EP3049202A1

EP3049202A1 - Process for producing a shiny laminate structure at low temperatures

Info

Publication number: EP3049202A1
Application number: EP14772154.2A
Authority: EP
Inventors: Susanne Behl; Kai-Ulrich Boldt
Original assignee: Heraeus Deutschland GmbH and Co KG
Current assignee: Heraeus Deutschland GmbH and Co KG
Priority date: 2013-09-24
Filing date: 2014-09-24
Publication date: 2016-08-03
Also published as: US10384266B2; WO2015044189A1; CN105764635B; US20160236280A1; KR20160060135A; CN105764635A; JP6667433B2; JP2017501015A

Abstract

A process for producing a laminate structure (2), comprising the steps of: E1) providing a composition (6) comprising: i) gold (Au) particles in an amount within a range from 0.1% to 50% by weight; ii) remainder to 100% by weight of a polar protic organic solvent; iii) less than 5% by weight of water, where the percentages by weight, based in each case on the total mass of composition (6) add up to 100% by weight; E2) applying the composition (6) to a substrate (4) to obtain a precursor (12); E3) heating the precursor (12) to a temperature within a range from 25 to 200°C to obtain the laminate structure (2).

Description

Method for producing a glossy layer structure at low temperatures

The invention relates to a method for producing a layer structure comprising the steps: El. Providing a composition comprising i. Gold Au particles in an amount ranging from 0.1 to 50% by weight; ii. Remainder to 100% by weight of a polar, protic organic solvent; iii. less than 5% by weight of water, the weight%, based in each case on the total mass of the composition, being 100% by weight; E2. Applying the composition to a substrate to obtain a precursor; E3. Heating the precursor to a temperature in a range of 25 to 200 ° C to obtain the coated layer structure.

Furthermore, the invention relates to a precursor of a layer structure obtainable after the steps El. and E2. of the method described above and a layer structure obtainable by the method described above. Moreover, the invention relates to a composition comprising: zl. Gold (Au) particles in an amount ranging from 0.1 to 50 Au wt.%, Based on the total weight of the composition; z2. Water in a range of 0 to 5% by weight, based on the total weight of the composition; z3. a polar, protic, organic solvent as balance to 100% by weight based on the total weight of the composition. Furthermore, the invention relates to an article comprising a layer structure according to the invention or a layer structure obtainable by the process according to the invention.

Methods for the production of metal layers on ceramic materials are known from the prior art. Thus, in WO00 / 10941A1, an aqueous solution of a gold thiolate compound is applied to a ceramic in order to achieve a colored decoration by heating. The heating takes place here at temperatures between 400 and 1200 ° C. The prior art does not describe the possibility of applying gold particles to a substrate and of forming a bright gold layer by means of low temperature. Generally, it is an object of the present invention to at least partially overcome the disadvantages of the prior art.

Another object is to form gold particles at low temperature on a substrate to a shiny layer.

In addition, it is an object to provide an efficient and inexpensive method for producing a layered structure with a gold layer.

Another object is to provide a most environmentally friendly method for producing a layer structure.

In addition, an object is to be able to provide a layer structure with a gold layer, the thickness of which can be varied over a wide range. Furthermore, it is an object to provide a method to produce a layer structure with an adherent gold coating as possible.

It is also an object to be able to produce a layer structure with a possible glossy surface.

It is also an object to provide a composition containing gold particles in a solvent from which a gold layer is moldable at low temperature. A first subject of the present invention is a method for producing a layer structure comprising the steps:

E 1. Providing a composition comprising i. Gold (Au) particles in an amount ranging from 0.1 to 50

Wt .-%;

ii. Balance to 100% by weight of a polar protic organic solvent;

iii. less than 5% by weight of water,

the weight%, based in each case on the total mass of the composition, being 100% by weight;

E2. Applying the composition to a substrate to obtain a precursor;

E3. Heating the precursor to a temperature in a range of 25 to 300 ° C, preferably in a range of 25 to 250 ° C, and more preferably in a range of 25 to 200 ° C, to obtain the layer structure.

Providing the composition in step El. may be done in any way that the skilled person would choose to provide the composition for such a process. Preferably, the composition is provided in a container suitable for applying the composition in step E2. suitable is. Further preferably, the container is a container having a valve for metered dispensing of the composition.

The composition includes gold (Au) particles in an amount in a range of 0.1 to 50 wt%, preferably in a range of 0.5 to 40 wt%, or preferably in a range of 1 to 20 Wt .-%, based on the total mass of the composition. Furthermore, the composition contains less than 5 wt .-%, preferably less than 4 wt .-%, or preferably less than 3 wt .-% water based on the total weight of the composition. The composition may additionally comprise at least one further component.

The composition contains as balance to 100% by weight, based on the total mass of the composition, of a polar, protic, organic solvent, the weight%, based in each case on the total mass of the composition, being 100% by weight. The polar, protic, organic solvent can be any polar, protic, organic solvent which the skilled person would use for the procedure. According to the invention, protic solvents contain hydrogen atoms which are bonded to more electronegative elements and therefore can be easily cleaved off. Preferably, the polar, protic, organic solvent has carbon atoms in a number in the range of 2 to 20. Furthermore, the polar, protic, organic solvent has at least one polar, protic radical, such as -OH, -SH, -NH, -NH 2, -COOH. Typical examples of polar, protic, organic solvents are alcohols, amines (amines are aliphatic and cycloaliphatic amines), acid amides and carboxylic acids. These are preferably lower alcohols, in particular methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol and 2-methyl-2-propanol, methoxypropanol , Ethoxypropanol, methoxyethanol, ethoxyethanol, 4-hydroxymethyl-l, 3-dioxalon, preferably methanol, ethanol, propanol, butanol or a mixture of at least two thereof. Furthermore, the polar, organic, organic solvents may be selected from the group consisting of a glycol, an amine, an acid amide and a carboxylic acid or a mixture of at least two thereof. The glycol may be selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,2,3-propanetriol (glycerol), 1,2-butanediol,

1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2,3-butanetriol, 1,2-dihydroxybenzene, 1,3-dihydroxybenzene, 1,4-dihydroxybenzene, 1,2,3-trihydroxybenzene, 1,2,4-trihydroxybenzene,

1,4-dihydroxy-2,5-dinitrobenzene, L-adrenaline, a monosaccharide, a disaccharide, a monosaccharide or disaccharide in mixtures with a liquid polyol, 1,1,1-tris (hydroxymethyl) propane, 2,2-dimethylpropanediol -l, 3, a polyethylene glycol, preferably with repeating units in a range of 3 to 500, such as mono-l, 2-propylene glycol, di-l, 2-propylene glycol, 1,2-butylene glycol, 2,3-butylene glycol or a mixture at least two of them. The amine can be selected from the group consisting of ammonia, methylamine, ethylamine, n-propylamine, i-propylamine, n-butylamine, dimethylamine, diethylamine, di-n-propylamine, di-n-butylamine, pyrrolidine, piperidine, Piperazine, N-methylpiperazine, N-ethylpiperazine, morpholine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, di (2-cyanoethyl) amine, di- (2-aminoethyl) amine, tri- (2 -aminoethyl) amine, ethanolamine, diethanolamine, triethanolamine, propanolamine, dipropanolamine and tripropa nolamin or a mixture of at least two thereof. The acid amide can be selected from the group consisting of formamide, acetamide, propionamide, butanamide, pentanamide, hexanamide, heptanamide, octanamide or a mixture of at least two thereof. The carboxylic acid may be selected from the group consisting of formic, acetic, acrylic, oxalic, citric, benzoic, nicotinic, succinic, maleic, salicylic or a mixture of at least two thereof. The designated alcohols are to be regarded as preferred.

In addition to the polar, protic, organic solvent, the composition preferably includes at least one other non-protic solvent. The non-protic solvent may be selected from the group consisting of a ketone, an aldehyde and a sulfoxide or a mixture of at least two thereof. The ketone may be selected from the group consisting of ethylene carbonate, N-methylpyrrolidone, N-ethylpyrrolidone, cyclohexanone. The aldehyde may be selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, caprylaldehyde or a mixture of at least two thereof. The sulfoxide may be, for example, dimethylsulfoxide. The composition preferably has the non-protic solvent in a range of 0.1 to 10% by weight, or preferably in a range of 0.2 to 9% by weight, in a range of 0.5 to 5% by weight. -%, based on the total mass of the composition.

The application of the composition to the substrate to obtain the precursor can be accomplished in any manner that would be appreciated by those skilled in the art for applying the composition in such a process. In this case, the substrate, hereinafter also referred to as the substrate layer, is preferably superimposed at least in part with the composition.

Preferably, the application may be a deposition of the composition or a dip in the composition or a combination of the two. The application by depositing the composition may, for. Example by spin coating, impregnation, pouring, dripping, spraying, spraying, knife coating, brushing or printing, for example via a metering pump or inkjet, screen, gravure, offset or pad printing done on the substrate layer. The composition is preferably used via a metering pump, an inkjet printing, a screen printing or gravure printing applied to the substrate layer. Preferably, the composition in a wet film thickness of 0.01 μιη to 250 μιη, preferably applied in a wet film thickness of 0.1 μι Μβ 50 μιη. Deposition according to the invention is understood to mean that the composition used for application, preferably also called liquid or printing material, is applied by means of an aid in the form of the nozzle on the surface to be overlaid. This can be done by different aids. Thus, the printing material used for applying or superimposing can be sprayed onto the substrate layer through a nozzle, sprayed or deposited through a slot nozzle. Other methods are curtain casting and spin coating. In addition, the printing material used for applying or superimposing can be applied or printed onto the surface of the substrate, for example via a roller or roller. As a spraying or spraying process, for example, the micro-dosing or digital printing via a nozzle are known. In this case, pressure can be exerted on the pressure mass used for application or superposition or the pressure mass used for application is simply applied dropwise to the surface through the nozzle.

As a further printing method, a screen printing method can be preferably used. In the screen printing process, a sieve, consisting of a dimensionally stable as possible material, such as wood; Metal, preferably steel; a ceramic or a plastic with a selected mesh size on the object to be overlaid or over the object to be overlaid, such as the substrate arranged here. On this sieve is applied via the nozzle used for applying or superimposing pressure mass and pressed with a squeegee through the mesh. In this case, due to a pattern in the screen at different locations different amounts of pressure applied for application or superimposition can be applied. Thus, due to the geometry and arrangement of the stitches, either a uniform film of the printing material used for overlaying can be applied or areas with little or no pressure applied for application can alternate with areas with a large amount of pressure applied for application. Preferably, a uniform film of the printing material used for superimposing is transferred to the surface. The screen meshes can also be partially covered by appropriately applied materials (copy layers, screen printing stencils). be concluded, so that the print mass is transferred only in defined areas with open meshes on the substrate, so as to obtain, for example, a defined structure as a pattern. Furthermore, instead of screening thin films with defined openings (stencil) can be used to superimpose the print mass.

Depending on the design of the nozzle or roller or roller and the viscosity and polarity of the composition used for superimposing, layers of different thicknesses can be applied to the desired surface of the substrate layer. The layer applied during application or superposition is preferably applied with a thickness in a range from 0.5 to 100 μm, preferably in a range from 1 to 50 μm, particularly preferably in a range from 2 to 30 μm. The thickness of the layer applied during the application is referred to below as the wet layer thickness. The wet layer thickness depends on the particular material that is applied when superposing. The wet film thickness is measured directly after the overlaying step.

In diving, for example, the surface to be coated is drawn through a bath having the composition used for application. Alternatively, the surface may also be simply dipped into the composition used for application and withdrawn, as practiced in dip coating. By repeated dipping different thicknesses of the coating can be achieved during application. In addition, the thickness of the coating depends on the choice of composition used for application, as mentioned above. In this way, wet layer thicknesses of the respective coating when applied in a range between 0.5 to 100 μιη, preferably in a range of 1 to 50 μιη, particularly preferably in a range of 2 to 30 μιη can be achieved. It is also conceivable to carry out a combination of the depositing and dipping processes.

In one embodiment, the applied composition is applied by an application opening provided over the respective surface of the layer to be overlaid, such as the substrate. In this case, the application opening is preferably connected to the surface via the composition used for application. This procedure Ren, also known as micro-dosing, has the special property that this makes it possible to easily apply different thicknesses of the overlying coating on objects, such as here the substrate surface. The application opening can be of any shape and size. It can, for example, be an application opening with a shape selected from the group of round, oval, angular and star-shaped or combinations thereof. The application opening may have an area of 10 nm ² to 1 mm ² , preferably of 100 nm ² to 0.5 mm ² , particularly preferably of 100 nm ² to 100 μm ² . Preferably, the composition used for the application, by means of a pressure in a range of 2000 to 10,000 mbar, preferably applied in a range of 2500 to 5000 mbar, more preferably in a range of 3000 to 4000 mbar through the nozzle on the surface. By combining the composition used for superimposition with the surface of the substrate, it is possible to avoid that there is a tear in the composition used for application on the surface during the application. This can be achieved that a very homogeneous film can be applied to the surface.

The application of the composition preferably takes place by means of a screen printing method or a gravure printing method. In a preferred embodiment of the method, the composition is applied during printing by a sieve or a printing cylinder. The sieve preferably includes a frame made of steel or stainless steel. In the frame, a grid or sieve is preferably arranged, which also preferably consists of stainless steel wires or high-strength synthetic fibers.

A preferred embodiment of the method is that the sieve has a mesh size in a range from 1 to 300 μm, preferably in a range from 2 to 200 μm, or preferably in a range from 3 to 90 μm. This corresponds in each case to a number of stitches of approximately 70 to 635 mesh, or of approximately 100 to 600 mesh or of approximately 200 to 500 mesh, mesh corresponding to the unit of wire mesh / inch or wire mesh / 2.54 cm. When applying by screen printing, any standard squeegee can be used as the squeegee. Preferably, the doctor includes a plastic. Preferably, the doctor has a doctor blade hardness in a range of 40 to 80 Shore A. The composition has preferably a viscosity in a range of 500 to 100,000 mPa * s, or preferably in a range of 700 to 50,000 mPa * s.

The substrate may have any shape that allows application of the composition to the substrate. The substrate preferably has at least one coherent surface. The at least one contiguous surface preferably has an area in a range from 1 mm ² to 10 m ² , or preferably in a range from 10 mm ² to 5 m ² , or preferably in a range from 100 mm ² to 1 m ² . The substrate may be round, circular, angular, conical or oval. Preferably, the shape of the substrate is selected from the group consisting of a sphere; a cone; a circle; a polygon such as a triangle, a square, a rectangle, a trapezoid, a pentagon, a hexagon, a heptagon, or an octagon; an oval or a combination of at least two of them. The substrate is preferred from the composition when applied in step E2. in a range of 5 to 100%, or preferably in a range of 10 to 100%, or preferably in a range of 15 to 100%, based on the entire contiguous surface of the substrate, superimposed. The composition can be applied flat on the surface of the substrate or in patterns. Thus, composition-overlapping regions on the substrate may alternate with non-overlapping regions. The pattern may have a regular shape, such as a checkered, honeycomb, or diamond pattern. Alternatively or additionally, the composition may be applied to the substrate in an irregular shape.

To the application of the composition in step E2. to obtain the precursor, heating of the precursor follows in step E3. to a temperature in a range of 25 to 200 ° C, preferably in a range of 40 to 180 ° C, or preferably in a range of 50 to 150 ° C at. The heating can be done in any way on the precursor which would be chosen by the skilled person for this purpose. The heating is preferably heating by a method selected from the group consisting of irradiation, heating in an oven, heating with hot gas, or a combination of at least two. The irradiation can be effected, for example, by means of IR radiation, laser radiation, UV radiation or a combination thereof. Heating in an oven, such as a In a hot air oven, for example, can be discontinuous or continuous. Heating with a hot gas may be accomplished, for example, by passing a hot gas stream such as air, nitrogen, oxygen or a mixture thereof over the applied composition. The duration of heating in step E3. preferably takes place in a range of 0.5 to 10 hours, or preferably in a range of 0.5 to 5 hours, or preferably in a range of 0.5 to 3 hours. By heating, a layer structure is obtained, including at least the substrate and a gold-containing layer, also referred to below as the gold layer. In a preferred embodiment of the method, the gold particles have a diameter in a range from 2 to 25 nm, preferably in a range from 3 to 20 nm, or preferably in a range from 4 to 18 nm. The diameter of the gold particles should be considered as the mean diameter of the particles. The diameter of the gold particles can be determined by microscopic observation of the mixture. For a precise determination of the size, a circle is fictitiously placed around the two furthest points of the particles. The diameter of the fictive circle corresponds to the diameter of the particles. Preferably, the gold particles have a round to oval extent. The gold (Au) particles preferably have a particle size distribution D ₅₀ of 20 nm, or preferably of 15 nm, or preferably of 12 nm, which means that not more than 50% of the particles are larger than the specified diameter. The particle size can be determined by various methods. The particle size is preferably determined by means of laser diffraction, light microscopy, optical single particle counting or a combination of at least two of these. Furthermore, the determination of the particle size as well as the particle size distribution is preferably carried out on the basis of individual optical evaluation of images by means of transmission electron microscopy (TEM).

In a preferred embodiment of the method, the viscosity of the composition is selected in a range from 1 to 100,000 mPas, preferably in a range from 10 to 90,000 mPas, or preferably in a range from 20 to 50,000 mPas. The viscosity was determined at a shear rate of 1/500 s. In a preferred embodiment of the process, the protic polar organic solvent comprises at least 20% by weight of a polyhydric alcohol. The polyhydric alcohol is an organic compound having at least two alcoholic groups. Preferably, the polyalcohol has alcoholic radicals in an amount ranging from 2 to 10. The polyhydric alcohol may have further functional groups. The at least one further functional group may be selected from the group consisting of -S-, -SH, -O-, -OOH, = O, -N-, -NH, -NH ₂ , -P, -P (OH) ₃ , -Cl, -F, -Br or a combination of at least two thereof.

In a preferred embodiment of the process, the polyhydric alcohol has carbon atoms in a number in the range of 2 to 20.

In a preferred embodiment of the process, the polyhydric alcohol is selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2,3-propanetriol (glycerol), 1,2- Butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2,3-butanetriol, 1,2-dihydroxybenzene, 1, 3-dihydroxybenzene, 1, 4-dihydroxybenzene, 1,2, 3-trihydroxybenzene, 1,2,4-trihydroxybenzene, 1,4-dihydroxy-2,5-dinitrobenzene, L-adrenaline, a monosaccharide, a disaccharide, a monosaccharide or disaccharide in admixture with a liquid polyol, I, I, I Tris (hydroxymethyl) propane, 2,2, -dimethylpropanediol-1,3, a polyethylene glycol, preferably having repeating units in a range of 3 to 500, or a mixture of at least two thereof.

In a preferred embodiment of the method, the composition further comprises a mercapto-carboxyl compound of the general formula (I),

wherein

Ri is a substituted, unsubstituted, branched or unbranched, cyclic or polycyclic C ₁ -C 20 -hydrocarbon radical, or at least one salt of this mercapto-carboxyl compound. In a preferred embodiment of the process, the substituted, unsubstituted, branched or unbranched, cyclic or polycyclic C 1 -C 20 -hydrocarbon radical has at least one, preferably two or all of the following properties: el. at least one of the C atoms of the Ci - C2o hydrocarbon radical by at least one nitrogen atom, an oxygen atom, a phosphorus atom, a sulfur atom, a hydroxyl group, a carboxyl group, a halide, an amine, an amide, a phosphate group, a sulfate group or a combination of at least two have been replaced; or

e2. the C 1 -C 20 -hydrocarbon radical may be substituted or branched with further substituted, unsubstituted, branched or unbranched C 1 -C 20 -hydrocarbon radicals; or

e3. at least one of the C atoms of the Ci - C2o hydrocarbon radical is replaced by an aromatic radical or a 5-, 6- or 7-membered heteroaromatic ring with 1, 2, 3 or 4 nitrogen, oxygen and sulfur atoms, wherein the heteroaromatic radical having halogen atoms, hydroxyl, nitro, amino groups, protected amino radicals, cyano, trifluoromethyl groups, hydrocarbon radicals having 1 to 4 carbon atoms, alkoxy radicals having 1 to 4 carbon atoms may be substituted.

An unsubstituted C 1 -C 20 -hydrocarbon radical is to be understood as meaning a hydrocarbon radical consisting of 1 to 20 -CH ₂ - or -CH groups. In the context of the invention, a substituted C 1 -C 20 -hydrocarbon radical is to be understood as meaning a hydrocarbon radical consisting of 1 to 20 -CH ₂ groups in which at least one -CH ₂ - or -CH- group is an H atom by another type Atom or another atomic group is replaced. The different atom may be selected from the group consisting of a carbon atom, a nitrogen atom, an oxygen atom, a phosphorus atom, a sulfur atom, a halide, or a combination of at least two thereof. The different atomic group may be selected from the group consisting of a substituted hydrocarbon radical, a non-substituted hydrocarbon radical, a branched hydrocarbon radical, an unbranched hydrocarbon radical, a saturated hydrocarbon radical, a hydrocarbon radical, an unsaturated hydrocarbon radical, a cyclic hydrocarbon radical, a polycyclic hydrocarbon radical, an aromatic hydrocarbon radical, a non-aromatic hydrocarbon radical, an acyl group, a hydroxyl group, a carboxyl group, a primary amine, a secondary amine, a tertiary amine, an amide, a phosphate group, a sulfate group, a sulfonate group, a thiol group or a combination of at least two thereof.

Under an unbranched Ci - C ₂ o-hydrocarbon radical is a straight hydrocarbon radical comprising from 1 to 20 -CH ₂ - or -CH understand groups. Under a comparable branched Ci - C ₂ o-hydrocarbon radical of 1 to 20, a hydrocarbon radical consisting - CH ₂ - or -CH-groups to understand, in which at least one CH ₂ - or -CH-group, a H atom by replaced another hydrocarbon radical. This further hydrocarbon radical may likewise be substituted or unsubstituted, branched or unbranched, but also cyclic or polycyclic.

Under a cyclic Ci - C ₂ o-hydrocarbon radical, a hydrocarbon radical consisting of 1 to 20 -CH ₂ - or -CH-groups to understand, in which the carbon atoms are arranged in a ring. Under a polycyclic Ci - C ₂ o-hydrocarbon radical, a hydrocarbon radical consisting of 1 to 20 -CH ₂ - or -CH-groups to understand, in which the carbon atoms are annularly arranged in two or more rings. The cyclic and polycyclic hydrocarbon radicals may also have aromatic rings.

The substituted, unsubstituted, branched or unbranched, cyclic or polycyclic C ₁ -C 20 -hydrocarbon radical may have the properties mentioned in one of the following combinations:

LI substituted C ₁ -C 20 -hydrocarbon radical;

L2 unsubstituted C ₁ -C 20 -hydrocarbon radical;

L3 substituted, branched C ₁ -C 20 -hydrocarbon radical;

L4 substituted, unbranched C ₁ -C 20 -hydrocarbon radical;

L5 unsubstituted, branched C ₁ -C 20 -hydrocarbon radical; L6. unsubstituted, unbranched C 1 -C 20 -hydrocarbon radical;

L7. substituted, branched, cyclic C 1 -C 20 -hydrocarbon radical;

L8. substituted, unbranched, cyclic C 1 -C 20 -hydrocarbon radical;

L9. unsubstituted, branched, cyclic C 1 -C 20 -hydrocarbon radical;

L10. unsubstituted, unbranched, cyclic C 1 -C 20 -hydrocarbon radical;

LI 1. Substituted, branched, polycyclic C 1 -C 20 -hydrocarbon radical;

LI 2. substituted, unbranched, polycyclic C 1 -C 20 -hydrocarbon radical;

LI 3. unsubstituted, branched, polycyclic C 1 -C 20 -hydrocarbon radical;

LI 4. unsubstituted, unbranched, polycyclic C 1 -C 20 -hydrocarbon radical.

As already mentioned, the substituted hydrocarbon radicals can again have the abovementioned properties or combinations of properties.

In a preferred embodiment of the method, the composition includes the mercapto-carboxyl compound in a range of 0, 1 to 4 wt .-%, preferably in a range of 0.5 to 3.5 wt .-%, or preferably in one Range of 0.3 to 3.0 wt .-%, based on the total mass of the composition.

In a preferred embodiment of the method, the mercapto-carboxyl compound is selected from the group consisting of L-cysteine, D-cysteine, γ-L-glutamyl-L-cysteinyl-glycine (glutathione), (RS) -N- (2 -Mercapto-l-oxopropyl) -glycine (tiopronine), mercaptosuccinic acid, N-acetylcysteine, thiosalicylic acid, dimercaptosuccinic acid, L-methionine, D-methionine, thiourea, 2-mercaptopropionic acid, thioglycerol, thiodipropionic acid, cystine, methyl-3-mercaptopropionate , Na thioglycolate or a mixture of at least two thereof.

In a preferred embodiment of the method, the composition comprises at least one further metal selected from the group consisting of silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), rhodium (Rh) or a combination of at least two thereof , The at least one further metal may be present as metal particles or present as a further organometallic complex. The composition contains the additional metal preferably in a range of 0.1 to 5 wt .-%, or preferably in a range of 0.2 to 4.5 wt .-%, or preferably in a range of 0.5 to 4 wt .-%, based on the total mass of the composition. The organic component of the organometallic complex preferably includes a molecule having at least one, at least two or more carbon atoms, preferably in a range of 2 to 100, or preferably in a range of 4 to 50, or preferably in a range of 5 to 20 carbon atoms. It is preferable that the organic component includes one or two or more non-metallic atoms other than carbon. It is further preferred that at least one of the at least one non-metallic atoms interact at least coordinatively, preferably ionically, with the metallic component of the organic compound. It is also possible to form a covalent bond between at least one nonmetallic atom and the metallic component. The non-metallic atoms are preferably selected from the group consisting of oxygen, sulfur, nitrogen, phosphorus, silicon, a halogen or a mixture of at least two thereof. The at least one carbon atom preferably forms an organic compound together with the at least one non-metallic atom in the organic component of the organometallic compound. In a preferred embodiment of the process, the organometallic compound comprises an organic component selected from the group consisting of a carbonate, an oxalate, an ester, a carboxylate, a halocarboxylate, a hydroxycarboxylate, an acetonate, a ketonate, a phosphate, a phosphite, a Phosphide, a phosphine, a sulfonate and a sulforesinate or a mixture of at least two of them. The organic component is preferably selected from the group consisting of acetate, propionate, butanoate, isobutanoate, ethyl butyrate, pentanoate, hexanoate, heptanoate, octanoate, isooctanoate, nonanoate, decanoate, isononate, pivalate, cyclohexane butyrate, acetylacetonate, ethylhexanoate, hydroxypropionate, trifluoroacetate Hexafluoro-2,4-pentadionate; Neodecanoates, methanesulfonate, ethanesulfonate, propanesulfonate, trifluoromethanesulfonate, p-toluenesulfonate, benzenesulfonates, sulfurized unsaturated natural and / or synthetic resins, for example, turpentine, rosin and copaiba balsam, or a mixture of at least two thereof.

As already mentioned above, the composition may contain at least one further component in addition to the components already mentioned. The at least one further component is preferably selected from the group consisting of a binder, a further solvent, a crosslinker, another additive or a mixture of at least two thereof. The binders used can be, for example, polyurethane, polyacrylates, polyesters, polyvinyl alcohols, polysulfones or a mixture of at least two thereof. The further solvent is preferably selected from the group consisting of dimethyl sulfoxide (DMSO), ethylene glycol, N-methyl-2-pyrrolidone (NMP), ammonia, an alcohol such as ethanol, isopropanol or hexanol, ethoxyethanol, methoxyethanol, methoxypropanol, ethoxyethanol or a mixture of at least two of them. The crosslinker may be, for example, a silane. The further additive can be selected from the group consisting of nonionic surfactants, such as polyalkylene glycol ethers or alkyl polyglucosides, ionic surfactants, such as alkyl carboxylates, alkylbenzenesulfonates or alkanesulfonates, or a mixture of at least two thereof. The composition preferably contains the at least one further component in a range from 0.1 to 5% by weight, preferably in a range from 0.5 to 4.5% by weight, or preferably in a range from 1 to 4 wt .-%, based on the total mass of the composition.

In a preferred embodiment of the method, the composition has a pH in a range from 3 to 8, or preferably in a range from 4 to 7. In a preferred embodiment of the method, the composition further comprises a surface-active substance. The composition preferably contains the surfactant in a range of 0.001 to 5 wt%, preferably in a range of 0.005 to 4 wt%, or preferably in a range of 0.0 to 3 wt%. The surfactant may be selected from the group consisting of a nonionic surfactant, an anionic surfactant, a cationic surfactant and an amphoteric surfactant, or a mixture of at least two thereof. All surfactants mentioned include a non-polar part and a polar part. The non-polar part may be selected from the group consisting of an alkyl group, an alkylbenzene group or a combination thereof. The polar portion of the nonionic surfactants may be selected from the group consisting of an alcohol group, an ether group, an acrylate group, or a combination of at least two thereof. The polar portion of the anionic surfactant may be selected from the group consisting of a carboxylate, a sulfonate, a sulfate or a mixture of at least two thereof. The polar part of the cationic surfactant may be, for example, a quaternary ammonium group. The polar portion of the amphoteric surfactant may be selected from a combination of at least one polar portion of a cationic and an anionic surfactant. Further preferably, the surfactant includes a silicon-containing compound. Examples thereof are dimethylpolysiloxane having a molecular weight in a range from 400 to 10,000 g / mol, preferably in a range from 500 to 9000 g / mol, or preferably in a range from 600 to 8000 g / mol. Examples of commercially available surfactant products are polyether-modified polydimethylsiloxane as BYK-333 ^®, polyacrylate, BYK-381 ^®, and polypropylene glycol available as DISPERBYK-193 ^®, all at Byk-Chemie GmbH, Wesel.

In a preferred embodiment of the method is in a further step E4. a protective layer applied to at least a portion of the layer structure. The protective layer is preferably selected from the group consisting of physically drying lacquers, oxidatively crosslinking lacquers, thermally crosslinking lacquers (for example commercially available clearcoats for cars) and radiation-crosslinking lacquers.

The substrate to which the composition is applied as described above can be any material that would be used by those skilled in the art to make a layered construction. In a preferred embodiment of the method, the substrate is selected from the group consisting of a paper, a wood, a textile, a glass, a polymer, a metal, a ceramic, a horny layer, in particular fingernails or toenails, or a combination of at least two from that. The paper can be any type of paper that would be selected by those skilled in the substrate in the process. The paper preferably has a density in a range of 10 to 500 g / m ² , or preferably in a range of 20 to 400 g / m ² , or preferably in a range of 50 to 350 g / m ² . The wood can be any type and form of wood that would be selected by the person skilled in the art for the substrate in the process. The textile may be any textile that would be selected by a person skilled in the art for the substrate in a layered construction. The textile may be in the form of fibers, fabrics or as a flow. The textile can be woven, braided, knitted, knitted or unwoven. The textile may be made of natural fabrics such as wool, cotton, silk, cellulose or other natural fibers. The textile can also consist of fibers of artificial materials, such as, for example, nylon, polyesters, polyacrylic acids, polyacrylonitriles, polyamides, polyaramides or other polymers, or of carbon, glass or metal fibers (wires). The textile may also consist of mixtures of at least two of the mentioned materials.

The glass can be any glass that would be selected by the person skilled in the art for the substrate in a layered structure. The glass is preferably selected from the group consisting of an alkali glass, a non-alkali glass, a silicate glass or a mixture of at least two thereof. The glass is preferably selected from the group consisting of a soda-lime glass, a lead caliglas, borosilicate glass, aluminum silicate glass, quartz glass or a mixture of at least two thereof.

The polymer may be any polymer that would be selected by a person skilled in the art for the substrate in a layered construction. The polymer is preferably selected from the group consisting of a polyethylene, polypropylene, a polyethylene terephthalate, a polyvinyl alcohol, a polyvinyl pyrrolidone, a polyvinyl chloride, a polyvinyl acetate, a polyvinyl butyrate, a polyacrylic acid ester, a polyacrylic acid amide, a polymethacrylic acid ester, a polymethacrylic acid amide, a Polyacrylonitrile, a styrene / acrylic acid ester, a vinyl acetate / acrylic ester and an ethylene / vinyl acetate copolymer, a polybutadiene, a polyisoprene, a polystyrene, a polyether, a polyester, a polycarbonate, a polyurethane, a polyamide, a polyimide, a polysulfone, a melamine-formaldehyde resin, an epoxy resin, a silicone resin, or a mixture of at least two thereof. The metal may be any metal that would be selected by those skilled in the substrate in a layered construction. Preferably, the metal is selected from the group consisting of iron, steel, aluminum, silver, titanium, copper, gold, tin, zinc, lead, silicon or a mixture or combination of at least two thereof.

The ceramic may be any ceramic material that would be selected by one skilled in the art for the substrate in a layered construction. The ceramic is preferably selected from the group consisting of an oxide ceramic, a silicate ceramic, a non-oxide ceramic or a mixture of at least two thereof.

The oxide ceramic is preferably selected from the group consisting of a metal oxide, a semi-metal oxide or a mixture thereof. The metal of the metal oxide may be selected from the group consisting of aluminum, beryllium, barium, boron, calcium, magnesium, sodium, potassium, iron, zirconium, titanium or a mixture of at least two thereof. The metal oxide is preferably selected from the group consisting of aluminum oxide (Al ₂ O ₃ ), sodium oxide, boron oxide, calcium oxide, magnesium oxide (MgO), silicon oxide (SiO ₂ ), zirconium oxide (ZrO ₂ ), yttrium oxide (Y ₂ O ₃ ), aluminum titanate (Al ₂ Ti0 ₅ ) or a mixture of at least two thereof. The semimetal of the semimetal oxide is preferably selected from the group consisting of boron, silicon, arsenic, tellurium or a mixture of at least two thereof.

The silicate ceramic is preferably selected from the group consisting of a steatite (Mg ₃ [Si ₄ Oio (OH) ₂ ]), cordierite (Mg, Fe ²⁺ ) ₂ (Al ₂ Si) [Al ₂ Si ₄ O ₈ ]), Mullite (Al ₂ Al _{2 + 2x} Si ₂ _ _2x Oi ₀ _-x with x = oxygen vacancies per unit cell), feldspar (Ba, Ca, Na, K, NH ₄ ) (Al, B, Si) 408) or a mixture of at least two of them. The silicate ceramic is preferably a porcelain.

The non-oxide ceramic may be selected from the group consisting of a carbide, a nitride or a mixture thereof. The carbide may be selected from the group consisting of silicon carbide (SiC), boron carbide (B ₄ C), titanium carbide (TiC), tungsten carbide, cementite (Fe 3 C). The nitride may be selected from the group consisting of silicon nitride (S1 ₃ N ₄ ), aluminum nitride (A1N), silicon aluminum oxynitride (SIALON) or a mixture of at least two thereof.

In a preferred embodiment of the method, the substrate has a conductivity of less than 10 ¹³ S / cm. Preferably, the substrate has an electrical conductivity in a range of 10 ³ S / cm to 10 ^-13 S / cm, or preferably in a range of 10 ² S / cm to 10 ^" S / cm, or in a range of 10 ¹ S. / cm to 10 ^{~ 8} S / cm.

In a preferred embodiment of the method, the application of the composition takes place in step E2. through a brush, a screen, a felt-tip pen, a fountain pen or a nozzle. As a brush, any conventional brush can be used, which would select the expert for this. The selection and dimensions of the screen and the nozzle have already been given above. Another object of the present invention is a precursor of a layer structure obtainable according to the process steps El and E2 of the method described above.

In a preferred embodiment of the precursor, the precursor has at least one of the following properties:

VI. a thickness of the substrate in a range of 0, 1 mm to 5 cm;

V2. a thickness of step E2. applied composition in a range of 0.1 μιη to 70 μιη, preferably in a range of 0.1 to 10 μιη, or preferably in a range of 0.1 to 1 μηι;

V3. a conductivity of the substrate of less than 10 ¹³ S / cm;

V4. a conductivity of in step E2. applied composition in a range of 10 ^"1 S / cm to 10 ^{~ 8} S / cm;

Another object of the present invention is a layer structure obtainable by the method described above. In a preferred embodiment of the layer structure, the layer structure has at least one of the following properties:

51. wherein the layer structure comprises a metal layer containing at least 70% by weight of gold in a thickness in a range from 0.05 μm to 1 μm;

52. a conductivity of less than 10 ¹³ S / cm;

53. a gloss in a range of 500 to 1300 GE;

54. a density in a range of 10 to 20 kg / 1; preferably in a range of 12 to 19.6 kg / l, or preferably in a range of 15 to 19.4 kg / l.

Another object of the present invention is a composition comprising: zl. Gold (Au) particles in an amount ranging from 0.1 to 50% by weight; z2. Water in a range of 0 to 5% by weight;

z3. a polar, protic, organic solvent as balance to 100% by weight; wherein the wt .-%, in each case based on the total mass of the composition, 100

% By weight.

In a preferred embodiment of the composition, the composition includes at least one further component, preferably two further components, or preferably all further components selected from:

z4. Polyvinylpyrrolidone in an amount ranging from 0 to 10% by weight, based on the total weight of the composition;

z5. a polyhydric alcohol in an amount ranging from 0 to 90% by weight, based on the total weight of the composition;

In a preferred embodiment of the composition, the polyhydric alcohol is selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,2,3-propanetriol (glycerol), 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2,3-butanetriol, 1,2-dihydroxybenzene, 1, 3-dihydroxybenzene, 1, 4-dihydroxybenzene, 1,2,3-trihydroxybenzene, 1,2, 4-trihydroxybenzene, 1,4-dihydroxy-2,5-dinitrobenzene, L-adrenaline, a monosaccharide, a disaccharide, a monosaccharide or disaccharide in mixtures with a liquid polyol, 1,1-tris (hydroxymethyl) propane, 2,2, -dimethylpropanediol-1, 3, a polyethylene glycol, preferably with repeat units ranging from 3 to 500, or a mixture of at least two thereof.

In a preferred embodiment of the composition, the gold (Au) particles have a particle size D ₅₀ of 20 nm or less, preferably 17 nm or less, or preferably 15 nm or less.

Another object of the present invention is an article comprising a previously described layer structure or a layer structure obtainable by the previously described method. The article may be any item that would be selected by the skilled person. The article may be selected from the group consisting of a glass plate, a cylindrical glass body, an irregularly shaped glass body, a tile, a stone plate, a metal plate, a wooden plate, a plastic plate or foil, a vase, a plate, a cup, a Cup or a combination of at least two of them.

The invention will now be explained in more detail by means of measuring methods, non-limiting examples and exemplary figures. measurement methods

Unless otherwise stated, the test methods and examples are performed under standard conditions. Unless otherwise indicated,% ranges are% by weight ranges.

substrates:

The screen-printable pastes were printed on flat glass plates measuring 10 × 7 × 0.3 cm. The Planglasplatten were purchased from the company Leco glass in Schönsee. Viscosity:

The viscosity of the printing compounds was measured using a Physica MCR 301 plate-cone system with Rheoplus Version 32 V3.40 software (by Anton Paar) at a temperature of 20 ± 0.1 ° C using a CP 25-1 measuring cone (angle 1 ° ). After 30 seconds of temperature control, a ramp of the shear rate of 1 s ^"1 to 500 s ^{" 1} was generated with 25 equidistant steps, each step being kept the same for a duration of 30 seconds. The shear rate of 500 s ^-1 was maintained for 30 seconds, after which the shear rate was reduced in 25 equidistant increments as above to 1 s ^-1 . The viscosity was determined at a shear rate of 500 s ^-1 at the end of 30 seconds.

Wet film thickness:

To measure the layer thickness of the layers cured as described above, a Zeiss 5104775 light-section microscope was used at 200 × magnification. For the measurements, the printed and cured sample was placed on the sample table and the 0 position was set. Subsequently, the horizontal line of the reticle was aligned with the surface of the substrate. The crosshair was then aligned with the surface of the layer and the measured value read off. The measurements were carried out at room temperature (23 to 25 ° C).

Transmission Electron Microscopy (TEM):

For transmission electron microscopy, a Phillips EM420 device with an acceleration voltage of 120 KV was used. From the sample to be tested, 1 drop was dropped on the TEM grid. Subsequently, the TEM grid was inserted into the device. During the generation of the high vacuum of 10 ^"4 Pa required for the measurement, the solvents present in the suspension evaporated completely.The particles detectable in the images were all measured individually, as far as detectable. The particle size data are based on the statistical evaluation of the individual values obtained. Conductivity:

To measure the conductivity of the solutions, a Seven Go ™ SG3 (from Mettler-Toledo) with an Inlab 738 probe (Mettler Toledo) was used. The calibration was carried out using aqueous solutions with a concentration of 0.1 and 0.01 mol / 1 KCl.

Shine:

The measurement was carried out in accordance with EN ISO 2813: 1999. A device type GL0030 from TQC Therminport Quality Control GmbH was used. The measurement was carried out at a Einstrahl- / measurement angle of 20 °. Glass was used as substrate, the layer thickness was about 0.3 cm after drying at 150 ° C for one hour. Calibration was carried out using the polished black glass plate integrated in the device. PH value:

The pH of the solution was measured directly using a pH meter type Portamess (Knick Elektronische Messgeräte GmbH & Co. KG). The glass electrode, type SE200N with integrated temperature measurement-PT100 resistance sensor; against 3 mol / 1 KCL solution - was immersed in the solution to be measured until a constant pH was indicated.

Screen printing:

The pastes were applied by hand pressure (plastic blade) through a polyester fabric (with or without structure) 120/34 (120 threads / cm with a diameter of 34 μιη), commercially available from Sefar AG, directly on glass plates. The prints were in each case at room temperature and normal pressure. drying:

The printed glass plates were placed in a heated at 150 ° C drying oven (Thermo Scientific, type UT6060) and left there for 60 minutes.

Examples Example 1:

Preparation of a nanogold solution:

A) reduction

In a 3 liter beaker, a solution of 427 grams of distilled water, 7 g of polyvinylpyrrolidone type K-15 (AppliChem GmbH, Darmstadt), 22.3 g of anhydrous trinitrate citrate (Merck KGaA, Darmstadt) with stirring heated to 99 to 100 ° C within 25 minutes. The beaker was covered with a watch glass. The temperature was monitored with a thermometer. When the temperature was reached, 46.0 g of a 21.75 percent sodium-gold (III) chloride solution (Heraeus Precious Metals GmbH) (adjusted to pH = 6.9) were added with vigorous stirring within 15 seconds. With vigorous foaming, a quick color change from yellow to black to purple began. Subsequently, the solution was stirred for a further 10 minutes at 97-98 ° C. to complete the reaction. The solution was cooled to room temperature.

B) Precipitation

The deep red solution was filtered through a paper filter (Schleicher & Schuell GmbH, Dassel) with a pore size of 15 to 20 microns and then with concentrated hydrochloric acid (Merck KGaA, Darmstadt) to a pH of 3.0 to 3 , Set to 1/25 ° C. Subsequently, the nanogold was precipitated as a black precipitate at room temperature by dropwise addition of a 5% aqueous solution of the precipitants indicated in Table 1. The precipitation process is over when the color of the solution turns black without leaving a bluish tint. When using mercapto Succinic acid as precipitant required 300 ml of precipitating solution to obtain a black precipitate.

C) cleaning

The black precipitate was allowed to settle overnight and carefully decant the supernatant clear, brown mother liquor. The precipitate was then washed 6 times with 100 g of acidic distilled water (pH 1.0-1.2) at room temperature. For each wash, it was stirred for 10 minutes and allowed to settle for at least 3 hours. After 3 hours, the wash solution was decanted. It was then washed with enough distilled water so that the pH of the decanted water was 1.8-2.0 at 25 ° C. The wash water had a dry residue at 100 ° C of less than 0.02%. If the dry residue is higher than 0.02%, further washes with wash solution or distilled water are necessary until a dry residue (100 ° C) of 0.02%) or less is reached.

D) Disperse

The black residue was slurried in 40 g of deionized water (2.5-3.0 μ 8 / ΰΐ conductivity) and adjusted to pH 4.5-5.0 / 25 ° C with 10% aqueous ammonia solution. The result was a deep red dispersion which was filtered through paper filters (20-30 micrometers pore size) (Schleicher & Schuell GmbH, Dassel). The gold content of the resulting suspension was 20%> Au (gravimetric determination of the ignition residue).

Table 1: Mean particle size D50 for different precipitants:

The mercaptosuccinic acid was obtained from Alfa Aesar GmbH & Co. Kg, Karlsruhe, N-acetylcysteine from Merck KGaA, Darmstadt), thiodiethanol from the company Fluka Chemie GmbH, CH-Buchs. The optical properties were visually assessed.

From the results of Table 1 it can be seen that an increase in the particle size leads to a change in the optical properties of the composition. If the particle size is below 15 nm, a glossy composition is obtained. If the particle size is above 20 nm, a silk-matt composition is obtained. On the basis of the particle size, therefore, the gloss property of the composition can be controlled. Examples of screen-printable pastes

Example I, II and III ::

Table 2 lists the ingredients for three different screen-print capable paste I, II and III containing gold:

Table 2: Example formulations for screen-printable pastes Components 1-6 were weighed into a glass jar of at least 500 g in turn. While stirring with a magnetic stirrer at 85 ° C each 40g of water were evaporated. After complete cooling, the component 7 was added and homogenized by means of a three-roll mill (EXAKT, Norderstedt, laboratory roller mill) at room temperature. Two homogenization passes were performed.

Subsequently, the solution from Example 1 with the precipitant mercaptosuccinic acid sample la) or the pastes from Examples I to III were applied to various substrates, also called application. The conditions, the nature of the application and the heating conditions are summarized in Table 3. Table 3 also lists the results of this application.

Table 3: Examples of the inventive application and heating of different substrates with compositions according to the invention in the form of solutions and pastes.

Examples IV and V

Table 4 lists the ingredients for two different screen printable pastes IV and V which contain gold, platinum and palladium for a white gold treatment:

Table 4: Examples of the inventive application and heating of different substrates with compositions according to the invention in the form of solutions or pastes

Components 1-7 of Table 4 were weighed into a corresponding tray in turn. While stirring with a magnetic stirrer at 85 ° C 279g of water were evaporated. After complete cooling, the component 8 is added and homogenized by means of a three-roll mill (EXAKT, Norderstedt, laboratory roller mill) at room temperature. Two homogenization passes were performed. Nano-platinum solution, or nano-palladium solution can be commercially available from the company. Strem Chemicals Inc. in Kehl. The following is a schematic representation of the method steps of a method according to the invention;

schematic representation of a precursor according to the invention; schematic representation of a layer structure according to the invention;

schematic representation of a layer structure according to the invention with additional protective layer;

schematic representation of an article with inventive layer structure;

an electron micrograph of a composition according to the invention according to Example 1 sample a);

an electron micrograph of a further inventive composition according to Example 1 sample b);

an electron micrograph of a further inventive composition according to Example 1 sample c); shown.

FIG. 1 schematically shows the steps of the method according to the invention. In step El 30, the composition 6 of example 1 is provided in a container. In step E2 40, the composition 6 is applied to a substrate 4, for example in the form of a glass pane with the dimensions 7 * 10 cm by means of screen printing with a mesh size of 150 μιη means of a 70 shore rubber squeegee. The wet film thickness of the composition 6 is about 20 μιη. The substrate 4 together with the composition 6 forms the precursor 12 according to the invention. The substrate 4 together with the composition 6 becomes in step E3. 50 in a hot air oven, Fisher Scientific, type UT6060 for 1 h at 150 ° C under atmospheric pressure. In this case, a gold layer 8 is formed from the composition 6 and in this way an inventive layer structure 2 is obtained. Optionally available in Step E4. at least on the gold layer 8 formed from the composition 6 or over the entire layer structure 2, a protective layer 10 in the form of a commercial transparent lacquer (eg clear lacquer for car painting, such as Profix 2K MS clearcoat CP400 or Pro fix 2K clearcoat matt CM 10).

FIG. 2 a shows a precursor 12 which consists of a substrate 4 to which a composition 6 has been applied. The substrate 4 may be, for example, a paper, a glass or a ceramic. In this example, the substrate 4 is a 1 mm thick polypropylene film measuring 20 * 20 cm.

As described for FIG. 1, a layer structure 2, as shown in FIG. 2 b, is formed by heating at 50 ° C. of the precursor 12 from FIG. 2 a. This layer structure 2 consists of the substrate 4 and a gold layer 8. The gold layer has a thickness of 1 μιη. FIG. 2c shows the layer structure 2 from FIG. 2b, with a protective layer 10 additionally being applied to the gold layer 8. Alternatively or additionally, the protective layer 10 can also be applied to the underside of the substrate 4.

FIG. 2d shows an article 20 consisting of a table top 22 onto which a layer structure 2 has been applied. The layer structure 2 includes the substrate 4, the gold layer 8 and the protective layer 10. The layer structure 2 may have the same dimensions and materials as described in FIGS. 2a and 2b.

FIG. 3 shows a transmission electron microscopy image of a composition 6 according to the invention. The composition corresponds to Example 1 sample a). The magnification of the transmission electron microscopy images was 45000. It can be clearly seen that the round to oval-shaped gold particles have a diameter in a range of 1 to 10 μιη, wherein about half of the particles have a diameter of below 5 μιη, which corresponds to a D ₅₀ of 4.9 nm. 10% of the particles have a diameter of 2.8 nm and smaller, which corresponds to a D ₁₀ of 2.8 nm, and 90% of the particles have a diameter of 10.1 nm and smaller, giving a D ₉₀ of 10.1 nm. In this case, particles that adhere to other particles were considered as individual particles. The diameter was determined on a free side of the adhered particles. FIG. 4 shows a photograph with a transmission electron microscope (TEM) of the same type as described in FIG. FIG. 4 shows a composition 6 according to example 1 of sample b. FIG. 4 was measured at a magnification of 45,000. It can be seen in FIG. 4 that the gold particles have diameters in a range from 3 to 16 nm, with approximately half of the particles having a diameter of less than 10 nm, which corresponds to a D50 of 9.1 nm. 10% of the particles have a diameter of 5.5 nm and smaller, which corresponds to a D ₁₀ of 5.5 nm, and 90% of the particles have a diameter of 15.8 nm and smaller, giving a D ₉₀ of 15.8 nm corresponds. In this case, particles that adhere to other particles were considered as individual particles. The diameter was determined on a free side of the adhered particles.

FIG. 5 shows a photograph with a transmission electron microscope of the same type as described in FIG. FIG. 5 shows a composition 6 of example 1 sample c) with a magnification of 45,000. In FIG. 5 it can be seen that the gold particles have diameters in a range from 7 to 40 nm. About half of the particles have a diameter of less than 27 nm, which corresponds to a D50 of 24.9 nm. In this case, particles that adhere to other particles were considered as individual particles. The diameter was determined on a free side of the adhered particles.

As can already be seen from Table 1, the gloss of the composition 6 depends on the particle size of the Au particles. While the composition 6 of Figures 3 and 4 appear glossy, the composition 6 of Figure 5 is semi-gloss.

The TEM images were taken on carbon filament-loaded copper meshes as commonly used for TEM recordings. LIST OF REFERENCE NUMBERS

2 layer construction

4 substrate

6 composition

8 gold layer

10 protective layer

12 precursors

20 Subject

22 table top

30 step El.

40 step E2.

50 step E3.

60 step E4.

Claims

claims

1. A method for producing a layer structure (2) comprising the steps:

El. Providing a composition (6)

i. Gold (Au) particles in an amount ranging from 0.1 to 50% by weight;

ii. Balance to 100% by weight of a polar protic organic solvent;

iii. less than 5% by weight of water,

wherein the wt .-%, each based on the total mass of the composition (6), 100 wt .-% result;

E2. Applying the composition (6) to a substrate (4) to obtain a precursor (12);

E3. Heating the precursor (12) to a temperature in a range of 25 to 300 ° C to obtain the layered structure (2).

2. The method of claim 1, wherein the gold particles have a diameter in a range of 1 to 25 nm.

3. The method according to any one of the preceding claims, wherein the viscosity of the composition (6) is selected in a range of 1 to 100,000 mPas.

The process of any one of the preceding claims wherein the protic polar organic solvent comprises at least 20% by weight of a polyhydric alcohol.

5. The process according to the preceding claim, wherein the polyhydric alcohol has carbon atoms in a number in a range of 2 to 20.

6. The method according to one of the two preceding claims, wherein the polyhydric alcohol is selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,3- Propanediol, 1,2,3-propanetriol (glycerol), 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2,3-butanetriol, 1,2-dihydroxybenzene , 1, 3-dihydroxybenzene, 1, 4-dihydroxybenzene, 1, 2,3-trihydroxybenzene, 1, 2,4-trihydroxybenzene, 1,4-dihydroxy-2,5-dinitrobenzene, L-adrenaline, a monosaccharide, a disaccharide , a monosaccharide or disaccharide in mixtures with a liquid polyol, 1,1,1-tris- (hydroxymethyl) propane, 2,2-dimethylpropanediol-1,3, a polyethylene glycol, preferably with repeating units in a range from 3 to 500, or a mixture of at least two thereof.

7. The method according to any one of the preceding claims, wherein the composition (6) further comprises a mercapto-carboxyl compound of the general formula (I),

wherein

Ri is a substituted, unsubstituted, branched or unbranched, cyclic or polycyclic C 1 -C 20 -hydrocarbon radical, or contains at least one salt of this mercapto-carboxyl compound.

8. The process according to the preceding claim, wherein the substituted, unsubstituted, branched or unbranched, cyclic or polycyclic C ₁ -C 20 -hydrocarbon radical has at least one, preferably two or all of the following properties: el. at least one of the C atoms of the C ₁ -C 20 -hydrocarbon radical by at least one nitrogen atom, an oxygen atom, a phosphorus atom, a sulfur atom, a hydroxyl group, a carboxyl group, a halide, an amine, an amide, a phosphate group, a sulfate group or a Combination of at least two is replaced; or e2. the C 1 -C 20 -hydrocarbon radical may be substituted or branched with further substituted, unsubstituted, branched or unbranched, cyclic or polycyclic C 1 -C 20 -hydrocarbon radicals; or e3. at least one of the C atoms of the Ci - C2o hydrocarbon radical is replaced by an aromatic radical or a 5-, 6- or 7-membered heteroaromatic ring with 1, 2, 3 or 4 nitrogen, oxygen and sulfur atoms, wherein the heteroaromatic radical having halogen atoms, hydroxyl, nitro, amino groups, protected amino radicals, cyano, trifluoromethyl groups, hydrocarbon radicals having 1 to 4 carbon atoms, alkoxy radicals having 1 to 4 carbon atoms may be substituted.

The method according to one of the two preceding claims, wherein the composition (6) includes the mercapto-carboxyl compound in a range of 0.1 to 4% by weight based on the total mass of the composition.

10. The method according to any one of the three preceding claims, wherein the mercapto-carboxyl compound is selected from the group consisting of L-cysteine, D-cysteine, γ-L-glutamyl-L-cysteinyl-glycine (glutathione), (RS ) -N- (2-mercapto-1-oxopropyl) -glycine (tiopronine), mercaptosuccinic acid, N-acetylcysteine, thiosalicylic acid, dimercaptosuccinic acid, L-methionine, D-methionine, thiourea, 2-mercaptopropionic acid, thioglycerol, thiodipropionic acid, cystine , Methyl 3-mercaptopropionate, Na thioglycolate or a mixture of at least two thereof.

11. The method according to any one of the preceding claims, wherein the composition (6) comprises at least one further metal selected from the group consisting of silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), rhodium (Rh ) or a combination of at least two thereof.

12. The method according to any one of the preceding claims, wherein the composition (6) has a pH in a range of 3 to 8.

The method of any one of the preceding claims, wherein the composition (6) further includes a surfactant.

14. The method according to any one of the preceding claims, wherein in a further step E4. a protective layer (10) is applied to at least a portion of the layer structure (2).

15. The method of claim 1, wherein the substrate is selected from the group consisting of a paper, a wood, a textile, a glass, a polymer, a metal, a ceramic, a horny layer or a combination of at least two of them.

16. The method according to any one of the preceding claims, wherein the substrate (4) has a conductivity of less than 10 ¹³ S / cm.

17. The method according to any one of the preceding claims, wherein the application of the composition (6) in step E2. by a brush, a screen, a felt-tip pen, a fountain pen or a nozzle.

18. A precursor (12) of a layer structure (2) obtainable according to the process steps El and E2 of the method according to one of the preceding claims.

19. The precursor (12) according to the preceding claim, wherein the precursor (12) has at least one of the following properties:

VI. a thickness of the substrate (4) in a range of 0.1 mm to 5 cm;

V2. a thickness of step E2. applied composition in one area

V3. a conductivity of the substrate (4) of less than 10 ¹³ S / cm;

V4. a conductivity of in step E2. applied composition (6) in a range of 10 ^"1 S / cm to 10 ^{" 8} S / cm;

20. A layer structure (2) obtainable by a method according to one of the preceding claims 1 to 17.

21. The layer structure (2) according to the preceding claim, wherein the layer structure (2) has at least one of the following properties:

51. wherein the layer structure (2) comprises a metal layer containing at least 70% by weight of gold in a thickness in a range from 0.05 μm to 1 μm;

52. a conductivity of less than 10 ¹³ S / cm;

53. a gloss in a range of 500 to 1300 GE;

54. a density in a range of 10 to 20 kg / 1.

22. A composition (6) comprising:

zl. Gold (Au) particles in an amount ranging from 0.1 to 50% by weight; z2. Water in a range of 0 to 5% by weight;

z3. a polar, protic, organic solvent as balance to 100% by weight; wherein the wt .-%, each based on the total mass of the composition (6), 100 wt .-% result.

23. The composition (6) according to the preceding claim, wherein the composition (6) comprises at least one further component selected from:

z4. Polyvinylpyrrolidone in an amount ranging from 0 to 10% by weight, based on the total weight of the composition (6);

z5. a polyhydric alcohol in an amount ranging from 0 to 90% by weight based on the total weight of the composition (6);

The composition (6) of the preceding claim wherein the polyhydric alcohol is selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,2,3-propanetriol (glycerol), 1,2-butanediol , 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2,3-butanetriol, 1,2-dihydroxybenzene, 1,3-dihydroxybenzene, 1,4-dihydroxybenzene, 1,2,3 Trihydroxybenzene, 1,2,4-trihydroxybenzene, 1,4-dihydroxy-2,5-dinitrobenzene, L- Epinephrine, a monosaccharide, a disaccharide, a monosaccharide or disaccharide in mixtures with a liquid polyol, 1,1,1-tris (hydroxymethyl) propane, 2,2,1-dimethylpropanediol-1,3, a polyethylene glycol, preferably with Repeating units in a range of from 3 to 500, or a mixture of at least two thereof.

The composition (6) according to any one of claims 22 to 24, wherein the gold (Aul particles have a particle size D50 of 20 nm or less.

26. An article (20) comprising a layer structure (2) according to any one of claims 20 or 21 or obtainable by a method according to any one of claims 1 to 17.