Tyre with self-sealing layer
View Patent ↗Tubeless tire in the form of a torus open radially inwards with an outer wall and an inner wall, characterized in that at least part of the inner wall is covered with a self-sealing layer comprising a thermoplastic styrene (TPS) elastomer having a Shore 0 hardness of less than 35.
1. A tubeless tyre having a shape of a torus open radially inwards, the tyre comprising:
an outer wall;
an inner wall; and
a self-sealing layer covering at least part of the inner wall, the self-sealing layer including a thermoplastic styrene (TPS) elastomer having a dynamic modulus G* of less than 0.01 MPa, the dynamic modulus G* being measured at a frequency of 10 Hz and a temperature of 60° C.
2. The tyre according to claim 1 , wherein the self-sealing layer has a Shore 0 hardness of less than 35.
3. The tyre according to claim 1 , wherein the Shore 0 hardness of the self-sealing layer is less than 20.
4. The tyre according to claim 3 , wherein the Shore 0 hardness of the self-sealing layer is less than 10.
5. The tyre according to claim 1 , wherein, on a side facing an internal cavity of the tyre, the self-sealing layer is covered with a film.
6. The tyre according to claim 5 , wherein the film is an extensible thermoplastic film chosen from a group that includes a polypropylene (PP) film, a polyethylene (PE) film, a polyvinyl chloride (PVC) film, and a polyvinylidene chloride (PVDC) film.
7. The tyre according to claim 5 ,
wherein the film is an extensible thermoplastic film, and
wherein, if a puncture hole occurs in the inner wall, the thermoplastic film is sufficiently extensible to extend into the puncture hole when the tyre is inflated to an operating inflation pressure.
8. The tyre according to claim 7 , wherein a thickness of the thermoplastic film is less than 100 μm.
9. The tyre according to claim 8 , wherein the thickness of the thermoplastic film is between 5 μm and 50 μm.
10. The tyre according to claim 1 , wherein the TPS is a predominant elastomer of the self-sealing layer.
11. The tyre according to claim 1 , wherein the TPS elastomer is chosen from a group of block copolymers that includes any one of styrene/butadiene/styrene (SBS), styrene/isoprene/styrene (SIS), styrene/isoprene/butadiene/styrene (SIBS), styrene/ethylene-butylene/styrene (SEBS), styrene/ethylene-propylene/styrene (SEPS), styrene/ethylene-ethylene-propylene/styrene (SEEPS), and blends of these copolymers.
12. The tyre according to claim 11 , wherein the TPS elastomer is chosen from a group of copolymers that includes SEBS copolymers, SEPS copolymers, and blends of these copolymers.
13. The tyre according to claim 1 , wherein the self-sealing layer includes an extender oil in an amount greater than 200 phr (parts by weight per hundred parts of rubber or elastomer).
14. The tyre according to claim 1 , further comprising an air-tight layer that includes a rubber composition substantially air-tight to an inflation gas and substantially covering an entirety of the inner wall of the tyre, wherein the self-sealing layer at least partly covers the air-tight layer on a side facing an internal cavity of the tyre.
15. The tyre according to claim 1 , wherein the self-sealing layer is positioned at a crown of the tyre.
16. The tyre according to claim 1 , wherein the tyre is suitable for a cycle.
17. The tyre according to claim 16 , wherein a thickness of the self-sealing layer is between 0.6 and 1.5 mm.
18. The tyre according to claim 17 , wherein the thickness of the self-sealing layer is between 0.8 and 1.2 mm.