JPS606768A - Writing ink - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel writing ink, particularly a writing ink with a dark <Il[Y] color that enables clear writing and also allows handwriting to be erased with a special erasing material if necessary. It is something.

Various methods have been developed for erasing ink handwriting. For example, (1) 19 a method of erasing handwriting made with ink using easily bleachable dyes with bleach, 21 a method of kneading a coloring agent into a rubber-like polymer substance and dissolving it in a solvent to form ink, and using this ink, etc. There are methods such as erasing the marks with an eraser. however(]
) method overcomes the disadvantages of easily yellowing the erased traces and poor stability of bleach over time. On the other hand, method (2) requires a pressurized ballpoint pen structure because the ink becomes highly viscous, and ti is not necessarily required in terms of erasing performance.

υcolor is developed by the exchange of electrons between the color-forming substance and the color developer,
A writing method that utilizes a reversible reaction in which the exchange of electrons is inhibited with a desensitizer to make the paper colorless has also been proposed. For example, a writing material is made of a dye with a color-developing component structure in its molecule (color-forming substance), a compound with an acidic hydroxyl group in its molecule (developer), and a polar solvent (desensitizer). It is described in Japanese Patent Publication No. 48-21649.This writing ink aims to be a special ink that is colorless until just before writing, and after writing, the handwriting appears only by evaporation and evaporation of the right-polar solvent. Because the handwriting can be heard at the same time as it is written, it is not suitable for regular ink for elderly tools.Furthermore, Bamboo's 111'351 48085 contains electronic ij1, a dynamic organic compound (color-forming substance), and phenol. A coloring agent for writing instruments is described that is composed of a compound having a functional hydroxyl group (a color developer) and a non-volatile compound (desensitizer) that desensitizes the color reaction of the two compounds. is colored immediately after it is written, but it can be made colorless by washing out the color developer in the handwriting with water that has been heated and volatilized. Since it is not easy to use, it is not suitable for use as an erasable ink for ordinary writing instruments.

SUMMARY OF THE INVENTION Therefore, the present invention has been made for the purpose of providing a novel writing device that allows for dark and clear writing with a pencil as well as easy erasing of handwriting depending on the thickness of the pencil. It is.

That is, the gist of the present invention is to provide a writing ink comprising a color developer having a carphokyl group, a colorless electrolytic organic compound that develops color with the color developer, and a bath agent that does not inhibit the color reaction. be.

The writing ink of the present invention contains an electron-donating organic compound that is colored by a color developer, and has a dark color similar to that of general oil-based inks, resulting in dark and clear handwriting. be able to.

The color developer having a carphokyfur group used as an ink component is sufficiently non-volatile (preferably has a melting point of 1.
Any substance can be used without particular limitation as long as it has the slenderness that it can be made into an ink and its solubility in a solvent, such as l-ruic acid, pimelic acid, IT-butylmalonic acid,
Citric acid, salicylic acid, 6,4-dimethylbenzoic acid, tricarballylic acid, 212-diphenylpropionic acid, dimethylmalonic acid, 2,3-dioxybenzoic acid, 3-oxybenzoic acid, tartaric acid, α, β, γ resorcyl acid, 4-oxybenzoic acid, 4-oh+cy-2-naphthoic acid, diphenic acid, trimellidic acid, ethylmalonic acid, benzylmalonic acid, cetylmalonic acid, diethylmalonic acid, +-lylic acid,
Malonic acid, hydroatrobic acid, / black buta 7-4,1-
dicarboxylic acid, fuclobutane-112-dicarboxylic acid,
Examples include speric acid, sepanonic acid, diphenylacetic acid, phenylmalonic acid, adipic acid, trimethylbenzoic acid, triphenylacetic acid, gallic acid, and anacardic acid. These color developers may be used alone or in combination of two or more.

Examples of colorless electron-donating organic compounds that develop color with the above color developer include phthalide-based color-forming organic compounds such as crystal violet lactone and malachite green lactone; 6-dimethylamino-6-methoxy/fluoran; -) Ethoxyfluorane, 112-penno-6-ethylaminofluorane, 2-anilino-6
-Methyl-6-birolindino-fluorane, 3', 6
'-bis-(jeddylamino)spiro-(phthalane-1
, 9-xanthine), 1,1-bis-(p-aminophenyl)-phthacine; di-β-naphtho-spiropyran, xantho-β-naphtho-spiropyran, benzo-β-naphtho - Spiropyran-based color-forming organic compounds such as inospiropyran can be used.

The amount of the electron-donating organic compound to be used is preferably about 1 to 40% by weight based on the total ftK in terms of concentration and dissolution stability of the ink. It is important to note that the color developer and electron-donating organic compound should be used in a ratio of 1:6 to 20:1.
This is preferable from the viewpoint of color development stability of the ink.

The ink solvent may be used without particular limitation as long as it can easily inhibit the color-forming reaction between the color developer and the electron-donating organic compound described in ``2'' and can dissolve them. For example, aromatic alcohols and/or ethylene glycol monophenyl ethers can also be preferably used. Since these solvents are polar compounds, they have a desensitizing effect and therefore, at first glance, they cannot be used as ink solvents because they inhibit the color development reaction in colorless dye-developer type inks. Nevertheless, these polar solvents can be used as effective solvents in the present invention because they dissolve the color developer and the colorless dye very well, promoting the color reaction between them, and thus desensitizing the polar solvent. It is thought that the color developing effect of the color developer is greater than that of the color developer, and that a dark and clear colored ink is obtained. Examples of aromatic alcohols include evabenzyl alcohol, β-phenylethyl alcohol, 6-phenyl-1-propatol,
Among 4-phenyl-2-butanol and methylphenicols, ethylene glycol monophenyl ether was particularly used because its desensitizing effect is weaker than that of other glycols. These solvents may be used alone or in combination of two or more. The amount of solvent to be used is preferably about 25 to 5% of the total amount of ink from the viewpoint of stability and fluidity of the ink.

Alternatively, a resin that does not prevent color development may be used to adjust the viscosity of the ink and the fixation of handwriting, and a lubricant may be appropriately selected and used as necessary to adjust the lubricity of the ink.

Next, to briefly describe the method for manufacturing the ink of the present invention, the color developer, the electron-donating compound, and the solvent are mixed using equipment normally used for ink manufacturing, such as a kneader, a three-roll roll, and a heated stirring mixer. Easily obtained by mixing. Incidentally, when adding resins, lubricants, etc. as necessary, they may be added to the above components and mixed in the same manner.

The ink thus obtained was used as an ink for pens, such as ballpoint pens, which have traditionally been used.
It can be used as a pen-shaped writing instrument that is housed in the ink storage part of a felt-tip pen, felt-tip pen, marker, fountain pen, etc. and supported on the pen shaft so that the ink oozes out from the tip of the pen, or as a recording instrument for printers, etc. .

Handwriting based on the above ink can be easily erased, if necessary, with an erasing agent containing a desensitizing polar compound such as alcohol, ketone, ester, ether, amine, or amide. That is, it is thought that the color-forming complex generated by the reaction between the color developer and the electron-donating organic compound is decomposed by the desensitizing action of the polar compound, resulting in complete colorlessness.

The present invention will be further explained below with reference to Examples. Note that "parts" in the examples indicate parts by weight.

Example 1 6.4-dimethylbenzoic acid 25 parts Crystal violet lactone 15 parts Benzyl alcohol 30 parts Phenyl glycol 20 parts Dikanol 11P (resin, manufactured by Mitsubishi Gas Chemical ■) 15 parts The above mixture was heated at 100°C for 1 hour. After dissolving the mixture, it was filtered to remove a small amount of insoluble matter, and an ink with a blue color was obtained. Apply this ink to a ballpoint pen (J I 5-
8-6039-1980 (E type for fine print) and paper (J
When a line was drawn on the ISP'-3201 writing paper A), it could be written smoothly in the same manner as with ordinary ballpoint pen ink, and a clear blue line was obtained. This line is 1 at '50℃
It remained solid without fading even after being left for 0 days.

In addition, the above lines can be completely erased by gently wiping with paper soaked in 50% acetone solution, and the color will not come back even if left at 50℃ for 10 days. It showed stable erasability.

Example 2 2.2-Diphenylpropionic acid 15 parts 2-anilino-6-methyl-6-pyrrolidino-fluoran 15 parts β-phenylethyl alcohol 15 parts Benzyl alcohol 65 parts Phenyl glycol 20 parts The above formulation was prepared at 100°C. After heating for 1 hour to dissolve, a small amount of insoluble matter was removed by filtration to obtain a black colored ink. This ink is applied to oil-based marker parts (MM
50. (manufactured by Pentel) and paper (JI, S-
When lines were drawn on S'-3201 paper A), a clear black color was obtained. This line remained robust without fading even after being left at 50°C for 10 days.

As can be seen from the above explanation, since the ink used for writing according to the present invention contains an electron-donating organic compound that has already been darkly colored by a color developer, it has a dark color similar to ordinary writing ink. It can produce clear handwriting. Furthermore, the handwriting made with the above-mentioned ink has the excellent feature that the desensitizing polar compound that makes the colored electron-donating organic compound colorless can be easily and completely erased as needed in the layer.

Special r “Applicant: Bentel Co., Ltd.

Claims (1)

[Scope of Claims] 1. A writing ink comprising a color developer having a carboxyl group, a colorless electrodynamic organic compound that develops color with the color developer, and a δ agent that does not inhibit the color development reaction. 2 The color developer that cures the carboxyl group has a melting point of 100°C
The writing ink according to claim 1, which is the above compound.