Abstract: A process for the in situ blending of polymers comprising continuously contacting, under polymerization conditions, a mixture of ethylene and at least one alpha-olefin having at least 3 carbon atoms with a catalyst in at least two fluidized bed reactors connected in series, said catalyst comprising:(i) a complex consisting essentially of magnesium titanium, a halogen, and an electron donor;(ii) at least one activator compound for the complex having the formula AlR".sub.e X'.sub.f H.sub.g wherein X' is Cl or OR'"; R" and R'" are saturated aliphatic hydrocarbon radicals having 1 to 14 carbon atoms and are alike or different; f is 0 to 1.5; g is 0 or 1; and e+f+g=3; and(iii) a hydrocarbyl aluminum cocatalyst, the polmerization conditions being such that ethylene copolymer having a high melt index in the range of about 0.1 to about 1000 grams per 10 minutes is formed in at least one reactor and ethylene copolymer having a low melt index in the range of about 0.001 to about 1.

Abstract: A process for the in situ blending of polymers comprising continuously contacting, under polymerization conditions, a mixture of ethylene and at least one alpha-olefin having at least 3 carbon atoms with a catalyst in at least two fluidized bed reactors connected in series, said catalyst comprising:(i) a complex consisting essentially of magnesium titanium, a halogen, and an electron donor;(ii) at least one activator compound; and(iii) a hydrocarbyl aluminum cocatalyst, the polymerization conditions being such that ethylene copolymer having a high melt index in the range of about 0.1 to about 1000 grams per 10 minutes is formed in at least one reactor and ethylene copolymer having a low melt index in the range of about 0.001 to about 1.0 gram per 10 minutes is formed in at least one other reactor, each copolymer having a density of about 0.860 to about 0.965 gram per cubic centimeter and a melt flow ratio in the range of about 22 to about 70, and being admixed with active catalyst.

Abstract: A process for the in situ blending of polymers comprising continuously contacting, under polymerization conditions, a mixture of ethylene and at least one alpha-olefin having at least 3 carbon atoms present in an amount of about 0.1 to 3.5 mole per mole of ethylene with a catalyst in at least two fluidized bed reactors connected in series, said catalyst comprising:(i) a complex consisting essentially of magnesium titanium, a halogen, and an electron donor;(ii) at least one activator compound for the complex having the formula A1R".sub.e X'.sub.f H.sub.g wherein X' is C1 or OR"'; R" and R"' are saturated aliphatic hydrocarbon radicals having 1 to 14 carbon atoms and are alike or different; f is 0 to 1.5; g is 0 or 1; and e+f+g=3; and(iii) a hydrocarbyl aluminum cocatalyst, the polymerization conditions being such that ethylene copolymer having a high melt index in the range of about 0.