Catalyst composition for polymerizing polyolefin, method for producing polyolefin, and polyolefin resin

A method for producing a polyolefin comprising polymerizing ethylene and an alpha-olefin comonomer in the presence of a polyolefin polymerization catalyst composition,

• wherein the catalyst composition comprises:
• at least one first organometallic compound represented by following Formula 1;
• at least one second organometallic compound represented by following Formula 2;
• and
• aluminoxane,
• (L1)(L2)(X1)(X2)M1 [Formula 1]
• in Formula 1, M1 is hafnium (Hf);
• (L1) and (L2) each is a cyclopentadienyl group having an alkyl substituent of 3 to 4 carbon atoms;
• (X1) and (X2) each is independently F, Cl, Br, I or a hydrocarbon group of 1 to 10 carbon atoms;
• in Formula 2, R1 is a methyl group and R2 to R6 each is independently hydrogen or an alkyl group laving 1 to 10 carbon atoms;
• X1 and X2 each is independently F, Cl, Br, I or a hydrocarbon group of 1 to 10 carbon atoms,
• wherein the polyolefin satisfies following properties (i) to (iv) and (vi),
• (i) melt flow index (measured according to ASTM D1238), measured at 190° C., under a load of 2.16 kg:
• 0.1 to 1.5 g/10 min;
• (ii) density:
• 910 to 930 kg/m3;
• (iii) ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn), as measured by gel permeation chromatography:
• 3.2 to 6.0;
• (iv) ratio (Mz/Mw) of Z-average molecular weight (Mz) to weight-average molecular weight (Mw), as measured by gel permeation chromatography:
• 2.4 to 3.4;
• (vi) when a TREF (temperature rising elution fractionation) curve of multimodal distribution is deconvoluted, an area of the TREF curve having a peak at 50 to 74° C. is 40 to 75% of a total area of the TREF curve of multimodal distribution.