加せず、樹脂系フレーク顔料を同量（３．９９重量％）添加した。
【００７２】
【表１１】

【００７３】
上表より明らかなように、樹脂系フレーク顔料を用いた場合でも、アルミフレーク顔料の場合と同様に、扁平形顔料粒子を含有するインキを用いたときは、顔料粒子の長径の最大値Ｌmaxがボールペンチップの最小隙間ａより大きくてもボールペンチップは詰まらず、筆記は可能である。
【００７４】
以上説明した実施例は、いずれもアルミニウムフレーク顔料又は樹脂系フレーク顔料を含有するインキを使用したものであるが、ガラスフレーク顔料や金属被覆無機顔料を使用する場合においても同様の効果が得られる。
【００７５】
【発明の効果】
以上、説明したように、本発明によれば、扁平状の顔料粒子とボールペンチップとの組合せにより、ボールペンチップの最小隙間を大きくしすぎないで粒子径の大きい光輝性顔料を含有するインキを、ボールペンチップの詰まりの心配なく使用することができ、強い光輝感、立体感を有する筆跡乃至塗膜を得ることができる。
また、扁平状の顔料粒子を用いることにより、球状の顔料粒子を用いたときよりも、同粒径で詰まりにくく、大粒径の粒子を用いることができるので、強い光輝感、立体感を有する筆跡乃至塗膜を得ることができる。
【図面の簡単な説明】
【図１】 （ａ）は、本発明の一実施例に係るボールペンのボールペンチップの先端部分の断面図であり、（ｂ）は、（ａ）のＡ−Ａ断面図である。
【図２】 図１のボールペンの要部縦断面図である。
【図３】 粒子の長径および短径を表す説明図である。
【図４】 扁平形顔料粒子を概念的に示した説明図である。
【図５】 アルミニウム粉顔料「アルペーストＷＸＭ０６５０」の粒子の長径の分布を示すグラフである。
【図６】 アルミニウム粉顔料「アルペーストＷＸＭ７４９３」の粒子の長径の分布を示すグラフである。
【図７】 アルミニウム粉顔料「アルペーストＷＸＭ０６５０」と「アルペーストＷＸＭ７４９３」を混合した顔料の粒子の長径の分布を示すグラフである。
【図８】 （ａ）は、本発明の一実施例に係るボールペンのボールペンチップの先端部分の断面図であり、（ｂ）は、（ａ）のＡ−Ａ断面図である。
【符号の説明】
１ ボールペン
５ ボールペンチップ
７ インキ収納管（インキ収納部）
１０ 筆記用ボール
３０ 水性インキ
４５ 座部
４７ 溝
４８ 隙間（インキ流通路）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ballpoint pen or a ballpoint pen tip, and more particularly to a ballpoint pen or a ballpoint pen tip using an ink containing a pigment.
[0002]
[Prior art]
A ballpoint pen is a well-known writing instrument. A ball for writing is rotatably held in a ballpoint pen tip, the ink in the ink storage section is guided to the ball for writing, and the ink is attached to paper etc. according to the rotation of the ball for writing. It is something to be made.
Focusing on the shape of the ball-point pen tip, the ball-point pen tip is composed of a tip body 100 and a writing ball 102 as shown in FIGS. 8A and 8B. The ball 102 is inserted into the ball storage chamber 103, and the ball 102 is held between the tips 101 of the chip body 100.
[0003]
The inner structure of the ballpoint pen tip has a concave ball storage chamber 103 at the front end and an ink conduction opening at the rear end. The central pore 110 passes through the ball storage chamber 103 and the ink conduction opening. A radial groove 107 called an arrow groove may be provided on the seating surface 105 of the ball storage chamber 103.
[0004]
[Problems to be solved by the invention]
By the way, the present applicant has disclosed an aqueous ink composition containing glitter pigments such as glass flake pigments and metal-coated inorganic pigments in Japanese Patent Application No. 11-76868. In this water-based ink composition, the average particle diameter of the pigment is recommended to be about 20 to 50 μm. According to the water-based ink composition using the glitter pigment having such a particle size, the water-based ink composition using the glitter pigment having a conventionally known glitter pigment has a stronger glitter feeling and a strong stereoscopic effect. A handwriting or a coating film can be obtained.
[0005]
However, the use of a bright pigment having a large particle size has been considered to be difficult to use because of the fear of ink clogging.
That is, if the particle size is large, the ink may be clogged during writing, and there is a risk that writing may be impossible. For this reason, it has been considered that the maximum value of the particle diameter should be smaller than the minimum gap of the ballpoint pen tip. Usually, the maximum value of the particle size is often about 2 to 3 times the average particle size, and the minimum gap of the ballpoint pen tip is about 60 μm at most, so it is dangerous to make the average particle size 30 μm or more. It was thought.
If the minimum clearance of the ballpoint pen tip is made larger, a pigment with a larger particle size can be used, but there is a problem that the ball becomes unstable and drops off in extreme cases, so it is also possible to increase the minimum clearance There was a limit.
[0006]
Therefore, the present invention uses an ink containing a bright pigment having a large particle diameter without excessively increasing the minimum gap between the ballpoint pen tips without worrying about the clogging of the ballpoint pen tip, and a handwriting or a three-dimensional impression with a strong glitter feeling. The purpose is to obtain a coating film.
[0007]
[Means for Solving the Problems]
The present inventors have found that when a flat flaky pigment is used, ink clogging may not occur even when the major axis of the pigment particle is larger than the minimum gap of the ballpoint pen tip, and the present invention has been completed.
[0008]
The invention described in claim 1 of the present invention includes a substantially cylindrical ball housing and a ball housing. , Some exposed from the ball housing A ballpoint pen tip with a ball and an ink tank that is connected to the ballpoint pen tip and filled with ink. A gap is formed between the ball and the ball housing on the exposed side of the ball from a position cut by a plane perpendicular to the central axis of the ball housing and passing through the center of the ball. Act as a road In the ballpoint pen to do When the ball is in contact with the bearing surface of the ball housing and the center of the ball is located on the central axis of the ball housing, The ink contains flat pigment particles, The gap The minimum gap is larger than the maximum value of the minor axis of the flat pigment particle and smaller than the maximum value of the major axis of the flat pigment particle, and is the longest length drawn so as not to intersect the ball or the ball housing in the front view of the ballpoint pen tip. The length of the line segment is larger than the maximum value of the major axis of the flat pigment particles More than 4.75 times the major axis of the flat pigment particles This is a ballpoint pen.
[0009]
Here, “major axis” is the longest length when the particles are projected onto the projection plane while variously changing the direction of the particles with respect to the projection plane, and “minor axis” is the projection plane parallel to the major axis direction. The minimum value among the maximum widths of the particles measured in the direction orthogonal to the major axis direction in the projection view when the direction of the particles is variously changed while projecting the particles. For example, as shown in FIG. 3, in the case of a spherical particle, the major axis (L) and the minor axis (D) are the diameter of the sphere, and in the case of a discoidal particle, the major axis (L) is the disc diameter, minor axis ( D) is the thickness of the disk, and for cylindrical particles, the major axis (L) is approximately the length of the cylinder and the minor axis (D) is the diameter of the cylinder. Since the size of the major axis and minor axis of the pigment particles varies depending on the individual particles, the maximum value in the distribution becomes a problem.
[0010]
In this ballpoint pen, the ink contains flat pigment particles, and the maximum value (Lmax) of the major axis (L) of the flat pigment particles is larger than the minimum gap (a) of the ballpoint pen tip. The maximum length (Tmax) of the short diameter (T) of the flat pigment particles is smaller than the length (b) of the longest line segment drawn so as not to intersect the ball housing, and is smaller than the minimum clearance (a) of the ballpoint pen tip. The size of the ballpoint pen tip and the size of the flat pigment particles are selected so as to be small.
[0011]
The invention described in claim 2 of the present invention includes at least one of a glass flake pigment, a metal-coated inorganic pigment, a metallic luster pigment, and a resin flake pigment as a flat pigment. In It is a ball-point pen of description.
[0012]
The invention described in claim 3 of the present invention includes an aluminum flake pigment as the flat pigment. In It is a ball-point pen of description.
[0013]
According to a fourth aspect of the present invention, there is provided a ballpoint pen tip for using an ink containing a flat pigment, a substantially cylindrical ball housing, and a ball housing that is held in the ball housing. , Some exposed from the ball housing With a ball When the ball abuts the seat surface of the ball housing and the center of the ball is located on the center axis of the ball housing, the ball is between the ball housing and the ball housing and is perpendicular to the center axis of the ball housing. A gap is formed on the exposed side of the ball from a position cut by a plane passing through the center, and the gap The minimum gap is the longest line drawn so as not to intersect the ball or ball housing in the front view of the ballpoint pen tip when it is larger than the maximum value of the minor axis of the flat pigment particle and smaller than the maximum value of the major axis of the flat pigment particle. The length of the minute is greater than the maximum length of the flat pigment particles More than 4.75 times the major axis of the flat pigment particles This is a ballpoint pen tip.
[0014]
The invention described in claim 5 of the present invention includes at least one of a glass flake pigment, a metal-coated inorganic pigment, a metallic luster pigment, and a resin flake pigment as the flat pigment. In It is a ball-point pen tip of description.
[0015]
The invention described in claim 6 of the present invention includes an aluminum flake pigment as the flat pigment. In It is a ball-point pen tip of description.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Since the ball-point pen of this embodiment is based on the premise that a special ink is used, the properties of the ink to be used will be described prior to the description of the physical structure of the ball-point pen.
The ink used for the ballpoint pen of this embodiment is a water-based ink having thixotropic properties, and contains a glass flake pigment, a metal-coated inorganic pigment, a metallic luster pigment, or a resin-based flake pigment. Of course, you may contain 2 or more types among these.
[0017]
Here, the glass flake pigment refers to a pigment having a structure in which flaky glass is coated with a metal, a semimetal, or the like, and has a glittering feeling and a three-dimensional feeling. As the metalloid, for example, bismuth, antimony, gray arsenic, or the like can be used.
FIG. 4 is an explanatory diagram conceptually showing particles of glass flake pigment.
The glass flake pigment particles are flat and have a thickness of about 1 μm. However, when the glass flake pigment particles blended as the ink composition are individually viewed, the major axis has a certain degree of variation as shown in FIG.
In order to express glitter and stereoscopic effect, when a glass flake pigment is blended in the ink of the ballpoint pen, it is appropriate to select one having an average major axis of 20 μm or more. That is, when the average major axis of the glass flake pigment is less than 20 μm, since the flake particles are too small, the glitter is inferior and is not worth blending in the ink.
[0018]
As described above, since the particle diameters of the glass flake pigments to be mixed vary, the ink contains a pigment having a particle having a larger major axis or a pigment having a smaller major axis than the average major axis. It becomes. If the glass flake pigment has an average major axis of 20 μm, particles having a major axis of about 40 μm are generally included as the maximum. Therefore, in order to express the glitter and stereoscopic effect, it is appropriate to select a material having a maximum diameter of 40 μm or more.
[0019]
Currently available glass flake pigments include those in which flake glass is coated with a metal by an electroless plating method. Specific examples include trade names “Metashine REFSX-2015PS”, “Metashine REFSX-2025PS” and “Metashine REFSX-2040PS” manufactured by Toyo Aluminum Co., Ltd. coated with silver.
[0020]
A pigment obtained by coating a glass flake with a metal by a sputtering method is also an example of a glass flake pigment. These include trade names “Crystal Color GF2125”, “Crystal Color GF2125-M”, “Crystal Color GF2140”, and “Crystal Color GF2140-M” manufactured by Toyo Aluminum Co., Ltd. coated with silver. In addition, there are trade names “Crystal Color GF2525”, “Crystal Color GF2525-M”, “Crystal Color GF2540”, and “Crystal Color GF2540-M” manufactured by the same company that are coated with nickel, chrome, and molybdenum. In addition, there is a product name “GF250” manufactured by the company coated with brass, a product name “GF1345” manufactured by the company coated with a silver alloy, and a product name “GF1445” manufactured by the company coated with titanium.
These glass flake pigments can be used alone or in combination of two or more.
[0021]
The glass flake pigment described above is contained in an amount of 0.1 to 20.0% by weight based on the total amount of the ink composition. That is, when the glass flake pigment is less than 0.1% by weight in the total amount of the ink composition, the glitter and stereoscopic effect are not sufficient. When the glass flake pigment exceeds 20.0% in the total amount of the ink composition, the viscosity of the ink is excessively increased and the fluidity is lowered. The optimum amount of the glass flake pigment is 1.0 to 10.0% by weight.
[0022]
Next, the metal-coated inorganic pigment will be described. The metal-coated inorganic pigment is a generic term for inorganic pigments coated with at least one of a metal and a metal oxide.
The metal-coated inorganic pigment is configured as an inorganic pigment coated with a metal and / or metal oxide, for example, by metal vapor deposition, and can be used as a bright pigment. Examples of commercially available products include aluminum coated with iron (III) oxide. For example, trade names “Paliocrom Gold L2000 / L2002”, “Paliocrom Gold L2020 / L2022”, “Paliocrom Gold 2025” manufactured by BASF Corporation, An example is “Paliocrom Orange L2800”.
[0023]
Mica coated with iron (III) oxide is also known as one of metal-coated inorganic pigments. For example, there are trade names “Paliocrom Red Gold L2500” and “Paliocrom Red L4000” manufactured by BASF Corporation. In addition, there are also mica-like iron oxides (III) coated with aluminum-manganese, and examples thereof include trade names “Paliocrom Copper L3000” and “Paliocrom Copper L3001” manufactured by BASF Corporation. Mica coated with reduced titanium dioxide is also known as one of metal-coated inorganic pigments. Further, mica coated with titanium dioxide is one of the metal-coated inorganic pigments.
These metal-coated inorganic pigments can also be used alone or in combination of two or more.
[0024]
For the same reason as the glass flake pigment, the above metal-coated inorganic pigment is preferably 20 μm or more for the average major axis and 40 μm or more for the maximum major axis. The blending amount is also equivalent to the glass flake pigment described above.
[0025]
As the metallic luster pigment, aluminum powder, brass powder, copper powder, gold powder, or silver powder can be used. The aluminum powder pigment may be a leafing type or a non-leafing type. Specifically, trade names “Alpaste WXM1440”, “Alpaste WXM1415”, “Alpaste WXM5423”, “Alpaste WXM5422”, “Alpaste WJP-U75C”, “Alpaste WE1200” manufactured by Toyo Aluminum Co., Ltd. "Alpaste WXM7675", "Alpaste WXM0630", trade names "1110W" and "2172SW" manufactured by Showa Aluminum, and trade names "AW-808C" and "AW-7000R" manufactured by Asahi Kasei. Colored aluminum pigments such as trade names “F500-RG”, “F500BG-W”, and “F701RE-G” manufactured by Showa Aluminum Co., Ltd. can also be used.
As other metal powder pigments, specific examples of brass powder pigments include trade names “BS-605” and “BS-607” manufactured by Toyo Aluminum Co., Ltd. and “Bronze” manufactured by Nakajima Metal Foil Powder Co., Ltd. There are “Powder P-555” and “Bronze Powder P-777”.
These metallic luster pigments can also be used alone or in combination of two or more.
[0026]
For the same reason as the glass flake pigment, the above metallic luster pigment is preferably 20 μm or more for the average major axis and 40 μm or more for the maximum major axis. The blending amount is also equivalent to the glass flake pigment described above.
[0027]
Next, the resin flake pigment will be described. A resin-based flake pigment is a pigment having a multilayer structure composed of only a resin or a resin and a metal. A multilayer film composed of only a resin layer or a resin layer and a metal layer is formed into a powder by punching or cutting. Is. The resin used for the resin-based flake pigment can be freely colored, and the color tone can be freely selected. Since the resin-based flake pigment has a multilayer structure, it can be colored like a crystal by refraction of light. In the case of including a metal layer, more complex color is generated due to reflection of light on the metal surface. In addition, in order to reflect more complicated light, a resin layer or a metal layer with unevenness can be used.
Specifically, trade names “ELG Color # 200” and “ELG Color # 325” manufactured by Oike Kogyo Co., Ltd., “Crystal Color X-5”, “Rainbow Flake No. 55”, “Diamond” manufactured by Dia Kogyo Co., Ltd. “Piece No. 55”, “Diamond piece H25”, “Diamond piece H55”, and “Diamond hologram HG-5EP”. In particular, in “LG color # 200” and “LG color # 325”, the resin layer has a color, and a pigment having excellent glitter and three-dimensional effect can be selected in relation to the ink color. In addition, “Diamond Hologram HG-5EP” has a holographic property in the pigment itself. Therefore, when “Diamond Hologram HG-5EP” is used, the color changes depending on the angle at which the handwriting and the coating film are viewed. Can give a radiant shine.
These resin flake pigments can also be used alone or in combination of two or more as well as other pigments.
[0028]
For the same reason as the glass flake pigment, the resin flake pigment is preferably 20 μm or more for the average major axis and 40 μm or more for the maximum major axis. The blending amount is also equivalent to the glass flake pigment described above.
[0029]
Next, the physical structure of the ballpoint pen according to the embodiment of the present invention will be described.
The physical structure of the ballpoint pen of the embodiment of the present invention is basically not different from the conventional one.
FIG. 2 shows a ballpoint pen 1 according to an embodiment of the present invention. 1A is a cross-sectional view of the tip portion of the ball-point pen tip of the ball-point pen of FIG. 2, and FIG. 1B is a cross-sectional view taken along line AA of FIG.
A ballpoint pen 1 according to an embodiment of the present invention shown in FIG. 2 includes a cylindrical main body shaft 2 and an ink core 3. The ink core 3 has a ballpoint pen tip 5 on which a writing ball 10 is rotatably held. The tip 5 is attached to the tip of an ink storage tube (ink storage portion) 7 via a joint member 6. It is a thing. A spherical valve body 8 is provided inside the joint member 6.
[0030]
The ballpoint pen tip 5 is composed of a tip body 11 and a writing ball 10, and a writing ball 10 is provided at the tip of the tip body 11. The chip body 11 is made by cutting a metal material such as free-cutting steel. As the material of the chip body 11, for example, free cutting stainless steel or brass can be used.
The outer shape of the chip body 11 is such that the tip portion 17 has a conical shape and the rear side 18 has a cylindrical shape. Further, a step 19 is provided at the rear end portion, and the rear end side is made slightly smaller in diameter than the step 19.
The schematic shape of the interior of the ballpoint pen tip is as shown in FIG. 2, and has a ball storage chamber 40 in which the writing ball 10 is stored at the tip portion, and an ink conduction hole 12 communicating from the ball storage chamber 40 to the rear end side. Is provided.
[0031]
A valve receiver is formed in the vicinity of the rear end opening of the ink conduction hole 12.
In the ball storage chamber 40 of the chip body 11, the writing ball 10 is rotatably stored. The details of the ball storage chamber 40 are as shown in FIG. That is, the ball storage chamber 40 has a concave shape with an open end, and has a cylindrical wall 41. Also, the open end is somewhat cautious and narrowed.
[0032]
A seat portion 45 is provided at a portion facing the open side of the ball storage chamber 40. The seat 45 is a tapered surface having an inclination of about 30 °, converges in the central hole 46, and communicates with the ink conduction hole 12. Here, the central hole 46 of the ball storage chamber 40 has a diameter of about 0.3 mm to 0.5 mm.
A groove 47 extending radially in the shape of a cross is provided on the seating surface of the seat 45. In the ballpoint pen 1 of the present embodiment, the tip end portion of the ink conduction hole 12 has an inner diameter substantially the same as the inner diameter of the ball storage chamber 40, and the groove 47 described above is formed from the ball storage chamber 40 as shown in FIG. It penetrates to the ink conduction hole 12.
And in the ball-point pen 1 of this embodiment, the width W of the groove | channel 47 is wider than a normal thing, and is 0.15-0.5 mm, More preferably, it is 0.20-0.35 mm. The width W of the groove 47 is suitably 15% to 50%, more preferably about 25% to 35% of the diameter d of the writing ball 10.
[0033]
The writing ball 10 is a sphere having a diameter of 0.3 to 1.2 mm. However, since the ballpoint pen of the present embodiment uses a water-based ink containing a pigment having a relatively large particle size as described later, The diameter of 10 is desirably 0.8 to 1.1 mm. A more recommended range is 0.9 to 1.1 mm.
The material of the writing ball 10 is not particularly limited, and stainless steel, alumina sintered body, zirconia, SiC, WC, and other known materials can be used.
[0034]
The writing ball 10 is rotatably held in the ball storage chamber 40 of the ball-point pen chip, and a part thereof is exposed from the opening of the ball storage chamber 40.
The exposure amount H of the writing ball 10 is such that when the writing ball comes into contact with the seat surface of the ball storage chamber and the center of the writing ball is located on the central axis of the ball storage chamber as shown in FIG. It is 20% to 35% of the diameter d, and more desirably 25% to 30%.
[0035]
Regarding the relationship between the diameter d of the writing ball 10 and the inner diameter D of the cylindrical wall 41 of the ball storage chamber 40, the inner diameter D of the cylindrical wall 41 is 40 μm to 120 μm larger than the diameter d of the ball 10. That is, when the writing ball 10 is placed at the position shown in FIG. 1, the equator of the writing ball 10 (position cut at a plane perpendicular to the central axis of the ball storage chamber and passing through the center of the ball 10: dimension d). A gap 48 of 20 to 60 μm is formed between the writing ball 10 and the ball storage chamber 40 in the outer peripheral portion of the line position.
[0036]
Further, as described above, the opening portion of the ball storage chamber 40 is caulked, and the portion of the writing ball 10 on the exposed side from the equator and within the ball storage chamber 40 is 20 to 60 μm in any portion. A gap 48 is secured.
The gap 48 between the writing ball 10 and the ball storage chamber 40 functions as an ink flow path. However, the ballpoint pen of this embodiment uses water-based ink containing a pigment having a relatively large particle size as described later. Therefore, a wider interval is provided than a normal ballpoint pen. The lower limit of the gap 48 between the writing ball 10 and the ball storage chamber 40 is an appropriate example when a pigment having an average particle diameter of 20 to 50 μm is used. When the gap 48 is smaller than this, the pigment is a ball. It is clogged in the storage room 40. On the other hand, when the gap 48 between the writing ball 10 and the ball storage chamber 40 exceeds the upper limit of 60 μm, the operation of the ball 10 is not stable, and in a severe case, the writing ball 10 jumps out of the ball storage chamber 40. End up. For the stability of the operation of the ball 10, it is more desirable that the gap 48 is 40 μm or less.
Note that the shape and structure of the chip described above are merely examples, and other embodiments are possible. For example, the number of grooves 47 may be 3, 5, or the like.
[0037]
The connecting member 6 is made by injection molding using a thermoplastic resin such as polypropylene resin as a raw material, and the outer shape is not much different from a known one. That is, the front end 20 of the connecting member 6 has a conical shape. The rear end side has a two-stage cylindrical shape, and a large diameter portion 21 and a small diameter portion 22 are sequentially provided. A communication hole 23 penetrating in the axial direction is provided at the center of the connecting member 6. A valve seat 25 is provided at an intermediate portion of the communication hole 23. A positioning step 31 is provided on the tip end side of the communication hole 23.
[0038]
The valve body 8 is a sphere made of a material that is not easily rusted and has a certain weight, such as stainless steel, cemented carbide, or ceramics.
[0039]
The ink storage tube (ink storage portion) 7 is made by extrusion molding using polyethylene resin, polypropylene resin or the like as a raw material, and the inside thereof is filled with the above-described aqueous ink 30 having thixotropy.
The viscosity of the glittering water-based ink 30 used in this embodiment is 1000 to 10,000 mPa · s (ELD viscometer manufactured by Tokimec Co., Ltd., 3 ° R14 cone, rotation speed: 0.5 rpm, 20 ° C). The rear end portion of the water-based ink 30 is sealed with a gel sealant (not shown) such as polybutene.
[0040]
As shown in FIG. 2, the ink core 3 is formed by connecting a ballpoint pen tip 5 and an ink storage tube 7 via a connecting member 6, and the ballpoint pen tip 5 is disposed on the tip side of the communication hole 23 of the connecting member 6. The ink storage tube 7 is inserted into the small diameter portion 22 at the rear end portion of the connection member 6. And the valve body 8 is inserted in the connection member 6 between the valve receiver 15 of the ball-point pen tip 5 and the valve seat 25 so as to be movable in the axial direction. The ballpoint pen 1 of the present embodiment is one in which the main body shaft 2 is externally mounted on the large diameter portion 21 of the connecting member 6 of the ink core 3 described above.
[0041]
When writing characters or the like using the ballpoint pen 1 of the present embodiment, the water-based ink 30 enters the ball storage chamber 40 of the ballpoint pen tip 5 from the ink storage tube 7 and is applied to paper or the like via the writing ball 10. .
In the ballpoint pen 1 of the present embodiment, the gap 48 between the writing ball 10 and the ball storage chamber 40 is large enough for the flat pigment particles to pass through. The glass flake pigment and the like pass smoothly between them.
[0042]
【Example】
Next, an experiment conducted for confirming the effect of the present invention will be described.
As an example of the present invention, a ballpoint pen having the structure shown in FIG.
An ink containing a pigment composed of flat (scale-like) particles was prepared and filled in a ballpoint pen, and the evaluation of the writing property was judged. An aluminum paste was used as the scale-like color material.
The composition of the ink is as shown in the table below.
[0043]
[Table 1]

[0044]
Details of the pigments composed of scale-like particles are as shown in the table below. Here, L50 is the median value of the long diameter distribution of the flat pigment particles.
[0045]
[Table 2]

[0046]
For comparison, an ink containing a pigment composed of spherical particles was prepared. The composition is as shown in the table below.
[0047]
[Table 3]

[0048]
Details of the pigments composed of spherical particles are as shown in the table below. Here, Lav is an average value of the diameters of the spherical particles.
[0049]
[Table 4]

[0050]
These inks were filled into an ink tank of a ballpoint pen, and the writing property was evaluated by a continuous writing test and a sensory test by handwriting.
Details of the chips used in the experiment are shown in the table below. The socket is made of free-cutting stainless steel and the ball is made of black safarin.
Since the short diameter of the flat pigment particles is about 1 μm, the minimum gap (a) is sufficiently larger than the maximum short diameter (Tmax) of the flat pigment particles in any chip.
[0051]
[Table 5]

[0052]
Here, the length (b) of the longest line segment drawn so as not to intersect the ball or the ball housing in the front view of the ballpoint pen tip is calculated from the relationship shown in FIG.
[0053]
[Expression 1]

[0054]
A “29-4” chip was used as the chip, and the writing property was evaluated by changing the type of ink. The results are shown in the table below. ○ is writable, × is not writable. At this time, the minimum gap (a) of the ballpoint pen tip is 51.2 μm, and the length (b) of the longest line segment drawn so as not to intersect the ball or the ball housing in the front view of the ballpoint pen tip is 450 μm.
[0055]
[Table 6]

[0056]
As can be seen from this result, writing is possible even when the maximum value Lmax of the long diameter of the flat pigment particles is 80 μm, which is larger than the minimum gap a (51.2 μm) of the ballpoint pen tip. On the other hand, when Lmax is 150 μm, writing is impossible. The length b of the longest line drawn so as not to cross the ball or ball housing in the front view of the ball-point pen tip is 450 μm, so it seems that writing is possible by simple thinking, but actually it is caused by the entanglement between the pigment particles. It is thought to cause clogging. Here, clogging occurs when b / Lmax = 3.0, and clogging does not occur when b / Lmax = 5.63.
[0057]
In the above experimental results, since there was a threshold value between Lmax of 80 μm and 150 μm, the same writing performance evaluation was performed by changing the dimensions of the ballpoint pen tip without changing the ball diameter with Lmax being 80 μm and 150 μm. The results are shown in the table below. In addition, writing property evaluation was performed also about the ink containing a spherical particle.
[0058]
[Table 7]

[0059]
As can be seen from the above table, the ink containing flat particles clogs when the tip opening is small even at Lmax = 80 μm, and does not clog when the tip opening is large even at Lmax = 150 μm. Specifically, when Lmax = 80 μm, clogging occurs when b = 350 μm (b / Lmax = 4.38), and clogging does not occur when b = 380 μm (b / Lmax = 4.75). Lmax = 150 μm is clogged when b = 450 μm (b / Lmax = 3.00) and is not clogged when b = 470 μm (b / Lmax = 3.13).
For ink containing spherical particles, the ink clogs if Lmax is larger than the minimum gap a of the ball-point pen tip, and does not clog if it is small.
[0060]
As a chip, a “0.8” chip having a ball diameter of 0.8 mm was used, and the same writing property evaluation was performed by changing the type of ink containing flat particles. The results are shown in the table below. At this time, the minimum gap (a) of the ballpoint pen tip is 34.7 μm, and the length (b) of the longest line segment drawn so as not to intersect the ball or the ball housing in the front view of the ballpoint pen tip is 330 μm.
[0061]
[Table 8]

[0062]
Also in this result, writing is possible even when the maximum value Lmax of the major axis of the flat pigment particles is 80 μm, which is larger than the minimum gap a (34.7 μm) of the ballpoint pen tip. On the other hand, when Lmax is 150 μm, writing is impossible. Since the length b of the line segment is 330 μm, it seems to be writable when considered simply, but it is thought that clogging actually occurs due to the entanglement of the pigment particles. Here, clogging occurs when b / Lmax = 2.20, and clogging does not occur when b / Lmax = 4.13.
[0063]
For ink containing spherical particles, the same “0.8” chip was used as a chip, and the same writing property evaluation was performed by changing the type of ink. The results are shown in the table below.
[0064]
[Table 9]

[0065]
In this result, when the maximum value Lmax of the diameter of the spherical pigment particles is 40.3 μm, which is larger than the minimum clearance a (34.7 μm) of the ballpoint pen tip, writing is impossible. In contrast to the flat particles, writing is possible even when Lmax is 80 μm.
[0066]
An experiment was conducted to investigate the relationship between the distribution of pigment particle diameter and the writing ability. As a pigment for ink, a “WXM0650” pigment having a relatively small particle size and a “WXM7493” pigment having a relatively large particle size were used. The distribution of the major axis of the particles in each pigment is shown in FIGS. Ink containing 4% of “WXM0650” pigment (A), Ink containing 4% of “WXM7493” pigment (B), Ink containing 2% of “WXM0650” pigment and “WXM7493” pigment (C), “WXM7493 An ink (D) containing 2% pigment was prepared. The distribution of the major axis of the particles in ink (C) is shown in FIG. These inks were written using a “29-4” chip. The results are shown in the table below.
[0067]
[Table 10]

[0068]
As can be seen from the comparison of ink (B) and ink (C), and ink (B) and ink (D) in the above table, even if the values of Lmax and b / Lmax are the same, the proportion of large particles present is If it decreases, it can flow out.
[0069]
This is thought to be because small-diameter particles enter between pigments of large-diameter particles, and a gap is formed between the large-diameter particles.
[0070]
As described above, when ink containing flat pigment particles is used, even if the maximum value Lmax of the major axis of the pigment particles is larger than the minimum gap a of the ballpoint pen tip, the ballpoint pen tip is not clogged and writing is possible.
Whether or not the ball-point pen tip is clogged at the time of writing is considered to depend on the relationship between the size of each part of the ball-point pen tip and the diameter distribution of the pigment particles. Although the quantitative calculation method of the threshold value is still unclear, the value of b / Lmax seems to be an important factor.
In order to reduce the possibility of clogging sufficiently from the experimental data, the length (b) of the longest line drawn so as not to cross the ball or ball housing in the front view of the ballpoint pen tip is a flat pigment. It is preferable that it is larger than 3 times the maximum value (Lmax) of the major axis of the particles, and it is considered that it is preferably larger than 5 times the maximum value (Lmax) of the major axis of the flat pigment particles in order to reliably eliminate clogging. It is done.
[0071]
The following resin flake pigments were used, and the writing performance was evaluated in the same manner as the aluminum flake pigments. The resin flake pigments used and the evaluation results are shown in the table below. In addition, in the composition of the ink, the same amount (3.99% by weight) of the resin-based flake pigment was added without adding the aluminum paste in the composition of Table 1.
[0072]
[Table 11]

[0073]
As is clear from the above table, even when a resin-based flake pigment is used, as in the case of an aluminum flake pigment, when an ink containing flat pigment particles is used, the maximum value Lmax of the major axis of the pigment particles is Even if it is larger than the minimum clearance a of the ball-point pen tip, the ball-point pen tip is not clogged and writing is possible.
[0074]
In the examples described above, inks containing aluminum flake pigments or resin flake pigments are used, but similar effects can be obtained when glass flake pigments or metal-coated inorganic pigments are used.
[0075]
【The invention's effect】
As described above, according to the present invention, according to the present invention, an ink containing a bright pigment having a large particle diameter without excessively increasing the minimum gap between the ballpoint pen tips by combining the flat pigment particles and the ballpoint pen tips, It can be used without worrying about the clogging of the ballpoint pen tip, and a handwriting or coating film having a strong radiance and stereoscopic effect can be obtained.
In addition, by using flat pigment particles, it is less likely to be clogged with the same particle size than when spherical pigment particles are used, and particles having a large particle size can be used. A handwriting or a coating film can be obtained.
[Brief description of the drawings]
1A is a cross-sectional view of a tip portion of a ball-point pen tip of a ballpoint pen according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA of FIG.
2 is a longitudinal sectional view of a main part of the ballpoint pen of FIG. 1;
FIG. 3 is an explanatory diagram showing the major axis and minor axis of a particle.
FIG. 4 is an explanatory view conceptually showing flat pigment particles.
FIG. 5 is a graph showing a distribution of major diameters of particles of an aluminum powder pigment “Alpaste WXM0650”.
FIG. 6 is a graph showing the distribution of the major axis of particles of aluminum powder pigment “Alpaste WXM7433”.
FIG. 7 is a graph showing a distribution of major diameters of pigment particles obtained by mixing aluminum powder pigments “Alpaste WXM0650” and “Alpaste WXM7493”.
8A is a cross-sectional view of a tip portion of a ball-point pen tip of a ballpoint pen according to an embodiment of the present invention, and FIG. 8B is a cross-sectional view taken along line AA of FIG.
[Explanation of symbols]
1 Ballpoint pen
5 Ballpoint pen tip
7 Ink storage tube (ink storage unit)
10 Writing balls
30 Water-based ink
45 Seat
47 Groove
48 Clearance (ink flow path)

Claims (6)

A substantially cylindrical ball housing, is held in the ball housing, partially possess an ink tank ballpoint pen tip and ballpoint pen tip communicating with the ink is filled and a ball which is exposed from the ball housing, and the ball A gap is formed between the ball housing and the exposed side of the ball from a position cut by a plane perpendicular to the central axis of the ball housing and passing through the center of the ball, and the gap functions as an ink flow path . In a ballpoint pen that
With ball abuts the seating surface of the ball housing, when the position is the center of the ball on the center axis of the ball housing, the ink contains a flat-shaped pigment particles, a minimum clearance of the gap is short of the flat-shaped pigment particles Larger than the maximum value of the diameter and smaller than the maximum value of the long diameter of the flat pigment particles,
The longest line drawn so as not to intersect with the ball or the ball housing in a front view of the ballpoint pen tip length of major axis diameter of greater than the maximum value rather, and flat-shaped pigment particles of flat-shaped pigment particle 4.75 Ballpoint pen characterized by being more than doubled . 2. The ballpoint pen according to claim 1 , wherein the flat pigment includes at least one of a glass flake pigment, a metal-coated inorganic pigment, a metallic luster pigment, and a resin-based flake pigment. The ballpoint pen according to claim 2 , wherein the flat pigment contains an aluminum flake pigment. A ballpoint pen tip for using an ink containing a flat pigment, comprising a substantially cylindrical ball housing, and a ball held in the ball housing and partially exposed from the ball housing ,
When the ball abuts the seat surface of the ball housing and the center of the ball is located on the center axis of the ball housing, the ball is between the ball housing and the ball housing and is perpendicular to the center axis of the ball housing. A gap is formed on the exposed side of the ball from the position cut by a plane passing through the center,
The minimum gap of the gap is larger than the maximum value of the short diameter of the flat pigment particles and smaller than the maximum value of the long diameter of the flat pigment particles,
Longest length of a line drawn so as not to intersect with the ball or the ball housing in a front view of the ballpoint pen tip is much larger than the maximum value of the long diameter of the flat-shaped pigment particles,
A ballpoint pen tip that is 4.75 times or more the major axis of the flat pigment particles . The ballpoint pen tip according to claim 4 , wherein the flat pigment includes at least one of a glass flake pigment, a metal-coated inorganic pigment, a metallic luster pigment, and a resin flake pigment. 6. The ballpoint pen tip according to claim 5 , wherein the flat pigment includes an aluminum flake pigment.

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