Pneumatic tires

Abstract

To provide tires having good wet skid resistance, low rolling resistance, and good wear characteristics, tires reduced in rolling resistance and improved in treadwear characteristics, and tires having treads for promoting traction on snowy surfaces.SOLUTION: The present invention is directed to a pneumatic tire having a tread comprising a vulcanizable rubber composition comprising, based on 100 pts.wt. of elastomer (phr): (A) about 20 to about 100 phr of a solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) in the range from -85°C to -50°C; (B) 0 to about 40 phr of a natural rubber or synthetic polyisoprene; (C) 0 to about 30 phr of cis-1,4-polybutadiene having a Tg from -110°C to -90°C; (D) 0 to 50 phr of a process oil; (E) 20 to 80 phr of a hydrocarbon resin having a Tg of at least 30°C; and (F) 90 to 150 phr of silica.SELECTED DRAWING: None

Description

[Technical field]

[0001] [Background technology]

[0002]

[0001] It is highly desirable for a tire to have good wet skid resistance, low rolling resistance and good wear characteristics. It has been very difficult to improve the wear characteristics of a tire without sacrificing the wet skid resistance and traction characteristics. These properties are highly dependent on the dynamic viscoelastic properties of the rubber used in manufacturing the tire.

[0003]

[0002] To reduce the rolling resistance and improve the treadwear characteristics of tires, high resilience rubbers have traditionally been used in making tire tread rubber compounds. On the other hand, to increase the wet skid resistance of tires, rubbers that suffer from high energy loss have generally been used in tire treads. To balance these two viscoelastically incompatible properties, various types of synthetic and natural rubber blends are commonly used in tire treads.

[0004]

[0003] It may be desirable to have a tire with a tread to enhance traction on snowy surfaces. Various rubber compositions can be proposed for the tire tread. The challenge here is to reduce the cured stiffness of the tread rubber composition, as indicated by having a lower storage modulus G' at -20°C, when the tread is intended for low temperature winter conditions, particularly for use in snow driving of vehicles.

[0005] It is believed that providing such a tire tread rubber composition presents a significant challenge in terms of maintaining both wet traction while promoting low temperature (eg, winter) performance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 7,342,070 [Patent Document 2] International Publication No. 2007 / 047943 [Patent Document 3] U.S. Patent No. 7,214,731 [Patent Document 4] U.S. Patent No. 4,704,414 [Patent Document 5] U.S. Patent No. 6,123,762 [Patent Document 6] U.S. Patent No. 6,573,324 [Patent Document 7] U.S. Patent No. 6,608,125 [Patent Document 8] US Patent Application Publication No. 2003 / 0130535 [Non-patent literature]

[0007] [Non-Patent Document 1] Standard Methods for Analysis&Testing of Petroleum and Related Products and British Standard 2000 Parts, 2003, 62nd edition, the Institute of Petroleum, United Kingdom [Non-Patent Document 2] Journal of the American Chemical Society, Volume 60, Page 304 (1930) [Non-Patent Document 3] The Vanderbilt Rubber Handbook (1978), pp. 344-346 Summary of the Invention [Means for solving the problem]

[0008]

[0005] The present invention relates to a composition comprising, based on 100 parts by weight (phr) of elastomer: (A) about 20 to about 100 phr of solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) in the range of -85°C to -50°C; (B) natural rubber or synthetic polyisoprene, 0 to about 40 phr; (C) 0 to about 30 phr of cis-1,4 polybutadiene having a Tg of -110°C to -90°C; (D) process oil 0-50 phr; (E) 20 to 80 phr of a hydrocarbon resin having a Tg of at least 30° C.; and (F) Silica 90~150phr The present invention is directed to a pneumatic tire having a tread comprising a vulcanizable rubber composition comprising:

[0009] The present invention is further directed to a method of manufacturing a tire. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Based on 100 parts by weight (phr) of elastomer, (A) about 20 to about 100 phr of solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) in the range of -85°C to -50°C; (B) natural rubber or synthetic polyisoprene, 0 to about 40 phr; (C) 0 to about 30 phr of cis-1,4 polybutadiene having a Tg of -110°C to -90°C; (D) process oil 0-50 phr; (E) 20 to 80 phr of a hydrocarbon resin having a Tg of at least 30° C.; and (F) Silica 90~150phr A pneumatic tire is disclosed having a tread comprising a vulcanizable rubber composition comprising:

[0011] Also disclosed is a method of manufacturing a tire. The rubber composition comprises 20-100 phr, alternatively 70-90 phr, of a styrene-butadiene rubber having a glass transition temperature (Tg) in the range of -85°C to -50°C. The styrene-butadiene rubber may be functionalized with various functional groups or the styrene-butadiene rubber may be unfunctionalized. In one embodiment, the styrene-butadiene rubber is functionalized with alkoxysilane groups and at least one of primary amine groups and thiol groups. In one embodiment, the styrene-butadiene rubber is obtained by copolymerization of styrene and butadiene, characterized in that the styrene-butadiene rubber has primary amino and / or thiol groups and alkoxysilyl groups attached to the polymer chain. In one embodiment, the alkoxysilyl groups are ethoxysilyl groups. In one embodiment, the styrene-butadiene rubber is unfunctionalized.

[0012]

[0010] The primary amino group and / or thiol group may be bonded to any of the polymerization initiation end, polymerization termination end, main chain and side chain of the styrene-butadiene rubber, so long as it is bonded to the styrene-butadiene rubber chain. However, the primary amino group and / or thiol group is preferably introduced to the polymerization initiation end or polymerization termination end, since the energy dissipation at the polymer end is suppressed and the hysteresis loss characteristic is improved.

[0013]

[0011] Furthermore, the content of alkoxysilyl groups bonded to the polymer chain of the (co)polymer rubber is preferably 0.5 to 200 mmol / kg of styrene-butadiene rubber, more preferably 1 to 100 mmol / kg of styrene-butadiene rubber, and particularly preferably 2 to 50 mmol / kg of styrene-butadiene rubber.

[0014]

[0012] The alkoxysilyl group may be bonded to any of the polymerization initiation end, polymerization termination end, main chain and side chain of the (co)polymer, so long as it is bonded to the (co)polymer chain. However, since the energy dissipation can be suppressed from the (co)polymer end and the hysteresis loss characteristic can be improved, the alkoxysilyl group is preferably introduced to the polymerization initiation end or polymerization termination end.

[0015]

[0013] Styrene-butadiene rubber can be produced by anionic polymerization of styrene and butadiene in a hydrocarbon solvent, using an organic alkali metal and / or organic alkaline earth metal as initiator, adding a terminator compound having a protected primary amino group and / or a protected thiol group and an alkoxysilyl group to react with the living polymer chain end when the polymerization is substantially complete, followed by deblocking, for example, by hydrolysis or other suitable procedure. In one embodiment, styrene-butadiene rubber can be produced as disclosed in U.S. Pat. No. 7,342,070. In another embodiment, styrene-butadiene rubber can be produced as disclosed in WO 2007 / 047943.

[0016] In one embodiment, and as taught in US Pat. No. 7,342,070, the styrene-butadiene rubber is of formula (I) or (II):

[0017] [ka]

[0018] [wherein P is a conjugated diolefin or a (co)polymer chain of a conjugated diolefin and an aromatic vinyl compound; R 1 is an alkylene group having 1 to 12 carbon atoms, R 2 and R 3are each independently an alkyl group, an allyl group, or an aryl group having 1 to 20 carbon atoms, n is an integer 1 or 2, m is an integer 1 or 2, and k is an integer 1 or 2, with the proviso that n+m+k is an integer 3 or 4.

[0019] [ka]

[0020] [In the formula, P, R 1 , R 2 and R 3 has the same definition as given for formula I above, j is an integer from 1 to 3, and h is an integer from 1 to 3, with the proviso that j+h is an integer from 2 to 4.

[0021] The terminator compound having a protected primary amino group and an alkoxysilyl group may be any of a variety of compounds known in the art. In one embodiment, the compound having a protected primary amino group and an alkoxysilyl group may be, for example, N,N-bis(trimethylsilyl)aminopropylmethyldimethoxysilane, 1-trimethylsilyl-2,2-dimethoxy-1-aza-2-silacyclopentane, N,N-bis(trimethylsilyl)aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminopropylmethyldieth ... The compounds may include N,N-bis(trimethylsilyl)aminoethyltriethoxysilane, N,N-bis(trimethylsilyl)aminoethylmethyldimethoxysilane, N,N-bis(trimethylsilyl)aminoethylmethyldiethoxysilane, etc., with 1-trimethylsilyl-2,2-dimethoxy-1-aza-2-silacyclopentane, N,N-bis(trimethylsilyl)aminopropylmethyldimethoxysilane and N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane being preferred. In one embodiment, the compound having a protected primary amino group and an alkoxysilyl group is N,N-bis(trimethylsilyl)aminopropyltriethoxysilane.

[0022] In one embodiment, the compound having a protected primary amino group and an alkoxysilyl group has the formula III RN-(CH2) X Si(OR')3, III wherein R is a protected amine group which, in combination with the nitrogen (N) atom, gives a primary amine upon suitable post-treatment; R' represents a group having 1-18 carbon atoms selected from alkyl, cycloalkyl, allyl or aryl; and X is an integer from 1 to 20. In one embodiment, at least one R' group is an ethyl radical. A suitable post-treatment to give a primary amine means that the protecting group is removed following reaction of the living polymer with a compound having a protected primary amino group and an alkoxysilyl group. In the case of a bis(trialkylsilyl) protecting group, such as in N,N-bis(trimerylsilyl)aminopropyltriethoxysilane, hydrolysis is used to remove the trialkylsilyl group and leave the primary amine.

[0023] In one embodiment, the rubber composition comprises from about 40 to about 60 phr of a styrene-butadiene rubber functionalized with alkoxysilane groups and primary amine or thiol groups.

[0024] Suitable styrene-butadiene rubbers functionalized with alkoxysilane groups and primary amine groups are commercially available, such as HPR 340 from Japan Synthetic Rubber (JSR).

[0025] In one embodiment, the solution polymerized styrene-butadiene rubber is as disclosed in WO 2007 / 047943 and is functionalized with alkoxysilane groups and thiols, and is comprised of a living anionic polymer and a copolymer of formula IV (R 4 O) x R 4 y Si-R 5 -S-SiR 4 3IV where Si is silicon; S is sulfur; O is oxygen; x is an integer selected from 1, 2, and 3; y is an integer selected from 0, 1, and 2; x+y=3; R 4 are the same or different, (C1-C16 ) alkyl; R' is aryl and alkylaryl or (C1-C 16 In one embodiment, R 5 (C1-C 16 ) alkyl. In one embodiment, each R 4 groups are the same or different and each is independently C1-C5 alkyl; R 5 is C1-C5 alkyl.

[0026]

[0020] Solution polymerized styrene-butadiene rubber has a glass transition temperature in the range of -85°C to -50°C. References to the glass transition temperature or Tg of an elastomer or elastomeric composition, as referred to herein, refer to the glass transition temperature of the respective elastomer or elastomeric composition in the uncured state or possibly in the cured state in the case of the elastomeric composition. Tg may be suitably determined by differential scanning calorimetry (DSC), for example as the peak midpoint at a heating rate of 10°C per minute according to ASTM D7426 or equivalent.

[0027] Suitable styrene-butadiene rubbers functionalized with alkoxysilane and thiol groups are commercially available, such as Sprintan SLR 3402 from Trinseo.

[0028] Another component of the rubber composition is from about 0 to about 40 phr, alternatively from 10 to 30 phr, of natural rubber or synthetic polyisoprene. In one embodiment, the rubber composition comprises from 15 to 25 phr of natural rubber or synthetic polyisoprene. In one embodiment, the rubber composition comprises from 5 to 15 phr of natural rubber or synthetic polyisoprene.

[0029] Another component of the rubber composition is cis-1,4 polybutadiene in an amount of from about 0 to about 30 phr, alternatively from 0 to 20 phr. The rubber composition may contain 0 to 50 phr of processing oil, alternatively 1 to 10 phr, alternatively 1 to 5 phr. The processing oil may be included in the rubber composition as an extender oil, typically used to extend the elastomer. The processing oil may also be included in the rubber composition by direct addition of oil during rubber compounding. The processing oil used may be included in both the extender oil present in the elastomer and the processing oil added during compounding. Suitable processing oils include various oils known in the art, including aromatic, paraffinic, naphthenic, and low PCA oils, such as MES, TDAE, and heavy naphthenic oils, vegetable oils, such as sunflower, soybean, and safflower oils, and monoesters of fatty acids selected from the group consisting of alkyl oleates, alkyl stearates, alkyl linoleates, and alkyl palmitates.

[0030]

[0025] Suitable low PCA oils include those having a polycyclic aromatic content of less than 3 weight percent as determined by IP 346. The procedure for the IP 346 method can be found in Standard Methods for Analysis & Testing of Petroleum and Related Products and British Standard 2000 Parts, 2003, 62nd Edition, published by the Institute of Petroleum, United Kingdom.

[0031] Suitable TDAE oils are available as Tudalen SX500 from Klaus Dahleke KG, VivaTec 400 and VivaTec 500 from H&R Group, Enerthene 1849 from BP, and Extensoil 1996 from Repsol. The oils may be available alone as oils or together with elastomers in the form of extended elastomers.

[0032] Suitable vegetable oils include, for example, soybean oil, sunflower oil and canola oil, which contain a certain degree of unsaturation in the form of esters. The rubber composition comprises from 20 to 80 phr, alternatively from 55 to 80 phr, of a hydrocarbon resin having a Tg greater than 30°C.

[0033] Representative hydrocarbon resins include coumarone-indene resins, petroleum resins, C5, C9, C5 / C9 resins, DCPD and modified DCPD resins, terpene resins, alpha methyl styrene resins and mixtures and / or modifications and / or hydrogenations thereof.

[0034]

[0030] Coumarone-indene resins are commercially available in many forms with melting points (as measured by the ring and ball method) ranging from 10°C to 160°C. Preferably, the melting point is in the range of 30°C to 100°C. Coumarone-indene resins are well known. Various analyses show that such resins are primarily polyindenes, but generally contain polymer units derived from either methylindenes, coumarones, methylcoumarones, styrene and methylstyrene.

[0035] Petroleum resins are commercially available with softening points ranging from 10°C to 120°C. Preferably, the softening point is in the range of 30°C to 100°C. Suitable petroleum resins include both aromatic and non-aromatic types. Several types of petroleum resins are available. Some resins have low unsaturation and high aromatic content, while others are highly unsaturated and nevertheless do not contain any aromatic structures. The differences in resins are mainly due to the olefins in the feedstock from which they are derived. Traditional derivatives in such resins include their dimers and diolefins such as dicyclopentadiene, cyclopentadiene, isoprene and piperylene. Copolymers of these monomers with each other or with aromatics such as styrene and alpha methyl styrene are also included.

[0036] In one embodiment, the resin is an aromatic modified polydicyclopentadiene.

[0033] Terpene resins are produced industrially from the polymerization of mixtures of alpha, beta or any of the pinene isomers and their modifications. Resins are usually supplied with a variety of melting points ranging from 10°C to 135°C.

[0037] In one embodiment, the resin is derived from styrene and alpha methyl styrene. In one aspect, it is believed that its glass transition temperature (Tg) characteristics, combined with its molecular weight (Mn) and molecular weight distribution (Mw / Mn), provide the appropriate compatibility of the resin in the rubber composition, the degree of compatibility being directly related to the properties of the rubber composition.

[0038]

[0035] The presence of styrene / alpha methyl styrene resin containing rubber blends including the presence of styrene-butadiene elastomer is believed to be beneficial due to the observed viscoelastic properties of the tread rubber composition, such as complex and storage modulus, loss modulus, tangent delta and loss compliance at different temperatures / frequencies / strains as generally described herein below.

[0039] The properties of complex and storage modulus, loss modulus, tangent delta and loss compliance are generally understood to be well known to those skilled in the art and are described generally below.

[0040] The molecular weight distribution of the resin, visualized herein as the ratio of the molecular weight average (Mw) to the molecular weight number average (Mn) values ​​of the resin, is believed to be in the range of about 1.5 / 1 to about 2.5 / 1, which is believed to be relatively narrow. This is believed to be advantageous for selective compatibility with the polymer matrix and for the intended use of the tire in wet and dry conditions over a wide temperature range.

[0041] The glass transition temperature, Tg, of the copolymer resin is believed to range from about 20° C. to about 100° C., alternatively from about 30° C. to about 80° C., depending somewhat on the intended use of the tire produced herein and the nature of the polymer blend for the tire tread. A suitable measure of Tg for the resin is DSC according to ASTM D6604 or equivalent.

[0042] Styrene / alpha-methylstyrene resins are herein considered to be relatively short chain copolymers of styrene and alpha-methylstyrene having a styrene / alpha-methylstyrene molar ratio in the range of about 0.40 to about 1.50. In one embodiment, such resins may be suitably prepared, for example, by cationic copolymerization of styrene and alpha-methylstyrene in a hydrocarbon solvent.

[0043]

[0040] Thus, a contemplated styrene / alpha-methylstyrene resin can be characterized, for example, by its chemical structure, i.e., its styrene and alpha-methylstyrene content, and its softening point, and also, if desired, by its glass transition temperature, molecular weight and molecular weight distribution.

[0044] In one embodiment, the styrene / alpha-methylstyrene resin is composed of from about 40 to about 70 percent units derived from styrene and, correspondingly, from about 60 to about 30 percent units derived from alpha-methylstyrene. In one embodiment, the styrene / alpha-methylstyrene resin has a softening point according to ASTM No. E-28 in the range of from about 80° C. to about 145° C.

[0045] A suitable styrene / alpha methyl styrene resin is commercially available from Eastman as Resin 2336 or from Arizona Chemical as Sylvares SA85.

[0046] In one embodiment, the resin is a C5 / C9 hydrocarbon resin comprising a C5 and a C9 hydrocarbon fraction, having a glass transition temperature greater than 30° C. A suitable measurement of Tg for a resin is DSC according to ASTM D6604 or equivalent. Hydrocarbon resins have a softening point, sometimes referred to as the Ring and Ball softening point, between 0° C. and 160° C. as measured by ASTM E28.

[0047]

[0044] Suitable C5 / C9 resins may contain both aromatic and non-aromatic components. The difference between C5 / C9 resins is mainly due to the olefins in the feedstock from which the hydrocarbon components are derived. C5 / C9 resins may contain "aliphatic" hydrocarbon components with the hydrocarbon chain formed from C4-C6 fractions containing variable amounts of piperylene, isoprene, monoolefins, and non-polymerizable paraffinic compounds. Such C5 / C9 resins are based on pentene, butane, isoprene, piperylene, and contain small amounts of cyclopentadiene or dicyclopentadiene. C5 / C9 resins may also contain "aromatic" hydrocarbon structures with the polymer chain formed from aromatic units such as styrene, xylene, alpha methyl styrene, vinyl toluene, and indene.

[0048]

[0045] In accordance with the present invention, the C5 / C9 resin used in the rubber compounding contains olefins such as piperylene, isoprene, amylene, and cyclic components. The C5 / C9 resin may also contain aromatic olefins such as styrene-based and indenic components.

[0049]

[0046] Piperylene is generally a distillate or synthetic mixture of C5 diolefins, including, but not limited to, cis-1,3-pentadiene, trans-1,3-pentadiene, and mixed 1,3-pentadienes. Generally, piperylene does not include branched C5 diolefins such as isoprene. In one embodiment, the C5 / C9 resin has 40-90% (by weight), or 50-90%, more preferably 60-90% piperylene. In a particularly preferred embodiment, the C5 / C9 resin has 70-90% piperylene.

[0050] In one embodiment, the C5 / C9 resin is substantially free of isoprene. In another embodiment, the C5 / C9 resin contains up to 15% isoprene, or less than 10% isoprene. In yet another embodiment, the C5 / C9 resin contains less than 5% isoprene.

[0051] In one embodiment, the C5 / C9 resin is substantially free of amylene. In another embodiment, the C5 / C9 resin contains up to 40% amylene, or less than 30% amylene, or less than 25% amylene. In yet another embodiment, the C5 / C9 resin contains up to 10% amylene.

[0052] Cyclic moieties are generally distillates or synthetic mixtures of C5 and C6 cyclic olefins, diolefins, and dimers therefrom. Cyclic moieties include, but are not limited to, cyclopentene, cyclopentadiene, dicyclopentadiene, cyclohexene, 1,3-cyclohexadiene, and 1,4-cyclohexadiene. A preferred cyclic moiety is cyclopentadiene. Dicyclopentadiene may be in either the endo or exo form. Cyclic moieties may be substituted or unsubstituted. Preferred substituted cyclic moieties include cyclopentadiene and dicyclopentadiene substituted with C1-C40 linear, branched, or cyclic alkyl groups, preferably one or more methyl groups. In one embodiment, the C5 / C9 resin may contain up to 60% cyclic moieties or up to 50% cyclic moieties. Typical minimum limits include at least about 0.1% or at least about 0.5% cyclic moieties, or about 1.0% cyclic moieties. In at least one embodiment, the C5 / C9 resin may contain up to 20% cyclics, or more preferably up to 30% cyclics. In particularly preferred embodiments, the C5 / C9 resin contains from about 1.0 to about 15% cyclics, or from about 5 to about 15% cyclics.

[0053]

[0050] Preferred aromatics that may be present in the C5 / C9 resin include one or more of styrene, indene, derivatives of styrene, and derivatives of indene. Particularly preferred aromatic olefins include styrene, alpha-methylstyrene, beta-methylstyrene, indene, and methylindene, and vinyltoluene. The aromatic olefins are generally present in the C5 / C9 resin at 5-45%, or more preferably 5-30%. In a particularly preferred embodiment, the C5 / C9 resin contains 10-20% aromatic olefins.

[0054]

[0051] Styrenic components include styrene, derivatives of styrene, and substituted styrenes. Generally, styrenic components do not contain fused rings, such as indenes. In one embodiment, the C5 / C9 resin contains up to 60% styrenic components or up to 50% styrenic components. In one embodiment, the C5 / C9 resin contains 5-30% styrenic components or 5-20% styrenic components. In a preferred embodiment, the C5 / C9 resin contains 10-15% styrenic components.

[0055]

[0052] The C5 / C9 resin may contain less than 15% indenic components, or less than 10% indenic components. The indenic components include indene and derivatives of indene. In one embodiment, the C5 / C9 resin contains less than 5% indenic components. In another embodiment, the C5 / C9 resin is substantially free of indenic components.

[0056]

[0053] The preferred C5 / C9 resin has a melt viscosity of 300-800 centipoise (cP) at 160° C., or more preferably, 350-650 cP at 160° C. In particularly preferred embodiments, the melt viscosity of the C5 / C9 resin is 375-615 cP at 160° C. or 475-600 cP at 160° C. The melt viscosity can be measured by a Brookfield viscometer using an ASTM D6267 "J" type spindle.

[0057]

[0054] Generally, the C5 / C9 resin has a weight average molecular weight (Mw) of greater than about 600 g / mol, or greater than about 1000 g / mol. In at least one embodiment, the C5 / C9 resin has a weight average molecular weight (Mw) of 1650 to 1950 g / mol, or 1700 to 1900 g / mol. Preferably, the C5 / C9 resin has a weight average molecular weight of 1725 to 1890 g / mol. The C5 / C9 resin may have a number average molecular weight (Mn) of 450 to 700 g / mol, or 500 to 675 g / mol, or more preferably 520 to 650 g / mol. The C5 / C9 resin may have a z-average molecular weight (Mz) of 5850 to 8150 g / mol, or more preferably 6000 to 8000 g / mol. Mw, Mn and Mz can be measured by gel permeation chromatography (GPC).

[0058] In one embodiment, the C5 / C9 resin has a polydispersity index ("PDI", PDI=Mw / Mn) of less than or equal to 4. In a particularly preferred embodiment, the C5 / C9 resin has a PDI of 2.6 to 3.1.

[0059]

[0056] Preferred C5 / C9 resins have a glass transition temperature (Tg) of about -30°C to about 100°C, or about 0°C to 80°C, or about 40-60°C, or 45-55°C, or more preferably 48-53 degrees Celsius. Differential scanning calorimetry (DSC) may be used to measure the Tg of the C5 / C9 resins.

[0060] In another embodiment, the C5 / C9 resin may be hydrogenated.

[0058] In one embodiment, the C5 / C9 resin contains 50-90% (by weight) piperylene, 0-5% isoprene, 10-30% amylene, 0-5% cyclic, 0-10% styrenic, and 0-10% indenic.

[0061]

[0059] In one embodiment, the C5 / C9 resin contains 50-90% (by weight) piperylene, 0-5% isoprene, 10-30% amylene, 2-5% cyclic, 4-10% styrenic, and 4-10% indenic.

[0062]

[0060] In one embodiment, C5 / C9 contains about 60% piperylene (by weight), about 22% amylene, about 3% cyclics, about 6% styrene, and about 6% indene, and further has a melt viscosity of 436 cP at 160°C; Mn of 855 g / mol; Mw of 1595 g / mol; Mz of 3713 g / mol; PDI of 1.9; and Tg of 47°C.

[0063]

[0061] The C5 / C9 resin or DCPD / C9 resin may be further characterized by its aromatic hydrogen content as measured by 1H NMR. In one embodiment, the C5 / C9 resin has an aromatic hydrogen content of less than 25 mole percent. In one embodiment, the C5 / C9 resin has an aromatic hydrogen content between 3 and 15 mole percent.

[0064]

[0062] Examples of useful hydrocarbon polymer additives are the Oppera series of polymer additives, including, but not limited to, Oppera 373, available from ExxonMobil Chemical Company.

[0065] In one embodiment, the resin is a DCPD-based resin which may contain substituted or unsubstituted units derived from cyclopentadiene homopolymer or copolymer resins (referred to as CPD), dicyclopentadiene homopolymer or copolymer resins (referred to as DCPD or (D)CPD), terpene homopolymer or copolymer resins, pinene homopolymer or copolymer resins, C5 fraction homopolymer or copolymer resins, C9 fraction homopolymer or copolymer resins, alpha methylstyrene homopolymer or copolymer resins, and combinations thereof. The DCPD-based resin may further include units derived from (D)CPD / vinyl aromatic copolymer resins, (D)CPD / terpene copolymer resins, terpene / phenol copolymer resins, (D)CPD / pinene copolymer resins, pinene / phenol copolymer resins, (D)CPD / C5 fraction copolymer resins, (D)CPD / C9 fraction copolymer resins, terpene / vinyl aromatic copolymer resins, terpene / phenol copolymer resins, pinene / vinyl aromatic copolymer resins, pinene / phenol resins, C5 fraction / vinyl aromatic copolymer resins, and combinations thereof. The phrase "units derived from dicyclopentadiene" includes units derived from substituted DCPDs such as methyl DCPD or dimethyl DCPD.

[0066]

[0064] Preferably, the DCPD-based resin contains up to 100 mol% of units derived from dicyclopentadiene, more preferably in the range of about 5 to about 90 mol% of units derived from DCPD, and most preferably in the range of about 5 to about 70 mol% of units derived from DCPD. Preferably, the DCPD-based resin contains up to about 15% piperylene, up to about 15% isoprene, up to about 15% amylene, up to about 20% indene, and in the monomer mix, from about 60% to about 100% cyclic and up to about 20% styrene by weight of monomer. Although DCPD polymers are mentioned, any polymer composed of cyclic units as recited herein is suitable for the present invention.

[0067]

[0065] The cyclics are generally C5 and C6-C15 cyclic olefins, diolefins, dimers, co-dimers and trimers from distillates. Cyclic species include, but are not limited to, cyclopentene, cyclopentadiene, DCPD, cyclohexene, 1,3-cyclohexadiene and 1,4-cyclohexadiene. A preferred cyclic species is cyclopentadiene. DCPD may be either endo or exo. Cyclic species may be substituted or unsubstituted. Preferred substituted cyclic species include cyclopentadiene and DCPD substituted with C1-C40 linear, branched or cyclic alkyl groups, preferably one or more methyl groups. Preferably, the cyclic component is selected from the group consisting of cyclopentadiene, cyclopentadiene dimer, cyclopentadiene trimer, cyclopentadiene-C5 codimer, cyclopentadiene-piperylene codimer, cyclopentadiene-C4 codimer, cyclopentadiene-methylcyclopentadiene codimer, methylcyclopentadiene, methylcyclopentadiene dimer, and mixtures thereof.

[0068]

[0066] In some embodiments, the DCPD resin is substantially free of piperylene. In other embodiments, the DCPD resin contains up to about 15% by weight piperylene, or preferably from about 5 to about 10% by weight piperylene. In some embodiments, the DCPD resin is substantially free of amylene. In other embodiments, the DCPD resin contains up to about 15% by weight amylene, or preferably from about 5 to about 10% by weight amylene. In some embodiments, the DCPD resin is substantially free of isoprene. In other embodiments, the DCPD resin contains up to about 15% by weight isoprene, or preferably from about 5 to about 10% by weight isoprene. In some embodiments, the DCPD resin is substantially free of styrene. In other embodiments, the DCPD resin contains up to about 20% by weight styrene, or preferably from about 5 to about 15% by weight styrene. In some embodiments, the DCPD resin is substantially free of indene. In other embodiments, the DCPD based resin contains up to about 20% by weight indene, or preferably from about 5 to about 15% by weight indene. In one embodiment, the DCPD based resin may contain up to about 60% by weight cyclics, or up to about 50% by weight cyclics. In some embodiments, the DCPD based resin contains cyclics in an amount ranging from about 0.1% to about 50% by weight, or from about 0.5% to about 30% by weight cyclics, or from about 1.0% to about 20% by weight cyclics. In other embodiments, the DCPD based resin contains from about 5% to about 15% by weight cyclics.

[0069]

[0067] Preferably, the DCPD resin has a refractive index greater than 1.5. Preferably, the DCPD resin has a softening point (as measured by Ring and Ball, ASTM E-28) of about 80°C or higher, preferably about 80°C to about 150°C, preferably about 90°C to about 120°C, preferably about 100°C to about 120°C, preferably about 102°C. Preferably, the DCPD resin has a glass transition temperature (Tg) (as measured by ASTM E 1356 using a TA Instruments Model 2920 machine) of about -30°C to about 100°C, preferably about 0°C to about 80°C, preferably about 50°C to about 70°C, preferably 55°C. Preferably, the DCPD resin contains olefinic unsaturation, e.g., at least 1 mol% olefinic hydrogen, based on the total moles of hydrogen in the interpolymer, as determined by 1H-NMR. Alternatively, the DCPD resin contains 1-20 mol% aromatic hydrogens, preferably 2-15 mol% aromatic hydrogens, more preferably 2-10 mol% aromatic hydrogens, and preferably 9 mol% aromatic hydrogens, based on the total moles of hydrogen in the polymer. In another embodiment, the DCPD resin has a weight average molecular weight (Mw) greater than about 600 g / mol. In at least one embodiment, the DCPD resin has a Mw in the range of about 600 to about 1000 g / mol, preferably about 700 to about 900 g / mol, and preferably about 800 g / mol. The DCPD resin may have a number average molecular weight (Mn) in the range of about 300 to about 700 g / mol, preferably about 400 to about 600 g / mol, and preferably about 500 g / mol. In one embodiment, the DCPD resin has a polydispersity index ("PDI", PDI=Mw / Mn) of about 4 or less, and preferably the DCPD resin has a PDI in the range of about 1.4 to about 1.8.

[0070] In one embodiment, DCPD-based resins may be prepared by thermal polymerization. For example, the resins may be thermally polymerized from a cyclopentadiene-containing feedstock in benzene or toluene solvent at 220°C to 280°C and a pressure of about 14 bar (1.4 MPa) for 2.0 to 4.0 hours, with conditions adjusted to control the molecular weight and softening point of the resin. The feedstock may further include other acyclic dienes such as alkylcyclopentadienes, dimers and co-dimers of cyclopentadiene and methylcyclopentadiene, and 1,3-piperylene and isoprene. Other copolymerizable unsaturated monomers such as styrene, methylstyrene, vinyl aromatics such as indene and vinyl toluene may also be present.

[0071] A suitable DCPD based resin for use in the present invention is Oppera™ 383 resin, available from ExxonMobil Chemical Company. Oppera™ 383 is an aromatic modified alicyclic hydrogenated hydrocarbon resin having a softening point of about 102.5° C., a Mw of about 800 g / mol and a Mn of about 500 g / mol, a Tg of about 55° C. and an aromaticity of about 9.8% aromatic protons.

[0072] The phrase "rubber or elastomer containing olefinic unsaturation" is intended to include natural rubber and both its various raw and reclaim forms as well as various synthetic rubbers. In describing this invention, the terms "rubber" and "elastomer" may be used interchangeably unless otherwise specified. The terms "rubber composition," "compounded rubber," and "rubber compound" are used interchangeably to refer to rubber blended or mixed with various raw materials and ingredients, such terms being well known to those skilled in the rubber mixing or rubber compounding art.

[0073] The vulcanizable rubber composition may contain from about 90 to about 150 phr of silica.

[0072] Commonly used siliceous pigments which may be used in the rubber compounds include conventional pyrogenic and precipitated siliceous pigments (silica), with precipitated silicas being preferred. The conventional siliceous pigments preferably used in the present invention are precipitated silicas such as those obtained by the acidification of a soluble silicate, e.g., sodium silicate.

[0074] Such conventional silicas may be characterized as having a BET surface area, as measured, for example, using nitrogen gas, preferably in the range of about 40 to about 600 square meters per gram, more usually in the range of about 50 to about 300 square meters per gram. The BET method for measuring surface area is described in the Journal of the American Chemical Society, Vol. 60, p. 304 (1930).

[0075] Conventional silicas may also be characterized as having a dibutyl phthalate (DBP) absorption value, typically in the range of about 100 to about 400, more usually in the range of about 150 to about 300.

[0075] Conventional silica can be expected to have an average ultimate particle size in the range of 0.01 to 0.05 microns as determined, for example, by electron microscopy, although the silica particles may be smaller or possibly larger in size.

[0076]

[0076] Various commercially available silicas may be used, such as, by way of example only and not limitation, silicas commercially available from PPG Industries under the Hi-Sil trademark having the designations 210, 243, 315, etc.; silicas available from Rhodia having the designations, e.g., Z1165MP and Z165GR, and silicas available from Degussa AG having the designations, e.g., VN2 and VN3.

[0077]

[0077] Prehydrophobized precipitated silica may be used. Prehydrophobized means that the silica is pretreated, i.e., prior to its addition to the rubber composition, the prehydrophobized precipitated silica is hydrophobized by treatment with at least one silane. Suitable silanes include, but are not limited to, alkylsilanes, alkoxysilanes, organoalkoxysilyl polysulfides, and organomercaptoalkoxysilanes. Alternatively, instead of reacting the precipitated silica in situ with the silica coupling agent within the rubber, the precipitated silica may be pretreated with a silica coupling agent, for example, composed of an alkoxyorganomercaptosilane or a combination of an alkoxysilane and an alkoxyorganomercaptosilane, before mixing the rubber with the pretreated silica. See, for example, U.S. Pat. No. 7,214,731. For various pretreated precipitated silicas, see, for example, U.S. Pat. Nos. 4,704,414, 6,123,762, and 6,573,324. Suitable pretreated or pre-hydrophobized silicas are commercially available, for example as Agilon 400 from PPG.

[0078] The vulcanizable rubber composition may contain from about 1 to about 20 phr of carbon black, alternatively from 1 to 5 phr.

[0079] Commonly used carbon blacks can be used as conventional fillers. Representative examples of such carbon blacks include N110, N121, N134, N220, N231, N234, N242, N293, N299, S315, N326, N330, M332, N339, N343, N347, N351, N358, N375, N539, N550, N582, N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990 and N991. These carbon blacks have iodine absorptions ranging from 9 to 145 g / kg and iodine absorptions ranging from 34 to 150 cm. 3 / 100g range of DBP numbers.

[0079]

[0080] Preferably, the rubber composition used in the tire component may further comprise a conventional sulfur-containing organosilicon compound. Examples of suitable sulfur-containing organosilicon compounds include those represented by the formula: Z-Alk-S n -Alk-Z V [In the formula, Z is

[0080] [ka]

[0081] wherein R 6 is an alkyl group having 1 to 4 carbon atoms, cyclohexyl or phenyl; R 7 is an alkoxy of 1 to 8 carbon atoms or a cycloalkoxy of 5 to 8 carbon atoms; Alk is a divalent hydrocarbon of 1 to 18 carbon atoms, and n is an integer from 2 to 8.

[0082] Specific examples of sulfur-containing organosilicon compounds which may be used in accordance with the present invention include the following: 3,3'-bis(trimethoxysilylpropyl) disulfide, 3,3'-bis(triethoxysilylpropyl) disulfide, 3,3'-bis(triethoxysilylpropyl) tetrasulfide, 3,3'-bis(triethoxysilylpropyl) octasulfide, 3,3'-bis(trimethoxysilylpropyl) tetrasulfide, 2,2'-bis(triethoxysilylethyl) tetrasulfide, 3,3'-bis(trimethoxysilylpropyl) trisulfide, 3,3'-bis(triethoxysilylpropyl) trisulfide, 3,3'-bis(tributoxysilylpropyl) dis ...propyl) tetrasulfide, 2,2'-bis(triethoxysilylpropyl) trisulfide, 2,2'-bis(triethoxysilylpropyl) trisulfide, 2,2'-bis(triethoxysilylpropyl) trisulfide, 2,2'-bis(trimethoxysilylpropyl) trisulfide, 2,2'-bis(triethoxysilylpropyl) trisulfide, 2,2'-bis(triethoxysilylpropyl) trisulfide, 2,2'-bis(triethoxysilylpropyl) trisulfide, 2,2'-bis(triethoxysilylpropyl) trisulfide, 2,2'- 2,2'-bis(methoxydiethoxysilylethyl)tetrasulfide, 2,2'-bis(tripropoxysilylethyl)pentasulfide, 3,3'-bis(tricyclonexoxysilylpropyl)hexasulfide, 3,3'-bis(trimethoxysilylpropyl)octasulfide, 3,3'-bis(trioctaoxysilylpropyl)tetrasulfide, 3,3'-bis(trihexaoxysilylpropyl)disulfide, 3,3'-bis(tri-2''-ethylhexaoxysilylpropyl)trisulfide, 3,3'-bis(triisooctaoxysilylpropyl)tetrasulfide, 3,3'-bis(tri-t-butoxysilylpropyl)disulfide, 2,2'-bis(methoxydiethoxysilylethyl)tetrasulfide, 2,2'-bis(trippropoxysilylethyl)pentasulfide, 3,3'-bis(tricyclonexoxysilylpropyl)tetrasulfide (tricyclonexoxysilylpropyl)tetrasulfide), 3,3'-bis(tricyclopentoxysilylpropyl) trisulfide, 2,2'-bis(tri-2''-methylcyclohexoxysilylethyl) tetrasulfide, bis(trimethoxysilylmethyl) tetrasulfide, 3-methoxyethoxypropoxysilyl 3'-diethoxybutoxy-silylpropyl tetrasulfide, 2,2'-bis(dimethylmethoxysilylethyl) disulfide, 2,2'-bis(dimethylsec.butoxysilylethyl) trisulfide, 3,3'-bis(methylbutylethoxysilylpropyl) tetrasulfide, 3,3 '-Bis(di-t-butylmethoxysilylpropyl)tetrasulfide, 2,2'-bis(phenylmethylmethoxysilylethyl)trisulfide, 3,3'-bis(diphenylisopropoxysilylpropyl)tetrasulfide, 3,3'-bis(diphenylcyclohexoxysilylpropyl)disulfide, 3,3'-bis(dimethylethylmercaptosilylpropyl)tetrasulfide, 2,2'-bis(methyldimethoxysilylethyl)trisulfide, 2,2'-bis(methylethoxypropoxysilylethyl)tetrasulfide, 3,3'-bis(diethylmethoxysilylpropyl)tetrasulfide, 3,3'-bis(ethyldi-sec.butoxysilylpropyl) disulfide, 3,3'-bis(propyldiethoxysilylpropyl) disulfide, 3,3'-bis(butyldimethoxysilylpropyl) trisulfide, 3,3'-bis(phenyldimethoxysilylpropyl) tetrasulfide, 3-phenylethoxybutoxysilyl 3'-trimethoxysilylpropyl tetrasulfide, 4,4'-bis(trimethoxysilylbutyl) tetrasulfide, 6,6'-bis(triethoxysilylhexyl) tetrasulfide, 12,12'-bis(triisopropoxysilyldodecyl) disulfide , 18,18'-bis(trimethoxysilyl octadecyl) tetrasulfide, 18,18'-bis(tripropoxysilyl octadecenyl) tetrasulfide, 4,4'-bis(trimethoxysilyl-buten-2-yl) tetrasulfide, 4,4'-bis(trimethoxysilyl cyclohexylene) tetrasulfide, 5,5'-bis(dimethoxymethylsilyl pentyl) trisulfide, 3,3'-bis(trimethoxysilyl-2-methylpropyl) tetrasulfide, 3,3'-bis(dimethoxyphenylsilyl-2-methylpropyl) disulfide.

[0083] The preferred sulfur containing organosilicon compounds are 3,3'-bis(trimethoxy or triethoxysilylpropyl) sulfides. The most preferred compounds are 3,3'-bis(triethoxysilylpropyl) disulfide and 3,3'-bis(triethoxysilylpropyl) tetrasulfide. Thus, for formula V, preferably Z is

[0084] [ka]

[0085] is [In the formula, R 7 is an alkoxy of 2 to 4 carbon atoms, with 2 carbon atoms being particularly preferred; alk is a divalent hydrocarbon of 2 to 4 carbon atoms, with 3 carbon atoms being particularly preferred; and n is an integer of 2 to 5, with 2 and 4 being particularly preferred.

[0086] In another embodiment, suitable sulfur-containing organosilicon compounds include those disclosed in U.S. Patent No. 6,608,125. In one embodiment, the sulfur-containing organosilicon compound includes 3-(octanoylthio)-1-propyltriethoxysilane, CH3(CH2)6C(=O)-S-CH2CH2CH2Si(OCH2CH3)3, commercially available as NXT™ from Momentive Performance Materials.

[0087] In one embodiment, the sulfur-containing organosilicon compound comprises the reaction product of a hydrocarbon diol (e.g., 2-methyl-1,3-propanediol) with S-[3-(triethoxysilyl)propyl]thiooctanoate. In one embodiment, the sulfur-containing organosilicon compound is NXT-Z™ from Momentive Performance Materials.

[0088] In another embodiment, suitable sulfur-containing organosilicon compounds include those disclosed in US Patent Application Publication No. 2003 / 0130535. In one embodiment, the sulfur-containing organosilicon compound is Si-363 from Degussa.

[0089]

[0086] The amount of the sulfur-containing organosilicon compound in the rubber composition may vary depending on the level of other additives used. Generally speaking, the amount of the compound of formula I ranges from 0.5 to 20 phr. Preferably, the amount ranges from 1 to 10 phr.

[0090] It will be readily understood by those skilled in the art that the rubber composition can be compounded by methods generally known in the rubber compounding art, such as, for example, mixing the various components of the sulfur vulcanizable rubber with sulfur donors, curing aids, such as activators and retarders, and various commonly used additive materials, such as processing additives, fillers, pigments, fatty acids, zinc oxide, waxes, antioxidants, antiozonants and peptizers. Depending on the intended use of the sulfur vulcanizable and sulfur vulcanized materials (rubbers), as known to those skilled in the art, the additives listed above are selected and generally used in conventional amounts. Representative examples of sulfur donors include elemental sulfur (free sulfur), amine disulfides, polymeric polysulfides and sulfur olefin adducts. Preferably, the sulfur vulcanizing agent is elemental sulfur. The sulfur vulcanizing agent ranges from 0.5 to 8 phr, with a range of 1 to 6 phr being preferred. Typical amounts of antioxidants include from about 1 to about 5 phr. Representative antioxidants may be, for example, diphenyl-p-phenylenediamine and others such as those disclosed in, for example, The Vanderbilt Rubber Handbook (1978), pages 344-346. Typical amounts of antiozonants include about 1-5 phr. Typical amounts of fatty acids, which, if used, may include stearic acid, include about 0.5 to about 5 phr. Typical amounts of zinc oxide include about 2 to about 5 phr. Typical amounts of wax include 1-5 phr. Microcrystalline wax is often used. Typical amounts of peptizers include 0.1-1 phr. Typical peptizers may be, for example, pentachlorothiophenol and dibenzamidodiphenyl disulfide.

[0091] Accelerators are used to control the time and / or temperature required for vulcanization and to improve the properties of the vulcanizate. In one embodiment, a single accelerator system may be used, i.e., a primary accelerator. The primary accelerator(s) may be used in a total amount ranging from 0.5 phr to 4 phr, preferably from about 0.8 to about 2.0 phr. In another embodiment, a combination of primary and secondary accelerators may be used, with the secondary accelerator being used in a lower amount, such as from about 0.05 to about 3 phr, to activate and improve the properties of the vulcanizate. These accelerator combinations can be expected to produce a synergistic effect on the final properties, which are somewhat better than those produced by the use of either accelerator alone. In addition, delayed action accelerators may be used which are not affected by normal processing temperatures but produce a satisfactory cure at normal vulcanization temperatures. Vulcanization retarders may also be used. Suitable types of accelerators which may be used in the present invention are amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates and xanthates. Preferably, the primary accelerator is a sulfenamide. If a second accelerator is used, the secondary accelerator is preferably a guanidine, dithiocarbamate or thiuram compound.

[0092]

[0089] The mixing of the rubber composition can be accomplished by methods known to those skilled in the rubber mixing art. For example, the raw materials are usually mixed in at least two stages, namely, at least one non-productive stage followed by a productive mix stage. The final curatives, including sulfur vulcanizing agents, are usually mixed in a final stage, conventionally referred to as the "productive" mix stage, in which mixing is usually carried out at a temperature or at a final temperature, which is lower than the mixing temperature(s) of the preceding non-productive mix stage(s). The terms "non-productive" and "productive" mix stages are well known to those skilled in the rubber mixing art. The rubber composition may be subjected to a thermodynamic mixing step. The thermodynamic mixing step generally involves mechanical operation in a mixer or extruder for a period of time suitable to produce a rubber temperature between 140°C and 190°C. The suitable duration of the thermodynamic operation varies as a function of the operating conditions and the amounts and nature of the components. For example, the thermodynamic operation may be from 1 to 20 minutes.

[0093]

[0090] The rubber composition may be incorporated into the tread of a tire. The pneumatic tire of the present invention may be a race tire, passenger tire, aircraft tire, farm tire, earthmover, off-road, truck tire, etc. Preferably the tire is a passenger or truck tire. The tire may also be radial or bias, although radial is preferred.

[0094]

[0092] Vulcanization of the pneumatic tires of this invention is generally carried out at conventional temperatures ranging from 100°C to 200°C. Preferably, vulcanization is carried out at a temperature ranging from 110°C to 180°C. Any of the usual vulcanization methods may be used, such as heating in a press or mold, heating with superheated steam or hot air, etc. Such tires may be built, shaped, molded and cured by a variety of methods known and readily apparent to those skilled in the art.

[0095] Alternatively, the rubber compositions may be used in the form of components for shoes, shoe soles, power transmission belts, hoses, vibration dampers, air springs, conveyor belts, and track belts.

[0096] The following examples are presented for the purpose of illustrating, but not limiting, the present invention. All parts are by weight unless otherwise specified. EXAMPLES

[0097] In this example, three rubber compounds are compared: Sample 1 represents a control sample; Samples 2 and 3 are representative of the present invention. The elastomers were compounded using a multi-stage mix procedure with standard amounts of conventional curatives and processing aids (all in phr amounts) as shown in Table 1 and cured using a standard cure cycle. Tires having treads made from compounds Samples 1-3 were tested for various performance criteria as shown in Table 2 (normalized values ​​with control=100, higher is better).

[0098] [Table 1]

[0099]

[0097] Although certain representative embodiments and details have been shown for the purpose of explaining the subject invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the subject invention.

[0100] [Mode of the invention] 1. Based on 100 parts by weight of elastomer (phr), (A) about 20 to about 100 phr of solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) in the range of -85°C to -50°C; (B) natural rubber or synthetic polyisoprene, 0 to about 40 phr; (C) 0 to about 30 phr of cis-1,4 polybutadiene having a Tg of -110°C to -90°C; (D) process oil 0-50 phr; (E) 20 to 80 phr of a hydrocarbon resin having a Tg of at least 30° C.; and (F) Silica 90~150phr A pneumatic tire having a tread comprising a vulcanizable rubber composition comprising: 2. The pneumatic tire of claim 1, wherein the hydrocarbon resin is selected from the group consisting of styrene / alpha methyl styrene copolymer resins, C5 / C9 copolymer resins, dicyclopentadiene resins and aromatic dicyclopentadiene resins. 3. The pneumatic tire according to 1, wherein the resin is an aromatic modified dicyclopentadiene resin. 4. The pneumatic tire of 1, wherein the resin is a styrene / alpha methyl styrene copolymer resin. 5. The pneumatic tire according to 1, wherein the resin is a DCPD-based resin containing about 5 to about 90 mol % of units derived from DCPD. 6. The pneumatic tire according to 1, wherein the resin is a DCPD-based resin containing 1 to 20 mol % of aromatic hydrogen. 7. The pneumatic tire of claim 1, wherein the resin is a C5 / C9 resin containing 50-90% (by weight) piperylene, 0-5% isoprene, 10-30% amylene, 2-5% cyclics, 4-10% styrenes, and 4-10% indenes. 8. The pneumatic tire of claim 1, wherein the resin is a C5 / C9 resin containing an aromatic hydrogen content between 3 and 15 mole percent. 9. The pneumatic tire of claim 1, wherein the solution polymerized styrene-butadiene rubber is functionalized with at least one functional group selected from the group consisting of alkoxysilane groups, and primary amines and thiols. 10. The pneumatic tire of claim 1, wherein the oil is selected from the group consisting of aromatic, paraffinic, naphthenic, MES, TDAE, heavy naphthenic oils and vegetable oils. 11. The pneumatic tire of 1, wherein the solution polymerized styrene-butadiene rubber is functionalized with alkoxysilane groups and primary amine groups and is represented by formula (1) or (2).

[0101] [ka]

[0102] [wherein P is a polymer or copolymer chain of a conjugated diolefin or a conjugated diolefin and an aromatic vinyl compound; R 1 is an alkylene group having 1 to 12 carbon atoms, R 2 and R 3 are each independently an alkyl group, an allyl group, or an aryl group having 1 to 20 carbon atoms, n is an integer 1 or 2, m is an integer 1 or 2, and k is an integer 1 or 2, with the proviso that n+m+k is an integer 3 or 4.

[0103] [ka]

[0104] [In the formula, P, R 1 , R 2 and R 3 has the same definition as given in formula (1) above, j is an integer from 1 to 3, and h is an integer from 1 to 3, with the proviso that j+h is an integer from 2 to 4. 12. Solution polymerized styrene-butadiene rubber was functionalized with alkoxysilane and primary amine groups to form living polymer chains and the formula RN-(CH2) X -Si-(OR ’ )3, I wherein R in combination with the nitrogen (N) atom is a protected amine group that upon suitable work-up provides a primary amine; R ’ represents a group having 1 to 18 carbon atoms selected from alkyl, cycloalkyl, allyl, or aryl; and X is an integer from 1 to 20. 13. Solution polymerized styrene-butadiene rubber was functionalized with alkoxysilane groups and thiols to give living anionic polymers and the formula (R 4 O)x R 4 y Si-R 5 -S-SiR 4 3 where Si is silicon; S is sulfur; O is oxygen; x is an integer selected from 1, 2, and 3; y is an integer selected from 0, 1, and 2; x+y=3; R 4 are the same or different, (C1-C 16 ) alkyl; R 5 is aryl, alkylaryl, or (C1-C 16 2. The pneumatic tire according to claim 1, comprising a reaction product of a silane sulfide modifier represented by the formula: 14. The pneumatic tire according to 1, wherein the amount of styrene-butadiene rubber is in the range of 70 to 90 phr. 15. A pneumatic tire as described in 1, wherein the amount of natural rubber or synthetic polyisoprene is in the range of 15 to 30 phr. 16. The pneumatic tire according to 1, wherein the amount of polybutadiene is in the range of 5 to 15 phr. 17. A pneumatic tire as described in 1, wherein the amount of oil is in the range of 1 to 20 phr. 18. A pneumatic tire as described in 1, wherein the amount of resin is in the range of 55 to 80 phr. 19. A vulcanizable rubber composition comprising: (A) about 20 to about 100 phr of solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) in the range of -85°C to -50°C; (B) natural rubber or synthetic polyisoprene, 0 to about 40 phr; (C) 0 to about 30 phr of cis-1,4 polybutadiene having a Tg of -110°C to -90°C; (D) process oil 0-50 phr; (E) 20 to 80 phr of a hydrocarbon resin having a Tg of at least 30° C.; and (F) A vulcanizable rubber composition containing 90 to 150 phr of silica. 20. The vulcanizable rubber composition of claim 18 in the form of a component of an article selected from the group consisting of shoes, shoe soles, power transmission belts, hoses, vibration dampers, air springs, conveyor belts, and track belts.

Claims

1. Based on 100 parts by weight of elastomer (phr), (A) 20 to 100 phr of a solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) in the range of -85°C to -50°C; (B) 0 to 40 phr of natural rubber or synthetic polyisoprene; (C) 0 to 30 phr of cis-1,4 polybutadiene having a Tg of -110°C to -90°C; (D) process oil 1 to 5 phr; (E) 55 to 80 phr of a hydrocarbon resin having a Tg of at least 30° C.; and (F) Silica 90 to 150 phr A pneumatic tire comprising a tread comprising a vulcanizable rubber composition comprising:

2. 2. The pneumatic tire of claim 1, wherein the hydrocarbon resin is selected from the group consisting of styrene / alpha methyl styrene copolymer resins, C5 / C9 copolymer resins, dicyclopentadiene resins and aromatic dicyclopentadiene resins.

3. The pneumatic tire according to claim 1 , wherein the resin is an aromatic modified dicyclopentadiene resin.

4. 2. The pneumatic tire according to claim 1, wherein the resin is a DCPD-based resin containing 1 to 20 mol % of aromatic hydrogen.

5. 2. The pneumatic tire of claim 1, wherein the solution polymerized styrene-butadiene rubber is functionalized with at least one functional group selected from the group consisting of an alkoxysilane group, and a primary amine and a thiol.

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