JPH07138066A - Clay for pottery - Google Patents

Abstract

PURPOSE:To obtain white clay for pottery improved in fluidity and plasticity by incorporating specific bone china body with a polyglycol-based plasticizer, polyethylene glycol-or polyacrylic emulsion-based binder, binder modifier and additive(s). CONSTITUTION:Firstly, bone china body is prepared by wet pulverization of a composition comprising (A) 30-50wt.% of bone ash consisting mainly of 4Ca3(PO4)2.CaCO3, (B) 15-35wt.% of kaolin, (C) 15-20wt.% of feldspar and (D) 3-15wt.% of silica rock, followed by drying. Second, 100 pts.wt. of this body is incorporated with (1) 1-5 pts.wt. of a polyglycol-based plasticizer, (2) 2-10 pts.wt. of a polyethylene glycol-or polyacrylic emulsion-based binder, (3) 2-10 pts.wt. of a binder modifier, (4) 0.6-3.5 pts.wt. of additive(s) such as anti-drying agent and/or preservative, etc., and (5) water to produce a kneaded product. This product is molded and air-dried, and then baked at 1200+ or -50 deg.C, thus obtaining the objective white, light-transmitting clay for pottery.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the technical field of clay for work, which is mainly used for handicrafts.

[0002]

2. Description of the Related Art As conventional clay for pottery, siliceous material for skeleton formation, kaolinic material for imparting plasticity and fluidity, and feldspar for glassy formation are wet-milled and dehydrated into kneaded clay. Rokuro molding, cast molding and drying,
It has been used for glazing and firing. In particular, when it is used for handicrafts, in order to give it plasticity, it has been prepared mainly by adding a small amount of an organic substance to these, mainly kibushi clay, frog eye clay, sericite clay and the like.

[0003]

However, in the case of clay having a conventional composition, particularly when Kikibushi clay, frog eye clay, sericite clay and the like are used as plasticizers, impurities such as iron oxide and titanium oxide are contained. Therefore, the color tone is dull when fired, and it is difficult to obtain a white light-transmissive one.

When an organic substance is used in place of the colored inorganic plastic clay, bubbles tend to remain during heating and firing. Therefore, when small bubbles are contained, it is difficult to obtain a dense porcelain substance, and addition is required. The polymer substance thus produced may remain as ash during heating and firing, and has a drawback that it vaporizes during firing and produces a bad odor.

Many kinds of bone china are used, but when it contains a large amount of siliceous material, it becomes brittle, and when it contains a large amount of alumina material, it becomes dense but the firing temperature becomes high, resulting in high energy consumption. However, the life of the firing furnace was shortened, resulting in an increase in production cost.

The object of the present invention is to provide a clay which is whiter than commercially available white cloud pottery, white pottery, porcelain or ordinary bone china products, and has suitable flowability and plasticity during molding.

[0007]

In the present invention, as a plasticizer, mixing of knotoshi clay, frog eye clay or sericite clay, which causes coloring of the product, is stopped, and a polyethylene glycol type of nonionic surfactant is used. Alternatively, by blending a water-soluble cellulose derivative, an acrylic emulsion, an alginate, or the like, sufficient fluidity and plasticity for molding can be imparted, and at the same time, deformation and cracking during drying do not occur.

In the present invention, most of the binder is vaporized at a relatively low temperature of about 400 ° C., and the binder is baked at 1200 ± 50 ° C. while leaving almost no bubbles, thereby forming a strong bond between the molecules and increasing the hardness. The second characteristic is to obtain a white and translucent fired product.

In the present invention, a mixture of silica stone 90 and lithium carbonate 10 was previously calcined at 1000 ° C. in a bone china, and wet-milled to give an external split 5-1.
By mixing 0 parts, the firing temperature is 50% compared to the conventional example.
The third feature is that the temperature and the economic efficiency of the firing furnace can be improved by lowering the temperature by 100 ° C to 100 ° C.

[0010]

Example: Bone ash 40%, Kaolin 35%, Feldspar 15%,
A mixture prepared by adding 5 parts of the above calcined product to 100 parts of bone china consisting of 10% silica stone was finely pulverized with a ball mill and then dehydrated to obtain a kneaded clay.
Bone china kneaded clay dry powder 100 sieved to mesh
6 parts of polyvinyl alcohol, 3 parts of polyglycol derivative, 6 parts of crushed pulp as a binder modifier
Parts, 1.7 parts of glycerin as a drying inhibitor and 0.3 parts of a triazine compound as a preservative were mixed and kneaded with water using a kneader. In this case, the amount of water added was about 30% based on the total amount of the blended samples.

The kneaded material obtained was passed through a vacuum clay kneader to obtain clay for work. This clay has good fluidity, moldability, and shape retention. After an object molded with this clay is naturally dried, organic substances are vaporized at about 400 ° C in a firing furnace and burned at 1000 ° C or less. Sake, and then at 1150 ℃ to make a squeeze base, and grit frit glaze on it 1
By glazing at 080 ° C., it was possible to obtain a white porcelain having good transparency and high hardness and a theoretical density of 99% or more.

[0012]

As described above, according to the present invention, it is possible to mix a synthetic or natural organic substance without using the knotobushi clay, the frog-eyed clay or the sericite clay conventionally used as a plasticizer. Proper fluidity when kneaded with water,
It is characterized in that it produces a clay having elasticity and obtains a white and translucent fired product having high hardness by firing without being deformed or cracked after drying.

The clay according to the invention is a calcined product (90% silica stone,
By blending 10% or less of lithium carbonate 10%), the firing temperature can be 1200 ° C. or less, and a hard porcelain can be fired.

Further, in the present invention, by heating in a stepwise manner during firing, the mixed organic substance is vaporized and burned to give a tight bond between the molecules to obtain a robust and translucent fired product. have.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Minoru Ohashi, No. 30 of the floating surface of Iseta-cho, Uji City, Kyoto Prefecture 5 (72) Inventor Shigeko Kubo 38, Harajoji Temple, Sakyo-ku, Kyoto City

Claims (1)

[Claims] 1. Bone ash (main component 4Ca ₃ (PO ₄ ) ₂ C)
aCO ₃ ) 30 to 50%, kaolin 15 to 35%, feldspar 15 to 20%, and silica 3 to 15% to 100 parts of bone china kneaded clay, polyglycol plasticizer 1 to
5 parts, polyethylene glycol-based or polyacrylic emulsion-based binder 2-10 parts, binder modifier 2
10 to 10 parts and 0.6 to 3.5 parts of additives, 12
A clay for ceramics, which is white and translucent when fired at 00 ± 50 ° C.