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公开(公告)号:US4788092A
公开(公告)日:1988-11-29
申请号:US535011
申请日:1983-09-09
IPC分类号: G11B5/82 , C09D5/23 , C09D127/04 , C09D127/06 , C09D175/00 , C09D175/04 , G11B5/70 , G11B5/706 , G11B5/845 , G11B5/714
CPC分类号: G11B5/70 , Y10S428/90 , Y10T428/25 , Y10T428/257
摘要: The present invention provides a disc-shaped magnetic recording medium particularly suitable for high density recording obtainable a high output power with low noise. In the disc-shaped magnetic recording medium according to the present invention, a ferromag netic powder having a coercive force of about 1,000 Oe or higher and a BET specific surface area in the range from about 25 to 70 m.sup.2 /g is employed. This allows a decrease in noise level and satisfies the electromagnetic performance requirements for high density recording. A random (unoriented) orientation or a circumferential orientation of the ferromagnetic powder in the magnetic layer provides high output power without causing a variation in output power.
摘要翻译: PCT No.PCT / JP83 / 00007 Sec。 371日期1983年9月9日 102(e)1983年9月9日PCT PCT 1月10日PCT公布。 出版物WO83 / 02520 日期:1983年7月21日。本发明提供一种特别适合于高密度记录的盘形磁记录介质,可获得具有低噪声的高输出功率。 在根据本发明的盘形磁记录介质中,采用矫顽力为约1000Oe或更高,BET比表面积为约25至70m2 / g的铁粉。 这允许降低噪声水平并满足高密度记录的电磁性能要求。 磁性层中的铁磁性粉末的随机(无取向)取向或圆周方向提供高输出功率而不引起输出功率的变化。
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公开(公告)号:US4613545A
公开(公告)日:1986-09-23
申请号:US598325
申请日:1984-03-01
申请人: Ryoji Chubachi , Nobuyuki Nihei
发明人: Ryoji Chubachi , Nobuyuki Nihei
IPC分类号: C09D5/23 , C09D127/04 , C09D127/06 , C09D167/00 , C09D175/00 , C09D175/04 , G11B5/702 , G11B5/706 , G11B5/70
CPC分类号: G11B5/702 , Y10S428/90 , Y10T428/256 , Y10T428/257 , Y10T428/31609 , Y10T428/31786 , Y10T428/31935
摘要: A magnetic recording medium has on a nonmagnetic support, a magnetic layer consisting mainly of an acicular magnetic powder and a binder. The medium has excellent magnetic characteristics required for short-wave recording and has an excellent durability. For this purpose, the medium contains a ferromagnetic metal powder which has a coercive force of not less than 1,000 Oe and a specific surface area as determined by the BET method, of not less that 45 m.sup.2 /g. The medium contains in the binder not less than 50% by weight of a resin which has a high dispersibility owing to the introduction of at least one polar group selected from the group consisting of polar groups having the general formulas of: ##STR1## (wherein M is hydrogen, lithium, sodium or potassium; and M.sub.1 and M.sub.2 are hydrogen, lithium, sodium, potassium or alky groups).
摘要翻译: PCT No.PCT / JP83 / 00211 Sec。 371日期1984年3月1日 102(e)日期1984年3月1日PCT提交1983年7月1日PCT公布。 公开号WO84 / 00241 日期1984年1月19日。磁记录介质在非磁性载体上,主要由针状磁性粉末和粘合剂组成的磁性层。 该介质具有优异的短波记录所需的磁特性,并且具有优异的耐久性。 为此目的,该介质含有不小于45m 2 / g的矫顽力不小于1000Oe的铁磁性金属粉末和通过BET法测定的比表面积。 介质中含有不少于50重量%的树脂,其由于引入至少一种极性基团而具有高分散性,所述极性基团选自具有以下通式的极性基团:其中 M是氢,锂,钠或钾; M1和M2是氢,锂,钠,钾或烷基)。
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公开(公告)号:US4654260A
公开(公告)日:1987-03-31
申请号:US444572
申请日:1982-11-16
CPC分类号: G11B5/706 , Y10S428/90 , Y10T428/256 , Y10T428/31609 , Y10T428/31935
摘要: The present invention makes it possible that in a magnetic recording medium having a magnetic layer which contains therein ferromagnetic powder and serving as a magnetic recording medium for short wavelength recording in, for example, a video tape recorder, when the coercive force of the magnetic layer is over 1000 Oe, the specific surface area of its ferromagnetic alloy powder measured according to BET adsorption method is made 45 m.sup.2 /g or above, and the high density recording where the central recording wavelength is not more than 1 .mu.m is carried out thus recording and playback with low noise and high output being made.
摘要翻译: PCT No.PCT / JP82 / 00074 Sec。 371日期1982年11月16日 102(e)日期1982年11月16日PCT申请日1982年3月17日PCT公布。 公开号WO82 / 03292 日本1982年9月30日。本发明使得在具有磁性层的磁性记录介质中,其中含有铁磁性粉末并且用作例如磁带录像机中的短波长记录介质的磁记录介质, 磁性层的矫顽力超过1000Oe,根据BET吸附法测定的铁磁性合金粉末的比表面积为45m 2 / g以上,中心记录波长不大于 因此进行1微米的记录和播放,具有低噪声和高输出。
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