The magnetic tape has a magnetic layer and a backcoat layer, wherein the Ra on the magnetic layer side surface is less than or equal to 1.8 nm, the coefficient of friction measured on the base portion of the magnetic layer side surface is less than or equal to 0.35, the Ra measured on the backcoat layer side surface is less than or equal to 5.0 nm, the backcoat layer contains a fatty acid ester, the FWHM.sub.before measured on the backcoat layer side surface before vacuum heating is greater than 0 nm but less than or equal to 10.0 nm, the FWHM.sub.after after vacuum heating is greater than 0 nm but less than or equal to 10.0 nm, and the difference between the spacing measured on the backcoat layer side surface after and before vacuum heating is greater than 0 nm but less than or equal to 8.0 nm.

The magnetic tape has a magnetic layer and a backcoat layer, wherein, each of the magnetic layer and backcoat layer contains a fatty acid ester, the Ra measured on the magnetic layer side surface is less than or equal to 2.8 nm, the difference between the spacing measured by optical interferometry on the magnetic layer side surface after and before vacuum heating is greater than 0 nm but less than or equal to 8.0 nm, the FWHM.sub.before on the backcoat layer side surface is greater than 0 nm but less than or equal to 10.0 nm, the FWHM.sub.after on the backcoat layer side surface is greater than 0 nm but less than or equal to 10.0 nm; and the difference between the spacing measured on the backcoat layer side surface after and before vacuum heating is greater than 0 nm but less than or equal to 8.0 nm.

The magnetic tape has a magnetic layer and a backcoat layer, wherein, each of the magnetic layer and backcoat layer contains a fatty acid ester, the Ra measured on the magnetic layer side surface is less than or equal to 2.8 nm, the difference between the spacing measured by optical interferometry on the magnetic layer side surface after and before vacuum heating is greater than 0 nm but less than or equal to 8.0 nm, the FWHM.sub.before on the backcoat layer side surface is greater than 0 nm but less than or equal to 10.0 nm, the FWHM.sub.after on the backcoat layer side surface is greater than 0 nm but less than or equal to 10.0 nm; and the difference between the spacing measured on the backcoat layer side surface after and before vacuum heating is greater than 0 nm but less than or equal to 8.0 nm.

A magnetic recording medium includes: a substrate that is long in shape; and a magnetic layer containing magnetic powder and a binder. The glass transition point of the binder is not lower than 75° C. In a case where atomic force microscope observation images in a 10 μm×10 μm rectangular shape are acquired at five locations randomly selected from the surface on the side of the magnetic layer, any linear protrusion that is 3 nm to 20 nm in height, is 0.3 μm to 1.0 μm in width, and extends across two sides of the observation image does not exist in the observation images of four locations among the acquired observation images of the five locations.

The magnetic recording medium includes a non-magnetic support; a magnetic layer including a ferromagnetic powder on one surface of the non-magnetic support; and a back coating layer including a non-magnetic powder on the other surface of the non-magnetic support, in which a difference (S.sub.after−S.sub.before) between a spacing S.sub.after measured by optical interferometry regarding a surface of the back coating layer after ethanol cleaning and a spacing S.sub.before measured by optical interferometry regarding the surface of the back coating layer before ethanol cleaning is greater than 0 nm and equal to or smaller than 15.0 nm, and the non-magnetic support is an aromatic polyester support having a moisture absorption of 0.3% or less.

An aspect of the present invention relates to a magnetic recording medium, which comprises a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic support, wherein the magnetic layer further comprises a compound which has a weight average molecular weight of equal to or more than 1,000 but less than 20,000 and is denoted by formula (1): ##STR00001##
wherein, in formula (1), A.sup.1 denotes a monovalent polymer group, each of R.sup.1 and R.sup.2 independently denotes a single bond or a divalent connecting group, R.sup.11 denotes a hydrogen atom or a monovalent substituent, m denotes an integer of equal to or greater than 2, multiple instances of R.sup.1, R.sup.2, A.sup.1, and R.sup.11 that are present can be identical or different, A.sup.2 denotes a hydrogen atom or a monovalent substituent denoted by —OR.sup.3—Z, R.sup.3 denotes a single bond or a divalent connecting group, Z denotes a monovalent acid group, among multiple instances of A.sup.2 that are present, at least one denotes a monovalent group denoted by —O—R.sup.3—Z, and X denotes a connecting group of valence m.

A magnetic recording medium is a magnetic recording medium having a tape-like shape and includes a base substrate and a magnetic layer provided on the base substrate. A plurality of data tracks can be formed in the magnetic layer, a width of a data track is 2900 nm or less, and in a case of defining, as w.sub.max and w.sub.min, a maximum value and a minimum value respectively out of average values of a width of the magnetic recording medium measured under four kinds of environment in which temperature and relative humidity are set to (10° C., 10%), (10° C., 80%), (29° C., 80%), and (45° C., 10%), w.sub.max and w.sub.min satisfy a relation of (w.sub.max−w.sub.min)/w.sub.min≤400 [ppm].

The magnetic tape includes a non-magnetic support; a magnetic layer including a ferromagnetic powder and a binding agent on one surface of the non-magnetic support; and a back coating layer including a non-magnetic powder and a binding agent on the other surface of the non-magnetic support, in which a center line average surface roughness Ra measured regarding a surface of the back coating layer is equal to or smaller than 7.0 nm, and a difference between a spacing S.sub.after measured by optical interferometry regarding the surface of the back coating layer after methyl ethyl ketone cleaning and a spacing S.sub.before measured by optical interferometry regarding the surface of the back coating layer before methyl ethyl ketone cleaning is greater than 0 nm and equal to or smaller than 30.0 nm.

A tape-shaped magnetic recording medium includes a substrate; and a magnetic layer that is provided on the substrate and contains a magnetic powder. An average thickness of the magnetic layer is not more than 90 nm, an average aspect ratio of the magnetic powder is not less than 1.0 and not more than 3.0, the coercive force Hc1 in a vertical direction is not more than 3000 Oe, and the coercive force Hc1 in the vertical direction and a coercive force Hc2 in a longitudinal direction satisfy a relationship of Hc2/Hc1≤0.8.

The magnetic tape includes a non-magnetic support; and a magnetic layer in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference between a value L.sub.99.9 of a cumulative distribution function of 99.9% and a value L.sub.0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and a difference between a spacing S.sub.after measured on a surface of the magnetic layer by an optical interferometry after methyl-ethyl-ketone cleaning and a spacing S.sub.before measured on the surface of the magnetic layer by an optical interferometry before methyl-ethyl-ketone cleaning is greater than 0 nm and 15.0 nm or less.