| 摘要 |
PURPOSE: To provide a photographic base excellent in transparency and "mechanical strength, having a small winding curl, having few coating failure after an undercoating layer is applied, and excellent in flatness. CONSTITUTION: This photographic base is made of a biaxial oriented polyester film. The longitudinal heat contraction coefficient of the biaxial oriented polyester film is adjusted within the range from -0.05% to 0.20%, the lateral heat contraction coefficient is adjusted within the range from 0.0% to 0.30%, then the biaxial oriented polyester film is heat-treated into a roll shape at the temperature lower by 30 deg.C than its glass transition temperature. |
