JPH0633025B2 - 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) Since the viscosity of the oil-based ink 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 for storing this When the inner diameter 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, the ink will flow toward the pen tip as the ink is consumed by writing. It is possible to prevent the ink from leaking 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. 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.

(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 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. It was found that the one obtained by adding a gelling agent and a sorbitan fatty acid ester to the base of a volatile organic liquid or a non-volatile organic liquid as a base is the most suitable, and finally completed the present invention.

(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 a water-based ink having a viscosity of 50 to 2000 CPS at 25 ° C. The substance is based on a hardly volatile organic liquid or a non-volatile organic liquid selected from hydrocarbons, to which a gelling agent and one or more sorbitan fatty acid esters are added. The present invention is directed to a water-based ballpoint pen ink backflow preventive composition.

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 olegomers, spindle oils, 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 sorbitan fatty acid esters which are the features of the present invention will be described.

As described above, the sorbitan fatty acid ester is added to prevent the ink backflow preventive composition from adhering to the inner surface of the ink containing tube. Specifically, sorbitan monocaprylate and sorbitan monoester are added. Examples thereof include laurate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, sorbitan monoisostearate, sorbitan monopalmitate, and sorbitan monostearate. These are 1
It is possible to use one kind or a mixture of two or more kinds, and the usage amount is 1 to 10 with respect to the total weight of the ink backflow prevention composition.
Weight percent is preferred. This is because if it is less than 1% by weight, the effect is not so great, and even if it exceeds 10% by weight, the effect is not so different to the left.

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 Polypten LV-100 (manufactured by Nippon Oil Co., Ltd.) 90
Part Leopard KE (gelling agent, manufactured by Chiba Flour Milling Co., Ltd.) 5
Part Aerosil R972 (gelling agent, Nippon Aerosil Co., Ltd.
3 parts) Sorbitan monooleate (NIKKOL.SO-10 manufactured by Nikko Chemical Co., Ltd.) 2 parts The above composition is put in a kneader and heated and stirred for 2 to 3 hours to prepare an ink backflow preventive composition for an aqueous ball-point pen. Got

Example 2 Polybutene HV-15 (manufactured by Nippon Oil Co., Ltd.) 93 parts Aerosil R972 (gelling agent, manufactured by Nippon Aerosil Co., Ltd.) 6 parts Sorbitan monoisostearate (NIKKOL.SI)
-10R, manufactured by Nikko Chemical Co., Ltd. 1 part By the same method as in Example 1 above, an aqueous ink backflow preventive composition for a ballpoint pen was obtained.

Comparative Example A comparative example was prepared in the same manner as in Example 1 except that the sorbitan monooleate 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, Sanyo Kasei Co., Ltd.) 10 parts water 57 parts As is apparent from the above description, the aqueous ink composition for backflow preventives for ballpoint pens according to the present invention has a viscosity of 50 to 2000 CPS when used with an aqueous ink.
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.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-50-129640 (JP, A) JP-A-51-79647 (JP, A) JP-A-55-99166 (JP, A) JP-A-58- 112798 (JP, A)

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 ink backflow preventive composition for an aqueous ball-point pen, which comprises a base, and a gelling agent and one or more kinds of sorbitan fatty acid esters added thereto.