JPH0633024B2 - Ink backflow prevention composition for water-based ballpoint pen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a ballpoint pen using a water-based ink having a viscosity of 50 to 2000 CPS (at 25 ° C.), and an ink backflow preventive member provided on the upper part of the ink in the ink containing tube. The present invention relates to an improvement in the composition, and more particularly to an ink backflow preventive composition for an aqueous ball-point pen, which is prevented from adhering to the inner surface of the ink containing tube as much as possible.

(Prior art) Since the viscosity of the oil-based ink that has been conventionally used for ballpoint pens and the like using oil-based ink is extremely high, such as several thousand to 10,000 CPS, the inner diameter of the ink storage tube that stores this If the inner diameter is 2.8 (mm) or less, it is not always necessary to equip the ink backflow preventive composition, but if the inner diameter is 2.8 (mm) or more, the ink will surely advance toward the pen tip as the ink is consumed by writing. In addition, since there is a concern about ink leakage from the rear end of the ink containing tube when the writing instrument is shocked or placed in a high temperature environment, vaseline or silicone grease that can prevent this It is known that it is necessary to provide an ink backflow preventer composition composed of a mixture of silicone oil, silicone oil, or liquid paraffin and petrolatum on the upper portion of the ink in the ink containing tube. .

Due to the high viscosity of the ink, the oil-based ballpoint pen equipped with such an ink backflow preventive composition is led to the pen tip without excess or deficiency by using the atmospheric pressure or its own weight during writing. The ink backflow preventive composition also follows the ink without sticking to the inner surface of the ink containing tube as the ink is consumed, and can prevent ink leakage from the rear end of the ink containing 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 ballpoint pen using a water-based ink of about 2000 CPS, the following problems will occur.

That is, the amount of ink discharged from the pen tip of a ball-point pen using a low-viscosity water-based ink is about 0.2 (g / 200m), which is about 0.03 (g / 200m), which is the value of general oiliness.
m), so that the follow-up speed of the ink backflow preventive composition in the water-based ballpoint pen with respect to the ink is naturally high. Therefore, this ink backflow preventer composition is required to respond promptly to ink consumption and to reliably follow the ink consumption. As a result, compared to the oil-based one, the ink is more likely to adhere to the inner surface of the ink containing tube, which causes ink ejection failure due to the reduced pressure in the ink containing tube, and the ink backflow prevention composition is gradually removed. Deficiency occurs in the bones, decreases, and eventually disappears,
The problem is that the original purpose cannot be achieved.

(Object of the Invention) In view of the above-mentioned circumstances, the present inventors have a viscosity of 50 to 200.
As a result of research on various additives to prevent such an ink backflow prevention composition from adhering to the inner surface of the ink containing tube in a ball-point pen using 0 CPS water-based ink, it was found that it is difficult to volatilize selected from hydrocarbons. It was found that an organic liquid or a non-volatile organic liquid as a base, to which a gelling agent and a polyoxyethylene alkyl ether and / or a polyoxyethylene sorbitan fatty acid ester are added, is optimum, and finally, the present invention. Is completed.

(Structure of the Invention) That is, the present invention provides an ink backflow preventive composition for an aqueous ballpoint pen in which an ink containing tube is filled with an aqueous ink having a viscosity of 50 to 2000 CPS at 25 ° C. The base material is a hardly volatile organic liquid or a non-volatile organic liquid selected from hydrocarbons, to which a gelling agent and a polyoxyethylene alkyl ether and / or polyoxyethylene sorbitan fatty acid ester are added. The present invention is directed to a water-based ballpoint pen ink backflow preventing composition.

As the hardly volatile organic liquid or the non-volatile organic liquid selected from the hydrocarbons as the base used 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, etc. 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.), and soroid (three). Cellulose-based products such as Akira Co., Ltd., metal soaps, bentonite and the like can be mentioned. If, for example, fine particle silica having a silanol group on the surface and a primary particle size of several mμ to 50 mμ is used as a gelling agent, a transparent feeling as an ink backflow preventive composition is produced, and the ink containing tube itself Also, if it is transparent, a product that looks good in appearance can be obtained.

Examples of the polyoxyethylene alkyl ether used in the present invention include polyoxyethylene lauryl ether and polyoxyethylene oleyl ether, and examples of the polyoxyethylene sorbitan fatty acid ester include polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan monoester. Examples thereof include palmitate, and these can be used alone or in a mixture.

The aqueous ink to which the ink backflow preventive composition according to the present invention is applied has a viscosity of 50 to 20 at 25 ° C.
It is preferably 00 CPS. This is because the inventors
Both the advantage that the conventional oil-based ballpoint pen has is structurally simple, and the advantage that a conventional water-based ballpoint pen that uses an ink with an extremely low viscosity of a few CPS provides a vivid and clear handwriting. This is based on one finding that was obtained after various studies to obtain a ballpoint pen having the combined function.

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

Example 1 Polypten HV-15 (manufactured by Nippon Oil Co., Ltd.) 94.6 parts Aerosil R972 (gelling agent, Nippon Aerosil Co., Ltd.)
5.0 parts Polyoxyethylene sorbitan monolaurate (Reodol TW-L120, manufactured by Kao Soap Co., Ltd.)
0.4 parts or more of the above composition was put in a kneader and heated and stirred for 2 to 3 hours to obtain an ink backflow preventive composition for an aqueous ballpoint pen.

Example 2 Polybutene LV-100 93 parts Aerosil R972 6.0 parts Polyoxyethylene lauryl ether (NIKKOL BL-2, manufactured by Nikko Chemical Co., Ltd.)
By the same method as in Example 1, 1.0 part or more of the above composition was obtained to obtain an ink backflow preventive composition for an aqueous ballpoint pen.

Comparative Example A comparative example was made in the same manner as in Example 1 except that the polyoxyethylene sorbitan monolaurate in Example 1 was removed.

(Effects of the Invention) Each of the ink backflow preventive compositions obtained in Comparative Example 1.2 above was filled with a water-based ink having a viscosity of 250 CPS having the following composition, and a nickel-white ballpoint pen tip was attached to one end. Fill the upper part of the ink inside the ink storage tube (material: polypropylene, inner diameter: 3.2 mm) with a writing load of 100.
Spiral writing was performed under the conditions of g, writing angle of 70 °, and writing speed of 7 cm / Sec.

The results are shown in the table below.

(Composition of water-based ink) Water black 187 L (manufactured by Orient Chemical Industry Co., Ltd.) 8.0 parts Polyvinylpyrrolidone K-90 10 parts Ethylene glycol 15 parts Sannix PP-400 (Lubricant, Sanyo Kasei Co., Ltd.) 10 parts Water 57 parts As is clear from the above description, according to the ink backflow preventive composition for water-based ballpoint pens of the present invention, even when the water-based ink having a viscosity of 50 to 2000 CPS is used, the ink consumption is reduced. It reliably follows the inner surface of the ink containing tube without adhering to it, and the ink backflow preventive composition does not disappear during the process.
It can be said that it has an excellent effect.

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 is a non-volatile organic liquid or a non-volatile organic liquid selected from hydrocarbons. A water-based ink backflow preventive composition for a ballpoint pen, which comprises a base material, and a gelling agent, and a polyoxyethylene alkyl ether and / or polyoxyethylene sorbitan fatty acid ester added thereto.