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US4764213A
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US
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Lithographic fountain solution containing mixed colloids
Assignee: Celanese Corp
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Filing: 1986-06-16
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Granted: 1988-08-16
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Expires: 2006-06-16
Abstract
Abstract A lithographic fountain solution concentrate is disclosed, the essential components of which comprises an aqueous mixture of: (a) from about 0.1 to 1.5 percent by weight of a water soluble film forming hydrophilic gum; (b) from about 0.75 to about 8.5 percent by weight of Polyvinyl Pyrrolidone; (c) from about 5.0 to about 30.0 percent by weight of a water soluble acid etchant; (d) from about 20.0 to about 50.0 percent by weight of a water soluble or water miscible glycol; and (e) from about 0.01 to about 1.25 percent by weight of a phosphate/phosphoric acid buffer system. The concentrate is adapted for further dilution by water to yield a fountain solution which when used in the printing process offers decreased scumming and blinding of printing plates while at the same time permitting a reduction in the amount of water applied to the plate. Improved print quality, reduced tendency to wet the paper, faster ink drying and improved ink/water balance is thereby achieved.
Inventors
- 👤 Henry Gventer
- 👤 Raymond Hamilton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:07
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
136 words
In an offset printing process, the improvement which comprises dampening a printing plate with a fountain solution comprising a mixture of the following non-aqueous components: (a) from about 0.1 to about 1.5 percent by weight of a water soluble film forming hydrophilic gum; (b) from about 0.75 to about 8.5 percent by weight of polyvinyl pyrrolidone; (c) from about 5 to about 30 percent by weight of an acid etchant; (d) from about 20 to about 50 percent by weight of a water soluble or water miscible glycol; and (e) from about 0.01 to about 1.25 percent by weight of a phosphate/phosphoric acid buffer system; said mixture being mixed with sufficient water such that the amount of non-aqueous components present in the solution is in the range of about 0.1 to about 0.9 percent by weight.
Claim 2
Dependent Claim
136 words
In an offset printing process, the improvement which comprises dampening a printing plate with a fountain solution comprising a mixture of the following non-aqueous components: (a) from about 0.1 to about 1.5 percent by weight of a water soluble film forming hydrophilic gum; (b) from about 0.75 to about 8.5 percent by weight of polyvinyl pyrrolidone; (c) from about 5 to about 30 percent by weight of an acid etchant; (d) from about 20 to about 50 percent by weight of a water soluble or water miscible glycol; and (e) from about 0.01 to about 1.25 percent by weight of a phosphate/phosphoric acid buffer system; said mixture being mixed with sufficient water such that the amount of non-aqueous components present in the solution is in the range of about 0.1 to about 0.9 percent by weight.
Claim 3
Dependent Claim
32 words
The process of claim 1 wherein the ratio of polyvinyl pyrrolidone to gum is within the range of about 10 to 1 to 4 to 1 respectively on a dry weight basis.
Claim 4
Dependent Claim
12 words
The process of claim 2 wherein said hydrophilic gum is gum arabic.
Claim 5
Dependent Claim
11 words
The process of claim 2 wherein said glycol is ethylene glycol.
Claim 6
Dependent Claim
24 words
The process of claim 4 wherein said ethylene glycol is present at a level of from about 30 to about 45 percent by weight.
Claim 7
Dependent Claim
28 words
The process of claim 2 wherein said acid etchant is selected from the group consisting of citric, ascorbic, sulfanilic, tartaric, lactic, maleic, phosphoric, acetic and dilute sulfuric acids.
Claim 8
Dependent Claim
24 words
The process of claim 6 wherein said acid etchant is present at a level of from about 10 to about 25 percent by weight.
Claim 9
Dependent Claim
12 words
The process of claim 6 wherein said acid etchant is citric acid.
Claim 10
Dependent Claim
127 words
In an offset printing process, the impovement which comprises dampening a printing plate with a fountain solution consisting essentially of a mixture of the following non-aqueous components: (a) from about 0.1 to about 1.5 percent by weight of gum arabic; (b) from about 0.75 to about 8.5 percent by weight of polyvinyl pyrrolidone; (c) from about 5 to about 30 percent by weight of citric acid; (d) from about 20 to about 50 percent by weight of ethylene glycol; and (e) from about 0.01 to about 1.25 percent by weight of a phosphate/phosphoric acid buffer system; said mixture being mixed with sufficient water such that the amount of non-aqueous components present in the solution is in the range of about 0.1 to about 0.9 percent by weight.
Claim 11
Dependent Claim
127 words
In an offset printing process, the impovement which comprises dampening a printing plate with a fountain solution consisting essentially of a mixture of the following non-aqueous components: (a) from about 0.1 to about 1.5 percent by weight of gum arabic; (b) from about 0.75 to about 8.5 percent by weight of polyvinyl pyrrolidone; (c) from about 5 to about 30 percent by weight of citric acid; (d) from about 20 to about 50 percent by weight of ethylene glycol; and (e) from about 0.01 to about 1.25 percent by weight of a phosphate/phosphoric acid buffer system; said mixture being mixed with sufficient water such that the amount of non-aqueous components present in the solution is in the range of about 0.1 to about 0.9 percent by weight.
Claim 12
Dependent Claim
34 words
The process of claim 9 wherein the ratio of polyvinyl pyrrolidone to gum arabic is within the range of about 10 to 1 to about 4 to 1 respectively on a dry weight basis.
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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) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |