SHEAR BAND HAVING ULTRA-LOW HYSTERESIS RUBBER

• US 20190322137A1
• Filed: 11/30/2017
• Published: 10/24/2019
• Est. Priority Date: 11/30/2016
• Status: Active Grant

• Current Assignee: Compagnie Generale DES Etablissements Michelin SCA
• Original Assignee: Compagnie Generale DES Etablissements Michelin SCA
• Inventors: WILSON, Clifford, BOHN, Jr., Clayton, RHYNE, Timothy Brett, CRON, Steven M
• Granted Patent: US 11,420,474 B2
• Time in Patent Office: Days
• CPC Class Codes: B29D 30/02 Solid tyres ; Moulds therefor
• CPC Class Codes: B60C 1/00 Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
• CPC Class Codes: B60C 1/0016 Compositions of the tread
• CPC Class Codes: B60C 1/0041 Compositions of the carcass layers
• CPC Class Codes: B60C 2001/0091 Compositions of non-inflatable or solid tyres
• CPC Class Codes: B60C 7/00 Non-inflatable or solid tyres B60C1/00 takes precedence
• CPC Class Codes: B60C 7/102 Tyres built-up with separate rubber parts
• CPC Class Codes: B60C 7/14 using springs
• CPC Class Codes: B60C 7/146 extending substantially radially, e.g. like spokes
• CPC Class Codes: B60C 7/18 disposed radially relative to wheel axis
• CPC Class Codes: B60C 7/22 having inlays other than for increasing resiliency, e.g. for armouring
• CPC Class Codes: C08J 2467/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08J2467/06 takes precedence
• CPC Class Codes: C08J 2477/00 Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08J2479/06; of polyamide-imides or polyamide acids C08J2479/08; Derivatives of such polymers
• CPC Class Codes: C08J 5/041 with metal fibres
• CPC Class Codes: C08J 5/043 with glass fibres
• CPC Class Codes: C08J 5/046 with synthetic macromolecular fibrous material
• CPC Class Codes: C08K 2201/006 Additives being defined by their surface area
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C08K 7/14 Glass
• CPC Class Codes: C08L 2312/00 : Crosslinking
• CPC Class Codes: C08L 7/00 : Compositions of natural rubber
• CPC Class Codes: C08L 9/06 : Copolymers with styrene

Abstract

A shear band that may be used e.g., in a non-pneumatic tire is provided. The shear band uses interlaced reinforcing elements positioned within a shear layer of elastomeric material. A variety of configurations may be used to create the interlaced positioning of the reinforcing elements including e.g., a horizontal diamond or vertical diamond configuration. The shear layer formed from a rubber composition having a very low hysteresis reinforced with silica.

Claims

1. An annular shear band defining axial, radial and circumferential directions, the annular shear band comprising:

an annular shear layer constructed from a rubber composition;

a plurality of discrete, annular reinforcing elements positioned along a plurality of axially-oriented rows throughout the annular shear layer, the reinforcing elements separated from one another by a predetermined distance, each reinforcing element having a centerpoint, wherein the reinforcing elements are interlaced along the axial or radial direction of the shear band such that the centerpoints of reinforcing elements of adjacent, axially-oriented rows are arranged to form a rhombus having non-orthogonal angles between sides of the rhombus, wherein the rubber composition is based upon a cross-linkable rubber composition, the cross-linkable rubber composition comprising, in parts by weight per 100 parts by weight of rubber (phr);

between 50 phr and 100 phr of a natural rubber;

between 0 phr and 50 phr of a second rubber component selected from the group consisting of polybutadiene rubber, a copolymer of polybutadiene and styrene wherein the copolymer has no more than 5 mol % styrene and combinations thereof;

between 15 phr and 40 phr of a silica reinforcing filler that is limited to a first portion that is between 35 wt % and 70 wt % of the total silica and has a target surface area of between 25 m²/g and 39 m²/g and a second portion that is between 30 wt % and 65 wt % of the total silica and has a target surface area of between 125 m²/g and 145 m²/g; and

a sulfur cure system.

2. The annular shear band of claim 1, wherein the silica reinforcing filler is between 20 phr and 40 phr.

3. The annular shear band of claim 1, wherein the cross-linkable rubber composition comprises no more than 6 phr of a carbon black.

4. The annular shear band of claim 1, wherein the target surface area of the first portion of the silica is between 29 m²/g and 39 m²/g.

5. The annular shear band of claim 1, wherein the target surface area of the second portion of the silica is between 130 m²/g and 140 m²/g.

6. The annular shear band of claim 1, wherein the rubber composition includes 100 phr of natural rubber.

7. The annular shear band of claim 1, wherein the cross-linkable rubber composition further comprises between 0 phr and 20 phr of a third rubber component that is a functionalized styrene-butadiene copolymer having between 1 mol % and 35 mol % styrene, wherein the styrene-butadiene copolymer is functionalized with a moiety capable of bonding with the silica reinforcing filler.

8. The annular shear band of claim 1, wherein the rubber composition has a tan delta measured at 23°

C. and at 80% strain of between 0.013 and 0.025, a shear modulus G* measured at 23°

C. and at 80% strain of at least 1.30 MPa, and a strain at break of greater than 80%.

9. The annular shear band of claim 8, wherein the tan delta is between 0.013 and 0.022.

10. The annular shear band of claim 8, wherein the shear modulus G* is between 1.30 MPa and 1.80 MPa.

11. The annular shear band of claim 1, wherein the reinforcing elements are interlaced along the axial direction.

12. The annular shear band of claim 1, wherein the reinforcing elements are interlaced along the radial direction.

13. The annular shear band of claim 1, wherein the reinforcing elements each have a nominal diameter Φ

, and wherein adjacent, axially-oriented rows of the reinforcing elements are separated from each other by a predetermined distance, w_s, in the range of between Φ

/2 and Φ

/10.

14. The annular shear band of claim 13, wherein the predetermined distance, w_s, separating adjacent, axially-oriented rows of said reinforcing elements is Φ

/4.

17. The annular shear band of claim 11, wherein said reinforcing elements each have a nominal diameter Φ

, wherein non-adjacent, axially-oriented rows of said reinforcing elements are separated from each other by a predetermined distance, w_s, of about Φ

/4, and wherein adjacent, axially-oriented rows of said reinforcing elements are separated from each other by the predetermined distance, w_s, of about Φ

/4.

18. The annular shear band of claim 12, wherein said reinforcing elements each have a nominal diameter Φ

, wherein adjacent, axially-oriented rows of said reinforcing elements are separated from each other by a predetermined distance, w_s, of about Φ

/4, and wherein adjacent reinforcing elements along an axially-oriented row of said reinforcing elements are separated from each other by the predetermined distance, w_s, of about Φ

/4.

19. The annular shear band of claim 1, the shear band having a nominal diameter ND, and wherein said reinforcing elements each have a nominal diameter Φ

that is in the range of about ND/200 to about ND/1000.

20. The annular shear band of claim 1, wherein the reinforcing elements comprise metal, nylon, PET, or glass fibers impregnated in a thermosetting resin.

21. A non-pneumatic wheel comprising the annular shear band of claim 1.

15. (canceled)

16. (canceled)