JPH0243780B2 - MUSHOKUSENRYOOKENSHOKUZAIKEIINKINOSHOKYOZAI - Google Patents

Description

Detailed Description of the Invention The present invention comprises a color developer having a phenolic hydroxyl group, a colorless electron-donating organic compound (hereinafter referred to as colorless dye) that develops color with the color developer, and a colorless organic compound that does not inhibit the color development reaction. The present invention relates to an erasing material for erasing handwriting made with ink (hereinafter referred to as colorless dye-developer ink) made of a solvent.

Colorless dye-color developer ink contains a colorless dye that is colored by a color developer, and because it is darkly colored like normal oil-based ink, 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 base is decomposed by the desensitizing action of the polar compound, resulting in complete colorlessness.

A patent application has already been filed for an erasing material for colorless dye-developer ink by the same applicant as the present application (Japanese Patent Application No. 57-11999). This erasing material has a melting point of 60
It consists of a solution in which a desensitizing organic compound with a vapor pressure of 1 mmHg or less at 150°C or higher is dissolved in a solvent with a boiling point of 160°C or lower, and in the solution state, it exhibits a desensitizing effect and cannot erase ink. However, since we use a non-volatile desensitizing organic compound that is solid at room temperature and loses its desensitizing effect once the solvent evaporates, the erased surface can be painted with the same ink immediately after erasing (within about 3 minutes). This has the advantage that even if the handwriting is rewritten, the handwriting will not become colorless again.

Furthermore, the solution viscosity of the above erasing material is 10~
By adjusting to 200 centipoise (25℃),
It has been found that it is possible to provide an erasing material that does not erase or smear handwriting on the back side of the erasing paper or on the second sheet of paper (Japanese Patent Application No. 57-91106).

However, when ink handwriting on paper is erased using the ink eraser mentioned above, the non-volatile desensitizer in the eraser remains on the paper, making the paper appear more transparent than necessary. This phenomenon is often observed. In this case, there are disadvantages in that the erased ink traces appear slightly black and, furthermore, the erased traces appear white when the paper is diazo copied due to the increased transmittance of the paper.

Therefore, an object of the present invention is to provide an ink erasing material that can eliminate the above-mentioned drawbacks and prevent even the slightest erased traces of ink from appearing black or from being copied whiter than necessary when diazocopied. As a result of extensive research, the inventors discovered that by adding and dissolving a fluorescent brightener in the ink erasing material described above, it was possible to obtain an ink erasing material free from the above-mentioned drawbacks, and the present invention was completed. It is something.

That is, the present invention provides an erasing material for a colorless dye-developer ink, which is obtained by dissolving a nonvolatile desensitizer that makes a colorless dye-developer color ink colorless in a solvent. This is an erasing material for colorless dye-developer ink, which is characterized by adding and dissolving 0.001 to 2% by weight of a fluorescent whitening agent.

Examples of non-volatile desensitizers that can be used in the present invention include benzoguanamine (mp 228°C), 4,4'-sulfonylbis(acetanilide) (mp 290°C),
p-aminoacetanilide (mp164℃), benzacetin (mp189℃), 4-butoxy-N-hydroxybenzeneacetamide (mp153℃), 2,
3-dihydro-2,2-dimethyl-7-benzofuranol methyl carbamate (mp150℃), cotoine (mp131℃), diaminodiphenylmethane (mp92℃), dianisidine (mp137℃), 4-
(phenylmethylphenol) carbamate (m.
p.147℃), galactitol (mp188℃), diphenyl phthalate (mp73℃), 4′-(methylsulfamoyl)-sulfanylanilide (mp141℃),
4,4'-tetramethyldiaminodiphenylmethane (mp90℃), polyvinylpyrrolidone, polyvinyl acetate, N-vinylpyrrolidone-vinyl acetate copolymer, ketone resin, oligo-N-methylmorpholinium propylene oxide, polyacrylate ,
Polymethacrylate, polyester, urea-formaldehyde resin, ethylene urea-formaldehyde resin, ethylene urea-butyraldehyde resin, poly-N-butoxymethylacrylamide,
Examples include vinyl acetate-maleic acid copolymer.

Any solvent that can dissolve the above-mentioned non-volatile desensitizer which is solid at room temperature can be used as the solvent, but from the viewpoint of rewriting on the erased surface, it is desirable to use a volatile solvent with a boiling point of 160° C. or lower. Such solvents include, for example, methanol, ethanol, propanol, butanol, tetrahydrofuran, diisopropyl ether, acetone, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene,
Xylene, 1,1,1-trichloroethane, trichlorethylene, perchloroethylene, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, dimethylformamide, 2-nitropropane, dioxane, etc. can be used. Among these solvents, alcohols, esters, ethers,
Ketones or mixed solvents thereof are particularly preferable because they have a strong ability to dissolve handwriting, smooth the reaction between the ink and the desensitizer, and quickly exhibit the erasing action.

The fluorescent whitening agent to be added to the ink erasing material solution in which a non-volatile desensitizer is dissolved in the above-mentioned solvent may be appropriately selected as long as it is colorless or light in color and dissolves in the ink erasing material solution. For example, naphthalimide fluorescent brighteners [e.g. Mikawhite ACRcono., Mikawhite
ATconc., Mikawhite ATNconc., Mikawhite BTNconc. (all products of Nippon Kayaku Co., Ltd.), etc.], pyrazoline-based fluorescent brighteners [e.g. Kycol C (product of Nisso Kako Co., Ltd.), etc.], stilbene system fluorescent brighteners [e.g. Mikahole TBconc., Mikahole TA,
Mikahol TAconc. (both manufactured by Mitsui Toatsu Chemical Co., Ltd.), coumarin-based fluorescent brighteners (such as Kycor E (made by Nisso Kako Co., Ltd.), White Floor B
(products of Sumitomo Chemical Co., Ltd.), etc., and bisoxazole-based fluorescent brighteners (for example, Whytex SNK, Whytex SNP, Whytex NKR, all products of Sumitomo Chemical Co., Ltd.).

The amount of fluorescent brightener to be added may be the amount necessary for its whitening effect and the white bleeding prevention effect during diazo copying, but it is generally added at least 2% by weight based on the ink erasing agent solution. This is undesirable because the whitening effect and the whitening prevention effect during diazo copying become too strong, and addition of 0.001% by weight or less is insufficient for both effects, so it is added and dissolved in the range of 0.001 to 2% by weight.

In addition, if a good balance between the brightening effect of preventing the ink erased traces from becoming dark and the effect of preventing whitening during diazo copying cannot be achieved by using one type of fluorescent brightener, It is preferable to use two or more fluorescent brighteners in appropriate combination.

In addition, in order to prevent the ink eraser solution from penetrating into the back side of the paper, the viscosity of the eraser solution should be
It is desirable to adjust to 200cps (25℃). The viscosity of the eraser solution can be adjusted by adjusting the amount of a non-volatile desensitizer, or by using a polymer desensitizer (preferably with a molecular weight of 1000 or more) that has a relatively weak desensitizing effect but has a thickening effect. However, organic polymer compounds such as hydroxypropylcellulose, polyvinyl butyral, high molecular weight polyvinylpyrrolidone, cellulose acetate butyrate, ethylene-vinyl acetate copolymer, etc. It is preferable to adjust the viscosity by the method of addition.

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

As explained above, the present invention has a colorless dye-developer type ink that has a non-volatile desensitizer dissolved in a solution and a fluorescent brightener added to and dissolved in the colorless dye-developer ink erasing material. When handwriting made with colored ink is erased with this eraser, the whitening effect can eliminate the defect that the erased trace appears slightly dark, so not only can a clean erased trace be obtained, but it can also be used for diazo copying after erasing. In some cases, the fluorescent brightener is sensitive to light with a wavelength shorter than that of the diazocopy.
It is possible to eliminate the defect that the erased portion is copied whiter than other portions.

The present invention will be explained in more detail below with reference to Examples and Comparative Examples. Note that "parts" in Examples and Comparative Examples all indicate parts by weight.

Example 1 [Preparation of colorless dye-developer ink] Phenol resin "Tamanol #510" (Arakawa Chemical Co., Ltd.)
Co., Ltd.) [Developer] 25 parts p-cresol-formalin initial condensate [Developer] 10 parts Crystal Violet Lactone [Colorless dye] 20 parts Phenyl glycol [Solvent] 20 parts Benzyl alcohol [Solvent] 25 parts Mix the above ingredients and stir at 100℃ for 30 minutes.
A blue ink was obtained. Fill a ballpoint pen (JIS S 6039-1980 medium type E type) with this ink,
A writing instrument that can be erased using the erasable material of the present invention was produced.

[Preparation of eraser] N-vinylpyrrolidone-vinyl acetate copolymer (3:7) [desensitizer] 10 parts Ethanol [solvent] 80 parts Dioxane [solvent] 8 parts High molecular weight polyvinylpyrrolidone (average molecular weight
360,000) [Viscosity modifier] 1.5 parts coumarin-based fluorescent whitening agent "White Floor B" (manufactured by Sumitomo Chemical Co., Ltd.) 0.01 part naphthalimide-based fluorescent brightening agent "Mikawhite ACRconc." (Nippon Kayaku Co., Ltd.) (manufactured by Co., Ltd.)
0.5 part The above ingredients were mixed and stirred at 50℃ for 1 hour.
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 Co., Ltd.) to make an eraser, and write the handwriting with the blue ink ballpoint pen on the paper (JIS P 3201, writing paper A) for 2 to 3 seconds.
After rubbing it three times, it was completely erased, and the erased marks were as white as the paper and were completely inconspicuous. In addition, when I wrote again on this erased trace 60 seconds later with the same blue ink ballpoint pen as above, I was able to write clearly. When the erased marks and rewritten marks were copied using a diazo copy machine (Ricopy Super Dry 455 machine, manufactured by Ricoh Co., Ltd.) at speeds of 4 to 7, the erased marks and rewritten marks were not noticeable at all.

Comparative Example 1 An ink erasing material was prepared in exactly the same manner as in Example 1 except that no fluorescent brightener was used, and a marker type eraser was produced. When I used this eraser to rub the handwriting from the blue ink ballpoint pen prepared in Example 1 on the paper surface (JIS P3201, writing paper A), I was able to completely erase it, but the erased marks looked like oil stains. slightly recognized. After 60 seconds, I wrote again on this erased mark with the same blue ink ballpoint pen as above and was able to write clearly. When the erased traces and rewritten traces were copied using the same diazo copy machine used in Example 1 at speeds 4 to 7, the erased traces and rewritten traces were not noticeable at speeds 4 to 5.5, but In cases 6 and 7, the erased traces became slightly whiter and more noticeable.

Example 2 Ethylene urea-butyraldehyde resin [desensitizer] 10 parts Ethanol [solvent] 70 parts Dioxane [solvent] 18 parts High molecular weight polyvinylpyrrolidone (average molecular weight
360,000) [Viscosity modifier] 1.5 parts Coumarin-based fluorescent whitening agent "Kycor E" (manufactured by Nisso Kako Co., Ltd.) 0.05 parts The above components were mixed and stirred at 50°C for 1 hour.
An ink erasing material of the present invention was obtained. This was filled into the parts of a permanent marker (manufactured by Pentel Co., Ltd., M-10) to make an eraser, and the blue ink ballpoint pen prepared in Example 1 was used to mark 2 to 3 handwritings on file paper (ivory). After several times of rubbing, it was completely erased, and the erased traces on the paper surface had almost no change in gloss and were not noticeable.

Comparative Example 2 An ink erasing material was prepared in exactly the same manner as in Example 2 except that no fluorescent brightener was used, and a marker type eraser was produced. When I used this eraser to rub the handwriting made with the blue ink ballpoint pen prepared in Example 1 on file paper (ivory), I was able to completely erase it, but the gloss of the erased paper surface changed and the ivory coloring changed. It became slightly more visible and could be distinguished from other parts as erased marks.

Claims (1)

[Claims] 1 Erasure of colorless dye-developer ink made by dissolving a non-volatile desensitizer in a solvent to make colorless ink containing a color developer and a colorless dye developed by the color developer An erasing material for a colorless dye-developer ink, characterized in that a fluorescent brightener is added and dissolved in the erasing material in an amount of 0.001 to 2% by weight of the erasing material.