JPS6155174A - Ball point ink composition - Google Patents

Abstract

PURPOSE:To prevent a ball seat from being worn, by blending a polyether polyol contg. primary or secondary alcohol groups at its terminals in a ball point ink compsn. whose viscosity is set to a specified value by using a resin. CONSTITUTION:A dye (e.g. Water Black), a resin (e.g. polyvinylpyrrolidone), a solvent (e.g. ethylene glycol), water and a polyether polyol contg. primary or secondary alcohol groups at its terminal are mixed together to obtain the desired ball point ink compsn. having a viscosity of 50-2,000cp. Preferred example of the polyether polyols are Sunnix PP-400 and GP-400 (trade name). It is used in a quantity of pref. 5-30wt% based on the entire quantity of the ink compsn.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides an ink composition for a ballpoint pen that prevents wear of the ball seat due to the rotation of the ball as much as possible, thereby ensuring good ink ejection properties. It is about things.

(Prior art) Oil-based or water-based ballpoint pens are known as conventional ballpoint pens, but oil-based ballpoint pens have the advantage of having an extremely simple structure and being able to see the amount of ink remaining at a glance. On the other hand, since the ink has a high viscosity of several thousand to 10,000 CPS, the penetration of the ink into the writing surface is poor (
As a result, water-based ballpoint pens have the disadvantage of causing smudges and cracked handwriting, and in the case of water-based ballpoint pens, contrary to oil-based pens, smudges do not occur (although they produce fresh and clear handwriting, .

Both methods have their own advantages and disadvantages, as they tend to be structurally complex, such as by interposing an ink relay member between the ink storage section and the ballpoint pen tip.

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 50-20DOC.
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 resin or the like and used for writing, the ball seat will wear out 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 with the ink ejection performance, and finally causing new problems such as the inability to write. In conventional water-based ballpoint pens, the ink used has a low viscosity of a few CPS, so
Even if pole sinking occurs, 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 improves the ink ejection properties.
There were not many problems.

(Objective of the Invention) The present invention was made in view of the above situation, and is the result of studies on various additives to prevent wear of the ball seat in ballpoint pens using ink with a viscosity of 50 to 2000 CPS. .

It was discovered that a polyether polyol having a primary or secondary alcohol group at the end of the molecule is optimal, and the present invention was finally completed.

(Structure of the Invention) That is, the present invention provides an ink composition for a ballpoint pen, comprising at least a dye, a resin, a solvent, and water and having a viscosity of 50 to 2000 CPS, the ink composition for a ballpoint pen having a primary or The gist of the present invention is an ink composition for a ballpoint pen characterized by containing a polyether polyol having a secondary alcohol group.

A specific example of the polyether polyol having a primary or secondary alcohol group at the molecular end used in the present invention is Sannisox P'P-200. Same PP
-400, same GP-250. Same GP-400. Same 'I'
p-200, TP-400. Same GL-3000, same G
L-2800, GEP-2800, FP-750 (
The above products are manufactured by Sanyo Chemical Co., Ltd.), etc.

These can be used singly or in combination, and the amount used is 5 to 50% based on the total weight of the ink composition.
Particularly preferred is 30% by weight. If the content of polyether polyol is less than 5% by weight, it will be difficult to obtain the desired lubricity;
Moreover, if it exceeds 30% by weight, handwriting tends to smudge, making it unsuitable for practical use.

The other components used in the present invention, such as dye, resin, and solvent, are no different from the components of conventionally known aqueous inks. Examples include water-soluble dyes as dyes, pyrrolidone resins and celluloses as resins, and water-soluble organic solvents such as ethylene glycol as solvents.

(Example) The present invention will be described in more detail based on Examples below, and in the Examples, "parts" refers to parts by weight.

Example 1 Water black 187L 8 parts (manufactured by Orient Kagaku ■) Polyvinylpyrrolidone -9010 // Ethylene glycol 15 Sanni, Kusu pp-40
0 (Polyether polyol, manufactured by Sanyo Chemical) 107/water
57//Pour the above formulation into a flask equipped with a reflux condenser, stir and dissolve while heating at 60 to 80°C, and filter to remove undissolved residue to obtain a black ballpoint pen ink composition with a viscosity of 250 CPS. I got something.

Example 2 Water Blue #9 8 parts Hydroxypropylcellulose H7tt (manufactured by Nippon Soda ■) Ethylene glycol 16 parts Sasuninox TP-400 (polyether polyol, manufactured by Sanyo Kasei ■) 15〃Water
54 Viscosity a by the same method as in Example 1
A blue ballpoint pen ink composition of o ocps was obtained.

Comparative Example Sunix PP-400 in Example 1 was removed,
All the same as Example 1 except that ethylene glycol was 25 parts.
The same procedure as above was used as a comparative example. (viscosity 200CP
S) (Effect of the invention) Above are Examples 1 and 2. The ink composition for a ballpoint pen obtained in the comparative example was filled into a transparent ink storage tube having a nickel silver ballpoint pen tip, a writing load of 1oooy, a writing angle of 70°,
Marked line writing was performed at a writing speed of 7 ctm/36 C, and the writing distance until the amount of ball sinking was 3/100 (mm) was measured.

The results are shown in the table below.

As is clear from the table above (1) 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 pole can be prevented as much as possible.

It can solve the problem of inability to write due to the pole sinking as much as possible, and it can be said that it is an excellent ballpoint pen ink composition that also has the respective advantages of conventional oil-based ballpoint pens and water-based ballpoint pens as mentioned at the beginning.

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 polyether polyol having a primary or secondary alcohol group at the end of the molecule.