Biaxially oriented laminate polyester film for magnetic recording medium
    3.
    发明授权
    Biaxially oriented laminate polyester film for magnetic recording medium 有权
    用于磁记录介质的双轴取向叠层聚酯薄膜

    公开(公告)号:US06670030B1

    公开(公告)日:2003-12-30

    申请号:US09582820

    申请日:2000-07-03

    IPC分类号: B32B516

    摘要: A biaxially oriented laminate polyester film for magnetic recording medium, which is a laminate film comprising a base layer (A) formed of a polyester resin and a coating layer (B) which exists on one surface of the base layer (A) and contains a binder resin, added fine particles and a surfactant, wherein the base layer (A) is a biaxially oriented film which substantially contains no fine particles added or contains 0.001 to 0.1% by weight of added fine particles having an average particle diameter of 0.005 to 0.3 &mgr;m, the coating layer (B) has a surface having a central plane roughness (SRa) of 5 nm or less, the surface of the coating layer (B) has protrusions having a major diameter of 0.05 &mgr;m or more in a density of 80,000 pieces/mm2 or less and has extra-large protrusions having a major diameter of 10 &mgr;m or more in a density of 20 pieces/cm2 or less. Further, a thin film layer (C) may be further laminated on a surface on the side of the base layer (A) of the laminate polyester film which side is not in contact with the coating layer (B). According to the present invention, there is provided a biaxially oriented laminate polyester film useful as a base film for a magnetic recording medium which has excellent running durability and electromagnetic conversion characteristics and is almost free from drop-out.

    摘要翻译: 一种用于磁记录介质的双轴取向叠层聚酯膜,它是一种层叠膜,它是由聚酯树脂形成的基层(A)和在基层(A)的一个表面上存在的涂层(B))构成的, 粘合剂树脂,添加的微粒和表面活性剂,其中,基层(A)是基本不含有微粒子的双轴取向膜,或者含有0.001〜0.1重量%的平均粒径为0.005〜0.3的微粒子 所述涂布层(B)具有中心平面粗糙度(SRa)为5nm以下的表面,所述涂布层(B)的表面的密度为80,000以下,具有0.05μm以上的大径的突起 片/ mm 2或更小,并且具有20个/ cm 2或更小的密度的大直径为10μm或更大的超大突起。 此外,也可以在层叠聚酯膜的与涂层(B)不接触的一侧的基材层(A)侧的表面上进一步层叠薄膜层(C)。根据本发明 提供了一种双轴取向的层叠聚酯薄膜,其可用作磁记录介质的基膜,其具有优异的运行耐久性和电磁转换特性,几乎不会脱落。