Fuji Photo Film Company, Limited

Shu Watarai

Seiji Horie

Nobuo Suzuki

Kenji Sano

Kazuo Ishii

Takeshi Takayama

Hideo Sato

Naonori Makino

Hiroaki Yokoya

Hiromichi Tachikawa

A liquid developer for electrostatic photography comprising resin grains dispersed in a non-aqueous solvent having a volume specific resistivity of at least 10.sup.9 .OMEGA.cm, wherein the resin grains are obtained by polymerizing (a) at least one monomer selected from benzyl methacrylate, benzyl acrylate, styrene and a styrene derivative, and (b) at least one monomer selected from acrylic acid esters and methacrylic acid esters having an alkyl group having not more than 3 carbon atoms which are soluble in the non-aqueous solvent but become insoluble therein by being polymerized, in the presence of a dispersion stabilizing resin which mainly comprises a graft copolymer composed of at least one macromonomer (M) containing a polymer component represented by the general formula (Ia) or (Ib) defined herein. The liquid developer is excellent in dispersion stability, and toner images having resist with high resistivity to etching solutions can be formed in electrostatic photography.

Liquid developer for electrostatic photography

A liquid developer for electrostatic photography comprising resin grains dispersed in a non-aqueous solvent having a volume specific resistivity of at least 10.sup.9 .OMEGA.cm, wherein the resin grains are obtained by polymerizing (a) at least one monomer selected from methyl methacrylate and ethyl methacrylate soluble in said non-aqueous solvent and (b) at least one monomer selected from acrylic acid esters and methacrylic acid esters having an alkyl group having not more than 4 carbon atoms which are soluble in the non-aqueous solvent but become insoluble therein by being polymerized, in the presence of a dispersion stabilizing resin which is dissolved or dispersed in a colloidal form in the non-aqueous solvent and which mainly comprises a graft copolymer composed of

A positively chargeable liquid developer for electrostaticphotography comprising a non-aqueous solvent having a volume specific resistance of at least 10.sup.9 .OMEGA.cm and resin grains dispersed therein, wherein the resin grains contain a dispersion stabilizing resin which is dissolved or dispersed in a colloidal form in the non-aqueous solvent and which mainly comprises a graft copolymer composed of (1) at least one macromonomer (M) having a weight average molecular weight of from 1.times.10.sup.3 to 1.times.10.sup.5 obtained by bonding a terminal carboxyl group bonded to the main chain of a polymer containing at least one specific polymer component to an epoxy compound having at least one polymerizable double bond group, using a quaternary ammonium salt as a reaction catalyst, and (2) at least one specific monomer, which gives the definite chargeability, easily controls the charge amount, is excellent in dispersion stability and endures long-term use and storage.

Light-sensitive compositions are provided, containing at least one bisazulenium salt compound of the general formulae (1) and (2): ##STR1## wherein all the symbols are defined in the specification. Electrophotographic photoreceptors containing the present composition have high sensitivity and stable potential characteristic in repeated use. The present compositions are further usable in optical information-recording media, and the media containing the present composition have sufficient preservation stability, high sensitivity and sufficient S/N ratio.

Light-sensitive bisazulenium salt compound compositions and

An electrophotographic light-sensitive material is described, comprising, provided on an electrically conductive support, a light-sensitive layer containing at least one hydrazone compound selected from particular groups of hydrazone compounds.

Electrophotographic light-sensitive hydrazone material

A liquid developer for electrostatic images which comprises toner particles dispersed in a nonaqueous medium having an electrical resistance of 10.sup.9 .OMEGA..multidot.cm or more and a dielectric constant of 3 or less, wherein said toner particles are composed of a resin polymer comprised of monomer units selected from the group of monomers represented by the following formula (I) and a coloring agent: ##STR1## wherein X represents ##STR2## and n represents an integer of 1-6, wherein R.sup.1 and R.sup.2 each represents an alkyl group having 1-18 carbon atoms, and alkyl substituted or nonsubstituted aryl group (the substituent being an alkyl group having 1-12 carbon atoms), or an aralkyl group (substituent alkyl groups in case that the benzene nucleus is substituted by alkyl groups have 1-12 carbon atoms, and the alkylene group has 1-12 carbon atoms).

Liquid developer comprising aminoalkyl styrene polymer for electrostatic

A triphenylmethane polymer, a process for production thereof, and photoconductive compositions and a member containing the polymer are described; the polymer is represented by formula (I) ##STR1## wherein R is an alkyl group, X is H or a methyl group, Z is an alkylene group or a p-xylylene group, Y is H, a methyl group, a methoxy group, a tertiary amino group, halogen, a nitro group or a cyano group, Q is H or a methyl group, and n represents a polymerization degree sufficient to obtain the intrinsic viscosity [.eta.] of the polymer from 0.005 to 1.000.

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Kanagawa, Japan

Shu Watarai