Eastman-kodak Company

Other

Gary R Miller

Paul R West

Raymond W Ryan, Jr

James E Mitchell

Paul R Josephson, Jr

John E Walls

Kevin Wieland

Melanie A Felker

Melanie Ann Roth

Richard E Gilson

Eric E Clark

Melanie Kelim

Kevin Barry Ray

Ting Tao

Neil F Haley

William P Smith

Thomas J Huddleston

Jeffery A Gurney

Jr, Raymond Ryan

A method for providing a lithographic printing plate includes developing an exposed imageable element with an alkali silicate-containing developer composition having a pH of at least 12.0. The developer composition is regenerated by adding to it an alkali silicate-containing regenerator composition having a pH of at least 12.0. Conductivity of both the developer and regenerator compositions is suppressed from the presence of one or more conductivity reducing agents (such as glycerin). This conductivity suppression in the developer composition is greater than the suppression of the conductivity of the regenerator composition.

Use of highly alkaline developer regenerator composition

An imaged and developed element, such as a lithographic printing plate, is provided by infrared radiation imaging of a negative-working imagable element having an outermost imagable layer that includes a free radically polymerizable component, a free radical initiator composition comprising a diaryliodonium borate, and an infrared radiation absorbing compound. The imagable layer also includes a polymeric binder that is represented by the following Structure (I):-(A)-(A')-&#x2003;&#x2003;(I)wherein A represents recurring units comprising a pendant reactive vinyl group, A&#x2032; represents recurring units other than those represented by A, w is from about 1 to about 70 mol %, and w&#x2032; is from about 30 to about 99 mol %. The imagewise exposed element is developed with a gum to remove only the non-exposed regions. The gum has a pH greater than 7 and up to about 11 and at least 1 weight % of an anionic surfactant.

Methods for imaging and processing negative-working imageable elements

The present invention provides an aqueous regenerator for addition to an aqueous developer that contains an organic solvent, a dispersing agent and a weak base, and has a pH of between about 8 and less than about 13. The aqueous regenerator includes an organic solvent, dispersing agent, and an effective amount of a strong base such that the regenerator has a greater pH than the developer into which the regenerator is to be added.

Developer regenerators

A positive-working lithographic printing plate is used to provide a positive image without a post-exposure baking step and without any floodwise exposure steps. The printing plate includes a layer that is imageable using an infrared radiation laser. This layer consists essentially of a phenolic resin, an infrared radiation absorbing compound, and a dissolution inhibitor that is non-photosensitive and is capable of providing sites for hydrogen bonding with the phenolic moieties of the binder resin. These printing plates are developed with an alkaline composition that includes an alkali metal silicate, a thickener and a fluorosurfactant or phosphate ester hydrotrope.

Methods of imaging and printing with a positive-working infrared

Aqueous alkaline developing compositions useful in the development of negative-working lithographic printing plates are comprised of an organic solvent, an anionic surface active agent, an alkali metal tetraborate, an aliphatic monocarboxylic acid, an aliphatic dicarboxylic acid, an alkali metal citrate, a poly(alkylene glycol), an alkali metal salt of an hydroxylated aromatic carboxylic or sulfonic acid and sufficient alkaline buffering system to provide an alkaline pH. The developing composition is resistant to oxidation, highly effective in dissolution-type processing, able to effectively desensitize the background areas of the printing plate, and capable of preventing excessive deposits in a processing machine and rapidly redissolving deposits that do form.

Aqueous developer for lithographic printing plates which exhibits

Aqueous alkaline developing compositions useful in the development of negative-working lithographic printing plates are comprised of an organic solvent, an anionic surface active agent, an alkali metal tetraborate, an aliphatic monocarboxylic acid, an aliphatic dicarboxylic acid, a long chain aliphatic amine and sufficient alkaline buffering system to provide an alkaline pH. The developing composition is resistant to oxidation, highly effective in dissolution-type processing, able to effectively desensitize the background areas of the printing plate, and effective in enhancing the oleophilicity of the image areas of the printing plate.

Aqueous developer for lithographic printing plates which provides

A negative-working lithographic printing plate having a radiation-sensitive layer comprising a diazo resin, an acid-substituted ternary acetal polymer and an unsaturated polyester is developed with an aqueous developing composition comprising an organic solvent, an anionic surface active agent, sodium oxalate, sodium nitrate or an alkali metal tetraborate an aliphatic monocarboxylic acid, an aliphatic dicarboxylic acid and sufficient alkaline buffering system to provide an alkaline pH. The method effectively avoids problems of blinding and background sensitivity which are of critical concern in the printing art.

Method for developing lithographic printing plates

Aqueous alkaline developing compositions useful in the development of negative-working lithographic printing plates are comprised of an organic solvent, an anionic surface active agent, sodium oxalate, sodium nitrate or an alkali metal tetraborate, an aliphatic monocarboxylic acid, an aliphatic dicarboxylic acid and sufficient alkaline buffering system to provide an alkaline pH. The developing composition is resistant to oxidation, highly effective in dissolution-type processing, and able to effectively desensitize the background areas of the printing plate.

Aqueous developer for lithographic printing plates with improved

Radiation-sensitive compositions which are especially useful in the production of negative-working lithographic printing plates comprise a photocrosslinkable polymer containing the photosensitive group ##STR1## as an integral part of the polymer backbone and, in an amount sufficient to improve the properties of the composition, a polymer of vinyl pyrrolidone. The polymer of vinyl pyrrolidone improves the properties of the radiation-sensitive composition in regard to such factors as shelf life, image contrast, and developability and thereby provides a superior lithographic printing plate.

Radiation-sensitive composition containing a vinyl pyrrolidone polymer

Radiation-sensitive compositions which are especially useful in the production of negative-working lithographic printing plates comprise a photocrosslinkable polymer containing the photosensitive group ##STR1## as an integral part of the polymer backbone and, in an amount sufficient to improve the properties of the composition, both a polymer of vinyl pyrrolidone and an unsaturated polyester such as a polyester derived from fumaric acid and a 4,4'-isopropylidine-diphenol. The combination of a polymer of vinyl pyrrolidone and an unsaturated polyester improves the properties of the radiation-sensitive composition in regard to such factors as shelf life, image contrast, developability and ink receptivity and thereby provides a superior lithographic printing plate.

Radiation-sensitive composition containing both a vinyl pyrrolidone

Radiation-sensitive compositions which are especially useful in the production of negative-working lithographic printing plates comprise a photocrosslinkable polymer containing the photosensitive group ##STR1## as an integral part of the polymer backbone and, in an amount sufficient to improve the properties of the composition, an unsaturated polyester such as a polyester derived from fumaric acid and a 4,4'-isopropylidenediphenol. The unsaturated polyester additive improves the properties of the radiation-sensitive composition in regard to processing characteristics and ink receptivity and thereby provides a superior lithographic printing plate.

Radiation-sensitive composition containing an unsaturated polyester and

Radiation-sensitive compositions which are especially useful in the production of negative-working lithographic printing plates comprise a photocrosslinkable polymer containing the photosensitive group ##STR1## as an integral part of the polymer backbone and, in an amount sufficient to improve the properties of the composition, both a poly(N-acyl-alkyleneimine) and an unsaturated polyester such as a polyester derived from fumaric acid and a 4,4'-isopropylidenediphenol. The combination of a poly(N-acylalkyleneimine) and an unsaturated polyester improves the properties of the radiation-sensitive composition in regard to such factors as shelf life, image contrast, developability, ink receptivity and reduction in mottle and thereby provides a superior lithographic printing plate.

Radiation-sensitive composition containing both a

Radiation-sensitive compositions which are especially useful in the production of negative-working lithographic printing plates comprise a photocrosslinkable polymer containing the photosensitive group ##STR1## as an integral part of the polymer backbone and, in an amount sufficient to improve the properties of the composition, a poly(N-acyl-alkleneimine). The poly(N-acyl-alkyleneimine) improves the properties of the radiation-sensitive composition in regard to such factors as shelf life, image contrast, developability and reduction in mottle and thereby provides a superior lithographic printing plate.

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Fort Collins, CO, United States of America

Gary R Miller