Tire composition and method for producing the same

Abstract

To provide a rubber composition that has a combination of both improved wet grip and good rolling resistance.SOLUTION: The disclosure relates to tire tread compositions and methods for making. The compositions include a rubber, a rosin ester resin and at least one filler. The rosin ester resin is characterized as having a PAN number of less than 25, an acid number less than 20, a hydroxyl number of less than 30, a combined acid number and hydroxyl number of less than 50. The tire tread composition has a ratio of a wet grip resistance indicator to a rolling resistance indicator ((tan δ at 0°C) / (tan δ at 60°C)) higher than a tire tread composition containing a comparable amount of a rosin ester having a combined acid number and hydroxyl number of more than 50.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to a rubber composition containing a rosin ester for use in tire applications. [Background technology]

[0002] High-performance tire treads are expected to have safe and outstanding traction and handling, wet grip, rolling resistance, and good wear characteristics. These characteristics may depend on the dynamic viscoelasticity of the rubber composition used in manufacturing the tire.

[0003] Rubber tires used for transportation and other applications should ideally have a rubber tread with excellent wet grip (wet traction) and rolling resistance, such as the resistance to the tire's movement as it rolls across the surface. While dry grip is usually maintained by many rubber compositions, satisfactory wet grip is often not achieved. Rubber compositions with good wet grip improve wet skid resistance, but increase rolling resistance, leading to reduced fuel efficiency.

[0004] Reducing rolling resistance and improving wet grip performance are generally influenced by conflicting properties. Optimizing tread rolling resistance often compromises wet grip, and optimizing wet grip often negatively impacts rolling resistance. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] It is well known in the art that resins are used in tire compositions to improve wet grip performance. Therefore, there remains a need for rubber compositions that have a combination of both improved wet grip and good rolling resistance. [Means for solving the problem]

[0006] (Summary of the invention) In one embodiment, a tire tread composition is disclosed. This composition comprises a rubber component, and, per 100 parts by weight (phr) of the rubber component, 5 to 75 phr of a rosin ester resin having a PAN number of less than 25, an acid value of less than 20, a hydroxyl value of less than 30, and a sum of acid and hydroxyl values ​​of less than 50, 30 to 200 phr of a filler, and 0 to 75 phr of a plasticizer.

[0007] In another embodiment, a method for preparing a tire rubber composition is disclosed. This method includes (a) preparing 0 to 100 parts by weight (phr) of a rubber component; (b) preparing 5 to 75 phr of a rosin ester resin having a PAN number of less than 25, an acid value of less than 20, a hydroxyl value of less than 30, and a sum of acid and hydroxyl values ​​of less than 50; 30 to 200 phr of a filler; and optionally a plasticizer of 75 phr or less; (c) mixing the rubber component, the rosin ester resin, the filler, and the optionally selected plasticizer to form a mixture; (d) kneading the mixture; and (e) incorporating a crosslinking system into the kneaded mixture to form a tire rubber composition. [Modes for carrying out the invention]

[0008] Unless otherwise indicated, the following terms have the following meanings:

[0009] PHR stands for the number of units per 100 units of elastomer (rubber).

[0010] Elastomers and rubbers are used interchangeably.

[0011] Polymers and interpolymers are used interchangeably and include copolymers, terpolymers, tetrapolymers, etc., meaning they contain higher-order oligomers with a number-average molecular weight (Mn) of 100 or more.

[0012] M w (Weight-average molecular weight) and M n(Number average molecular weight) is determined using GPC-SEC (gel permeation-size exclusion chromatography) in accordance with ASTM D5296 (2005). The polydispersity (PDI) is represented by M w / M n .

[0013] M z is

[0014]

Number

[0015] Tg (glass liquid transition or glass transition) can be determined in accordance with ASTM D6604 (2013).

[0016] Tsp (softening point) is determined by ASTM E28, ASTM 218, the ring and ball or ring and cup softening point test.

[0017] The hydroxyl value is determined in accordance with ASTM E222.

[0018] The acid value is determined using ASTM D5974-14.

[0019] The PAN number refers to the sum of the weight percentages of the parastric acid, abietic acid, and neoabietic acid moieties of the rosin ester determined in accordance with ASTM D5974-00 (2010).

[0020] The viscoelastic polymeric material has a complex elastic modulus G* can be characterized by measuring. The absolute value of the complex elastic modulus |G * | is [(G’) 2 +(G”) 2 1 / 2 and is defined as, where G’ is the storage elastic modulus and G” is the loss elastic modulus. G’, G”, the phase angle (C), and attenuation can be measured as functions of strain amplitude at temperatures from -100 °C to +100 °C using dynamic mechanical analysis (DMA) in accordance with ASTM D7605. The properties can be indicators of characteristics such as durability, traction, and handling. The absolute value of the storage elastic modulus (G’) at -20 °C and -30 °C can be used as an indicator of ice grip. Tan delta (tanδ) is represented by G’ / G”. The tanδ value at 0 °C is generally used as an indicator of wet grip, and the tanδ value at 60 °C is generally used as an indicator of rolling resistance. The absolute value of tanδ at -20 °C can be used as an indicator of snow grip.

[0021] Tanδ can be obtained using a dynamic viscoelastic tester. High values of G” (loss elastic modulus) and tan delta at 0 °C are predicted to indicate good wet traction. Low tanδ values at temperatures above 50 °C indicate low rolling resistance. Tanδ at 100 °C can be used as an indicator of improving tire grip and other performance characteristics under severe usage conditions. Tanδ is determined by DMA using Metravib + 450N at 10 Hz with a heating rate of 1 °C / min and dynamic strains of 0.1% (-60 °C to -5 °C) and 3% (-5 °C to 100 °C) in a temperature sweep / mode of double shear mode from -60 °C to +100 °C.

[0022] Tensile strength, elongation, and modulus can be measured in accordance with ASTM D412.

[0023] Hardness refers to Shore A hardness according to DIN53506.

[0024] The Mooney viscosity MS or ML(1+4) at 100°C can be measured according to DIN 53523.

[0025] This specification discloses rubber compositions comprising a rubber component, a rosin ester resin having a PAN number of less than 25, an acid value of 0 to 20, a hydroxyl value of 0 to 30, and a sum of the acid value and hydroxyl value of less than 50, a filler, and an optional plasticizer.

[0026] Rubber component: The rubber or elastomer component includes both natural rubber and its various raw and recycled forms, as well as various synthetic rubbers. In embodiments, the rubber component includes any unsaturated diene elastomer selected from polybutadiene, natural rubber, synthetic polyisoprene, butadiene copolymer, isoprene copolymer, and mixtures thereof.

[0027] In one embodiment, the rubber is selected from butyl rubber, halogenated butyl rubber, and EPDM (ethylene propylene diene monomer rubber) and mixtures thereof. In another embodiment, the rubber component is natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber, synthetic polyisoprene rubber, epoxidized natural rubber, polybutadiene rubber, e.g., high-cis polybutadiene rubber, nitrile-hydrogenated butadiene rubber (HNBR), hydrogenated SBR, ethylene propylene diene monomer rubber, ethylene propylene rubber, maleic acid-modified ethylene propylene rubber, butyl rubber, isobutylene-aromatic vinyl or diene monomer copolymer, brominated NR, chlorinated NR, brominated isobutylene p-methylstyrene copolymer, chloroprene rubber, epichlorohydrin homopolymer rubber, epichlorohydrin-ethylene oxide Selected from cyd or allyl glycidyl ether copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, chlorosulfonated polyethylene, chlorinated polyethylene, maleic acid-modified chlorinated polyethylene, methyl vinyl silicone rubber, dimethyl silicone rubber, methylphenyl vinyl silicone rubber, polysulfide rubber, vinylidene fluoride rubber, tetrafluoroethylene-propylene rubber, fluorinated silicone rubber, fluorinated phosphagen rubber, styrene elastomer, thermoplastic olefin elastomer, polyester elastomer, urethane elastomer, polyamide elastomer, and combinations thereof.

[0028] Examples of SBR rubber include emulsion-polymerized styrene-butadiene rubber (unmodified E-SBR), solution-polymerized styrene-butadiene rubber (unmodified S-SBR), and modified SBR (modified E-SBR and S-SBR) obtained by modifying the ends. The rubber components may include components other than SBR and BR, such as natural rubber (NR), isoprene rubber (IR), epoxidized natural rubber (ENR), butyl rubber, acrylonitrile butadiene rubber (NBR), ethylene propylene diene rubber (EPDM), chloroprene rubber (CR), and styrene-isoprene-butadiene rubber (SIBR), which may be used alone or in combination.

[0029] The rubber component may be coupled, star-branched, branched, and / or functionalized with coupling agents and / or star-branching agents or functionalizing agents. In embodiments, the rubber is coupled, star-branched, or functionalized with at least a sulfur compound, a silanol group, a silane group, or an epoxy group. In embodiments, the branched rubber may be any of branched ("star-branched") butyl rubber, halogenated star-branched butyl rubber, poly(isobutylene-co-p-methylstyrene), brominated butyl rubber, chlorinated butyl rubber, star-branched polyisobutylene rubber, or mixtures thereof.

[0030] In embodiments, the rubber is functionalized at the end groups to improve its affinity for fillers such as carbon black and / or silica. Examples of coupling and / or star branching or functionalization include coupling with carbon black as a filler, for example, coupling with functional groups containing C-Sn bonds or amination functional groups such as benzophenone, silanol functional groups or polysiloxane functional groups having silanol ends, alkoxysilane groups, and polyether groups.

[0031] Rosin ester resin components: References to rosin esters include modified rosin esters, e.g., rosin treated with aldehydes, dibasic acids, or combinations thereof, acid-modified rosin esters, and phenol-modified rosin esters. Rosin esters can be obtained from rosin and suitable alcohols by esterification reactions using various methods known in the art.

[0032] In this embodiment, the rosin ester resin is a phenol-modified rosin ester prepared by reacting rosin with a formaldehyde-containing compound and a phenol compound to produce an intermediate phenol resin, which is then esterified with a polyhydric alcohol.

[0033] In some embodiments, rosin ester resins are produced by methods known in the art, such as hydrogenation, dehydrogenation, disproportionation, dimerization, and strengthening. In certain embodiments, rosin is esterified after being treated with one or more of these methods to improve the chemical and physical properties of the resulting rosin ester. Where chemically permissible, such methods may also be carried out in combination with and / or after esterification to obtain rosin esters having the desired chemical and physical properties, which are discussed in more detail below. In one embodiment, the rosin ester resin is produced by a method using disproportionating agents known in the art, which include 2,2'-thiobisphenol, 3,3'-thiobisphenol, 4,4'-thiobis(resorcinol) and t,t'-thiobis(pyrogallol), 4,4'-15-thiobis(6-t-butyl-m-cresol) and 4 / 4'-thiobis(6-t-butyl-o-cresol)thiobisnaphthol, thiobisnaphthol containing 2,2'-thio-bisphenol and 3,3'-thio-bisphenol, metals including palladium, nickel and platinum, iodine or iodide (e.g., iron iodide), sulfide (e.g., iron sulfide), and combinations thereof.

[0034] In the embodiment, the rosin ester resin has Mn in the range of 600-1400 Da (Daltons), 650-1200 Da, or 700-1100 Da. In the embodiment, the rosin ester resin has Mw in the range of 700-1500 Da, 800-1300 Da, or 850-1200 Da. In the embodiment, Mz is in the range of 800-2000 Da, 900-2000 Da, or 1000-1500 Da. In the embodiment, the rosin ester resin has a polydispersity index (PDI) of 1.05-1.45, alternatively 1.1-1.4, or 1.1-1.3.

[0035] In other embodiments, the rosin ester resin has a low PAN number of 25 or less, 20 or less, 15 or less, or 10 or less.

[0036] In the embodiment, the rosin ester resin has a hydroxyl value (OH) of 0 to 30, 0 to 20, 0 to 15, 0 to 10, or less than 10. In the embodiment, the rosin ester has an acid value of 0 to 20, 0 to 15, 0 to 10, 0 to 9, 0 to 8, 0 to 7, or less than 7. In the embodiment, the sum of the hydroxyl value and acid value of the rosin ester resin may be in the range of less than 50, less than 45, less than 40, less than 35, less than 30, less than 25, less than 20, less than 15, less than 10, or between 1 and 8.

[0037] In the embodiment, the rosin ester resin has a Tsp of higher than 60°C, higher than 80°C, 60°C to 170°C, 75°C to 160°C, or 100°C to 150°C.

[0038] In the embodiment, the rosin ester resin has a Tg of 0°C to 115°C, 5°C to 100°C, 10°C to 80°C, 20°C to 70°C, or 30°C to 60°C.

[0039] In the embodiment, the rosin ester resin has the properties in the above combination. For example, it has a PAN of less than 20, less than 15, or less than 10, in combination with one or more of the following: a Tsp of at least 60°C, higher than 80°C, or 60°C to 170°C, or 75°C to 160°C, or 100°C to 150°C; an acid value of 0 to 20, or 0 to 15, or 0 to 10, or 0 to 9, or 0 to 8, or 0 to 7, or an acid value in the range of less than 50, less than 45, less than 40, or less than 35, less than 30, or less than 25, or less than 20, less than 15, or less than 10, or the sum of an acid value and hydroxyl value in the range of 1 to 8.

[0040] In the embodiment, the rosin ester resin has a melt viscosity at 150°C (also referred to as melt viscosity (150°C)) of 12,000 to 15,000 mPa·s, or alternatively, greater than 12,500 mPa·s or less than 14,500 mPa·s. The melt viscosity (Brookfield viscosity) of the resin is measured using a Brookfield RTV viscometer at a temperature of 150°C with a spindle speed of 3 rpm.

[0041] In this embodiment, the rosin ester resin has a refractive index greater than 1.5 and a Brookfield viscosity (ASTM D-3236) of 50 to 25,000 mPa·s at 177°C, measured at 3 rpm according to ASTM D3236.

[0042] A blend of more than one type of rosin ester resin may be used in amounts of 5 to 100 phr, 10 to 80 phr, 15 to 50 phr, or 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 phr, or any range between the aforementioned numbers, per 100 parts of the rubber component.

[0043] Filler: The rubber composition further comprises a filler of 30-200 phr or 50-200 phr. Examples include, but are not limited to, calcium carbonate, carbon nanotubes, clay, mica, silica, silicate, talc, titanium dioxide, alumina, zinc oxide, starch, wood flour, carbon black, or mixtures thereof. The filler may be of any size, for example, 0.0001 μm to 100 μm.

[0044] Other fillers include, but are not limited to, particulate fillers containing ultra-high molecular weight polyethylene (UHMWPE), particulate polymer gels, and plasticized starch composite fillers known in the art.

[0045] In the embodiment, the filler may be surface-treated, for example, coated with a resin or blended with a resin, or coated with a terpene-derived silane or reacted with said silane.

[0046] In the embodiment, the composition contains carbon black filler in an amount of 5 to 70 phr, 20 to 60 phr, 30 to 50 phr, or 40 to 60 phr.

[0047] Optional Plasticizer Components: "Plasticizers" (also referred to as process oils) refer to petroleum-derived process oils and synthetic plasticizers used to extend elastomers and improve the processability of polymer compositions. Suitable plasticizers include, but are not limited to, fatty acid esters, hydrocarbon process oils, tall oil pitch, modified tall oil pitch, and combinations thereof.

[0048] In this embodiment, the plasticizer is a modified tall oil pitch selected from the group consisting of pitch ester, decarboxylated tall oil pitch, tall oil pitch soap, heat-treated tall oil pitch, heat-treated or catalytically treated tall oil pitch, and combinations of the above.

[0049] In some embodiments, the plasticizer includes both an extender oil present in the elastomer and a process oil added during formulation. Suitable process oils include aromatic oils, paraffinic oils, naphthenic oils, and low-PCA oils such as MES, TDAE, and heavy naphthenic oils, as well as vegetable oils such as sunflower oil, soybean oil, canola oil, and safflower oil. Examples of low-PCA oils include oils with a polycyclic aromatic content of less than 3% by weight.

[0050] If present, plasticizers are added in amounts of 75 phr or less, or 5-70 phr, 5-60, 5-50, 5-40, 5-30, 5-20, or 5-15 phr.

[0051] Coupling Agents: In embodiments, the rubber composition further comprises coupling agents. "Coupling agent" means any agent that can facilitate stable chemical and / or physical interactions between two species that would otherwise not interact, such as a filler such as silica and an elastomer. The coupling agent causes the filler, such as silica, to exert a reinforcing effect on the rubber. In embodiments, coupling agents include sulfur-based coupling agents, organic peroxide-based coupling agents, inorganic coupling agents, polyamine coupling agents, resin coupling agents, sulfur compound-based coupling agents, oxime-nitrosamine-based coupling agents, sulfur, and combinations thereof.

[0052] In embodiments, the coupling agent is bifunctional, for example, an organosilane or polyorganosiloxane. Other examples of suitable coupling agents include silane polysulfides. The coupling agent may be a bifunctional polyorganosiloxane or a hydroxysilane polysulfide. The coupling agent may also include other silane sulfides, for example, a silane having at least one thiol (-SH) functional group and / or at least one masked thiol functional group. The coupling agent may be a combination of more than one coupling agent. In embodiments, the coupling agent is an alkoxysilane or polysulfurized alkoxysilane.

[0053] In the embodiment, the coupling agent may be present in an amount of 1 to 20 phr, 1 to 10 phr, or 3 to 15 phr.

[0054] Crosslinking agents: The rubber components in the composition may be crosslinked by adding curing agents, such as sulfur, metals, metal oxides such as zinc oxide, peroxides, organometallic compounds, radical initiators, fatty acids, and other agents known in the art. Other known curing methods that may be used include peroxide curing systems, resin curing systems, and thermal or radiation-induced crosslinking of polymers. Accelerators, activators, and retarders may also be used in the curing process.

[0055] The crosslinking agent may be used in an amount of 0.3 to 10 phr, 0.5 to 5.0 phr, or at least 0.5 phr.

[0056] Other additives: The rubber composition may be compounded with other components known in the art in amounts of 10 phr or less, such as sulfur donors, curing aids, processing additives, pigments, organic carboxylic acids, lubricants, waxes, degradation inhibitors, antioxidants, ozone degradation inhibitors, and compounding accelerators.

[0057] Methods for forming rubber compositions: Rubber compositions can be formed by methods known in the field of rubber mixing. For example, the components are typically mixed in two or two stages, for example, in a production mixing stage following at least one non-production stage. The final curing agent, for example, a sulfur vulcanizing agent, is typically mixed in a final stage conventionally called the "production" mixing stage, in which mixing is typically carried out at a lower temperature than that used in the preceding non-production mixing stage.

[0058] The rubber composition can be subjected to a thermomechanical mixing step, which generally involves mechanical processing in a mixer or extruder for a time suitable for achieving a rubber temperature of 140°C to 190°C. The time of the thermomechanical processing varies depending on the operating conditions, the volume and properties of the composition. For example, the thermomechanical processing may last from 1 to 20 minutes.

[0059] Characteristics: The tire rubber composition containing rosin ester resins with low acid value and low hydroxyl value, as described above, exhibits a significant reduction in rolling resistance and improvement in wet grip performance, with performance comparable to that observed with hydrocarbon resins, such as C5 hydrocarbon resins, C9 hydrocarbon resins, and alpha-methylstyrene resins.

[0060] In the embodiment, with respect to reducing rolling resistance, the tire composition containing rosin ester has a tanδ at 60°C equivalent to that of a composition containing an equal amount of alpha-methylstyrene resin, and with respect to wet traction (wet grip), the composition exhibits a tanδ at 0°C equivalent to that of a composition containing an equal amount of alpha-methylstyrene resin.

[0061] In the embodiment, the tire tread composition has a higher ratio of the wet grip resistance index to the rolling resistance index ((tanδ at 0°C) / (tanδ at 60°C)) than the tire tread composition containing an equivalent amount of rosin ester, where the sum of the acid value and hydroxyl value is greater than 50.

[0062] In the embodiment, a tire tread composition containing a rosin ester resin having a PAN number of less than 10 exhibits an increase in tanδ of less than 3% at 60°C and a decrease in tanδ of less than 1% at 0°C after the resin has been aged for more than 10 months.

[0063] Industrial applicability: In addition to tire applications, the composition can be extruded, compressed, blow-molded, injected, or laminated to produce various molded articles such as fibers, thin films, laminates, layers, and industrial parts such as automotive components, equipment housings, consumer products, and packaging.

[0064] In tire applications, rubber compositions are useful for producing various types of tires, including truck tires, bus tires, automobile tires, motorcycle tires, off-road tires, and aircraft tires. Rubber compositions can also be processed into tire components, such as treads, sidewalls, chafer strips, tire rubber layers, reinforcing cord coatings, and cushioning layers. Rubber compositions may also be useful in other applications, particularly tire curing bladders, inner tubes, air sleeves, hoses, belts, footwear components, rollers for graphic art applications, vibration damping devices, pharmaceutical devices, adhesives, caulking, sealants, glazing compounds, protective coatings, air cushions, air springs, air bellows, accumulator bags, and various types of bladders for fluid retention and curing processes.

[0065] The rubber composition can also be used in the production of molded rubber parts such as automotive suspension bumpers, automotive exhaust hangers, and body mounts. Furthermore, in other applications, the rubber composition can be used in medical applications such as pharmaceutical stoppers and closures, as well as coatings for medical devices. [Examples]

[0066] The following exemplary examples are intended to be non-limiting. In the examples, the following resins were incorporated into tire tread rubber compositions and their performance was tested. Table 1 shows the properties of the resins, where AN represents the acid value and OH represents the hydroxyl value, both expressed in mg KOH / g.

[0067] [Table 1]

[0068] The resin was incorporated into the rubber compound as shown in Table 2. The compound was mixed in a 379 ml Banbury-type closed mixer using a three-step mixing protocol known in the art.

[0069] Examples 1, B, F, and G used both "fresh" and "aged" resins. "Fresh" refers to using resins produced within one month of production as samples. "Aged" refers to using resins stored at room temperature (approximately 23°C) for 10 to 12 months. The performance characteristics shown in Table 3 indicate whether the resin used was fresh or aged. The normalized Tanδ data in Table 3 are normalized to the values ​​for the fresh resin in Example 1. PAN indicates how the resin has aged; for example, a low PAN means the resin has not aged / changed, and aged resin yields similar results to fresh resin.

[0070] Tanδ was determined by DMA using a Metravib+450N with a heating rate of 1°C / min at 10 Hz, 0.1% dynamic strain (-60°C to -5°C), and 3% dynamic strain (-5°C to 100°C), under a temperature sweep / mode in a two-sided shear mode from -60°C to +100°C. Properties such as tensile strength, elongation, and modulus were measured according to the procedure described in ISO 37.

[0071] [Table 2]

[0072] [Table 3]

[0073] As used herein, the term “comprising” means including the element or step specified after the term, but such element or step is not exclusive, and embodiments may include other elements or steps. The terms “comprising” and “including” have been used herein to describe various embodiments, but to provide more detailed embodiments of this disclosure, the terms “essentially consisting of” and “consisting of” may be used and disclosed instead of the terms “comprising” and “including.”

Claims

1. A rubber component, and with respect to 100 parts by weight (phr) of the rubber component, Rosin ester resins with a 5 to 75 phr value, wherein the PAN number is less than 10, the acid value is less than 20, the hydroxyl value is less than 30, and the sum of the acid value and hydroxyl value is less than 50, Filler with 30-200 phr, Plasticizers in the range of 0 to 75 phr and Includes a blend of The rosin ester resin has a softening point (Tsp) of 75°C to 160°C as measured according to ASTM E28. After the resin has been stored at room temperature for 10 to 12 months, the increase in the rolling resistance index (Tanδ at 60°C) is less than 3%, and the decrease in the wet grip index (Tanδ at 0°C) is less than 1%. Tire tread composition.

2. The tire tread composition according to claim 1, wherein the sum of the acid value and hydroxyl value is less than 30.

3. The tire tread composition according to claim 1, wherein the ratio of the wet grip resistance index to the rolling resistance index ((tanδ at 0°C) / (tanδ at 60°C)) is higher than that of a tire tread composition containing an equivalent amount of rosin ester having a sum of acid value and hydroxyl value greater than 50.

4. The tire tread composition according to claim 1, further comprising a coupling agent selected from the group consisting of sulfur-based coupling agents, organic peroxide-based coupling agents, inorganic coupling agents, polyamine coupling agents, resin coupling agents, and oxime-nitrosamine-based coupling agents.

5. The rubber component may be natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), synthetic polyisoprene rubber, epoxidized natural rubber, nitrile-hydrogenated butadiene rubber (NHBR), hydrogenated styrene-butadiene rubber (HSBR), ethylene propylene diene monomer rubber, ethylene propylene rubber, maleic acid-modified ethylene propylene rubber, butyl rubber, isobutylene-aromatic vinyl or diene monomer copolymer, brominated NR, chlorinated NR, brominated isobutylene p-methylstyrene copolymer, chloroprene rubber, epichlorohydrin homopolymer rubber, epichlorohydrin-ethylene oxide or allyl glycidyl ether copolymer A tire tread composition according to claim 1, selected from the group consisting of rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer rubber, chlorosulfonated polyethylene, chlorinated polyethylene, maleic acid-modified chlorinated polyethylene, methyl vinyl silicone rubber, dimethyl silicone rubber, methylphenyl vinyl silicone rubber, polysulfurized rubber, vinylidene fluoride rubber, tetrafluoroethylene-propylene rubber, fluorinated silicone rubber, fluorinated phosphagen rubber, styrene elastomer, thermoplastic olefin elastomer, polyester elastomer, urethane elastomer, polyamide elastomer, and combinations thereof.

6. The tire tread composition according to claim 1, wherein the plasticizer is selected from fatty acid esters, hydrocarbon process oils, tall oil pitch, modified tall oil pitch, and combinations thereof.

7. The tire tread composition according to claim 1, wherein the filler is selected from calcium carbonate, carbon nanotubes, clay, mica, silica, silicate, talc, titanium dioxide, alumina, zinc oxide, starch, wood flour, carbon black, ultra-high molecular weight polyethylene (UHMWPE), particulate polymer gel, plasticized starch composite, and mixtures thereof.

8. A method for preparing a tire rubber composition, Steps to prepare the rubber component, Based on 100 parts by weight (phr) of the rubber component, A step of preparing a rosin ester resin with a density of 5 to 75 phr, having a PAN number of less than 10, an acid value of less than 20, a hydroxyl value of less than 30, a sum of the acid value and hydroxyl value of less than 50, and a softening point (Tsp) measured according to ASTM E28 of 75°C to 160°C. A step of preparing a filler with a concentration of 50 to 200 phr, and optionally a plasticizer with a concentration of 75 phr or less. A step of mixing the rubber component, the rosin ester resin, the filler, and the optionally selected plasticizer to form a mixture, The step of kneading the mixture, The process includes the step of incorporating a crosslinking system into the kneaded mixture to form the tire rubber composition, The tire rubber composition exhibits an increase of less than 3% in the rolling resistance index (Tanδ at 60°C) and a decrease of less than 1% in the wet grip index (Tanδ at 0°C) after the rosin ester resin has been stored at room temperature for 10 to 12 months. method.

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