Vulcanizable rubber compositions and vulcanizates therefrom that are free of metal-containing accelerators

Abstract

A vulcanizable composition of matter comprising (a) a vulcanizable rubber; (b) a curative; (c) a filler; and (d) a Type I or Type II eutectic composition; where the composition is substantially devoid of a metal-containing accelerator.

Description

VULCANIZABLE RUBBER COMPOSITIONS AND VULCANIZATES THEREFROM THAT ARE FREE OF METAL-CONTAINING ACCELERATORSFIELD OF THE INVENTION

[0001] Embodiments of the invention are directed toward vulcanizable compositions that include a eutectic composition and are substantially free of metal-containing accelerators or the residue thereof.BACKGROUND OF THE INVENTION

[0002] The art of making tires, zinc oxide, together with stearic acid, has played an important role in vulcanization. It is believed that the zinc oxide, or perhaps a salt formed by the combination of zinc oxide and stearic acid, interacts with sulfur to provide a desired crosslink density of the rubber matrix. Societies nonetheless seek to reduce the use of zinc oxide in the manufacture of tires based upon a belief that the zinc oxide, or residue thereof, has a negative impact on the environment.

[0003] Attempts have been made to reduce the amount of zinc oxide employed in the tire manufacturing process. For example, WO 2019 / 089788 teaches vulcanizable rubber compositions that include reduced levels of zinc oxide due to the presence of a eutectic solvent. In the presence of a eutectic solvent, particularly a deep eutectic solvent such as reline, vulcanizable compositions with as little as 0.05 parts zinc oxide, per 100 parts of rubber, were found to be useful for preparing tire components.

[0004] Despite these findings, there remains a desire to further reduce the level of zinc oxide used in the manufacture of tires.SUMMARY OF THE INVENTION

[0005] One or more embodiments of the present invention provide a vulcanizable composition of matter comprising (a) a vulcanizable rubber; (b) a curative; (c) a filler; and (d) a Type 1 or Type 11 eutectic composition; where the composition is substantially devoid of a metal-containing accelerator.

[0006] Other embodiments of the present invention provide a method of preparing a vulcanizate, the method comprising the steps of (i) providing a vulcanizable composition including an elastomer, a filler, a curative, and a Type 1 or Type 11 eutectic composition, where the composition is substantially devoid of a metal-containing accelerator; (ii) fabricating the vulcanizable composition into a green article; and (in) subjecting the green article to curing conditions.

[0007] Still other embodiments of the present invention provide a tire component comprising a vulcanized rubber matrix including filler dispersed therein, where the rubber matrix includes a Type I or Type 11 eutectic composition, and where the rubber matrix is substantially devoid of a metal-containing accelerator or residue thereof.DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0008] Embodiments of the invention are based, at least in part, on the discovery of vulcanizable compositions that are useful for preparing vulcanized articles including tire components. According to embodiments of the invention, the vulcanizable compositions include a Type I or Type 11 eutectic compositions and are free or essentially free of metalcontaining activators, such as zinc oxide, or the residue thereof. While the prior art contemplates vulcanizable compositions including a eutectic composition, the prior does so in the presence of metal activators (e.g. reduced amounts of zinc oxide). It has now unexpectedly been discovered that the use of certain eutectic compositions, particularly Type I and Type 11 eutectic compositions, allow for the formation of useful vulcanizable compositions that do not require metal-containing activators such as zinc oxide.VULCANIZABLE COMPOSITIONS

[0009] In one or more embodiments, the vulcanizable compositions of this invention, include a vulcanizable rubber, a filler, a curative, and a Type 1 or Type 11 eutectic composition. The compositions may also include other ingredients such as those common in the art of making vulcanizable rubber compositions such as, but not limited to, reinforcing fillers, antidegradants, cure activators, cure accelerators, oils, resins, plasticizers, pigments, fatty acids, zinc oxide, and peptizing agents.VULCANIZABLE RUBBER

[0010] In one or more embodiments, the vulcanizable rubber, which may also be referred to as an elastomeric polymer, rubber polymer, vulcanizable polymer, or simply an elastomer, may include those polymers that can be vulcanized to form compositions possessing rubbery or elastomeric properties. These elastomers may include natural and synthetic rubbers. The synthetic rubbers typically derive from the polymerization of conjugated diene monomer, the copolymerization of conjugated diene monomer with other monomer such as vinyl-substituted aromatic monomer, or the copolymerization of ethylene with one or more ot-olefins and optionally one or more diene monomers.

[0011] Exemplary elastomers include natural rubber, 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. These elastomers may also include one or more functional units, which typically include heteroatoms. In particular embodiments, a vulcanizable composition includes a blend of natural rubber and synthetic diene rubber such as polybutadiene. In other embodiments, a vulcanizable composition includes olefinic rubber such ethylene-propylene-diene rubber (EPDM).

[0012] The elastomers may be characterized by their number average molecular weight (Mn), which may be measured by using gel permeation chromatography using polystyrene standards and adjusted with Mark-Houwink parameters. According to embodiments of the present invention, the elastomers may have a Mn of greater than 120, in other embodiments greater than 150, and in other embodiments greater than 180 kg / mol. In these or other embodiments, the elastomers may have a Mn of less than 800, in other embodiments less than 600, and in other embodiments less than 400 kg / mol. In one or more embodiments, the elastomers have a Mn of from about 120 to about 800, in other embodiments from about 150 to about 600, and in other embodiments from about 180 to about 400 kg / mol.CURATIVE

[0013] 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. 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. In one or more embodiments, the curative is a sulfur- containing vulcanizing agent. Examples of suitable sulfur-containing vulcanizing agents include “rubbermaker's” soluble sulfur; sulfur donating vulcanizing agents, such as an amine disulfide, polymeric polysulfide or sulfur olefin adducts; and insoluble polymeric sulfur. Vulcanizing agents may be used alone or in combination. The skilled person will be able to readily select the amount of vulcanizing agents to achieve the level of desired cure.

[0014] In one or more embodiments, the curative is employed in combination with a cure accelerator. In one or more embodiments, accelerators are used to control the time and / or temperature required for vulcanization and to improve properties of the vulcanizate. Examples of cure accelerators include thiazol vulcanization accelerators, such as 2- mercaptobenzothiazol, dibenzothiazyl disulfide, N-cyclohexyl-2-benzothiazyl-sulfenamide [CBS], and the like, and guanidine vulcanization accelerators, such as diphenylguanidine [DPG] and the like. Specifically excluded from the cure activators are metal-containing activators such as one or more of zinc oxide, magnesium hydroxide, iron oxide, and cobalt carboxylates. In particular embodiments, zinc oxide is excluded. For purposes of this specification, metal halides and metal halide hydrates are not considered to be metalcontaining accelerators.TYPE I AND TYPE II EUTECTIC COMPOSITION

[0015] As the skilled person appreciates, a eutectic composition includes those compositions formed by combining two or more compounds that provide a resultant combination having a melting point lower than the respective compounds that are combined. For purposes of this specification, the eutectic composition may be referred to as a eutectic mixture, a eutectic complex, or a eutectic pair. Each of the compounds that are combined may be referred to, respectively, as a eutectic ingredient, eutectic constituent, eutecticmember, complexing agent, or compound for forming a eutectic composition (e.g. first and second compound).

[0016] Without wishing to be bound by any particular theory, it is believed that the eutectic ingredients combine or otherwise interact to form a complex. Thus, any reference to eutectic mixture, or eutectic combination, eutectic pair, or solid eutectic complex will include combinations and reaction products or complexes between the constituents that are combined and yield a composition having a lower melting point than the respective constituents. In one or more embodiments, useful eutectic compositions include a combination of an acid and a base, where the acid and base may include Lewis acids and bases or Bronsted acids and bases. In one or more embodiments, the eutectic composition is a solid at standard conditions of temperature and pressure. In other embodiments, the eutectic composition is a liquid at standard conditions of temperature and pressure.

[0017] In one or more embodiments, eutectic compositions can generically be defined by the formula 1:where Cat+is a cation, X“ is a counter anion (e.g. Lewis Base), and z refers to the number of Y molecules that interact with the counter anion (e.g. Lewis Base).

[0018] As indicated above, the eutectic compositions employed in the practice of this invention include Type I and Type II eutectic compositions. The skilled person understands that Type 1 eutectic compositions include a combination of a quaternary ammonium salt (as the Lewis base) with a metal halide (as the Lewis acid). The skilled person also understands that Type II eutectic compositions include a combination of a quaternary ammonium salt (as the Lewis base) and a metal halide hydrate (as the Lewis Acid). Analogous combinations of sulfonium or phosphonium in lieu of ammonium compounds can also be employed and can be readily envisaged by those having skill in the art.QUATERNARY AMMONIUM SALT

[0019] In one or more embodiments, useful quaternary ammonium salts, which may also be referred to as ammonium compounds, may be defined by the formula II:where each Rj, R2, R3, and R4 is individually hydrogen or a monovalent organic group, or, in the alternative, two of R^, R2, R3, and R4 join to form a divalent organic group, and <t> is a counter anion. In one or more embodiments, at least one, in other embodiments at least two, and in other embodiments at least three of R^, R2, R3, and R4 are not hydrogen.

[0020] In one or more embodiments, the counter anion (e.g.) is selected from the group consisting of halide (X"), nitrate (NOg-), tetrafluoroborate (BF4-), perchlorate (CIO4"), triflate (SO3CF3-), trifluoroacetate (COOCF3"). In one or more embodiments, <J>—is a halide ion, and in certain embodiments a chloride ion.

[0021] In one or more embodiments, the monovalent organic groups include hydrocarbyl groups, and the divalent organic groups include hydrocarbylene groups. In one or more embodiments, the monovalent and divalent organic groups include a heteroatom, such as, but not limited to, oxygen and nitrogen, and / or a halogen atom. Accordingly, the monovalent organic groups may include alkoxy groups, siloxy groups, ether groups, and ester groups, as well as carbonyl or acetyl substituents. In one or more embodiments, the hydrocarbyl groups and hydrocarbylene group include from 1 (or the appropriate minimum number] to about 18 carbon atoms, in other embodiments from 1 to about 12 carbon atoms, and in other embodiments from 1 to about 6 carbon atoms. The hydrocarbyl and hydrocarbylene groups may be branched, cyclic, or linear. Exemplary types of hydrocarbyl groups include alkyl, cycloalkyl, aryl and alkylaryl groups. Exemplary types of hydrocarbylene groups include alkylene, cycloalkylene, arylene, and alkylarylene groups. In particular embodiments, the hydrocarbyl groups are selected from the group consisting of methyl, ethyl, octadecyl, phenyl, and benzyl groups. In certain embodiments, the hydrocarbyl groups are methyl groups, and the hydrocarbylene groups are ethylene or propylene group.

[0022] Useful types of ammonium compounds include secondary ammonium compounds, tertiary ammonium compounds, and quaternary ammonium compounds. In these or other embodiments, the ammonium compounds include ammonium halides such as, but not limited to, ammonium chloride. In particular embodiments, the ammonium compound is a quaternary ammonium chloride (e.g. choline chloride). In certainembodiments, Rp R2, R3, and R4 are hydrogen, and the ammonium compound is ammonium chloride. In one or more embodiments, the ammonium compounds are asymmetric.

[0023] In one or more embodiments, the ammonium compound includes an alkoxy (hydroxy alkyl) group and can be defined by the formula III:where each R-p R2, and R3 is individually hydrogen or a monovalent organic group, or, in the alternative, two of Rp R2, and R3 join to form a divalent organic group, R4 is a divalent organic group, and <t>- is a counter anion. In one or more embodiments, at least one, in other embodiments at least two, and in other embodiments at least three of Rp R2, and R3, and are not hydrogen.

[0024] Examples of ammonium compounds defined by the formula 111 include, but are not limited to, N-ethyl-2-hydroxy-N,N-dimethylethanaminium chloride, 2-hydroxy -N,N,N- trimethylethanaminium chloride (which is also known as choline chloride), and N-benzyl-2- hydroxy-N,N-dimethlethanaminium chloride.

[0025] In one or more embodiments, the ammonium compound includes a halogencontaining substituent and can be defined by the formula IV:where each Rj, R2, and R3 is individually hydrogen or a monovalent organic group, or, in the alternative, two of Rp R2, and R3 join to form a divalent organic group, R4is a divalent organic group, X is a halogen atom, and C>_is a counter anion. In one or more embodiments, at least one, in other embodiments at least two, and in other embodiments at least three of Rp R2, and R3, are not hydrogen. In one or more embodiments, X is chlorine.

[0026] Examples of ammonium compounds defined by the formula IV include, but are not limited to, 2-chloro-N,N,N-trimethylethanaminium (which is also referred to as choline chloride), and 2-(chlorocarbonyloxy)-N,N,N-trimethylethanaminium chloride.METAL HALIDES

[0027] Types of metal halides include, but are not limited to, chlorides, bromides, iodides and fluorides. In one or more embodiments, these metal halides include, but are not limited to, transition metal halides. The skilled person can readily envisage the corresponding metal halide hydrates.

[0028] Specific examples of useful metal halides include, but are not limited to, aluminum chloride, aluminum bromide, aluminum iodide, zinc chloride, zinc bromide, zinc iodide, tin chloride, tin bromide, tin iodide, iron chloride, iron bromide, iron iodide, and combinations thereof. The skilled person can readily envisage the corresponding metal halide hydrates. For example, aluminum chloride hexahydrate and copper chloride dihydrate correspond to the halides mentioned above.METAL HALIDE HYDRATES

[0029] The skilled person understands that metal halide hydrates includes those metal halides that have water associated therewith (e.g. complexed thereto]. In one or more embodiments, metal halide hydrates include water molecules combined in a definite ratio as an integral part of the compound crystal. These water molecules can be bound to the metal atom, or in other embodiments, the water molecule may be crystallized with the metal complex, which refers to metal halides that contain water of crystallization or water of hydration. In view of the exemplary metal halides outlined above, the skilled person can readily envisage the corresponding metal halide hydrates. For example, aluminum chloride hexahydrate and copper chloride dihydrate correspond to the halides mentioned above.FORMATION OF EUTECTIC COMPLEX

[0030] The skilled person can select the appropriate eutectic members at the appropriate molar ratio to provide the desired eutectic composition. The skilled person appreciates that the molar ratio of the first compound (e.g. Lewis base] of the pair to the second compound (e.g. Lewis acid] of the pair will vary based upon the compounds selected. As the skilled person will also appreciate, the melting point suppression of a eutectic solvent includes the eutectic point, which is the molar ratio of the first compound to the second compound that yields the maximum melting point suppression (i.e. deep eutectic solvent]. The molar ratio of the first compound to the second compound can, however, be varied tononetheless produce a suppression in the melting point of the eutectic composition relative to the individual melting points of the first and second compounds that is not the minimum melting point (i.e. not the point of maximum suppression). Practice of one or more embodiments of the present invention therefore includes the formation a eutectic composition at molar ratios outside of the eutectic point.

[0031] In one or more embodiments, the compounds of the eutectic pair, as well as the molar ratio of the first compound to the second compound of the pair, are selected to yield a mixture having a melting point below 130 °C, in other embodiments below 110 °C, in other embodiments below 100 °C, in other embodiments below 80 °C, in other embodiments below 60 °C, in other embodiments below 40 °C, and in other embodiments below 30 °C. In these or other embodiments, the compounds of the eutectic pair, as well as the molar ratio of the compounds, are selected to yield a mixture having a melting point above 0 °C, in other embodiments above 10 °C, in other embodiments above 20 °C, in other embodiments above 30 °C, and in other embodiments above 40 °C.

[0032] In one or more embodiments, a eutectic solvent is formed by combining the first compound with the second compound at an appropriate molar. The mixture may be mechanically agitated by using various techniques including, but not limited to, solid state mixing or blending techniques. Also, the mixture may be formed at elevated temperatures. For example, the eutectic solvent may be formed by heating the mixture to a temperature of greater than 50 °C, in other embodiments greater than 70 °C, and in other embodiments greater than 90 °C. Mixing may continue during the heating of the mixture. Once a desired mixture is formed, the eutectic solvent can be cooled to room temperature. In one or more embodiments, the cooling of the eutectic solvent may take place at a controlled rate such as at a rate of less than 1 °C / min.FILLER

[0033] As suggested above, the vulcanizable compositions of this invention may include a filler. The filler may include one or more conventional reinforcing or non-reinforcing fillers. For example, useful fillers include carbon black, silica, alumina, and silicates such as calcium, aluminum, and magnesium silicates.

[0034] 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 (SAF) blacks, intermediate super abrasion furnace (ISAF) blacks, high abrasion furnace (HAF) blacks, fast extrusion furnace (FEF) blacks, fine furnace (FF) blacks, semireinforcing furnace (SRF) blacks, medium processing channel blacks, hard processing channel blacks, conducting channel blacks, and acetylene blacks. Representative carbon blacks useful in one or more embodiments may include those designated by ASTM D1765 as N326, N330, N339, N343, N347, N351, N358, N550, N650, N660, N762, N772, and N774.

[0035] In one or more embodiments, the carbon blacks may have a surface area of at least 20 m2 / g, in other embodiments at least 35 m2 / g, in other embodiments at least 50 m2 / g, and in other embodiments at least 60 m2 / g. In these or other embodiments, the carbon blacks have a surface area of from about 20 to about 110 m2 / g, in other embodiments from about 25 to about 80 m2 / g, in other embodiments from about 30 to about 60 m2 / g, in other embodiments from about 60 to about 110 m2 / g, and in other embodiments from about 40 to about 50 m2 / g. For purposes of this specification, and unless otherwise specified, carbon black surface area values are 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.

[0036] In one or more embodiments, the filler may include silica. When silica is used as a filler, the silica may be employed in conjunction with a coupling agent. In these or other embodiments, the silica may be used in conjunction with a silica dispersing agent.

[0037] In one or more embodiments, useful silicas include, but are not limited to, precipitated amorphous silica, wet silica (hydrated silicic acid), dry silica (anhydrous silicic acid), fumed silica, calcium silicate, and the like. Other suitable fillers include aluminum silicate, magnesium silicate, and the like. In particular embodiments, the silica is a precipitated amorphous wet-processed hydrated silica. In one or more embodiments, these silicas are produced by a chemical reaction in water, from which they are precipitated as ultra-fine, spherical particles. These primary particles are believed to strongly associate into aggregates, which in turn combine less strongly into agglomerates.

[0038] Some commercially available silicas that may be used include Hi-SiK™) 215, Hi- SiK™) 233, and Hi-SiK™) 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).

[0039] 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., vol. 60, p. 309 et seq.) 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.

[0040] In one or more embodiments, the pH of silica may be from about 5 to about 7 or slightly over 7, or in other embodiments from about 5.5 to about 6.8.

[0041] In one or more embodiments, useful silica coupling agents include sulfur- containing silica coupling agents. Examples of sulfur-containing silica coupling agents include bis(trialkoxysilylorgano)polysulfides or mercapto-organoalkoxysilanes. Types of bis(trialkoxysilylorgano)polysulfides include bis (trialkoxysilylorgano) disulfide and bis(trialkoxysilylorgano)tetrasulfides. Exemplary silica dispersing aids include, but are not limited to an alkyl alkoxysilane, a fatty acid ester of a hydrogenated or nonhydrogenated C5 or C6 sugar, a polyoxyethylene derivative of a fatty acid ester of a hydrogenated or non-hydrogenated C5 or C6 sugar, and mixtures thereof, or a mineral or non-mineral additional filler.PROCESSING / EXTENDER OILS

[0042] In one or more embodiments, the vulcanizable compositions of this invention include processing oils, which may also be referred to as extender oils. In one or more embodiments, the vulcanizable compositions are devoid or substantially devoid of processing oils.

[0043] In particular embodiments, the oils that are employed include those conventionally used as extender oils. Useful oils or extenders that may be employed include, but are not limited to, aromatic oils, paraffinic oils, naphthenic oils, vegetable oils other than castor oils, low PCA oils including MES, TDAE, and SRAE, and heavy naphthenic oils. Suitablelow PCA oils also include various plant-sourced oils such as can be harvested from vegetables, nuts, and seeds. Non-limiting examples include, but are not limited to, soy or soybean oil, sunflower oil, safflower oil, corn oil, linseed oil, cotton seed oil, rapeseed oil, cashew oil, sesame oil, camellia oil, jojoba oil, macadamia nut oil, coconut oil, and palm oil. As is generally understood in the art, oils refer to those compounds that have a viscosity that is relatively compared to other constituents of the vulcanizable composition, such as the resins.REINFORCING RESINS

[0044] In one or more embodiments, the vulcanizable compositions of this invention include a reinforcing resin, which may also be referred to as a thermosetting resin. Exemplary reinforcing resins include acrylic resins, alkyd resins, amine resins, amide resins, maleimide resins, maleic resins, epoxy resins, furan resins, phenolic resins, phenol formaldehyde resins, polyamide resins, polyester resins, urethane resins, vinyl resins, vinyl ester resins, cyanoacrylic resins, silicone resins, siloxane resins, melamine resins, ureaformaldehyde resins and fumaric resins. Examples of phenol resins suitable as reinforcing resins include novolac-type phenol resins, novolac-type cresol resins, novolac-type xylenol resins, novolac-type resorcinol resins, and oil-modified resins therefrom.PLASTICIZING RESINS

[0045] In one or more embodiments, the vulcanizable compositions of the invention may include one or more plasticizing resins. These resins generally include hydrocarbon resins such as cycloaliphatic resins, aliphatic resins, aromatic resins, terpene resins, and combinations thereof.

[0046] In one or more embodiments, hydrocarbon resins may be characterized by a glass transition temperature (Tg) of from about 30 to about 160 °C, in other embodiments from about 35 to about 60 °C, and in other embodiments from about 70 to about 110 °C. In one or more embodiments, hydrocarbon resins may also be characterized by its softening point being higher than its Tg. In certain embodiments, hydrocarbon resins have a softening point of from about 70 to about 160 °C, in other embodiments from about 75 to about 120 °C, and in other embodiments from about 120 to about 160 °C.Low MOLECULAR WEIGHT, HIGH VINYL ADDITIVE

[0047] In one or more embodiments, the vulcanizable compositions include a low molecular weight, high vinyl polydienes. The polydienes derive from the polymerization of conjugated diene monomer or the copolymerization of conjugated diene monomer with other monomer such as vinyl-substituted aromatic monomer. Exemplary low molecular weight, high vinyl polydienes include polyisoprene, polybutadiene, polyisobutylene-co- isoprene, poly(styrene-co-butadiene), poly(styrene-co-isoprene), poly(styrene-co-isoprene- co-butadiene), and poly(isoprene-co-butadiene), and mixtures thereof.

[0048] The low molecular weight, high vinyl polydienes may be characterized by their number average molecular weight (Mn), which may be measured by using gel permeation chromatography using polystyrene standards and adjusted with Mark-Houwink parameters. According to embodiments of the present invention, the low molecular weight, high vinyl polydienes may have a Mn of greater than 30, in other embodiments greater than 40, and in other embodiments greater than 50 kg / mol. In these or other embodiments, the low molecular weight, high vinyl polydienes may have a Mn of less than 120, in other embodiments less than 100, and in other embodiments less than 80 kg / mol. In one or more embodiments, the low molecular weight, high vinyl polydienes have a Mn of from about 30 to about 115, in other embodiments from about 40 to about 100, and in other embodiments from about 50 to about 80 kg / mol.

[0049] The low-molecular weight, high-vinyl polydienes may be characterized by their molecular weight distribution, which may also be referred to as polydispersity, and is represented by the ratio of the weight-average molecular weight (Mw) to the numberaverage molecular weight (Mn), which may be measured by using gel permeation chromatography using polystyrene standards and adjusted with Mark-Houwink parameters. According to embodiments of the present invention, the low-molecular weight, high-vinyl polydienes may have a polydispersity (Mw / Mnj of less than 2.0, in other embodiments less than 1.7, in other embodiments less than 1.4, in other embodiments less than 1.3, in other embodiments less than 1.2, and in other embodiments less than 1.1.

[0050] In one or more embodiments, the low molecular weight, high vinyl polydienes may be characterized by vinyl content, which may be described as the number ofunsaturations 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 FTIR analysis. In one or more embodiments, the low molecular weight, high vinyl poly dienes include greater than 40%, in other embodiments greater than 50%, and in other embodiments greater than 60% vinyl. In these or other embodiments, the low molecular weight, high vinyl polydienes include less than 95%, in other embodiments less than 90%, and in other embodiments less than 88%. In one or more embodiments, the low molecular weight, high vinyl polydienes include from about 40 to about 95%, in other embodiments from about 50 to about 90%, and in other embodiments from about 60 to about 88% vinyl.

[0051] Useful a low molecular weight, high vinyl polydienes are described in U.S. Publication No. 2011 / 0190440, which is incorporated herein by reference.OTHER INGREDIENTS

[0052] Other ingredients that are typically employed in rubber compounding may also be added to the vulcanizable compositions. These other ingredients may include waxes, scorch inhibiting agents, processing aids, stearic acid, peptizers, and antidegradants such as antioxidants and antiozonants. On or more of these additional ingredients can be excluded from the vulcanizable compositions of the invention.INGREDIENT AMOUNTSRUBBER

[0053] In one or more embodiments, the vulcanizable compositions include greater than 20, in other embodiments greater than 30, and in other embodiments greater than 40 percent by weight of the rubber component, based upon the entire weight of the composition. In these or other embodiments, the vulcanizable compositions include less than 90, in other embodiments less than 70, and in other embodiments less than 60 percent by weight of the rubber component based on the entire weight of the composition. In one or more embodiments, the vulcanizable compositions include from about 20 to about 90, in other embodiments from about 30 to about 70, and in other embodiments from about 40 to about 60 percent by weight of the rubber component based upon the entire weight of the composition.EUTECTIC COMPOSITION

[0054] In one or more embodiments, the vulcanizable compositions include greater than 0.005, in other embodiments greater than 0.01, in other embodiments greater than 0.02, and in other embodiments greater than 0.025 parts by weight (pbw) of the eutectic composition per 100 parts by weight rubber (phr). In these or other embodiments, the vulcanizable compositions include less than 2, in other embodiments less than 1.0, and in other embodiments less than 0.1 pbw of the eutectic composition phr. In one or more embodiments, the vulcanizable compositions include from about 0.005 to about 3, in other embodiments from about 0.01 to about 1.5, in other embodiments from about 0.02 to about 1.0, and in other embodiments from about 0.025 to about 0.1 pbw ofthe eutectic composition phr.FILLER

[0055] In one or more embodiments, the vulcanizable compositions include greater than 0, in other embodiments greater than 10, in other embodiments greater than 25, in other embodiments greater than 35, in other embodiments greater than 45, in other embodiments greater than 55, and in other embodiments greater than 65 parts by weight (pbw) of filler per 100 parts by weight rubber (phr). In these or other embodiments, the vulcanizable composition includes less than 200, in other embodiments less than 150, in other embodiments less than 120, in other embodiments less than 100, and in other embodiments less than 80 pbw of filler phr. In one or more embodiments, the vulcanizable composition includes from about 0 to about 200, in other embodiments from about 35 to about 120, and in other embodiments from about 45 to about 100 pbw of filler phr.CARBON BLACK

[0056] In one or more embodiments, the vulcanizable compositions include greater than 0, in other embodiments greater than 10, in other embodiments greater than 25, in other embodiments greater than 45, in other embodiments greater than 55, in other embodiments greater than 60, in other embodiments greater than 65, and in other embodiments greater than 75 parts by weight (pbw) of a carbon black per 100 parts by weight rubber (phr). In these or other embodiments, the vulcanizable composition includes less than 200, in other embodiments less than 150, and in other embodiments less than 100pbw of a carbon black phr. In one or more embodiments, the vulcanizable composition includes from about 10 to about 200, in other embodiments from about 40 to about 150, and in other embodiments from about 50 to about 100 pbw of a carbon black phr.SILICA

[0057] In one or more embodiments, the vulcanizable compositions include greater than 0.1, in other embodiments greater than 2.5, and in other embodiments greater than 5.0 parts by weight [pbw] silica per 100 parts by weight rubber [phr]. In these or other embodiments, the vulcanizable composition includes less than 50, in other embodiments less than 30, in other embodiments less than 25, in other embodiments less than 20, in other embodiments less than 18, in other embodiments less than 15, in other embodiments less than 10, in other embodiments less than 5, in other embodiments less than 3, and in other embodiments less than 1 pbw of silica phr. In one or more embodiments, the vulcanizable composition includes from about 0.1 to about 50, in other embodiments from about 2.5 to about 30, and in other embodiments from about 3 to about 20 pbw of silica phr. In one or more embodiments, the vulcanizable compositions are devoid or substantially devoid of silica.FILLER RATIO

[0058] In one or more embodiments, the vulcanizable compositions can be characterized by the ratio of carbon black to other filler compounds such as silica. In one or more embodiments, carbon black is used in excess relative to the other fillers such as silica. In one or more embodiments, the ratio of the amount of carbon black to silica, based upon a weight ratio, is greater than 2:1, in other embodiments greater than 3:1, in other embodiments greater than 5:1, in other embodiments greater than 7:1, in other embodiments greater than 10:1, in other embodiments greater than 15:1, and in other embodiments greater than 20:1.SILICA COUPLING AGENT

[0059] In one or more embodiments, the vulcanizable compositions include greater than 1, in other embodiments greater than 2, and in other embodiments greater than 5 parts by weight (pbw) silica coupling agent per 100 parts by weight silica. In these or other embodiments, the vulcanizable composition includes less than 20, in other embodimentsless than 15, and in other embodiments less than 10 pbw of the silica coupling agent per 100 parts by weight silica. In one or more embodiments, the vulcanizable composition includes from about 1 to about 20, in other embodiments from about 2 to about 15, and in other embodiments from about 5 to about 10 pbw of silica coupling agent per 100 parts by weight silica. In one or more embodiments, the vulcanizable compositions are devoid or substantially devoid of silica coupling agents.RESIN

[0060] In one or more embodiments, the vulcanizable compositions include greater than 1, in other embodiments greater than 15, and in other embodiments greater than 25 parts by weight (pbw) of resin (e.g. hydrocarbon resin) per 100 parts by weight rubber (phr). In these or other embodiments, the vulcanizable composition includes less than 150, in other embodiments less than 120, in other embodiments less than 90, in other embodiments less than 80, in other embodiments less than 60, and in other embodiments less than 45 pbw of resin (e.g. hydrocarbon resin) phr. In one or more embodiments, the vulcanizable composition includes from about 1 to about 150, in other embodiments from about 15 to about 100, and in other embodiments from about 25 to about 80 pbw of resin (e.g. hydrocarbon resin) phr. In one or more embodiments, the vulcanizable compositions are devoid or substantially devoid of resin.PROCESSING / EXTENDER OILS

[0061] In one or more embodiments, the vulcanizable compositions include greater than 0.1, in other embodiments greater than 1, and in other embodiments greater than 2 parts by weight (pbw) of a processing oil (e.g. naphthenic oil) per 100 parts by weight rubber (phr). In these or other embodiments, the vulcanizable composition includes less than 20, in other embodiments less than 18, in other embodiments less than 15, in other embodiments less than 12, in other embodiments less than 10, and in other embodiments less than 8 pbw of a processing oil phr. In one or more embodiments, the vulcanizable composition includes from about 0.1 to about 20, in other embodiments from about 0.5 to about 18, in other embodiments from about 1 to about 15, and in other embodiments from about 2 to about 12 pbw of oil phr. In one or more embodiments, the vulcanizable compositions are devoid or substantially devoid of oils.PLASTICIZING ADDITIVES

[0062] In one or more embodiments, the plasticizing resin and processing oils may be collectively referred to as plasticizing additives, ingredients, or constituents. In one or more embodiments, the vulcanizable compositions of this invention include greater than 0.1, in other embodiments greater than 1, and in other embodiments greater than 2 parts by weight [pbw] of plasticizing additives per 100 parts by weight rubber [phr]. In these or other embodiments, the vulcanizable composition includes less than 15, in other embodiments less than 12, in other embodiments less than 10, in other embodiments less than 7, in other embodiments less than 5, and in other embodiments less than 3 pbw of plasticizing additives phr. In one or more embodiments, the vulcanizable composition includes from about 0.1 to about 15, in other embodiments from about 0.5 to about 10, in other embodiments from about 1 to about 7, and in other embodiments from about 2 to about 5 pbw of plasticizing additives phr.REINFORCING RESINS

[0063] In one or more embodiments, the vulcanizable compositions include greater than 0.1, in other embodiments greater than 1, and in other embodiments greater than 2 parts by weight [pbw] of a reinforcing resin (e.g. novolac resin] per 100 parts by weight rubber [phr]. In these or other embodiments, the vulcanizable composition includes less than 8, in other embodiments less than 6, in other embodiments less than 5, and in other embodiments less than 4 pbw reinforcing resin phr. In one or more embodiments, the vulcanizable composition includes from about 0.1 to about 8, in other embodiments from about 0.5 to about 6, and in other embodiments from about 2 to about 4 pbw reinforcing resin phr. In one or more embodiments, the vulcanizable compositions are devoid or substantially reinforcing resins.Low MOLECULAR WEIGHT, HIGH VINYL ADDITIVE

[0064] In one or more embodiments, the vulcanizable compositions include greater than 0.5, in other embodiments greater than 1.5, and in other embodiments greater than 1.7 parts by weight [pbw] of a low molecular weight, high vinyl polydienes per 100 parts by weight rubber [phr]. In these or other embodiments, the vulcanizable composition includes less than 5.0, in other embodiments less than 4.0, in other embodiments less than3.0 pbw of a low molecular weight, high vinyl polydienes phr. In one or more embodiments, the vulcanizable composition includes from about 0.5 to about 5.0, in other embodiments from about 1.5 to about 4.0, in other embodiments from about 1.7 to about 3.0 pbw of low molecular weight, high vinyl polydienes phr. In one or more embodiments, the vulcanizable compositions are devoid or substantially devoid of low molecular weight, high vinyl polydienes.METAL-CONTAINING ACTIVATORS

[0065] As suggested above, the vulcanizable compositions of this invention are at least substantially free metal-containing activators or the residue thereof. The skilled person readily appreciates that reference to residue thereof refers to the reaction product or complex that may be formed when a metal-containing activator is combined with other constituents of the mixture such as stearic acid. In one or more embodiments, the metalcontaining activators are selected from the group consisting of zinc oxide, magnesium hydroxide, iron oxide and cobalt carboxylates. Reference to substantially free refers to that amount or less of a metal-containing activator that does not have an appreciable impact on the vulcanizable compositions of this invention. In one or more embodiments, the vulcanizable composition includes less than 0.05, in other embodiments less than 0.03, and in other embodiments less than 0.01 pbw of metal-containing activator (e.g. zinc oxide) phr. In one or more embodiments, the vulcanizable composition is devoid is devoid of a metalcontaining activator (e.g. devoid of zinc oxide).ORGANIC ACID

[0066] In one or more embodiments, the vulcanizable compositions include greater than 0.5, in other embodiments greater than 0.7, and in other embodiments greater than 1.0 parts by weight (pbw) of organic acid (e.g. stearic acid) per 100 parts by weight rubber (phr). In these or other embodiments, the vulcanizable composition includes less than 5, in other embodiments less than 3, and in other embodiments less than 2 pbw of organic acid (e.g. stearic acid) phr. In one or more embodiments, the vulcanizable composition includes from about 0.5 to about 5, in other embodiments from about 0.7 to about 3, and in other embodiments from about 1.0 to about 2 pbw of organic acid (e.g. stearic acid) phr.PREPARATION OF VULCANIZABLE COMPOSITIONS

[0067] In one or more embodiments, vulcanizable compositions are prepared by mixing a vulcanizable rubber and one or more of the other ingredients to form a masterbatch, and then subsequently adding a curative to the masterbatch. The preparation of the masterbatch may take place using one or more sub-mixing steps where, for example, one or more ingredients may be added to the composition sequentially after an initial mixture is prepared by mixing two or more ingredients. Also, using conventional technology, additional ingredients can be added in the preparation of the vulcanizable compositions such as, but not limited to, carbon black, additional fillers, chemically-treated inorganic oxide, silica, silica coupling agent, silica dispersing agent, processing oils, processing aids such as zinc oxide and fatty acid, and antidegradants such as antioxidants or antiozonants.

[0068] In one or more embodiments, the Type I or Type II eutectic composition is prepared prior to introducing the eutectic composition to the vulcanizable rubber. In other words, the first constituent of the mixture is pre-combined with the second constituent of the mixture prior to introducing the mixture to the vulcanizable composition. In one or more embodiments, the combined constituents of the mixture are mixed until a homogeneous liquid composition is observed.

[0069] In one or more embodiments, especially where the Type 1 or Type II eutectic composition is in the liquid state, the eutectic composition may be pre-combined with one or more ingredients of the rubber formulation prior to introducing the eutectic mixture to the vulcanizable composition. In other words, in one or more embodiments, a constituent of the vulcanizable composition (e.g. filler ] is combined with the eutectic mixture to form a precombination or masterbatch prior to introducing the pre-combination to the mixer in which the rubber is mixed. In other embodiments, the eutectic composition is the minor component of the pre-combination, and therefore the constituent that is pre-mixed with the eutectic composition acts as a carrier for the eutectic composition. In other embodiments, one of the members of the eutectic pair acts as a solid carrier for the eutectic composition, and therefore the combination of the first and second ingredients of the eutectic composition form a pre-combination that can be added as a solid to the rubber within the mixer. The skilled person will appreciate that mixtures of this nature can be formed by combining anexcess of the first or second eutectic member relative to the other eutectic member to thereby maintain a solid composition at the desired temperature.

[0070] In one or more embodiments, the eutectic solvent is introduced to the vulcanizable rubber as an initial ingredient in the formation of a rubber masterbatch. As a result, the eutectic solvent undergoes high shear, high temperature mixing with the rubber. In one or more embodiments, the eutectic solvent undergoes mixing with the rubber at minimum temperatures in excess of 110 °C, in other embodiments in excess of 130 °C, and in other embodiments in excess of 150 °C. In one or more embodiments, high shear, high temperature mixing takes place at a temperature from about 110 °C to about 170 °C.

[0071] In other embodiments, the eutectic solvent is introduced to the vulcanizable rubber, either sequentially or simultaneously, with the sulfur-based curative. As a result, the eutectic solvent undergoes mixing with the vulcanizable rubber at a maximum temperature below 110 °C, in other embodiments below 105 °C, and in other embodiments below 100 °C. In one or more embodiments, mixing with the curative takes place at a temperature from about 70 °C to about 110 °C.MIXING CONDITIONS

[0072] In one or more embodiments, a vulcanizable composition is prepared by first mixing a vulcanizable rubber and the eutectic solvent at a temperature of from about 140 to about 180 °C, or in other embodiments from about 150 to about 170 °C. In certain embodiments, following the initial mixing, the composition (i.e., masterbatch] is cooled to a temperature of less than 100 °C, or in other embodiments less than 80 °C, and a curative is added. In certain embodiments, mixing is continued at a temperature of from about 90 to about 110 °C, or in other embodiments from about 95 to about 105 °C, to prepare the final vulcanizable composition.

[0073] In one or more embodiments, the masterbatch mixing step, or one or more substeps of the masterbatch mixing step, may be characterized by the peak temperature obtained by the composition during the mixing. This peak temperature may also be referred to as a drop temperature. In one or more embodiments, the peak temperature of the composition during the masterbatch mixing step may be at least 140 °C, in other embodiments at least 150 °C, and in other embodiments at least 160 °C. In these or otherembodiments, the peak temperature of the composition during the masterbatch mixing step may be from about 140 to about 200 °C, in other embodiments from about 150 to about 190 °C, and in other embodiments from about 160 to about 180 °C.FINAL MIXING STEP

[0074] Following the masterbatch mixing step, a curative or curative system is introduced to the composition and mixing is continued to ultimately form the vulcanizable composition of matter. This mixing step may be referred to as the final mixing step, the curative mixing step, or the productive mixing step. The resultant product from this mixing step may be referred to as the vulcanizable composition.

[0075] In one or more embodiments, the final mixing step may be characterized by the peak temperature obtained by the composition during final mixing. As the skilled person will recognize, this temperature may also be referred to as the final drop temperature. In one or more embodiments, the peak temperature of the composition during final mixing may be at most 130 °C, in other embodiments at most 110 °C, and in other embodiments at most 100 °C. In these or other embodiments, the peak temperature of the composition during final mixing may be from about 80 to about 130 °C, in other embodiments from about 90 to about 115 °C, and in other embodiments from about 95 to about 105 °C.MIXING EQUIPMENT

[0076] All ingredients of the vulcanizable compositions can be mixed with standard mixing equipment such as internal mixers (e.g. Banbury or Brabender mixers), extruders, kneaders, and two-rolled mills. Mixing can take place singularly or in tandem. As suggested above, the ingredients can be mixed in a single stage, or in other embodiments in two or more stages. For example, in a first stage (i.e., mixing stage), which typically includes the rubber component and filler, a masterbatch is prepared. 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. Additional mixing stages, sometimes called remills, can be employed between the masterbatch mixing stage and the final mixing stage.INDUSTRIAL APPLICABILITYPREPARATION OF TIRE

[0077] The vulcanizable 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 may be 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.

[0078] As indicated above, the vulcanizable compositions of the present invention can be cured to prepare various tire components. These tire components include, without limitation, tire treads, tire sidewalls, belt skims, innerliners, and bead apex.EXPERIMENTALFORMATION OF FIRST EUTECTIC COMPOSITION

[0079] A first eutectic composition of choline chloride and magnesium (II) chloride hydrate (MgC12»H20) was prepared by mixing the ingredients at one to one molar ratio at 100 °C in an oil bath with magnetic rod stirring at 60 rpm. The composition, which will be referred to as ChCl:MgC12, was determined to have a melt temperature of 27 °C (DSC measurement).FORMATION OF SECOND EUTECTIC COMPOSITION

[0080] A second eutectic composition of choline chloride and zinc (II) chloride (ZnC12) was prepared by mixing one mole of choline chloride with two moles of zinc (II) chloride (1:3 choline chloride to zinc chloride) at 100 °C in an oil bath with magnetic rod stirring at 60 rpm. The composition, which will be referred to as ChCl:ZnC12, was determined to have a melt temperature of 21 °C (DSC measurement).FORMATION OF VULCANIZABLE COMPOSITIONS

[0081] Vulcanizable compositions were prepared using the rubber formulation and mixing order provided in Table I. This rubber formulation was indicative of a rubber formulation that is useful in the manufacture of tire treads. The mix procedure was a three- step mix procedure including a masterbatch mix step, a "remill mix step,” and a final mix step. The various mixing steps were performed within a 65-gram Banbury-style mixer. During preparation of the masterbatch, the mixer was operated at 60 rpm for five minute or until a peak compositional temperature of 170 °C was attained. At that point in time, the composition was dropped from the mixer and allowed to cool to below about 85 °C. At this point in time, the composition was then reintroduced to the mixer along with the additional ingredients for the “remill stage,” and mixing was continued at 60 rpm for five minute or until a peak compositional temperature of about 170 °C was achieved. The composition was again dropped from the mixer and allowed to cool to below about 50 °C. Then, the composition was again reintroduced to the mixer along with the ingredients identified for the “final mix stage.” Included among these ingredients was the ChCl:MgC12 or ChCl:ZnC12, as provided in Table 11. Mixing was continued at 40 rpm for two- and one-half minutes or until a peak compositional temperature of about 100 °C was attained. The composition was then dropped from the mixer and samples were obtained from the composition for purposes of the analytical testing. As noted in Table II, the ingredients introduced in the final mix stage were varied as reported in Table II, which also provides the results of the analytical testing.Table I

[0082] Rheometer measurements were taken using an MDR 2000 operating at temperatures as specified in the Tables. The tensile mechanical properties (Max Stress, Modulus, Elongation, and Toughness) of the vulcanizates were measured by using the standard procedure described in ASTM-D412.Table II

[0083] 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

CLAIMSWhat is claimed is:

1. A vulcanizable composition of matter comprising:[a] a vulcanizable rubber;(b) a curative;(cj a filler; and(dj a Type 1 or Type II eutectic composition; where the composition is substantially devoid of a metal-containing accelerator.

2. The vulcanizable composition of claim 1, where the vulcanizable composition includes a Type 1 eutectic composition that is a combination of a metal halide and salt selected from the group consisting of quaternary ammonium salts, quaternary sulfonium salts, and quaternary phosphonium salts.

3. The vulcanizable composition of any of the preceding claims, where the vulcanizable composition includes a Type 11 eutectic composition that is a combination of a metal halide hydrate and salt selected from the group consisting of quaternary ammonium salts, quaternary sulfonium salts, and quaternary phosphonium salts.

4. The vulcanizable composition of any of the preceding claims, where the vulcanizable composition includes a Type I eutectic composition formed by combining magnesium [11] chloride hydrate and choline chloride.

5. The vulcanizable composition of any of the preceding claims, where the vulcanizable composition includes a Type 11 eutectic composition formed by combining zinc [11] chloride and choline chloride.

6. The vulcanizable composition of the preceding claims, where the vulcanizable composition includes from about 0.005 to about 3 parts by weight of the Type I or Type 11 eutectic composition per 100 parts by weight of the rubber.

7. The vulcanizable composition of the preceding claims, where the vulcanizable composition includes from about 35 to about 120 parts by weight of the filler per 100 parts by weight of the rubber.

8. The vulcanizable composition of the preceding claims, where the composition is devoid of zinc oxide.

9. The vulcanizable composition of the preceding claims, where the composition includes less than 0.05 parts by weight metal-containing activators per 100 parts by weight rubber.

10. The vulcanizable composition of any of the preceding claims, where eutectic composition is defined by the formula Cat+X"zY, where Cat+is a cation, X" is a counter anion (e.g. Lewis Base], and z refers to the number of Y molecules that interact with the counter anion (e.g. Lewis Base],11. The vulcanizable composition of any of the preceding claims, where Cat+is an ammonium, phosphonium, or sulfonium cation and X" is a halide ion.

12. A method of preparing a vulcanizate, the method comprising the steps of:[i] providing a vulcanizable composition including an elastomer, a filler, a curative, and a Type 1 or Type 11 eutectic composition, where the composition is substantially devoid of a metal-containing accelerator;[ii] fabricating the vulcanizable composition into a green article; and [hi] subjecting the green article to curing conditions.

13. The vulcanizable composition of any of the preceding claims, where the vulcanizable composition includes a Type I eutectic composition that is a combination of a metal halide and salt selected from the group consisting of quaternary ammonium salts, quaternary sulfonium salts, and quaternary phosphonium salts.

14. The vulcanizable composition of any of the preceding claims, where the vulcanizable composition includes a Type II eutectic composition that is a combination of a metal halide hydrate and salt selected from the group consisting of quaternary ammonium salts, quaternary sulfonium salts, and quaternary phosphonium salts.

15. The vulcanizable composition of any of the preceding claims, where the vulcanizable composition includes a Type I eutectic composition formed by combining magnesium (II) chloride hydrate and choline chloride.

16. The vulcanizable composition of any of the preceding claims, where the vulcanizable composition includes a Type II eutectic composition formed by combining zinc (II) chloride and choline chloride.

17. The vulcanizable composition of the preceding claims, where the vulcanizable composition includes from about 0.005 to about 3 parts by weight of the Type I or Type II eutectic composition per 100 parts by weight of the rubber.

18. The vulcanizable composition of the preceding claims, where the vulcanizable composition includes from about 35 to about 125 parts by weight of the filler per 100 parts by weight of the rubber.

19. The vulcanizable composition of the preceding claims, where the composition is devoid of zinc oxide.

20. The vulcanizable composition of the preceding claims, where the composition includes less than 0.05 parts by weight metal-containing activator per 100 parts by weight rubber.

21. The method of any of the preceding claims, where eutectic composition is defined by the formula Cat+X‘zY, where Cat+is a cation, X" is a counter anion (e.g. Lewis Base), and z refers to the number of Y molecules that interact with the counter anion (e.g. Lewis Base).

22. The method of any of the preceding claims, where Cat+is an ammonium, phosphonium, or sulfonium cation and X" is a halide ion.

23. The method of any of the preceding claims, where the eutectic composition is formed by combining an ammonium compound with a metal halide, a metal halide hydrate, or a hydrogen bond donor.

24. The method of any of the preceding claims, where the metal halide is selected from the group consisting of aluminum chloride, aluminum bromide, aluminum iodide, zinc chloride, zinc bromide, zinc iodide, tin chloride, tin bromide, tin iodide, iron chloride, iron bromide, iron iodide, and combinations thereof.

25. The method of matter of any of the preceding claims, where the vulcanizable composition includes from about 0.005 to about 3 pbw of the eutectic composition per 100 pbw rubber.

26. The method of matter of any of the preceding claims, where the vulcanizable composition includes from about 0.01 to about 1 pbw of the eutectic composition per 100 pbw rubber.

27. The method of any of the preceding claims, where the vulcanizable composition includes a low molecular weight, high vinyl polydiene.

28. A tire component comprising: a vulcanized rubber matrix including filler dispersed therein, where the rubber matrix includes a Type I or Type II eutectic composition, and where the rubber matrix is substantially devoid of a metal-containing accelerator or residue thereof.

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