Abstract: A particle including a polymer which has a repeating unit derived from a vinyl-based monomer. The particle has a specific structure containing a carboxy group, and a surface of the particle contains a water-soluble polymer.

Abstract: Provided is a liquid developer containing a carrier liquid with an SP value of not more than 8.20, a toner particle that is insoluble in the carrier liquid, and a toner particle dispersing agent, wherein the toner particle contains a polyester resin with an acid value of from 5 mg KOH/g to 50 mg KOH/g, a number-average molecular weight of the polyester resin is from 3,500 to 20,000, the toner particle dispersing agent is a polymer having a primary amino group, an amine value of the polymer having the primary amino group is from 30 mg KOH/g to 200 mg KOH/g, and a ratio of a total number of acid groups in the polyester resin relative to a total number of amino groups in the polymer having the primary amino group is from 1.0 to 10.0.

Abstract: Provided are a latex agglutination reagent containing polyoxazoline that is preferable for use in a latex agglutination reaction and has a high sensitization action of sensitivity while a non-specific reaction can be suppressed, and a method for measuring a target substance in a specimen by a latex agglutination method. A latex agglutination reagent used in a method for measuring a target substance in a specimen by a latex agglutination method using an insoluble carrier that carries an antibody or an antigen contains polyoxazoline having a repeating unit represented by the following General Formula (in Formula (1), R represents a hydrogen atom or a methyl group, an ethyl group, or a propyl group, and n is an integer of 100 or greater).

Abstract: To provide a method for producing a particle that can suppress non-specific adsorption without using BSA. A method for producing a particle, including: a first step of mixing a radically polymerizable monomer, an organic silane compound having a silicon atom to which an alkoxy group is bonded and having radical polymerizability, a radical polymerization initiator, a water-soluble polymer, and an aqueous medium to prepare an emulsion; and a second step of adding a specific reactive compound after the first step.

Abstract: The particle is a particle including, in a surface layer thereof, a copolymer having a repeating unit A having a side chain A having, at a terminal thereof, a carboxy group to be bonded to a ligand and a repeating unit B having a side chain B having a hydroxy group at a terminal thereof, wherein when the particle is dispersed in ion-exchanged water, the surface layer of the particle is hydrated to form a swollen layer, wherein the density of the carboxy groups to be incorporated into the swollen layer satisfies a value of from 0.04 group/nm3 to 0.15 group/nm3, and wherein the ratio of a particle diameter in water to be measured when the particle is dispersed in ion-exchanged water to a dry particle diameter to be measured when the particle is dried satisfies a value of from 1.10 to 1.40.

Abstract: Provided is a magnetic particle excellent in detection speed when a substance to be measured, such as an antigen or an antibody, is detected from a specimen. The particle includes a magnetic particle containing a magnetic material, wherein the magnetic particle has a resin on a surface, wherein the particle has a volume average particle diameter of 0.4 ?m or more and 1.5 ?m or less, wherein the particle has a density of 5.1 g/cm3 or more and 10.0 g/cm3 or less, and wherein the resin has a functional group capable of binding a ligand.

Abstract: The present disclosure provides a particle showing a small non-specific adsorption, having a reactive functional group for chemically bonding a ligand thereto, and being suitable for an agglutination method; a particle for the agglutination method having a ligand chemically bonded to the particle; a reagent, a kit and a method for detecting a target substance, each for in vitro diagnosis, each of which contains the particle. The particle includes a polymer having a unit having a linker A in a side chain, wherein when both terminals of the linker A are represented by X1 and X2, the linker A has a reactive functional group for chemically bonding a ligand thereto in one of X1 and X2; one of X1 and X2 includes an ester structure; and a sum of bonds between atoms linearly connecting X1 and X2 is 18 to 24 and the X1 and X2 contain CH2 or CH.

Abstract: The present invention provides a particle that shows a small non-specific adsorption, has a reactive functional group for chemically bonding a ligand thereto, and is suitable for an agglutination method. The particle includes a polymer having a unit having a side chain A and a unit having a side chain B, wherein the side chain A has a carboxyl group at a terminal thereof, and has an ester bond and an amide bond in a molecular structure thereof; the side chain B has an alkyl group at a terminal thereof; and a zeta potential at the time when the particles are dispersed in water is minus 40 mV or higher and minus 5 mV or lower.

Abstract: Provided is a liquid developer containing a carrier liquid with an SP value of not more than 8.20, a toner particle that is insoluble in the carrier liquid, and a toner particle dispersing agent, wherein the toner particle contains a polyester resin with an acid value of from 5 mg KOH/g to 50 mg KOH/g, a number-average molecular weight of the polyester resin is from 3,500 to 20,000, the toner particle dispersing agent is a polymer having a primary amino group, an amine value of the polymer having the primary amino group is from 30 mg KOH/g to 200 mg KOH/g, and a ratio of a total number of acid groups in the polyester resin relative to a total number of amino groups in the polymer having the primary amino group is from 1.0 to 10.0.

Abstract: A liquid developer comprising a carrier liquid, a toner particle insoluble in the carrier liquid, and a polymer having a primary amino group and soluble in the carrier liquid, wherein the toner particle comprises a polyester resin having an acidic group, an acid value of the polyester resin is at least 5 mg KOH/g, a pKa of the acidic group is not more than 3.4, and the polymer having a primary amino group has a primary amino group at a position other than the end of a main chain of the polymer, and method of producing thereof.

Abstract: A method for producing a liquid developer, the method including a step of producing a toner particle by applying a shear force to a mixture of a polyester resin A and B, and a toner particle dispersing agent in a liquid a, wherein the polyester resin A has a number-average molecular weight from 3,000 to 7,000, an acid value of at least 5, and a carboxy group; the polyester resin B has a number-average molecular weight from 4,000 to 20,000 and an acid value of not more than 2; the toner particle dispersing agent has a primary amino group and an amine value of at least 40; the mass ratio (B/(A+B)) for the polyester resin B is 0.3 to 0.9; and the following relationship is satisfied: SP value of liquid a<SP value of the toner particle dispersing agent<SP value of polyester resin B.

Abstract: Provided is a liquid developer with excellent image quality, fixability and storage stability, containing a toner particle with both good dispersion stability and good surface smoothness, the liquid developer contains an insulating liquid and a toner particle that is insoluble in the insulating liquid, and the toner particle contains a colorant having an acidic group and a binder resin, or a colorant and a binder resin having an acidic group, and a polyamine compound.

Abstract: A method for producing a liquid developer, the method including a step of producing a toner particle by applying a shear force to a mixture of a polyester resin A and B, and a toner particle dispersing agent in a liquid a, wherein the polyester resin A has a number-average molecular weight from 3,000 to 7,000, an acid value of at least 5, and a carboxy group; the polyester resin B has a number-average molecular weight from 4,000 to 20,000 and an acid value of not more than 2; the toner particle dispersing agent has a primary amino group and an amine value of at least 40; the mass ratio (B/(A+B)) for the polyester resin B is 0.3 to 0.9; and the following relationship is satisfied: SP value of liquid a<SP value of the toner particle dispersing agent<SP value of polyester resin B.

Abstract: The liquid developer according to the present invention includes a toner particle containing a polyester resin and a pigment and includes a carrier liquid comprising a nonaqueous solution, the polyester resin contains a monomer unit derived from trimellitic acid, and the content of the monomer unit derived from trimellitic acid in the total acid component-derived monomer unit constituting the polyester resin is from 2.0 mol % to 60.0 mol %, the polyester resin also contains a monomer unit derived from an ethylene oxide adduct on bisphenol A, and the content of the monomer unit derived from the ethylene oxide adduct on bisphenol A in the total alcohol component-derived monomer unit constituting the polyester resin is from 50.0 mol % to 100.0 mol %, and the average circularity of the toner particle is at least 0.950.

Abstract: A liquid developer comprising a carrier liquid, a toner particle insoluble in the carrier liquid, and a polymer having a primary amino group and soluble in the carrier liquid, wherein the toner particle comprises a polyester resin having an acidic group, an acid value of the polyester resin is at least 5 mg KOH/g, a pKa of the acidic group is not more than 3.4, and the polymer having a primary amino group has a primary amino group at a position other than the end of a main chain of the polymer, and method of producing thereof.

Abstract: A curable liquid developer containing: a toner particle containing a pigment and a binder resin; a toner particle dispersing agent; and a cationically polymerizable liquid monomer, wherein the binder resin contains a polyester resin having an acid value of at least 5 mg KOH/g; the polyester resin contains an alcohol component-derived monomer unit and an acid component-derived monomer unit; the alcohol component-derived monomer unit and the acid component-derived monomer unit contain specific monomer units in specific proportions; and the content of the polyester resin in the binder resin is at least 50 mass % and not more than 100 mass %.

Abstract: A curable liquid developer production method that can efficiently produce a curable liquid developer is provided. A curable liquid developer is also provided. The method is a method of producing a curable liquid developer containing a pigment, a binder resin, a toner particle dispersing agent, and a curable insulating liquid, this method including: a pigment dispersion step of preparing a pigment dispersion containing a pigment, a binder resin, a toner particle dispersing agent, and a solvent; a mixing step of mixing the pigment dispersion with a curable insulating liquid; and a distillative removal step of distillatively removing the solvent from a mixture obtained in the mixing step.

Abstract: A method for producing a curable liquid developer including a toner particle including a colorant and a binder resin, a dispersant, and an insulating liquid (a) which does not dissolve the binder resin, the method including a step (1) of preparing a liquid mixture including the colorant, the binder resin, the insulating liquid (a), a solvent (b) which dissolves the binder resin, and the dispersant which is soluble in both the insulating liquid (a) and the solvent (b), and a step (2) of distilling off the solvent (b), wherein the insulating liquid (a) includes a monomer having a polymerizable functional group, and a molar average number of functional groups, a molar average SP value and an average molecular weight of the insulating liquid (a) are in specific range.

Abstract: A curable liquid developer production method that can efficiently produce a curable liquid developer is provided. A curable liquid developer is also provided. The method is a method of producing a curable liquid developer containing a pigment, a binder resin, a toner particle dispersing agent, and a curable insulating liquid, this method including: a pigment dispersion step of preparing a pigment dispersion containing a pigment, a binder resin, a toner particle dispersing agent, and a solvent; a mixing step of mixing the pigment dispersion with a curable insulating liquid; and a distillative removal step of distillatively removing the solvent from a mixture obtained in the mixing step.

Abstract: The ultraviolet-curable liquid developer contains a hydrophobic cationically polymerizable liquid monomer, a photopolymerization initiator, a toner particle insoluble in the liquid monomer, and a toner particle dispersing agent, wherein the toner particle contains a binder resin that has an acid value of at least 5 mg KOH/g; the toner particle dispersing agent is a polymer that contains at least both a monomer unit represented by general formula (1) and a monomer unit represented by general formula (2); and the toner particle dispersing agent has a monomer unit represented by general formula (1) at a position other than the terminal position.