NOVELTY - Inorganic oxide particle-containing silicone resin sheet, comprises a silicone resin composition comprising a crosslinked structure in which an inorganic oxide particle dispersed in a polysiloxane resin and the polysiloxane resin are crosslinked through a chemical bond.    USE - The inorganic oxide particle-containing silicone resin sheet is useful for applications requiring size reduction, thickness reduction and weight reduction e.g. as surface sheets of flexible displays, flexible solar cells and organic LED illuminations, and as sheets attached on curved surfaces.    ADVANTAGE - The resin sheet: has a tensile elongation of 5-15%; has a tensile elastic modulus of 50-250 MPa; exhibits a 5% weight loss temperature of greater than or equal to 380 degrees C; at thickness of 100 mu m, has a total light transmittance of greater than or equal to 88%; has a tensile strength of greater than or equal to 8 N/mm2 (claimed); and thus exhibits high heat resistance and strength, excellent flexibility and excellent transparency.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a primer composition (for a carboxy group-containing adhesive, and used for a pressure-sensitive adhesive sheet (4) having a pressure-sensitive adhesive layer (3) comprising a carboxy group-containing polymer as a base polymer) comprising a crosslinked structure in which a polysiloxane compound is crosslinked through a chemical bond to a surface of a core comprising an inorganic oxide particle; and    (2) a pressure-sensitive adhesive sheet (having a base material (1) and the pressure-sensitive adhesive layer) comprising an undercoat layer (2) formed of the primer composition between the base material and the pressure-sensitive adhesive layer, where the carboxy group-containing polymer is an acrylic polymer containing 1-10 wt.% of a structural unit originated from a carboxy group-containing monomer based on all monomer structural units.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic enlarged cross-sectional diagram of the pressure-sensitive adhesive sheet.    Base material (1)    Undercoat layer (2)    Pressure-sensitive adhesive layer (3)    Pressure-sensitive adhesive sheet (4)