A process for producing a carbonic acid ester is provided, the process comprising a step of synthesizing a saturated alkyl carbonic acid ester represented by Formula (1) so as to give the saturated alkyl carbonic acid ester represented by Formula (1) as a crude product and a step of subjecting the crude product to liquid-liquid extraction using a saturated hydrocarbon solvent and a solvent comprising an organic solvent that is not infinitely miscible with the saturated hydrocarbon solvent so as to give the saturated alkyl carbonic acid ester represented by Formula (1) as a purified product
(in Formula (1), R
1
and R
2
independently denote a saturated hydrocarbon group provided that the sum of the number of carbons in R
1
and the number of carbons in R
2
is at least 12 but no greater than 50). There are also provided a carbonic acid ester produced by the production process, and a magnetic recording medium comprising a non-magnetic support and, above the non-magnetic support, a magnetic layer comprising a ferromagnetic powder dispersed in a binder, the magnetic layer comprising the carbonic acid ester and having on the surface a number of protrusions that satisfies Formula (2)
0.01≦H
15
/H
10
<0.20 (2)
(H
10
denotes the number of protrusions per unit area on the surface of the magnetic layer that have a height of less than 10 nm (number/μm
2
), and H
15
denotes the number of protrusions per unit area on the surface of the magnetic layer that have a height of 15 nm or greater (number/μm
2
)).
提供了一种制备
碳酸酯的工艺,该工艺包括合成由式(1)表示的饱和烷基
碳酸酯的步骤,以便将由式(1)表示的饱和烷基
碳酸酯作为粗产品,并使用饱和烃溶剂和不与饱和烃溶剂无限混溶的有机溶剂的溶剂进行液-液萃取的步骤,以便将由式(1)表示的饱和烷基
碳酸酯作为纯化产品(在式(1)中,R1和R2独立表示饱和烃基,但R1中碳数和R2中碳数之和至少为12但不大于50)。还提供了通过生产工艺生产的
碳酸酯,以及包括非磁性支撑和在非磁性支撑上的磁性层的磁记录介质,其中磁性层包括分散在粘合剂中的
铁磁性粉末,磁性层包括
碳酸酯,并在表面具有满足公式(2)的许多突起0.01≦H15/H10<0.20(2)(其中H10表示磁性层表面每单位面积具有高度小于10 nm的突起的数量(数量/μm2),而H15表示磁性层表面每单位面积具有高度为15 nm或更高的突起的数量(数量/μm2))。