发明名称 |
MAGNETIC IRON OXIDE PIGMENT AND MANUFACTURE |
摘要 |
Magnetic iron oxide pigments useful in magnetic signal recordings having a dependence of coercivity on temperature in the temperature range of from 76K to 298K of less than 0.13 kA/mK and having a coercivity on powder compressed to 0.9 g/cm3 of greater than 51 kA/m are prepared by coating a magnetic iron oxide core material having the composition FeOx where x is a number from 1.33 to 1.5 in a first step with a compound containing divalent and trivalent iron having a ratio of Fe(III): Fe(II) from 0.01 to less than 2, and then in a second step coating the pre-coated core with a second coating of a cobalt compound. |
申请公布号 |
JPS6374921(A) |
申请公布日期 |
1988.04.05 |
申请号 |
JP19870227578 |
申请日期 |
1987.09.12 |
申请人 |
BAYER AG |
发明人 |
HENDORIKU KATORAIN;PEETAA KIIMURE;FURITSUTSU RODEI;AROISU AIRINGU |
分类号 |
C01G49/00;G11B5/706;H01F1/11 |
主分类号 |
C01G49/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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