Basf Aktiengesellschaft

Peter Richter

August Wigger

Wolfgang F Mueller

Mong-Jon Jun

Gerhard Hoffmann

Gerhard Heinz

August Lehner

Werner Lenz

Helmut Barzynski

Otto Volkert

Manfred Zuerger

Heinz-Ulrich Werther

Axel Sanner

Peter Rudolf

Klaus Bronstert

Erhard Seiler

Gunnar Schornick

Albert Kohl

Hermann Roller

Horst Koch

Gerhard Fahrbach

Herbert Stutz

Michael Bobrich

Albert Elzer

Karl Gerberding

Albrecht Eckell

Ludwig Kreitner

Reiner Hofmann

Lothar Metzinger

Horst Hoffmann

Siegfried Raiff

Eckhard Koplin

Helmut Kaufmann

Mixtures which can be crosslinked by photopolymerization and are based on binders, photopolymerizable monomers which are compatible with these, photoinitiators and thermal polymerization inhibitors contain, as the binder, polymers of the formula I ##STR1## where Pol is a radical of a block copolymer prepared by sequential anionic polymerization of conjugated dienes and vinyl aromatics,

Elements having layers containing mixtures which can be crosslinked by

The invention provides a novel photosensitive recording material in the shape of a multilayer element comprising

Photosensitive recording element containing an ionic polymer

In magnetic recording media consisting of a nonmagnetic base and, firmly applied to this, one or more magnetic layers based on a magnetic material finely dispersed in organic binders, the binder consists of not less than 50% by weight of a high molecular weight branched polyurethane elastomer possessing OH-containing urea groups at the chain ends.

Magnetic recording media

A photopolymerizable recording material for the production of relief plates comprises a photopolymerizable layer which can be developed in an alcoholic solution and contains a mixture of a photoinitiator, a photopolymerizable monomer and a linear, high molecular weight polyurethane which possesses activated double bonds in side branches, and is prepared using a polyether-diol from the group comprising the polyethylene glycols, propylene glycols and ethylene glycol/propylene glycol co-condensates.

Photopolymerizable recording material and the production of relief

A multi-layer element for the production of printing plates and relief plates which is based on an elastomeric polymer binder and is firmly anchored to a polyester base by means of an adhesive layer. The adhesive layer consists of a thermally hardened mixture which is insoluble in aromatic hydrocarbon solvents or aliphatic halohydrocarbon solvents and contains (c1) from 90 to 40% by weight, based on the sum of (c1) and (c2), of an hydroxyl-containing polyurethane, hydroxyl-containing epoxy, hydroxyl-containing phenoxy resin, polyester-ol or polyether-ol resin which has been hardened and crosslinked with isocyanate, and which has from about 4 to 20% by weight, based on the non-crosslinked and hardenable resin, of free OH groups before hardening and crosslinking with isocyanate, and (c2) from 10 to 60% by weight, based on the sum of (c1) and (c2), of an OH-free polycarbonate which is compatible with the resin (c1) before the latter is hardened and crosslinked.

Multi-layer elements suitable for the production of printing plates and

Photopolymerizable mixtures of (a) one or more block copolymers, (b) one or more photopolymerizable, ethylenically unsaturated, low molecular weight compounds and (c) a photopolymerization initiator, with or without (d) other additives, contain as component (a) block copolymers which are composed solely of elastomeric polymer blocks, and contain two or more elastomeric polymer blocks having a glass transition temperature of from -20.degree. C. to +15.degree. C., linked by one or more elastomeric polymer blocks having a glass transition temperature of below -20.degree. C.

Photopolymerizable mixtures containing elastomeric block polymers and

A multi-layer element contains a photosensitive layer composed of a mixture of an elastomeric polymer as a binder, a photopolymerizable monomer and a photopolymerization initiator, the photosensitive layer being bonded to a polyester base via an adhesive layer. The adhesive layer is composed of a reaction product, which is insoluble in the process solvents, of a hardenable cellulose ether and a polyisocyanate. The multi-layer element is particularly suitable for the production of printing plates and relief plates, and can be produced by applying a layer of an adhesive, which contains the hardenable cellulose ether and the polyisocyanate, to the polyester base, baking the adhesive to form the insoluble adhesive layer, and applying the photosensitive layer.

Photopolymerizable compositions based on an elastomeric styrene-diene block polymer, one or more photopolymerizable olefinically unsaturated monomers and one or more photopolymerization initiators exhibit improved properties if they contain, as an essential constituent, an elastomeric block copolymer of the general structure A-B-C, where A is a thermoplastic, non-elastomeric polymer block based on styrene compounds and having a second order transition point above +25.degree. C., B is an elastomeric polymer block based on butadiene and/or isoprene and having a second order transition point below -20.degree. C. and C is a polymer block, different from B, having a second order transition point of from -30.degree. C. to +15.degree. C., C being either a homopolymer or copolymer block based on butadiene or isoprene or a random copolymer block based on conjugated dienes and styrene compounds. The photopolymerizable compositions may be used, inter alia, for the production of photo-curable adhesives, resilient and flexible sheet material and, in particular, flexographic relief printing plates.

Photopolymerizable compositions containing elastomers and photo-curable

Laminates for the manufacture of flexographic printing plates and containing (a) a layer consisting essentially of a photocrosslinkable mixture of a two-block copolymer of from 30 to 95% w/w of a diene hydrocarbon and from 5 to 70% w/w of a styrene monomer or a partially hydrogenated product thereof with a compatible monomer having at least one C--C double bond, said mixture containing a photo-initiator, (b) a non-photocrosslinkable elastomeric underlayer having a Shore A hardness of from 15 to 70 and (c) a non-photocrosslinkable stablizing layer preferably between layers (a) and (b).

Laminates for the manufacture of flexographic printing plates using

An apparatus for treating photopolymer printing plates, which have already been exposed, with liquid media, in which the plate, mounted on a vertically movable holder, can be moved up and down between an upper loading and unloading chamber and a lower treatment chamber, separated from the upper chamber by a partially open partition, and in which upper and lower rim elements of the plate holder seal the aperture in the partition in a vapor-tight manner when the plate holder is in its terminal positions.

Apparatus for treating printing plates

A process for the manufacture of thin layers based on polyurethane elastomers. A liquid reaction mixture essentially consisting of (A) polyesters, polyethers, polyester urethanes or polyether urethanes, all of which contain at least two hydroxyl groups in the molecule, and diisocyanates or (B) prepolymers obtained from the hydroxyl-containing compounds mentioned under (A) above with an excess of diisocyanates, said prepolymers containing at least two isocyanate groups in the molecule, and at least one of the compounds mentioned under (A) above which are capable of reacting with isocyanates, to which reaction mixture a minor quantity of substantially compatible monomers having at least two photocrosslinkable C--C multiple bonds and optionally a photopolymerization initiator have been added, is applied to a substrate to form a coating thereon, which coating is then gelled by irradiation and finally thermocured. The process of the invention is particularly suitable for the continuous manufacture of uniformly thin layers of soft polyurethane elastomer showing narrow tolerance limits.

Manufacture of thin layers of polyurethane elastomers

The invention relates to relief plates for flexographic printing comprising a relatively soft elastomeric base (U) having a modulus of elasticity of from 10 to 200 kg/cm.sup.2 and a thickness of from 0.5 to 6 mm and, firmly bonded thereto, a thin, relatively hard, difficultly soluble intermediate layer Z having a modulus of elasticity of from 1 .times. 10.sup.3 to 2.1 .times. 10.sup.6 kg/cm.sup.2 and a thickness of from 5 to 500 .mu. and, firmly bonded to said intermediate layer Z, a relief layer P' consisting of a photocrosslinked elastomeric mixture having a modulus of elasticity of from 30 to 2000 kg/cm.sup.2 and a thickness of from 200 to 300 .mu., the modulus of elasticity of the photocrosslinked relief layer P' being the same as or higher than that of the base U and the neutral surface of the relief plate lying in or near the intermediate layer Z. The invention also relates to photosensitive laminates for the production of such plates.

Laminates for the manufacture of relief printing plates

Laminates for the production of relief plates for flexographic printing, by imagewise exposure and washing out with a developer solution have, on a base optionally provided with an elastomeric layer, a photo-crosslinkable layer containing a photoinitiator and consisting of a polyurethane elastomer which has been prepared in a special manner from an aliphatic saturated polyesterglycol, an aliphatic diisocyanate, but-1-ene-3,4-diol and, if desired, another diol and which has a Shore A hardness of 30 to 90.degree. in the photo-crosslinked state, the elastomer being optionally mixed with a photo-crosslinked monomer.

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Frankenthal, Germany

Peter Richter