JPS61174278A - Ink composition for ball-point pen - Google Patents

Abstract

PURPOSE:To provide an ink composition for a ball-point pen capable of preventing the abrasion of a ball seat and being discharged smoothly, which comprises a dye, a resin, water, a metal salt and/or amine salt of N- acylsarcosine. CONSTITUTION:A desired ink composition for a ball-point pen can be obtained by adding 0.5-5wt% of a metal salt and/or amine salt of N-acylsarcosine of the given formula (wherein R is an alkyl) to an ink composition for a ball-point pen having a viscosity of 500-2,000cps and comprising a dye, a resin, water and a water-soluble organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ink composition for a ballpoint pen that ensures good ink ejection properties by preventing as much as possible the wear of the ball seat due to the rotation of the ball. It is something.

(Prior art and its problems) Conventional ballpoint pens are known to be oil-based or water-based, but oil-based ballpoint pens have an extremely simple structure and are 92 cm in size.It is said that the remaining amount of ink can be seen at a glance. Although it has advantages, it has the disadvantage that the ink has a high viscosity of several thousand to 10,000 CPS, so the penetration of the ink into the writing surface is poor, and as a result, the bi marks where the smudges occur are cracked. In the case of a water-based ballpoint pen,
Contrary to oil-based brushes, they do not cause any smudges and produce fresh, clear handwriting.

This method has the disadvantage that it tends to be structurally complex, such as interposing an ink relay member between the ink storage section and the ballpoint pen nib.

Both had their advantages and disadvantages.

Based on these circumstances, the present inventors have conducted various studies in order to obtain a functionally and economically superior ballpoint pen that combines both the advantages of oil-based ballpoint pens and the advantages of water-based ballpoint pens.

One finding is that the viscosity of the ink is 50-2000C.
It has been found that it is optimal to prepare within the range of PS.

However, if a ballpoint pen is simply filled with ink whose viscosity is set within the above range using a resin or the like and the ballpoint pen is actually used for writing, the ball seat will be rubbed due to the rotational friction of the ball, resulting in the so-called sinking of the ball.

As a result, the ink flow groove in the ballpoint pen tip is blocked by the ball, causing a problem in ink ejection performance, and finally causing new problems such as the inability to write (15). In conventional water-based ballpoint pens, the ink used has a low viscosity of a few CPS, so
Even if the ball sinks, the amount of ink ejected can be maintained to a certain extent due to the capillary force, so this tendency is not seen as much as on the left.Also, even in oil-based ballpoint pens that use high viscosity ink of several thousand to 10,000 CPS, The ink itself acts as a lubricant due to its high viscosity, which prevents the balls from sinking, and there was no problem with the ink's ejection properties.

[Means for Solving the Problems] The present inventors have developed a ballpoint pen with a viscosity of 50 to 50 to prevent wear of the ball seat in a ballpoint pen that combines the advantages of conventionally known oil-based ballpoint pens and water-based ballpoint pens.
As a result of repeated studies on various additives to be added to the ink composition of 200001:'S, it was discovered that metal salts or amine salts of N-acylsarcosine were optimal, and the present invention was finally completed. .

That is, the present invention provides an ink composition for a ballpoint pen having a viscosity of 50 to 2000 CPS and comprising at least a dye, a resin, a solvent, and water, the ink composition for a ballpoint pen containing a metal salt and/or an amine salt of N-acylsarcosine. The gist of the present invention is an ink composition for a ballpoint pen, characterized in that it contains.

The metal salt or amine salt of N-acylsarcosine used in the present invention is N-acylsarcosine represented by the following general formula.

Hs ROO-N OH2000I-1 (R: 7 Ru # #
group) Specifically, N-lauroylsarcosine, N-myristoylsarcosine, N-balmitoylsarcosine, N-
It can be obtained by neutralizing oleoyl sarcosine etc. with sodium hydrate, triethanolamine, etc. These metal salts or amine salts of N-acylsarcosine can be used alone or in a mixture of two or more.

The amount used is light in the range of 05 to 5 weight relative to the total weight of the ink composition. If it is less than 0.05% by weight, it is difficult to obtain the desired lubrication effect within the ballpoint pen tip.
If it exceeds this, handwriting tends to smear and is not suitable for practical use.

Other components used in the present invention are dyes, resins,
The solvent is no different from the components of conventionally known water-based inks. Examples include water-soluble dyes as dyes, pyrrolidone resins, cellulose as resins,
Examples of the solvent include water-soluble organic solvents such as ethylene glycol.

(Examples) The present invention will be explained in more detail based on examples below.
In the examples, "1 part" indicates "part by weight."

Example 1 Water Black 187L 8 parts (manufactured by Orient Kagaku Kogyo (4)) Carboxymethylcellulose 05 parts Ethylene glycol 20 parts Glycerin
20 parts N-lauroylsarconate sodium 1.5 parts (sarcosinate LN, manufactured by Nikko Chemicals ■) Water
50 parts of the above formulation was placed in a flask equipped with a reflux condenser, stirred and dissolved under heating at 40°C, and filtered to remove undissolved residue to obtain a black 6 solid color ballpoint pen ink composition with a viscosity of 350 CPS. Obtained.

Example 2 Water Blue #9 8 parts Hydroxyglopyl cellulose 05 parts (I(PC~CI()
, Nippon Soda Co., Ltd. Ethylene Glycol
20 parts glycerin 20
Part N-Myristoylsarcone sodium (sarcosine) MN, manufactured by Nikko Chemicals ■) 15 parts Water

50 parts by the same method as Example 1. Viscosity: 350 CPS
An ink composition for a blue ballpoint pen was obtained.

Comparative Example A black ballpoint pen ink composition having a viscosity of 300 CPS was obtained in the same manner as in Example 1 except that the sodium N-lauroylsarcone in Example 1 was removed and the amount of water was changed to 515 parts.

(Effect of the invention) Examples 1 and 2 above. The ballpoint pen ink composition obtained in the comparative example was filled into a transparent ink storage tube having a nickel silver ballpoint pen tip (ball material: cemented carbide), and a writing load of 1 was applied.
00,9. Writing angle 70°, writing speed 7 cm/S
Spiral writing was performed under eC conditions, and the writing distance until the amount of ball sinking was 3/100 (recumbent) was measured.

The results are shown in the table below.

As is clear from the table above, according to the present invention, even if the viscosity of the ink is set to 50 to 2000 CPS and the ink is filled into a ballpoint pen for writing, wear of the ball seat due to the rotation of the ball can be prevented as much as possible, and the ball We provide an excellent ballpoint pen ink composition that can eliminate the problem of inability to write due to sinking as much as possible, and of course also has the respective advantages of conventional oil-based ballpoint pens and water-based ballpoint pens as mentioned at the beginning. It's something you get.

Claims (1)

[Claims] Consisting of at least dye, resin, solvent, and water, viscosity 50~
A 2000 CPS ballpoint pen ink composition,
An ink composition for a ballpoint pen, characterized in that the ink composition for a ballpoint pen contains a metal salt and/or an amine salt of N-acylsarcosine.