RECORDING MEDIUM AND ITS PRODUCTION

摘要

PURPOSE:To form films not causing peeling or cracking and to improve surface characteristics and durability by forming SiO2 films having a specified thickness by a sol-gel process on the surfaces of the inner and outer circumference edge parts of a glass substrate. CONSTITUTION:When SiO2 films are formed by a sol-gel process on the surfaces of the inner and outer circumference edge parts of a doughnut-shaped glass substrate 1, the thickness of the films 2 is regulated to >=50nm at the peaks of the rugged edge parts so as to prevent the leaching of glass components and it is regulated to <=1mum at the valleys so as to prevent cracking. The films 2 are formed by applying and firing a soln. prepd. by dissolving tetraalkoxysilane in alcohol having a larger mol. wt. than propanol as a solvent. The rate of vapor deposition of the SiO2 films is reduced, cracking is prevented and the durability of the resulting recording medium is improved.