HK1000596B

HK1000596B - Mono-noble-metal dithiolates and their use in the preparation of noble metal containing decorations on substrates capable of being fired

Info

Publication number: HK1000596B
Application number: HK97102187.3A
Authority: HK
Inventors: Schulz Andreas; Hofler Marco
Original assignee: Cerdec Aktiengesellschaft Keramische Farben
Priority date: 1994-02-21
Filing date: 1997-11-18
Publication date: 1998-04-09

Description

The invention relates to mono-di-thiolate, in particular water-soluble monogold (I) di-thiolate, the manufacture and use of which is used to make decorative articles containing precious metals, in particular highly glossy decorative articles made of a cohesive precious metal film, on flammable surfaces.

For the manufacture of a precious metal coating, in particular a coating consisting essentially of gold and/or silver in the form of a highly glossy metal film, including conductors made of gold in particular in integrated circuits, so-called precious metal preparations, such as glossy gold preparations and polished gold preparations, have long been used to produce a flammable substrate. Such preparations generally contain one or more sulphur-organic precious metal compounds soluble in a purely organic or organic aqueous medium, called precious metal thiolates, the precious metal being present in the case of agate and in the final oxidation stage. These preparations contain one or more of the non-precious metal compounds, such as a solvent or a solvent, and in addition a polymorphite, a solvent or a solvent, and a solvent, or a solvent, or a solvent, such as a solvent, or a solvent, and a solvent, such as a solvent, or a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a solvent, and a, and a solvent, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, and a, andThe precious metal preparations are applied to the surface to be coated by means of the usual direct and indirect printing methods, spraying or brushes or by the use of the abrasive technique. After evaporation of the solvent, a combustion process is followed at a temperature appropriate to the substrate and the gold preparation - usually the maximum combustion temperature is between 400 and 900 °C, but higher temperatures are also possible in some cases.It is well known to the professional world that in order to obtain high gloss precious metal films, the precious metal thiolates used, the binder and solvent systems must be carefully matched to produce brilliant and substrate-bound decorative films, including conductors for electrical/electronic purposes.

The sulphur organic compounds used for the above-mentioned decorative preparations were for a long time almost exclusively gold sulphoresinates, obtained from a gold salt and sulphurised, especially naturally occurring terpenes. In recent times, synthetically produced precious metal thiolates, especially gold ((I)) thiolates of the general formula Au-S-R, have gained importance, where R stands for an alkyl, cycloalkyl, aryl or aralkyl group or a bicyclic hydrocarbon residue. The gold ((I)) thiolates mentioned generally required the use of a purely organic solution system - for example, reference is made to EP-B 0 491 143

For reasons of occupational hygiene, safety and the environment, there is a growing interest in precious metal preparations for decorating flammable substrates in which the solvent system contains at least part of the organic solvent replaced by water. For example, a coating agent for applying a glaze decoration on porcelain is known from DE-OS 32 17 049 containing 15 to 40% by weight of polyvinylpyrrolidone or a mixture of polyvinylpyrrolidone and aqueous polyethylene oxide, 45 to 85% of ethylene glycol and/or propylene glycol and possibly water.

A polyvinylpyrrolidone-water polishing gold preparation containing as binding agent an aqueous acrylate tar dispersion and as colouring component gold powder and/or a hardly soluble gold compound is known from GB-A 22 16 536. Examples show that these preparations also contain alcoholic solvents. In addition, the sample preparations contain a non-nonionic net agent in a quantity of 5 and 6 g respectively. A suggestion to use an aqueous gold compound and to refrain from the presence of glycols and alcohols is not clear from this document.

The compositions contain 3 to 22% by weight of a precious metal thiolate, a polymer resin and a solvent system consisting of a mixture of water and an organic solvent (Cosolven), preferably a water-soluble alcohol, ether or ester. Both the precious metal thiolate and the binding acid are known to be soluble in water/Cosolven chemical. In the case of the preferably gold-alloyed gold, the most common examples are the general documents for the decomposition of RH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-OH-

The present invention is therefore intended to identify another group of precious metal thiolates suitable for the manufacture of highly glossy precious metal decoration on flammable materials. The new precious metal thiolates should be effective in glossy metal preparations with an aqueous-organic and, in particular, purely aqueous solvent system. The new precious metal thiolates should be safe to use and be of high aesthetic quality, in particular high glossy, pore- and stain-free, well-adhesive decoration on a flammable substrate.

Surprisingly, it was found that the introduction of a second sulphydryl group into the organic compound underlying the precious metal thiolate significantly improved the suitability of the precious metal thiolate as a component of precious metal decorative preparations for the manufacture of highly glossy decorative products. What does it mean? Em:a precious metal of the series Au I or Ag I or an equivalent of Pd II, Pt II or Rh IIIQ:a tetravalent organic residue containing 2 to 10 C atomsY:a hydrophilic group of the series -COOH, -COO-Kat+, where Kat+ stands for Li+, Na+, K+, NH4+, (C1- to C3-alkyl) n N+H(((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((()))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) with R1,R2 and R3 equal to or different from H or methyl and m equal to an integer from 1 to 12,Z:equal to Y or -H or a group from the series -OR', -SR', -SO3R', -NR'2, NR'3+X-, where X- is a mineral acid or carbonic acid anion and R' is hydrogen or the group and R1 and m have the above meanings.

Preferred mono-precious metal diolate containing gold or silver, especially gold, as a precious metal.

The tetravalent organic residue Q and the substituents Z and Y are preferably selected in such a way that the resulting monoethyl metal dithiolate has a high solubility in water, and good water solubility is obtained especially when Y and/or Z mean COO-Kat+.

In the case of alkyl ammonium cations, alkyl may mean methyl, ethyl, n-propyl or i-propyl; in the case of alkyl ammonium cations, it may be mono-, di-, tri-, or tetra-alkylammonium with the alkyl groups mentioned above, which may also be mixed. In the case of mono-, di-, tri-, or tetra-hydroxylammonium cations, the hydroxyalkylammonium group is hydroxymethyl, hydroxyethyl, 2-hydroxypropyl or 3-hydroxypropyl. The hydroxyl group can be produced by the same simple reaction of ammonium or sodium nitrate and/or carboxyl in the usual way.

Where Y stands for the group -COO(CHR1-CHR2-O) mR3, m preferably means an integer between 3 and 7. Monoethyl metal diolate with Z equal to hydrogen naturally have a lower solubility in water and thus a lower suitability for aqueous precious metal preparations than compounds in which Z itself is a hydrophilic group.

The organic residue Q contains between 2 and 10 C atoms; the residue may also contain oxygen, nitrogen or sulphur atoms, for example in the form of hydroxyl, carboxyl, alkoxy, amino, alkylamino, mercapto or alkyl mercaptogroups. In particular, the organic residue Q is preferably a C2, C3 or C4 alkanetetrayl residue. In another embodiment, the organic residue Q is a 5- or 6-membered 5-cloalic tetraethyl tetraethyl residue, wherein a C-ring member may be replaced by oxygen (-O-) or an amino group (-NH- or -NR-) tetraethyl; the most cyclic Q-members are some cyclohexantetraethyl, cyclopentetraethyl, cyclopentetraethyl, pyrentetraethyl or tetrahydroethylidrin.

Accordingly, monoethyl metal diolate, in particular monogold-I and monosilver diolate of dimeric sulphuric acid, 2,3-dimeric sulphuric acid and 2,3- or 3,4- or 2,5-dimeric sulphuric acid, and their salts with the cation+ group, are particularly suitable for the formation of triethyl monoethyl tri-methyl diethylamine, or triethyl tri-methyl tri-methyl diethylamine, or a mixture of these salts, or for the formation of triethyl tri-methyl tri-methyl or triethyl tri-methyl tri-methyl diethylamine.

Mono-diethylated metals with the structure shown above have never been described and have therefore not been proposed for use in the manufacture of metallic precious metal decorations on combustible materials. On the basis of the comparison of the properties of decorations produced with mono-diethylated metals of the invention and with pre-known structural-like precious metal thiolates which do not have an additional SH group, it is assumed that the mono-diethylated metals of the invention are stabilized by the additional SH group in such a way that during the combustion process, the mono-diethylated metals can be placed on a single-diethylated material, glass, porcelain and ceramic, which is a solid, cohesive and highly glossy film.

Manufacture of monoethylene diolate of general formula (A) according to the invention In the case of monogold ((I) -dithiolate, tetrachlorogold acid is formed by the addition of twice the equivalent amount of a thioether R''SR'' to form a gold ((I) complex of the formula AuCl ((R'SR'')), which is then converted into a solvent with an essentially equivalent molecule of a diethyl (dimercapt bond) of the general formula (B). A particularly useful thioether for the formation of the gold (((I) complex is methionine.

The production of the dithiol compound (B) is carried out using the usual steps of the process: for example, dimercaptoalkanedicarboxylic acids can be obtained by conversion of the corresponding alkyne dicarboxylic acids with thioacetic acid; another approach for aliphatic and cyclic dimercapto compounds of the general structure (B) is also to convert the corresponding dihalogen compound (Z-Q ((Hal) 2-Y)) with an alkali sulphide. Ag compounds according to the invention can be obtained in a simple way by conversion of a soluble Ag salt with a dithiol (B). In the corresponding way, Pd and Pt compounds according to the invention are obtained from a Pd ((II)) and Pd ((II)) respectively, and D-Dithyl salts, with a ratio of about 1 to 2 mol.

The mono-metal dietholates of the invention can be used as appropriate in the form of pre-forms containing precious metals for decorating combustible materials, in particular glass, porcelain and ceramics. Such preparations contain at least one mono-metal dietholate of the invention, one or more polymeric organic binders and solvents, preferably an aqueous organic or particularly preferably a purely aqueous solvent system, in order to dissolve the organic polymers and the mono-metal dietholate in them or otherwise to ensure a homogeneous distribution. Where necessary, the pre-forms also contain auxiliary materials which have certain processing properties, such as a low pressure and a high degree of corrosion resistance, and which achieve certain characteristics such as high pressure, corrosion resistance and corrosion resistance.

The use of selected monoethyl metal diolate according to the invention allows the production of essentially pure aqueous precious metal preparations. Such preparations are characterized by the presence of water as solvent and less than 2% by weight of organic solvents, depending on the preparation, the binding agent is water-soluble, the monoethyl metal diolate has at least one salt-forming functional group and is present in the form of an aqueous salt and a surfactant is present in an effective amount. In particular, the preference is given to preparations containing a salt of one or more caryl groups on a monoethyl metal diolate and a primary, secondary or tertiary amine or a hydrocyclic amine base. The percentage of residues mentioned above is less than 0%, for example, when these preparations are used in organic solvents and in the form of auxiliary substances.

The mono-di-thiolate mono-precious metals used in aqueous organic and pure aqueous preparations of the invention have structural elements, namely at least one acid or base group capable of forming salts, which give them sufficient solubility in water. The preparations generally contain 2 to 25% by weight, preferably 5 to 15% by weight, of the precious metal in the form of one or more thiolate. Accordingly, the water solubility of the thiolate must be higher at high precious metal content of the preparation than at low content. The aim is to achieve an organic decoration with the lowest possible amount of gold.

Aqueous preparations according to the invention contain such polymeric binders which are soluble in water or which form a clear dispersion in water. Useful binders are polyacrylic acid, polymethylic acid, polyvinylpyrrolidone, cellulose ether, in particular carboxyalkyl and hydroxyalkyl cellulose, polyalkylglycol, polyvinyl acetate, polyvinyl alcohol, polyamine, alkydharse and polyurethane resins. The binders may be obtained as homolymers or copolymers or block polymers individually or in the form of mixed applications. Particular preference is given to pure aqueous polyvinylpyrrolidone and those with high water content, such as polycopolymers or homolymers or polymers based on polymethylamine and hardenol.

The proportion of polymeric binders in the organic-aqueous and essentially pure-aqueous preparations is usually between 3 and 45% by weight, preferably between 3 and 20% by weight and in particular between 4 and 10% by weight. The ratio of binders to precious metal by weight in the preparations is conveniently in the range of 0.1 to 2 by weight, preferably between 0.3 and 1.2 by weight and in particular between 0.5 and 1.0 by weight. The water content of aqueous-organic preparations is generally between 10 and 80% by weight, preferably between 30 and 60% by weight, and the content of organic solvents in each of the preparations is between 10 and 40% by weight, depending on the purity.

Preparations with an aqueous organic solvent system contain as organic solvent one or more water-soluble organic solvents, in particular water-soluble alcohols, ethers and esters. In particular, glycols with 2 to 4 C atoms and oligo- and poly-C2- to C4-glycols or mono-C1- to C4-alkyl ethers of the said glycols or oligoglycols, as well as (C2- to C5-) hydroxycarbon acids or low alkyl esters thereof, such as in particular C1- to C3-alkyl lactate, are used.

The essential component of the invention for the essentially pure aqueous preparations is a surfactant from the series of anionic, non-ionic, zwitterionic and cationic surfactants in effective quantities which is compatible with the salt of thiolate. The tolerance and efficacy of a selected surfactant will be checked by the expert by means of indicative tests, since interactions may also occur with the other components of the preparation.

The surfactants contain in the molecule a hydrophobic residue of 8 to 26 and in particular 10 to 18 C atoms or another hydrophobic group such as a polydimethylsiloxane group and at least one anionic, zwitterionic, non-ionic or cationic water-soluble group.

The following are appropriate examples of anionic surfactants: straight-chain or branched-chain alkylbenzolesulfonates, especially those with a straight-chain C8 to C16 alkyl group, aliphatic and olefin (C8 to C18) sulfonates, hydroxyalkansulfonates, fatty acid esters of oxyethan sulfonic acid; fatty alcohol sulfates, sulphate fatty alkyl alkylolamides and fatty acid monoglycerides, and sulphate alkoxylation products of fatty alcohols, alkylphenols, fatty acid amides; saturated and unsaturated fatty acid condensates, alkylphenols and polyphenols of alkylphenols, containing an amino acid (C10 to C20 or an alkylphenol of 1 to 8%, respectively) containing a protein of 1 to 2% by weight, in the form of amyl sulfonate, and especially in the form of a sulphate of α-amino acids, containing a carboxylic acid, and a sulphate of 1 to 2% by weight; and products containing alkylphenols of the amino acid group.

Non-ionic surfactants are water-soluble due to the presence of polyether groups, amino-oxide, sulfoxide, phosphinoxide and alkylolamide groups.

Another group of non-ionic surfactants which are particularly effective in the essentially pure aqueous preparations of the invention are water-soluble polyethylene-polysiloxane polysiloxane polymers, which may have linear or branched block copolymer structures. The amount of polysiloxane used in this class is preferably between 0.1 and 2.0% by weight, particularly between 0.2 and 1.0%, depending on the preparation. The polyether segments are polyoxyethylene, polyoxypropylene or industrial polyethylene-oxypropylene segments, wherein polyoxyethylene polysiloxane segments and in particular with such 4 to 20 Oxyethylene-based units.

Zwitterionic surfactants contain both an acidic, such as a carboxyl, sulphonic, sulphuric acid, or phosphoric acid sub-ester group, and a basic, such as a primary, secondary, tertiary, quaternary ammonium group, hydrophilic group.

The cationic surfactants are usually substances of the formula where R1 is an alkyl or an alkenyl with 8 to 24 C atoms, R2 is an alkyl or hydroxyalkyl with 1 to 5 C atoms and X is a halogen.

In the case of gilding preparations, in particular gilding preparations and polishing preparations, these contain, for the purpose of colouring, a small quantity of one or more essentially soluble other precious metal compounds in the system in the form of resins or sulphuric acid or in the form of simple precious metal salts or complexes. In addition, the preparations usually contain fluids in the form of compounds, such as resins, salts, oxides or coordination compounds, one or more of the elements silicon, boron, boron, chromium, indium, tin, antimony, vismuth and rhodium. The amount of fluid used is usually in the range of 0.01 to 2%, depending on the weight of the material.

Other excipients in the preparations of the invention may include common substances to modify the rheological properties of the preparation, surfactants, adhesion-enhancing excipients and drying accelerators in the case of the use of a UV-curable resin. The additional use of an aqueous polysulphide solution has been shown to be appropriate in some cases, in particular in preparations containing polyvinylpyrrolidone.

The aqueous preparations are prepared by using directly a water-soluble salt of a monoethyl metal dithiolate or by forming the salt at room temperature or elevated temperature, preferably 30 to 80 °C in water in situ, from a monoethyl metal dithiolate having at least one acid functional group and a base such as an alkali alloy, ammonia or an amine or from a monoethyl metal dithiolate having one amino group and an acid such as a low carbonic acid.

The amount of base required to neutralize the acid groups is generally used per mole of thiolate; in some cases a complete solution is obtained at a base deficit. An excess of base is possible but not generally necessary. The liquid is added to the solution and dissolved. The binder is then directly introduced into the solution and dissolved in it. Alternatively, the binder or binder mixture may be dissolved in water, if necessary with the addition of additional preparations, such as a polysulphide solution, and this solution may be combined with the edimetallic solution. The tensor is added to the solution itself during the preparation of one of the preparations or at the end of the preparation.

The preparations of the invention containing monoethyl metal diolate may be applied directly to the surface to be decorated by means of ordinary decorative methods, such as sprays, brushes or known printing methods, in particular the screen printing method, and, after evaporation of the solvent components, the decoration may be fired at a temperature generally between 400 and 900 °C. Alternatively, the precious metal preparation of the invention may be transferred to the object to be decorated by the application of a printing medium. The manufacture of the printing medium is carried out in the manner described for the skilled worker, the solvent of the invention being monogold-diethyl metal diolate.

The invention provides a new class of material which is excellent for the manufacture of film-like precious metal decors. The decors are surprisingly high-gloss and adhere excellently to the substrate surface, forming a coherent film. The mono-precious metal diolate according to the invention provides a new class of material for the technical community, which can be used not only in conventional precious metal preparations which contain only organic solvents as solvents, but also in precious metal preparations which contain a water-organic solvent system or less than water as solvent. The new precious metal preparations, as well as their outstanding properties in terms of their content and purity, are not suitable for use in the manufacture of precious metal preparations.

The decorations produced with the inventive preparations are surprisingly high-gloss and adhere perfectly to the substrate surface, since a coherent film is formed.

In view of the state of the art, it was not possible to foresee the availability of precious metal preparations for the manufacture of precious metal decoration, in particular glossy gold decoration, in which the use of organic solvents is not required.

Example 1 Manufacture of monogold dimercaptopenic acid

Other (a) 0,035 mol = 18,49 g HAuCl4 (37,29 % Au) is dripped to a suspension of 0,07 mol methionine in 70 ml H2O by stirring. External cooling maintains the temperature to 0 to 5 °C. After completion of the reaction, the gold ((I) complex is dripped to a suspension of 0,035 mol = 6,38 g meso-2,3 dimercaptopenic acid in 150 ml dichloromethane within one hour. The precipitate is drained, washed several times with water and dried under vacuum in the exhaust manifold by blowing. The yield of monogold dimercaptopenic acid is 96,5% based on the gold used. Other

Analyse	Au	C	H	S
berechnet	52,09 %	12,70 %	1,33 %	16,96 %
gefunden	50,81 %	12,05 %	1,52 %	15,62 %
Zersetzungsbeginn: 194 °C

Other The maximum residue levels for the active substance shall be determined by the following equation: Other (b) Example 1a was repeated, but water was used instead of dichloromethane, and monogold ((I) dimercaptopenic acid was obtained again at high yield and purity.

Comparison example 1

Analogue comparison example 7 in EP-A 0 514 073 mixing the following components: Other

	Gewichtsteile
Polymethacrylatharz (Versicol K11 von Allied Colloids))	11
Goldmercaptobernsteinsäure	18
1,3-Propandiol	15
Wasser	40
Isopropanol	15
Rhodium-Komplex	0,04
Chromtrioxid	0,05

The preparation is brushed on porcelain and heated for 10 min at 820 °C, with a heating time of one hour, to produce a matte film.

Winkel	Glanzeinheiten	Standardabweichung
20 °	58,3	5,4
60 °	54,2	4,1

Err1:Expecting ',' delimiter: line 1 column 90 (char 89)

Comparison example 2

The following composition is prepared in analogy with comparison example 1: Other

	Gewichtseile
Polyvinylpyrrolidon (PVP K25 von Fluka)	8,1
Goldmercaptobernsteinsäure	17,2
1,2-Propandiol	8,1
Wasser	39,9
Ethyllactat	16,2
Rhodium-Komplex	0,15
Chromsulfat	0,04
Ammoniumwismutcitrat	0,44
Triethylamin	5,3
Ammoniumpolysulfidlösung (15 %ig in Wasser)	1,9
Silbermercaptopropionylglycin	2,6

The preparation is brushed on porcelain and heated for 10 min at 820 °C, with a heating time of one hour. Other

Winkel	Glanzeinheiten	Standardabweichung
20 °	20,1	4,6
60 °	38,2	2,1

Example 2

In contrast to the comparison example 2, the gold compound of the invention as described in example 1 was used in the following composition: Other

	Gewichtsteile
PVP K25	8,1
Monogolddimercaptobernsteinsäure	18,8
1,2-Propandiol	8,1
Wasser	38,3
Ethyllactat	16,2
Rhodium-Komplex	0,15
Chromsulfat	0,04
Ammoniumwismutcitrat	0,44
Triethylamin	5,3
Ammoniumpolysulfidlösung (15 %ig)	1,9
Silbermercaptopropionylglycin	2,6

The preparation is brushed on porcelain and heated for 10 min at 820 °C, with a heating time of one hour, to produce a glossy, adhesive film.

Winkel	Glanzeinheiten	Standardabweichung
20 °	741	42,4
60 °	503	6,4

Example 3

The following ingredients were mixed: Other

	Gewichtsteile
PVP K25	8,6
Monogolddimercaptobernsteinsäure	19,5
1,2-Propandiol	8,6
Wasser	34,3
Ethyllactat	17,3
Rhodium-Komplex	0,16
Chromsulfat	0,07
Ammoniumwismutcitrat	0,53
Triethylamin	5,7
Ammoniumpolysulfidlösung (15 %ig)	2,6
Monosilberdimercaptobernsteinsäure	2,6

The preparation is brushed on the porcelain and heated for 2 min at 880 °C, with a heating time of 30 min.

Examples 4 to 8

Similar to the method of production given in example 1, further monogold dimercapt compounds were produced by conversion of the gold ((I) methionine complex with further dimercapt compounds in a 1:1 molar ratio: Example 4:Conversion with 1,4-dimercapto-2,3-butandiol: The aqueous content of the isolated product was 67,01 % (theoretical 56.24).Example 5:Conversion with 2,3-dimercapto-1-propansulfonic acid sodium salts: aqueous content 57,45 % (theoretical 46,43 %).The pre-preparate, which is essentially of monogold complex and partially aqueous, is also very apparent from the aqueous distribution of the indicated sulfonic compounds in existing product in clear water.The decarboxylated product is a very fine product.The decarboxylated product is a very fine product.The example of E. dimercapto-51,3%, which is a very fine solution, is particularly suitable in comparison with the case of polymers of polymers of polymers of gold (see also: Poly-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methorphenol-methol-methorphenol-methol-

Example 9 Gloss gold preparation

In accordance with general working methods, an aqueous solution containing monogold ((I) dimercaptethylenic acid was prepared. Triethylamine was used as the base. Rhodium chloride, chromium sulphate and ammonium bismuth citrate were added as the fluid. An aqueous polyvinylpyrrolidone solution containing ammonium polysulphide was added to the resulting solution and a polyethermodified pre-prepared polydimethyl siloxane (ByK®346) was added as a surfactant. The preparation contained only about 0.5% of the organic solvent contained in the commercial aqueous solution and was at most pure aqueous.

The precious metal and liquid contents, calculated as indicated, and the binding, surfactant and excipient contents in the preparation are given in the table.

Bestandteile	Gew.-% im Präparat
Au-Gehalt	9,35
Rh-Gehalt	0,06
	0,13
	0,21
Polyvinylpyrrolidon (PVP K25 von Fluka)	5,2
Tensidlösung (ByK®346; Tensidgehalt 46 %)	1,0
	4,8
	0,15

Examples 10 and 11

Analogue Example 9 produced essentially pure aqueous glossy gold preparations, using as au-thiolate the product from Example 1 and additionally silver-2-mercaptopropionyl glycine as a silver thiolate. A hydroxyethyl cellulose (natrasol by Aqualon Ltd., UK) was used as a binder; polysulfide was not used. The preparation of the invention in Example 10 contained ByK®346 as a surfactant; the non-invention preparation in Example 11 contained no surfactant. The contents of the components are shown in the table.

Bestandteile	Beispiel 10	Beispiel 11
	(Gew.-% im Präparat)
Au-Gehalt	9,62	9,71
Ag-Gehalt	1,08	1,10
Rh-Gehalt	0,07	0,07
	0,01	0,01
	0,30	0,30
Hydroxyethylcellulose	5,3	5,3
Tensidlösung (ByK®346; Tensidgehalt 46 %)	1,0	-
	5,3	5,3

Example 12

Decoration of porcelain

Order the preparations of examples 9, 10 and 11 by screen printing (example 12/9, 12/10, 12/11).

Burning conditions: heating to 820 °C in 1 hour, holding time at 820 °C 10 minutes.

Using the preparations of the invention in examples 9 and 10 produced glossy and stainless, well-adhesive decorative films; using the non-tensil-free preparation of example 11 produced only spotted decorative films.

Claims

Mono-noble metal dithiolate of the general formula (A) in which
Em: denotes a noble metal from the series Au(I) or Ag (I) or an equivalent of Pd(II), Pt(II) or Rh(III)

Q: denotes a tetravalent organic radical having 2 to 10 C atoms

Y: denotes a hydrophilic group from the series -COOH, -COO^-cat⁺, wherein cat⁺ stands for Li⁺, Na⁺, K⁺, NH₄ ⁺, (C₁ to C₃ alkyl)_n N⁺H_(4-n) or (hydroxy-(C₁ to C₃)alkyl)_n N⁺H_(4-n) and n stands for an integer between 1 and 4, or having R¹, R² and R³, which are the same or different, H or methyl and having m equal to an integer from 1 to 12,

Z: is equal to Y or -H or a group from the series -OR', -SR', -SO₃R', -NR'₂, NR'₃ ⁺X^-, wherein X^- stands for a mineral acid anion or carboxylic acid anion and R' stands for hydrogen or the group and R¹ and m denote the same as hereinabove.
Mono-noble metal dithiolate according to Claim 1, characterised in that Em stands for gold or silver, in each case in the oxidation state (I).
Mono-noble metal dithiolate according to Claim 1 or 2, characterised in that it is water-soluble, and Y and/or Z denote COO^-cat⁺ or Y denotes a carboxyl group and Z an amino group of the formula -NR'₂ rendered capable of internal salt formation with the carboxyl group, wherein cat⁺ and R' denote the same as hereinabove.
Mono-noble metal dithiolate according to one of Claims 1 to 3, characterised in that the organic radical Q is an aliphatic C₂ to C₄ alkane tetrayl radical or a 5- or 6-membered cycloaliphatic tetrayl radical optionally containing an oxygen or an imine in the ring.
Mono-noble metal dithiolate according to one of Claims 1 to 4, characterised in that it is monogold(I) dimercaptosuccinic acid or monosilver dimercaptosuccinic acid or a salt thereof with the cation cat⁺ denoting the same as hereinabove.
Process for the preparation of mono-noble metal dithiolates of the general formula (A') in which Q, Z and Y denote the same as in Claim 1, by reacting an Au(I) complex of the formula Aucl · R"SR"', wherein R"SR"' is a thioether, preferably methionine, with a substantially equivalent molar quantity of a thiol in the presence of a solvent, characterised in that the thiol used is a thiol of the general formula (B) wherein Q, Y and Z denote the same as in the formula (A').
Process for the preparation of mono-noble metal dithiolates of the formula A according to Claim 1, wherein Em stands for Ag(I) or an equivalent of Pd(II) or Pt(II), by reacting a soluble salt of Ag(I), Pd(II) or Pt(II) with a thiol compound, characterised in that the thiol compound used is a dithiol compound of the formula B according to Claim 6.
Noble metal-containing preparation for decorating substrates capable of being fired, in particular glass, porcelain and ceramic, for the purpose of producing a noble metal decoration, in particular a high-gloss noble metal decoration, containing one or more noble metal thiolates, one or more polymeric organic binders, furthermore solvent for the noble metal thiolate(s) and the binder(s) and, where necessary, auxiliary substances for adjusting the processing characteristics of the preparation and the optical and service characteristics of the noble metal-containing decoration to be produced therewith, characterised in that it contains as the noble metal thiolate at least one mono-noble metal dithiolate of the Claims 1 to 5.
Preparation according to Claim 8, characterised in that it contains as the solvent a polar organic solvent, in particular from the series C₂ to C₄ glycols, oligo(C₂ to C₄) glycols, C₁ to C₄ monoethers of the named glycols and oligoglycols, (C₂ to C₃) hydroxycarboxylic acids and (C₁ to C₃ ) alkyl esters thereof, and water.
Noble metal-containing preparation according to Claim 8, characterised in that it contains as the solvent water and less than 2 wt.%, calculated on the preparation, of organic solvent, the binder is water-soluble, the mono-noble metal dithiolate exhibits at least one functional group rendered capable of forming salt and is present in the form of a water-soluble salt, and there is present additionally an effective quantity of a surfactant.
Preparation according to one of Claims 8 to 10, characterised in that the polymeric organic binder is selected from the series of polyvinyl pyrrolidone homopolymers or copolymers, polyacrylic acid homopolymers or copolymers, polymethacrylic acid homopolymers or copolymers and water-soluble cellulose ethers and mixtures of the named binders.
Preparation according to Claim 10 or 11, characterised in that it contains a water-soluble salt of a mono-noble metal dithiolate exhibiting one or more carboxyl groups and a primary, secondary or tertiary amine or an N-heterocyclic base.
Preparation according to one of Claims 10 to 12, characterised in that the mono-noble metal dithiolate is present in the form of a salt with tri(C₁ to C₃) alkylamine or mono, di or triethanolamine, and the preparation additionally contains conventional auxiliary substances for adjusting the optical and service characteristics of the decoration to be produced and/or the processing characteristics of the preparation.
Preparation according to one of Claims 8 to 13, characterised in that it contains a water-soluble salt of monogold(I) dimercaptosuccinic acid.
Preparation according to one of Claims 10 to 14, characterised in that it contains as the surfactant from 0.1 to 2.0 wt.%, preferably from 0.2 to 1.0 wt.%, of a polyoxyethylene polydimethyl siloxane.
Preparation according to one of Claims 10 to 15, characterised in that it contains as the surfactant a quantity of from 0.1 to 2 wt.%, preferably from 0.2 to 1 wt.%, of an alkylbenzene sulphonate having 8 to 14 C atoms in the alkyl group in the form of a salt with an amine.
Transfer picture for producing noble metal-containing decorations on substrates capable of being fired, in particular glass, porcelain and ceramic, containing in a decoration layer one or more noble metal thiolates, one or more polymeric organic binders and, if required, auxiliary substances from the production of the transfer picture and for influencing the optical and service characteristics of the noble metal-containing decoration to be produced, characterised in that there is present in homogeneous distribution as the noble metal thiolate a mono-noble metal dithiolate according to one of Claims 1 to 5.
Process for decorating substrates capable of being fired, in particular glass, porcelain or ceramic, by applying to the substrate a noble metal-containing preparation or a transfer picture containing such a preparation in the dried state, and firing at from 400 to 900°C, characterised in that there is applied a noble metal-containing preparation according to one of Claims 8 to 16 or a transfer picture according to Claim 17.