Ethylene .alpha.-olefin block copolymers and methods for production thereof

A block copolymer comprising an A block and a B block, wherein

• said A block consists of a high polymer of ethylene;
• said B block includes a first polymer segment contiguous to a junction of said A block and said B block, said first polymer segment including ethylene and an alpha-olefin other than ethylene;
• said B block including a tip segment, said tip segment being furthest from said junction, said tip segment being a polymer of ethylene, an alpha-olefin, and a non-conjugated diene, said diene being present in an mount up to about 10 mole percent based on total moles of the monomers of said block copolymer;
• wherein said block copolymer is formed in the presence of a vanadium catalyst system, said vanadium catalyst system having a vanadium compound and an organoaluminum compound.

A block copolymer comprising an A block and a B block, said B block having 2 or more segments, wherein the A block consists of a high polymer of ethylene, said B block having at least one ethylene, .alpha.-olefin copolymer segment, where said .alpha.-olefin is other than ethylene, and a non-conjugated diene,

• said tip segment being at the end of said B block, said tip segment being furthest of said segments from an A B junction;
• said block copolymer having a n-hexane soluble portion, not exceeding about 30 weight percent based on the total weight of the block copolymer;
• wherein said block copolymer is made by a process utilizing a vanadium catalyst system, wherein said vanadium catalyst system comprises a vanadium compound premixed with an organoaluminum compound, said premixing being for a sufficient time to produce an adequate quantity of active catalyst;
• wherein said vanadium compound is represented by one of the general formulas:
• ##STR10##
• VCl.sub.x (COOR).sub.3-x ;
• (2)
• where x=O to 3 and R=a hydrocarbon radical;
• VCl.sub.4 ;
• ##STR11## where AcAc=acetyl acetonate;
• V(AcAc).sub.3 ;
• ##STR12## where x=1 or 2;
• and
• VCl.sub.3.nB;
• where n=2 to 3 and B=Lewis base capable of making hydrocarbon-soluble complexes with VCl.sub.3, such as tetrahydrofuran, 2-methyl-tetrahydrofuran and dimethyl pyridine,
• where R represents a C.sub.1 to C.sub.10 aliphatic, acylic, or aromatic hydrocarbon radical;
• wherein the organoaluminum compound is represented by one of the formulas:
• AlR.sub.3, Al(OR')R.sub.2
• AlR.sub.2 X R.sub.2 Al--O--AlR.sub.2
• AlR'RX
• Al.sub.2 R.sub.3 X.sub.3
• AlRX.sub.2,
• where R and R' represent hydrocarbon radicals, said R and R' being the same or different, wherein X is a halogen selected from the group consisting of bromine, chlorine, and iodine;
• wherein a non-conjugated diene is present in said B block in the range of from about 0.03 to about 2 mole percent, based on the total moles of the monomers of said A B block copolymer;
• wherein said alpha-olefin in said B block is propylene;
• wherein said block copolymer is present at greater than about 50 weight percent based on the total weight of polymer, as polymerized;
• wherein said A B block copolymer has a Mw/Mn of less than about 2.5;
• wherein said A block comprises in the range of from about 20 to about 50 weight percent of said block copolymer;
• and
• wherein said block copolymer has a molecular weight of said block copolymer is in the range of from about 750 to about 20,000,000.

A process for preparing an olefin block copolymer, comprising:

• (a) forming a catalyst by premixing the reaction product of a vanadium compound represented by one of the formulas:
• ##STR13##
• VCl.sub.x (COOR).sub.3-x ;
• (2)
• where x=O to 3 and R=a hydrocarbon radical;
• VCl.sub.4 ;
• ##STR14## where AcAc=acetyl acetonate;
• V(AcAc).sub.3 ;
• ##STR15## where x=1 or 2;
• and
• VCl.sub.3.nB;
• where n=2 to 3 and B=Lewis base capable of making hydrocarbon-soluble complexes with VCl.sub.3, such as tetrahydrofuran, 2-methyl-tetrahydrofuran and dimethyl pyridine, where R represents a C.sub.1 to C.sub.10 aliphatic, acylic, or aromatic hydrocarbon radical;
• and an organoaluminum compound represented by one of the formulas:
• AlR.sub.3 Al(OR')R.sub.2
• AlR.sub.2 X R.sub.2 Al--O--AlR.sub.2
• AlR'RX
• Al.sub.2 R.sub.3 X.sub.3
• AlRX.sub.2,
• where R and R' represent hydrocarbon radicals, said R and R' being the same or different,
• wherein X is a halogen selected from the group consisting of bromine, chlorine, and iodine;
• said premixing being for a sufficient period of time to produce an adequate quantity of active catalyst;
• (b) feeding the reaction product of step (a) to a reactor concurrently with a feed stream consisting of ethylene to form an A block consisting of a high polymer of ethylene;
• and then
• (c) feeding at least a second monomer stream including ethylene and an .beta.-olefin other than ethylene, at a time of at least 0.1 seconds after step (b);
• (d) feeding a monomer stream including ethylene, an .alpha.-olefin other than ethylene and a non-conjugated diene.