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US4636561A
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Spiroindolinenaphthoxadine photochromic compounds
Assignee: Unitika Ltd
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Filing: 1985-12-05
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Granted: 1987-01-13
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Expires: 2005-12-05
Abstract
Abstract A photochromic compound represented by formula (I): <IMAGE> (I) wherein one of X1 and X2 represents a hydroxyl group, a sulfonic acid group or an alkali metal sulfonate base, and the other of X1 and X2 represents a hydrogen atom; X3 and X4 each represents a hydrogen atom, a lower alkyl group having from 1 to 3 carbon atoms, a lower alkoxy group having from 1 to 3 carbon atoms, a halogen atom, a nitro group or a cyano group; and R represents a straight chain alkyl group having from 1 to 30 carbon atoms. The compound exhibits excellent color developability.
Inventors
- 👤 Masahiro Hosoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:38
CPC Classifications
C; C07; C07D; C07D498/00; C07D498/02; C07D498/10; G; G03; G03C; G03C1/00; G03C1/685
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
90 words
A photochromic compound represented by formula (I): ##STR3## wherein one of X 1 and X 2 represents a hydroxyl group, and the other of X 1 and X 2 represents a hydrogen atom; X 3 and X 4 each represents a hydrogen atom, a lower alkyl group having from 1 to 3 carbon atoms, a lower alkoxy group having from 1 to 3 carbon atoms, a halogen atom, a nitro group or a cyano group; and R represents a straight chain alkyl group having from 1 to 30 carbon atoms.
Claim 2
Dependent Claim
90 words
A photochromic compound represented by formula (I): ##STR3## wherein one of X 1 and X 2 represents a hydroxyl group, and the other of X 1 and X 2 represents a hydrogen atom; X 3 and X 4 each represents a hydrogen atom, a lower alkyl group having from 1 to 3 carbon atoms, a lower alkoxy group having from 1 to 3 carbon atoms, a halogen atom, a nitro group or a cyano group; and R represents a straight chain alkyl group having from 1 to 30 carbon atoms.
Claim 3
Dependent Claim
13 words
A photochromic compound as in claim 1, wherein R is a methyl group.
Claim 4
Dependent Claim
14 words
A photochromic compound as in claim 1, wherein X 1 is a hydroxyl group.
Claim 5
Dependent Claim
14 words
A photochromic compound as in claim 1, wherein X 2 is a hydroxyl group.
Claim 6
Dependent Claim
28 words
A photochromic compound as in claim 1, wherein R is selected from the group consisting of a methyl group, an isopropyl, a hexadecyl group and an octadecyl group.
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) | 1990-01-12 | 1990-07-14 | 1991-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-12 | 1994-07-14 | 1995-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-12 | 1998-07-14 | 1999-01-13 | $7700.00 | Window Closed / Lapsed |