JPS58111083A - Teaching aid clay - 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 clay for teaching materials which is intended to prevent cracking after drying as much as possible, to be able to bake it, and to withstand rapid heating and cooling.

Traditionally, natural clay has been replaced with rubber, cellulose, or synthetic resin substances! Clay for teaching materials mixed with 1IIf order or a dispersion medium such as a glue is often used. However, many of these clays for teaching materials are less likely to crack due to drying when used alone or in combination with a core material.
Since it is mainly composed of organic matter, it cannot be fired.
Also, it does not give a sense of weight.

This invention was made by paying attention to the current situation, and consists of glass powder of 10~90% and 90% of glass powder.
The main component is a mixture with ~10% by weight of inorganic powder such as waxite, clay, pottery stone, stone powder, alumina, etc.
The company provides clay for teaching materials, and the details are described in "lal".

The glass used in this invention is silicate glass, phosphate glass, borate glass, etc., which are usually widely used from the point of view of price.Among them, alkali silicate glass, soda lime glass, potash lime glass, lead glass, Barium glass, borosilicate glass, etc. are manufactured by hand and spinning, which is very convenient. Materials with a low melting point are easier to work with than materials with a high melting point such as quartz glass, and therefore glazes
Even if it is a medicine (glaze), scrap glass, recovered glass, etc., this invention will not be hindered in any way. Such glass may be a single type or a mixed type, and in any case, it is used in unformed form, but the grain size is fine so that it can be mixed more homogeneously with the inorganic powder described below. The more the particle size is, the more preferable it is, and there is no need to particularly limit the particle size, but it is practically sufficient to use 200 meshes as a guideline.

In addition, the inorganic powder in this invention includes waxite, clay,
Powders of natural rocks such as stone powder and pottery stone, or artificial inorganic oxides such as alumina, and these powders may be of a single type or a mixture of types, and the particle size is the same as that of the glass powder described above. In order to make the particles more homogeneous, the finer the particle size, the more preferable it is, and there is no need to particularly limit the particle size, but for practical purposes, 200 meshes may be used as a rough guideline. As for such inorganic powder, wax stone is most preferable, followed by clay, kogi, zarani, potter's stone, stone powder, alumina, etc.

At the same time, the glass powder and inorganic powder described above are mixed, and the mixing ratio of the rain sound is 10 to 90 tonne weight% (preferably 20 to 80 weight%) and 90 to 10 weight% (preferably 80 weight%), respectively. ~20@amount%). This is because glass powder acts as a binder after firing, that is, after melting, and a small amount of less than 10% is insufficient to fulfill this role, and a large amount exceeding 90% This is because if this happens, the effect of mixing the inorganic powder will not appear. On the other hand, if the mixing ratio of the inorganic powder is less than 10% by weight, the effect of preventing cracking or resistance to rapid heating and cooling is insufficient, and if the mixing ratio is more than 90% by weight, the binder effect due to glass binding is insufficient. It's low and undesirable.

Here, simply mixing such glass powder and inorganic powder has no E'lI properties or shape retention properties, so for example, if a sizing agent such as carboxymethyl cellulose (CMC), gum arabic, or starch glue is used, Add an appropriate amount of the aqueous solution and mix thoroughly. The concentration and grade of the aqueous sizing solution at this time vary depending on the type and mixing ratio of the raw material powder, and it is impossible to limit these in advance. It is necessary to make appropriate adjustments to exhibit shape retention. In addition, when kneading, pulp, straw, cotton, hemp, and other vegetable fibers, animal fibers and other animal fibers, or synthetic fibers and other organic fibers (these fibers are not necessarily long) There is no reason that it has to be made of fibers; it may be scraps of short fibers), which improves ductility during forming, and most of these fibers and sizing agents are burned away during firing. However, it is extremely effective in sufficiently preventing cracks before firing. However, if the amount of organic fiber is too large, the product after firing tends to become brittle, so it is preferably about 10% or less. It goes without saying that colorants such as Bengara and other inorganic pigments may be added as appropriate.

The mixture of glass powder and inorganic powder thus kneaded is fired at a temperature equal to or higher than the melting point of the glass powder.

At this time, instead of the glue and organic fibers that are burned out, the glass powder is melted and serves as a binder for the inorganic powder, which is a shape-retaining agent, to maintain the shape formed before firing.

121 The clay of this invention mentioned above does not crack even if it is pasted around a core material (for example, a metal product such as wire or a ceramic product such as a glass bottle) and then dried. Furthermore, even when it is fired, there are almost no abnormalities such as cracks, so it is an extremely inexpensive and excellent clay, and is especially suitable as a teaching material for children and students. Examples and comparative examples of the present invention are shown below. Note that all % represents ff11%.

[Example 1] Glass powder 6 with a melting point of 800°C and a particle size of 200 mesh
0%, 35% waxite powder with a particle size of 200 mesh, and 5 pieces of pulp fiber, mixed with an appropriate amount of starch paste, and kneaded. The core was pasted on the entire surface to a thickness of about 6 mm. At this time, the color of the material (hereinafter referred to as F clay) used was light gray. When this was air-dried at room temperature (12℃), the drying progressed ≦ The whiteness increased due to tangles, but
No abnormalities such as cracks were observed, and after 20 hours 3
Dry outdoors in the sun until the 0th hour, then dry naturally indoors at a room temperature of 10'C until the 50th hour.
After 0 hours, it was dried in the sun under strong wind, and it reached complete dryness after about 60 hours. However, during this time, no abnormalities such as cracks appeared, except for the color changing to a slightly grayish white. Then, over a period of about 5 hours, the temperature was gradually lowered to 9oo.
When the clay was fired at a temperature of 1.5'c, the clay was completely sintered without cracking, resulting in a light brown bisque with white edges. This bisque fired material did not develop any cracks even after cooling, and was extremely desirable. A summary of the above findings is summarized in the table below.

[Example 2] CMC glue ill aqueous solution was added to a mixture of 70% of the same glass powder and 30% of waxite powder used in Example 1, and kneaded.
The sample was pasted to a thickness of 6 am on the same glass bottle as in Example 1, and subjected to exactly the same treatment as the sample in Example 1.

The results are summarized in the table. Approximately 10 hours after the start of drying, thin cracks with a length of about 1.5σ appeared on the neck, and after about 20 hours, these cracks had grown to a length of about 3. However, new cracks with a length of approximately 1σ appeared in a part of the body, but these cracks hardly changed after 60 hours when it was completely dry. It was not a problem. Further, even after firing, the two cracks did not grow significantly, and almost no changes were observed.

Table [Example 3] Same glass powder 70% as used in Example 1 and frog's eye clay 3
A CMC aqueous solution was added to the 0% mixture and kneaded in the same manner as in Example 2, and the mixture was pasted to a thickness of 6 mm in a thermoplastic resin container of the same shape as the core glass bottle used in Example 1. Exactly the same treatment as the sample of Example 1 was performed. The results are summarized in the table, and one thin crack about 2 cm in length appeared on the body about 10 hours after the start of drying, and about 20 hours later, this crack had grown to about 3.5 cm. ,
No other abnormality was observed by the time of complete drying 60 hours later. Furthermore, after firing, in addition to the one crack mentioned above, two new small cracks with a length of 1 cIn or less were generated. The core material at this time melts during firing and deforms to the extent that it no longer retains its original shape, and there are many joints where it is judged that cracks have increased due to this deformation. It turns out that if there are cracks in the pipe, it won't cause any problems with the real flute guard.

Claims (1)

[Claims] A clay for teaching materials, characterized in that the main component thereof is a mixture of glass powder of 10 to 90% and inorganic powder such as waxite, clay, pottery stone, stone powder, alumina, etc. of 90 to 10%.