Abstract: A resin particle having a sufficiently narrow particle size distribution obtainable by using a supercritical fluid, and a production method for obtaining a resin particle having a sufficiently narrow particle size distribution by using a supercritical fluid are provided. The present invention provides a resin particle (C) having a microparticle (A) fixed to or formed as a film on a surface of a resin particle (B) containing a resin (b), wherein the degree of swelling of the microparticle (A) by liquid or supercritical carbon dioxide (X) at a temperature lower than the glass transition temperature or the melting point of the microparticle (A) is 16% or less, and the microparticle (A) is at least one kind selected from the group consisting of a crystalline resin (a1), a noncrystalline resin (a2), and an inorganic compound (a3).

Abstract: A resin particle having a sufficiently narrow particle size distribution obtainable by using a supercritical fluid, and a production method for obtaining a resin particle having a sufficiently narrow particle size distribution by using a supercritical fluid are provided. The present invention provides a resin particle (C) having a microparticle (A) fixed to or formed as a film on a surface of a resin particle (B) containing a resin (b), wherein the degree of swelling of the microparticle (A) by liquid or supercritical carbon dioxide (X) at a temperature lower than the glass transition temperature or the melting point of the microparticle (A) is 16% or less, and the microparticle (A) is at least one kind selected from the group consisting of a crystalline resin (a1), a noncrystalline resin (a2), and an inorganic compound (a3).

Abstract: A photosensitive resin having at least one group as shown below in Chemical Formula (1) in a molecule. ##STR1## wherein n represents an integer from 1 to 10. Since the photosensitive resin has an azido group in a molecule having an adsorption region higher than 300 nm, the resin is highly sensitive. Therefore, an emulsion coating photo mask or a soda glass photo mask, which allows light permeation within the abosorption region of the azido group and is cheap in industry, can be used as the photo mask for the photosensitive resin of the invention. The photosensitive resin is particularly useful as a photo resist.