Patent ID: 9156241
Filing Date: 2015-10-13
Classification: B41C,B41N,Y10T

Abstract:
1. A flexographic printing precursor that is laser-engraveable to provide a relief image, the flexographic printing precursor comprising: a laser-engraveable layer having been prepared from a laser-engraveable composition comprising one or more EPDM elastomeric rubbers in an amount of at least 30 weight % and up to and including 80 weight %, based on the total laser-engraveable composition dry weight, the one or more EPDM elastomeric rubbers comprising one or more first EPDM elastomeric rubbers, each first EPDM elastomeric rubber comprising at least 8 weight % and up to and including 15 weight % of polyene recurring units provided from cyclic or non-cyclic dienes or cyclic or non-cyclic trienes, the total of the one or more first EPDM elastomeric rubbers comprising at least 50 weight % of the total elastomeric rubber weight, the laser-engraveable composition further comprising: a) at least 2 phr and up to and including 60 phr of a near-infrared radiation absorber, b) at least 3 phr and up to and including 20 phr of a sulfur vulcanizing composition comprising a sulfur-containing vulcanizing compound, and c) one or more second EPDM elastomeric rubbers different from the one or more first EPDM elastomeric rubbers, wherein the laser-engraveable composition is essentially free of peroxides, the weight ratio of the near-infrared radiation absorber to the vulcanizing composition is from 1:10 to and including 20:1, and the weight ratio of total first EPDM elastomeric rubbers to total second EPDM elastomeric rubbers is from 0.67:1 to and including 4:1.