Improvement of a crosslinking reactivity of polyvinyl acetal as alternatives for polyvinyl chloride

摘要

In order to conserve the global environment and improve the performance of the particulate magnetic recording media, a new binder material, Polyvinyl Acetal (PVAc) is developed to replace the current, polyvinyl chloride (PVC). PVAc synthesized from the condensation of polyvinyl alcohol and aldehyde has sulfonate group to disperse magnetic particles (Fig. 1). The magnetic tape used PVAc was slightly superior to PVC in the magnetic and electromagnetic properties [1]. In the coating formulation of particulate media, isocyanate derivatives are added as hardening agents and cured at an elevated temperature to improve mechanical and thermal properties. In this paper, the reactivity of isocyanate with PVAc was examined in order to improve durability from the point of the arrangement of the hydroxyl group.