| 摘要 |
PURPOSE:To improve heat resistance, electrostatic applying casting properties, etc. by mixing polyester containing a Mg compound and a P compound and polyester containing the P compound within the ranges of specific quantities and melt-extruding a mixture to a sheet shape. CONSTITUTION:A mixture satisfying formulae I , II, III (In the formulae, PM and PB each represent the contents of a P compound originating in polyester M, B and a unit represents g atomicity of P atoms to 1mol total acid component constituting polyesters in a mixed liquid. Mg represents g atomicity of Mg atoms to 1mol total acid component constituting polyesters after mixing.) is prepared regarding polyester M containing a Mg compound and the P compound and polyester B, which does not contain the Mg compound and contains the P compound. The mixture is melt-extruded to a sheet shape and cooled and solidified, and an obtained sheet not oriented is biaxially-oriented, thus acquiring a polyester film. |
