Patent ID: 6152037
Filing Date: 2000-11-28
Classification: B41C,B41M,C09D

Abstract:
A method of lithographic printing comprising forming an image based on signals of image data directly on a printing plate precursor mounted on a plate cylinder, of a printing press, thereby preparing a printing plate, and conducting lithographic printing, wherein the formation of the image on the printing plate precursor is carried out by an ink jet recording method in which oil-based ink is ejected utilizing an electrostatic field, wherein the oil-based ink is a dispersion comprising hydrophobic resin particles which are solid in the temperature range from 15.degree. to 35.degree. C. dispersed in a nonaqueous solvent having an electric resistance of 10.sup.9 .OMEGA.cm or more and a dielectric constant of 3.5 or below, the hydrophobic resin particles are stabilized in the non-aqueous solvent by means of a dispersing polymer and the dispersing polymer comprises a repeating unit which is soluble in the nonaqueous solvent and represented by the following formula (I): ##STR4## wherein X.sub.1 represents --COO--, --OCO-- or --O--; R represents an alkyl or alkenyl group having from 10 to 32 carbon atoms; and a.sup.1 and a.sup.2, which may be the same or different, each represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group having from 1 to 3 carbon atoms, --COO--Z.sub.1 or --CH.sub.2 COO--Z.sub.1 wherein Z.sub.1 represents a hydrogen atom or a hydrocarbon group having not more than 22 carbon atoms.