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US4024085A Expired / Lapsed US ⏱️ 0.0 years remaining

Gum removing solution for lithographic plate

Assignee: Fujifilm Holdings Corp
•
Filing: 1974-10-03
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Granted: 1977-05-17
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Expires: 1994-10-03
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Abstract

Abstract A gum removing solution for a lithographic plate containing at least one compound selected from the group consisting of compounds containing ##STR1## linkage where M represents a hydrogen atom, an ammonium group or an alkali metal atom and cyclic esters and cyclic amides having 3 to 6 carbon atoms. The solution can further contain at least one compound selected from the group consisting of phosphoric acid and polyphosphoric acid and the metal salts and ammonium salts of these acids, and optionally a water-soluble colloid. The solution has a pH of 1 to 5.5.

Inventors

  • 👤 Kesanao Kobayashi
  • 👤 Hiroshi Matsumoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 15:48
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/08

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 141 words
A process for removing gum arabic or cellulose gum from lithographic plates comprising applying to the surface of a lithographic printing plate a gum removing solution consisting essentially of an aqueous solution of at least one compound selected from the group consisting of i. compounds selected from the group consisting of lactic acid, citric acid, tartaric acid, Rochelle salt, hydroxyacetic acid, sodium citrate, potassium citrate, ammonium citrate, sodium lactate, ammonium lactate and potassium lactate, and ii. compounds selected from the group consisting of propiolactone, butyrolactone, valerolactone, propiolactam, valerolactam, hexanolactone, pyrrolidone, methylpyrrolidone and γ-caprolactone, said aqueous solution containing 4.5 to 16.7 weight percent of said compounds selected from said group, the substantial balance of said solution being water, and said solution having a pH of about 1 to 5.5; and removing said gum removing solution from said surface without damaging the image.
Claim 2
Dependent Claim 141 words
A process for removing gum arabic or cellulose gum from lithographic plates comprising applying to the surface of a lithographic printing plate a gum removing solution consisting essentially of an aqueous solution of at least one compound selected from the group consisting of i. compounds selected from the group consisting of lactic acid, citric acid, tartaric acid, Rochelle salt, hydroxyacetic acid, sodium citrate, potassium citrate, ammonium citrate, sodium lactate, ammonium lactate and potassium lactate, and ii. compounds selected from the group consisting of propiolactone, butyrolactone, valerolactone, propiolactam, valerolactam, hexanolactone, pyrrolidone, methylpyrrolidone and γ-caprolactone, said aqueous solution containing 4.5 to 16.7 weight percent of said compounds selected from said group, the substantial balance of said solution being water, and said solution having a pH of about 1 to 5.5; and removing said gum removing solution from said surface without damaging the image.
Claim 3
Dependent Claim 34 words
The process of claim 1, wherein said gum removing solution consists essentially of an aqueous solution of at least one compound selected from the group consisting of said compound (i) and said compound (ii).
Claim 4
Dependent Claim 79 words
The process of claim 1, wherein said gum removing solution consists essentially of (a) at least one compound selected from the group consisting of said compound (i), said compound (ii) and said compound (iii), and (b) at least one compound selected from the group consisting of a phosphoric acid and a polyphosphoric acid and the metal salts and the ammonium salts of these acids, said component (b) being present in an amount of about 0.3 to 15% by weight.
Claim 5
Dependent Claim 45 words
The process of claim 3, wherein said gum removing solution additionally contains (c) a water-soluble colloid selected from the group consisting of gum arabic, cellulose gum, starch and sodium aliginate, said component (c) being present in an amount of about 0.1 to 28% by weight.
Claim 6
Dependent Claim 49 words
The process of claim 3, wherein the component (b) comprises a combination of (i) at least one compound selected from the group consisting of the metal salts and the ammonium salts of phosphoric acid and the metal salts and the ammonium salts of polyphosphoric acid and (ii) phosphoric acid.
Claim 7
Dependent Claim 17 words
The process of claim 3, wherein the metal salts of component (b) are the alkali metal salts.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-05-16 1980-11-15 1981-05-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-05-16 1984-11-15 1985-05-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-05-16 1988-11-15 1989-05-17 $7700.00 Window Closed / Lapsed

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