Patent US4421844A successfully refreshed from Google Patents.
US4421844A
Expired / Lapsed
US
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Process for the preparation of relief copies
Assignee: Hoechst AG
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Filing: 1981-10-09
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Granted: 1983-12-20
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Expires: 2001-10-09
Abstract
Abstract Disclosed is a process for the preparation of relief copies, comprising the steps of imagewise irradiating a radiation-sensitive copying material comprising a layer support and a radiation-sensitive layer comprising (a) a compound which upon irradiation splits off acid, and (b) a compound possessing at least one acid-cleavable C--O--C group; heating the imagewise irradiated copying material to a temperature above room temperature for a period of time sufficient to produce an increase in radiation sensitivity of the radiation-sensitive layer; and washing out the irradiated layer areas by means of a developer.
Inventors
- 👤 Gerhard Buhr
- 👤 Marie-Luise Geus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:27
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/38; Y; Y10; Y10S; Y10S430/00; Y10S430/146; Y10S430/167; Y10S430/168
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
179 words
A process for the preparation of relief copies, comprising the steps of: imagewise irradiating a radiation-sensitive copying material comprising a layer support and a radiation-sensitive layer comprising (a) a compound which upon irradiation splits off acid, and (b) a compound possessing at least one acid-cleavable C--O--C group comprising an orthocarboxylic acid ester grouping or a carboxylic amide acetal grouping, or an organic polymeric compound containing recurring acetal or ketal groupings in the main chain and whose solubility in a developer liquid is increased by the action of an acid, wherein said polymeric compound is produced by reaction of an aldehyde and/or ketone with a bivalent alcohol and wherein each alpha-carbon atom of the alcohol constituent of the acetal or ketal groupings is aliphatic; after said irradiating step and before developing, heating the imagewise irradiated copying material to a temperature in the range of between 65° and 90° C. for a period of time sufficient to produce an increase in radiation sensitivity of the radiation-sensitive layer; and washing out the irradiated layer areas with a developer, after said heating step.
Claim 2
Dependent Claim
179 words
A process for the preparation of relief copies, comprising the steps of: imagewise irradiating a radiation-sensitive copying material comprising a layer support and a radiation-sensitive layer comprising (a) a compound which upon irradiation splits off acid, and (b) a compound possessing at least one acid-cleavable C--O--C group comprising an orthocarboxylic acid ester grouping or a carboxylic amide acetal grouping, or an organic polymeric compound containing recurring acetal or ketal groupings in the main chain and whose solubility in a developer liquid is increased by the action of an acid, wherein said polymeric compound is produced by reaction of an aldehyde and/or ketone with a bivalent alcohol and wherein each alpha-carbon atom of the alcohol constituent of the acetal or ketal groupings is aliphatic; after said irradiating step and before developing, heating the imagewise irradiated copying material to a temperature in the range of between 65° and 90° C. for a period of time sufficient to produce an increase in radiation sensitivity of the radiation-sensitive layer; and washing out the irradiated layer areas with a developer, after said heating step.
Claim 3
Dependent Claim
25 words
A process as claimed in claim 1, wherein the imagewise irradiated copying material is heated for a period of from about 0.5 to 2 minutes.
Claim 4
Dependent Claim
19 words
A process as claimed in claim 1, wherein the imagewise irradiation is performed by means of a laser beam.
Claim 5
Dependent Claim
19 words
A process as claimed in claim 1, wherein the irradiated layer areas are washed out with an aqueous-alkaline solution.
Claim 6
Dependent Claim
35 words
A process as claimed in claim 1, wherein the compound, which upon irradiation splits off acid, comprises an s-triazine derivative containing two halogenoalkyl groups and an aryl group as the substituents on the triazine nucleus.
Claim 7
Dependent Claim
20 words
A process as claimed in claim 1, wherein said polymeric compound comprises a polyacetal of aliphatic aldehyde and diol units.
Claim 8
Dependent Claim
18 words
A process as claimed in claim 1, wherein said compound having an acid-cleavable group comprises bis-(5-butyl-5-ethyl-1,3-dioxan-2-yl)-ether of 2-butyl-2-ethyl-propane-1,3-diol.
Claim 9
Dependent Claim
22 words
A process as claimed in claim 1, wherein said compound having an acid-cleavable group comprises a polyacetal of n-pentanal and triethylene glycol.
Claim 10
Dependent Claim
30 words
A process as claimed in claim 1, wherein said compound having an acid-cleavable group comprises a polymeric ortho carboxylic acid ester, prepared by condensing trimethyl ortho formate with 4-oxa-6,6-bis-hydroxymethyl oxtan-1-ol.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |