Abstract: There is provided a pigment dispersant that is a block polymer P in which a hydrophobic polymer block A and a hydrophilic polymer block B containing an anionic group are linked to each other. The block polymer P has a number average molecular weight ranging from 1000 to 4000; and where the block polymer P is subjected to 100% neutralization of the anionic group with a basic compound and dispersed in water and where the fine particles of the dispersed block polymer P are subjected to measurement of a scattering profile by small- or ultra-small-angle X-ray scattering that involves use of synchrotron radiation, at least one minimum value in the scattering profile is present within the range of a scattering vector q from 0.1 to 1 nm?1. There is also provided an aqueous pigment dispersion containing the pigment dispersant, a pigment, a basic compound, and an aqueous medium.

Abstract: There is provided a pigment dispersant that is a block polymer P in which a hydrophobic polymer block A and a hydrophilic polymer block B containing an anionic group are linked to each other. The block polymer P has a number average molecular weight ranging from 1000 to 4000; and where the block polymer P is subjected to 100% neutralization of the anionic group with a basic compound and dispersed in water and where the fine particles of the dispersed block polymer P are subjected to measurement of a scattering profile by small- or ultra-small-angle X-ray scattering that involves use of synchrotron radiation, at least one minimum value in the scattering profile is present within the range of a scattering vector q from 0.1 to 1 nm?1. There is also provided an aqueous pigment dispersion containing the pigment dispersant, a pigment, a basic compound, and an aqueous medium.

Abstract: An absorbent material which comprises an absorbent resin containing a polyacidic amino acid as a constituent component of the resin and having a structure in which primary particles are agglomerated and including pores having a total pore volume as measured by a mercury penetration method of 0.5 to 5.0 cm3/g.

Abstract: An image forming apparatus includes a developing unit for toner-developing a latent image formed on a photoreceptor, and a dual-component developer consisting of carrier particles and toner particles is contained in the developing unit. A toner concentration in the developing unit is sensed by a magnetic sensor. An output voltage of the magnetic sensor is applied to a microcomputer through an analog-to-digital converter. The microcomputer sets a toner supply time in accordance with a fuzzy inference based on the output voltage of the magnetic sensor and a change amount of the output voltage of the magnetic sensor. A toner supply motor is driven for the set time. Consequently, the toner supply roller supplies toner particles to the developing unit from a toner box.