US4581996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aluminum support useful for lithography
Assignee: CNA Holdings LLC
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Filing: 1982-03-15
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Granted: 1986-04-15
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Expires: 2002-03-15
Abstract
Abstract An improved substrate suitable for use as a base for a lithographic printing plate, especially a plate useful for the production of continuous tone images. The substrate is produced by extremely uniformly graining an aluminum sheet which has a highly polished, mirror-like surface.
Inventors
- 👤 Stephan J. Platzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:17
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/03
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
148 words
A support for a lithographic plate comprising an aluminum or aluminum-alloy plate, the surface of which has been treated and grained such that the treated portion has a grain structure which comprises pits and; (i) has a distribution of pit diameters such that the arithmetic mean of the pit diameters (Da) is in the range of about 0.5μ≦Da≦4.0μ; and (ii) at least about 99% of all pits have a diameter (D99)≦10 μ; and (iii) a pit diameter directionality (Dd)≦ about 10%; and (iv) a total surface area (A) of said treated plate portion having either no pits or pits with a diameter of less than or equal to 0.5μ, is less than about 20% of said surface area; and (v) a center-line average roughness (Ra) of said treated surface is in the range of from about 0.2 to about 1.4μ; and (vi) a roughness directionality (Rd)≦ about 10%.
Claim 2
Dependent Claim
148 words
A support for a lithographic plate comprising an aluminum or aluminum-alloy plate, the surface of which has been treated and grained such that the treated portion has a grain structure which comprises pits and; (i) has a distribution of pit diameters such that the arithmetic mean of the pit diameters (Da) is in the range of about 0.5μ≦Da≦4.0μ; and (ii) at least about 99% of all pits have a diameter (D99)≦10 μ; and (iii) a pit diameter directionality (Dd)≦ about 10%; and (iv) a total surface area (A) of said treated plate portion having either no pits or pits with a diameter of less than or equal to 0.5μ, is less than about 20% of said surface area; and (v) a center-line average roughness (Ra) of said treated surface is in the range of from about 0.2 to about 1.4μ; and (vi) a roughness directionality (Rd)≦ about 10%.
Claim 3
Dependent Claim
15 words
The support of claim 1 further comprising an anodic coating applied to said grained structure.
Claim 4
Dependent Claim
15 words
The support of claim 1 further comprising a hydrophilizing agent applied to the grained surface.
Claim 5
Dependent Claim
15 words
The support of claim 2 further comprising a hydrophilizing agent applied to said anodized surface.
Claim 6
Dependent Claim
26 words
The support of claim 1, 2, 3, or 4 further comprising a lithographic photosensitive composition applied to at least a portion of said treated support surface.
Claim 7
Dependent Claim
19 words
The support of claim 5 wherein said lithographic photosensitive composition comprises a material capable of producing continuous tone images.
Claim 8
Dependent Claim
12 words
The support of claim 6 wherein said photosensitive composition is positive working.
Claim 9
Dependent Claim
24 words
The support of claim 6 wherein said photosensitive composition comprises a compound selected from the group consisting of diazonium salts, diazides, azides and photopolymers.
Claim 10
Dependent Claim
29 words
The support of claim 8 wherein said photosensitive composition further comprises one or more ingredients selected from the group consisting of binding resins, uv absorbers, colorants, solvents and plasticizers.
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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) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |