NOVELTY - A dispersing agent for non-aqueous dispersion medium contains a compound with polymerizable carbon-carbon double bond.    USE - A dispersing agent for non-aqueous dispersion medium used for solid particle dispersion composition used in coating composition for cured material preparation (all claimed). Uses include but not limited to hybrid material, surface-protection agent, electrically conductive paste, electroconductive ink, sensor, accurate analysis element, optical memory, LCD element, nano magnet, heat-transfer medium, high functional catalyst for fuel cells, organic solar cell, nanotechnology glass device, polishing agent, drug carrier, environmental catalyst, coating material, printing ink, ink for inkjets, resist for color filters, ink for writing instruments, optical thin film, adhesive, antireflective film, and hard-coat film.    ADVANTAGE - The dispersing agent exhibits excellent dispersion stability and can improve resin material fall by bleed-out, and the resin cured material has improved hardness, scratch strength, and water resistance.    DETAILED DESCRIPTION - A dispersing agent for non-aqueous dispersion medium contains a compound with polymerizable carbon-carbon double bond formula (1).    R1=6-30C alkyl, alkenyl, or aryl;    R2=group with polymerizable carbon-carbon double bond;    l=1-2;    A1O, A2O=1-4C oxyalkylene;    k, m=0-3;    X=coupling group containing greater than or equal to 1 C, greater than or equal to 1 H, and/or greater than or equal to O;    n=0 or 1; and    Z=COOH, sulfo group, sulfuric ester, or phosphate ester which may form salt.    INDEPENDENT CLAIMS are included for:    (1) solid particle which is formed by coating or impregnating with dispersing agent for non-aqueous dispersion medium;    (2) solid particle dispersion composition which is formed by dispersing organic particles or inorganic particles in non-aqueous dispersion medium using the dispersing agent; and    (3) cured material which is obtained by hardening the coating composition.