Basf Aktiengesellschaft

Basf Lacke+farben Ag

Basf Lacke & Farben

Manfred Zuerger

Thomas Telser

Heinz-Ulrich Werther

Bernd Bronstert

Werner Lenz

Horst Koch

August Wigger

Peter Richter

Karl-Rudolf Kurtz

Rudolf Vyvial

Heinrich Hartmann

Gerhard Hoffmann

Dieter Littmann

Christof Taubitz

Otto Volkert

John Lynch

Guenther Schulz

Lothar Schlemmer

Gerhard Bleckmann

Albert Elzer

Heino Thiele

Wolfgang Huemmer

Klaus Borho

Josef Woellhaf

Paul Hecke

Klaus Spreng

Milan Obradovic

Heinrich Krieger

Flexible printing plates are produced from printing plates consisting essentially of a dimensionally stable substrate (1) and a recording layer (2) by a process in which the printing plate is produced alternatively either by photochemical or by mechanical structuring, and in the case of photochemical structuring the photosensitive recording layer (2) is exposed imagewise and the unexposed parts of the recording layer (2) are washed out with a developer and in the case of mechanical structuring the originally photosensitive, uniformly exposed recording layer (2) is cut imagewise and the nonprinting parts of the recording layer (2) are peeled off from the substrate (1). The printing plates produced by this process are suitable for the production of products printed by the flexographic method and for lacquering products printed by the offset method.

Photochemical or mechanical production of flexible printing plates

Flexible printing plates are produced from printing plates consisting essentially of a dimensionally stable substrate (1) and a recording layer (2) by a process in which the printing plate is produced alternatively either by photochemical or by mechanical structuring, and in the case of photochemical structuring the photosensitive recording layer (2) is exposed imagewise and the unexposed parts of the recording layer (2) are washed out with a developer and in the case of mechanical structuring the originally photosensitive, uniformly exposed recording layer (2) is cut imagewise and the nonprinting parts of the recording layer (2) are peeled off from the substrate (1).

A novel, improved continuous process for the production of a photosensitive recording element is described, whose photopolymerizable recording layer (A) consists of two or more individual strata (a.sub.n) lying one on top of the other and firmly bonded to one another. The individual strata (a.sub.n) may be of the same or roughly the same composition or of different compositions. In the novel, improved continuous process, the mixtures (a.sub.n) used for the production of the individual strate (a.sub.n) are prepared separately from one another and melted and, as separate molten material streams (a.sub.n), are combined even before entering the nip of a calender, without the said streams mixing as a result of turbulence. During, before or directly after they have been combined, the molten material streams (a.sub.n) are formed into molten sheet-like structures (a.sub.n) lying one on top of the other, without the said streams mixing as a result of turbulence. Thereafter, the molten sheet-like structures (a.sub.n) lying one on top of the other are introduced into the calender nip, one or both of the two outer molten sheet-like structures (a.sub.n) in contact with the calender rollers forming a rotating melt bead or rotating bank. In the calender nip itself, the said sheet-like structures (a.sub.n) are then calendered with production of the photopolymerizable recording layer (A) consisting of individual strata (a.sub.n) lying one on top of the other and firmly bonded to one another.

Continuous production of a photosensitive recording element

A light-sensitive recording element useful for preparing photopolymer flexographic relief printing plates, comprising at least one photopolymerizable recording layer having a thickness of from 0.1 to 7 mm and made up of:

Sheetlike light-sensitive recording

Multilayer, photosensitive recording materials which can be developed with aqueous media contain one or more layers of a mixture which is crosslinkable by photopolymerization, soluble or dispersible in aqueous media and based on polymer containing hydroxyl and/or amide groups, as binders, compatible photopolymerizable monomers and photopolymerization initiators, which mixture contains from 0.1 to 10% by weight, based on its total amount, of an aldehyde of the general formula I ##STR1## where R is hydrogen, hydroxyl, C.sub.1 -C.sub.6 -alkyl, C.sub.1 -C.sub.6 -alkoxy, C.sub.6 -C.sub.10 -aryl or C.sub.6 -C.sub.10 -aryloxy.

Mixture crosslinkable by photopolymerization

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.

Light-sensitive photopolymerizable laminate material

A photosensitive recording material for the production of printing plates, relief plates or resist images comprises a photocurable relief-forming layer (RL) which is applied onto a dimensionally stable base and consists of

Photosensitive recording material which can be developed with water, for

A sheet-like structure is produced from a vinyl alcohol polymer by a method wherein, in a self-cleaning multi-screw extruder, the polymer is mixed with a small amount of water, the mixture is melted, homogenized, devolatilized and finally extruded as a melt, and the extrudate is shaped in a conventional manner into the sheet-like structure.

Process for producing sheet-like structures from vinyl alcohol polymers

Multi-layer photopolymer elements, which are suitable for the production of relief printing plates and contain photosensitive polyvinyl alcohol/monomer layers which can be developed with water, can be improved in respect of their production, drying and shelf life by the application of a thin layer of a highly hydrolyzed low molecular weight polyvinyl alcohol.

Multi-layer elements with polyvinyl alcohol overcoat suitable for the

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.

Photopolymerizable composition for the manufacture of relief printing

A process and apparatus for the production of exposed printing plates consisting of a resin layer and a support, said resin layer being prepared from a fluid photopolymerizable material which is introduced into a mold having at least one transparent wall which is covered with an image-bearing transparency, and being exposed through said image-bearing transparency, which causes photopolymerization of the exposed areas of the resin layer and bonds these areas to the support which is provided with an adhesive layer. The improved process comprises introducing a predetermined amount of fluid photopolymerizable material, said amount corresponding substantially to the volume of the resin layer of the exposed printing plate; adjusting said support and said transparent wall of the mold so that they are equidistant from one another, adjustment being advantageously effected by bending or doming the support relative to the transparent wall after the latter has been bent or domed by the fluid material introduced into the mold under pressure. Further embodiments of the invention serve to minimize the loss of photopolymerizable material and to avoid the formation of foam when the fluid material is introduced into the mold. The apparatus of the invention can be manufactured and operated easily and economically.

Apparatus for the production of exposed 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.

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Sinsheim, Germany

Manfred Zuerger