Claims
- 1. A method of making a printing plate comprising:
- a) forming a positive working photoresist solution from a film forming polymeric resin, an organo azide compound and a dye that absorbs in the infrared region of the spectrum admixed with a solvent,
- b) applying the photoresist solution to form a layer on a printing plate substrate,
- c) pattern exposing the photoresist layer with a laser that emits light having a frequency in the infrared region of the spectrum that is absorbed by the dye and converted to heat energy that dissociates the organo azide compound, and
- d) contacting the resultant photoresist layer with a developer solvent that solubilizes the exposed photoresist, thereby removing the exposed photoresist and leaving a pattern of non-exposed photoresist on said substrate.
- 2. A method according to claim 1 wherein said laser is computer controlled.
- 3. A method according to claim 1 wherein said printing plate substrate is a copper clad aluminum plate.
- 4. A method according to claim 3 comprising after step d), etching the exposed regions of the substrate through the copper layer to the aluminum plate.
- 5. A method according to claim 1 wherein said photoresist additionally includes a pigment that does not absorb the laser light.
- 6. A method according to claim 1 wherein after pattern exposure of the photoresist layer, the layer is flood exposed with ultraviolet light.
- 7. A method of making a printing plate comprising
- a) forming a positive working photoresist solution from a film forming polymeric resin, an organo azide compound, a dye that absorbs light in the infrared region of the spectrum and a solvent,
- b) applying the photoresist solution to form a layer on a printing plate substrate,
- c) flood exposing the photoresist layer with ultraviolet light,
- d) pattern exposing the photoresist layer with a pulsed infrared laser light that is absorbed by the dye and converted to heat energy, and
- e) contacting the resultant photoresist layer with a developer solvent that solubilizes the exposed photoresist, thereby removing the exposed photoresist and leaving a pattern of non-exposed photoresist on said substrate.
- 8. A method of making a printing plate according to claim 7 wherein said developer solvent contains an acid.
- 9. A method of making a printing plate according to claim 8 wherein said developer solvent contains an acid selected from the group consisting of hydroxyethane diphosphonic acid, trifluoroacetic acid and p-toluene sulfonic acid.
- 10. A method according to claim 9 wherein the developer solvent further contains a surfactant.
- 11. A method according to claim 7 wherein said printing plate substrate is a copper clad aluminum plate.
- 12. A method according to claim 7 wherein the photoresist further includes a colorant or pigment that does not absorb the laser light.
- 13. A method according to claim 7 wherein after pattern exposure of the photoresist layer with a laser, the substrate is flood exposed with ultraviolet light.
Parent Case Info
This invention is a continuation-in-part of our copending application Ser. No. 08/666,169 filed Jun. 19, 1996.
US Referenced Citations (7)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2171472 |
Jan 1996 |
CAX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
666169 |
Jun 1996 |
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