Patent ID: 8197741

Claim:
A method for producing a clay thin film, which is formed of clay alone or in combination with an additive and has a structure where oriented clay particles are laminated, the method comprising: paste-making in which clay alone or in combination with an additive are dispersed in a dispersion medium formed of water, an organic solvent, or a mixed solvent of water and an organic solvent to prepare clay paste; coating in which a thin film is formed by coating the clay paste on a substrate; planarization in which the thin film is planarized; drying in which the water, the organic solvent, or the water and the organic solvent are removed from the thin film; and separation in which the thin film is separated from the substrate, wherein the planarization comprises a treatment using a roll having a degree of flatness of 100 nm or less in terms of surface roughness Ra and wherein the total light transmittance of the thin film is not less than 80% and haze is not more than 5%.