US3673099A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and composition for stripping cured resins from substrates
Assignee: AT&T Inc
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Filing: 1970-10-19
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Granted: 1972-06-27
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Expires: 1990-10-19
Abstract
Abstract Cured resins, such as silicones or polyvinyl cinnamate are stripped from substrates by exposure to a mixture of N-methyl-2pyrrolidone and a strong base, such as an alkyl or substituted alkyl ammonium hydroxide, to which may be added other compatible organic solvents such as ethylene glycol monoethyl ether.
Inventors
- 👤 William Joseph Corby
- 👤 Victor Charles Garbarini
- 👤 Malcolm Lunt White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:28
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/42; G03F7/422; G03F7/425; C; C09; C09D; C09D9/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
29 words
Method in accordance with claim 1 wherein said solvent contains ethylene glycol monomethyl ether, the volume ratio of ethylene glycol monomethyl ether to N-methyl-2-pyrrolidone ranging from 1:1 to 4:1.
Claim 2
Dependent Claim
13 words
The method of claim 1 wherein the strong base is tetramethyl ammonium hydroxide.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein the strong base is tetrabutyl ammonium hydroxide.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein the strong base is trimethylbenzyl ammonium hydroxide.
Claim 5
Dependent Claim
141 words
Composition for stripping a cured resin selected from the group consisting of methyl phenyl silicones and polyvinyl cinnamates consisting of a mixture of I. a solute consisting of a strong base selected from the group consisting of a. inorganic alkali hydroxides; b. guanidine carbonate; and c. substituted ammonium hydroxides of the general formula wherein x ranges from 0 to 4, R is an alkyl radical having the general formula CnH2n 1, where n is an integer from 1 to 4 and R'' is an aryl substituted radical having the general formula where n'' is an integer ranging from 1 to 4; II. a solvent consisting essentially of N-methyl-2 -pyrrolidone; the solute being present in an amount of at least 0.1 per cent by weight of the solution; and III. a dissociating medium selected from the group consisting of water and methanol.
Claim 6
Dependent Claim
14 words
Composition in accordance with claim 6 wherein said solvent includes ethylene glycol monomethyl ether.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |