JPS588709B2 - Special pencil that can be used on blackboards, paper blackboards, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a pencil that can draw finely written characters, strokes, lines, etc. on a paper blackboard, blackboard, paper, etc., and that can erase the drawn characters, strokes, lines, etc. very easily. It is related to.

Conventionally, chalk has been used for blackboards and paper blackboards with resin-treated paper surfaces, pastel, crepas, creon, and pencils have been used for paper, and chalk pencils have been used for cloth.

Chalk drawings can be easily erased with a blackboard wipe, but in this case, the chalk powder scatters and stains your hands and the substrate, and it is also difficult to draw fine letters or figures that require precision. Pastels, crepas, and creon are too brittle to form cores, so not only can you not draw fine letters or figures, but you can't erase them.

Colored pencils and Chaco pencils also have wax mixed into their composition, so they cannot be erased.
Even when no wax is mixed in, the core is too hard and when used on a paper blackboard with a resin-treated surface, it is difficult to draw letters and figures unless strong pressure is applied, making it difficult to erase the drawings. There is a drawback.

The present invention was made to solve these drawbacks and difficulties, and it is possible to easily draw and draw fine details even on a paper blackboard whose surface has been treated with resin, and to erase them easily with a blackboard wipe or the like. I am trying to provide a pencil that can be used.

In order to easily draw letters, figures, etc. on a paper blackboard whose surface has been treated with resin, the inventor of the present invention has determined that the smoothness of the lead is affected by the smoothness of the lead, and if the smoothness is thick, it is difficult to draw, so it is necessary to reduce the smoothness. In addition, in order to make it easier to erase drawn letters, figures, etc., we considered that wax should not be used as a component of the wick and that the wick should not be hard.As a result of intensive research, we found that barium sulfate Carboxy methyl cellulose (hereinafter abbreviated as C, MC) is used as a pigment, which is mainly composed of carboxy methyl cellulose (hereinafter abbreviated as C, MC), and inorganic or organic pigments or mixtures thereof as necessary.

) It has been found that an excellent pencil can be obtained when bentonite and talc are added, kneaded with water, molded and dried, and the present invention has been completed.

The barium sulfate used in the present invention is titanium oxide,
It has a smaller impica than white pigments such as zinc oxide, and has the property of easily absorbing moisture.

This characteristic is utilized, and the production work is easy, and since the impeller is small, it is easy to erase.

If necessary, barium sulfate may be mixed with an inorganic pigment such as precipitated calcium carbonate or aluminum oxide, an organic pigment, or a mixture thereof.

C. M. C does not use wax and acts to bind n-lithium sulfate, and when this is used, hardness is not excessively increased and mold retention is good.

Bentonite is used to increase solid strength, and talc is used to improve smoothness.

Therefore, due to the combined effect of these mixtures, it is possible to easily draw fine details not only on ordinary blackboards but also on paper blackboards with resin-treated surfaces, and the lead of the pencil can be easily erased with an eraser, blackboard wipe, etc. It was successfully obtained.

The barium sulfate pigment has particles of about 300 mesh, and the bentonite and talc have particles of about 250 mesh. M. C and water are added and kneaded using a three-roll kneader or the like, formed into a core shape, and dried.

C. for pigments. M. The mixing ratio of C and bentonite varies somewhat depending on the type of pigment, but C, M, CO. 0.8 to 0.13 parts by weight, and 0.8 to 1.8 parts by weight of bentonite or talc.

It is desirable to dry the core at a temperature of about 40 to 60°C.

If the temperature is too high, the core will curve, making straight machining difficult, and C, M, and C will harden too much, making the core too hard.

It is preferable that the molding be performed by a vacuum molding method.

Example: Mix the following composition without water thoroughly using a mixer until it becomes homogeneous, then add water and knead it using a three-roll kneader, and use a vacuum forming machine to make 3.8 to 4.5 nL. After processing the core into a core of the same diameter, dry the core at 50°C, cover the core with core-coated wood, wood tape, etc., and form it into a pencil, or use the core with a mechanical pencil. Hold it with a core holding material.

(2) Based on the above white core blending ratio, organic pigments of yellow, blue, red, etc. are further added in an amount of 0.01 to 0. A colored core corresponding to the color of the organic pigment can be obtained by mixing the amount of O3l.

Organic pigments are not specified.

The obtained pencil can very easily draw fine letters and figures even on a paper blackboard, and the drawings on paper can be erased very easily.

Claims (1)

[Scope of Claims] 1. A blackboard consisting of a core made of a pigment mainly composed of barium sulfate, mixed with carboxymethylcellulose, bentonite, and talc, mixed with water, molded and dried,
A special pencil that can be used on paper blackboards, etc. 2. The special pencil according to claim 1, wherein the pigment mainly composed of barium sulfate is a mixture of barium sulfate and an inorganic or organic pigment or a mixed pigment thereof.