US4142902A
Expired / Lapsed
US
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Electroless gold plating baths
Assignee: MSA Safety Inc
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Filing: 1978-01-09
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Granted: 1979-03-06
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Expires: 1998-01-09
Abstract
Abstract Improved electroless gold plating baths, free of cyanide ion, comprise an alkaline aqueous solution of a soluble gold (III) salt and an ether substituted tertiary amine borane. Metallic and non-metallic substrates having catalytically activated surfaces are plated by immersing the substrate in the plating bath.
Inventors
- 👤 Aaron R. Burke
- 👤 William V. Hough
- 👤 Gerald T. Hefferan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:41
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/42; C23C18/44
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
96 words
In a cyanide free electroless gold plating bath consisting essentially of an aqueous solution of a gold (III) salt and a reducing agent therefor, the improvement of a tertiary amine borane reducing agent of the formula RO(C.sub.a H.sub.2a O).sub.x C.sub.b H.sub.2b NR'R"BH.sub.3 wherein a is a zero or an integer from 1 to 3, x is zero or an integer from 1 to 4, b is an integer from 1 to 5 and R, R' and R" are alkyl groups containing up to 5 carbon atoms, said bath being maintained at a pH above about 12.
Claim 2
Dependent Claim
96 words
In a cyanide free electroless gold plating bath consisting essentially of an aqueous solution of a gold (III) salt and a reducing agent therefor, the improvement of a tertiary amine borane reducing agent of the formula RO(C.sub.a H.sub.2a O).sub.x C.sub.b H.sub.2b NR'R"BH.sub.3 wherein a is a zero or an integer from 1 to 3, x is zero or an integer from 1 to 4, b is an integer from 1 to 5 and R, R' and R" are alkyl groups containing up to 5 carbon atoms, said bath being maintained at a pH above about 12.
Claim 3
Dependent Claim
19 words
The bath of claim 1 in which the pH is maintained by the addition of alkali metal hydroxide thereto.
Claim 4
Dependent Claim
13 words
The bath of claim 1 in which the pH is greater than 13.
Claim 5
Dependent Claim
16 words
The bath of claim 1 in which the gold salt is an alkali metal gold halide.
Claim 6
Dependent Claim
16 words
The bath of claim 1 in which the amine borane contains at least two oxygen atoms.
Claim 7
Dependent Claim
32 words
The bath of claim 1 in which the concentration of gold salt is between about 0.0005 and 0.004 M, and the concentration of amine borane is between about 0.01 and 0.02 M.
Claim 8
Dependent Claim
39 words
The bath of claim 1 in which the pH is greater than 13, the concentration of gold salt is between about 0.0005 and 0.004 M and the concentration of the amine borane is between about 0.01 and 0.02 M.
Claim 9
Dependent Claim
107 words
In a method of gold plating a substrate having a catalytically active surface comprising contacting said substrate with a bath consisting essentially of an aqueous solution of a gold (III) salt and a reducing agent therefor, the improvement of a tertiary amine borane reducing agent of the formula RO(C.sub.a H.sub.2a O).sub.x C.sub.b H.sub.2b NR'R"BH.sub.3 wherein a is zero or an integer from 1 to 3, x is zero or an integer from 1 to 4, b is an integer from 1 to 5 and R, R' and R" are alkyl groups containing up to 5 carbon atoms, said bath being maintained at a pH above about 12.
Claim 10
Dependent Claim
107 words
In a method of gold plating a substrate having a catalytically active surface comprising contacting said substrate with a bath consisting essentially of an aqueous solution of a gold (III) salt and a reducing agent therefor, the improvement of a tertiary amine borane reducing agent of the formula RO(C.sub.a H.sub.2a O).sub.x C.sub.b H.sub.2b NR'R"BH.sub.3 wherein a is zero or an integer from 1 to 3, x is zero or an integer from 1 to 4, b is an integer from 1 to 5 and R, R' and R" are alkyl groups containing up to 5 carbon atoms, said bath being maintained at a pH above about 12.
References Cited (Backward Citations)
US4005229A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-05 | 1982-09-04 | 1983-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-05 | 1986-09-04 | 1987-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-05 | 1990-09-04 | 1991-03-06 | $7700.00 | Window Closed / Lapsed |