US4046946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lithographic printing plate
Assignee: SCM Corp
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Filing: 1975-11-24
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Granted: 1977-09-06
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Expires: 1995-11-24
Abstract
Abstract The desirable attributes of both a barrier coat and a face coat and elimination of a coating step are obtained in manufacture of a lithographic printing plate having a paper base and a lithographic printing surface thereon, wherein said surface comprises a coating of positively charged colloidal silica and insolubilized hydrophilic polymer, by including in said coating non-flocculating pigment and resinous binder that is cationic or nonionic or mixed cationic and nonionic.
Inventors
- 👤 Michael J. Shaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:01
CPC Classifications
B; B41; B41C; B41C1/00; B41C1/10; B41C1/1091; B41N; B41N3/00; B41N3/03; B41N3/036; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/252; Y10T428/256; Y10T428/258; Y10T428/259; Y10T428/27; Y10T428/273; Y10T428/277; Y10T428/31504; Y10T428/31971; Y10T428/31993
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
151 words
In a lithographic printing plate having a paper base and a lithographic printing surface thereon comprising a face coating of positively charged colloidal silica and insolubilized hydrophilic polymer, in the ratio by weight of about two parts silica:one part polymer to about six parts silica:one part polymer, the improvement for reduction or elimination of a barrier coat on said base which comprises including in the face coating from about 10% to about 60% by weight of a fine particle size pigment which is non-flocculating and about 5% to about 30% by weight of a resinous binder which is cationic, nonionic or mixed cationic and nonionic, the hydrophilic polymer comprising about 5% to about 25% of the face coating and the positively charged colloidal silica comprising about 10% to about 70% by weight of the face coating, said weight percents being based on the dried lithographic printing surface coating free of volatiles.
Claim 2
Dependent Claim
151 words
In a lithographic printing plate having a paper base and a lithographic printing surface thereon comprising a face coating of positively charged colloidal silica and insolubilized hydrophilic polymer, in the ratio by weight of about two parts silica:one part polymer to about six parts silica:one part polymer, the improvement for reduction or elimination of a barrier coat on said base which comprises including in the face coating from about 10% to about 60% by weight of a fine particle size pigment which is non-flocculating and about 5% to about 30% by weight of a resinous binder which is cationic, nonionic or mixed cationic and nonionic, the hydrophilic polymer comprising about 5% to about 25% of the face coating and the positively charged colloidal silica comprising about 10% to about 70% by weight of the face coating, said weight percents being based on the dried lithographic printing surface coating free of volatiles.
Claim 3
Dependent Claim
21 words
The lithographic printing plate of claim 1 wherein said hydrophilic polymer is polyvinyl alcohol and said nonflocculating pigment is titanium dioxide.
Claim 4
Dependent Claim
20 words
The printing plate of claim 1 wherein said pigment has an average particle size not substantially above about 0.44 micron.
Claim 5
Dependent Claim
27 words
The printing plate of claim 1 wherein said face coating is applied at the rate of about 2 to about 20 pounds per ream of base paper.
Claim 6
Dependent Claim
26 words
The plate of claim 1 wherein the pigment comprises at least one of the following: finely-divided silica, talc, neutral clay, acid clay, and TiO 2 .
Claim 7
Dependent Claim
16 words
The plate of claim 1 wherein the pigment comprises anionic clay protected by a protective colloid.
Claim 8
Dependent Claim
21 words
The plate of claim 6 wherein the protective coating for said clay is latently reactable with the positively charged colloidal silica.
Claim 9
Independent Claim
111 words
A method of making a lithographic printing plate which comprises forming an aqueous coating composition comprising an insolubilized hydrophilic polymer, a positively charged colloidal silica, a fine particle size pigment which is nonflocculating, and a resinous binder which is cationic, nonionic or mixed cationic and nonionic, the coating composition having the following approximate proportions by weight: positively charged colloidal silica: about 10-70% insolubilized hydrophilic polymer: about 5-25% non-flocculating pigment: about 10-60% resinous binder: about 5-30% the ratio of colloidal silica to insolubilized hydrophilic polymer being in the range of about 2:1 to about 6:1; applying said coating composition to a paper base; and drying the coating composition on said paper base.
Claim 10
Independent Claim
111 words
A method of making a lithographic printing plate which comprises forming an aqueous coating composition comprising an insolubilized hydrophilic polymer, a positively charged colloidal silica, a fine particle size pigment which is nonflocculating, and a resinous binder which is cationic, nonionic or mixed cationic and nonionic, the coating composition having the following approximate proportions by weight: positively charged colloidal silica: about 10-70% insolubilized hydrophilic polymer: about 5-25% non-flocculating pigment: about 10-60% resinous binder: about 5-30% the ratio of colloidal silica to insolubilized hydrophilic polymer being in the range of about 2:1 to about 6:1; applying said coating composition to a paper base; and drying the coating composition on said paper base.
Claim 11
Independent Claim
111 words
A method of making a lithographic printing plate which comprises forming an aqueous coating composition comprising an insolubilized hydrophilic polymer, a positively charged colloidal silica, a fine particle size pigment which is non-flocculating, and a resinous binder which is cationic, nonionic or mixed cationic and nonionic, the coating composition having the following approximate proportions by weight: positively charged colloidal silica: about 30-50% insolubilized hydrophilic polymer: about 10-20% non-flocculating pigment: about 30-50% resinous binder: about 10-20% the ratio of colloidal silica to insolubilized hydrophilic polymer being in the range of about 3:1 to about 5:1; applying said coating composition to a paper base; and drying the coating composition on said paper base.
Claim 12
Independent Claim
111 words
A method of making a lithographic printing plate which comprises forming an aqueous coating composition comprising an insolubilized hydrophilic polymer, a positively charged colloidal silica, a fine particle size pigment which is non-flocculating, and a resinous binder which is cationic, nonionic or mixed cationic and nonionic, the coating composition having the following approximate proportions by weight: positively charged colloidal silica: about 30-50% insolubilized hydrophilic polymer: about 10-20% non-flocculating pigment: about 30-50% resinous binder: about 10-20% the ratio of colloidal silica to insolubilized hydrophilic polymer being in the range of about 3:1 to about 5:1; applying said coating composition to a paper base; and drying the coating composition on said paper base.
Claim 13
Dependent Claim
26 words
The method of claim 9 wherein said pigment comprises at least one of the following; finely-divided silica, talc, neutral clay, acid clay and TiO 2 .
Claim 14
Dependent Claim
23 words
The method of claim 9 wherein said coating composition is applied at the rate of about 2-20 pounds per ream of paper base.
Claim 15
Dependent Claim
20 words
The method of claim 9 wherein said pigment has an average particle size of not substantially above about 0.44 micron.
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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) | 1980-09-05 | 1981-03-07 | 1981-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-05 | 1985-03-07 | 1985-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-05 | 1989-03-07 | 1989-09-06 | $7700.00 | Window Closed / Lapsed |