FLEXOGRAPHIC ELEMENT AND METHOD OF IMAGING

摘要

A relief (or flexographic) printing precursor has first and second radiation-sensitive layers, or a plurality of radiation-sensitive layers. The first radiation-sensitive layer is sensitive to a first imaging radiation having a first ?max. The second radiation-sensitive layer is disposed on the first radiation-sensitive layer and is sensitive to a second imaging radiation having a second ?max that differs from the first ?max by at least 25 nm. An infrared radiation ablatable layer can be present and is opaque or insensitive to the first and second imaging radiations and contains an infrared radiation absorbing compound. These relief printing precursors can be used to prepare flexographic printing plates, cylinders, or sleeves where the ablatable layer is used to form an integral mask on the element. Use of the invention provides a relief image without any loss in the strength of the small dots and can be carried out using multiple irradiation steps using the same apparatus.