| 摘要 |
PURPOSE:To improve moisture resistance and adhesion at the time of the coating of a coating agent, etc., by bringing the rate of change of surface roughness (Ra) before and after dipping in a solvent in at least one surface to 10-300%. CONSTITUTION:The rate of change of surface roughness (Ra) before and after dipping in a solvent in at least one surface is made 10-300%. Adhesion and moisture resistance are deteriorated when the rate of change of the surface roughness is too low, and adhesion is lowered, gloss at the time of printing is reduced and appearance is often damaged when the rate of the change is too high. Alcohols such as methyl alcohol, ethyl alcohol, etc., ketones such as acetone, methyl ethyl ketone, etc., halogens such as trichloroethane, fluorocarbon etc,, petroleums, aromatic groups such as benzene, toluene, etc., esters such as ethyl acetate, etc., are exampled as a solvent. Accordingly, a polyester film, which has excellent adhesive properties with printing ink or a coating agent and adhesion of which is not lowered even under high humidity particularly, is acquired. |
