Novel supported and non-supported metallocene catalysts for Olefin polymerization

Abstract

Novel metallocene catalysts, $1,2-[4-\{ (C_5Me_nH_{4-n}) CpZrCl_2 \} C_6H_4]_2 (CH_2CH_2)_m$ (n=2 or 4, m=0 or 1) and $\{ 1-(E_n-Ph)-3,4-Me_2C_5H_2 \}_2 ZrCl_2$ ($E=NMe_2$, OMe; n=1, 2) were used in ethylene and propylene polymerization, respectively in order to study on characteristics of polymerization and commercial applicability of them. The novel dinuclear metallocene catalysts, $1,2-[4-\{ (C_5Me_nH_{4-n}) CpZrCl_2 \} C_6H_4]_2 (CH_2CH_2)_m$, showed higher activity than a conventional metallocene catalyst, $Cp_2ZrCl_2$ in polymerization at 6 bar of ethylene and the highest activity of the catalysts was 100 kg-PE/(mmol-Zr)˙(hr). The molecular weight of polyethylenes from the catalysts was much higher than that from $Cp_2ZrCl_2$ and the highest molecular weight was over 1,000,000. In commercial point of view, high activity of the catalysts and high molecular weight of polyethylenes are most important because high activity leads to decrease of cost of catalysts and high molecular weight leads to production of various kinds of polyethylene products. Therefore, the novel dinuclear metallocene catalysts in this study showed commercial applicability to polyethylene industry very much. In case of ethylene/1-hexene copolymerization, elastomers could be prepared from the catalysts and properties of the elastomers were comparable to those of commercial ones. One of the novel dinuclear metallocene catalysts was supported on silica. When it was used in ethylene polymerization or ethylene/1-hexene copolymerization after prepolymerization in 1 L of n-Hexane solvent, polyethylenes which have density above 0.919 g/ml were prepared. The polyethylene particles replicated the shape of the supported catalyst and bulk density of polyethylene was above 0.3 g/ml with no fouling in the reactor when 60 ml or less of 1-hexene was used in the polymerization. Bulk density higher than 0.3 g/ml with no fouling also supports the commercial applicability of the supported novel metall...