US 5,962,192 A · Photoresists and method for making printing plates

Abstract

Printing plates having a photoresist layer thereon that can be exposed by a computer controller laser have improved sensitivity and do not require a photomask step. We have found photoresists that include a film forming polymer, an organo azide and a photosensitive dye that absorbs light at the frequency of the patterning laser and converts it to heat energy. The heat energy in turn elevates the temperature of the organo azide above its dissociation temperature, destroying the azide in areas exposed to the light source, and solubilizing those regions. Flood exposure with ultraviolet light hardens the resist and can be performed prior to or after pattern exposure.

Claims13

Dependent claims

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.

1 more element

Dependencies are inferred from the claim text.

Photoresists and method for making printing plates

Life of this patent

Photoresists and method for making printing plates

Life of this patent

Abstract

Claims13