UV-radiation-curable precious-metal preparation, transfer pictures containing said preparation, and process for decoration
View Patent ↗The invention relates to a radiation-curable precious-metal preparation, in particular a bright-gold preparation, that contains—in addition to a gold compound, which in particular is soluble in the printing medium, and further customary organometallic compounds—a radiation-curable, in particular UV-curable, printing medium, the polymerisation being initiated by the UV radiation and proceeding in accordance with a cationic mechanism which may optionally be assisted by y process that takes place simultaneously in accordance with a radical mechanism. The invention also relates to a transfer picture containing the precious-metal preparation, and to a process for decorating substrates that are suitable for decoration firing by direct application/printing and indirect printing (decalcomania).
1. A radiation-curable precious-metal-containing preparation comprising:
at least one soluble precious metal compound containing an element selected from the group consisting of Au, Ag, Pt and Pd;
one or more fluxing agents selected from the group consisting of organic metalloidal compounds and/or organometallic compounds; and
a radiation-curable printing medium, wherein the radiation-curable printing medium comprises at least one radiation-curable cationically polymerisable monomeric compound selected from the group consisting of oxiranes, oxetanes, vinyl ethers and combinations thereof.
2. The preparation according to claim 1 , wherein:
the oxiranes are cationically polymerisable epoxides selected from the group consisting of cycloaliphatic bisepoxides, bisphenol A bisepoxides, novolak epoxides, terpene epoxides, alkanediol bisglycidyl ethers, and 1,2-epoxysilanes;
the oxetanes are aliphatically substituted oxetanes; and
the vinyl ethers are aliphatically substituted vinyl ethers.
3. The preparation according to claim 1 , wherein:
when the at least one radiation-curable cationically polymerisable monomeric compound is one or more oxiranes or oxetanes, said oxiranes or oxetanes are present in a quantity of 10-90 wt. % relative to the precious-metal-containing -prepartion, and
when the at least one radiation-curable cationically polymerisable monomeric compound is one or more vinyl ethers in combination with oxiranes and/or oxetanes, said vinyl ethers in combination with said oxiranes and/or oxetanes are present in a quantity of 5-50 wt. % relative to the precious-metal -containing-preparation.
4. The preparation according to claim 1 , further comprising:
one or more radiation-polymerisable oligomers selected from the group consisting of oxiranes, oxetanes, oxolanes, vinyl ethers and combinations thereof, wherein said radiation-polymerisable oligomers are present in a quantity of 10-80 wt. % relative to the precious-metal-containing-preparation, and
optionally, soluble, inert polymers not involved in the polymerisation and/or sulfur and/or sulfur-containing compounds, wherein said soluble, inert polymers, sulfur and/or sulfur-containing compounds are present in a quantity of 0-60 wt. % relative to the precious-metal-containing-preparation.
5. The preparation according to claim 1 , wherein the printing medium further comprises at least one additional radically initiatable, radiation-curable monomeric compound selected from olefinic compounds containing a heterocyclic ring.
6. The preparation according to claim 5 , wherein the heterocyclic ring contains 4 to 8 ring members and by way of heteroatom one or more nitrogen and/or oxygen atoms, at least one radiation-polymerisable vinyl, acrylic or methacrylic group is bonded to the heterocyclic ring directly or via a one-membered to six-membered bridge cross-link, and a carbon atom adjacent to a ring heteroatom exhibits at least one abstractable hydrogen atom.
7. The preparation according to claim 5 , wherein the at least one additional radiation-curable monomeric compound and the radiation-curable cationically polymerisable monomeric compound are present in a ratio from 1:infinity to 1:0.2.
8. The preparation according to claim 5 , wherein the heterocyclic ring of the additional radiation-curable monomeric compound is selected from the group consisting of:
dihydro-2-H-pyran, tetrahydro-2-H-pyran, 1,3-dioxolane, 1,3-dioxan, 1,4-dioxan, benzo-dihydrofuran, isobenzodihydrofuran, 2-H-chromene, 1-H-isochromene, chroman, isochroman, 3-benzoxepine,
pyrroline, pyrrolidine, imidazoline, imidazolidine, piperidine, indoline, isoindoline, 1,2-dihydroquinoline, tetrahydroquinoline, isoquinoline, piperazine, perhydropyrimidine,
morpholine, perhydro-1,3-oxazine, 4H-dihydro-3,1 -benzoxazine, 1,3-oxazoline, and 1,3-oxazolidine.
9. The preparation according to claim 8 , wherein the additional radiation-curable monomeric compound exhibits a five-membered to seven-membered lactam ring, and the polymerisable group is bonded to the lactam nitrogen.
10. The preparation according to claim 8 , wherein the additional radiation-curable monomeric compound exhibits a 1,3-dioxolane ring, a 1,3- or 1,4-dioxan ring and a (meth) acryloyloxy-(C1-C4)-alkyl or (meth) acryloylamino-(C1-C4)-alkyl substituent.
11. The preparation according to claim 1 , wherein the one or more fluxing agents are metalloidal compounds and/or organometallic compounds of elements selected from the group consisting of Al, B, Ba, Bi, Ca, Ce, Co, Cr, Cu, Fe, Ga, Ge, Ir, Mn, Mo, Ni, Os, Pb, Rh, Ru, Se, Si, Sn, Ta, Ti, V, W, Zn and Zr.
12. The preparation according to claim 1 , wherein the printing medium contains 1-20 wt. % of a photoinitiator relative to the precious-metal-containing-preparation.
13. The preparation according to claim 1 , further comprising one or more additives selected from the group consisting of defoamers, phthalate plasticisers, surface-modification agents, thixotroping agents and dispersing agents, and wherein the total quantity of said additives is up to 10 wt. % relative to the precious-metal-containing-preparation.
14. The preparation according to claim 1 , wherein the precious-metal content is between 6% and 30 wt. % relative to the precious-metal -containing-preparation.
15. The preparation according to claim 1 , further comprising matting agents selected from the group consisting of oxides, silicates and aluminosilicates.
16. The preparation according to claim 1 , further comprising precious-metal powder and/or at least one insoluble precious-metal compound, the precious-metal content amounting to 12-50 wt. %, relative to the precious-metal-containing-preparation.
17. A transfer picture for producing precious-metal decorations, comprising a flexible supporting material, a separation layer capable of being activated by water or thermally, thereupon a picture layer and, thereabove, a covering layer, wherein the picture layer has been obtained by applying a radiation-curable precious-metal-containing-preparation according to claim 1 .
18. A process for producing a precious-metal decoration onto a ceramic substrate comprising:
overprinting a precious-metal-containing-preparation according to claim 1 onto the ceramic substrate or onto a transfer support to form decorative layer and, in the case where the precious-metal-containing-preparation is overprinted on the transfer support, transferring the decorative layer from the transfer support onto the ceramic substrate;
irradiating the ceramic substrate to cure the decorative layer; and
stoving the decorative layer under decoration firing conditions.