Process for preparing polymers from 3-methylbut-1-ene

A process for preparing a copolymer, the process comprising:

• copolymerizing a monomer comprising ethene and a comonomer comprising 3-methybut-1-ene, in the presence of a cocatalyst comprising an aluminum- or boron-comprising compound and a catalyst of formula I
• wherein:
• Cp* is selected from the group consisting of a substituted cyclopentadienyl group, an unsubstituted cyclopentadienyl group, an unsubstituted indenyl group, a substituted indenyl group, an unsubstituted tetrahydroindenyl group, a substituted tetrahydroindenyl group, an unsubstituted octahydrofluorenyl group, a substituted octahydrofluorenyl group, an unsubstituted fluorenyl group, and a substituted fluorenyl group;
• Y is selected from the group consisting of a substituted cyclopentadienyl group, an unsubstituted cyclopentadienyl group, an unsubstituted indenyl group, a substituted indenyl group, an unsubstituted tetrahydroindenyl group, a substituted tetrahydroindenyl group, an unsubstituted octahydrofluorenyl group, a substituted octahydrofluorenyl group, an unsubstituted fluorenyl group, and a substituted fluorenyl group, or
• an anionic ligand group comprising nitrogen, phosphorus, oxygen, or sulfur, and up to 20 atoms which are not hydrogen, wherein Cp* and Y are optionally joined to one another covalently or via a Z group;
• 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,
• wherein the copolymer produced comprises 1 to 10 mol% 3-methylbut-1-ene and has a melting point between 90 and 130° C. and a weight average molar mass of 6500 to 8500 g/mol, or
• wherein the copolymer produced comprises 0.5 to 6 mol% 3-methylbut-1-ene and has a melting point between 90 and 130° C. and a weight average molar mass of 10,000 to 500,000 g/mol, or
• wherein the copolymer produced comprises 3 to 6 mol% 3-methylbut-1-ene and has a melting point between 90 and 115° C. and a weight average molar mass of 15,000 to 75,000 g/mol,
• with the proviso that the compound of formula I is not [Me2C(3-MeCp)(Flu)]ZrCl2 or [Me2Si(Ind)(Flu)]ZrCl2.