US4472249A
Expired / Lapsed
US
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Bright chromium plating baths and process
Assignee: M&T HARSHAW
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Filing: 1981-08-24
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Granted: 1984-09-18
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Expires: 2001-08-24
Abstract
Abstract The invention provides a hexavalent chromium plating bath containing chromic acid, an iodine releasing compound and/or a bromine releasing compound such as iodate, periodate, bromate or perbromate, and a carboxylate which is stable in the bath. Exemplary stable carboxylates include acetic acid, propionic acid, chloroacetic acid, trichloroacetic acid, succinic acid, sulfoacetic acid, benzoic acid, picolinic acid, and nicotinic acid. Bright chromium deposits can be produced with these baths at high current efficiencies employing high temperatures with substantially no low current density etch.
Inventors
- 👤 Hyman Chessin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:08
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/04
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
50 words
A hexavalent chromium plating bath containing as additives thereto: (a) an iodine releasing compound, and (b) a stable carboxylate selected from the group consisting of acetic acid, propionic acid, chloroacetic acid, trichloroacetic acid, trifluoroacetic acid, sulfoacetic acid, succinic acid, benzoic acid, nicotinic acid, picolinic acid, salts thereof and anhydrides thereof.
Claim 2
Dependent Claim
50 words
A hexavalent chromium plating bath containing as additives thereto: (a) an iodine releasing compound, and (b) a stable carboxylate selected from the group consisting of acetic acid, propionic acid, chloroacetic acid, trichloroacetic acid, trifluoroacetic acid, sulfoacetic acid, succinic acid, benzoic acid, nicotinic acid, picolinic acid, salts thereof and anhydrides thereof.
Claim 3
Dependent Claim
12 words
The chromium plating bath of claim 1 which further comprises boric acid.
Claim 4
Dependent Claim
17 words
The chromium plating bath of claim 1 wherein the concentration of CrO 3 is about 800 g/l.
Claim 5
Dependent Claim
13 words
The chromium plating bath of claim 1 which further comprises a catalyst ion.
Claim 6
Dependent Claim
41 words
The chromium plating bath of claim 1 wherein said iodine releasing compound is selected from the group consisting of iodine, hydroiodic acid and salts thereof, iodic acid and salts thereof, periodic acid and salts thereof, organo iodides and hydrolyzable metal polyiodides.
Claim 7
Dependent Claim
77 words
A process for forming bright chromium deposits on a basis metal comprising electrodepositing chromium on said metal at temperatures from about 40° C. to 60° C. from a hexavalent chromium plating bath containing as additives thereto: (a) an iodine releasing compound; and (b) a stable carboxylate selected from the group consisting of acetic acid, propionic acid chloroacetic acid, trichloroacetic acid, trifluoroacetic acid, sulfoacetic acid, succinic acid, benzoic acid, nicotinic acid, picolinic acid, salts thereof and anhydrides thereof.
Claim 8
Dependent Claim
77 words
A process for forming bright chromium deposits on a basis metal comprising electrodepositing chromium on said metal at temperatures from about 40° C. to 60° C. from a hexavalent chromium plating bath containing as additives thereto: (a) an iodine releasing compound; and (b) a stable carboxylate selected from the group consisting of acetic acid, propionic acid chloroacetic acid, trichloroacetic acid, trifluoroacetic acid, sulfoacetic acid, succinic acid, benzoic acid, nicotinic acid, picolinic acid, salts thereof and anhydrides thereof.
Claim 9
Dependent Claim
54 words
A hexavalent chromium plating bath containing: (a) an iodo-oxy ion; and (b) a stable carboxylate selected from the group consisting of a monocarboxylic acid having from 2 to 6 carbon atoms, an anion of said monocarboxylic acid, a dicarboxylic acid having from 4 to 8 carbon atoms and an anion of said dicarboxylic acid.
Claim 10
Dependent Claim
54 words
A hexavalent chromium plating bath containing: (a) an iodo-oxy ion; and (b) a stable carboxylate selected from the group consisting of a monocarboxylic acid having from 2 to 6 carbon atoms, an anion of said monocarboxylic acid, a dicarboxylic acid having from 4 to 8 carbon atoms and an anion of said dicarboxylic acid.
Claim 11
Dependent Claim
25 words
The chromium plating bath of claim 7 wherein said iodo-oxy ion is selected from the group consisting of iodate anion, periodate anion and mixtures thereof.
Claim 12
Dependent Claim
17 words
The chromium plating bath of claim 7 wherein said stable carboxylate is acetic acid or propionic acid.
Claim 13
Dependent Claim
25 words
The chromium plating bath of claim 7 wherein said stable carboxylate is selected from the group consisting of chloroacetic acid, trichloroacetic acid and trifluoroacetic acid.
Claim 14
Dependent Claim
14 words
The chromium plating bath of claim 7 wherein said stable carboxylate is succinic acid.
Claim 15
Dependent Claim
14 words
The chromium plating bath of claim 7 wherein said stable carboxylate is benzoic acid.
Claim 16
Dependent Claim
14 words
The chromium plating bath of claim 7 wherein said stable carboxylate is sulfoacetic acid.
Claim 17
Dependent Claim
17 words
The chromium plating bath of claim 7 wherein said stable carboxylate is nicotinic acid or picolinic acid.
Claim 18
Dependent Claim
31 words
The chromium plating bath of claim 7 wherein said bath contains chromic acid added as CrO 3 , the concentration of said CrO 3 being from 200 g/l to 1600 g/l.
Claim 19
Dependent Claim
17 words
The chromium plating bath of claim 7 wherein the concentration of CrO 3 is about 800 g/l.
Claim 20
Dependent Claim
13 words
The chromium plating bath of claim 7 which further comprises a catalyst ion.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |