Patent ID: 6402315
Filing Date: 2002-06-11
Classification: C09D

Abstract:
An oil-based ink for an electrostatic ink jet process, comprising:a nonaqueous carrier liquid having an electric resistance of 109 &OHgr;cm or more and a dielectric constant of 3.5 or less; and chargeable resin particles dispersed in the nonaqueous carrier liquid, wherein the resin particles dispersed are copolymer resin particles obtained by 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 monomer (A); and at least one resin for dispersion stabilization (P) which is a polymer soluble in the nonaqueous solvent and comprising a component represented by formula (II) shown below, a part of the polymer main chain being crosslinked: wherein R1 and R2, 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 R1 and R2 may combine with each other to form a ring together with the nitrogen atom in formula (I); wherein V0 represents â€”COOâ€”, â€”OCOâ€”, â€”(CH2)rCOOâ€”, â€”(CH2)rOCOâ€”, â€”Oâ€” or wherein X represents a direct bond, â€”Oâ€”, â€”OCOâ€” or â€”COOâ€”; 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; a1 and a2, which may be the same or different, each independently represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, â€”COOâ€”D1 or â€”COOâ€”D1 linked through a hydrocarbon group, wherein D1 represents a hydrogen atom or a hydrocarbon group.