Precious metal composition and luster composition for direct and indirect screen printing

0001The invention relates to precious metal preparations and luster preparations and those containing decals, which are preferably used in indirect and direct screen printing.

0002Precious metal preparations for decorating glass, ceramics, porcelain, bone china, Fltesen or other silicate substrates are typically solutions of organic gold, palladium and Platlnverbindungen (which are usually dissolved in organic carrier materials), artificial or natural resins and fluxes, which ensure the bonding strength to the respective support material. As flux usually certain organometallic compounds, eg. As alcoholates, carboxylates, resinates or sulphoresinates the elements rhodium, silver, chromium, bismuth, vanadium, Sillcium and so on. During firing, the organic compounds decompose to the corresponding oxides or metals, thereby the adhesive strength and optical properties of the metal film can be effected on the substrate.

0003The decoration of silicate substrates such as glass, ceramics, porcelain and bone china with ceramic pigments, a distinction is the type of application. also common screen printing process - So Apart from decoration by hand using brush application, stamping, neoprene transfer, Netsch, Pad printing - direct and indirect. Due to the various applications and advantages of screen printing, this method is one of the most common. Here again, a distinction is the direct and indirect screen printing. When direct screen printing is printed directly by means of a mask on the substrate to be decorated and, if this process is repeated with other pastes. During indirect screen printing you can print with a mask on a special paper, which is coated with either a dextrin or a wax layer, the advantage of this method is the ability to fit to print multiple colors and thus producing sophisticated designs. To be able to apply the decorations thus produced, one needs a resist mask, which can also be applied by screen printing. The decals so produced - are in the case of printing onto a paper coated with dextrin - superseded by soaking in water from the backing paper or in the case of printing onto the wax layer by back heating Subsequently, the decorations are transferred to the respective substrates. In the former case it must be ensured that no water is present under the decal before firing (this would may tear in the decor when heated to steam, the holes). In the other case, there remains a small amount of wax under the decal that burns during firing.

0004In <patcit id="pcit0001" dnum="EP863187B1"><text>EP 863 187B1</text></patcit>, Paragraph [0020] are enumerated possible binders for liquid or paste-type decorative pigments, including a number homopolymers, copolymers and block copolymers - include polyamides - which may include, if necessary, solubilizing groups, including amino or ammonium groups.

0005In <patcit id="pcit0002" dnum="DE10146684A1"><text>DE 101 46 684A1</text></patcit> are mentioned as binders for preparations for direct printing amino resins.

0006<patcit id="pcit0003" dnum="EP0972793A"><text>EP0972793</text></patcit> discloses a commercially available bright gold preparation for indirect printing on glass and bone china, the product GGP 1230 from Heraeus containing amide groups which make the presence of a polyamide likely.

0007For direct and indirect screen printing, the preparations must have certain characteristics and meet the requirements which are explained in more detail below.

0008Polyamide and colophony resin containing noble metal preparations, which are suitable for screen printing, for example, are in <patcit id="pcit0004" dnum="DE19831141A1"><text>DE 198 31 141 A1</text></patcit>. <patcit id="pcit0005" dnum="DE19831141C2"><text>DE 198 31 141 C2</text></patcit> and <patcit id="pcit0006" dnum="EP514073A2"><text>EP 514 073 A2</text></patcit> described. Such noble metal preparations tend to aging effects, ie the storage time, the viscosity of the preparations, said this is a function of temperature. This can in a relatively short time lead at room temperature to the fact that these products are unsuitable for the production of decals and become unusable. Especially during transportation and delivery in countries with high average temperatures the preparations to respond more quickly to and become highly viscous. Moreover, many preparations tend also in the printed decal to aging in the form of embrittlement which becomes apparent by cracking during application and firing. Also not inconsiderable is the part cases during printing of the preparations thickening of the products by oxidative reactions which may occur through the loss of solvent in addition to the increase in viscosity.

0009There is a further requirement for preparations which do not have the disadvantages mentioned and which are resistant to aging and temperature resistant.

0010It has been found that noble metal preparations containing polyaminoamides are surprisingly resistant to aging and all other requirements regarding pastes for screen printing - meet are found in excellent shape - directly and indirectly.

0011Polyaminoamides are as epoxy hardeners known (publication of Bakelite AG, S. 5, column 3, <patcit id="pcit0007" dnum="DE3711947A1"><text>DE 37 11 947 A1</text></patcit>). "Polyaminoamide s" in the sense it is the reaction products of the invention from the condensation reaction between a polymeric fatty acid such as a dimeric odertrimeren acid and polyethylene polyamine. Since in this example the polymeric fatty acid is a mixture of about 70 to 80 wt.% Dimer, about 15 to 25 wt.% Trimer and tetramer, and less than 10 wt.% Is monomer, to obtain a lot of different polyaminoamides again depend on the type and quantity of the polyamine used. In this respect, an accurate structural formula does not specify.

0012In question for use in the invention are primarily representative of the class of compounds "Potyaminoamide" whose viscosity is compatible with the use in precious metal preparations

0013A particular advantage of the use of polyaminoamides in bright noble metal preparations is that without the usual additions of natural resins (such as rosin or dammar) can produce formulations. It is independent of the quality fluctuations, which are subject to such natural compounds in this manner on one side. On the other hand, known from the prior art binder systems for preparations for indirect screen printing of relatively many components are made that costly manner and mixed and chemically reacted.

0014The problem and the challenge in preparing a decalcomania but primarily in the fact that the printed decals have to be very flexible and elastic and can not be attacked by the resist mask sowle that no internal disturbances may be caused by these. These properties are achieved previously only with expensive binder systems described above. This is inventively possible by adding a single class of resin.

0015Is expedient to employ 3 to 50% by weight of polyaminoamide in the preparations a, preferably 3 to 30 wt.%, Particularly preferably 3 to 20% of a reaction product of the polyaminoamide with at least aequlmolaren amount of carboxylic acid in the presence of a solvent, such as in Example 1 or 4 described.

0016It is further advantageous to use the polyaminoamides so that the amino functions are initially inactivated or partly inactivated, because by the free amino groups can occur in conjunction with the organometallic shares of precious metal preparation to undesired polymerization. It may also be advantageous to add an inactivator over the stoichiometric ratio beyond which blocks the amino groups

0017The inactivators are appropriately used quantity which is equimolar to the free amino groups, but it can also be a slight shortfall or surplus are used to large surpluses, such as a 2- to 5-fold molar excess, particularly a 2- to 4-fold excess.

0018A possibility of blocking of the amino groups can be achieved by the protonated form in the simplest case. For this purpose, the polyaminoamide is used in a solvent containing an acid. Apart from the usual carboxylic acids such as acetic, formic, benzoic or citric acid for coming more exotic acids such as 2-ethyl hexyl or furan carboxylic acid in question, but also dicarboxylic acids. Furthermore, a controlled amount of an epoxide can be used for the purpose of inactivation. By the reaction with the epoxy group of the amine function is also inactivated.

0019As inactivators also natural components that are already used in precious metal preparations, such as sulphurised gum dammar and, surprisingly even bases such as sodium are. If used, the use of 6 to 20% is a 50% sodium hydroxide solution expediently.

0020In addition to the polyaminoamides compositions of the invention may contain the usual ingredients in this field, for example, comprise metal resinates, organometallic compounds, natural resins, synthetic resins, resin oils, organic dyes and fillers, thixotropic agents, solvents and antifoams.

0021The preparations contain, for example, one or more soluble compounds of the noble metals from the series gold, silver, ruthenium, rhodium, palladium, osmium, iridium and platinum. But it is possible also the addition in elemental form. The noble metal compounds are usually in the form of organic compounds, in which the noble metal bonded through a sulfur or oxygen bridge to an organic skeleton Since these are often mixtures of substances, they are referred to as noble metal resinates and noble sulphoresinates The Flussmitteiverbindungen is itself. particular, resinates and sulphoresinates of elements of the third to fifth main group and third to eighth subgroup of the Periodic Table The carrier media are mostly a combination of at least one solvent and a binder. The liquid carrier medium can be purely organic, organic-aqueous or essentially purely aqueous. The organic media are frequently those based on hydrocarbons, alcohols and sulfur-containing compounds such as sulfurized Terpenkohienwasserstoffen and terpene alcohols and sulphurised natural resins which then serve simultaneously as binders and the optical and mechanical properties of the fired decorations influence and for processing properties of these preparations play an essential role.

0022The noble metal content of the preparation is usually in the range of 6 to 16 wt.% Precious metals, based on the preparation, preferably in the range of 8 to 15 wt .-% and particularly preferably in the range of 9 to 12 wt .-%.

0023In the case of the luster preparation, the noble metal content is below 6%, and depending on the color and composition may be free from noble metal products.

0024The noble metal compounds contained in the bright noble metal preparations according to the invention are organic compounds which are soluble in the organic, organic-aqueous or essentially aqueous medium. The organic noble metal compounds are in particular those in which the noble metal is bound via a sulfur or oxygen bridge to an organic skeleton. In particular, there are so-called sulforesinates resulting from the implementation of a gold compound with a sulphurised resinous compound, and thioesters and in particular thiolates based on aliphatic, cycloaliphatic and aromatic mercaptans. Provided that the precious metal preparation contains an aqueous or organic-aqueous medium, the organic noble metal compound in addition solubilizing groups selected from -COOH, -SO₃H, -OH, -CONH₂, NH₂ and -OP (O) (OH)₂ on. In an organic carrier medium soluble organic noble metal compounds in the art are well known, by way of example reference is made to the documents cited. In an aqueous-organic carrier medium soluble gold compounds are known from<patcit id="pcit0008" dnum="EP0514073B"><text>EP-B 0514073</text></patcit> and <patcit id="pcit0009" dnum="EP0668265B"><text>EP-B 0668265</text></patcit> known.

0025In addition to the organic noble metal compounds, the inventive preparations can contain organic and / or inorganic non-which are soluble in the preparation and form the corresponding element oxide under the firing conditions. The selection of the organic or inorganic residue of base metal compounds can be carried out freely, as long as the compound in the selected carrier medium is homogeneously soluble and the connection with the burnout to form the elemental is residue-free decomposable. Similar to the noble metal compounds, this may be low-molecular alcoholates and thiolates and so-called resinates and sulphoresinates. Some flux elements, including cobalt and chromium, can such as pentanedionates or mixtures of these compounds are also used in the form of salts of aliphatic or aromatic carboxylic acids such as Ethylhexanoate or octanoate, or complexes with aliphatic diketones. Inorganic fluxes can be used in preparations with an aqueous or aqueous organic medium. Organic and / or inorganic non-noble metal compounds usually contain metal ions of groups 3a and b, 4a and b, 5a and b, 6b, 7b, 8b, 1 b and 2b. Precious metal preparations can thus at least one further element from the group Ru, Si, Zr, V, Cr, Os, Ni, Mn, Fe, Co, Bi, W, Ce, Ta, Mo, Ba, B, Pb, Ge, Ca, Ir, Al, Ti, Cu, Sn, Zn, Ga in the form of organic and / or inorganic compounds which serve to modify the gloss and color characteristics as well as the improvement of the mechanical and chemical resistance. are preferably about at luster preparations one or more compounds of the elements of the series boron, and aluminum; indium; Scandium, yttrium, lanthanum, cerium; Chromium and silicon, germanium and tin; Titanium and zirconium; Bismuth; Vanadium, niobium and tantalum; Iron and copper. Although rhodium belongs to the noble metals, rhodium compounds have a flux effect.

0026As carrier media are those which, as they are known in the prior art noble metal preparations with an organic or organic-aqueous medium. Typically, the carrier medium comprises both an organic binder and an organic, organic-aqueous or substantially purely aqueous solvent. The composition of the carrier medium and the use amount thereof are selected such that the organic noble metal compounds and organic non-noble is a clear solution and the preparation suitable for the chosen application type viscosity and good film properties of the dried but not yet baked film having. Preferably, the organic noble metal compounds and organic non-noble form after drying a homogeneous system or a solution. The binder or binders present should be as clear as possible dissolved in the present solvent or solvent mixture. Known binders for bright noble metal preparations are polyacrylic and polymethacrylic resins, polyvinyl, cellulose ethers such as hydroxyalkyl, alkoxy and carboxyalkyl, polyamides, polyalkylene glycols such as polyethylene glycol, polyester, polyacrylamide, polyvinyl acetate, polyvinyl alcohol, alkyd, polyamine, polyurethane resins, hydrocarbon resins, urea-formaldehyde resins, modified urea-formaldehyde resins, melamine resins, alkyd resins, polyurethane resins or epoxy (or mixtures thereof), as well as natural resins and sulfurized natural resins such as dammar sulfurized. Asphalt, rosin, rosin esters, rosin resins, amino resins based on natural ingredients, nitrocellulose, ketone, sulfurized terpene resins.

0027Noble metal preparations with an essentially organic carrier medium generally contain 10 to 40 wt .-% of one or more organic solvent. Suitable are aliphatic, cycloaliphatic and aromatic hydrocarbons, in particular alkylated aromatics, and terpene hydrocarbons, ketones, alcohols and ethers; suitable are also essential oils.

0028Effective binder components are also maleic acid, modified rosin and rosin-phenolic resins. As the binder, waxes from the series of fatty alcohols, fatty amides, polyolefin waxes and polyalkylene glycols are also suitable. Usually, non-aqueous bright noble metal preparations an organic carrier medium comprising one or more binders and one or more organic solvents in a total amount of about 20 to 60 wt .-%, based on the preparation.

0029The bright noble metal preparations can be prepared in the usual way by homogenising the organic noble metal compounds, flux compounds and the solvents and / or carrier medium containing binder. The preparation may additionally comprise a sulfurization step in which unsaturated binder and / or solvent and optionally noble metal compounds are linked via sulfur bridges. Application and firing conditions follow.

0030It is also possible, by reactions and additions of further resins (synthetic or natural origin - for example asphalt) to produce preparations that optimizes and further improved in hue and the mechanical and chemical resistance of the decorations produced therefrom are. The same is true for the organometallic composition. This concerns both the field of gloss and luster, polishing and silk matt preparations.

0031For the formulations suitable polyaminoamides example Aradur 100 BD or Aradur 350 BD from Vantico, Basel.

0032The following example illustrates the pretreatment of the polyaminoamide:

Example 1:

0033A solution of 26% isopropanol, 24% and 50% ethylhexanoic polyamino amidhärter Aradur 100 BD (Vantico) wird½ h treated at 120 ° C. The resulting solution is used directly in a recipe for a noble metal preparation

0034To illustrate particular embodiments of the invention, in other examples, recipes for bright noble metal preparations for glass and porcelain / ceramics are described (% data in% by weight).<tables id="tabl0001" num="0001"><table frame="none"><tgroup cols="3" colsep="0"><colspec colnum="1" colname="col1" colwidth="78mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><colspec colnum="3" colname="col3" colwidth="14mm" /><thead><row><entry valign="top">Example 2: For porcelain</entry><entry valign="top" /><entry valign="top">%</entry></row></thead><tbody><row><entry>Goldsulforesinat</entry><entry>(54% Au)</entry><entry>22.2</entry></row><row><entry>Silbersulforesinat</entry><entry>(52% Ag)</entry><entry>2.88</entry></row><row><entry>Rhodium resinate dissolved in Pine-oil</entry><entry>(5% Rh)</entry><entry>2.0</entry></row><row><entry>Siliciumresinat dissolved in Pine-oil</entry><entry>(10% Si)</entry><entry>1.5</entry></row><row><entry>Wismutresinat</entry><entry>(10% Bi)</entry><entry>0.5</entry></row><row><entry>Polyaminoamide (50% lg in soln. In Example 1)</entry><entry>20.0</entry></row><row><entry>Pine-oil</entry><entry>48,60</entry></row><row><entry>thixotropic agents</entry><entry>2.0</entry></row><row><entry>defoamers</entry><entry>0.3</entry></row></tbody></tgroup><tgroup cols="3" colsep="0"><colspec colnum="1" colname="col1" colwidth="78mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><colspec colnum="3" colname="col3" colwidth="14mm" /><thead><row><entry valign="top" /><entry valign="top" /><entry valign="top" /></row></thead><tbody><row><entry>Example 3: For Glass</entry><entry>%</entry></row><row><entry>Goldsulforesinat</entry><entry>(54% Au)</entry><entry align="right">22.2</entry></row><row><entry>Silbersulforesinat</entry><entry>(52% Ag)</entry><entry align="right">2.88</entry></row><row><entry>Rhodium resinate dissolved in Pine Oil</entry><entry>(5% Rh)</entry><entry align="right">2.0</entry></row><row><entry>Siliciumresinat dissolved in Pine Oil</entry><entry>(10% Si)</entry><entry align="right">1.5</entry></row><row><entry>Chromhexanoat</entry><entry>(10% Cr)</entry><entry align="right">0.5</entry></row><row><entry>Vanadiumresinat dissolved in Pine Oil</entry><entry>(3% V)</entry><entry align="right">1.0</entry></row><row><entry>Polyaminoamide resin (50% in soln. In Example 1)</entry><entry align="right">20.0</entry></row><row><entry>Pine oil</entry><entry align="right">48,60</entry></row><row><entry>thixotropic agents</entry><entry align="right">2.0</entry></row><row><entry>defoamers</entry><entry align="right">0.3</entry></row></tbody></tgroup></table></tables>

0035The pastes thus produced are printed with a 400 mesh steel screen, and dried with a resist mask (32er polyester varnish L 406 from Heraeus) overpainted. After drying, the resist mask may be baked after applying the decoration.

Example 4:

0036Reacting Aradur 100 BD (Vantico) with 2-furan carboxylic acid and subsequent reaction and reaction with remaining paste components:<tables id="tabl0002" num="0002"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="52mm" /><colspec colnum="2" colname="col2" colwidth="17mm" /><tbody><row><entry>Aradur 100 BD</entry><entry align="right">10.00%</entry></row><row><entry>Pine oil (compensation component)</entry><entry align="right">56.18%</entry></row><row><entry>furoic</entry><entry align="right">3.50%</entry></row></tbody></tgroup></table></tables> • reaction at 130 ° C for 30 min and then adding<tables id="tabl0003" num="0003"><table frame="none"><tgroup cols="3" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><colspec colnum="3" colname="col3" colwidth="17mm" /><tbody><row><entry>Goldsufforesinat</entry><entry>(54% Au)</entry><entry align="center">22:20%</entry></row><row><entry>Silbersulforesinat</entry><entry>(52% Ag)</entry><entry align="center">2.12%</entry></row><row><entry>Rhodium resinate dissolved in pine oil</entry><entry>(5% Rh)</entry><entry align="center">1.00%</entry></row><row><entry>Siliciumresinat dissolved in pine oil</entry><entry>(10% Si)</entry><entry align="center">2.00%</entry></row><row><entry>Wismutresinat</entry><entry>(10% Bi)</entry><entry align="center">1.00%</entry></row><row><entry>sulphurised gum dammar</entry><entry align="center">2.00%</entry></row></tbody></tgroup></table></tables> • Through short reaction at 125 ° C to gel the paste

Example 5:

0037Reacting Aradur 350 BD (Vantico) with 2-furan carboxylic acid:<tables id="tabl0004" num="0004"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><tbody><row><entry>Aradur 350 BD</entry><entry align="right">43.00%</entry></row><row><entry>furoic</entry><entry align="right">4.80%</entry></row><row><entry>Pine oil (compensation component)</entry><entry align="right">52.20%</entry></row></tbody></tgroup></table></tables>

Reaction at 130 ° C for 30 min.

Example 6:

0038Reacting Aradur 350 BD (Vantico) with dammar geschwefelt:<tables id="tabl0005" num="0005"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><tbody><row><entry>Aradur 350 BD</entry><entry align="right">43.00%</entry></row><row><entry>sulphurised gum dammar</entry><entry align="right">43.00%</entry></row><row><entry>Pine oil (compensation component)</entry><entry align="right">7:00 %</entry></row></tbody></tgroup></table></tables>

Example 7:

0039<tables id="tabl0006" num="0006"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><tbody><row><entry>Aradur 350 BD</entry><entry align="right">43.00%</entry></row><row><entry>Caustic soda 50% solution</entry><entry align="right">10.00%</entry></row><row><entry>Pine oil (compensation component)</entry><entry align="right">47.00%</entry></row></tbody></tgroup></table></tables>

example 8

0040The so manufactured resin solutions (Examples 5 to 7) are incorporated in the following recipe for porcelain: manufacturing: <tables id="tabl0007" num="0007"><table frame="none"><tgroup cols="3" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><colspec colnum="3" colname="col3" colwidth="17mm" /><tbody><row><entry>Goldsulforesinat</entry><entry align="center">(54% Au)</entry><entry align="right">22:20%</entry></row><row><entry>Silbersulforesinat</entry><entry align="center">(52% Ag)</entry><entry align="right">2.12%</entry></row><row><entry>Rhodium resinate dissolved in pine oil</entry><entry align="center">(5% Rh)</entry><entry align="right">1.00%</entry></row><row><entry>Siliciumresinat dissolved in pine oil</entry><entry align="center">(10% Si)</entry><entry align="right">2.00%</entry></row><row><entry>Wismutresinat</entry><entry align="center">(10% Bi)</entry><entry align="right">1.00%</entry></row><row><entry>Pine oil (balance to 100%)</entry><entry align="center" /><entry align="right" /></row><row><entry>sulphurised gum dammar</entry><entry align="center" /><entry align="right">2.00%</entry></row></tbody></tgroup></table></tables>

0041The above components are gelled at 120 ° C. After cooling, the resin is added and homogenised:<tables id="tabl0008" num="0008"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="64mm" /><colspec colnum="2" colname="col2" colwidth="17mm" /><tbody><row><entry>polyaminoamide <b>(Example 5, 6 or 7)</b></entry><entry align="right">20.00%</entry></row></tbody></tgroup></table></tables>

0042The 3 mixtures of example 8 are printed with a 350 mesh fabric, dried and mixed with a resist mask (32 he polyester varnish L 406 from Heraeus) painted, applied dried and then baked and. The pastes prepared in this way with respect to their storage stability (this is at 80 ° C in a drying cabinet checked as a rapid test) Award and are workable even after years of storage.