Tread compound

Abstract

The present disclosure provides a tread compound prepared by a method comprising: a) mixing at least one elastomer, at least one filler, and insoluble sulfur to form a vulcanizable composition, wherein the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70 after heating the insoluble sulfur at 115 °C for 15 minutes, or a total insoluble sulfur mass fraction of at least 0.87 after heating the insoluble sulfur at 105 °C for 15 minutes; (b) forming the vulcanizable composition of (a) into a tread; and (c) vulcanizing the vulcanizable composition of (b) at a temperature of about 150 °C to about 220 °C; to provide the tread compound.

Description

Technical Field

[0001] This disclosure provides tread compounds prepared by the methods disclosed herein. This disclosure also provides methods for preparing tread compounds. Background Technology

[0002] In rubber compounds (e.g., treads of vehicle tires), sulfur is widely used to crosslink rubber polymers and achieve satisfactory stiffness and mechanical properties. Based on its solubility and molecular structure in the rubber composition, sulfur can be classified into two categories: soluble sulfur and insoluble sulfur. The type of sulfur used to prepare rubber compounds can have a considerable impact on the curing characteristics of the compound, resulting in different mechanical properties. Insoluble sulfur is typically used in high-sulfur-load tire structural components (such as belts, carcasses, carcass ply, etc.) to prevent sulfur migration to the surface of the components (a phenomenon known as sulfur bloom) and other phase separation events that occur when sulfur is utilized above its solubility limit in the rubber compound. On the other hand, tread compounds are typically prepared using soluble sulfur (e.g., rubber manufacturer's sulfur (RMS)) because RMS is relatively inexpensive and the sulfur content used in the formulation is low. However, there is still a need to improve the properties of tread compounds (e.g., strength and abrasion resistance), which in turn affects tire wear and life. Summary of the Invention

[0003] This disclosure provides a tread compound prepared by a method comprising the following:

[0004] (a) Mixing at least one elastomer, at least one filler and insoluble sulfur to form a vulcanizable composition, wherein, as described in ISO 8332 (9.2 Method A, using toluene as a solvent "Determination of thermal reversion of insoluble sulfur"), after heating the sample at 115°C for 15 minutes, the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70, or after heating the insoluble sulfur at 105°C for 15 minutes, the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.87;

[0005] (b) Forming the vulcanizable composition of (a) into a tire tread; and

[0006] (c) Vulcanizing the vulcanizable composition of (b) at a temperature of about 150°C to about 220°C;

[0007] To provide the tread compound.

[0008] This disclosure also provides a method for preparing a tread compound, the method comprising:

[0009] (a) Mixing at least one elastomer, at least one filler and insoluble sulfur to form a vulcanizable composition, wherein, as described in ISO 8332 (9.2 Method A, using toluene as a solvent "Determination of thermal reversal of insoluble sulfur"), the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70 after heating the sample at 115°C for 15 minutes, or the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.87 after heating the insoluble sulfur at 105°C for 15 minutes;

[0010] (b) Forming the vulcanizable composition of (a) into a tire tread; and

[0011] (c) Vulcanizing the vulcanizable composition of (b) at a temperature of about 150°C to about 220°C;

[0012] To provide the tread compound.

[0013] Typical specifications for the thermal stability of insoluble sulfur at 105°C (as measured as described in ISO 8332) range from about 0.75 to about 0.8; and typical specifications for the thermal stability of insoluble sulfur at 115°C (as measured as described in ISO 8332) range from about 0.6 to about 0.64. See, for example, Ignatz-Hoover, F. RubberWorld 258 (5), August 2018. The applicant unexpectedly discovered that insoluble sulfur with higher thermal stability (e.g., having a total insoluble sulfur mass fraction of at least 0.70 after heating insoluble sulfur at 115°C for 15 minutes, or having a total insoluble sulfur mass fraction of at least 0.87 after heating insoluble sulfur at 105°C for 15 minutes) can be used to prepare tread compounds at high vulcanization temperatures (e.g., from about 150°C to about 220°C) with improved properties (e.g., strength and elongation retention) compared to tread compounds prepared using insoluble sulfur with lower thermal stability.

[0014] Further embodiments and advantages of this disclosure will be set forth in part in the description which follows, and will be derived from the description, or may be learned by practice of this disclosure. The embodiments and advantages of this disclosure will be realized and obtained by means of the elements and combinations particularly pointed out in the appended claims.

[0015] It should be understood that the foregoing description of the invention and the following detailed description are merely exemplary and illustrative, and do not limit the scope of the claimed invention. Attached Figure Description

[0016] Figure 1This is a set of six scatter plots depicting the breaking strength, elongation at break, and M100 of tread compounds 1-S12 (insoluble sulfur: cyclododecyl sulfur), 1-CP (insoluble sulfur: polymeric sulfur), 1-RMS (soluble sulfur: S8), and 1-HD (insoluble sulfur: polymeric sulfur) when vulcanized at 150°C (left) and 170°C (right).

[0017] Figure 2 It is a set of nine scatter plots depicting the breaking strength, elongation at break, and M100 of tread compounds 2-S12 (insoluble sulfur: cyclododecyl sulfur), 2-CP (insoluble sulfur: polymeric sulfur), 2-RMS (soluble sulfur: S8), and 2-HD (insoluble sulfur: polymeric sulfur) when vulcanized at 130°C (left), 150°C (middle), and 170°C (right).

[0018] Figure 3 It is a set of nine scatter plots depicting the breaking strength, elongation at break, and M100 of tread compounds 3-S12 (insoluble sulfur: cyclododecyl sulfur), 3-CP (insoluble sulfur: polymeric sulfur), 3-RMS (soluble sulfur: S8), and 3-HD (insoluble sulfur: polymeric sulfur) when vulcanized at 130°C (left), 150°C (middle), and 170°C (right).

[0019] Figure 4 It is a set of six scatter plots depicting the breaking strength, elongation at break, and M100 of the tread compounds 1-CP and 1-RMS before aging (top) and after aging (bottom).

[0020] Figure 5 It is a set of two bar graphs depicting the strength (top) and elongation (bottom) retained after aging of the tread compounds 1-CP and 1-RMS.

[0021] Figure 6 It is a scatter plot depicting the vulcanization and curing history curves of tread compounds prepared using Cure Pro (solid line) or RMS (dashed line).

[0022] Figure 7 It is a line graph depicting the fatigue-to-failure test of tread compounds prepared using Cure Pro or RMS. Detailed Implementation

[0023] definition

[0024] Unless otherwise indicated, the terms “a,” “an,” and “the,” and similar pronouns used in the context of describing this disclosure (especially in the context of the claims) should be interpreted as encompassing both the singular and plural. Unless otherwise specified herein, descriptions of value ranges herein are intended only to serve as a shorthand for individually referring to each individual value falling within the range, and each individual value is incorporated into this specification as if individually described herein. Unless otherwise stated, the use of any and all example or exemplary language (e.g., “such”) provided herein is intended to better elucidate this disclosure and is not intended to limit the scope of this disclosure. No language in this specification should be construed as indicating any unclaimed element as necessary for practicing this disclosure.

[0025] As used herein, the term “about” indicates that the value of a given quantity has changed by ±5%. For example, “about 100 nm” covers a range of 95 nm to 105 nm (inclusive).

[0026] As used herein, the term "phr" refers to the number of parts per 100 parts by weight of rubber. Parts by weight of a single component are based on 100 parts by weight of the total mass of one or more elastomers present in the composition.

[0027] As used herein, the term "insoluble sulfur" refers to sulfur that is insoluble in toluene. Insoluble sulfur is generally polymeric in nature, but certain non-polymeric allotropic isoforms of sulfur are also insoluble in toluene and can therefore be considered insoluble sulfur, such as cyclododecyl sulfur (S₂O₃). 12 Insoluble sulfur is typically processed into dispersions (e.g., compositions containing insoluble sulfur and a carrier (e.g., processing oils or other binder compositions)). Non-limiting examples of compositions containing insoluble sulfur include Crystex. TM Cure Pro and Crystex TM HD OT 20.

[0028] As used herein, the term "total insoluble sulfur mass fraction" refers to the weight fraction of insoluble sulfur relative to the total amount of sulfur (soluble and insoluble sulfur), i.e., the mass of insoluble sulfur present in the sample / (mass of insoluble sulfur and soluble sulfur). The total insoluble sulfur mass fraction can be measured by methods known in the art (e.g., the procedure described in ISO 8332, which is incorporated herein by reference in its entirety). In some embodiments, the total insoluble sulfur mass fraction is measured using the procedure described in Section 8 of ISO 8332, wherein toluene is the solvent used to dissolve the soluble sulfur. In some embodiments, as described in Section 9 of ISO 8332 (9.2 Method A, "Determination of Thermal Reversal of Insoluble Sulfur" using toluene as a solvent), the total insoluble sulfur mass fraction is measured after heating the insoluble sulfur in mineral oil (for a specific period of time (e.g., 15 minutes) and at a specific temperature (e.g., 105°C or 115°C)), wherein toluene is the solvent used to dissolve the soluble sulfur. Although Section 9 of ISO 8332 describes heating insoluble sulfur at 105°C, those skilled in the art will understand that other temperatures (e.g., 115°C or 120°C) may also be used.

[0029] As used herein, the term "elastomer" is a polymer that is viscoelastic (i.e., possessing both viscosity and elasticity), typically exhibiting low intermolecular forces, low Young's modulus, and high breaking strain. Elastomers can generally be crosslinked by heating in the presence of one or more crosslinking agents; this process is known as curing or vulcanization. Rubber is a type of elastomer. Non-limiting types of rubber include natural rubber (NR), synthetic rubber, and blends thereof. As used herein, the term "natural rubber" refers to naturally occurring elastomers obtainable from the rubber tree (Hevea brasiliensis). Non-limiting types of synthetic rubber include unsaturated rubber, saturated rubber, rubber (FKM) having fluorine and fluoroalkyl or fluoroalkoxy substituents on the polymer chain, silicone rubber (Q), and blends thereof. Non-limiting examples of unsaturated rubbers include polyisoprene rubber (IR), butyl rubber (IIR), polybutadiene rubber (BR), styrene-isoprene-butadiene rubber (SIBR), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), chloroprene rubber (CR), ethylene propylene diene rubber (EPDM), and blends thereof. These unsaturated rubbers undergo cyclization and crosslinking reactions, which lead to hardening of aged components. Partial oxidation of vulcanized rubber results in performance loss in applications such as vehicle tire sidewalls. Saturated rubber is rubber that does not contain C=C unsaturation, and includes, but is not limited to, acrylic rubber (ACM), chlorinated polyethylene (CM), chlorosulfonated polyethylene (CSM), polychloromethyloxetine (CO), ethylene-ethyl acrylate copolymer (EAM), epichlorohydrin rubber (ECO), ethylene propylene rubber (EPM), ethylene vinyl acetate copolymer (EVM), rubber with fluorine and fluoroalkyl or fluoroalkoxy substituents on the polymer chain (FKM), silicone rubber (Q), and blends thereof.

[0030] In some embodiments, the natural rubber comprises rubber derived from alternative rubber plants. As used herein, the term "natural rubber comprises rubber derived from alternative rubber plants" refers to a natural elastomer obtainable from a "non-Hedysarum trifoliata" source. In some embodiments, the alternative rubber plant is *Gynostemma pentaphyllum* (Gynostemma pentaphyllum). Parthenium argentatum (Guayule) or rubber grass Taraxacum kok-saghyz (Russian dandelion)

[0031] As used herein, the term “recycled rubber” refers to an elastomer recovered from waste materials such as waste tires.

[0032] As used herein, the term "filler" is a substance that reinforces an elastomer composition or imparts other properties to an elastomer composition, including but not limited to increasing the volume of the composition. Non-limiting examples of fillers include carbon black, silica, kaolin, calcium silicate, talc, carbon nanotubes (CNTs), carbon fibers (HCF), graphite, graphene, aluminosilicates, starch, and fibers, as well as combinations thereof.

[0033] As used herein, the term "plasticizer" refers to a processing aid used to reduce viscosity, improve plasticity, and / or increase the volume of a composition. Plasticizers facilitate mixing and the formation of a composition containing an elastomer before the composition is vulcanized. The term "processing oil" may also be used to refer to a plasticizer. Non-limiting examples of plasticizers include mineral oils (paraffin, aromatic, or naphthenic), organic esters, resins, waxes, ester plasticizers, and naturally derived oils such as soybean oil, vegetable oil, or orange oil.

[0034] As used herein, the term "rubber chemicals" refers to compounds or substances used to promote the vulcanization, protection, or performance of rubber, rubber compounds, or related rubber products (such as tires or hoses). Rubber chemicals include, but are not limited to, vulcanizing agents, accelerators, activators, and pre-vulcanization inhibitors, as well as anti-degradation agents (including anti-ozone agents, antioxidants, and anti-fatigue agents), coupling agents, resins, performance resins, or other additives known to those skilled in the art.

[0035] As used herein, the term "vulcanization" refers to the process by which cross-links are formed between elastomers, influencing changes in the material properties of the elastomers. Specifically, vulcanization typically improves the stiffness and durability of elastomers. Vulcanization is carried out at room temperature or high temperatures, depending on the nature of the elastomers, fillers, and rubber chemicals used. The term "curing" is also used in the art to describe this process.

[0036] As used herein, the term "accelerator" refers to any substance that increases the kinetics of vulcanization. In some embodiments, accelerators enable vulcanization to be carried out at lower temperatures and / or more efficiently utilize the vulcanizing agent (e.g., sulfur). Non-limiting examples of accelerators include guanidine, thiazoles, sulfenamides, thiuram, dithiocarbamates, xanthate esters, and thiophosphate esters. Non-limiting examples of guanidine include diphenylguanidine (DPG). Non-limiting examples of thiazoles include 2-mercaptobenzothiazole (MBT), zinc 2-mercaptobenzothiazole (ZMBT), mercaptobenzothiazole disulfide (MBTS), and... N -tert-butyl-2-benzothiazole sulfenamide (TBSI). Non-limiting examples of sulfenamides include N 2-tert-butyl-2-benzothiazole sulfenamide (TBBS) N -Cyclohexylbenzothiazole-2-sulfenamide (CBS), dicyclohexyl-2-benzothiazole-sulfenamide (DCBS)N 2-O-diethylbenzylthiazolylsulfonamide (OBTS) N -O-diethylidene thiocarbamoyl- N' -Oxydiethylthionylsulfenamide (OTOS) and thiocarbamoylsulfenamide. Non-limiting examples of thiuram include dimethylthiocarbamate dithioperoxyanhydride (thiram), bispentamethylenethiuram tetrasulfide (DPIT), tetrabenzylthiuram disulfide (TBzTD), tetraethylthiuram disulfide (TETD), tetramethylthiuram disulfide (TMTD), and tetramethylthiuram monosulfide (TMTM). Non-limiting examples of dithiocarbamates include zinc dimethyl dithiocarbamate (ZDMC), zinc diethyl dithiocarbamate (ZDEC), zinc dibutyl dithiocarbamate (ZDBC), nickel dibutyl dithiocarbamate (NDBC), sodium dibenzyl dithiocarbamate (SBEC), sodium diethyl dithiocarbamate (SDEC), tellurium diethyl dithiocarbamate (TDEC), and zinc dibenzyl dithiocarbamate (ZEBC).

[0037] As used herein, the term "activator" refers to any substance that activates a vulcanizing agent and enables it to crosslink an elastomer as described above. Activators can function through a variety of mechanisms, including but not limited to forming chemical complexes with accelerators or coordinating with sulfur (when sulfur is used as a vulcanizing agent). Non-limiting examples of activators include metal oxides, acids, glycols and polyols, amines, amides, ureas, and their metal complexes. Non-limiting examples of metal oxides include zinc oxide, magnesium oxide, and lead oxide. Non-limiting examples of acids include stearic acid and lauric acid. Non-limiting examples of metal complexes include zinc ethylhexanoate.

[0038] As used herein, the term "pre-vulcanization inhibitor" refers to a compound that delays the onset and / or rate of vulcanization. These compounds are also referred to as "restrictors." Non-limiting examples of pre-vulcanization inhibitors include... N -(cyclohexylthio)phthalimide (CTP), benzoic anhydride, salicylic anhydride and phthalic anhydride.

[0039] As used herein, the term “breaking strength” refers to the maximum amount of stress or tension that a rubber compound can withstand before breaking.

[0040] As used herein, the term "elongation at break" refers to the amount of stretching or deformation that a rubber compound can undergo before breaking during a tensile test. The term indicates the elongation or extension of the rubber compound at the point of fracture.

[0041] As used herein, the term "M100" refers to the modulus at 100% elongation. The term is a measure of the stiffness or resistance to deformation of a rubber material at a given level of elongation.

[0042] Tread compounds and methods for their preparation

[0043] This disclosure provides a tread compound prepared by a method comprising the following:

[0044] (a) Mixing at least one elastomer, at least one filler and insoluble sulfur to form a vulcanizable composition, wherein, as described in ISO 8332 (9.2 Method A, using toluene as a solvent "Determination of thermal reversal of insoluble sulfur"), the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70 after heating the sample at 115°C for 15 minutes, or the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.87 after heating the insoluble sulfur at 105°C for 15 minutes;

[0045] (b) Forming the vulcanizable composition of (a) into a tire tread; and

[0046] (c) Vulcanizing the vulcanizable composition of (b) at a temperature of about 150°C to about 220°C;

[0047] To provide the tread compound.

[0048] This disclosure also provides a method for preparing a tread compound, the method comprising:

[0049] a) Mixing at least one elastomer, at least one filler, and insoluble sulfur to form a vulcanizable composition, wherein, as described in ISO 8332 using toluene as a solvent, the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70 after heating at 115°C for 15 minutes, or has a total insoluble sulfur mass fraction of at least 0.87 after heating at 105°C for 15 minutes;

[0050] (b) Forming the vulcanizable composition of (a) into a tire tread; and

[0051] (c) Vulcanizing the vulcanizable composition of (b) at a temperature of about 150°C to about 220°C;

[0052] To provide the tread compound.

[0053] In some embodiments, such as those described in ISO 8332 which uses toluene as a solvent, the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70 after heating at 115°C for 15 minutes.

[0054] In some embodiments, such as those described in ISO 8332 which uses toluene as a solvent, the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.88 after heating at 105°C for 15 minutes.

[0055] Vulcanizable Composition

[0056] In some embodiments, the concentration of insoluble sulfur in the vulcanizable composition is from about 0.5 phr to about 18 phr. In some embodiments, the concentration of insoluble sulfur in the vulcanizable composition is from about 0.1 phr to about 0.5 phr, from about 0.1 phr to about 1 phr, from about 0.1 phr to about 1.5 phr, from about 0.1 phr to about 2 phr, from about 0.1 phr to about 2.5 phr, from about 0.1 phr to about 3 phr, from about 0.1 phr to about 5 phr, from about 0.5 phr to about 1 phr, from about 0.5 phr to about 1.5 phr, from about 0.5 phr to about 2 phr, from about 0.5 phr to about 2.5 phr, from about 0.5 phr to about 3 phr, from about 0.5 phr to about 18 phr. hr to about 5 phr, about 1 phr to about 1.5 phr, about 1 phr to about 2 phr, about 1 phr to about 2.5 phr, about 1 phr to about 3 phr, about 1 phr to about 5 phr, about 1.5 phr to about 2 phr, about 1.5 phr to about 2.5 phr, about 1.5 phr to about 3 phr, about 1.5 phr to about 5 phr, about 2 phr to about 2.5 phr, about 2 phr to about 3 phr, about 2 phr to about 5 phr, about 2.5 phr to about 3 phr, about 2.5 phr to about 5 phr or about 3 phr to about 5 phr. In some embodiments, the concentration of insoluble sulfur in the vulcanizable composition is about 1 phr to about 10 phr, about 1 phr to about 20 phr, about 1 phr to about 30 phr, about 1 phr to about 40 phr, about 1 phr to about 50 phr, about 1 phr to about 60 phr, about 10 phr to about 20 phr, about 10 phr to about 30 phr, about 10 phr to about 40 phr, about 10 phr to about 50 phr, about 10 phr to about 60 phr, about 20 phr to about 30 phr, about 20 phr to about 40 phr, about 20 phr to about 50 phr, about 20 phr to about 60 phr, about 30 phr to about 40 phr, about 30 phr to about 50 phr, about 30 phr to about 60 phr, about 40 phr to about 50 phr, about 40 phr to about 60 phr, or about 50 phr to about 60 phr.In some embodiments, the concentration of insoluble sulfur in the vulcanizable composition is about 2 phr to about 12 phr, about 2 phr to about 14 phr, about 2 phr to about 16 phr, about 2 phr to about 18 phr, about 4 phr to about 12 phr, about 4 phr to about 14 phr, about 4 phr to about 16 phr, about 4 phr to about 18 phr, about 6 phr to about 12 phr, about 6 phr to about 14 phr, about 6 phr to about 16 phr, about 6 phr to about 18 phr, or about 8 phr. From about 12 phr, about 8 phr to about 14 phr, about 8 phr to about 16 phr, about 8 phr to about 18 phr, about 10 phr to about 12 phr, about 10 phr to about 14 phr, about 10 phr to about 16 phr, about 10 phr to about 18 phr, about 12 phr to about 14 phr, about 12 phr to about 16 phr, about 12 phr to about 18 phr, about 14 phr to about 16 phr, about 14 phr to about 18 phr or about 16 phr to about 18 phr.

[0057] In some embodiments, the concentration of insoluble sulfur in the vulcanizable composition is about 1 phr. In some embodiments, the concentration of insoluble sulfur in the vulcanizable composition is about 0.1 phr, about 0.5 phr, about 1.5 phr, about 2 phr, about 2.5 phr, about 3 phr, about 3.5 phr, about 4 phr, about 4.5 phr, about 5 phr, about 6 phr, about 7 phr, about 8 phr, about 9 phr, about 10 phr, about 20 phr, about 30 phr, about 40 phr, about 50 phr, or about 60 phr.

[0058] In some embodiments, at least one elastomer is natural rubber (NR), polyisoprene rubber (IR), butyl rubber (IIR), polybutadiene rubber (BR), styrene-butadiene rubber (SBR), or a blend thereof. In some embodiments, at least one elastomer is natural rubber (NR), polybutadiene rubber (BR), and styrene-butadiene rubber (SBR).

[0059] In some implementations, one or more elastomers further comprise recycled rubber.

[0060] In some embodiments, the concentration of each elastomer in the vulcanizable composition is independently from about 1 phr to about 100 phr. In some embodiments, the concentration of each elastomer in the vulcanizable composition is independently from about 1 phr to about 5 phr, about 1 phr to about 10 phr, about 1 phr to about 25 phr, about 1 phr to about 50 phr, about 1 phr to about 75 phr, about 1 phr to about 100 phr, about 5 phr to about 10 phr, about 5 phr to about 25 phr, about 5 phr to about 50 phr, about 5 phr to about 75 phr, about 5 phr to... Approximately 100 phr, approximately 10 phr to approximately 25 phr, approximately 10 phr to approximately 50 phr, approximately 10 phr to approximately 75 phr, approximately 10 phr to approximately 100 phr, approximately 25 phr to approximately 50 phr, approximately 25 phr to approximately 50 phr, approximately 25 phr to approximately 75 phr, approximately 25 phr to approximately 100 phr, approximately 50 phr to approximately 75 phr, approximately 50 phr to approximately 100 phr, or approximately 75 phr to approximately 100 phr.

[0061] In some embodiments, the concentration of each elastomer in the vulcanizable composition is independently about 5 phr, about 10 phr, about 15 phr, about 20 phr, about 25 phr, about 30 phr, about 35 phr, about 40 phr, about 45 phr, about 50 phr, about 55 phr, about 60 phr, about 65 phr, about 70 phr, about 75 phr, about 80 phr, about 85 phr, about 90 phr, about 95 phr, or about 100 phr.

[0062] In some embodiments, at least one filler is carbon black, silica, kaolin, calcium silicate, talc, carbon nanotubes (CNTs), carbon fibers (HCF), graphite, graphene, aluminosilicate, starch, fiber, or a combination thereof. In some embodiments, the at least one filler is derived from a natural source. For example, silica may be derived from rice husks.

[0063] In some embodiments, the at least one filler is carbon black. In some embodiments, the at least one filler is silicon dioxide.

[0064] In some embodiments, the concentration of each filler in the vulcanizable composition is independently from about 1 phr to about 200 phr. In some embodiments, the concentration of each filler in the vulcanizable composition is independently from about 1 phr to about 25 phr, about 1 phr to about 50 phr, about 1 phr to about 75 phr, about 1 phr to about 100 phr, about 1 phr to about 125 phr, about 1 phr to about 150 phr, about 1 phr to about 175 phr, about 1 phr to about 200 phr, about 25 phr to about 50 phr, about 25 phr to about 75 phr, about 25 phr to about 100 phr, about 25 phr to about 125 phr, about 25 phr to about 150 phr, about 25 phr to about 175 phr, about 25 phr to about 200 phr, about 50 phr to about 75 phr, about 50 phr to about 100 phr, about 50 phr to about 125 phr. r, about 50 phr to about 150 phr, about 50 phr to about 175 phr, about 50 phr to about 200 phr, about 75 phr to about 100 phr, about 75 phr to about 125 phr, about 75 phr to about 150 phr, about 75 phr to about 175 phr, about 75 phr to about 200 phr, about 100 phr to about 125 phr, about 100 phr to about 150 phr, about 100 phr to about 175 phr, about 100 phr to about 200 phr, about 125 phr to about 150 phr, about 125 phr to about 175 phr, about 125 phr to about 200 phr, about 150 phr to about 175 phr, about 150 phr to about 200 phr or about 175 phr to about 200 phr.

[0065] In some embodiments, the concentration of each filler in the vulcanizable composition is independently about 5 phr, about 10 phr, about 15 phr, about 20 phr, about 25 phr, about 30 phr, about 35 phr, about 40 phr, about 45 phr, about 50 phr, about 55 phr, about 60 phr, about 65 phr, about 70 phr, about 75 phr, about 80 phr, about 85 phr, about 90 phr, about 95 phr, about 100 phr. phr, approximately 105 phr, approximately 110 phr, approximately 115 phr, approximately 120 phr, approximately 125 phr, approximately 130 phr, approximately 135 phr, approximately 140 phr, approximately 145 phr, approximately 150 phr, approximately 155 phr, approximately 160 phr, approximately 165 phr, approximately 170 phr, approximately 175 phr, approximately 180 phr, approximately 185 phr, approximately 190 phr, approximately 195 phr, or approximately 200 phr.

[0066] In some embodiments, the at least one plasticizer is a mineral oil, organic ester, resin, wax, ester plasticizer, natural oil, or a combination thereof. In some embodiments, the mineral oil is a naphthenic oil, paraffin oil, or aromatic oil. In some embodiments, the at least one plasticizer is both mineral oil and wax.

[0067] In some embodiments, the concentration of each plasticizer in the vulcanizable composition is independently about 1 phr to about 5 phr, about 1 phr to about 10 phr, about 1 phr to about 20 phr, about 1 phr to about 30 phr, about 1 phr to about 40 phr, about 1 phr to about 50 phr, about 5 phr to about 10 phr, about 5 phr to about 20 phr, about 5 phr to about 30 phr, about 5 phr to about 5 phr, about 5 phr to about 50 phr, about 10 phr to about 20 phr, about 10 phr to about 30 phr, about 10 phr to about 40 phr, about 10 phr to about 50 phr, about 20 phr to about 30 phr, about 20 phr to about 40 phr, about 20 phr to about 50 phr, about 30 phr to about 40 phr, about 30 phr to about 50 phr, or about 40 phr to about 50 phr.

[0068] In some embodiments, the concentration of each plasticizer in the vulcanizable composition is independently about 1 phr, about 5 phr, about 10 phr, about 15 phr, about 20 phr, about 25 phr, about 30 phr, about 35 phr, about 40 phr, about 45 phr, or about 50 phr.

[0069] In some embodiments, the vulcanizable composition comprises one or more rubber chemicals. In some embodiments, the one or more rubber chemicals comprise one or more accelerators, one or more activators, one or more pre-vulcanization inhibitors, or combinations thereof.

[0070] In some embodiments, one or more promoters are guanidine, thiazole, sulfenamide, thiuram, dithiocarbamate, xanthate, thiophosphate, or combinations thereof. In some embodiments, the guanidine is diphenylguanidine (DPG). In some embodiments, the thiazole is 2-mercaptobenzothiazole (MBT), zinc 2-mercaptobenzothiazole (ZMBT), or mercaptobenzothiazole disulfide (MBTS). N -tert-butyl-2-benzothiazole sulfenamide (TBSI) or combinations thereof. In some embodiments, the sulfenamide is... N 2-tert-butyl-2-benzothiazole sulfenamide (TBBS) N -Cyclohexylbenzothiazole-2-sulfenamide (CBS), dicyclohexyl-2-benzothiazole-sulfenamide (DCBS) N2-O-diethylbenzylthiazolylsulfonamide (OBTS) N -O-diethylidene thiocarbamoyl- N' β-oxydiethylethylene sulfenamide (OTOS), thiocarbamoyl sulfenamide, or combinations thereof. In some embodiments, the sulfenamide is... N -Cyclohexylbenzothiazole-2-sulfenamide (CBS). In some embodiments, thiuram is dimethylthiocarbamate dithioperoxyanhydride (Fram), bis(pentamethylenethiuram) tetrasulfide (DPIT), tetrabenzylthiuram disulfide (TBzTD), tetraethylthiuram disulfide (TETD), tetramethylthiuram disulfide (TMTD), tetramethylthiuram monosulfide (TMTM), or combinations thereof. In some embodiments, the dithiocarbamate is zinc dimethyl dithiocarbamate (ZDMC), zinc diethyl dithiocarbamate (ZDEC), zinc dibutyl dithiocarbamate (ZDBC), nickel dibutyl dithiocarbamate (NDBC), sodium dibenzyl dithiocarbamate (SBEC), sodium diethyl dithiocarbamate (SDEC), tellurium diethyl dithiocarbamate (TDEC), zinc dibenzyl dithiocarbamate (ZEBC), or combinations thereof.

[0071] In some embodiments, the one or more activators are metal oxides, acids, metal complexes, or combinations thereof. In some embodiments, the metal oxide is zinc oxide, magnesium oxide, lead oxide, or combinations thereof. In some embodiments, the acid is stearic acid, lauric acid, or combinations thereof. In some embodiments, the metal complex is zinc ethylhexanoate.

[0072] In some implementations, the one or more pre-vulcanization inhibitors are N -(cyclohexylthio)phthalimide (CTP), benzoic anhydride, salicylic anhydride, phthalic anhydride or combinations thereof.

[0073] In some embodiments, the concentration of each rubber chemical in the vulcanizable composition is independently about 1 phr to about 5 phr, about 1 phr to about 10 phr, about 1 phr to about 20 phr, about 1 phr to about 30 phr, about 1 phr to about 40 phr, about 1 phr to about 50 phr, about 5 phr to about 10 phr, about 5 phr to about 20 phr, about 5 phr to about 30 phr, about 5 phr to about 5 phr, about 5 phr to about 50 phr, about 10 phr to about 20 phr, about 10 phr to about 30 phr, about 10 phr to about 40 phr, about 10 phr to about 50 phr, about 20 phr to about 30 phr, about 20 phr to about 40 phr, about 20 phr to about 50 phr, about 30 phr to about 40 phr, about 30 phr to about 50 phr, or about 40 phr to about 50 phr.

[0074] In some embodiments, the concentration of each plasticizer in the vulcanizable composition is independently about 1 phr, about 2 phr, about 3 phr, about 4 phr, about 5 phr, about 6 phr, about 7 phr, about 8 phr, about 9 phr, about 10 phr, about 15 phr, about 20 phr, about 25 phr, about 30 phr, about 35 phr, about 40 phr, about 45 phr, or about 50 phr.

[0075] In some embodiments, the vulcanizable composition comprises an anti-degradation agent. In some embodiments, the anti-degradation agent is an anti-ozone agent. Non-limiting examples of anti-degradation agents include p-phenylenediamine (PPD), trimethyl-dihydroquinoline (TMQ), phenols, alkylated diphenylamine (DPA), diphenylamine-ketone condensates, and natural anti-degradation agents. Non-limiting examples of PPD include... N 1 -(4-Methylpent-2-yl)- N 4 1,4-Phenylenol-1,4-Diamine (6PPD) N -(1,4-Dimethylpentyl)- N' 7-Phenylene-p-phenylenediamine (7PPD) N 1 -phenyl- N 4 1,4-(propyl-2-yl)phenyl-1,4-diamine (IPPD) N , N' -di-sec-butyl-p-phenylenediamine (44PD) N,N' -Bis(1,3-dimethylbutyl)-p-phenylenediamine (66PD) N , N' -bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD) and N -N' -Dioctyl-p-phenylenediamine (88PD). Non-limiting examples of TMQ include 2,2,4-trimethyl-1,2-dihydroquinoline and its oligomers or polymers.

[0076] In some embodiments, the vulcanizable composition comprises about 1 phr to about 5 phr of an anti-degradation agent. In some embodiments, the vulcanizable composition comprises about 0.001 phr to about 0.01 phr, about 0.001 phr to about 0.1 phr, about 0.001 phr to about 1 phr, about 0.001 phr to about 5 phr, about 0.001 phr to about 7.5 phr, about 0.001 phr to about 10 phr, about 0.01 phr to about 0.1 phr, about 0.01 phr to about 1 phr, or about 0.01 phr to about 5 phr. Anti-degradation agents of about 0.01 phr to about 7.5 phr, about 0.01 phr to about 10 phr, about 0.1 phr to about 1 phr, about 0.1 phr to about 5 phr, about 0.1 phr to about 7.5 phr, about 0.1 phr to about 10 phr, about 1 phr to about 7.5 phr, about 1 phr to about 10 phr, about 5 phr to about 7.5 phr, about 5 phr to about 10 phr, or about 7.5 phr to about 10 phr.

[0077] In some embodiments, the vulcanizable composition comprises about 3 phr of an anti-degradation agent. In some embodiments, the vulcanizable composition comprises about 0.001 phr, about 0.01 phr, about 0.1 phr, about 1 phr, about 2 phr, about 4 phr, about 5 phr, about 7.5 phr, or about 10 phr of an anti-degradation agent.

[0078] Method variables

[0079] In some embodiments, the mixing in step (a) of the method disclosed herein is performed in multiple steps. In some embodiments, non-curing active chemicals (e.g., fillers and elastomers, and optionally coupling agents, anti-degradation agents, and / or plasticizers) are mixed in the first step at a relatively high temperature (e.g., about 120°C to about 170°C); and curing active chemicals (e.g., insoluble sulfur) are mixed in the second step at a relatively low temperature (e.g., about 80°C to about 130°C). In some embodiments, the first step of mixing in step (a) is performed with a mixing time of about 1 minute to about 10 minutes. In some embodiments, the second step of mixing in step (a) is performed with a mixing time of about 0.5 minutes to about 2 minutes.

[0080] In some embodiments, this disclosure provides a tread compound prepared by a method comprising the following:

[0081] (a)(i) Mixing at least one elastomer with at least one filler at a temperature of about 120°C to about 170°C to obtain a partially finished compound;

[0082] (a) and (ii) mixing insoluble sulfur with a portion of the finished compound of (a) and (i) at about 80°C to about 130°C to form a vulcanizable composition;

[0083] Wherein, as described in ISO 8332, which uses toluene as a solvent, the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70 after being heated at 115°C for 15 minutes, or has a total insoluble sulfur mass fraction of at least 0.87 after being heated at 105°C for 15 minutes.

[0084] (b) Forming the vulcanizable composition of (a) and (ii) into a tread; and

[0085] (c) Vulcanizing the vulcanizable composition of (b) at a temperature of about 150°C to about 220°C;

[0086] To provide the tread compound.

[0087] In some embodiments, the mixing in step (a) (i) is carried out at a temperature of about 120°C to about 170°C. In some embodiments, the mixing in step (a) (i) is carried out at a temperature of about 120°C to about 125°C, about 120°C to about 130°C, about 120°C to about 140°C, about 120°C to about 150°C, about 125°C to about 130°C, about 125°C to about 140°C, about 125°C to about 150°C, about 130°C to about 140°C, about 130°C to about 150°C, about 140°C to about 150°C, about 120°C to about 160°C, about 130°C to about 160°C, about 130°C to about 170°C, about 140°C to about 160°C, about 140°C to about 170°C, about 150°C to about 160°C, about 150°C to about 170°C, or about 160°C to about 170°C.

[0088] In some embodiments, the mixing in step (a) (i) is carried out at a temperature of about 120°C. In some embodiments, the mixing in step (a) (i) is carried out at a temperature of about 125°C, about 130°C, about 135°C, about 140°C, about 145°C, about 150°C, about 155°C, about 160°C, about 165°C, about 170°C, or about 175°C.

[0089] In some embodiments, the mixing in steps (a) and (ii) is carried out at a temperature of about 80°C to about 130°C. In some embodiments, the mixing in steps (a) and (ii) is carried out at a temperature of about 80°C to about 90°C, about 80°C to about 100°C, about 80°C to about 110°C, about 80°C to about 120°C, about 90°C to about 100°C, about 90°C to about 110°C, about 90°C to about 120°C, about 90°C to about 130°C, about 100°C to about 110°C, about 100°C to about 120°C, about 100°C to about 130°C, about 110°C to about 120°C, about 110°C to about 130°C, or about 120°C to about 130°C.

[0090] In some embodiments, the mixing in steps (a) and (ii) is carried out at a temperature of about 90°C. In some embodiments, the mixing in steps (a) and (ii) is carried out at a temperature of about 80°C, about 85°C, about 95°C, about 100°C, about 105°C, about 110°C, about 115°C, about 120°C, about 125°C, or about 130°C.

[0091] In some embodiments, the vulcanization in step (c) of the method disclosed herein is carried out at a temperature of about 170°C to about 200°C. In some embodiments, the vulcanization is carried out at temperatures of about 140°C to about 150°C, about 140°C to about 160°C, about 140°C to about 170°C, about 140°C to about 180°C, about 140°C to about 190°C, about 140°C to about 200°C, about 140°C to about 210°C, about 140°C to about 220°C, about 150°C to about 160°C, about 150°C to about 170°C, about 150°C to about 180°C, about 150°C to about 190°C, about 150°C to about 200°C, about 150°C to about 210°C, about 150°C to about 220°C, about 160°C to about 170°C, about 160°C to about 180°C, about 1... The temperature is 60°C to about 190°C, about 160°C to about 200°C, about 160°C to about 210°C, about 160°C to about 220°C, about 170°C to about 180°C, about 170°C to about 190°C, about 170°C to about 210°C, about 170°C to about 220°C, about 180°C to about 190°C, about 180°C to about 200°C, about 180°C to about 210°C, about 180°C to about 220°C, about 190°C to about 200°C, about 190°C to about 210°C, about 190°C to about 220°C, about 200°C to about 210°C, about 200°C to about 220°C, or about 210°C to about 220°C.

[0092] In some embodiments, the vulcanization in step (c) of the method disclosed herein is performed at a temperature of about 170°C. In some embodiments, the vulcanization is performed at a temperature of about 140°C, about 145°C, about 150°C, about 155°C, about 160°C, about 165°C, about 175°C, about 180°C, about 185°C, about 190°C, about 195°C, about 200°C, about 205°C, about 210°C, about 215°C, or about 220°C.

[0093] Characteristics of tread compounds

[0094] In some embodiments, the tread compound produced by the methods disclosed herein has a breaking strength of about 10 MPa to about 25 MPa. In some embodiments, the tread compound produced by the methods disclosed herein has a breaking strength of about 7.5 MPa to about 10 MPa, about 7.5 MPa to about 15 MPa, about 7.5 MPa to about 20 MPa, about 7.5 MPa to about 25 MPa, about 7.5 MPa to about 30 MPa, about 10 MPa to about 15 MPa, about 10 MPa to about 20 MPa, about 10 MPa to about 30 MPa, about 15 MPa to about 20 MPa, about 15 MPa to about 25 MPa, about 15 MPa to about 30 MPa, about 20 MPa to about 25 MPa, about 20 MPa to about 30 MPa, or about 25 MPa to about 30 MPa.

[0095] In some embodiments, the tread compound produced by the methods disclosed herein has a tensile strength of about 15 MPa. In some embodiments, the tread compound produced by the methods disclosed herein has a tensile strength of about 7.5 MPa, about 10 MPa, about 20 MPa, about 25 MPa, or about 30 MPa.

[0096] In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the tread compound produced by the methods disclosed herein has a breaking strength of about 7.5 MPa to about 10 MPa, about 7.5 MPa to about 15 MPa, about 7.5 MPa to about 20 MPa, about 7.5 MPa to about 25 MPa, about 7.5 MPa to about 30 MPa, about 10 MPa to about 15 MPa, about 10 MPa to about 20 MPa, about 10 MPa to about 25 MPa, about 10 MPa to about 30 MPa, about 15 MPa to about 20 MPa, about 15 MPa to about 25 MPa, about 15 MPa to about 30 MPa, about 20 MPa to about 25 MPa, about 20 MPa to about 30 MPa, or about 25 MPa to about 30 MPa.

[0097] In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the tread compound produced by the methods disclosed herein has a tensile strength of about 15 MPa relative to before aging. In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the tread compound produced by the methods disclosed herein has a tensile strength of about 7.5 MPa, about 10 MPa, about 15 MPa, about 20 MPa, about 25 MPa, or about 30 MPa relative to before aging.

[0098] In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the breaking strength of the tread compound produced by the methods disclosed herein is reduced by less than 10% compared to before aging. In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the breaking strength of the tread compound produced by the methods disclosed herein is reduced by less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, or less than 5% compared to before aging.

[0099] In some embodiments, the tread compound produced by the methods described herein has an elongation at break of about 200% to about 700%. In some embodiments, the tread compound produced by the methods described herein has an elongation at break of about 150% to about 200%, about 150% to about 300%, about 150% to about 400%, about 150% to about 500%, about 150% to about 600%, about 150% to about 700%, about 200% to about 300%, about 200% to about 400%, about 200% to about 500%, about 200% to about 600%, about 300% to about 400%, about 300% to about 500%, about 300% to about 600%, about 300% to about 700%, about 400% to about 500%, about 400% to about 600%, about 400% to about 700%, about 500% to about 600%, about 500% to about 700%, or about 600% to about 700%.

[0100] In some embodiments, the tread compound produced by the methods described herein has an elongation at break of about 400%. In some embodiments, the tread compound produced by the methods described herein has an elongation at break of about 150%, about 200%, about 250%, about 300%, about 350%, about 450%, about 500%, about 550%, about 600%, about 650%, or about 700%.

[0101] In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the elongation at break of the tread compound produced by the methods disclosed herein is about 200% to about 700% compared to before aging. In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the elongation at break of the tread compound produced by the methods disclosed herein is about 110% to about 125%, about 110% to about 150%, about 110% to about 200%, about 125% to about 150%, about 125% to about 200%, about 125% to about 300%, about 150% to about 200%, about 150% to about 300%, about 150% to about 400%, about 150% to about 500%, and about 150%. From about 600%, about 150% to about 700%, about 200% to about 300%, about 200% to about 400%, about 200% to about 500%, about 200% to about 600%, about 300% to about 400%, about 300% to about 500%, about 300% to about 600%, about 300% to about 700%, about 400% to about 500%, about 400% to about 600%, about 400% to about 700%, about 500% to about 600%, about 500% to about 700%, or about 600% to about 700%.

[0102] In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the elongation at break of the tread compound produced by the method described herein is about 400% relative to before aging. In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the elongation at break of the tread compound produced by the method described herein is about 110%, about 125%, about 150%, about 200%, about 250%, about 300%, about 350%, about 450%, about 500%, about 550%, about 600%, about 650%, or about 700% relative to before aging.

[0103] In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the elongation at break of the tread compound produced by the methods disclosed herein is reduced by less than 30% compared to before aging. In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the elongation at break of the tread compound produced by the methods disclosed herein is reduced by less than 50%, less than 45%, less than 40%, less than 35%, less than 25%, less than 20%, less than 15%, less than 10%, or less than 5% compared to before aging.

[0104] In some embodiments, the M100 of the tread compound produced by the methods disclosed herein is from about 2.0 MPa to about 5.8 MPa. In some embodiments, the M100 of the tread compound produced by the methods disclosed herein is from about 2.0 MPa to about 2.5 MPa, from about 2.0 MPa to about 3.0 MPa, from about 2.0 MPa to about 3.5 MPa, from about 2.0 MPa to about 4.0 MPa, from about 2.0 MPa to about 4.5 MPa, from about 2.0 MPa to about 5.0 MPa, from about 2.0 MPa to about 5.5 MPa, from about 2.0 MPa to about 6.0 MPa, from about 2.0 MPa to about 6.5 MPa, from about 2.0 MPa to about 7.0 MPa, from about 2.0 MPa to about 8.0 MPa, from about 2.5 MPa to about 3.0 MPa, and from about 2.5 MPa to about 3.5 MPa. MPa, about 2.5 MPa to about 4.0 MPa, about 2.5 MPa to about 4.5 MPa, about 2.5 MPa to about 5.0 MPa, about 2.5 MPa to about 5.5 MPa, about 2.5 MPa to about 6.0 MPa, about 2.5 MPa to about 6.5 MPa, about 2.5 MPa to about 7.0 MPa, about 2.5 MPa to about 8.0 MPa, about 3.0 MPa to about 3.5 MPa, about 3.0 MPa to about 4.0 MPa, about 3.0 MPa to about 4.5 MPa, about 3.0 MPa to about 5.0 MPa, about 3.0 MPa to about 5.5 MPa, about 3.0 MPa to about 6.0 MPa, about 3.0 MPa to about 6.5 MPa, about 3.0 MPa to about 7.0 MPa, about 3.0 MPa to about 8.0 MPa, about 3.5 MPa to about 4.0 MPa, about 3.5 MPa to about 4.5 MPa, about 3.5 MPa to about 5.0 MPa, about 3.5 MPa to about 5.5 MPa, about 3.5 MPa to about 6.0 MPa, about 3.5 MPa to about 6.5 MPa, about 3.5 MPa to about 7.0 MPa, about 3.5 MPa to about 8.0 MPa, about 4.0 MPa to about 4.5 MPa, about 4.0 MPa to about 5.0 MPa, about 4.0 MPa to about 5.5 MPa, about 4.0 MPa to about 6.0 MPa, about 4.0 MPa a to about 6.5 MPa, about 4.0 MPa to about 7.0 MPa, about 4.0 MPa to about 8.0 MPa, about 4.5 MPa to about 5.0 MPa, about 4.5 MPa to about 5.5 MPa, about 4.5 MPa to about 6.0 MPa, about 4.5 MPa to about 6.5 MPa, about 4.5 MPa to about 7.0 MPa, about 4.5 MPa to about 8.0 MPa, about 5.0 MPa to about 5.5 MPa, about 5.0 MPa to about 6.0 MPa, about 5.0 MPa to about 6.5 MPa, about 5.0 MPa to about 7.0 MPa, about 5.0 MPa to about 8.0 MPa, about 5.5 MPa to about 6.0 MPa, about 5.5 MPa to about 6.5 MPa, about 5.5 MPa to about 7.0 MPa, about 5.5 MPa to about 8.0 MPa, about 6.0 MPa to about 6.5 MPa, about 6.0 MPa to about 7.0 MPa, about 6.0 MPa to about 8.0 MPa, about 6.5 MPa to about 7.0 MPa, about 6.5 MPa to about 8.0 MPa, or about 7.0 MPa to about 8.0 MPa.

[0105] In some embodiments, the M100 of the tread compound produced by the methods disclosed herein is about 5.0 MPa. In some embodiments, the M100 of the tread compound produced by the methods disclosed herein is about 2.0 MPa, about 2.5 MPa, about 3.0 MPa, about 3.5 MPa, about 4.0 MPa, about 4.5 MPa, about 5.5 MPa, about 6.0 MPa, about 6.5 MPa, about 7.0 MPa, or about 8.0 MPa.

[0106] In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the M100 of the tread compound produced by the methods disclosed herein is about 2 MPa to about 16 MPa. In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the M100 of the tread compound produced by the methods disclosed herein is about 2 MPa to about 4 MPa, about 2 MPa to about 6 MPa, about 2 MPa to about 8 MPa, about 2 MPa to about 10 MPa, about 2 MPa to about 12 MPa, about 4 MPa to about 14 MPa, about 4 MPa to about 16 MPa, about 4 MPa to about 6 MPa, about 4 MPa to about 8 MPa, about 4 MPa to about 10 MPa, about 4 ... a to about 16 MPa, about 6 MPa to about 8 MPa, about 6 MPa to about 10 MPa, about 6 MPa to about 12 MPa, about 6 MPa to about 14 MPa, about 6 MPa to about 16 MPa, about 8 MPa to about 10 MPa, about 8 MPa to about 12 MPa, about 8 MPa to about 14 MPa, about 8 MPa to about 16 MPa, about 10 MPa to about 12 MPa, about 10 MPa to about 14 MPa, about 10 MPa to about 16 MPa, about 12 MPa to about 14 MPa, about 12 MPa to about 16 MPa or about 14 MPa to about 16 MPa.

[0107] In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the M100 of the tread compound produced by the methods disclosed herein is about 5 MPa. In some embodiments, after the tread compound has been aged at about 77°C for about 7 days, the M100 of the tread compound produced by the methods disclosed herein is about 2 MPa, about 3 MPa, about 4 MPa, about 5 MPa, about 6 MPa, about 7 MPa, about 8 MPa, about 9 MPa, about 10 MPa, about 11 MPa, about 12 MPa, about 13 MPa, about 14 MPa, about 15 MPa, or about 16 MPa.

[0108] Specific implementation plan

[0109] This disclosure also provides the following specific implementation methods.

[0110] Implementation Scheme 1. A tread compound, said tread compound being prepared by a method comprising the following:

[0111] (a) Mixing at least one elastomer, at least one filler and insoluble sulfur to form a vulcanizable composition, wherein, as described in ISO 8332 using toluene as a solvent, the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70 after heating at 115°C for 15 minutes, or has a total insoluble sulfur mass fraction of at least 0.87 after heating at 105°C for 15 minutes;

[0112] (b) Forming the vulcanizable composition of (a) into a tire tread; and

[0113] (c) Vulcanizing the vulcanizable composition of (b) at a temperature of about 150°C to about 220°C;

[0114] To provide the tread compound.

[0115] Implementation Scheme 2. The tread compound according to Implementation Scheme 1, wherein the vulcanization in step (c) is carried out at a temperature of about 170°C to about 200°C.

[0116] Implementation Scheme 3. The tread compound according to Implementation Scheme 1 or 2, wherein at least one elastomer is natural rubber (NR), polyisoprene rubber (IR), butyl rubber (IIR), polybutadiene rubber (BR), styrene-butadiene rubber (SBR), or blends thereof.

[0117] Implementation Scheme 4. The tread compound according to Implementation Scheme 3, wherein the at least one elastomer is natural rubber (NR), polybutadiene rubber (BR), and styrene-butadiene rubber (SBR).

[0118] Implementation Scheme 5. The tread compound according to Implementation Scheme 4, wherein the concentration of natural rubber (NR) in the vulcanizable composition is from 0 phr to about 100 phr.

[0119] Implementation Scheme 6. The tread compound according to Implementation Scheme 5, wherein the concentration of natural rubber (NR) in the vulcanizable composition is from about 5 phr to about 80 phr.

[0120] Implementation Scheme 7. The tread compound according to Implementation Scheme 4, wherein the concentration of polybutadiene rubber (BR) in the vulcanizable composition is from 0 phr to about 60 phr.

[0121] Implementation Scheme 8. The tread compound according to Implementation Scheme 7, wherein the concentration of polybutadiene rubber (BR) in the vulcanizable composition is from about 5 phr to about 25 phr.

[0122] Implementation Scheme 9. The tread compound according to Implementation Scheme 4, wherein the concentration of styrene-butadiene rubber (SBR) in the vulcanizable composition is from 0 phr to about 100 phr.

[0123] Implementation Scheme 10. The tread compound according to Implementation Scheme 9, wherein the concentration of styrene-butadiene rubber (SBR) in the vulcanizable composition is from about 15 phr to about 80 phr.

[0124] Implementation Scheme 11. The tread compound according to any one of Implementation Schemes 1 to 10, wherein the at least one filler is carbon black, silica, kaolin, calcium silicate, talc, carbon nanotubes (CNT), carbon fiber (HCF), graphite, graphene, aluminosilicate, starch, fiber, or a combination thereof.

[0125] Implementation Scheme 12. The tread compound according to Implementation Scheme 11, wherein the at least one filler is carbon black.

[0126] Implementation Scheme 13. The tread compound according to Implementation Scheme 12, wherein the concentration of carbon black in the vulcanizable composition is from 0 phr to about 100 phr.

[0127] Implementation Scheme 14. The tread compound according to Implementation Scheme 11, wherein at least one filler is silica.

[0128] Implementation Scheme 15. The tread compound according to Implementation Scheme 14, wherein the concentration of silica in the vulcanizable composition is from 0 phr to about 180 phr.

[0129] Implementation Scheme 16. The tread compound according to Implementation Scheme 14, wherein the concentration of silica in the vulcanizable composition is from about 80 phr to about 160 phr.

[0130] Implementation Scheme 17. The tread compound according to any one of Implementation Schemes 1 to 16, further comprising at least one plasticizer.

[0131] Implementation Scheme 18. The tread compound according to Implementation Scheme 17, wherein the at least one plasticizer is a mineral oil, an organic ester, a resin, a wax, an ester plasticizer, a naturally derived oil, or a combination thereof.

[0132] Implementation Scheme 19. The tread compound according to Implementation Scheme 18, wherein the mineral oil is a naphthenic oil, paraffin oil, or aromatic oil.

[0133] Implementation Scheme 20. The tread compound according to Implementation Scheme 18 or 19, wherein at least one plasticizer is a mineral oil and a wax.

[0134] Implementation Scheme 21. The tread compound according to any one of Implementation Schemes 18 to 20, wherein the concentration of at least one plasticizer in the vulcanizable composition is from about 5 phr to about 25 phr.

[0135] Implementation Scheme 22. The tread compound according to any one of Implementation Schemes 1 to 21, wherein the composition comprises one or more rubber chemicals.

[0136] Implementation Scheme 23. The tread compound according to Implementation Scheme 22, wherein the one or more rubber chemicals comprise one or more accelerators, one or more activators, one or more pre-vulcanization inhibitors, or combinations thereof.

[0137] Implementation Scheme 24. The tread compound according to Implementation Scheme 23, wherein the one or more rubber chemicals comprise one or more accelerators.

[0138] Implementation Scheme 25. The tread compound according to Implementation Scheme 24, wherein one or more accelerators are guanidine, thiazole, sulfenamide, thiuram, dithiocarbamate, xanthate, thiophosphate, or combinations thereof.

[0139] Implementation Scheme 26. The tread compound according to Implementation Scheme 25, wherein the guanidine is diphenylguanidine (DPG).

[0140] Implementation Scheme 27. The tread compound according to Implementation Scheme 25, wherein the thiazole is 2-mercaptobenzothiazole (MBT), zinc 2-mercaptobenzothiazole (ZMBT), or mercaptobenzothiazole disulfide (MBTS).N -tert-butyl-2-benzothiazole sulfenamide (TBSI) or combinations thereof.

[0141] Implementation Scheme 28. The tread compound according to Implementation Scheme 25, wherein the sulfenamide is N 2-tert-butyl-2-benzothiazole sulfenamide (TBBS) N -Cyclohexylbenzothiazole-2-sulfenamide (CBS), dicyclohexyl-2-benzothiazole-sulfenamide (DCBS) N 2-O-diethylbenzylthiazolylsulfonamide (OBTS) N -O-diethylidene thiocarbamoyl- N' 2-O-diethylethylene sulfenamide (OTOS), thiocarbamoyl sulfenamide, or combinations thereof.

[0142] Implementation Scheme 29. The tread compound according to Implementation Scheme 28, wherein the sulfenamide is N -Cyclohexylbenzothiazole-2-sulfenamide (CBS).

[0143] Implementation Scheme 30. The tread compound according to Implementation Scheme 25, wherein the thiuram is dimethylthiocarbamate dithioperoxyanhydride (Thimeros), bispentamethylene thiuram tetrasulfide (DPIT), tetrabenzylthiuram disulfide (TBzTD), tetraethylthiuram disulfide (TETD), tetramethylthiuram disulfide (TMTD), tetramethylthiuram monosulfide (TMTM), or a combination thereof.

[0144] Implementation Scheme 31. The tread compound according to Implementation Scheme 25, wherein the dithiocarbamate is zinc dimethyl dithiocarbamate (ZDMC), zinc diethyl dithiocarbamate (ZDEC), zinc dibutyl dithiocarbamate (ZDBC), nickel dibutyl dithiocarbamate (NDBC), sodium dibenzyl dithiocarbamate (SBEC), sodium diethyl dithiocarbamate (SDEC), tellurium diethyl dithiocarbamate (TDEC), zinc dibenzyl dithiocarbamate (ZEBC), or a combination thereof.

[0145] Implementation Scheme 32. The tread compound according to any one of Implementation Schemes 24 to 31, wherein the concentration of the one or more accelerators in the vulcanizable composition is from about 1 phr to about 20 phr.

[0146] Implementation Scheme 33. The tread compound according to any one of Implementation Schemes 23 to 32, wherein the one or more rubber chemicals comprise one or more activators.

[0147] Implementation Scheme 34. The tread compound according to Implementation Scheme 33, wherein one or more activators are metal oxides, acids, metal complexes, or combinations thereof.

[0148] Implementation Scheme 35. The tread compound according to Implementation Scheme 34, wherein the metal oxide is zinc oxide, magnesium oxide, lead oxide, or a combination thereof.

[0149] Implementation Scheme 36. The tread compound according to Implementation Scheme 34, wherein the acid is stearic acid, lauric acid, or a combination thereof.

[0150] Implementation Scheme 37. The tread compound according to Implementation Scheme 34, wherein the metal complex is zinc ethylhexanoate.

[0151] Implementation Scheme 38. The tread compound according to any one of Implementation Schemes 33 to 37, wherein the concentration of the one or more activators is from about 1 phr to about 10 phr.

[0152] Implementation Scheme 39. The tread compound according to any one of Implementation Schemes 23 to 38, wherein the one or more rubber chemicals comprise one or more pre-vulcanization inhibitors.

[0153] Implementation Scheme 40. The tread compound according to Implementation Scheme 39, wherein one or more pre-vulcanization inhibitors are N -(cyclohexylthio)phthalimide (CTP), benzoic anhydride, salicylic anhydride, phthalic anhydride or combinations thereof.

[0154] Implementation Scheme 41. The tread compound according to any one of Implementation Schemes 1 to 40, wherein the concentration of insoluble sulfur in the vulcanizable composition is from about 0.1 phr to about 30 phr.

[0155] Implementation Scheme 42. The tread compound according to Implementation Scheme 41, wherein the concentration of insoluble sulfur in the vulcanizable composition is from about 0.5 phr to about 2 phr.

[0156] Implementation Scheme 43. The tread compound according to any one of Implementation Schemes 1 to 42, wherein the vulcanization in step (c) is carried out at a temperature of about 170°C.

[0157] Implementation Scheme 44. The tread compound according to any one of Implementation Schemes 1 to 43, wherein the tread compound has a breaking strength of about 10 MPa to about 25 MPa.

[0158] Implementation Scheme 45. The tread compound according to any one of Implementation Schemes 1 to 44, wherein after the tread compound has been aged at 77°C for 7 days, the tread compound has a tensile strength of about 10 MPa to about 25 MPa.

[0159] Implementation Scheme 46. The tread compound according to any one of Implementation Schemes 1 to 45, wherein after the tread compound has been aged at 77°C for 7 days, the breaking strength of the tread compound decreases by less than 10% relative to before aging.

[0160] Implementation Scheme 47. The tread compound according to any one of Implementation Schemes 1 to 46, wherein the elongation at break of the tread compound is about 200% to about 700%.

[0161] Implementation Scheme 48. The tread compound according to any one of Implementation Schemes 1 to 47, wherein after the tread compound has been aged at 77°C for 7 days, the elongation at break of the tread compound is about 200% to about 700%.

[0162] Implementation Scheme 49. The tread compound according to any one of Implementation Schemes 1 to 48, wherein after the tread compound has been aged at 77°C for 7 days, the elongation at break of the tread compound decreases by less than 30% relative to before aging.

[0163] Implementation Scheme 50. The tread compound according to any one of Implementation Schemes 1 to 49, wherein the M100 of the tread compound is from about 2.0 MPa to about 5.8 MPa.

[0164] Implementation Scheme 51. The tread compound according to any one of Implementation Schemes 1 to 50, wherein after the tread compound has been aged at 77°C for 7 days, the M100 of the tread compound is about 4.0 MPa to about 7.7 MPa.

[0165] Implementation Scheme 52. A method for preparing a tread compound, the method comprising:

[0166] (a) Mixing at least one elastomer, at least one filler and insoluble sulfur to form a vulcanizable composition, wherein, as described in ISO 8332 using toluene as a solvent, the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70 after heating the sample at 115°C for 15 minutes, or the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.87 after heating the insoluble sulfur at 105°C for 15 minutes;

[0167] (b) Forming the vulcanizable composition of (a) into a tire tread; and

[0168] (c) Vulcanizing the vulcanizable composition of (b) at a temperature of about 150°C to about 220°C;

[0169] To provide the tread compound.

[0170] Implementation Scheme 53. The method according to Implementation Scheme 52, wherein the vulcanization in step (c) is carried out at a temperature of about 170°C to about 200°C.

[0171] Implementation Scheme 54. The method according to Implementation Scheme 52 or 53, wherein the at least one elastomer is natural rubber (NR), polyisoprene rubber (IR), butyl rubber (IIR), polybutadiene rubber (BR), styrene-butadiene rubber (SBR), or a blend thereof.

[0172] Implementation Scheme 55. The method according to Implementation Scheme 54, wherein at least one elastomer is natural rubber (NR), polybutadiene rubber (BR), and styrene-butadiene rubber (SBR).

[0173] Implementation Scheme 56. The method according to Implementation Scheme 55, wherein the concentration of natural rubber (NR) in the vulcanizable composition is from 0 phr to about 100 phr.

[0174] Implementation Scheme 57. The method according to Implementation Scheme 56, wherein the concentration of natural rubber (NR) in the vulcanizable composition is from about 5 phr to about 80 phr.

[0175] Implementation Scheme 58. The method according to Implementation Scheme 55, wherein the concentration of polybutadiene rubber (BR) in the vulcanizable composition is from 0 phr to about 60 phr.

[0176] Implementation Scheme 59. The method according to Implementation Scheme 58, wherein the concentration of polybutadiene rubber (BR) in the vulcanizable composition is from about 5 phr to about 25 phr.

[0177] Implementation Scheme 60. The method according to Implementation Scheme 59, wherein the concentration of styrene-butadiene rubber (SBR) in the vulcanizable composition is from 0 phr to about 100 phr.

[0178] Implementation Scheme 61. The method according to Implementation Scheme 60, wherein the concentration of styrene-butadiene rubber (SBR) in the vulcanizable composition is from about 15 phr to about 85 phr.

[0179] Implementation Scheme 62. The method according to any one of Implementation Schemes 52 to 61, wherein the at least one filler is carbon black, silica, kaolin, calcium silicate, talc, carbon nanotubes (CNT), carbon fiber (HCF), graphite, graphene, aluminosilicate, starch, fiber, or a combination thereof.

[0180] Implementation Scheme 63. The method according to Implementation Scheme 62, wherein at least one filler is carbon black.

[0181] Implementation Scheme 64. The method according to Implementation Scheme 63, wherein the concentration of carbon black in the vulcanizable composition is from 0 phr to about 100 phr.

[0182] Implementation Scheme 65. The method according to Implementation Scheme 62, wherein at least one filler is silica.

[0183] Implementation Scheme 66. The method according to Implementation Scheme 65, wherein the concentration of silica in the vulcanizable composition is from 0 phr to about 180 phr.

[0184] Implementation Scheme 67. The method according to Implementation Scheme 66, wherein the concentration of silica in the vulcanizable composition is from about 80 phr to about 160 phr.

[0185] Implementation Scheme 68. The method according to any one of Implementation Schemes 52 to 67, wherein step (a) further comprises mixing at least one plasticizer to form the vulcanizable composition.

[0186] Implementation Scheme 69. The method according to any implementation scheme 68, wherein the at least one plasticizer is a mineral oil, an organic ester, a resin, a wax, an ester plasticizer, a natural source oil, or a combination thereof.

[0187] Implementation Scheme 70. The method according to Implementation Scheme 69, wherein the mineral oil is a naphthenic oil, paraffin oil, or aromatic oil.

[0188] Implementation Scheme 71. The method according to Implementation Scheme 69 or 70, wherein at least one plasticizer is mineral oil and wax.

[0189] Implementation Scheme 72. The method according to any one of Implementation Schemes 69 to 71, wherein the concentration of at least one plasticizer in the vulcanizable composition is from about 0 phr to about 25 phr.

[0190] Implementation Scheme 73. The method according to any one of Implementation Schemes 52 to 72, wherein the composition comprises one or more rubber chemicals.

[0191] Implementation Scheme 74. The method according to Implementation Scheme 73, wherein the one or more rubber chemicals comprise one or more accelerators, one or more activators, one or more pre-vulcanization inhibitors, or combinations thereof.

[0192] Implementation Scheme 75. The method according to Implementation Scheme 74, wherein one or more rubber chemicals comprise one or more accelerators.

[0193] Implementation Scheme 76. The method according to Implementation Scheme 75, wherein the one or more promoters are guanidine, thiazole, sulfenamide, thiuram, dithiocarbamate, xanthate, thiophosphate, or a combination thereof.

[0194] Implementation Scheme 77. The method according to Implementation Scheme 76, wherein the guanidine is diphenylguanidine (DPG).

[0195] Implementation Scheme 78. The method according to Implementation Scheme 76, wherein the thiazole is 2-mercaptobenzothiazole (MBT), zinc 2-mercaptobenzothiazole (ZMBT), or mercaptobenzothiazole disulfide (MBTS). N -tert-butyl-2-benzothiazole sulfenamide (TBSI) or combinations thereof.

[0196] Implementation Scheme 79. The method according to Implementation Scheme 76, wherein the sulfenamide is N 2-tert-butyl-2-benzothiazole sulfenamide (TBBS) N -Cyclohexylbenzothiazole-2-sulfenamide (CBS), dicyclohexyl-2-benzothiazole-sulfenamide (DCBS) N 2-O-diethylbenzylthiazolylsulfonamide (OBTS) N -O-diethylidene thiocarbamoyl- N' 2-O-diethylethylene sulfenamide (OTOS), thiocarbamoyl sulfenamide, or combinations thereof.

[0197] Implementation Scheme 80. The method according to Implementation Scheme 79, wherein the sulfenamide is N -Cyclohexylbenzothiazole-2-sulfenamide (CBS).

[0198] Implementation Scheme 81. The method according to Implementation Scheme 76, wherein the thiuram is dimethylthiocarbamate dithioperoxyanhydride (Thimeros), bispentamethylene thiuram tetrasulfide (DPIT), tetrabenzylthiuram disulfide (TBzTD), tetraethylthiuram disulfide (TETD), tetramethylthiuram disulfide (TMTD), tetramethylthiuram monosulfide (TMTM), or a combination thereof.

[0199] Implementation Scheme 82. The method according to Implementation Scheme 76, wherein the dithiocarbamate is zinc dimethyl dithiocarbamate (ZDMC), zinc diethyl dithiocarbamate (ZDEC), zinc dibutyl dithiocarbamate (ZDBC), nickel dibutyl dithiocarbamate (NDBC), sodium dibenzyl dithiocarbamate (SBEC), sodium diethyl dithiocarbamate (SDEC), tellurium diethyl dithiocarbamate (TDEC), zinc dibenzyl dithiocarbamate (ZEBC), or a combination thereof.

[0200] Implementation Scheme 83. The method according to any one of Implementation Schemes 75 to 82, wherein the concentration of the one or more accelerators in the vulcanizable composition is from about 1 phr to about 10 phr.

[0201] Implementation Scheme 84. The method according to any one of Implementation Schemes 74 to 83, wherein the one or more rubber chemicals comprise one or more activators.

[0202] Implementation Scheme 85. The method according to Implementation Scheme 84, wherein one or more activators are metal oxides, acids, metal complexes, or combinations thereof.

[0203] Implementation Scheme 86. The method according to Implementation Scheme 85, wherein the metal oxide is zinc oxide, magnesium oxide, lead oxide, or a combination thereof.

[0204] Implementation Scheme 87. The method according to Implementation Scheme 85, wherein the acid is stearic acid, lauric acid, or a combination thereof.

[0205] Implementation Scheme 88. The method according to Implementation Scheme 85, wherein the metal complex is zinc ethylhexanoate.

[0206] Implementation Scheme 89. The method according to any one of Implementation Schemes 84 to 88, wherein the concentration of the one or more activators is from about 1 phr to about 10 phr.

[0207] Implementation Scheme 90. The method according to any one of Implementation Schemes 74 to 89, wherein the one or more rubber chemicals comprise one or more pre-vulcanization inhibitors.

[0208] Implementation Scheme 91. The method according to Implementation Scheme 90, wherein the one or more pre-vulcanization inhibitors are N -(cyclohexylthio)phthalimide (CTP), benzoic anhydride, salicylic anhydride, phthalic anhydride or combinations thereof.

[0209] Implementation Scheme 92. The method according to any one of Implementation Schemes 52 to 91, wherein the concentration of insoluble sulfur in the vulcanizable composition is from about 0.1 phr to about 20 phr.

[0210] Implementation Scheme 93. The method according to Implementation Scheme 92, wherein the concentration of insoluble sulfur in the vulcanizable composition is from about 0.5 phr to about 2 phr.

[0211] Implementation Scheme 94. The method according to any one of Implementation Schemes 52 to 93, wherein the vulcanization in step (c) is carried out at about 170°C.

[0212] Implementation Scheme 95. The method according to any one of Implementation Schemes 52 to 94, wherein the tread compound has a breaking strength of about 10 MPa to about 25 MPa.

[0213] Implementation Scheme 96. The method according to any one of Implementation Schemes 52 to 95, wherein after the tread compound has been aged at 77°C for 7 days, the tread compound has a tensile strength of about 10 MPa to about 25 MPa.

[0214] Implementation Scheme 97. The method according to any one of Implementation Schemes 52 to 96, wherein after the tread compound has been aged at 77°C for 7 days, the breaking strength of the tread compound decreases by less than 10% relative to before aging.

[0215] Implementation Scheme 98. The method according to any one of Implementation Schemes 52 to 97, wherein the elongation at break of the tread compound is about 200% to about 700%.

[0216] Implementation Scheme 99. The method according to any one of Implementation Schemes 52 to 98, wherein after the tread compound has been aged at 77°C for 7 days, the elongation at break of the tread compound is about 200% to about 700%.

[0217] Implementation Scheme 100. The method according to any one of Implementation Schemes 52 to 99, wherein after the tread compound has been aged at 77°C for 7 days, the elongation at break of the tread compound decreases by less than 30% relative to before aging.

[0218] Implementation Scheme 101. The method according to any one of Implementation Schemes 52 to 100, wherein the M100 of the tread compound is about 2.0 MPa to about 5.8 MPa.

[0219] Implementation Scheme 102. The method according to any one of Implementation Schemes 52 to 101, wherein after the tread compound has been aged at 77°C for 7 days, the M100 of the tread compound is about 4.0 MPa to about 7.7 MPa.

[0220] Example

[0221] Example 1

[0222] Preparation of tread compounds

[0223] Using methods known in the art, insoluble sulfur (cyclododecyl sulfate (S)) is used. 12 All-season, summer, and winter passenger car radial tire (PCR) treads (treads 1, 2, and 3, respectively) were prepared using Crystex Cure Pro (CP) or Crystex HD OT 20 (HD) or soluble sulfur (RMS from the rubber manufacturer). The formulations used to prepare treads 1, 2, and 3 are shown in Tables 1, 3, and 5, respectively. The mixing procedures used to prepare treads 1, 2, and 3 are shown in Tables 2, 4, and 6, respectively.

[0224] Table 1

[0225]

[0226]

[0227] Table 2

[0228]

[0229]

[0230] Table 3

[0231]

[0232]

[0233] Table 4

[0234]

[0235]

[0236] Table 5

[0237]

[0238]

[0239] Table 6

[0240]

[0241]

[0242] Example 2

[0243] Thermal stability of tread compounds

[0244] The breaking strength, elongation at break, and M100 (stress value when the compound is stretched to 100% strain) of the tread compound prepared in Example 1 were tested using experimental procedures known in the art (such as ASTM D-412).

[0245] Figure 1 The fracture strength, elongation at break, and M100 of tread compounds 1-S12, 1-CP, 1-RMS, and 1-HD are shown when vulcanized at 150°C (left) and 170°C (right). Figure 2 The fracture strength, elongation at break, and M100 of tread compounds 2-S12, 2-CP, 2-RMS, and 2-HD are shown when vulcanized at 130°C (left), 150°C (middle), and 170°C (right). Figure 3 The breaking strength, elongation at break, and M100 of tread compounds 3-S12, 3-CP, 3-RMS, and 3-HD are shown when vulcanized at 130°C (left), 150°C (middle), and 170°C (right).

[0246] The selected samples were also aged at 77°C for 7 days. Figure 4 The breaking strength, elongation at break, and M100 of the tread compounds 1-CP and 1-RMS are shown before aging (top) and after aging (bottom). Figure 5 As described, the Cure Pro tread retains higher strength and elongation compared to the RMS-containing tread.

[0247] Tread compounds prepared using Crystex Cure Pro and RMS exhibit similar vulcanization-curing history curves and dynamic fatigue properties, as shown below. Figure 6 and 7 As shown.

[0248] The methods, compounds, and compositions described herein have now been fully described, and those skilled in the art will understand that these methods, compounds, and compositions can be performed within a wide and equivalent range of conditions, formulations, and other parameters without affecting the scope of the methods, compounds, and compositions provided herein or any embodiments thereof. All patents, patent applications, and publications cited herein (including standard test methods, such as ASTM and ISO methods and procedures) are incorporated herein by reference in their entirety.

Claims

1. A tread compound, said tread compound being prepared by a method comprising the following: (a) Mixing at least one elastomer, at least one filler and insoluble sulfur to form a vulcanizable composition, wherein, as described in ISO 8332 (9.2 Method A, using toluene as a solvent "Determination of thermal reversion of insoluble sulfur"), after heating the insoluble sulfur at 115°C for 15 minutes, the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70, or after heating the insoluble sulfur at 105°C for 15 minutes, the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.87; (b) Forming the vulcanizable composition of (a) into a tire tread; and (c) Vulcanizing the vulcanizable composition of (b) at a temperature of about 150°C to about 220°C; To provide the tread compound.

2. The tread compound according to claim 1, wherein the vulcanization in step (c) is carried out at a temperature of about 170°C to about 200°C.

3. The tread compound according to claim 1 or 2, wherein the at least one elastomer is natural rubber (NR), polyisoprene rubber (IR), butyl rubber (IIR), polybutadiene rubber (BR), styrene-butadiene rubber (SBR), or a blend thereof.

4. The tread compound according to claim 3, wherein the at least one elastomer is natural rubber (NR), polybutadiene rubber (BR), and styrene-butadiene rubber (SBR).

5. The tread compound according to claim 4, wherein the concentration of natural rubber (NR) in the vulcanizable composition is from 0 phr to about 100 phr.

6. The tread compound according to claim 5, wherein the concentration of natural rubber (NR) in the vulcanizable composition is from about 5 phr to about 25 phr.

7. The tread compound according to claim 4, wherein the concentration of polybutadiene rubber (BR) in the vulcanizable composition is from 0 phr to about 60 phr.

8. The tread compound according to claim 7, wherein the concentration of polybutadiene rubber (BR) in the vulcanizable composition is from about 5 phr to about 25 phr.

9. The tread compound according to claim 4, wherein the concentration of styrene-butadiene rubber (SBR) in the vulcanizable composition is from 0 phr to about 100 phr.

10. The tread compound according to claim 9, wherein the concentration of styrene-butadiene rubber (SBR) in the vulcanizable composition is from about 15 phr to about 85 phr.

11. The tread compound according to any one of claims 1 to 10, wherein the at least one filler is carbon black, silica, kaolin, calcium silicate, talc, carbon nanotubes (CNT), carbon fiber (HCF), graphite, graphene, aluminosilicate, starch, fiber, or a combination thereof.

12. The tread compound according to claim 11, wherein at least one filler is carbon black.

13. The tread compound according to claim 12, wherein the concentration of carbon black in the vulcanizable composition is from 0 phr to about 100 phr.

14. The tread compound according to claim 11, wherein at least one filler is silica.

15. The tread compound of claim 14, wherein the concentration of silica in the vulcanizable composition is from 0 phr to about 180 phr.

16. The tread compound of claim 14, wherein the concentration of silica in the vulcanizable composition is from about 80 phr to about 160 phr.

17. The tread compound according to any one of claims 1 to 16, further comprising at least one plasticizer.

18. The tread compound of claim 17, wherein the at least one plasticizer is a mineral oil, an organic ester, a resin, a wax, an ester plasticizer, a naturally derived oil, or a combination thereof.

19. The tread compound according to claim 18, wherein the mineral oil is a naphthenic oil, paraffin oil, or aromatic oil.

20. The tread compound according to claim 18 or 19, wherein the at least one plasticizer is mineral oil and wax.

21. The tread compound according to any one of claims 18 to 20, wherein the concentration of at least one plasticizer in the vulcanizable composition is from about 0 phr to about 25 phr.

22. The tread compound according to any one of claims 1 to 21, wherein the composition comprises one or more rubber chemicals.

23. The tread compound of claim 22, wherein the one or more rubber chemicals comprise one or more accelerators, one or more activators, one or more pre-vulcanization inhibitors, or combinations thereof.

24. The tread compound of claim 23, wherein the one or more rubber chemicals comprise one or more accelerators.

25. The tread compound according to claim 24, wherein one or more accelerators are guanidine, thiazole, sulfenamide, thiuram, dithiocarbamate, xanthate, thiophosphate, or combinations thereof.

26. The tread compound of claim 25, wherein the guanidine is diphenylguanidine (DPG).

27. The tread compound according to claim 25, wherein the thiazole is 2-mercaptobenzothiazole (MBT), zinc 2-mercaptobenzothiazole (ZMBT), or mercaptobenzothiazole disulfide (MBTS). N -tert-butyl-2-benzothiazole sulfenamide (TBSI) or combinations thereof.

28. The tread compound of claim 25, wherein the sulfenamide is N 2-tert-butyl-2-benzothiazole sulfenamide (TBBS) N -Cyclohexylbenzothiazole-2-sulfenamide (CBS), dicyclohexyl-2-benzothiazole-sulfenamide (DCBS) N 2-O-diethylbenzylthiazolylsulfonamide (OBTS) N -O-diethylidene thiocarbamoyl- N' 2-O-diethylethylene sulfenamide (OTOS), thiocarbamoyl sulfenamide, or combinations thereof.

29. The tread compound according to claim 28, wherein the sulfenamide is N -Cyclohexylbenzothiazole-2-sulfenamide (CBS).

30. The tread compound according to claim 25, wherein the thiram is dimethylthiocarbamate dithioperoxyanhydride (thiram), bispentamethylene thiram tetrasulfide (DPIT), tetrabenzylthiram disulfide (TBzTD), tetraethylthiram disulfide (TETD), tetramethylthiram disulfide (TMTD), tetramethylthiram monosulfide (TMTM), or a combination thereof.

31. The tread compound according to claim 25, wherein the dithiocarbamate is zinc dimethyl dithiocarbamate (ZDMC), zinc diethyl dithiocarbamate (ZDEC), zinc dibutyl dithiocarbamate (ZDBC), nickel dibutyl dithiocarbamate (NDBC), sodium dibenzyl dithiocarbamate (SBEC), sodium diethyl dithiocarbamate (SDEC), tellurium diethyl dithiocarbamate (TDEC), zinc dibenzyl dithiocarbamate (ZEBC), or a combination thereof.

32. The tread compound according to any one of claims 24 to 31, wherein the concentration of the one or more accelerators in the vulcanizable composition is from about 0.5 phr to about 20 phr.

33. The tread compound according to any one of claims 23 to 32, wherein the one or more rubber chemicals comprise one or more activators.

34. The tread compound of claim 33, wherein one or more activators are metal oxides, acids, metal complexes, or combinations thereof.

35. The tread compound of claim 34, wherein the metal oxide is zinc oxide, magnesium oxide, lead oxide, or a combination thereof.

36. The tread compound of claim 34, wherein the acid is stearic acid, lauric acid, or a combination thereof.

37. The tread compound according to claim 34, wherein the metal complex is zinc ethylhexanoate.

38. The tread compound according to any one of claims 33 to 37, wherein the concentration of the one or more activators is from about 1 phr to about 10 phr.

39. The tread compound according to any one of claims 23 to 38, wherein the one or more rubber chemicals comprise one or more pre-vulcanization inhibitors.

40. The tread compound of claim 39, wherein one or more pre-vulcanization inhibitors are N -(cyclohexylthio)phthalimide (CTP), benzoic anhydride, salicylic anhydride, phthalic anhydride or combinations thereof.

41. The tread compound according to any one of claims 1 to 40, wherein the concentration of insoluble sulfur in the vulcanizable composition is from about 0.1 phr to about 60 phr.

42. The tread compound of claim 41, wherein the concentration of insoluble sulfur in the vulcanizable composition is from about 0.5 phr to about 2 phr.

43. The tread compound according to any one of claims 1 to 42, wherein the vulcanization in step (c) is carried out at a temperature of about 170°C.

44. The tread compound according to any one of claims 1 to 43, wherein the tread compound has a breaking strength of about 10 MPa to about 25 MPa.

45. The tread compound according to any one of claims 1 to 44, wherein after the tread compound has been aged at 77°C for 7 days, the tensile strength of the tread compound is about 10 MPa to about 25 MPa.

46. ​​The tread compound according to any one of claims 1 to 45, wherein after the tread compound has been aged at 77°C for 7 days, the breaking strength of the tread compound decreases by less than 10% relative to before aging.

47. The tread compound according to any one of claims 1 to 46, wherein the elongation at break of the tread compound is about 200% to about 700%.

48. The tread compound according to any one of claims 1 to 47, wherein after the tread compound has been aged at 77°C for 7 days, the elongation at break of the tread compound is about 200% to about 700%.

49. The tread compound according to any one of claims 1 to 48, wherein after the tread compound has been aged at 77°C for 7 days, the elongation at break of the tread compound decreases by less than 30% relative to before aging.

50. The tread compound according to any one of claims 1 to 49, wherein the M100 of the tread compound is from about 2.0 MPa to about 5.8 MPa.

51. The tread compound according to any one of claims 1 to 50, wherein after the tread compound has been aged at 77°C for 7 days, the M100 of the tread compound is about 4.0 MPa to about 7.7 MPa.

52. A method for preparing a tread compound, the method comprising: (a) Mixing at least one elastomer, at least one filler and insoluble sulfur to form a vulcanizable composition, wherein, as described in ISO 8332 (9.2 Method A, using toluene as a solvent "Determination of thermal reversal of insoluble sulfur"), the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.70 after heating the sample at 115°C for 15 minutes, or the insoluble sulfur has a total insoluble sulfur mass fraction of at least 0.87 after heating the insoluble sulfur at 105°C for 15 minutes; (b) Forming the vulcanizable composition of (a) into a tire tread; and (c) Vulcanizing the vulcanizable composition of (b) at a temperature of about 150°C to about 220°C; To provide the tread compound.

53. The method of claim 52, wherein the vulcanization in step (c) is carried out at a temperature of about 170°C to about 200°C.

54. The method according to claim 52 or 53, wherein the at least one elastomer is natural rubber (NR), polyisoprene rubber (IR), butyl rubber (IIR), polybutadiene rubber (BR), styrene-butadiene rubber (SBR), or a blend thereof.

55. The method according to claim 54, wherein the at least one elastomer is natural rubber (NR), polybutadiene rubber (BR), and styrene-butadiene rubber (SBR).

56. The method of claim 55, wherein the concentration of natural rubber (NR) in the vulcanizable composition is from 0 phr to about 100 phr.

57. The method of claim 56, wherein the concentration of natural rubber (NR) in the vulcanizable composition is from about 5 phr to about 25 phr.

58. The method of claim 55, wherein the concentration of polybutadiene rubber (BR) in the vulcanizable composition is from 0 phr to about 60 phr.

59. The method of claim 58, wherein the concentration of polybutadiene rubber (BR) in the vulcanizable composition is from about 5 phr to about 25 phr.

60. The method of claim 59, wherein the concentration of styrene-butadiene rubber (SBR) in the vulcanizable composition is from 0 phr to about 100 phr.

61. The method of claim 60, wherein the concentration of styrene-butadiene rubber (SBR) in the vulcanizable composition is from about 85 phr to about 100 phr.

62. The method according to any one of claims 52 to 61, wherein the at least one filler is carbon black, silica, kaolin, calcium silicate, talc, carbon nanotubes (CNT), carbon fiber (HCF), graphite, graphene, aluminosilicate, starch, fiber, or a combination thereof.

63. The method according to claim 62, wherein at least one filler is carbon black.

64. The method of claim 63, wherein the concentration of carbon black in the vulcanizable composition is from 0 phr to about 100 phr.

65. The method according to claim 62, wherein the at least one filler is silicon dioxide.

66. The method of claim 65, wherein the concentration of silica in the vulcanizable composition is from 0 phr to about 180 phr.

67. The method of claim 66, wherein the concentration of silica in the vulcanizable composition is from about 80 phr to about 160 phr.

68. The method according to any one of claims 52 to 67, wherein step (a) further comprises mixing at least one plasticizer to form the vulcanizable composition.

69. The method according to any claim 68, wherein the at least one plasticizer is a mineral oil, an organic ester, a resin, a wax, an ester plasticizer, a naturally derived oil, or a combination thereof.

70. The method of claim 69, wherein the mineral oil is a naphthenic oil, paraffin oil, or aromatic oil.

71. The method according to claim 69 or 70, wherein the at least one plasticizer is mineral oil and wax.

72. The method according to any one of claims 69 to 71, wherein the concentration of at least one plasticizer in the vulcanizable composition is from about 5 phr to about 25 phr.

73. The method according to any one of claims 52 to 72, wherein the composition comprises one or more rubber chemicals.

74. The method of claim 73, wherein the one or more rubber chemicals comprise one or more accelerators, one or more activators, one or more pre-vulcanization inhibitors, or combinations thereof.

75. The method of claim 74, wherein the one or more rubber chemicals comprise one or more accelerators.

76. The method of claim 75, wherein the one or more promoters are guanidine, thiazole, sulfenamide, thiuram, dithiocarbamate, xanthate, thiophosphate, or a combination thereof.

77. The method of claim 76, wherein the guanidine is diphenylguanidine (DPG).

78. The method according to claim 76, wherein the thiazole is 2-mercaptobenzothiazole (MBT), zinc 2-mercaptobenzothiazole (ZMBT), or mercaptobenzothiazole disulfide (MBTS). N -tert-butyl-2-benzothiazole sulfenamide (TBSI) or combinations thereof.

79. The method of claim 76, wherein the sulfenamide is N 2-tert-butyl-2-benzothiazole sulfenamide (TBBS) N -Cyclohexylbenzothiazole-2-sulfenamide (CBS), dicyclohexyl-2-benzothiazole-sulfenamide (DCBS) N 2-O-diethylbenzylthiazolylsulfonamide (OBTS) N -O-diethylidene thiocarbamoyl- N' 2-O-diethylethylene sulfenamide (OTOS), thiocarbamoyl sulfenamide, or combinations thereof.

80. The method of claim 79, wherein the sulfenamide is N -Cyclohexylbenzothiazole-2-sulfenamide (CBS).

81. The method according to claim 76, wherein the thiuram is dimethylthiocarbamate dithioperoxyanhydride (Framed), bispentamethylene thiuram tetrasulfide (DPIT), tetrabenzylthiuram disulfide (TBzTD), tetraethylthiuram disulfide (TETD), tetramethylthiuram disulfide (TMTD), tetramethylthiuram monosulfide (TMTM), or a combination thereof.

82. The method according to claim 76, wherein the dithiocarbamate is zinc dimethyl dithiocarbamate (ZDMC), zinc diethyl dithiocarbamate (ZDEC), zinc dibutyl dithiocarbamate (ZDBC), nickel dibutyl dithiocarbamate (NDBC), sodium dibenzyl dithiocarbamate (SBEC), sodium diethyl dithiocarbamate (SDEC), tellurium diethyl dithiocarbamate (TDEC), zinc dibenzyl dithiocarbamate (ZEBC), or a combination thereof.

83. The method according to any one of claims 75 to 82, wherein the concentration of the one or more accelerators in the vulcanizable composition is from about 0.5 phr to about 10 phr.

84. The method according to any one of claims 74 to 83, wherein the one or more rubber chemicals comprise one or more activators.

85. The method of claim 84, wherein one or more activators are metal oxides, acids, metal complexes, or combinations thereof.

86. The method of claim 85, wherein the metal oxide is zinc oxide, magnesium oxide, lead oxide, or a combination thereof.

87. The method of claim 85, wherein the acid is stearic acid, lauric acid, or a combination thereof.

88. The method of claim 85, wherein the metal complex is zinc ethylhexanoate.

89. The method according to any one of claims 84 to 88, wherein the concentration of the one or more activators is from about 1 phr to about 10 phr.

90. The method according to any one of claims 74 to 89, wherein the one or more rubber chemicals comprise one or more pre-vulcanization inhibitors.

91. The method of claim 90, wherein the one or more pre-vulcanization inhibitors are N -(cyclohexylthio)phthalimide (CTP), benzoic anhydride, salicylic anhydride, phthalic anhydride or combinations thereof.

92. The method according to any one of claims 52 to 91, wherein the concentration of insoluble sulfur in the vulcanizable composition is from about 0.1 phr to about 30 phr.

93. The method of claim 92, wherein the concentration of insoluble sulfur in the vulcanizable composition is from about 0.75 phr to about 2 phr.

94. The method according to any one of claims 52 to 93, wherein the vulcanization in step (c) is carried out at about 170°C.

95. The method according to any one of claims 52 to 94, wherein the tread compound has a breaking strength of about 10 MPa to about 25 MPa.

96. The method according to any one of claims 52 to 95, wherein after the tread compound has been aged at 77°C for 7 days, the tensile strength of the tread compound is about 10 MPa to about 25 MPa.

97. The method according to any one of claims 52 to 96, wherein after the tread compound has been aged at 77°C for 7 days, the breaking strength of the tread compound decreases by less than 10% relative to before aging.

98. The method according to any one of claims 52 to 97, wherein the tread compound has an elongation at break of about 200% to about 700%.

99. The method according to any one of claims 52 to 98, wherein after the tread compound has been aged at 77°C for 7 days, the elongation at break of the tread compound is about 200% to about 700%.

100. The method according to any one of claims 52 to 99, wherein after the tread compound has been aged at 77°C for 7 days, the elongation at break of the tread compound decreases by less than 30% relative to before aging.

101. The method according to any one of claims 52 to 100, wherein the M100 of the tread compound is from about 2.0 MPa to about 5.8 MPa.

102. The method according to any one of claims 52 to 101, wherein after the tread compound has been aged at 77°C for 7 days, the M100 of the tread compound is about 4.0 MPa to about 7.7 MPa.

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