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
  • C25D3/56—Electroplating: Baths therefor from solutions of alloys
  • C25D3/60—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of tin
• • 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
  • C25D3/56—Electroplating: Baths therefor from solutions of alloys
  • C25D3/62—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of gold

Definitions

• the present invention relates to a bath for the deposition of gold alloys by electroplating, which is not subject to ageing, that is to say, the yield of which, computed on the basis of the current consumed as compared to the weight of the metal deposited, measured when the bath has just been prepared, remains constant during the whole life of the bath.
• This bath contains the gold intended for plating in the form of alkaline aurocyanide. It is characterized by the fact that, apart from the said aurocyanide, it is free from any other cyanide and by the fact that it contains an organo metallic compound of the metal to be alloyed with gold, soluble in water and hav: ing a low dissociation constant.
• this organo-metallic compound other than a cyanide, which supplies the metal to be alloyed with the gold at the time of formation of the gold alloy deposit.
• the metal of this compound may thus be copper, nickel, cadmium, zinc. It has been found that when the metal to be alloyed with gold. is introduced into the bath in a form other than cyanide, the bath does not age.
• the said organo-rnetallic compound may include in its molecule the group -N(CH2COO--)2. It may be a salt of an organic acid and of the metal to be alloyed with gold, insofar as this salt has a low dissociation constant. Among the salts fulfilling this condition, one may. mention those of the acids presenting in their molecule the above mentioned group, such as those of imido-diacetic acid and its derivatives, for instance ethylene-diaminotetraacetic acid, nitrilo-tri'a'cetic acid, :anthranilic-diacetic acid, uranil-diacetic acid, aminomalonic-diacetic acid.
• conducting s'al'ts such as phosphates and sulphites can be completely omitted from the bath and replaced by the potassium and sodium salts of the organo-n1etallic compound above referred to.
• the bath does not contain any free cyanide.
• EXAMPLE 1 Bath for the deposition of thick coatings (pink colour) g. per litre Gold (as potassium aurocyanide) a 12 Cu (as copper salt of ethylene-diamino-tetraacetic acid) 2.5 Zn (as Zinc salt of ethylene-diamino-tetraacetic acid) 2 Ni (as nickel salt of ethylene-diamino-tetraacetic acid) 2 Potassium salt of ethylene-diamino-tetraacetic acid- 5 EXAMPLE 2 Bath for the deposition of thin gold coatings (yellow and pale yellow colours) g.
• a bath for the deposition of an alloy of gold with at least one metal selected from the group consisting of copper, nickel, cadmium and zinc said bath containing exclusively an alkaline aurocyanide and at least one organometallic compound selected from the group consisting of the copper, nickel, cadmium and zinc salts of ethylene-diamino-tetraacetic acid, nitrilo-triacetic acid, anthranilic-diacetic acid, uranil-diacetic acid and aminomalonic-diacetic acid, characterized by the yield, computed on 4- the basis of the current consumed as compared tothe Weight of metal deposited, remains constant during the whole life of the bath.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electroplating And Plating Baths Therefor (AREA)

Applications Claiming Priority (1)

Publications (1)

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ID=4531337

Family Applications (1)

Country Status (5)

Cited By (19)

Families Citing this family (3)

Citations (1)

Family Cites Families (1)

• 1952
  • 1952-05-08 CH CH286123D patent/CH286123A/fr unknown
  • 1952-07-21 US US300127A patent/US2724687A/en not_active Expired - Lifetime
  • 1952-09-23 GB GB23796/52A patent/GB718574A/en not_active Expired
  • 1952-12-11 FR FR1067620D patent/FR1067620A/fr not_active Expired
  • 1952-12-13 DE DES31496A patent/DE1033987B/de active Pending

Patent Citations (1)

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