Abstract: A process for preparing flexographic printing plates wherein the photopolymerizable material is imagewise exposed from the cover layer side, followed by an overall exposure through the support. The resulting flexographic printing plate has improved relief depths and a lower tonal value increase on printing.

Abstract: Photosensitive composition comprising, inter alia, thermoplastic-elastomer block copolymer binders and addition-polymerizable monomer having terminal ethylenically unsaturated end groups wherein at least one monomer has one acrylate or methacrylate group, said monomer forms a homopolymer having a solubility parameter in the range between 7.6 and 9.6 and a glass transition temperature below 0.degree. C. and, further wherein, at least one monomer has more than one acrylate or methacrylate groups, said monomer forms a homopolymer having a solubility parameter in the range between 9.6 and 12.

Abstract: The invention relates to a process for producing flexographic printing reliefs by:(a) forming at least one photopolymerizable layer on a support, said layer being crosslinkable by photopolymerization;(b) imagewise exposing the layers to actinic radiation; and(c) removing the noncrosslinked portions of the layers with developer solvents;wherein the improvement comprises using developer solvents which have at least one component selected from the group consisting of: (a) diethylene glycol dialkyl ethers wherein the alkyl group has 1-5 carbon atoms; (b) acetic acid esters of alcohols selected from the group consisting of saturated alcohols having 6-10 carbon atoms and alkoxy substituted saturated alcohols having 6-10 carbon atoms; (c) carboxylic acid esters of acids having 6-10 carbon atoms and alcohols having 1-6 carbon atoms; and (d) esters of alkoxy substituted carboxylic acids wherein the acid has from 2-4 carbon atoms, the alkoxy substituent has from 1-4 carbon atoms, and alcohols having 1-4 carbon atoms.

Abstract: A process is described for cementing together the edges of photopolymerizable flexographic printing elements for printing plates that contain as an elastomeric binder a block copolymer whose polymer blocks are polystyrene and polyisoprene and/or polybutadiene or their copolymers.

Abstract: The invention relates to a process for the ozone protection of an imagewise exposed and developed photopolymer flexographic printing plate, having an elastomeric, thermoplastic polymeric binder, which comprises applying to the exposed and developed surface of the flexographic printing plate at least one known liquid polyether of the formulas: ##STR1## wherein R.sub.1 =H, or methylR.sub.2 =H, alkyl or alkylene with C.sub.12 -C.sub.18, and saturated and unsaturated fatty acid radicals with C.sub.12 -C.sub.18.p=1-4and wherein n, m and m.sub.1-4 and x, y, and z are so selected that the molecular weight (M.sub.n) of the molecule is about 500 to 5000.

Abstract: Direct positive film with incorporated developer having improved sensitometric properties and storage stability is obtained with a developer combination of hydroquinone monosulfonate and a superadditive developer of the 3-pyrazolidone or the N-methyl-p-aminophenol sulfate types.