Patent ID: 6302537
Filing Date: 2001-10-16
Classification: B41C,B41J,C09D

Abstract:
An oil-based ink for an electrostatic ink jet process, comprising:a nonaqueous carrier liquid having an electric resistance of 10.sup.9 .OMEGA.cm or more and a dielectric constant of 3.5 or less; andchargeable resin particles dispersed in the nonaqueous carrier liquid,wherein the resin particles dispersed are copolymer resin particles obtained by a polymerization granulation of a solution containing:at least one monofunctional monomer (A) which is soluble in a nonaqueous solvent and becomes insoluble in the nonaqueous solvent by polymerization;at least one monofunctional monomer (B) having an amino group represented by formula (I) shown below and being copolymerizable with the monomer (A); andat least one resin for dispersion stabilization (P) comprising a component represented by formula (II) shown below: ##STR70##wherein R.sup.1 and R.sup.2, which may be the same or different, each independently represents a hydrogen atom or a hydrocarbon group having from 1 to 22 carbon atoms, or R.sup.1 and R.sup.2 may combine with each other to form a ring together with the nitrogen atom in formula (I); ##STR71##wherein, V.sup.0 represents --COO--, --OCO--, (CH.sub.2).sub.r COO--, --(CH.sub.2).sub.r OCO--, --O-- or ##STR72##wherein X represents a direct bond, --O--, --OCO-- or --COO--; r represents an integer of 1 to 12; L represents an alkyl group having from 8 to 32 carbon atoms or an alkenyl group having from 8 to 32 carbon atoms; a.sup.1 and a.sup.2, which may be the same or different, each independently represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, --COO--D.sup.1 or --COO--D.sup.1 linked through a hydrocarbon group, wherein D.sup.1 represents a hydrogen atom or a hydrocarbon group.