A magnetic recording disk having a flexible non-magnetic support, a non-magnetic layer of 0.5 to 5 µm thick which is arranged on the support and is composed of a non-magnetic inorganic powder, a lubricant and carbon black in a binder, and a magnetic layer of 0.02 to 0.5 µm thick which is composed of a ferromagnetic powder and a lubricant in a binder and has been formed on the non-magnetic layer when the non-magnetic layer has had wet surface is improved by the use of a non-magnetic inorganic powder having two or more kinds of non-magnetic inorganic powders of different mean particle sizes, one of which has a mean particle size of 10-80% of the thickness of the non-magnetic layer and another of which has a mean particle size of 0.5-10% of the thickness of the non-magnetic layer. The former large powder and the latter small powder should be contained in a weight ratio of 3:97 to 40:60.
一种磁记录磁盘,它有一个柔性非磁性支架,一个厚度为 0.5 至 5 微米的非磁层,它排列在支架上,由粘结剂中的非磁性无机粉末、润滑剂和碳黑组成,以及一个厚度为 0.02 至 0.5 微米的磁层,它由粘结剂中的
铁磁性粉末和润滑剂组成,在非磁层表面
潮湿时形成在非磁层上。5微米厚的磁性层,该磁性层是在非磁性层表面
潮湿时,由粘结剂中的
铁磁性粉末和润滑剂组成并在非磁性层上形成的,通过使用具有两种或两种以上平均粒度不同的非磁性无机粉末的非磁性无机粉末进行改进,其中一种粉末的平均粒度为非磁性层厚度的10-80%,另一种粉末的平均粒度为非磁性层厚度的0.5-10%。前一种大粉末和后一种小粉末的重量比为 3:97 至 40:60。