Patent US3901918A successfully refreshed from Google Patents.
US3901918A
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Fluoran compounds
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1972-10-27
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Granted: 1975-08-26
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Expires: 1992-10-27
Abstract
Abstract Novel fluoran compounds such as 2-bis-(5'',6'',7'', 8''-tetrahydro2''-naphthylmethyl)amino-6-diethylaminofluoran and 2-(2''thenylamino)-8-dimethylbenz(c)fluoran, which are useful as a coloring material for record material systems, such as pressuresensitive copying paper or heat-sensitive copying paper, wherein colored images formed by an electron-donor-acceptor color-forming reaction between coloring material and acidic material.
Inventors
- 👤 Koichi Koga
- 👤 Yukiaki Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:04
CPC Classifications
C; C09; C09B; C09B11/00; C09B11/04; C09B11/10; C09B11/24; B; B41; B41M; B41M5/00; B41M5/124; B41M5/132; B41M5/136; B41M5/145; B41M5/1455; B41M5/26; B41M5/30; B41M5/323; B41M5/327; B41M5/3275; C07; C07D; C07D493/00; C07D493/02; C07D493/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
5 words
A COMPOUND OF THE FORMULA
Claim 2
Dependent Claim
5 words
A COMPOUND OF THE FORMULA
Claim 3
Dependent Claim
1 words
2-(2''-Benzylcyclohexylamino)-8-diethylaminobenz(c)fluoran.
Claim 4
Dependent Claim
1 words
2-(2''-Benzylcyclohexylamino)-8-diethylaminobenz(c)fluoran.
Claim 5
Dependent Claim
1 words
2-Cyclohexylamino-8-diethylaminobenz(c)fluoran.
Claim 6
Dependent Claim
1 words
2-Cyclohexylamino-8-diethylaminobenz(c)fluoran.
References Cited (Backward Citations)
US3501331A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |