Gold polish preparation

A water compatible gold polish preparation is described containing gold compounds, organic carriers and flux materials wherein the organic carrier mixture is formed of 50 to 100% of 1 or more N-substituted -2-pyrrolidones and 0 to 50% of one or more water dilutable synthetic resins.

The present invention relates to a gold polish preparation formulated to 
contain a gold compound soluble in organic solvents, optionally a gold 
powder and/or a gold compound insoluble in organic solvents, an organic 
carrier, a fluxing agent and color influencing additives. 
Gold polishing preparations have been known for many years. Generally they 
contain finely divided gold powder which can be created, either partially 
or entirely, from thermally decomposable organic compounds, a fluxing 
agent and an organic carrier. In addition thereto, there can be components 
present in the preparation which influence the color of the gold film, 
such as for example salts and resinates of silver, paladium, platinum or 
rhodium. 
The gold compounds of such prior known compositions and preparations are 
generally derivatives of cyclic terpenes and sulfur, such as for example 
sulfur resinates or mercaptides. In recent times there is more generally 
used Gold-(I) mercaptide, which because of its polymeric characteristic is 
itself insoluble in organic solvents, however through the substitution of 
particular substituent groups on the mercaptide can be converted to a 
soluble form. Representative soluble gold mercaptides which are soluble in 
organic solvents are shown for example in German DAS Nos. 12 84 807, 12 84 
808, 12 86 866 and 12 98 828. 
The flux material is generally a typical salt or resinate of bismuth, lead, 
boron, silicon, chromium, tin, copper and others, which determines the 
behavorial characteristics of the gold film during the burning operation, 
improves the adhesion of the gold film on the substrate and raises the 
resistance of the gold film to abrasion and corrosive chemicals. 
The choice of the organic carrier is dependent upon the various methods of 
applying the coating of the gold polish preparation. Known organic 
carriers are for example methylethyl ketone, cyclohexanone, ethylacetate, 
xylol, petroleum ether, terpene, turpentine oil, asphalts, balsams, 
natural and synthetic resins, either individually or in mixtures. See DAS 
Nos. 12 84 807 and 12 84 808. However, these carriers can be, to a partial 
extent, hazardous to health and in addition are not water soluble or 
capable of being diluted with water. 
It is known in the art to prepare a paint material for on glaze decoration 
which is formed from organic compounds and gold powder. See DOS No. 32 17 
049. This paint material is dilutable with water and is not injurious to 
health. It contains polyvinylpyrrolidone or a mixture of 
polyvinylpyrrolidone and aqueous polyethylene oxide, dissolved in ethylene 
glycol and/or propyleneglycol and eventually water. In these organic 
carriers however, the known soluble gold mercaptides are not themselves 
soluble. 
It is therefore an object of the present invention to provide a gold polish 
preparation which contains gold compounds which are soluble in organic 
solvents, optionally a gold powder and/or a gold compound which is not 
soluble in organic solvents, an organic carrier, a flux material and 
optionally a color influencing additive, in which the organic carrier is 
compatible with water and does not lead to hazardous conditions for 
health, and further, which also is capable of dissolving the known gold 
mercaptides. 
The object of the present invention is achieved by utilizing as the organic 
carrier a mixture of 50-100% of one or more heterocyclic ketones 
represented by the structural formula: 
##STR1## 
In which R is a straight or branched chain alkyl containing 1 to 6 carbon 
atoms, and 0 to 50% by weight of one or more synthetic resins which are 
dilutable with water and which are selected from the group consisting of 
amine, phenolic, acrylic, alkyd and epoxy resins. 
Preferably the organic carrier is 1-methyl-2-pyrrolidone. 
The organic carrier is formed of a solvent material and, optionally, an 
additional binder. Particularly well suited as solvent materials are the 
N-substituted 2-pyrrolidones. A substituent can be a straight or branch 
chained alkyl containing 1 to 6 carbon atoms. Advantageous as the solvent 
material is 1-methyl-2-pyrrolidone which is frequently used in the dye and 
polymer industry. Its solubility parameters lie within the range of a 
large number of polymers. It is miscible with water and most organic 
solvent materials. It has been found that it is also an outstanding 
material capable of dissolving gold-sec.-alkylmercaptides and 
goldsulforesinates. The solvent material represents 50 to 100 weight 
percent of the components of the carrier system. As solvent materials, the 
N-substituted 2-pyrrolidones are used when the gold polish preparation 
contains a minimum of 3, preferably 5 weight percent gold in the form of a 
soluble sulforesinate. The desireable solvent capabilities as well as the 
dispersability of solid material components operates to enable the streak 
free application of the gold polish preparations with a brush. 
In combination with the 1-methyl-2-pyrrolidone there are a large amount of 
water dilutable polymers suitable as binders. The most important of these 
are polyvinylpyrrolidone, copolymers of vinylpyrrolidonevinylacetate; 
vinylpyrrolidone-styrene; polyvinylalcohol; polyvinylacetate; 
polyethyleneglycol, polypropyleneglycol; copolymers of 
ethyleneglycol-propyleneglycol; copolymers of ethylene-maleic acid. 
methylvinylether-maleic acid; styrene-maleic acid, and styrene-maleic acid 
monoesters. As binder materials, conventional synthetic resins are 
suitable which can be diluted with water either by themselves or after the 
addition of acids or bases. Therefore there may be utilized for these 
purposes the synthetic resins which are dilutable with water including 
amine, phenolic, alkyd, acrylic, and epoxy resins which dry in air 
according to an oxidative and/or cross linking principle. 
Examples of amine resins are complete or partial methyl etherated melamine 
or urea formaldehyde condensation products, which are obtainable in 
solvent free, solvent containing or water dilutable form. With using mono 
or low molecular weight types, such as for example 
hexamethoxymethylmelamine, it is desireable to add an acid catalyst such 
as for example hydrochloric acid, phosphoric acid, p-toluolsulfonic acid 
or maleic acid in a concentration of from 1 to 8 weight percent, based on 
the solid material portion of the binder. The amine resins can be used as 
sole binder materials or in combination with complementary resins such as 
acrylic, alkyd and epoxy resins. For the control of the drying velocity, 
an acid catalyst can be also introduced into the system. Binder material 
mixtures are particularly advantageously composed of 10 to 20 weight 
percent amine resin and 80 to 90 weight percent of a complementary resin. 
As an example of an oxidatively drying, water dilutable resin there may be 
noted alkyl resins based on an unsaturated acid such as for example a 
fatty acid with an oil content of 20 to 70 weight percent, also epoxy 
esters based on unsaturated acids such as for example linseed oil-wood oil 
epoxy resins. 
The binder material content of the carrier system ranges from 0 to 50 
weight percent. The carrier system can also contain water up to a 
concentration of 20 weight percent and other water miscible solvent 
materials such as for example alcohols, glycols, glycol ethers, in a 
maximum concentration of up to about 40 weight percent. To vary the gold 
tone these preparations can also include silver, paladium or platinum 
compounds. Advantageously one may use Rhodium(III)-chloride.

The invention is further illustrated in the following examples where 
representative compositions of the inventive gold polish preparation are 
shown: 
EXAMPLE 1 
______________________________________ 
Weight Percent Component 
______________________________________ 
51.75 Goldsulforesinate, dissolved 
in 1-methyl-2-pyrrolidone 
(7.7 weight percent gold) 
24.00 Gold powder (particle size 
0.5-1.0 .mu.m) 
5.00 Gold(III)sulfide (80 weight 
percent gold) 
4.00 Silver powder (particle size 
0.5-1.0 .mu.m) 
0.50 Bismuth subnitrate 
0.25 Rhodium(III)chloride 
1.80 Melamine-Formaldehyde resin 
75 weight percent dissolved 
in water 
12.70 Alkyd resin (oil content 45 
weight percent; neutralized 
form) 65 weight percent in 
glycol ether 
______________________________________ 
The gold sulforesinate (50 percent by weight of gold) is first dissolved in 
1-methyl-2-pyrrolidone and then mixed with the remaining components for 48 
hours in a ball mill. 
EXAMPLE 2 
______________________________________ 
Weight Percent Component 
______________________________________ 
65.35 Gold sulforesinate, 
dissolved in 1-methyl 
2-pyrrolidone (15.3 weight 
percent gold) 
8.00 Gold powder (0.5-1.0 .mu.m) 
2.00 Silver powder (0.5-1.0 .mu.m) 
24.00 Linseed oil-wood oil epoxy 
ester (acid number 40-50) 70 
weight percent in glycol ether 
0.50 Bismuth subnitrate 
0.15 Rhodium(III)chloride 
______________________________________ 
EXAMPLE 3 
______________________________________ 
Weight Percent Component 
______________________________________ 
92.35 Gold sulforesinate, 
dissolved in 1-methyl 
2-pyrrolidone (17.3 weight 
percent gold) 
5.00 Gold powder (0.5-1.0 .mu.m) 
2.00 Silver powder (0.5-1.0 .mu.m) 
0.50 Bismuth subnitrate 
0.15 Rhodium(III)chloride 
______________________________________ 
All three gold polish preparations were suitable for brush applications. 
Further variations and modifications of the foregoing invention will be 
apparent to those skilled in the art and are intended to be encompassed by 
the claims appended hereto. 
The German application No. P 35 44 339.1 relied on and incorporated herein 
by reference.