Tie based on grafted polyethylene and on high-impact or crystal polystyrene with cohesive failure

Tie comprising, (% by total weight of the said tie):

• from 10 to 79% of a polyethylene (PE) (A) which is a very low density polyethylene (VLDPE) with a density of between 0.870 and 0.910 g/cm3 or of a blend of at least two polyethylenes, PE (A1) and PE(A2), where:
• PE (A2), which is a VLDPE with a density of between 0.870 and 0.910 g/cm3, is different from PE (A1),
• PE (A) is grafted or the blend PE (A1) and (A2) is grafted or co-grafted,lend
• PE(A), PE(A1) or PE(A2) are chosen from PE homopolymers and copolymers, said copolymers comprising at least 51 mole % of ethylene and a comonomer selected from the group consisting of:
• an alpha-olefin chosen from propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, 1-dococene, 1-tetracocene, 1-hexacocene, 1-octacocene, 1-triacontene and mixtures thereof;
• and wherein said PE (A) or blend of at least two polyethylenes, PE (A1) and PE(A2) is not selected from the group consisting of esters of unsaturated carboxylic acids, vinylesters of saturated carboxylic acids, and dienes;
• from 21 to 50% of a grafted or ungrafted high-impact PS(B) or a grafted or ungrafted crystal PS (B);
• and
• from 0 to 70% of an ungrafted PE(C) obtained by Ziegler-Natta catalysis.