Liquid developer for electrostatic photography
AssigneeFuji Photo Film Co., Ltd.
InventorEiichi Kato
Life of this patent
Estimating the term…
Loading patent…
AssigneeFuji Photo Film Co., Ltd.
InventorEiichi Kato
Estimating the term…
A liquid developer for electrostatic photography is disclosed. The liquid developer comprises at least resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA.cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are copolymer resin grains obtained buy polymerizing a solution containing (1) at least one monofunctional monomer (A) which is soluble in the above-described non-aqueous solvent but becomes insoluble therein by being polymerized, (2) at least one monomer (C) which contains a specific substituent and which is copolymerizable with said monofunctional monomer (A) represented by the general formula (I) below, (3) at least one polyfunctional monomer (D) having at least two polymerizable functional groups which are copolymerizable with said monofunctional monomer (A), and (4) at least one dispersion-stabilizing resin (P) soluble in said non-aqueous solvent, which is a polymer containing a repeating unit represented by the general formula (II) and the main chain of said polymer is partially crosslinked, or at least one dispersion-stabilizing resin (P') soluble in the non-aqueous solvent, which is an AB type block copolymer. The liquid developer of the present invention is excellent in dispersibility and redispersibility of resin grains, and resistivity, and provide a master plate for offset printing having high printing durability.
A liquid developer for electrostatic photography comprising at least resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA.cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are copolymer resin grains obtained by polymerizing a solution containing (1) at least one monofunctional monomer (A) which is soluble in said non-aqueous solvent but becomes insoluble therein by being polymerized, (2) at least one monomer (C) represented by the general formula (I) below which contains a specific substituent and which is copolymerizable with said monofunctional monomer (A), (3) at least one polyfunctional monomer (D) having at least two polymerizable functional groups which are copolymerizable with said monofunctional monomer (A), and (4) at least one dispersion-stabilizing resin (P) soluble in said non-aqueous solvent, which is a polymer containing a repeating unit represented by the general formula (II) and the main chain of said polymer is partially crosslinked, or at least one dispersion-stabilizing resin (P') soluble in said non-aqueous solvent, which is an AB block copolymer having a weight average molecular weight from 1.times. 10.sup.4 to 5.times.10.sup.5 composed of an A block containing at least a polymerizable component represented by the general formula (II') described below and a B block comprising a polymerizable component containing at least one polar group selected from a carboxy group, a sulfo group, a hydroxyl group, a formyl group, an amino group, a phosphono group, a ##STR171## group (wherein R.sup.1 represents --R.sup.2 or --OR.sup.2 (wherein R.sup.2 represents a hydrocarbon group)), a ##STR172## group, a ##STR173## group (wherein R.sup.3 and R.sup.4 each represents a hydrogen atom or a hydrocarbon group) and a cyclic acid anhydride-containing group, and/or a polymerizable component corresponding to the monofunctional monomer (A);
Dependencies are inferred from the claim text.