| 摘要 |
PURPOSE:To obtain a polyester compsn. for a capacitor film having improved electric properties by selecting a specific polyester which mainly comprises repeating units consisting of ethylene terephthalate and contains Mg and P. CONSTITUTION:The title compsn. comprises a polyester comprising repeating units consisting of ethylene terephthalate, contg. Mg and P, and satisfying formulas: Tc'-Tc>=60 deg.C and 0.1<=M/P<=1.6. In the formulas, Tc' is the falling temperature of crystallization temp. ( deg.C); Tc is the rising temperature of crystallization temp. ( deg.C); and M/P is the molar ratio of Mg to P contained in the polyester. The compsn., having a high crystallinity and a specified molar ratio of Mg to P, can be molded into a film which gives a capacitor having greatly improved electric properties including insulation resistance and dielectric dissipation factor. |
