US4077325A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing waterless printing masters
Assignee: Xerox Corp
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Filing: 1977-03-10
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Granted: 1978-03-07
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Expires: 1997-03-10
Abstract
Abstract Improved waterless lithographic printing masters are provided having minimum background ink reflection density. The master comprises a crosslinked block copolymer containing elastomeric, ink releasing siloxane blocks chemically linked to organic image accepting thermoplastic blocks, said copolymer having a molecular weight for the organic blocks sufficient to provide strength and a background ink reflection density of less than 0.02 and preferably less than 0.01.
Inventors
- 👤 Thomas J. Pacansky
- 👤 Alan B. Amidon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:32
CPC Classifications
B; B41; B41N; B41N1/00; B41N1/003
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
101 words
A method of preparing a printing master comprising: a. providing a self-supporting master substrate; b. providing a block film forming ink releasing copolymer consisting of from 10 to 20 weight percent polyalphamethylstyrene having a molecular weight of between 6,000 and 11,000 and from 90 to 80 weight percent polydimethylsiloxane; c. coating said substrate with said copolymer; d. depositing an ink accepting particulate material in image configuration on said master; e. heating the master to crosslink the siloxane blocks and soften the styrene blocks; and f. allowing the coating to cool so as to bond the particulate imaging material to the master.
Claim 2
Independent Claim
101 words
A method of preparing a printing master comprising: a. providing a self-supporting master substrate; b. providing a block film forming ink releasing copolymer consisting of from 10 to 20 weight percent polyalphamethylstyrene having a molecular weight of between 6,000 and 11,000 and from 90 to 80 weight percent polydimethylsiloxane; c. coating said substrate with said copolymer; d. depositing an ink accepting particulate material in image configuration on said master; e. heating the master to crosslink the siloxane blocks and soften the styrene blocks; and f. allowing the coating to cool so as to bond the particulate imaging material to the master.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein the particulate imaging material deposited is a thermoplastic polymer.
Claim 4
Independent Claim
104 words
A method of preparing a printing master comprising: a. providing a self-supporting master substrate; b. providing a block film forming ink releasing copolymer having from 90 to 80 weight percent polydimethylsiloxane blocks and 10 to 20 weight percent polyalphamethylstyrene blocks with a molecular weight between 6,000 and 11,000; c. coating said substrate with said copolymer; d. heating the master to crosslink the siloxane blocks; e. depositing an ink accepting particulate material in image configuration on said master; f. heating the master to soften the styrene blocks; and g. allowing the coating to cool so as to bond the particulate imaging material to the master.
Claim 5
Independent Claim
104 words
A method of preparing a printing master comprising: a. providing a self-supporting master substrate; b. providing a block film forming ink releasing copolymer having from 90 to 80 weight percent polydimethylsiloxane blocks and 10 to 20 weight percent polyalphamethylstyrene blocks with a molecular weight between 6,000 and 11,000; c. coating said substrate with said copolymer; d. heating the master to crosslink the siloxane blocks; e. depositing an ink accepting particulate material in image configuration on said master; f. heating the master to soften the styrene blocks; and g. allowing the coating to cool so as to bond the particulate imaging material to the master.
Claim 6
Dependent Claim
15 words
The method of claim 3 wherein the particulate imaging material deposited is a thermoplastic polymer.
Claim 7
Dependent Claim
20 words
The method of claim 3 wherein the siloxane blocks are slightly crosslinked prior to imaging and further crosslinked after imaging.
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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) | 1981-03-06 | 1981-09-05 | 1982-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-06 | 1985-09-05 | 1986-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-06 | 1989-09-05 | 1990-03-07 | $7700.00 | Window Closed / Lapsed |