JP2851070B2 - Manufacturing method of clay for craft - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for producing a working clay based on a starchy material.

[Conventional technology]

Conventional clays made from starch-based materials have been studied for their high safety, low viscosity change due to temperature, no oil leaching, no odor, and easy availability of materials. In recent years, it has been widely used in place of play clay (for example, bentonite, wood wax or paraffin mixed with oil and kneaded, or plastic or rubber based clay). In addition, the clay for crafting using such a starchy material as a main raw material is excellent not only in learning and play but also in dolls and flowers because of its excellent plasticity and coloring properties in addition to the above-mentioned properties. Recently, it has been widely used as a molding material for producing various crafts.

And, the clay for working using such a starchy material as a main material (hereinafter referred to as “starchy working clay”) is usually prepared by adding a synthetic resin emulsion such as a polyvinyl acetate emulsion, a salting-out astringent, Filler, wet lubricant, borax,
It is manufactured by adding and kneading other compounding agents. Such a conventional starchy clay for work has the above-mentioned good properties, but tends to turn brown in a short period of time especially when wheat flour is used as a main raw material. The browning has made the product extremely poor in quality and color tone, especially when the clay is colored, making it difficult to produce a workpiece having a desired color. In addition, when raw starch is used as a starchy material, starch is gelatinized due to a rise in temperature during stirring or the like during the production of clay, and such gelatinization of starch cannot form good clay. It was necessary to control and regulate the temperature so as to keep the temperature at about 60 ° C. or less at all times.

[Content of the invention]

The purpose of the present inventors is to obtain a starchy working clay that does not require strict temperature control during the production of the clay, and that can maintain a beautiful color tone without discoloring for a long time after the product is completed. I have been studying. as a result,
When a gel is prepared in advance from one or both of boric acid and borax and polyvinyl alcohol, and the gel is mixed with a clay base for working based on a starchy material to produce clay, the above-mentioned purpose is obtained. Have been achieved, and the present invention has been completed.

Accordingly, the present invention provides a method for producing boric acid and / or borax,
A gel for clay is prepared in advance by mixing a polyvinyl alcohol with water in the presence of water, and the gel is mixed with a clay base for clay mainly composed of a starchy material. It is a manufacturing method of.

In the present invention, the above-mentioned gel-like substance is usually used in an amount of about 1 part by weight of boric acid and / or borax (hereinafter referred to as “boric acid / borax”) to about 1 part by weight of polyvinyl alcohol. ~ 20 parts and water about 1 ~
It can be manufactured by mixing at a ratio of 60 parts. Above all, if boric acid / borax: polyvinyl alcohol: water is mixed at a weight ratio of about 1: 2 to 15: 1 to 60, it is easy to mix and disperse it into a clay base for working made of a starchy material. In addition, it is possible to obtain a gel-like material that improves the quality (discoloration resistance, tackiness, touch, moldability, viscoelasticity, etc.) of the produced clay for work.

In this case, any polyvinyl alcohol that can be dissolved or swelled in water or warm water can be used, and modified polyvinyl alcohol can also be used.

The mixing of boric acid / borax, polyvinyl alcohol and water can be performed by any method.
For example, by mixing the three simultaneously, or by adding boric acid /
One of borax and polyvinyl alcohol is mixed or dissolved in water in advance and the rest is added thereto, or each of boric acid / borax and polyvinyl alcohol is separately mixed or dissolved in water and both are mixed. Can be performed. Here, the mixing of the three is usually performed at about 30 to 90 ° C. In particular, forming an aqueous solution in advance from polyvinyl alcohol and water, and mixing and stirring this with a boric acid / borax aqueous solution formed in advance at about 50 to 80 ° C. can quickly produce a uniform gel-like substance. It is preferable in forming. In this case, the concentration of the aqueous polyvinyl alcohol solution is preferably about 5 to 30% by weight, and the concentration of the boric acid / borax aqueous solution is preferably about 2 to 15% by weight for gel formation.

The gel prepared in this way can be used immediately for the production of clay for work, or it can be stored in containers or other packaging materials and used at any time for the production of clay for work. You may. If you want to save, usually about 10 ~
Cold storage at a temperature of 25 ° C is desirable from the viewpoint of suitability for clay.

The gel prepared by mixing the boric acid / borax, polyvinyl alcohol and water is non-greasy, stretches loosely and stretches like chewing gum,
It is a transparent jelly-like product that cuts easily when pulled strongly.

As described above, in the present invention, boric acid and / or borax can be used for the preparation of a gel-like material, but among them, it is particularly preferable to use boric acid to prepare the gel-like material. The reason is that when borax is used, a slightly sticky gel-like substance with a little stickiness is produced, whereas when boric acid is used, there is no stickiness and the elongation is very good. A gel-like material that is easy to process is obtained, and when this is mixed with a clay base for working using a starchy material as a main raw material, it can be easily broken by hand into a desired size. This is because clay for business can be manufactured.

In addition, alcohol or the like may be added for the purpose of improving the extensibility or the like, if necessary, during the production of the gel-like material.

Next, the gel material prepared as described above is mixed with a clay base for working mainly composed of a starchy material, and kneaded to produce a working clay.

In this case, the starchy material includes flour such as wheat flour, rice flour, buckwheat flour, rye flour; corn starch, potato starch,
Products consisting of starches such as wheat starch, sweet potato starch and cassava starch; and flours such as bread can be used. The starchy material may be used alone or in combination of two or more. And among the above starchy materials,
Potato starch, corn starch, wheat flour and rice flour are preferred in terms of extensibility and processability. Further, as the starchy material, both non-gelatinized and non-gelatinized ones can be used, and further, both gelatinized and non-gelatinized ones may be used in combination. When both pregelatinized and non-pregelatinized ones are used together, a work clay which has quick drying properties and is suitable as a craft clay is obtained.

The above-mentioned “working clay base material based on a starchy material” (hereinafter referred to as “starch working clay base material”) for producing a working clay by mixing with a gel-like material includes ( 1)
It is preferable to use either the starchy material itself or (2) a combination of the starchy material and a synthetic resin.

In the case of using a starchy material itself as a starchy clay base material to produce a working clay, usually a starchy material 10
It is preferable to mix and knead about 1 to 100 parts, particularly about 2 to 10 parts, of the gel-like substance with respect to 0 parts. The mixing and kneading of the two can be usually performed at a temperature of about 15 to 60 ° C, and it is preferable to mix and knead at about 30 to 40 ° C from the viewpoint of preventing deterioration of the starchy material. As a result of the mixing and kneading of the above-mentioned gelled material and the starch material, no discoloration (browning) occurs over a long period of time, undesired gelatinization of the starch does not occur during kneading, and the tackiness, touch, moldability, viscosity, etc. An excellent work clay having good properties such as elasticity is produced.

In the case of using a combination of a starchy material and a synthetic resin as a starchy clay base material, a synthetic resin such as polyvinyl acetate, polyvinyl chloride, or poly (meth) acrylate may be used in the form of an emulsion. It is preferred that such a synthetic resin emulsion be used in combination with a starchy material together with a small amount of polyvinyl alcohol powder prepared separately for the production of the above-mentioned gel. As the synthetic resin emulsion, the synthetic resin solid content concentration in the emulsion is about 1 to 1.
It is preferable to use 35% by weight, and among the synthetic resin emulsions, a polyvinyl acetate emulsion is particularly preferable. In this case, about 10 to 50 parts of the synthetic resin and about 0.1 part of the polyvinyl alcohol powder were used for 100 parts of the gel.
It is advisable to mix at a rate of ~ 10 parts.

Mixing and kneading of the gel, starchy material, synthetic resin emulsion and polyvinyl alcohol powder are carried out at a temperature of usually about 15 to 60 ° C, preferably about 30 to 40 ° C, as described above.

As a result of such mixing and kneading, there is also no discoloration (browning) for a long period of time, and undesired pregelatinization of the starch does not occur during kneading, and it has good properties in tackiness, touch, viscoelasticity, etc. Craft clays with excellent shrinkage properties are produced.

Further, in the present invention, when mixing the gel material and a starchy clay base for working to produce a working clay, in addition to the above components, aluminum sulfate, potassium sulfate, sodium sulfate, sodium chloride, Low-toxicity salting-out astringents such as alum; glycerin, propylene glycol, paraffin,
Plasticizers (wet lubricants) such as sorbitol, vegetable oil, mineral oil, lecithin, glycerin fatty acid ester, sucrose fatty acid ester, propylene glycol, dibutyl phthalate; fillers such as talc, clay, diatomaceous earth, calcined clay, silica, alumina; Sorbitan fatty acid esters,
Emulsifiers such as carboxymethylcellulose and propylene glycol fatty acid esters; coloring agents such as food coloring pigments; antioxidants and the like can be added as required, whereby the properties of the working clay can be further improved. .
In particular, when the boric acid / borax gel material is mixed and kneaded with a starchy working clay base material composed of a starchy material, a synthetic resin emulsion and polyvinyl alcohol powder to produce a working clay, a salting-out astringent, When an emulsifier, a plasticizer, and the like are blended, a work clay having more excellent properties such as discoloration resistance, tackiness, texture, moldability, and viscoelasticity is produced.

〔The invention's effect〕

In the present invention, a gel material is prepared in advance from boric acid and / or borax and polyvinyl alcohol, and this gel material is mixed with a clay material for working mainly composed of a starchy material to produce a working clay. By doing so, it is superior in tackiness, touch, moldability and viscoelasticity, and has a color tone free from discoloration (browning) over a long period of time, as compared with a case where a clay for manufacturing is produced without previously preparing the gel-like material. Can be manufactured, and as a result, it is possible to produce a desired color of a work without discoloration, and the discoloration resistance is based on the use of wheat flour as the main raw material of starch. This is particularly noticeable in the case where it is performed.

Further, in the present invention, a good viscosity can be produced without strictly controlling and adjusting the temperature so that the temperature during the production of the clay is always kept at 60 ° C. or lower.

Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 and Comparative Example 1 14 g of polyvinyl alcohol (hereinafter referred to as “PVA”) (degree of polymerization 500 to 2500) and 43 g of water were mixed, and the mixture was mixed for about 7 hours.
The mixture was stirred at a temperature of 5 to 80 ° C. for 30 minutes to prepare an aqueous PVA solution.

Separately, 4.5 g of boric acid is dissolved in 38.5 g of boiling water at about 75 ° C. to prepare a boric acid aqueous solution, and the boric acid aqueous solution is added to the PVA aqueous solution while maintaining the liquid temperature at about 70 to 80 ° C., and stirred for 5 minutes. Then, a boric acid gel was prepared.

 48g corn starch, 2.3g pregelatinized flour, PVA powder (polymerized
0.3 g of aluminum sulfate (concentration of salting out)
Agent) was mixed at room temperature to prepare a mixed powder. This mix
Enter the mixed powder into a kneader-type mixing / kneading machine (manufactured by Inoue Seisakusho)
And a polyvinyl acetate aqueous solution (polyvinyl acetate content
2.8% by weight) 35g, span (Emulsifier) 0.5 g, propylene
About 30-40 by adding 3 g of glycol (plasticizer) and 7.8 g of water
Stir and mix at a temperature of 25 ° C for 25 minutes, then add
Add 2.8 g of the prepared gel and knead it at room temperature for 25 minutes to work
Production clay (A-1) was produced (Example 1).

Separately, without preparing the gel-like material in advance, put the same kind and the same amount of components as used in Example 1 at once into the same mixing and kneading machine as above, and knead at about 30 to 40 ° C for 25 minutes. Thus, a clay for work (A-2) was produced (Comparative Example 1).

Various properties of the clays for work A-1 and A-2 produced above were examined.

First, regarding the measurement of the discoloration property, the number of days until the discoloration was examined by leaving the manufactured clays A-1 and A-2 at room temperature.

In addition, the adhesiveness, tactile sensation, moldability and viscoelasticity were evaluated by five panelists according to the following criteria, and the average values were rounded off.

Criteria for tackiness 3 ‥‥ No work clay adheres to hands and crafted bars.

2) Clay for work slightly adheres to hand and wand.

1 粘土 Clay adheres to hand and wand, making it impossible to work.

Tactile criterion 4 ‥‥ Fine and soft touch of craft clay.

3) The texture of the clay for crafting is slightly rough and has a slightly hard texture.

2) The texture of the clay for the work is fine and sticky.

1) The texture of the clay for work is rough and hard.

Judgment Criteria for Formability 4 ‥‥ Very good unity when several small pieces of clay for work are collected and kneaded.

3) When several small pieces of clay for work are collected and kneaded, the unity is good, but it is soft.

2) When several small pieces of clay for work are collected and kneaded, the unity is somewhat poor and too soft.

1) It is hard to get together when you collect and knead a few small pieces of clay for crafting.

Measurement of viscoelasticity 3. When about 50g of clay for work is rolled and then stretched with both hands, it cuts after stretching moderately.

2 ‥‥ About 50g of clay is rolled up and stretched with both hands.

1 ‥‥ About 50g of clay for work is rolled and then stretched out with both hands.

 The results obtained above are shown in Table 1 below.

[Table 1] Example A-1 A-2 Discoloration No discoloration even after 2 months Browning after 2 months Adhesion 31 Tactile feel 4 2 Moldability 41 Viscoelasticity 31 From the results in Table 1 above, polyvinyl alcohol and boric acid In the first embodiment of the present invention in which a gel-like material is prepared in advance and mixed with a starchy material to produce a working clay, all the components are mixed in advance without preparing a gel-like material. Compared with Comparative Example 1 in which a working clay is produced, the obtained working clay has very little browning over time,
It can be seen that the adhesiveness, touch, moldability and viscoelasticity are also excellent.

Example 2 and Comparative Example 2 In the same manner as in Example 1, a gel was prepared in advance from boric acid and polyvinyl alcohol.

3 g of this boric acid gel and 100 g of corn starch were used in Example 1.
Into the same mixing and kneading machine used at about 30-40 ° C
Was mixed and kneaded for 25 minutes to produce a working clay (B-1) (Example 2).

On the other hand, PVA, boric acid, corn starch and water were simultaneously and directly introduced into the above-mentioned mixing and kneading machine in the same amounts as in Example 2 and mixed and kneaded at about 30 to 40 ° C. for 25 minutes to obtain a clay for work (B).
-2) (Comparative Example 2).

The quality of the working clays B-1 and B-2 produced above was examined in the same manner as in Example 1 and Comparative Example 1.

 The results are shown in Table 2 below.

[Table 2] Example B-1 B-2 Discoloration No discoloration even after 2 months Browning after 2 months Adhesion 31 Touch 31 Moldability 41 Viscoelasticity 31 Example 3 and Comparative Example 3 Example 1 and Comparative Example 3 Similarly, a gel was prepared in advance from boric acid and polyvinyl alcohol.

34 g of flour, 3.5 g of pregelatinized potato starch, and 0.2 g of PVA powder (degree of polymerization: about 500 to 2500) were mixed at room temperature to prepare a mixed powder. This mixed powder was placed in the same mixing and kneading machine as used in Example 1, and 30.3 g of an aqueous polyvinyl acetate solution (polyvinyl acetate content: 28% by weight) was added thereto. Then, 32 g of the gel material prepared above was added thereto, and the mixture was kneaded at room temperature for 25 minutes to produce a working clay (C-1) (Example 3).

Separately, without preparing the gel-like material in advance, put the same kind and the same amount of components as used in Example 3 at once into the same mixing / kneading machine as above, and knead at about 30 to 40 ° C for 25 minutes. Thus, a clay for work (C-2) was produced (Comparative Example 3).

The quality of the working clays C-1 and C-2 produced above was examined in the same manner as in Example 1 and Comparative Example 1.

 The results are shown in Table 3 below.

[Table 3] Example C-1 C-2 Discoloration No discoloration even after 2 months Browning after 2 months Adhesion 31 Touch feeling 22 Moldability 42 Viscoelasticity 31

Continuation of the front page (56) References JP-A-62-87457 (JP, A) JP-B-62-27022 (JP, B2) JP-B-56-17206 (JP, B2) (58) Fields investigated (Int .Cl. ⁶ , DB name) C04B 33/13

Claims (1)

(57) [Claims] 1. A gel-like material is prepared in advance by mixing boric acid and / or borax and polyvinyl alcohol in the presence of water, and the gel-like material is used as a base material for a clay based on a starchy material. A method for producing a clay for working, characterized by mixing materials.