JPH05263103A - Noble-metal plastic composition - Google Patents

Abstract

PURPOSE:To obtain a noble-metal plastic composition having sufficient self- stickiness and elongation and low stickiness with other substances, excellent in formability and easy to handle. CONSTITUTION:This composition consists of 82-96wt.% of a powder selected from a noble-metal powder and/or noble-metal alloy powder or a mixture of a noble metal powder or a noble-metal alloy powder and a metal powder or a metallic alloy powder, a thermoplastic resin, a plasticizer and the balance inevitable inpurities. The binder contains 2-10wt.% of the thermoplastic resin, 2-10wt.% of the plasticizer and the balance inevitable impurities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noble metal plastic composition suitable for use as a material for molding arts and crafts.

[0002]

2. Description of the Related Art Conventionally, a noble metal such as Au, Ag, Pt, or Pd or an alloy material containing these metals as a main component is used as a molding material for arts and crafts, etc. to form an article having a complicated shape. However, the main processing methods are casting and rolling.

However, such a processing method not only requires large-scale equipment, but also has a problem that, depending on the metal, for example, Pt has a high melting point, which makes molding by casting difficult. It is left.

Therefore, the applicant of the present application previously proposed a clay-like noble metal excellent in moldability by mixing the above-mentioned noble metal powder or noble metal alloy powder with a water-soluble binder. (JP-A-4-26707)

[0005]

The above-mentioned precious metal clay is a very useful molding material in that it is excellent in moldability and can easily form various complicated shapes. The following characteristics have been demanded.

That is, the plasticity is such that it can be processed at a temperature close to the body temperature of the operator, and when individual clays are kneaded, they are easily and uniformly integrated (in other words, they are integrated). , High self-adhesiveness), and low adhesiveness to other substances such as hands, wooden patterns, rubber, plastics, etc.,
Further, when stretched, the elongation rate is large and cracks and the like do not occur.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to effectively solve the above-mentioned conventional demands.
The described invention is a noble metal powder and / or noble metal alloy powder,
Alternatively, a powder selected from a mixed powder of noble metal powder or noble metal alloy powder and metal powder or metal alloy powder; 82% by weight to 9
6% by weight, a binder comprising a thermoplastic resin, a plasticizer, and unavoidable impurities; the rest is mixed, and the binder is a thermoplastic resin; 2% by weight to 10% by weight, a plasticizer; 2% by weight to 10% by weight % By weight inevitable impurities; characterized by comprising the balance. The invention according to claim 2 is characterized in that the precious metal powder according to claim 1 is a mixed powder of one kind or two or more kinds selected from Au, Ag, Pt, and Pd. The invention described in claim 3 is claim 1
The noble metal alloy powder in is a powder of one kind or two or more kinds selected from an Au alloy, an Ag alloy, a Pt alloy, and a Pd alloy. According to a fourth aspect of the present invention, the metal powder according to the first aspect is Al, Ni, Co, F.
e, Cu, Ti, Zn, Sn, Zr, V, Pb, and Cr, which is a mixed powder of one or more kinds. The invention described in claim 5 is claim 1
The metal powder in is Al alloy, Ni alloy, Co alloy, F
e alloy, Cu alloy, Ti alloy, Zn alloy, Sn alloy, Z
It is characterized in that it is a mixed powder of one kind or two kinds or more selected from r alloy, V alloy, Pb alloy, and Cr alloy. The invention according to claim 6 is that the thermoplastic resin according to claim 1 is an acrylic resin, and the plasticizer is one or more selected from phthalic acid compounds or polyethylene glycol. Is characterized by.

[0008]

The noble metal plastic composition according to any one of claims 1 to 3 softens at a temperature near body temperature and is not sticky, has good plasticity, that is, moldability, and is pressed or kneaded with a separate composition. In that case, they can be easily integrated and sprinkled easily (they have good self-adhesiveness), and cracks do not occur even when stretched by about 10 times.

Further, the noble metal plastic composition according to claims 4 and 5 is provided with various color tones by the mixed metal powder.

Further, according to claim 6, the characteristics of the noble metal plastic composition according to claim 1 are preferably embodied.

Here, specific examples of each component and the reasons for limiting the above-mentioned formulation examples will be described. (A) Noble metal powder or noble metal alloy powder As the noble metal powder, spherical, irregularly shaped or flattened powder having an average particle diameter of 200 μm or less can be used. As the noble metal forming the noble metal powder, one or more selected from Au, Ag, Pt, and Pb or alloys thereof are used. This noble metal powder is a main component constituting the noble metal plastic composition and is an important factor for determining the color tone of the product, but when the content is less than 82% by weight,
The color becomes unclear, or the precious metal plastic composition does not sinter well, and if it exceeds 96% by weight, the elongation (tackiness) and the plasticity of the obtained precious metal plastic composition deteriorate, and cracking occurs. Etc. are likely to occur.

(B) Composition of Binder (a) Thermoplastic Resin The thermoplastic resin is an acrylic resin such as polymethylmethacrylate, which maintains the shape of the noble metal plastic composition in a good condition and which is combined with a plasticizer. Depending on the combination, the noble metal plastic composition has a plasticity in the vicinity of the body temperature of the operator,
It imparts characteristics such as self-adhesiveness, elongation, and crack prevention. The acrylic resin is usually stored in a state of being dissolved in a solvent such as toluene or ethanol, but these solvent components are removed by evaporation in the manufacturing process of the noble metal plastic composition. Compounding amount of this thermoplastic resin (ie,
If the compounding amount (after the solvent component is removed) is less than 2% by weight, the properties such as self-adhesiveness, elongation, and crack prevention cannot be sufficiently obtained, while if it exceeds 10% by weight, molding is performed. When degreasing / sintering the body, deformation of the molded body, sagging, foaming, etc. occur, and a sintered body having a desired shape cannot be obtained. Therefore, the blending amount of the thermoplastic resin is 2% by weight to 10% by weight. I decided. (B) Plasticizers Plasticizers include phthalic acid compounds such as DBP (diN-butyl phthalate), DEP (diethylhexyl phthalate), DOP (diN-octyl phthalate), polyethylene glycol, ethylene glycol, glycerin and the like. One or more selected from alcohols are used. This plasticizer, when combined with the thermoplastic resin, imparts the noble metal plastic composition with properties such as plasticity, self-adhesiveness, elongation, and prevention of cracking in the vicinity of the body temperature of the operator, as described above. However, the compounding amount is 2
If it is less than 10% by weight, properties such as plasticity, elongation, and crack prevention cannot be sufficiently obtained, while if it exceeds 10% by weight, the self-adhesiveness is lowered, and the internal properties of the molded product during molding are deteriorated. Since many air bubbles are involved, the strength of the molded body is reduced and molding becomes difficult, and there is a problem that it becomes greasy and the feel is bad, etc.
The compounding amount of the plasticizer was set to 2% by weight to 10% by weight. (C) Dispersant The dispersant is preferably added, for example, a surfactant such as Span 80 (sorbitan monooleate) is used, which enhances the mixing property of the powder and the binder, and is unavoidable. 0.05% to 6% by weight including impurities
Is added within the range. (D) Blending Ratio of Thermoplastic Resin and Plasticizer The reason why the blending amounts of the thermoplastic resin and the plasticizer are almost the same is that if either is large, the self-adhesiveness of the resulting noble metal plastic composition decreases. It also causes stickiness during handling.

(C) Metal powder or metal alloy powder These are Al, Ni, Co, Fe, Cu, Ti and Z.
n, Sn, Zr, V, Pb, and Cr, or
One or two or more kinds of mixed powder selected from these alloys are used and added to adjust the strength and color tone of the resulting noble metal plastic composition, and the addition amount is the desired strength and color tone. It is set appropriately according to.

[0014]

EXAMPLES The present invention will be described below with reference to examples. Acrylic resin: 50 wt%, toluene: 50 wt% Acrylic resin solution, PEG, DBP, and Span 80 in ethanol at room temperature so that the blending ratio after evaporation and drying is the blending ratio shown in Table 1. To produce a binder solution, and add an average particle size of 20 μm to each of these binder solutions.
m Au powder, Ag powder having an average particle size of 30 μm, and
Cu powder having an average particle diameter of 25 μm was mixed in the same mixing ratio as shown in Table 1 after evaporation and drying, and the mixed solution thus obtained was spread on a vat and kept at a temperature of 40 ° C. for 24 hours. By doing so, it was naturally dried to obtain Noble Metal Plastic Compositions 1-5. The composition of the noble metal plastic composition in Table 1 is a value calculated from the charged amount at the time of production, assuming that toluene and ethanol are completely removed in the drying step, and excludes a trace amount of unavoidable impurities. It is the value calculated by

[0015]

[Table 1]

Each of the thus obtained noble metal plastic compositions was tested for self-adhesion at room temperature, elongation, and adhesion with other substances (stickiness), and the results are shown in Table 2. It was shown to. Test conditions Self-adhesiveness: After pressure-bonding the noble metal plastic composition divided into two, a tensile force is applied with the pressure-bonded surface as a boundary,
At this time, check for the presence or absence of peeling on the pressure-bonded surfaces of both test pieces,
The case where there was no peeling was marked with “◯”, the case where peeling was slight was marked with “Δ”, and the case where peeling was large was marked with “x”. Elongation: Tensile force was applied to the noble metal plastic composition, and the elongation rate at the time when rupture occurred was measured. Adhesion with other substances; When the noble metal plastic composition is kneaded by hand, the state of adhesion to the hand is examined. When there is no adhesion, it is "○", when a small amount of adhesion is produced, "△"",Also,
The case where there was a large amount of adhesion was designated as "x".

[0017]

[Table 2]

Further, as comparative examples, compositions 6 to 11 having the compounding amounts shown in Table 3 which deviated from the upper limit value and the lower limit value of the thermoplastic resin and the plasticizer, respectively, were prepared, and the present compositions were carried out. A test similar to the example was conducted, and the results are shown in Table 4.

[0019]

[Table 3]

[0020]

[Table 4]

As is clear from these results, when the composition and the compounding ratio of this example are within the ranges, the self-adhesiveness and the elongation at room temperature are sufficient, and the adhesiveness with other substances is low, A noble metal plastic composition having excellent plasticity and easy to handle is obtained, and it is preferably used as a molding material.

The noble metal plastic composition thus produced is molded into a desired shape and then fired to obtain a noble metal article.

Here, the firing conditions differ depending on the types of the noble metal powder and the metal powder contained in the noble metal plastic composition. For example, when the noble metal powder and the metal powder contained are pure Ag powder only, in the air, By firing at 900 ° C. for 1 hour or more, in the case of pure Au powder only,
By firing in air at 1050 ° C for 1 hour or more,
Further, in the case of the Au-Ag-Cu mixed powder, it is heated to 700 ° C. at a temperature rising rate of 1 ° C./minute in a H 2 gas stream, held for 5 hours to remove the binder, and then fired at 860 ° C. for 1 hour or more. As a result, desired noble metal articles can be obtained.

In the above embodiment, the powder A
Although g is shown as an example, the present invention is not limited to this, and it is of course possible to use other precious metal powders or alloys thereof, or those to which other metals or alloys thereof are added.

[0025]

As described above, according to the present invention,
At room temperature, a self-adhesiveness and elongation are sufficient, and the adhesion with other substances is low, and a plastic composition with excellent plasticity and easy handling can be obtained. It has excellent effects such as obtaining a composition.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Akira Mori Inventor Mita City, Hyogo Prefecture Techno Park 12 No. 6 Sanritsu Material Co., Ltd. Mita Factory

Claims (6)

[Claims] 1. Noble metal powder and / or noble metal alloy powder,
Alternatively, a powder selected from a mixed powder of noble metal powder or noble metal alloy powder and metal powder or metal alloy powder; 82% by weight to 9
6 wt%, a binder consisting of a thermoplastic resin, a plasticizer, and inevitable impurities; the remainder is mixed, and the binder is a thermoplastic resin; 2 wt% to 10 wt%, a plasticizer; 2 wt% to 10 wt% % By weight inevitable impurities; the balance comprises the balance, a noble metal plastic composition. 2. The noble metal plastic composition according to claim 1, wherein the noble metal powder is one or a mixture of two or more selected from Au, Ag, Pt, and Pd. 3. The noble metal plastic powder according to claim 1, wherein the noble metal alloy powder is one kind or a mixed powder of two or more kinds selected from Au alloy, Ag alloy, Pt alloy and Pd alloy. Composition. 4. The metal powder is Al, Ni, Co, F
The noble metal plastic composition according to claim 1, which is a mixed powder of one or more selected from e, Cu, Ti, Zn, Sn, Zr, V, Pb, and Cr. 5. The metal powder is an Al alloy, a Ni alloy, or C
o alloy, Fe alloy, Cu alloy, Ti alloy, Zn alloy, S
The noble metal plastic composition according to claim 1, which is a mixed powder of one kind or two kinds or more selected from an n alloy, a Zr alloy, a V alloy, a Pb alloy, and a Cr alloy. 6. The thermoplastic resin is an acrylic resin, and the plasticizer is one or more selected from phthalic acid compounds and polyethylene glycol. 1. The noble metal plastic composition according to 1.