US3836366A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Planographic printing plates and method for their preparation
Assignee: Lith-Kem Corp
•
Filing: 1972-09-11
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Granted: 1974-09-17
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Expires: 1992-09-11
Abstract
Abstract A planographic printing plate base coated with a polymeric hydrophilic material sensitizable by a diazo compound wherein the surface of the polymeric hydrophilic material is coated with a diazo resin sensitizer and a diazonium salt sensitizer. The resulting printing plate is highly resistant to ''''scumming'''' over extended usage, is also highly resistant to dot sharpening and is characterized by quick start-up and long run.
Inventors
- 👤 J Silver
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:01
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/016; G03F7/038; G03F7/0381; G03F7/09; G03F7/095
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
23 words
A planographic printing plate as in claim 1 wherein: said coating is an intimate mixture of diazo resin sensitizer and diazonium salt sensitizer.
Claim 2
Dependent Claim
35 words
A planographic printing plate as in claim 1 wherein said coating includes: a layer of diazo resin sensitizer on said hydrophilic material; and a layer of diazonium salt sensitizer on the layer of diazo resin.
Claim 3
Dependent Claim
39 words
The planographic printing plate base of claim 1 wherein said association product hydrophilic material comprises: the cured association product of an ethylene oxide polymer and a phenolic resin formed by the condensation of a phenolic compound and an aldehyde.
Claim 4
Dependent Claim
30 words
The planographic printing plate of claim 4 wherein said association product comprises from about 0.2 to about 3.0 parts by weight of ethylene oxide polymer per part of phenolic resin.
Claim 5
Dependent Claim
29 words
The planographic printing plate of claim 1 wherein the weight ratio of said diazo resin to said diazonium salt in said coating is from about 2:1 to about 1:2.
Claim 6
Dependent Claim
22 words
The planographic printing plate of claim 1 wherein said diazo resin is the condensation product of an aldehyde and a diazo salt.
Claim 7
Dependent Claim
13 words
The planographic printing plate base of claim 7 wherein said aldehyde is formaldehyde.
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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) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |