Polymers and their use in imageable products and image-forming methods
AssigneeKodak Polychrome Graphics LLC
InventorsEduard Kottmair, Hans-Horst Glatt, Stefan Hilgart, Paul West
Life of this patent
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Abstract
Infra-red absorbing polymers useful in imageable products and the lithographic printing field comprise infra-red absorbing groups carried as pendent groups on a polymer backbone. Certain infra-red absorbing groups may also act to insolublize the polymer in a developer, until it is imagewise exposed to infra-red radiation. The resulting heat renders the polymer soluble in the developer. Imageable products employing the infra-red absorbing polymers may include positive working lithographic printing plates.
Claims7
A process for the preparation of a polymer the process comprising:
- (a) providing a parent polymer;
- and
- (b) reacting the parent polymer with a dye having a labile halogen atom, under alkaline conditions at an elevated temperature, such that the resulting polymer comprises at least one pendent infra-red absorbing group, wherein the resulting polymer does not dissolve in a developer liquid, but upon being subjected to infra-red radiation, the resulting polymer dissolves in the developer liquid.
A method of producing a lithographic printing form the method comprising:
- (a) providing a lithographic printing form precursor which comprises (i) a substrate and (ii) a thermally imageable coating on the substrate, wherein the coating comprises a thermally imageable composition which comprises a polymer which comprises at least one pendent infra-red absorbing group, with the proviso that when the composition is carried as a dry coating on the substrate the composition does not dissolve in a developer liquid, and the composition dissolves in the developer liquid upon being subjected to infra-red radiation;
- (b) imagewise exposing areas of the composition to infra-red radiation;
- and
- (c) contacting the precursor with a developer liquid to remove the exposed areas of the composition.
A lithographic printing form prepared by the method comprising:
- (a) providing a lithographic printing form precursor which comprises (i) a substrate and (ii) a thermally imageable coating on the substrate, wherein the coating comprises a thermally imageable composition which comprises a polymer which comprises at least one pendent infra-red absorbing group, with the proviso that when the composition is carried as a dry coating on the substrate the composition does not dissolve in a developer liquid, and the composition dissolves in the developer liquid upon being subjected to infra-red radiation;
- (b) imagewise exposing areas of the composition to infra-red radiation;
- and
- (c) contacting the precursor with a developer liquid to remove the exposed areas of the composition.
A method of producing lithographic printing form the method comprising:
- (a) providing a lithographic printing form precursor which comprises (i) a substrate and (ii) a thermally imageable coating on the substrate, wherein the coating comprises a thermally imageable composition which comprises a polymer which comprises at least one pendent infra-red absorbing group, with the proviso that when the composition is carried as a dry coating on the substrate the composition has a first dissolution rate in a developer liquid prior to exposure to infra-red radiation, and a second dissolution rate in the developer liquid after exposure to infra-red radiation, wherein the second dissolution rate is greater than the first dissolution rate;
- (b) imagewise exposing areas of the composition to infra-red radiation;
- and
- (c) contacting the precursor with a developer liquid to remove the exposed areas of the composition.
A lithographic printing form precursor prepared by the method comprising:
- (a) providing a lithographic printing form precursor which comprises (i) a substrate and (ii) a thermally imageable coating on the substrate, wherein the coating comprises a thermally imageable composition which comprises a polymer which comprises at least one pendent infra-red absorbing group, with the proviso that when the composition is carried as a dry coating on the substrate the composition has a first dissolution rate in a developer liquid prior to exposure to infra-red radiation, and a second dissolution rate in the developer liquid after exposure to infra-red radiation, wherein the second dissolution rate is greater than the first dissolution rate;
- (b) imagewise exposing areas of the composition to infra-red radiation;
- and
- (c) contacting the precursor with a developer liquid to remove the exposed areas of the composition.
Dependencies are inferred from the claim text.