Solid catalyst for propylene polymerization and a method for preparation of polypropylene using the same
Provided are a solid catalyst for propylene polymerization which includes titanium, magnesium, halogen and an internal electron donor mixture of two or more compounds wherein the internal electron donor mixture includes at least one selected from the bicycloalkanes or bicycloalkenes and at least one selected from diethers and succinates, and a method for preparing propylene using the same. As disclosed, it is possible to prepare polypropylene having an excellent stereoregularity with a high production yield.
1. A solid catalyst for propylene polymerization, wherein the solid catalyst comprises titanium, magnesium, halogen and an internal electron donor mixture of two or more compounds, wherein the internal electron donor mixture comprises at least one donor selected from bicycloalkane dicarboxylates or bicycloalkene dicarboxylates represented by formula (II), formula (III), formula (IV) or formula (V), and at least one donor selected from diether compounds represented by formula (VI) and succinate compounds represented by formula (VII):
wherein R 1 and R 2 , which may be the same or different, are each a linear, branched or cyclic C 1-20 alkyl, alkenyl, aryl, arylalkyl or alkylaryl group; and respectively; R 3 , R 4 , R 5 , R 6 , R 7 and R 8 , which may be the same or different, are each a hydrogen or a linear, branched or cyclic C 1-20 alkyl, alkenyl, aryl, arylalkyl or alkylaryl group.
2. The solid catalyst for propylene polymerization according to claim 1 , comprising magnesium 5-40 wt %, titanium 0.5-10 wt %, halogen 50-85 wt % and the internal electron donor mixture 2.5-30 wt %.
3. A method for preparing polypropylene comprising polymerizing propylene or copolymerizing propylene with other alpha-olefins, in the presence of a solid catalyst according to claim 1 , AlR 3 , wherein R is C 1-8 alkyl group as a cocatalyst and R 1 m R 2 n Si(OR 3 ) (4-m-n) , wherein R 1 and R 2 , which are the same or different, are each a linear, branched or cyclic C 1-12 alkyl or aryl group; R 3 is a linear or branched C 1-6 alkyl group; m and n are 0 or 1, respectively, provided that m+n is 1 or 2, as an external electron donor.
4. Method for preparing polypropylene comprising polymerizing propylene or copolymerizing propylene with other alpha-olefins, in the presence of a solid catalyst according to claim 2 , AlR 3 , wherein R is C 1-8 alkyl group as a cocatalyst and R 1 m R 2 n Si(OR 3 ) (4-m-n) , wherein R 1 and R 2 , which are the same or different, are each a linear, branched or cyclic C 1-12 alkyl or aryl group; R 3 is linear or branched C 1-6 alkyl group; m and n are 0 or 1, respectively, provided that m+n is 1 or 2, as an external electron donor.