Abstract: An inkjet ink that contains at least water; a water-soluble organic solvent; a pigment; and a copolymer or a salt thereof. The copolymer or the salt thereof has at least a structural unit represented by Formula 1, a structural unit represented by Formula 2, and a structural unit represented by Formula 3 or 4. In Formula 1, R1 represents a methyl group or a hydrogen atom, M+s each represent a hydrogen ion, an alkali metal ion, or an organic ammonium ion, and m and n each, independently represent 0 or an integer of from 1 to 6 excluding a case of both m and n being 0 at the same time. In Formula 2, R2 represents a methyl group or a hydrogen atom. In Formula 3, R3 represents a methyl group or a hydrogen atom.

Abstract: An ink for inkjet recording, which is used for recording on a paper having a concentration of an eluted Ca ion of from 1.0×10?4 to 5.0×10?4 g/g when dipped in pure water. The ink includes at least a pigment, a pigment dispersant, a water-soluble organic solvent and water. The pigment dispersant is a copolymer synthesized using at least (1) unsaturated ethylene monomer having a phosphoric acid group or a phosphonic acid group and (2) unsaturated ethylene monomer having an alkyl group having 12 to 22 carbon atoms.

Abstract: An electrophotographic photoconductor including: an electrically conductive substrate; and at least a photoconductive layer on the electrically conductive substrate, wherein the electrophotographic photoconductor includes an uppermost surface layer, and the uppermost surface layer includes an inorganic filler, an acidic disperser and a three-dimensionally crosslinked polymer, wherein the three-dimensionally crosslinked polymer is formed through polymerization among compounds each containing a charge transporting compound and three or more [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups where the charge transporting compound has one or more aromatic rings and the [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups are bound to the aromatic rings of the charge transporting compound, and wherein the polymerization proceeds after some of the [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups have been partially cleaved and eliminated with an acid catalyst.

Abstract: An image bearing member includes a substrate, and a photosensitive layer overlying the substrate, wherein an uppermost surface layer of the image bearing member has a hydrocarbon compound represented by the following Chemical Formula 1; and a three-dimensionally cross-linked polymer formed by polymerization reaction of a charge transport compound having three or more [tetrahydro-2H-pyran-2-yl)oxy]methyl groups linked with aromatic rings, wherein, in the polymerization reaction, part of the three or more [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups is severed and detached from the charge transport compound, Ph1-Q1-Ph2-Q2-Ph3??Chemical Formula 1 where Q1 and Q2 independently represent methylene groups or ethylene groups, Ph1 and Ph3 independently represent phenyl groups with which one or two methyl groups are bonded, and Ph2 represents a phenylene group or a phenylene group having one methyl group.

Abstract: An ink for inkjet recording includes water; a water-soluble solvent; a pigment; and a copolymer including a salt of phosphonic acid group.

Abstract: An ink for inkjet recording includes water, a water-soluble solvent, a pigment and a copolymer including a salt of phosphonic acid group. The copolymer including a salt of phosphonic acid group includes structural units having the following formulae (1) and (2) or (3): wherein not less than half or all of M+ represent a cation of alkali metals or an organic ammonium ion, and the rest represents proton; wherein Ar1 represents a monovalent group of benzene or naphthalene; and wherein R1 represents an alkyl group having 5 to 20 carbon atoms.

Abstract: An ink composition contains a pigment represented by the following chemical formula 1; a hydrosoluble solvent; and water, wherein the pigment satisfies the following relation 1: 0.040<Y/X<0.200 (Relation 1), where, in a CuK? X-ray diffraction spectrum having a wavelength of 1.541 ?, X represents a peak intensity at a Bragg (2?±0.2°) angle in a range of 2? of from 26.5° to 27.5° and Y represents a peak intensity at a Bragg (2?±0.2°) angle in a range of 2? of from 11.0° to 11.

Abstract: A photoreceptor including an electroconductive substrate; and a photosensitive layer overlying the electroconductive substrate, wherein the uppermost surface layer of the photosensitive layer has a three-dimensional cross-linked product formed by polymerization reaction of a charge transport compound A represented by the following Chemical Structure 1 and a charge transport compound B having three or more [tetrahydro-2H-pyran-2-yl)oxy]methyl groups linked with aromatic rings in which part of the [tetrahydro-2H-pyran-2-yl)oxy]methyl groups is severed and detached. In the Chemical Structure 1, Ar1 represents an aromatic hydrocarbon group having 6 to 20 carbon atoms that may have an alkyl group having one to four carbon atoms as a substitution group.

Abstract: An electrophotographic photoconductor including: a conductive substrate; and at least a photoconductive layer on the conductive substrate, wherein an uppermost surface layer of the photoconductive layer includes a three-dimensionally crosslinked film formed through polymerization among compounds each containing a charge transporting compound and three or more [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups where the charge transporting compound has one or more aromatic rings and the [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups are bound to the aromatic rings of the charge transporting compound, wherein the polymerization starts after some of the [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups have been partially cleaved and eliminated, and wherein the three-dimensionally crosslinked film has a dielectric constant of lower than 3.5.

Abstract: An electrophotographic photoconductor including: a conductive substrate; and at least a photoconductive layer on the conductive substrate, wherein an uppermost surface layer of the photoconductive layer includes a three-dimensionally crosslinked film formed through polymerization among compounds each containing a charge transporting compound and three or more [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups where the charge transporting compound has one or more aromatic rings and the [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups are bound to the aromatic rings of the charge transporting compound, wherein the polymerization starts after some of the [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups have been partially cleaved and eliminated, and wherein the three-dimensionally cross-linked film has an ionization potential of 5.4 or higher.

Abstract: An electrophotographic photoconductor including: an electrically conductive substrate; and at least a photoconductive layer on the electrically conductive substrate, wherein the electrophotographic photoconductor includes an uppermost surface layer, and the uppermost surface layer includes an inorganic filler, an acidic disperser and a three-dimensionally crosslinked polymer, wherein the three-dimensionally crosslinked polymer is formed through polymerization among compounds each containing a charge transporting compound and three or more [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups where the charge transporting compound has one or more aromatic rings and the [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups are bound to the aromatic rings of the charge transporting compound, and wherein the polymerization proceeds after some of the [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups have been partially cleaved and eliminated with an acid catalyst.

Abstract: A photoreceptor including an electroconductive substrate; and a photosensitive layer overlying the electroconductive substrate, wherein the uppermost surface layer of the photosensitive layer has a three-dimensional cross-linked product formed by polymerization reaction of a charge transport compound A represented by the following Chemical Structure 1 and a charge transport compound B having three or more [tetrahydro-2H-pyran-2-yl)oxy]methyl groups linked with aromatic rings in which part of the [tetrahydro-2H-pyran-2-yl)oxy]methyl groups is severed and detached. In the Chemical Structure 1, Ar1 represents an aromatic hydrocarbon group having 6 to 20 carbon atoms that may have an alkyl group having one to four carbon atoms as a substitution group.