Title: Chromium electroplating baths

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Claims: We claim:

1. An aqueous chromium electroplating bath having a pH between 1.8 and 4.9 consisting essentially of water, from 0.05 moles to saturation of ammonia and a water soluble complex of trivalent chromium with (A) glycolic acid, and (B) 0.1 to 3.5 moles of a halide per mole of chromium, said chromium being present in an amount sufficient to provide 0.5 to 3 moles per liter of trivalent chromium.

2. A bath as claimed in claim 1 wherein there is additionally present at least 0.1 moles of borate.

3. A bath as claimed in claim 2 wherein the halide is selected from fluoride and chloride.

4. A bath as claimed in claim 3 additionally containing salts selected from the sulphates, chlorides and fluorides of sodium and potassium.

5. An aqueous chromium electroplating bath having a pH of from 1.8 to 4.9 and consisting essentially of water, from 0.2 to 4 molar ammonium, from 1 to 5 molar of at least one salt selected from the chlorides and sulphates of sodium and potassium and a complex of trivalent chromium with (A) from 0.7 to 3 moles of glycolic acid per mole of chromium and (B) from 0.1 to 1 mole of chloride per mole of trivalent chromium.

Other info:

Inventors: Crowther, John C. (Stourbridge, EN)

Application Number: 717765
Filing Date: 1976-08-25
Publication_date: 1977-10-11
Assignee: Albright & Wilson Limited (Warley, EN)
Primary Class(es): 205/286 205/289, 205/290
Other Classes:
US Patent Ref:

3006823	Oct, 1961	Deyrup	204/51.
3706639	Dec, 1972	Bride et al.	204/51.
3733346	May, 1973	Bride	204/51.
3733347	May, 1973	Bride	204/51.
3788957	Jan, 1974	Christie et al.	204/51.
3833485	Sep, 1974	Crowther et al.	204/43.
3954574	May, 1976	Gyllenspetz et al.	204/51.

Other Refs: 668,751

Nov, 1929	FR

Primary Examiner: Kaplan, G. L.
Assistant Examiner:
Attorney: Flynn & Frishauf