To provide a polyester release film for various applications, specifically various release films suitable for green sheets used in production of ceramic capacitors, for protection of liquid crystal polarizing plates, for photoresists, and for multilayer boards produced by coating an epoxy resin or the like on a polyester film, and to provide a film having good antistatic properties by specifying charge density on a film surface, thereby reducing fraction defective due to cissing when a release agent is applied.
The biaxially stretched polyester release film has, on one surface of the film, a surface density of charge σA measured in air of -50 μC/m2 or more and 50 μC/m2 or less, an absolute value of the difference (σA-σB) between σA and surface density of charge σB measured on a conductor of 0.01 μC/m2 or more and 50 μC/m2 or less, a surface roughness SRa of 0.010-0.050 μm, and a slip coefficient μs of 0.3-1.0.
MINAMIZAWA HIDEHITO
KAWAJI NAOKI
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