US4567131A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lithographic printing plates
Assignee: Agfa Gevaert NV
•
Filing: 1984-07-11
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Granted: 1986-01-28
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Expires: 2004-07-11
Abstract
Abstract A lithographic printing plate having metallic silver image areas is treated with a proteolytic enzyme and an oleophilizing compound to improve ink receptivity.
Inventors
- 👤 Philip J. Watkiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:19
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/06; G03F7/063
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
33 words
A finishing composition for treating a lithographic printing plate having image areas of metallic silver, the composition comprising (i) a proteolytic enzyme and (ii) a compound capable of rendering the image areas oleophilic.
Claim 2
Dependent Claim
33 words
A finishing composition for treating a lithographic printing plate having image areas of metallic silver, the composition comprising (i) a proteolytic enzyme and (ii) a compound capable of rendering the image areas oleophilic.
Claim 3
Dependent Claim
19 words
A composition as claimed in claim 1 wherein the enzyme is trypsin, pepsin, ficin, papain or a bactericidal proteinase.
Claim 4
Dependent Claim
14 words
A composition as claimed in claim 1 wherein said compound is a mercapto compound.
Claim 5
Dependent Claim
14 words
A composition as claimed in claim 3 wherein said compound is 2-mercaptobenzthiazole or phenylmercaptotetrazole.
Claim 6
Dependent Claim
14 words
A composition as claimed in claim 1 wherein said compound is a cationic surfactant.
Claim 7
Dependent Claim
17 words
A composition as claimed in claim 5 wherein said compound is cetyltrimethyl ammonium bromide or cetylpyridinium chloride.
Claim 8
Dependent Claim
14 words
A composition as claimed in claim 1 and additionally including a lithographic desensitizing compound.
Claim 9
Dependent Claim
17 words
A composition as claimed in claim 7, wherein said lithographic desensitizing compound is gum arabic or dextrin.
Claim 10
Independent Claim
35 words
A method of treating a lithographic printing plate having image areas of metallic silver, the method comprising applying a proteolytic enzyme and subsequently or simultaneously applying a compound capable of rendering the image areas oleophilic.
Claim 11
Independent Claim
35 words
A method of treating a lithographic printing plate having image areas of metallic silver, the method comprising applying a proteolytic enzyme and subsequently or simultaneously applying a compound capable of rendering the image areas oleophilic.
Claim 12
Dependent Claim
15 words
A method according to claim 9, comprising simultaneously or subsequently applying a lithographic desensitizing compound.
References Cited (Backward Citations)
US2870704A
Cited
US3099209A
Cited
US3565618A
Cited
US3830649A
Cited
US3620737A
Cited
US3532599A
Cited
US3813342A
Cited
US3819374A
Cited
US4230792A
Cited
US4285276A
Cited
US4299912A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-01-27 | 1989-07-29 | 1990-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-27 | 1993-07-29 | 1994-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-27 | 1997-07-29 | 1998-01-28 | $7700.00 | Window Closed / Lapsed |