Patent ID: 6265512
Filing Date: 2001-07-24
Classification: C07F,C08F,C08L,Y10S

Abstract:
A propylene homopolymer, said polymer being elastomeric and being soluble in at least one nonpolar organic solvent selected from the group consisting of toluene, xylene, heptane, and hexane, said polymer comprisinga) greater than 3 weight percent and up to 45 weight percent homotactic sequences each having only r or m diads, all of which homotactic sequences have a helical length in the range of 20 to 150 .ANG., andb) in the range of 55 to 97 weight percent of the polymer being the sum of1) homotactic sequences, each having only r or m diads, and being less than 20 .ANG. in helical length, and having fewer than 10 repeat units with mmmm pentads being present in the range of 0 to 35 weight percent of the polymer, and2) heterotactic sequences having unequal numbers of r and m diads, said polymer having a molecular weight (M.sub.w) of at least 70,000;wherein said polymer is prepared by a metallocene catalyst having the formula{ligand1-bridge-ligand2}MX.sub.2wherein ligand1 and ligand2 are different and are selected from the group consisting of cyclopentadienyl (Cp) indenyl (ind), fluorenyl (flu), 4,5-dihydrocyclopentaphenathryl (H.sub.2 CPA), and cyclopentaphenanthryl (Cring groups, wherein, the ring groups can be substituted by groups selected from the group consisting ofi) C.sub.1 -C.sub.4 straight-chain or branched alkyl,uu) C.sub.6 -C.sub.20 aryl,1iii) C.sub.7 -C.sub.20 alkylaryl,iv) C.sub.4 -C.sub.7 cycloalkyl,v) (--CH.sub.2 --).sub.n wherein n=3, 4, or 5, or (--CH.dbd.CH--).sub.m wherein m is 1, 2, 3, or 4, connecting adjacent or non-adjacent ring carbon atoms in the same ring structure,vi) fused aromatic rings, andvii) fused aromatic rings substituted by any one of groups i)-iv);bridge is a linking group joining ligand 1 and ligand2 at C-1 position of Cp and ind ligands or C-9 position of flu and CPA ligands and is selected from the group consisting ofi) >CR.sup.1 R.sup.2ii) >SiR.sup.1 R.sup.2iii) --CR.sup.1 R.sup.2 --CR.sup.3 R.sup.4 --iv) --SiR.sup.1 R.sup.2 --SiR.sup.3 R.sup.4 --v) --CR.sup.1 R.sup.2 --SiR.sup.3 R.sup.4 --vi) --SiR.sup.1 R.sup.2 --CR.sup.3 R.sup.4 --,wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 can be the same or different and are selected from the group consisting of H, C.sub.1 -C.sub.20 straight-chain or branched alkyl, C.sub.6 -C.sub.20 aryl, and C.sub.3 -C.sub.8 cycloalkyl,M is a metal atom selected from the group consisting of Zr, Hf, and Ti, andX is selected from the group consisting of Cl, Br, I, C.sub.1 -C.sub.20 straight-chain or branched alkyl, C.sub.6 -C.sub.20 aryl, C.sub.7 -C.sub.20 alkaryl, and C.sub.7 -C.sub.20 aralkyl;wherein said metallocene catalyst exhibits C.sub.s point group symmetry; andwherein said metallocene catalyst has an asymmetry parameter of at least 1.03 and less than 2.09;wherein ligand1 is fluorenyl and ligand2 is: ##STR9##wherein strap is selected from the group consisting of --CH.dbd.CH-- and --CH.sub.2 --CH.sub.2 --.