JP3435508B2 - Clay composition and method for producing shaped article made of metal or ceramic using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to jewelry, arts and crafts,
The present invention relates to a clay composition effective as a material for producing a shaped article such as a decorative article, and a method for producing a shaped article made of metal or ceramics using the clay composition.

[0002]

2. Description of the Related Art In recent years, as a method for producing metal shaped articles such as jewelry, arts and crafts, and ornaments, it is not convenient to use the conventional metal melting casting method because of the convenience that anyone can easily process and fire them. A method of processing and molding a metal clay composition and firing the same has become popular.

Such a metal clay composition is generally composed of a noble metal powder and an organic binder resin as a basic component to which an additive such as a surfactant or oil is added. As a specific example thereof, for example, "one in which a specific proportion of starch and a water-soluble cellulose resin (methyl cellulose) are used as an organic binder resin" (JP-A-8-269503, JP-A-9-227904, Japanese Unexamined Patent Publication (Kokai) No. 10-215506), "A cellulose-based water-soluble binder resin (ethyl cellulose) is used as an organic binder resin and a noble metal powder having a specific particle size" is known.

However, since the former clay composition is insufficiently viscous and brittle, it is difficult to perform fine molding such as thin stretching or bending, and it is possible to produce shaped products and small-lot products with high designability. On the other hand, the latter one has a problem that the amount of metal powder with respect to clay is relatively low and the shrinkage during sintering becomes large when trying to obtain a viscosity having an appropriate deformation characteristic. There was a point.

[0005]

DISCLOSURE OF THE INVENTION The present invention is not only excellent in fine moldability such as exhibiting sufficient viscosity and being thinly stretched or bent, but also has a shrinkage ratio of a worked molded body during sintering. It is an object of the present invention to provide a clay composition which is relatively small and can be advantageously manufactured into a molded product or a small lot product having a high design property, and an advantageous method for manufacturing a molded product made of metal or ceramics using the clay composition.

[0006]

Means for Solving the Problems As a result of diligent studies, the present inventors have found that a composition obtained by adding borax to a slurry prepared by mixing an aqueous polyvinyl alcohol solution with a metal powder or a ceramic powder is effective for the above problems. The present invention has been completed, that is, according to the present invention,
In addition, (1) polyvinyl alcohol aqueous solution, (2) metal powder
A powder consisting of powder or ceramic powder, and (3) borax.
A soil composition is provided. Second, (1) polyvinyl al
Aqueous coal solution, (2) metal powder or ceramic powder,
And (3) borax, a clay composition is formed into a desired shape.
Metal or shape characterized by being shaped and then dried and sintered
Provides a method of manufacturing shaped articles made of ceramics.
It

[0007]

The present invention will be described in more detail below.

(1) As the polyvinyl alcohol, any conventionally known polyvinyl alcohol can be used, but the molecular weight is 5,000 to 5,000.
It is desirable to use the one having a saponification degree of 50000 or more at 500000. The concentration of the aqueous solution is 0.5 to 30% by weight, preferably 1 to 20% by weight. If the concentration of the aqueous solution exceeds 30 wt%, the viscosity becomes too high, and 0.5
If it is less than%, a sufficient viscosity cannot be obtained, which is not preferable. Since the viscosity of the aqueous solution changes depending on the relationship between the concentration and the degree of polymerization of the polyvinyl alcohol used, it is desirable to prepare these appropriately.

Examples of the metal powder (2) include noble metal powders of gold, platinum, palladium, silver and the like, alloy powders thereof, cemented carbide powder, stainless steel, nickel base alloy steel, tool steel,
In addition to high-speed steel powder, metal powder that does not change rapidly even when contacted with water is included. Examples of the ceramic powder (2) include ceramic powders such as alumina, zirconia and PZT. There is no special limitation on the particle size of metal powder and ceramic powder, and the average particle size is 200μ.
A powder of m to submicron, preferably about 50 μm is used.

There is no particular restriction on the use ratio of the polyvinyl alcohol of (1) and the metal powder or ceramic powder of (2), but the polyvinyl alcohol solution of (1) by volume ratio: the metal powder or ceramics of (2). Powder = 1: 5
4: 1 preferably 1: 3 to 3: 1.

The borax of (3) imparts an appropriate viscosity to the clay composition of the polyvinyl alcohol of (1) and the metal powder or ceramic powder of (2), and can be stretched or bent thinly. It is used to improve fine workability and to relatively reduce the shrinkage rate of the work-formed body at the time of sintering, and to provide advantageous productivity of shaped articles and small lot articles with high designability. The amount used may be appropriately set so that the above-mentioned actions and functions are expressed, but usually,
To 100 parts by weight of the slurry of polyvinyl alcohol (1) and metal powder or ceramic powder (2),
0.002-0.1 parts by weight, preferably 0.01-0.0
2 parts by weight is preferable.

The clay composition of the present invention essentially comprises the above-mentioned components (1) to (3). If necessary, conventional components such as a surfactant, which are added to this type of clay composition, It may also contain a plasticizer, fats and oils and the like.

In order to prepare the clay composition of the present invention, for example, a mixture of a predetermined amount of the aqueous solution of polyvinyl alcohol (1) and the metal powder or ceramic powder (2) is kneaded and defoamed to obtain a slurry (a muddy state). ), And then an appropriate amount of (3) borax is added, and if necessary, other conventional components may be added.

The clay composition of the present invention exhibits appropriate viscous properties and is excellent in fine workability and formability such as being finely stretched or bent, and shrinkage of the workability product during sintering. The rate can be made relatively small. Therefore, after being molded or dried while being molded, it is necessary to have good fine workability not only for molded products of ordinary thickness but also thin molded products and thin molded products. Highly shaped products and small lot products can be easily molded into any shape, and by sintering under the same temperature conditions and atmosphere as the materials used, the shape shrinks similarly to the shape of the molded body, It is possible to obtain a shaped article of. Further, in particular, a molded product having a thin shape or a thin molded product produced by the clay composition according to the present invention regains plasticity by applying a small amount of humidity after drying, so that it is easily desired. It is possible to modify the shape.

[0015]

EXAMPLES The present invention will now be described in more detail with reference to examples.

Example 1 As a metal powder, SUS304L having an average particle size of 6.3 μm
Stainless steel powder (Pacific Metals Co., Ltd. PF10) was used. A 10% aqueous solution of polyvinyl alcohol (generally used as a washing paste) and this stainless powder were mixed at a volume ratio of 11: 9 to form a slurry. Borax in this slurry
A 1.2 wt% aqueous solution was added at a ratio of 2 g to 100 g of the slurry and mixed to obtain a clay composition for stainless steel modeling. This clay composition had a moderate stickiness but had a small stickiness. Then, this clay composition is molded and dried, and then the hydrogen atmosphere is heated at a temperature of 1350 ° C. for 2 hours.
A stainless steel-less shaped product was obtained by sintering for a time. In this shaped product, a thin portion having a sheet shape of 50 μm was also accurately formed, and the shrinkage rate after sintering was also small.

Comparative Example 1 A clay composition was obtained in the same manner as in Example 1 except that borax was omitted. This product had extremely low stickiness and was inferior in moldability. Further, since the thin portion cannot be accurately formed and processed, it was not possible to obtain a thin shaped article as in Example 1.

Example 2 As the metal powder, silver powder having an average particle diameter of 40 μm (Fukuda foil powder Ag-E-200) was used. 10% of polyvinyl alcohol
An aqueous solution (generally used as a laundering paste) and this silver powder were mixed at a volume ratio of 8: 7 to form a slurry. A 1.2 wt% aqueous solution of borax was added to this slurry to obtain 100 g of the slurry.
The mixture was added and mixed at a ratio of 2 g to obtain a clay composition for silver modeling. Next, this clay composition was molded, dried, and then sintered at 850 ° C. for 2 hours in a hydrogen atmosphere to obtain a stainless steel shaped product. In this shaped product, a thin portion of 100 μm was accurately formed, and the shrinkage rate after sintering was small.

Example 3 Alumina powder (Tymicron) having an average particle diameter of 0.2 μm was used as the alumina powder. 10% of polyvinyl alcohol
Aqueous solution (generally used as laundry paste) and this alumina powder were mixed at a volume ratio of 1: to form a slurry.
A 1.2 wt% aqueous solution of borax was added to this slurry to form a slurry 10.
An alumina modeling clay composition was obtained by adding and mixing 8 g with respect to 0 g. Next, this clay composition was molded, dried, and then sintered at a temperature of 1300 ° C. for 2 hours in a hydrogen atmosphere to obtain a stainless steel shaped product.
In this shaped product, a thin portion having a thickness of 20 μm was accurately formed, and the shrinkage rate after sintering was small.

[0020]

EFFECTS OF THE INVENTION The clay composition of the present invention exhibits appropriate toughness and is excellent in fine workability such as being finely stretched or bent, and a work-formed product at the time of sintering. It is possible to make the shrinkage ratio of the resin relatively small. Therefore, after being molded or dried while being molded, it is necessary to have a fine workability such as a thin molded body as well as a thin molded body of ordinary thickness. Highly shaped products and small lot products can be easily molded into any shape, and by sintering under the same temperature conditions and atmosphere as the materials used, the shape shrinks similarly to the shape of the molded body, It is possible to obtain a shaped article of. Further, in particular, a molded product having a thin shape or a thin molded product produced by the clay composition according to the present invention regains plasticity by applying a small amount of humidity after drying, so that it is easily desired. It is possible to modify the shape.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B22F 3 / 02,3 / 10 C04B 33/13

Claims (2)

(57) [Claims] 1. A polyvinyl alcohol aqueous solution ( 1),
(2) Metal powder or ceramic powder, and (3) Boron
Metal or ceramic characterized by containing sand
A clay composition for the production of a shaped article composed of a diamond. 2. A polyvinyl alcohol aqueous solution ( 1),
(2) Metal powder or ceramic powder, and (3) Boron
A clay composition containing sand is shaped into a desired shape, and
Metal or ceramic characterized by being dried and sintered by
A method of manufacturing a molded article made of cus.