公开(公告)号：US20040072033A1

公开(公告)日：2004-04-15

申请号：US10629766

申请日：2003-07-30

Applicant: TDK CORPORATION

Inventor： Tsutomu Ide ,  Katsuhiko Yamazaki

IPC: G11B005/66

CPC classification number: G11B5/735 ,  Y10T428/257

Abstract: A magnetic recording medium comprises a back coat layer containing carbon black and alumina as nonmagnetic powder. The relationship between the abrasivity (y) in microns of the back coat layer and the alumina content (x) parts by weight to 100 parts by weight of non-magnetic powder excluding alumina satisfies four equations ynull4.6xnull12.2, ynull4.1xnull10.8, ynull13, ynull17. The abrasivity is measured such that an edge of a prismatic Sendust bar is pushed perpendiculary onto the back coat layer such that the magnetic recording medium_is pressed at an approaching angle of 12 degree, and the magnetic recording medium is supported by a tension of 0.526 N/cm per unit width and a 50-m length thereof is moved back and forth one time over the Sendust bar at a running speed of 0.3 m/s.

Abstract translation: 磁记录介质包括含有炭黑和氧化铝作为非磁性粉末的背涂层。 背涂层的研磨性（y）与氧化铝含量（x）重量份之间的关系与100重量份除氧化铝之外的非磁性粉末的关系满足四个等式y <= 4.6x + 12.2，y> = 4.1x + 10.8，y> = 13，y <= 17。 测量磨损性，使得棱柱形塞斯特斯特棒的边缘被垂直地推到背涂层上，使得磁记录介质以12度的接近角度被按压，并且磁记录介质由0.526N / 厘米每单位宽度，其长度为50米的长度以0.3米/秒的运行速度在Sendust杆上前后移动一次。

公开(公告)号：US20040185303A1

公开(公告)日：2004-09-23

申请号：US10765139

申请日：2004-01-28

Applicant: TDK Corporation

Inventor： Katsuhiko Yamazaki ,  Tsutomu Ide ,  Hiroyuki Tanaka

IPC: B32B003/00

CPC classification number: G11B5/714 ,  G11B5/842 ,  H01F1/0027 ,  H01F1/44 ,  H01F41/16

Abstract: A method for manufacturing magnetic paint is provided, wherein a dispersion condition is appropriately controlled to excellently disperse a magnetic powder composed of fine particles adaptable for a higher recording density, so that magnetic paint having excellent dispersibility can be prepared, and a magnetic recording medium having excellent surface roughness is provided. The magnetic paint is prepared by the step of subjecting a mixed solution containing at least a binder, a solvent, and a magnetic powder to a dispersion treatment with a dispersion device by the use of dispersion media through at least dispersion step, wherein the dispersion in the main dispersion step is carried out by the use of dispersion media having an average particle diameter y (mm) satisfying the relationship, which is represented by formula ynull0.01x, with the average maximum diameter x (nm) of the magnetic powder.

Abstract translation: 提供一种制造磁性涂料的方法，其中适当地控制分散条件，以使由适合于较高记录密度的微粒组成的磁性粉末非常好地分散，从而可以制备具有优异分散性的磁性涂料，以及具有 提供优异的表面粗糙度。 该磁性涂料是通过至少分散步骤，通过使用分散介质使至少含有粘合剂，溶剂和磁性粉末的混合溶液用分散装置进行分散处理的步骤来制备的，其中分散体 主分散步骤通过使用平均粒径y（mm）的分散介质进行，该分散介质满足由公式y <= 0.01x表示的关系，其中磁粉的平均最大直径x（nm） 。

公开(公告)号：US20040214048A1

公开(公告)日：2004-10-28

申请号：US10829283

申请日：2004-04-22

Applicant: TDK CORPORATION

Inventor： Tsutomu Ide ,  Katsuhiko Yamazaki

IPC: B32B005/16

CPC classification number: G11B5/7085 ,  G11B5/842

Abstract: The present invention provides a magnetic recording medium having high durability and reliability compatible with MR heads by satisfactorily controlling the grinding ability irrespective of materials, dispersion methods, application methods and other manufacturing methods. The invention provides a recording medium at least having a nonmagnetic layer and magnetic layer sequentially laminated on one surface of a nonmagnetic substrate. The magnetic layer contains a magnetic powder, a binder resin and an abrasive, and an average height of protrusion of the abrasive from the surface of the magnetic layer measured using an AFM is in the range of 7.0 to 15.0 nm.

Abstract translation: 本发明提供了一种磁性记录介质，其具有与MR磁头兼容的高耐久性和可靠性，通过令人满意地控制研磨能力，而不考虑材料，分散方法，应用方法和其它制造方法。 本发明提供一种至少具有非磁性层和顺序层压在非磁性基底的一个表面上的磁性层的记录介质。 磁性层包含磁性粉末，粘合剂树脂和研磨剂，并且使用AFM测量的研磨剂从磁性层表面的平均高度突出在7.0至15.0nm的范围内。

公开(公告)号：US20040013795A1

公开(公告)日：2004-01-22

申请号：US10446847

申请日：2003-05-29

Applicant: TDK CORPORATION

Inventor： Katsuhiko Yamazaki ,  Tsutomu Ide

IPC: B05D005/12

CPC classification number: C09D5/36 ,  C08J3/212 ,  G11B5/70 ,  G11B5/73

Abstract: A method for manufacturing magnetic paint or non-magnetic paint, which can produce a magnetic recording medium having excellent surface smoothness by appropriately setting the condition of a dispersion process for improving the dispersibility of the paint, and a magnetic recording medium are provided. The magnetic paint or the non-magnetic paint is produced by performing a dispersion process of a mixed solution, in which a magnetic powder or a non-magnetic powder is mixed into a binder solution containing a binder and a solvent, with a medium dispersion device. The method includes the steps of adjusting the viscosity of the mixed solution to 1,500 cP or less on a BL type viscometer at 20 rpm basis, and performing a dispersion process with the medium dispersion device using dispersion media having an average particle diameter of 0.5 mm or less at a dispersion circumferential speed of 8 to 15 m/s.

Abstract translation: 提供一种制造磁性涂料或非磁性涂料的方法，其可以通过适当地设定用于改善涂料分散性的分散方法的条件和磁记录介质来制备具有优异表面光滑度的磁记录介质。 磁性涂料或非磁性涂料是通过将磁性粉末或非磁性粉末混合到含有粘合剂和溶剂的粘合剂溶液中的混合溶液的分散方法与中等分散装置 。 该方法包括在BL型粘度计上以20rpm为基准将混合溶液的粘度调节至1,500cP以下的步骤，并使用平均粒径为0.5mm的分散介质和介质分散装置进行分散处理，或 较少的分散圆周速度为8至15m / s。