Method of treating telechelic polymers for mooney viscosity

Abstract

A method for treating a telechelic polymer, the method comprising providing a telechelic polymer, and introducing a strong base to the telechelic polymer to thereby form a mixture.

Description

P23038W001(P2089)METHOD OF TREATING TELECHELIC POLYMERS FOR MOONEY VISCOSITYFIELD OF THE INVENTION

[0001] Embodiments of the present invention provide methods for treating telechelic polymers to stabilize the polymers and prevent deleterious Mooney viscosity.BACKGROUND OF THE INVENTION

[0002] It is common in the rubber industry, such as the tire industry, to reinforce rubber compositions with particulate filler. Among the advantages of doing so, the particulate filler can bolster the modulus of the rubber composition. For example, silica has advantageously been employed as a filler. The use of silica filler within tire treads produces, among other advantages, improved wear.

[0003] While fillers offer advantages in rubber compositions, the presence of the filler impacts the dynamic properties of the rubber compositions. Namely, hysteretic loss increases with filler concentration. This can be disadvantageous, especially in passenger tire treads, because hysteretic loss is inversely proportional to rolling resistance.

[0004] It is known that polymers can be modified with certain functionalities that react or interact with filler and thereby reduce hysteretic loss. This reaction or interaction between the polymer functionality and the filler particle is believed to reduce polymer loose ends and disassociate filler agglomerates. For example, it is known to functionalize polymer chains with silicon-containing functionalities that react or interact with, or that can be hydrolyzed to form functionalities that react or interact with, the silica filler. While these functionalities have proven useful in reducing hysteretic loss, the presence of these functionalities can present processing issues.

[0005] For example, the presence of a silicon-interactive terminal functionalities, such as an alkoxysilane functionalities, which can hydrolyze into silanol functionalities, serve as locations where the polymer chains can couple (i.e. hydrolytic coupling], especially over time. While, as suggested above, polymer coupling can be advantageous for polymer isolation, long-term growth in polymer molecular weight, also known as Mooney growth, is not desirable. Indeed, long-term Mooney growth can frustrate future processing of the polymer, which takes place when, for example, the polymer is employed in the production ofP23038W001(P2089)tires. Attempts have been made to alleviate this Mooney growth. For example, U. S. Patent No.5,659,056 teaches the addition of a stabilizing agent that does not react with the polymer functionality but instead serves to neutralize the bi-product lithium compounds that may be present from polymer initiators. At neutral pH, the Mooney viscosity jump is less severe. Alternatively, U. S. Patent No. 6,279,632 teaches a method for stabilizing Mooney viscosity growth by treating these polymers with long-chain alcohols. And, U. S. Patent No. 6,255,404 teaches a method for stabilizing Mooney viscosity growth by treating polymers with silicon-containing functionalities with alkyl alkoxysilanes.

[0006] With respect to polymer functionality, polydienes, such as poly(butadiene) and diene copolymers, such as poly(styrene-co-butadiene), are often made by employing anionic polymerization techniques whereby diene monomer, optionally together with copolymerizable monomer such as vinyl aromatics, are polymerized using an anionic initiator. The use of anionic polymerization techniques leads to several advantages including the ability to control molecular weight, prepare relatively linear polymer chains, and functionalize the polymer chain through a chain termination reaction. Useful anionic initiators may include, for example, alkyl lithium compounds such as n-butyl lithium. Multifunctional initiators can be formed by reacting, for example, an alkyl lithium compound with a dialkenyl compound such as diisopropenylbenzene. Polymers prepared by using multifunctional initiators have multiple reactive chain ends, which provides the ability to functionalize both ends of a polymer chain to form a telechelic polymer.

[0007] Those skilled in the art appreciate that hydrolytic coupling of monofunctional polymers results in polymer coupling and, generally speaking, a doubling of the polymer molecular weight. Where telechelic polymers are involved, coupling proceeds in a stepgrowth fashion where the increase in molecular weight is exponential and ultimately results in the polymer gel (i.e. an infinite polymer network).SUMMARY OF THE INVENTION

[0008] One or more embodiments of the present invention provide a method for treating a telechelic polymer, the method comprising providing a telechelic polymer, and introducing a strong base to the telechelic polymer to thereby form a mixture.P23038W001(P2089)

[0009] Other embodiments of the present invention provide a vulcanizate, including tire components, prepared by vulcanizing a vulcanizable composition of matter including the treated polymer telechelic polymers of this disclosure.DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0010] Embodiments of the invention are based, at least in part, on the discovery of telechelic polymer compositions that are stabilized against deleterious Mooney growth. According to embodiments of the invention, telechelic polymer compositions, which include telechelic polymers with hydrolysable chain ends, are stabilized by treating the polymers with a strong base. While the prior art contemplates the use of strong bases to promote the interaction or reaction of hydrolysable chain ends with silica particles, it has now been discovered that certain strong bases stabilize the telechelic polymer compositions from excessive hydrolysis and its corresponding deleterious Mooney growth. Without wishing to be bound by any particular theory, it is believed that the strong base creates a dynamic network wherein both hydrolytic coupling and decoupling reactions take place, which results in a decrease or stabilization of the Mooney viscosity.TELECHELIC POLYMER COMPOSITIONS

[0011] In one or more embodiments, the telechelic polymer compositions treated according to the invention include polymers with multiple hydrolysable chain-end functionalities. These telechelic polymers may be prepared by reacting a difunctional or di-reactive base polymer with a functionalizing agent that imparts a hydrolysable functionality to each end of the difunctional chain. These telechelic polymers can be prepared by employing known methods including, but not limited to, those methods described in WO 2024 / 148082 and WO 2024 / 148086, which are incorporated herein by reference.

[0012] In one or more embodiments, the telechelic polymers are prepared by reacting diene-based polymers with a functionalizing agent. As the skilled person appreciates, the term diene-based polymer refers to those polymers (e.g. homopolymers] and copolymers synthesized by the polymerization of one or more conjugated diene monomer optionally together with a copolymerizable monomer. Exemplary conjugated diene monomer may include, but is not limited to, 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene,P23038W001(P2089)2,3-dimethyl-l,3-butadiene, 2-ethyl-l,3-butadiene, 2-methyl-l,3-pentadiene, 3-methyl-l,3-pentadiene, 4-methyl- 1,3 -pentadiene, and 2,4-hexadiene. Copolymerizable monomer includes, but is not limited to, vinyl aromatic monomer. Exemplary vinyl aromatic monomer may include, but is not limited to, styrene, p-methylstyrene, α-methylstyrene, and vinylnaphthalene. Exemplary diene-based polymers include, but are not limited to, polybutadiene, polyisoprene, poly(butadiene-co-isoprene), poly(styrene-co-butadiene), poly(styrene-co-isoprene), and poly(styrene-co-butadiene-isoprene). CHARACTERISTICS OF BASE POLYMER

[0013] Prior to functionalization, which is further described below, the prefunctionalized polymers may be characterized by their molecular weight, which may include number average molecular weight (Mn), weight average molecular weight (Mw), and peak molecular weight (Mp). As those skilled in the art will appreciate, molecular weight can be determined, for example, by using gel permeation chromatography (GPC) together with an UV absorption, differential refractometer (DRI), refractive index (RI), infrared (IR) absorption detector and by employing appropriate calibration standards and THF as a solvent. For purposes of this specification, GPC measurements employ polystyrene standards and polystyrene Mark Houwink constants unless otherwise specified. For purposes of this specification, prior to functionalization, the polymer may be referred to as the base polymer or pre-functionalized, and the pre-functionalized characteristics of the polymer may be referred to as the characteristics of the base polymer.

[0014] In one or more embodiments, the pre-functionalized polymers have an Mp, which may also be referred to as the base Mp, of greater than 120 kg / mol, in other embodiments greater than 140 kg / mol, and in other embodiments greater than 160 kg / mol. In these or other embodiments, the pre-functionalized polymers have a base Mp of less 750 kg / mol, in other embodiments less than 500 kg / mol, and in other embodiments less than 350 kg / mol. In one or more embodiments, the pre-functionalized polymers have a base Mp of from about 120 to about 750 kg / mol, in other embodiments from about 140 to about 500 kg / mol, and in other embodiments from about 160 to about 350 kg / mol.

[0015] In one or more embodiments, the pre-functionalized polymers have an Mn, which may also be referred to as the base Mn, of greater than 120 kg / mol, in otherP23038W001(P2089)embodiments greater than 140 kg / mol, and in other embodiments greater than 160 kg / mol. In these or other embodiments, the pre-functionalized polymers have a base Mn of less 750 kg / mol, in other embodiments less than 500 kg / mol, and in other embodiments less than 10 kg / mol. In one or more embodiments, the pre-functionalized polymers have a base Mn of from about 120 to about 750 kg / mol, in other embodiments from about 140 to about 500 kg / mol, and in other embodiments from about 160 to about 350 kg / mol.

[0016] In one or more embodiments, the pre-functionalized polymers have an Mw, which may also be referred to as the base Mw, of greater than 140 kg / mol, in other embodiments greater than 160 kg / mol, and in other embodiments greater than 180 kg / mol. In these or other embodiments, the pre-functionalized polymers have a base Mw of less 800 kg / mol, in other embodiments less than 600 kg / mol, and in other embodiments less than 400 kg / mol. In one or more embodiments, the pre-functionalized polymers have a base Mw of from about 140 to about 800 kg / mol, in other embodiments from about 160 to about 700 kg / mol, and in other embodiments from about 180 to about 600 kg / mol.

[0017] In one or more embodiments, the pre-functionalized polymers is monomodal. In these or other embodiments, the base polymer may be characterized by a polydispersity, which may also be referred to as a molecular weight distribution (Mw / Mn) of less than of less than 3.0, in other embodiments less than 2.0, in other embodiments less than 1.5, and in other embodiments less than 1.1.

[0018] The pre-functionalized polymers produced according to aspects of the present invention may be characterized by vinyl content, which may be described as the number of unsaturations in the 1,2-microstructure relative to the total unsaturations within the polymer chain. As the skilled person will appreciate, vinyl content can be determined by NMR analysis at 400 MHz using CDCl3as a solvent. In one or more embodiments, the prefunctionalized polymers include greater than 35%, in other embodiments greater than 40%, in other embodiments greater than 45%, in other embodiments greater than 50%, and in other embodiments greater than 60% vinyl. In these or other embodiments, the prefunctionalized polymers include less than 85%, in other embodiments less than 80%, and in other embodiments less than 75%. In one or more embodiments, the pre-functionalizedP23038W001(P2089)polymers include from about 35% to about 85%, in other embodiments from about 40% to about 80%, and in other embodiments from about 60% to about 75% vinyl.

[0019] The pre-functionalized polymers produced according to aspects of the present invention may be characterized by bound styrene content (i.e. the amount of styrene incorporated in the polymer chains), which refers to the weight percent vinyl aromatic monomer incorporated into polydiene copolymers. As the skilled person appreciates, bound styrene can be determined with reference to the relative weight of vinyl monomer included into the polymerization mixture relative to the diene monomer. Alternatively, bound styrene can be determined by NMR analysis at 400 MHz using CDCl3as a solvent. In one or more embodiments, the pre-functionalized polymers include greater than 5 wt %, in other embodiments greater than 15 wt %, and in other embodiments greater than 25 wt % bound styrene. In these or other embodiments, the pre-functionalized polymers include less than 60 wt %, in other embodiments less than 50 wt %, and in other embodiments less than 40 wt % bound styrene. In one or more embodiments, the pre-functionalized polymers include from about 5 to about 15 wt %, in other embodiments from about 15 to about 30 wt %, and in other embodiments from about 30 to about 55 wt % bound styrene.

[0020] In one or more embodiments, the pre-functionalized polymers include greater than 30 wt %, in other embodiments greater than 40 wt %, and in other embodiments greater than 45 wt % micro-block styrene. In these or other embodiments, the prefunctionalized polymers include less than 60 wt %, in other embodiments less than 55 wt %, and in other embodiments less than 50 wt % micro-block styrene. In one or more embodiments, the pre-functionalized polymers include from about 30 to about 60 wt %, in other embodiments from about 40 to about 55 wt %, and in other embodiments from about 45 to about 50 wt % micro-block styrene.

[0021] In one or more embodiments, the pre-functionalized polymers include greater than 7 wt %, in other embodiments greater than 10 wt %, and in other embodiments greater than 15 wt % chemical block styrene. In these or other embodiments, the pre-functionalized polymers include less than 30 wt %, in other embodiments less than 25 wt %, and in other embodiments less than 20 wt % chemical block styrene. In one or more embodiments, the pre-functionalized polymers include from about 7 to about 30 wt %, in other embodimentsP23038W001(P2089)from about 10 to about 25 wt %, and in other embodiments from about 15 to about 20 wt % chemical block styrene.

[0022] The pre-functionalized telechelic polymers produced according to aspects of the present invention may be characterized by a glass transition temperature [Tg], which is determined according to ASTM E1356-08 by using differential scanning calorimetry [DSC techniques. In one or more embodiments, the Tg of the copolymers is greater than -85, in other embodiments greater than -50, and in other embodiments greater than 0 °C. In these or other embodiments, the Tg of the copolymers is less than 40 °C, in other embodiments less than 25 °C, and in other embodiments less than 0 °C. In one or more embodiments, the functionalized low-molecular weight copolymers have a Tg of from about -85 to about -50 °C, in other embodiments from about -20 to about 0 °C, and in other embodiments from about 0 to about 40 °C.SYNTHESIS OF TELECHELIC POLYMER

[0023] In one or more embodiments, the pre-functionalized polymers are prepared by polymerizing diene monomer, optionally together with vinyl aromatic monomer, with a dilithium initiator. The dilithium initiator can be prepared by reacting an alkyl lithium compound with a dialkenyl compound. In one or more embodiments, the dilithium initiator is aged in an appropriate solvent in the presence of a Lewis base prior to its use in polymerization.INITIATOR PREPARATION AND AGING

[0024] As indicated above, the dilithium initiator can be prepared by combining a dialkenyl compound with an alkyl lithium compound within a solvent that forms a reaction mixture in which the reactants and product are at least partially soluble. The initiator may then be aged in an appropriate solvent in the presence of a Lewis base.

[0025] In one or more embodiments, the dialkenyl compound is a 1,3-dialkenylbenzene compound such as 1,3-diisopropenylbenzene. In one or more embodiments, the alkyl lithium compound is a butyl lithium compound such as n-butyl lithium, t-butyl lithium, and / or sec-butyl lithium. In particular embodiments, sec-butyl lithium is employed.

[0026] The Lewis base may include any Lewis base that does not include an active hydrogen atom, where the presence of an active hydrogen atom is determined by theP23038W001(P2089)Zerewitinoff test. Exemplary Lewis bases include oxolanyl propanes such as 2,2-bis(2-oxolanyl) propane (also known as 2,2-ditetrahydrofurylpropane), meso-2,2-diterahydrofurylpropane, DL-2,2,-ditetrahdydrofurlypropane, tetramethylethylenediamine, and mixtures thereof, as well as trialkyl amines such as triethyl amine. In particular embodiments, triethyl amine is employed.

[0027] The amount of alkyl lithium compound reacted with the dialkenyl compound may be quantified based upon the molar ratio of lithium to alkenyl groups; that is, equivalents of lithium associated with the alkyl lithium compound (i.e. mole of Li) relative to the equivalents of alkenyl groups within the dialkenyl compound (e.g. equivalents of isopropenyl groups within 1,3-diisopropenylbenzene. In one or more embodiments, the molar ratio of moles of Li associated with the alkyl lithium to equivalents of alkenyl groups associated with the dialkenyl compound may be from about 1.95:1 to about 2.05:1, in other embodiments from about 1.97:1 to about 2.03:1, and in other embodiments from about 1.99:1 to about 2.01:1. Where sec-butyl lithium is reacted with 1,3-diisopropenylbenzene, 2.00 moles of sec-butyl lithium may be reacted with each mole of 1,3-diisopropenylbenzene.

[0028] The synthesis of the initiator takes place within a solvent in which the reactants and the product is at least partially soluble. Useful solvents include, but are not limited to, hydrocarbons with a low or relatively low boiling point such as aromatic hydrocarbons, aliphatic hydrocarbons, and cycloaliphatic hydrocarbons. Non-limiting examples of aromatic hydrocarbons include benzene, toluene, xylenes, ethylbenzene, diethylbenzene, and mesitylene. Non-limiting examples of aliphatic hydrocarbons include n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, isopentane, isohexanes, isopentanes, isooctanes, 2,2-dimethylbutane, petroleum ether, kerosene, and petroleum spirits. And, non-limiting examples of cycloaliphatic hydrocarbons include cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane. Mixtures of the above hydrocarbons may also be used.

[0029] As indicated above, the dilithium initiator formed by the foregoing reaction is aged within an appropriate solvent (e.g. within the reaction medium) in the presence of a Lewis base. In one or more embodiments, the Lewis base is present at the introduction of the reactants to the reaction mixture. In other embodiments, the Lewis base is introducedP23038W001(P2089)after synthesis of the dilithium initiator, and aging takes place after introduction of the Lewis base.

[0030] The amount of Lewis base introduced to the reaction mixture maybe quantified based upon the moles of Lewis base (e.g.2,2-ditetrahydrofurylpropane) relative to the moles of lithium associated with the alkyl lithium compound (i.e. molar ratio of moles Lewis base to moles of lithium). In one or more embodiments, the molar ratio of moles of Lewis base introduced to the reaction medium to moles of lithium introduced with the alkyl lithium compound is from about 0.05:1 to about 1:1, in other embodiments from about 0.1:1 to about 0.6:1, and in other embodiments from about 0.2:1 to about 0.45:1.

[0031] In one or more embodiments, aging of the initiator takes place under an inert atmosphere at atmospheric conditions at a temperature of from about 0 to about 150 °C, in other embodiments from about 25 to about 100 °C, and in other embodiments from about 35 to about 60 °C. In one or more embodiments, the initiator is aged for greater than 15 minutes, in other embodiments greater than 20 minutes, in other embodiments greater than 25 minutes, and in other embodiments greater than 30 minutes before introducing the initiator to the monomer to be polymerized. In one or more embodiments, the initiator is aged for from about 15 minutes to about 4 hours, in other embodiments from about 20 minutes to about 3 hours, and in other embodiments from about 30 minutes to about 2 hours before introducing the initiator to the monomer to be polymerized. The appropriate aging time is temperature dependent; that is, the time necessary to age the initiator decreases with increased temperature. Likewise, the maximum amount of aging decreases with temperature. It should also be appreciated that the temperature dependence of the aging process may allow for longer storage times at cold temperatures. For example, it is believed that the initiator (i.e. the combination of the dialkenyl compound and the alkyl lithium) can be stored for periods of, for example, 24 hours at temperatures below 0 °C.POLYMERIZATION REACTION

[0032] The dilithium initiator as prepared above, and optionally aged, is combined with monomer to be polymerized, within an appropriate a solvent to form a polymerization mixture in which the monomer and resulting polymer are at least partially soluble. In oneP23038W001(P2089)or more embodiments, the initiator is also at least partially soluble within the polymerization mixture.

[0033] Generally speaking, the polymerization of monomer by the initiator proceeds by anionic polymerization techniques. The preparation of polymer by employing anionic polymerization techniques is generally known. The key mechanistic features of anionic polymerization have been described in books (e.g., Hsieh, H. L.; Quirk, R. P. Anionic Polymerization: Principles and Practical Applications; Marcel Dekker: New York, 1996) and review articles (e.g., Hadjichristidis, N.; Pitsikalis, M.; Pispas, S.; latrou, H.; Chem. Rev. 2001, 101(12), 3747-3792). Anionic initiators may advantageously produce polymer having reactive chain ends (e.g., living polymers) that, prior to quenching, are capable of reacting with additional monomers for further chain growth or reacting with certain functionalizing agents to give functionalized polymers. The polymers having reactive polymer chain ends may simply be referred to as reactive polymers. As those skilled in the art appreciate, these reactive polymers include a reactive chain end, which is believed to be ionic, at which a reaction between a functionalizing agent and the reactive chain end of the polymer can take place, which thereby imparts a functionality or functional group to the polymer chain end, or which may couple multiple polymers together.

[0034] The polymerization mixture can be formed by introducing the various constituents in any order. For example, in one or more embodiments, the monomer, and solvent can first be combined, and then the aged initiator can be introduced to the mixture.

[0035] As indicated above, the monomer to be polymerized includes conjugated diene monomer and optionally vinyl-substituted aromatic monomer, which may also be referred to as vinyl aromatic monomer or comonomer. Examples of conjugated diene monomer include 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-l,3-butadiene, 2-ethyl-l,3-butadiene, 2-methyl- 1,3-pentadiene, 3-methyl-l,3-pentadiene, 4-methyl-1,3-pentadiene, and 2,4-hexadiene. Mixtures of two or more conjugated dienes may also be utilized in copolymerization. Examples of vinyl-substituted aromatic monomer include styrene, p-methylstyrene, α-methylstyrene, and vinylnaphthalene.

[0036] The amount of the initiator to be employed may depend on the interplay of various factors such as the type of initiator employed, the purity of the ingredients, theP23038W001(P2089)polymerization temperature, the polymerization rate and conversion desired, the molecular weight desired, and many other factors. In one or more embodiments, the amount of initiator employed may be expressed as the mmols of initiator per weight of monomer. In one or more embodiments, the amount of initiator introduced to the polymerization mixture is from about 0.1 to about 100 mmol, or in other embodiments from about 0.2 to about 50 mmol, or in other embodiments from about 0.3 to about 15 mmol of the initiator per 100 gram of monomer within the polymerization mixture (i.e. monomer to be polymerized).

[0037] In one or more embodiments, suitable solvents include those organic compounds that will not undergo polymerization or incorporation into propagating polymer chains during the polymerization of monomer in the presence of catalyst. In one or more embodiments, these organic species are liquid at ambient temperature and pressure. In one or more embodiments, these organic solvents are inert to the catalyst. Exemplary organic solvents include hydrocarbons with a low or relatively low boiling point such as aromatic hydrocarbons, aliphatic hydrocarbons, and cycloaliphatic hydrocarbons. Non-limiting examples of aromatic hydrocarbons include benzene, toluene, xylenes, ethylbenzene, diethylbenzene, and mesitylene. Non-limiting examples of aliphatic hydrocarbons include n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, isopentane, isohexanes, isopentanes, isooctanes, 2,2-dimethylbutane, petroleum ether, kerosene, and petroleum spirits. And, non-limiting examples of cycloaliphatic hydrocarbons include cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane. Mixtures of the above hydrocarbons may also be used. The low-boiling hydrocarbon solvents are typically separated from the polymer upon completion of the polymerization. Other examples of organic solvents include high-boiling hydrocarbons of high molecular weights, such as paraffinic oil, aromatic oil, or other hydrocarbon oils that are commonly used to oil-extend polymers. Since these hydrocarbons are non-volatile, they typically do not require separation and remain incorporated in the polymer.

[0038] The polymerization reaction may be conducted in the presence of a modifier, which may also be referred to as a polar coordinator or a vinyl modifier. As those skilled in the art appreciate, these compounds may serve multiple roles in the polymerization. For example, they can assist in randomizing comonomer throughout the polymer chain; theyP23038W001(P2089)may also modify the vinyl content of the mer units deriving from dienes. Compounds useful as modifiers include those having an oxygen or nitrogen heteroatom and a non-bonded pair of electrons. Examples include linear and cyclic oligomeric oxolanyl alkanes; dialkyl ethers of mono and oligo alkylene glycols (also known as glyme ethers); "crown" ethers; tertiary amines; linear THF oligomers; and the like. Linear and cyclic oligomeric oxolanyl alkanes are described in U.S. Patent Nos. 4,429,091 and 9,868,795, which are incorporated herein by reference. Specific examples of compounds useful as randomizers include 2,2-bis(2-oxolanyl] propane (also known as 2,2-ditetrahydrofurylpropane], meso-2,2-diterahydrofurylpropane, DL-2,2,-ditetrahdydrofurlypropane, and mixtures thereof, 1,2-dimethoxyethane, N,N,N',N'-tetramethylethylenediamine (TMEDA), tetrahydrofuran (THF], 1,2-dipiperidylethane, dipiperidylmethane, hexamethylphosphoramide, N-N'-dimethylpiperazine, diazabicyclooctane, dimethyl ether, diethyl ether, tri-n-butylamine, and mixtures thereof. In other embodiments, potassium alkoxides can be used to randomize the styrene distribution. In one or more embodiments, a randomizer other than a potassium alkoxide is employed. In other embodiments, potassium alkoxide is the only randomizer present within the polymerization mixture.

[0039] The amount of randomizer to be employed may depend on various factors such as the desired microstructure of the polymer, the ratio of monomer to comonomer, the polymerization temperature, as well as the nature of the specific randomizer employed. POLYMERIZATION CONDITIONS AND TECHNIQUES

[0040] The anionic initiator and the randomizer can be introduced to the polymerization system by various methods. In one or more embodiments, the anionic initiator and the randomizer may be added separately to the monomer to be polymerized in either a stepwise or simultaneous manner.

[0041] As indicated above, polymerization of conjugated diene monomer and vinyl aromatic monomer, in the presence of an effective amount of initiator, produces a reactive polymer. The introduction of the initiator, the conjugated diene monomer, the comonomer, and the solvent forms a polymerization mixture in which the reactive polymer is formed. Polymerization within a solvent produces a polymerization mixture in which the polymerP23038W001(P2089)product is dissolved or suspended in the solvent. This polymerization mixture may be referred to as a polymer cement.

[0042] In one or more embodiments, the polymerization may be conducted in any conventional polymerization vessel known in the art. For example, the polymerization can be conducted in a conventional stirred-tank reactor. In one or more embodiments, all of the ingredients used for the polymerization can be combined within a single vessel (e.g., a conventional stirred-tank reactor], and all steps of the polymerization process can be conducted within this vessel. In other embodiments, two or more of the ingredients can be pre-combined in one vessel and then transferred to another vessel where the polymerization of monomer (or at least a major portion thereof] may be conducted. Because various embodiments of the present invention include the use of multiple reactors or reaction zones, the vessel (e.g., tank reactor] in which the polymerization is conducted may be referred to as a first vessel or first reaction zone.

[0043] The polymerization can be carried out as a batch process, a continuous process, or a semi-continuous process. In the semi-continuous process, the monomer is intermittently charged as needed to replace that monomer already polymerized. In one or more embodiments, the heat of polymerization may be removed by external cooling by a thermally controlled reactor jacket, internal cooling by evaporation and condensation of the monomer through the use of a reflux condenser connected to the reactor, or a combination of the two methods. Also, conditions maybe controlled to conduct the polymerization under a pressure of from about 0.1 atmospheres to 50 atmospheres, in other embodiments from about 0.5 atmosphere to about 20 atmospheres, and in other embodiments from about 1 atmosphere to about 10 atmospheres. In one or more embodiments, the pressures at which the polymerization may be carried out include those that ensure that the majority of the monomer is in the liquid phase. In these or other embodiments, the polymerization mixture may be maintained under anaerobic conditions.

[0044] In one or more embodiments, the conditions under which the polymerization proceeds may be controlled to maintain the peak polymerization temperature of the polymerization mixture at greater than 30 °C, in other embodiments greater than 50 °C, and in other embodiments greater than 70 °C. In these or other embodiments, the conditionsP23038W001(P2089)under which the polymerization proceeds may be controlled to maintain the peak polymerization temperature of the polymerization mixture at less than 120 °C, in other embodiments less than 110 °C, and in other embodiments less than 100 °C. In one or more embodiments, the conditions under which the polymerization proceeds may be controlled to maintain the temperature of the polymerization mixture within a range from about -10 °C to about 200 °C, in other embodiments from about 0 °C to about 150 °C, and in other embodiments from about 20 °C to about 110 °C.POLYMER FUNCTIONALIZATION

[0045] As indicated above, the pre-functionalized polymers include reactive chain ends (i.e. the growing ends) that are capable of being modified, which may also be referred to as functionalized, to provide functionalized polymers having a functional group at both ends of a linear polymer, which may be referred to as a telechelic polymer. That is, the reactive ends of the polymer are modified, which may also be referred to as functionalized, by introducing a functionalizing agent to the polymerization mixture. It is believed that the polymer chain ends react with the functionalizing agent (which may also be referred to as a modifying agent) to provide a residue of the functionalizing agent at the end of the polymer chain. Accordingly, the reaction between the polymer and the functionalizing agents produces a polymer composition wherein both ends of a linear polymer include a terminal group deriving from the functionalizing agent. It should be appreciated that the reaction between the functionalizing agent and the reactive ends of the polymer can also result in polymer coupling of two or more polymer chains. In either event, the polymers bearing a chain-end functional group or polymers coupled with the residue of the functionalizing agent will both be referred to as modified or functionalized branched polymers unless otherwise designated. It should also be appreciated that the respective functionalizing agents that react with the respective reactive ends of the polymer may be of the same or different type of functionalizing agent; i.e. the maybe of the same or different chemical species. The skilled person appreciates that two or more functionalizing agents of different chemical species may be introduced to the reactive polymer and that different chemical species may react at each of the respective ends of the polymer chain. Alternatively, the same chemical species mayP23038W001(P2089)react at each end. The latter would be the result if one chemical species of functionalizing agent is introduced to the reactive polymer.FUNCTIONALIZING AGENTS

[0046] Useful functionalizing agents include those functionalizing agents conventionally employed in the art. In one or more embodiments, the functionalizing agent imparts a hydrolysable group to the chain end to which it is reacted. In one or more embodiments, the functionalizing agent imparts a terminal functionality that can be reactive or interactive with other polymer chains (propagating and / or non-propagating] or with other materials in a rubber compound such as particulate reinforcing fillers (e.g. carbon black or silica). As described above, enhanced interactivity between a polymer and particulate fillers in rubber compounds improves the mechanical and dynamic properties of resulting vulcanizates. For example, certain functionalizing agents can impart a terminal functionality that includes one or more heteroatoms. In one or more embodiments, the functionalizing agent may produce a functionalized polymer that can be used in rubber compositions from which vulcanizates can be provided, and these vulcanizates can possess high temperature (e.g., 50 °C) hysteresis losses that are less than those possessed by vulcanizates prepared from similar rubber compounds that do not include the functionalized polymers. Reductions in high temperature hysteresis loss can be at least 5%, sometimes at least 10%, and occasionally at least 15%.

[0047] Exemplary types of compounds that can be used to end-functionalize the reactive branched polymers of this invention include imines, amines, hydro carbyloxy silanes, amine-containing hydrocarbyloxy silanes, halogenated organics, trialkyl tin compounds, carbon dioxide, benzophenones, benzaldehydes, imidazolidones, pyrrolidinones, carbodiimides, ureas, isocyanates, and Schiff bases. It should also be appreciated that two or more different species of functionalizing agent can be employed in practicing the present invention.HYDROCARBYLOXY SILANE FUNCTIONALIZING AGENTS

[0048] In one or more embodiments, hydrocarbyloxy silane functionalizing agents may be defined by the formula:(Rl)4-z-ySi(R2) y (OR2)ZP23038W001(P2089)where R1is a halogen atom or a monovalent organic group, eachis a monovalent organic group, z is an integer from 1 to 4, and y is an integer from 0 to 2. In one embodiment, the halogen atom is chlorine.

[0049] In one or more embodiments, the monovalent organic groups include hydrocarbyl groups such as, but not limited to, alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl, allyl, aralkyl, alkaryl, or alkynyl groups. Hydrocarbyl groups also include substituted hydrocarbyl groups, which refer to hydrocarbyl groups in which one or more hydrogen atoms have been replaced by a substituent such as a hydrocarbyl group. In one or more embodiments, these groups may include from one, or the appropriate minimum number of carbon atoms to form the group, to about 20 carbon atoms. These groups may or may not contain heteroatoms. Suitable heteroatoms include, but not limited to, nitrogen, boron, oxygen, silicon, sulfur, tin, and phosphorus atoms. In one or more embodiments, the cycloalkyl, cycloalkenyl, and aryl groups are non-heterocyclic groups. In these or other embodiments, the substituents forming substituted hydrocarbyl groups are non-heterocyclic groups.

[0050] Suitable examples of siloxane terminating agents include tetraalkoxysilanes, alkylalkoxysilanes, arylalkoxysilanes, alkenylalkoxysilanes, and haloalkoxysilanes.

[0051] Examples of tetraalkoxysilane compounds include tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, tetrabutyl orthosilicate, tetra(2-ethylhexyl) orthosilicate, tetraphenyl orthosilicate, and tetratoluyloxysilane.

[0052] Examples of alkylalkoxysilane compounds 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, and diphenyldimethoxysilane.

[0053] Examples of arylalkoxysilane compounds include phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltri-n-butoxysilane, and phenyltriphenoxysilane.P23038W001(P2089)

[0054] Examples of alkenylalkoxysilane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n-propoxysilane, vinyltri-n-butoxysilane, vinyltriphenoxysilane, allyltrimethoxysilane, octenyltrimethoxysilane, and divinyldimethoxysilane.

[0055] Examples of haloalkoxysilane compounds include trimethoxychlorosilane, triethoxychlorosilane, tri-n-propoxy chlorosilane, tri-n-butoxy chlorosilane, triphenoxychlorosilane, dimethoxydichlorosilane, diethoxydichlorosilane, di-n-propoxydichlorosilane, diphenoxydichlorosilane, methoxytrichlorosilane, ethoxytrichlorosilane, n-propoxytrichlorosilane, phenoxytrichlorosilane, trimethoxybromosilane, triethoxybromosilane, tri-n-propoxybromosilane, triphenoxybromosilane, dimethoxy dibromosilane, 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, and phenoxytriiodosilane.

[0056] Techniques for preparing functionalized polymers by using hydrocarbyloxy silane compounds are set forth in U.S. Patent Nos. 3,244,664; 6,008,295; 6,228,908; and 4,185,042, which are incorporated herein by reference.

[0057] In one or more embodiments, hydrocarbyloxy silane functionalizing agents is an imino-containing hydrocarbyloxy silane that may be defined by the formula:R3R5R2- C^=N - R4- Si - R6OR7where R2, R3, and R7are monovalent organic groups, R4is a divalent organic group, and where R5and R6are each independently hydrocarbyloxy groups or hydrocarbyl groups.P23038W001(P2089)

[0058] In one or more embodiments, the divalent organic group is a hydrocarbylene groups such as, but not limited to, alkylene, cycloalkylene, alkenylene, cycloalkenylene, alkynylene, cycloalkynylene, or arylene groups. Hydrocarbylene groups include substituted hydrocarbylene groups, which refer to hydrocarbylene groups in which one or more hydrogen atoms have been replaced by a substituent such as a hydrocarbyl group. In one or more embodiments, these groups may include from one, or the appropriate minimum number of carbon atoms to form the group, to about 20 carbon atoms. These groups may or may not contain heteroatoms. Suitable heteroatoms include, but not limited to, nitrogen, boron, oxygen, silicon, sulfur, tin, and phosphorus atoms. In one or more embodiments, the cycloalkylene, cycloalkenylene, and arylene groups are non-heterocyclic groups. In these or other embodiments, the substituents forming substituted hydrocarbylene groups are non-heterocyclic groups.

[0059] Examples of these imino-containing hydro carb yloxy silane compounds include tri ethoxy compounds such as, but are not limited to, N-(l,3-dimethylbutylidene)-3-( tri ethoxysilyl) -1-propaneamine, N-(l-methylethylidene)-3-(triethoxysilyl)-l-propaneamine, N-ethylidene-3-(triethoxysilyl)-l-propaneamine, N-(l-methylpropylidene)-3-(tri ethoxysilyl) -1-propaneamine, N-(4-N, N-dimethylaminobenzylidene)-3- (triethoxysilyl)-l-propaneamine, and N-(cyclohexylidene)-3-(triethoxysilyl)-l-propaneamine. Other examples include trimethoxy compounds such as, but not limited to, N-(l,3-dimethylbutylidene)-3-(trimeth oxysilyl) -1-propaneamine, N-(l-methylethylidene)-3-(trimethoxysilyl)-l-propaneamine, N-ethylidene-3-(trimethoxysilyl)-l-propaneamine, N-(l-methylpropylidene)-3-(trimethoxysilyl) -1-propaneamine, N-(4-N, N-dimethylaminobenzylidene)-3-(trimethoxysilyl)- 1-propaneamine, and N- (cyclohexylidene)-3-(trimethoxysilyl)-l-propaneamine. Other examples include methyldiethoxy compounds such as, but not limited to, N-(l,3-dimethylbutylidene)-3-(methyldiethoxysilyl) -1-propaneamine, N-(l-methylethylidene)-3-(methyldiethoxysilyl)-l-propaneamine, N-ethylidene-3-(methyldiethoxysilyl)- 1-propaneamine, N-(l-methylpropylidene)-3-(methyldiethoxysilyl) -1-propaneamine, N-(4-N, N-dimethylaminobenzylidene)-3-(methyldiethoxysilyl)-l-propaneamine, and N-(cyclohexylidene)-3-(methyldiethoxysilyl) -1-propaneamine. Other examples includeP23038W001(P2089)ethyldimethoxy compounds such as, but not limited to, N-(l,3-dimethylbutylidene]-3-(ethyldimethoxysilyl]-l-propaneamine, N-(l-methylethylidene)-3-(ethyldimethoxysilyl]-l-propaneamine, N-ethylidene-3-(ethyldimethoxysilyl]-l-propaneamine, N-(l-methylpropylidene)-3-(ethyldimethoxysilyl)-l-propaneamine, N-(4-N, N-dimethylaminobenzylidene)-3-(ethyldimethoxysilyl]-l-propaneamine, and N-(cyclohexylidene)-3-(ethyldimethoxysilyl)-l-propaneamine.

[0060] Techniques for preparing functionalized polymers by using imine-containing hydrocarbyloxy compounds are disclosed in U. S. Publication Nos. 2005 / 0009979; 2010 / 0113683; and 2011 / 0092633, which are incorporated herein by reference.

[0061] In one or more embodiments, hydrocarbyloxy silane functionalizing agents is a hydrocarbyloxy silane defined by the formula:R5A - R4- Si - R6OR7where R4is a divalent organic group, where R5and R6are each independently hydrocarbyloxy groups or hydrocarbyl groups, R5is a monovalent organic group, and A is selected from the group consisting of carboxylic ester, cyclic tertiary amine, non-cyclic tertiary amine, pyridine, silazane, and sulfide groups.

[0062] Examples of hydrocarbyloxy silane compounds including a carboxylic ester group include, but are not limited to, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3 -methacryloyloxypropylmethyldi ethoxysilane, and 3-methacryloyloxypropyltriisopropoxysilane.

[0063] Examples of hydrocarbyloxy silane compounds including a cyclic tertiary amine group include, but are not limited to, 3-(l-hexamethyleneimino]propyltriethoxysilane, 3-(l-hexamethyleneiminojpropyltrimethoxysilane, (l-hexamethyleneimino]methyltriethoxysilane, (1-hexamethyleneimino) methyltrimethoxysilane, 2-(l-hexamethyleneiminojethyltriethoxysilane, 3-(l-hexamethyleneimino]ethyltrimethoxysilane, 3-(l-pyrrolidinyl]propyltrimethoxysilane, 3-(l-pyrrolidinyl] propyltri ethoxysilane, 3-(l-P23038W001(P2089)heptamethyleneimino) propyltriethoxysilane, 3-(l-dodecamethyleneimino)propyltriethoxysilane, 3-(l-hexamethyleneiminojpropyldiethoxyethylsilane, and 3- [10-(tri ethoxysilyl) decyl] -4-oxazoline.

[0064] Examples of hydrocarbyloxy silane compounds including a non-cyclic tertiary amine group include, but are not limited to, 3-dimethylaminopropyltriethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 3-di ethylaminopropyltri ethoxysilane, 2-dimethylaminoethyltriethoxysilane, 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyldiethoxymethylsilane, 3-di ethylaminopropyldi ethoxymethylsilane,3-dimethylaminopropyldimethoxymethylsilane, 3-di ethylaminopropyldimethoxymethylsilane, and 3-dibutylaminopropyltriethoxysilane

[0065] Examples of hydrocarbyloxy silane compounds including a pyridine group include, but are not limited to, 2-trimethoxysilylethylpyridine.

[0066] Examples of hydrocarbyloxy silane compounds including a silazane group include, but are not limited to, N, N-bis(trimethylsilyl)-aminopropylmethyldimethoxysilane, l-trimethylsilyl-2,2-dimethoxy-l-aza-2 -silacyclopentane, N, N-bis(trimethylsilyl)aminopropyltrimethoxysilane, N, N-bis(trimethylsilyl)aminopropyltriethoxysilane, N, N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane, N, N-bis(trimethylsilyl)aminoethyltrimethoxysilane, N, N-bis(trimethylsilyl)aminoethyltrieth oxysilane, N, N-bis(trimethylsilyl)aminoethylmethyldimethoxysilane, and N, N-bis(trimethylsilyl)aminoethylmethyldiethoxysilane.

[0067] Still other specific examples of useful functionalizing agents include trialkyltin halides such as triisobutyltin chloride, as disclosed in U. S. Patent Nos.4,519,431; 4,540,744; 4,603,722; 5,248,722; 5,349,024; 5,502,129; and 5,877,336, which are incorporated herein by reference. Examples of useful halogenated organic compounds include cyclic amino compounds such as hexamethyleneimine alkyl chloride, as disclosed in U. S. Patent Nos.5,786,441; 5,916,976; and 5,552,473, which are incorporated herein by reference.P23038W001(P2089)Additional examples include cyclic sulfur-containing or oxygen containing azaheterocycles such as disclosed in WO 2004 / 020475; U. S. Publication No. 2006 / 0178467; and U. S. Patent No.6,596,798, which are incorporated herein by reference. Other examples include boron-containing terminators such as disclosed in U. S. Patent No. 7,598,322, which is incorporated herein by reference. Still other examples include cyclic siloxanes such as hexamethylcyclotrisiloxane, including those disclosed in U. S. Patent No. 9,920,149, which is incorporated herein by reference. Yet other examples include polydimethylsiloxanes.AMOUNT OF FUNCTIONALIZATION AGENT USED

[0068] The amount of functionalizing employed in the practice of the present invention can be described with respect to the lithium or metal cation associated with the initiator. In one or more embodiments, the amount of functionalizing agent introduced to the polymerization mixture is greater than 0.70, in other embodiments greater than 0.75, in other embodiments greater than 0.80, in other embodiments greater than 0.85, and in other embodiments greater than 0.90 moles of functionalizing agent per mole of lithium in the initiator. In these or other embodiments, less than 0.99, in other embodiments less than 0.97, and in other embodiments less than 0.95 moles of functionalizing agent per mole of lithium is introduced to the polymerization mixture. In one or more embodiments, from about 0.7 to about 1.0, in other embodiments from about 0.75 to about 0.99, and in other embodiments from about 0.80 to about 0.97 moles of functionalizing agent per mole of lithium is introduced to the polymerization mixture.POST FUNCTIONALIZATION POLYMER STABILIZATION

[0069] In one or more embodiments, following modification, the modified polymer (i.e. the telechelic polymer) may optionally be stabilized i.e. post-functionalization stabilized). That is, the modified polymer may be stabilized by introducing a stabilizing agent to the polymerization mixture including the modified polymer. It is believed that the stabilizing agent reacts with certain terminal functional groups (e.g. a hydrocarbyloxy substituent), and it is believed that this reaction may take place at the introduction of the two molecules or after aging of the composition.P23038W001(P2089)

[0070] In one or more embodiments, stabilizing agents known in the art may be used. For example, the stabilizing agents may include alkylalkoxy silanes as disclosed in U. S. Patent No. 6,255,404, which is incorporated herein by reference. Exemplary alkylalkoxy silanes include octyltriethoxy silane. In other embodiments, the stabilizing agent may include long-chain alcohols as disclosed in U. S. Patent No. 6,279,632, which is incorporated herein by reference. Exemplary long chain alcohols include sorbitan stearate or sorbitan monooleate. In still other embodiments, the polymers maybe stabilized by treatment with an alkylalkoxy silane followed by treatment with a silane including a hydrolyzable group that forms an acidic species upon hydrolysis, such as methyl trichlorosilane, as disclosed in U. S. Patent No.9,546,237, which is incorporated herein by reference.

[0071] In one or more embodiments of this invention, the use of aryl silanols (also known as hydroxy phenyl silanes) is advantageously used as a stabilizing agent. Useful aryl silanols are disclosed in U. S. Patent No. 9,255,167, which is incorporated herein by reference. Exemplary aryl silanols include, but are not limited to, triphenylsilanol, which is also referred to as hydroxytriphenylsilane, diphenylsilanediol, which is also referred to as dihydroxydiphenylsilane, and phenylsilanetriol, which is also referred to as trihydroxy(phenyl)silane.

[0072] In one or more embodiments, the functionalized polymers of this invention may be stabilized by treatment with an aryl silanol (e.g. aryl silane diol or aryl silane triol) contemporaneously or followed by treatment with a silane including a hydrolyzable group that forms an acidic species upon hydrolysis. Silanes including a hydrolyzable group that form an acidic species upon hydrolysis are disclosed in U. S. Patent No. 9,546,237, which is incorporated herein by reference. In particular embodiments, the functionalized polymers are treated with diphenyl silane diol and trimethyl silyl chloride.

[0073] In one or more embodiments, the stabilizing agent is added to the polymer cement after a sufficient time is provided to allow completion of the reaction between the reactive polymer and the functionalizing agent. In one or more embodiments, the stabilizing agent is introduced to the polymer cement after 30 minutes, in other embodiments after 15 minutes, and in other embodiments after 10 minutes from the time that the functionalizing agent is introduced to the polymer cement.P23038W001(P2089)

[0074] The amount of stabilizing agent (e.g. aryl silanol) employed in the practice of the present invention can be described with respect to the moles of lithium associated with the initiator. In one or more embodiments, greater than 0.5, in other embodiments greater than 1, in other embodiments greater than 2, and in other embodiments greater than 3 moles of stabilizing agent per mole of lithium in the initiator is introduced to the polymerization mixture. In these or other embodiments, less than 8, in other embodiments less than 7, in other embodiments less than 6, in other embodiments less than 5, and in other embodiments less than 4.5 moles of stabilizing agent per mole of lithium is introduced to the polymerization mixture. In one or more embodiments, from about 1 to about 7, in other embodiments from about 2 to about 6, and in other embodiments from about 3 to about 5 moles of stabilizing agent per mole of lithium is introduced to the polymerization mixture.

[0075] In other embodiments, the amount of stabilizing agent (e.g. aryl silanol) employed in the practice of the present invention can be described as a molar ratio relative to the moles of functionalizing agent employed. In one or more embodiments, the ratio of the moles of stabilizing agent to the moles of functionalizing agent employed is from about 0.5:1 to about 8:1; in other embodiments from about 1:1 to about 7:1, in other embodiment from about 2:1 to about 6:1, and in other embodiments from about 3:1 to about 5:1. In these or other embodiments, the ratio of the moles of stabilizing agent to the moles of functionalizing agent employed is less than 7:1, in other embodiments less than 6:1, in other embodiments less than 5.5:1, in other embodiments less than 5:1, and in other embodiments less than 4.5:1.

[0076] Where two reagents are employed, such as where the polymer is treated with an aryl silanol (e.g. aryl silane diol or aryl silane triol) together with a silane including a hydrolysable group that forms an acidic species upon hydrolysis (e.g. hydrocarbyl silyl chloride such as trimethyl silyl chloride), the amount of the respective reagents employed may be the same or different. In one or more embodiments, the total amount of stabilizer employed (i.e. both compounds) is, when described as a molar ratio relative to the moles of functionalizing agent, from about 3:1 to about 10:1, in other embodiments from about 4:1 to about 8:1, and in other embodiments from about 5:1 to about 7:1. In these or other embodiments, the molar ratio of the aryl silanol to the silane including a hydrolysable groupP23038W001(P2089)that forms an acidic species upon hydrolysis is from about 0.5:1 to about 4:1, in other embodiments from about 1:1 to about 3:1, and in other embodiments from about 1.5:1 to about 2.5:1.

[0077] In one or more embodiments, the stabilization of the polymer (i.e., introduction of the stabilizing agent) takes place within the same vessel in which the polymerization took place. In these embodiments, this will include the same vessel in which the modification took place. In other embodiments, stabilization of the polymer (i.e., introduction of the stabilizing agent) takes place outside of the vessel in which the polymerization took place. Likewise, in one or more embodiments, stabilization of the polymer takes place outside of the vessel in which the modification of the polymer took place. For example, in one or more embodiments, the stabilizing agent can be added to the polymerization mixture (i.e., polymer cement) in a vessel or transfer line that is downstream of the vessel in which the polymerization took place and that is downstream of the vessel in which the polymer modification took place. For purposes of this specification, relative to the polymerization vessel, the vessel or conduit in which the stabilizing agent is introduced may be referred to as a second vessel or second reaction zone. In other embodiments, the stabilizing agent may be introduced to the polymer while the polymer is suspended or dissolved within monomer. CONDENSATION ACCELERATOR

[0078] In one or more embodiments, after the introduction of the functionalizing agent to the reactive polymer, optionally after the addition of a quenching agent and / or antioxidant, optionally after or together with the stabilizing agent, and optionally after recovery or isolation of the functionalized polymer, a condensation accelerator can be added to the polymerization mixture. Useful condensation accelerators include tin and / or titanium carboxylates and tin and / or titanium alkoxides. One specific example is titanium 2-ethylhexyl oxide. Useful condensation catalysts and their use are disclosed in U. S. Publication No. 2005 / 0159554 (Patent No. US 7,683,151), which is incorporated herein by reference. In other embodiments, an organic acid can be used as a condensation accelerator. Useful types of organic acids include aliphatic, cycloaliphatic and aromatic monocarboxylic, dicarboxylic, tricarboxylic and tetracarboxylic acids. Specific examples of useful organicP23038W001(P2089)acids include, but are not limited to, acetic acid, propionic acid, butyric acid, hexanoic acid, 2-methylhexanoic acid, 2-ethylhexanoic acid, cyclohexanoic acid and benzoic acid.

[0079] The amount of condensation accelerator employed in the practice of the present invention can be described with respect to the moles of lithium associated with the initiator. In one or more embodiments, the moles of condensation accelerator per mole of lithium is greater than 1.0, in other embodiments greater than 1.5, and in other embodiments greater than 1.8 moles of condensation accelerator per mole of lithium in the initiator. In these or other embodiments, less than 4.0, in other embodiments less than 3.3, and in other embodiments less than 3.0 moles of condensation accelerator per mole of lithium is introduced to the polymerization mixture. In one or more embodiments, from about 1.0 to about 4.0, in other embodiments from about 1.5 to about 3.3, and in other embodiments from about 1.8 to about 3.0 moles of condensation accelerator per mole of lithium is introduced to the polymerization mixture.ANTIOXIDANT

[0080] In one or more embodiments, after the introduction of the functionalizing agent to the reactive polymer, optionally after the addition of a quenching agent and / or antioxidant, optionally after or together with the stabilizing agent, and optionally after recovery or isolation of the functionalized polymer, an antioxidant can be added to the polymerization mixture. Exemplary antioxidants include 2,6-di-tert-butyl-4-methylphenol.

[0081] In one or more embodiments, after formation of the polymer, a processing aid and other optional additives such as oil can be added to the polymer cement. OPTIONAL QUENCHING

[0082] In one or more embodiments, after the polymerization reaction, or after the reaction between the reactive polymer and the functionalizing agent has been accomplished or completed, a quenching agent can be added to the polymerization mixture in order to inactivate any residual reactive polymer chains and the catalyst or catalyst components. The quenching agent may include a protic compound, which includes, but is not limited to, an alcohol, a carboxylic acid, an inorganic acid, water, or a mixture thereof. The amount of quenching agent employed may be in the range of 0.5 to 10 moles of quenching agent per mole of lithium used to initiate the polymerization.P23038W001(P2089)POLYMER DESOLVENTIZATION

[0083] Following polymerization and / or polymer modification, optional stabilization, optional introduction of a condensation accelerator and / or introduction of an antioxidant, the polymer product can be separated from the solvent, which may be referred to as desolventization. In other words, as described above, the polymers are synthesized in an organic solvent, and during the step of desolventization, the organic solvent is separated from the resulting polymer.

[0084] In particular embodiments, desolventization includes hot water and / or steam coagulation. For example, the polymerization mixture, which includes the blend of modified polymers, can be combined with a steam or hot water stream. The heat associated with the steam or hot water stream volatilizes the solvent and any unreacted monomer. The polymer product is then dispersed within an aqueous phase in, for example, the form of polymer crumb. The nature and size of the polymer crumb can generally be manipulated by the introduction of mechanical energy (e.g., in the form of mixers).

[0085] In one or more embodiments, the polymer crumb is temporarily stored as a crumb dispersion within the water until subsequent drying steps, which are described below. The crumb dispersion is generally a mixture of polymer particles or crumb and water. The polymer particles, which may also be referred to as coagulated polymer, are generally on the macroscale and have at least one dimension that is greater than one mm. This crumb dispersion may be contained within a tank, such as a conventional reactor tank such as a continuously stirred tank reactor.

[0086] In one or more embodiments, the polymer crumb can be further processed to remove residual solvent and dry the polymer (i.e., separate the polymer from the water). In practicing the present invention, the polymer can be dried by using conventional techniques, which may include one or more of filtering, pressing, and heating. Following desolventization and drying, the volatile content of the dried polymer can be below 2.0%, in other embodiments below 1.0%, and in other embodiments below 0.5% by weight of the polymer.

[0087] In other embodiments, the polymer product can be desolventized by employing devolatilizers, which are extruder-type devices that can operate in conjunction with heat and / or vacuum. In yet other embodiments, the polymerization mixture can be directly drum dried.P23038W001(P2089)

[0088] Regardless of the methods used to desolventize and dry the polymer, the finished polymer product may be referred to as a dried polymer. Using conventional techniques, the dried polymer can be molded or otherwise manipulated into a bale. CHARACTERISTICS OF TELECHELIC POLYMER

[0089] According to one or more embodiments, as a result of the functionalization reaction, greater than 60 mol %, in other embodiments greater than 70 mol %, in other embodiments greater than 80 mol %, in other embodiments greater than 85 mol %, in other embodiments greater than 90 mol %, and in other embodiments greater than 95 mol % of the polymer chains within the polymer cement include a terminal functional group (i.e. the residue of a functionalizing agent). In one or more embodiments, from about 60 to about 100 mol %, in other embodiments from about 70 to about 99 mol %, in other embodiments from about 80 to about 98 mol %, and in other embodiments from about 90 to about 97 mol % of the polymer chains within the polymer composition include the terminal functional group.

[0090] According to one or more embodiments, as a result of the functionalization reaction, greater than 60 mol %, in other embodiments greater than 70 mol %, in other embodiments greater than 80 mol %, and in other embodiments greater than 90 mol % of the polymer chains within the polymer cement include terminal functional groups at both ends of the polymer (i.e. are telechelic polymers).COMBINING TELECHELIC POLYMER AND STRONG BASE

[0091] As indicated above, a strong base is introduced to the telechelic polymer. In one or more embodiments, the strong base is introduced to the telechelic polymer while the telechelic polymer is in solution (i.e. it is added to a polymer cement). This may include the polymer cement, which may also be referred to as a polymerization mixture, that directly results from the synthesis of the telechelic polymer. In other embodiments, the telechelic polymer maybe dissolved, or partially dissolved, in a solvent to form a cement that is distinct from the polymerization mixture in which it was synthesized, and then the strong base can be added to the cement that is formed. In one or more embodiments, the polymer cement may include from about 10 to about 40% solids.

[0092] In those embodiments where the polymer cement derives from the synthesis of the polymer, the strong base is added to the polymer cement after the polymerizationP23038W001(P2089)mixture has been quenched. In one or more embodiments, an antioxidant is introduced to the polymerization mixture after quenching, and the strong base can be added before introducing the antioxidant, in conjunction with the antioxidant, or after introducing the antioxidant. In one or more embodiments, an extender oil is introduced to the polymerization mixture after quenching, and the strong base can be added before introducing the extender oil, in conjunction with the extender oil, or after introducing the extender oil.

[0093] After introducing the strong base to the polymer cement, the polymer, and at least a portion of the strong base, is isolated from the solvent (i.e. the polymer cement is desolventized). The skilled person appreciates that several methods can be used to desolventize a polymer cement. These methods may include, but are not limited to, those described above with reference to polymer synthesis.

[0094] In one or more embodiments, the polymer cement including the strong base (e.g., polymerization mixture following addition of the strong base) is optionally aged in solution (i.e., prior to desolventization). In one or more embodiments, the polymerization mixture may undergo mixing or other agitation during the aging process. In one or more embodiments, aging of this mixture takes place at a temperature of from about 10 to about 80 °C, in other embodiments from about 12 to about 65 °C, and in other embodiments from about 15 to about 45 °C. In one or more embodiments, aging may take place for a time of from about 1 hour to about 100, or in other embodiments from about 2 to about 48 hours. In one or more embodiments, aging takes place for greater than 3 hours, in other embodiments greater than 5 hours, and in other embodiments greater than 10 hours. Aging can also take place after desolventization. This post desolventization aging can take place at higher temperatures, such as those described below relative to solid state aging.

[0095] In other embodiments, the strong base is introduced to the telechelic polymer while the telechelic polymer in the solid state, which may be referred to as dry mixing. In other words, the strong base is introduced to the telechelic polymer in the absence or substantial absence of solvent, which refers to that amount of solvent or less than would otherwise have an appreciable impact on the mixing. In one or more embodiments, the telechelic polymer undergoes solid-state mixing during and / or after introduction of theP23038W001(P2089)strong base. The skilled person will understand that several techniques are available for mixing the telechelic polymer and the strong base. For example, mixing can take place within an internal mixer, such as those internal mixers that are employed to mix rubber formulations for the production of rubber for tire components. Useful mixing devices include, but are not limited to Banbury mixers, Brabender mixers, intermesh mixers including tandem intermesh mixers, extruders, kneaders, and two-roll mills.

[0096] In one or more embodiments, the introduction and mixing (either solid state mixing or solution mixing) of the telechelic polymer and strong base takes place in the absence of threshold amounts of silica, which mixing step may be referred to as premasterbatch mixing. In one or more embodiments, the introduction and mixing of telechelic polymer and strong base takes place in the presence of less than 10 parts by weight, in other embodiments less than 5 parts by weight, in other embodiments less than 3 parts by weight, in other embodiments less than 1 part by weight silica. In one or more embodiments, the introduction and mixing of the telechelic polymer and strong base takes place in the substantial absence of silica, which represents that amount or less of silica that would otherwise have an appreciable impact on the introduction and mixing of the telechelic polymer and strong base. In other embodiments, the introduction and mixing of the telechelic polymer and strong base takes place in the absence silica.

[0097] In one or more embodiments, the solid-state mixture of the telechelic polymer and the strong base are aged, optionally at an elevated temperature. In one or more embodiments, aging may take place for a time of from about 1 hour to about 100, or in other embodiments from about 2 to about 48 hours. In one or more embodiments, aging of the solid-state mixture takes place for greater than 3 hours, in other embodiments greater than 5 hours, and in other embodiments greater than 10 hours. In one or more embodiments, aging takes place at a temperature of from about 40 to about 145 °C, in other embodiments from about 70 to about 140 °C, in other embodiments from about 100 to about 140 °C, and in other embodiments from about 125 to about 135 °C.

[0098] In one or more embodiments, the telechelic polymer and strong base are heated during introduction and mixing and / or during aging of the solid-state mixture. In one or more embodiments, the mixture (i.e., mixture of polymer and strong base) is heated to aP23038W001(P2089)compositional temperature of greater than 40 °C, in other embodiments greater than 60 °C, in other embodiments greater than 80 °C, in other embodiments greater than 100 °C, in other embodiments greater than 120 °C, in other embodiments greater than 130°C , and in other embodiments greater than 135 °C. In one or more embodiments, the temperature of the telechelic polymer and the strong base (i.e. the pre-masterbatch), either during introduction and mixing, or during aging following introduction and mixing, is maintained at a temperature (i.e. the temperature of the mixture) of less than 145 °C, in other embodiments less than 130 °C, and in other embodiments less than 115 °C.STRONG BASES

[0099] In one or more embodiments, the strong bases that are useful in the practice of this invention are characterized by a pKa in water of greater than 14, in other embodiments greater than 15, in other embodiments greater than 16, in other embodiments greater than 18, in other embodiments greater than 20, in other embodiments greater than 22, in other embodiments greater than 24, in other embodiments greater than 26, and in other embodiments greater than 28. In these or other embodiments, the strong bases that are useful in the practice of this invention are characterized by a pKa in water of less than 50, in other embodiments less than 48, in other embodiments less than 46, in other embodiments less than 44, in other embodiments less than 42, in other embodiments less than 40, in other embodiments less than 38, in other embodiments less than 36, and in other embodiments less than 35. In one or more embodiments, the strong bases that are useful in the practice of this invention are characterized by a pKa in water of from about 14 to about 50, in other embodiments from about 16 to about 48, in other embodiments from about 18 to about 46, in other embodiments from about 20 to about 44, and in other embodiments from about 22 to about 35.

[0100] In one or more embodiments, the strong bases that are useful in the practice of this invention are characterized by a pKa in DMSO of greater than 14, in other embodiments greater than 15, in other embodiments greater than 16, in other embodiments greater than 18, in other embodiments greater than 20, in other embodiments greater than 22, in other embodiments greater than 24, in other embodiments greater than 26, and in other embodiments greater than 28. In these or other embodiments, the strong bases that areP23038W001(P2089)useful in the practice of this invention are characterized by a pKa in DMSO of less than 50, in other embodiments less than 48, in other embodiments less than 46, in other embodiments less than 44, in other embodiments less than 42, in other embodiments less than 40, in other embodiments less than 38, in other embodiments less than 36, and in other embodiments less than 35. In one or more embodiments, the strong bases that are useful in the practice of this invention are characterized by a pKa in DMSO of from about 14 to about 50, in other embodiments from about 16 to about 48, in other embodiments from about 18 to about 46, in other embodiments from about 20 to about 44, and in other embodiments from about 22 to about 35.

[0101] In one or more embodiments, the strong bases that are useful in the practice of this invention are characterized by their ability to dissolve in alkanes or alcohols at standard conditions of temperature and pressure. In one or more embodiments, the ability to dissolve refers to the complete dissolution without the presence of visible (with naked eye) solid particles in the solvent. In particular embodiments, the strong based used in the present invention are soluble in technical hexanes.

[0102] In one or more embodiments, strong bases that are useful in the practice of this invention are nitrogen-containing compounds. Exemplary nitrogen-containing compounds include amides, diazines, diazoles, azoles, purines, amidines, histidines, and guanidines and derivatives of these compounds. Acyclic and cyclic derivatives of these compounds may be used. Useful cyclic compounds may include monocyclic, bicyclic, and tricyclic compounds. Useful cyclic derivatives of these compounds may include nitrogen-containing heterocycles. Useful cyclic derivates may also include aromatic and non-aromatic compounds.

[0103] Exemplary diazoles include imidazoles. Exemplary diazines include pyrimidines. Exemplary azoles include thiazoles and thiazolines. Exemplary purines include adenines. A specific example of a useful guanidine is 1,1,3,3-tetramethylguanidine. A specific example of a useful bicyclic guanidine is 1,5,7-triazabicyclo[4.4.0]dec-5-ene.

[0104] In one or more embodiments, the strong bases that are useful in the practice of the present invention include alkali metal alkoxy salts and alkaline earth metal alkoxy salts. As the skilled person appreciates, alkali metals include, but are not limited to, lithium, sodium, and potassium. The skilled person also appreciates that alkaline earth metalsP23038W001(P2089)include, but are not limited to, calcium, magnesium, and strontium. The alkoxy ligands may include, for example, methoxy, ethoxy (e.g. calcium ethoxide), n-propoxy, isopropoxy, n-butoxy, t-butoxy, neo-pentoxy, n-pentoxy, n-hexoxy, and 2-ethyl-hexoxy groups, dodecoxy. Specific useful examples of alkali metal alkoxy salts include potassium methoxide and lithium isopropoxide.

[0105] In one or more embodiments, the strong bases that are useful in the practice of the present invention include alkali metal amide salts and alkaline earth metal amide salts. The amide ligands may include, for example, dialkyl amides, and alkyl silyl amides. Specific useful examples of alkali metal amide salts include lithium diisopropyl amide and lithium bis trimethylsilyl amide.

[0106] Useful strong bases are also disclosed in U. S. Publ. No. 2010 / 0216910, which is incorporated herein by reference.LOADING OF STRONG BASE

[0107] In one or more embodiments, the amount of strong base introduced to the telechelic polymer can be described with respect to the moles of end groups associated with the polymer. Since the living polymer giving rise to telechelic polymer includes two lithium atoms associated with each di-living chain, the loading of strong base can be represented as a molar ratio relative to the moles of lithium used to initiate the polymer.

[0108] In one or more embodiments, the amount of strong base introduced to the telechelic polymer can be represented as a molar ratio of strong base (i.e. moles of strong base) to lithium used to initiate the polymer (i.e. moles of lithium used at initiation). In one or more embodiments, the molar ratio of strong base to lithium is greater than 0.1:1, in other embodiments greater than 0.5:1, in other embodiments greater than 1:1, in other embodiments greater than 2:1, in other embodiments greater than 3:1, in other embodiments greater than 5:1, and in other embodiments greater 7:1. In these or other embodiments, the molar ratio of strong base to lithium is less than 12:1, in other embodiments less than 10:1, in other embodiments less than 7:1, in other embodiments less than 5:1, in other embodiments less than 3:1, and in other embodiments less than 2:1. In one or more embodiments, the molar ratio of strong base to lithium is from about 0.1:1 toP23038W001(P2089)about 10:1, in other embodiments from about 0.5:1 to about 8:1, in other embodiments from about 0.7 to about 5:1, and in other embodiments from about 1:1 to about 3:1. CHARACTERISTIC OF TELECHELIC POLYMERS TREATED WITH STRONG BASE

[0109] In one or more embodiments, the solid blend of the telechelic polymer and the strong base (e.g. in a bale) has a Mooney viscosity (ML 1+4 @ 100 °C) that is less than 70%, in other embodiments less than 60%, in other embodiments less than 50%, and in other embodiments less than 40% of the Mooney viscosity of the telechelic polymer in the absence of the strong base.

[0110] In one or more embodiments, the blend of the telechelic polymer and the strong base has a Mooney viscosity (ML 1+4 @ 100 °C) that is less than 100, in other embodiments less than 90, in other embodiments less than 80, and in other embodiments less than 70. INDUSTRIAL APPLICABILITY

[0111] In one or more embodiments, the blend ofthe telechelic polymers and the strong base may be used in formulating vulcanizable rubber composition that may, for example, be useful in the preparation of tire components. Rubber compounding techniques and the additives employed therein are generally disclosed in The Compounding and Vulcanization of Rubber, in Rubber Technology (2ndEd. 1973).

[0112] Generally speaking, these vulcanizable rubber compositions include a vulcanizable rubber component, reinforcing filler, and a curative or curative system. These compositions may also optionally include metal activators, resins, and processing oils, as well the various ingredients that may be conventionally included in these vulcanizable rubber compositions.

[0113] In one or more embodiments, the telechelic polymers that are combined with the strong base may form part of the rubber component of the vulcanizable compositions. That is, the rubber component may include other vulcanizable rubbers, which may also be referred to as elastomeric polymers or simply elastomers.

[0114] The rubber compositions can be prepared by using the telechelic polymers of this invention together with other elastomers (i.e., polymers that can be vulcanized to form compositions possessing rubbery or elastomeric properties). Other elastomers that may be used include natural and synthetic rubbers. The synthetic rubbers typically derive from theP23038W001(P2089)polymerization of conjugated diene monomers, the copolymerization of conjugated diene monomers with other monomers such as vinyl-substituted aromatic monomers, or the copolymerization of ethylene with one or more α-olefins and optionally one or more diene monomers.

[0115] Exemplary synthetic rubbers, 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. 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.

[0116] Generally, the rubber compositions of this invention include from about 30 to about 65, in other embodiments from about 35 to about 60, and in other embodiments from about 40 to about 55 weight percent rubber (i.e. the rubber component), based on the total weight of the tire component, of rubber.

[0117] In one or more embodiments, the rubber component of the rubber compositions of this invention include from about 1 to about 50 wt %, in other embodiments from about 10 to about 30 wt %, and in other embodiments from about 15 to about 20 wt % of the low-molecular weight telechelic copolymers produced by the techniques of this invention.

[0118] As indicated above, the rubber compositions may include fillers such as inorganic and organic fillers. Examples of organic fillers include carbon black and starch. Examples of inorganic fillers include silica, aluminum hydroxide, magnesium hydroxide, mica, talc (hydrated magnesium silicate), and clays (hydrated aluminum silicates). Carbon blacks and silicas are the most common fillers used in manufacturing tires. In certain embodiments, a mixture of different fillers may be advantageously employed.

[0119] The amount of total filler employed in the rubber compositions can be up to about 150 parts by weight per 100 parts by weight of rubber (phr), with about 5 to aboutP23038W001(P2089)125 phr, or about 30 to about 110 phr, being typical. In certain embodiments the total filler content is greater than about 100 phr. In other embodiments, the total filler content is from about 50 to about 100 phr, and in in further embodiments from about 55 to about 95 phr.

[0120] 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.

[0121] 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.

[0122] In one or more embodiments, the amount of carbon black employed in the rubber compositions can be up to about 75 parts by weight per 100 parts by weight of rubber (phr), with about 5 to about 6 parts by weight phr, or about 10 to about 55 parts by weight phr, being used in exemplary embodiments.

[0123] 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 150 to about 220 m2 / g. In one or more embodiments, the silica may be characterized by a pH of from about 5 to about 7 or slightly over 7, or in other embodiments from about 5.5 to about 6.8.

[0124] In certain embodiments, the silica employed in the rubber composition is derived from rice husk ash only, and in other embodiments the rubber compositions do not include silica from non-rice husk ash derived processes.P23038W001(P2089)

[0125] Some commercially available silicas which may be used 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, NJ], Rhodia Silica Systems (Cranbury, NJ], and J. M. Huber Corp. (Edison, NJ].

[0126] In one or more embodiments, the rubber compositions may include from about 1 to about 150, in other embodiments from about 5 to about 140, and in other embodiments from about 10 to about 130 parts by weight silica per 100 parts by weight rubber. In particular embodiments, the present invention includes rubber compositions with high silica loadings, such as loadings greater than 70, in other embodiments greater than 90, and in other embodiments greater than 110 parts by weight silica per 100 parts by weight rubber, with the useful upper end being limited by the high viscosity imparted by silica. When silica is used together with carbon black, the amount of the silica or carbon black can be can be as low as about 1 phr. In one or more embodiments, where carbon black and silica are employed in combination as a filler, the weight ratio of silica to total filler may be from about 5% to about 99% of the total filler, or in other embodiments from about 10% to about 90% of the total filler, or in yet other embodiments from about 50% to about 85% of the total filler.

[0127] In one or more embodiments, where silica is employed as a filler (alone or in combination with other fillers], a coupling agent may be added to the rubber compositions during mixing in order to enhance the interaction of silica with the elastomers. Useful coupling 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.

[0128] In one or more embodiments, the amount of coupling agent may be from about 2 to about 30 wt %, in other embodiments from about 4 to about 25 wt %, and in other embodiments from about 6 to about 20 wt % based on the weight of silica within the composition.

[0129] In one or more embodiments, where silica is employed as a filler (either alone or in combination with other fillers], a silica dispersing agent, which may include silicaP23038W001(P2089)shielding agents, may be included in the rubber formulations. The use of one or more silica dispersing agents has been found to be particularly useful in practicing the present invention in view of the telechelic polymers and / or high silica loadings. In one or more embodiments, useful silica dispersing agents include alkyl alkoxysilanes, fatty acid esters of hydrogenated or non-hydrogenated C5 or C6sugars, polyoxyethylene derivatives of fatty acid esters of hydrogenated or non-hydrogenated C5 or C6sugars, and esters of polyols, including glycols and polyhydroxy compounds, and mixtures thereof. In particular embodiments, the silica dispersing agent is glycol monostearate. Useful silane dispersing agents are disclosed in U. S. Patent Nos. 6,608,145, 7,799,870, 7,897,661, 8,962,746, 9,758,639, 9,951,208, and U. S. Publication Nos.2004 / 0152811, and 2005 / 0070672, which are incorporated herein by reference.

[0130] In other embodiments, useful silica dispersing agents include metal glycerolates such as zinc glycerolate, calcium glycerolate, and magnesium glycerolate. These compounds are described in greater detail in U. S. Patent Nos. 10,087,306 and 11,220,595, and U. S. Publication No. 2021 / 0388188, which are incorporated herein by reference.

[0131] In one or more embodiments, the rubber compositions of the invention may include from about 0.1 to about 30 wt %, in other embodiments from about 1.0 to about 25 wt %, in other embodiments from about 3.0 to about 20 wt %, and in other embodiments from about 4.0 to about 10 wt % silica dispersing agent based on the weight of the silica within the composition. In one or more embodiments, the rubber compositions include greater than 3 wt %, in other embodiments greater than 5 wt %, and in other embodiments greater than 7 wt % dispersing agent based upon the weight of the silica. In these or other embodiments, the rubber compositions may include greater than 3 parts by weight, in other embodiments greater than 4 parts by weight, in other embodiments greater than 5 parts by weight, and in other embodiments greater than 6 parts by weight silica dispersing agent per 100 parts by weight rubber.

[0132] A multitude of rubber curing agents (also called vulcanizing agents) may be employed, including sulfur or peroxide-based curing systems. Curing agents are described in Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 20, pgs. 365-468, (3rdEd.P23038W001(P2089)1982), particularly Vulcanization Agents and Auxiliary Materials, pgs. 390-402, and A. Y. Coran, Vulcanization, Encyclopedia of Polymer Science and Engineering, (2ndEd. 1989), which are incorporated herein by reference. Vulcanizing agents may be used alone or in combination.

[0133] Other ingredients that are typically employed in rubber compounding may also be added to the rubber compositions. These include 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. In particular embodiments, the oils that are employed include those conventionally used as extender oils, which are described above. 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.

[0134] All ingredients of the rubber compositions can be mixed with standard mixing equipment such as, but not limited to, Banbury mixers, Brabender mixers, intermesh mixers including tandem intermesh mixers, extruders, kneaders, and two-roll mills. In one or more embodiments, the ingredients are mixed in two or more stages. In the first stage (often referred to as the masterbatch mixing stage), a so-called masterbatch, which typically includes the rubber component and filler, is prepared. To prevent premature vulcanization (also known as scorch), the masterbatch may exclude vulcanizing agents. The masterbatch may be mixed at a starting temperature of from about 25 °C to about 125 °C with a discharge temperature of about 135 °C to about 180 °C. Once the masterbatch is prepared, the vulcanizing agents may be introduced and mixed into the masterbatch in a final mixing stage, which is typically conducted at relatively low temperatures so as to reduce the chances of premature vulcanization. Optionally, additional mixing stages, sometimes called remills, can be employed between the masterbatch mixing stage and the final mixing stage. One or more remill stages are often employed where the rubber composition includes silica as the filler. Various ingredients including the polymers of this invention can be added during these remills.P23038W001(P2089)

[0135] The mixing procedures and conditions particularly applicable to silica-filled tire formulations are described in U. S. Patent Nos. 5,227,425; 5,719,207; and 5,717,022, as well as European Patent No. 890,606, all of which are incorporated herein by reference. In one embodiment, the initial masterbatch is prepared by including the polymer and silica in the substantial absence of coupling agents and shielding agents.

[0136] The rubber compositions prepared from the polymers of this invention are particularly useful for forming tire components such as treads, subtreads, sidewalls, body ply skims, bead filler, and the like. In one or more embodiments, these tread or sidewall formulations may include from about 10% to about 100% by weight, in other embodiments from about 35% to about 90% by weight, and in other embodiments from about 50% to about 80% by weight of the polymer of this invention based on the total weight of the rubber within the formulation.

[0137] Where the rubber compositions are employed in the manufacture of tires, these compositions can be processed into tire components according to ordinary tire manufacturing techniques including standard rubber shaping, molding and curing techniques. Typically, vulcanization is effected by heating the vulcanizable composition in a mold; e.g., it may be heated to about 140 °C to about 180 °C. Cured or crosslinked rubber compositions maybe referred to as vulcanizates, which generally contain three-dimensional polymeric networks that are thermoset. The other ingredients, such as fillers and processing aids, may be evenly dispersed throughout the crosslinked network. Pneumatic tires can be made as discussed in U. S. Patent Nos. 5,866,171; 5,876,527; 5,931,211; and 5,971,046, which are incorporated herein by reference.EXAMPLES

[0138] In order to demonstrate the practice of the present invention, the following examples have been prepared and tested. The examples should not, however, be viewed as limiting the scope of the invention. The claims will serve to define the invention.P23038W001(P2089)SAMPLES 1-9SYNTHESIS OF DIFUNCTIONAL INITIATOR

[0139] To a nitrogen-purged 187 mL glass bottle were added 1,3-diisopropenyl benzene (0.97 mL, 0.8924 g), sec-BuLi solution (7.51 mL], and triethylamine (0.79 mL, 0.5688 g). The bottle was placed into a heated water bath held at 50 °C and agitated for 30 minutes. After 30 minutes, 50 mL of anhydrous hexanes was added to the bottle to complete the initiator solution.SYNTHESIS OF DIFUNCTIONAL POLYMER

[0140] To a 5-gallon nitrogen-purged reactor equipped with turbine agitator blades were added 1.31 kg of hexane, 0.21 kg of 32.5 wt % styrene in hexane, and 2.92 kg of 21.0 wt % 1,3-butadiene in hexane. Next, 1.70 mL 1.6 M 2,2-Di(2-tetrahydrofuryl) propane diluted in 50 mL hexane was added to the reactor, followed by the addition of the difunctional initiator prepared above. The reactor jacket temperature was then set to 62.8 °C. The polymerization had an exotherm of 96.6 °C after 25 minutes of polymerization. GPC showed the difunctional base polymer to have an Mn of about 205 kg / mol using polystyrene standards adjust with Mark Houwink constants.

[0141] After 30 minutes of polymerization time, 4.00 mL 3-(diethoxymethylsilyl)-N-(1,3-dimethylbutylidene)-1-propanamine (neat 3.12 M, 1.1:1 to s-BuLi), diluted with approximately 50 mL of hexane was added to the reactor. After an additional 30 minutes (60 minutes total), the resulting polymer cement was then transferred into ten 750 mL champagne bottles, each containing 3 mL of isopropanol containing antioxidant (1.8 g / L 2,5-di-tert-butyl-4-methylphenol) (BHT). The polymer cement was then steam desolventized in a hot water bath held at 80 °C by a steam source, agitated by a blade-type stirrer, and using Polycoat (~18 mg / mL polymer cement) to coagulate the polymer sample. The collected polymer was massaged to remove excess water and then oven dried at 70 °C for 16 hours. DRY MILLING OF ORGANIC BASE COMPOUNDS INTO DRIED POLYMER

[0142] The dried polymer was divided into nine samples and 1,5,7-triazabicyclo[4.4.0]dec-5-ene [TBD], which has a pKa of 15 in water, or diphenylguanidine [DPG], which has a pKa of 10 in water, as added to the sample as identified in Table 1. The addition and mixing of the TBD or DPG into the polymer samples took place on an open two-P23038W001(P2089)roll mixing mill with a friction ratio of 1:1.25 operating at 60 °C. A total of 15 passes through the mill were completed, with the polymer being folded and turned 90° prior to feeding back through the mill rollers to ensure even distribution of the organic base within the polymer matrix. The polymer samples were analyzed for Mooney Viscosity (at 100 °C and 130 °C) and T80. The loading of the TBD or DPG, as well as the results of the testing are summarized in Table I.Table ISample 1 2 3 4 5 6 7 8 9 Base — TBD DPG — TBD TBD TBD TBD TBD Loading(Moles Base / Moles LI) — 5 5 — 1 2.5 5 1 5 ML(1+4)@100°C 166.51 73.42 164.27 169.16 139.52 126.67 59.7 — — ML(1+4)@130°C — — — — — — — 67.89 60.82 T80 (sec) 748.16 303.16 567.00 — — — — — —

[0143] The data in Table I indicates that the strength of the base impacts its ability to stabilize the telechelic polymer compositions from excessive hydrolysis and its corresponding deleterious Mooney growth. This is demonstrated by the reduction in viscosity compared to the control polymer, which is evident when comparing Samples 2 and 3 relative to Sample 1. Sample 2 and 3 each employed 5 mol % base (TBD and DPG, respectively), and TBD lowered the Mooney Viscosity significantly at 100 °C while DPG had negligible impact. The data also shows the impact of temperature. In this respect, a comparison of Samples 5 and 8 is useful. At 1 mol % loading TBD, Mooney Viscosity at 130 °C in Sample 8 was significantly lower than Mooney Viscosity at 100 °C in Sample 5 at the same loading of base.SAMPLES 10-13SYNTHESIS OF DIFUNCTIONAL INITIATOR

[0144] To a nitrogen-purged 187 ml glass bottle were added 1,3-diisopropenyl benzene (1.94 mL, 1.79 g), sec-BuLi solution (15.02 mL), and triethylamine (1.58 mL, 1.14 g). The bottle was placed into a heated water bath held at 50 °C and agitated for 30 minutes.P23038W001(P2089)After 30 minutes, 50 mL of anhydrous hexanes was added to the bottle to complete the initiator solution.SYNTHESIS OF DIFUNCTIONAL POLYMER AND ADDITION OF BASE TO CEMENT

[0145] To a 5-gallon nitrogen-purged reactor equipped with turbine agitator blades were added 1.27 kg of hexane, 0.21 kg of 32.5 wt % styrene in hexane, and 2.96 kg of 21.0 wt % 1,3-butadiene in hexane. Next, 3.40 mL 1.6 M 2,2-di(2-tetrahydrofuryl) propane diluted in 50 mL hexane was added to the reactor, followed by the addition of the difunctional initiator solution. The reactor jacket temperature was then set to 62.8 °C. The polymerization had an exotherm of 95 °C after 19 minutes of polymerization. GPC showed the difunctional base polymer to have an Mn of about 102 kg / mol using polystyrene standards adjust with Mark Houwink constants.

[0146] After 24 minutes of polymerization time, 4.00 mL 3-(diethoxymethylsilyl)-N-(1,3-dimethylbutylidene)-1-propanamine (neat 3.12 M, 1.1:1 to s-BuLi), diluted with approximately 50 mL of hexane was added to the reactor.

[0147] After an additional 30 minutes (55 minutes total), the resulting polymer cement was then transferred into ten 750 mL champagne bottles, each containing 3 mL of isopropanol containing antioxidant (1.8 g / L 2,5-di-tert-butyl-4-methylphenol).

[0148] A pre-determined concentration of organic base was dissolved in an alkane / alcohol mixture (hexane isomers / isopropanol, 10:1 v:v) to ensure solubility of the base and miscibility with the polymer cement solution. The bases included 1,5,7-triazabicyclo [4.4.0] dec-5-ene [TBD], which has a pKa of about 15, and potassium methoxide [KOCH3], which has a pKa of about 15. The solution of one of the respective bases was then injected into each of the bottles of polymer cement as provided in Table II. The bottles were loaded into a carousel of a rotating water bath held at 50 °C and aged for 4 hours to allow for reaction to occur.

[0149] The polymer cement was then steam desolventized in a hot water bath held at 80 °C by a steam source, agitated by a blade-type stirrer, and using Polycoat [a coagulation additive] (~18 mg / mL polymer cement) to coagulate the polymer sample. The collected polymer was massaged to remove excess water and then oven dried at 70 °C for 16 hours.P23038W001(P2089)The dried polymer samples were subjected to Mooney Viscosity testing at 100 °C, and the results of the testing are reported in Table II.Table IISample 10 11 12 13Base — TBD TBD KOCH3 Loading(Moles Base / Moles Li) — 4.31 4.31 8.56 ML(1+4)@100°C 194.08 97.54 99.3 86.6

[0150] The data in Table II shows the strong base added to a polymer solution that then undergoes steam desolventization likewise stabilizes a telechelic polymer as indicated by a marked reduction in Mooney Viscosity. And, the potassium salt performs on par with an organic-based TBD in organic solution.

[0151] The microstructure content of the polymers was determined by 400 MHz NMR using CDCl3as the solvent. Polymer Mooney viscosities were determined using a Monsanto Mooney viscometer. The ML(1+4)values were measured on a large rotor at 100 °C for 4 mins with a 1 min warm up time. The number average [Mn] molecular weight, weight average [Mwj molecular weight, and polydispersity [PDI] were determined by gel permeation chromatography (GPC) using a TOSOH Ecosec HLC-8320 GPC system and TOSOH TSKgel GMHxl-BS columns with THF as a solvent. The system was calibrated using polystyrene [PS] standards and referenced to PS standards. Molecular weights were corrected to SBR values by re-calculating the GPC styrene-butadiene calibration curve using polystyrene standards that were adjusted for the Mark-Houwink relationship.

[0152] Various modifications and alterations that do not depart from the scope and spirit of this invention will become apparent to those skilled in the art. This invention is not to be duly limited to the illustrative embodiments set forth herein.

Claims

1. P23038W001(P2089)CLAIMSWhat is claimed is:

1. A method for treating a telechelic polymer, the method comprising:(i) providing a telechelic polymer; and(ii) introducing a strong base to the telechelic polymer to thereby form a mixture.

2. The method of claim 1, where said providing includes providing the telechelic polymer within a solution in which the telechelic is at least partially dissolved in a solvent, and where said introducing a strong base forms a solution mixture.

3. The method of any of the preceding claims, further comprising the step of isolating the telechelic polymer and at least a portion of the strong base from the solvent.

4. The method of any of the preceding claims, further comprising the step of aging the solution mixture prior to isolating the telechelic polymer and at least a portion of the strong base from the solvent.

5. The method of any of the preceding claims, where said providing includes providing a telechelic polymer in the form of a solid, and where said introducing a strong base forms a solid state mixture.

6. The method of any of the preceding claims, where said solid state mixture includes less than 10 parts by weight silica.

7. The method of any of the preceding claims, where said introducing includes introducing a molar ratio of strong base to functional chain ends of from about 0.1:1 to about 12:1.P23038W001(P2089)8. The method of any of the preceding claims, where said strong base has a pKa of greater than 14.

9. The method of any of the preceding claims, where said strong base is selected from the group consisting of amides, diazines, diazoles, azoles, purines, amidines, histidines, and guanidines and derivatives of these compounds.

10. The method of any of the preceding claims, where said strong base is a metal alkoxide.

11. The method of any of the preceding claims, where said strong base is a metal amide.

12. The method of any of the preceding claims, where the mixture is heated to a temperature of greater than 100 °C.

13. The method of any of the preceding claims, where the mixture is aged for greater than 3 hours.

14. A vulcanizate prepared by vulcanizing the vulcanizable composition of matter of any of the preceding claims.

15. A tire component prepared from the vulcanizable composition of any of the preceding claims.

16. A tire tread prepared from the vulcanizable composition of any of the preceding claims.

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