| 摘要 |
<p>PURPOSE:To raise the orienting property, wear-resisting property and running durability of magnetic video recording tape, by using a specific copolymer of vinyl chloride with vinyl acetate as a binder together with a polyester resin and cellulose nitrate. CONSTITUTION:100 parts by weight of magnetic powder, about 3 to 10 parts by weight of the copolymer consisting of vinyl chloride and vinyl acetate and containing 10% or more by weight of vinyl alcohol, about 5 to 20 parts by weight of the polyester resin, about 3 to 10 parts by weight of cellulose nitrate, 150 to 250 parts by weight of an appropriate solvent and about 1 to 2 parts by weight of a lubricant such as silicone oil are mixed well with one another. Then, an appropriate quantity of a hardener such as polyisocyanate is added to the mixture. The mixture is stirred, thereby preparing a coating liquid. This liquid is coated at a uniform thickness on an appropriate substrate. The resulting magnetic layer is calendered and hardened by heating.</p> |
