JPH06210990A - Ball-point pen using oil based ink - Google Patents

Abstract

PURPOSE:To provide a ball-point pen tip of good quality and a ball-point pen which have no adverse effect on the performance of a ink being used, by constructing the tip of a ball made of ceramic and of a holder made of stainless steel having a good machinability. CONSTITUTION:A tip for a ball-point pen is formed of a ball made of ceramic and of a holder made of stainless steel having a good machinability. The ball- point pen is manufactured by using this tip, while ink containing an organic acid or fluorescent ink is used for the ball-point pen using oil based ink. As for the stainless steel being excellent in cutting properties, free-cutting stainless steel of which the content of Cr is 8 to 30%, the content of S 0.01 to 0.5%, the content of Ni 1% or less and the content of Mo 0.1 to 10% is suitable. As for the ink for the ball-point pen, ink containing a coloring agent, an organic solvent, resin, etc., can be used. The ball-point pen thus obtained causes no galvanic corrosion, since the ball is a ceramic ball being a nonconducting material.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an oil-based ballpoint pen. More specifically, it relates to a ballpoint pen having a novel tip having corrosion resistance and wear resistance.

[0002]

2. Description of the Related Art Recent ballpoint pen tips have a tendency to employ stainless steel for a holder in order to minimize deterioration of quality caused by wear when used. However, since stainless steel with high corrosion resistance such as SUS304 is very tenacious and inferior in machinability, it is very difficult to process it into a shape like a ballpoint pen tip, and mass production at low cost. Is almost impossible to use. Therefore, it is unavoidable to use stainless steel (free-cutting stainless steel) having excellent machinability. Further, as the balls, cemented carbide balls are used in consideration of corrosion resistance and wear resistance.

The material of each of the holder and the ball shows good corrosion resistance to the oil-based ballpoint pen ink when it is used alone, but when used in combination like a tip, it is affected by the water content in the ink. Since a battery is formed between the ball and the holder, galvanic corrosion occurs in the ball or the holder, and the writing performance is significantly deteriorated. In severe cases, insoluble matter is generated due to the influence of the eluted metal, and writing becomes impossible. This phenomenon is observed in a general oil-based ballpoint pen when the water content in the ink is large or when a highly corrosive ink is used. Strongly corrosive inks include, for example, inks that use fluorescent dyes whose stable range is in the weakly acidic range of pH 4 to 7, or oleic acid in order to make the ink appear smooth during writing and to give a smooth writing feel. It is an ink containing organic acids such as.

Conventionally, in order to solve these problems, it has been proposed to add various rust preventive agents or function improvers having no corrosive property to the ink, but the rust preventive effect is insufficient. Conversely, the stability of the ink itself may be destroyed. In many cases, the water in the ink causes galvanic corrosion, which causes the formation of batteries, so it is sufficient to keep the water content in the ink below 2%, but in reality it absorbs moisture when left standing. There is a problem that cannot be solved by adjusting the water content during ink preparation.

Further, it is conceivable to use a material other than free-cutting stainless steel for the holder, for example, resin, copper, copper alloy, etc., or use the same stainless steel as the holder for the ball. Since these materials are inferior in wear resistance, they deteriorate significantly during use and their initial performance cannot be maintained. Further, when the fluorescent ink is used in the copper alloy holder, there is a drawback that the ink is discolored due to the influence of elution of copper ions and the fluorescent property is lost in a short period of time.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, exhibiting excellent storage stability even when an ink having no special anticorrosion effect is used, and It is to provide a high-quality ballpoint pen tip and ballpoint pen that does not adversely affect the performance of the ink used, while maintaining the initial high writing quality even when it is used up.

[0007]

As a result of intensive studies to solve the above-mentioned problems, the inventor of the present invention has found that when a ceramic having a hardness similar to that of a cemented carbide is used for the ball, the holder and the ball are It was found that there is no galvanic corrosion due to the formation of a battery between the above and the present invention, and the present invention has been completed based on this finding. That is,

The structure of the present invention comprises the following (1) to (4) (1) A ball-point pen tip composed of a ceramic ball and a holder made of stainless steel excellent in machinability. (2) A ballpoint pen having a tip composed of a ceramic ball and a holder made of stainless steel having excellent machinability. (3) The ballpoint pen according to item (2), which uses an oil-based ink for a ballpoint pen. (4) The ballpoint pen according to item (3), wherein the oil-based ballpoint pen ink is an organic acid-containing ink or a fluorescent ink.

Specific examples of the ball material of the ceramic ball according to the present invention include silica, alumina, zirconia, and silicon carbide.

The stainless steel excellent in machinability according to the present invention has a chromium content of 8 to 30%, a sulfur content of 0.01 to 0.5%, and a nickel content of 1% or less. , Free-cutting stainless steel having a molybdenum content of 0.01 to 10% can be mentioned. However, machinability,
From the viewpoint of cost and wear resistance, the chromium content is 10-25
%, The content of sulfur is 0.15 to 0.3%, the content of nickel is 0.5% or less, and the content of molybdenum is 0.2 to 3
% Is the most desirable. The provisions here do not prevent the inclusion of elements not shown in the composition of the free-cutting stainless steel used, and include cesium, phosphorus, lead, and aluminum as free-cutting elements as necessary. Can be included.

The ink used in the ballpoint pen of the present invention is a general oil-based ballpoint pen ink, that is, a colorant,
Any ink containing an organic solvent, resin, etc. can be used.

As the colorant, all known dyes and pigments used in conventional ballpoint pen inks can be used. For example, as the oil-soluble dye, a dye soluble in the solvent used, such as Varifast Color (registered trademark of Orient Chemical Industry Co., Ltd.), Aizen spirone dye, Aizen SOT dye (Hodogaya Chemical Industry Co., Ltd. ), Registered trademark name) and the like. As the pigment, titanium oxide, carbon black, inorganic pigments such as metal powder,
Or azo lake, insoluble azo pigment, chelate azo pigment, phthalocyanine pigment, perylene and perylene pigment,
Anthraquinone pigment, quinacridone pigment, dye lake,
Examples include organic pigments such as nitro pigments and nitroso pigments.

As the organic solvent, a solvent which is used in a usual oil-based ballpoint pen ink, that is, a solvent which dissolves or disperses the above-mentioned colorant and has a relatively high boiling point is used. Examples of such substances include benzyl alcohol, phenoxyethanol, carbitols and cellosolves. These may be used alone or in combination of two or more, and the blending amount thereof is preferably in the range of 20 to 70% by weight based on the total amount of the ink.

As the resin, a resin commonly used in ordinary oil-based ballpoint pen inks, for example, a ketone resin, a sulfamide resin, a malein resin, an ester gum, a xylene resin, an alkyd resin, a phenol resin, a rosin resin, polyvinylpyrrolidone, or the like is used. These resins may be used alone or in combination of two or more, and the compounding amount thereof is in the range of 5 to 30% by weight based on the total amount of the ink. These resins act to keep the ink at a high viscosity.

Further, other additives used in ordinary oil-based inks for ballpoint pens, such as surfactants, antibacterial agents,
It can be used even if rust preventive agent, lubricating oil, etc. are added.

However, the ink that can be used most effectively in the ballpoint pen of the present invention is characterized in that it is an ink in which the problems of corrosion and wear occur in conventional ballpoint pens and chips. For example, in chips consisting of carbide balls and stainless steel holders, galvanic corrosion elutes metal ions, which causes insoluble substances to be generated and impedes the flow of ink. Examples include fluorescent ink that loses its properties, and ink to which an organic acid such as oleic acid or ricinoleic acid is added in order to smooth out the ink when writing and to obtain a good writing feel. Fluorescent ink is an ink prepared using a fluorescent paint or fluorescent pigment.

[0017]

The present invention will be described in more detail with reference to examples. In addition, the ballpoint pen used in the test, the forced deterioration test,
The writing test and the method for measuring the physical properties of the ink are as follows. Ballpoint Pen A ballpoint pen having an ink storage tube made of a polypropylene tube having an inner diameter of 1.2 mm was attached with a predetermined tip and a holder shown in Examples and Comparative Examples and filled with a predetermined ink. Forced deterioration test After leaving in a constant temperature and humidity chamber at 50 ° C and 80% RH for a predetermined time,
The sample was allowed to cool to room temperature and spirally written by hand to check the writing performance. Further, regarding the fluorescent ink, the spiral drawn line at the start was visually compared with the above-mentioned drawn line to confirm discoloration and deterioration of fluorescence. Written test A test of writing 40 characters of "Mitsubishi Pencil" continuously on the manuscript paper of 400 characters was executed on 40 monitors. Ink physical property pH: Add an equal amount of purified water to the ink and boil for 5 minutes, collect the purified water, allow to cool to room temperature, and measure with a pH meter. Viscosity: Measured with a cone-plate type viscometer. Moisture content: By Karl Fischer moisture meter.

(Example 1) Chip: Holder Free-cutting stainless steel (stainless steel having a similar composition to SUS416 containing Mo and Pb) Ball Zirconia Diameter 1.0 mm * 1 Ink: Fluorescent pink pH 5.0 Viscosity 10.0 Pa.sec
Moisture content less than 1% by weight Dye "MPI-507C" (pink) * 2 45 Resin "Hirac 111" * 3 5 Resin "PVP K-90" * 4 0.5 Lubricant Oleic acid 3.0 Solvent Benzyl alcohol 5.0 Solvent 2-Phenoxyethanol 41.5

(Example 2) Chip: Holder Free-cutting stainless steel (stainless steel having a composition similar to SUS416 containing Mo and Pb) Ball Silicon carbide (black safaline) Diameter 0.7 mm * 5 Ink: Black pH 5.5 Viscosity 12 0.0 Pa.sec Moisture content less than 1% by weight Dye "Spiron Black GCH" * 6 20 Dye "Varifast Yellow 1105" * 7 5 Dye "Spiron Violet C-RH" * 6 15 Resin "High" Rack 111 "* 3 15 Resin" PVP K-90 "* 4 0.5 Lubricant Oleic acid 5.0 Solvent Benzyl alcohol 5.0 Solvent 2-Phenoxyethanol 34.5

(Example 3) Chip: Holder Free-cutting stainless steel (S, Mo, Ni
Containing stainless steel with similar composition to SUS430) Ball Zirconia Diameter 0.7mm * 1 Ink: Blue pH 6.0 Viscosity 13.0Pa.sec Moisture content less than 1% Weight part Dye "Varifast Blue 1603" * 7 10 Dye "Neptune Blue Base 634" * 8 10 resin "Luviscor K-30" * 8 10 resin "Luviscor K-90" * 8 0.5 Lubricant Oleic acid 5.0 Solvent Benzyl alcohol 5.0 Melt Agent 2-phenoxyethanol 59.5

(Embodiment 4) Chip: Holder Free cutting stainless steel (18 to 22% C
r, 1 to 3% Mo, stainless steel characterized by containing 1% or more of S) Ball Silicon Carbide (Black Safari) Diameter 0.7mm * 6 Ink: Black pH 5.5 Viscosity 8.0Pa.sec Water content 5
% Parts by weight Dyeing “Spiron Black GCH” * 6 20 Dyeing “Varifast Yellow 1105” * 7 5 Dyeing “Spiron Violet C-RH” * 6 15 Resin “Rubiskor K-30” * 8 8 Resin "PVP K-90" * 4 0.3 Lubricant Oleic acid 5.0 Solvent Benzyl alcohol 5.0 Solvent 2-Phenoxyethanol 41.7 * 1 (Corning Glass Works) * 2 (Japan Fluorescence Chemicals Co., Ltd., registered trademark name * 3 (Hitachi Chemical Co., Ltd., registered trademark name) * 4 (GAF) * 5 (Kyocera Corporation, registered trademark name) * 6 Tsuchiya Chemical Industry Co., Ltd., registered trademark name) * 7 (Orient Chemical Industry Co., Ltd., registered trademark name) * 8 (BASF Corporation) The ballpoint pens obtained in the examples have problems even after 120 days in the forced deterioration test. Can be written without writing, and the fluorescent in of Example 1 It was not observed in the discoloration and the fluorescence of the deterioration. Also, in the writing test, all 40 monitors were able to write without much difference from the initial stage until the final writing, showing excellent writability.

Comparative Example 1 The same combination as in Example 1 except that the zirconia ball diameter was changed from 1.0 mm to a cemented carbide ball diameter of 1.0 mm.

(Comparative Example 2) The same combination as in Example 2 except that the diameter of the silicon carbide ball was changed from 0.7 mm to the cemented carbide ball diameter of 0.7 mm.

(Comparative Example 3) The same combination as in Example 3 except that the zirconia ball diameter was changed from 0.7 mm to a cemented carbide ball diameter of 0.7 mm.

(Comparative Example 4) The same combination as in Example 4 except that the diameter of the silicon carbide ball was changed from 0.7 mm to a cemented carbide ball diameter of 0.7 mm. The ball-point pens obtained in Comparative Examples 1 to 4 showed no problem in the writing test as in the case of the example, but in the forced deterioration test, the writing became impossible within 60 days, and the deterioration with time was far more than in the examples. It was great. Particularly, in Comparative Example 4, even when stored at room temperature, 3
It became impossible to write within 0 days.

(Comparative Example 5) The same combination as in Example 2 except that the holder was changed to nickel silver instead of free-cutting stainless steel.

Comparative Example 6 The same combination as in Example 3 except that the holder is changed from free-cutting stainless steel to brass. In the ballpoint pens obtained in Comparative Example 5 and Comparative Example 6, in the writing test, the initial writability could not be maintained due to chip wear, and deterioration of the writability was observed. Specifically, when half of the ink was used, a sharp increase in bloating was observed.

(Comparative Example 7) A holder was made of free-cutting stainless steel to free-cutting phosphor bronze, and balls were made of zirconia balls having a diameter of
The ink was filled with the same ink as in Example 1 except that the diameter of the cemented carbide ball was changed from 0 mm to 1.0 mm. Comparative Example 7
The oil-based ball-point pen obtained in 1. showed a result that was not much different from the examples in the writability of the writing test and the forced deterioration test, but when comparing the hue of the drawn line obtained by the spiral writing of the forced deterioration test with the initial one, it was significantly larger. It was discolored and almost no fluorescence was observed.

[0029]

EFFECTS OF THE INVENTION Initial writing performance cannot be sustained due to tip wear. In order to minimize so-called deterioration of writing performance, it is desirable to use stainless steel having excellent wear resistance in oil-based ballpoint pens. With chips made of cemented carbide balls and free-cutting stainless steel holders up to, since both balls and holders are conductors, galvanic corrosion easily occurs in the presence of moisture, and ink other than some corrosion prevention measures can only be used . Also,
Various rust preventives have been proposed, but they are not sufficiently effective, and their addition often adversely affects the quality of the ink. However, in the oil-based ballpoint pen of the present invention, galvanic corrosion does not occur because the ball is a non-conducting ceramic ball, and the holder is made of stainless steel, so it has excellent wear resistance. It is not necessary to apply a special corrosion prevention effect,
In addition, the long-term storage stability of the ink is maintained. Therefore, it is possible to minimize deterioration of the writability due to wear of the tip.

Claims (4)

[Claims] 1. A ball-point pen tip comprising a ceramic ball and a holder made of stainless steel having excellent machinability. 2. A ball-point pen comprising a tip made up of a ceramic ball and a holder made of stainless steel having excellent machinability. 3. The ballpoint pen according to claim 2, wherein an oil-based ink for a ballpoint pen is used. 4. The ballpoint pen according to claim 3, wherein the oil-based ballpoint pen ink is an ink containing an organic acid or a fluorescent ink.