| 摘要 |
PURPOSE:To obtain a lubricating composition which can be firmly held by the protective layer of a recording medium and has excellent sliding properties and sufficient durability by mixing a silicone oil and a fatty-acid-modified silicone as the essential components with a fatty acid ester as an optional component. CONSTITUTION:The composition comprises a silicone oil (a) and a fatty-acid- modified silicone (b) of the formula (wherein R is an aliphatic hydrocarbon group; m is 5-500; and n is 1 or greater) as the essential components and a fatty acid ester (c) as an optional component and satisfying the relationships: 0.1<=a/(a+b)<=0.98, 0.5<=b/(b+c)<=0.9, and 0.01<=c/(c+a)<=0.1 (wherein a, b and c are the amounts (pts.wt.) of the components, respectively) and the relationships: 1<=Ma/Mb<=100, 2<=Mb/Mc<=50, and 0.002<=Mc/Ma<=0.2 (wherein Ma, Mb and Mc are the number-average molecular weights, respectively). A recording medium which slidably contacts with the head is prepared by forming a recording layer on a transparent disc base, forming a protective coating layer comprising a synthetic resin on the recording layer, and applying the lubricating composition to form a 1nm to 1mum-thick lubricating layer on the protective layer. |
