Basf Drucksysteme Gmbh

Xsys Print Solutions Deutschland, Gmbh

Flint Group Germany Gmbh

Wolfgang Wenzl

Margit Hiller

Thomas Telser

Jens Schadebrodt

Uwe Stebani

Jürgen Kaczun

Alfred Leinenbach

Laser-engravable flexographic printing elements for the production of flexographic printing plates have relief layers comprising blends of hydrophilic polymers and hydrophobic elastomers. Said flexographic printing elements are used for the production of flexographic printing plates by means of laser engraving.

Laser-engravable flexo printing elements for the production of flexo printing forms containing blends of hydrophilic polymers and hydrophobic elastomers

Laser-engravable flexographic printing elements including a thermally crosslinked, elastomeric, laser-engravable relief-forming layer E are made by producing a multilayer composite which has at least a two-layer composite formed of a depot layer D and an uncrosslinked precursor layer V for the relief-forming layer E which is directly adjacent to the depot layer D. Optionally, the multilayer composite may include further layers, such as support foils or films and/or protective films. The precursor layer V most preferably includes at least one elastomeric binder, and at least one ethylenically unsaturated monomer and, optionally an absorber for laser radiation and/or further additives. The depot layer D most preferably includes at least one elastomeric binder, and at least one thermally decomposing polymerization initiator and, optionally, an absorber for laser radiation and/or further additives. The thermally decomposing polymerization initiators are allowed to diffuse out of the depot layer D into the precursor layer V. If desired the depot layer D may be removed. Thermal crosslinking of the precursor layer V thereby yields the crosslinked elastomeric, laser-engravable, relief-forming layer E.

Method for the production of thermally cross-linked laser engravable flexographic elements

Graft copolymers are used for the production of laser-engravable relief printing plates, the graft copolymers being obtained by free radical polymerization of vinyl esters in the presence of polyalkylene oxides and subsequent hydrolysis of the ester function. Processes for the production of transparent flexographic printing plates by means of laser engraving using said graft copolymers are described.

Use of graft copolymers for the production of laser-engravable relief printing elements

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Mannheim, Germany

Wolfgang Wenzl