RUBBER COMPOSITION AND TIRE

Abstract

The present invention is directed to a rubber composition comprising: 70 phr to 100 phr of at least one styrene butadiene rubber, 0 phr to 30 phr of at least one further diene-based rubber, from 40 phr to 200 phr of at least one filler, at least 5 phr of aluminum hydroxide, and at least 10 phr of at least one hydrocarbon resin selected from one or more of DCPD resins, CPD resins, and C5 resins. Furthermore, the present invention is directed to a tire comprising such a rubber composition.

Claims

1. A rubber composition comprising: 70 phr to 100 phr of at least one styrene butadiene rubber, 0 phr to 30 phr of at least one further diene-based rubber, from 40 phr to 200 phr of at least one filler, at least 5 phr of aluminum hydroxide, and at least 10 phr of at least one hydrocarbon resin selected from one or more of DCPD resins, CPD resins, and C5 resins.

2. The rubber composition according to claim 1 wherein the rubber composition comprises from 5 phr to 80 phr of the aluminum hydroxide.

3. The rubber composition according to claim 1 wherein the rubber composition comprises from 15 phr to 80 phr of the hydrocarbon resin.

4. The rubber composition according to claim 1 wherein the hydrocarbon resin is a hydrogenated hydrocarbon resin.

5. The rubber composition according to claim 1 wherein the hydrocarbon resin is aromatically modified.

6. The rubber composition according to claim 1 wherein the resin has a glass transition temperature within a range of 35° C. to 65° C.

7. The rubber composition according to claim 1 wherein the at least one styrene butadiene rubber is a solution polymerized styrene butadiene rubber and wherein the diene-based rubber is one or more of synthetic polyisoprene and natural rubber.

8. The rubber composition according to claim 6 wherein the at least one styrene butadiene rubber comprises (i) a first styrene butadiene rubber having a glass transition temperature within a range of −51° C. to −86° C., and (ii) a second styrene butadiene rubber having a glass transition temperature within a range of −10° C. to −45° C.

9. The rubber composition according to claim 8 wherein at least one of said first and second styrene butadiene rubbers is functionalized for the coupling to silica.

10. The rubber composition according to claim 1 wherein the filler is comprised predominantly of silica.

11. The rubber composition according to claim 1 wherein the filler comprises less than 10 phr carbon black and at least 40 phr of silica.

12. The rubber composition according to claim 1 wherein the rubber composition comprises at most 85 phr of silica.

13. The rubber composition according to claim 1 wherein the aluminum hydroxide has one or more of (i) a D50 particle diameter within a range of 0.2 μm and 5 μm, or (ii) a BET surface area within a range of 1 m.sup.2/g to 20 m.sup.2/g.

14. The rubber composition according to claim 1 wherein the silica has a BET surface area within a range of 150 m.sup.2/g and 220 m.sup.2/g.

15. The rubber composition according to claim 1 which comprises one or more of (i) 0 phr to less than 5 phr of further resins apart from said hydrocarbon resin; and (ii) 0 phr to less than 5 phr of oil.

16. The rubber composition according to claim 6 wherein the resin has an aromaticity within a range of 8% to 12%.

17. The rubber composition according to claim 6 wherein the resin has a softening point within a range of 88° C. to 110° C.

18. The rubber composition according to claim 8 wherein one of the first and second styrene butadiene rubbers is functionalized with at least one thiol group and another one of the first and second styrene butadiene rubbers is functionalized with at least one of an amino silane or amino siloxane group.

19. A tire comprising the rubber composition according to claim 1.

20. The tire of claim 19 comprising a tread with a radially outermost tread cap layer comprising said rubber composition.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0085] The structure, operation, and advantages of the invention will become more apparent upon contemplation of the following description taken in conjunction with the accompanying drawings, wherein

[0086] FIG. 1 is a schematic cross section of a tire comprising a rubber component with the rubber composition in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0087] FIG. 1 is a schematic cross-section of a tire 1 according to an embodiment of the invention. The tire 1 has a plurality of tire components such as a tread 10, an innerliner 13, a belt comprising four belt plies 11, a carcass ply 9, two sidewalls 2, and two bead regions 3, bead filler apexes 5 and beads 4. The example tire 1 is suitable, for example, for mounting on a rim of a vehicle, e.g. a truck or a passenger car. As shown in FIG. 1, the belt plies 11 may be covered by an overlay ply 12 and/or may include one or more breaker plies. The carcass ply 9 includes a pair of axially opposite end portions 6, each of which is associated with a respective one of the beads 4. Each axial end portion 6 of the carcass ply 9 may be turned up and around the respective bead 4 to a position to anchor each axial end portion 6. The turned-up portions 6 of the carcass ply 9 may engage the axial outer surfaces of two flippers 8 and axial inner surfaces of two chippers 7 which are also considered as tire components. As shown in FIG. 1, the example tread 10 may have circumferential grooves 20, each groove 20 essentially defining a U-shaped opening in the tread 10. The main portion of the tread 10 may be formed of one or more tread compounds. Moreover, the grooves 20, in particular the bottoms and/or sidewalls of the grooves 20 could be reinforced by a rubber compound having a higher hardness and/or stiffness than the remaining tread compound. Such a reinforcement may be referred to herein as a groove reinforcement.

[0088] While the embodiment of FIG. 1 suggests a plurality of tire components including for instance apexes 5, chippers 7, flippers 8 and overlay 12, such and further components are not mandatory for the invention. Also, the turned-up end of the carcass ply 9 is not necessary for the invention or may pass on the opposite side of the bead area 3 and end on the axially inner side of the bead 4 instead of the axially outer side of the bead 4. The tire could also have for instance a different number of grooves 20, e.g. less than four grooves.

[0089] In an embodiment, the tread 10 of the tire 1 or of another tire comprises a rubber composition according to the Inventive Example as identified in Table 1 below. The rubber composition in accordance with a preferred embodiment of the invention is used in a tread or tread layer contacting the road.

TABLE-US-00001 TABLE 1 (phr) Comparative Inventive Material Example Example SSBR1.sup.1 30 30 SSBR2.sup.2 50 50 Polyisoprene.sup.3 20 20 Resin 1.sup.4 22 0 Resin 2.sup.5 0 22 Aluminum hydroxide.sup.6 10 10 Silica.sup.7 60 60 Silane 1.sup.8 7.2 7.2 Silane 2.sup.9 1 1 Stearic Acid 2.5 2.5 Waxes 2.3 2.3 Zinc Oxide 2 2 Antidegradants.sup.10 6.3 6.3 Sulfur 1 1 BDBzTH.sup.11 2.2 2.2 Further Curatives.sup.12 3 3 Carbon black 1 1 .sup.1as Sprintan ™ SLR 3402 from Trinseo, having a Tg of −62° C. and a thiol-alkoxysilane functionalization .sup.2as HPR 355H from JSR, having a Tg of about −27° C. and an aminosilane functionalization .sup.3natural rubber .sup.4Dercolyte ™ A115 from DRT, having a Tg of about 70° C. .sup.5as Oppera ™ 383 from Exxon Mobil, having Tg of about 54° C. .sup.6Al(OH).sub.3 having a BET surface area of 15 m.sup.2/g, d50 of 0.4 μm, d90 of 0.8 μm, and d10 of 0.3 μm, and a material density of 2.4 g/cm.sup.3 .sup.7as Zeosil ™ Premium 200 MP from Solvay, having a BET surface area of 215 m.sup.2/g .sup.8bis-triethoxysilylpropyl disulfide .sup.9bis-triethoxysilylpropyl tetrasulfide .sup.10based on dihydroquinolines and phenylenediamines .sup.111,6-bis(N,N-dibenzylthiocarbamoyldithio)hexane as Vulcuren TM from the company Lanxess, including about 10% oil and carbon black .sup.12TBBS and DPG types

[0090] Table 2 shows tire properties obtained on the basis of the Comparative Example and the Inventive Example listed above in Table 1. As apparent from the below results, wet grip and tread wear are surprisingly significantly improved for the Inventive Example, by change of the resin type. Moreover, wet grip stays flat so that the overall balance of these properties has been improved according to Inventive Example 1.

TABLE-US-00002 TABLE 2 Property Comparative Example Inventive Example Rolling resistance .sup.a 100 107 Wet handling .sup.b 100 100 Tread wear .sup.c 100 107 .sup.a Laboratory test, results in percent, normalized to the Comparative Example, based on dynamical mechanical analysis (DMA) of tangent delta shear response at 30° C. .sup.b Laboratory test, results in percent, normalized to the Comparative Example, based on the determination of a transmittable friction force on a linear friction tester .sup.c Laboratory test, results in percent, normalized to the Comparative Example, based on abrasion determined according to ASTM D5963

[0091] While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention.