JPH0647318B2 - 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.).
Improvement of the ink backflow preventive composition provided on the upper part of the ink in the ink containing tube in the ballpoint pen using the above water-based ink, especially the 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) Since the viscosity of the oil-based ink that has been conventionally used for ball-point 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 When the inner diameter is 2.8 (mm) or less, it is not necessary to equip the ink backflow preventive composition, but when the inner diameter is 2.8 (mm) or more, the ink may flow toward the pen tip as the ink is consumed by writing. It is possible to prevent this because the ink leaks from the rear end of the ink containing tube when the writing instrument is positively impacted and the writing instrument is impacted or is placed in a high temperature environment. It is necessary to provide an ink backflow preventive composition composed of petrolatum, silicone grease, silicone oil, or a mixture of liquid paraffin and petrolatum on the upper portion of the ink in the ink containing tube. It is known.

Due to the high viscosity of the ink, the oil-based ballpoint pen provided 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 lower than that of an oil-based ink in an amount of 50 to 2
If it is used as it is for a ballpoint pen using a water-based ink of about 000 CPS, the following problems will occur.

That is, the discharge amount of the ink at the pen tip of the ballpoint pen using the low-viscosity water-based ink is about 0.2 compared with the value of about 0.03 (g / 200 m) which is the value of general oiliness.
(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 to the oil-based one, which causes ink ejection failure due to the reduced pressure in the ink containing tube, and the ink backflow preventive composition is gradually removed. The problem is that defects occur, decrease, and eventually disappear, making it impossible to achieve the original purpose.

(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 intensive studies on various additives to prevent such an ink backflow prevention composition from adhering to the inner surface of the ink containing tube in a ballpoint pen using 0 CPS water-based ink, liquid polybutene was used as a base, It was found that the one obtained by adding a gelling agent and glyceryl dioleate and / or polyethylene glycol diisostearate is optimum, and finally the present invention has been completed.

(Structure of the Invention) That is, the present invention relates to an ink backflow preventive 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. The product is based on liquid polybutene,
A water-based ballpoint pen ink backflow preventive composition characterized in that a gelling agent and glyceryl dioleate and / or polyethylene glycol diisostearate are added thereto.

The base used in the present invention is liquid polybutene, and as an example of a commercially available product, polybutene LV-100,
HV-15, HV-35 (Nippon Oil Co., Ltd.)
Manufactured) and the like.

The gelling agent used in the present invention includes fine particle silica such as Aerosil (manufactured by Nippon Aerosil Co., Ltd.), hydrogen castor oil-based one such as DISPARLON 305 (manufactured by Kusumoto Kasei Co., Ltd.), and soroid (Sanshin). Cellulose-based products such as those manufactured by Co., Ltd., as well as metal soaps and bentonite. If, for example, fine particle silica having a silanol group on the surface and a primary particle size of mμ to 50 mμ is used as a gelling agent, a transparent feeling as an ink backflow preventive composition can be produced, and the ink containing tube itself If it is transparent, it will look good in appearance.

As described above, glyceryl dioleate and / or polyethylene glycol diisostearate is added to prevent the ink backflow preventive composition from adhering to the inner surface of the ink containing tube. At the same time, for example, It can also exhibit excellent followability capable of sufficiently responding to the ink consumption speed even for fast writing such as a writing speed of 15 cm / sec.

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 present inventors have a structurally simple point which is an advantage of the conventional oil-based ballpoint pen, and a vivid and vivid point which is an advantage of the conventional water-based ballpoint pen using an ink having an extremely low viscosity of several CPS. This is based on one finding that has been obtained after various studies to obtain a ballpoint pen having both of the points where handwriting can be obtained.

(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 Polybutene LV-100 (manufactured by Nippon Oil Co., Ltd.) 91 parts Leopard KE (gelling agent, manufactured by Chiba Flour Milling Co., Ltd.) 5 parts Aerosil R972 (gelling agent, manufactured by Nippon Aerosil Co., Ltd.) 3 parts Polyethylene Glycol diisostearate 1 part (manufactured by CDIS-400 Nikko Chemical Co., Ltd.) 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-15 (manufactured by Nippon Oil Co., Ltd.) 93 parts Aerosil R972 (gelling agent, manufactured by Nippon Aerosil Co., Ltd.) 6 parts Glyceryl dioleate (DGO-8, manufactured by Nikko Chemical Co., Ltd.) 1 By the same method as in Example 1, the above composition was used to obtain an ink backflow preventive composition for an aqueous ballpoint pen.

Comparative Example A comparative example was prepared in the same manner as in Example 1 except that polyethylene glycol diisostearate was omitted.

(Effect of the Invention) Each of the ink backflow preventive compositions obtained in Comparative Example 1.2 above has a viscosity of 250 CPS having the following composition inside.
Fill the upper part of the ink in the ink storage tube (material: polypropylene, inner diameter: 3.2 mm) with a nickel-white ball-point pen tip attached at one end, and write a load of 10
Spiral writing was performed under the conditions of 0 g, a writing angle of 70 °, and a writing 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 ink backflow preventive composition for an aqueous ball-point pen of the present invention, the use of an aqueous ink having a viscosity of 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. 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 ballpoint pen filled with an aqueous ink of 0 to 2000 cps, wherein the ink backflow preventer composition is based on liquid polybutene, on which a gelling agent and glyceryl dioleate are added. And / or polyethylene glycol diisostearate is added to the ink composition.