Laser-imageable flexographic printing precursors and methods of relief imaging
AssigneeEastman Kodak Company
InventorsOphira Melamed, Mazi Amiel-Levy
Life of this patent
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Abstract
A laser-engravable composition comprises one or more EPDM elastomeric rubbers, at least one of which comprises at least 8 weight % polyene recurring units. This laser-engravable composition of elastomeric rubbers can be quickly crosslinked using sulfur-containing vulcanizing compositions to provide laser-engravable compositions and layers in flexographic printing plate precursors. These precursors can be laser-engraved to provide relief images for flexographic printing.
Claims22
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.
A patternable article that is laser-engraveable to provide a relief image, the patternable article comprising a substrate, and a laser-engraveable layer disposed over the substrate,
- 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 a 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.
Dependencies are inferred from the claim text.