Patent ID: 6880461

Claim:
A process for the production of flexographic printing plates by means of laser engraving, in which the starting material used is a crosslinkable, laser-engravable flexographic printing element which at least comprises, arranged one on top of the other, a dimensionally stable substrate, at least one crosslinkable, laser-engravable relief-forming layer having a thickness of at least 0.2 mm, at least comprising an elastomeric binder, a plasticizer and components for crosslinking, and which process comprises at least the following steps: (a) uniform crosslinking of the relief-forming layer and (b) engraving of a print relief into the crosslinked relief layer with the aid of a laser, the height of the relief elements to be engraved with the laser being at least 0.03 mm, wherein the binder is a styrene/butadiene block copolymer having an average molecular weight M w of from 100 000 to 250 000 g/mol, a Shore A hardness of from 55 to 85 and a styrene content of 20-40% by weight, based on the binder, and the amount of the plasticizer is from 20 to 40% by weight, based on the sum of all components of the layer.