申请人:FUJI PHOTO FILM CO., LTD.
公开号:EP1022726A1
公开(公告)日:2000-07-26
The magnetic recording medium of the invention comprises a substrate and a magnetic layer stacked thereon and composed of a dispersion of a ferromagnetic powder in a binder, and is characterized in that the binder contains a polyurethane resin 1 obtained by polymerization of a dial compound having a cyclic structure and a long-chain form of alkyl chain with a diisocyanate compound. Preferably, the polyurethane resin contains as dial components a dimer dial and an aliphatic dial having a medium-chain form of alkyl branched chain. The polyurethane resin may comprise a polyether polyol having a cyclic structure. A dibasic acid in the polyester polyol may contain an aliphatic dibasic acid, the dial component may contain an aliphatic diol that does not include a cyclic structure having an alkyl branched chain, and an chain extender may include a polyester polyol comprising an aliphatic diol having an alkyl branched chain.
本发明的磁记录介质包括基板和叠在基板上的磁层,磁层由分散在粘结剂中的铁磁性粉末组成,其特征在于粘结剂中含有一种聚氨酯树脂 1,这种聚氨酯树脂是由具有环状结构和长烷基链形式的二元化合物与二异氰酸酯化合物聚合而成。聚氨酯树脂最好含有二聚体二元醇和具有中链烷基支链的脂肪族二元醇作为二元醇组分。聚氨酯树脂可包含具有环状结构的聚醚多元醇。聚酯多元醇中的二元酸可包含脂肪族二元酸,转盘组分可包含不包含具有烷基支链的环状结构的脂肪族二元醇,扩链剂可包含包含具有烷基支链的脂肪族二元醇的聚酯多元醇。