| 摘要 |
1525965 Photo-crosslinkable printing plate precursors BASF AG 28 Nov 1975 [29 Nov 1974] 48977/75 Heading G2C A printing plate precursor comprises (a) a photocrosslinkable layer comprising an organic solvent soluble polymer which may be partially hydrogenated, a monomer with a photo-crosslinkable carbon, carbon double bond and a photo-initiator (b) a non- photo-crosslinkable elastomeric underlayer which has a Shore A hardness of from 15 to 70 and (c) a non-photo crosslinkable stabilizing layer. The block polymer is a copolymer comprising 30 to 95 wt. per cent of a C4 or C5 diene hydrocarbon and 5 to 70 wt. per cent of a monomer of Formula in which R is H or CH 3 and R<SP>1</SP> is phenyl or C 1-4 alkyl substituted phenyl. The copolymer has a viscosity number (0À5% w/w sol. in toluene at 25‹C) of 60 to 350 ml/g. The stabilizing layer is between layers (a) and (b) or under layer (b) and preferably comprises reinforced fabrics, metal or plastics. The elastomeric layer is a natural or synthetic rubber, preferably polyurethane. Also it may be formed by overall exposure of a layer having the same composition as the photo-crosslinkable layer. The photo-crosslinkable layer may be covered by a non- tacky coating e.g. a polyamide, over which there is a removable cover sheet. |
