Electrolyte and process for depositing a matt metal layer
View Patent ↗An electrolytic composition for the deposition of a matt metal layer onto a substrate and deposition process where the composition comprises a source of metal from the group consisting of Cr, Mn, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, In, Sn, Sb, Re, Pt, Au, Bi, and combinations thereof; a substituted or unsubstituted polyalkylene oxide or its derivative as an emulsion and/or dispersion former; and a compound comprising fluorated or perfluorated hydrophobic chains or which is a polyalkylene oxide substituted quaternary ammonium compound as wetting agent; wherein the electrolytic composition forms a microemulsion and/or dispersion.
1. An electrolytic composition for the deposition of a matt metal layer onto a substrate comprising:
a source of Ni ions;
an unsubstituted polyalkylene oxide as an emulsion and/or dispersion former; and
a fluorinated wetting agent having the general formula
R f CH 2 CH 2 O(CH 2 CH 2 O) x H
with R f ═F(CF 2 CF 2 ) n , wherein X=6 to 15 and n=2 to 10; and
polytetrafluoroethylene particles with an average particle diameter of about 10 to about 1000 nm at a concentration of about 0.5 to 5 mg/L;
wherein the electrolytic composition forms a microemulsion and/or dispersion.
2. The electrolyte composition of claim 1 wherein said emulsion and/or dispersion former is selected from the group consisting of a polyethylene oxide, polypropylene oxide, polypropylene-polyethylene oxide block copolymer, and a mixture thereof.
3. The electrolyte composition of claim 2 wherein the emulsion and/or dispersion former has an average molecular weight >200 g/mol.
4. The electrolyte composition of claim 2 wherein the emulsion and/or dispersion former has a high percentage of hydrophobic structures and a molecular weight between about 200 and about 2000 g/mol.
5. The electrolyte composition of claim 2 wherein the emulsion and/or dispersion former has a high percentage of hydrophilic structures and a molecular weight >4000 g/mol.
6. The electrolyte composition of claim 1 wherein the average molecular weight of the fluorinated wetting agent is between about 550 and about 1000 g/mol.
7. The electrolyte composition of claim 1 wherein the average molecular weight of the fluorinated wetting agent is between about 700 and about 1000 g/mol.
8. The electrolytic composition of claim 1 wherein the polytetrafluoroethylene particles have an average particle diameter of about 100 to about 300 nm.
9. The electrolytic composition of claim 1 further comprising a wetting agent comprising a polyethylene oxide-substituted quaternary ammonium compound having the following general formula
wherein one radical R 1 , R 2 , R 3 or R 4 is a polyethylene oxide substituent and the remaining radicals independently are same or different straight-chained or branched saturated or unsaturated C 1 to C 18 alkyl chains and X − is a halide, a sulfate anion or anion of a C 1 to C 6 carboxylic acid.