Abstract: The invention relates to a method for producing flexographic printing forms by engraving a printing relief on a flexographic printing element that can be laser engraved, said element having a photochemically cross-linked relief layer. The relief layer is transparent and comprises oxidic, siliceous or zeolitic solid matter with a particle size between 1 and 400 nm in a quantity of between 0.1 and 8 wt. % in relation to the quantity of all components in the relief layer.

Abstract: A method for the production of flexographic printing forms by means of laser engraving, wherein at least one elastomer relief layer is applied to a dimensionally-stable carrier. The relief layer comprises at least one elastomer binding agent and at least one absorber for laser radiation; the relief layer is entirely cross-linked by means of electron radiation at a minimum overall dose of 40 kGy; a printed relief is engraved into the cross-linked relief layer by means of a laser. The invention also relates to flexographic printing forms which can be obtained according to said method.

Abstract: Photopolymeric sleeves for flexographic printing are marketed by a method in which a customer is supplied with a suitable apparatus and necessary know-how for producing photopolymeric sleeves so that said customer is enabled to produce photopolymeric sleeves himself.

Abstract: Flexographic printing plates are produced by thermal development by a process in which an imagewise exposed flexographic printing element is developed by heating and removing the softened, unpolymerized parts of the relief-forming layer, the flexographic printing element used comprising an olefin/(meth)acrylate copolymer having an olefin content of from 50 to 94 mol %. The photopolymerizable flexographic printing element comprises an olefin/(meth)acrylate copolymer having a content of from 50 to 94 mol % of olefin monomers, from 6 to 50 mol % of (meth)acrylate monomers and from 0 to 5 mol % of further comonomers. This flexographic printing element is used for the production of flexographic printing plates both by thermal development and by development by means of washout compositions.

Abstract: A description is given of a laser-engravable recording material for producing relief printing plates, in particular for producing flexographic printing plates, comprising a dimensionally stable support and a recording layer comprising silicone rubbers and inorganic ferrous solids and/or carbon black as absorbers for laser radiation; of processes for producing relief printing plates by laser engraving such recording materials; and of relief printing plates having a printing relief comprising silicone rubbers and inorganic ferrous solids and/or carbon black.

Abstract: 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.

Abstract: A process for the production of flexographic printing plates by laser engraving, in which the recording layer of a crosslinkable, laser-engravable flexographic printing element is crosslinked by the combination of a full-area crosslinking step with a crosslinking step which only acts at the surface, and a printing relief is engraved into the crosslinked recording layer by means of a laser, and flexographic printing plates obtainable by the process.

Abstract: The present invention relates to a liquid-crystalline composition which comprises, as components

Abstract: A liquid-crystalline composition contains, as components, a liquid-crystalline mixture containing at least one compound having two polymerizable groups and at least one compound having only one polymerizable group, and optional further additives. The liquid crystalline composition can be used for printing or coating substrates, in electro-optical components, for counterfeiting-proof marking of articles and for the production of films or coatings which selectively reflect light in the wavelength range from 250 to 1300 nm.

Abstract: 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.

Abstract: A photosensitive flexographic printing element for the production of flexographic printing plates by digital imaging by means of lasers which has an IR-ablative layer with a polyether-polyurethane as binder. A process for the production of flexographic printing plates using an element of this type.

Abstract: A photopolymerizable composition which comprises a mixture of thermoplastic-elastomeric SIS and SBS block copolymers as binder, ethylenically unsaturated monomers, plasticizer and photoinitiator. Photopolymerizable flexographic printing element whose photopolymerizable layer comprises this composition. Use of photopolymerizable flexographic printing elements of this type for the production of flexographic printing plates.

Abstract: Photosensitive printing element for preparing flexographic printing plates via computer-to-plate technology with a support, a photopolymerizable layer and an IR-ablatable layer substantially opaque to actinic radiation which comprises at least one heat-combustible polymeric binder, at least one IR-absorbing material and at least one aliphatic diester, and a process for making a flexographic printing plate using such an element.

Abstract: A description is given of a laser-engravable recording material for producing relief printing plates, in particular for producing flexographic printing plates, comprising a dimensionally stable support and a recording layer comprising silicone rubbers and inorganic ferrous solids and/or carbon black as absorbers for laser radiation; of processes for producing relief printing plates by laser engraving such recording materials; and of relief printing plates having a printing relief comprising silicone rubbers and inorganic ferrous solids and/or carbon black.

Abstract: A photopolymerizable printing plate has a dimensionally stable support, a photopolymerizable layer, a top layer located thereon comprising two mutually incompatible, elastomeric block copolymers, and a protective sheet. Disclosed are processes for producing such a photopolymerizable printing plate, processes for producing relief printing plates, especially flexographic printing plates, and also relief printing plates having ink cells in the relief surface.

Abstract: Large-format composite relief printing plates are produced by applying individual photopolymerizable relief printing plates to a large-format substrate, by a process in which the image information is transmitted to the individual relief printing plates by means of a laser. The individual photopolymerizable relief printing plates are positioned on the substrate with the aid of a laser. A composite of relief printing plates comprises a substrate, a laser-structurable layer applied thereon and insoluble in printing inks and printing plate developers, and relief printing plates applied thereon and having an IR-ablatable layer.

Abstract: A process for the production of a photosensitive recording material for producing relief printing plates is described, in which a photosensitive layer is laminated with a composite element comprising a protective cover sheet, a release layer and, if required, a further layer, wherein the surface of the uppermost layer of the composite element or the surface of the photosensitive layer is subjected to a corona treatment immediately before contact. As a result of the corona treatment, the adhesion of the applied layer is substantially increased.

Abstract: A material for gravure recording by means of coherent electromagnetic radiation for letterpress printing, consisting of a substrate and a crosslinkable layer, with or without a release layer and/or cover sheet, the layer containing at least one ethylenically unsaturated compound, a polymerization initiator and at least one polymeric binder which consists of polyvinyl alcohol and/or at least one copolymer having a substantial proportion of the structural unit and containing a filler having a ceiling temperature of less than 800K, in particular less than 600K, e.g. polystyrene, polymethyl methacrylate, poly(ethylene)ketone, polyoxymethylene or poly(&agr;-methylstyrene), in particular having a spherical or roughly spherical form with a maximum dimension of about 5-10 &mgr;m. The material is very suitable for laser-engravable letterpress printing plates.

Abstract: A multilayer element comprising a substrate, an intermediate layer and a photopolymerizable or photocrosslinkable layer in the stated order is used for producing printing or relief plates. The intermediate layer contains a copolymer of a monomer (A) of the formula (I) or (II) and a copolymerizable monomer (B) ##STR1## where R.sup.1 is vinyl, propen-2-yl, 1-buten-2-yl or styryl or a radical R.sup.2 --O--CO--CH.dbd.CH--, R.sup.2 is an alkyl, aryl, aralkyl or cycloalkyl radical of up to 10 carbon atoms, R.sup.3 is H, methyl or ethyl and n is from zero to 5. The intermediate layer in the multilayer element has improved adhesion in the laminate. It is initially nontacky and does not become tacky until after the application of the photopolymerizable layer, as a result of the interaction with said layer. The improved adhesion in the laminate is retained even after storage and repeated use of the finished printing plates.

Abstract: A photosensitive recording material having a dimensionally stable substrate and a photosensitive layer which is applied thereon and containsA) an elastomeric block copolymer as a binder,B) a polymerizable compound andC) a compound capable of initiating the polymerization of the compound B under the action of actinic radiation,is described, the elastomeric block copolymer A being a block copolymer having blocks of polymerized1. styrene units,2. alkylene units and3. diene units.The material is suitable for the production of relief printing plates, especially flexographic printing plates, which are distinguished by higher resistance to swelling in the presence of printing inks containing ester solvents or UV-curable components.