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

1. 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 [Me 2 C(3-MeCp)(Flu)]ZrCl 2 or [Me 2 Si(Ind)(Flu)]ZrCl 2 .

2. The process of claim 1 , wherein the copolymerizing is performed in the presence of a catalyst of formula Ia

3. The process of claim 2 , wherein Z is a CR 2 R 3 group or an SiR 2 R 3 group where R 2 and R 3 are the same or different and are each hydrogen or an aromatic or aliphatic radical.

4. The process of claim 1 , wherein the aluminum-comprising compound is present and is methylaluminoxane (MAO).

5. The process of claim 1 , wherein the copolymerizing is performed at a molar ratio of metal of the catalyst of formula I to aluminum or boron of the cocatalyst of 1:0.1 to 1:100 000.

6. The process of claim 1 , wherein the copolymerizing is performed at a molar ratio of monomers to the catalyst of formula I of 1×10 10 :1 to 100:1.

7. The process of claim 1 , wherein the copolymerizing is performed in a solvent selected from the group consisting of butane, hexane, heptane, toluene, xylene, and ethylbenzene.

8. The process of claim 1 , wherein the copolymerizing is performed at a temperature of −30° C. to 250° C.

9. The process of claim 1 , wherein the copolymerizing is performed at a pressure of 0.1 to 1 MPa.

10. The process of claim 1 , wherein a molar proportion of 3-methylbut-1-ene in a reaction mixture, with respect to a sum of 3- methylbut-1-ene and ethene and propene, is at least 20%.

11. The process of claim 10 , wherein the molar proportion of 3-methylbut-1-ene in the reaction mixture is 40 to 80%.

12. The process of claim 1 , wherein Cp* and Y are the same or different and are each a group selected from the group consisting of a cyclopentadienyl group, an indenyl group, and a fluorenyl group,

Z is a hydrocarbon group,

M is a metal of group 4 of the Periodic Table of the Elements,

X is a halogen, and

m is two.

13. The process of claim 12 , wherein the catalyst of formula I is a catalyst of formula II, III, or V:

14. The process of claim 1 , wherein

Cp* is a cyclopentadienyl group substituted by 1 to 4 methyl groups,

Y is a nitrogen-comprising group,

Z is a silicon-comprising group,

M is a metal of group 4 of the Periodic Table of the Elements,

X is a halogen, and

m is two.

15. The process of claim 14 , wherein the catalyst of formula I is a catalyst of formula IV

16. The process of claim 1 , wherein the 3-methylbut-1-ene is obtained by

a) hydroformylating isobutene to 3-methylbutanal,

b) hydrogenating the 3-methylbutanal to 3-methylbutanol, and

c) eliminating water from 3-methylbutanol, and wherein

the 3-methylbut-1-ene obtained from the eliminating c) is employed directly without performing a chemical purification.

17. The process of claim 1 , wherein the copolymerizing is performed at a temperature of 50 to 80° C.

18. The process of claim 1 , wherein the metal of the catalyst is Zr.

19. The process of claim 1 , wherein the metal of the catalyst is Ti.

20. The process of claim 1 , wherein the metal of the catalyst is Hf.

21. The process of claim 1 , wherein Cp* is a substituted cyclopentadienyl group.

22. The process of claim 1 , wherein Cp* is an unsubstituted cyclopentadienyl group.

23. The process of claim 1 , wherein Cp* is an unsubstituted indenyl group.

24. The process of claim 1 , wherein Cp* is a substituted indenyl group.

25. The process of claim 1 , wherein Cp* is a tetrahydroindenyl group.

26. The process of claim 1 , wherein Cp* is an octahydrofluorenyl group.

27. The process of claim 1 , wherein Cp* is a fluorenyl group.