发明授权
US06670030B1 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
- 专利标题: Biaxially oriented laminate polyester film for magnetic recording medium
- 专利标题(中): 用于磁记录介质的双轴取向叠层聚酯薄膜
-
申请号: US09582820申请日: 2000-07-03
-
公开(公告)号: US06670030B1公开(公告)日: 2003-12-30
- 发明人: Toshikazu Uchida , Mitsuo Tojo , Toshifumi Osawa , Akira Kameoka , Tomokatsu Ura , Masahiko Kosuge
- 申请人: Toshikazu Uchida , Mitsuo Tojo , Toshifumi Osawa , Akira Kameoka , Tomokatsu Ura , Masahiko Kosuge
- 优先权: JP10-311963 19981102; JP10-311964 19981102; JP11-44183 19990223; JP11-44184 19990223
- 主分类号: B32B516
- 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.