Magnetic recording medium
    51.
    发明授权
    Magnetic recording medium 失效
    磁记录介质

    公开(公告)号:US5098773A

    公开(公告)日:1992-03-24

    申请号:US492164

    申请日:1990-03-13

    摘要: A magnetic recording medium having at least two magnetic layers is disclosed, comprising first and second mangetic layers which are successively formed in order on a nonmagnetic support, wherein a coercive force (Hc) of said second magnetic layer is 5.times.10.sup.4 to 1.5.times.10.sup.5 A/m, a ratio (Br/Hc) of a residual magnetic flux density (Br) of said second magnetic layer to the coercive force (Hc) is 2.0.times.10.sup.-6 H/m or more, SFD of said second magnetic layer is 0.6 or less, an average length in the long axis of magnetic particles in said second magnetic layer is 0.25 microns or less, a center line average surface roughness (Ra) of said second magnetic layer is 1/10 or less of the average length in the long axis of the magnetic particles, and a coercive force (Hc') of said first magnetic layer is 2.times.10.sup.4 to 1.times.10.sup.5 A/m.

    摘要翻译: 公开了具有至少两个磁性层的磁记录介质,包括在非磁性载体上依次形成的第一和第二凹凸层,其中所述第二磁性层的矫顽力(Hc)为5×10 4至1​​.5×10 5 A / m 所述第二磁性层的剩余磁通密度(Br)与所述矫顽力(Hc)的比(Br / Hc)为2.0×10 -6 H / m以上,所述第二磁性层的SFD为0.6以下 所述第二磁性层中的磁性粒子长轴的平均长度为0.25微米以下,所述第二磁性层的中心线平均表面粗糙度(Ra)为长轴的平均长度的1/10以下 的磁性颗粒,并且所述第一磁性层的矫顽力(Hc')为2x104至1×105A / m。

    Magnetic recording medium
    52.
    发明授权
    Magnetic recording medium 失效
    磁记录介质

    公开(公告)号:US5089317A

    公开(公告)日:1992-02-18

    申请号:US468327

    申请日:1990-01-22

    IPC分类号: G11B5/712 G11B5/716

    摘要: A magnetic recording medium comprising two or more magnetic layers containing ferromagnetic substance dispersed in a binder provided on a non-magnetic substrate is disclosed, which is characterized in that a ferromagnetic substance whose water content is adjusted within the range of from 0.4 to 2.0 wt. % by moisture conditioning is used in the upper layer of the magnetic layers and a ferromagnetic substance having an water content less than by at least 0.1 wt. % than that of the feromagnetic substance used in the upper layer is used in the lower layer of the magnetic layers.

    摘要翻译: 公开了一种包含分散在设置在非磁性基板上的粘合剂中的含有铁磁性物质的两层以上的磁性层的磁记录介质,其特征在于,将含水量调节在0.4〜2.0重量%的范围内的铁磁性物质。 通过湿度调节的%用于磁性层的上层和含水量低于0.1重量%的铁磁物质。 比上层使用的铁磁性物质的摩尔数低于磁性层的下层。

    Magnetic recording medium
    53.
    发明授权
    Magnetic recording medium 失效
    磁记录介质

    公开(公告)号:US5080967A

    公开(公告)日:1992-01-14

    申请号:US420422

    申请日:1989-10-12

    摘要: A magnetic recording medium comprising a non-magnetic support having provided thereon in this order, a first magnetic layer containing ferromagnetic particles dispersed in a binder and a second magnetic layer containing ferromagnetic particles dispersed in a binder, whereinsaid second magnetic layer contains particles of an abrasive material having a Mohs' hardness of 8 or more in an amount of 1 to 15 wt % based on the weight of the ferromagnetic particles contained in the second magnetic layer,said first magnetic contains particles of an abrasive material having a Mohs' hardness less than 8 in an amount of 5 to 50 wt % based on the weight of the ferromagnetic particles contained in the first magnetic layer, andthe proportion of the abrasive material to the ferromagnetic particles in said first magnetic layer is larger than that in said second magnetic layer.

    摘要翻译: 一种磁记录介质,其特征在于,具有依次设置在其上的非磁性载体,包含分散在粘合剂中的铁磁性粒子的第一磁性层和分散在粘合剂中的含有铁磁性粒子的第二磁性层,其中,所述第二磁性层含有 摩尔氏硬度为8以上的摩擦硬度为1〜15重量%,含有第2磁性层的铁磁性粒子的重量,所述第1磁性体含有莫氏硬度较低的研磨材料粒子 基于第一磁性层中所含的铁磁颗粒的重量为5〜50重量%,并且所述研磨材料与所述第一磁性层中的铁磁性粒子的比例大于所述第二磁性层 层。

    Method of producing a magnetic recording medium
    54.
    发明授权
    Method of producing a magnetic recording medium 失效
    制造磁记录介质的方法

    公开(公告)号:US5073406A

    公开(公告)日:1991-12-17

    申请号:US682767

    申请日:1991-04-09

    IPC分类号: G11B5/716 G11B5/842

    CPC分类号: G11B5/716 G11B5/842

    摘要: A method of producing a magnetic recording medium comprises the steps of kneading and dispersing ferromagnetic powder, binder and non-ferromagnetic powder to obtain magnetic coating solutions, and applying a plurality of the magnetic coating solutions on a non-ferromagnetic substrate to form a plurality of magnetic layers on the substrate. In the kneading and dispersing step, a magnetic coating composition containing a ferromagnetic powder and a solvent of 15 to 30 wt % of the ferromagnetic powder is kneaded by a two-shaft continuous kneading and mixing machine and then dispersed by a pin type sand grinder to obtain a first magnetic solution. Another magnetic coating composition containing a ferromagnetic powder and a solvent of 30 to 50 wt % of the ferromagnetic powder is kneaded by a double-arm open kneader and then dispersed by a pin type sand grinder, and finally dispersed by a disk type sand grinder to obtain a second magnetic coating solution. In the magnetic solution applying step, the first magnetic coating solution is at first applied on said substrate and then the second magnetic coating solution is applied thereon.

    摘要翻译: 一种制造磁记录介质的方法包括以下步骤:将铁磁性粉末,粘合剂和非铁磁性粉末混合和分散以获得磁性涂层溶液,并将多个磁性涂覆溶液施加在非铁磁性基底上以形成多个 基底上的磁性层。 在捏合分散工序中,将含有铁磁性粉末和15〜30重量%的铁磁粉末的溶剂的磁性涂料组合物通过双轴连续捏合混合机进行混炼,然后用针式砂磨机分散 获得第一磁性溶液。 含有铁磁性粉末和铁磁性粉末的含量为30〜50重量%的溶剂的磁性涂料组合物用双臂开口捏合机捏合,然后用针式砂磨机分散,最后用盘式砂磨机分散 获得第二磁性涂层溶液。 在磁性溶液涂布步骤中,首先将第一磁性涂布溶液涂布在所述基材上,然后将第二磁性涂布液涂布在其上。

    Magnetic recording medium
    55.
    发明授权
    Magnetic recording medium 失效
    磁记录介质

    公开(公告)号:US5051320A

    公开(公告)日:1991-09-24

    申请号:US309580

    申请日:1989-02-13

    摘要: A magnetic recording medium comprises a non-magnetic support having provided thereon a lower magnetic layer having a thickness of 2.5 .mu.m or higher and an upper magnetic layer having a thickness of 2 .mu.m or lower in this order, wherein both the upper and lower magnetic layers contain ferromagnetic particles, and the lower magnetic layer contains carbon black having an average primary particle diameter of less than 20 .mu.m in the amount of from 1.0 to 20 parts by weight per 100 parts by weight of the ferromagnetic particles contained in the lower magnetic layer, and the upper magnetic layer contains carbon black having an average primary particle diameter of at least 40 .mu.m but less than 80 .mu.m in an amount of from 0.1 to 10.0 parts by weight per 100 parts by weight of the ferromagnetic particles contained in the upper magnetic layer, but less than the amount of carbon black used in the lower magnetic layer.

    摘要翻译: 磁记录介质包括具有厚度为2.5μm或更高的下磁性层和厚度为2μm或更小的上磁层的非磁性载体,其中上和下两个 磁性层含有铁磁性粒子,下部磁性层含有平均一次粒径小于20μm的碳黑,相对于100重量份以下的铁磁性粒子为100重量份,1.0〜20重量份 磁性层,上部磁性层含有平均一次粒径为40μm以上且小于80μm的碳黑,相对于100重量份含有的铁磁性粒子,为0.1〜10.0重量份 在上磁性层中,但低于下磁性层中使用的炭黑的量。

    Magnetic recording medium
    56.
    发明授权
    Magnetic recording medium 失效
    磁记录介质

    公开(公告)号:US5051303A

    公开(公告)日:1991-09-24

    申请号:US424004

    申请日:1989-10-19

    摘要: A magnetic recording medium is disclosed, comprising a nonmagnetic support having thereon plural magnetic layers comprising ferromagnetic particles dispersed in a binder, said ferromagnetic particles consisting of an iron oxide or a cobalt-containing iron oxide, said plural magnetic layers comprising at least an upper magnetic layer and a lower magnetic layer, wherein said upper magnetic layer has a coercive force (Hc) of from 650 to 1000 Oe, a crystallite size of the ferromagnetic particles contained in said upper magnetic layer is less than 500 .ANG. as measured by a X-ray diffraction method, an average length in the long axis of the ferromagnetic particles contained in said upper magnetic layer is from 0.1 microns to less than 0.25 microns as measured by a transmission type electronmicroscope, said lower magnetic layer has a coercive force (Hc) of from 0.6 to 1.0 times that of said upper magnetic layer, a crystallite size of the ferromagnetic particles contained in said lower magnetic layer is larger than that of said upper magnetic layer and is in the range of 500 .ANG. or less, and an average length in the long axis of the ferromagnetic particles contained in said lower magnetic layer is larger than that of said upper magnetic layer and is in the range of from more than 0.1 microns to less than 0.25 microns.

    摘要翻译: 公开了一种磁记录介质,其包括非磁性载体,其上具有包含分散在粘合剂中的铁磁性颗粒的多个磁性层,所述铁磁颗粒由氧化铁或含钴氧化铁组成,所述多个磁性层至少包括上磁 层和下磁性层,其中所述上磁性层具有650至1000Oe的矫顽力(Hc),所述上磁性层中所含的铁磁性颗粒的微晶尺寸小于500, 通过透射型电子显微镜测定,所述上磁性层中含有的铁磁粒子的长轴的平均长度为0.1微米〜小于0.25微米,所述下磁性层的矫顽力(Hc)为 是所述上磁性层的0.6至1.0倍,所述下部磁铁中包含的铁磁颗粒的微晶尺寸 所述上磁性层的磁性粒子的长轴的平均长度大于所述上磁性层的长轴的平均长度, 在大于0.1微米至小于0.25微米的范围内。