JPH0967538A - Water-base ink composition for writing utensil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-base ink compsn. for writing utensils which does not blur written lines on paper and exhibits improved resistance to capping and dryablity of written lines by mixing a colorant, a water-retaining org. solvent, a specific additive, and water. SOLUTION: A product obtd. by the fermentation of plant seeds (e.g. peaches, apricots, or walnuts) and egg shells by microorganisms is extracted to give a water-sol. ionized mineral comprising an org. acid salt contg. metal ions (e.g. Ca, Mg, K, and Na ions). This compsn. is prepd. by mixing 1-10wt.% colorant selected from among water-sol. dyes (e. g. acid dyes, direct dyes, and food dyes), 10-30wt.% water-retaining org. solvent, 0.003-0.03wt.% above-obtd. mineral as an additive, water, and, if necessary, 0.1-2wt.% polvacrylic acid resin or water-sol. gum comprising a polysaccharide (e.g. xanthane gum, cargeenan gum, guar gum, or succinoglycan).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a water-based ink composition for writing instruments.

[0002]

2. Description of the Related Art When a writing instrument such as a marking pen or a ballpoint pen is being written or left with the cap removed, the built-in aqueous ink is solidified by evaporation of water at the pen tip exposed to the atmosphere. Block the pen tip to prevent ink from leaking. In order to suppress the occurrence of this phenomenon, a water-retaining organic solvent such as polyhydric alcohol is generally added to the water-based ink. However, if a water-retaining organic solvent is blended in an amount sufficient to suppress the drying at the pen tip, the ink easily bleeds onto the paper surface, and the drying of the handwriting is delayed, causing stains.

[0003]

DISCLOSURE OF THE INVENTION The present invention suppresses the drying of the pen tip when the writing instrument is in use or when the pen tip is left with the cap removed, that is, when the pen tip is exposed to the atmosphere. It is intended to provide an aqueous ink composition for a writing instrument that exhibits an action (hereinafter, referred to as cap-off resistance), but does not cause bleeding of handwriting on a paper surface and has good handwriting drying property.

[0004]

The aqueous ink composition for a writing instrument of the present invention comprises a colorant, a water-retaining organic solvent, an additive and water, and the additive contains at least a water-soluble ionized mineral. The colorant is a water-soluble dye such as an acid dye, a direct dye and an edible dye. I. Direct Black 19 and 154, C.I. I. Direct Blue 1 and 87, C.I. I. Direct Yellow 13
2, C.I. I. Acid Black 2 and 21, C.I. I.
Acid Blue 1, 22, 90, 93, 103 and 10
4, C.I. I. Acid Red 1,18,51,52,7
3,92 and 94, C.I. I. Acid Orange 10 and 20, C.I. I. Acid Yellow 1, 3, 9 and 13
1, C.I. I. Acid Violet 49, C.I. I. Acid Green 16, C.I. I. Food Black 2, C.I.
I. Food Yellow 3 and 4, C.I. I. Hood Red 7 and 14, C.I. I. Dyes classified into Food Blue 2 and the like can be mentioned. These dyes are used in the ink composition from 1 to 1
Used in the range of 0% by weight. The water-retaining organic solvent is selected from polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, butylene glycol and glycerin, and one or more of them is used in the range of 10 to 30% by weight in the ink composition. The water-soluble ionized mineral is an extract from a fermented body obtained by fermenting the seeds and egg shells of plants such as peach, apricot and walnut with microorganisms, and contains metal ions such as calcium, magnesium, potassium and sodium. It is an organic acid salt.
Ionized minerals are contained in the ink composition in an amount of 0.003 to 0.03% by weight, preferably 0.00
It is used in the range of 5 to 0.015% by weight. Furthermore, to make an ink for a water-based ballpoint pen using a gel-like water-based ink, xanthan gum, carrageenan gum, guar gum,
A water-soluble gum or polyacrylic acid-based resin composed of a polysaccharide such as succinoglycan is added in the range of 0.1 to 2% by weight in the ink composition. In addition, if necessary, surfactants and antiseptics, antiseptic agents, antirust agents, lubricants (for ballpoint pens) to improve the wettability to writing instrument members and to improve the penetrability of ink ) Or the like may be added in an appropriate amount.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The water-based ink of the present invention is prepared by adding a colorant and a water-retaining organic solvent to a predetermined amount of water, stirring and dissolving the mixture with heating as necessary, dissolving the components, and then dissolving the ionized mineral and It is prepared by adding the lost water and thoroughly stirring. However, for the inks of Example 4 and Comparative Example 4 below, an aqueous paste obtained by previously dissolving a water-soluble gum in water is mixed with the coloring aqueous solution prepared by the above method and stirred to homogenize. Is prepared by.

[0006]

EXAMPLES Example inks and comparative example inks were prepared by the above-mentioned ink preparation method, and examples 1 to 3 and comparative example 1 were prepared.
For the inks Nos. 3 to 3, each sample ink is provided in a predetermined amount on a marking pen which is provided with a synthetic resin pen body having an axial capillary ink passage at its tip and which is composed of a shaft cylinder containing an ink occlusion body made of fiber bundles. A sample pen was prepared by filling. With respect to the inks of Example 4 and Comparative Example 4, each sample ink was filled in a predetermined amount in an ink storage unit made of a polypropylene pipe having a socket provided with a ballpoint nib at the tip, and then fitted into a plastic barrel. And used as a sample pen. Each sample pen was subjected to the following tests. (1) Observation of Bleeding Degree of Handwriting Prescribed characters were written on writing paper A (JIS P3201) with each sample pen, and the degree of handwriting bleeding was observed. (2) Room temperature (20 ° C. to 27 ° C.) and humidity 55 to 75% R of each of the sample pens with the pen tip exposed without a cap
It was placed horizontally under the condition of H and left for 10 days, and it was examined how many blank writings were required before being able to write a test on the writing paper (writing ink flows out from the pen tip). The composition of the sample ink and the test results are shown in Table 1. The numerical values of the compositions in the table are expressed in parts by weight.

[Table 1]

The contents of the raw materials in the table will be described along with the note numbers. (1) C.I. I. Acid Black 2 (2) C.I. I. Food Black 2 (3) C.I. I. Acid Blue 90 (4) C.I. I. Acid Red 87 (5) C.I. I. Acid Red 92 (6) C.I. I. Direct Black 19 (7) Aquamax MM-1 (Aquamax Co., Ltd.)
Product name), ionized mineral solution (total mineral content
5.6% by weight) (8) Proxel XL-2 (trade name of Zeneca Co., Ltd.) (9) Kerzan (trade name of Sansan Co., Ltd.) (10) PRYSURF M208B (Daiichi Kogyo Seiyaku Co., Ltd.) (11) Bellson Crystal 120 (trade name of Daiwa Kasei Co., Ltd.)

The contents of symbols for evaluation of test results are as follows. (1) Cap off resistance ◎: Immediate writing is possible ○: Writing is possible within 1 line (continuous circular writing about 15 cm, the same applies below) △: Writing is possible within 1 to 3 lines ×: Until writing is possible 3 lines or more of blank writing is required (2) Bleeding degree ○: Substantially no blurring ×: Remarkable blurring

[0009]

Summarizing the test results, the performance of the water-based ink containing the ionized mineral of the present invention is improved as follows in comparison with the ink containing no ion. (1) When the amount of the water-retaining organic solvent is the same, the cap-off resistance is remarkably improved (comparison between Example 1 and Comparative Example 1 and Example 3 and Comparative Example 3). (2) Even if the amount of the water-retaining organic solvent is reduced, the cap-off resistance is slightly improved, and the blurring of handwriting is remarkably improved (Example 2 and Comparative Example 2 and Example 4 and Comparative Example 4).
Contrast with). Regarding the effect of adding ionized minerals, water forms large molecular groups (clusters) due to hydrogen bonding, but when ionized minerals are added, the molecular groups of water undergo reorganization centering on the minerals, resulting in clusters. Becomes a small group. As a result, the penetrating power of water with respect to the solute component such as the dye is increased, and as a result, the solute is more stably dissolved in water. Therefore, it is presumed that precipitation of solutes such as dyes does not easily occur even when the water content of the pen tip of the writing instrument decreases, and the cap-off resistance can be improved without using a large amount of water-retaining organic solvent. As described above, the water-based ink for a writing instrument of the present invention exhibits excellent cap-off resistance in a writing instrument, and also provides handwriting without bleeding on the paper surface.

Claims (1)

[Claims] 1. A water-based ink composition for a writing instrument, comprising a colorant, a water-retaining organic solvent, an additive and water, wherein the additive contains a water-soluble ionized mineral as an essential component.