JPH01168497A - Writing utensil - Google Patents

Abstract

PURPOSE:To obtain a writing utensil capable of writing on any material and being used without causing staining of a hand, by dispersing microcapsules containing a color forming dye therein and microcapsules containing a color developer therein, in a dispersant which is solid at normal temperature. CONSTITUTION:A writing utensil generally comprises a color forming dye and a color developer, the dye being an electron-donative organic compound capable of a color reaction with the color developer. To produce the writing utensil, the dye and the color developer are separately dissolved in respective solvents, and the resultant solutions are separately encapsulated. An oil or fat and a wax, which are solid at normal temperature, as dispersants are placed in a double pot, and are melted by steam heating and melted, and the microcapsules containing the dye and the color developer are put into the mixture, followed by mixing uniformly. The mixture thus obtained is poured into a mold having the shape of a rodlike writing utensil, followed by slow cooling to mold the mixture into the shape of the rodlike writing utensil. In use of the writing utensil, the microcapsules are broken due to a writing pressure and frictional movements, and the dye and the color developer are mixed with each other to form a color.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to a writing instrument that does not stain hands during use and has excellent color development.

[Prior art and its problems] Traditionally, as a type of writing instrument used for drawing paintings, etc., crayons, fraypas, and containers are made by uniformly kneading various pigments in a dispersion medium made of wax, and hardening the mixture into a rod shape. etc.

Since the dispersion medium of these writing instruments is soft, they can be freely drawn on paper, wood boards, glass, cloth, plastic molded objects, etc.

However, when using these writing instruments, there is an inconvenience that if you hold them directly in your hand, the dispersion medium will soften due to your body temperature and the pressure of gripping the writing instrument, making your hands dirty.

This invention was made to solve the above problems, and aims to provide a writing instrument that can be used to draw on any material and that does not stain hands during use.

[Means for Solving the Problems] The present invention is characterized in that microcapsules containing a color-forming dye and microcapsules containing a color developer are dispersed in a dispersion medium that is solid at room temperature, and formed into the shape of a writing instrument. was the solution.

[Function] The color-forming dye and the developer for coloring it are separately encapsulated in microcapsules, and these are uniformly dispersed in a dispersion medium that is solid at room temperature, so when using this writing instrument, Even if you hold it directly in your hand and the dispersion medium softens and sticks to your hand due to your body temperature and the pressure of gripping the writing instrument, the color-forming dye and developer are contained in microcapsules, so
Your hands won't get dirty. Further, even if the microcapsules on the side of the writing instrument are destroyed by the pressure of gripping the writing instrument, the color-forming dye and the color developer are not mixed with each other, so your hands will not get dirty.

On the other hand, if you do not use the writing instrument of this invention,
When pressed or slid onto the material to be written on with a certain amount of writing pressure, the microcapsules are destroyed and the color-forming dye and developer are mixed to form a color, making it useful as a writing instrument. .

The present invention will be described in detail below.

The writing instrument of the present invention is generally composed of a color-forming dye and a color developer, and the color-forming dye is an electron-donating organic compound that has color reactivity with the color developer. Although this color-forming dye is not particularly limited, for example, the following compounds can be suitably used.

■Triarylmethane compounds.

3.3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide or crystal violet lactone, 3.3-bis(p-dimethylaminophenyl)
-3-(1,2-dimethylindol-3-yl)phthalide and the like.

■Diphenylmethane compounds.

4.4-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl-leukoolamine, etc.

■Xanthine compounds.

Rhodamine B-anilinolactam, 3-dimethylamino-7-medoxyfluorane, etc.

■Thiazine compounds.

Benzyl leucomethylene blue, p-nitrobenzyl leucomethylene blue, etc.

■ Spiro compounds.

3-Methyl-spiro-dinaphthopyran, 3-medyru (
3-methoxy-benzo)-spiropyran and the like.

and mixtures of the above compounds.

Further, the color developer that causes this color-forming dye to develop color is an electron acceptor compound, and although these are not particularly limited, for example, the following compounds can be suitably used.

■Phenol resin and its derivatives.

The phenol resin used as a color developer is a novolac type, has a structure that does not contain a methylol group, and has an unreacted phenolic hydroxyl group. Examples of those that are preferably used include phenolic resin. A dylene polymer, a phenol-aldehyde polymer, p-phenylphenol formalin resin, p-cumylphenol formalin resin, p-ter-butylphenol formalin resin, p-ocdylphenol formalin resin, or a cocondensate thereof. .

■Aromatic carboxylic acids and their derivatives.

It has one carboxyl group per aromatic nucleus, such as benzoic acid, toluic acid, salicylic acid, cresotic acid, anacardic acid, naphthoic acid, etc. Salicylic acid derivatives are preferable as derivatives of these acids, for example, 3 .5-di-te'-butylsalicylic acid, 3.5-
Di(α-methylbenzyl)salicylic acid, 3-cyclohexyl-5-(2,2-dimethylbenzyl)salicylic acid,
In addition to 3-phenyl-5-(2,2-dimethylbenzyl)salicylic acid, hydroxyarylcarboxylic acid esters, salicylic acid alkyl esters, and the like can be mentioned.

■Metal salts of the above phenolic resins and aromatic carboxylic acids.

For example, it is used as a metal salt of calcium, magnesium, copper, iron, aluminum, etc., and zinc is particularly preferably used.

In order to manufacture the writing instrument of the present invention using such a color-forming dye and a color developer, the color-forming dye and the color developer are each dissolved in a solvent and encapsulated separately, and then A method is used in which the materials are kneaded together in a dispersion medium that is solid at room temperature and then formed into a rod-like writing instrument shape.

As the solvent for dissolving the color-forming dye and color developer, natural or synthetic solvents can be used alone or in combination. Specific examples of solvents include cottonseed oil, kerosene, paraffin,
Naphtenura, alkylated biphenyls, alkylated terphels, chlorinated paraffins, alkylated naphthalenes, etc. can be mentioned.

The chromogenic dye and developer dissolved in these solvents are
They are microencapsulated by being surrounded by a wall material such as melamine formaldehyde, gelatin, or gum arabic. The method for manufacturing this capsule is described in U.S. Patent No. 28004
57, a method using coacervation of a hydrophilic colloid sol described in British Patent No. 2800458, an interfacial polymerization method described in British Patent No. 867797, British Patent No. 950443, British Patent No. 989264, British Patent No. 109176, etc. be able to.

To form a writing instrument by kneading microcapsulated color-forming dyes and color developers in a dispersion medium that is solid at room temperature, oils and waxes that are solid at room temperature are placed in a double kettle and heated with steam to melt them. Then, microcapsules containing a color-forming dye and a color developer are added to the mixed mixture, and the mixture is thoroughly and uniformly mixed.Then, the mixture is poured into a rod-shaped writing instrument mold and gradually cooled.

The hardness of the manufactured writing instrument can be adjusted by changing the mixing ratio of wax and oil.

Oils, fats and waxes that can be used as dispersion media are not particularly limited as long as they are non-toxic.
Preferred waxes include paraffin wax, wood wax, beeswax, carnauba wax, hydrogenated oil, and stearin.

[Example 2] Crystal violet lactone was used as a color-forming dye.
After dissolving 0 parts in 80 parts of alkylnaphthalene, 100 parts of salicylic acid alkyl ester as a color developer were microencapsulated. For microencapsulation, an interfacial polymerization method was used and the wall material was melamine formaldehyde. 10 parts of color-forming microcapsules and 10 parts of color developer microcapsules were dispersed in 80 parts of stearic acid to obtain three white crayon-like writing instruments with a diameter of 1 am and a height of loc+a. When I drew several types of figures on paper, synthetic plastic plates, and glass plates using this writing instrument, I was able to draw them in blue, and my hands did not get dirty while holding this writing instrument.

Furthermore, I was able to enjoy the unexpectedness of being able to draw blue colors using this white crayon-like writing instrument.

[Effects of the Invention] As explained above, the writing instrument of the present invention is made by dispersing microcapsules containing a color-forming dye and microcapsules containing a color developer in a dispersion medium that is solid at room temperature, and molding them into the shape of a writing instrument. When used, the microcapsules are destroyed by the pressure and sliding of the pen, and the color-forming dye and developer are mixed together to form a color, making it useful as a writing instrument. Until the colorants are mixed with each other,
Since it is colorless, your hands will not get dirty while holding the writing instrument. Furthermore, even if the writing instrument is gripped tightly during use and the microcapsules on the side surface of the writing instrument are destroyed, the color-forming dye and color developer are not mixed, so the hands will not get dirty.

In addition, the material that can be used to draw with this writing instrument only needs to be one in which the dispersion medium is solidified by the pressure of the pen when using the writing instrument, and there is no need to choose a particular material, and you can draw on any material. It is convenient.

Furthermore, color-forming dyes and color developers are colorless until they are mixed with each other, and by appropriately combining them, it is possible to create various colors such as black and navy blue. Even the writing instrument can be white, which is the color of the dispersion medium itself, and it is possible to use a white writing instrument to draw different colors and enjoy the unexpectedness.

Applicant Teikoku Ink Manufacturing Co., Ltd.

Claims (1)

[Claims] A writing instrument characterized in that microcapsules containing a color-forming dye and microcapsules containing a color developer are dispersed in a dispersion medium that is solid at room temperature, and formed into the shape of a writing instrument.