Rubber formulations comprising hydrogenated elastomer, natural rubber, and reinforced filler

Abstract

Embodiments of the present disclosure are directed to rubber formulations, wherein the rubber formulations include hydrogenated elastomer having a silane-functionalized end group and a degree of hydrogenation of greater than or equal to 50 mol.%. The hydrogenated elastomer includes, based on the total weight of the hydrogenated elastomer, a vinyl content of greater than or equal to about 15 wt.%, a cis content of about 30 wt.% to about 85 wt.%, and a styrene content of about 0 wt.% to about 15 wt.%. The rubber formulation further includes natural rubber in an amount of at least 50 phr and reinforcing filler including, based on a total weight of the reinforcing filler, 0 wt.% to 50 wt.% silica and 50 wt.% to 100 wt.% carbon black.

Description

RUBBER FORMULATIONS COMPRISING HYDROGENATED ELASTOMER, NATURAL RUBBER, AND REINFORCED FILLERCROSS REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Patent Application Serial Number 63 / 615,334, filed on December 28, 2023, entitled "Rubber Formulations Comprising Hydrogenated Elastomer, Natural Rubber and Reinforced Filler," the entire contents of which are incorporated by reference in the present disclosure.TECHNICAL FIELD

[0002] Embodiments of the present disclosure are generally related to hydrogenated elastomers, and are specifically related to rubber formulations including hydrogenated elastomer, natural rubber, and reinforced filler, which have improved tensile strength and wear resistance.BACKGROUND

[0003] Rubber formulations comprising natural rubber, butadiene rubber, and reinforced filler are commonly used in tire applications, for example, tire tread. In certain applications, it may be desirable for the rubber formulations to have relatively greater mechanical properties, such as tensile strength and wear resistance. However, achieving such greater mechanical properties may be difficult due to relatively low polymer entanglement of the butadiene rubber.

[0004] Accordingly, a continual need exists for improved rubber formulations that have increased polymer entanglement, thereby providing improved mechanical properties.SUMMARY

[0005] Embodiments of the present disclosure are directed to rubber compositions comprising hydrogenated elastomers, which provide improved mechanical strength, such as in tread tire applications. Specifically, these rubber compositions may demonstrate improvement in improved tensile properties and wear resistance. These improved mechanical properties are achieved through increased polymer entanglement by replacing butadiene rubber with hydrogenated elastomer. The hydrogenated elastomer may experience increased entanglement, which may increase the mechanical strength of the formula. By increasing the mechanical strength, these hydrogenated elastomers may desirably improve tire performance.

[0006] One embodiment of the present disclosure is directed to a rubber formulation comprising hydrogenated elastomer having a silane-functionalized end group and a degree of hydrogenation of greater than or equal to 50 mol.%. The hydrogenated elastomer comprises, based on the total weight of the hydrogenated elastomer: a vinyl content of greater than or equal to about 15 wt.%, a cis content of about 30 wt.% to about 95 wt.%, and a styrene content of about 0 wt.% to about 15 wt.%. The rubber formulation further comprises natural rubber in an amount of at least 50 phr and reinforcing fdler comprising, based on a total weight of the reinforcing fdler 0 wt.% to 50 wt.% silica and 50 wt.% to 100 wt.% carbon black.

[0007] Additional features and advantages of the embodiments described herein will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, and the claims.DETAITED DESCRIPTION

[0008] Embodiments of the present disclosure are directed to rubber formulations, wherein the rubber formulations include hydrogenated elastomer having a silane-functionalized end group and a degree of hydrogenation of greater than or equal to 50 mol.%. The hydrogenated elastomer includes, based on the total weight of the hydrogenated elastomer, a vinyl content of greater than or equal to about 15 wt.%, a cis content of about 30 wt.% to about 95 wt.%, and a styrene content of about 0 wt.% to about 15 wt.%. The rubber formulation further includes natural rubber in an amount of at least 50 phr and reinforcing fdler including, based on a total weight of the reinforcing fdler, 0 wt.% to 50 wt.% silica and 50 wt.% to 100 wt.% carbon black.

[0009] The disclosure should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the subject matter to those skilled in the art.

[0010] Definitions

[0011] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in the disclosure herein is for describing particular embodiments only and is not intended to be limiting.

[0012] Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0013] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification.

[0014] As used in the specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise.

[0015] The term “phr,” as described herein, refers to parts by weight of the identified component per 100 parts rubber.

[0016] As used herein, the term “hydrogenated polybutadiene” is used to indicate a polymer that is manufactured from hydrogenated butadiene monomers. The term hydrogenated polybutadiene is also used interchangeably with the phrase “hydrogenated polybutadiene rubber” and the abbreviation “H-BR.”

[0017] As used herein, the terms “hydrogenated styrene-butadiene copolymer,” “hydrogenated styrene-butadiene rubber” or “H-SBR” mean a copolymer manufactured from styrene and hydrogenated butadiene monomers.

[0018] As used herein, the terms “natural rubber” or "NR" mean naturally occurring rubber such as can be harvested from sources such as Hevea rubber trees, and non-Hevea source (e.g., guayule shrubs).

[0019] As used herein, the term "polybutadiene" is used to indicate a polymer that is manufactured from 1,3-butadiene monomers. The term polybutadiene is also used interchangeably with the phrase "polybutadiene rubber" and the abbreviation "BR."

[0020] As used herein, the term “hydrogenated elastomer” refers to an elastomer produced from a hydrogenated polymer, such as H-BR, S-BR, or a combination of both, and additional fdlers and additives blended therewith in tire and non-tire applications.

[0021] As used herein, the term “polymer entanglement” refers to the intermingling or intertwining of polymer chains in a polymeric material. When many polymer chains are present in a material, they can become entangled with each other. This entanglement occurs due to the long and flexible nature of polymer chains, allowing them to weave through and around each other. The degree of polymer entanglement may have a significant impact on the mechanical properties of the material. For example, higher levels of entanglement may lead to increased strength, toughness, and resistance to deformation.

[0022] The term “rubber formulation,” as described herein, refers to the rubber (i.e., hydrogenated elastomer comprising natural rubber and a hydrogenated polymer) and the additional fillers and additives blended therewith in tire and non-tire applications.

[0023] The term “vinyl content,” as described herein, refers to the percentage of vinyl 1,2 linkages in a polydiene, such as the functionalized conjugated diene polymer. The “vinyl content” is determined by 400 MHz Nuclear Magnetic Resonance using CDCh as the solvent.

[0024] The term “cis content,” as described herein, refers to the percentage of cis 1,4 linkages in the polydiene.

[0025] The term “high-cis,” as used herein, means a cis-l,4-linkage content of 60 wt.% or greater in the resulting polydiene.

[0026] The term “low-cis,” as used herein, means a cis-l,4-linkage content of less than 60 wt.% in the resulting polydiene.

[0027] The term “control rubber formulation,” as used herein refers to a rubber formulation that includes natural rubber, polybutadiene rubber, and carbon black and does not include a hydrogenated elastomer.

[0028] Number average molecular weight Mn, weight average molecular weight Mw, and peak molecular weight Mp, as described herein.

[0029] Glass transition temperature Tg, as described herein, is measured by differential scanning calorimetry.

[0030] The tensile mechanical properties modulus at 100% strain Ml 00, modulus at 300% strain M300, stress at break (Tb), and maximum strain (Eb), described herein, are determined in accordance with ASTM D412.

[0031] The viscoelastic property change in storage modulus AG' (0.25-10%)), as described herein, is measured by a strain sweep test conducted with an Advanced Rheometric Expansion System from TA instruments

[0032] The loss tangent tan 8 at 60 °C, as described herein, is measured by a temperature sweep test conducted with a GABO Eplexor at 2% strain with varied temperature.

[0033] As used herein, the term “sustainable,” refers to a material that comes from biological or recycled sources or is certified using a mass balance approach.

[0034] As discussed hereinabove, natural and butadiene rubber blends including reinforced filler (e.g., carbon black, silica) are commonly used in tire tread applications. However, the polymer entanglement of the butadiene may be relatively low when compared to formulas comprising hydrogenated elastomer, leading to a relative decrease in mechanical properties.

[0035] Disclosed herein are rubber formulations which mitigate the aforementioned problems. Specifically, fully replacing the butadiene rubber with hydrogenated elastomer may result in betterpolymer entanglement, which translates to improved mechanical properties. Specifically, the increase in polymer entanglement shows improved tensile strength and wear resistance compared to the control rubber formulation comprising natural rubber and butadiene rubber.

[0036] The rubber formulations disclosed herein may generally be described as comprising hydrogenated elastomer, natural rubber, and reinforcing filler.

[0037] Hydrogenated Elastomer

[0038] As described hereinabove, replacing natural rubber with hydrogenated elastomers may improve polymer entanglement, leading to improved mechanical properties. The single bonds within the polymer backbone allow for more freedom of motion than double bonded carbon polymers. Without being bound by any theory, due to the higher entanglement resulting from the motion, there may be a restriction of the relative chain movements, which may lead to higher viscosity and modulus properties.

[0039] In embodiments, the hydrogenated elastomer may comprise hydrogenated styrenebutadiene rubber (H-SBR), hydrogenated polybutadiene rubber (H-BR), or a combination thereof. In embodiments, the hydrogenated elastomer may comprise a sustainable hydrogenated elastomer.

[0040] The hydrogenated elastomers described herein have a silane-functionalized end group, improving rheological properties. The silane-based functional groups of the hydrogenated elastomer may react with reinforced fdler (e.g., carbon black) and improve dispersion in the natural rubber phase. The improved fdler dispersion through polymer-fdler interaction manifests in improved rheological properties, such as reduced change in storage modulus AG', which correlates to improved fdler dispersion, and a decrease in loss tangent tan 8 at 60 °C, which correlates to reduced rolling resistance, as compared to a control rubber formulation having natural rubber and high-cis 1,4-polybutadiene rubber.

[0041] Exemplary silane-functionalized end groups include one or a combination of alkoxysilyl, hydroxyl, polyalkylene glycol, silanol, silyl halide, anhydride, organic acid, amines, heterocycles, and epoxy groups.

[0042] Various alkoxysilyl compositions are contemplated, for example and not by way of limitation, alkoxysilane compounds, aralkyloxysilane compounds, tetraalkoxysilane compounds, alkylalkoxysilane compounds, alkenylalkoxysilane compounds, halogenoalkoxysilanecompounds, or combinations therein. These may include one or more of dimethoxysilanes and trimethoxy silanes .

[0043] Examples of the tetraalkoxysilane compound may include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra(2-ethylhexanoxy)silane, tetraphenoxysilane, tetratoluyloxysilane, and the like.

[0044] Examples of the alkylalkoxysilane may include methyltrimethoxysilane, methyltriethoxysilane, methyltri -n-propoxysilane, methyltri-n-butoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltri-n-butoxysilane, ethyltriphenoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n-propoxysilane, dimethyldi-n-butoxysilane, dimethyldiphenoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, 3- glycidoxypropyltrimethoxysilane (GPMOS), y-methacryloxy propyl trimethoxysilane, and combinations thereof.

[0045] Examples of the arylalkoxysilane compound may include phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltri-n-butoxysilane, phenyltriphenoxysilane, and combinations thereof.

[0046] Examples of the alkenylalkoxysilane compound may include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n-propoxysilane, vinyltri-n-butoxysilane, vinyltriphenoxysilane, allyltrimethoxysilane, octenyltrimethoxysilane, divinyldimethoxysilane, styryltrimethoxysilane, and combinations thereof.

[0047] Examples of the halogenoalkoxysilane compound may include trimethoxychlorosilane, triethoxychlorosilane, tri-n-propoxychlorosilane, tri-n-butoxychlorosilane, triphenoxychlorosilane, dimethoxydichlorosilane, diethoxydichlorosilane, di-n- propoxydichlorosilane, diphenoxydichlorosilane, methoxytrichlorosilane, ethoxytrichlorosilane, n-propoxytrichlorosilane, phenoxytrichlorosilane, trimethoxybromosilane, triethoxybromosilane, tri-n-propoxybromosilane, triphenoxybromosilane, dimethoxydibromosilane, diethoxydibromosilane, di-n-propoxydibromosilane, diphenoxydibromosilane, methoxytribromosilane, ethoxytribromosilane, n-propoxytribromosilane, phenoxytribromosilane, trimethoxyiodosilane, triethoxyiodosilane, tri-n-propoxyiodosilane, triphenoxyiodosilane,dimethoxydiiodosilane, di-n-propoxydiiodosilane, diphenoxydiiodosilane, methoxytriiodosilane, ethoxytriiodosilane, n-propoxytriiodosilane, phenoxytriiodosilane, and combinations thereof.

[0048] Additionally, the alkoxysilyl compositions may include trimethoxysilane compositions, such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (ECETMOS), methyltrimethoxysilane (MeSi(OMe)3), 3-glycidylpropyltrimethoxysilane, y-glycidoxypropyltrimethoxysilane, or 3-(l ,3- dimethylbutylidene)aminopropyltriethoxysilane. Additionally, the alkoxysilyl compositions may include tetraethylorthosilicate, 3-glycidylpropylmethyldimethoxysilane, or combinations thereof.

[0049] In embodiments, the hydrogenated elastomer may have a vinyl content greater than or equal to 10 wt.%. In embodiments, the hydrogenated elastomer may have a vinyl content greater than or equal to about 10 wt.%, greater than or equal to about 15 wt.%, greater than or equal to about 20 wt.%, greater than or equal to about 25 wt.%, or even greater than or equal to about 30 wt.%. In embodiments, the hydrogenated elastomer may have a vinyl content less than or equal to about 40 wt.%, less than or equal to about 35 wt.%, less than or equal to about 30 wt.%, less than or equal to about 25 wt.%, or even less than or equal to about 20 wt.%. In embodiments, the hydrogenated elastomer may have a vinyl content from about 10 wt.% to about 40 wt.%, from about 10 wt.% to about 35 wt.%, from about 10 wt.% to about 30 wt.%, from about 10 wt.% to about 25 wt.%, from about 10 wt.% to about 20 wt.%, from about 15 wt.% to about 40 wt.%, from about 15 wt.% to about 35 wt.%, from about 15 wt.% to about 30 wt.%, from about 15 wt.% to about 25 wt.%, from about 15 wt.% to about 20 wt.%, from about 20 wt.% to about 40 wt.%, from about 20 wt.% to about 35 wt.%, from about 20 wt.% to about 30 wt.%, from about 20 wt.% to about 25 wt.%, from about 25 wt.% to about 40 wt.%, from about 25 wt.% to about 35 wt.%, from about 25 wt.% to about 30 wt.%, from about 30 wt.% to about 40 wt.%, or even from about 30 wt.% to about 35 wt.%, or any and all sub-ranges formed from any of these endpoints.

[0050] In embodiments, the hydrogenated elastomer may be a high-cis elastomer or a low-cis elastomer. In embodiments, the hydrogenated elastomer may have a cis content greater than or equal to 30 wt.%. In embodiments, the hydrogenated elastomer may have a cis content greater than or equal to about 30 wt.%, greater than or equal to about 35 wt.%, greater than or equal to about 40 wt.%, greater than or equal to about 45 wt.%, or even greater than or equal to about 50 wt.%. In embodiments, the hydrogenated elastomer may have a cis content less than or equal to about 85 wt.%, less than or equal to about 80 wt.%, less than or equal to about 75 wt.%, less than or equal to 70 wt.%, or even less than or equal to 65 wt.%. In embodiments, the hydrogenatedelastomer may have a cis content from about from about 30 wt.% to about 85 wt.%, from about 30 wt.% to about 80 wt.%, from about 30 wt.% to about 75 wt.%, from about 30 wt.% to about 70 wt.%, from about 30 wt.% to about 65 wt.%, from about 35 wt.% to about 85 wt.%, from about 35 wt.% to about 80 wt.%, from about 35 wt.% to about 75 wt.%, from about 35 wt.% to about 70 wt.%, from about 35 wt.% to about 65 wt.%, from about 40 wt.% to about 85 wt.%, from about 40 wt.% to about 80 wt.%, from about 40 wt.% to about 75 wt.%, from about 40 wt.% to about 70 wt.%, from about 40 wt.% to about 65 wt.%, from about 45 wt.% to about 85 wt.%, from about 45 wt.% to about 80 wt.%, from about 45 wt.% to about 75 wt.%, from about 45 wt.% to about 70 wt.%, from about 45 wt.% to about 65 wt.%, from about 50 wt.% to about 85 wt.%, from about 50 wt.% to about 80 wt.%, from about 50 wt.% to about 75 wt.%, 50 wt.% to about 70 wt.%, or even from 50 wt.% to about 65 wt.%, or any and all sub-ranges formed from any of these endpoints.

[0051] In embodiments, the hydrogenated elastomer may have a styrene content greater than or equal to 0 wt.%. In embodiments, the hydrogenated elastomer may have a styrene content greater than or equal to about 0 wt.%, greater than or equal to about 2 wt.%, greater than or equal to about 4 wt.%, or even greater than or equal to about 6 wt.%. In embodiments, the hydrogenated elastomer may have a styrene content less than or equal to about 15 wt.%, less than or equal to about 13 wt.%, less than or equal to about 11 wt.%, less than or equal to about 9 wt.%, less than or equal to about 7 wt.%, or even less than or equal to about 5 wt.%. In embodiments, the hydrogenated elastomer may have a styrene content from about 0 wt.% to about 15 wt.%, from about 0 wt.% to about 13 wt.%, from about 0 wt.% to about 11 wt.%, from about 0 wt.% to about 9 wt.%, from about 0 wt.% to about 7 wt.%, about 2 wt.% to about 15 wt.%, from about 2 wt.% to about 13 wt.%, from about 2 wt.% to about 11 wt.%, from about 2 wt.% to about 9 wt.%, from about 2 wt.% to about 7 wt.%, about 4 wt.% to about 15 wt.%, from about 4 wt.% to about 13 wt.%, from about 4 wt.% to about 11 wt.%, from about 4 wt.% to about 9 wt.%, from about 4 wt.% to about 7 wt.%, from about 6 wt.% to about 15 wt.%, from about 6 wt.% to about 13 wt.%, from about 6 wt.% to about 11 wt.%, from about 6 wt.% to about 9 wt.%, from about 6 wt.% to about 7 wt.%, or any and all sub-ranges formed from any of these endpoints.

[0052] In embodiments, the hydrogenated elastomer may have a weight average molecular weight Mwof about 75,000 g / mol to about 1,000,000 g / mol. In embodiments, the hydrogenated elastomer may have a weight average molecular weight Mwgreater than or equal to 75,000 g / mol, greater than or equal to 100,000 g / mol, greater than or equal to 200,000 g / mol, or even greaterthan or equal to 300,000 g / mol. In embodiments, hydrogenated elastomer may have a weight average molecular weight Mwless than or equal to 1,000,000 g / mol, less than or equal to 800,000 g / mol, less than or equal to 600,000 g / mol, or even less than or equal to 400,000 g / mol. In embodiments, the hydrogenated elastomer may have a molecular weight Mwfrom about 75,000 g / mol to about 1,000,000 g / mol, from about 75,000 g / mol to about 800,000 g / mol, from about 75,000 g / mol to about 600,000 g / mol, from about 75,000 g / mol to about 400,000 g / mol, from about 100,000 g / mol to about 1,000,000 g / mol, from about 100,000 g / mol to about 800,000 g / mol, from about 100,000 g / mol to about 600,000 g / mol, from about 100,000 g / mol to about 400,000 g / mol, from about 200,000 g / mol to about 1,000,000 g / mol, from about 200,000 g / mol to about 800,000 g / mol, from about 200,000 g / mol to about 600,000 g / mol, from about 200,000 g / mol to about 400,000 g / mol, from about 300,000 g / mol to about 1,000,000 g / mol, from about 300,000 g / mol to about 800,000 g / mol, from about 300,000 g / mol to about 600,000 g / mol, or even from about 300,000 g / mol to about 400,000 g / mol, or any and all sub-ranges formed from any of these endpoints.

[0053] In embodiments, the hydrogenated elastomer may have a number average molecular weight Mnof about 75,000 g / mol to about 1,000,000 g / mol. In embodiments, the hydrogenated elastomer may have a number average molecular weight Mngreater than or equal to 75,000 g / mol, greater than or equal to 100,000 g / mol, greater than or equal to 200,000 g / mol, or even greater than or equal to 300,000 g / mol. In embodiments, the hydrogenated elastomer may have a number average molecular weight Mnless than or equal to 1,000,000 g / mol, less than or equal to 800,000 g / mol, less than or equal to 600,000 g / mol, or even less than or equal to 400,000 g / mol. In embodiments, the hydrogenated elastomer may have a molecular weight Mnfrom about 75,000 g / mol to about 1,000,000 g / mol, from about 75,000 g / mol to about 800,000 g / mol, from about 75,000 g / mol to about 600,000 g / mol, from about 75,000 g / mol to about 400,000 g / mol, from about 100,000 g / mol to about 1,000,000 g / mol, from about 100,000 g / mol to about 800,000 g / mol, from about 100,000 g / mol to about 600,000 g / mol, from about 100,000 g / mol to about 400,000 g / mol, from about 200,000 g / mol to about 1,000,000 g / mol, from about 200,000 g / mol to about 800,000 g / mol, from about 200,000 g / mol to about 600,000 g / mol, from about 200,000 g / mol to about 400,000 g / mol, from about 300,000 g / mol to about 1,000,000 g / mol, from about 300,000 g / mol to about 800,000 g / mol, from about 300,000 g / mol to about 600,000 g / mol, or even from about 300,000 g / mol to about 400,000 g / mol, or any and all sub-ranges formed from any of these endpoints.

[0054] In embodiments, the hydrogenated elastomer may have a peak molecular weight Mpof about 75,000 g / mol to about 1,000,000 g / mol. In embodiments, the hydrogenated elastomer may have a peak molecular weight Mpgreater than or equal to 75,000 g / mol, greater than or equal to 100,000 g / mol, greater than or equal to 200,000 g / mol, or even greater than or equal to 300,000 g / mol. In embodiments, the hydrogenated elastomer may have a molecular weight Mwless than or equal to 1,000,000 g / mol, less than or equal to 800,000 g / mol, less than or equal to 600,000 g / mol, or even less than or equal to 400,000 g / mol. In embodiments, hydrogenated elastomer may have a peak molecular weight Mpfrom about 75,000 g / mol to about 1,000,000 g / mol, from about 75,000 g / mol to about 800,000 g / mol, from about 75,000 g / mol to about 600,000 g / mol, from about 75,000 g / mol to about 400,000 g / mol, from about 100,000 g / mol to about 1,000,000 g / mol, from about 100,000 g / mol to about 800,000 g / mol, from about 100,000 g / mol to about 600,000 g / mol, from about 100,000 g / mol to about 400,000 g / mol, from about 200,000 g / mol to about 1,000,000 g / mol, from about 200,000 g / mol to about 800,000 g / mol, from about 200,000 g / mol to about 600,000 g / mol, from about 200,000 g / mol to about 400,000 g / mol, from about 300,000 g / mol to about 1,000,000 g / mol, from about 300,000 g / mol to about 800,000 g / mol, from about 300,000 g / mol to about 600,000 g / mol, or even from about 300,000 g / mol to about 400,000 g / mol, or any and all sub-ranges formed from any of these endpoints.

[0055] In embodiments, the amount of hydrogenated elastomer in the rubber formulation may be greater than about 10 phr, greater than or equal to about 20 phr, greater than or equal to about 30 phr, or even greater than or equal to about 40 phr. In embodiments, the amount of hydrogenated elastomer in the rubber formulation may be less than or equal to about 50 phr, less than or equal to about 47 phr, or even less than or equal to about 45 phr. In embodiments, the amount of hydrogenated elastomer in the rubber formulation may be from about 10 phr to about 50 phr, from about 10 phr to about 47 phr, from about 10 phr to about 45 phr, from about 20 phr to about 50 phr, from about 20 phr to about 47 phr, from about 20 phr to about 45 phr, from about 30 phr to about 50 phr, from about 30 phr to about 47 phr, from about 30 phr to about 45 phr, from about 40 phr to about 50 phr, from about 40 phr to about 47 phr, or even from about 40 phr to about 45 phr, or any and all sub-ranges formed from any of these endpoints.

[0056] Polymerization

[0057] In embodiments, the hydrogenated elastomers of the present disclosure may be made by a method comprising polymerizing conjugated diene monomer (e.g., 1,3-butadiene), andoptionally vinyl aromatic monomer (e.g., styrene), in the presence of an anionic initiator to produce polymer chains with a living end. Polymerization is begun by introducing the monomers and solvent to a suitable reaction vessel, followed by the addition of the anionic polymerization initiators. The polymerization reaction may be carried out in a batch polymerization reactor system or a continuous polymerization reactor system. Polymerization conditions such as temperature, pressure and time may be suitable for polymerizing. For example, for illustrative purposes only, the temperature employed in the polymerization is generally not critical and may range from about -60 °C to about 150 °C. Exemplary polymerization temperatures may range from about 25 °C to about 130 °C for a polymerization time of a few minutes to up to 24 hours or more, and employing pressures generally sufficient to maintain polymerization admixtures substantially in the liquid phase, for example, at or near atmospheric pressure, depending on the temperature and other reaction parameters. The procedure may be carried out under anhydrous, anaerobic conditions.

[0058] Polymerization of any of the monomers in the presence of an organolithium initiator results in the formation of a "living" polymer. The lithium proceeds to move down the growing chain as polymerization continues. Throughout formation or propagation of the polymer, the polymeric structure may be anionic and living. In other words, a carbon anion is present. A new batch of monomer subsequently added to the reaction can add to the living ends of the existing chains and increase the degree of polymerization. A living polymer or copolymer, therefore, may include a polymeric segment having an anionic reactive end.

[0059] Functional groups, such as the silane groups described herein, may then be applied to the anionic reactive end of the living polymer to cap or terminate the living polymer.

[0060] In embodiments, the anionic initiator may be a hydrocarbyl lithium compound. In embodiments, the anionic initiator may comprise ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-octyl lithium, n-decyl lithium, phenyl lithium, 2- naphthyl lithium, 2-butyl-phenyl lithium, 4-phenyl-butyl lithium, cyclohexyl lithium, cyclopentyl lithium, a reaction product of diisopropenylbenzene and butyl lithium, and combinations thereof. In embodiments, the anionic initiator may be n-butyl lithium.

[0061] Polymerization may be conducted in an alkane solvent, such as the various pentanes, hexanes, heptanes, octanes, mixtures thereof, and the like.

[0062] Additionally, in order to promote randomization in copolymerization and to control vinyl content, one or more polymeric modifiers may optionally be added to the polymerization ingredients. Amounts of polymeric modifier may range from 0 to about 90 or more equivalents per equivalent of initiator (e.g., lithium catalyst). Compounds useful as polymeric modifiers are typically organic and include those having an oxygen or nitrogen hetero-atom and a non-bonded pair of electrons. Examples include dialkyl ethers of mono and oligo alkylene glycols, "crown" ethers, tertiary amines such as tetramethyethylene diamine (TMEDA), tetrahydrofuran (TEIF), 2,2-bis(2'-tetrahydrofuryl)propane, TEIF oligomers linear and cyclic oligo meric oxolanyl alkanes (e.g., cyclic oligomeric oxolanyl propanes), potassium i-amylate (KTA), or combinations thereof.

[0063] The process of the present disclosure may optionally also include a stabilizing agent, for example, a silane stabilizing agent. One suitable silane stabilizing agent is octyltriethoxysilane. Moreover, an antioxidant such as 2,6-di-t-butyl-4-methylphenol (also called butylated hydoxytoluene (BHT)) may be added to reduce the likelihood of Mooney viscosity instability due to oxidative coupling. The stabilizing agent may be added to the reactor or another mixer downstream of the reactor. Similarly, the antioxidant may be added to the reactor or another mixer downstream of the reactor.

[0064] Optionally, upon termination, the functional terminated polymer may be quenched, if necessary, and dried. Quenching may be conducted by contacting the functional copolymer with a quenching agent for about 0.05 to about 2 hours at temperatures of from about 30° C to about 120° C to insure complete reaction. Suitable well known quenching agents include alcohols, water, carboxylic acids such 2-ethyl hexanoic acid (EHA), acetic acid and the like. Coagulation is typically done with alcohols such as methanol or isopropanol. Alternative to, or in combination with, the step of quenching, the functional polymer may be drum dried as known in the art. The use of steam or high heat to remove solvent is also considered suitable.

[0065] Hydrogenation

[0066] After production of the functionalized elastomer, the functional elastomer is hydrogenated by mixing the functionalized elastomer with a solvent and a hydrogenation catalyst in the presence of a hydrogen stream. The solvent may include one or more of the solvents described above. In one embodiment, the hydrogenation catalyst may comprise nickel. In further embodiments, the hydrogenation catalyst may comprise nickel and aluminum. In one or moreembodiments, the nickel of the hydrogenation catalyst may comprise an organic nickel compound such as nickel octoate. For hydrogenation catalysts including nickel and aluminum, the aluminum may also include an organic aluminum compound. In one embodiment, the organic aluminum compound may be triethylaluminum. The nickel and aluminum may be included in various amounts. For example, the aluminum and nickel may be added at an Al / Ni molar ratio of 1 :1 to 5:1, or from 2:1 to 4:1.

[0067] In the hydrogenation process, pressurized hydrogen may be added at a pressure from 1 to 100 atm. Like the above polymerization, additional components, such as the quenching agents and antioxidants, may be added to the reactor.

[0068] The following exemplary reaction depicted in Formula 1 below illustrates the hydrogenation of a styrene-butadiene copolymer.SBR

[0069] While not shown in Formula 1 above, the styrene-butadiene copolymer may be functionalized with a functional group comprising silica reactive moieties prior to hydrogenation.

[0070] In specific embodiments, the hydrogenated elastomer may have a degree of hydrogenation greater than or equal to 50 mol. %, for example, from 50 mol.% to 95 mol.% as measured using proton nuclear magnetic resonance spectroscopy (^H NMR), or from 60 mol.% to80 mol.%, or from 70 mol.% to 75 mol.%. Without being limited to theory, these levels of hydrogenation in the hydrogenated elastomer correlate to improved mechanical performance.

[0071] While the hydrogenation reduces the number of double bonds, the functional elastomer may, in one or more embodiments, have an initial vinyl content prior to hydrogenation from 15 wt.% to 40 wt.%, or from 30 wt.% to 60 wt.%. Without being bound by theory, controlling the initial vinyl content can maintain the amorphous nature of the functional copolymer, thereby reducing crystal formation that can degrade performance of the tire tread.

[0072] Without wishing to be bound by theory, it is believed that the hydrogenated elastomers described herein exhibit improved microphase separation. More specifically, it is believed that the hydrogenated elastomer may not be homogeneously hydrogenated along the polymer chain, but rather, the hydrogenated elastomer may be hydrogenated in a block-like fashion, leading to the separation of the elastomer into hydrogenated and non-hydrogenated domains. The nonhydrogenated domains may be available for a sulfur curing reaction, which is discussed below. The hydrogenated domains may not be available for the sulfur curing reaction, which leads to a system with harder cured domains in a softer elastomer matrix (termed “microphase separation”).

[0073] While the above describes the use of the rubber compositions in tire treads, the rubber compositions of the present disclosure may be utilized in various other components or articles, which utilize such rubber compositions. Typical articles may include, but are not limited to, tire sidewalls, inner-tubes and tire inner liners, air cushions, pneumatic sprays, air bags, tire-curing bladders, high temperature hoses and conveyor belts, damping mounts for engines and the like.

[0074] Natural Rubber

[0075] In embodiments, the amount of natural rubber in the rubber formulation may be greater than or equal to about 50 phr, greater than or equal to about 60 phr, greater than or equal to about 70 phr, greater than or equal to about 80 phr, or even greater than or equal to about 90 phr. In embodiments, the amount of natural rubber in the rubber formulation may be less than or equal to about 90 phr, or even less than or equal to about 80 phr. In embodiments, the amount of natural rubber in the rubber formulation may be from about 50 phr to about 90 phr, from about 50 phr to about 80 phr, from about 50 phr to about 70 phr, from about 50 phr to about 60 phr, from about 60 phr to about 90 phr, from about 60 phr to about 80 phr, from about 60 phr to about 70 phr, fromabout 70 phr to about 90 phr, from about 70 phr to about 80 phr, or even from about 80 phr to about 90 phr, or any and all sub-ranges formed from any of these endpoints.

[0076] Reinforcing Filler

[0077] Conventional carbon black can be used, which is generally known in the art. In one or more embodiments, carbon blacks include furnace blacks, channel blacks, and lamp blacks. More specific examples of carbon blacks include super abrasion furnace blacks, intermediate super abrasion furnace blacks, high abrasion furnace blacks, fast extrusion furnace blacks, fine furnace blacks, semi-reinforcing furnace blacks, medium processing channel blacks, hard processing channel blacks, conducting channel blacks, and acetylene blacks.

[0078] In particular embodiments, the carbon blacks may have a surface area (EMSA) of at least 20 m2 / g and in other embodiments at least 35 m2 / g; surface area values can be determined by ASTM D-1765 using the cetyltrimethylammonium bromide (CTAB) technique. The carbon blacks may be in a pelletized form or an unpelletized flocculent form. The preferred form of carbon black may depend upon the type of mixing equipment used to mix the rubber compound.

[0079] In one or more embodiments, carbon black can be sourced from a recycled material. Such recycled material can include reclaimed or recycled vulcanized rubber, whereby the vulcanized rubber is typically reclaimed from manufactured articles such as a pneumatic tire, an industrial conveyor belt, a power transmission belt, and a rubber hose. The recycled carbon black may be obtained by a pyrolysis process or other methods known for obtaining recycled carbon black. In an aspect, a recycled carbon black can be formed from incomplete combustion of recycled rubber feedstock or rubber articles. In another aspect, the recycled carbon black can be formed from the incomplete combustion of feedstock including oil resulting from the tire pyrolysis process. The carbon blacks utilized in the preparation of the vulcanizable elastomeric compositions can be in pelletized form or an unpelletized flocculent mass.

[0080] In embodiments, the amount of carbon black in the reinforcing fdler may be greater than or equal to about 10 phr, greater than or equal to about 12 phr, or even greater than or equal to about 15 phr. In embodiments, the amount of carbon black in the reinforcing filler may be less than or equal to 70 phr, less than or equal to 60 phr, less than or equal to 50 phr, or even less than or equal to 40 phr. In embodiments, the amount of carbon black in the reinforcing filler may be from about 10 phr to about 70 phr, from about 10 phr to about 60 phr, from about 10 phr to about50 phr, from about 10 phr to about 40 phr, from about 12 phr to about 70 phr, from about 12 phr to about 60 phr, from about 12 phr to about 50 phr, from about 12 phr to about 40 phr, from about 15 phr to about 70 phr, from about 15 phr to about 60 phr, from about 15 phr to about 50 phr, or even from about 15 phr to about 40 phr, or any and all sub-ranges formed from any of these endpoints.

[0081] In embodiments, the rubber formulation may further comprise silica as a reinforcing fdler in addition to the carbon black. In embodiments, the silica may comprise silicon compounds such as wet silica (hydrated silicic acid), dry silica (anhydrous silicic acid), calcium silicate, aluminum silicate, or a combination thereof.

[0082] Commercially available silicas which may be used for the current invention include Hi- Sil™ 215, Hi-Sil™ 233, and Hi-Sil™ 190 (PPG Industries, Inc.; Pittsburgh, Pa.). Other suppliers of commercially available silica include Grace Davison (Baltimore, Md.), Degussa Corp. (Parsippany, N.J.), Rhodia Silica Systems (Cranbury, N.J.), and J.M. Huber Corp. (Edison, N.J.). Such silicas may be considered as sustainable materials. Other sustainable silicas include those derived from rice husk ash.

[0083] In one or more embodiments, silicas may be characterized by their surface areas, which give a measure of their reinforcing character. The Brunauer, Emmet and Teller ("BET") method (described in J. Am. Chem. Soc., 1939, vol. 60, 2 p. 309-319) is a recognized method for determining the surface area. The BET surface area of silica is generally less than 450 m2 / g. Useful ranges of surface area include from about 32 to about 400 m2 / g, about 100 to about 250 m2 / g, and about 130 to about 240 m2 / g, and about 170 to about 220 m2 / g. In certain embodiments, the silica may have a BET surface area of about 190 to about 280 m2 / g. The pH's of the silicas are generally from about 5 to about 7 or slightly over 7, or in other embodiments from about 5.5 to about 6.8.

[0084] In one or more embodiments, where silica is employed as a fdler (alone or in combination with other fdlers), a coupling agent and / or a shielding agent may be added to the rubber compositions during mixing in order to enhance the interaction of silica with the elastomers. Useful coupling agents and shielding agents are disclosed in U.S. Patent Nos. 3,842,111; 3,873,489; 3,978,103; 3,997,581; 4,002,594; 5,580,919; 5,583,245; 5,663,396;5,674,932; 5,684,171; 5,684,172; 5,696,197; 6,608,145; 6,667,362; 6,579,949; 6,590,017; 6,525,118; 6,342,552; and 6,683,135; which are incorporated herein by reference.

[0085] In embodiments, the amount of silica in the reinforcing fdler may be greater than or equal to 0 phr, greater than or equal to 4 phr, greater than or equal to about 8 phr, greater than or equal to about 12 phr, greater than or equal to about 16 phr, or even greater than or equal to about 20 phr. In embodiments, the amount of silica in the reinforcing fdler may be less than or equal to about 30 phr, less than or equal to about 26 phr, less than or equal to about 24 phr, or even less than or equal to about 22 phr. In embodiments, the amount of silica in the reinforcing fdler may be from about 0 phr to about 30 phr, from about 0 phr to about 26 phr, from about 0 phr to about 24 phr, from about 0 phr to about 22 phr, from about 4 phr to about 30 phr, from about 4 phr to about 26 phr, from about 4 phr to about 24 phr, from about 4 phr to about 22 phr, from about 8 phr to about 30 phr, from about 8 phr to about 26 phr, from about 8 phr to about 24 phr, from about 8 phr to about 22 phr, from about 12 phr to about 30 phr, from about 12 phr to about 26 phr, from about 12 phr to about 24 phr, from about 12 phr to about 22 phr, from about 16 phr to about 30 phr, from about 16 phr to about 26 phr, from about 16 phr to about 24 phr, from about 16 phr to about 22 phr, from about 20 phr to about 30 phr, from about 20 phr to about 26 phr, from about 20 phr to about 24 phr, or even from about 20 phr to about 22 phr, or any and all sub-ranges formed from any of these endpoints.

[0086] In embodiments, the reinforcing fdler may comprise about 0 wt.% to about 50 wt.% silica and about 50 wt.% to 100 wt.% carbon black, about 5 wt.% to about 45 wt.% silica and about 55 wt.% to about 95 wt.% carbon black, or even from about 20 wt.% to about 30 wt.% silica and about 70 wt.% to about 80 wt.% carbon black.

[0087] In embodiments, in addition to carbon black and silica, other fdler may be included in the rubber formulation. The fdlers that may be included are conventionally employed in the manufacture of tires, including starch, aluminum hydroxide, magnesium hydroxide, clays (hydrated aluminum silicates), and combinations thereof. In certain embodiments, a mixture of different fdlers may be advantageously employed.

[0088] The rubber composition can further include fdler in the form of one or more recycled rubbers in a particulate form. Recycled particulate rubber is typically broken down and reclaimed (or recycled) by any of a plurality of processes, which can include physical breakdown, grinding,chemical breakdown, devulcanization, cryogenic grinding, a combination thereof, etc. The term recycled particulate rubber can relate to both vulcanized and devulcanized rubber, where devulcanized recycle or recycled rubber (reclaim rubber) relates to rubber which has been vulcanized, ground into particulates and may have further undergone substantial or partial devulcanization. In an example, the recycled particulate rubber used in the rubber composition is essentially free of recycled rubber resulting from devulcanization. In a situation where the vulcanized rubber contains wire or textile fiber reinforcement, such wire or fiber reinforcement can be removed by any suitable process such as magnetic separation, air aspiration and / or air flotation step. In certain embodiments, the "recycled particulate rubber" comprises cured, i.e., vulcanized (crosslinked) rubber that has been ground or pulverized into particulate matter having a mean average particle size as discussed below.

[0089] Curative

[0090] As used herein, curatives are vulcanizing agents used in the vulcanization of the functionalized copolymer. In one or more embodiments, the curative includes a sulfur-based curative or a peroxide-based curative. In embodiments, the curative may be a sustainable curative. Examples of specific suitable sulfur curatives include "rubbermaker's" soluble sulfur; sulfur donating curing agents, such as an amine disulfide, polymeric poly sulfide, or sulfur olefin adducts; and insoluble polymeric sulfur. In one embodiment, the sulfur curative comprises soluble sulfur or a mixture of soluble and insoluble polymeric sulfur. For a general disclosure of suitable curatives and other components used in curing, e.g., vulcanizing inhibitor and anti- scorching agents, one can refer to Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd ed., Wiley Interscience, N.Y. 1982, Vol. 20, pp. 365 to 468, particularly Vulcanization Agents and Auxiliary Materials, pp. 390 to 402, or Vulcanization by A. Y. Coran, Encyclopedia of Polymer Science and Engineering, Second Edition (1989 John Wiley & Sons, Inc.), both of which are incorporated herein by reference. While various amounts are contemplated, the curatives may be used in an amount ranging from 0.1 to 10 phr, including from 1 to 7.5 phr, including from 1 to 5 phr, and preferably from 1 to 3.5 phr.

[0091] Additional Rubbers

[0092] In embodiments, the rubber formulation may comprise additional rubbers that are not the hydrogenated elastomer or the natural rubber. These additional rubbers may also include othersynthetic rubber, such as synthetic rubber that derives from petroleum-based raw materials, synthetic rubber that derives from other sustainable processes. As the skilled person understands, natural rubber is synthesized by and obtained from plant life. For example, natural rubber can be obtained from Hevea rubber trees, guayule shrub, gopher plant, mariola, rabbitbrush, milkweeds, goldenrods, pale Indian plantain, rubber vine, Russian dandelions, mountain mint, American germander, and tall bellflower.

[0093] Other synthetic polymers, if used, can include, without limitation, synthetic polyisoprene, polybutadiene, polyisobutylene-co-isoprene, neoprene, poly(ethylene-co- propylene), poly(styrene-co-butadiene), poly(styrene-co-isoprene), poly(styrene-co-isoprene-co- butadiene), poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene), polysulfide rubber, acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber, and mixtures thereof. These elastomers can have a myriad of macromolecular structures including linear, branched, and star-shaped structures.

[0094] Other Components

[0095] Other ingredients that are typically employed in rubber compounding may also be added to the rubber compositions. These include coupling agent (e.g., silane), accelerators, accelerator activators, oils, plasticizer, waxes, scorch inhibiting agents, processing aids, zinc oxide, tackifying resins, reinforcing resins, fatty acids such as stearic acid, peptizers, and antidegradants such as antioxidants and antiozonants.

[0096] As described herein, in embodiments, the rubber formulation may comprise sulfur as a vulcanizing agent. A vulcanization accelerator may be used along with a vulcanizing agent to control the time and / or temperature required for vulcanization and to improve properties of the vulcanizate. The vulcanization accelerators suitable for use in the disclosed compositions are not particularly limited. Examples of vulcanization accelerator include thiazol vulcanization accelerators, such as 2-mercaptobenzothiazol, dibenzothiazyl disulfide, N-cyclohexyl-2- benzothiazyl-sulfenamide, N-tert-butyl-2-benzothiazyl sulfenamide, and the like; guanidine vulcanization accelerators, such as diphenylguanidine and the like; amines; disulfides; thiurams; sulfenamides; dithiocarbamates; xanthates; and thioureas; among others.

[0097] With regard to oils, sustainable oils, which include plant-based oils and bio-based oils, may be used. Plant-based oils may include plant-based triglycerides. Exemplary oils include,without limitation, palm oil, soybean oil (also referred to herein as soy oil), rapeseed oil, sunflower seed, peanut oil, cottonseed oil, oil produced from palm kernel, coconut oil, olive oil, corn oil, grape seed oil, hemp oil, linseed oil, rice oil, safflower oil, sesame oil, mustard oil, flax oil. Other examples include nut-derived oils such oils obtained from beech nuts, cashews, mongongo nuts, macadamia nuts, pine nuts, hazelnuts, chestnuts, acorns, almonds, pecans, pistachios, walnuts, or brazil nuts. As the skilled person will appreciate, these oils can be produced by any suitable process such as mechanical extraction (e.g., using an oil mill), chemical extraction (e.g., using a solvent, such as hexane or carbon dioxide), pressure extraction, distillation, leaching, maceration, purification, refining, hydrogenation, sparging, etc.

[0098] Bio-based oils, also referred to as bio-oils, can include oils produced by a recombinant cell. For example, bio-oils produced by recombinant cells can be produced using a select strain of algal cells that are fed with a supply of sugars (e.g., sucrose) and then allowed to ferment and produce a bio-oil with a selected profile; after sufficient growth or fermentation has taken place, the bio-oil is isolated from the cells and collected.

[0099] Useful processing or extender oils may also be included. In embodiments, oils may include those that are commercially available as paraffinic, aromatic, or naphthenic oils. In embodiments, the major constituent of the oil may be paraffinic. In embodiments, the extender oil may be oil extended sulfur

[0100] Generally, the rubber compositions of this invention can include from about 1 to about 70 parts by weight, or in other embodiments from about 5 to about 50 parts weight total oil per 100 parts by weight rubber. The amount of sustainable oil, relative to the total weight of oil included, may be from about 1 wt.% to about 99 wt.%, or in other embodiment from about 20 wt.% to about 80 wt.%.

[0101] With regard to waxes, the rubber compositions can include one or more sustainable waxes, which include natural waxes. A natural wax, or one with no petroleum as its raw material, can include carnauba wax, candelilla wax (e.g., extracted from candelilla flowers), rice wax (e.g., separated from rice bran oil) and Japan wax (e.g., extracted from Japanese wax tree).

[0102] Generally, the rubber compositions of this invention include from about 1 to about 5 parts by weight, or in other embodiments from about 2 to about 4 parts by weight total wax per 100 parts by weight rubber. The amount of sustainable wax, relative to the total weight of waxincluded, may be from about 1 wt.% to about 99 wt.%, or in other embodiment from about 20 wt.% to about 80 wt.% of the total wax. In certain embodiments, the rubber composition includes sustainable waxes only.

[0103] In embodiments, the rubber formulation may further comprise a heat curable resin. Non-limiting examples of such resins include epoxies, urethanes and phenol-formaldehydes, and combinations of one or more of the foregoing may also be utilized. In embodiments, the rubber formulation may comprise at least one of the following types of resins: (1) phenolic resins such as phenol novolak resins, phenol-formaldehyde resins, resorcinol-formaldehyde resins, reactive resol resins (which can react with unsaturation in an elastomer or rubber to contribute to crosslinking), and reactive novolak type phenol-formaldehyde resins (which can crosslink with methylene donors); (2) aliphatic resins such as Cs fraction homopolymer or copolymer resins, optionally in combination with one or more of e.g., cycloaliphatic, aromatic, hydrogenated aromatic, or terpene resins and / or optionally partially or fully hydrogenated; (3) cycloaliphatic resins (such as cyclopentadiene homopolymer or copolymer resins, and dicyclopentadiene homopolymer or copolymer resins), optionally in combination with one or more of aliphatic, aromatic, hydrogenated aromatic, or terpene resins, and / or optionally partially or fully hydrogenated; (4) aromatic resins (such as coumarone-indene resins and alkyl-phenol resins as well as vinyl aromatic homopolymer or copolymer resins such as those including one or more of the following monomers: alpha-methylstyrene, styrene, ortho-methylstyrene, metamethylstyrene, para-methylstyrene, vinyltoluene, par a(tert-butyl) styrene, methoxystyrene, chlorostyrene, hydroxystyrene, vinylmesitylene, divinylbenzene, vinylnaphthalene or any vinyl aromatic monomer resulting from C9 fraction or Cs-Cio fraction), optionally in combination with one or more of aliphatic, cycloaliphatic, hydrogenated aromatic, or terpene resins, and / or optionally partially or fully hydrogenated; (5) terpene resins (such as alpha-pinene resins, betapinene resins, limonene resins (e.g., L-limonene, D-limonene, dipentene which is a racemic mixture of L- and D-isomers), beta-phellandrene, delta-3 -carene, and delta-2-carene), optionally in combination with one or more of aliphatic, cycloaliphatic, aromatic, or hydrogenated aromatic resins, and / or optionally partially or fully hydrogenated resin, and tall oil rosin, glycerin ester rosins, and pentaerythritol ester rosins (optionally partially hydrogenated and / or polymerized); (6) rosin resins (such as gum rosin, wood rosin, and tall oil rosin, glycerin ester rosins, and pentaerythritol ester rosins (optionally partially hydrogenated and / or polymerized)), optionally in combination with one or more of aliphatic, cycloaliphatic, aromatic, hydrogenated aromatic, orterpene resins, and / or optionally partially or fully hydrogenated; or (7) guayule resins. A mixture of one or more resins also can be used.

[0104] The anti-ozonants may comprise N,N'-disubstituted-p-phenylenediamines, such as N- l,3-dimethylbutyl-N'-phenyl-p-phenylenediamine, N,N'-bis(l,4-dimethylpently)-p- phenylenediamine, N-phenyl-N-isopropyl-p- phenylenediamine, and N-phenyl-N'-(l,3- dimethylbutyl)-p-phenylenediamine. Other examples of anti-ozonants may include, acetone diphenylamine condensation product, 2,4-trimethyl-l,2-dihydroquinoline, Octylated Diphenylamine, and 2,6-di-t-butyl-4-methyl phenol.

[0105] Rubber Formulation

[0106] As described herein, the rubber formulations disclosed herein replace butadiene rubber with hydrogenated elastomers.

[0107] In embodiments, replacing butadiene rubber with hydrogenated elastomer shows improved tensile properties compared to the control (e.g., modulus at 300% strain M300, stress at break Tb, and maximum strain Eb). For example, the modulus at 300% strain M300 may be from 5 to 30, and the modulus at 100% strain Ml 00 may be from 3 to 10.

[0108] In embodiments, replacing butadiene rubber with hydrogenated elastomer shows improved wear resistance compared to the control. For example, when measured using a lab lambourn wear tester and corrected using VAL method, a 5% to 20% improvement can be seen over the control.

[0109] As indicated by a reduction in change in storage modulus AG' as compared to a control rubber formulation as measured in strain sweep from 0.25% to 10% strain, run at 60 °C and 10 Hz, while preferentially being miscible with the natural rubber, the hydrogenated elastomer may react with the carbon black and improve carbon black dispersion in the natural rubber phase.

[0110] The rubber formulations disclosed herein have a decrease in the loss tangent tan 8 at 60 °C as compared to a control rubber formulation, which correlates to reduced rolling resistance.

[0111] Moreover, replacing butadiene rubber with hydrogenated elastomer has minimal to no effect on compound viscosity compared to the control.

[0112] Embodiments may be further described with respect to the clauses below:

[0113] 1. A rubber formulation comprising: hydrogenated elastomer having a silane- functionalized end group and a degree of hydrogenation of greater than or equal to 50 mol.%, the hydrogenated elastomer comprising, based on the total weight of the hydrogenated elastomer: a vinyl content of greater than or equal to about 15 wt.%, a cis content of about 30 wt.% to about 85 wt.%, and a styrene content of about 0 wt.% to about 15 wt.%, natural rubber in an amount of at least 50 phr; and reinforcing fdler comprising, based on a total weight of the reinforcing fdler: 0 wt.% to 50 wt.% silica; and 50 wt.% to 100 wt.% carbon black.

[0114] 2. The rubber formulation of any preceding clause, wherein the hydrogenated elastomer comprises hydrogenated styrene -butadiene rubber (H-SBR) or hydrogenated polybutadiene rubber (H-BR).

[0115] 3. The rubber formulation of any preceding clause, wherein the hydrogenated elastomer has an average molecular weight Mwof about 150,000 g / mol to about 200,000 g / mol.

[0116] 4. The rubber formulation of any preceding clause, wherein the silane-functionalized end group comprises an alkoxysilyl group, a hydroxyl group, a polyalkylene glycol group, a silanol group, a silyl halide group, an anhydride group, an organic acid group, an epoxy group, or combinations thereof.

[0117] 5. The rubber formulation of any preceding clause, wherein the silane-functionalized end group comprises the alkoxysilyl group.

[0118] 6. The rubber formulation of any preceding clause, wherein the alkoxysilyl group comprises alkoxysilane compounds, aralkyloxysilane compounds, tetraalkoxysilane compounds, alkyalkoxysilane compounds, alkenyalkoxysilane compounds, halogenoalkoxysilane compounds, or combinations thereof.

[0119] 7. The rubber formulation of any preceding clause, wherein the alkoxsilyl functional group comprises 2-(3,4 epoxy cyclohexyl) ethyltrimethoxysilane (ECETMOS), methyltrimethoxysilane (MeSi(OMe)3), 3-glycidylpropyltrimethoxysilane, y- glycidoxypropyltrimethoxysilane, 3-(l,3-dimethylbutylidene)aminopropyltriethoxysilane, tetraethylorthosilicate, 3-glycidylpropylmethyldimethoxysilane, or combinations thereof.

[0120] 8. The rubber formulation of any preceding clause, wherein the hydrogenated elastomer has a degree of hydrogenation of about 50 mol.% to about 95 mol.%, or about 60 mol.% to about 80 mol.%, or about 70 mol.% to about 75 mol.%.

[0121] 9. The rubber formulation of any preceding clause, wherein the hydrogenated elastomer has a vinyl content of about 15% to about 40%, or about 20% to about 35%, or about 25% to about 30%.

[0122] 10. The rubber formulation of any preceding clause, wherein the hydrogenated elastomer has a styrene content greater than 0% to about 15%, or about 3% to about 12%, or about 6% to about 9%.

[0123] 11. The rubber formulation of any preceding clause, wherein the rubber formulation further comprises from about 10 phr to 50 phr of hydrogenated elastomer.

[0124] 12. The rubber formulation of any preceding clause, wherein the reinforcing fdler comprises about 1 phr to about 14 phr silica.

[0125] 13. The rubber formulation of any preceding clause, wherein the reinforcing fdler comprises carbon black and silica in an amount of about 40 phr to about 70 phr.

[0126] 14. The rubber formulation of any preceding clause, wherein the reinforcing fdler comprises: about 10 phr to about 70 phr carbon black; and about 0 phr to about 30 phr silica.

[0127] 15. The rubber formulation of any preceding clause, wherein the hydrogenated elastomer comprises hydrogenated styrene-butadiene rubber (H-SBR) and hydrogenated polybutadiene rubber (H-BR).

[0128] It will be apparent that modifications and variations are possible without departing from the scope of the disclosure defined in the appended claims. More specifically, although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.

Claims

CLAIMS1. A rubber formulation comprising: hydrogenated elastomer having a silane-functionalized end group and a degree of hydrogenation of greater than or equal to 50 mol.%, the hydrogenated elastomer comprising, based on the total weight of the hydrogenated elastomer: a vinyl content of greater than or equal to about 15 wt.%, a cis content of about 30 wt.% to about 85 wt.%, and a styrene content of about 0 wt.% to about 15 wt.%, natural rubber in an amount of at least 50 phr; and reinforcing fdler comprising, based on a total weight of the reinforcing fdler:0 wt.% to 50 wt.% silica; and50 wt.% to 100 wt.% carbon black.

2. The rubber formulation of claim 1, wherein the hydrogenated elastomer comprises hydrogenated styrene-butadiene rubber (H-SBR) or hydrogenated polybutadiene rubber (H-BR).

3. The rubber formulation of claim 1 or claim 2, wherein the hydrogenated elastomer has an average molecular weight Mwof about 150,000 g / mol to about 200,000 g / mol.

4. The rubber formulation of claim 1 or claim 2, wherein the silane-functionalized end group comprises an alkoxysilyl group, a hydroxyl group, a polyalkylene glycol group, a silanol group, a silyl halide group, an anhydride group, an organic acid group, an epoxy group, or combinations thereof.

5. The rubber formulation of claim 4, wherein the silane-functionalized end group comprises the alkoxy silyl group.

6. The rubber formulation of claim 5, wherein the alkoxysilyl group comprises alkoxysilane compounds, aralkyloxysilane compounds, tetraalkoxysilane compounds, alkyalkoxysilane compounds, alkenyalkoxysilane compounds, halogenoalkoxysilane compounds, or combinations thereof.

7. The rubber formulation of claim 6, wherein the alkoxsilyl functional group comprises 2-(3,4 epoxycyclohexyl) ethyltrimethoxysilane (ECETMOS), methyltrimethoxysilane (MeSi(0Me)3), 3-glycidylpropyltrimethoxysilane, y-glycidoxypropyltrimethoxysdane, 3-(l,3- dimethylbutylidene)aminopropyltriethoxysilane, tetraethylorthosilicate, 3- glycidylpropylmethyldimethoxysilane, or combinations thereof.

8. The rubber formulation of claim 1 or claim 2, wherein the hydrogenated elastomer has a degree of hydrogenation of about 50 mol.% to about 95 mol.%, or about 60 mol.% to about 80 mol.%, or about 70 mol.% to about 75 mol.%.

9. The rubber formulation of claim 1 or claim 2, wherein the hydrogenated elastomer has a vinyl content of about 15% to about 40%, or about 20% to about 35%, or about 25% to about 30%.

10. The rubber formulation of claim 1 or claim 2, wherein the hydrogenated elastomer has a styrene content greater than 0% to about 15%, or about 3% to about 12%, or about 6% to about 9%.

11. The rubber formulation of claim 1 or claim 2, wherein the rubber formulation further comprises from about 10 phr to 50 phr of hydrogenated elastomer.

12. The rubber formulation of claim 1 or claim 2, wherein the reinforcing fdler comprises about 1 phr to about 14 phr silica.

13. The rubber formulation of claim 12, wherein the reinforcing fdler comprises carbon black and silica in an amount of about 40 phr to about 70 phr.

14. The rubber formulation of claim 1 or claim 2, wherein the reinforcing fdler comprises: about 10 phr to about 70 phr carbon black; and about 0 phr to about 30 phr silica.

15. The rubber formulation of claim 1 or claim 2, wherein the hydrogenated elastomer comprises hydrogenated styrene-butadiene rubber (H-SBR) and hydrogenated polybutadiene rubber (H-BR).

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