4results about "Coating by liquid dispersion" patented technology

The present invention provides hexagonal ferrite magnetic powder which is extremely useful in achieving both an increase in recording density and an increase in SNR of a magnetic recording medium, is crystalline and has a high saturation magnetization. The hexagonal ferrite magnetic powder contains Bi in a range of a Bi / Fe molar ratio of 0.035 or less, has a saturation magnetization σs of 42.0 Am 2 / kg or more, and a Dx volume of 1800 nm 3 or less, based on a microcrystal diameter. The magnetic powder can be produced by a method for producing hexagonal ferrite magnetic powder, comprising a process of immersing hexagonal ferrite magnetic powder containing Bi in a solution in which a compound X that forms a complex with Bi is dissolved, thereby performing a treatment of dissolving a part of the Bi present in the hexagonal ferrite magnetic powder into the solution.

The purpose of the present invention is to provide a magnetic recording medium that has excellent running stability even when stored in a high-temperature environment.　The present invention provides a magnetic recording medium in which, when dynamic viscoelasticity measurement is performed on the magnetic recording medium at a frequency of 10 Hz and a heating rate of 2°C / min, the average value A(E") of the loss elastic modulus E" in the temperature range of 60°C to 65°C is 0.06 GPa or less, and the average height Rpk of the protruding peaks measured using a non-contact profilometer using optical interference is 2.4 nm or less.

Product that features: - a recording layer (1008) which includes: - encapsulated nanoparticles (1010) each comprising exactly one magnetic nanoparticle encapsulated by an aromatic, polymer (1014) based encapsulation layer, and - a polymeric binder (1016) that binds the encapsulated nanoparticles (1010), - a sublayer (1006), wherein the recording layer (1008) is formed on the sublayer (1006), wherein the recording layer (1008) is not physically mixed with the sublayer (1006) in the product, such that an upper surface of the sublayer (1006) is substantially flat, with a modulation of less than 25% of the thickness of an interface between the sublayer (1006) and the recording layer, wherein the sublayer is electrically conductive to assist in the dissipation of a charge in the product, and - wherein the sublayer comprises encapsulated magnetic nanoparticles (1010) with a coercive force of less than 200 Oersted (Oe).

Provided is a magnetic recording medium in which aggregation of magnetic particles is suppressed in a magnetic layer.　The magnetic recording medium is in tape-form and comprises a magnetic layer containing magnetic particles, a dispersant having an adsorption group, and a solvent. The absolute value of the difference between the dissolution parameter of the dispersant as calculated by the Fedors method from the structural formula excluding the adsorption group and the dissolution parameter of the solvent as calculated by the Fedors method is no greater than 0.50 (cal / cm3)1 / 2.