JPH07113101B2 - Writing instrument with slide stopper - Google Patents

Description

The present invention relates to a writing instrument with a slide stopper.

[Prior art and its problems] A bottomed ink cylinder is filled with water and a dye as essential components, and a water-based ink consisting of a moisturizer and a surfactant optionally added, and the ink is used as a pen body. In a writing instrument that transmits to and writes with, a pen core is usually interposed between an ink cylinder and a pen body. The pen core has a function of introducing air into the ink cylinder in an amount equal to the amount of ink consumed for writing, and a function of storing excessively discharged ink and preventing ink dripping. Here, the ink is ejected excessively because the writing instrument is left in a high temperature place, or when the body temperature of the hand of the writer is transmitted and the temperature in the ink cylinder rises, the air in the ink cylinder expands. , The pressure inside the ink cylinder increases,
This is because the ink is pushed out by this, but since the ink storage capacity of the pen core is limited, if the ejection amount exceeds this limit, the ink drops.

Therefore, if the slide stopper is placed in the ink cylinder without using the pen core, and the slide stopper advances as the ink is consumed without replacing the ink with the air, the air will not flow into the ink cylinder. Since there is no ink, it is possible to prevent the ink from flapping off due to the increase in pressure.
There are advantages that the number of parts is reduced, the capacity of the ink cylinder is increased, and the writable distance is increased.

In such a writing instrument with a slide stopper, it is necessary to place the slide stopper liquid-tight in the ink cylinder with a large sliding resistance,
On the other hand, it is required that the ink can be easily slid in the ink cylinder in order to smoothly eject the ink during writing.
As described above, the sliding resistance value of the slide plug is important, and it is necessary to set it to an appropriate value, but this is quite difficult. Therefore, as shown in FIG. 1, a valve stopper 4 having a valve function is arranged in front of the slide stopper 3 in the ink cylinder 1 to divide the ink cylinder 1 into a main ink chamber 6 and a sub ink chamber 7. Then, ink is supplied from the sub-ink chamber 7 to the pen body 2, and when the ink in the sub-ink chamber 7 is consumed by writing and the pressure in the sub-ink chamber 7 drops, the valve of the valve plug 4 opens and the main ink is opened. Ink is supplied from the chamber 6 to the sub-ink chamber 7, and the sub-ink chamber 7 that is always filled with ink has been put into practical use. Further, even when the ink cylinder 1 is shocked and a large pressure change occurs momentarily, such as when the writing instrument is dropped on the floor, the valve plug 4 buffers the ink, thereby preventing ink dripping. There are advantages.

By the way, when assembling such a writing instrument, since defoaming cannot be completed completely, some air bubbles remain in the sub ink chamber, but when this air bubble is small, there is no problem in writing and it is normal until ink is almost completely consumed. Can be written on. But,
If left unused for a long time, the ink will gradually evaporate from the pen even with the cap attached,
This means that a small amount of ink is continuously consumed, but with such continuous small consumption, the pressure difference between the main ink chamber and the sub ink chamber does not increase and the valve plug does not open, so the ink in the sub ink chamber is consumed. However, it is not replenished from the main ink chamber. When the pen body is made of fiber chips, the air remaining in the pen body may replace the ink and enter the sub ink chamber. Furthermore, the gas dissolved in the ink may evaporate over time to form bubbles. Therefore, these causes overlap and if left for a long time, the bubbles in the sub-ink chamber become large, and in some cases, the ink in the sub-ink chamber may run out and become empty. If a large bubble is present in the sub ink chamber, the bubble may thermally expand during writing and the ink may drop off. Further, if the bubble becomes large and the ink is divided, writing becomes impossible.

[Object of the Invention]

Therefore, it is an object of the present invention to provide a writing instrument with a slide stopper in which bubbles in the sub ink chamber between the pen body and the valve stopper do not increase even when left for a long time.

[Structure of the Invention and Its Action] In the present invention, a slide stopper that advances as ink is consumed is arranged in an ink cylinder, and a valve stopper that allows ink to pass only in the direction of the pen body is provided between the slide stopper and the pen body. In the arranged writing instrument with a slide stopper, a composition comprising water as an essential component, a dye, and a moisturizer and a surfactant optionally added, is added to L-ascorbic acid, an ascorbic acid isomer, and an ascorbic acid derivative. A water-based ink composition obtained by adding one or two or more is filled in the ink cylinder.

That is, the present inventor variously studied from a mechanical aspect in order to prevent the bubbles in the sub-ink chamber from increasing without adversely affecting the basic operation of the writing instrument with a slide stopper, but no good result was obtained. Therefore, as a result of diligent studies from the viewpoint of the composition of the water-based ink to be filled in the ink cylinder, an ink composition obtained by adding one or more of L-ascorbic acid, an ascorbic acid isomer, and an ascorbic acid derivative to the conventional water-based ink is used. The present invention has been completed by finding that an excellent effect can be obtained by filling a cylinder.

The reason why good results are obtained by adding L-alcorbic acid or the like is not always clear, but ascorbic acid compounds are generally known as reducing agents and are poorly stable substances. Therefore, it is inferred that the decomposition is gradually progressing in the water-based ink, and the coexisting gaseous substance is consumed in the decomposition process, so that the bubbles in the ink do not increase but rather decrease. However, other reducing agents were tested, but no good results were obtained. In addition, the water-based ink containing an ascorbic acid compound has excellent lubricity, and the slide stopper and valve stopper operate smoothly, and even when the ink is continuously consumed in a small amount when left unattended, it works as an auxiliary ink. It is considered that the supply to the chamber is one of the causes, but in any case, it is inferred that a good result can be obtained by the synergistic effect of these chemical factors and physical factors.

Next, specific examples of the water-based ink composition used in the writing instrument with a slide stopper of the present invention will be described. The notation of “part” in the following formulation represents part by weight.

[Example 1] Moisturizer (glycerin) 20 parts Surfactant (Asahi Denka Kogyo Adekatol NP-72) 2 parts
Dye (Rhodamine 6GCP-N) 0.15 parts L-ascorbic acid 1 part Pure water 78 parts [Example 2] Moisturizer (triethylene glycol) 20 parts Surfactant (Asahi Denka ADECATOL NP-72) 2 parts
Dye (Rhodamine 6GCP-N) 0.15 part L-ascorbic acid 0.5 part D-isoascorbic acid 0.5 part Pure water 78 parts [Example 3] Moisturizer (glycerin) 20 parts Surfactant (Asahi Denka Kogyo Adekatol NP-72) 2 copies
Dye (Rhodamine 6GCP-N) 0.15 parts D-isoascorbic acid 1 part Pure water 78 parts [Example 4] Moisturizer (triethylene glycol) 20 parts Surfactant (Asahi Denka Kogyo Adekatol NP-72) 2 parts
Dye (Rhodamine 6GCP-N) 0.15 parts D-isoascorbic acid 1 part Pure water 78 parts [Example 5] Moisturizer (glycerin) 20 parts Surfactant (Toho Kagaku 10% GAFAC RS-710) 5 parts Dye (Water) BE # 9) 0.5 part L-ascorbic acid 1 part Pure water 75 parts [Example 6] Moisturizer (triethylene glycol) 20 parts Surfactant (Toho Kagaku 10% GAFAC RS-710) 5 parts Dye (Water VT # 1) 0.4 parts Sodium isoascorbate 1 part Pure water 75 parts [Example 7] Moisturizer (glycerin) 5 parts Moisturizer (ethylene glycol) 15 parts Surfactant (Toho Kagaku 10% GAFAC RS-710) 5 parts Dye (Water YW # 6) 0.4 part L-ascorbic acid 0.3 part D-isoascorbic acid 0.3 part Sodium isocorcorbate 0.4 part Pure water 75 parts [Comparative Example 1] to [Comparative Example 7] Moisturizer, surfactant, The dye and pure water are the same as those in [Example 1] to [Example 7]. A formulation, L- ascorbic acid, D
-Comparative Examples 1 to 7 were prepared by adding neither isoascorbic acid nor sodium isoascorbate.

The above formulations were mixed and stirred and dissolved at room temperature to obtain 14 types of water-based ink.

The writing instruments with slide plugs shown in FIG. 1 filled with the respective water-based inks were manufactured for 10 minutes each, and allowed to stand at room temperature for 1 week and at 40 ° C. for 2 days to observe changes in bubbles in the sub ink chamber. The results are shown in Table 1.

As can be seen from Table 1, all of the inks filled with the water-based inks of Examples 1 to 7 were at room temperature for 1 week and
Even when left at 40 ° C for 2 days, the small bubbles that were initially present did not increase, but on the contrary, they were completely reduced. On the other hand, Comparative Examples 1 to 1
In Comparative Example 7, air bubbles increased.

The effective range of the amount of L-ascorbic acid added is
About 0.05 to 10% is suitable, and preferably 0.1 to 1%. If it is less than 0.05%, the effect is small, and on the contrary, even if the addition amount is unnecessarily increased, the effect is not significantly different.

〔The invention's effect〕

As described above, the writing instrument with a slide stopper of the present invention,
An ink in which one or more of L-ascorbic acid, an ascorbic acid isomer, and an ascorbic acid derivative are added to a composition consisting of water as an essential component, a dye, and a humectant and a surfactant added as necessary. Since the composition is used, it is possible to completely eliminate small bubbles generated in the sub ink chamber between the valve plug and the pen body of the writing instrument with a slide stopper.

[Brief description of drawings]

 FIG. 1 is an explanatory view of a writing instrument with a slide stopper. 1 ... Ink cylinder, 2 ... Pen body, 3 ... Slide stopper 4 ... Valve stopper, 6 ... Main ink chamber, 7 ... Sub ink chamber

Claims (1)

[Claims] 1. A writing instrument with a slide stopper, in which a slide stopper that advances as ink is consumed is arranged in an ink cylinder, and a valve stopper that allows ink to pass only in the direction of the pen body is arranged between the slide stopper and the pen body. In addition, one or two of L-ascorbic acid, an ascorbic acid isomer, and an ascorbic acid derivative are added to a composition consisting of water as an essential component, a dye, and a humectant and a surfactant added as necessary. A writing instrument with a slide stopper, characterized in that an aqueous ink composition obtained by adding the above is filled in the ink cylinder.