A magnetic recording medium that can exhibit good traveling performance during use is provided. This magnetic recording medium is a tape-shaped magnetic recording medium, and includes a substrate including a polyester as a main component, a base layer disposed on the substrate, and a magnetic layer disposed on the base layer. The kurtosis of the surface of the magnetic layer is 3.0 or more. The base layer and the magnetic layer each include a lubricant including a fatty acid and a fatty acid ester. In the lubricant, a ratio of the content of the fatty acid to the content of the fatty acid ester is less than 0.6.

An object is to provide a magnetic recording medium having excellent traveling stability and a thin total thickness.

The present technology provides a tape-shaped magnetic recording medium including: a magnetic layer; an underlayer; a base layer; and a back layer, in which a surface on a side of the magnetic layer has a kurtosis of 3.0 or more, a surface on a side of the back layer has a kurtosis of 2.0 or more, the surface on the magnetic layer side has arithmetic average roughness R.sub.a of 2.5 nm or less, the base layer includes a polyester as a main component, the magnetic recording medium has an average thickness t.sub.T of 5.6 μm or less, the magnetic recording medium includes a lubricant, the lubricant includes a fatty acid and a fatty acid ester, and a mass ratio between the fatty acid and the fatty acid ester extracted with hexane satisfies fatty acid/fatty acid ester ≤0.6, and the magnetic recording medium has pores, and the pores have an average diameter of 6 nm or more and 11 nm or less when the diameters of the pores are measured in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried.

An object is to provide a magnetic recording medium having excellent traveling stability and a thin total thickness.

The present technology provides a tape-shaped magnetic recording medium including: a magnetic layer; an underlayer; a base layer; and a back layer, in which a surface on a side of the magnetic layer has a kurtosis of 3.0 or more, a surface on a side of the back layer has a kurtosis of 2.0 or more, the surface on the magnetic layer side has arithmetic average roughness R.sub.a of 2.5 nm or less, the base layer includes a polyester as a main component, the magnetic recording medium has an average thickness t.sub.T of 5.6 μm or less, the magnetic recording medium includes a lubricant, the lubricant includes a fatty acid and a fatty acid ester, and a mass ratio between the fatty acid and the fatty acid ester extracted with hexane satisfies fatty acid/fatty acid ester ≤0.6, and the magnetic recording medium has pores, and the pores have an average diameter of 6 nm or more and 11 nm or less when the diameters of the pores are measured in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried.

To provide a magnetic recording medium that has excellent traveling stability in spite of having a thin total thickness and a thin thickness of an underlayer, and is suitable for use in a recording/reproducing device for adjusting the width of the magnetic recording medium by adjusting a tension of the magnetic recording medium in a longitudinal direction thereof.

The present technology provides a tape-shaped magnetic recording medium including: a magnetic layer; an underlayer; a base layer; and a back layer, in which the underlayer has a thickness of 0.5 μm or more and 0.9 μm or less, the magnetic recording medium has an average thickness t.sub.T of 5.6 μm or less, the magnetic recording medium includes a lubricant, the magnetic recording medium has pores, and the pores have an average diameter of 6 nm or more and 11 nm or less when the diameters of the pores are measured in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried, and the Young's modulus in a longitudinal direction is 7.90 GPa or less.

To provide a magnetic recording medium that has excellent traveling stability in spite of having a thin total thickness and a thin thickness of an underlayer, and is suitable for use in a recording/reproducing device for adjusting the width of the magnetic recording medium by adjusting a tension of the magnetic recording medium in a longitudinal direction thereof.

The present technology provides a tape-shaped magnetic recording medium including: a magnetic layer; an underlayer; a base layer; and a back layer, in which the underlayer has a thickness of 0.5 μm or more and 0.9 μm or less, the magnetic recording medium has an average thickness t.sub.T of 5.6 μm or less, the magnetic recording medium includes a lubricant, the magnetic recording medium has pores, and the pores have an average diameter of 6 nm or more and 11 nm or less when the diameters of the pores are measured in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried, and the Young's modulus in a longitudinal direction is 7.90 GPa or less.

A magnetic recording medium is a magnetic recording medium in the form of a tape and includes a substrate, a foundation layer provided on the substrate, and a magnetic layer provided on the foundation layer and containing a magnetic powder. The foundation layer and the magnetic layer each contain a lubricant. A squareness ratio of the magnetic layer in a perpendicular direction is equal to or higher than 65%, an average thickness of the magnetic recording medium is equal to or smaller than 5.6 μm, a plurality of recessed portions each having a depth corresponding to 20% or higher of the average thickness of the magnetic layer is provided on a surface of the magnetic layer, and the number of the recessed portions per unit area of 1,600 μm.sup.2 of the surface of the magnetic layer is equal to or greater than 20 and equal to or smaller than 200, and an amount of exudation of the lubricant per unit region of 12.5 μm×9.3 μm on the surface of the magnetic layer in a vacuum is equal to or greater than 3.0 μm.sup.2 and equal to or smaller than 6.5 μm.sup.2.

A magnetic recording medium is a magnetic recording medium in the form of a tape and includes a substrate, a foundation layer provided on the substrate, and a magnetic layer provided on the foundation layer and containing a magnetic powder. The foundation layer and the magnetic layer each contain a lubricant. A squareness ratio of the magnetic layer in a perpendicular direction is equal to or higher than 65%, an average thickness of the magnetic recording medium is equal to or smaller than 5.6 μm, a plurality of recessed portions each having a depth corresponding to 20% or higher of the average thickness of the magnetic layer is provided on a surface of the magnetic layer, and the number of the recessed portions per unit area of 1,600 μm.sup.2 of the surface of the magnetic layer is equal to or greater than 20 and equal to or smaller than 200, and an amount of exudation of the lubricant per unit region of 12.5 μm×9.3 μm on the surface of the magnetic layer in a vacuum is equal to or greater than 3.0 μm.sup.2 and equal to or smaller than 6.5 μm.sup.2.

A tape-shaped magnetic recording medium is provided with a base, an underlayer provided on the base, and a magnetic layer provided on the underlayer including magnetic powder including hexagonal ferrite. The underlayer and the magnetic layer include lubricant. The magnetic layer includes a surface provided with a large number of holes, and arithmetic average roughness Ra of the surface is 2.5 nm or smaller. A BET specific surface area of a whole of the magnetic recording medium in a state in which the lubricant is removed is 3.5 m.sup.2/mg or larger. A square ratio in a vertical direction is 65% or larger, an average thickness of the magnetic layer is 90 nm or smaller, and an average thickness of the magnetic recording medium is 5.6 μm or smaller.

A tape-shaped magnetic recording medium is provided with a base, an underlayer provided on the base, and a magnetic layer provided on the underlayer including magnetic powder including hexagonal ferrite. The underlayer and the magnetic layer include lubricant. The magnetic layer includes a surface provided with a large number of holes, and arithmetic average roughness Ra of the surface is 2.5 nm or smaller. A BET specific surface area of a whole of the magnetic recording medium in a state in which the lubricant is removed is 3.5 m.sup.2/mg or larger. A square ratio in a vertical direction is 65% or larger, an average thickness of the magnetic layer is 90 nm or smaller, and an average thickness of the magnetic recording medium is 5.6 μm or smaller.

The magnetic tape in which the followings are satisfied, after the magnetic layer is pressed at a pressure of 70 atm. A full width at half maximum of a spacing distribution measured by optical interferometry regarding a surface of the magnetic layer before performing a vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 15.0 nm; a full width at half maximum of a spacing distribution measured after performing the vacuum heating is greater than 0 nm and equal to or smaller than 15.0 nm; and a difference (S.sub.after−S.sub.before) between a spacing S.sub.after measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape and a spacing S.sub.before measured before performing the vacuum heating is greater than 0 nm and equal to or smaller than 12.0 nm.