Presensitised plate for prodn. of lithographic printing plates - has substrate, primer, light-sensitive layer contg. unsatd. monomer or oligomer, photo-initiator and di:azo-resin etc.

摘要

Presensitised plate for lithographic printing applications (I) comprises (A) substrate, (B) primer layer, (C) light-sensitive resin layer and (D) silicone rubber layer; layer (C) contains a monomer or oligomer with photo-polymerisable or -crosslinkable olefinic double bond(s) (II), a photoinitiator and 0.01-4 wt% diazo-resin (III). (III) is the reaction prod. of an anion with a condensate of a diazo-monomer (IV) and a condensing agent (V); (IV) is 4-diazo-diphenylamine, 1-diazo-4-N,N-dimethylaminobenzene, etc. (25 cpds. listed); (V) is formaldehyde, acetaldehyde, propionaldehyde, n- or iso-butyraldehyde, benzaldehyde, or a mixt. thereof; anion is PF6, tri-isopropyl-naphthalenesulphonate, 2,5-dimethylbenzenesulphonate, etc. (15 anions listed), pref. the three specified anions; mol. ratio (IV):(V) is (1:1)-(1:0.5), pref. (1:0.8)-(1:0.6); layer (C) contains 0.03-3 wt% (III); (II) is PEG- or PPG-mono(meth)acrylate or -di(meth)-acrylate, urethane acrylates, epoxy-acrylates, etc. (23 types listed); (C) contains 1-70 (pref. 3-50) wt% (II); initiator is a polyketaldonyl cpd., alpha-carbonyl cpd., polynuclear quinone, benzthiazole cpd., trihalomethyl-s-triazine with chromophoric gps., etc. (14 types listed); (C) contains 0.1-20 (pref. 1-10) wt% initiator; layer (C) also contains a film-forming polymer, pref. (meth)acrylic acid copolymer, acid cellulose deriv., PVP, PUR, epoxy resin, etc. (24 types listed). USE/ADVANTAGE - For prodn. of lithographic printing plates; the invention provides a PS plate with good image-reprodn. properties without the use of damping water.