Abstract: The invention relates to a radiation-curable mixture for generating relief structures, comprising a) at least one functionalized, part-hydrolyzed polyvinyl acetate comprising (i) vinyl alcohol units, (ii) vinyl acetate units, and (iii) vinyl acrylate units, where the vinyl acrylate units, which can be substituted, have the general structure where R is hydrogen or a linear or branched aliphatic or heteroaliphatic radical having 1 to 12 carbon atoms, or a cycloaliphatic, heterocyclic or aromatic radical having 3 to 12 carbon atoms, as component A, b) at least one initiator as component B, c) at least one ethylenically unsaturated compound different from component A, as component C, d) one or more adjuvants as component D, wherein the amount of vinyl acrylate units (iii) in the functionalized, part-hydrolyzed polyvinyl acetate a), based on all the units (i), (ii), and (iii), is 0.1 to <3 mol %, and component D comprises an additive capable of hydrogen bonding, in an amount of 0.

Abstract: A method for the production of functionalized partially hydrolyzed polyvinyl acetate comprising vinyl alcohol, vinylacetate and functionalized vinyl alcohol units by reacting in a melt a partially hydrolyzed polyvinyl acetate as component A with a reactive compound carrying at least one ethylenically unsaturated group and at least one reactive group reactive with hydroxyl or acetate groups as component B, in the presence of at least one stabilizer as component C and in the presence of at least one catalyst selected from the group consisting of tertiary amines and nitrogen-containing heterocycles as component D, the method comprising the steps: feeding the components into a mixing device capable of heating, melting and mixing components A, B, C and D, heating, melting and mixing components A, B, C and D in the device to give a melt and reacting components A and B in the melt.

Abstract: A method for the production of functionalized partially hydrolyzed polyvinyl acetate comprising vinyl alcohol, vinyl acetate and functionalized vinyl alcohol units by reacting in a melt a partially hydrolyzed polyvinyl acetate as component A with a reactive compound carrying at least one ethylenically unsaturated group and at least one reactive group reactive with hydroxyl or acetate groups as component B, in the presence of at least one stabilizer as component C and in the presence of at least one catalyst selected from the group consisting of tertiary amines and nitrogen-containing heterocycles as component D, the method comprising the steps: a) optionally drying one or more of components A, B, C and optionally D, b) optionally pre-mixing two or more of components A, B, C and optionally D, c) feeding the components into a mixing device capable of heating, melting and mixing components A, B, C and D, d) heating, melting and mixing components A, B, C and D in the device to give a melt and reacting components

Abstract: The invention relates to a radiation-curable mixture for generating relief structures, comprising a) at least one functionalized, part-hydrolyzed polyvinyl acetate comprising (i) vinyl alcohol units, (ii) vinyl acetate units, and (iii) vinyl acrylate units, where the vinyl acrylate units, which can be substituted, have the general structure where R is hydrogen or a linear or branched aliphatic or heteroaliphatic radical having 1 to 12 carbon atoms, or a cycloaliphatic, heterocyclic or aromatic radical having 3 to 12 carbon atoms, as component A, b) at least one initiator as component B, c) at least one ethylenically unsaturated compound different from component A, as component C, d) one or more adjuvants as component D, wherein the amount of vinyl acrylate units (iii) in the functionalized, part-hydrolyzed polyvinyl acetate a), based on all the units (i), (ii), and (iii), is 0.1 to <3 mol %, and component D comprises an additive capable of hydrogen bonding, in an amount of 0.

Abstract: Laminate comprising a) a photopolymerizable relief-forming layer, at least containing an elastomeric binder, ethylenically unsaturated monomers and a photoinitiator and optionally further additives, b) an optionally photopolymerizable elastomeric substrate layer, at least containing an elastomeric binder, optionally ethylenically unsaturated monomers and a photoinitiator and optionally further additives, the relief-forming layer a) having a hardness of 30 to 70° Shore A and the elastomeric substrate layer b) having a hardness of 75° Shore A to 70° Shore D in each case in the photopolymerized state, and the layer b) having a hardness of at least 5° Shore A greater than the layer a).

Abstract: The invention relates to photopolymerizable flexographic printing elements which contain ethylenically unsaturated, alicyclic monomers and hard flexographic printing plates, in particular cylindrical continuous seamless flexographic printing plates, which can be produced therefrom.

Abstract: Processes comprising providing a layer composite comprising a layer of photopolymerizable material and a removable substrate film disposed on one side of the layer of photopolymerizable material, wherein the photopolymerizable material comprises an elastomeric binder, an ethylenically unsaturated monomer and a photoinitiator; and (a) miter-cutting two edges of the layer composite to be joined, to form two miter-cut ends; (b) providing a hollow cylinder on a rotatably mounted support cylinder, wherein the hollow cylinder has an outer surface and is in a temporarily locked position relative to the support cylinder; (c) applying an adhesion-promoting layer to the outer surface of the hollow cylinder; (d) applying the layer composite to the hollow cylinder bearing the adhesive-promoting layer, wherein the layer composite is disposed on the hollow cylinder such that the removable substrate film faces away from the hollow cylinder and the two miter-cut ends lie substantially one on top of the other, but not overlap

Abstract: Laminate comprising a) a photopolymerizable relief-forming layer, at least containing an elastomeric binder, ethylenically unsaturated monomers and a photoinitiator and optionally further additives, b) an optionally photopolymerizable elastomeric substrate layer, at least containing an elastomeric binder, optionally ethylenically unsaturated monomers and a photoinitiator and optionally further additives, the relief-forming layer a) having a hardness of 30 to 70° Shore A and the elastomeric substrate layer b) having a hardness of 75° Shore A to 70° Shore D in each case in the photopolymerized state, and the layer b) having a hardness of at least 5° Shore A greater than the layer a).

Abstract: The invention relates to photopolymerizable flexographic printing elements which contain ethylenically unsaturated, alicyclic monomers and hard flexographic printing plates, in particular cylindrical continuous seamless flexographic printing plates, which can be produced therefrom.

Abstract: Processes comprising providing a layer composite comprising a layer of photopolymerizable material and a removable substrate film disposed on one side of the layer of photopolymerizable material, wherein the photopolymerizable material comprises an elastomeric binder, an ethylenically unsaturated monomer and a photoinitiator; and (a) miter-cutting two edges of the layer composite to be joined, to form two miter-cut ends; (b) providing a hollow cylinder on a rotatably mounted support cylinder, wherein the hollow cylinder has an outer surface and is in a temporarily locked position relative to the support cylinder; (c) applying an adhesion-promoting layer to the outer surface of the hollow cylinder; (d) applying the layer composite to the hollow cylinder bearing the adhesive-promoting layer, wherein the layer composite is disposed on the hollow cylinder such that the removable substrate film faces away from the hollow cylinder and the two miter-cut ends lie substantially one on top of the other, but not overlap

Abstract: Photopolymerizable cylindrical, continuously seamless flexographic printing elements are produced by applying a layer of a photopolymerizable material to the outer surface of a hollow cylinder and joining the edges by calendering. Flexographic printing elements produced in this manner are used for the production of flexographic printing plates.