US4123282A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photothermographic toners
Assignee: 3M Co
•
Filing: 1976-08-09
•
Granted: 1978-10-31
•
Expires: 1996-08-09
Abstract
Abstract A combination of phthalazine and certain aromatic acids or anhydrides thereof serves as a toner during heat development of exposed dry silver image forming sheet materials.
Inventors
- 👤 John M. Winslow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:20
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/494; G03C1/498; G03C1/49836; G03C1/49845; Y; Y10; Y10S; Y10S430/00; Y10S430/166
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
In a photosensitive, heat-developable, dry silver sheet material containing an image-forming system including a preformed photosensitive silver halide catalyst-forming means and, as heat sensitive image forming means, an organic silver compound and a reducing agent therefor, the oxidation reduction reaction of which to produce a visible image is accelerated by said catalyst, and sufficient toner to increase the density of said visible image, the improvement characterized by said toner being a mixture of (a) phthalazine and (b) at least one acid of the formula: R - A - R.sub.1 wherein A is phenyl or naphthyl and R and R 1 are selected from --COOH and CH 2 COOH, R and R 1 bonded respectively to the 2 and 3 positions of A 1 and anhydrides of said acid R - A - R 1 .
Claim 2
Dependent Claim
135 words
In a photosensitive, heat-developable, dry silver sheet material containing an image-forming system including a preformed photosensitive silver halide catalyst-forming means and, as heat sensitive image forming means, an organic silver compound and a reducing agent therefor, the oxidation reduction reaction of which to produce a visible image is accelerated by said catalyst, and sufficient toner to increase the density of said visible image, the improvement characterized by said toner being a mixture of (a) phthalazine and (b) at least one acid of the formula: R - A - R.sub.1 wherein A is phenyl or naphthyl and R and R 1 are selected from --COOH and CH 2 COOH, R and R 1 bonded respectively to the 2 and 3 positions of A 1 and anhydrides of said acid R - A - R 1 .
Claim 3
Dependent Claim
17 words
The dry silver sheet material of claim 1 wherein said reducing agent is a weak reducing agent.
Claim 4
Dependent Claim
14 words
The dry silver sheet material of claim 1 wherein said (b) is phthalic acid.
Claim 5
Dependent Claim
14 words
The dry silver sheet material of claim 1 wherein said (b) is phthalic anhydride.
Claim 6
Dependent Claim
15 words
The dry silver sheet material of claim 1 wherein said (b) is 2,3-naphthalene dicarboxylic acid.
Claim 7
Dependent Claim
28 words
The dry silver sheet material of claim 1 wherein A is substituted in the 4 or 5 position by an alkyl or alkoxy group of 1-20 carbon atoms.
Claim 8
Dependent Claim
14 words
The dry silver sheet material of claim 6 wherein (b) is 4-methyl phthalic acid.
References Cited (Backward Citations)
US3218166A
Cited
US3589903A
Cited
US3745009A
Cited
JPS4917229A
Cited
US3856526A
Cited
US3994732A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-30 | 1982-05-01 | 1982-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-30 | 1986-05-01 | 1986-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-30 | 1990-05-01 | 1990-10-31 | $7700.00 | Window Closed / Lapsed |