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US4143021A Expired / Lapsed US ⏱️ 0.0 years remaining

Composition suitable for use as desensitizing gumming solution for lithographic printing plates

Assignee: Dow Chemical Co
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Filing: 1976-07-23
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Granted: 1979-03-06
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Expires: 1996-07-23
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Abstract

Abstract An aqueous solution is provided which is suitable for use as a desensitizing gum for treating imaged lithographic printing plates, comprising (1) water, (2) an active polymer component for rendering non-image areas of a lithographic printing plate hydrophilic, comprised of a polyacrylamide-based polymer or copolymer or a blend of polyacrylamide and polyacrylic acid, or the like, said polymer or copolymer or blend having an average molecular weight of from about 5,000 to about 10 6 and having from about 3 to about 70 percent of the carbonyl sites as carboxyl groups, said active polymer component being present in an amount of from about 3 to about 30 weight percent of active polymer component, based on the weight of the active polymer component and the water, and (3) a suitable polyoxyalkylene glycol in an amount which is effective to reduce tackiness while the composition is drying and which does not adversely affect the printing properties of a plate treated with said composition, said polyoxyalkylene glycol being selected from the group consisting of (a) a polyethylene glycol with an average molecular weight of at least about 200; (b) a polypropylene glycol with an average molecular weight of at least about 200; (c) a mixture of components from (a) and (b); (d) a triether of glycerine with a mixture of polypropylene and polyethylene oxides; and (e) a triether of glycerine with polypropylene oxides. The solution is particularly suited for treating imaged lithographic printing plates since, unlike earlier solutions, it does not go through a tacky state when drying.

Inventors

  • 👤 Walter L. Garrett

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 16:59
CPC Classifications
C; C08; C08L; C08L33/00; C08L33/24; C08L33/26; B; B41; B41N; B41N3/00; B41N3/08; C08K; C08K5/00; C08K5/04; C08K5/06; C08L71/00; C08L71/02

Claims Analysis

Total Claims: 27
Claim 1
Independent Claim 173 words
An improved composition, suitable for use as a desensitizing gum for treating imaged lithographic printing plates, comprising water, an active polymer component, as defined in the specification, for rendering non-image areas of the lithographic plate hydrophilic, said active polymer component being present in an amount of from about 3 to about 30 weight percent active polymer component, based on the weight of the active polymer component and the water, and a suitable polyoxyalkylene glycol in an amount which is effective to reduce tackiness while the composition is drying and which does not adversely affect the printing properties of a plate treated with said composition, said polyoxyalkylene glycol being selected from the group consisting of (a) a polyoxyethylene glycol with an average molecular weight of at least about 200; (b) a polyoxypropylene glycol with an average molecular weight of at least about 200; (c) a mixture of components from a and b; (d) a triether of glycerine with a mixture of polypropylene and polyethylene oxides; and (e) a triether of glycerine with polypropylene oxides.
Claim 2
Dependent Claim 173 words
An improved composition, suitable for use as a desensitizing gum for treating imaged lithographic printing plates, comprising water, an active polymer component, as defined in the specification, for rendering non-image areas of the lithographic plate hydrophilic, said active polymer component being present in an amount of from about 3 to about 30 weight percent active polymer component, based on the weight of the active polymer component and the water, and a suitable polyoxyalkylene glycol in an amount which is effective to reduce tackiness while the composition is drying and which does not adversely affect the printing properties of a plate treated with said composition, said polyoxyalkylene glycol being selected from the group consisting of (a) a polyoxyethylene glycol with an average molecular weight of at least about 200; (b) a polyoxypropylene glycol with an average molecular weight of at least about 200; (c) a mixture of components from a and b; (d) a triether of glycerine with a mixture of polypropylene and polyethylene oxides; and (e) a triether of glycerine with polypropylene oxides.
Claim 3
Dependent Claim 25 words
The composition of claim 1 wherein the polyoxyalkylene glycol is item (a) and has an average molecular weight of from about 200 to about 800.
Claim 4
Dependent Claim 21 words
The composition of claim 2 wherein the polyoxyalkylene glycol has an average molecular weight of from about 300 to about 600.
Claim 5
Dependent Claim 18 words
The composition of claim 3 wherein the concentration of the polyoxyalkylene glycol is at least about 1 percent.
Claim 6
Dependent Claim 16 words
The composition of claim 4 wherein the concentration of the polyoxyalkylene glycol is about 5 percent.
Claim 7
Dependent Claim 25 words
The composition of claim 1 wherein the polyoxyalkylene glycol is item (b) and has an average molecular weight of from about 200 to about 600.
Claim 8
Dependent Claim 21 words
The composition of claim 6 wherein the polyoxyalkylene glycol has an average molecular weight of from about 250 to about 400.
Claim 9
Dependent Claim 17 words
The composition of claim 7 wherein the concentration of polyoxyalkylene glycol is at least about 1 percent.
Claim 10
Dependent Claim 16 words
The composition of claim 8 wherein the concentration of the polyoxyalkylene glycol is about 5 percent.
Claim 11
Dependent Claim 50 words
The composition of claim 1 wherein the polyoxyalkylene glycol is item (c) and the components of said mixture are selected from polyoxyethylene glycol with an average molecular weight of from about 200 to about 800 and polyoxypropylene glycol with an average molecular weight of from about 200 to about 600.
Claim 12
Dependent Claim 43 words
The composition of claim 10 wherein the components of said mixture are selected from polyoxyethylene glycol with an average molecular weight of from about 300 to about 600 and polyoxypropylene glycol with an average molecular weight of from about 250 to about 400.
Claim 13
Dependent Claim 20 words
The composition of claim 11, wherein the concentration of the mixture of polyoxyalkylene glycols is at least about 1 percent.
Claim 14
Dependent Claim 18 words
The composition of claim 12 wherein the concentration of the mixture of polyoxyalkylene glycols is about 5 percent.
Claim 15
Dependent Claim 25 words
The composition of claim 1 wherein the polyoxyalkylene glycol is item (d) and has an average molecular weight of from about 2,000 to about 3,000.
Claim 16
Dependent Claim 17 words
The composition of claim 14 wherein the concentration of said triether is at least about 1 percent.
Claim 17
Dependent Claim 15 words
The composition of claim 15 wherein the concentration of said triether is about 5 percent.
Claim 18
Dependent Claim 16 words
The composition of claim 14 wherein said triether has an average molecular weight of about 2,500.
Claim 19
Dependent Claim 17 words
The composition of claim 17 wherein the concentration of said triether is at least about 1 percent.
Claim 20
Dependent Claim 15 words
The composition of claim 18 wherein the concentration of said triether is about 5 percent.
Claim 21
Dependent Claim 25 words
The composition of claim 1 wherein the polyoxyalkylene glycol is item (e) and has an average molecular weight of from about 200 to about 750.
Claim 22
Dependent Claim 16 words
The composition of claim 20 wherein said triether has an average molecular weight of about 250.
Claim 23
Dependent Claim 17 words
The composition of claim 21 wherein the concentration of said triether is at least about 1 percent.
Claim 24
Dependent Claim 15 words
The composition of claim 22 wherein the concentration of said triether is about 5 percent.
Claim 25
Dependent Claim 18 words
The composition of cliam 1 wherein the concentration of said polyoxyalkylene glycol is at least about 1 percent.
Claim 26
Dependent Claim 18 words
The composition of cliam 1 wherein the concentration of said polyoxyalkylene glycol is at least about 1 percent.
Claim 27
Dependent Claim 16 words
The composition of claim 24 wherein the concentration of said polyoxyalkylene glycol is about 5 percent.

References Cited (Backward Citations)

US3136636A Cited
US3211686A Cited
US3265504A Cited
US3374094A Cited
US3803070A Cited
US3733200A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-03-05 1982-09-04 1983-03-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-03-05 1986-09-04 1987-03-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-03-05 1990-09-04 1991-03-06 $7700.00 Window Closed / Lapsed

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