| 摘要 |
PURPOSE:To obtain the subject film excellent in adhesivity and the blocking resistance by coating an aqueous primer solution containing a specific acrylic copolymer on a polyester film prior to the completion of crystallization and orientation to form a primer thin film. CONSTITUTION:An aqueous primer solution containing a copolymer is coated on at least one surface of a polyester film prior to the completion of crystallization and orientation, and the primer solution-coated film is subsequently dried, stretched and further thermally treated to provide the objective polyester film useful as the base film of a magnetic tape. The primer solution is obtained by radically polymerizing radically polymerizable monomers containing an acrylic monomer such as an alkyl acrylate as a main component in the presence of a modified polyester modified with a sulfone quaternary phosphonium salt of the formula (A is aromatic group, aliphatic group; X1 is ester-forming functional group; X2 is ester-forming functional group, H; R1-R4 are alkyl, aryl) in the aqueous phase. |
