JP2000127670A - Retractable ball-point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retractable ball-point pen which does not leak ink from the tip of a ball-point pen tip, even when the ball-point pen tip is held downwardly and also is free from an ink swallow which causes the ink to flow back from the interior of the ball-point pen tip to an ink storage barrel side during ejecting the ball-point pen tip or by an impact generated when the pen falls and ensure the reliable writing performance, in the retractable ball-point pen of such a type that the ink storage barrel is directly filled with the aqueous ink. SOLUTION: A ball-point pen tip 7 is arranged on the tip of an ink storage barrel 8. Behind the ball-point pen tip 7, an ink passageway 12 for limiting an ink flow rate is linearly provided. The ink passageway 12 is formed in such a way that the sectional area of the smallest sectional area part of the ink passageway 12 is at least 0.4-0.8 mm2. The ink storage barrel 8 is directly filled with an aqueous ink whose viscosity at 1.9 sec-1 shear rate under measurement environments at 20 deg.C is 900-2,500 mPa.s.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball-point pen tip of a ball-point pen refill in which an ink container is directly filled with water-based ink. It relates to a knock-type ballpoint pen that was made possible.

[0002]

2. Description of the Related Art Conventionally, a ballpoint pen refill containing ink for a writing instrument is slidably disposed in a shaft cylinder by biasing it toward the rear end of the shaft cylinder by a spring. Knock-type ballpoint pens that are capable of appearing and retracting from the front end opening of the barrel by actuation of a knock-type writing body retracting mechanism are well known.
A knock-type ballpoint pen is provided in which a water-based ink is directly filled in an ink container of a ballpoint pen feel.

[0003]

However, in the case of a knock-type ball-point pen in which a ball-point pen refill in which aqueous ink is directly filled in an ink container is inserted into a shaft cylinder, the ball-point pen is inserted and held in a pocket or the like. The tip of the tip is held in a downward position, causing the ink inside the ballpoint pen tip to flow back to the ink storage cylinder side due to the problem of ink leakage from the pen tip or the impact of knocking or dropping, that is, ink The problem of swallowing was easy to occur.

[0004] The present invention has been made in view of the above facts, and is based on the fact that there is no leakage of ink from the pen tip, no swallowing of ink due to the impact during knocking operation, and good writing performance. It is an object of the present invention to obtain a knock-type ballpoint pen in which a directly-filled ballpoint pen feel is inserted into a barrel.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a knock-type writing / unloading mechanism, in which a tip portion of a ball-point pen tip of a ball-point pen refill obtained by directly filling aqueous ink into an ink container of a ball-point pen refill is used. In the knock-type ball-point pen that can be retracted from the opening at the front end of the barrel, the ball-point pen is provided with a ball-point pen tip that protrudes a part of the ball from the tip and rotatably holds it in front of the ink container. At least 0.4 in the internal position behind the rear end of the ballpoint pen tip
An ink flow path formed in linear shape for restricting the flow of ink having a minimum sectional area portion ranging to 0.8 mm ² is provided,
2 containing a shear-thinning agent inside the ink container.
A water-based ink having a viscosity of 900 to 2,500 mPa · s at a shear rate of 1.9 sec ⁻¹ under a measurement environment of 0 ° C. is directly packed.

In the case where the ballpoint pen refill has a structure in which a ballpoint pen tip is disposed via a chip holder, the ink flow passage for limiting the flow rate of the ink can be provided by reducing the inner diameter of the chip holder.
In the case of a structure in which the ballpoint pen tip is disposed at the tip of the ink container, the tip can be provided by reducing the inner diameter of the ink container. Alternatively, an ink flow path may be provided by fitting a member having an ink flow path that restricts the flow rate of the ink into an interior of the ink storage cylinder behind the rear end of the ballpoint pen tip.

Examples of the viscosity reducing agent include a crosslinked acrylic acid polymer, xanthan gum and the like. These may be used alone, but a mixture of a crosslinked acrylic acid polymer, xanthan gum and succinoglycan is used. In that case, the compounding amount is 0.2 to the total amount of the ink.
0.8% by weight is contained.

Although the above-described ink flow passage must be formed in a straight line, the straight line in the present invention does not mean only a straight line, but may be formed in a meandering or zigzag state. good. The minimum cross-sectional area in the ink flow passage may be located at any position in the ink flow passage, but is preferably formed on the rear end side. Further, the minimum sectional area portion does not need to have a fixed length. For example, the ink flow passage may be formed in a tapered shape, and the smaller diameter side of the tapered shape may be a portion having a minimum cross-sectional area.
The sectional shape of the ink flow passage is not particularly limited, and may be circular or non-circular.

In the present invention, the knocking type writing body retracting mechanism is a well-known retracting mechanism using a rotating cam, a mechanism in which a projection is locked in a locking hole or the like, or a heart cam groove. And other mechanisms. In other words, the mechanism is such that the tip of the ballpoint pen tip of the ballpoint pen refill housed in the barrel can be protruded and retracted from the tip opening of the barrel by pressing the knock body. In the present invention, any mechanism may be used.

[0010]

Embodiments of the present invention will be described with reference to the drawings. The same members and the same portions are indicated by the same reference numerals.

A knock-type ballpoint pen 1 according to a first embodiment of the present invention has a ballpoint pen refill 3 slidably inserted in a shaft cylinder 2 as shown in FIG. It is urged toward the rear end of the cylinder 2. Behind the ballpoint pen feel 3, there is a rear end opening 2 of the barrel 2.
b, a cam body (not shown) provided at the tip of the knock body 5, a rotary cam 6, and a cam groove (not shown) formed on the inner wall surface of the barrel 2. ), And a knocking type writing body retracting mechanism that is a known technique. By pressing the knock body 5, the tip portion of the ballpoint pen tip 7 of the ballpoint pen refill 3 housed in the barrel comes out of the tip end opening 2 a of the barrel 2.

The ballpoint pen feel 3 is shown in FIGS.
As shown in FIG.
A ball-point pen tip 7 which is rotatably held by protruding a part of the tip from the front end is fitted to the engagement hole 11 of the chip holder 10 with the rear end 7a, and disposed via the chip holder 10. . An ink flow passage 12 communicating with the engagement hole 11 having a small inner wall is formed behind the engagement hole 11 of the chip holder 10. The ink flow passage 12 is formed in a tapered shape having a large diameter at the front opening side 12a and a small diameter at the rear end opening side 12b, and the rear end opening 12b has a cross-sectional area of 0.4 to 0.8 mm. ² is a straight-shaped minimum cross-sectional area portion 12c having a width of 1 mm and provided in the range of ² .

In the ball-point pen tip 7, a coil spring 13 having a straight tip 13a for pushing the ball 9 toward the tip is formed in a stepped shape at the tip of an ink flow passage 12 having a rear end 13b formed in the tip holder 10. The holding unit 14 has become
It is held and arranged.

In the ink container 8, the viscosity at a shear rate of 1.9 sec ^-1 under the measurement environment of 20 ° C. is 900 to 900.
The water-based ink 15 of 2,500 mPa · s is directly packed. The rear end of the water-based ink 15 is directly filled with a grease-like ink follower 16 that follows the consumption of the water-based ink 15 and prevents the backflow of the water-based ink 15. A tail plug 18 having a through hole 17 communicating the inside and the outside of the ink container 8 is inserted into the rear end opening 8b of the ink container 8.

A knock-type ballpoint pen (not shown) according to the second embodiment is similar to the knock-type ballpoint pen 1 according to the first embodiment, and has cam grooves (FIG. ) (Not shown).

As shown in FIG. 4, the ball-point pen refill 21 has a ball-point pen tip 7 which rotatably holds a part of the ball 9 at the tip 22a of the ink container 22 so as to protrude from the tip. . An inner wall of the ink storage cylinder 22 located behind the ballpoint pen tip 7 forms a portion 23 having a reduced inner diameter, and an ink flow passage 24 is provided.
The ink flow passage 24 is formed in a straight straight line,
The cross-sectional area is set in the range of 0.4 to 0.8 mm ² .

In the ball-point pen tip 7, like the ball-point pen refill 3 of the knock-type ball-point pen 1 of the first embodiment, a tip 13 for pressing the ball 9 to the tip side.
The coil spring 13 having a straight line a
b is held and disposed in a stepped holding portion 25 at the tip of a portion 23 having a reduced inner diameter of the ink container 22. Although not shown, the ink container 22 is directly filled with a water-based ink and a grease-like ink follower, similar to the ballpoint pen refill 3 in the first embodiment. A tail plug having a through-hole communicating the inside and outside of the ink container is inserted into the rear end opening.

A knock type ballpoint pen (not shown) according to the third embodiment is similar to the knock type ballpoint pen 1 according to the first embodiment. ) (Not shown).

As shown in FIG. 5, the ball-point pen refill 31 has a shape of an ink container 32 and a ball-point pen tip 7.
The ball-point pen tip 7 has a shape including a small-diameter portion 33 and a large-diameter portion 34 to which the rear end portion 7a is fitted. Is arranged. Inside the ink container 32, a small-diameter distal end portion 35 fitted to the small-diameter portion 33 to which the rear end portion 7a of the ballpoint pen tip 7 is fitted, and the main body portion 3 inside the large-diameter portion 34
And a member 38 for controlling the flow of ink, having a small-diameter ink flow passage 37 penetrating the front and rear ends. The ink flow passage 37 is formed in a straight straight line, and has a sectional area in the range of 0.4 to 0.8 mm ² .

In the ball-point pen tip 7, a coil spring 13 having a linear tip 13a for pushing the ball 9 toward the distal end is provided in the same manner as the ball-point pen refill 3 in the knock-type ball-point pen 1 according to the first embodiment of the present invention. The rear end portion 13b is held and disposed by a step-like holding portion 39 formed on the inner wall of the ink container 32. Although not shown, the ink container 33 is directly filled with a water-based ink and a grease-like ink follower, similar to the ballpoint pen refill 3 in the above-described embodiment. A tail plug having a through-hole communicating the inside and outside of the ink container 32 is inserted into the opening.

In each of the embodiments described above, the ball 9 is pressed directly by the tip of the coil spring 13, but a pressing element may be interposed between the ball 9 and the coil spring 13. Further, a structure in which the ball 9 is not pressed by the coil spring 13, that is, a structure without the coil spring 13 may be used.

[0022]

Example 1 First, an aqueous ink 15 comprising the composition shown below was prepared. Direct Black 154 7.5% by weight Ethylene glycol 25.0% by weight Rust preventive lubricant 1.0% by weight pH adjuster 2.0% by weight Antibacterial agent 0.5% by weight Crosslinked acrylic acid polymer 0.25% by weight % Xanthan gum 0.10% by weight Succinoglycan 0.05% by weight Ion-exchanged water 63.6% by weight Ion-exchanged water 63.6% by weight, ethylene glycol 2
5.0% by weight is heated and mixed with a magnet hot stirrer at 60 ° C. Next, 1.0% by weight of Plysurf A-208S (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) which is a phosphate ester surfactant as a rust preventive lubricant, 2.0% by weight of triethanolamine as a pH adjuster, 0.5% by weight of 1,2-benzisothiazolin-3-one as a bactericide and 7.5% by weight of Direct Black 154 as a dye were similarly mixed and stirred to completely dissolve. Next, as a crosslinked acrylic acid polymer, trade name: Hibiswako 104
0.25% by weight (manufactured by Wako Pure Chemical Industries, Ltd.), trade name Kerzan (manufactured by Sansho Co., Ltd.) 0.1 as xanthan gum
0% by weight and 0.05% by weight of Meipoly (manufactured by Sansho Co., Ltd.) as succinoglycan were added and mixed and stirred using a homogenizer stirrer until a uniform state was obtained, to obtain an aqueous ink. The viscosity of the aqueous ink at a shear rate of 1.9 sec ^-1 (under a measurement environment of 20 ° C.)
It was 900 mPa · s when measured using a mold viscometer.

Next, the ink follower 16 was prepared by mixing and stirring the following components. Silicon oil (KF96-5000) 46.0% by weight Silicon oil (KF96-3000) 45.7% by weight Hydrophobic silica (R-927) 8.0% by weight Polyester plasticizer (SP-105) 0.3% by weight %

The water-based ink 15 and the ink follower 1
6 is a ball-point pen refill 3 according to the first embodiment, in which the cross-sectional area of the front end opening side 12a of the ink flow passage 12 formed in the tip holder 10 is 1.54 mm ² and the straight shape 12c of the rear end opening side 12b is set. The cross-sectional area of the part
4 mm ² ball-point refill 3 ink container 8
To obtain a knock-type ballpoint pen.

Examples 2 to 8 Example 1 was repeated except that the composition of the ink was as shown in Table 1.
The ink is adjusted in the same procedure as described above, and the cross-sectional area of the rear end opening side 12a of the ink flow passage 12 formed in the chip holder 10 is formed as shown in Table 1 in the ballpoint pen refill 3 shown in FIG.
To obtain a knock-type ballpoint pen according to the first embodiment. In addition, 1.9 sec of each aqueous ink
Viscosity at shear rate of c ^-1 (under measurement environment of 20 ° C)
Was measured using an E-type viscometer, and the values were as shown in Table 1.

[0026]

[Table 1]

Comparative Example Example 1 was repeated except that the composition of the ink was as shown in Table 2.
The ink is adjusted in the same procedure as described above, and the cross-sectional area of the rear end opening side 12a of the ink flow passage 12 formed in the chip holder 10 is formed as shown in Table 2 in the ballpoint pen refill 3 shown in FIG.
To obtain a knock-type ballpoint pen according to the first embodiment. In addition, 1.9 sec of each aqueous ink
Viscosity at shear rate of ^-1 (under measurement environment of 20 ° C)
Was measured using an E-type viscometer, and the respective values were as shown in Table 2.

[0028]

[Table 2]

Tests and Evaluations The knock-on ballpoint pens of Examples 1 to 8 and Comparative Examples 1 to 6 were evaluated by performing the following experiments. Ink leakage from the pen tip; leave the ballpoint pen tip 7 facing down for 2 hours in an environment of 30 ° C. and 80% RH, and check the ink leakage from the tip of the ballpoint pen tip 7. A sample in which no ink leakage occurred was evaluated as ◎, a sample in which the tip of the ball-point pen tip 7 was wet to the degree of weeping was evaluated as ○, and a sample in which an ink droplet was generated in the tip of the ball-point pen tip 7 was evaluated as ×. Ink swallowing by impact: The knock-type ball-point pen 1 was dropped onto a cedar board 10 times continuously with the ballpoint pen tip 7 facing upward from a height of 1 m, and the degree of ink swallowing was determined by writing. Those that could be written well within 3 cm were rated as ◎, those that could be written well at 3-5 cm were rated as ○, and those that were not well written within 5 cm were rated as x. Writing performance: ◎ indicates that the ink can be written satisfactorily with appropriate ink output without breathing and blurring, and ○ indicates that it is slightly inferior but does not cause any problem in practical use. What was done was evaluated as x.

Table 1 shows the evaluation results of the examples and comparative examples.
It is as shown in Table 2.

In Comparative Example 1, although the viscosity of the ink at a shear rate of 1.9 sec ^-1 (hereinafter referred to simply as the "viscosity of the ink" under a measurement environment of 20 ° C.) was at the lower limit, the chip holder 10 had Since the cross-sectional area of the formed minimum cross-sectional area 12c of the ink flow passage 12 is too small, good ink does not flow out to the tip of the ballpoint pen tip 7, and as a measure against ink leakage from the pen tip or ink swallowing due to impact. Was effective, but when writing continuously with little ink, a breathing phenomenon occurred, and good writing performance was not obtained.

In Comparative Example 2, since the viscosity of the ink was too low, the cross-sectional area of the minimum cross-sectional area 12c of the ink flow passage 12 was set to the lower limit, and ink leakage from the pen tip hardly occurred. However, it was not possible to withstand an impact with such an ink viscosity. In addition, since good ink swallowing occurred, good writing performance was not obtained.

In Comparative Example 3, since the cross-sectional area of the minimum cross-sectional area 12c of the ink flow passage 12 was set large, the viscosity of the ink was set to the upper limit. Occurred.

In Comparative Example 4, since the cross-sectional area of the minimum cross-sectional area 12c of the ink flow passage 12 was set large and the viscosity of the ink was high, the viscosity of the ink was too high. Minimum sectional area portion 12 of flow passage 12
Although a good ink flow to the tip of the ball-point pen tip 7 was obtained by setting the cross-sectional area of c to be large, good writing performance was not obtained due to blurred handwriting and poor writing taste. Therefore, even if it has excellent ink leakage and impact resistance, it cannot be used as a writing instrument.

Comparative Examples 5 and 6 are examples in which the shear thinning agent is xanthan gum alone. Comparative Example 5 is an example where the cross-sectional area of the minimum cross-sectional area portion 12c of the ink flow passage 12 is too small, and Comparative Example 6 is an example where it is too large. Result is,
Comparative Example 5 was the same as Comparative Example 1, and Comparative Example 6 was the same as Comparative Example 3. From this result, it can be seen that it does not depend on the type of the shear thinning agent.

[0036]

Since the knock-type ballpoint pen of the present invention has the above-described structure, there is no leakage of ink from the pen tip, there is no drip of ink due to the impact at the time of knocking operation, and the ballpoint pen refill has good writing performance. It was possible to provide a knock-type ballpoint pen of a type in which aqueous ink was directly filled in an ink storage cylinder.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a knock-type ballpoint pen, showing a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a ballpoint pen refill housed in a barrel of the knocking ballpoint pen according to the embodiment.

FIG. 3 is an enlarged sectional view of a tip portion of the ballpoint pen refill in FIG. 2;

FIG. 4 is an enlarged cross-sectional view of a tip portion of a ballpoint pen refill housed in a barrel of a knock-type ballpoint pen according to a second embodiment.

FIG. 5 is an enlarged cross-sectional view of a tip portion of a ballpoint pen refill housed in a barrel of a knock-type ballpoint pen according to a third embodiment.

[Theory of code]

 DESCRIPTION OF SYMBOLS 1 Knock-type ball-point pen 3 Ball-point refill 5 Knock body 6 Rotating cam 7 Ball-point tip 8 Ink container 9 Ball 10 Tip holder 12 Ink passage 15 Water-based ink 21 Ball-point refill 22 Ink container 23 Part 24 Ink passage 31 Ball-point refill 32 Ink Storage cylinder 37 Ink flow passage 38 Member

Claims (5)

[Claims] 1. A ball-point pen refill having a ball-point pen tip, which is provided with a part of a ball protruding from the front end thereof and rotatably held forward of the ink container, at least at an internal position behind a rear end of the ball-point pen tip. 0.4-0.8
A 20 ° C. measurement environment containing a shear thinning agent was provided inside the ink container, provided with a linearly formed ink flow passage for restricting the flow rate of the ink having a minimum cross-sectional area in the range of mm ^2. Below, a viscosity at a shear rate of 1.9 sec ^-1 is 9
A water-based ink of 00 to 2,500 mPa · s was directly filled, and the tip of the ballpoint pen tip of the ballpoint pen refill was made to be able to protrude and retract from the front end opening of the barrel by the operation of the knock-type writing body retraction mechanism. Knock ballpoint pen. 2. An ink flow in which the ball-point pen tip is disposed via a chip holder, and the inside diameter of the tip holder is reduced by reducing the inner diameter of the chip holder inside the chip holder behind the rear end of the ball-point tip. The knock-type ballpoint pen according to claim 1, wherein a path is provided. 3. The flow rate of ink is restricted by disposing the ball-point pen tip at the tip of the ink containing cylinder and reducing the inner diameter of the ink containing cylinder inside the ink containing cylinder behind the rear end of the ball-point pen tip. 2. The knock-type ball-point pen according to claim 1, further comprising an ink flow passage. 4. The ball-point pen tip is disposed at the tip of an ink containing cylinder, and a member having an ink flow passage for restricting the flow rate of the ink is fitted inside the ink containing cylinder behind the rear end of the ball-point pen tip. The knock-type ballpoint pen according to claim 1, which is worn. 5. The method of claim 1, wherein the viscosity reducing agent is a mixture of a cross-linked acrylic acid polymer, xanthan gum and succinoglycan, and 0.2 to 0.8% by weight based on the total amount of the ink.
The knock-type ball-point pen according to claim 1, 2, 3, or 4, comprising: