Magnetic recording medium having a magnetic layer with specified limits of both RA and R10Z surface roughness

Abstract

Disclosed are a magnetic recording medium which comprises a non-magnetic support, one or more coating layers provided on the non-magnetic support and an upper layer of the coating layers being a magnetic layer containing ferromagnetic metallic powder with the total thickness of the coating layers being 0.5 to 2.5 .mu.m, wherein the magnetic layer has a surface roughness Ra of 1.0 to 4.6 nm and a surface roughness R10z of 8.0 to 35.0 nm, which satisfy the relations of:Ra.ltoreq.-0.47t+0.5/t+3.8 andR10z.ltoreq.-1.50t+6.0/t+23.0where t is the total thickness of the coating layers in terms of .mu.m,and an aliphatic acid ester is contained in the surface portion of the magnetic layer in an amount of 5 to 50 mg/m.sup.2, and a process for preparing the same.

Claims

2. The medium of claim 1 wherein the medium has a total thickness of 7.5.mu.m or less.

3. The medium of claim 1 wherein the non-magnetic powder is at least one selected from the group consisting of carbon black, CaCO.sub.3, TiO.sub.2, barium sulfate,.alpha.-Al.sub.2 O.sub.3,.alpha.-Fe.sub.2 O.sub.3,.alpha.-FeOOH and Cr.sub.2 O.sub.3.

5. The process of claim 4, wherein said kneading device is a pressure kneader or a continuous kneader.