| 摘要 |
<p>Water-developable, photocrosslinkable compsn. for printing plates comprises (a) an olefinically unsatd. monomer or oligomer based on (meth)acrylic acid modified epoxy resins with an acid value of less than 0.2, pref. less than 0.1 Val/kg, which can be polymerised to a cross linked polymer, and (b) 0.1-30 wt. % (on (a)) of a photoinitiator and/or sensitizer. The layer is free of cpds., esp. polymers, which can be removed from unexposed or uncrosslinked areas of the layer with water. The compsn. may also contg. up to 50 wt.% (on (a)) of a photopolymerisable cpd.CH2:C(R1)-CO-NH-X-NH-CO-C(R1)=CH2 in which R1 is H or CH3 and X is a 1-12C methylene chin, -CH(CH3)-, -C(CH3)2- or -CH(CCl3)-, and (d) opt. other adjuvants such as epoxide-novolak resins, polymerisation inhibitors, dyes, flow agents, etc. The compsns. are esp. useful for the prodn. of offset printing plates. They can be made without using the alkali-soluble copolymers or water-soluble cellulosic materials used in previous compsns. The compsns. have a high sensitivity to light and give sharp images. Storage stability without protective layers is more than 6 months, compared with 2 weeks for prior art materials.</p> |
