JPH09302298A - Oil-base ballpoint pen ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an oil-base ballpoint pen ink which can show good ink follow, good suitability of writing even when it is applied after storage at high temperatures and does not drip by using a specified component. SOLUTION: This ink is prepared by adding a fatty acid amide wax having a melting temperature of 140 deg.C or above to an oil-base ballpoint pen ink containing a colorant, a polar solvent and a resin. The fatty acid amide wax is desirably used in an amount of 0.1-5.0wt.%. An oil and fat type synthetic wax, such as hydrogenated castor oil or a fatty acid amide wax, having a melting temperature of below 140 deg.C can be used in combination with the above fatty acid amide wax. The mixing ratio by weight is desirably in the range of 10:0 to 1:9 (a ratio of the fatty acid amide wax having a melting temperature of 140 deg.C or above to the oil and fat type synthetic wax having a melting temperature of below 140 deg.C).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ink for oil-based ballpoint pens.

[0002]

2. Description of the Related Art Heretofore, oil-based inks for ballpoint pens have a drawback that the touch during writing is heavy due to the high viscosity of the ink.

Therefore, there is a demand for an oil-based ballpoint pen that has a low viscosity and a writing feel as light as an aqueous ballpoint pen. However, there is a problem in that the ink drips from the chip when the ink is directly filled in the ink containing tube only by making the viscosity low. Therefore, a proposal has been made to improve this problem by adding a thixotropic agent of an oil-based synthetic wax to an oil-based ballpoint pen ink containing a colorant, a solvent, and a binder resin (JP-A-7-26826).
8, JP-A-7-196972).

The above thixotropic agent forms a network structure in the ink, and its action imparts thixotropy. Therefore, when the ballpoint pen is stationary, that is, when it is not used, the ink has a high viscosity to prevent ink from dripping from the ballpoint pen tip, and when used, the ball of the ballpoint pen tip gives a shearing force to the ink to make it a low viscosity state. The ink flows out from the ballpoint pen tip, giving a light touch like an aqueous ballpoint pen.

[0005]

However, when the ink containing such a thixotropic agent is packed in a ball-point pen and stored at a high temperature such as 50 ° C., it is then cooled to room temperature (2
When the temperature is returned to around 0 ° C), reproducibility of the ink viscosity cannot be obtained, and the ink itself thickens, resulting in defective ink tracking.
Alternatively, there is a drawback that the viscosity decreases and sagging occurs.

Oil-based synthetic waxes blended in conventional oil-based ballpoint pen inks such as hydrogenated castor oil (melting temperature 86 ° C.) and trade name Tarlen BA-600 (melting temperature 13
A fatty acid amide wax such as 7 ° C.) has a low melting temperature and a low melting temperature in a polar solvent. The ink added with the former has a drawback that the network structure of the wax is destroyed after high temperature storage, and thereafter the ink cannot be restored, and the viscosity of the ink increases, resulting in poor tracking of the ink. In addition, the ink added with the latter has a drawback that the network structure is partially separated and agglomerated after storage at high temperature, resulting in a decrease in viscosity of the ink and a drooping of the ink. In other words, in either case, reproducibility of ink viscosity cannot be obtained after storage at high temperature.

According to the present invention, the ink follows well even after writing at a high temperature as described above, and a light writing feel is obtained.
Another object of the present invention is to provide an ink for oil-based ballpoint pens that does not cause ink dripping.

[0008]

Means for Solving the Problems As a result of studies to achieve the above object, the present inventor has found that in an oil-based ballpoint pen ink containing a colorant, a polar solvent and a resin, a fatty acid amide having a melting temperature of 140 ° C. or higher is used. They have found that the problem can be solved by adding wax, and have completed the present invention.

That is, the present invention provides "1. An oil-based ballpoint pen ink containing a colorant, a polar solvent and a resin, wherein a fatty acid amide wax having a melting temperature of 140 ° C or higher is added. .
2. The ink for oil-based ballpoint pens according to item 1, wherein the fatty acid amide wax having a melting temperature of 140 ° C. or higher is blended in an amount of 0.1 to 5.0% by weight based on the total amount of the ink. About.

The reason why the fatty acid amide wax having a melting temperature of 140 ° C. or higher is effective for the ink follow-up property after storage at a high temperature of 50 ° C. and the prevention of ink dripping is not always clear, but the present inventors have found that the melting temperature 140 Fatty acid amide wax above ℃ has a relatively high melting temperature,
Along with this, the solubility temperature in polar solvents such as alcohol-based and cellosolve-based is also high. From this fact, the ink viscosity in which an appropriate amount of the fatty acid amide wax is added does not change even when stored at high temperature, and therefore the viscosity increases We believe that ink does not follow poorly and that ink does not drip due to reduced viscosity.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Melting temperature used in the present invention: 140 ° C.
The above fatty acid amide wax includes methylenebisstearic acid amide (melting temperature 143 ° C), ethylenebiscapric acid amide (same 161 ° C), ethylenebislauric acid amide (same 157 ° C), ethylenebisstearic acid amide (same 143 ° C). ), Ethylenebishydroxystearic acid amide (the same 144 ° C), ethylenebisbehenic acid amide (the same 141 ° C), hexamethylenebisstearic acid amide (the same 146 ° C), hexamethylenebisbehenic acid amide (the same 143 ° C), N , N'-distearyl adipic acid amide (the same 144 ° C), N, N'-ethylenebis (12-hydroxystearic acid amide (the same 144 ° C) and the like.

Specifically, trade names of Sripax C (melting temperature 161 ° C.) and Sripax L manufactured by Nippon Kasei Co., Ltd.
(Same 157 ° C), same Sripax E (same 143 ° C), same Sripax H (same 144 ° C), same Sripax B (same 141 ° C), same Sripax ZHS (same 146 ° C), same Sripax ZHB (same 143 ° C) , The same Sripax Z
SA (same 144 ° C), same bisamide LA (same 143)
℃), the same diamond bis 200LA (143 ℃),
Kyoeisha Chemical Co., Ltd. product name Flownon SH-290
(Melting temperature 193 ° C.), Kawaken Fine Chemicals Co., Ltd. trade name Parisin 285 (melting temperature 144 ° C.) and the like.

The above fatty acid amide wax can be used alone or as a mixture, and the shape of the paste can be either powdery or powdery. Since the paste-like product is already a pregel, it can be mixed and stirred with other components as it is. The powdery substance is heated and dissolved in a solvent, cooled and re-precipitated, and the pre-gel is prepared by dispersing it with a three-roll or the like, and used.

The fatty acid amide wax used in the present invention can prevent ink dripping with a small amount of the compound, and if it is too much, the ink will not follow properly, so the amount is preferably 0.1 to 5.0% by weight.

Incidentally, oil-based synthetic waxes having a melting temperature of less than 140 ° C. such as hydrogenated castor oil and fatty acid amide wax can be used as a mixture with the fatty acid amide wax used in the present invention. In this case, the mixing ratio of the fatty acid amide wax having a melting temperature of 140 ° C. or more: the fat-based synthetic wax having a melting temperature of less than 140 ° C. is 10: 10 by weight.
The range of 0 to 1: 9 is preferable.

As the colorant used in the present invention, any pigment or dye conventionally used in oil-based inks for ballpoint pens can be used without particular limitation. Examples of pigments include inorganic, organic and processed pigments such as carbon black, phthalocyanine pigments, azo pigments, quinacridone pigments, anthraquinone pigments and indigo pigments. In addition, alcohol-soluble dyes, oil-soluble dyes, acid dyes, basic dyes, metal-containing dyes, and various salt-forming dyes can be used as dyes. Moreover, these can be used individually or in mixture. The mixing ratio is preferably 5 to 50% by weight with respect to the total amount of the ink.

The polar solvent used in the present invention is used for the purpose of imparting viscosity to the ink, as well as a colorant, a dispersion medium of oil-based synthetic wax, a solvent of resin, etc., and is an organic organic solvent used in conventional inks for oil-based ballpoint pens. Can be used. Specifically, alcohol-based and glycol-based such as benzyl alcohol, propylene glycol, butylene glycol, cellosolve-based such as phenyl cellosolve, carbitol-based such as phenylcarbitol, and nitrogen-containing solvent-based solvent such as N-methylpyrrolidone, alone or mixed. And can be used. These are about 30 to the total amount of ink.
Although 90% by weight is sufficient, 30-70% by weight is optimal in consideration of viscosity.

The resin used in the present invention is used for the purpose of fixing the colorant after writing, adjusting the viscosity of the ink, and the like, and the resin conventionally used in the ink for oil-based ballpoint pens can be used. . Specific examples thereof include phenol resin, amide resin, xylene resin, hydrogenated rosin resin and ketone resin. These can be used alone or in combination. The blending amount is preferably 0.5 to 40% by weight with respect to the total amount of the ink.

If necessary, other additives such as surfactants, dispersants, rust preventives, antibacterial agents, lubricants, pH adjusters,
A dye dissolution stabilizer or the like can be appropriately selected and added.

[0020]

【Example】

Examples 1 to 3 and Comparative Examples 1 to 3 Ink for oil-based ballpoint pens having the composition shown in Table 1 was prepared.
The method for preparing the ink is as follows.

1) Example 1, Example 3, Comparative Example 1 and Comparative Example 3 After mixing the compounding ingredients in the table, the mixture was heated and stirred at 50 ° C. to dissolve the dye and the resin to obtain a black oil-based ink for a ballpoint pen. .

2) Example 2 10% by weight of parisin 285, 54% by weight of ethylene glycol monophenyl ether and 36% by weight of benzyl alcohol were mixed and heated and stirred at 100 ° C. to dissolve parisin 285 and then ice water. It was rapidly cooled in it and kneaded with three rolls to prepare a pregel. Next, after mixing this pregel and the other ingredients in the table, the mixture is heated and stirred at 50 ° C.
The resin was dissolved to give a black oil-based ink for a ballpoint pen.

3) Comparative Example 2 10% by weight of Kao wax 85-P, 54% by weight of ethylene glycol monophenyl ether and 36% by weight of benzyl alcohol were mixed and stirred with heating at 50 ° C. to obtain Kao wax P- After dissolving 85, quench it in ice water and add it to 3
First, a pregel was prepared by kneading with a main roll. Next, after mixing this pregel and the other components in the table, the mixture was heated and stirred at 50 ° C. to dissolve the dye and the resin to obtain a black oil-based ballpoint pen ink.

The blending percentage of each component in Table 1 is based on the weight percentage. In Table 1, the manufacturers and trade names of dyes, resins, solvents, fatty acid amide wax, hydrogenated castor oil are added in parentheses.

[0025]

[Table 1]

The inks for oil-based ballpoint pens of the above Examples and Comparative Examples were filled in a refill using a tip having a ball diameter of 1 mm, and at the initial stage and after leaving the refill at 50 ° C. for 30 days, a writing test, an ink sag test and an ink follow-up test, respectively. A sex test was conducted. The writing test was performed by writing on a copy paper and evaluating the smoothness of the writing feeling. The ink dripping test was performed by observing the ink outflow from the tip of the chip after leaving the chip downward in an atmosphere of 30 ° C. and 95% RH for 24 hours. The ink followability test was carried out by observing the state of line breakage when continuously writing on copy paper. The oil viscosity of the oil-based ballpoint pens of the above Examples and Comparative Examples was also observed after the ink was left in the screw tube at 50 ° C. for 30 days. The results are shown in Table 2.

[0027]

[Table 2]

Judgment criteria Writing quality ○: Smooth ×: Not smooth Ink sag ○: None ×: Yes Ink followability ○: No line breaks ×: Line breaks

[0029]

As is clear from the above description, the ink for oil-based ballpoint pens of the present invention has a smooth writing feel, no ink dripping, and excellent ink followability not only at the initial stage but also after high temperature storage. is there. Therefore,
Even if it is stored in a hot place such as a warehouse in the summer, the ink quality is not deteriorated.

Claims (2)

[Claims] 1. An oil-based ball-point pen ink containing a colorant, a polar solvent, and a resin, wherein a fatty acid amide wax having a melting temperature of 140 ° C. or higher is added. 2. The oil-based ink for a ballpoint pen according to claim 1, wherein the fatty acid amide wax having a melting temperature of 140 ° C. or higher is blended in an amount of 0.1 to 5.0% by weight based on the total amount of the ink.