Multilayer laminate which can be used for the reinforcement of a tyre belt
A multilayer laminate, which is usable as a reinforcing element for a finished article or for a semifinished product made of rubber, such as a tire, includes at least one polymer film having, in any tensile direction in the film's plane, a Young's modulus that is greater than 500 MPa. The film is positioned between and in contact with two layers formed of a rubber composition, such as natural rubber. Each layer formed of the rubber composition exhibits, in a crosslinked state, a secant modulus that, in extension at 10% elongation, is greater than 30 MPa, with between 30 and 150 MPa being preferable for the secant modulus.
1. A tyre comprising a multilayer laminate,
wherein the multilayer laminate includes at least one polymer film,
wherein each polymer film has a Young's modulus E, in any tensile direction in a plane of the film, greater than 500 MPa,
wherein each polymer film is positioned between and in contact with two layers formed of a rubber composition, and
wherein each layer formed of the rubber composition exhibits, in a crosslinked state, a secant modulus Ms, in extension at 10% elongation, greater than 40 MPa.
2. The tyre according to claim 1 , wherein the multilayer laminate is included as a reinforcement in a belt of the tyre.
3. The tyre according to claim 2 , wherein the belt includes the multilayer laminate in combination with circumferential reinforcing threads embedded in at least one rubber layer other than the layers formed of the rubber composition.
4. The tyre according to claim 1 , wherein the Young's modulus E, for each polymer film in any tensile direction in the plane of the film, is greater than 2000 MPa.
5. The tyre according to claim 1 , wherein each polymer film exhibits a maximum tensile stress σ max greater than 100 MPa, in any tensile direction considered in a plane of the polymer film.
6. The tyre according to claim 1 , wherein the rubber composition includes a diene rubber.
7. The tyre according to claim 6 , wherein the diene rubber is selected from a group of elastomers consisting of: polybutadienes, natural rubber, synthetic polyisoprenes, butadiene copolymers, isoprene copolymers, and mixtures thereof.
8. The tyre according to claim 7 , wherein each layer formed of the rubber composition includes from 50 to 100 phr of natural rubber.
9. The tyre according to claim 1 , wherein each layer formed of the rubber composition includes more than 5 phr of a plasticizing agent, with between 5 and 30 phr of the plasticizing agent being preferable.
10. The tyre according to claim 1 , wherein each layer formed of the rubber composition includes a tackifying resin at a content of greater than 3 phr.
11. The tyre according to claim 1 , wherein the secant modulus Ms of each layer formed of the rubber composition is between 40 and 150 MPa.
12. The tyre according to claim 1 , wherein the Young's modulus E, for each polymer film in any tensile direction in the plane of the film, is greater than 1000 MPa.
13. The tyre according to claim 1 , wherein each polymer film exhibits a maximum tensile stress σ max greater than 80 MPa, in any tensile direction considered in a plane of the polymer film.
14. The tyre according to claim 1 , wherein the polymer film is a thermoplastic polymer film.
15. The tyre according to claim 14 , where the thermoplastic polymer film exhibits, after 30 minutes at 150° C., a relative contraction in length of less than 5%.
16. The tyre according to claim 14 , wherein the thermoplastic polymer film includes a polyester or a polyamide.
17. The tyre according to claim 14 , wherein the thermoplastic polymer film includes a polyester, and wherein the polyester is a polyethylene terephthalate or a polyethylene naphthalate.