US4439280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phenothiazine leucodyes for electrochromic recording
Assignee: International Business Machines Corp
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Filing: 1982-09-29
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Granted: 1984-03-27
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Expires: 2002-09-29
Abstract
Abstract An electrochromic recording substrate comprising bromide ions and a leucodye having the structure ##STR1## wherein R is lower alkyl, lower alkoxy, lower thioalkyl, lower dialkylamino, or diarylamino.
Inventors
- 👤 Paul L. Gendler
- 👤 Robert J. Twieg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:36
CPC Classifications
C; C09; C09B; C09B21/00; B; B41; B41M; B41M5/00; B41M5/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
32 words
A substrate for electrochromic recording comprising bromide ions and characterized by also comprising a leucodye having the structure ##STR3## wherein R is lower alkyl, lower alkoxy, lower thioalkyl, lower dialkylamino, or diarylamino.
Claim 2
Dependent Claim
32 words
A substrate for electrochromic recording comprising bromide ions and characterized by also comprising a leucodye having the structure ##STR3## wherein R is lower alkyl, lower alkoxy, lower thioalkyl, lower dialkylamino, or diarylamino.
Claim 3
Dependent Claim
12 words
A substrate as claimed in claim 1 wherein the substrate is paper.
Claim 4
Dependent Claim
18 words
A substrate as claimed in claim 1 which contains approximately 10 mg of leucodye material per standard page.
Claim 5
Dependent Claim
12 words
A substrate as claimed in claim 1 wherein the leucodye is 3-hydroxy-10-(4-methoxybenzoyl)-10H-phenothiazine.
Claim 6
Dependent Claim
12 words
A substrate as claimed in claim 1 wherein the leucodye is 3-hydroxy-10-(4-ethoxybenzoyl)-10H-phenothiazine.
Claim 7
Dependent Claim
12 words
A substrate as claimed in claim 1 wherein the leucodye is 3-hydroxy-10-(4-t-butylbenzoyl)-10H-phenothiazine.
Claim 8
Dependent Claim
12 words
A substrate as claimed in claim 1 wherein the leucodye is 3-hydroxy-10-(4-diethylaminobenzoyl)-10H-phenothiazine.
Claim 9
Dependent Claim
12 words
A substrate as claimed in claim 1 wherein the leucodye is 3-hydroxy-10-(4-diphenylaminobenzoyl)-10H-phenothiazine.
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) | 1987-03-27 | 1987-09-26 | 1988-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-27 | 1991-09-26 | 1992-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-27 | 1995-09-26 | 1996-03-27 | $7700.00 | Window Closed / Lapsed |