Patent ID: 6913869

Claim:
A process for the production of laser-engravable flexographic printing elements, at least comprising a flexible metallic support and a crosslinked elastomeric layer which comprises at least one absorber for laser radiation, which comprises the following steps: (a) preparation of a thermally crosslinked mixture by intimate mixing of at least one elastomeric binder, 0.5 to 20% by weight of at least one absorber for laser radiation and at least one polymerization initiator whose 10 h-t 1/2 10 hour half-life temperature is at least 60° C., in a suitable solvent, (b) application of the mixture to a temporary support, (c) evaporation of the solvent at a temperature T 1 , (d) lamination of the dried layer by means of the side facing away from the support onto a flexible metallic support, (e) optionally removal of the temporary support, and (f) thermal crosslinking of the polymerizable layer by warming to a temperature T 2 where T 2 is at least 80° C. and T 2 is greater than T 1 , the thickness of the crosslinked elastomeric layer being from 0.5 to 5 mm.