摘要:
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.
摘要:
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:from 20 to 99.499% by weight of at least one polymeric binder which may be random ethylene-propylene-alkadiene terpolymers having an ethylene content of from 40 to 80% by weight and a double bond content of from 2 to 20 olefinic double bonds per 1,000 carbon atoms;from 0.001 to 10% by weight of at least one photopolymerization initiator,from 0.5 to 50% by weight of at least one monomer which is compatible with the binder and has at least one photopolymerizable olefinic double bond, andfrom 0.001 to 2% by weight of at least one inhibitor of thermally initiated polymerization and from 0.0001 to 5% by weight of at least one antioxidant as assistants.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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(a) a water-soluble or water-dispersible polyvinyl alcohol derivative containing from 1 to 12 mole % of olefinically unsaturated photopolymerizable or photocrosslinkable side groups, in particular of .alpha.,.beta.-olefinically unsaturated carboxylic acids, not more than 30 mole % of hydroxyl groups which are esterified and/or etherified with other non-olefinic radicals, and not less than 65 mole % of free hydroxyl groups and(b) one or more photopolymerization initiators, with or without(c) conventional non-photopolymerizable assistants and/or additives.
摘要:
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.
摘要:
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.