Tire comprising a layer of circumferential reinforcing elements

Patent metadata

Field	Value
Publication number	US-10399385-B2
Application number	US-201515319112-A
Country	US
Kind code	B2
Filing date	May 27, 2015
Priority date	Jun 26, 2014
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

Tire comprising a crown reinforcement formed of at least two working crown layers each being formed of reinforcing elements inserted between two skim layers of rubber compound, a first layer S of polymer compound being in contact with at least one working crown layer and in contact with the carcass reinforcement and the crown reinforcement comprising at least one layer of circumferential reinforcing elements. The elastic modulus under tension at 10% elongation of at least one skim layer of at least one working crown layer is greater than 9 MPa, the maximum value of tan(δ), denoted tan(δ)max, of the at least one skim layer of at least one working crown layer is less than 0.100 and the complex dynamic shear modulus G*, measured at 10% and 60° C. on the return cycle, of the first layer S of polymer compound is greater than 1.35 MPa.

First claim

The invention claimed is:

1. A tire with a radial carcass reinforcement comprising a crown reinforcement formed of at least two working crown layers of reinforcing elements, crossed from one layer to the other making with the circumferential direction angles comprised between 10° and 45°, said at least two working crown layers each being formed of reinforcing elements inserted between two skim layers of rubber compound, a first layer of polymer compound being in contact with at least one working crown layer and in contact with the carcass reinforcement, said first layer of polymer compound extending axially as far as at least the axial end of the tread, said tread radially capping the crown reinforcement and being connected to two beads by two sidewalls, the crown reinforcement comprising at least one layer of circumferential reinforcing elements, wherein the elastic modulus under tension at 10% elongation of at least one skim layer of at least one working crown layer is greater than 9 MPa, wherein the maximum value of tan(δ), denoted tan(δ)max, of said at least one skim layer of at least one working crown layer is less than 0.100, wherein the complex dynamic shear modulus, measured at 10% and 60° C. on the return cycle, of said first layer of polymer compound is greater than 1.35 MPa and less than 2 MPa, and wherein the maximum value of tan(δ), denoted tan(δ) max , of the first layer is less than 0.100.

2. The tire according to claim 1 , wherein said first layer of polymer compound comprises a reinforcing filler composed of:
a) either carbon black with a BET specific surface area of between 30 and 160 m 2 /g, used in a content equal to or greater than 15 phr and less than or equal to 28 phr,
b) or a white filler of the silica and/or alumina type comprising SiOH and/or AlOH surface functional groups selected from the group formed of precipitated or pyrogenated silicas, aluminas or aluminosilicates or alternatively carbon blacks modified during or after synthesis with a specific surface area of between 30 and 260 m 2 /g used at a content greater than or equal to 15 phr and less than or equal to 55 phr,
c) or a blend of carbon black described at a) and a white filler described at b), in which the overall filler content is greater than or equal to 15 phr and less than or equal to 50 phr and the white filler phr content is greater than or equal to the phr content of carbon black minus 5.

3. The tire according to claim 1 , wherein said at least one skim layer of at least one working crown layer is an elastomer compound based on natural rubber or based on synthetic polyisoprene with a predominance of cis-1,4 chains and possibly at least one other diene elastomer, natural rubber or synthetic polyisoprene in the case of a blend being present at a content that predominates over the content of the other diene elastomer or elastomers used and of a reinforcing filler made up of:
a) either carbon black of BET specific surface area less than 60 m 2 /g whatever its oil absorption number, used at a content of between 40 and 100 phr,
b) or a white filler of the silica and/or alumina type comprising SiOH and/or AlOH functional groups at the surface, selected from the group formed of precipitated or pyrogenated silicas, aluminas or aluminosilicates or alternatively still carbon blacks modified during or after the synthesis with BET specific surface area of between 30 and 260 m 2 /g used at a content of between 40 and 100 phr,
c) or a blend of carbon black described at (a) and of a white filler described at (b), in which blend the overall filler content is between 40 and 100 phr.

4. The tire according to claim 1 , the tire comprising a second layer of polymer compound axially in contact with the first layer of polymer compound radially between the carcass reinforcement and the radially innermost layer of reinforcing elements of the crown reinforcement, wherein the complex dynamic shear modulus, measured at 10% and 60° C. on the return cycle, of said first layer of polymer compound is greater than 1.35 MPa.

5. The tire according to claim 4 , wherein the complex shear modulus, measured at 10% and 60° C. on the return cycle, of the second layer of polymer compound is less than 2 MPa.

6. The tire according to claim 4 , wherein the maximum tan (δ) value, denoted tan(δ)max, of the second layer of polymer compound is less than 0.100.

7. The tire according to claim 4 , wherein said second layer of polymer compound comprises a reinforcing filler made up of:
a) either carbon black with a BET specific surface area of between 30 and 160 m 2 /g, used in a content equal to or greater than 15 phr and less than or equal to 28 phr,
b) or a white filler of the silica and/or alumina type comprising SiOH and/or AlOH surface functional groups selected from the group formed of precipitated or pyrogenated silicas, aluminas or aluminosilicates or alternatively carbon blacks modified during or after synthesis with a specific surface area of between 30 and 260 m 2 /g used at a content greater than or equal to 15 phr and less than or equal to 55 phr,
c) or a blend of carbon black described at a) and a white filler described at b), in which the overall filler content is greater than or equal to 15 phr and less than or equal to 50 phr and the white filler phr content is greater than or equal to the phr content of carbon black minus 5.

8. The tire according to claim 1 , a layer of rubber compound being placed between at least the ends of said at least two working crown layers and said at least two working crown layers having unequal axial widths, wherein the distance d between the end of the axially narrowest working layer and the working layer separated from the axially narrowest working layer by the layer of rubber compound is such that 1.1ø<d<2.2ø, ø being the diameter of the reinforcing elements of said at least one layer of circumferential reinforcing elements and wherein, in a meridian plane, the thickness of the layer of rubber compound is substantially constant over the axial width comprised between the axially interior end of the layer of rubber compound and the end of the axially narrowest working layer.

9. The tire according to claim 1 , wherein said reinforcing elements of at least one working crown layer are cords with saturated layers, at least one internal layer being sheathed by a layer made of a polymer composition such as a non-crosslinkable, crosslinkable or crosslinked rubber composition.

10. The tire according to claim 1 , wherein the layer of circumferential reinforcing elements is positioned radially between two working crown layers.

11. The tire according to claim 1 , wherein the reinforcing elements of at least one layer of circumferential reinforcing elements are metallic reinforcing elements having a secant modulus at 0.7% elongation comprised between 10 and 120 GPa and a maximum tangent modulus less than 150 GPa.

12. The tire according to claim 1 , wherein the reinforcing elements of the working crown layers are inextensible.

13. The tire according to claim 1 , wherein the crown reinforcement is supplemented radially on the outside by at least one additional ply, referred to as a protective ply, of reinforcing elements referred to as elastic elements, which are oriented with respect to the circumferential direction at an angle of between 10° and 45° in the same direction as the angle formed by the elements of the working ply radially adjacent to it.

14. The tire according to claim 1 , wherein the crown reinforcement further comprises a triangulation layer formed of metallic reinforcing elements making angles greater than 60° with the circumferential direction.

Assignees

• Michelin & Cie
• Michelin Rech Tech

Inventors

• Rehab Hichem
• Parmentier Jean-François

Classifications

• B60C2001/0066

  Compositions of the belt layers · CPC title

• B60C2009/1878

  with flat cushions or shear layers between the carcass and the belt · CPC title

• B60C2001/0075

  Compositions of belt cushioning layers · CPC title

• B60C2200/06

  for heavy duty vehicles · CPC title

• B60C9/2006

  consisting of steel cord plies only · CPC title