JPH08252998A - Oil ink ball-point pen having medium viscosity - Google Patents

Abstract

PURPOSE: To provide an oil ink ball-point pen which endures a high writing pressure and provides an excellent smooth writing touch by adjusting a viscosity of an ink to an oil ball-point pen ink within a specified range and setting a projected area of a ball seat to a fixed value or above. CONSTITUTION: An ink of medium viscosity having an ink viscosity of 2000-10000mPa.s at 20 deg.C is used. A part wherein a ball 2 of a ball-point pen chip 1 consisting of the ball 2 and a holder material 3 comes in contact with the holder i.e., a projected area of a ball seat 3a is set to 0.09mm<2> or above. Thus, a ball-point pen which has a light and smooth writing touch like with a water base ball-point pen, is not deteriorated in the performance even by a high writing pressure at writing on a cutform, and is suitable for both business purpose and general purpose can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-based ballpoint pen using a medium-viscosity ink, and more particularly to an oil-based ballpoint pen having a light and smooth writing feel comparable to a water-based ballpoint pen and excellent in high writing pressure resistance. Is.

[0002]

2. Description of the Related Art Conventionally, an oil-based ink ballpoint pen has been used as a writing instrument for office work suitable for writing slips requiring high writing pressure. In this type of oil-based ballpoint pen, the part of the ballpoint pen tip that is formed by the ball and the holder material, that is, the ball seat, is formed into a ball shape to withstand high writing pressure, and there is sufficient contact between the ball and the holder. A high-viscosity ink having high lubricity, that is, 20
15,000 to 25,000 mPa. Use an ink of viscosity s. Therefore, since the writing is heavy and the fingers, arms, etc. become tired when used for a long time, it is often used by devising such measures as winding an elastic body around the grip portion of the shaft or providing slip prevention.

On the other hand, a water-based ballpoint pen having a low ink viscosity has a smooth and light writing feel, and its demand is expanding. However, the contact area between the ball and the holder is reduced so that the ball rotates smoothly. For writing with a high writing pressure such as writing on a slip, the performance is remarkably deteriorated due to wear or deformation of the ball seat, resulting in a loss of smooth and light writing quality.

The present invention was brought about by the idea that it is possible to combine the advantages of a conventional oil-based ballpoint pen with a high writing pressure with the advantages of a smooth, well-written aqueous ballpoint pen. .

[0005]

SUMMARY OF THE INVENTION In order to combine the advantages of the oil-based ballpoint pen and the water-based ballpoint pen described above, the present invention first has a viscosity of 2,000 to 10,000 mPa.s at 20.degree.
The oil-based ballpoint pen ink is prepared within the range of s, and the ballpoint pen tip for this is prepared by preparing several types by changing the area of the so-called ball seat where the carbide ball and the holder made of stainless steel contact. As a result of experimentally examining the writing quality and high pressure resistance writing, the projected area of the ball seat is 0.09m.
It was found that at m ² or more, the balance between writing quality and high writing pressure resistance can be satisfied.

[0006]

According to the present invention, 2,000 to 10, at 20 ° C,
000 mPa. In the ballpoint pen using the medium viscosity oil ink of s, the portion where the ball comes into contact with the holder under the pressure of the ballpoint pen tip formed by the ball and the holder material, that is, the projected area of the ball seat is 0.09 mm ²
With the above settings, it has a writing feel as light and smooth as a water-based ballpoint pen, and it does not cause performance deterioration even with high writing pressure due to writing slips, providing a ballpoint pen suitable for office work and general writing It became possible to do.

[0007]

EXAMPLES Examples of the present invention and comparative examples will be described below in order.

First, regarding inks, A ink and B ink described later are prepared. Ink A: Nigrosine EX (manufactured by Orient Chemical Co., Ltd.) 30.0% by weight Hirac 111 (ketone resin manufactured by Hitachi Chemical) 4.0% by weight Oleic acid 5.0% by weight Phenyl glycol 48.5% by weight Benzyl alcohol 12.0% by weight % PVP K-120 (manufactured by GAF) 0.5% by weight Of the above components, phenyl glycol, benzyl alcohol, and oleic acid were first weighed out, heated to 60 ° C., and added with Hirac 111, and the mixture was stirred and dissolved. Add PVP K-120 with stirring to completely dissolve. Finally, nigrosine EX was added with stirring so that it would not be left as it was, and after the addition was completed, the mixture was heated and stirred for 2 hours to completely dissolve nigrosine and prepare a black ink for oil-based ballpoint pens. The viscosity of this ink at 20 ° C. was measured with a B-type viscometer at a rotation speed of 20 rpm, and it was about 6,000.
mPa. It was s.

Ink B: Nigrosine EX (manufactured by Orient Chemical Co., Ltd.) 30.0% by weight Hirac 111 (ketone resin manufactured by Hitachi Chemical) 10.0% by weight Oleic acid 5.0% by weight Phenyl glycol 43.5% by weight Benzyl alcohol 11 0.0 wt% PVP K-120 (manufactured by GAF) 0.5 wt% Ink viscosity at 20 ° C. of about 22,000 mPa. An ink for black oil-based ballpoint pen of s was prepared.

Next, the ball-point pen tip 1 has a diameter of 0.7
mm and φ1.2 mm tungsten carbide type carbide balls 2 and holder material 3 made of stainless steel (Cr
Using the content rate of about 13%), the chip size of each part was prepared as 5 specifications of a, b, c, d, and e listed in Table 1. It is to be noted that the four specifications (1) to (4) are based on the assumption that a φ0.7 mm ball is used, but the hammer ring allowance for molding the ball seat 3a is changed as shown in FIG. 1, that is, the ball except for the capillary hole 3b and the ink channel 3c. 2 was prepared so that the area of the ball seat 3a, which is the contact part between the holder material 3 and the holder material 3, was changed little by little in order to confirm how the degree of influence on writing quality and high writing pressure would change. It is a thing. The ball seat 3a, which is in contact with the holder under the pressure of writing, has a spherical surface as shown in FIG.
It should be noted that the area is expressed as a projected area, which is shown as a plane in the figure.

[0011]

[Table 1]

Ballpoint pens of Examples 1, 2 and 3 and Comparative Examples 1, 2 and 3 were prepared by combining the above A ink and B ink with a ballpoint pen tip I, B, C, D and E specifications shown in Table 2. , Each of them was tested on the test items of writing quality and resistance to high writing pressure.

[0013]

[Table 2]

Test item Writing quality: The smoothness of the writing feeling is judged by a handwriting sensory test. ○: Smooth writing quality ×: Heavy writing feeling High writing pressure resistance Writing: Using a writing tester, a writing angle of 70 degrees, a load of 500 g, a writing speed of 4 m / min, and an ink amount of 0.3 g, continuous spiral writing was performed. The handwriting state until the end of the ink was tested. The number of samples is 4 each. ◯: 4 out of 4, good handwriting until the end of ink. X: One or more out of four, defective handwriting such as fading, or inability to write. The test results are shown in Table 3.

[0015]

[Table 3]

The test results revealed in Table 3 are:
In the φ0.7 mm ball chips of Examples 1 and 2, the ball seat projected area of the portion where the ball and the holder material are in contact with each other is 0.09 mm ² or more, and the A ink, that is, the viscosity at 20 ° C. is about 6. 000 mPa. In the combination of the medium-viscosity oil-based ink of s, good results were obtained in writing quality and high writing pressure resistance writing.
Although it was an m ball chip, similar to the conditions of Examples 1 and 2, the ball seat projected area where the ball and the holder material are in contact with each other is 0.09 mm ² or more, and A ink is used. Good results were obtained for writing quality and high pressure resistance writing.

On the other hand, Comparative Examples 1 and 2 are φ0.7 mm ball chips similar to Examples 1 and ² , but the projected area of the ball seat where the ball and the holder material are in contact with each other is 0.09 mm ² or less. Since it was a ballpoint pen using ink, good results were obtained in writing quality, but it was impossible to write in the middle of high pressure resistance writing. In Comparative Example 3, the same chip as in Example 1 was combined with B ink, but good results were obtained in writing with high pressure resistance, but as expected, Examples 1 and 2 had a heavy writing feel. The result was less than a few.

From the above results, it is clear and can be inferred that the viscosity of the ink should be 20 in order to maintain good writing quality.
2,000-10,000 mPa. In order to maintain the durability for high pressure writing, please use ball 2
In addition to the condition that the projected area of the ball seat 3a with which the holder material 3 contacts with the writing pressure is 0.09 mm ² or more and the holder material is stainless steel, in this case, the ball 2 is preferably Although it may be a cemented carbide ball containing tungsten carbide as a main component, there is no problem even if it is a ceramic ball made of silica, alumina, zirconia, silicon carbide or the like.

[0019]

[Effect] As described above, the ballpoint pen according to the present invention provides a light and smooth writing feel of a water-based ballpoint pen in terms of writing feel and also has robustness to withstand high writing pressure required for conventional oil-based ballpoint pens such as slip writing. Since it can be held together, it is suitable for both office use and general writing, that is,
This is the birth of a ball-shaped product that satisfies all the quality characteristics required for a ballpoint pen.

[Brief description of drawings]

FIG. 1 is a partially cutaway vertical sectional view showing a main part of a ballpoint pen tip.

FIG. 2 is a sectional view taken along the line AA of FIG. 1 excluding the ball, and is an explanatory view of a ball seat of a contact portion between the ball and the holder material.

[Explanation of symbols] 1 ballpoint pen tip 2 ball 3 holder material 3a ball seat

Front page continuation (72) Inventor Ryohiro Shiobara 174-2 Naganumacho, Isesaki-shi, Gunma Pilot Isesaki Factory

Claims (2)

[Claims] 1. The ink viscosity at 20 ° C. is 2,000 to.
10,000 mPa.s In the ballpoint pen using the medium viscosity oil-based ink of s, the portion of the ballpoint pen tip ( 1 ) formed by the ball (2) and the holder material (3) in contact with the holder, that is, the projected area of the ball seat (3a) is A medium-viscosity oil-based ink ballpoint pen having a size of 0.09 mm ² or more. 2. The medium-viscosity oil-based ink ballpoint pen according to claim 1, wherein the material of the holder material (3) of the ballpoint pen tip ( 1 ) is stainless steel.