| 摘要 |
<p>A magnetic recording element comprises a support bearing a magnetic coating comprising (i) a polyester urethane binder, (ii) a magnetic pigment uniformly dispersed in the binder, (iii) 1-10 wt.% w.r.t. (ii) of a dispersing agent for the (ii) consisting a a polyester urethane having a mol. wt. of 1000-10,000, and opt. (iv) a wetting agent used in an amt. of at most 1 wt.% w.r.t. (ii). Spec. the dispersing agent (ii) is prepd. e.g.50,000-150,000, by treatment with an acid or base in an organic medium to give the desired mol. wt. of 1000-10,000, followed by neutralisation.</p> |
