JPS59217771A - Erasing material for colorless dye-developer based ink - Google Patents

Abstract

PURPOSE:The titled erasing material, obtained by dissolving a nonvolatile desensitizer in a solvent of a minimum-boiling-point azeotropic mixture, consisting of a good solvent and a poor solvent at a low mixing ratio, preventing the drying of the tip of a pen and weight loss due to premeation through the axial cylinder, and capable of rewriting in a short time. CONSTITUTION:An erasing material obtained by dissolving (A) a nonvolatile desenstizer, e.g. diphenyl phthalate, consisting of (i) a developer and (ii) a colorless dye in (B) a solvent of a minimum-boiling-point azeotropic mixture consisting of (i) a good solvent for a coloring ink, e.g. methyl acetate, in a lower mixing proportion than the composition ratio of the azeotropic mixture and (ii) a poor solvent for the coloring ink, e.g. ethyl alcohol.

Description

Detailed Description of the Invention The present invention relates to a color developer having a phenolic hydroxyl group and a colorless electron-donating organic compound (
(hereinafter referred to as colorless dye).

The present invention relates to an erasing material for erasing handwriting made with ink (hereinafter referred to as colorless dye-developer ink) and a solvent that does not inhibit the color reaction.

Colorless dye - Color developer ink contains a colorless dye that is colored by a color developer. 1 It has a deep color similar to normal oil-based ink, so it can produce dark and clear handwriting. It has the advantage that it can be easily erased using a polar compound that has a desensitizing effect. That is, it is believed that the color complex generated by the reaction between the color developer and the colorless dye paste is decomposed by the desensitizing action of the polar compound, resulting in complete colorlessness.

A patent application has already been filed by the same applicant for colorless dye-developer ink erasing material (Japanese Patent Application No. 1983).
-11999). This erasing material consists of a solution in which a desensitizing organic compound with a melting point of 60°C or more and a vapor pressure of 1 fin HI or less at 150°C is dissolved in a solvent with a boiling point of 160°C or less.

It uses a non-volatile desensitizing organic compound that is solid at room temperature and can be used to erase ink by exerting a desensitizing effect in a solution state, but once the solvent evaporates, it solidifies and loses its desensitizing effect. For.

It has the advantage that the handwriting will not become colorless again even if it is rewritten on the erased surface ' with the same ink immediately after erasing (within about 3 minutes).

However, from a practical standpoint, rewriting in a shorter time is strongly desired. For this purpose, a solvent with a lower boiling point should be used as the erasing agent solvent.

When such a low-boiling point solvent is used, there are disadvantages such as the pen tip of the eraser easily drying out, and the loss of solvent permeation through the barrel of the eraser increases after a long period of time. This is preferable from a practical point of view.

Therefore, the present invention can eliminate the above-mentioned drawbacks.

Moreover, with the aim of providing a practical erasing material that can be rewritten in a short period of time, we have conducted extensive research and found that the above-mentioned colored ink can form a lowest boiling point azeotrope with the solvent of the ink erasing material. By using a mixed solvent consisting of a good solvent and a poor solvent, and making the mixing ratio of the good solvent lower than the composition ratio of the azeotrope, an ink erasing material without the above-mentioned drawbacks can be obtained. Heading 2 O which completes the present invention That is, 2 the present invention uses a nonvolatile desensitizer as a solvent to make colorless ink containing a color developer and a colorless dye that develops color with the developer. In an erasing material for colorless dye-developer ink formed by dissolution.

A mixed solvent consisting of a good solvent and a poor solvent for the coloring ink capable of forming a lowest boiling point azeotrope is used as the solvent for the erasing material, and the mixing ratio of the good solvent is lower than the composition ratio of the azeotrope. The gist of this paper is an erasing material for colorless dye-developer ink.

Examples of non-volatile desensitizers that can be used in the present invention include Example Id,
Diphenyl phthalate, diphenyl urethane, pentaerythritol tetraacetate, pentaerythritol tetrabenzoate.

Diphenyl glycolic acid, ethylene glycol, N-
7-enyl anthranilic acid methyl ester, benzoguanamine, 4,4'-methylenebis(acetanilide), 4
．． 4'-sulfonylbis(acetanilide), p-aminoacetanilide, benzacetin, 4-butoxy-N
-Hydroxybenzeneacetamide, 2,3-dihydro-2,2-dimethyl-7-benzofuranol methyl carbamate, cotoine, diaminodiphenylmethane, dianisidine, 4-(phenylmethylphenol) carbamate, galactitol.

Diphenyl phthalate al-(methylsulfamoyl)
-Sulfanilanilide, 4,4'-tetramethyldiaminodiphenylmethane, polyvinylpyrrolidone, polyvinyl acetate, N-vinylpyro5-lydone-vinyl acetate copolymer, ketone resin, oligo-N
- Methylmorpholinium propylene oxide, polyacrylate, polymethacrylate, polyester, urea-formaldehyde resin, ethylene urea-formaldehyde resin.

Examples include ethylene urea-butyraldehyde resin, poly-N-butoxymethylacrylamide, and vinyl acetate-maleic acid copolymer.

Any solvent that can dissolve the above-mentioned non-volatile desensitizers that are solid at room temperature can be used as the solvent; however, in the present invention, from the viewpoint of rewriting on the erased surface, in particular, the lowest boiling point azeotrope is used as the solvent. A mixed solvent consisting of a good solvent and a poor solvent for the colored ink that can be formed is used, and the mixing ratio of the good solvent is lower than the composition ratio of the azeotrope. Because of its strong force, it facilitates the reaction between the ink and the desensitizer, and quickly exerts its erasing action. or.

The mixed solvent is likely to form an azeotrope with the lowest boiling point, and if the mixing ratio of the good solvent is lower than the composition ratio of the azeotrope, the boiling point of the good solvent will decrease.

At the same time as volatilization becomes faster, the mixing ratio of good solvent in the gas phase is always higher than the mixing ratio of good solvent in the erasing material, and the mixing ratio of poor solvent in the erasing material of the erased traces increases rapidly. Even if the handwriting is rewritten with the same colored ink, the handwriting will not be erased because the dissolving power for the handwritten marks is weak and therefore reaction between the colored ink and the desensitizer is unlikely to occur. That is, it becomes possible to rewrite in a short time. In addition, since we use a mixed solvent that can form an azeotropic mixture with the lowest boiling point, it is possible to prevent as much as possible the loss of weight due to drying of the pen tip of the eraser or permeation through the barrel of the eraser after a long period of time. .

Good solvents for the coloring ink include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, propyl formate, butyl formate, methyl propionate, inpropyl ether, tetrahydrofuran, dioxane, tetrahydropyran, jetoxymethane, methyl ethyl ketone, and acetone. , methyl isobutyl ketone, nitroethane and the like.

As the poor solvent for the coloring ink, one that can form a lowest boiling point azeotrope with the good solvent can be used, although it varies depending on the good solvent to be used.

Examples: idm, ethyl alcohol, methyl alcohol.

Water, isopropyl alcohol, n-7”-IF-alcohol, isophthyl alcohol + 1.1.1-)
+) Chlorethane, trichlene, toluene, xylene,
Examples include heptane, hexane, methylcyclohexane, cyclohexane, ethylbenzene, phthyl chloride, and the like.

The mixed solvent that can form the lowest boiling point azeotrope is a combination of the above-mentioned good solvent and poor solvent, and Table 1 shows an example of the combination, the composition ratio of the azeotrope, and the azeotropic temperature.

Table-1 9- The mixing ratio of these good solvents and poor solvents is shown in Table-1.If the good solvent ratio is lower than the good solvent ratio of the azeotrope composition ratio, the solubility of the nonvolatile desensitizer They may be appropriately selected and used depending on the solubility of the one-color ink.

To erase handwriting made with colorless dye-color developer ink using such an erasing agent solution, apply the erasing agent solution onto the handwriting with a brush, or use a container for a writing instrument such as a felt-tip pen or felt-tip pen. Can be filled and used.

The present invention will be explained in more detail below with reference to Examples and Comparative Examples. In the Examples and Comparative Examples, "part" means 1 part by weight.

Example 1 [Preparation of colorless dye-developer-based ink] Novolak type phenolic resin "Tamanol PAJ (manufactured by Arayo Kagaku ■) [Developer] 10 parts p-cresol-formalin initial condensate 10- [Developer] ] 20 parts Fluorane colorless dye rBK-14J (manufactured by Yamada Chemical Industry ■) 15 parts Crystal violet lactone [Colorless dye] 2 parts Benzyl alcohol 30 parts Ethylene glycol monophenyl ether 23 parts The above components were mixed and heated at 100°C. After heating and dissolving for 1 hour, a small amount of insoluble matter was removed by filtration to obtain a black ink.This ink was injected into a ballpoint pen (JIS
8 6039-1980 A writing instrument erasable with the erasable material of the present invention was prepared by filling an E type for fine print) with the erasable material of the present invention.

[Preparation of erasing material]

N-vinylpyrrolidone-vinyl acetate copolymer (S Near)
(Desensitizer) 10 parts Ethyl acetate (boiling point 76.8°C) 20 parts Ethyl alcohol (boiling point 78.3°C) 70 parts
After stirring for a period of time, an ink erasing material of the present invention was obtained. Fill this into the parts of an oil-based marker (M-10 manufactured by Pentel) to make an eraser, and use the black ink ballpoint pen as described above to erase the paper surface (
When I rubbed the handwriting on the JIS P 3201° writing paper A) two to three times, I was able to completely erase it.

After 15 seconds of erasing, I wrote again on this erased trace with the black ink ballpoint pen mentioned above, and was able to write clearly.

Comparative Example 1 [Adjustment of erasing material] N-vinylpyrrolidone-vinyl acetate copolymer (3-nea)
(Desensitizer) 10 parts Ethyl acetate (boiling point 76.8°C) 90 parts An ink erasing material was prepared using the above components in the same manner as in Example 1, and a marker type eraser was produced.

When this eraser was used to rub the handwriting made with the black ink ballpoint pen in Example 1, it was possible to completely erase it.

After 15 seconds of erasing, I wrote again on this erased trace with the black ink ballpoint pen mentioned above, and the handwriting became so faint that I could hardly write on it.

It took 40 seconds for me to be able to write clearly again.

Comparative Example 2 [Preparation of erasing material] N-vinylpyrrolidone-vinyl acetate copolymer (-S Near) (desensitizer) 10 parts Ethyl alcohol (boiling point 78.3°C) 90 parts Above each component was added to Example 1 An ink eraser was prepared in the same manner as above, and a marker type eraser was produced.

When the black ink ballpoint pen handwriting created in Example 1 was rubbed with this eraser, the erasing was somewhat poor and some areas remained that could not be completely erased.Example 2 [Preparation of erasing material] 13- Ethylene Urea-butyraldehyde resin (desensitizer) 10 parts Dioxane (boiling point 101°C7C775O#)
25 parts to butane (boiling point 98.35°C) 65 parts The above components were mixed and stirred at 50°C for 1 hour to obtain two ink erasers of the present invention. An eraser was prepared by filling the parts of an oil-based marker (M-10 manufactured by Pentel), and the black ink ballpoint pen of Example 1 was used to erase the paper surface (JIS P
When I rubbed the handwriting on the 3201° writing paper A) two to three times, I was able to completely erase it.

When the erased trace was rewritten with the black ink ballpoint pen described above 20 seconds after erasing, it was possible to write clearly.

Comparative Example 3 [Preparation of erasing material] Ethylene urea-butyraldehyde resin (desensitizer) 10 parts dioxane (boiling point 101°C/750wnH,!?)
90 parts 14- An ink erasing material was prepared using the above ingredients in the same manner as in Example 2, and marker type erasers 1 to 1 were made.

When this eraser was used to rub the handwriting made with the black ink ballpoint pen in Example 1, it was possible to completely erase it.

After 20 seconds of erasing, I wrote again on this erased trace with the black ink ballpoint pen mentioned above, and the handwriting became so faint that I could hardly write on it.

It took 90 seconds for me to be able to write clearly again.

Comparative Example 4 [Preparation of erasing material] Ethylene urea-butyraldehyde resin (desensitizer) 10 parts Hebutane (boiling point 98.35°C) 90 parts An ink erasing material will be prepared in the same manner as in Example 2 above. However, the desensitizer did not dissolve sufficiently and it was impossible to prepare.
No erasing material was obtained.

As shown above, the colorless dye-developer ink erasing material of the present invention has excellent erasability, rewriting properties, and practicality.

Patent applicant: Pentel Co., Ltd.

Claims (1)

[Claims] A colorless dye-developer-based ink erasing material prepared by dissolving in a solvent a nonvolatile desensitizer that decolorizes a color-forming ink containing a color developer and a colorless dye developed by the color developer, A mixed solvent consisting of a good solvent and a poor solvent for the coloring ink capable of forming a lowest boiling point azeotrope is used as the solvent for the erasing material, and the mixing ratio of the good solvent is lower than the composition ratio of the azeotrope. Characteristic colorless dye-developer ink erasing material.