| 摘要 |
PROBLEM TO BE SOLVED: To obtain an oily ink which is used for electrostatic type ink jets, has excellent ink extrusion stability and excellent brilliant image-forming property, gives images having excellent strengths, and enables the formation of printing plates that can form many printed products having brilliant images. SOLUTION: This oily ink for electrostatic ink jet is obtained by dispersing copolymer resin particles in a non-aqueous carrier liquid having an electric resistance of >=109 Ω.cm and a dielectric constant of <=3.5. The copolymer resin particles are obtained by subjecting a solution containing (A) a monofunctional monomer which is soluble in non-aqueous solvents but can be polymerized into a polymer insoluble in the solvents, (B) a monofunctional monomer which contains an amino group and can be copolymerized with the monomer (A), (C) a monofunctional monomer which contains a SO3H group and/or a SO2H group and can be copolymerized with the monomer (A), (MA) a monofunctional macromonomer in which a polymerizable double bond group is bound to only one end of the main chain of a polymer containing specific structure repeating units, and (P) a dispersion-stabilizing resin which contains a component for solubilizing the resin in a dispersing solvent, to a copolymerizing and particularizing treatment. |
