JPS582367A - Ink composition - Google Patents

Abstract

PURPOSE:The titled composition providing letters, images and lines capable of being erased by a rubber on the market, capable of rewriting letters, etc. on the erased position without causing blur, obtained by blending an aqueous solution of alkaline earth metal compound with pigment or dye. CONSTITUTION:(A) An aqueous solution of an alkaline earth metal compound [preferably oxide (hydroxide), halide, organic or inorganic salt of calcium, magnesium, strontium, barium]is blended with (B) pigment or dye (preferably oil-in- water type emulsion pigment), and, preferably (C) glycerol, to give the desired composition. In a preferable composition ratio, the amount of the component A is 5-50wt%, the amount of the component B is 0.05-20wt%, and the amount of the component C is 5-50wt%. USE:Writing ink for a signature pen, ball-point pen, and fountain pen.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel ink composition, and more particularly to a writing ink composition from which written characters and strokes can be erased with a commercially available eraser.

BACKGROUND ART When writing ink used in conventional fountain pens, felt-tip pens, etc. is written on paper, it is almost impossible to erase the written information with an eraser. To erase items written in traditional ink,
Generally, eraser liquid is used. However, when using such erasing fluid, the erased marks are wet, so it is not possible to write on them immediately after erasing them. needed to be completely dried. Even if characters are written while the eraser remains wet with the eraser, the characters may smudge or the written characters i may be erased again by the action of the eraser.

The inventor of the present invention has conducted extensive research to develop an ink composition that allows written characters and lines to be easily erased with a conventional eraser, without using the above-mentioned erasing liquid. The inventors discovered that matters written using an ink composition formed by adding pigments or dyes to an aqueous solution of an alkaline earth metal compound can be erased with an ordinary eraser, and the present invention was completed. .

That is, according to the present invention, there is provided an ink composition formed by adding and mixing a pigment or dye to an aqueous solution containing an appropriate amount of an alkaline earth metal compound.

The alkaline earth metal compound used in the present invention is a compound of a metal selected from calcium, magnesium, strontium, and hyhalium, and includes oxides, hydroxides, halides, and salts of various organic and inorganic acids. It will be done. In the present invention, any alkaline earth metal compound may be used as long as it exhibits the required water solubility. The concentration of the alkaline earth metal compound in the aqueous solution is usually 5% by weight or more, preferably 10% by weight or more, and it is desirable that the concentration is as high as possible, and the upper limit of the concentration is the saturation solubility. .

The dye or pigment used in the present invention is not particularly limited, and direct dyes, acid dyes, basic dyes, reactive dyes, and various pigments can be used. In the present invention, oil-in-water (0/W) emulsion pigments are preferably applied. This V-type emulsion type face is formed by using water as a continuous phase, emulsifying a water-insoluble organic solvent and resin in the presence of an emulsifier, and further dispersing pigment particles in water. be. The concentration of the dye or pigment is not particularly limited as long as it provides an appropriate ink concentration, but it is generally between 0.05 and 0.05.
It is 20% by weight.

In the present invention, when adding a direct dye or an acidic dye forming a sodium salt to an aqueous solution of an alkaline earth metal compound, in order to prevent the dye from becoming insolubilized due to reaction with alkaline earth metal ions, It is advisable to add metal salts such as thorium chloride, sodium nitrate, etc. The addition of such alkali metal salts prevents insolubilization or solubility reduction of direct or acid dyes in the presence of high concentrations of alkaline earth metal ions.

In the ink composition of the present invention, glycerin can be added as an auxiliary agent. The addition of glycerin provides an ink composition with an even greater erasing effect by an eraser. The concentration of glycerin in the composition is preferably 5% by weight or more, preferably 10 to 40% by weight.

Preferred ink compositions according to the invention contain no pigment or dye.
05-20% by weight, preferably 01-15% by weight, alkaline earth metal compound 5-50% by weight, preferably 10-15% by weight
40% by weight, optionally glycerin 5-50% by weight
, preferably 10 to 40% by weight.

The ink composition of the present invention is applied as a writing ink, and is preferably applied as an ink for writing brushes such as felt-tip pens, ballpoint pens, and fountain pens. Characters and lines written using the ink composition of the present invention can be erased with a commercially available eraser, and the erased traces can be erased again.
It is possible to write characters and strokes without bleeding.

The reason why characters and lines drawn using the ink composition of the present invention can be erased with an eraser has not yet been clearly elucidated. It is thought that this prevents it from penetrating into the paper surface. This means that the written characters and strokes are
This is understood from the fact that as the date and time pass, it becomes more difficult to erase than immediately after it was written.

As mentioned above, the ink composition of the present invention is preferably used as an ink for brushes, but it can also be used for type printing by adding an appropriate fixing agent to make it easy to apply to the surface of paper or cloth. Used as ink for paper ribbons and various types of copying paper.

You can also do that.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Anhydrous calcium chloride 401 was dissolved in water iooy, and 151 1 of a φ emulsion type pigment (Helirazalinb TT) was dissolved in this aqueous solution to prepare a uniform black ink.

Next, this ink was impregnated into the wadding of a felt-tip pen, so that it would ooze out from the pen core. When I wrote letters on paper with this pen and erased them with a commercially available eraser, the letters were erased. Furthermore, when another character was immediately written on this erased trace, the character was written in a normal state without any bleeding or the like.

Example 2 In the same manner as in Example 1, an ink composition having the following component composition was prepared.

Table-1 Ink Composition 7- Using the ink composition having the component composition shown in the above-mentioned Clothing-1,
When an erasing test was conducted on the written characters in the same manner as in Example 1, it was confirmed that all characters could be erased with an eraser. In this case, composition A 1 containing glycerin,
It was confirmed that II&, 4, A5 and Ya7 were easier to eliminate than those containing no glycerin. In addition, in the case where an alkaline earth metal compound is not added to the above composition, agent: Satoshi Ikeura, patent attorney
Ming 8-

Claims (5)

[Claims] (1) An ink composition characterized in that a pigment or dye is added and mixed to an aqueous solution containing an appropriate amount of an alkaline earth metal compound. (2) The composition according to claim 1, which contains 5% by weight or more of an alkaline earth metal compound. (3) An ink composition characterized in that a pigment or dye is added and mixed with glycerin to an aqueous solution containing an appropriate amount of an alkaline earth metal compound. (4) The composition λ of claim 3 containing 5% by weight or more of an alkaline earth metal compound. (5) The composition according to claim 3 or 4, containing 5% by weight or more of glycerin.