Patent US3801320A successfully refreshed from Google Patents.
US3801320A
Expired / Lapsed
US
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Photoimaging in presence of oxygen
Assignee: Monsanto Co
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Filing: 1971-10-18
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Granted: 1974-04-02
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Expires: 1991-10-18
Abstract
Abstract This invention concerns a photoimaging procedure in which the image is characterized by a differential concentration of sulfate groups, depending upon the degree of light exposure, and is developable by selective absorption of dyes and other procedures. The sulfate groups can be obtained by SO2 treatment of hydroperoxy groups produced in a photooxidation imaging procedure.
Inventors
- 👤 F Erickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:41
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/72; G03C1/73; G03C1/733
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
16 words
The method of claim 1 in which the coating is heated to develop a visible image.
Claim 2
Dependent Claim
13 words
The method of claim 1 in which the coating is treated with ammonia.
Claim 3
Dependent Claim
15 words
The method of claim 1 in which the substrate comprises a polymer of a diolefin.
Claim 4
Independent Claim
51 words
The method of obtaining a latent image which comprises exposing imagewise to light in the presence of oxygen a photooxidizable substrate and a photosensitizing catalyst to form hydroperoxy groups in exposed areas and reacting said coating with sulfur dioxide to convert at least some of the hydroperoxy groups to sulfate groups.
Claim 5
Dependent Claim
28 words
The method of claim 5 in which the substrate contains carbon-to-carbon double bond unsaturation and the photosensitizer causes formation of excited state oxygen which adds to the substrate.
Claim 6
Dependent Claim
30 words
The method of obtaining a visible image which comprises forming a latent image in accord with claim 5 and adding coloring materials to the coating to selectively color areas thereof.
Claim 7
Dependent Claim
30 words
The method of obtaining a visible image which comprises forming a latent image in accord with claim 5 and selectively removing areas of said coating by treatment with a liquid.
Claim 8
Dependent Claim
23 words
The method of claim 5 in which the substrate comprises a solid high molecular weight polymer having carbon-to-carbon unsaturation and a porphyrin photosensitizer.
Claim 9
Dependent Claim
13 words
The method of claim 9 in which the polymer is a styrene-butadiene copolymer.
Claim 10
Dependent Claim
17 words
The method of claim 9 in which the polymer is a hydrocarbon polymer with a residual unsaturation.
Claim 11
Dependent Claim
11 words
The method of claim 9 in which the photosensitizer is tetraphenylporphin.
Claim 12
Independent Claim
64 words
The method of forming an image which comprises incorporating a porphyrin photosensitizer and sulfur dioxide into a coating comprising a photochemically oxidizable high molecular weight polymer having aliphatic carbon-to-carbon unsaturation and effecting image-wise exposure to light in the presence of oxygen to effect a transfer of oxygen to form a chemical bond between the oxygen and the polymer in exposed areas of the coating.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |