US4233113A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dissolution of metals utilizing an aqueous H2 O2 -H2 SO4 -thioamide etchant
Assignee: Dart Industries Inc
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Filing: 1979-06-25
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Granted: 1980-11-11
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Expires: 1999-06-25
Abstract
Abstract Improved metal dissolution rates are obtained when using a solution containing sulfuric acid, hydrogen peroxide and a catalytic amount of a thioamide having the general formula <IMAGE> wherein R is an aryl or a heterocyclic group.
Inventors
- 👤 Silvester P. Valayil
- 👤 Moenes L. Elias
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:39
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; H; H05; H05K; H05K3/00; H05K3/02; H05K3/06; H05K3/067
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
107 words
A method of metal dissolution which comprises contacting a metal with an aqueous solution containing from about 0.2 to about 4.5 gram moles per liter of sulfuric acid, from about 0.25 to about 8 gram moles per liter of hydrogen peroxide and a catalytically effective amount of a thioamide additive having the general formula ##STR3## wherein R is either an aryl or a heterocyclic group and the aryl group is selected from phenyl, alkyl substituted phenyl groups containing from 7 to 10 carbon atoms and amino substituted phenyl groups and the heterocyclic group is selected from those containing at least one nitrogen atom in the ring structure.
Claim 2
Independent Claim
107 words
A method of metal dissolution which comprises contacting a metal with an aqueous solution containing from about 0.2 to about 4.5 gram moles per liter of sulfuric acid, from about 0.25 to about 8 gram moles per liter of hydrogen peroxide and a catalytically effective amount of a thioamide additive having the general formula ##STR3## wherein R is either an aryl or a heterocyclic group and the aryl group is selected from phenyl, alkyl substituted phenyl groups containing from 7 to 10 carbon atoms and amino substituted phenyl groups and the heterocyclic group is selected from those containing at least one nitrogen atom in the ring structure.
Claim 3
Dependent Claim
21 words
The method of claim 1, wherein said additive is provided at a concentration of at least about 0.1 gram per liter.
Claim 4
Dependent Claim
25 words
The method of claim 1, wherein said additive is provided at a concentration in the range from about 0.5 to about 10 grams per liter.
Claim 5
Dependent Claim
27 words
The method of claim 1, wherein the aqueous solution contains sodium phenolsulfonate as a stabilizer to reduce the degrading effect of heavy metal ions on hydrogen peroxide.
Claim 6
Dependent Claim
22 words
The method of claim 1, wherein the hydrogen peroxide concentration is maintained between about 1 and about 4 gram moles per liter.
Claim 7
Dependent Claim
22 words
The method of claim 1, wherein the sulfuric acid concentration is maintained between about 0.3 and about 4 gram moles per liter.
Claim 8
Dependent Claim
15 words
The method of claim 1, wherein the metal is copper or an alloy of copper.
Claim 9
Dependent Claim
25 words
The method of claim 1, wherein the dissolution is carried out in the presence of free chloride or bromide ions in excess of 2 ppm.
Claim 10
Dependent Claim
11 words
The method of claim 1, wherein R is a heterocyclic group.
Claim 11
Dependent Claim
11 words
The method of claim 1, wherein the thioamide additive is thioisonicotinamide.
Claim 12
Dependent Claim
102 words
A composition for metal dissolution comprising an aqueous solution of from about 2.0 to about 4.5 gram moles per liter of sulfuric acid, from about 0.25 to about 8 gram moles per liter of hydrogen peroxide and a catalytically effective amount of a thioamide additive having the general formula ##STR4## wherein R is either an aryl or a heterocyclic group and the aryl group is selected from phenyl, alkyl substituted phenyl groups containing from 7 to 10 carbon atoms and amino substituted phenyl groups and the heterocyclic group is selected from those containing at least one nitrogen atom in the ring structure.
Claim 13
Dependent Claim
102 words
A composition for metal dissolution comprising an aqueous solution of from about 2.0 to about 4.5 gram moles per liter of sulfuric acid, from about 0.25 to about 8 gram moles per liter of hydrogen peroxide and a catalytically effective amount of a thioamide additive having the general formula ##STR4## wherein R is either an aryl or a heterocyclic group and the aryl group is selected from phenyl, alkyl substituted phenyl groups containing from 7 to 10 carbon atoms and amino substituted phenyl groups and the heterocyclic group is selected from those containing at least one nitrogen atom in the ring structure.
Claim 14
Dependent Claim
21 words
The composition of claim 11, wherein the additive is provided at a concentration of at least about 0.1 gram per liter.
Claim 15
Dependent Claim
25 words
The composition of claim 11, wherein the additive is provided at a concentration in the range from about 0.5 to about 10 grams per liter.
Claim 16
Dependent Claim
24 words
The composition of claim 11, additionally containing sodium phenolsulfonate as a stabilizer for reducing the degrading effect of heavy metal ions on hydrogen peroxide.
Claim 17
Dependent Claim
22 words
The composition of claim 11, wherein the hydrogen peroxide concentration is maintained between about 1 and about 4 gram moles per liter.
Claim 18
Dependent Claim
22 words
The composition of claim 11, wherein the sulfuric acid concentration is maintained between about 0.3 and about 4 gram moles per liter.
Claim 19
Dependent Claim
16 words
The composition of claim 11, containing more than 2 ppm of free chloride or bromide ions.
Claim 20
Dependent Claim
11 words
The composition of claim 11, wherein R is a heterocyclic group.
Claim 21
Dependent Claim
11 words
The composition of claim 11, wherein the thioamide additive is thioisonicotinamide.
References Cited (Backward Citations)
US3102808A
Cited
US3341384A
Cited
US3412032A
Cited
US3537895A
Cited
US3514409A
Cited
US3597290A
Cited
US3668131A
Cited
US3773577A
Cited
US3905907A
Cited
US3948703A
Cited
US3939089A
Cited
US4086176A
Cited
US4144119A
Cited
US4130455A
Cited
US4174253A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-11 | 1984-05-12 | 1984-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-11 | 1988-05-12 | 1988-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-11 | 1992-05-12 | 1992-11-11 | $7700.00 | Window Closed / Lapsed |