Patent ID: 8202959

Claim:
A process for preparing at least one copolymer comprising propene as a monomer and 3-methylbut-1-ene as a comonomer, the process comprising: copolymerizing a reaction mixture comprising propene and 3-methylbut-1-ene in the presence of a catalyst of formula (I) and aluminum-comprising compound or boron-comprising compound as a cocatalyst, to obtain the copolymer, wherein a proportion of the 3-methylbut-1-ene in the copolymer is 1 to 10 mol %, wherein the copolymer has a melting point of 90 to 125° C., wherein the copolymer has a molar mass of 6500 to 8500, and wherein, in the catalyst of formula (I) Cp* is selected from the group consisting of a substituted cyclopentadienyl, an unsubstituted cyclopentadienyl, a substituted indenyl, an unsubstituted indenyl, a substituted tetrahydroindenyl, an unsubstituted tetrahydroindenyl, a substituted octahydrofluorenyl, an unsubstituted octahydrofluorenyl, a substituted flourenyl, and an unsubstituted fluorenyl group, Y is selected from the group consisting of a substituted cyclopentadienyl, an unsubstituted cyclopentadienyl, a substituted indenyl, an unsubstituted indenyl, a substituted tetrahydroindenyl, an unsubstituted tetrahydroindenyl, a substituted octahydrofluorenyl, an unsubstituted octahydrofluorenyl, a substituted flourenyl, an unsubstituted fluorenyl group, or an anionic ligand group comprising nitrogen, phosphorus, oxygen, or sulfur, and up to 20 atoms which are not hydrogen, or Cp* and Y are joined to one another covalently or via a Z group, wherein Z is boron or a group which comprises an element of group 14 of the Periodic Table of the Elements, and has up to 20 atoms which are not hydrogen atoms, M is a metal of group 3 to 10, with the exception of scandium, or of the lanthanoids, of the Periodic Table of the Elements, X is in each case independently a halogen atom, a pseudohalogen, a hydrogen atom, a silyl group, a phosphide, a sulfide, or an organic radical, and m is a number which is sufficient to saturate the valences of M with the X, an aluminum- or boron-comprising compound as a cocatalyst.