abstract |
A TFE polymer capable of giving a stretch film excellent in homogeneity. It is a tetrafluoroethylene polymer which has stretchability, is processable in a nonmelted state, and has a normal specific gravity of 2.140-2.165. The tetrafluoroethylene polymer is characterized in that when an unburned sample of the polymer which has not been heated to a temperature of 300°C or higher is analyzed with a differential scanning calorimeter at a heating rate of 2 °C/min, it gives a heat-of-fusion curve in which the ratio of the endotherm S2 (mJ/mg) in the range of from the temperature (T0 °C) which is lower by 2.5°C than the temperature Tp (°C ) corresponding to a maximum (provided that 340≤Tp≤345) to 350°C to the endotherm S1 (mJ/mg) in the range of from 320°C to T0 (°C), [S2/S1], is 0.90 or higher. |