Hydrogenated polymers produced using antioxidant, and rubber compositions incorporating same

Abstract

Embodiments of the present disclosure are directed to hydrogenated functionalized polymers produced from the steps of: producing a living polymer from the anionic polymerization of a conjugated diolefin monomer in the presence of a solvent; producing a functionalized polymer by reacting the living polymer with at least one silane modifier; adding an antioxidant to the functionalized polymer in the solvent; and producing the hydrogenated functionalized polymer by hydrogenating the functionalized polymer in the solvent in the presence of a hydrogenation catalyst. The antioxidant does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree of hydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy (1H NMR).

Description

HYDROGENATED POLYMERS PRODUCED USING ANTIOXIDANT, AND RUBBER COMPOSITIONS INCORPORATING SAMETECHNICAL FIELD

[0001] Embodiments of the present disclosure are generally related to hydrogenated polymers, and are specifically related to hydrogenated functionalized polymers produced in the presence of an antioxidant.BACKGROUND

[0002] Rubber compositions comprising hydrogenated polymers are commonly used in tire applications, such as tire tread, because of their improved wear performance and tensile strength. In certain instances, it may be desirable to store and / or ship the polymer prior to hydrogenation. As such, the polymer may have an antioxidant added thereto to prevent oxidation / decomposition of the polymer due to the presence of air / moisture. However, some antioxidants inhibit hydrogenation catalysts, thereby effecting the amount of hydrogenation achieved.

[0003] Accordingly, a continual need exists for improved polymers that may be stored and / or shipped without effecting the hydrogenation thereof.SUMMARY

[0004] Embodiments of the present disclosure are directed to hydrogenated functionalized polymers produced in the presence of an antioxidant that does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree of hydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy ('H NMR).

[0005] According to one embodiment, a hydrogenated functionalized polymer is provided. The hydrogenated functionalized polymer is produced from the steps of producing a living polymer from the anionic polymerization of a conjugated diolefm monomer in the presence of a solvent, producing a functionalized polymer by reacting the living polymer with at least one silane modifier, adding anantioxidant to the functionalized polymer in the solvent, and producing the hydrogenated functionalized polymer by hydrogenating the functionalized polymer in the solvent in the presence of a hydrogenation catalyst. The antioxidant does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree of hydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy (JH NMR).

[0006] According to another embodiment, method of making a hydrogenated functionalized polymer is provided. The method of making a hydrogenated functionalized polymer comprises introducing an anionic polymerization initiator, a conjugated diolefin monomer, and a solvent to a reactor to produce a living polymer via anionic polymerization, reacting at least one silane modifier with the living polymer to produce a functionalized polymer, adding an antioxidant to the functionalized polymer in the solvent, and hydrogenating the functionalized polymer by mixing the functionalized polymer in the solvent with a hydrogenation catalyst and introducing a hydrogen stream. The antioxidant does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree of hydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy (^H NMR).

[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.DETAILED DESCRIPTION

[0008] Embodiments of the present disclosure are directed to hydrogenated functionalized polymers. The polymer may be produced from the steps of producing a living polymer from the anionic polymerization of a conjugated diolefin monomer in a solvent, producing a functionalized polymer by reacting the living polymer with at least one silane modifier, adding an antioxidant to the functionalized polymer in the solvent, and producing the hydrogenated functionalized polymer by hydrogenating the functionalized polymer in the solvent in the presence of a hydrogenation catalyst. The antioxidant does not inhibit the hydrogenation catalyst such that the hydrogenated functionalizedpolymer has a degree of hydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy (^H NMR).

[0009] The present disclosure will now be described by reference to more detailed embodiments, but 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] 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.

[0011] Definitions

[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] As used herein, the term "phr" means the parts by weight of the identified component per 100 parts of rubber. If the rubber composition comprises more than one rubber, "phr" means the parts by weight per hundred parts of the sum of all rubbers.

[0016] 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."

[0017] As used herein, the term "styrene-butadiene copolymer", “styrene-butadiene rubber” or "SBR" means a copolymer manufactured from styrene and 1,3-butadiene monomers.

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

[0019] A used herein, the term “homopolymer” refers to a polymer produced from one monomer.

[0020] As used herein, the term “copolymer” refers to a polymer produced from two or more monomers, and thus could encompass polymers produced from two monomers or more than two monomers, such as terpolymers.

[0021] As used herein, “rubber composition” refers to the polymer (e.g., the functionalized, hydrogenated polymer) and the additional fillers and additives blended therewith for use in tire and non-tire applications.

[0022] As used herein, "vinyl content" refers to the percentage of 1,2-vinyl double bonds in the polymer (e.g., the functionalized polymer).

[0023] As used herein, “does not inhibit” when describing an antioxidant means the antioxidant does not impede hydrogenation such that the polymer achieves a degree of hydrogenation less than 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy ('HNMR).

[0024] As discussed hereinabove, hydrogenated polymers are commonly used in tire applications, such as tire tread applications. In certain instances, it may be desirable to store and / or ship the polymer prior to hydrogenation. As such, the polymer may have an antioxidant added thereto to prevent oxidation / decomposition of the polymer due to the presence of air / moisture. However, some antioxidants inhibit hydrogenation catalysts, thereby effecting the amount of hydrogenation achieved.

[0025] Disclosed herein are hydrogenated functionalized polymers, which mitigate the aforementioned problems. Specifically, the hydrogenated functionalized polymers disclosed herein are produced in the presence of an antioxidant that does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree of hydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy (XH NMR).

[0026] Monomers

[0027] Various monomers are contemplated for the conjugated diolefin monomers and the vinyl aromatic monomers.

[0028] The conjugated diolefin monomers may include various hydrocarbon compositions. For example, in embodiments, the conjugated diolefins may include those having from about 4 to about 12 carbon atoms, such as 1,3 -butadiene, 1,3-cyclohexadiene, isoprene, 1,3 -pentadiene, 1,3 -hexadiene, 2,3-dimethyl-l,3-butadiene, 2-ethyl- 1,3 -butadiene, 2-methyl-l,3 pentadiene, 3-methyl-l,3- pentadiene, 4-methyl- 1,3 -pentadiene, and 2,4-hexadiene, or combinations thereof. The conjugated diolefins also may encompass trienes such as myrcene. At least two conjugated diolefin monomers may polymermize to produce a homopolymer, such as polybutadiene.

[0029] The vinyl aromatic monomers may copolymerize with the conjugated diolefin monomers to produce a copolymer or terpolymers. In embodiments, the vinyl aromatic monomers may comprise hydrocarbons having from about 8 to about 20 carbon atoms, or from about 8 to 10 carbon atoms. These vinyl aromatic monomers may include, for example, monovinyl aromatic hydrocarbons. Inone or more embodiments, the vinyl aromatic monomers may comprise styrene, alpha-methyl styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 1-alpha-methylvinylnaphthalene, 2-alphamethyl- vinylnaphthalene, and mixtures of these as well as halo, alkoxy, alkyl, cycloalkyl, aryl, alkaryl and aralkyl derivatives thereof in which the total number of carbon atoms in the combined hydrocarbon is generally not greater than 12. Examples of these latter compounds include 4-methyl styrene, vinyl toluene, 3,5-diethylstyrene, 2-ethyl-4-benzylstyrene, 4-phenyl styrene, 4-para-tolyl styrene, and 4,5- dimethyl- 1-vinylnaphthalene, or mixtures thereof.

[0030] In embodiments, the polymers may comprise from about 60 wt% to about 100 wt%, or from about 60 wt% to about 95 wt%, or from about 60 wt% to about 90 wt%, or from about 70 wt% to about 100 wt%, or from about 70 wt% to about 95 wt%, or from about 70 wt% to about 90 wt%, or from about 80 wt% to about 100 wt%, or from about 80 wt% to about 95 wt%, or from about 80 wt% to about 90 wt% of conjugated diolefin monomers. Conversely, the polymers may comprise from about 0 wt% to about 40 wt%, or from about 0 wt% to about 30 wt%, or from about 0 wt% to about 20 wt%, or from about 5 wt% to about 40 wt%, or from about 5 wt% to about 30 wt%, or from about 5 wt% to about 20 wt% or from about 10 wt% to about 40 wt%, or from about 10 wt% to about 30 wt%, or from about 10 wt% to about 20 wt% of vinyl aromatic monomers. The polymers may be random copolymers or block copolymers. In one embodiment, the conjugated diolefin monomer may be 1,3-butadiene and the vinyl aromatic monomer may styrene, which copolymerize to produce styrene butadiene copolymers. In some embodiments, the copolymer may be a random styrene butadiene copolymer.

[0031] Solvents

[0032] The polymerizations of the present disclosure are conducted in the presence of solvent, for example, inert solvent. The term "inert solvent" means that the solvent does not enter into the structure of the resulting polymer, does not adversely affect the properties of the resulting polymer, and does not adversely affect the activity of the catalyst employed. Suitable inert solvents include hydrocarbon solvents, which may contain aliphatic, aromatic or cycloaliphatic hydrocarbons such as hexane, pentane, toluene, benzene, cyclohexane and the like. Ethers such as tetrahydrofuran and tertiary amines such as triethylamine and tributylamine may also be used as solvents, but these maymodify the polymerization as to styrene distribution, vinyl content and rate of reaction. In one or more embodiments, the solvent may comprise hexane, or blends and mixtures of hexanes (e.g., linear and branched), for example, cyclohexane alone or mixed with other forms of hexane.

[0033] Anionic Polymerization Initiator

[0034] Various anionic polymerization initiators are contemplated for the anionic polymerization processes of the present disclosure. In embodiments, the anionic polymerization initiator may comprise a lithium catalyst, such as an organolithium anionic initiator catalyst. The organolithium initiator employed may be any anionic organolithium initiator useful in the polymerization of conjugated diolefin monomers (e.g., 1,3-butadiene monomers). In general, the organolithium compounds may include hydrocarbon containing lithium compounds of the formula R(Li)x, wherein R represents hydrocarbon groups containing from about 1 to about 20 carbon atoms, such as from about 2 to about 8 carbon atoms, and x is an integer from 1 to 2. Although the hydrocarbon group may be an aliphatic group, in other embodiments, the hydrocarbon group may be cycloaliphatic or aromatic. In embodiments, the aliphatic groups may be primary, secondary, or tertiary groups. Examples of aliphatic hydrocarbyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, secbutyl, t-butyl, n- amyl, sec-amyl, n-hexyl, sec-hexyl, n-heptyl, n-octyl, n-nonyl, n-dodecyl, and octadecyl. The aliphatic groups may contain some unsaturation such as allyl, 2-butenyl, and the like. Cycloalkyl groups may be exemplified by cyclohexyl, methylcyclohexyl, ethyl cyclohexyl, cycloheptyl, cyclopentylmethyl, and methylcyclopentylethyl. Examples of aromatic hydrocarbyl groups include phenyl, tolyl, phenylethyl, benzyl, naphthyl, phenyl cyclohexyl, and the like. Mixtures of different lithium initiator compounds also may be employed such, as those containing one or more lithium compounds, such as R(Li)x, R and x as defined above. Other lithium catalysts that may be employed alone or in combination with the hydrocarbyl lithium initiators may be tributyl tin lithium, lithium dialkyl amines, lithium dialkyl phosphines, lithium alkyl aryl phosphines and lithium diaryl phosphines. In one embodiment, the organolithium initiator may be n-butyl lithium.

[0035] The amount of initiator required to effect the desired polymerization may be varied over a wide range depending upon a number of factors, such as the desired polymer molecular weight, the desired 1,2- and 1,4-content of the conjugated diene, and the desired physical properties for thepolymer produced. In general, the amount of initiator utilized may vary from as little as 0.2 millimole of lithium per 100 grams of monomers up to about 100 millimoles of lithium per 100 grams of monomers, depending upon the desired polymer molecular weight (typically 1,000 to 10,000,000 grams / mole average molecular weight).

[0036] Polymerization is begun by introducing the monomer(s) and solvent to a suitable reaction vessel, followed by the addition of the anionic polymerization initiator. 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 are well known in the art for polymerizing the monomers as described with the anionic polymerization initiator as described. 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. Polymerization of any of the above-identified 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 may 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.

[0037] Functional Groups

[0038] Functional groups may then be applied to the anionic reactive end of the living polymer to cap or terminate the living polymer. For the present functional polymers, the functional groups may be silica-reactive, and optionally carbon black reactive. The silica-reactive moieties encompass one or more reactive groups that will react with silica reinforcing filler to form an ionic or covalent bond. While many of the functional groups focus on being reactive with silica, it is contemplated that thefunctional group may be reactive with both silica and carbon black. Useful functional groups that react with silica typically are electron donors or are capable of reacting with a proton. Exemplary groups include one or a combination of alkoxysilyl, hydroxyl, polyalkylene glycol, silanol, silyl halide, anhydride, organic acid, amines, heterocycles, and epoxy groups. Useful silica-reactive compounds containing one or more of these functional groups include functionalized elastomers, silica coupling agents, and silica-reactive dispersing aids.

[0039] In one or more embodiments, the functional group may be a silane modifier. Silane modifiers may include a silica atom bonded with hydrocarbon groups that may include heteroatoms (where the silica atom usually is bonded with four hydrocarbon groups). The hydrocarbon groups bonded to the silica may include cyclic moi eties, and may be branched or straight-chained. For example, various alkoxysilyl compositions are contemplated, for example and not by way of limitation, alkoxysilane compounds, aralkyloxysilane compounds, tetraalkoxysilane compounds, alkylalkoxysilane compounds, alkenylalkoxysilane compounds, halogenoalkoxysilane compounds, or combinations therein. These may include one or more of dimethoxy silanes and trimethoxy silanes.

[0040] Examples of the tetraalkoxysilane compound include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra(2-ethylhexanoxy)silane, tetraphenoxysilane, tetratoluyloxysilane, and combinations thereof.

[0041] Examples of the alkylalkoxysilane compound include methyltrimethoxysilane, methyltri ethoxysilane, methyltri-n-propoxysilane, methyltri-n-butoxysilane, methyltriphenoxysilane, ethyltrimethoxy silane, ethyltri ethoxy silane, ethyltri-n-propoxy silane, ethyltri -n-butoxy silane, ethyltriphenoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n- propoxysilane, dimethyldi-n-butoxysilane, dimethyldiphenoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane (GPMOS), y-methacryloxy propyl trimethoxysilane, and combinations thereof.

[0042] Examples of the arylalkoxysilane compound include phenyltrimethoxysilane, phenyltri ethoxysilane, phenyltri-n-propoxysilane, phenyltri-n-butoxysilane, phenyltriphenoxysilane, and combinations thereof.

[0043] Examples of the alkenylalkoxysilane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n-propoxysilane, vinyltri-n-butoxysilane, vinyltriphenoxysilane, allyltrimethoxysilane, octenyltrimethoxysilane, divinyldimethoxysilane, styryltrimethoxysilane, and combinations thereof.

[0044] Examples of the halogenoalkoxysilane compound include trimethoxychlorosilane, triethoxy chlorosilane, tri-n-propoxychlorosilane, tri -n-butoxy chlorosilane, triphenoxy chlorosilane, dimethoxy di chlorosilane, di ethoxydichlorosilane, di-n-propoxydi chlorosilane, diphenoxy di chlorosilane, methoxytrichlorosilane, ethoxytrichlorosilane, n-propoxytri chlorosilane, 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.

[0045] Additionally, the alkoxysilyl compositions may include trimethoxysilane compositions, such as 2-(3,4-epoxycy cl ohexyl)ethyltrimethoxy silane (ECETMOS), methyltrimethoxy silane (MeSi(OMe)s), 3-glycidylpropyltrimethoxysilane, y-glycidoxypropyltrimethoxysilane, or 3-(l,3- dimethylbutylidene)aminopropyltriethoxysilane. Additionally, the alkoxysilyl compositions may include tetraethylorthosilicate, 3-glycidylpropylmethyldimethoxysilane, or combinations thereof.

[0046] According to one or more embodiments, the silane modifier may comprise an oxygencontaining moiety where the oxygen atom of the oxygen-containing moiety may not be directly bonded with the silicon atom of the silane modifier. For example, the oxygen-containing moiety may be attached to the silicon atom of the silane modifier with a carbon molecule. It should be understood that in such embodiments, other moieties attached to the silica atom may be attached with an oxygen atom, such as an alkoxy group. However, at least one group (for example, of the four groups attached to the silica atom) may include an oxygen atom that is not directly bonded with the central silicon atom.

[0047] In additional embodiments presently described, the oxygen-containing moiety may include an oxygen heteroatom in a ring structure. For example, the oxygen-containing moiety may include a six-carbon ring structure with an oxygen atom bonded to any two carbons (sometimes adjacent carbons) in the six-carbon ring. The six-carbon ring may be attached to silicon atom of the silane modifier by, for example, an alkyl carbon chain.

[0048] According to further embodiments, the oxygen containing moiety may include an oxygen heteroatom that is a terminal oxygen atom. As presently described, a terminal atom may include an atom which is the furthest from the silicon molecule of the silane modifier (e.g., terminating a hydrocarbon chain) and additionally may include terminal molecules on side branches of a branched hydrocarbon moiety. The terminal atom may also include heteroatoms attached to or included in cyclic functionalities at the end of a hydrocarbon chain. For example, an oxygen-containing moiety attached to adjacent carbon molecules in a six-carbon cyclic moiety that terminates a carbon chain may be considered a terminal atom.

[0049] In additional embodiments, the silane modifier may be free of one or more of sulfur, phosphorous, or nitrogen. For example, in some embodiments, the silane modifier may be free of all sulfur, phosphorous, and nitrogen. In additional embodiments, the silane modifier may be free of any one or two of the sulfur, phosphorous, or nitrogen but include the third (in any combination).

[0050] In further embodiments, the functional group may comprise carbon black reactive moieties. The carbon reactive moieties may include amine functional groups. Various amines are contemplated, for example, primary amines (e.g., NH2), secondary amines, or tertiary amines. Moreover, the amine functional groups may include aliphatic or aromatic moieties. In other embodiments, the functional group may comprise a tin compound to make the functionalized polymer carbon-black reactive. Various tin compounds are contemplated, for example, monofunctional alkyl tin compounds including but not limited to, butyltin tris-(2-ethylhexanoate), butyltin chloride dihydroxide, butyltin hydroxide oxide hydrate, dibutyltin dilaurate, and dibutyltin dimaleate. Mixtures of monofunctional alkyl tin compounds may also be employed. Additionally, inorganic tin functional groups, such as tin tetrachloride (SnCU) are contemplated.

[0051] The polymerization conditions and reactants may dictate how much of the functional group is added. In one or more embodiments, the functional group may be present in a molar ratio (to initiator) of about 0.25 to 2, or about 0.5 to 1.

[0052] Additional Polymerization Ingredients

[0053] 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 may be organic and may 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 tetramethy ethylene diamine (TMEDA), tetrahydrofuran (THF), 2,2-bis(2’- tetrahydrofuryl)propane, THF oligomers linear and cyclic oligomeric oxolanyl alkanes (e.g., cyclic oligomeric oxolanyl propanes), potassium / -amyl ate (KTA), or combinations thereof.

[0054] The process of the present disclosure may optionally also include a stabilizing agent, for example, a silane stabilizing agent. One suitable silane stabilizing agent may be octyltriethoxysilane. The stabilizing agent may be added to the reactor or another mixer downstream of the reactor.

[0055] Optionally, upon termination, the functionalized terminated polymer may be quenched, if necessary, and dried. Quenching may be conducted by contacting the functionalized polymer 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 functionalized polymer may be drum dried as known in the art. The use of steam or high heat to remove solvent may also be considered suitable.

[0056] Antioxidant

[0057] After production of the functionalized polymer, an antioxidant is added to the functionalized polymer in the solvent. The antioxidant is added after production of the functionalizedpolymer because the antioxidant may deactivate the anionic polymerization initiator, stopping the polymerization from occurring. Moreover, if the antioxidant is added before the at least silane modifier, the antioxidant may react with the live polymer end, which may result in a polymer functionalized with the antioxidant instead of a silane functionalized polymer.

[0058] As described herein, the hydrogenated functionalized polymers disclosed herein are produced in the presence of an antioxidant. That is, the antioxidant is introduced prior to hydrogenation of the functionalized polymer. The antioxidant may prevent oxidation / decomposition of the polymer due to the presence of air / moisture, such as during storage and shipment of the polymer. Additionally, the antioxidant does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree of hydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy ('H NMR).

[0059] In embodiments, the antioxidant may comprise an amine, such as a secondary amine. In embodiments, the secondary amine may comprise N,N'-bis(l,4-dimethylpentyl)-p- phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, N-(l,4-dimethylpentyl)-N'-phenyl-p- phenylendiamine, N-(l,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, or combinations thereof.

[0060] In embodiments, the amount of antioxidant may be from about 0.035 phr to about 1.5 phr, from about 0.035 phr to about 1.0 phr, from about 0.035 phr to about 0.5 phr, from about 0.035 phr to about 0.1 phr, from about 0.035 phr to about 0.05 phr, from about 0.05 phr to about 1.5 phr, from about 0.05 phr to about 1.0 phr, from about 0.05 phr to about 0.5 phr, from about 0.05 phr to about 0.1 phr, from about 0.1 phr to about 1.5 phr, from about 0.1 phr to about 1.0 phr, from about 0.1 phr to about 0.5 phr, from about 0.5 phr to about 1.5 phr, or from about 0.5 phr to about 1.0 phr.

[0061] In embodiments, the antioxidant may remain present throughout hydrogenation. In embodiments, the antioxidant may remain present through any rubber curing.

[0062] Hydrogenation

[0063] After addition of the antioxidant, the functionalized polymer is hydrogenated by mixing the functionalized polymer in the solvent with a hydrogenation catalyst and introducing a hydrogen stream. The antioxidant may be added before mixing the functionalized polymer in the solvent withthe hydrogenation catalyst or may be added at the same time as mixing with the hydrogenation catalyst.

[0064] In embodiments, the functionalized polymer in the solvent may be diluted with additional solvent prior to hydrogenation. The additional solvent may be the same as or similar to the solvent used in polymerization.

[0065] In one embodiment, the hydrogenation catalyst may comprise nickel. In further embodiments, the hydrogenation catalyst may comprise at least one nickel-containing composition, such as nickel octoate. In some embodiments, the hydrogenation catalyst may comprise at least one nickel compound and at least one aluminum compound. In one or more embodiments, the nickel of the hydrogenation catalyst may comprise an organic nickel compound such as a nickel carboxylane complex, such as nickel octoate. For hydrogenation catalysts including nickel and aluminum, the aluminum may also include an organic aluminum compound. Additional nickel-including compounds are contemplated for use in the hydrogenation catalyst such as, but not limited to, nickel alkoxides, nickel aryloxides, nickel halides, and nickel beta-diketonates. 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.

[0066] According to additional embodiments, the hydrogenation catalyst may include one or more of ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir), or platinum (Pt). Various ligands including these contemplated catalytic materials may be contemplated as hydrogenation catalysts. However, in some embodiments, the hydrogenation catalyst may be free of titanium (Ti). Without being limited by any particular theory, it is believed that Ti may be undesirable as a hydrogenation catalyst when oxygen heteroatoms are present in the functional group that may react with the living polymer to produce a functionalized polymer. For example, a functional group including a silane modifier comprising an oxygen heteroatom indirectly attached to the silicon of the silane may react with the Ti catalyst and inhibit hydrogenation, change the preferred chemistry of the functionalized polymer, or both. It has been observed that hydrogenation catalysts which include nickel may provide superior catalytic performance when such functional groups are utilized. Additionally, other non-Tibased hydrogenation catalysts may provide enhanced functionality as compared with Ti based hydrogenation catalysts.

[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, 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] As described herein, the hydrogenated functionalized polymers disclosed herein are produced in the presence of an antioxidant that does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree of hydrogenation of greater than or equal toabout 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy (XH NMR). In embodiments, the functional polymer may have a degree of hydrogenation from about 75 mol% to about 98 mol%, from about 75 mol% to about 95 mol%, from about 80 mol% to about 98 mol%, from about 80 mol% to about 95 mol%, from about 85 mol% to about 98 mol%, from about 85 mol% to about 95 mol%, from about 90 mol% to about 98 mol%, or from about 90 mol% to about 95 mol%. Without being limited to theory, these higher levels of hydrogenation in the functionalized polymer may correlate to improved mechanical performance.

[0071] While the hydrogenation reduces the number of double bonds, the functionalized polymer may, in one or more embodiments, have an initial vinyl content prior to hydrogenation from about 10% to about 60%, from about 10% to about 50%, from about 10% to about 40%, from about 10% to about 30%, from about 15% to about 60%, from about 15% to about 50%, from about 15% to about 40%, from about 15% to about 30%, from about 20% to about 60%, from about 20% to about 50%, from about 20% to about 40%, from about 20% to about 30%, from about 25% to about 60%, from about 25% to about 50%, from about 25% to about 40%, or from about 25% to about 30%. Without being bound by theory, controlling the initial vinyl content can maintain the amorphous nature of the functionalized polymer, thereby reducing crystal formation that can degrade performance of the tire tread.

[0072] Rubber Compositions

[0073] As stated previously, the hydrogenated, functionalized polymers detailed above, may be included in rubber compositions for tire and non-tire applications. The rubber composition may also include at least one curative and at least one reinforcing fdler.

[0074] Curative

[0075] As used herein, curatives are vulcanizing agents used in the vulcanization of the functionalized polymer. In one or more embodiments, the curative may include a sulfur-based curative or a peroxide-based curative. Examples of specific suitable sulfur curatives include "rubbermaker's" soluble sulfur; sulfur donating curing agents, such as an amine disulfide, polymeric polysulfide, or sulfur olefin adducts; and insoluble polymeric sulfur. In one embodiment, the sulfurcurative may comprise 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 about 0.1 phr to about 10 phr, including from about 1 phr to about 7.5 phr, including from about 1 phr to about 5 phr, and preferably from about 1 phr to about 3.5 phr.

[0076] Reinforcing Filler

[0077] As used herein, “reinforcing fdler” may refer particulate material that has a nitrogen absorption specific surface area (N2SA) of more than about 100 m2 / g, and in certain instances more than 100 m2 / g, more than about 125 m2 / g, more than 125 m2 / g, or even more than about 150 m2 / g or more than 150 m2 / g. Alternatively, “reinforcing filler” may also be used to refer to a particulate material that has a particle size of about 10 nm to about 50 nm.

[0078] In one or more embodiments, the reinforcing filler may comprise silica, carbon black, or combinations thereof.

[0079] Various carbon black compositions are considered suitable. Among the useful carbon blacks are furnace black, channel blacks, and lamp blacks. More specifically, examples of useful carbon blacks include super abrasion furnace (SAF) blacks, high abrasion furnace (HAF) blacks, fast extrusion furnace (FEF) blacks, fine furnace (FF) blacks, intermediate super abrasion furnace (ISAF) blacks, semi-reinforcing furnace (SRF) blacks, medium processing channel blacks, hard processing channel blacks and conducting channel blacks. Other carbon blacks which may be utilized include acetylene blacks. In certain embodiments, the rubber composition may include a mixture of two or more of the foregoing carbon blacks.

[0080] Various amounts of carbon black are contemplated. In one or more embodiments, the total amount of the reinforcing carbon black filler may be from about 5 phr to about 200 phr, including from about 5 phr to about 175 phr, from about 5 phr to about 150 phr, from about 5 phr to about 100 phr, from about 5 phr to about 80 phr, from about 10 phr to about 200 phr, from about 10 phr to about 175 phr, from about 10 phr to about 150 phr, from about 10 phr to about 100 phr, from about 10 phr to about 80 phr, from about 20 phr to about 200 phr, from about 20 phr to about 175 phr, from about 20 phr to about 150 phr, from about 20 phr to about 100 phr, from about 20 phr to about 80 phr, from about 25 phr to about 200 phr, from about 25 phr to about 175 phr, from about 25 phr to about 150 phr, from about 25 phr to about 100 phr, from about 25 phr to about 80 phr, from about 30 phr to about 200 phr, from about 30 phr to about 175 phr, from about 30 phr to about 150 phr, from about 30 phr to about 100 phr, from about 30 phr to about 80 phr, from about 35 phr to about 200 phr, from about 35 phr to about 175 phr, from about 35 phr to about 150 phr, from about 35 phr to about 100 phr, or from about 35 phr to about 80 phr. The carbon blacks utilized may be in pelletized form or an unpelletized flocculent mass. For more uniform mixing in the rubber composition, unpelletized carbon black may be used in some embodiments.

[0081] Moreover, silica filler may also be used as reinforcing filler. Examples of reinforcing silica fillers suitable for use include, but are not limited to, precipitated amorphous silica, wet silica (hydrated silicic acid), dry silica (anhydrous silicic acid), fumed silica, calcium silicate and the like. Other suitable silica fillers for use in rubber compositions of certain embodiments of the disclosed herein include, but are not limited to, aluminum silicate, magnesium silicate (e.g., Mg2SiO4, MgSiO ), magnesium calcium silicate (CaMgSiO4), aluminum calcium silicate (e.g., AhO3.CaO2SiO2), and the like.

[0082] Like the carbon black, various amounts of silica are contemplated for use as reinforcing filler. In one or more embodiments, the total amount of the reinforcing silica filler or silica filler may be from about 5 to about 175 phr, include from about 5 phr to about 150 phr, from about 5 phr to about 125 phr, from about 5 phr to about 100 phr, from about 5 phr to about 80 phr, from about 10 phr to about 175 phr, from about 10 phr to about 150 phr, from about 10 phr to about 125 phr, from about 10 phr to about 100 phr, from about 10 phr to about 80 phr, from about 20 phr to about 175 phr, from about 20 phr to about 150 phr, from about 20 phr to about 125 phr, from about 20 phr to about100 phr, from about 20 phr to about 80 phr, from about 25 phr to about 175 phr, from about 25 phr to about 150 phr, from about 25 phr to about 125 phr, from about 25 phr to about 100 phr, from about 25 phr to about 80 phr, from about 30 phr to about 175 phr, from about 30 phr to about 150 phr, from about 30 phr to about 125 phr, from about 30 phr to about 100 phr, from about 30 phr to about 80 phr, from about 35 phr to about 175 phr, from about 35 phr to about 150 phr, from about 35 phr to about 125 phr, from about 35 phr to about 100 phr, or from about 35 phr to about 80 phr.

[0083] In other embodiments, the rubber composition may comprise at least one reinforcing filler other than carbon black or silica, or alternatively in addition to reinforcing carbon black and reinforcing silica fillers. Non-limiting examples of suitable such reinforcing fillers for use in the rubber compositions disclosed herein include, but are not limited to, aluminum hydroxide, talc, alumina (AI2O3), aluminum hydrate (AI2O3H2O), aluminum hydroxide (Al(0H)3), aluminum carbonate (Ah(CO3)2), aluminum magnesium oxide (MgOAhCh), pyrofilite (AhCMSiCh.ILO), bentonite (Al2O3.4SiO2.2H2O), mica, kaolin, glass balloon, glass beads, calcium oxide (CaO), calcium hydroxide (Ca(OH)2), calcium carbonate (CaCOs), magnesium carbonate, magnesium hydroxide (Mg(0H)2), magnesium oxide (MgO), magnesium carbonate (MgCCh), potassium titanate, barium sulfate, zirconium oxide (ZrO2), zirconium hydroxide [Zr(OH)2.nH2O], zirconium carbonate [Zr(CO3)2], crystalline aluminosilicates, reinforcing grades of zinc oxide (i.e., reinforcing zinc oxide), and combinations thereof. When at least one reinforcing filler other than or alternatively in addition to reinforcing carbon black filler and reinforcing silica filler) is present, the total amount of all reinforcing fillers may be from about 5 to about 200 phr). In other words, when at least one reinforcing filler is present in addition to carbon black silica, or both, the amount of reinforcing carbon black filler and reinforcing silica filler is adjusted so that the total amount of reinforcing filler is from about 5 to about 200 phr.

[0084] Additional Rubber

[0085] In further embodiments, the rubber composition may comprise an additional rubber component comprising natural rubber, synthetic rubber, or combinations thereof. For example, and not by way of limitation, the synthetic rubber may comprise synthetic polyisoprene, polyisobutylene- co-isoprene, neoprene, poly(ethylene-co-propylene), poly(styrene-co-butadiene), poly(styrene-co-isoprene), and 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, or combinations thereof.

[0086] Additional Additives

[0087] Optionally, a silane coupling agent may be blended with the silica reinforcing filler further improve the reinforcing properties. For example, the silane coupling agent may include bis(3- triethoxysilylpropyl) tetrasulfide, bis(3-triethoxysilylpropyl) trisulfide, bis(3-triethoxysilylpropyl) disulfide, bis(2-triethoxysilylethyl) tetrasulfide, bis(3-trimethoxysilylpropyl) tetrasulfide, bis(2- trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxy silane, 3 -mercaptopropyltri ethoxy silane, 2-mercaptoethyltrimethoxy silane, 2-mercaptoethyltri ethoxy silane, 3 -trimethoxy silylpropyl- N,N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3 -trimethoxysilylpropyl benzothiazole tetrasulfide, 3 -tri ethoxy silylpropyl benzothiazole tetrasulfide, 3 -tri ethoxy silylpropyl methacrylate monosulfide, 3 -trimethoxy silylpropyl methacrylate monosulfide, bis(3- di ethoxymethylsilylpropyl) tetrasulfide, 3 -mercaptopropyl dimethoxymethyl silane, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, dimethoxymethylsilylpropyl benzothiazole tetrasulfide, 3 -hexanoylthiopropyltri ethoxy silane, 3- octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, 3- lauroylthiopropyltriethosysilane, 2-hexanoylthioethyltri ethoxysilane, 2- octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2- lauroylthioethyltriethoxysilane, 3-hexanoylthiopropyltrimethoxysilane, 3- octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3- lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2- octanoylthioethyltrimethoxysilane, 2-decanoylthioethyltrimethoxysilane and 2- lauroylthioethyltrimethoxysilane, and the like. These silane coupling agents may be used alone or in a combination of two or more.

[0088] Useful processing or extender oils may also be included. Such oils include those that are commercially available as paraffinic, aromatic, or naphthenic oils. In one or more embodiments, themajor constituent of the oil may be naphthenic. The rubber compositions may also include other additives such as anti-ozonants, waxes, scorch inhibiting agents, processing aids, zinc oxide, tackifying resins, reinforcing resins, fatty acids such as stearic acid, peptizers, and one or accelerators.

[0089] The anti-ozonants may comprise N,N'disubstituted-p- phenylenediamines, such as N-1,3- 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 include, acetone diphenylamine condensation product, 2,4-trimethyl-l,2-dihydroquinoline, octylated diphenylamine, and 2,6-di-t-butyl-4-methyl phenol.

[0090] The curing accelerators may include, but are not limited to, dithiocarbamate accelerators, including the metal dialkyldithiocarbamates such as, for example, zinc dibutyldithiocarbamate, zinc diethyldithiocarbamate, zinc dimethyldithiocarbamate, and ferric dimethyldithiocarbamate; thiazole accelerators including 2-mercaptobenzothiazole, the benzothiazole disulfides such as, for example, mercaptobenzothiazole disulfide; the benzothiazole sulfenamides, such as, for example, n- cyclohexyl-2 -benzothiazole sulfenamide; and sulfenamide accelerators such as, for example, / -butyl - 2-benzothiazyl sulfenamide.

[0091] The rubber compositions may include at least 3 parts by weight filler per 1000 parts rubber (phr), or from about 5 to about 1000 phr, or from about 20 to about 80 phr, or from about 30 to about 50 phr. The rubber compositions may also include from about 0 to about 80 parts processing or extender oil per 100 parts by weight rubber, or from about 5 to about 50 phr, or from about 10 to about 30 phr.

[0092] Of the total hundred parts rubber, the functionalized polymer may include from about 20 to about 100 parts of the 100 total, or from about 25 to about 75 parts of the 100 total, or from about 30 to about 60 parts of the 100 total.

[0093] The rubber composition may be obtained by milling with a milling machine such as rolls, an internal mixer or the like, which can be shaped and vulcanized for use in tire applications such asa tread, an under tread, a carcass, a sidewall, a bead and the like as well as a rubber cushion, a belt, a hose and other industrial products, but it is particularly suitable for use in the tire tread.

[0094] EXAMPLES

[0095] The hydrogenated functionalized polymers described herein will be further described in the following examples, which are not intended to restrict the polymers.

[0096] Measurements

[0097] The number average molecular weight (Mn), weight average molecular weight (Mw), and peak molecular weight (MP) were determined by gel permeation chromatography using a TOSOH Esosec HLC-8320 GPC system and TOSOH TSKgel GMHxl-BS columns with THF as the solvent. The system was calibrated using polystyrene standards.

[0098] The cis content, vinyl content, and hydrogenation level were determined by 'H- Nuclear Magnetic Resonance spectroscopy in chloroform-dl at room temperature.

[0099] Example 1: Synthesis ofECETMOS Functionalized SBR

[0100] ECETMOS [(2-(3,4-epoxycyclohexyl)ethyltrimethoxy silane] functionalized styrenebutadiene copolymer (SBR) was prepared according to the following process. To a five-gallon (approximately 18.9 liter) N2 purged reactor equipped with a stirrer was added 3.358 kilograms of hexane, 0.266 kilograms of 32.2 weight% styrene in hexane, and 7.756 kilograms of 21.0 weight% 1,3-butadiene in hexane. The reactor was charged with 1.97 milliliters of 2,2-bis(2’- tetrahydrofuryl)propane (OOPS, 1.60 Molar in hexane), followed by 5.72 milliliters o / 7?-butyllithium (BuLi, 2.50 Molar in hexane), and the reactor jacket was heated to 50 °C. After 46 minutes, the batch temperature peaked at 82 °C. After an additional 40 minutes, the anionic polymerization reaction was terminated by adding 2.48 milliliters of ECETMOS. After an additional 30 minutes, 1.09 milliliters of isopropyl alcohol was added. After an additional 10 minutes, a 550 mL sample of polymer cement was collected for use in the high throughput hydrogenations. Polymer characterization data of the non-hydrogenated functionalized SBR is summarized in Table 1.

[0101] Table 1 : SBR prior to hydrogenation

[0102] Example 2: Synthesis ofECETMOS Functionalized SBR

[0103] ECETMOS [2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane] functionalized styrenebutadiene copolymer (SBR) was prepared according to the following process. To a five-gallon (approximately 18.9 liter) N2 purged reactor equipped with a stirrer was added 3.608 kilograms of hexane, 0.266 kilograms of 32.2 weight% styrene in hexane, and 7.506 kilograms of 21.7 weight% 1,3-butadiene in hexane. The reactor was charged with 1.57 milliliters of 2,2-bis(2’- tetrahydrofuryl)propane (OOPS, 1.60 Molar in hexane), followed by 4.57 milliliters o / ’«-butyllithium (BuLi, 2.50 Molar in hexane), and the reactor jacket was heated to 50 °C. After 40 minutes, the batch temperature peaked at 82 °C. After an additional 40 minutes, the anionic polymerization reaction was terminated by adding 2.65 milliliters of ECETMOS. After an additional 30 minutes, 0.87 milliliters of isopropyl alcohol was added. The cement was transferred to a storage vessel in preparation for transfer to a hydrogenation reactor. Polymer characterization data of the non-hydrogenated functionalized SBR is summarized in Table 2.

[0104] Table 2: SBR prior to hydrogenation

[0105] Example 3: Preparation ofNi Catalyst

[0106] To a nitrogen purged dry bottle, 11.5 mb of hexane and 0.63 mL of 1.03 M triethylaluminum was added, followed by dropwise addition of 0.70 mL of nickel octoate (1.59 wt% Ni in hexane, 0.80 mmol Ni phgm), resulting in a Ni / Al catalyst (Al / Ni=3.3 / 1.0).

[0107] Example 4: Preparation of Ni Catalyst

[0108] To a nitrogen purged dry bottle, 250 mL of hexane and 12.1 mL of 1.0 M tri ethylaluminum was added, followed by dropwise addition of 2.2 mL of nickel octoate (10 wt% Ni in hexane), resulting in a Ni / Al catalyst (Al / Ni=3.3 / 1.0).

[0109] Example 5: Hydrogenation of SBR from Example 1

[0110] To each of 6 Optimization Sampling Reactors (OSR) on an Unchained Synthesis Unit under a nitrogen atmosphere, 20 mL of the Example 1 functionalized SBR solution in hexane was introduced and the reactors were sealed. The reactor was purged 3 times with 50 psi hydrogen and the reactor jacket was heated to 50 °C, at which point the desired amount of butylated hydroxytoluene (BHT), as shown in Table 3, dissolved in toluene was added to the reactor using the OSR tip. The reactor was immediately pressurized to 150 psi with hydrogen and 0.75 mL of the Example 3 catalyst solution was transferred into each reactor using the OSR tip. After 120 minutes of hydrogenation reaction, hydrogen was released from the reactor and the polymer cement was coagulated inisopropanol and drum dried at 120 °C. Polymer characterization data of the hydrogenated functionalized SBR is summarized in Table 3.

[0111] Table 3: Effect of antioxidant on hydrogenation

[0112] Example 6: Hydrogenation of SBR from Example 2

[0113] To a 11.7 gallon (approximately 44.3 liter) stirred reactor under nitrogen atmosphere, 5.035 kg of the Example 2 ECETMOS functionalized SBR solution in hexane was introduced, followed by 21.32 kg of hexane, which resulted in a 5.0 wt% SBR solution. Before addition to the reactor, a solution of the antioxidant, as shown in Table 4, in hexane, was added to the polymer cement. The reactor was purged 3 times with 20 psi hydrogen and the reactor j acket was heated to 50 °C. The Example 4 catalyst solution was transferred into the reactor, and the reactor was immediately pressurized to 75 psi with hydrogen. The hydrogenation was allowed to continue until the reaction finished consuming hydrogen. Hydrogen was released from the reactor and the polymer cement was dropped into a can, then coagulated in isopropanol and drum dried at 120 °C. Polymer characterization data of the hydrogenated functionalized SBR is summarized in Table 4.

[0114] Table 4: Effect of antioxidant on hydrogenation1N,N'-bis(l,4-dimethylpentj l)-p-phenylenediamine

[0115] As shown in Tables 3 and 4, BHT, a secondary alcohol present in various amounts, inhibited the hydrogenation catalyst such that the hydrogenated functionalized SBRs had degrees ofhydrogenation less than 75 mol%, down from 96 mol% as shown in Sample 5-1, a polymer produced without the use of an antioxidant. Santoflex 77PD, a secondary amine, did not inhibit the hydrogenation catalyst as the hydrogenated functionalized SBR had a degree of hydrogenation of 95 mol%. While not wishing to be bound by theory, it is believed that the hydroxyl group of BHT reacts with the hydrogenation catalyst, thereby inhibiting hydrogenation catalyst. On the other hand, Santoflex 77PD does not include any terminal amines and, thus, reaction with the hydrogenation catalyst may not be hindered.

[0116] As exemplified in Tables 3 and 4, hydrogenated functionalized polymers may be hydrogenated in the presence of an antioxidant without inhibiting the hydrogenation catalyst.

[0117] Embodiments may be further described with respect to the clauses below:

[0118] 1. A hydrogenated functionalized polymer produced from the steps of: producing a living polymer from the anionic polymerization of a conjugated diolefin monomer in the presence of a solvent; producing a functionalized polymer by reacting the living polymer with at least one silane modifier; adding an antioxidant to the functionalized polymer in the solvent; and producing the hydrogenated functionalized polymer by hydrogenating the functionalized polymer in the solvent in the presence of a hydrogenation catalyst, wherein the antioxidant does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree of hydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy ('I I NMR).

[0119] 2. The hydrogenated functionalized polymer of any preceding clause, wherein the antioxidant comprises an amine.

[0120] 3. The hydrogenated functionalized polymer of any preceding clause, wherein the amine comprises a secondary amine.

[0121] 4. The hydrogenated functionalized polymer of any preceding clause, wherein the secondary amine comprises N,N'-bis(l,4-dimethylpentyl)-p-phenylenediamine, N,N'-di-sec-butyl-p- phenylenediamine, N-(l,4-dimethylpentyl)-N'-phenyl-p-phenylendiamine, N-(l,3-dimethylbutyl)- N'-phenyl-p-phenylenediamine, or combinations thereof.

[0122] 5. The hydrogenated functionalized polymer of any preceding clause, wherein the hydrogenated functionalized polymer has a degree of hydrogenation of about 75 mol% to about 98 mol%, as measured using proton nuclear magnetic resonance spectroscopy ('H NMR).

[0123] 6. The hydrogenated functionalized polymer of any preceding clause, wherein the hydrogenation catalyst comprises nickel, aluminum, ruthenium, rhodium, palladium, iridium, platinum, or combinations thereof.

[0124] 7. The hydrogenated functionalized polymer of any preceding clause, wherein the hydrogenation catalyst comprises nickel and aluminum.

[0125] 8. The hydrogenated functionalized polymer of any preceding clause, wherein the hydrogenation catalyst comprises nickel octoate.

[0126] 9. The hydrogenated functionalized polymer of any preceding clause, wherein the silane modifier 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.

[0127] 10. The hydrogenated functionalized polymer of any preceding clause, wherein the silane modifier comprises the alkoxysilyl group.

[0128] 11. The hydrogenated functionalized polymer of any preceding clause, wherein the alkoxysilyl group comprises alkoxysilane compounds, aralkyloxysilane compounds, tetraalkoxysilane compounds, alkyalkoxysilane compounds, alkenyalkoxysilane compounds, halogenoalkoxysilane compounds, or combinations thereof.

[0129] 12. The hydrogenated functionalized polymer of any preceding clause, wherein alkoxysilyl functional group comprises trimethoxysilane, dimethoxysilane, or combinations thereof.

[0130] 13. The hydrogenated functionalized polymer of any preceding clause, wherein producing the living polymer further comprises the anionic polymerization of the conjugated diolefin monomer and a vinyl aromatic monomer.

[0131] 14. The hydrogenated functionalized polymer of any preceding clause, wherein the conjugated diolefin monomer comprises 1,3 butadiene, isoprene, myrcene, or combinations thereof, and wherein the vinyl aromatic monomer comprises styrene, alpha methyl styrene, or combinations thereof.

[0132] 15. The hydrogenated functionalized polymer of any preceding clause, wherein the polymer is a styrene butadiene copolymer.

[0133] 16. The hydrogenated functionalized polymer of any preceding clause, wherein the functionalized polymer has a vinyl content, prior to hydrogenation, of from about 10% to about 60%.

[0134] 17. A rubber composition comprising: the hydrogenated functionalized polymer of any preceding clause; at least one curative; and reinforcing filler.

[0135] 18. The rubber composition of any preceding clause, further comprising an additional rubber comprising natural rubber, synthetic rubber, or combinations thereof.

[0136] 19. The rubber composition of any preceding clause, wherein the reinforcing filler comprises silica, carbon black, or combinations thereof, and the curative comprises sulfur.

[0137] 20. A method of making a hydrogenated functionalized polymer, comprising: introducing an anionic polymerization initiator, a conjugated diolefin monomer, and a solvent to a reactor to produce a living polymer via anionic polymerization; reacting at least one silane modifier with the living polymer to produce a functionalized polymer; adding an antioxidant to the functionalized polymer in the solvent; and hydrogenating the functionalized polymer by mixing the functionalized polymer in the solvent with a hydrogenation catalyst and introducing a hydrogen stream, wherein the antioxidant does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree of hydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy (XH NMR).

[0138] 21. The method of any preceding clause, wherein the antioxidant comprises an amine.

[0139] 22. The method of any preceding clause, wherein the amine comprises a secondary amine.

[0140] 23. The method of any preceding clause, wherein the secondary amine comprises N,N'- bis(l,4-dimethylpentyl)-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, N-(l,4- dimethylpentyl)-N'-phenyl-p-phenylendiamine, N-(l,3-dimethylbutyl)-N'-phenyl-p- phenylenediamine, combinations thereof.

[0141] 24. The method of any preceding clause, wherein the hydrogenated functionalized polymer has a degree of hydrogenation of about 75 mol% to about 98 mol%, as measured using proton nuclear magnetic resonance spectroscopy f'H NMR).

[0142] 25. The method of any preceding clause, wherein the hydrogenation catalyst comprises nickel, aluminum, ruthenium, rhodium, palladium, iridium, platinum, or combinations thereof.

[0143] 26. The method of any preceding clause, wherein the hydrogenation catalyst comprises nickel and aluminum.

[0144] 27. The method of any preceding clause, wherein the hydrogenation catalyst comprises nickel octoate.

[0145] 28. The method of any preceding clause, wherein the anionic polymerization initiator is a lithium catalyst.

[0146] 29. The method of any preceding clause, wherein the silane modifier 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.

[0147] 30. The method of any preceding clause, wherein the silane modifier comprises the alkoxysilyl group.

[0148] 31 The method of any preceding clause, wherein the alkoxysilyl group comprises alkoxysilane compounds, aralkyloxysilane compounds, tetraalkoxysilane compounds, alkyalkoxysilane compounds, alkenyalkoxysilane compounds, halogenoalkoxysilane compounds, or combinations thereof.

[0149] 32. The method of any preceding clause, wherein alkoxysilyl functional group comprises trimethoxysilane, dimethoxysilane, or combinations thereof.

[0150] 33. The method of any preceding clause, wherein the method further comprises introducing a vinyl aromatic monomer to the reactor.

[0151] 34. The method of any preceding clause, wherein the conjugated diolefin monomer comprises 1,3 butadiene, isoprene, myrcene, or combinations thereof, and wherein the vinyl aromatic monomer comprises styrene, alpha methyl styrene, or combinations thereof.

[0152] 35 The method of any preceding clause, wherein the polymer is a styrene butadiene copolymer.

[0153] 36 The method of any preceding clause, wherein the functionalized polymer has a vinyl content, prior to hydrogenation, of from about 10% to about 60%.

[0154] 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 hydrogenated functionalized polymer produced from the steps of producing a living polymer from the anionic polymerization of a conjugated diolefin monomer in the presence of a solvent; producing a functionalized polymer by reacting the living polymer with at least one silane modifier; adding an antioxidant to the functionalized polymer in the solvent; and producing the hydrogenated functionalized polymer by hydrogenating the functionalized polymer in the solvent in the presence of a hydrogenation catalyst, wherein the antioxidant does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree of hydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy (^H NMR).

2. The hydrogenated functionalized polymer of claim 1, wherein the antioxidant comprises an amine.

3. The hydrogenated functionalized polymer of claim 2, wherein the amine comprises a secondary amine.

4. The hydrogenated functionalized polymer of claim 3, wherein the secondary amine comprises N,N'-bis(l,4-dimethylpentyl)-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, N-(l,4- dimethylpentyl)-N'-phenyl-p-phenylendiamine, N-(l,3-dimethylbutyl)-N'-phenyl-p- phenylenediamine, or combinations thereof.

5. The hydrogenated functionalized polymer of any of claims 1-4, wherein the hydrogenated functionalized polymer has a degree of hydrogenation of about 75 mol% to about 98 mol%, as measured using proton nuclear magnetic resonance spectroscopy ('H NMR).

6. The hydrogenated functionalized polymer of any of claims 1-4, wherein the hydrogenation catalyst comprises nickel, aluminum, ruthenium, rhodium, palladium, iridium, platinum, or combinations thereof.

7. The hydrogenated functionalized polymer of claim 6, wherein the hydrogenation catalyst comprises nickel and aluminum.

8. The hydrogenation functionalized polymer of claim 6, wherein the hydrogenation catalyst comprises nickel octoate.

9. The hydrogenated functionalized polymer of any of claims 1-4, wherein the silane modifier 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.

10. The hydrogenated functionalized polymer of claim 9, wherein the silane modifier comprises the alkoxysilyl group.

11. The hydrogenated functionalized polymer of claim 10, wherein the alkoxy silyl group comprises alkoxysilane compounds, aralkyloxysilane compounds, tetraalkoxysilane compounds, alkyalkoxysilane compounds, alkenyalkoxysilane compounds, halogenoalkoxysilane compounds, or combinations thereof.

12. The hydrogenated functionalized polymer of claim 10, wherein alkoxysilyl functional group comprises trimethoxy silane, dimethoxysilane, or combinations thereof.

13. The hydrogenated functionalized polymer of any of claims 1-4, wherein producing the living polymer further comprises the anionic polymerization of the conjugated diolefin monomer and a vinyl aromatic monomer.

14. The hydrogenated functionalized polymer of claim 13, wherein the conjugated diolefin monomer comprises 1,3 butadiene, isoprene, myrcene, or combinations thereof, and wherein the vinyl aromatic monomer comprises styrene, alpha methyl styrene, or combinations thereof.

15. The hydrogenated functionalized polymer of claim 14, wherein the polymer is a styrene butadiene copolymer.

16. The hydrogenated functionalized polymer of any of claims 1-4, wherein the functionalized polymer has a vinyl content, prior to hydrogenation, of from about 10% to about 60%.

17. A rubber composition comprising: the hydrogenated functionalized polymer of any of claims 1-4; at least one curative; and reinforcing filler.

18. The rubber composition of claim 17, further comprising an additional rubber comprising natural rubber, synthetic rubber, or combinations thereof.

19. The rubber composition of claim 17, wherein the reinforcing filler comprises silica, carbon black, or combinations thereof, and the curative comprises sulfur.

20. A method of making a hydrogenated functionalized polymer, comprising: introducing an anionic polymerization initiator, a conjugated diolefin monomer, and a solvent to a reactor to produce a living polymer via anionic polymerization; reacting at least one silane modifier with the living polymer to produce a functionalized polymer; adding an antioxidant to the functionalized polymer in the solvent; and hydrogenating the functionalized polymer by mixing the functionalized polymer in the solvent with a hydrogenation catalyst and introducing a hydrogen stream, wherein the antioxidant does not inhibit the hydrogenation catalyst such that the hydrogenated functionalized polymer has a degree ofhydrogenation of greater than or equal to about 75 mol%, as measured using proton nuclear magnetic resonance spectroscopy (XH NMR).

21. The method of claim 20, wherein the antioxidant comprises an amine.

22. The method of claim 21, wherein the amine comprises a secondary amine.

23. The method of claim 22, wherein the secondary amine comprises N,N'-bis(l,4- dimethylpentyl)-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, N-(l,4- dimethylpentyl)-N'-phenyl-p-phenylendiamine, N-(l,3-dimethylbutyl)-N'-phenyl-p- phenylenediamine, combinations thereof.

24. The method of any of claims 20-23, wherein the hydrogenated functionalized polymer has a degree of hydrogenation of about 75 mol% to about 98 mol%, as measured using proton nuclear magnetic resonance spectroscopy ('H NVIR).

25. The method of any of claims 20-23, wherein the hydrogenation catalyst comprises nickel, aluminum, ruthenium, rhodium, palladium, iridium, platinum, or combinations thereof.

26. The method of claim 25, wherein the hydrogenation catalyst comprises nickel and aluminum.

27. The method of claim 25, wherein the hydrogenation catalyst comprises nickel octoate.

28. The method of any of claims 20-23, wherein the anionic polymerization initiator is a lithium catalyst.

29. The method of any of claims 20-23, wherein the silane modifier 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.

30. The method of claim 29, wherein the silane modifier comprises the alkoxysilyl group.

31. The method of claim 30, wherein the alkoxysilyl group comprises alkoxysilane compounds, aralkyloxysilane compounds, tetraalkoxysilane compounds, alkyalkoxysilane compounds, alkenyalkoxysilane compounds, halogenoalkoxysilane compounds, or combinations thereof.

32. The method of claim 30, wherein alkoxysilyl functional group comprises trimethoxysilane, dimethoxysilane, or combinations thereof.

33. The method of any of claims 20-23, wherein the method further comprises introducing a vinyl aromatic monomer to the reactor.

34. The method of any of claims 33, wherein the conjugated diolefin monomer comprises 1,3 butadiene, isoprene, myrcene, or combinations thereof, and wherein the vinyl aromatic monomer comprises styrene, alpha methyl styrene, or combinations thereof.

35. The method of any of claim 34, wherein the polymer is a styrene butadiene copolymer.

36. The method of any of claims 20-23, wherein the functionalized polymer has a vinyl content, prior to hydrogenation, of from about 10% to about 60%.

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