Magnetic recording medium having a dimensional variation
摘要
說明書
Acicular iron oxide powder: 100 parts by mass
(α-Fe2O3, average major axis length 0.15 μm)
Vinyl chloride resin: 55.6 parts by mass
(Resin solution: resin content 30% by mass, cyclohexanone 70% by mass)
Carbon black: 10 parts by mass
(Average particle size 20 nm)
(Fourth Composition)
Polyurethane resin UR8200 (manufactured by Toyobo Co., Ltd.): 18.5 parts by mass
n-Butyl stearate: 2 parts by mass
Methyl ethyl ketone: 108.2 parts by mass
Toluene: 108.2 parts by mass
Cyclohexanone: 18.5 parts by mass
Finally, as a curing agent, 4 parts by mass of polyisocyanate (trade name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 2 parts by mass of myristic acid were added to the paint for base layer formation, prepared in the way described above.
(Preparation Step of Paint for Back Layer Formation)
A paint for back layer formation was prepared as follows. The following raw materials were mixed in a stirring tank equipped with a disperser, and subjected to a filter treatment to prepare a paint for back layer formation.
Carbon black (manufactured by Asahi Corporation, trade name: #80): 100 parts by mass
Polyester polyurethane: 100 parts by mass
(Trade name: N-2304, manufactured by Nippon Polyurethane Industry Co., Ltd.)
Methyl ethyl ketone: 500 parts by mass
Toluene: 400 parts by mass
Cyclohexanone: 100 parts by mass
