Patent US3634086A successfully refreshed from Google Patents.
US3634086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solvent development of light-sensitive diazo layers
Assignee: Howson Algraphy Ltd
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Filing: 1967-05-17
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Granted: 1972-01-11
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Expires: 1987-05-17
Abstract
Abstract The development of positive-working light-sensitive diazo layers for use as lithographic printing plates and photoresists is effected using selectively acting organic solvents to dissolve light-struck areas.
Inventors
- 👤 Leslie Edward Lawson
- 👤 Frank Edward Smith
- 👤 Peter John Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:08
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
29 words
Process in accordance with claim 1, wherein the developer includes a desensitizer to render hydrophilic the underlying areas of the support revealed on selective removal of the light-struck areas.
Claim 2
Dependent Claim
17 words
Process in accordance with claim 1, wherein the developer is in the form of an aqueous emulsion.
Claim 3
Dependent Claim
29 words
Process in accordance with claim 1, wherein said organic solvent is selected from the group consisting of 2-ethyl-hexanol; 1-octanol; 2,6-dimethyl-4-heptanone; 6-methyl-3-heptanone; 3-methyl-2-pentanone; n-hexyl acetate; diethyl phthalate and diethyl carbonate.
Claim 4
Dependent Claim
21 words
Process in accordance with claim 1, wherein the developer includes a resin which is deposited on the nonlight-struck areas during development.
Claim 5
Dependent Claim
21 words
Process in accordance with claim 5, wherein the resin is selected from the group consisting of novolak resins and epoxy resins.
Claim 6
Dependent Claim
36 words
Process in accordance with claim 1, wherein the developer includes a material selected from the group consisting of dyes and pigments which is deposited on the nonlight-struck areas during development to render said areas more visible.
Claim 7
Dependent Claim
30 words
A process as claimed in claim 1, wherein the developer includes a photodesensitizing dye which is deposited on the nonlight-struck areas during development to render said areas insensitive to light.
Claim 8
Dependent Claim
10 words
Process according to claim 1, wherein said support is metal.
Claim 9
Dependent Claim
27 words
Process according to claim 1, wherein a tough nonphotosensitive layer is interposed between the photosensitive material and the support, said nonphotosensitive layer being soluble in the developer.
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |