| 摘要 |
PURPOSE:To improve durability and the dispersibility of magnetic powder by using a binder contg. a modified polyurethane resin contg. polyurethane molecules having OH at other than both terminals of the main chain, a vinyl chloride-vinyl propionate copolymer and a specific urethane prepolymer. CONSTITUTION:A magnetic tape which is superior in the dispersibility of magnetic powder and durability is obtained by using the binder which contains a modified polyurethane resin contg. polyurethane molecules having OH at other than both terminals of the main chain (both terminals may or may not have OH or only one of them may have OH, and OH may exist in the side chain), and a vinyl chloride- vinyl propionate copolymer (contg. a copolymer of >=3 elements of vinyl alcohol and others) in 1:9-9:1 ratio range by weight and contains a urethane prepolymer having NCO at both terminals of the main chain in 5-50wt% of the total amount of this prepolymer and said compounded copolymer. Further, abrasion resistance, heat resistance, etc. are more improved by contg. low mol.wt. polyisocyanate. |
