Magnetic recording medium comprising a polyethylene-2,6-naphthalate multilayered film coated on both sides by a coating layer

A magnetic recording medium comprising:

• a stretched polyethylene-2,6-naphthalate multilayered film having a high-roughness surface of a center-line average roughness of 0.001 to 0.010 .mu.m and a low-roughness surface having a center-line average roughness which is less than that of the high-roughness surface and less than 0.004 .mu.m, and wherein the low-roughness surface is on the side of the medium opposite from the high-roughness surface;
• a coating layer (A) comprising a polymeric binder and lubricant particles and having characteristics represented by the formulae
• 0.01.ltoreq.Ha.ltoreq.0.08 (1)
• 10,000.ltoreq.Na.ltoreq.60,000 (2)
• 10.ltoreq.HD.ltoreq.150 (3)
• wherein Ha represents a three-dimensional average protuberance height measured in .mu.m in the surface of the coating layer (A);
• Na represents the number of the protuberances/mm.sup.2 in the surface of the coating layer (A);
• HD represents a surface hardness in units of .mu.m.sup.-2 of the coating layer (A) which is obtained by calculating from Vickers hardness measured by using a dynamic ultra-microhardness tester;
• and wherein coating layer (A) is formed on the high-roughness surface of said multilayered film;
• a coating layer (B) comprising a polymeric compound and having characteristics represented by the formula (4),
• 0.001.ltoreq.Hb.ltoreq.0.008 (4)
• wherein Hb represents a three-dimensional average protuberance height measured in .mu.m in the surface of the coating layer (B);
• and wherein coating layer (B) is formed on the low-roughness surface of said multilayered film;
• and wherein a ferromagnetic metal thin film is formed on said coating layer (B).