Patent US3568834A successfully refreshed from Google Patents.
US3568834A
Expired / Lapsed
US
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Filtering alkaline metal cleaner
Assignee: Dow Chemical Co
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Filing: 1969-11-05
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Granted: 1971-03-09
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Expires: 1989-11-05
Abstract
Abstract Process of fine filtering an alkaline metal cleaner containing emulsified soluble oil in which the requisite amount of aminopolyacetic acid or ammonium or alkali metal salt thereof is added to the cleaner periodically to maintain unchelated hardness in the range of zero to about 400 p.p.m. hardness expressed as CaCO3, and up to 2 percent by weight of free polyacetic acid or ammonium or alkali metal salt thereof, and the cleaner is filtered through a medium capable of removing solids larger than about 0.1 to 10 microns major dimension.
Inventors
- 👤 Lyle G Treat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:27
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/36; B; B01; B01D; B01D37/00; B01D37/03; C11; C11D; C11D3/00; C11D3/16; C11D3/26; C11D3/33; B01D2201/00; B01D2201/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
27 words
The method as in claim 1 in which the unchelated hardness is maintained in the range of about 5 to 150 parts per million, expressed as CaCO3.
Claim 2
Dependent Claim
32 words
The method as in claim 1 in which the emulsion is maintained at a temperature in the range of about ambient room temperature to the incipient boiling temperature of the metal cleaner.
Claim 3
Dependent Claim
24 words
The method as in claim 3 in which the emulsion is maintained at a temperature in the range of about 70 to 180* F.
Claim 4
Dependent Claim
23 words
The method as in claim 1 in which the metal cleaner has a pH in the range of about 7.01 to about 13.
Claim 5
Dependent Claim
22 words
The method as in claim 5 in which the metal cleaner has a pH in the range of about 8.5 to 10.5.
Claim 6
Dependent Claim
24 words
the method as in claim 1 in which a greater volume of metal cleaner is filtered than is concurrently applied in metal cleaning operations.
Claim 7
Dependent Claim
31 words
The method as in claim 1 in which additions of aminopolyacetic acid or ammonium or alkali metal salt thereof are made at least once during each 8-hour period of cleaning operation.
Claim 8
Dependent Claim
14 words
The method as in claim 1 in which the filter medium is diatomaceous earth.
Claim 9
Dependent Claim
23 words
The method as in claim 1 in which the polyacetic acid is ethylene diamine tetracetic acid or an ammonium or sodium salt thereof.
Claim 10
Dependent Claim
23 words
The method as in claim 1 in which the metal cleaner is circulated and maintained for at least six months before being discarded.
Claim 11
Dependent Claim
24 words
The method as in claim 1 in which the metal cleaner contains from about 0.1 to 5 percent by weight of neat soluble oil.
References Cited (Backward Citations)
US3408843A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |