US4374744A
Expired / Lapsed
US
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Stripping solution for tin or tin alloys
Assignee: MEC Co Ltd
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Filing: 1982-04-06
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Granted: 1983-02-22
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Expires: 2002-04-06
Abstract
Abstract A stripping solution for tin or tin alloys which comprises an inorganic and/or organic acid, an oxidizing agent and a heterocyclic compound free of a sulfur atom but containing a nitrogen atom in the form of =NH or 3BOND N as a ring-forming member.
Inventors
- 👤 Yutaka Kawanabe
- 👤 Takeyoshi Kishimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:25
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/44; H; H05; H05K; H05K3/00; H05K3/02; H05K3/06; H05K3/067
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
40 words
A stripping solution for tin and tin alloys comprising an inorganic and/or organic acid, an oxidizing agent and a heterocyclic compound free of sulfur but containing a nitrogen atom in the form of ═NH or .tbd.N as a ring-forming member.
Claim 2
Dependent Claim
40 words
A stripping solution for tin and tin alloys comprising an inorganic and/or organic acid, an oxidizing agent and a heterocyclic compound free of sulfur but containing a nitrogen atom in the form of ═NH or .tbd.N as a ring-forming member.
Claim 3
Dependent Claim
27 words
The stripping solution as in claim 1, wherein the tin alloys are tin-lead alloy containing at least 10 wt % of tin and the balance of lead.
Claim 4
Dependent Claim
25 words
The stripping solution as in claim 1, wherein the inorganic acid is hydrochloric acid, nitric acid, sulfuric acid, borofluoric acid, boric acid or chloric acid.
Claim 5
Dependent Claim
25 words
The stripping solution as in claim 1, wherein the organic acid is oxalic acid, acetic acid, propionic acid, gluconic acid, tartaric acid or formic acid.
Claim 6
Dependent Claim
22 words
The stripping solution as in claim 1, wherein the oxidizing agent is ferric chloride, potassium permanganate peroxoborate, perchlorate, persulfate or hydrogen peroxide.
Claim 7
Dependent Claim
33 words
The stripping solution as in claim 1, wherein the heterocyclic compound is pyrrole and a derivative thereof, pyrazole and a derivative thereof, imidazole and a derivative thereof, or triazole and a derivative thereof.
Claim 8
Dependent Claim
22 words
The stripping solution as in claim 6, wherein the pyrrole and a derivative thereof are pyrrole, pyrrolecarboxylic acid, indole, or indolylacetic acid.
Claim 9
Dependent Claim
22 words
The stripping solution as in claim 6, wherein the pyrazole and a derivative thereof are pyrazole, pyrazole hydrochloride, pyrazolecarboxylic acid, or indazole.
Claim 10
Dependent Claim
23 words
The stripping solution as in claim 6, wherein the imidazole and a derivative thereof are imidazole, N-methyl-substituted imidazole, N-ethyl-substituted imidazole, or urocanic acid.
Claim 11
Dependent Claim
21 words
The stripping solution as in claim 6, wherein the triazole and a derivative thereof are triazole, triazole hydrochloride, naphthotriazole, or benzotriazole.
Claim 12
Dependent Claim
19 words
The stripping solution as in claim 1 or 6, wherein the heterocyclic compound is pyrrole, pyrazole, imidazole, or triazole.
Claim 13
Dependent Claim
82 words
The stripping solution as in claim 1, wherein the solution comprises an inorganic and/or organic acid in a range of 50 to 800 g per liter of the solution, an oxidizing agent in a range of 0.1 to 400 g per liter of the solution, and a heterocyclic compound free of sulfur atom but containing a nitrogen atom in the form of ═NH or .tbd.N as a ring-forming member in a range of 0.1 to 100 g per liter of the solution.
References Cited (Backward Citations)
US4251384A
Cited
US4297257A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-21 | 1986-08-23 | 1987-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-21 | 1990-08-23 | 1991-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-21 | 1994-08-23 | 1995-02-22 | $7700.00 | Window Closed / Lapsed |