| abstract |
The present invention provides a syndiotactic propylene polymer having excellent moldability, and a molded article obtained from the polymer and having a good balance between heat resistance, transparency, mechanical properties and strength. A propylene polymer containing 90 mol% to 100 mol% of propylene and 0 mol% to 10 mol% of an α-olefin having 2 to 20 carbon atoms (excluding propylene) and satisfying the following requirements. [1] The syndiotactic pentad fraction (rrrr fraction) measured by 13 C-NMR is 85% or more. [2] The melting point (Tm) determined by a differential scanning calorimeter (DSC) is 145 ° C. or higher, and the heat of fusion (ΔH) is 40 mJ / mg or higher. [3] When isothermal crystallization temperature obtained with a differential scanning calorimeter is T iso , and the half crystallization time at the isothermal crystallization temperature T iso is t 1/2 , a range of 110 ≦ T iso ≦ 150 (° C.) Satisfies the following formula (Eq-1). [Selection figure] None |