公开(公告)号：US6432508B2

公开(公告)日：2002-08-13

申请号：US75834201

申请日：2001-01-12

申请人： TODA KOGYO CORP

发明人： HAYASHI KAZUYUKI ,  IWASAKI KEISUKE ,  TANAKA YASUYUKI ,  MORII HIROKO

IPC分类号： C01G49/06 ,  G11B5/708 ,  G11B5/73 ,  G11B5/738 ,  G11B5/84

CPC分类号： B82Y30/00 ,  C01G49/06 ,  C01P2004/10 ,  C01P2004/54 ,  C01P2004/62 ,  C01P2004/64 ,  C01P2004/84 ,  C01P2006/12 ,  C01P2006/22 ,  C01P2006/40 ,  C01P2006/42 ,  C01P2006/80 ,  G11B5/708 ,  G11B5/738 ,  Y10T428/24355 ,  Y10T428/257 ,  Y10T428/265 ,  Y10T428/2991

摘要： High-density acicular hematite particles comprise acicular hematite particles and a coat comprising an oxide of tin or oxides of tin and antimony, formed on at least a part of surfaces of said acicular hematite particles; and have an average major axial diameter of not more than 0.3 mum, a pH value of not less than 8, a soluble sodium salt content of not more than 300 ppm, calculated as Na, and a soluble sulfate content of not more than 150 ppm, calculated as SO4. Such high-density acicular hematite particles is suitable as non-magnetic particles for a non-magnetic undercoat layer of a magnetic recording medium using magnetic particles containing iron as a main ingredient, have an excellent dispersibility in vehicle and a low volume resistivity.

摘要翻译： 高密度针状赤铁矿颗粒包括针状赤铁矿颗粒和在所述针状赤铁矿颗粒的至少一部分表面上形成的包含锡或锡和氧化物的氧化物的涂层; 平均主轴径不大于0.3μm，pH值不小于8，可溶钠盐含量不超过300ppm，以Na计算，可溶性硫酸盐含量不大于150ppm ，以SO4计算。 这种高密度针状赤铁矿颗粒适用于使用以铁为主要成分的磁性颗粒的磁记录介质的非磁性底涂层的非磁性颗粒，在车辆中具有优异的分散性和低体积电阻率。