Bath for the electrochemically depositing highly lustrous white rhodium coatings and whitening agent for the same
AssigneeUmicore Galvanotechnik GmbH
InventorUwe Manz
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Abstract
The invention concerns a bath for the electrochemical deposition of high-gloss white rhodium coatings and a whitening agent for the same. The brightness or degree of whiteness of the deposited coatings is significantly increased by means of compounds having the formula I R—SOm—H (I) wherein m is the numbers 3 or 4 and R is a straight-chain or branched or cyclic alkyl group having up to 20 C atoms, as whitening agents. The thickness of the coating that can be deposited without a bloom is also significantly increased.
Claims5
Bath for the electrochemical deposition of high-gloss white rhodium coatings, containing rhodium in dissolved form optionally with an organic compound as brightening additive,
- characterised in that
- the bath contains as whitening agent at least one compound having the general formula
- R—SOm—H (I)
- wherein
- m is the numbers 3 or 4 and
- R is a straight-chain or branched or cyclic alkyl group having up to 20 C atoms.
Use of compounds having the general formula
- R—SOm—H (I)
- wherein
- m is the numbers 3 or 4 and
- R is a straight-chain or branched or cyclic alkyl group having up to 20 C atoms,
- as whitening agents in baths for the electrochemical deposition of glossy rhodium coatings, containing rhodium in dissolved form, and optionally an organic compound as brightening additive and a wetting agent.
Dependencies are inferred from the claim text.