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 number of recesses having a depth of 20% or more of the thickness of the magnetic layer is 10 or more and 200 or less per surface area of 1600 μm.sup.2, the base layer includes a polyester as a main component, a surface on a side of the back layer has a kurtosis of 2.0 or more and 4.4 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.

Provided are a magnetic tape including: a non-magnetic support; a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support, in which an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5, and an isoelectric point of a surface zeta potential of the back coating layer is equal to or greater than 4.5, a magnetic tape cartridge, and a magnetic tape apparatus including this magnetic tape.

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 the number of recesses having a depth of 20% or more of the thickness of the magnetic layer is 10 or more and 200 or less per surface area of 1600 μm.sup.2, the base layer includes a polyester as a main component, a surface on a side of the back layer has a kurtosis of 2.0 or more and 4.4 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.

Provided are: a magnetic recording medium including a non-magnetic support and a magnetic layer containing a ferromagnetic powder, in which the ferromagnetic powder is an ε-iron oxide powder, a vertical magnetization amount Φm per unit area of the magnetic recording medium is 5 G.Math.μm or more and 100 G.Math.μm or less at a measurement temperature of 25° C., and an inclination of Φm obtained from Φm at a measurement temperature of 10° C., Φm at a measurement temperature of 25° C., and Φm at a measurement temperature of 40° C. is −0.20 G.Math.μm/° C. or more and −0.03 G.Math.μm/° C. or less; a magnetic tape cartridge including the magnetic recording medium which is a magnetic tape; and a magnetic recording and reproducing device including the magnetic recording medium.

Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.

Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.

Provided are: a magnetic recording medium including a non-magnetic support and a magnetic layer containing a ferromagnetic powder, in which the ferromagnetic powder is an ε-iron oxide powder, a vertical magnetization amount Φm per unit area of the magnetic recording medium is 5 G.Math.μm or more and 100 G.Math.μm or less at a measurement temperature of 25° C., and an inclination of Φm obtained from Φm at a measurement temperature of 10° C., Φm at a measurement temperature of 25° C., and Φm at a measurement temperature of 40° C. is −0.20 G.Math.μm/° C. or more and −0.03 G.Math.μm/° C. or less; a magnetic tape cartridge including the magnetic recording medium which is a magnetic tape; and a magnetic recording and reproducing device including the magnetic recording medium.

Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.

The magnetic recording medium includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder in which the ferromagnetic powder is ε-iron oxide powder, and a vertical magnetization amount Φm per unit area of the magnetic recording medium measured after pressing the magnetic layer at a pressure of 70 atm is 8.0 G.Math.μm to 80.0 G.Math.μm.

Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which a total thickness of the magnetic tape is equal to or smaller than 5.30 m, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value N of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.