METALLOCENE CATALYST FOR PREPARING POLYETHYLENE AND PROCESS FOR PREPARING POLYETHYLENE USING CATALYST

摘要

PURPOSE: A catalyst is provided which has a good thermal stability. A polyethylene is also provided which has a uniform composition and molecular distribution degree by using the catalyst. CONSTITUTION: A metallocene catalyst of formula 1 and 2 is provided, wherein M is transition metal selected from 3- 10 group and lanthanide metal; Cp is cyclopentanyl; D is N or P; LB is Lewis base electron donor selected from OR, SR, PR2 or NR2; LA is organic compound Lewis acid selected from trialkyl aluminum, dialkyl haloaluminum, alkyl dihaloaluminum, dialkyl magnesium and alkyl halomagnesium; B is cross linking group selected from SiR2, CR2, SiR2SiR2, CR2CR2, CR=CR, CR2SiR2, GeR2, BR2; L is one or two substituted group selected from halogen, alkyl, allyl, sillyl, amine, amide, allyloxy, alkoxy, haloalkyl and haloallyl; R is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, cyclohexyl, dicyclohexyl methyl, phenyl, methyl phenyl and adamantyl. Polyethylene is prepared at 0-300C, 1-1,000 atm in the presence of the metallocene catalyst, and methyl aluminoxane, alkyl haloaluminum or boron organic amine as a co catalyst, 1-100 mole ratio of alkyl aluminum to remove impurity of monomer and solvent.