JPH0633026B2 - Ink backflow prevention composition for water-based ballpoint pen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field The present invention has a viscosity of 50 to 2000 CPS (at 25 ° C.).
In regard to a ballpoint pen using the water-based ink of (1), the present invention relates to improvement of an ink backflow preventive composition provided on the ink upper part in the ink containing tube, and particularly to an ink backflow preventive composition for an aqueous ballpoint pen in which adhesion to the inner surface of the ink containing tube is prevented as much as possible. Regarding things.

(Prior art and its problems) Since the viscosity of the oil-based ink conventionally used for ball-point pens and the like using the oil-based ink is extremely high, such as several thousand to 10,000 CPS, an ink containing the ink is contained. When the inner diameter of the storage tube is 2.8 (mm) or less, it is not always necessary to equip the ink backflow preventive composition, but when the inner diameter is 2.8 (mm) or more, according to the consumption of ink by writing. Prevents the ink from leaking from the rear end of the ink storage tube when the writing instrument is shocked or placed in a high temperature environment without fail because it moves forward in the direction of the pen tip. An ink backflow preventer composition composed of petrolatum, silicone grease, silicone oil, or a mixture of liquid paraffin and petrolatum, which can be used, must be provided above the ink in the ink container. It is known that there is.

Due to the high viscosity of the ink, the oil-based ballpoint pen equipped with such an ink backflow preventive composition is delivered to the pen tip without excess or deficiency by using the atmospheric pressure or its own weight during writing. In addition, the ink backflow prevention composition does not adhere to the inner surface of the ink storage tube with the consumption of the ink and can follow the ink without fail to prevent ink leakage from the rear end of the ink storage tube. However, such an ink backflow preventive composition has a viscosity of 50 to 50, which is lower in viscosity than oil-based inks.
If it is used as it is for a ball-point pen using a water-based ink of about 2000 CPS, the following problems will occur.

That is, the discharge amount of ink at the pen tip of a ballpoint pen using a low-viscosity water-based ink is about 0.2 compared with that of a general oiliness of about 0.03 (g / 200 m).
(G / 200 m), which is very large, and therefore the follow-up speed of the ink backflow preventive composition in the water-based ballpoint pen to the ink is naturally high. Thus, the ink backflow preventive composition is required to respond to ink consumption promptly and surely, but in actuality, the ink backflow preventive composition does not affect the ink consumption rate. It becomes impossible to follow, and as a result, it is more likely to adhere to the inner surface of the ink containing tube as compared with the oil-based one, and not only ink discharge failure due to depressurization in the ink containing tube but also ink backflow preventive composition gradually increases. The problem is that it causes defects, decreases, and eventually disappears, making it impossible to achieve its original purpose.

(Means for explaining problems) In view of the above-mentioned circumstances, the present inventors have a viscosity of 50 to 200.
As a result of extensive research on various additives for preventing such an ink backflow preventive composition from adhering to the inner surface of the ink containing tube in a ball-point pen using 0 CPS aqueous ink, it was found that the difficult volatilization selected from hydrocarbons. The present invention has been completed by finally finding out that the one obtained by adding a gelling agent and a polyoxyethylene hydrogenated castor oil to a base of a volatile organic liquid or a non-volatile organic liquid is finally completed.

That is, the present invention provides an ink backflow preventer composition for an aqueous ballpoint pen in which an ink containing tube is filled with a water-based ink having a viscosity of 50 to 2000 CPS at 25 ° C. An ink backflow preventive composition for water-based ballpoint pens, characterized in that a gelling agent and polyoxyethylene hydrogenated castor oil are added to a base material selected from a hardly volatile organic liquid or a non-volatile organic liquid Things are the gist.

As the hardly volatile organic liquid or the non-volatile organic liquid selected from the hydrocarbons used as the base in the present invention, polybutene LV-100, HV-15 and HV-
35 (above, Nippon Oil Co., Ltd.), liquid paraffin, α
Examples thereof include olefin oligomer, spindle oil, petrolatum, and the like, and these can be used alone or in combination of two or more.

The gelling agent used in the present invention includes fine particle silica such as Aerosil (manufactured by Nippon Aerosil Co., Ltd.), hydrogenated castor oil-based one such as Disparlon 305 (manufactured by Kusumoto Kasei Co., Ltd.), soroid, and leopard. KE (Sansho Co., Ltd.)
Cellulose type such as), metal soaps,
Examples include bentonite. As a gelling agent, for example, it has a silanol group on the surface and its primary particle size is several mμ
When fine particle silica having a particle size of 50 μm is used, a transparent feeling as an ink backflow preventive composition is produced, and if the ink containing tube itself is transparent, a good-looking appearance can be obtained.

The blending ratio of these gelling agents is preferably 1 to 20% by weight. When it is 1% by weight or less, the gelling strength of the ink backflow preventive composition becomes weak and the ink easily flows backward, and when it is 20% by weight or more, the gelling strength is too strong to follow the ink. There is a tendency for the sex to deteriorate.

Next, the polyoxyethylene hydrogenated castor oil, which is a feature of the present invention, will be described.

The polyoxyethylene hydrogenated castor oil as an additive is added in order to prevent the ink backflow preventive composition from adhering to the inner surface of the ink containing tube. Specifically, as a commercially available product, NIKKOLHCO-5 and HCO -10, same HC
O-20, the same HCO-30, the same HCO-40 (above, Nikko Chemical Co., Ltd. make) etc. are mentioned. These can also be used alone or as a mixture.

The water-based ink to which the ink backflow preventive composition according to the present invention is applied has a viscosity of 50 to 2 at 25 ° C.
It is preferably 000 CPS. This is because the inventors of the present invention have the structurally simple point that the conventional oil-based ballpoint pen has, and the advantage that the conventional water-based ballpoint pen that uses an extremely low-viscosity ink of several CPS has a fresh and clear handwriting. This is due to one finding that has been obtained after various studies to obtain a ballpoint pen having both of the following points.

(Examples) Hereinafter, the present invention will be described in more detail with reference to examples. In the examples, "parts" means "parts by weight".

Example 1 Polybutene HV-15 (manufactured by Nippon Oil Co., Ltd.) 94.6 parts Aerosil R972 (gelling agent, manufactured by Nippon Aerosil Co., Ltd.) 5.0 parts Polyoxyethylene hydrogenated castor oil (NIKKOL HCO-10, Nikko) Chemical Co., Ltd. 0.4 parts The above ingredients were put in a kneader and heated and stirred for 2 to 3 hours to obtain an aqueous ink backflow preventive composition for a ballpoint pen.

Example 2 Polybutene LV-100 (manufactured by Nippon Oil Co., Ltd.) 93 parts Aerosil R972 (gelling agent, manufactured by Nippon Aerosil Co., Ltd.) 6.0 parts Polyoxyethylene hydrogenated castor oil (NIKKOL HCO-20, Nikko Chemical ( Co., Ltd.) 1.0 parts By the same method as in Example 1 above, an ink backflow preventive composition for an aqueous ballpoint pen was obtained.

Comparative Example A comparative example was made in the same manner as in Example 1 except that the polyoxyethylene hydrogenated castor oil in Example 1 was removed.

(Effects of the Invention) Each of the ink backflow preventive compositions obtained in the above Example 1.2 and Comparative Example has a viscosity of 250C including the following composition inside.
It is filled with PS water-based ink and filled in the upper part of the ink in an ink storage tube (material: polypropylene, inner diameter: 3.2 mm) with a nickel-white ball-point pen tip attached at one end. Writing load 100 g, writing angle 70 °, writing Spiral writing was performed at a speed of 7 cm / Sec.

The results are shown in the table below.

(Composition of water-based ink) Water black 187L (manufactured by Orient Chemical Industry Co., Ltd.) 8.0 parts Polyvinylpyrrolidone K-90 10 parts Ethylene glycol 15 parts Sannix PP-400 (Lubricant, manufactured by Sanyo Kasei Co., Ltd.) 10 Part Water 57 parts As is clear from the above description, according to the water-based ink backflow preventive composition for a ball-point pen of the present invention, when the viscosity of the water-based ink is 50 to 2000 CPS,
As the consumption of ink decreases, it does not adhere to the inner surface of the ink containing tube and reliably follows it without causing ink ejection failure, and the ink backflow prevention composition does not disappear in the middle of the process. According to the experiments conducted by the present inventors, most of the above-mentioned Examples 1 and 2 were found to be effective when writing with the pen tip facing upward. Although no change is observed, in the comparative example, backflow of the ink occurs, and in the normal state, for example, in the case of rapid writing such as 12 Cm / sec, Example 1,
No. 2 did not run out of ink, and on the other hand, ink rubs in the comparative example. Good results were obtained for both the upward writing performance of the pen tip and the quick writing property. An ink backflow preventive composition can be provided.

Claims (1)

[Claims] 1. A viscosity at 25 ° C. in an ink containing tube is 5
An ink backflow preventer composition for an aqueous ball-point pen filled with an aqueous ink of 0 to 2000 CPS, wherein the ink backflow preventer composition comprises a hardly volatile organic liquid or a non-volatile organic liquid selected from hydrocarbons. An aqueous ink backflow preventive composition for a ballpoint pen, which comprises a base, and a gelling agent and polyoxyethylene hydrogenated castor oil added thereto.