Magnetic paints are used as coatings to control the magnetic field.We are surrounded by products using this type of coating.
In addition to VTR tapes, audio cassette tapes, and MTs for computers, this type of coating is used for various items that are necessary for industry and in our daily lives, such as credit cards, train tickets, commuter passes, highway passes, bus tickets, telephone cards, orange cards, etc.
Magnetic paints are comprised of a magnetic substance (powder), binder resin, additives, solvents, and other substances.A typical magnetic powder is the metal powder containing γFe₂O₃,CrO₂, and Fe as the main ingredients.
Magnetic paints are largely classified into two categories according to the recording density: Ba ferrite,γ-Fe₂O₃･Fe₃O₄,and Co-γFe₂O₃･CrO₂are used for horizontal recording; while metal powder･Co-FeOx, Ba ferrite･hexagonal-plate vapor deposition, and sputter･Co-Cr are used for vertical recording.
Materials such as polyurethane and vinyl chloride-vinyl acetate copolymer are used for the binder resin, which increases various characteristics such as adhesive performance with the base PET (polyethylene terephthalate), abrasion resistance, rigidity, slippage, and dispersion property of the magnetic powder.

Required characteristics for magnetic films and their predominant factors are shown in [Table 1].

Required characteristics for magnetic films and their predominant factors are shown in [Table 1].

The recording density is improving year after year.