US4168625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
N-thiophthalimide composition for forming thermoparticulating coating
Assignee: Westinghouse Electric Corp
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Filing: 1976-09-23
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Granted: 1979-09-25
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Expires: 1996-09-23
Abstract
Abstract A composition is disclosed of an N-thiophthalimide, a resinous carrier, and a solvent. The composition is applied to a portion of an electrical apparatus which is exposed to a gas stream. The solvent in the composition is evaporated to produce a thermoparticulating coating. When the electrical apparatus overheats the N-thiophthalimide in the coating forms particles in the gas stream which are detected by a monitor.
Inventors
- 👤 James D. B. Smith
- 👤 Joseph F. Meier
- 👤 David C. Phillips
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:11
CPC Classifications
G; G01; G01K; G01K11/00; C; C08; C08K; C08K5/00; C08K5/0008; C08K5/0016; C08K5/36; C08K5/43; C09; C09D; C09D163/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
69 words
A composition comprising: (1) an N-thiophthalimide having the general formula ##STR2## where R' is hydrogen, alkyl to C 20 , aryl, aralkyl, alkylaryl, cycloaliphatic, aliphatic, heterocyclic, or substitutions thereof, and each R group is independently selected from the group consisting of R', halide, nitro, alkoxy, and keto; and (2) a solution of an air-dryable resinous carrier curable at room temperature, stable at 60° C., and unreactive with said N-thiophthalimide.
Claim 2
Dependent Claim
69 words
A composition comprising: (1) an N-thiophthalimide having the general formula ##STR2## where R' is hydrogen, alkyl to C 20 , aryl, aralkyl, alkylaryl, cycloaliphatic, aliphatic, heterocyclic, or substitutions thereof, and each R group is independently selected from the group consisting of R', halide, nitro, alkoxy, and keto; and (2) a solution of an air-dryable resinous carrier curable at room temperature, stable at 60° C., and unreactive with said N-thiophthalimide.
Claim 3
Dependent Claim
22 words
A composition according to claim 1 wherein R' is hydrogen, alkyl to C 6 , alkylaryl, or cycloaliphatic and R is hydrogen.
Claim 4
Dependent Claim
22 words
A composition according to claim 2 wherein said N-thiophthalimide is selected from the group consisting of N-(isopropyl thio)phthalimide, N-(cyclohexyl)(thio)phthalimide, and N-(benzyl thio)phthalimide.
Claim 5
Dependent Claim
41 words
A composition according to claim 1 wherein the amount of said N-thiophthalimide is about 20 to about 250 phr and the amount of the solvent in said solution is about 25 to about 75% (by weight based on said resinous carrier).
Claim 6
Dependent Claim
38 words
A composition according to claim 4 wherein the amount of said N-thiophthalimide is about 40 to about 60 phr and the amount of said solvent is about 45 to about 55% (by weight based on said resinous carrier.
Claim 7
Dependent Claim
14 words
A composition according to claim 1 wherein said resinous carrier is an epoxy resin.
Claim 8
Dependent Claim
21 words
A composition according to claim 6 which includes about 0.1 to about 3 phr of a drier for said epoxy resin.
Claim 9
Dependent Claim
26 words
A composition according to claim 7 which is prepared by first mixing said solution of resinous carrier and said drier and then mixing in said N-thiophthalimide.
Claim 10
Dependent Claim
14 words
A composition according to claim 1 where the solvent in said solution is toluene.
Claim 11
Dependent Claim
14 words
A composition according to claim 1 wherein said N-thiophthalimide is dispersed in said solution.
Claim 12
Dependent Claim
86 words
A method of protecting electrical apparatus from change due to overheating and for thereafter determining the location of said overheating, said apparatus including a gas stream and a monitor for detecting particles in said gas stream and for emitting a signal when said particles are detected comprising: (1) preparing a composition according to claim 1; (2) applying said composition to said electrical apparatus at positions exposed to said gas stream; (3) evaporating said solvent; and (4) monitoring said gas stream for the presence of particles therein.
Claim 13
Dependent Claim
33 words
A method according to claim 11 including the additional last step of inspecting said apparatus visually for blistered and darkened areas, after a signal has been emitted, to locate the area of overheating.
Claim 14
Dependent Claim
29 words
A method according to claim 12 including the additional last steps of collecting a sample of said gas stream after a signal has been emitted, and analyzing said sample.
Claim 15
Dependent Claim
57 words
A thermoparticulating coating comprising a solid layer of a cured resinous carrier containing an unreacted N-thiophthalimide having the general formula ##STR3## where R' is hydrogen, alkyl to C 20 , aryl, aralkyl, alkylaryl, cycloaliphatic, aliphatic, heterocyclic, or substitutions thereof, and each R group is independently selected from the group consisting of R', halide, nitro, alkoxy, and keto.
Claim 16
Dependent Claim
57 words
A thermoparticulating coating comprising a solid layer of a cured resinous carrier containing an unreacted N-thiophthalimide having the general formula ##STR3## where R' is hydrogen, alkyl to C 20 , aryl, aralkyl, alkylaryl, cycloaliphatic, aliphatic, heterocyclic, or substitutions thereof, and each R group is independently selected from the group consisting of R', halide, nitro, alkoxy, and keto.
Claim 17
Dependent Claim
15 words
A coating according to claim 14 which is about 1/16 to about 1/2 inch thick.
Claim 18
Dependent Claim
44 words
A thermal detection system for electrical apparatus cooled by a gas stream, comprising a coating according to claim 14 on a portion of said electrical apparatus exposed to said gas stream and a monitor for detecting the presence of particles in said gas stream.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-09-24 | 1983-03-26 | 1983-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-24 | 1987-03-26 | 1987-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-24 | 1991-03-26 | 1991-09-25 | $7700.00 | Window Closed / Lapsed |