Ultrahigh molecular weight propylene (co)polymer
Provided is a propylene homopolymer or a copolymer of propylene and a 30 wt % or less α-olefin having 2 or 4 to 8 carbon atoms, having a intrinsic viscosity of more than 20 dl/g, as measured in a tetralin solvent at 135° C.
1. A copolymer of propylene and a 30 wt % or less α-olefin having 2 or 4 to 8 carbon atoms, the copolymer having an intrinsic viscosity of more than 20 dl/g, as measured in a tetralin solvent at 135° C.
2. The copolymer according to claim 1 , wherein the α-olefin is ethylene.
3. The copolymer according to claim 2 , the copolymer having a value of the intrinsic viscosity of 23 dl/g or more and a content of the ethylene of 3 to 30 wt %.
4. The copolymer according to claim 2 , the copolymer having a melting point determined using a differential scanning calorimeter (DSC) at a heating rate of 10° C./min, wherein the melting point, Tm (° C.), of the copolymer and the content of the ethylene in the copolymer, C2 (wt %), satisfy formula (1) below:
Tm≥− 3.4× C 2+162 (1).
5. A method for producing the copolymer according to claim 1 , comprising the polymerization of flail corresponding monomers using a catalyst to prepare the copolymer,
wherein the catalyst contains:
(A) a solid catalyst containing magnesium, titanium, halogen, and an electron donor compound as essential components;
(B) an organoaluminum compound; and
(C) an external electron donor compound as necessary.
6. A polypropylene-based resin composition comprising the copolymer according to claim 1 , wherein
a content of the copolymer is 0.1 to 20 wt % with respect to a total weight of resin components constituting the composition.