Rubber composition with plasticizer and recycled carbon black and methods of making the rubber composition

Abstract

The interaction of rCB and plasticizer behavior disclosed herein allows for formula adjustments which minimize negative property impacts that are historically experienced when utilizing rCB. The more rCB that is used the compound that less plasticizer needs to be added to counteract the tendency of the rCB to affect the absorption of the plasticizer, particularly the tendency of the ash in the rCB prevent absorption by CB of the plasticizer. Low plasticizer compounds with high rCB content and vice-versa are included herein.

Description

Rubber Composition with Plasticizer and Recycled Carbon Black and Methods of Making the Rubber CompositionCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to US 63 / 740,665, filed on December 31, 2024. That prior application is incorporated herein by reference for all purposes.FIELD

[0002] This application is directed to carbon black filled tire rubber compositions and related methods. More specifically, it is directed to tire rubber composition comprising carbon black in particular.BACKGROUND

[0003] Tires comprise many components including, for example, road-contacting tread, sidewalls, carcass layers, bead apexes, and other components. The particular ingredients used to prepare the rubber composition that comprises the tire tread may vary. Formulation of tire tread rubber compositions is a complex science since changes to the formulation that result in an improvement in one property (e.g., wear resistance) may result in deterioration of another property (e.g., traction). Improvements in tire wear resistance are always desirable to provide a product that lasts longer.

[0004] Carbon black is a common component in rubber compositions, especially tire rubber compositions. It is often used in high ratios of the total compound weight. Providing a recyclable carbon black in appreciable quantities that at least maintains comparable properties with compositions that include virgin carbon black is a challenge.

[0005] Plasticizers are also components of many rubber compositions that aid in processing and properties of cured compounds. Plasticizers may include oils, resins, and softeners of various types that generally reduce the Tg of the cured compound and / or more importantly (typically) the viscosity of the rubber composition prior to curing. Interactions of recycled carbon black with other components in rubber compositions is often unpredictable as it provides differing results from what is known of virgin carbon blacks in rubber compositions.SUMMARY

[0006] The technology disclosed herein addresses the challenge to replace virgin carbon black with recycled or sustainable carbon black. The following is a brief summary of subject matter that is described in greater detail herein. This summary is not intended to be limiting as to the scope of the claims.

[0007] In some aspects, the techniques described herein relate to a tire component including: a polymer composition including: a rubber component including a conjugated diene polymer; and a reinforcing filler component including a recycled carbon black having a percentage ash content of 5% to 25%; wherein the polymer composition meets formula (III):(III) rCB x A x P = X;wherein rCB is an amount of recycled carbon black in the polymer composition in phr and rCB is at least 10; A is the percentage ash content of the recycled carbon black; P is phr of a plasticizer and is at least 15; and X is about 20 to about 140.

[0008] In some aspects, the techniques described herein relate to a tire component including: a polymer composition including: a rubber component including a conjugated diene polymer; a reinforcing filler component including a recycled carbon black having an ash content of about 5% to about 25%; and 0 to about 5 phr plasticizer; wherein the reinforcing filler component is present in an amount of about 30 to about 110 phr; wherein the recycled carbon black is at least 40% of the total reinforcing filler component wherein the tire component is a sidewall, carcass layer, or bead component wherein the polymer composition meets formula (V):(V) (rCBxA) / P ≥ 0.1wherein rCB is an amount of recycled carbon black in the polymer composition in phr; A is the percentage ash content of the recycled carbon black; and P is phr of a plasticizer.

[0009] In some aspects, the techniques described herein relate to a method for making a polymer composition for a tire component, including the steps of: mixing a polymer component including a conjugated diene polymer; and either (1) or (2):(1) Adding a reinforcing filler component including a recycled carbon black having a percentage ash content of about 5% to about 25%; wherein the polymer composition meets formula (III):(III) rCB x A x P = Xwherein rCB is an amount of recycled carbon black in the polymer composition in phr and rCB is at least about 10; A is the percentage ash content of the recycled carbon black; P is phr of a plasticizer and is at least about 15; and X is about 20 to 1 about 40; or(2) adding a reinforcing filler component in an amount of about 30 to about 110 phr, the reinforcing filler component including a recycled carbon black having an ash content of about 5% to about 25%, wherein the recycled carbon black is at least about 40% of the total reinforcing filler component; adding 0 to about 5 phr of liquid plasticizer; adding a primary accelerator and a sulfur-based curing agent; and vulcanizing the polymer composition in a mold to form the tire component wherein the tire component is a sidewall, carcass layer, or bead component; wherein the polymer composition meets formula (V):(V) (rCBxA) / P ≥ 0.1wherein rCB is an amount of recycled carbon black in the polymer composition in phr; A is the percentage ash content of the recycled carbon black; and P is phr of a plasticizer.

[0010] The above summary presents a simplified summary in order to provide a basic understanding of some aspects of the systems and / or methods discussed herein. This summary is not an extensive overview of the systems and / or methods discussed herein. It is not intended to identify key / critical elements or to delineate the scope of such systems and / or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.DETAILED DESCRIPTION

[0011] Historically, recycled carbon black (rCB) has been known to reduce various performance metrics when utilized in tire rubber compounds in place of standard or virgin carbon black (vCB). The inventors explored the impact of rCB material properties, as well its interactions with other raw materials in rubber formulations in tire rubber compounds. In particular, this application discloses interactions of recycled carbon black with plasticizers, which led to some unexpected results. Determination of these property interactions allows for improvement of rCB utilization in tire rubber compounds with reduced / minimal compound property impact and / or allowing for additional utilization of rCB amounts in rubber compounds with suitable retained properties for certain tire components.

[0012] After extensive analysis, it was determined that for rCB raw material properties, the rCB ash % (inorganic residue remaining from pyrolysis) was of particular concern in that some level of correlation was observed relating high ash content to lowered compound bound rubber and cured M300 (static modulus / stiffness) properties. Ash % was also correlated with increased scorch and cure times generally, suggesting crosslink density and compound cure profiles are impacted.

[0013] In addition, the interaction of rCB with other formula materials, specifically plasticizers (oils, resins, other softeners) is of interest for designing compounds to use higher levels of rCB. A correlation was observed between green dynamic stiffness (G') at low strain (1%) and a rCB / softener % loading interaction parameter, showing that G'@l% strain was more significantly reduced when both rCB and softener were present. This parameter correlation suggested that rCB and plasticizer materials had a different interaction in rubber compounds than that of virgin CB with plasticizer materials in rubber compounds. Without being bound to theory, a hypothesis proposed is that rCB ash and other rCB residues (e.g., silica, zinc, zinc-containing compounds (such as zinc sulfide or zinc oxide), calcium, aluminum, iron, silica, and magnesium oxide, or other inorganic fillers) impact how CB absorbs plasticizers in the rubber compound. Surprisingly, this interaction results in less plasticizer absorption, and thus more oil, resin, or other softener residing within the compound matrix than in a similarly loaded compound with vCB. There are other known and hypothesized mechanisms for G' softening within rCB compounds (reduced filler-filler interactions, potentially reduced cure state / crosslink density), but this interaction parameter revealed a suggestion that softener plays a role in formula dependency for rCB formulations.

[0014] The interaction of rCB and plasticizer behavior disclosed herein allows for formula adjustments which minimize negative property impacts that are historically experienced when utilizing rCB.

[0015] The relation of rCB and ash with plasticizer disclosed herein informs the development of a formula for making a tire component that allows for higher amounts of rCB and / or lower amounts of plasticizer. In an embodiment, the tire component includes: a polymer composition comprising a rubber component including a conjugated diene polymer; and areinforcing filler component including a recycled carbon black having an ash content of 5% to 25%; wherein the polymer composition meets formula (III):(III) rCB x A x P = X;wherein rCB is an amount of recycled carbon black in the polymer composition in phr and rCB is at least 10; A is the percentage ash content of the recycled carbon black; P is phr of a plasticizer and is at least 15; and X is 20 to 140. Ash percentage can be entered in the formula as a decimal, e.g., 18% is entered as 0.18.

[0016] In an embodiment, X may be, for example, about 25 to about 100, about 22 to about 55, about 27 to about 40, about 50 to about 120, or about 70 to about 100. In an embodiment, the rCB may be, for example, about 12 to about 20 phr, about 15 phr to about 25 phr, about 30 phr to about 55 phr, or about 35 phr to about 45 phr, or any of the amounts and ranges disclosed herein for rCB content. In an embodiment, the plasticizer may be present in an amount of, for example, about 15 to about 80 phr, about 17 to about 35 phr, about 15 phr to about 25 phr, about 20 phr to about 80 phr, about 40 phr to about 60 phr, about 45 phr to about 55 phr, or any of the amounts and ranges disclosed herein for plasticizer content. In an embodiment, a carbon black with high ash content, e.g., about 10% to about 25%, about 12% to about 20%, or about 15% to about 18% is used. In an embodiment, a carbon black with a low to medium ash content is used, e.g., about 5% to about 9%, about 6% to about 8%, or about 6.5% to about 7.5% is used.

[0017] In an embodiment. rCB is used with vCB or sCB to provide suitable characteristics for tire rubber compounds, including for treads, sidewalls, and other components listed herein. In an embodiment, the total overall ash content the carbon black component may be, e.g., about 1% to about 20%, such as, e.g., about 3% to about 12%, or about 5% to about 10%. Plasticizer is appropriately adjusted according to principals disclosed herein to provide suitable characteristics for the tire rubber compounds.

[0018] In an embodiment, the rubber polymer composition meets formula (IV):(IV) 0.55 ≤ X*(TD / Eb) ≤ 8.3

[0019] wherein TD is tan 6 at 60 °C at conditions further specified below and Eb is elongation at break at 25°C. TD may be, for example, 0.16 to 0.26 or any other value or rangedisclosed herein for the rubber composition. In an embodiment, Eb is 425% or greater, or any other value or range disclosed herein. EB values are to be entered in the formula as decimals, e.g., 450% can be entered as 4.5. A minimum for X*(TD / Eb) can be 1, 2, or 3. A maximum for X*(TD / Eb) can be 7.5, 7, or 6. In an embodiment, a tire component is a sidewall, carcass layer, or bead component and includes a rubber component including a conjugated diene polymer such as those disclosed herein, and a reinforcing filler component including a recycled carbon black having an ash content of about 5% to about 25%. Plasticizer may be present in an amount of 0 to about 5 phr. The total reinforcing filler component may be present in an amount of about 30 to about 150 phr, such as about 40 to about 120 phr, or about 50 to about 90 phr, or any other value or range disclosed herein, and the recycled carbon black is at least about 40% of the total reinforcing filler component.

[0020] In an embodiment, a carbon black with high ash content, e.g., ash content (A) of 10% to 25%, 12% to 25%, or 15% to 20%, is used with vCB or sCB to provide suitable characteristics for tire rubber compounds, including for treads, sidewalls, and other components listed herein. In an embodiment, the total overall ash content the carbon black component may be, e.g., 1% to 20%, such as, e.g., 3% to 12%, or 5% to 10%. Plasticizer is appropriately adjusted according to principals disclosed herein to provide suitable characteristics for the tire rubber compounds.

[0021] The term "ash" means the non-carbon content of the carbon black. The term stems from the use of a standard ASTM ash test (ASTM D8621) which is used to determine the level of inorganic content in recycled carbon black. The main non-carbon components of rCB, that is, ash, are silica, zinc, zinc-containing compounds (such as zinc sulfide or zinc oxide), calcium, aluminum, iron, silica, and magnesium oxide or other inorganic fillers.

[0022] In an embodiment, the composition meets the requirements of formula (V):(V) (rCBxA) / P ≥ 0.1wherein rCB is an amount of recycled carbon black in the polymer composition in phr; A is the percentage ash content of the recycled carbon black; and P is phr of a plasticizer. The rCB, A, and P values and ranges may be any of those disclosed herein. The right side of the formula (V) inequality can be, for example, ≥ 0.2, ≥ 0.3, or ≥ 0.5. An upper limit for (rCBxA) / P can be, forexample, 2, 1.5, 1.2, 0.9, or 0.6. Percentage ash content, as used in formulas herein, refers to the decimal equivalent, i.e., 10% is 0.10 in the formula.

[0023] Suitable characteristics for tire rubber compounds as mentioned above include about the same or better modulus, TB, EB, G' and / or DIN abrasion values according to DIN ISO 53516 and / or wear performance (as measured by ISO 23337:2016)) of a control. For example, suitable characteristics or an effective amount of rCB may be at least 90%, at least 95%, or at least 100% of an equivalent control with all virgin carbon black.

[0024] It is contemplated that recycled carbon black (rCB) is used the embodiments disclosed herein. However, in many embodiments, the rCB will be blended with virgin carbon black (vCB) and / or in some cases, blended with sustainably sourced carbon black (sCB).Accordingly, amounts and properties of suitable rCB, vCB, and sCB are provided below.

[0025] Recycled carbon black can be obtained from sources including reclaimed or recycled vulcanized rubber, whereby the vulcanized rubber is typically reclaimed from manufactured articles such as a pneumatic tire, an industrial conveyor belt, a power transmission belt, and a rubber hose. The recycled carbon black may be obtained by a pyrolysis process or other methods known for obtaining recycled carbon black. In an aspect, a recycled carbon black can be formed from incomplete combustion of recycled rubber feedstock or rubber articles. In another aspect, the recycled carbon black can be formed from the incomplete combustion of feedstock including oil resulting from the tire pyrolysis process. Any of the carbon blacks described herein and utilized in the inventive compounds can be in pelletized form or an unpelletized flocculent mass.

[0026] In an embodiment, the rCB is utilized in the rubber compositions in an amount of about 1 to about 80 phr. One or more than one rCB may be utilized to comprise the about 1 to about 80 phr. In certain embodiments, rCB can be present in amounts ranging from about 1 to about 75 phr, including about 1 to about 70 phr, about 15 to about 60 phr, about 20 to 50 phr, about 25 to about 60 phr, about 30 to about 65 phr, about 35 to about 50 phr, or about 35 to about 45 phr.

[0027] In certain embodiments, the rCB is the majority of the carbon black component of the compound, at least about 65% of the carbon black component of the compound, about50% to about 95%, about 60% to about 80% of the carbon black component of the component. In certain embodiments, the rCB is the entire filler component of the compound, at least about 20% of the filler component of the compound, or about 30% to about 55%, or about 40% to about 75% of the reinforcing filler component of the component. In an embodiment, the rubber composition or tire component has no more than 15 phr of silica, such as no more than 10 phr, no more than 5 phr, no more than 1 phr, or no silica other than what may be contained in the carbon black as ash.

[0028] In an embodiment, the rCB is derived from end of life tires through methods known by those of ordinary skill in the art.

[0029] In an embodiment sustainable carbon black is, one that is sourced from sustainable or otherwise non-fossil fuel sources, such as tire pyrolysis oil, plastic pyrolysis oil, pyrolyzed or otherwise processed vegetable or biomass feedstock, such as rice husk, bagasse, dead leaf, biochar, Palm kernel shells and oil palm fronds. This is in contrast to virgin carbon black which originates from a fossil fuel source.

[0030] In an embodiment, the sCB is utilized in the rubber compositions in an amount of about 1 to about 80 phr. One or more than one sCB may be utilized to comprise the about 1 to about 80 phr. In certain embodiments, sCB can be present in amounts ranging from about 1 to about 75 phr, including about 1 to about 70 phr, about 15 to about 60 phr, about 20 to 50 phr, about 25 to about 60 phr, about 30 to about 65 phr, about 35 to about 50 phr, or about 35 to about 45 phr.

[0031] In certain embodiments, the sCB is the majority of the carbon black component of the compound, at least about 65% of the carbon black component of the compound, about 50% to about 95%, about 60% to about 80% of the carbon black component of the component. In certain embodiments, the sCB is the entire filler component of the compound, at least about 25% of the filler component of the compound, or about 35% to about 55%, or about 40% to about 75% of the reinforcing filler component of the component.

[0032] Among the useful virgin carbon blacks are furnace black, channel black, and lamp blacks. More specifically, examples of useful carbon blacks include super abrasion furnace (SAF) blacks, high abrasion furnace (HAF) blacks, fast extrusion furnace (FEF) blacks, fine furnace (FF)blacks, intermediate super abrasion furnace (ISAF) blacks, semi-reinforcing furnace (SRF) blacks, medium processing channel blacks, hard processing channel blacks and conducting channel blacks. Other carbon blacks which can be utilized include acetylene blacks. Recycled carbon black can also be recycled versions of such virgin carbon blacks.

[0033] Examples of suitable virgin carbon blacks for use in certain embodiments are N-110, N-220, N-339, N-330, N-351, N-550, and N-660, as designated by ASTM D-1765-82a. The recycled carbon black can also be recycled versions of such virgin carbon blacks. Sustainable carbon blacks can have properties that match these ASTM grade carbon blacks.

[0034] In an embodiment, the vCB is utilized in the rubber compositions in an amount of about 1 to about 80 phr. One or more than one vCB may be utilized to comprise the about 1 to about 80 phr. In certain embodiments, vCB can be present in amounts ranging from about 1 to about 75 phr, including about 1 to about 70 phr, about 15 to about 60 phr, about 20 to 50 phr, about 25 to about 60 phr, about 30 to about 65 phr, about 35 to about 50 phr, or about 35 to about 45 phr.

[0035] In certain embodiments, the vCB is the majority of the carbon black component of the compound, at least about 65% of the carbon black component of the compound, about 50% to about 95%, about 60% to about 80% of the carbon black component of the component. In certain embodiments, the vCB is the entire filler component of the compound, at least about 25% of the filler component of the compound, or about 35% to about 55%, or about 40% to about 75% of the reinforcing filler component of the component.

[0036] In an embodiment, a percentage or ratio at which rCB is blended into the vCB or sCB material would be such that minimal or no adverse property changes were observed during or after the compounding and vulcanization process. The appropriate % rCB for addition to the rubber composition would depend upon rCB source, type, quality, and the virgin or sustainable carbon black material with which it's being co-pelletized. For example, an N660 type vCB may be blended with higher rCB percentages while an N330 vCB may be blended with lower percentages of rCB. N660 has a higher structure and finer particles than N330. This is theoretically driven by different material interactions but also simply the baseline colloidal properties of the carbon black, e.g. surface area and structure.

[0037] In an embodiment, the rCB is in a weight, amount with the vCB and / or rCB in a ratio of about 10: about 90 (rCB:vCB+vCB) to about. 90: about 10; about 20: about 80 to about 80: about 20; about 30: about 70 to about 70: about 30; or about 45: about 55 to about 55: about 45.

[0038] Generally, suitable carbon blacks for use as a reinforcing filler in the rubber composition of certain embodiments include any of the commonly available, commercially- produced virgin carbon blacks, and sustainable or recycled carbon blacks having a surface area of at least about 35 m2 / g up to about 300 m2 / g, about 50 m2 / g to about 200 m2 / g, and about 75 m2 / g to about 175 m2 / g, as determined by ASTM D-1765 using the cetyltrimethyl-ammoniiim bromide (CTAB) technique.

[0039] The virgin carbon black, sustainable carbon black and recycled carbon black may have a surface area of at least about 20 m2 / g, including at least about 35 m2 / g up to about 300 m2 / g, about 50 m2 / g to about 200 m2 / g, and about 65 m2 / g to about 155 m2 / g, as determined by BET N2SA. The BET N2SA surface area can be determined in accordance with ASTM D-6556.

[0040] Average primary particle diameter of any of the carbon blacks may range from 15 to 100 nm, such as 20 to 70 nm, or 30 to 60 nm per ASTM D3849.

[0041] In an embodiment, the sustainable or virgin carbon black has an oil absorption number (OAN) of 50 m2 / 100 g to 200 m2 / 100 g. In another embodiment, the OAN value is 6.5 m2 / 100 g to 150 m2 / 100 g, 70 m2 / 100 g to 130 m2 / 100 g, or 75 m2 / 100 g to 130 m2 / 100 g, or 80 m2 / 100 g to 120 m2 / 100 g. The OAN absorption is determined according to the standard 5 ASTM D 2414-00.

[0042] In an embodiment, the sustainable or virgin carbon black has a compressed sample oil absorption number (C-OAN) of 45 m2 / 100 g to 1800 m2 / 100 g. In another embodiment, the C-OAN value is 55 m2 / 100 g to 140 m2 / 100 g, 60 m2 / 100 g to 120 m2 / 100 g, 70 m2 / 100 g to 115 m2 / 100 g, or 80 m2 / 100 g to 110 m2 / 100 g. The C-OAN absorption is determined according to the standard 5 ASTM D 3493-21. Recycled carbon black is generally not suitable for OAN or C-OAN testing under normal methods.

[0043] In an embodiment, the recycled, sustainable, or virgin carbon black has a void volume as a function of mean pressure measured by a Dynamic Void Volume Analyzer (DVVA)according to ASTM D7854-16 has a value of about 25 to about 120, such as about 30 to about 90, about 40 to about 70, or about 45 to about 65.

[0044] Tint Strength can be determined by ASTM Test Procedure D3265-85a. In an embodiment, the tint of the carbon black (recycled, sustainable, or virgin) can range from about 35 to about 120, such as, for example, about 40 to about 110, or about 50 to about 92.

[0045] In an embodiment, the carbon black (recycled, sustainable, or virgin) may have a tinting strength in accordance with the following formula: (TINT)>0.363×CTAB+71.792. Tinting strength in accordance with the formula (TINT)>0.363×CTAB+71.792 may improve the reinforcing property of the rubber with the carbon black.

[0046] In an embodiment, the carbon black (recycled, sustainable, or virgin) has a (TINT)<0.363xCTAB+ 71.792 and (TINT)> about 50. In this case, the dispersibility of the carbon black in the rubber may be improved and contribute to lowering the heat buildup of rubber. In case that TINT is more than about 50, strength and wear resistance may be improved.

[0047] In an embodiment, percent toluene discoloration of the carbon black (recycled, sustainable, or virgin) can be measured by Item 8, B-process of ASTM D1618 and represented by a percentage to pure toluene. The percent toluene discoloration can be in a range of about 80% to about 125%, such as, about 90% to about 110%, or about 92% to about 103%.

[0048] In an embodiment, the carbon black (recycled, sustainable, or virgin) in a 15% suspension in distilled water has a pH value of greater than about 6, greater than about 7, or greater than about 8. In an embodiment, the pH value of a 15% suspension of the particulate carbon material in distilled water is less than about 10, or less than about 9. ASTM D-1512 can be used to determine the pH.

[0049] In an embodiment, the carbon black (recycled, sustainable, or virgin) has a DIG signal ratio in the Raman spectrum of 0.20 to 0.90, such as 0.40 to 0.75, such as 0.45 to 0.70. This provides a measure of the content of graphitic carbon.

[0050] In one embodiment, the carbon black (recycled, sustainable, or virgin) has an iodine absorption in the range of 50 to 210 g / kg according to ASTM-D1510, such as 70 to 180 g / kg, or 90 to 150 g / kg. Iodine can be difficult to measure in recycled carbon blacks since it canreact with or be sequestered by components of the ash, namely the silica. The Iodine adsorption is determined in accordance with ASTM D-1510.

[0051] A percent sulfur of the recycled carbon black can be determined by JIS K2213. Recycled carbon black may have a higher percent sulfur in general than a virgin carbon black. This may be in a range, for example, of about 0.8% to about 5%, such as, about 1% to about 3%, or about 1.2% to about 2%. Virgin or sustainable carbon black may have a lower sulfur content, such as, for example, about 0.01 to about 0.8%, 0.1 to about 0.6%, or about 0.2% to about 0.4%.

[0052] In an embodiment, the carbon black (sustainable or virgin) has a volatiles or moisture content by ASTM D1509 of about 1% to about 5%, such as, about 1.3% to about 4.5%, or about 1.5% to about 4%. The recycled carbon black can have a hydrocarbon volatile content as determined by ASTM D8474 of about 1% to about 5%, such as, about 1.3% to about 4.5%, or about 1.5% to about 4%.

[0053] In an embodiment, the carbon black (recycled, sustainable, or virgin) has a PAH content (mg / kg, ppm) less than about 3, such as, about 0.05 to about 1, or about 0.00001 to about 0.03, measured according to ASTM D8143.

[0054] In an embodiment, the carbon black (recycled, sustainable, or virgin) has a crystalline silica content (%) of less than about 0.1, such as about 0.05 to about 0.01, or about 0.8 to about 0.001, measured according to XRD. The present invention also relates to the use of a scrap rubber derived carbon black powder discussed above, or obtained according to the method discussed above, as a filler or a reinforcing agent in a rubber composition, an ink, a paint, a bitumen, a thermoplastic composition or a thermoplastic elastomer.

[0055] In an embodiment, the carbon black (recycled, sustainable, or virgin) can have a particle size according to DCP (disc centrifuge photosedimentometry), d90 (μm) of about 0.1 to about 1, such as, about 0.2 to about 0.5, or about 0.28 to about 0.35. d90 means that 90% of the total particles are smaller than the given size.

[0056] In an embodiment, the recycled carbon black has an ash content of about 1% to about 25%, such as, about 2% to about 15%, or about 5% to about 12%. Ash content can be difficult to limit in recycled carbon black. Accordingly, in certain embodiments of recycledcarbon black with limited ash content, the ash content is about 1% to about 5%, or about 1.3% to about 4%, or 1.5% to about 3.5%. In some rubber compositions, lower ash content may lead to improved properties. Accordingly, in certain embodiments of recycled carbon black with high ash content, the ash content may be 10% to about 25%, or about 13% to about 24%, or 15% to about 21%. Sustainable carbon black may also have low ash content, e.g., less than 1%, less than 0.5%, or less than 0.1%. Virgin carbon black has very low ash content, e.g., less than 1%, less than 0.5%, or less than 0.1%.

[0057] The term "ash" means the non-carbon content of the rCB. The term stems from the use of a standard ASTM ash test which is used to determine the level of inorganic content in rCB. The main non-carbon components of rCB, that is, ash, are silica, zinc sulfide and zinc oxide.

[0058] In an embodiment, the % heating loss of the carbon black (recycled, sustainable, or virgin) has a value of about 0.05% to about 4%, such as, about 0.1% to about 2%, or about 0.5 to about 1.2%. ASTM D1509-18 can be used to determine this property. Heating loss of carbon black is an indication of moisture content.

[0059] The properties disclosed above are with respect to distinct types of carbon blacks prior to any mixing. The same property ranges can be applied to mixed combinations of multiple types of blended carbon blacks.

[0060] Plasticizers as disclosed herein, include resins, oils, and other components that reduce uncured compound Mooney viscosity and / or cured compound glass transition temperature. Plasticizers are widely used in the rubber tire industry. They can reduce rubber viscosity and thus improve the processing properties and filler dispersion to enhance viscoelasticity. This also enables a reduction in processing energy inputs. Plasticizers can also increase free volume between polymer chains, spacing them apart. This enables polymer chains to slide past each other at lower temperatures resulting in a decrease in Tg. Oils are generally used to reduce viscosity / improve processability. Resins and liquid polymers also can be used to reduce viscosity, but may also be used to alter the Tg / viscoelastic curve of the composition.

[0061] The inventors determined that the more rCB that is used the compound that less plasticizer needs to be added to counteract the tendency of the rCB to affect the absorption ofthe plasticizer, particularly the tendency of the ash in the rCB to prevent absorption by CB of the plasticizer.

[0062] In certain embodiments, the tire tread rubber composition comprises about 1 to about 35 phr (e.g., 5, 15, 20, 25, 29, 30, 31, 32, 33, 34, or 35 phr) of at least one hydrocarbon resin having a Tg of about 30 to about 50 °C (e.g., 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 42, 44, 45, 46, 48, or 50 °C). The tire tread rubber composition may comprise 25-35 phr (e.g., 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35 phr) of at least one aromatic hydrocarbon resin having a Tg of about 30 to about 50 °C or 30-50 °C (e.g., 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 42, 44, 45, 46, 48, or 50 °C). In certain embodiments, the tire tread rubber composition comprises 30-35 phr (e.g., 30, 31, 32, 33, 34, or 35 phr) of at least one hydrocarbon resin, such as an aromatic hydrocarbon resin, having a Tg of 30-50 °C, or a range within that range, as discussed infa. Hydrocarbon resin Tg can be determined by DSC, according to the procedure discussed above for elastomer Tg measurements. In certain embodiments, the at least one hydrocarbon resin has a Tg of about 35 to about 50 °C, 35- 50 °C (e.g., 30, 32, 34, 35, 36, 38, 40, 42, 44, 45, 46, 48, or 50 °C), about 35 to about 45 °C, or 35-45 °C (e.g., 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, or 45 °C) and may be present in one of the foregoing discussed amounts.

[0063] In an embodiment, the hydrocarbon resin comprises an aromatic resin optionally in combination with one or more additional resins selected from aliphatic, cycloaliphatic, and terpene resins; in those embodiments wherein one or more additional resins are present, the total amount of such additional resin(s) is, for example, no more than 5 phr, less than 5 phr, less than 4 phr, less than 3 phr, less than 2 phr, or less than 1 phr (and in each instance no more than 10% by weight, or no more than 5% by weight of the overall amount of hydrocarbon resin). In other embodiments, the hydrocarbon resin consists of (only) an aromatic hydrocarbon resin. When an aromatic resin is used, one or more than one aromatic hydrocarbon resin may be utilized. In embodiments, the hydrocarbon resin includes less than 5 phr of terpene resin, and may exclude any terpene resin (i.e., 0 phr of terpene resin is present in the tire tread rubber composition). As used herein, the term aromatic resin or aromatic hydrocarbon resin should be understood to include both aromatic homopolymer resins and aromatic copolymer resins. An aromatic copolymer resins refers to a hydrocarbon resin whichcomprises a combination of one or more aromatic monomers in combination with one or more other (non-aromatic) monomers, with the largest amount of any type of monomer being aromatic. An aromatic copolymer resin would include a hydrocarbon resin having 45% by weight aromatic monomers, in addition to 25% by weight cycloaliphatic monomers and 30% by weight aliphatic monomers as well as a hydrocarbon resin having 55% by weight aromatic monomers, in addition to 30% by weight cycloaliphatic monomers and 15% by weight aliphatic monomers. In certain embodiments, the hydrocarbon resin comprises one or more aromatic copolymer resins having a majority by weight of all monomers being aromatic (e.g., 51%, 55%, 60%, 65%, etc.). Non-limiting examples of aromatic resins suitable for use as the hydrocarbon resin in certain embodiments include coumarone-indene resins and alkyl- phenol resins as well as vinyl aromatic homopolymer or copolymer resins such as those including one or more of the following monomers: alpha-methylstyrene, styrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, vinyltoluene, para(tert-butyl)styrene, methoxystyrene, chlorostyrene, hydroxystyrene, vinylmesitylene, divinylbenzene, vinylnaphthalene or any vinyl aromatic monomer resulting from C9 fraction or C8-C10 fraction. Non-limiting examples of vinylaromatic copolymer resins include vinylaromatic / terpene copolymer resins (e.g., limonene / styrene copolymer resins), vinylaromatic / C5 fraction resins (e.g., C5 fraction / styrene copolymer resin), vinylaromatic / aliphatic copolymer resins (e.g., CPD / styrene copolymer resin, and DCPD / styrene copolymer resin). Non-limiting examples of alkyl-phenol resins include alkylphenol-acetylene resins such as p-tert-butylphenol-acetylene resins, alkylphenol-formaldehyde resins (such as those having a low degree of polymerization). Exemplary such aromatic resins are commercially available from various companies including Chemfax, Dow Chemical Company, Eastman Chemical Company, Idemitsu, Neville Chemical Company, Nippon, Polysat Inc., Resinall Corp., and Zeon under various trade names.

[0064] In certain embodiments, the hydrocarbon resin comprises an aromatic resin based upon one or more of the above-mentioned vinyl aromatic monomers (e.g., styrene, alpha-methylstyrene); in certain such embodiments at least 80% by weight, at least 85% by weight, at least 90% by weight, at least 95% by weight, at least 98% by weight, at least 99% by weight, or even 100% by weight of the monomers in the aromatic resin are aromaticmonomers. In certain embodiments, the hydrocarbon resin consists of an aromatic resin based upon one or more of the above- mentioned vinyl aromatic monomers (e.g., styrene, alphamethylstyrene); in certain such embodiments at least 80% by weight, at least 85% by weight, at least 90% by weight, at least 95% by weight, at least 98% by weight, at least 99% by weight, or even 100% by weight of the monomers in the aromatic resin are aromatic monomers. In certain embodiments, the aromatic resin may include a hydrogenated form of one of the aromatic resins discussed above (i.e., a hydrogenated aromatic resin). In other embodiments, the aromatic resin excludes any hydrogenated aromatic resin; in other words, in such embodiments, the aromatic resin is not hydrogenated.

[0065] As mentioned above, in certain embodiments, the at least one hydrocarbon resin comprises (i) an aromatic resin in combination with (ii) an aliphatic resin. Non-limiting examples of aliphatic resins include C5 fraction homopolymer and copolymer resins. In an embodiment, the total amount of any aliphatic resin used in combination with the aromatic resin is no more than 5 phr, less than 5 phr, less than 4 phr, less than 3 phr, less than 2 phr, or less than 1 phr (and in each instance no more than 20% by weight, such as no more than 15% or no more than 10% by weight of the overall amount of hydrocarbon resin.

[0066] As mentioned above, in certain embodiments, the at least one hydrocarbon resin comprises (i) an aromatic resin in combination with (ii) a cycloaliphatic resin. Nonlimiting examples of cycloaliphatic resins include cyclopentadiene (" CPD") homopolymer or copolymer resins, dicyclopentadiene (" DCPD") homopolymer or copolymer resins, and combinations thereof. The total amount of any cycloaliphatic resin used in combination with the aromatic resin is, e.g., may be no more than 5 phr, less than 5 phr, less than 4 phr, less than 3 phr, less than 2 phr, or less than 1 phr (and in each instance no more than 20% by weight, no more than 15%, or no more than 10% by weight of the overall amount of hydrocarbon resin.

[0067] In certain embodiments the at least one hydrocarbon resin comprises (i) an aromatic resin in combination with (ii) a terpene resin. Non-limiting examples of terpene resins include alpha-pinene resins, beta-pinene resins, limonene resins (e.g., L-limonene, D-limonene, dipentene which is a racemic mixture of L- and D-isomers), beta-phellandrene, delta-3-carene, delta-2-carene, and combinations thereof. The total amount of any terpene resin used incombination with the aromatic resin is, e.g., no more than 5 phr, less than 5 phr, less than 4 phr, less than 3 phr, less than 2 phr, or less than 1 phr (and in each instance no more than 20% by weight, such as no more than 15%, or no more than 10% by weight of the overall amount of hydrocarbon resin. As mentioned above, in embodiments, the hydrocarbon resin includes no terpene resin (i.e., 0 phr).

[0068] In certain embodiments, the hydrocarbon resin has a softening point of about 70 to about 100 °C or 70-100 °C (e.g., 70, 75, 80, 85, 90, 95, or 100 °C), about 75 to about 95 °C or 75-95 °C (e.g., 75, 76, 77, 78,79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, or 95 °C), or about 80 to about 90 °C or 80-90 °C (e.g., 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, or 90 °C). Generally the softening point of a hydrocarbon resin will have a relationship to its Tg such that the Tg is lower than its softening point, and such that the lower the Tg the lower the softening point. As a non- limiting example, for two hydrocarbon resins having Tg's of 70 and 100 °C, the resin with the Tg of 70 °C will have a lower softening point than the resin with the Tg of 100 °C.

[0069] In certain embodiments, the hydrocarbon resin meets at least one of the following: (a) a Mw of 1000 to about 4000 grams / mole, 1000-4000 grams / mole (e.g., 1000, 1100. 1200. 1300. 1400. 1500. 1600. 1700. 1800. 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, or 4000 grams / mole), about 1000 to about 3000 grams / mole, 1000-3000 grams / mole (e.g., 1000, 1100, 1200. 1300. 1400. 1500. 1600. 1700. 1800. 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, or 3000 grams / mole), about 1000 to about 2500 grams / mole, 1000-2500 grams / mole (e.g., 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, or 2500 grams / mole), about 1000 to about 2000 grams / mole, 1000-2000 grams / mole (e.g., 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, or 2000 grams / mole), about 1100 to about 1800 grams / mole, or 1100-1800 grams / mole (e.g., 1100, 1200, 1300, 1400, 1500, 1600, 1700, or 1800 grams / mole); (b) a Mn of about 700 to about 1500 grams / mole, 700-1500 grams / mole (e.g., 700, 800, 900, 1000, 1100, 1200, 1300, 1400, or 1500 grams / mole), about 800 to about 1400 grams / mole, 800-1400 grams / mole (e.g., 800, 900, 1000, 1100, 1200, 1300, or 1400 grams / mole), about 800 to about 1300 grams / mole, 800-1300 grams / mole (e.g., 800, 900, 1000, 1100, 1200, or 1300 grams / mole), about 900 to about 1200grams / mole, or 900-1200 grams / mole (e.g., 900, 950, 1000, 1050, 1100, 1150, or 1200 grams / mole); or (c) a polydispersity (Mw / Mn) of about 1 to about 2, 1-2 (e.g., 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2), about 1.1 to about 1.8, 1.1-1.8 (e.g., 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, or 1.8), about 1.1 to about 1.7, 1.1-1.7 (e.g., 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, or 1.7), about 1.2 to about 1.5, or 1.2 to 1.5 (e.g., 1.2, 1.3, 1.4, or 1.5). In certain embodiments, the hydrocarbon resin has a Mw according to one of the ranges provided above, in combination with a Mn according to one of the ranges provided above, further in combination with a Mw / Mn according to one of the ranges provided above; in certain such embodiments, the hydrocarbon resin is an aromatic resin.

[0070] In certain embodiments, the hydrocarbon resin comprises an aromatic resin (as discussed above) having an aromatic monomer content of at least about 40% by weight, at least 40% by weight (e.g., 40, 45, 50, 51, 55, 60% by weight, or more), about 40% to about 65% by weight, 40-65% by weight (e.g., 40, 42, 44, 45, 46, 48, 50, 52, 54, 55, 56, 58, 60, 62, 64, or 65% by weight), at least about 45% by weight, at least 45% by weight (e.g., 45, 50, 51, 55, 60% by weight, or more), about 45% to about 65% by weight, 45-65% by weight (e.g., 45, 47, 49, 50, 51, 53, 55, 57, 59, 60, 61, 63, or 65% by weight), at least 51% by weight (e.g., 51, 55, 60, 65% by weight, or more), about 51% to about 65% (e.g., 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, or 65%), 51-65%, about 51% to about 60%, 51-60% (e.g., 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%), about 51% to about 55%, or 51-55% (e.g, 51, 52, 53, 54, or 55%). The amounts of aromatic monomer content are weight percentages based upon the total weight of the respective hydrocarbon resin.

[0071] The tire tread rubber composition may comprise 0 to about 35 phr of liquid plasticizer (e.g., about 1 to about 35 phr, about 5 to about 25 phr, about 10 to about 20 phr, such as 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 phr), which may include at least one oil. In embodiments, the 11-20 phr of liquid plasticizer comprises at least one oil. In an embodiment, the 11-20 phr of liquid plasticizer consists of (only) at least one oil. In certain embodiments, the tire tread rubber composition comprises 15 to 20 phr of liquid plasticizer (e.g., 15, 16, 17, 18, 19, or 20 phr).

[0072] The term liquid plasticizer is used to refer to plasticizer ingredients which are liquid at room temperature ( / .e., liquid at 25 °C and above) and to distinguish hydrocarbon resin plasticizers which will generally be solid at room temperature. Generally, liquid plasticizers will have a Tg below 0 °C, generally well below such as less than -30 °C, less than -40 °C, or less than -50 °C. In certain embodiments, the liquid plasticizer has a Tg of less than 0 °C to -100 °C, a Tg of -30 °C to -100 °C, or a Tg of -50 to -100 °C. Liquid plasticizers include both oils (e.g., petroleum oils as well as plant oils) and other non-oil liquid plasticizers including, but not limited to, ether plasticizers, ester plasticizers, phosphate plasticizers, and sulfonate plasticizers. Moreover, the term liquid plasticizer is meant to encompass both free liquid plasticizer (which is usually added during the compounding process) and extender oil (which is used to extend a rubber). Thus, by stating that the tire tread rubber composition comprises 11-20 phr of liquid plasticizer it should be understood that the total amount of any free liquid plasticizer (both oil plasticizer and nonoil liquid plasticizer) and any extender oil is 11-20 phr.

[0073] In certain embodiments, the tire tread rubber composition contains onlyfree liquid plasticizer in an amount of about 1-30 phr, 3-15 phr, or 5-10 phr. In other embodiments, the tire tread rubber composition contains only extender oil in an amount of about 1-30 phr, 3-15 phr, or 5 to 10 phr. In yet other embodiments, the tire tread rubber composition includes both free liquid plasticizer and extender oil in a total amount of about 1-30 phr, 3-15 phr, or 5-10 phr.

[0074] In those embodiments wherein an oil-extended rubber is used, the amount of oil used to prepare the oil-extended rubber may vary. In those embodiments wherein an oil-extended rubber is used (e.g., an oil-extended SBR for (i)) and according to embodiments wherein the SBR (i) is oil-extended, the amount of oil used to prepare the oil-extended rubber may vary; in certain such embodiments, the amount of extender oil present in the oil-extended rubber (polymer) or SBR is 10-50 parts oil per 100 parts of rubber (e.g., 10, 15, 20, 25, 30, 35, 40, 45 or 50 parts of oil per 100 parts or rubber), such as 10-40 parts oil per 100 parts or rubber, or 20-40 parts oil per 100 parts of rubber. As a non-limiting example, extender oil could be used in an amount of 40 parts oil per 100 parts rubber in an SBR for (i) which SBR is used in an amount of 40 parts (the 40 parts being the amount of polymer of the oil-extended SBR, asdiscussed previously) in the overall tread rubber composition and, thus, the amount of oil contributed by the oil-extended SBR to the tire tread rubber composition would be 16 phr. Oilextension of rubbers (especially styrene- butadiene rubbers) can be beneficial to ease of processing or mixingwhen the SBR has a relatively high Mw and / or a relatively high Mooney viscosity.

[0075] In certain embodiments disclosed herein, the styrene-butadiene rubber as used in (i) is an oil-extended styrene-butadiene rubber having a polymer Mooney viscosity ML1+4 at 100 °C of at least 100. By polymer Mooney viscosity is meant the Mooney viscosity of the rubber or polymer before oil- extension. When an oil-extended rubber is used in the elastomer component of the tire tread rubber composition disclosed herein, the amounts specified for (i) (and (ii)) should be understood to refer to the amounts of rubber only rather than the amounts of oil-extended rubber. As used herein, oil refers to both petroleum based oils (e.g., aromatic, naphthenic, and low PCA oils) as well as plant oils (such as can be harvested from vegetables, nuts, and seeds). Plant oils will generally comprise triglycerides and the term should be understood to include synthetic triglycerides as well as those actually sourced from a plant.

[0076] Various types of processing and extender oils may be utilized as the at least one liquid plasticizer, including, but not limited to aromatic, naphthenic, and low PCA oils (petroleum-sourced or plant-sourced). Suitable low PCA oils include those having a polycyclic aromatic content of less than 3 percent by weight as determined by the IP346 method.Procedures for the IP346 method may be found in Standard Methods for Analysis & Testing of Petroleum and Related Products and British Standard 2000 Parts, 2003, 62nd edition, published by the Institute of Petroleum, United Kingdom. Exemplary petroleum-sourced low PCA oils include mild extraction solvates (MES), treated distillate aromatic extracts (TDAE), TRAE, and heavy naphthenics. Exemplary MES oils are available commercially as CATENEX SNR from SHELL, PROREX 15, and FLEXON 683 from EXXONMOBIL, VIVATEC 200 from BP, PLAXOLENE MS from TOTAL FINA ELF, TUDALEN 4160 / 4225 from DAHLEKE, MES-H from REPSOL, MES from Z8, and OLIO MES S201 from AGIP. Exemplary TDAE oils are available as TYREX 20 from EXXONMOBIL, VIVATEC 500, VIVATEC 180, and ENERTHENE 1849 from BP, and EXTENSOIL 1996 from REPSOL. Exemplary heavy naphthenic oils are available as SHELLFLEX 794, ERGON BLACKOIL, ERGON H2000, CROSS C2000, CROSS C2400, and SAN JOAQUIN 2000L. Exemplary low 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 (including high oleic 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. The foregoing processing oils can be used as an extender oil, i.e., to prepare an oil-extended polymer or copolymer, or as a processing or free oil.

[0077] The liquid plasticizer may in certain embodiments include a non-oil plasticizer, non-limiting examples of which include ether plasticizers, ester plasticizers, phosphate plasticizers, and sulfonate plasticizers. In those embodiments where a non-oil plasticizer is present, optionally only a portion of the liquid plasticizer (e.g., less than 50%, no more than 40%, no more than 30%, no more than 20%, no more than 10%, or even no more than 5% is provided by the non-oil plasticizer). Exemplary ether plasticizers include polyethylene glycols and polypropylene glycols. Exemplary ester plasticizers include triesters and diesters in particular (which may be selected from the group consisting of di- and triesters of carboxylic acid, of phosphoric acid, or of sulphonic acid, and mixtures of these triesters). More specifically, exemplary carboxylic acid ester plasticizers include compounds selected from the group consisting of trimellitates, pyromellitates, phthalates, 1,2-cyclohexanedicarboxylates, adipates, azelates, sebacates, glyercol triesters, and mixtures of the foregoing. More specifically as to glycerol triesters, these may include more than 50% by weight, or more than 80% by weight of an unsaturated C18 fatty acid (e.g., oleic acid, linoleic acid, linolenic acid, and mixtures thereof). Otherexemplary carboxylicacid ester plasticizers include stearicacid esters, ricinoleic acid esters, phthalic acid esters (e.g., di-2-ethylhexyl phthalate and diosodecyl phthalate), isophthalic acid esters, tetrahydrophthalic acid esters, adipic acid esters (e.g., di(2-ethylhexyl)adipate and diisooctyl adipate), malic acid esters, sebic acid esters (e.g., di(2-ethylhexyl)sebacate and diisooctyl sebacate), and fumaric acid esters. Exemplary phosphate plasticizers include those with a tri-hydrocarbyl phosphate and di-hydrocarbyl phosphate structures (where each hydrocarbyl is independently selected from alkyl of Cl to C12, Cl to C8, and aromatic of C6 to C12 (both substituted and un-substituted), when aromatic C6 is eithersubstituted or un-substituted. More specifically, exemplary phosphate plasticizers include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, dioctyl phosphate, 2- ethylhexyl diphenyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, isodecyl diphenyl phosphate, tricresyl phosphate, tritolyl phosphate, trixylenyl phosphate, tris(chloroethyl) phosphate, and diphenyl mono-o-xenyl phosphate. Exemplary sulfonate plasticizers include sulfonic acid esters such as sulfone butylamide, toluenesulfonamide, N-ethyl-toluenesulfonamide, and N-cyclohexyl-p-toluencesulfonamide.

[0078] In certain embodiments, any oil utilized has a Tg of about -40 to about -100 °C, -40 to -100 °C (e.g., -40, -45, -50, -55, -60, -65, -70, -75, -80, -85, -90, -95, or -100°C), about -40 to about -90 °C, -40 to -90 °C (e.g., -40, -45, -50, -55, -60, -65, -70, -75, -80, -85, or -90 °C), about -45 to about -85 °C, -45 to -85 °C (e.g., -45, -50, -55, -60, -65, -70, -75, -80, or -85°C), about -50 to about -80 °C, or -50 to -80 °C (e.g., -50, -55, -60, -65, -70, -75, or -80 °C).

[0079] In certain embodiments, the tire tread rubber composition contains less than 5 phr (e.g., 4.5, 4, 3, 2, 1, or 0 phr) of MES or TDAE oil, or even no MES or TDAE oil (i.e., 0 phr). In certain embodiments, the tire tread rubber composition contains no petroleum oil (i.e., 0 phr) and instead any oil utilized is a plant oil. In certain embodiments, the tire tread rubber composition contains soybean oil in one of the above-mentioned amounts. In certain embodiments, the tire tread rubber composition contains no sunflower oil (i.e., 0 phr).

[0080] In certain embodiments the tire tread rubber composition includes one or more ester plasticizers. Suitable ester plasticizers are known to those of skill in the art and include, but are not limited to, phosphate esters, phthalate esters, adipate esters and oleate esters (i.e., derived from oleic acid). Taking into account that an ester is a chemical compound derived from an acid wherein at least one -OH is replaced with an -O- alkyl group, various alkyl groups may be used in suitable ester plasticizers for use in the tire tread rubber compositions, including generally linear or branched alkyl of Cl to C20 (e.g., Cl, C2, C3, C4, C5, C6, C7, C8, C9, CIO, Cll, C12, C13, C14, C15, C16, C17, C18, C19, C20), or C6 to C12. Certain of the foregoing esters are based upon acids which have more than one -OH group and, thus, can accommodate one or more than one O-alkyl group (e.g., trialkyl phosphates, dialkyl phthalates, dialkyladipates). Non-limiting examples of suitable ester plasticizers include trioctyl phosphate, dioctyl phthalate, dioctyl adipate, nonyl oleate, octyl oleate, and combinations thereof. The use of an ester plasticizer such as one or more of the foregoing may be beneficial to the snow or ice performance of a tire made from a tread rubber composition containing such ester plasticizer at least in part due to the relatively low Tg of ester plasticizers. In certain embodiments, the tire tread rubber composition includes one or more ester plasticizers having a Tg of -40 °C to -70 °C (e.g., -40, -45, -50, -55, -60, -65, or -70°C), or -50 °C to -65 °C (e.g., -50, -51, -52, -53, -54, -55, -56, -57, -58, -59, -60, -61, -62, -63, -64, or -65 °C ). In those embodiments wherein one or more ester plasticizers is utilized the amount utilized may vary. In certain embodiments, one or more ester plasticizers are utilized in a total amount of 1-12 phr (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 phr), 1-10 phr (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 phr), 2-6 phr (e.g., 2, 3, 4, 5, or 6 phr) or 2-5 phr (e.g., 2, 3, 4, or 5 phr). In certain embodiments, one or more ester plasticizers is used in combination with oil in one of the foregoing amounts.

[0081] In an embodiment, the total amount of at least one hydrocarbon resin (which can be a plasticizing resin) and at least one liquid plasticizer is 0 to about 50 phr (e.g., about 1 to about 40 phr, about 5 phr to about 35 phr, or about 10 phr to about 20 phr, such as, e.g., 18, 22, 24, 26, 28, 30, 32, 34, 36, or 38 phr). In certain embodiments, the total amount of hydrocarbon resin and liquid plasticizer is about 40 to about 50 phr (e.g., 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 phr). In certain embodiments, the total amount of hydrocarbon resin and liquid plasticizer is no more than 49 phr (e.g., 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, or 36 phr, or a range from the foregoing, such as 36-49 phr). In an embodiment the total resin or total plasticizing resin content is less than 15 phr, such as 1 to 10 phr, or 2 to 7 phr.

[0082] In certain embodiments, the amount of hydrocarbon resin is greater than the amount of liquid plasticizer. In certain such embodiments, the hydrocarbon resin and liquid plasticizer may be present in a weight ratio of at least 1.5:1, such as 1.5:1 to 3:1 (e.g., 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, or 3:1), or 1.6:1 to 2.8: (e.g., 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, or 2.8:1).

[0083] As used herein, the term "reinforcing" with respect to "reinforcing carbon black filler," "reinforcing silica filler," and "reinforcing filler" generally should be understood to encompass both fillers that are traditionally described as reinforcing as well as fillers that may traditionally be described as semi-reinforcing. Traditionally, the term "reinforcing filler" is used to refer to a particulate material that has a nitrogen absorption specific surface area (N2SA) of more than about 100 m2 / g, and in certain instances more than 100 m2 / g, more than about 125 m2 / g, more than 125 m2 / g, or even more than about 150 m2 / g or more than 150 m2 / g.Alternatively (or additionally), the traditional use of the term "reinforcing filler" can also be used to refer to a particulate material that has a particle size of about 10 nm to about 50 nm (including 10 nm to 50 nm). Traditionally, the term "semi-reinforcing filler" is used to refer to a filler that is intermediary in either particle size, surface area (N2SA), or both, to a non-reinforcing filler (as discussed below) and a reinforcing filler. The copelleted carbon black described herein is considered to be a reinforcing filler.

[0084] In embodiments disclosed herein, the term "reinforcing filler" is used to refer to a particulate material that has a nitrogen absorption specific surface area (N2SA) of about 20 m2 / g or greater, including 20 m2 / g or greater, more than about 50 m2 / g, more than 50 m2 / g, more than about 100 m2 / g, or more than 100 m2 / g. In certain embodiments disclosed herein, the term "reinforcing filler" is used to refer to a particulate material that has a particle size of about 10 nm up to about 1000 nm, including 10 nm to 1000 nm, about 10 nm up to about 50 nm and 10 nm to 50 nm.

[0085] In an exemplary embodiment, the tire tread rubber composition is exclusive or substantially exclusive of silica reinforcing filler. In an embodiment, the rubber composition may comprise at least one reinforcing silica filler in an amount of about 0.001 to about 5 phr (e.g., about 0.01 to about 3 phr, about 0.1 to about 2.5 phr, or about 0.2 phr to about 1 phr), having a surface area of about 100 to about 300 m2 / g (e.g., 110, 120, 130, 140, 150, 160, 180, 200, 220, 240, 260, 280, or 300 m2 / g), such as, about 150 to about 300 m2 / g, or about 180 to about 250 m2 / g. In embodiments, the only reinforcing silica filler(s) used in the tire tread rubber composition have a surface area outside of those discussed above; in suchembodiments, the tire tread rubber composition can be understood as being free of (i.e., contains 0 phr of) reinforcing silica filler having a surface area inside the above-discussed ranges.

[0086] In an exemplary embodiment, the tire tread rubber composition is exclusive or substantially exclusive of silica reinforcing filler. In an embodiment, the rubber composition may comprise at least one reinforcing silica filler in an amount of about 1 to about 50 phr (e.g., about 10 to 20, about 20 to 30, or about 30 to 45 phr), having a surface area of about 100 to about 300 m2 / g (e.g., 110, 120, 130, 140, 150, 160, 180, 200, 220, 240, 260, 280, or 300 m2 / g), such as, about 150 to about 300 m2 / g, or about 180 to about 250 m2 / g. In certain embodiments disclosed herein, the tire tread rubber compositions comprise at least one reinforcing silica filler in an amount of about 55 to about 120 phr (e.g., 70 to 110 phr, 75 to 100 phr, or 80 to 95 phr), having a surface area of values disclosed above. In embodiments, one or more than one reinforcing silica filler having a surface area as discussed above may be utilized; in those embodiments where more than one such reinforcing silica filler is utilized, the foregoing amounts refer to the total amount of all reinforcing silica fillers. In certain embodiments, only one reinforcing silica filler having a surface area as discussed above is utilized. In embodiments, the only reinforcing silica filler(s) used in the tire tread rubber composition have a surface area as discussed above; in such embodiments, the tire tread rubber composition can be understood as being free of (i.e., contains 0 phr of) reinforcing silica filler having a surface area outside the above-discussed ranges.

[0087] Non- limiting examples of reinforcing silica fillers suitable for use in certain embodiments 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 reinforcing silica fillers for use in certain embodiments include, but are not limited to, aluminum silicate, magnesium silicate (Mg2SiO4, MgSiOS etc.), magnesium calcium silicate (CaMgSiO4), calcium silicate (Ca2SiO4 etc.), aluminum silicate (Al2SiO5, Al4.3SiO4.5H2O etc.), aluminum calcium silicate (Al2O3. CaO2SiO2, etc.), and the like. Among the listed reinforcing silica fillers, precipitated amorphous wet-process, hydrated silica fillers are often preferred. Such reinforcing silica fillers are produced by a chemical reaction in water, from which they are precipitated as ultrafine, spherical particles, with primary particles stronglyassociated into aggregates, which in turn combine less strongly into agglomerates. The surface area, as measured by the BET method, can be used to characterize the different reinforcing silica fillers. In certain embodiments disclosed herein, the tire tread rubber composition comprises a reinforcing silica filler having a surface area (as measured by the BET method), as discussed infra. In certain embodiments disclosed herein, the tire tread rubber composition comprises reinforcing silica filler having a pH of about 5.5 to about 8, 5.5 to 8 (e.g., 5.5, 5.7, 5.9, 6.1, 6.3, 6.5, 6.7, 6.9, 7.1, 7.3, 7.5, 7.7, 7.9, or 8), about 6 to about 8, 6 to 8 (e.g., 6, 6.2, 6.4, 6.6, 6.8, 7, 7.2, 7.4, 7.6, 7.8, or 8), about 6 to about 7.5, 6 to 7.5, about 6.5 to about 8, 6.5 to 8, about 6.5 to about 7.5, 6.5 to 7.5, about 5.5 to about 6.8, or 5.5 to 6.8. Some of the commercially available reinforcing silica fillers which can be used in certain embodiments include, but are not limited to, Hi-Sil® EZ120G, Hi-Sil® EZ120G-D, Hi- Sil® 134G, Hi-Sil ®EZ 160G, Hi-Sil® EZ 160G-D, Hi-Sil®190, Hi-Sil®190G-D, Hi-Sil® EZ 200G, Hi-Sil® EZ 200G-D, Hi-Sil® 210, Hi-Sil® 233, Hi-Sil® 243LD, Hi-Sil® 255CG-D, Hi-Sil® 315-D, Hi-Sil® 315G-D, Hi-Sil® HDP 320G and the like, produced by PPG Industries (Pittsburgh, Pa.) As well, a number of useful commercial grades of different reinforcing silica fillers are also available from Evonik Corporation (e.g., Ultrasil® 320 GR, Ultrasil® 5000 GR, Ultrasil® 5500 GR, Ultrasil® 7000 GR, Ultrasil® VN2 GR, Ultrasil® VN2, Ultrasil® VN3, Ultrasil® VN3 GR, Ultrasil®7000 GR, Ultrasil® 7005, Ultrasil® 7500 GR, Ultrasil® 7800 GR, Ultrasil® 9500 GR, Ultrasil® 9000 G, Ultrasil® 9100 GR), and Solvay (e.g., Zeosil® 1115MP, Zeosil® 1085GR, Zeosil® 1165MP, Zeosil® 1200MP, Zeosil® Premium, Zeosil® 195HR, Zeosil® 195GR, Zeosil® 185GR, Zeosil® 175GR, and Zeosil® 165GR).Silica Coupling Agent

[0088] In certain embodiments disclosed herein, one or more than one silica coupling agent may also (optionally) be utilized. In embodiments, at least one silica coupling agent is utilized. Silica coupling agents are useful in preventing or reducing aggregation of the silica filler in rubber compositions. Aggregates of the silica filler particles are believed to increase the viscosity of a rubber composition, and, therefore, preventing this aggregation reduces the viscosity and improves the processability and blending of the rubber composition.

[0089] Generally, any conventional type of silica coupling agent can be used, such as those having a silane and a constituent component or moiety that can react with a polymer,particularly a vulcanizable polymer. The silica coupling agent acts as a connecting bridge between silica and the polymer. Suitable silica coupling agents for use in certain embodiments disclosed herein include those containing groups such as alkyl alkoxy, mercapto, blocked mercapto, sulfide-containing (e.g., monosulfide-based alkoxy-containing, disulfide-based alkoxycontaining, tetrasulfide-based alkoxy-containing), amino, vinyl, epoxy, and combinations thereof. In certain embodiments, the silica coupling agent can be added to the rubber composition in the form of a pre-treated silica; a pre-treated silica has been pre-surface treated with a silane prior to being added to the rubber composition. The use of a pre-treated silica can allow for two ingredients ( / .e., silica and a silica coupling agent) to be added in one ingredient, which generally tends to make rubber compounding easier.

[0090] Alkyl alkoxysilanes have the general formula R10pSi(OR11)4-p where each R11is independently a monovalent organic group, and p is an integer from 1 to 3, with the proviso that at least one R10is an alkyl group. In an embodiment, p is 1. Generally, each R10independently comprises C1 to C20 aliphatic, C5 to C20 cycloaliphatic, or C6 to C20 aromatic; and each R11independently comprises C1 to C6 aliphatic. In certain exemplary embodiments, each R10independently comprises C6 to C15 aliphatic and in additional embodiments each R10independently comprises C8 to C14 aliphatic. Mercapto silanes have the general formula HS-R-*-^-Si( R14)(R15)2 where R-^^ is a divalent organic group, R is a halogen atom or an alkoxy group, each R 5 jsindependently a halogen, an alkoxy group or a monovalent organic group. The halogen is chlorine, bromine, fluorine, or iodine. The alkoxy group may have 1-3 carbon atoms. Blocked mercapto silanes have the general formula B-S-R16-Si-X3 with an available silyl group for reaction with silica in a silica-silane reaction and a blocking group B that replaces the mercapto hydrogen atom to block the reaction of the sulfur atom with the polymer. In the foregoing general formula, B is a block group which can be in the form of an unsaturated heteroatom or carbon bound directly to sulfur via a single bond; R16is C1 to C6 linear or branched alkylidene and each X is independently selected from the group consisting of C1 to C4 alkyl or C1 to C4 alkoxy.

[0091] Non-limiting examples of alkyl alkoxysilanes suitable for use in certain embodiments include, but are not limited to, octyltriethoxysilane, octyltrimethoxysilane, trimethylethoxysilane, cyclohexyltriethoxysilane, isobutyltriethoxy-silane, ethyltri methoxysilane, cyclohexyl-tributoxysilane, dimethyldiethoxysilane, methyltriethoxysilane, propyltriethoxysilane, hexyltriethoxysilane, heptyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, tetradecyltriethoxysilane, octadecyltriethoxysilane, methyloctyldiethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, propyltrimethoxysilane, hexyltrimethoxysilane, heptyltrimethoxysilane, nonyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetradecyltrimethoxysilane, octadecyltrimethoxysilane, methyloctyl dimethoxysilane, and mixtures thereof.

[0092] Non-limiting examples of bis(trialkoxysilylorgano)polysulfides suitable for use in certain embodiments include bis(trialkoxysilylorgano) disulfides and bis(trialkoxysilylorgano)tetrasulfides. Specific non-limiting examples of bis(trialkoxysilylorgano)disulfides include, but are not limited to, 3,3'-bis(triethoxysilylpropyl) disulfide, 3,3'-bis(trimethoxysilylpropyl)disulfide, 3,3'-bis(tributoxysilylpropyl)disu Ifide, 3,3'-bis(tri-t-butoxysilylpropyl)disulfide, 3,3'-bis(trihexoxysilylpropyl)disulfide, 2,2'-bis(dimethylmethoxysilylethyl)disulfide, 3,3'-bis(diphenylcyclohexoxysilylpropyl)disulfide, 3,3'-bis(ethyl-di-sec-butoxysilylpropyl)disulfide, 3,3'-bis(propyldiethoxysilylpropyl)disulfide, 12,12'-bis(triisopropoxysilylpropyl)disulfide, 3,3'-bis(dimethoxyphenylsilyl-2-methylpropyl)disulfide, and mixtures thereof. Non-limiting examples of bis(trialkoxysilylorgano)tetrasulfide silica coupling agents suitable for use in certain embodiments include, but are not limited to, bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl) tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, 3- trimethoxysilylpropyl-N, N- dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysi lyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropyl- benzothiazole tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, and mixtures thereof. Bis(3-triethoxysilylpropyl)tetrasulfide is sold commercially as Si69® by Evonik Degussa Corporation. In embodiments, the tire tread rubber composition includes a silica coupling agent in the form of a bis(trialkoxysilylorgano)polysulfides such as a bis(trialkoxysilylorgano) disulfide.

[0093] Non-limiting examples of mercapto silanes suitable for use in certain embodiments disclosed herein include, but are not limited to, 1-mercaptomethyltriethoxysilane, 2-mercaptoethyltriethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 2-mercaptoethyltripropoxysilane, 18-mercaptooctadecyldiethoxychlorosilane, and mixtures thereof.

[0094] Non-limiting examples of blocked mercapto silanes suitable for use in certain embodiments disclosed herein include, but are not limited to, those described in U. S. Pat. Nos.6,127,468; 6,204,339; 6,528,673; 6,635,700; 6,649,684; and 6,683,135, the disclosures of which are hereby incorporated by reference. Mixtures of various blocked mercapto silanes can be used. A further example of a suitable blocked mercapto silane for use in certain exemplary embodiments is NXTTMsilane (3- octanoylthio-1-propyltriethoxysilane), commercially available from Momentive Performance Materials Inc. of Albany, NY.

[0095] Non-limiting examples of pre-treated silicas ( / .e., silicas that have been pre-surface treated with a silane) suitable for use in certain embodiments disclosed herein include, but are not limited to, Ciptane® 255 LD and Ciptane® LP (PPG Industries) silicas that have been pretreated with a mercaptosilane, and Coupsil® 8113 (Degussa) that is the product of the reaction between organosilane bis(triethoxysilylpropyl) polysulfide (Si69) and Ultrasil® VN3 silica.Coupsil 6508, Agilon 400™ silica from PPG Industries, Agilon 454® silica from PPG Industries, and 458® silica from PPG Industries. In those embodiments where the silica comprises a pretreated silica, the pre-treated silica is used in an amount as previously disclosed for the silica filler.

[0096] When a silica coupling agent is utilized in an embodiment, the amount used may vary. In certain embodiments, the rubber compositions do not contain any silica coupling agent. In other embodiments, the silica coupling agent is present in an amount sufficient to provide a ratio of the total amount of silica coupling agent to silica filler of about 0.1:100 to about 1:5 ( / .e., about 0.1 to about 20 parts by weight per 100 parts of silica), including 0.1:100 to 1:5, about 1:100 to about 1:10, 1:100 to 1:10, about 1:100 to about 1:20, l:100to 1:20, about 1:100 to about 1:25, and 1:100 to 1:25 as well as about 1:100 to about 0:100 and 1:100 to0:100. In embodiments, the ratio of the total amount of silica coupling agent to silica filler falls within a ratio of 1:10 to 1:20 (i.e., 10 to 5 parts by weight per 100 parts of silica). In certain embodiments, the rubber composition comprises about 0.1 to about 15 ph r silica coupling agent, including 0.1 to 15 phr (e.g., 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 phr), about 0.1 to about 12 phr, 0.1 to 12 phr, about 0.1 to about 10 phr, 0.1 to 10 phr, about 0.1 to about 7 phr, 0.1 to 7 phr, about 0.1 to about 5 phr, 0.1 to 5 phr, about 0.1 to about 3 phr, 0.1 to 3 phr, about 1 to about 15 phr, 1 to 15 phr (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 phr), about 1 to about 12 phr, 1 to 12 phr (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 phr), about 1 to about 10 phr, 1 to 10 phr (e.g., 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 phr), about 1 to about 7 phr, 1 to 7 phr, about 1 to about 5 phr, 1 to 5 phr, about 1 to about 3 phr, 1 to 3 phr, about 3 to about 15 phr, 3 to 15 phr, about 3 to about 12 phr, 3 to 12 phr, about 3 to about 10 phr, 3 to 10 phr, about 3 to about 7 phr, 3 to 7 phr, about 3 to about 5 phr, 3 to 5 phr, about 5 to about 15 phr, 5 to 15 phr, about 5 to about 12 phr, 5 to 12 phr, about 5 to about 10 phr, 5 to 10 phr, about 5 to about 7 phr, or 5 to 7 phr. In embodiments, the rubber composition comprises silica coupling agent in an amount of 8 to 12 phr or one of the foregoing ranges falling within this range.

[0097] In certain embodiments, the tire tread rubber composition comprises a reinforcing filler other than carbon black or silica (i.e., an additional reinforcing filler). While one or more than one additional reinforcing filler may be utilized, their total amount may be limited to no more than 10 phr (e.g., 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 or 0 phr), or no more than 5 phr (e.g., 5, 4, 3, 2, 1, or 0 phr). In certain embodiments, the tire tread rubber composition contains no additional reinforcing filler (i.e., 0 phr); in other words, in such embodiments no reinforcing filler other than silica and optionally carbon black are present.

[0098] In those embodiments wherein an additional reinforcing filler is utilized, the additional reinforcing filler or fillers may vary. Non-limiting examples of suitable additional reinforcing fillers for use in the tire tread rubber compositions of certain embodiments include, but are not limited to, alumina, aluminum hydroxide, clay (reinforcing grades), magnesium hydroxide, boron nitride, aluminum nitride, titanium dioxide, reinforcing zinc oxide, and combinations thereof.

[0099] In certain embodiments, the tire tread rubber composition further comprises at least one non-reinforcing filler. In other embodiments, the tire tread rubber composition contains no non-reinforcing fillers (i.e., 0 phr). In embodiments wherein at least one nonreinforcing filler is utilized, the at least one non-reinforcing filler may be selected from clay (non-reinforcing grades), graphite, magnesium dioxide, aluminum oxide, starch, boron nitride (non-reinforcing grades), silicon nitride, aluminum nitride (non-reinforcing grades), calcium silicate, silicon carbide, ground rubber, and combinations thereof. The term "non- reinforcing filler" is used to refer to a particulate material that has a nitrogen absorption specific surface area (N2SA) of less than about 20 m2 / g (including less than 20 m2 / g), and in certain embodiments less than about 10 m2 / g (including less than 10 m2 / g). The N2SA surface area of a particulate material can be determined according to various standard methods including ASTM D6556. In certain embodiments, the term "non-reinforcing filler" is alternatively or additionally used to refer to a particulate material that has a particle size of greater than about 1000 nm (including greater than 1000 nm). In those embodiments, wherein a non-reinforcing filler is present in the rubber composition, the total amount of non- reinforcing filler may vary but may be no more than 10 phr {e.g., 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 phr), and in certain embodiments 1-10 phr, no more than 5 phr {e.g., 5, 4, 3, 2, or 1 phr), 1-5 phr, or no more than 1 phr.

[0100] The subject rubber compositions are used in preparing treads for tires, generally by a process which includes forming of a tread pattern by molding and curing one of the subject rubber compositions. Thus, the tire treads will contain a cured form of one of the tire tread rubber compositions. The tire tread rubber compositions may be present in the form of a tread which has been formed but not yet incorporated into a tire and / or they may be present in a tread which forms part of a tire. In an embodiment, a natural rubber composition such as ASTM D3192 may be used, or an styrene-butadiene rubber composition such as disclosed in ASTM D3191 may be used.

[0101] The Tg of the overall rubber composition may be referred to as a compound Tg or as a rubber composition Tg. In certain embodiments, the rubber composition has a compoundTg of -40 to -60 °C (e.g, -40, -42, -44, - 45, -46, -48, -50, -52, -54, -55, -56, -58, -60, -62, -64, -65, -66, -68, or -70 °C ), -50 to -70 °C (e.g. -50, -52, -54, -55, -56, -58, -60, -62, -64, -66, -68, or -70 °C ), -45 to -65 °C (e.g, -45, -46, -48, -50, -52, -54, -55, -56, -58, -60, -62, -64, or -65 °C ), -40 to -60 °C (e.g, -40, -42, -44, -45, -46, -48, -50, -52, -54, -55, -56, -58, or -60 °C), -40 to -50 °C (e.g, -40, -41, -42, -43, -44, -45, -46, -47, -48, -49, or -50 °C), -50 to -60 °C (e.g, -50, -51, -52, -53, -54, -55, -56, -57, -58, -59, or -60 °C), -60 to -70 °C (-60, -61, -62, -63, -64, -65, -66, -67, -68, -69, or -70 °C), -45 to -55 °C (-45, -46, -47, -48, -49, -50, -51, -52, -53, -54, or -55 °C), or -55 to -65 °C (e.g., -55, -56, -57, -58, -59, -60, -61, -62, -63, -64, or -64 °C) or a range within one of the foregoing ranges. The compound Tg of a rubber composition can be measured using a dynamic mechanical thermal spectrometer (such as the Gabo instrument described below, operating in tension mode) generally following the guidelines of ASTM D5992-96 (2011) and using a temperature sweep (from -70 to 65 °C), under specified test conditions (i.e., frequency 52 Hz, static strain of 6%, dynamic strain of 0.1%, sample geometry 4.75 mm wide x 29 mm long x 2 mm deep), with the measurement made on the sample after curing for 15 minutes at 170 °C, and using a vibratory method to estimate the Tg from the curve that results.

[0102] In an embodiment, the ingredients of the elastomer or rubber component include selected from the group consisting of: natural rubber, polyisoprene, polybutadiene, poly(styrene-butadiene), and combinations thereof. For example, the rubber component comprises about 40 to about 70 phr of natural rubber and / or polyisoprene; and about 5 to about 60 phr of styrene-butadiene rubber and / or polybutadiene. Natural rubber and / or polyisoprene may be a majority component of the composition.

[0103] The 100 parts of elastomer component may also further comprise 40 phr to about 90 phr of the rubber component being selected from the group consisting of: natural rubber, polyisoprene, styrene-butadiene rubber, polybutadiene, and combinations thereof. In an exemplary embodiment, the majority of the rubber component is selected from these rubber components. For example, the composition may comprise 51 to 90 phr (e.g., 52, 55, 60, 65, 70, 75, 80, 85, or 89 phr), such as 55 to 80 phr, or 60 to 75 phr of the natural rubber, polyisoprene, polybutadiene, or styrene-butadiene rubber.

[0104] In an exemplary embodiment, the composition may comprise about 40 to about 70 phr (e.g., 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, or 68 phr), such as about 45 to about 60 parts (e.g., 47, 49, 51, 53, 55, 57, or 59 phr), or about 50 to about 55 phr of at least one natural rubber or polyisoprene rubber.

[0105] In an exemplary embodiment, the composition may comprise at least one styrene-butadiene rubber having a Tg of about -10 to about -60 °C or -30 to -50 °C (e.g., 30, 30, 34, 35, 36, 38, 40, 42, 44, 45, 46, 48, or 50 °C). The at least one styrene-butadiene rubber may be present in the composition in an amount of about 5 phr to about 25 phr (e.g., 6, 9, 12, 15, 18, 21, or 23 phr)., such as, about 10 phr to 20 phr, or 11 phr to 17 phr. In certain embodiments, the elastomer component includes no more than 11 phr (e.g., 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 or even 0 parts) of styrene-butadiene rubber.

[0106] In certain embodiments the 100 parts of elastomer component consists essentially or consists only of at least one styrene-butadiene rubber, polybutadiene, and the natural rubber and / or polyisoprene in amounts as discussed above. In other embodiments, the 100 parts of elastomer component includes in addition to these one or more additional rubbers.

[0107] In certain embodiments, one or more additional rubbers are selected from diene monomer-containing rubbers; in certain such embodiments, the one or more additional rubbers are selected from the group consisting of styrene-isoprene rubber, butadiene-isoprene rubber, styrene-isoprene-butadiene rubber, butyl rubber (both halogenated and nonhalogenated), ethylene-propylene rubber (EPR), ethylene- butylene rubber (EBR), ethylene-propylene-diene rubber (EPDM), and combinations thereof. In yet other embodiments, the one or more additional rubbers are selected from natural rubber, polyisoprene, or a combination thereof; one or more styrene-butadiene rubbers other than the styrene-butadiene rubber, e.g., a SBR having a Tg of greater than -30 °C (e.g., -25 °C, -20 °C, -15 °C or higher) or having a Tg of less than -50 °C (e.g., -55, -60°C or lower); or from a polybutadiene, e.g., a polybutadiene having a low cis 1,-4 bond content (e.g., of less than 50%, less than 45%, less than 40%, etc.), a non-functionalized polybutadiene rubber having a cis bond content of at least 95% and a Tg of - 101 °C or lower, or a combination thereof; or a combination of the foregoing types of rubbers.

[0108] Tg values referred to herein for elastomers represent a Tg measurement made upon the elastomer without any oil-extension. In other words, for an oil-extended elastomer, the Tg values above refer to the Tg prior to oil extension or to a non-oil-extended version of the same elastomer. Elastomer or polymer Tg values may be measured using a differential scanning calorimeter (DSC) instrument, such as manufactured by TA Instruments (New Castle, Delaware), where the measurement is conducted using a temperature elevation of 10°C / minute after cooling at -120 °C. Thereafter, a tangent is drawn to the base lines before and after the jump of the DSC curve. The temperature on the DSC curve (read at the point corresponding to the middle of the two contact points) can be used asTg.

[0109] In certain embodiments, the average Tg of the elastomer component is -70 to -90 °C (e.g., -70, -71, -72, -73, -74, -75, -76, -77, -78, -79, -80, -81, -82, -83, -84, -85, -86, -87, -88, -89, or -90 °C), such as -75 to -85 °C (e.g., -75, -76, -77, -78, -79, -80, -81, -82, -83, -84, or -85 °C). The average Tg of the elastomer component can be calculated using the Tg of each rubber present in the 100 parts of elastomer component and accounting for their relative weight percentage. When one (or more) of the rubbers is oil-extended, only the amount of rubber (i.e., excluding any amount of oil) is utilized in calculating the average Tg of the elastomer component. When one (or more) of the rubbers is oil-extended, the Tg of the oil-extended rubber in its non-oil-extended form (i.e., rubber only) is utilized in calculating the average Tg of the elastomer component.

[0110] As mentioned above, the elastomer component of the tire tread rubber composition may include at least one styrene-butadiene rubber having a Tg of about -25 to about -65 °C or about -30 to about -55 °C (e.g., -30, -31, -32, -33, -34, -35, -36, -37, -38, -39, -40, -41, -42, -43, -44, -45, -46, -47, -48, -49, or -50 °C) and the elastomer component of the tire tread rubber composition may include a silica-reactive functional group, in an amount as discussed above. In certain embodiments, the at least one styrene- butadiene rubber has a Tg of about -40 to about -50 or -40 to -50 °C (e.g., -40, -41, -42, -43, -44, -45, -46, -47, -48, -49, or -50 °C), in an amount as discussed above.

[0111] The styrene monomer content (i.e., weight percent of the polymer chain comprising styrene units as opposed to butadiene units) of the at least one styrene-butadienerubber, as described above, may vary. In certain embodiments, the at least one styrenebutadiene rubber, as described above, has a styrene monomer content of about 20 to about 45% or 25 to 40% (e.g., 20%, 25%, 32%, 34%, or 36%) by weight of the total monomer content (i.e., 1,3-butadiene + styrene), including about 35 to about 40% by weight.

[0112] According to certain embodiments, the vinyl bond content (i.e., 1,2-microstructure) of the at least one styrene-butadiene rubber, as described above, may vary. In certain embodiments, the at least one styrene-butadiene rubber, as discussed above, has a vinyl bond content of about 15 to about 45%, about 20 to about 40% (e.g., 20%, 25%, 30%, 35%, or 38%), or about 21 to about 26%.

[0113] The at least one styrene-butadiene rubber, as described above, may have a vinyl bond content within one of the foregoing ranges, optionally in combination with one or more of the Mw, Mn, and / or Mw / Mn ranges discussed below, and in certain embodiments optionally in combination with one of the styrene monomer contents discussed above. The vinyl bond contents referred to herein should be understood as being for the vinyl bond content in the butadiene portion of the styrene-butadiene rubber polymer chain, and can be determined by H1-NMR and C13-NMR (e.g., using a 300 MHz Gemini 300 NMR Spectrometer System (Varian)). The styrene contents disclosed herein can be determined using a similar method and the same instrumentation.

[0114] Accordingto certain embodiments, the Mw of the at least one styrene-butadiene rubber, as described above, may vary. In certain embodiments disclosed herein, the at least one styrene-butadiene rubber (as described above), has a Mw of about 250,000 to about 550,000 grams / mole or 275,000 to 500,000 grams / mole (e.g., 300,000; 325,000; 350,000; 375,000; 400,000; 425,000; 450,000; 475,000; 500,000; 525,000; or 550,000 grams / mole), about 300,000 to about 500,000 or 300,000 to 500,000 grams / mole (e.g., 300,000; 325,000; 350,000; 375,000; 400,000; 425,000; 450,000; 475,000; or 500,000 grams / mole), or about 350,000 to about 450,000 or 350,000 to 450,000 grams / mole (e.g., 350,000; 375,000; 400,000; 425,000; or 450,000 grams / mole), according to a polystyrene standard (and as determined by GPC).

[0115] According to the embodiments disclosed herein, the Mn of the at least one styrene-butadiene rubber, as described above, may vary. In certain embodiments disclosed herein, the at least one styrene-butadiene rubber, as described above, has a Mn of about 1400,000 to about 450,000 grams / mole or 150,000 to 450,000 grams / mole (e.g., 156,000; 275,000; 300,000; 325,000; 350,000; 375,000; 400,000; 425,000; or 450,000 grams / mole), or about 300,000 to about 400,000 grams / mole or 300,000 to 400,000 grams / mole (e.g., 300,000; 325,000; 350,000; 375,000; or 400,000 grams / mole), according to a polystyrene standard (and as determined by GPC). When the at least one styrene-butadiene rubber, as described above, is a functionalized polymer, it should be understood that the foregoing Mw and Mn values refer to coupled Mw and coupled Mn rather than base polymer values. In certain embodiments, the at least one styrene-butadiene rubber, as described above, has a Mn within one of the foregoing ranges in combination with a Mw within one of the foregoing ranges, optionally in combination with a Mw / Mn value as discussed below.

[0116] The Mw / Mn of the at least one styrene-butadiene rubber, as described above, have a Mw / Mn (polydispersity) of about 1.2 to about 4.1 (e.g., 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2), such as about 1.5 to about 3.25, or about 2 to about 3. As mentioned above, in certain embodiments disclosed herein, the at least one styrene-butadiene rubber, as described above, has a Mw / Mn within one of the foregoing ranges, in combination with at least one of the Mw ranges or Mn ranges described above, such as in combination with one of the Mw ranges and one of the Mn ranges described above.

[0117] In certain embodiments disclosed herein, the at least one styrene-butadiene rubber, as described above, is an oil-extended rubber, incorporating oil in an amount as discussed further below. In other embodiments disclosed herein, the at least one styrene-butadiene rubber, as described above, is a non oil-extended rubber (i.e., the SBR is not extended with any oil).

[0118] The SBR(s) may be functionalized or non-functionalized. As used herein, the term functionalized should be understood to encompass the use of both functional groups and coupling agents. One or more than one type of functional group may be utilized for an SBR. Generally, a functional group may be present at the head of the polymer, at the tail of thepolymer, along the backbone of the polymer chain, or a combination thereof. Functional groups present at one or both terminals of a polymer are generally the result of the use of a functional initiator, a functional terminator, or both. Alternatively or additionally, the functional group may be present as a result of coupling of multiple polymer chains using a coupling agent. In certain embodiments, the rubber component includes at least one SBR which is nonfunctionalized ( / .e., contains no functional group and no coupling agent); in certain such embodiments, the only SBR(s) present in the rubber component are non-functionalized. In other embodiments, the rubber component includes at least one SBR which is functionalized with a silica-reactive functional group; in certain such embodiments, the only SBR(s) present in the rubber component is functionalized with a silica-reactive functional group. In yet other embodiments, the elastomer component includes more than one SBR (e.g., two, three, or more); in certain such embodiments, at least one SBR is non-functionalized. Non-limiting examples of silica-reactive functional groups generally include nitrogen-containing functional groups, silicon-containing functional groups, oxygen- or sulfur-containing functional groups, and metal-containing functional groups, as discussed in more detail below.

[0119] The at least one styrene-butadiene rubber may have silica or carbon black-reactive functional group. Non-limiting examples of silica-reactive functional groups generally include nitrogen-containing functional groups, silicon-containing functional groups, oxygen- or sulfur-containing functional groups, and metal-containing functional groups, as discussed in more detail below. A carbon-black reactive functional group includes for example HMI (hexamethyleneimine).

[0120] When the at least one styrene-butadiene rubber, as described above, has a filler-reactive functional group, the functionalization can be achieved during preparation of the polymer by adding a functional group to one or both terminus of the polymer, by adding a functional group to the backbone of the poly (or a combination of the foregoing) or by coupling more than one polymer chains to a coupling agent, or by a combination thereof. Such effects can be achieved by treating a living polymer with coupling agents, functionalizing agents, or a combination thereof which serve to couple and / or functionalize other chains. In certain embodiments, the at least one styrene-butadiene rubber having a silica-reactive functionalgroup contains one or more functional groups but is not coupled (i.e., does not contain any separate coupling agent). Generally, a coupling agent and / or functionalizing agent can be used at various molar ratios. Alternatively, in certain embodiments, the functionalized styrenebutadiene rubber of may be silica-reactive merely from the result of using a coupling agent. Although reference is made herein to the use of both coupling agents and functionalizing groups (and compounds used therefor), those skilled in the art appreciate that certain compounds may serve both functions. That is, certain compounds may both couple and provide the polymer chains with a functional group. Those skilled in the art also appreciate that the ability to couple polymer chains may depend upon the amount of coupling agent reacted with the polymer chains. For example, advantageous coupling may be achieved where the coupling agent is added in a one to one ratio between the equivalents of lithium on the initiator and equivalents of leaving groups (e.g., halogen atoms) on the coupling agent. Non-limiting examples of coupling agents include metal halides, metalloid halides, alkoxysilanes, alkoxystannanes, and combinations thereof. In embodiments, the at least one styrene-butadiene rubber has a silicareactive functional group (as discussed further, infra, as functional groups) but does not include any coupling agent selected from the group consisting of metal halides, metalloid halides, alkoxysilanes, alkoxystannanes, and combinationsthereof.

[0121] Non-limiting examples of nitrogen-containing functional groups that can be utilized in certain embodiments as a silica-reactive functional group for the SBR include, but are not limited to, a substituted or unsubstituted amino group, an amide residue, an isocyanate group, an imidazolyl group, an indolyl group, an imino group, a nitrile group, a pyridyl group, and a ketimine group. In certain embodiments when at least one SBR is present in the rubber component, the at least one SBR has a silica-reactive functional group including an unsubstituted amino group, a substituted amino group, or substituted imino group. The foregoing substituted or unsubstituted amino group should be understood to include a primary alkylamine, a secondary alkylamine, or a cyclic amine, and an amino group derived from a substituted or unsubstituted imine. In certain embodiments when at least one SBR is present in the rubber component, the at least one SBR has at least one silica-reactive functional group selected from the foregoing list of nitrogen-containing functional groups.

[0122] In certain embodiments, when at least one functional SBR is present, the SBR has a silica-reactive functional group from a compound which includes nitrogen in the form of an imino group. Such an imino-containing functional group may be added by reacting the active terminal of a polymer chain with a compound having the following formula (I):Si(OR)nR'3-n(CH<wherein R, R', R", and R'" each independently are selected from a group having 1 to 18 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 carbon atoms) selected from the group consisting of an alkyl group, an allyl group, and an aryl group; m and n are integers of 1 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20) and 1 to 3 (1, 2, or 3), respectively. Each of R, R', R", and R'" are preferably hydrocarbyl and contain no heteroatoms. In certain embodiments, each R and R' are independently selected from an alkyl group having 1 to 6 carbon atoms (e.g., 1, 2, 3, 4, 5, or 6 carbon atoms), preferably 1 to 3 carbon atoms (e.g., 1, 2, or 3 carbon atoms). In certain embodiments, m is an integer of 2 to 6 (e.g., 2, 3, 4, 5, or 6), preferably 2 to 3. In certain embodiments, R'" is selected from an alkyl group having 1 to 6 carbon atoms (e.g., 1, 2, 3, 4, 5, or 6 carbon atoms), preferably 2 to 4 carbon atoms (e.g., 2, 3, or 4 carbon atoms). In certain embodiments, R" is selected from an alkyl group having 1 to 6 carbon atoms (e.g., 1, 2, 3, 4, 5, or 6 carbon atoms), preferably 1 to 3 carbon atoms (e.g., 1, 2, or 3 carbon atoms), most preferably 1 carbon atom (e.g., methyl). In certain embodiments, n is 3 resulting in a compound with a trihydrocarboxysilane moiety such as a trialkoxysilane moiety. Non-limiting examples of compounds having an imino group and meeting formula (I) above, which are suitable for providing the silica-reactive functional group for the SBR include, but are not limited to, N-(l,3-dimethylbutylidene)-3-(triethoxysilyl)-l-propaneamine, N-(l-methylethylidene)-3-(triethoxysilyl)-l-propaneamine, N-ethylidene-3-(triethoxysilyl)-l-propaneamine, N-(l-methylpropylidene)-3-(triethoxysilyl)-l-propaneamine, and N-(4-N, N-dimethylaminobenzylidene )-3-( triethoxysilyl)-l-propaneamine.

[0123] Non-limiting examples of silicon-containing functional groups that can be utilized in certain embodiments, as a silica-reactive functional group for a SBR include, but are not limited to, an organic silyl or siloxy group, and more precisely, such a functional group may be selected from an alkoxysilyl group, an alkylhalosilyl group, a siloxy group, an alkylaminosilyl group, and an alkoxyhalosilyl group. Optionally, the organic silyl or siloxy group may also contain one or more nitrogens. Suitable silicon-containing functional groups for use in functionalizing diene-based elastomers also include those disclosed in U. S. Patent No. 6,369,167, the entire disclosure of which is herein incorporated by reference. In certain embodiments, the at least one styrene-butadiene rubber comprises at least one silica-reactive functional group selected from the foregoing list of silicon-containing functional groups.

[0124] In certain embodiments when the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group which includes a silicon-containing functional group having a siloxy group (e.g., a hydrocarbyloxysilane-containing compound), wherein the compound optionally includes a monovalent group having at least one functional group. Such a silicon-containing functional group may be added by reacting the active terminal of a polymer chain with a compound having the following formula (II):A3—Si — (ORe)3-b(")wherein A1represents a monovalent group having at least one functional group selected from epoxy, isocyanate, imine, cyano, carboxylic ester, carboxylic anhydride, cyclic tertiary amine, non-cyclic tertiary amine, pyridine, silazane and sulfide; Rcrepresents a single bond or a divalent hydrocarbon group having from 1 to 20 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms); Rdrepresents a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms), a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms (e.g., 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 carbon atoms) or a reactive group; Rerepresents a monovalent aliphatic hydrocarbon grouphaving 1 to 20 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms) or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms (e.g., 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 carbon atoms); b is an integer of 0 to 2; when more than one Rdor OReare present, each Rdand / or ORemay be the same as or different from each other; and an active proton is not contained in a molecule) and / or a partial condensation product thereof. As used herein, a partial condensation product refers to a product in which a part (not all) of a SiOR group in the hydrocarbyloxysilane compound is turned into a SiOSi bond by condensation. In certain embodiments, at least one of the following is met: (a) Rcrepresents a divalent hydrocarbon group having 1 to 12 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms), 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6 carbon atoms), or 2 to 3 carbon atoms (e.g., 2 or 3 carbon atoms); (b) Rerepresents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms), 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6 carbon atoms), or 1 to 2 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 8 carbon atoms; (c) Rdrepresents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms(e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms), 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6 carbon atoms), or 1 to 2 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 8 carbon atoms; in certain such embodiments, each of (a), (b) and (c) are met and Rc, Reand Rdare selected from one of the foregoing groups.

[0125] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group that results from a compound represented by Formula (II) wherein A1has at least one epoxy group. Non-limiting specific examples of such compounds include 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, (2-glycidoxyethyl)methyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (3-glycidoxypropyl)-methyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl(methyl)dimethoxysilane.

[0126] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group that results from a compoundrepresented by Formula (II) wherein A1has at least one isocyanate group. Non-limiting specific examples of such compounds include 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropylmethyldiethoxysilane, and 3-isocyanatopropyltriisopropoxysilane.

[0127] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group that results from a compound represented by Formula (II) wherein A1has at least one imine group. Non-limiting specific examples of such compounds include N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1-propaneamine, N-(1-methylethylidene)-3-(triethoxysilyl)-1-propaneamine, N-ethylidene-3-(triethoxysilyl)-1-propaneamine, N-(1-methylpropylidene)-3-(triethoxysilyl)-1-propaneamine, N-(4-N,N-dimethylaminobenzylidene)-3-(triethoxysilyl)-1-propaneamine, N-(cyclohexylidene)-3-(triethoxysilyl)-1-propaneamine and trimethoxysilyl compounds, methyldiethoxysilyl compounds, ethyldimethoxysilyl compounds, each corresponding to the above triethoxysilyl compounds. Also, the imine(amidine) group-containing compounds include 1-[3-trimethoxysilyl]propyl]-4,5-dihydroimidazole, 3-(1-hexamethyleneimino)propyl(triethoxy)silane, (1-hexamethyleneimino)methyl(trimethoxy)silane, N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole, N-(3-isopropoxysilylpropyl)-4,5-dihydroimidazole, and N-(3-methyldiethoxysilylpropyl)-4,5-dihydroimidazole.

[0128] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group that results from a compound represented by Formula (II) wherein A1has at least one carboxylic ester group. Non-limiting specific examples of such compounds include 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriisopropoxysilane.

[0129] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group that results from a compound represented by Formula (II) wherein A1has at least one carboxylic anhydride group. Nonlimiting specific examples of such compounds include 3-trimethoxysilylpropylsuccinic anhydride, 3-triethoxysilylpropylsuccinic anhydride, 3-methyldiethoxysilylpropylsuccinic anhydride.

[0130] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group that results from a compound represented by Formula (II) wherein A1has at least one cyano group. Non-limiting specific examples of such compounds include 2-cyanoethylpropyltriethoxysilane.

[0131] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group that results from a compound represented by Formula (II) wherein A1has at least one cyclic tertiary amine group. Non-limiting specific examples of such compounds include 3-(1-hexamethyleneimino)propyltriethoxysilane, 3-(1-hexamethyleneimino)propyltrimethoxysilane, (1-hexamethyleneimino)methyltriethoxysilane, (1-hexamethyleneimino)methyltrimethoxysilane, 2-(1-hexamethyleneimino)ethyltriethoxysilane, 3-(1-hexamethyleneimino)ethyltrimethoxysilane, 3-(1-pyrrolidinyl)propyltrimethoxysilane, 3-(1-pyrrolidinyl)propyltriethoxysilane, 3-(1-heptamethyleneimino)propyltriethoxysilane, 3-(1-dodecamethyleneimino)propyltriethoxysilane, 3-(1-hexamethyleneimino)propyldiethoxymethylsilane, 3-(1-hexamethyleneimino)propyldiethoxyethylsilane, and 3-[10-(triethoxysilyl)decyl]-4-oxazoline. Among them, 3-(1-hexamethyleneimino)propyltriethoxysilane and (1-hexamethyleneimino)methyltriethoxysilane can preferably be listed.

[0132] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group that results from a compound represented by Formula (II) wherein A1has at least one non-cyclic tertiary amine group. Nonlimiting specific examples of such compounds include 3-dimethylaminopropyltriethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 3-diethylaminopropyltriethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyldiethoxymethylsilane, and 3-dibutylaminopropyltriethoxysilane.

[0133] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group that results from a compound represented by Formula (II) wherein A1has at least one pyridine group. Non-limiting specific examples of such compounds include 2-trimethoxysilylethylpyridine.

[0134] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group that results from a compound represented by Formula (II) wherein A1has at least one silazane group. Non-limiting specific examples of such compounds include N, N-bis(trimethylsilyl)-aminopropylmethyldi methoxysilane, 1-trimethylsilyl-2,2-dimethoxy-1-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)aminoethyltriethoxysilane, N, N-bis(trimethylsilyl)aminoethylmethyldimethoxysilane, and N, N-bis(trimethylsilyl)aminoethyl methyldiethoxysilane.

[0135] In certain embodiments where the rubber component includes at least one functional SBR, the SBR has a silica-reactive functional group according to Formula (II) wherein A1contains one or more protected nitrogens (as discussed in detail above), the nitrogen(s) may be deprotected or deblocked by hydrolysis or other procedures to convert the protected nitrogen(s) into a primary nitrogen. As a non-limiting example, a nitrogen bonded to two trimethylsilyl groups could be deprotected and converted to a primary amine nitrogen (such a nitrogen would still be bonded to the remainder of the Formula (II) compound). Accordingly, in certain embodiments wherein a silica-reactive functional group of the SBR results from use of a compound according to Formula (II) wherein A1contains one or more protected nitrogens, the functionalized polymer can be understood as containing a functional group resulting from a deprotected (or hydrolyzed) version of the compound.

[0136] Non-limiting examples of oxygen- or sulfur-containing functional groups that can be utilized in certain embodiments as a silica-reactive functional group of the SBR include, but are not limited to, a hydroxyl group, a carboxyl group, an epoxy group, a glycidoxy group, a diglycidylamino group, a cyclic dithiane-derived functional group, an ester group, an aldehyde group, an alkoxy group, a ketone group, a thiocarboxyl group, a thioepoxy group, a thioglycidoxy group, a thiodiglycidylamino group, a thioester group, a thioaldehyde group, a thioalkoxy group, and a thioketone group. In certain embodiments of the first and secondembodiments, the foregoing alkoxy group may be an alcohol-derived alkoxy group derived from a benzophenone. In certain embodiments wherein the rubber component includes at least one functional SBR, the SBR has silica-reactive functional group selected from the foregoing list of oxygen- or sulfur-containing functional groups.

[0137] In an embodiment, the at least one styrene-butadiene rubber, whether having a silica-reactive functional group or not may be prepared by either solution polymerization or by emulsion polymerization. In certain embodiments, the only styrene-butadiene rubber(s) present, whether having a silica-reactive functional group or not is (are) prepared by solution polymerization. In other embodiments, the only styrene-butadiene rubber(s) present, whether having a silica-reactive functional group or not, is prepared by emulsion polymerization. In certain embodiments, when more than one styrene-butadiene rubber is used or when more than one styrene-butadiene rubber having a silica-reactive functional group is used, the rubbers are a combination of solution polymerized styrene-butadiene rubber and emulsion polymerized styrene-butadiene rubber (e.g., one solution styrene-butadiene rubber and one emulsion styrene-butadiene rubber). In certain embodiments, the only styrene-butadiene rubber(s) present in the elastomer component (including for the at least one styrene-butadiene rubber having a silica-reactive functional group) is (are) solution styrene-butadiene rubbers ( / .e., no emulsion styrene-butadiene rubber is present).

[0138] One or more BRs in the composition may have a cis bond content of at least 95% (e.g., 95%, 96%, 97%, 98%, 99%, or more), a Tg of less than -101 °C (e.g., -102, -103, -104, -105, -106, -107, -108, -109, -110, -111, -112 °C or less), -101 or -110 °C (e.g., -102, -103, -104, -105, -106, -107, -108, -109, or -110 °C), or -103 or -109 °C. In certain such embodiments, the Tg of the polybutadiene rubber (ii) is -101 to -110 °C. The cis bond content refers to the cis 1,4- bond content. The cis 1,4-bond contents and vinyl bond contents referred to herein for polybutadiene rubber are determined by FTIR (Fourier Transform Infrared Spectroscopy) wherein a polymer sample is dissolved in CS2 and then subjected to FTIR. In certain embodiments, the polybutadiene rubber of (ii) has a cis 1,4-bond content of at least 98% (e.g., 98%, 99%, or more) or at least 99% (e.g., 99%, 99.5%, or more). Since the cis bond content of the polybutadiene rubber (ii) is high (i.e., at least 95%, as discussed above), the vinyl bondcontent will be low. In certain embodiments, the polybutadiene rubber of (ii) has a vinyl bond content of less than 4% (e.g., 3.9%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, 0.5%, etc.), such as less than 3% (e.g., 2.5%, 2%, 1.5%, 1%, 0.5%, etc.), or less than 2% (e.g., 1.5%, 1.4%, 1.3%, 1.2%, 1.1%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, etc.). In certain embodiments, any polybutadiene rubber used in the tire tread rubber compositions has a Tg of -105 °C or less (e.g., -105, -106, -107, -108, -109 °C or less) such as -105 to -110 °C. In certain embodiments, any polybutadiene rubber used in the tire tread rubber compositions contains less than 3% by weight (e.g., 3%, 2%, 1%, 0.5%, or less), less than 1% by weight (e.g., 1%, 0.5%, or less) or 0% by weight syndiotactic 1,2-polybutadiene. Generally, one or more than one polybutadiene rubber having a cis bond content of at least 95%, a Tg of less than -101 °C, and a silica-reactive functional group maybe used for (ii). In certain embodiments, (ii) consists of only one polybutadiene rubber having a cis bond content of at least 95% (e.g., 95%, 96%, 97%, 98%, 99%, or more), a Tg of less than -101 °C, and a silica-reactive functional group. In certain embodiments, the amount of any polybutadiene rubber having a high vinyl content (i.e., above about 70%) is limited (in the overall tread rubber composition) to less than 25 parts, such as less than 10 parts, or less than 5 parts or 0 parts.

[0139] In an embodiment, one or more BRs having a cis bond content of at least 95% (e.g., 95%, 96%, 97%, 98%, 99%, or more), a Tg of less than -101 °C (e.g., -102, -103, -104, -105, -106, -107, -108, -109, -110, -111, -112 °C or less), such as, -101 or -110 °C (e.g., -102, -103, -104, -105, -106, -107, -108, -109, or -110 °C) are present in an amount of about 10 to about 65 parts (e.g., 15, 25, 35, 45, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64 or 65 parts), such as about 20 to about 50 phr, or about 30 to about 40 phr.

[0140] In certain embodiments, the polybutadiene rubber having a cis bond content of at least 95%, and Tg of less than -101 °C has a Mw of 150,000 to 700,000 grams / mole (e.g., 250,000; 300,000; 450,000; 550,000; 650,000; or 700,000 grams / mole), Mw ranges falling within the foregoing ranges such as 200,000 to 600,000 grams / mole, 350,000 to 500,000 grams / mole, 400,000 to 450,000 grams / mole, and 500,000 to 700,000 grams / mole can also be utilized in certain embodiments. In certain embodiments, the polybutadiene rubber having a cis bond content of at least 95%, a Tg of less than -101 °C has a Mn of 180,000 to 300,000grams / mole (e.g., 180,000; 200,000; 220,000; 240,000; 250,000; 260,000; 280,000; or 300,000 (g / mol), such as, a Mn of 200,000 to 280,000 grams / mole (e.g., 200,000; 210,000;220,000; 230,000; 240,000; 250,000; 260,000; 270,000; or 280,000 grams / mole). Mn ranges falling within the foregoing ranges such as 200,000 to 250,000 grams / mole, 230,000 to 280,000 grams / mole, 180,000 to 280,000 grams / mole, and 200,000 to 280,000 grams / mole can also be utilized in certain embodiments. The foregoing Mw and Mn values for the polybutadiene refer to values measured by GPC using a polystyrene standard. As well, the foregoing Mw and Mn values for the polybutadiene refer to coupled Mw and coupled Mn rather than base polymer values.

[0141] In certain embodiments disclosed herein, the at least one polybutadiene rubber, can be an oil-extended rubber, incorporating oil in an amount as discussed further below. In other embodiments disclosed herein, the at least one polybutadiene rubber (ii), as described above, is a non oil-extended rubber ( / .e., the BR is not extended with any oil).

[0142] In certain embodiments, the elastomer component may include up to 70 phr (e.g., 65, 55, 45, 35, 25, 15, or 5 parts) of natural rubber, polyisoprene, or a combination thereof, which can be referred to as isoprene-containing rubber. In certain embodiments, the amount of isoprene-containing rubber is 20 to 60 phr, and in other embodiments 40 to 50 phr parts. In certain embodiments, the isoprene-containing rubber consists (only) of natural rubber. In other embodiments, isoprene-containing rubber consists (only) of polyisoprene. In yet other embodiments, as previously mentioned, no natural rubber or polyisoprene is present or used in the tire tread rubber composition. When natural rubber is present for the elastomer component, it may include Hevea natural rubber, non-Hevea natural rubber (e.g., guayule natural rubber), or a combination thereof. When natural rubber is utilized in the tire tread rubber compositions, the natural rubber may have a Mw of 1,000,000 to 2,000,000 grams / mole (e.g., 1 million, 1.1 million, 1.2 million, 1.3 million, 1.4 million, 1.5 million, 1.6 million, 1.7 million, 1.8 million, 1.9 million, 2 million grams / mole); 1,250,000 to 2,000,000 grams / mole, or 1,500,000 to 2,000,000 grams / mole (as measured by GPC using a polystyrene standard). When natural rubber is utilized in the tire tread rubber compositions, the Tg of the natural rubber may vary. According to certain embodiments, when natural rubber is utilized it has a Tg of -65 to -80 °C(e.g., - 65, -66, -67, -68, -69, -70, -71-, -72, -73, -74, -75, -76, -77, -78, -79, or -80 °C), a Tgof -67 to -77 °C (e.g., -67, -68, -69, -70, -71, -72, -73, -74, -75, -76, or -77 °C). When polyisoprene is utilized in the tire tread rubber compositions, the Tg of the polyisoprene may vary. When polyisoprene is utilized it has a Tg of -55 to -75 °C (e.g., -55, -56, -57, -58, -59, -60, -61, -62, -63, - 64, -65, -66, -67, -68, -69, -70, -71, -72, -73, -74, or -75 °C), such as -58 to -74 °C (e.g., - 58, -59, -60, -61, -62, -63, -64, -65, -66, -67, -68, -69, -70, -71, -72, -73, or -74 °C).

[0143] The tire tread rubber composition includes a cure package. Although the contents of the cure package may vary according to the embodiments, generally, the cure package includes at least one of: a vulcanizing agent; a vulcanizing accelerator; a vulcanizing activator (e.g., zinc oxide, stearic acid, and the like); a vulcanizing inhibitor; and an anti-scorching agent. In certain embodiments, the cure package includes at least one vulcanizing agent, at least one vulcanizing accelerator, at least one vulcanizing activator and optionally a vulcanizing inhibitor and / or an anti-scorching agent. Vulcanizing accelerators and vulcanizing activators act as catalysts for the vulcanization agent. Various vulcanizing inhibitors and anti-scorching agents are known in the art and can be selected by one skilled in the art based on the vulcanizate properties desired.

[0144] Examples of suitable types of vulcanizing agents for use in certain embodiments, include but are not limited to, sulfur or peroxide- based curing components. Thus, in certain such embodiments, the curative component includes a sulfur-based curative or a peroxide-based curative. In embodiments, the vulcanizing agent is a sulfur-based curative; in certain such embodiments the vulcanizing agent consists of (only) a sulfur-based curative. Examples of specific suitable sulfur vulcanizing agents include "rubbermaker's" soluble sulfur; sulfur donating curing agents, such as an amine disulfide, polymeric polysulfide, or sulfur olefin adducts; and insoluble polymeric sulfur. The sulfur vulcanizing agent may be soluble sulfur or a mixture of soluble and insoluble polymeric sulfur. For a general disclosure of suitable vulcanizing agents and other components used in curing, e.g., vulcanizing inhibitor and antiscorching agents, one can refer to Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd ed., Wiley Interscience, N. Y. 1982, Vol. 20, pp. 365 to 468, particularly Vulcanization Agents and Auxiliary Materials, pp. 390 to 402, or Vulcanization by A. Y. Coran, Encyclopedia of PolymerScience and Engineering, Second Edition (1989 John Wiley & Sons, Inc.), both of which are incorporated herein by reference. Vulcanizing agents can be used alone or in combination. Generally, the vulcanizing agents may be used in certain embodiments in an amount ranging from about 0.1 to about 10 phr (e.g., about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 phr), including about 1 to about 7.5 phr (e.g., 1, 2, 3, 4, 5, 6, 7, or 7.5 phr), including about 1 to about 5 phr (e.g., 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 phr), and about 1 to about 3.5 phr (e.g., 1, 1.5, 2, 2.5, 3, or 3.5 phr).

[0145] Vulcanizing accelerators are used to control the time and / or temperature required for vulcanization and to improve properties of the vulcanizate. Examples of suitable vulcanizing accelerators for use in certain embodiments disclosed herein include, but are not limited to, thiazole vulcanization accelerators, such as 2-mercaptobenzothiazole, 2,2'-dithiobis(benzothiazole) (MBTS), N-cyclohexyl-2-benzothiazole- sulfenamide (CBS), N-tert-butyl-2-benzothiazole-sulfenamide (TBBS), and the like; guanidine vulcanization accelerators, such as diphenyl guanidine (DPG) and the like; thiuram vulcanizing accelerators; carbamate vulcanizing accelerators; and the like. Generally, the amount of the vulcanization accelerator used ranges from 0.1 to 10 phr (e.g., 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 phr), such as 0.5 to 5 phr (e.g., 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 phr). In an embodiment, any vulcanization accelerator used in the tire tread rubber compositions excludes any thiurams such as thiuram monosulfides and thiuram polysulfides (examples of which include TMTM (tetramethyl thiuram monosulfide), TMTD (tetramethyl thiuram disulfide), DPTT (dipentamethylene thiuram tetrasulfide), TETD (tetraethyl thiuram disulfide), TiBTD (tetraisobutyl thiuram disulfide), and TBzTD (tetrabenzyl thiuram disulfide)); in other words, embodiments of the tire tread rubber compositions contain no thiuram accelerators (i.e., 0 phr).

[0146] Vulcanizing activators are additives used to support vulcanization. Generally vulcanizing activators include both an inorganic and organic component. Zinc oxide is the most widely used inorganic vulcanization activator. Various organic vulcanization activators are commonly used including stearic acid, palmitic acid, lauric acid, and zinc salts of each of the foregoing. Generally, in certain embodiments the amount of vulcanization activator used ranges from 0.1 to 6 phr (e.g., 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, or 6 phr), such as 0.5 to4 phr (e.g., 0.5, 1, 1.5, 2, 2.5, 3 3.5, or 4 phr). In certain embodiments, one or more vulcanization activators are used which includes one or more thiourea compounds (used in one of the foregoing amounts), and optionally in combination with one or more of the foregoing vulcanization activators. Generally, a thiourea compound can be understood as a compound having the structure (R1)(R2)NS(=C)N(R3)(R4) wherein each of R1, R2, R3, and R4are independently selected from H, alkyl, aryl, and N-containing substituents (e.g., guanyl).Optionally, two of the foregoing structures can be bonded together through N (removing one of the R groups) in a dithiobiurea compound. In certain embodiments, one of R1or R2and one of R3or R4can be bonded together with one or more methylene groups (-CH2-) therebetween. In certain embodiments, the thiourea has one or two of R1, R2, R3and R4selected from one of the foregoing groups with the remaining R groups being hydrogen. Exemplary alkyl include Cl-C6 linear, branched or cyclic groups such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, pentyl, hexyl, and cyclohexyl. Exemplary aryl groups include C6-C12 aromatic groups such as phenyl, tolyl, and naphthyl. Exemplary thiourea compounds include, but are not limited to, dihydrocarbylthioureas such as dialkylthioureas and diarylthioureas. Non-limiting examples of particular thiourea compounds include one or more of thiourea, N, N'-diphenylthiourea, trimethylthiourea, N, N'- diethylthiourea (DEU), N, N'-dimethylthiourea, N, N'-dibutylthiourea, ethylenethiourea, N, N'- diisopropylthiourea, N, N'-dicyclohexylthiourea, l,3-di(o-tolyl)thiourea, l,3-di(p-tolyl)thiourea, l,l-diphenyl-2-thiourea, 2,5-dithiobiurea, guanylthiourea, 1-(1-naphthyl)-2-thiourea, 1-phenyl- 2-thiourea, p-tolylthiourea, and o-tolylthiourea. In certain embodiments, the activator includes at least one thiourea compound selected from thiourea, N, N'-diethylthiourea, trimethylthiourea, N, N'-diphenylthiourea, and N-N'-dimethylthiourea.

[0147] Vulcanization inhibitors are used to control the vulcanization process and generally retard or inhibit vulcanization until the desired time and / or temperature is reached. Common vulcanization inhibitors include, but are not limited to, PVI (cyclohexylthiophthalmide) from Santoga rd. Generally, in certain embodiments the amount of vulcanization inhibitor is 0.1 to 3 phr (e.g., 0.1, 0.5, 1, 1.5, 2, 2.5, or 3 phr), such as 0.5 to 2 phr (e.g., 0.5, 1, 1.5, or 2 phr).

[0148] The particular steps involved in preparing the tire tread rubber compositions disclosed herein are generally those of conventionally practiced methods comprising mixing the ingredients in at least one non- productive master-batch stage and a final productive mixing stage. In certain embodiments, the tire tread rubber composition is prepared by combining the ingredients for the rubber composition (as disclosed above) by methods known in the art, such as, for example, by kneading the ingredients together in a Banbury mixer or on a milled roll. Such methods generally include at least one non-productive master-batch mixing stage and a final productive mixing stage. The term non-productive master-batch stage is known to those of skill in the art and generally understood to be a mixing stage (or stages) where no vulcanizing agents or vulcanization accelerators are added. The term final productive mixing stage is also known to those of skill in the art and generally understood to be the mixing stage where the vulcanizing agents and vulcanization accelerators are added into the rubber composition. In certain embodiments, the tire tread rubber composition is prepared by a process comprising more than one non-productive master-batch mixingstage.

[0149] In certain embodiments, the tire tread rubber composition is prepared by a process wherein the master-batch mixing stage includes at least one of tandem mixing or intermeshing mixing. Tandem mixing can be understood as including the use of a mixer with two mixing chambers with each chamber having a set of mixing rotors; generally, the two mixing chambers are stacked together with the upper mixer being the primary mixer and the lower mixer accepting a batch from the upper or primary mixer. In certain embodiments, the primary mixer utilizes intermeshing rotors and in other embodiments the primary mixer utilizes tangential rotors. The lower mixer may utilize intermeshing rotors. Intermeshing mixing can be understood as including the use of a mixer with intermeshing rotors. Intermeshing rotors refers to a set of rotors where the major diameter of one rotor in a set interacts with the minor diameter of the opposing rotor in the set such that the rotors intermesh with each other.Intermeshing rotors must be driven at an even speed because of the interaction between the rotors. In contrast to intermeshing rotors, tangential rotors refers to a set of rotors where each rotor turns independently of the other in a cavity that may be referred to as a side. Generally, amixer with tangential rotors will include a ram whereas a ram is not necessary in a mixer with intermeshing rotors.

[0150] Generally, the rubbers (or polymers) and at least one reinforcing filler (as well as any silane coupling agent and liquid plasticizer) will be added in a non-productive or masterbatch mixing stage or stages. Generally, at least the vulcanizing agent component and the vulcanizing accelerator component of a cure package will be added in a final or productive mixing stage.

[0151] In certain embodiments, the tire tread rubber composition is prepared using a process wherein at least one non-productive master batch mixing stage is conducted at a temperature of about 130 °C to about 200 °C. In certain embodiments, the tire tread rubber composition is prepared using a final productive mixing stage conducted at a temperature below the vulcanization temperature in order to avoid unwanted pre-cure of the rubber composition. Therefore, the temperature of the productive or final mixing stage generally should not exceed about 120 °C and is typically about 40 °C to about 120 °C, or about 60 °C to about 110 °C and, especially, about 75 °C to about 100 °C. In certain embodiments, the tire tread rubber composition is prepared according to a process that includes at least one nonproductive mixing stage and at least one productive mixing stage. The use of silica fillers may optionally necessitate a separate re-mill stage for separate addition of a portion or all of such filler. This stage often is performed at temperatures similar to, although often slightly lower than, those employed in the masterbatch stage, i.e., ramping from about 90°C to a drop temperature of about 150°C.

[0152] The use of the rCB and plasticizer in combination with other components of the tire tread rubber compositions can, in certain embodiments, result in an improvement in rCB usage amounts or ratios. For example, 1 to 65 more phr of rCB can be used in a compound with appropriate adjustment of the plasticizer, such as, e.g., 3 to 35 phr more rCB, or 5 to 20 phr more rCB, while substantially maintaining other compound properties such as wear resistance, tan delta, EB, and / or G' values within 10%, 5% or 2% of compounds using the lower amount of rCB. Alternatively, 1 to 65% of rCB (wt rCB / wt total CB) can be used in a compound with appropriate adjustment of the plasticizer, such as, e.g., about 3 to about 35% rCB in totalCB, or about 5 to about 20% rCB, while substantially maintaining other compound properties such as wear resistance and G' values within 10%, 5% or 2% of compounds using the lower amount of rCB. Unexpectedly, the use of less plasticizer, e.g., oil, was determined to be the appropriate adjustment to efficiently utilize more rCB.

[0153] In certain embodiments, the tire tread rubber composition exhibits other equivalent properties to the composition formed with the non-functionalized hi-cis polybutadiene. In other words, in exemplary embodiments, an improvement was realized with no detriment to other properties that may include one or more of rolling resistance, snow or ice traction, wet traction, cut / stiffness, heat generation, and tear. One or more of such properties may be predicted based on the evaluation of rubber compounds for E' at 25°C, tan 6 at 100°C, and 100°C hot aged E. Additional equivalent or desirable properties may include elongation at break (Eb), tensile at break (Tb) and TbxEb. While these properties may be measured by various methods, the values referred to herein fare measured at the following temperatures and according to the following procedures. E' and tan 6 values can be measured with a dynamic mechanical thermal spectrometer (Eplexor® 500N from Gabo Qualimeter Testanlagen GmbH of Ahiden, Germany) generally following the guidelines of ASTM D5992-96 (2011) and under the following conditions: measurement mode: tensile test mode; measuring frequency: 52 Hz; applying 2% strain from 10 to 100 °C; collecting data approximately every 1 °C in order to provide measurements at temperatures of 25 °C, 60 °C, and 100 °C; sample shape: 4.75 mm wide x 29 mm long x 2.0 mm thick. Measurement is made upon a cured sample of rubber (cured for 33 minutes at 145°C).

[0154] In certain embodiments, the rubber composition has a value for tan 6 at 60 °C of about 0.16 to about 0.26 (e.g., about 0.17, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, or 0.25), 0.18 to 0.22 (e.g., 0.18, 0.19, 0.2, 0.21, or 0.22), or 0.18 to 0.2 (e.g., 0.18, 0.19, 0.2). A tan 6 at 60 °C within one of the foregoing ranges can be understood as being indicative of a tire (or more specifically, a tire tread) with moderate rolling resistance (as opposed to a tire with low rolling resistance which would generally be indicated by a tan 6 at 60 °C of less than or equal to 0.2). In certain embodiments, the value for tan 6 at 60 °C is combined with at least one of the following: (a) a value for tan 6 at -30 °C of no more than 2.5 times the tan 6 at 60 °C value (e.g.,2.5, 2.4, 2.2, 2.1, 2, 1.9, 1.8, etc. times ), 2.5 times and 2 times (e.g., 2.5, 2.4, 2.3, 2.2, 2.1, or 2 times) the tan 6 at 60 °C value; (b) a value for tan 6 at 30 °C of at least 1.4 times the tan 6 at 60°C value (e.g., 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, etc. times), 1.4 and 2 times (e.g., 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 times) the tan 6 at 60 °C value, or 1.5 and 1.8 times (e.g., 1.5, 1.6, 1.7, or 1.8 times) the tan 6 at 60 °C value; or (c) a value for tan 6 at 0 °C of at least 2.2 times the tan 6 at 60 °C value (e.g., 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, etc. times), 2.2 times to 3 times the tan 6 at 60 °C value (e.g., 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3 times), or 2.3 times to 2.8 times the tan 6 at 60 °C value (e.g., 2.3, 2.4, 2.5, 2.6, 2.7, or 2.8 times); in certain such embodiments, the value for tan 6 at 60 °C is combined with each of (a), (b), and (c). In certain embodiments, one of the foregoing values for tan 6 at 60 °C (e.g., 0.16 to 0.25, 0.18 to 0.22, 0.18 to 0.2, etc.) is combined with (a) a value for 6 at -30 °C of 2.5 times and 2 times (e.g., 2.5, 2.4, 2.3, 2.2, 2.1, or 2 times) the tan 6 at 60 °C value. In certain embodiments, one of the foregoing values for tan 6 at 60 °C (e.g., 0.16 to 0.25, 0.18 to 0.22, 0.18 to 0.2, etc.) is combined with (b) a value for 6 at 30 °C of 1.4 and 2 times (e.g., 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 times) the tan 6 at 60 °C value. In certain embodiments, one of the foregoing values for tan 6 at 60 °C (e.g., 0.16 to 0.25, 0.18 to 0.22, 0.18 to 0.2, etc.) is combined with (c) a value for 6 at 0 °C of 2.2 times to 3 times the tan 5 at 60 °C value (e.g., 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3 times) the tan 6 at 60 °C value. In certain embodiments, one of the foregoing values for tan 6 at 60 °C (e.g., 0.16 to 0.25, 0.18 to 0.22, 0.18 to 0.2, etc.) is combined with the values tan 6 at -30 °C and the values for tan 6 at 30 °C.

[0155] In certain embodiments, the tire tread rubber composition has a value for tan 6 at 60 °C of 0.16 to 0.25, such as 0.18 to 0.22, or 0.18 to 0.21, and meets at least one of the following: (a) has a value for tan 6 at -30 °C of no more than 2.5 times the tan 6 at 60 °C value, or 2.5 times and 2 times the tan 6 at 60 °C value; (b) has a value for tan 6 at 30 °C of at least 1.4 times the tan 6 at 60 °C value, 1.4 times and 2 times the tan 6 at 60 °C value, or 1.5 times and 1.8 times the tan 6 at 60 °C value; or (c) has a value for tan 6 at 0 °C of at least 2.2 times the tan 6 at 60 °C value, 2.2 times and 3 times the tan 6 at 60 °C value, or 2.3 times and 2.8 times the tan 6 at 60 °C value.

[0156] The wear performance of a tire tread rubber composition can be evaluated by various methods. Wear resistance can be measured by DIN abrasion values wherein a lower value (i.e., less material lost) indicates better wear. However, the absolute wear values refer to DIN abrasion values that can be measured by DIN ISO 53516. According to such method, the values represent the amount of material lost (in mm3) during the abrasion testing. When comparing two DIN abrasion values, a lower number indicates less material lost and corresponds to an improvement in wear. An improvement in wear can also be described as improved resistance to abrasion and is generally desirable in a tire tread since it leads to a tire having a longer lifespan (e.g., having a higher predicted mileage rating). In certain embodiments, the tire tread rubber composition has a DIN abrasion (according to DIN ISO 53516) of no more than 100 mm3(e.g., 100, 99, 98, 97, 96, 95, 94, 93, 92, 91, 90, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60 mm3or less), no more than no more than 95 mm3(e.g., 95, 94, 93, 92, 91, 90, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60 mm3or less), no more than 90 mm3(e.g., 90, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60 mm3or less), no more than no more than 85 mm3(e.g., 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60 mm3or less), no more than 80 mm3(e.g., 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60 mm3or less), no more than 75 mm3(e.g, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60 mm3or less), no more than 70 mm3(e.g, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60 mm3or less), or 100 to 60 mm3(including ranges within the foregoing), 95 to 60 mm3(including ranges within the foregoing), 90 to 60 mm3(including ranges within the foregoing), 85 to 60 mm3(including ranges within the foregoing), 80 to 60 mm3(including ranges within the foregoing), 75 to 60 mm3(including ranges within the foregoing), 70 to 60 mm3(including ranges within the foregoing), 100 to 70 mm3(including ranges within the foregoing), 95 to 70 mm3(including ranges within the foregoing), 90 to 70 mm3(including ranges within the foregoing), 85 to 70 mm3(including ranges within the foregoing), 80 to 70 mm3(including ranges within the foregoing), 100 to 80 mm3(includingranges within the foregoing), 95 to 80 mm3(including ranges within the foregoing), or 90 to 80 mm3(including ranges within the foregoing).

[0157] The tire tread rubber compositions can be considered to be particularly useful in terms of providing a tire tread with the same or improved wear performance. By stating that the wear performance is improved, it is meant that the wear performance (as measured by ISO 23337:2016)) is at least 101% of a control. As non-limiting examples, if a sample exhibited an abrasion loss of 0.0055 mg and its control exhibited an abrasion loss of 0.0050, the sample could be described as having a wear performance that is 95% of its control and if a sample exhibited an abrasion loss of 0.0054 mg and its control exhibited an abrasion loss of 0.0060 mg, the sample could be described as having a wear performance that is improved by 10% as compared to its control. According to the foregoing descriptions, a wear performance that is 100% of its control should be understood as having a wear performance that is equal to its control and the comparisons to control are calculated by dividing the control value by the sample value and multiplying by 100%.

[0158] In certain embodiments, the rubber composition has a room temperature Eb of at least 400% (e.g., 420%, 425%, 440%, 465%, 485%, 495%, 500%, 505%, 510%, 515%, 520%, 525%, 530%, 535%, 540%, 545%, 550%, 555%, 560%, 565%, 570%, 575%, 580%, 585%, 590%, 595%, 600%, 605%, 610%, 615%, 620%, 625%, 630%, 635%, 640%, 645%, 650%, or more) or within the range of 440 to 650% or a sub-range within that range, such as at least 470% (e.g., 475%, 480%, 500%, 515%, 520%, 525%, 530%, 535%, 540%, 545%, 550%, 555%, 560%, 565%, 570%, 575%, 580%, 585%, 590%, 595%, 600%, 605%, 610%, 615%, 620%, 625%, 630%, 635%, 640%, 645%, 650%, or more) or within the range of 500 to 650% or a sub-range within that range. The foregoing room temperature Eb values refer to measurements made at 23 ° C. Eb can be measured following the guidelines, but not restricted to, the standard procedure described in ASTM D-412, with dumbbell-shaped samples having a cross-section dimension of 4 mm in width and 1.9 mm in thickness at the center. During measurement, specimens may be strained at a constant rate (20% per second) and the resulting force recorded as a function of extension (strain).

[0159] In certain embodiments, the rubber composition has a hot Eb of at least 375%, (e.g., 375%, 380%, 385%, 390%, 395%, 400%, 405%, 410%, 415%, 420%, 425%, 430%, 435%, 440%, 445%, 450%, 455%, 460%, 465%, 470%, 475%, 480%, 485%, 490%, 495%, 499%, or more) or within a range of 375-499% or a sub-range within that range, such as at least 400% (e.g., 400%, 405%, 410%, 415%, 420%, 425%, 430%, 435%, 440%, 445%, 450%, 455%, 460%, 465%, 470%, 475%, 480%, 485%, 490%, 495%, 499%, or more) or within a range of 400-499% or a subrange within that range. The foregoing hot Eb values refer to measurements made at 100 °C. Eb can be measured following the guidelines, but not restricted to, the standard procedure described in ASTM D-412, with dumbbell-shaped samples having a cross-section dimension of 4 mm in width and 1.9 mm in thickness at the center. During measurement, specimens may be strained at a constant rate (20% per second) and the resulting force recorded as a function of extension (strain). Generally, a hot Eb value for a given tread rubber composition will be lower (i.e., less than) the room temperature Eb for that tread rubber composition.

[0160] In an embodiment, the tire tread rubber composition, as disclosed herein, will be utilized in a tire tread, or other component, for example, a passenger tire, off-the-road, or agricultural or alternatively, a TBR (truck and bus, radial) tire tread, such as a TBR steer tire tread) or passenger and light truck tire. Thus, also disclosed herein is a tire tread comprising the tire tread rubber composition. As well, such a tire tread or other component can be utilized in a tire (along with other components). Thus, also disclosed herein is a tire having a tread or other component comprising the tire tread rubber composition according embodiments, as discussed herein.

[0161] In an embodiment, the tire compound disclosed herein can be used in a tire carcass layer, a sidewall, an apex, a bead, an undertread, or a shoulder of a tire. In an embodiment, the rCB containing compound is used in a tire component that typically includes lower ASTM grade vCB, such as N600, N500, or N300 ASTM grade carbon black as a replacement for such ASTM grade carbon blacks.

[0162] A TBR tire is one that has a load index (LI) corresponding to the min and max values in Table 1 below and is distinguished from a passenger tire (PSR) as shown below:Table 1ETRTO min LI max LIPSR 62 122TBR 117 166

[0163] In an embodiment, the tire is passenger (PSR) tire; in another embodiment, the tire is a truck and bus radial (TBR) tire that has, e.g., an LI of about 123 to about 165, such as about 130 to about 160, or about 135 to about 155. Load index is a numerical code known and commonly used by those of skill in the art that indicates the maximum load that a tire can carry at the speed indicated by its speed index in the conditions of use specified by the manufacturer. In an embodiment, a TBR tire is one that is designed to support at least a vehicle weighing at least 6 tons. The TBR tread pattern may also be a continuous rib pattern. TBR tires sizes may be, for example, selected from the group consisting of: 6.50R16LT, 7.00R16LT, 7.50R16LT, 8.25R16LT, 9.00R20, 10.00R20, 11.00R20, 12.00R20, 11R22.5, 12R22.5, 13R22.5, 315 / 80R22.5, 12.00R24, 325 / 95R24, 295 / 80R22.5, 11R24.5, 12R24.5, 425 / 65R22.5, and 445 / 65R22.5.

[0164] The term "or" is intended to mean an inclusive "or" rather than an exclusive "or." That is, unless specified otherwise, or clear from the context, the phrase " X employs A or B" is intended to mean any of the natural inclusive permutations. That is, the phrase " X employs A or B" is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from the context to be directed to a singular form.

[0165] As used herein, the term "exemplary" is intended to mean serving as an illustration or example of something, and is not intended to indicate a preference.

[0166] Unless otherwise indicated, all numbers expressing quantities of components, molecular weights, molarities, voltages, capacities, and so forth, as used in the description are to be understood as being modified by the term "about." Accordingly, unless otherwise implicitly or explicitly indicated, or unless the context is properly understood by a person of ordinary skill in the art to have a more definitive construction, the numerical parameters setforth are approximations that may depend on the desired properties sought and / or limits of detection under standard test conditions / methods as known to those of ordinary skill in the art. When directly and explicitly distinguishing aspects of the present disclosure from discussed prior art, the stated numbers are not approximates unless the word "about" is recited.

[0167] As used herein the term "natural rubber" means naturally occurring rubber such as can be harvested from sources such as Hevea rubber trees and non- / 7eveo sources (e.g., guayule shrubs and dandelions such as TKS). In other words, the term "natural rubber" should be construed so as to exclude synthetic polyisoprene.

[0168] As used herein, the term "phr" means parts per one hundred parts rubber. The 100 parts rubber refers to 100 parts of the at least one conjugated diene monomer-containing rubber.

[0169] As used herein the term "polyisoprene" means synthetic polyisoprene. In other words, the term is used to indicate a polymer that is manufactured from isoprene monomers, and should not be construed as including naturally occurring rubber (e.g., Hevea natural rubber, guayule-sourced natural rubber, or dandelion-sourced natural rubber). However, the term polyisoprene should be construed as including polyisoprenes manufactured from natural sources of isoprene monomer.

[0170] Unless otherwise indicated herein, the term " Mooney viscosity" refers to the Mooney viscosity, ML1+4. Mooney viscosity is measured prior to vulcanization or curing.

[0171] As used herein, the term "natural rubber" means naturally occurring rubber such as can be harvested from sources such as Hevea rubber trees and non-Heveo sources (e.g., guayule shrubs and dandelions such as TKS). In other words, the term "natural rubber" should be construed so as to exclude synthetic polyisoprene.

[0172] As used herein, the term "phr" means parts per one hundred parts rubber. The one hundred parts rubber is also referred to herein as 100 parts of an elastomer component.

[0173] As used herein, the term "tread," refers to both the portion of a tire that comes into contact with the road under normal inflation and load as well as any subtread.

[0174] EXAMPLES

[0175] Several experiments were performed with rubber compositions with vCB and rCB and with plasticizer to determine the effects on the rubber composition.

[0176] Example 1

[0177] The data indicated that the G' change and M300 change is different for vCB vs. rCB loading. Plasticizer has more of an effect on compound G' and M300 in compounds with 100% phr rCB than in a compound with 100% vCB. In addition, replacing some amount of vCB with the same amount of rCB without adjusting the plasticizer or other components of the formulation, the compound was reduced in stiffness. Without being bound by theory, the rCB results in the plasticizer being more effective to plasticize the compound. Thus, in an embodiment, less plasticizer can be used, which can produce attendant benefits.

[0178] Example 2

[0179] The data also indicated that scorch time was increased as a function of rCB ash content and general rCB loading.

[0180] Example 3

[0181] The data indicated relationships between multiple rCB factors and compound T90 (time to 90% of cure). Higher ash was found to correlate to longer cure times.

[0182] Without being bound to theory, the data was interpreted to indicate that the increased oil leads to a dilution of the curatives in the compound and causes longer cure times / cure induction times (scorch), and slower cure rates. The rCB seemed to absorb less oil than traditional vCB. Due to this minimized interaction, more oil produced a slower cure. Also, it was theorized that there could also be an interaction between the rCB (rCB ash) and the curatives directly, reducing the curatives concentration in the bulk matrix overall. Cure differences impacted final rubber component properties such as G', M300, Eb, and tan delta.

[0183] What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable modification and alteration of the above devices or methodologies for purposes of describing the aforementioned aspects, but one of ordinary skill in the art can recognize that many further modifications and permutations of various aspects are possible. Accordingly, the described aspects are intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of theappended claims. Furthermore, to the extent that the term "includes" is used in either the details description or the claims, such term is intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim. The term "consisting essentially" as used herein means the specified materials or steps and those that do not materially affect the basic and novel characteristics of the material or method. If not specified above, the properties mentioned herein may be determined by applicable ASTM standards, or if an ASTM standard does not exist for the property, the most commonly used standard known by those of skill in the art may be used. The articles "a," "an," and "the," should be interpreted to mean "one or more" unless the context indicates the contrary.

Claims

CLAIMSWhat is claimed is:

1. A tire component comprising:a polymer composition including:a rubber component including a conjugated diene polymer; anda reinforcing filler component including a recycled carbon black having a percentage ash content of about 5% to about 25%;wherein the polymer composition meets formula (III):(III) rCB x A x P = Xwherein rCB is an amount of recycled carbon black in the polymer composition in phr and rCB is at least about 10;A is the percentage ash content of the recycled carbon black as a decimal;P is phr of a plasticizer and is at least about 15; andX is about 20 to about 140.

2. The tire component of claim 1, wherein the polymer composition meets formula (IV):(IV) 0.55 ≤ X*(TD / Eb) ≤ 8.3wherein TD is tan 6 at 60 °Cwherein Eb is a percentage of elongation at break at 25°C.

3. The tire component of claim 1 or 2, wherein TD = tan δ at 60 °C of about 0.16 to about 0.26 or wherein the tire component has an Eb at 23°C of at least about 425%.

4. The tire component of any of claims 1-3, wherein the polymer composition has a plasticizer content of about 40 phr or to about 80 phr.

5. The tire component of any of claims 1-4, wherein the plasticizer comprises an oil and the oil is selected from the group consisting of: naphthenic oil, aromatic oil, MES oil, TDAE oil, TRAE oil, and plant oil.

6. The tire component of any of claims 1-5, wherein the conjugated diene is selected from the group consisting of: natural rubber, polyisoprene, polybutadiene, poly(styrene- butadiene), and combinations thereof.

7. The tire component of any of claims 1-6, wherein the recycled carbon black is a majority of the reinforcing filler component and the plasticizer content is about 15 to about 25 phr.

8. The tire component of any of claims 1-7, wherein a majority of the rubber component comprises natural rubber and / or polyisoprene.

9. The tire component of any of claims 1-8, wherein the rubber component comprises about 30 to about 70 phr of natural rubber and / or polyisoprene; and about 5 to about 70 phr of styrene-butadiene rubber and / or polybutadiene.

10. The tire component of any of claims 1-9, wherein the tire component is a tread.

11. The tire component of any of claims 1-10, wherein the tire component is a tread for a tire having a size selected from the group consisting of: 6.50R16LT, 7.00R16LT, 7.50R16LT, 8.25R16LT, 9.00R20, 10.00R20, 11.00R20, 12.00R20, 11R22.5, 12R22.5, 13R22.5, 315 / 80R22.5, 12.00R24, 325 / 95R24, 295 / 80R22.5, 11R24.5, 12R24.5, 425 / 65R22.5, and 445 / 65R22.5.

12. The tire component of any of claims 1-11, wherein the tire component is a sidewall, carcass layer, or bead component.

13. A tire component comprising:a polymer composition including:a rubber component including a conjugated diene polymer;a reinforcing filler component including a recycled carbon black having an ash content of about 5% to about 25%; and0 to about 5 phr plasticizer;wherein the reinforcing filler component is present in an amount of about 30 to about 150 phr;wherein the recycled carbon black is at least about 40% of the total reinforcing filler component;wherein the tire component is a sidewall, carcass layer, or bead component wherein the polymer composition meets formula (V):(V) (rCBxA) / P ≥ 0.1wherein rCB is an amount of recycled carbon black in the polymer composition in phr;A is a percentage ash content of the recycled carbon black as a decimal; and P is phr of a plasticizer.

14. The tire component of claim 13, wherein the tire component has a value for tan δ at 60 °C of about 0.16 to about 0.26, or wherein the tire component has an Eb at 23°C of at least about 425%.

15. The tire component of any of claims 13 or 14, wherein the recycled carbon black is at least about 75% of all carbon black in the composition.

16. The tire component of any of claims 13-15, wherein the recycled carbon black is derived from end of life tires.

17. A method for making a polymer composition for a tire component, comprising the steps of:mixing a polymer component including a conjugated diene polymer; and either: (1) adding a reinforcing filler component including a recycled carbon black having a percentage ash content of about 5% to about 25%;wherein the polymer composition meets formula (III):(III) rCB x A x P = Xwherein rCB is an amount of recycled carbon black in the polymer composition in phr and rCB is at least about 10;A is the percentage ash content of the recycled carbon black;P is phr of a plasticizer and is at least 15; andX is about 20 to about 140;or(2) adding a reinforcing filler component in an amount of about 30 to about 110 phr, the reinforcing filler component including a recycled carbon black having an ash content of about 5% to about 25%, wherein the recycled carbon black is at least about 40% of the total reinforcing filler component;adding 0 to about 5 phr of liquid plasticizer;adding a primary accelerator and a sulfur-based curing agent; and vulcanizing the polymer composition in a mold to form the tire component wherein the tire component is a sidewall, carcass layer, or bead component; wherein the polymer composition meets formula (V):(V) (rCBxA) / P ≥ 0.1wherein rCB is an amount of recycled carbon black in the polymer composition in phr;A is the percentage ash content of the recycled carbon black; and P is phr of a plasticizer.

18. The method of claim 17, wherein the tire component has a value for tan δ at 60 °C of about 0.16 to about 0.26, or wherein the tire component has an Eb at 23°C of at least about 425%.

19. The tire component of any of claims 1-12 wherein the recycled carbon black has a void volume as a function of mean pressure measured by a Dynamic Void Volume Analyzer (DVVA) according to ASTM D7854-16 has a value of about 25 to about 120.

20. The tire component of any of claims 13-16, wherein the rubber component comprises about 30 to about 70 phr of natural rubber and / or polyisoprene; and about 5 to about 70 phr of styrene-butadiene rubber and / or polybutadiene.

21. The tire component of any of claims 13-16 or claim 20, wherein the rubber component comprises about 30 to about 70 phr of natural rubber and / or polyisoprene; and about 5 to about 25 phr of styrene-butadiene rubber or about 5 to about 25 phr ofpolybutadiene.

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