Runflat tire

• US 20080178981A1
• Filed: 07/25/2007
• Published: 07/31/2008
• Est. Priority Date: 10/10/2006
• Status: Active Grant

• Current Assignee: Goodyear Tire & Rubber Company
• Original Assignee: Goodyear Tire & Rubber Company
• Inventors: Weydert, Marc, Agostini, Giorgio, Corvasce, Filomeno Gennaro, Schmitz, Frank, Kaes, Christian, Gregorius, Leon Jean Mathias
• Granted Patent: US 7,789,119 B2
• Time in Patent Office: Days
• US Class Current: 152/517
• CPC Class Codes: B60C 17/00 Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor
• CPC Class Codes: B60C 17/0027 comprising portions of different rubbers in a single insert
• CPC Class Codes: B60C 2001/0033 Compositions of the sidewall inserts, e.g. for runflat
• CPC Class Codes: C08K 5/3415 Five-membered rings
• CPC Class Codes: C08K 5/39 Thiocarbamic acids; Derivatives thereof, e.g. dithiocarbamates
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/08 Homopolymers or copolymers according to C08L7/00 - C08L21/00; Derivatives thereof
• CPC Class Codes: C08L 7/00 Compositions of natural rubber
• CPC Class Codes: C08L 9/00 Compositions of homopolymers or copolymers of conjugated diene hydrocarbons

Abstract

A pneumatic runflat tire including at least one sidewall insert, the at least one sidewall insert including a heterogenous rubber compound comprising first rubber and second rubber composition phases, wherein the second rubber phase is further vulcanizable.

Claims

1. A pneumatic runflat tire comprising at least one sidewall insert, the at least one sidewall insert comprising a heterogenous rubber compound comprising first rubber and second rubber composition phases, wherein the second rubber phase is further vulcanizable.

4. The pneumatic runflat tire of claim 1, wherein the second rubber composition comprisesparts by weight of at least one diene-based elastomer;

and

from about 1 to about 10 parts by weight, per 100 parts by weight of elastomer, of a vulcanization modifier selected from the group consisting of α

,ω

-bis(N,N′

-dihydrocarbylthiocarbamamoyldithio)alkanes, bismaleimides, and biscitraconimides.

5. The pneumatic runflat tire of claim 1, wherein the second rubber composition comprises 100 parts by weight of at least one diene-based elastomer;

and

from about 1 to about 10 parts by weight, per 100 parts by weight of elastomer, of 1,3-bis(citraconimidomethyl)benzene.

6. The pneumatic runflat tire of claim 5, wherein the weight ratio of 1,3-bis(citraconimidomethyl)benzene in the first rubber composition to 1,3-bis(citraconimidomethyl)benzene in the second rubber composition is less than 1:

1.

7. The pneumatic runflat tire of claim 1, wherein the first and second rubber compositions each comprise at least one elastomer selected from the group consisting of emulsion polymerized styrene/butadiene copolymers, solution polymerized styrene/butadiene copolymers, natural rubber, c is 1,4-polybutadiene, synthetic cis 1,4-polyisoprene, styrene/isoprene copolymers, 3,4-polyisoprene, isoprene/butadiene copolymers, medium vinyl polybutadiene (20 percent to 60 percent by weight of vinyl units), styrene/isoprene/butadiene terpolymers, butyl rubber, polychloroprene, acrylonitrile/butadiene copolymers and ethylene/propylene/diene terpolymers;

and wherein the at least one elastomer of the first rubber composition is not identical to the at least one elastomer of the second rubber composition.

8. The pneumatic runflat tire of claim 1, wherein

the first rubber composition comprises from 70 to 90 parts by weight of natural rubber or synthetic polyisoprene;

and from 10 to 30 parts by weight of cis-1,4-polybutadiene; and

the second rubber composition comprises 100 parts by weight of natural rubber or synthetic polyisoprene.

9. The pneumatic runflat tire of claim 1, wherein

the first rubber composition comprises 100 parts by weight of an elastomer comprising from 70 to 90 parts by weight of natural rubber or synthetic polyisoprene, and from 10 to 30 parts by weight of cis-1,4-polybutadiene;

and

the second rubber composition comprises 100 parts by weight of natural rubber or synthetic polyisoprene, and from 2 to 8 parts by weight of 1,3-bis(citraconimidomethyl)benzene.

10. The pneumatic runflat tire of claim 1, wherein the heterogenous rubber compound comprises at least part of the first rubber composition phase as a continuous phase and at least part of the second rubber composition phase as a disperse phase dispersed in the at least part of the first rubber composition phase.

11. The pneumatic runflat tire of claim 1, wherein the second rubber composition comprisesparts by weight of at least one diene-based elastomer;

and

from about 1 to about 10 parts by weight, per 100 parts by weight of elastomer, of a vulcanization modifier selected from the group consisting of α

,ω

-bis(N,N′

-dihydrocarbylthiocarbamamoyldithio)alkanes, bismaleimides, and biscitraconimides.

2. A pneumatic runflat tire comprising at least one sidewall insert, the at least one sidewall insert comprising a heterogenous rubber compound comprising first rubber and second rubber composition phases, wherein the vulcanization state of the second rubber phase is between its T₂₀ and T₈₀ vulcanization states.

12. The pneumatic runflat tire of claim 2, wherein the second rubber composition comprisesparts by weight of at least one diene-based elastomer;

and

from about 1 to about 10 parts by weight, per 100 parts by weight of elastomer, of 1,3-bis(citraconimidomethyl)benzene.

13. The pneumatic runflat tire of claim 12, wherein the weight ratio of 1,3-bis(citraconimidomethyl)benzene in the first rubber composition to 1,3-bis(citraconimidomethyl)benzene in the second rubber composition is less than 1:

1.

14. The pneumatic runflat tire of claim 2, wherein the first and second rubber compositions each comprise at least one elastomer selected from the group consisting of emulsion polymerized styrene/butadiene copolymers, solution polymerized styrene/butadiene copolymers, natural rubber, c is 1,4-polybutadiene, synthetic cis 1,4-polyisoprene, styrene/isoprene copolymers, 3,4-polyisoprene, isoprene/butadiene copolymers, medium vinyl polybutadiene (20 percent to 60 percent by weight of vinyl units), styrene/isoprene/butadiene terpolymers, butyl rubber, polychloroprene, acrylonitrile/butadiene copolymers and ethylene/propylene/diene terpolymers;

and wherein the at least one elastomer of the first rubber composition is not identical to the at least one elastomer of the second rubber composition.

15. The pneumatic runflat tire of claim 2, wherein

the first rubber composition comprises from 70 to 90 parts by weight of natural rubber or synthetic polyisoprene;

and from 10 to 30 parts by weight of cis-1,4-polybutadiene; and

the second rubber composition comprises 100 parts by weight of natural rubber or synthetic polyisoprene and from 2 to 8 parts by weight of 1,3-bis(citraconimidomethyl)benzene.

3. A pneumatic runflat tire comprising at least one sidewall insert, the at least one sidewall insert comprising a heterogenous rubber compound comprising first rubber and second rubber composition phases, wherein the second rubber composition has a first modulus and a second modulus, the first modulus existing after a cure cycle of the tire, and the second modulus obtainable during a runflat condition of the tire, wherein the second modulus is greater than the first modulus, and the modulus of the first rubber composition is greater than the first modulus of the second rubber composition.

16. The pneumatic runflat tire of claim 3, wherein the second rubber composition comprisesparts by weight of at least one diene-based elastomer;

and

from about 1 to about 10 parts by weight, per 100 parts by weight of elastomer, of a vulcanization modifier selected from the group consisting of α

,ω

-bis(N,N′

-dihydrocarbylthiocarbamamoyldithio)alkanes, bismaleimides, and biscitraconimides.

17. The pneumatic runflat tire of claim 3, wherein the second rubber composition comprisesparts by weight of at least one diene-based elastomer;

and

from about 1 to about 10 parts by weight, per 100 parts by weight of elastomer, of 1,3-bis(citraconimidomethyl)benzene.

18. The pneumatic runflat tire of claim 17, wherein the weight ratio of 1,3-bis(citraconimidomethyl)benzene in the first rubber composition to 1,3-bis(citraconimidomethyl)benzene in the second rubber composition is less than 1:

1.

19. The pneumatic runflat tire of claim 3, wherein the first and second rubber compositions each comprise at least one elastomer selected from the group consisting of emulsion polymerized styrene/butadiene copolymers, solution polymerized styrene/butadiene copolymers, natural rubber, c is 1,4-polybutadiene, synthetic cis 1,4-polyisoprene, styrene/isoprene copolymers, 3,4-polyisoprene, isoprene/butadiene copolymers, medium vinyl polybutadiene (20 percent to 60 percent by weight of vinyl units), styrene/isoprene/butadiene terpolymers, butyl rubber, polychloroprene, acrylonitrile/butadiene copolymers and ethylene/propylene/diene terpolymers;

and wherein the at least one elastomer of the first rubber composition is not identical to the at least one elastomer of the second rubber composition.

20. The pneumatic runflat tire of claim 3, wherein

the first rubber composition comprises from 70 to 90 parts by weight of natural rubber or synthetic polyisoprene;

and from 10 to 30 parts by weight of cis-1,4-polybutadiene; and

the second rubber composition comprises 100 parts by weight of natural rubber or synthetic polyisoprene and from 2 to 8 parts by weight of 1,3-bis(citraconimidomethyl)benzene.