| 摘要 |
Presensitised dry lithographic printing plate consists of a substrate, primer coat, light-sensitive coat and silicone rubber coat. The novelty is that the primer coat contains protein(s) selected from casein, soya protein and albumin. The primer coat contains casein or a combination of this and soya protein and/or albumin and is 0.1-50, pref. 1.0-20 microns thick. The amt. of protein is 10-98, pref. 30-95 (wt.)% of the primer coat. This coat also contains a hardener for gelatin; and a silane coupler, pref. of formula R3-nSi(X)Yn (I). R = H or 1-5C alkyl; X = alkyl, vinyl or an organic gp. with a functional gp. which can be bound to or has an affinity for an organic matrix polymer; pref. methyl, N-(beta-aminoethyl)- gamma-aminopropyl, gamma-methacryloyl-oxypropyl, N-(beta-(N-vinylbenzyl amino)ethyl- gamma-aminopropyl, gamma-glycidoxypropyl, gamma-mercaptopropyl, gamma-chloropropyl, gamma-anilinopropyl or C18H37-N(+)(CH3)2-(CH2)3-; Y = an organic gp., which is hydrolysed to produce an OH gp.; pref. 1-5C alkoxy, 3-5C alkoxyalkoxy, 2-5C acyloxy, dialkylamino, Cl or trimethylsilylamino; n = 2 or 3. In particular, the coupler is N-(beta-aminoethyl) -gamma-aminopropyl -trimethoxysilane, N-(beta-aminoethyl)- gamma-aminopropylmethyl dimethoxysilane, gamma-glycidoxypropyl trimethoxysilane (IA) or vinyltrichlorosilane. It pref. is in a coupling layer between the substrate and primer coat and is used in an amt. of 1-50, pref. 3-20wt.% w.r.t. the protein. The light-sensitive coat pref. contains 1.0-99.9 pts. monomer with photopolymerisable, ethylenically unsatd. double bond(s) and a b.pt. not less than 100 deg.C, which is not volatile at room temp., or an oligomer of this, 0.1-200 pts. photopolymerisation initiator, 0.01-1.0 pts. thermal polymerisation inhibitor and 0.01-95.0 pts. polymer or inorganic powder as filler, to provide dimensional stability. USE/ADVANTAGE - The plate has solvent resistance, ink affinity and proofing properties |
