Cross-linkable ethylene polymer composition comprising epoxy-groups and a cross-linking agent

1. An ethylene polymer composition comprising:

(A) an ethylene polymer comprising epoxy-groups, and

(B) a cross-linking agent comprising

(B1) an organo-metallic Lewis acid, and at least one of:

(B2) a compound comprising at least one amino group; and

(B3) a compound comprising at least one hydroxyl group.

2. The ethylene polymer composition according to claim 1 , wherein said organo-metallic Lewis acid (B1) is a compound according to formula (I):

M m+ L n   (I)

wherein

M is an element selected from lanthanides or an element of groups 2 to 14 of the IUPAC periodic table (1989) except the elements of the group 7 of the IUPAC periodic table (1989) and Be, C, Si, Ge, Tl, Pb, Tc, Hg and Cd;

each L is the same or different and is a ligand linked to M; and

m is 1 to 4, and n is 1 to 4, with the proviso that m-n is 0.

3. The ethylene polymer composition according to claim 1 , wherein said organo-metallic Lewis acid is a compound of formula: TiL 4 .

4. The ethylene polymer composition according to claim 1 , wherein each L is a saturated hydrocarbyl group, each hydrocarbyl group independently containing one or more hetero atoms selected from N, O, P, S, or Si.

5. The ethylene polymer composition according to claim 1 , wherein said compound (B2) is a compound selected from the group consisting of: a saturated aliphatic (mono, di, or tri)amine with up to 50 carbon atoms; an unsaturated aliphatic (mono, di, or tri)amine with up to 50 carbon atoms; and an aromatic hydrocarbyl with up to 50 carbon atoms.

6. The ethylene polymer composition according to claim 1 , wherein said compound (B2) comprises at least two amino substituents.

7. The ethylene polymer composition according to claim 1 , wherein said compound (B3) is selected from aliphatic di- to hexa-alcohols or aromatic di- to hexa-alcohols.

8. The ethylene polymer composition according to claim 1 wherein the epoxy-group-containing monomer units are glycidyl methacrylate comonomer units.

9. The ethylene polymer composition according to claim 1 wherein the amount of epoxy-group-containing monomer units is at least 0.1 wt %, based on the amount of olefin polymer (A).

10. The ethylene polymer composition according to claim 1 , wherein the content of epoxy-group-containing monomer units is 20 wt % or less, based on the amount of olefin polymer (A).

11. A process for cross-linking the ethylene polymer composition of claim 1 , the process comprising cross-linking the ethylene polymer comprising epoxy-groups (A) using the cross-linking agent (B).

12. The process according to claim 11 , wherein said cross-linking takes place for 2 to 10 minutes.

13. The process according to claim 11 , wherein said cross-linking is carried out at a temperature of at least 150° C.

14. A method of use of a cross-linking agent (B) comprising:

(B1) an organo-metallic Lewis acid, and at least one of:

(B2) a compound comprising at least one amino group; and

(B3) a compound comprising at least one hydroxyl group;

the method comprising using the cross-linking agent (B) for cross-linking of an ethylene polymer comprising epoxy-groups (A).

15. The ethylene polymer composition according to claim 1 , wherein said compound (B2) is a compound selected from the group consisting of: a saturated aliphatic (mono, di, or tri)amine with 1 to 20 carbon atoms; an unsaturated aliphatic (mono, di, or tri)amine with 1 to 20 carbon atoms; and an aromatic hydrocarbyl with 1 to 20 carbon atoms.

16. The ethylene polymer composition according to claim 1 , wherein said compound (B3) is selected from aliphatic di-, tri- or tetra-alcohols or aromatic di-, tri- or tetra-alcohols.