US4100015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chromate-free etching process and composition for preparing aluminum for adhesive bonding
Assignee: United States Department of the Army
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Filing: 1977-06-21
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Granted: 1978-07-11
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Expires: 1997-06-21
Abstract
Abstract A chromate-free etching process and composition for treating aluminum parts to prepare a surface for durable adhesive bonding to other parts, which avoids the toxicity and disposal problems attending the use of conventional chromate containing etching baths. The process utilizes an etchant composition composed of an aqueous solution of nitric acid, alkali metal sulfate, ferric sulfate and preferably also sulfuric acid.
Inventors
- 👤 William J. Russell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:46
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
81 words
The method of adhesive bonding of aluminum parts, wherein the aluminum parts are subjected, prior to adhesive bonding, to an etching process to produce a surface preparatory to adhesive bonding, which comprises contacting the aluminum part with a chromate-free etching composition consisting essentially of: 1 to 25 weight percent nitric acid 0 to 10 weight percent sulfuric acid 5 to 8 weight percent alkali metal sulfate 0.2 weight percent to saturated solution of ferric sulfate 60 to 93 weight percent water
Claim 2
Independent Claim
81 words
The method of adhesive bonding of aluminum parts, wherein the aluminum parts are subjected, prior to adhesive bonding, to an etching process to produce a surface preparatory to adhesive bonding, which comprises contacting the aluminum part with a chromate-free etching composition consisting essentially of: 1 to 25 weight percent nitric acid 0 to 10 weight percent sulfuric acid 5 to 8 weight percent alkali metal sulfate 0.2 weight percent to saturated solution of ferric sulfate 60 to 93 weight percent water
Claim 3
Dependent Claim
18 words
The method of claim 1, wherein the composition contains at least about 1 percent by weight sulfuric acid.
Claim 4
Dependent Claim
13 words
The method of claim 1, wherein the alkali metal sulfate is sodium sulfate.
Claim 5
Dependent Claim
50 words
A composition for etching aluminum perparatory to adhesive bonding which consists essentially of: 1 to 25 weight percent nitric acid 0 to 10 weight percent sulfuric acid 5 to 8 weight percent alkali metal sulfate 0.2 weight percent to saturated solution of ferric sulfate 60 to 93 weight percent water
Claim 6
Dependent Claim
50 words
A composition for etching aluminum perparatory to adhesive bonding which consists essentially of: 1 to 25 weight percent nitric acid 0 to 10 weight percent sulfuric acid 5 to 8 weight percent alkali metal sulfate 0.2 weight percent to saturated solution of ferric sulfate 60 to 93 weight percent water
Claim 7
Dependent Claim
18 words
The composition of claim 4, wherein the content of sulfuric acid is at least about 1% by weight.
Claim 8
Dependent Claim
13 words
The composition of claim 4, wherein the alkali metal sulfate is sodium sulfate.
References Cited (Backward Citations)
US3009849A
Cited
US3510430A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |