JPH0729513B2 - 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 ball-point pen using a water-based ink having a viscosity of 50 to 2000 CPS (at 25 ° C.), and an ink backflow preventive member provided in 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 and its problems) Since the viscosity of the oil-based ink that has been conventionally used for ball-point pens and the like that use oil-based ink is extremely high, such as several thousand to 10,000 CPS, the ink that contains it If 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 if the inner diameter is 2.8 (mm) or more, the ink will 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 when writing by utilizing atmospheric pressure or its own weight. 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 2000, which is lower in viscosity than oil-based inks.
If it is used as it is for a ball-point pen that uses CPS-based water-based ink, the following problems will occur.

That is, the amount of ink discharged from the pen tip of a ballpoint pen using low-viscosity water-based ink is about 0.2 (g / 200m), compared to about 0.03 (g / 200m), which is the value for general oiliness. As described above, the ink backflow preventive composition in the water-based ballpoint pen naturally follows the ink at a high speed. 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, which causes ink ejection failure due to the reduced pressure in the ink containing tube, and the ink backflow preventive composition is gradually added. There is a problem that a defect occurs, decreases, and eventually disappears, and the original purpose cannot be achieved.

(Means for Solving Problems) In view of the above-mentioned circumstances, the present inventors have considered that the viscosity is 50 to 2000 CPS.
As a result of earnest research on various additives in order to solve the problem of adhesion of such an ink backflow preventive composition to the inner surface of the ink containing tube in the ballpoint pen using the above water-based ink, it was selected from hydrocarbons. It has been found that the one obtained by adding a gelling agent and glycerol borate fatty acid ester to the base of a hardly volatile organic liquid or a non-volatile organic liquid is the most suitable, and finally completed the present invention. .

That is, according to the present invention, the viscosity at 25 ° C in the ink containing tube is 50
An ink backflow preventer composition for a water-based ballpoint pen filled with a water-based ink of ˜2000 CPS, wherein the ink backflow preventer composition is based on a hardly volatile organic liquid or a non-volatile organic liquid selected from hydrocarbons. An essential feature of the present invention is to provide a water-based ink backflow preventive composition for ball-point pens, which comprises a gelling agent and glycerol borate fatty acid esters as an agent.

As the hardly volatile organic liquid or the non-volatile organic liquid selected from the hydrocarbons used as the base in the present invention, polypten LV-100, HV-15, HV-35 (above, Nippon Oil Co., Ltd. )), Liquid paraffin, α-olefin oligomer, spindle oil, vaseline 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.), 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.

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 back.
On the other hand, if it is 20% by weight or more, the gelling strength tends to be too strong, and the followability to ink tends to deteriorate.

Next, the glycerol borate fatty acid esters, which are the additives of the present invention, will be described.

These additives are added to prevent the ink backflow preventive composition from adhering to the inner surface of the ink containing tube. At the same time, however, the ink is added even for quick writing such as a writing speed of 15 cm / sec. It is also possible to exhibit excellent followability capable of sufficiently responding to the consumption speed of. Specific examples thereof include glycerol borate-laurate, glycerol borate-palmitate, glycerol borate-aterate, glycerol borate-oleate, glycerol borate-isostearate and the like. These may also be used alone or in admixture of two or more with the above-mentioned base.

The water-based ink to which the ink backflow preventive composition according to the present invention is applied has a viscosity of 50 to 2000 CP at 25 ° C.
It is preferably S. This is because the present inventors have a structurally simple point which is an advantage of the conventional oil-based ballpoint pen,
After conducting various studies in order to obtain a ballpoint pen that has both the advantage of a sharp, clear handwriting, which is an advantage of a water-based ballpoint pen that uses an ink with an extremely low viscosity of several CPS, we have obtained one. It comes from one finding.

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

Example-Polypten HV-15 (manufactured by Nippon Oil Co., Ltd.) 89 parts-Aerosil R-972 (gelling agent, manufactured by Nippon Aerosil Co., Ltd.) 3 parts-Reopearl KE (gelling agent, manufactured by Chiba Milling Co., Ltd.) ) 5 parts-Emulbon S-20 glycerol borate-laurate (manufactured by Toho Chemical Industry Co., Ltd.) 2 parts-Acroup 805 (polyalkylmethacrylate, Sanyo Kasei Co., Ltd.) 1 part The above ingredients are put in a kneader. After heating and stirring for 2 to 3 hours, an ink backflow preventive composition for an aqueous ballpoint pen was obtained.

Comparative Example An ink backflow preventive composition for an aqueous ball-point pen was obtained in the same manner as in the above-mentioned examples except that Emulbon S-20 was omitted.

(Effects of the Invention) An ink in which each of the ink backflow preventer compositions found in the above Examples and Comparative Examples is filled with a water-based ink having a viscosity of 250 CPS having the following composition, and a nickel-white ballpoint pen tip is attached to one end thereof. Storage tube (material: polypropylene, inner diameter: 3.2 mm)
Filled in the upper part of the ink inside, writing load 100g, writing angle 70
゜, Spiral writing 800m under the condition of writing speed 7cm / sec.

The results are shown in the table below.

(Composition of water-based ink) Water Black 187L (Orient Chemical Co., Ltd.)
Made) 8.0 parts Polyvinylpyrrolidone K-90 10 parts Ethylene glycol 15 parts Sannix PP-400 (lubricant, Sanyo Kasei Co., Ltd.) 10
Part 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, when the water-based ink having a viscosity of 50 to 2000 CPS is used, the ink consumption is reduced. Since it does not adhere to the inner surface of the ink containing tube and does not cause ink ejection failure, and the ink backflow prevention composition does not disappear in the middle, it is an excellent effect. Can be played.

Claims (1)

[Claims] 1. A viscosity of 50 to 50 at 25 ° C. in the ink containing tube.
An ink backflow preventer composition for an aqueous ball-point pen filled with an aqueous ink of 2000 CPS, wherein the ink backflow preventer composition is based on a hardly volatile organic liquid or a non-volatile organic liquid selected from hydrocarbons. And a gelling agent,
An ink backflow preventive composition for water-based ballpoint pens, characterized in that glycerol borate fatty acid esters are added.