Abstract: A method for producing pressure-responsive particles includes: adding an aggregating agent and a dispersion containing silica particles to a dispersion containing composite resin particles containing a styrene-based resin including a styrene compound and a vinyl monomer other than the styrene compound as polymer components and a (meth)acrylic acid ester-based resin including a (meth)acrylic acid ester compound as a polymer component to cause aggregation so as to form aggregated particles; and heating and fusing the aggregated particles to form pressure-responsive particles. The amount of the silica particles added by the dispersion containing the silica particles is 0.5 mass % or more and 10 mass % or less relative to a total mass of the composite resin particles. The mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin in the pressure-responsive particles is from 80:20 to 20:80.

Abstract: A cellulosic particle contains cellulose as its base constituent, and the percentage water absorption of the cellulosic particle measured by method B in ISO 15512:1999 is 11% or more and 20% or less.

Abstract: Cellulose particles include mother particles, containing cellulose as a principal component; and a coating layer that coats the mother particles, in which the average circularity of the cellulose particles is 0.97 or more, and the relation between carbon atom amount Cs and oxygen atom amount Os in the cellulose particles measured by X-ray photoelectron spectroscopy satisfies the formula A1: Cs/Os?2.0.

Abstract: A method for producing pressure-responsive particles includes: adding an aggregating agent to a dispersion containing composite resin particles containing a styrene-based resin including a styrene compound and a vinyl monomer other than the styrene compound as polymer components and a (meth)acrylic acid ester-based resin including a (meth)acrylic acid ester compound as a polymer component to aggregate the composite resin particles so as to form aggregated particles A; forming a shell by adding an aggregating agent and styrene-based resin particles containing a styrene compound and a vinyl monomer other than the styrene compound as polymer components to a dispersion containing the aggregated particles A to aggregate the styrene-based resin particles so as to form aggregated particles B; and heating and fusing the aggregated particles B to form pressure-responsive particles.

Abstract: Cellulose acetate particles include cellulose acetate as a main component, in which a total degree of acyl substitution of the cellulose acetate is 0.05 or more and less than 0.70.

Abstract: Cellulose particles each include: a base particle containing cellulose as a main component; and a coating layer that covers the base particle and contains a coating material other than a coupling agent.

Abstract: Pressure-responsive particles include pressure-responsive base particles and silica particles, in which the pressure-responsive base particles contain a styrene-based resin that contains styrene and other vinyl monomers as polymerization components and a (meth)acrylic acid ester-based resin that contains at least two kinds of (meth)acrylic acid esters as polymerization components and in which a ratio of a mass of the (meth)acrylic acid esters to a total mass of polymerization components is 90% by mass or more, the pressure-responsive particles have at least two glass transition temperatures, a difference between a lowest glass transition temperature and a highest glass transition temperature is 30° C. or higher, and a ratio of a surface coating rate Cs2 by the silica particles after application of the following first stress to a surface coating rate Cs1 by the silica particles before application of stress satisfies a relationship of 0.4?Cs2/Cs1?0.8.

Abstract: A cellulosic particle contains cellulose as its base constituent, and the percentage water absorption of the cellulosic particle measured by method B in ISO 15512:1999 is 11% or more and 20% or less.

Abstract: A cellulosic particle contains: cellulose as its base constituent; and at least one selected from the group consisting of a hydrocarbon ester and a ketone, and the amount of the hydrocarbon ester or ketone in the cellulosic particle is 3 ppm or more and 1000 ppm or less.

Abstract: A cellulosic particle contains cellulose as its base constituent, and the intensity of sodium fluorescent x-rays from the cellulosic particle measured by x-ray fluorescence analysis is 0.015 kps or more and 0.1 kps or less.

Abstract: A polyimide precursor solution contains: an aqueous solvent containing water; particles; and a polyimide precursor, wherein the polyimide precursor has a high molecular weight region A containing a high molecular weight side maximum value and a low molecular weight region B containing a low molecular weight side maximum value in an elution curve obtained by gel permeation chromatography, a weight average molecular weight in the high molecular weight region A is 50,000 or more, a weight average molecular weight in the low molecular weight region B is 10,000 or more and 30,000 or less, and a value of a/(a+b) is 0.60 or more and 0.98 or less in which a represents an area of the high molecular weight region A and b represents an area of the low molecular weight region B.

Abstract: An electrophotographic photosensitive member includes a conductive support and a photosensitive layer disposed on the conductive support. A top surface layer of the electrophotographic photosensitive member includes fluorine-containing resin particles, a fluorine-containing dispersant, and two or more charge transporting materials. When the charge transporting materials are listed in order of decreasing HOMO energy levels, a difference in HOMO energy level between each adjacent two of the charge The ratio A of the amount of each of the charge transporting materials to the total amount of the charge transporting materials satisfies the condition 1 below, [(100/N)?(100/N×0.3)]?A?[(100/N)+(100/N×0.3)]??Condition 1 where N represents the number of types of the charge transporting materials included in the top surface layer.

Abstract: A polyimide precursor solution includes: a polyimide precursor; polyester resin particles containing a polyester resin and having a volume average particle diameter of from 3 ?m to 50 ?m inclusive and an average circularity of 0.970 or more; and a solvent.

Abstract: A pressure sensitive toner includes toner particles containing a composite resin that includes a styrene-based resin and a (meth)acrylate-based resin. The difference between a lowest glass transition temperature of the composite resin and a highest glass transition temperature thereof is 30° C. or more, and the toner particles have a gel fraction of from 1.0% by mass to 8.0% by mass inclusive.

Abstract: A polyimide precursor solution includes: a polyimide precursor; polyester resin particles containing a polyester resin and having a volume average particle diameter of from 3 ?m to 50 ?m inclusive and an average circularity of 0.970 or more; and a solvent.

Abstract: A polyimide precursor solution includes an aqueous solvent including water, a polyimide precursor, resin particles, and an ionization agent X having a boiling point of 100° C. or more and 130° C. or less and an ionization agent Y having a boiling point of 250° C. or more and 300° C. or less.

Abstract: A polyimide precursor solution includes: a polyimide precursor that is a polymer of a tetracarboxylic dianhydride and a diamine compound; particles; a solvent; and a compound having at least four carboxy groups per molecule.

Abstract: Water purification particles have porous particles and photocatalyst particles formed of titanium-based compound particles that are supported on the porous particles, have absorption at a wavelength of 500 nm in a visible absorption spectrum, and have an absorption peak at 2,700 cm?1 to 3,000 cm?1 in an infrared absorption spectrum, and a metal compound having a metal atom and a hydrocarbon group is bonded to the surface of each of the titanium-based compound particles through an oxygen atom.

Abstract: A polyimide precursor film contains a polyimide precursor, in which a total content of a solvent containing water and a solvent other than water in the polyimide precursor film is 5 mass % or more and 40 mass % or less, and a mass ratio of water to the solvent other than water in the polyimide precursor film is 0 or more and 2.5 or less.

Abstract: A polyimide porous film includes: a polyimide porous film body; and at least one of resin particles and a resin porous film, the at least one of the resin particles and the resin porous film adhering to one surface or both surfaces of the polyimide porous film body, and containing a fluorine-based resin or containing a fluorine-based resin and an acrylic resin.