JPH029112B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gold-containing preparation for coating metal parts, in particular for coating baked alloys before coating with ceramic material in dental technology, which preparation and a binder, which is liquid at room temperature and volatilizes or burns at combustion temperatures, and consists of one or more organic solvents and one or more resin components.

It has been known for a long time in dental technology to cover calcined alloy crowns and bridges with ceramic materials. Primarily for aesthetic reasons, the metal crown or bridge base is then fully or partially coated with one or more tooth-colored ceramic layers. Similarly, primarily for aesthetic reasons, gold-enriched dental porcelains give slightly translucent dental porcelains a warmer-toned background than conventional fired alloys, which are often metallic white. An intermediate layer is used.

The gold-containing interlayer preparations known to date give extremely smooth surfaces and are virtually inoperable by the dental technician.

Previously known gold preparations are melted or calcined;
It also contains gold powder or spherical gold particles (German Patent Application No. 2851429), giving a uniform film thickness and an extremely smooth surface.

On the other hand, the importance of sufficient bonding properties for good bonding between metallic firing alloys and dental ceramics has also been known for a long time. The so-called physical bond depends very strongly on the area, shape and roughness of the surface to be bonded to the ceramic.

It is known from DE 25 25 274 A1 to use gold-containing preparations which, in addition to gold powder and flux, also contain porcelain and zirconium oxide powder with very small particle sizes. However, this preparation gives an unaesthetic off-white layer when baked onto the baking alloy.

The object of the invention is therefore to provide a coating with a ceramic material, in particular in dental technology, for coating metal parts consisting of gold powder, adhesive and a binder which is liquid at room temperature and volatilizes or burns at combustion temperatures. Gold-containing preparations for coating alloys before firing, which ensure the strongest possible bond with the dental ceramic after firing, have an aesthetic appearance and allow savings in gold consumption. The goal was to find a preparation for this purpose.

The problem is solved according to the invention by using 50-94% by weight of gold powder with a particle size smaller than 30 μm, 5-40% by weight of a binder, and a particle size larger than the particle size of the gold powder used and a melting point above the melting point of gold. gold-containing preparations consisting of 1 to 20% by weight of metal powder as adhesive.

Advantageously the preparation contains 65-80% by weight of gold powder, binder
It contains 15-25% by weight and 5-10% by weight of metal powder. Preferably, the particle size of the gold powder is less than 10 μm.

The binder is preferably one or more organic solvents.
90% by weight, in particular 65 to 85% by weight, and one or more resin components preferably 10 to 40% by weight, in particular 15 to 35% by weight.
It consists of % by weight. In particular, resin components include acrylate resin, methacrylate, nitrocellulose,
Ethylcellulose and natural or synthetic rubber are used. Glycols, glycol ethers, glycol esters, terpene hydrocarbons and high-boiling aliphatic hydrocarbons are used as solvents.

Palladium powder, cobalt powder and/or nickel powder and/or powders from palladium alloys, gold alloys, cobalt alloys and/or nickel alloys have proven advantageous as metal powders, and these particle sizes are used. The particle size must be larger than that of gold powder, and the melting point or solidus temperature must be higher than the melting point of gold (1063°C).
Advantageously, the alloy powder contains alloying elements that are also present in the metal part to be coated.

The pasty gold preparations according to the invention can be simply applied with a brush or felt onto the metal parts to be coated, for example crowns or bridges. The surface roughness caused by the metal powder additionally contained in the gold is maintained after baking the preparation if the baking temperature is below the melting point or solidus temperature of this metal powder additive. It was shown that Baking temperatures of 600-1100°C and baking times of 0.5-10 minutes have been shown to be advantageous. The gold layer becomes gold under this condition.
It forms an inseparable bond with all customary baking alloys based on platinum-palladium-silver, gold-silver, gold-palladium, nickel-chromium, cobalt-chromium and cobalt-palladium. It is therefore suitable for all noble metal-containing and noble metal-free baking alloys.

The intermediate layer produced in this way provides a very good adhesion between the ceramic layer and the metal crown or bridge part. All known dental ceramic materials are suitable for this purpose. Bending tests on ceramic-coated alloy plates coated with an intermediate layer consisting of a gold preparation according to the invention showed that failure occurred within the ceramic itself during forceful separation of the ceramic layer from the metal. Ta. No separation of the intermediate layer from the fired alloy or ceramic was observed in any case.

Some examples of the composition of gold-containing preparations according to the invention are listed below: 1 Gold powder crystalline, particle size <10 μm 75% Powder of palladium with 20% gold and 5% tin particle size <20 μm 5% diglycolic acetic acid Butyl 15% Polymethyl methacrylate 5% 2 Gold powder, crystalline, particle size <10 μm 65% Gold powder containing 10% platinum, 3% tin and 2% indium, particle size <37 μm 10% Butyl diglycol acetate 18% Ethyl cellulose 7 % 3 Gold powder, crystalline, <10 μm 70% Palladium powder, <37 μm 10% Terpineol 15% Nitrocellulose 5% 4 Gold powder, crystalline, <10 μm 40% Gold powder, plate-like, <10 μm 35% Cobalt powder 5 % High-boiling aliphatic hydrocarbons 16% Polyisobutylene 4% 5 Gold powder, crystalline, <10 μm 50% Gold powder, plate-like, <10 μm 25% CoCr27Mo5.5Si1Mn0.7Fe0.5 powder, <37 μm
5% Terpineol 15% Ethylcellulose 5%

Claims (1)

[Claims] 1. A metal comprising gold powder, an adhesive, and a binder consisting of one or more organic solvents and one or more resin components, which is liquid at room temperature and volatilizes or burns at combustion temperatures. In a gold-containing preparation for coating parts, 50-94% by weight of gold powder with a particle size smaller than 30 μm, 5-40% by weight of a binder and a particle size larger than the particle size of the gold powder used and the melting point of gold. Gold-containing preparation for coating metal parts, characterized in that it consists of 1 to 20% by weight of metal powder as adhesive, having a melting point above . 2. A preparation according to claim 1, containing 65-80% by weight of gold powder, 15-25% by weight of binder and 5-10% by weight of metal powder. 3. A preparation according to claim 1 or 2, wherein the particle size of the gold powder is less than 10 μm. 4. Claims 1 to 3, in which palladium powder, cobalt powder and/or nickel powder and/or powder from palladium alloy, cobalt alloy, nickel alloy and/or gold alloy is used as metal powder. A preparation according to any one of the following. 5. The metal powder contains an alloying element that is also contained as an alloying element in the metal part to be coated,
Preparation according to any one of claims 1 to 4. 6 Binder is resin 10-40% by weight and solvent 60-90%
% by weight.