METHOD FOR THE PRODUCTION OF GLASS SUBSTRATES FOR MAGNETIC RECORDING MEDIUMS.

摘要

A METHOD FOR THE PRODUCTION OF A GLASS SUBSTRATE FOR MAGNETIC RECORDING MEDIUMS IS HEREIN PROVIDED AND THIS METHOD IS CHARACTERIZED IN THAT THE FINAL CLEANING STEP IS PERFORMED IN TWO STAGES1 IN WHICH SCRUBBING AND DIP-CLEANING STEPS ARE CARRIED OUT AFTER THE COMPLETION OF THE FIRST CLEANING STAGE AND AFTER THE GROWTH OF NEEDLE-LIKE PROJECTIONS COMPRISING AN ALKALI METAL CARBONATE ON THE SURFACE OF THE GLASS SUBSTRATE. THE METHOD FOR THE PRODUCTION OF A GLASS SUBSTRATE FOR MAGNETIC RECORDING MEDIUMS DOES NOT REQUIRE THE USE OF AN EXPENSIVE DEVICE HAVING HIGH RESISTANCE TO ACIDS. MOREOVER, IN THE GLASS SUBSTRATE FOR MAGNETIC RECORDING MEDIUMS PRODUCED BY THE FOREGOING METHOD, ANY GROWTH OF NEED1E-LIKE PROJECTIONS CONTAINING AN ALKALI METAL CARBONATE ON THE SURFACE OF THE GLASS SUBSTRATE IS INHIBITED EVEN DURING TEMPORAL STORAGE OF THE SUBSTRATE.