Abstract: Photopolymerizable laminates suitable for producing flexible and resilient printing plates carry on a dimensionally stable base at least one intermediate layer and on top thereof a photopolymerizable layer which consists essentially of a mixture of a water-soluble copolymer or derivative of polyvinyl alcohol, a specific copolymerizable mono-functional (meth)acrylate, a photoinitiator and a thermal polymerization inhibitor.

Abstract: In hot embossing plates which are crosslinkable by photopolymerization and comprise(a) a heat-stable, dimensionally stable base and(b) a relief-forming layer which is crosslinkable by photopolymerization and soluble or dispersible in water and contains(b.sub.1) one or more partially or virtually completely hydrolyzed polyvinyl alkanecarboxylates as binders,(b.sub.2) one or more alkenecarbonylamino-N-methylene ethers of polyhydric alcohols as photopolymerizable monomers and(b.sub.3) photopolymerization initiators,the relief-forming layer (b) contains, as further binders (b.sub.1),(b.sub.11) alkenecarboxylates and/or alkenecarbonylamino-N-methylene ethers of partially or virtually completely hydrolyzed polyvinyl alkanecarboxylates and/or(b.sub.12) alkenecarboxylates and/or alkenecarbonylamino-N-methylene ethers of partially or virtually completely hydrolyzed graft copolymers of vinyl alkanecarboxylates and alkylene oxides,and is more than 0.8 mm thick.

Abstract: Photopolymerizable laminates suitable for producing printing plates have on a dimensionally stable base at least one intermediate layer and on top thereof a photopolymerizable relief-forming layer, the intermediate layer containing aryl glycidyl (meth)acrylate in an at least partially polymerized state.

Abstract: Novel photopolymerizable recording materials, in particular for the production of printing plates and relief plates, can be developed with water or an aqueous alkaline solution and predominantly consist of a photoinitiator-containing mixture of (a) one or more low molecular weight compounds having one or more photopolymerizable olefinically unsaturated double bonds and (b) one or more organic polymeric binders and contain a bisacylphosphine oxide as the photoinitiator.These recording materials are useful for the production of printing plates and relief plates.

Abstract: Relief plates and printing plates are produced by a positive-working process, using a photopolymerizable layer which contains one or more photopolymerizable, olefinically unsaturated compounds, one or more photoinitiators which can be activated by UV light, and a combination of a phenothiazinium, phenoxazinium, phenazinium or acridinium dye with a mild reducing agent which, on exposure to visible light, is capable of reducing the dye in the excited electronic state. The photopolymerizable layer is exposed imagewise to light having a wavelength longer than 450 nm, and simultaneously or subsequently exposed uniformly to light having a wavelength of from 300 to 420 nm, after which the unpolymerized areas of the layer are removed.

Abstract: Acylphosphine compounds of the formula I ##STR1## where X is oxygen, sulfur or an electron pair, R.sup.1 is R.sub.4 or OR.sup.4, R.sup.2 is --OM, where M is a monovalent cation, R.sup.3 is aryl which is substituted at least at the two positions ortho to the carbonyl group, and R.sup.4 is hydrogen, alkyl or aryl, are very effective photoinitiators for photopolymerizable materials, such as coating compositions, finishes, printing inks, unsaturated polyesters, recording media and preferably aqueous polymer dispersions or solutions.

Abstract: A photosensitive multi-layer material comprising a base, which may or may not be provided with an adhesion-promoting layer, and a photopolymerizable layer, consisting of a mixture of a photoinitiator, a binder and a photopolymerizable monomer, possesses, between the base and the photopolymerizable layer, an adhesive layer of a hardened mixture of a binder and an etherified melamine-formaldehyde condensate, hardenable at 60.degree.-120.degree. C.

Abstract: A photosensitive multi-layer material comprising a base and a photosensitive layer which has a polyamide binder and is soluble or dispersible in an alcoholic solvent contains two layers between the base and the photosensitive layer, namely (a) an adhesion-promoting layer, adjacent to the base, which is derived from a polyurethane binder, prepared by reacting a hydroxyl-containing epoxy resin and a polyisocyanate, and a pigment combination in which a white zinc sulfide pigment is the essential constituent, and (b) an adhesive layer, adjacent to the photosensitive layer, which consists of a baked mixture of an alcohol-soluble copolyamide and a melamine-formaldehyde resin.

Abstract: A photopolymerizable recording composition which comprises a mixture, containing a photoinitiator, of (a) a photopolymerizable olefinically unsaturated monomer and (b) an organic polymeric binder, wherein the photoinitiator is an acylphosphine oxide compound of the formula R.sup.1 R.sup.2 PO--CO--R.sup.3, where R.sup.1 and R.sup.2 are certain organic radicals and R.sup.3 is tert.-alkyl or a cyclic radical with two substituents in the ortho-position to the carbonyl group. The recording compositions have a high reactivity when irradiated with UV light and are used in particular for the preparation of printing plates, relief plates and photo-resists.

Abstract: A photopolymerizable recording composition which comprises a mixture, containing a photoinitiator, of (a) a photopolymerizable olefinically unsaturated monomer and (b) an organic polymeric binder, wherein the photoinitiator is an acylphosphine oxide compound of the formula R.sup.1 R.sup.2 PO-CO-R.sup.3, where R.sup.1 and R.sup.2 are certain organic radicals and R.sup.3 is tert.-alkyl or a cyclic radical with two substituents in the ortho-position to the carbonyl group. The recording compositions have a high reactivity when irradiated with UV light and are used in particular for the preparation of printing plates, relief plates and photoresists.

Abstract: A photopolymerizable composition for the manufacture of printing plates and relief plates, based on a mixture, containing a photoinitiator, of photopolymerizable olefinically unsaturated monomers and a polymeric binder, contains up to 0.1% by weight of an etherified thioanthraquinone for improving the relief image in the production of relief plates.The composition advantageously also contains a small amount of an organic tertiary amine or of an aromatic .alpha.-ketocarboxylic acid or its ester and/or of an inhibitor, e.g. the salt of an organic N-nitrosohydroxylamine.

Abstract: Photopolymerizable compositions for the production of printing plates and relief plates, consisting essentially of a photoinitiator-containing mixture of olefinically unsaturated photopolymerizable compounds with polymeric binders, contain up to 1% by weight of a compound having the structural element of anthrone, e.g. bianthrone and 9,9'-bianthryl, which results in an improved relief image in the production of relief plates.

Abstract: Photopolymerizable compositions for the manufacture of relief printing plates, especially relief plates for making mats, comprising an alcohol-soluble linear polyamide, a photoinitiator and a mixture of (a) a diether or triether obtained from 1 mole of an aliphatic diol or triol and from 2 to 3 moles of N-hydroxymethylacrylamide or N-hydroxymethylmethacrylamide and (b) an unsaturated ester-urethane obtained from 1 mole of toluylene diisocyanate and 2 moles of a hydroxyalkyl acrylate or methacrylate, (a) and (b) being mixed in specific ratios.