JP3439665B2 - Knock ballpoint pen - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip of a ballpoint pen tip of a ballpoint pen refill in which an ink container is directly filled with water-based ink, and is retracted from a front end opening of a shaft cylinder by the operation of a knock-type writing body retracting mechanism. The knock type ballpoint pen made possible.

[0002]

2. Description of the Related Art Conventionally, a ballpoint pen refill containing ink for writing instruments is slidably arranged in a barrel by a spring urging it toward the rear end of the barrel, and the tip of the ballpoint pen tip of the ballpoint refill is placed in the barrel. , A knock-type ballpoint pen that can be retracted from the front end opening of the barrel by the operation of the knock-type cursive body retracting mechanism is well known, but recently,
There is provided a knock type ballpoint pen in which a water-based ink is directly filled in an ink container of a ballpoint pen refill.

[0003]

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

The present invention has been made in view of these facts, and there is no ink leakage from the pen tip, there is no swallowing of ink due to the impact at the time of knocking operation, and good writing performance is achieved by using a water-based ink in an ink container. An object of the present invention is to obtain a knock type ballpoint pen in which a ballpoint pen refill that has been directly packed is inserted into a barrel.

[0005]

In order to achieve the above object, the present invention provides a knock-type writing / withdrawing mechanism for a tip of a ballpoint pen tip of a ballpoint pen refill in which an ink container of the ballpoint pen refill is directly filled with water-based ink. by the operation, the knock-type ballpoint pen and retractable from the front end opening of the barrel, the other party of the ink accommodating tube, ball <br/> having a ball and holding rotatably is protruded from the tip part Rupen tip through the tip holder,
Balls on the rear end opening portion of the chip holder of Bo <br/> point pen refill which is pressed against the distal end side by a coil spring, Ji
By reducing the inner diameter of the top holder, the ink flow passage having a minimum cross-sectional area in the range of at least 0.4 to 0.8 mm ² is formed. Provided, inside the ink container,
1. In a measurement environment at 20 ° C. containing a shear thinning agent.
Viscosity at shear rate of 9 sec ⁻¹ is 900 to 2.5
A water-based ink of 00 mPa · s is directly packed.

Alternatively , the tip of the ink containing cylinder may be partially
A ball with a ball that projects from the end and is rotatably held.
A ball pen coil is attached to the ball
The ball-point pen refill is pressed inward by the
Inside the rear of the rear end of the ball-point pen tip of the container,
At least by reducing the inner diameter of the ink container
An area having a minimum cross-sectional area portion in the range of 0.4 to 0.8 mm ^2.
A linear ink flow passage that limits the ink flow rate
Provided and contains a shear thinning agent inside the ink container
However, a shear rate of 1.9 sec ⁻¹ under a measurement environment of 20 ° C.
Water with a viscosity of 900 to 2,500 mPa · s
It is a direct ink filled with volatile ink.

Examples of the viscosity reducing agent include crosslinked acrylic acid polymers and xanthan gum, which may be used alone, but those obtained by mixing the crosslinked acrylic acid polymer, xanthan gum and succinoglycan. May be used, and the blending amount in that case is 0.2 to the total amount of the ink.
It contains 0.8% by weight.

Although the above-mentioned ink flow passage needs to 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 portion in the ink flow passage may be located at any position in the ink flow passage, but it is preferably formed on the rear end side. Further, the minimum cross-sectional area portion does not have to have a constant length. For example, the ink flow passage may be formed in a taper shape, and the taper-shaped small diameter side may be the minimum cross-sectional area portion.
The cross-sectional shape of the ink flow passage is not particularly limited and may be circular or non-circular.

In the present invention, the knock-type cursive body retracting mechanism is a well-known retracting mechanism using a rotating cam, a mechanism in which a protrusion is locked in a locking hole, or a heart cam groove. It was the mechanism that was used. That is, it is a mechanism that allows the tip of the ballpoint pen tip of the ballpoint pen refill housed in the barrel to be retracted from the tip opening of the barrel by pressing the knock body. Any mechanism may be used in the present invention.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. The same members and the same parts are designated by the same reference numerals.

As shown in FIG. 1, a knock type ball-point pen 1 according to a first embodiment of the present invention has a ball-point pen refill 3 slidably inserted in a barrel 2 and a coil spring 4 which allows the ball-point pen refill 3 to slide. It is biased toward the rear end of the cylinder 2. Behind the ball-point pen refill 3 is the rear end opening 2 of the barrel 2.
b, a cam portion (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 known knock-type cursive body retracting mechanism. By pressing the knock body 5, the tip of the ball-point pen tip 7 of the ball-point pen refill 3 housed in the barrel is projected and retracted from the tip opening 2 a of the barrel 2.

The ballpoint pen refill 3 is shown in FIGS.
As shown in FIG.
A ball-point pen tip 7 having a part thereof protruded from the tip end and rotatably held is fitted in the engagement hole 11 of the tip holder 10 at the rear end portion 7a and disposed through the tip holder 10. . Behind the engagement hole 11 of the chip holder 10, an ink flow passage 12 is formed which communicates with the engagement hole 11 whose inner wall has a small diameter. The ink flow passage 12 is formed in a taper shape having a large diameter on the front end opening side 12a and a small diameter on the rear end opening side 12b, and the rear end opening 12b has a cross-sectional area of 0.4 to 0.8 mm. ^It is a straight minimum cross-sectional area portion 12c having a width of 1 mm provided within the range of ² .

Inside the ball-point pen tip 7, a coil spring 13 having a linear tip 13a for pressing the ball 9 toward the tip side and a stepped shape of the tip of an ink flow passage 12 having a rear end 13b formed in the tip holder 10 are formed. Holding section 14
It is held and disposed in.

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

The knock type ball-point pen (not shown) of the second embodiment is similar to the knock-type ball-point pen 1 of the first embodiment, and has a cam groove (Fig. (Not shown) and a knock-type cursive body retracting mechanism.

As shown in FIG. 4, the ball-point pen refill 21 is provided with a ball-point pen tip 7 at an end 22a of an ink containing cylinder 22 in which a part of the ball 9 is projected from the end and rotatably held. . An inner wall of the ink container 22 located behind the ball-point pen tip 7 has a portion 23 having a narrowed inner diameter, and an ink flow passage 24 is provided.
The ink flow passage 24 is formed in a straight line shape,
Its cross-sectional area is set in the range of 0.4 to 0.8 mm ² .

In the ball-point pen tip 7, the tip 13 for pressing the ball 9 toward the tip side, as in the ball-point pen refill 3 in the knock type ball-point pen 1 of the first embodiment.
The coil spring 13 in which a is linear has a rear end portion 13
b is held and disposed by a stepped holding portion 25 at the tip of a portion 23 of the ink containing cylinder 22 in which the inner diameter is narrowed. Although not shown, the ink containing cylinder 22 is directly filled with a water-based ink and a grease-like ink follower similar to the ball-point pen refill 3 in the first embodiment. A tail plug having a through hole that communicates the inside and the outside of the ink containing cylinder is attached to the rear end opening.

The knock type ballpoint pen (not shown) of the third embodiment is similar to the knock type ballpoint pen 1 of the first embodiment in that the cam groove formed on the inner wall surface of the rotary cam and the shaft cylinder (see FIG. (Not shown) and a knock-type cursive body retracting mechanism.

In the ballpoint pen refill 31, as shown in FIG. 5, the shape of the ink container 32 is the ballpoint 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, and has a tip of the small-diameter portion 33 in which a part of the ball 9 is protruded from the tip and rotatably held. Is provided. In the ink containing cylinder 32, a small-diameter tip portion 35 fitted to a small-diameter portion 33 to which the rear end portion 7a of the ball-point pen tip 7 is fitted, and a main body portion 3 existing in the large-diameter portion 34.
And a member 38 for controlling the flow of ink, which has a small diameter ink flow passage 37 penetrating the front and rear ends thereof. The ink flow passage 37 is formed in a straight line shape and has a cross-sectional area of 0.4 to 0.8 mm ² .

Similar to the ballpoint pen refill 3 in the knock type ballpoint pen 1 according to the first embodiment, a coil spring 13 having a linear tip 13a for pressing the ball 9 toward the tip side is provided in the ballpoint pen tip 7. The rear end portion 13b is held and disposed by a stepped holding portion 39 formed on the inner wall of the ink containing cylinder 32. Although not shown, the ink containing cylinder 33 is directly filled with a water-based ink and a grease-like ink follower similar to the ball-point pen refill 3 in the above-mentioned embodiment. A tail plug having a through hole that communicates the inside and the outside of the ink containing cylinder 32 is inserted into the opening.

In each of the above-mentioned embodiments, the ball 9 is directly pressed by the tip of the coil spring 13, but a pressing member 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]

EXAMPLES Example 1 First, a water-based ink 15 made of 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 Crosslinking 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 wt% is mixed by heating with a magnet hot stirrer at 60 ° C. Next, as a rust preventive lubricant, a phosphoric acid ester-based surfactant, trade name PRYSURF A-208S (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.0% by weight, triethanolamine 2.0% by weight as a pH adjuster, 0.5% by weight of 1,2-benzisothiazolin-3-one as a bacteriostatic agent and 7.5% by weight of Direct Black 154 as a dye were similarly mixed and stirred to completely dissolve them. Next, as a cross-linked acrylic acid polymer, trade name: Hibiswako 104
0.25% by weight (manufactured by Wako Pure Chemical Industries, Ltd.), trade name KELZAN (manufactured by Sansho Co., Ltd.) as xanthan gum 0.1
0% by weight and 0.05% by weight of succinoglycan under the trade name of Mei Poly (manufactured by Sansho Co., Ltd.) 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 water-based ink at a shear rate of 1.9 sec ^-1 (under a measurement environment of 20 ° C.) is
It was 900 mPa * s when measured using the type 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 of the first embodiment, the cross-sectional area of the front end opening side 12a of the ink flow passage 12 formed in the chip holder 10 is 1.54 mm ^2, and the straight shape 12c of the rear end opening side 12b. The cross-sectional area of the part is
Ink container 8 for ball-point pen refill 3 with 4 mm ²
It was directly packed into a knock-type ballpoint pen.

Examples 2 to 8 Example 1 except that the ink formulation was as shown in Table 1.
The ink was adjusted in the same procedure as in 1. The ball-point pen refill 3 in which the cross-sectional area of the rear end opening side 12a of the ink flow passage 12 formed in the tip holder 10 was formed as shown in Table 1.
The knock type ballpoint pen of the first embodiment was obtained by accommodating the ink into the ink containing cylinder 8. 1.9se of each water-based ink
Viscosity at shear rate of c ^-1 (under measurement environment of 20 ℃)
Was measured using an E-type viscometer, and the values were as shown in Table 1.

[0026]

[Table 1]

Comparative Example 1 Example 1 except that the formulation of the ink was as shown in Table 2.
Ink was 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 tip holder 10 was formed as shown in Table 2.
The ink was stored in the ink container 8 of No. 1 to obtain the knock type ball-point pen of the first embodiment. In addition, 1.9 sec for each water-based ink
Viscosity at shear rate of ^-1 (under measurement environment of 20 ℃)
Was measured using an E-type viscometer, and the values were as shown in Table 2.

[0028]

[Table 2]

Test and Evaluation The knock type ball-point pens of Examples 1 to 8 and Comparative Examples 1 to 6 were evaluated by the following experiments. Ink leakage from pen tip: Leave the ballpoint pen tip 7 facing downward in an environment of 30 ° C. and 80% RH for 2 hours, and confirm ink leakage from the tip of the ballpoint pen tip 7. The case where ink leakage did not occur at all was marked with ⊚, the tip of the ballpoint pen tip 7 with a degree of weeping was marked with ◯, and the case where ink droplets occurred at the tip of the ballpoint pen tip 7 was marked with x. Ink swallowing by impact: From a height of 1 m, the knock type ballpoint pen 1 was dropped 10 times continuously on a cedar board with the ballpoint pen tip 7 facing upward, and the degree of ink swallowing was determined by writing. Those that could be successfully written out within 3 cm were marked with ⊚, those that could be successfully written out within 3 to 5 cm were marked with ◯, and those that could not be written out within 5 cm were marked with x. Writing performance: Able to write well without breathing or blurring with proper ink discharge is marked with ◎, and a slightly inferior one that does not pose any problems in practical use is marked with ○, and there is apparently little ink discharge or breathing or blurring. What was done was marked with x.

The evaluation results of each example and comparative example are shown in Table 1.
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 (under the measurement environment of 20 ° C., simply referred to as “ink viscosity”) is at the lower limit, the chip holder 10 has Since the cross-sectional area of the minimum cross-sectional area portion 12c of the formed ink flow passage 12 is too small, good ink cannot be discharged 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 good writing performance could not be obtained because there was little ink bleeding and continuous writing caused a breathing phenomenon.

In Comparative Example 2, since the viscosity of the ink is too low, the cross-sectional area of the minimum cross-sectional area portion 12c of the ink flow passage 12 is set to the lower limit value, so that ink leakage from the pen tip hardly occurs. However, it was not possible to withstand impact with such an ink viscosity. Further, good writing performance could not be obtained because remarkable ink swallowing occurred.

In Comparative Example 3, since the cross-sectional area of the minimum cross-sectional area portion 12c of the ink flow passage 12 was set to be large, the above-mentioned viscosity of the ink was set to the upper limit, but the ink could not withstand impact and marked ink swallowing occurred. Occurred.

In Comparative Example 4, since the minimum cross-sectional area portion 12c of the ink flow passage 12 was set to a large cross-sectional area and the viscosity of the ink was set to a high viscosity, the viscosity of the ink was too high. Minimum cross-sectional area portion 12 of flow passage 12
Although a good ink outflow to the tip of the ballpoint pen tip 7 was obtained by setting the cross-sectional area of c to be large, good writing performance was not obtained due to blurring of handwriting and poor writing quality. 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 in which 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 in which it is too large. Result is,
Comparative Example 5 was similar to Comparative Example 1 and Comparative Example 6 was similar to 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 structure as described above, there is no ink leakage from the pen tip, no ink is swallowed by the impact at the time of knocking operation, and the writing performance is good. It was possible to provide a knock-type ballpoint pen of a type in which an ink containing cylinder was directly filled with water-based ink.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a knock type ball-point 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 knock type ballpoint pen of the embodiment.

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

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 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.

[Sign name]

1 knock type ballpoint pen 3 Ballpoint pen refill 5 knock body 6 rotating cams 7 Ballpoint pen tip 8 Ink storage cylinder 9 balls 10 chip holder 12 Ink flow passage 15 Water-based ink 21 Ballpoint Pen Refill 22 Ink container 23 parts 24 ink passage 31 Ballpoint Pen Refill 32 ink container 37 Ink flow passage 38 members

Continuation of the front page (56) Reference JP 10-58887 (JP, A) JP 7-251593 (JP, A) JP 9-175079 (JP, A) JP 10-60358 (JP , A) JP-A-10-329476 (JP, A) JP-A-8-310184 (JP, A) Actual Kaihei 7-33678 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB) (Name) B43K 7/00-7/12

Claims (4)

(57) [Claims] The other party of claim 1 Ink accommodating tube, a ballpoint pen tip having a ball and holding rotatably is protruded from the tip part disposed through the chip holder, the ball
Insert the tip holder into the tip end opening of the tip holder of the ballpoint pen refill pressed by the coil spring.
By reducing the inner diameter of the dar, at least 0.4 ~
An ink flow passage that has a minimum cross-sectional area in the range of 0.8 mm ² and that restricts the flow rate of the ink is formed in a straight line that restricts the flow rate of the ink. 1.9sec under the measurement environment of 20 ℃
Viscosity at a shear rate of ^-1 is 900 to 2,500 mP
A knock that is characterized in that the water-based ink as as is directly filled and that the tip of the ballpoint pen tip of the ballpoint pen refill can be retracted and retracted from the front end opening of the barrel by the operation of a knock-type cursive body retracting mechanism. Ballpoint pen. 2. A part of the ink containing cylinder protrudes from the end.
A ballpoint pen with a ball that is held and rotatably held
Place the chip, and use the coil spring for the ball.
Ink storage cylinder of ballpoint pen refill pressed to the tip side
The ink is collected inside the rear end of the ballpoint pen tip of
By reducing the inner diameter of the container, at least 0.4 ~
Ink flow with a minimum cross-section area in the range 0.8 mm ^2.
A linear ink flow passage that limits the amount of ink is provided.
Inside the tank containing the shear thinning agent, 20
At a shear rate of 1.9 sec ⁻¹ under a measurement environment of ℃
Water-based ink having a viscosity of 900 to 2,500 mPa · s
Ballpoint pen refill ballpoint pen tip
The tip of the, by the operation of the knock-type writing body retracting mechanism,
Characterized by being able to emerge from the front end opening of the barrel
Knock type ballpoint pen. 3. A linear shape for limiting the flow rate of the ink
The diameter of the ink flow passage is larger on the ballpoint pen tip side.
2. A taper shape extending in a direction along the axis.
Alternatively, the knock-type ballpoint pen according to item 2. 4. The viscosity reducing agent is a mixture of a cross-linked acrylic acid polymer, xanthan gum and succinoglycan, and is 0.2 to 0.8% by weight based on the total amount of the ink.
The knock-type ballpoint pen according to claim 1, 2 or 3 , further comprising: