| 摘要 |
PURPOSE:To obtain a smooth coated surface and to improve the dispersibility and the orientation of magnetic powder by incorporating into a magnetic layer a graft copolymer whose principal chain part consists of the polymer of a vinyl compd. contg. a specified perfluoroalkyl group and whose graft chain part consists of the polymer of a nonfluoric compd. CONSTITUTION:The constitution unit of the principal chain part of a graft copolymer is constituted with a vinyl compd. contg. a 3-20 C perfluoroalkyl group. A graft chain part consisting of the polymer of a nonfluoric compd. and a coupling group is incorporated into the copolymer. For example, a reactive polymer corresponding to the graft chain part in the graft copolymer, contg. no fluorine and contg. a vinyl group at one terminal end is previously obtained from a vinyl compd. contg. no fluorine and a chain transfer agent. The macromonomer is copolymerized with a vinyl compd. contg. a perfluoroalkyl group and which is used in forming the constitution unit of the principal chain part in the graft copolymer, and the macromonomer is introduced as the graft chain part simultaneously with the formation of the principal chain part. Consequently, a domain consisting of the perfluoroalkyl group as a lubricating component and a domain consisting of the high-mol.wt. graft chain part having superior affinity for the resin component in the magnetic layer are obtained.
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