发明授权
- 专利标题： Magnetic iron oxide pigments and a process for their preparation
- 专利标题（中）： 磁性氧化铁颜料及其制备方法
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申请号： US91059申请日： 1987-08-31
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公开(公告)号： US4923519A公开(公告)日： 1990-05-08
- 发明人: Fritz Rodi , Peter Kiemle , Aloys Eiling , Hendrik Kathrein
- 申请人： Fritz Rodi , Peter Kiemle , Aloys Eiling , Hendrik Kathrein
- 申请人地址： DEX Leverkusen
- 专利权人： Bayer Aktiengesellschaft
- 当前专利权人： Bayer Aktiengesellschaft
- 当前专利权人地址： DEX Leverkusen
- 优先权： DEX3631193 19860913
- 主分类号： C01G49/00
- IPC分类号： C01G49/00 ; G11B5/706 ; H01F1/11
摘要：
Magnetic iron oxide pigments having a monomolecular coating of a cobalt compound useful in magnetic signal recordings having a dependence of coercivity on temperature in the temperature range of from 76 K to 298 K of less than 0.13 kA/mK and having a coercivity on powder compressed to 0.9 g/cm.sup.3 of greater than 51 kA/m are prepared applying a preliminary coating of Fe.sub.3 O.sub.4 or a bertholloid compound to a magnetic iron oxide core material having the composition FeO.sub.x where x is a number from 1.33 to 1.55 and then covering the preliminary coating with a cobalt compound.
公开/授权文献
- USD423354S Cover 公开/授权日：2000-04-25