| 摘要 |
<p>A concentrated dampening water composition for lithographic printing comprises a) 0.1 to 10% by weight of a hydrophilic polymeric compound having a film-forming ability; b) 0.01 to 15% by weight of a pH buffering agent; c) 5 to 80% by weight of a water-miscible organic solvent having a boiling point of not less than 140 DEG C and whose 1% by weight aqueous solution has a surface tension of not more than 60 dyn/cm; d) 0.05 to 10% by weight of a compound, for instance, represented by the following general formula (III); and e) 30 to 80% by weight of water: (III) R<8>-Z<1>(R<9>)(R<1><0>)-R<7> . X<1> wherein R<7> to R<1><0> each represents a C1-12 alkyl, cyclic alkyl, hydroxyalkyl, benzyl or substituted or unsubstituted phenyl group; Z<1> represents N, P or B; X<1> represents an anion or cation selected from the group consisting of halogen, nitrate, sulfate, phosphate, hydroxyl, PF6 <-> , BF4 <-> , Li <+> , Na <+> , K <+> and NH4 <+>. The composition shows good printing properties and does not impair image areas of printing plates although it comprises a high boiling point solvent. Further, it provides dampening water having excellent stability with time, satisfies the requirements stipulated in the Japanese Fire Services Act as well as Industrial Safety and Health Law and thus can steadily provide good copies.</p> |
