Multilayer film having high tear strength
The present invention relates to a multilayer film comprising a layer (a) and a layer (c), in each case based on at least one propylene copolymer in an amount of at least 15% by weight, at least one propylene polymer in an amount of at least 40% by weight, in each case based on the total weight of the layer (a)/(c), at least one multi-ply inner layer (b) based on at least one homo- and/or copolyamide comprising isophoronediamine units as a polyamide component, adhesion promoter layers (d) and (e), wherein the thickness of the multi-ply layer (b) is at least 40% of the total thickness of the multilayer film, preferably at least 45% or at least 50%.
1. A multilayer film comprising:
(a) one layer (a) based on
at least one propylene copolymer in an amount of at least 15% by weight,
at least one propylene homopolymer in an amount of at least 40% by weight, and
optionally up to 30% by weight of additives, based in each case on the total weight of the layer (a), the components always adding up to 100% by weight,
(b) one multi-ply, inner layer (b) based on at least one homo- and/or copolyamide having isophoronediamine units as a polyamide component,
(c) one layer (c) based on
at least one propylene copolymer in an amount of at least 15% by weight,
at least one propylene homopolymer in an amount of at least 40% by weight, and
optionally up to 30% by weight of additives, based in each case on the total weight of the layer (c), the components always adding up to 100% by weight, and
(d) one adhesion-promoter layer (d) arranged between the layer (a) and the layer (b), based on at least one modified thermoplastic olefin homo- or copolymer,
(e) one adhesion-promoter layer (e) arranged between the layer (b) and the layer (c), based on at least one modified thermoplastic olefin homo- or copolymer, the thickness of the multi-ply layer (b) being at least 40% of the total thickness of the multilayer film.
2. The multilayer film of claim 1 , wherein the thickness of the multi-ply layer (b) is at least 45% of the total thickness of the multilayer film.
3. The multilayer film of claim 1 , wherein the layer (b) is at least three ply.
4. The multilayer film as claimed in claim 1 , wherein all plies of the layer (b) are based on at least one homo- and/or copolyamide having isophoronediamine units as a polyamide component.
5. The multilayer film of claim 1 , wherein the plies of the layer (b) each have, independently of one another, a thickness within the range of 2 μm to 30 μm.
6. The multilayer film of claim 3 , wherein at least two plies of the multi-ply layer (b) have a different composition.
7. The multilayer film of claim 6 , wherein the multi-ply layer (b) includes two outer plies and one or more plies arranged between the two outer plies;
wherein the two outer plies of the multi-ply layer (b) differ in composition from the plies of the multi-ply layer (b) that are arranged between said two outer plies.
8. The multilayer film of claim 7 , wherein the plies of the multi-ply layer (b) that are arranged between said two outer plies have the same composition.
9. The multilayer film of claim 3 , wherein each of the plies of the multi-ply layer (b) comprises, as a polyamide component, at least one homo- and/or copolyamide having isophoronediamine units.
10. The multilayer film of claim 1 , wherein the proportion of isophoronediamine units in the copolyamide is at least 1% by weight, based in each case on the total weight of the copolyamide.
11. The multilayer film of claim 1 , wherein the isophoronediamine unit-comprising polyamide component of the multi-ply layer (b) has aliphatic or aromatic dicarboxylic acid units, and the copolyamide has ε-caprolactam units copolymerized with isophoronediamine units.
12. The multilayer film of claim 1 , wherein, for some of the plies of the multi-ply layer (b), the polyamide component having isophoronediamine units.
13. The multilayer film of claim 7 , characterized in that the two outer plies of the multi-ply layer (b) are based on a mixture of PA-6 and a copolyamide having isophoronediamine units, aromatic dicarboxylic acid units and copolymerized ε-caprolactam units.
14. The multilayer film of claim 1 , wherein the multi-ply layer (b) has a layer thickness of at least 25 μm.
15. The multilayer film of claim 1 , wherein the layer (a) and the layer (c) each contain, independently of one another, at least one propylene copolymer in an amount of up to 40% by weight, based in each case on the total weight of the layer (a) or the layer (c).
16. The multilayer film of claim 1 , wherein the multi-ply layer (b) serves as a barrier layer.
17. The multilayer film of claim 1 , wherein it is arranged symmetrically in relation to the central, multi-ply layer (b) and wherein the layer (a) and the layer (c) are each a surface layer.
18. The multilayer film of claim 1 , wherein the multilayer film includes at least one adhesion-capable layer of adhesive (f) and/or at least one layer (h) based on a sealing composition.
19. An adhesive tape comprising a multilayer film of claim 1 .
20. A waterproof sheeting material, preferably a bitumen-based waterproof sheeting material, against water and/or weathering effects, comprising a multilayer film of claim 1 , optionally wherein the waterproof sheeting material is a protective covering for roof, as external cladding, as protective covering for buildings or parts thereof or as pipe cladding.