申请人:TEIJIN LIMITED
公开号:EP0888884A1
公开(公告)日:1999-01-07
The film of the present invention is a biaxially oriented laminated polyester film for magnetic recording medium consisting of a polyester layer A containing fine particles and laminated to at least one surface of a polyester layer B, wherein the fine particles in the polyester layer A are composed of 0.001 to 0.03% by weight of crosslinked polymer particles (a) having an average particle diameter (da) of 0.9 to 1.6 µm, 0.1 to 0.8% by weight of inert particles (b) having an average particle diameter (db) of 0.4 to 0.8 µm and 0.05 to 1.0% by weight of inert inorganic particles (c) having an average particle diameter (dc) of 0.01 to 0.3 µm and a Mohs hardness of 7 or above, and the ratio of the thickness TA (µm) of the polyester layer A to the average particle diameter da (µm) of the crosslinked polymer particle (TA/da) is in the range of from 0.4 to 2.0. The film has excellent windability, abrasion resistance, transportation durability and electromagnetic conversion characteristics and is producible at a low production cost and useful especially as a base film of a magnetic recording medium for high-speed duplicator.
本发明的薄膜是一种用于磁记录介质的双向拉伸层压聚酯薄膜,由含有细颗粒的聚酯层A和层压到聚酯层B的至少一个表面组成,其中聚酯层A中的细颗粒由0.001至0.03%(重量)的平均颗粒直径(da)为0.9至1.6微米的交联聚合物颗粒(a)、0.1至0.8%(重量)的平均颗粒直径(db)为0.4至0.8微米的惰性颗粒(b)和0.05至1.0%(重量)的惰性无机颗粒(db)组成。8%(重量百分比)的惰性颗粒(b),其平均颗粒直径(db)为 0.4 至 0.8 微米,以及 0.05 至 1.0%(重量百分比)的惰性无机颗粒(c),其平均颗粒直径(dc)为 0.01 至 0.3 微米,莫氏硬度为 7 或以上,且聚酯层 A 的厚度 TA(微米)与交联聚合物颗粒的平均颗粒直径 da(微米)之比(TA/da)在 0.4 至 2.0 之间。这种薄膜具有优异的可卷绕性、耐磨性、运输耐久性和电磁转换特性,生产成本低廉,特别适合用作高速复制机磁性记录介质的基膜。