Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/50—Electroplating: Baths therefor from solutions of platinum group metals
  • C25D3/52—Electroplating: Baths therefor from solutions of platinum group metals characterised by the organic bath constituents used
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/30—Injector mixers
  • B01F25/31—Injector mixers in conduits or tubes through which the main component flows
  • B01F25/313—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/20—Mixing gases with liquids
  • B01F23/23—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
  • B01F23/236—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids specially adapted for aerating or carbonating beverages
  • B01F23/2361—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids specially adapted for aerating or carbonating beverages within small containers, e.g. within bottles
  • B01F23/23611—Portable appliances comprising a gas cartridge
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/20—Mixing gases with liquids
  • B01F23/23—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
  • B01F23/237—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids characterised by the physical or chemical properties of gases or vapours introduced in the liquid media
  • B01F23/2376—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids characterised by the physical or chemical properties of gases or vapours introduced in the liquid media characterised by the gas being introduced
  • B01F23/23761—Aerating, i.e. introducing oxygen containing gas in liquids

Definitions

• the invention relates to a galvanic bath for the deposition of high-gloss white rhodium coatings and a whitening agent for this purpose.
• Rhodium coatings are e.g. deposited as a tarnish protection on silver and should have high gloss and the brightest possible, white color, similar to that of silver.
• electrolytes are composed on the basis of rhodium sulfate, phosphate or sulfamate, sulfuric acid, phosphoric acid, alkanesulfonic acid or amidosulfuric acid.
• these usually contain certain organic compounds as brightener additives.
• Typical, very frequently used brightener additives are, as described, for example, in EP 0 056 590, the compounds pyridine-3-sulfonic acid and naphthalene-trisulfonic acid.
• a wetting agent and / or a phosphonic acid may additionally be contained in such a bath.
• a disadvantage of the existing systems lies in the fact that the very bright, white color of silver is not achieved and that with increasing layer thickness increasingly hazy deposition occurs.
• the whiteners according to formula I are selected compounds from the class of alkyl sulfates (first embodiment) or from the class of alkyl sulfates or alkyl sulfonates (second embodiment).
• R is a straight- or branched-chain or cyclic alkyl group having up to 20 C atoms.
• These compounds are sufficiently water-soluble and compatible with the electroplating bath.
• the compounds have surfactant properties wherein the corresponding effect is reduced to less than 4 for a total number of C atoms, and generally no sufficient solubility is given for a total number of C atoms greater than 20.
• Preferred brightener additives are compounds of the formula I in which R represents straight-chain or branched-chain or cyclic alkyl groups having 5 to 12 C atoms and in particular branched-chain alkyl groups having 6 to 10 C atoms.
• Branched-chain compounds are particularly useful in processes and equipment where there is a high degree of foaming, e.g. in air-agitated electrolytes, in drum processing, in high-speed separation equipment (spray equipment) and in selective deposition equipment, e.g. Diving cells.
• Typical whiteners according to the invention are Hexyl sulfate (first and second embodiments) Hexylsulfonate (second embodiment) 2-ethylhexyl sulfate (first and second embodiments) Heptyl sulfate (first and second embodiments) Octyl sulfate (first and second embodiments) Octylsulfonate (second embodiment) Decyl sulfate (first and second embodiments) Decyl sulfonate (second embodiment) Dodecyl sulfate (first and second embodiments) 7-ethyl-2-methyl-4-undecanol sulfate (first and second embodiments) Cyclohexylsulfate (First and Second Embodiments) and their isomers.
• the application of the whitening agent according to the invention in baths for the electrodeposition of rhodium layers is expediently carried out in a concentration range from 0.01 to 10 g / l.
• Baths according to the invention which contain the whitening agent according to formula I in a concentration of 0.1 to 6 g / l are particularly advantageous.
• the galvanic rhodium baths according to the invention typically contain about 0.1-20 g / l Rhodium as rhodium sulfate, phosphate, alkanesulfonate or sulfamate, 10-200 g / l Sulfuric acid, phosphoric acid, amidosulfuric acid or mixtures of these acids, 0 - 5 g / l Pyridine-3-sulfonic acid as brightener, 0.01-2 g / l wetting agent 0.1-10 g / l Compound of the formula I as a whitening agent according to the invention.
• the baths are usually operated at current densities of 0.5-5 A / dm 2 (rack operation) and temperatures up to 60 ° C.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Engineering & Computer Science (AREA)
• Electroplating And Plating Baths Therefor (AREA)
• Chemically Coating (AREA)
• Pyridine Compounds (AREA)
• Physical Vapour Deposition (AREA)
• Paper (AREA)
• Other Surface Treatments For Metallic Materials (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=7934370

Family Applications (1)

Country Status (9)

Families Citing this family (8)

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• 2000
  • 2000-12-15 US US10/168,241 patent/US6878411B2/en not_active Expired - Fee Related
  • 2000-12-15 CN CNB008174490A patent/CN1181226C/zh not_active Expired - Fee Related
  • 2000-12-15 EP EP00990767A patent/EP1244827B1/de not_active Expired - Lifetime
  • 2000-12-15 DE DE50012619T patent/DE50012619D1/de not_active Expired - Lifetime
  • 2000-12-15 WO PCT/EP2000/012796 patent/WO2001048273A1/de active IP Right Grant
  • 2000-12-15 JP JP2001548777A patent/JP4545367B2/ja not_active Expired - Fee Related
  • 2000-12-15 AT AT00990767T patent/ATE323789T1/de active
  • 2000-12-21 TW TW89127581A patent/TW573074B/zh not_active IP Right Cessation
• 2003
  • 2003-09-09 HK HK03106397.3A patent/HK1054057B/zh not_active IP Right Cessation

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