Tire tread rubber composition, preparation method thereof and obtained tire

Abstract

The invention discloses a tread rubber composition, a preparation method thereof and an obtained tire, and belongs to the technical field of tire rubber materials. The tire tread rubber composition comprises styrene butadiene rubber and modified resin, and the modified resin contains sulfydryl. The modified resin containing sulfydryl is used, so that the wet skid resistance of the tread rubber composition is effectively improved while low rolling resistance is maintained. The modified resin contains sulfydryl and can play a role of a silane coupling agent, so that the effects of reducing the use of the silane coupling agent and reducing the VOC (Volatile Organic Compounds) amount and the production cost of the rubber material in the production process of the rubber material are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of tire rubber materials, and in particular relates to a tire tread rubber composition, a preparation method thereof and the obtained tire. Background Art

[0002] Since the implementation of the EU tire labeling law, passenger car tires sold in the EU are required to clearly label information such as rolling resistance, wet grip performance, and noise level. This has also prompted tire manufacturers to continuously improve the overall performance of their products. Currently, a combination of solution-polymerized styrene-butadiene rubber (SBR) and silica is widely used in passenger car tire treads to reduce rolling resistance and improve wet skid resistance. SBR is a low-polarity polymer, while silica is a highly polar material with a rich surface hydroxyl group. Therefore, when adding silica to SBR, a silane coupling agent is also required to reduce the polarity of the silica and improve its dispersion. Furthermore, certain groups in the silane coupling agent can participate in vulcanization, further enhancing the dispersion of the silica.

[0003] In the prior art, one method to further improve the anti-wet skid performance of rubber is to add anti-wet skid resin to the rubber. The addition of anti-wet skid resin can increase the glass transition temperature of the rubber and increase the loss factor (tanδ) at 0°C, thereby improving the anti-wet skid performance of the rubber. Chinese patent CN114163702B discloses a low rolling impedance wet-slip all-season tire that prevents groove bottom cracking in winter. The patent's tread rubber formula includes solution-polymerized styrene-butadiene rubber, white carbon black, and a silane coupling agent, as well as a tread anti-wet skid resin. The tread anti-wet skid resin uses α-methylstyrene resin, or polyterpene resin, or C5 and C9 polymer modified resin, which improves the physical properties of the rubber, anti-wet skid and improves the rubber processability. However, after using the modified resin, the patent did not achieve the effect of reducing rolling resistance. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is to overcome the lack of tire auxiliary products in the existing technology that have the effect of reducing rolling resistance and improving anti-skid performance. A high anti-skid and low rolling resistance tire tread rubber composition, its preparation method and the resulting tire are proposed. After using a modified resin containing a mercapto group, the resulting rubber composition has the characteristics of good anti-skid performance and low rolling resistance.

[0005] In order to solve the technical problem, the technical solution adopted by the present invention is: A tire tread rubber composition comprises styrene-butadiene rubber and a modified resin. The modified resin is a mercapto-containing modified resin obtained by reacting a B resin with a mercapto-containing modifier to undergo a click reaction, followed by modification with a mercapto deprotection auxiliary agent.

[0006] Preferably, the styrene content of the styrene-butadiene rubber is 15%-35%, and the vinyl content is not less than 30%.

[0007] Preferably, the tire tread rubber composition is characterized in that, in parts by weight, it includes 65-75 parts of styrene-butadiene rubber, 10-40 parts of modified resin, 75-100 parts of white carbon black, 0-10 parts of silane coupling agent, 25-35 parts of natural rubber, 3-4 parts of zinc oxide, 2-3 parts of stearic acid, 3-5 parts of carbon black, 1-4 parts of antioxidant, 1-2.5 parts of protective wax, 10-20 parts of softener, 2-4 parts of cross-linking agent, and 2-6 parts of accelerator.

[0008] Preferably, the silane coupling agent is one of KH580, Si69, and Si75.

[0009] Preferably, the thiol-containing modifier is 4-methoxythiophenol.

[0010] Preferably, the method for preparing the modified resin comprises the following steps: First stage reaction: Dissolve resin B completely in an organic solvent, add a photoinitiator and a modifier, and then add a phosphine ligand to continue the reaction; Preparation of auxiliary agent: Add thiol deprotection auxiliary agent to anhydrous tetrahydrofuran solution and react until the solution changes from colorless to black; Second stage reaction: the intermediate product obtained in the first stage reaction step is dissolved in an organic solvent and added to the solution obtained in the auxiliary agent preparation step for reaction; Third-stage reaction: dissolving the intermediate product obtained in the second-stage reaction step in an organic solvent and adding the solution obtained in the auxiliary agent preparation step to react; Product separation: The intermediate product obtained in the three reaction steps was quenched with hydrochloric acid and reprecipitated with methanol to obtain a modified resin.

[0011] Preferably, the B resin is one of C5 petroleum resin, C9 petroleum resin, DCPD resin, and terpene resin; The photoinitiator is one of α-hydroxyisobutyrophenone, α-hydroxyalkylphenone and α-aminoalkylphenone; The organic solvent is at least two of tetrahydrofuran, 1,2-dichloroethane, dichloromethane, and acetonitrile, one of which is tetrahydrofuran; The phosphine ligand is one of triphenylphosphine, tri-o-tolylphosphine, and tricyclohexylphosphine; The thiol deprotection auxiliary agent is a lithium naphthalene composition or a lithium anthracene composition.

[0012] The present invention also provides a method for preparing a tread rubber composition according to any of the above technical solutions, comprising the following steps: One-stage mixing: natural rubber, styrene-butadiene rubber, zinc oxide, stearic acid, white carbon black, carbon black, silane coupling agent, modified resin, antioxidant, protective wax, and softener are mixed in an internal mixer, and the mixture is discharged after uniform mixing to obtain a masterbatch; Second stage mixing: the masterbatch, crosslinking agent and accelerator are mixed in an internal mixer, mixed evenly and then discharged to obtain the final rubber; Vulcanization: The final rubber is vulcanized to obtain the rubber compound.

[0013] The present invention also provides a tire, which is prepared from the tread rubber composition of any one of the above technical solutions.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The tire tread rubber composition provided by the present invention adopts a modified resin containing a mercapto group. On the one hand, the modified resin contains a mercapto group, which can disperse the silanization of silica, thereby improving dispersibility and enhancing interfacial interaction, inhibiting the mutual aggregation of white carbon black particles, improving filler dispersibility, and enhancing the overall performance of the rubber. On the other hand, the modified resin can effectively increase the tanδ value of the rubber at 0°C, enhance the anti-skid performance of the rubber, reduce the tanδ value of the rubber at 70°C, and improve the rolling resistance performance.

[0015] The tire tread rubber composition provided by the present invention comprises a modified resin containing a mercapto group which can partially replace a silane coupling agent and catalyze a silanization reaction. Therefore, silica dispersion is not difficult, the dynamic properties of the rubber compound can be improved, and the VOC content and rubber compound production cost can be effectively reduced during the rubber compound production process. DETAILED DESCRIPTION

[0016] The following is a detailed and complete description of the technical solutions in the specific embodiments of the present invention. Obviously, the described embodiments are only some specific implementation methods of the overall technical solution of the present invention, and are not all implementation methods. Based on the overall concept of the present invention, all other embodiments obtained by ordinary skill in the art are within the scope of protection of the present invention.

[0017] The invention provides a tire tread rubber composition, comprising: styrene-butadiene rubber and a modified resin, wherein the modified resin is a thiol-containing modified resin, and the thiol-containing modified resin is obtained by reacting a B resin with a thiol-containing modifier to undergo a click reaction, and then reacting with a thiol deprotection auxiliary agent to modify the resin.

[0018] The thiol-containing modifier is 4-methoxythiophenol. Resin B and the modifier 4-methoxythiophenol undergo an olefin click chemistry reaction to produce a resin B-4-methoxyphenyl sulfide derivative. The resin B-4-methoxyphenyl sulfide derivative then reacts with a thiol deprotection aid to produce a thiol-functionalized resin B.

[0019] The modified resin contains mercapto groups, which can disperse the silanization of silica, thereby improving dispersibility and enhancing interfacial interactions, inhibiting the mutual aggregation of white carbon black particles, improving filler dispersion, and improving the overall performance of the rubber; on the other hand, the modified resin can effectively increase the tanδ value of the rubber at 0°C, enhance the anti-skid performance of the rubber, reduce the tanδ value of the rubber at 70°C, and improve the rolling resistance performance.

[0020] In a preferred embodiment, the styrene content of the styrene-butadiene rubber is 15%-35%, and the vinyl content (in the butadiene structure) is not less than 30%. This embodiment further limits the styrene and vinyl contents of the styrene-butadiene rubber because, when a styrene content of less than 15 wt% (or greater than 35 wt%) and a vinyl content (in the butadiene structure) of less than 30 wt% is selected, the effect of the mercapto-containing modified resin is not as significant.

[0021] As a reaction site, if the content of vinyl is low, there are not enough reaction sites and it is difficult to react with the modified resin containing thiol. In addition, the modified resin itself has a large steric hindrance. If the styrene content is higher than 35wt%, it is difficult for the modified resin to be inserted into the polymer reaction, so the modification effect is poor. If the styrene content is lower than 15%, the polymer glass transition temperature Tg is low. In a flexible matrix, although the resin can locally increase the friction force, the mobility of the matrix chain segment remains high, making the improvement of the overall dynamic mechanical properties of the resin less significant than in a high glass transition temperature Tg matrix. The low hysteresis characteristics of the matrix weaken the hysteresis effect of the resin, and the styrene content affects the compatibility of the modified resin in the rubber matrix, and its effect is also affected.

[0022] In a preferred embodiment, the nitrogen adsorption specific surface area BET of white carbon black is 150-180m 2 / g.

[0023] In a preferred embodiment, the present invention comprises 65-75 parts of styrene-butadiene rubber, 10-40 parts of modified resin, 75-100 parts of white carbon black, 0-10 parts of silane coupling agent, 25-35 parts of natural rubber, 3-4 parts of zinc oxide, 2-3 parts of stearic acid, 3-5 parts of carbon black, 1-4 parts of antioxidant, 1-2.5 parts of protective wax, 10-20 parts of softener, 2-4 parts of crosslinking agent, and 2-6 parts of accelerator. This embodiment specifically defines the amounts of styrene-butadiene rubber, modified resin, white carbon black, silane coupling agent, natural rubber, zinc oxide, stearic acid, carbon black, antioxidant, protective wax, softener, crosslinking agent and accelerator. It can be understood that the amount of styrene-butadiene rubber can also be 65 parts, 70 parts, 75 parts and any value within the range thereof; the amount of silane coupling agent can be 2 parts, 4 parts, 6 parts, 8 parts and any value within the range thereof; the amount of white carbon black can be 80 parts, 85 parts, 90 parts, 95 parts and any value within the range thereof; the amount of modified resin containing mercapto group can be 15 parts, 20 parts, 25 parts, 30 parts, 35 parts and any value within the range thereof; the amount of natural rubber 25-35 parts can also be 25 parts, 30 parts, 35 parts and any value within the range thereof; the amount of zinc oxide 3-4 parts can also be 15 parts, 20 parts, 25 parts, 30 parts, 35 parts and any value within the range thereof; It can be 3.5 parts and any value within the range thereof; 2-3 parts of stearic acid can also be 2.5 parts and any value within the range thereof; 3-5 parts of carbon black can also be 3.5 parts, 4 parts, 4.5 parts and any value within the range thereof; 1-4 parts of antioxidant can also be 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts and any value within the range thereof; 1-2.5 parts of protective wax can also be 1.5 parts, 2 parts and any value within the range thereof; 10-20 parts of softener can also be 12 parts, 14 parts, 16 parts, 18 parts and any value within the range thereof; 2-4 parts of crosslinking agent can also be 2.5 parts, 3 parts, 3.5 parts and any value within the range thereof; 2-6 parts of accelerator can also be 3 parts, 4 parts, 5 parts and any value within the range thereof.

[0024] In a preferred embodiment, the silane coupling agent is one of KH580, Si69, and Si75. This embodiment specifically limits the type of silane coupling agent. It is understood that the silane coupling agent can also be other substances reasonably selected by those skilled in the art in combination with common knowledge in the art.

[0025] In a preferred embodiment, the antioxidant is a combination of RD and 4020; this embodiment specifically limits the type of antioxidant. It is understandable that the antioxidant can also be other substances reasonably selected by those skilled in the art in the art in combination with common knowledge in the art.

[0026] In a preferred embodiment, the softener is one of heavy cycloparaffin oil and environmentally friendly aromatic oil; this embodiment specifically limits the type of softener. It is understandable that the softener can also be other substances reasonably selected by those skilled in the art in the art in combination with common knowledge in the art.

[0027] In a preferred embodiment, the cross-linking agent is sulfur; In a preferred embodiment, the accelerator is a combination of CZ and DPG; this embodiment specifically limits the type of accelerator, and it is understandable that the accelerator may also be other substances reasonably selected by those skilled in the art in combination with common knowledge in the art.

[0028] In a preferred embodiment, the modifier is 4-methoxythiophenol. The thiol (-SH) group in the 4-methoxythiophenol molecule is highly reactive and can chemically react with a variety of functional groups. The methoxy group on the benzene ring is an electron-donating group that increases the electron density of the benzene ring, further enhancing the activity of the thiol group. This enhances the chemical reactivity between the modifier and the modified substance, thereby improving modification efficiency.

[0029] In a preferred embodiment, the method for preparing the modified resin comprises the following steps: First stage reaction: Dissolve resin B completely in an organic solvent, add a photoinitiator and a modifier, and react under ultraviolet light at room temperature for 4 hours; then add a phosphine ligand and continue the reaction for 2 hours; Preparation of auxiliary agent: Add the thiol deprotection auxiliary agent to anhydrous tetrahydrofuran solution, perform three evacuation operations, and react at room temperature until the solution changes from colorless to black; Second stage reaction: The intermediate product obtained in the first stage reaction step is dissolved in an organic solvent, added to the solution obtained in the auxiliary agent preparation step, and reacted at room temperature under nitrogen protection for 12 hours; Third-stage reaction: The intermediate product obtained in the second-stage reaction step is dissolved in an organic solvent, added to the solution obtained in the auxiliary agent preparation step, and reacted at room temperature under nitrogen protection for 12 hours; Product separation: The intermediate product obtained in the three reaction steps was quenched with hydrochloric acid and reprecipitated with methanol to obtain a modified resin.

[0030] The B resin and the modifier 4-methoxybenzenethiol undergo olefin click chemistry to generate a B resin-4-methoxyphenyl sulfide derivative, and the B resin-4-methoxyphenyl sulfide derivative reacts with a thiol deprotection auxiliary agent to generate a thiol-functionalized B resin.

[0031] Phosphine ligands regulate the active sites and pathways of the reaction, effectively enhancing the primary reaction and making it the dominant direction of the reaction. Phosphine ligands, by occupying steric hindrance or electron cloud density, inhibit active intermediates that may trigger side reactions, blocking the progression of side reactions and significantly reducing the amount of byproducts produced.

[0032] To ensure the thoroughness of the reaction and ensure that all initially introduced methoxyphenyl sulfide protecting groups are fully converted to sulfhydryl groups, the reaction procedure must be repeated. This process begins with a deprotection reaction to remove the methoxyphenyl sulfide protecting groups, followed by a mixing reaction under a reducing environment to promote the conversion to sulfhydryl groups. Repeating this reaction multiple times effectively increases the conversion rate and ensures adequate reaction conditions, thereby achieving maximum conversion.

[0033] After the three-stage reaction is completed, the reaction is quenched with hydrochloric acid, and the modified resin is obtained by reprecipitation with methanol. Specifically, the mixture after hydrochloric acid quenching is slowly added to methanol. Due to the low solubility of the modified resin in methanol, it gradually precipitates as solid particles, thus effectively separating the modified resin from other components and obtaining the desired modified resin product.

[0034] In a preferred embodiment, resin B is one of C5 petroleum resin, C9 petroleum resin, DCPD resin, and terpene resin. This embodiment specifically limits the type of resin B. It is understood that resin B may also be other substances reasonably selected by those skilled in the art based on common knowledge in the art.

[0035] In a preferred embodiment, the organic solvent is at least two of tetrahydrofuran, 1,2-dichloroethane, dichloromethane, and acetonitrile, one of which is tetrahydrofuran. This embodiment specifically limits the type of organic solvent. It is understood that the organic solvent may also be other substances reasonably selected by those skilled in the art in combination with common knowledge in the art.

[0036] In a preferred embodiment, the phosphine ligand is one of triphenylphosphine, tri-o-tolylphosphine, and tricyclohexylphosphine. This embodiment specifically limits the type of phosphine ligand. It is understood that the phosphine ligand may also be other substances reasonably selected by those skilled in the art in combination with common knowledge in the art.

[0037] In a preferred embodiment, the thiol deprotection aid is a lithium naphthalene composition or a lithium anthracene composition. This embodiment specifically limits the type of thiol deprotection aid. It is understood that the thiol deprotection aid can also be other substances reasonably selected in the art by those skilled in the art in combination with common knowledge in the art.

[0038] In a preferred embodiment, the tire tread rubber composition is prepared by the following method: One-stage mixing: natural rubber, styrene-butadiene rubber, zinc oxide, stearic acid, white carbon black, carbon black, silane coupling agent, modified resin, antioxidant, protective wax, and softener are mixed in an internal mixer. After mixing evenly, the rubber is discharged to obtain a masterbatch. The rotor speed of the internal mixer is 45-60 rpm, and the upper bolt pressure is 60 N / cm 2, the cooling water temperature of the internal mixer is 40-50℃, and the binder removal temperature is 140-155℃.

[0039] Second stage mixing: the masterbatch, crosslinking agent and accelerator are mixed in an internal mixer, mixed evenly and then discharged to obtain the final rubber; the rotor speed of the internal mixer is 45-60rpm, and the upper bolt pressure is 60N / cm 2 , the cooling water temperature of the internal mixer is 40-45℃, and the debinding temperature is 95-110℃.

[0040] Vulcanization: The final rubber is vulcanized to obtain the rubber compound.

[0041] Another aspect of the present invention provides a tire prepared from any one of the tire tread rubber compositions described above, wherein the tire has high wet skid resistance and low rolling resistance.

[0042] In order to more clearly and in detail introduce the tire tread rubber composition, its preparation method and the resulting tire provided by the embodiments of the present invention, they will be described below in conjunction with specific examples.

[0043] Example 1 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: The composition includes 30 parts natural rubber, 70 parts styrene-butadiene rubber (SBR), 80 parts 1165MP white carbon black, 8 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 10 parts modified resin. The SBR contains 21% styrene and 68% vinyl (in the butadiene structure). The modified resin is obtained by modifying DCPD resin. The photoinitiator used in the preparation is α-hydroxyisobutyrophenone, the organic solvents are tetrahydrofuran and 1,2-dichloroethane, the modifier is 4-methoxythiophenol, the phosphine ligand is triphenylphosphine, and the thiol deprotection aid is a lithium naphthalene combination.

[0044] The production method of the modified resin containing mercapto group is as follows: First stage reaction: Dissolve DCPD resin completely in an organic solvent, add α-hydroxyisobutyrophenone and 4-methoxythiophenol, and react under ultraviolet light at room temperature for 4 hours; then add triphenylphosphine and continue the reaction for 2 hours; Preparation of auxiliary agent: Add the lithium naphthalene composition, a thiol deprotection auxiliary agent, to anhydrous tetrahydrofuran solution, perform three evacuation operations, and react at room temperature until the solution changes from colorless to black; Second stage reaction: The intermediate product obtained in the first stage reaction step is dissolved in an organic solvent, added to the solution obtained in the auxiliary agent preparation step, and reacted at room temperature under nitrogen protection for 12 hours; Third-stage reaction: The intermediate product obtained in the second-stage reaction step is dissolved in an organic solvent, added to the solution obtained in the auxiliary agent preparation step, and reacted at room temperature under nitrogen protection for 12 hours; Product separation: The intermediate product obtained in the three reaction steps was quenched with hydrochloric acid and reprecipitated with methanol to obtain a modified resin.

[0045] The tire tread rubber composition is prepared as follows: First stage mixing: natural rubber, styrene-butadiene rubber, zinc oxide, stearic acid, white carbon black, carbon black, silane coupling agent, modified resin, antioxidant, bimodal microcrystalline wax, and heavy naphthenic oil are mixed in an internal mixer to obtain a masterbatch. The rotor speed of the internal mixer is 50 rpm, and the upper bolt pressure is 60 N / cm 2 , the cooling water temperature of the internal mixer is 50℃, and the discharge temperature is 145℃.

[0046] Second stage mixing: Mix the masterbatch, crosslinking agent and accelerator in an internal mixer to obtain the final rubber. The rotor speed of the internal mixer is 50 rpm and the upper bolt pressure is 60 N / cm 2 , the cooling water temperature of the internal mixer is 40℃, and the binder removal temperature is 100℃.

[0047] The final rubber is vulcanized to obtain a rubber compound.

[0048] Example 2 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: The composition includes 35 parts natural rubber, 65 parts styrene-butadiene rubber, 80 parts 1165MP white carbon black, 8 parts KH580 silane coupling agent, 3 parts N234 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 10 parts environmentally friendly aromatic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 2 parts accelerator D, and 15 parts modified resin. The styrene content in the styrene-butadiene rubber is 21% by weight, and the vinyl content (in the butadiene structure) is 68%. The modified resin is obtained by modifying DCPD resin. The photoinitiator used in the preparation process is α-hydroxyalkyl phenone, the organic solvents are tetrahydrofuran and dichloromethane, the modifier is 4-methoxythiophenol, the phosphine ligand is tri-o-tolylphosphine, and the thiol deprotection aid is a lithium naphthalene combination.

[0049] The production method of the modified resin containing mercapto group is as follows: First stage reaction: DCPD resin is completely dissolved in tetrahydrofuran and dichloromethane organic solvents, α-hydroxyalkyl phenone and 4-methoxythiophenol are added, and the mixture is reacted under ultraviolet light at room temperature for 4 hours; tri-o-tolylphosphine is then added and the reaction is continued for 2 hours; Preparation of auxiliary agent: Add the lithium naphthalene composition, a thiol deprotection auxiliary agent, to anhydrous tetrahydrofuran solution, perform three evacuation operations, and react at room temperature until the solution changes from colorless to black; Second stage reaction: The intermediate product obtained in the first stage reaction step is dissolved in an organic solvent, added to the solution obtained in the auxiliary agent preparation step, and reacted at room temperature under nitrogen protection for 12 hours; Third-stage reaction: The intermediate product obtained in the second-stage reaction step is dissolved in an organic solvent, added to the solution obtained in the auxiliary agent preparation step, and reacted at room temperature under nitrogen protection for 12 hours; Product separation: The intermediate product obtained in the three reaction steps was quenched with hydrochloric acid and reprecipitated with methanol to obtain a modified resin.

[0050] The tire tread rubber composition is prepared as follows: First stage mixing: natural rubber, styrene-butadiene rubber, zinc oxide, stearic acid, white carbon black, carbon black, silane coupling agent, modified resin, antioxidant, bimodal microcrystalline wax, and heavy naphthenic oil are mixed in an internal mixer to obtain a masterbatch. The rotor speed of the internal mixer is 60 rpm, and the upper bolt pressure is 60 N / cm 2 , the cooling water temperature of the internal mixer is 45℃, and the binder removal temperature is 150℃.

[0051] Second stage mixing: Mix the masterbatch, crosslinking agent and accelerator in an internal mixer to obtain the final rubber. The rotor speed of the internal mixer is 60 rpm and the upper bolt pressure is 60 N / cm 2 , the cooling water temperature of the internal mixer is 45℃, and the discharge temperature is 110℃.

[0052] Vulcanization: The final rubber is vulcanized to obtain the rubber compound.

[0053] Example 3 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: The composition includes 25 parts natural rubber, 75 parts styrene-butadiene rubber (SBR), 80 parts 1165MP white carbon black, 8 parts Si75 silane coupling agent, 3 parts N234 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 20 parts environmentally friendly aromatic oil, 3 parts zinc oxide, 2 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part DPG accelerator, and 10 parts modified resin. The SBR contains 21% styrene and 68% vinyl (in the butadiene structure). The modified resin is obtained by modifying DCPD resin. The photoinitiator used in the preparation is α-aminoalkylphenone, the organic solvents are tetrahydrofuran and acetonitrile, the modifier is 4-methoxythiophenol, the phosphine ligand is tricyclohexylphosphine, and the thiol deprotection aid is a lithium anthracene combination.

[0054] The production method of the modified resin containing mercapto group is as follows: First stage reaction: DCPD resin is completely dissolved in tetrahydrofuran and acetonitrile organic solvents, α-hydroxyalkyl phenone and 4-methoxythiophenol are added, and the mixture is reacted under ultraviolet light at room temperature for 4 hours; tricyclohexylphosphine is then added and the reaction is continued for 2 hours; Preparation of auxiliary agents: Add the lithium anthracene composition, a thiol deprotection auxiliary agent, to an anhydrous tetrahydrofuran solution, perform three evacuation operations, and react at room temperature until the solution changes from colorless to black; Second stage reaction: The intermediate product obtained in the first stage reaction step is dissolved in an organic solvent, added to the solution obtained in the auxiliary agent preparation step, and reacted at room temperature under nitrogen protection for 12 hours; Third-stage reaction: The intermediate product obtained in the second-stage reaction step is dissolved in an organic solvent, added to the solution obtained in the auxiliary agent preparation step, and reacted at room temperature under nitrogen protection for 12 hours; Product separation: The intermediate product obtained in the three reaction steps was quenched with hydrochloric acid and reprecipitated with methanol to obtain a modified resin.

[0055] The tire tread rubber composition is prepared as follows: First stage mixing: natural rubber, styrene-butadiene rubber, zinc oxide, stearic acid, white carbon black, carbon black, silane coupling agent, modified resin, antioxidant, bimodal microcrystalline wax, and heavy naphthenic oil are mixed in an internal mixer to obtain a masterbatch. The rotor speed of the internal mixer is 45 rpm, and the upper bolt pressure is 60 N / cm 2 , the cooling water temperature of the internal mixer is 40℃, and the discharge temperature is 140℃.

[0056] Second stage mixing: Mix the masterbatch, crosslinking agent and accelerator in an internal mixer to obtain the final rubber. The rotor speed of the internal mixer is 45 rpm and the upper bolt pressure is 60 N / cm 2 , the cooling water temperature of the internal mixer is 43℃, and the discharge temperature is 95℃.

[0057] Vulcanization: The final rubber is vulcanized to obtain the rubber compound.

[0058] Example 4 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: The composition includes 30 parts natural rubber, 70 parts styrene-butadiene rubber (SBR), 80 parts 1165MP white carbon black, 8 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 10 parts modified resin. The SBR contains 15% styrene and 30% vinyl (in the butadiene structure). The modified resin is obtained by modifying DCPD resin. The photoinitiator used in the preparation is α-hydroxyisobutyrophenone, the organic solvents are tetrahydrofuran and 1,2-dichloroethane, the modifier is 4-methoxythiophenol, the phosphine ligand is triphenylphosphine, and the thiol deprotection aid is a lithium naphthalene combination.

[0059] The preparation method is the same as that in Example 1.

[0060] Example 5 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: The composition includes 30 parts natural rubber, 70 parts styrene-butadiene rubber (SBR), 80 parts 1165MP white carbon black, 8 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 10 parts modified resin. The SBR contains 41% styrene and 34% vinyl (in the butadiene structure). The modified resin is obtained by modifying DCPD resin. The photoinitiator used in the preparation is α-hydroxyisobutyrophenone, the organic solvents are tetrahydrofuran and 1,2-dichloroethane, the modifier is 4-methoxythiophenol, the phosphine ligand is triphenylphosphine, and the thiol deprotection aid is a lithium naphthalene combination.

[0061] The preparation method is the same as that in Example 1.

[0062] Example 6 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: The composition includes 30 parts natural rubber, 70 parts styrene-butadiene rubber (SBR), 80 parts 1165MP white carbon black, 6 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 20 parts modified resin. The SBR contains 21% styrene and 68% vinyl (in the butadiene structure). The modified resin is obtained by modifying DCPD resin. The photoinitiator used in the preparation is α-hydroxyisobutyrophenone, the organic solvents are tetrahydrofuran and 1,2-dichloroethane, the modifier is 4-methoxythiophenol, the phosphine ligand is triphenylphosphine, and the thiol deprotection aid is a lithium naphthalene combination.

[0063] The preparation method is the same as that in Example 1.

[0064] Example 7 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: The composition includes 30 parts natural rubber, 70 parts styrene-butadiene rubber (SBR), 80 parts 1165MP white carbon black, 4 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 30 parts modified resin. The SBR contains 21% styrene and 68% vinyl (in the butadiene structure). The modified resin is obtained by modifying DCPD resin. The photoinitiator used in the preparation is α-hydroxyisobutyrophenone, the organic solvents are tetrahydrofuran and 1,2-dichloroethane, the modifier is 4-methoxythiophenol, the phosphine ligand is triphenylphosphine, and the thiol deprotection aid is a lithium naphthalene combination.

[0065] The preparation method is the same as that in Example 1.

[0066] Example 8 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: The composition includes 30 parts natural rubber, 70 parts styrene-butadiene rubber (SBR), 80 parts 1165MP white carbon black, 8 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 10 parts modified resin. The SBR contains 21% styrene and 68% vinyl (in the butadiene structure). The modified resin is derived from C5 petroleum resin. The photoinitiator used in the preparation is α-hydroxyisobutyrophenone, the organic solvents are tetrahydrofuran and 1,2-dichloroethane, the modifier is 4-methoxythiophenol, the phosphine ligand is triphenylphosphine, and the thiol deprotection aid is a lithium naphthalene combination.

[0067] The preparation method is the same as that in Example 1.

[0068] Example 9 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: The composition includes 30 parts natural rubber, 70 parts styrene-butadiene rubber, 80 parts 1165MP white carbon black, 8 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 10 parts modified resin. The styrene content in the styrene-butadiene rubber is 21% by weight, and the vinyl content (in the butadiene structure) is 68%. The modified resin is obtained by modifying C9 petroleum resin. The photoinitiator used in the preparation process is α-hydroxyisobutyrophenone, the organic solvents are tetrahydrofuran and 1,2-dichloroethane, the modifier is 4-methoxythiophenol, the phosphine ligand is triphenylphosphine, and the thiol deprotection aid is a lithium naphthalene combination.

[0069] The preparation method is the same as that in Example 1.

[0070] Example 10 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: The composition includes 30 parts natural rubber, 70 parts styrene-butadiene rubber, 80 parts 1165MP white carbon black, 8 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 10 parts modified resin. The styrene-butadiene rubber contains 21% styrene and 68% vinyl (in the butadiene structure). The modified resin is obtained by modifying a terpene resin. The photoinitiator used in the preparation process is α-hydroxyisobutyrophenone, the organic solvents are tetrahydrofuran and 1,2-dichloroethane, the modifier is 4-methoxythiophenol, the phosphine ligand is triphenylphosphine, and the thiol deprotection aid is a lithium naphthalene combination.

[0071] The preparation method is the same as that in Example 1.

[0072] Comparative Example 1 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: 30 parts natural rubber, 70 parts styrene-butadiene rubber, 80 parts 1165MP white carbon black, 8 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 10 parts DCPD resin. The styrene content of the styrene-butadiene rubber is 21% by weight, and the vinyl content (in the butadiene structure) is 68%.

[0073] The tire tread rubber composition is prepared as follows: First stage mixing: natural rubber, styrene-butadiene rubber, zinc oxide, stearic acid, white carbon black, carbon black, silane coupling agent, DCPD resin, antioxidant, bimodal microcrystalline wax, and heavy naphthenic oil are mixed in an internal mixer to obtain a masterbatch. The rotor speed of the internal mixer is 50 rpm, and the upper bolt pressure is 60 N / cm 2 , the cooling water temperature of the internal mixer is 50℃, and the discharge temperature is 145℃.

[0074] Second stage mixing: Mix the masterbatch, crosslinking agent and accelerator in an internal mixer to obtain the final rubber. The rotor speed of the internal mixer is 50 rpm and the upper bolt pressure is 60 N / cm 2 , the cooling water temperature of the internal mixer is 40℃, and the binder removal temperature is 100℃.

[0075] The final rubber is vulcanized to obtain a rubber compound.

[0076] Comparative Example 2 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: 30 parts natural rubber, 70 parts styrene-butadiene rubber, 80 parts 1165MP white carbon black, 8 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 10 parts DCPD resin. The styrene content of the styrene-butadiene rubber is 15wt%, and the vinyl content (in the butadiene structure) is 30%.

[0077] The preparation method is the same as that of Comparative Example 1.

[0078] Comparative Example 3 This embodiment provides a tire tread rubber composition and a preparation method thereof, as follows: The tire tread rubber composition formulation, calculated by weight, comprises: 30 parts natural rubber, 70 parts styrene-butadiene rubber, 80 parts 1165MP white carbon black, 8 parts Si69 silane coupling agent, 3 parts N375 carbon black, 2.5 parts 4020 antioxidant, 1.5 parts RD antioxidant, 1.5 parts bimodal microcrystalline wax, 17.5 parts heavy naphthenic oil, 3 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts sulfur, 2.2 parts CZ accelerator, 1 part D accelerator, and 10 parts DCPD resin. The styrene content of the styrene-butadiene rubber is 41% by weight, and the vinyl content (in the butadiene structure) is 34%.

[0079] The preparation method is the same as that of Comparative Example 1.

[0080] Performance Testing The performance tests were conducted on the rubber materials prepared in Examples 1-10 and Comparative Examples 1-3. The specific test methods and test results are as follows: (1) Rubber material testing method: The Shore A hardness test is carried out in accordance with GB / T531.1-2008. The tensile strength, 100% modulus, 300% modulus, and elongation at break are tested in accordance with GB / T528-2009. The tear strength test is carried out in accordance with GB / T529-2008. The rebound resilience test is carried out in accordance with GB / T1681-2009. Tg, 0°C tanδ, and 70°C tanδ are obtained by dynamic mechanical thermal analysis (DMTA) in accordance with GB / T9870.1-2006. The DIN abrasion test is carried out in accordance with GB / T9867-2008.

[0081] (2) Rubber test results are shown in Table 1 Table 1 Performance test results of the rubber materials prepared in Examples 1-10 and Comparative Examples 1-3

[0082] The results show that compared to Comparative Example 1, the tire tread rubber composition prepared in Example 1, using a modified resin containing a mercapto group, exhibits significantly better performance than the tire tread rubber composition prepared using a conventional anti-skid resin (i.e., Comparative Example 1), effectively improving anti-skid performance and reducing rolling resistance. The tire tread rubber composition prepared in Example 1 exhibits comparable 100% modulus, 300% modulus, tensile strength, and resilience, while exhibiting improved DIN abrasion resistance, significantly enhanced anti-skid performance (tan δ at 0°C), and significantly reduced rolling resistance (tan δ at 70°C). This is due to the mercapto group-containing modified resin dispersing the silanized silica, thereby improving dispersibility and enhancing interfacial interactions, inhibiting the aggregation of silica particles, improving filler dispersion, and enhancing overall rubber performance. Furthermore, the modified resin effectively increases the rubber's tan δ value at 0°C, enhancing its anti-skid performance, while reducing its tan δ value at 70°C and improving rolling resistance.

[0083] Examples 2-3 adjust the raw rubber ratio and the amounts of heavy naphthenic oil and resin to achieve similar glass transition temperatures (Tg) of the rubber compositions. The results show that Example 2 improves both wet slip and rolling resistance over Comparative Example 1 by changing the formulation, reducing the amounts of styrene-butadiene rubber and heavy naphthenic oil, and increasing the amount of modified resin. Example 3 also improves both wet slip and rolling resistance over Comparative Example 1 by increasing the amounts of styrene-butadiene rubber and heavy naphthenic oil and reducing the amount of modified resin. This demonstrates that by adjusting the formulation, when the glass transition temperatures (Tg) of the rubber compositions are similar, both can achieve results exceeding those of Comparative Example 1.

[0084] The test results of Examples 4-5 and Comparative Examples 2-3 show that the effect of the modified resin is not as significant when selecting styrene-butadiene rubber with a styrene content below 15wt% (or above 35wt%) or a vinyl content (in the butadiene structure) below 30wt%. The modified resin itself has a large steric hindrance. If the styrene content is above 35wt%, the modified resin has difficulty inserting into the polymer reaction, resulting in poor modification effect. If the styrene content is below 15%, the polymer glass transition temperature (Tg) is low. In a flexible matrix, although the resin can locally improve friction, the mobility of the matrix chain segments remains high, making the resin's improvement in overall dynamic mechanical properties less significant than in a high-Tg matrix. The low hysteresis characteristics of the matrix weaken the hysteresis effect of the resin, and the styrene content affects the compatibility of the modified resin in the rubber matrix, thus affecting its effectiveness.

[0085] In Examples 6-7, modified resin was used in place of the silane coupling agent. The hardness of the rubber compound decreased slightly. As the amount of modified resin increased, the hardness gradually decreased, while the 300% modulus and tear strength gradually increased. The glass transition temperature (Tg) of the rubber compound increased with the increase in modified resin dosage. The wet skid resistance (tanδ at 0°C) improved significantly with increasing the amount of modified resin. Correspondingly, the rolling resistance (tanδ at 70°C) of the rubber compound increased slightly.

[0086] Increasing the glass transition temperature (Tg) improves the rubber's wet-slip resistance and slightly increases rolling resistance. This is due to the mutual constraints between the amount of modified resin used and the modifying groups. Traditional silane coupling agents can form a siloxane interfacial layer on the silica surface, thereby improving the interaction between the filler and the polymer. The thiol groups in the modified resin can interact with the hydroxyl groups on the silica surface, thereby coating the silica surface. The modified resin on the coated filler particles creates a large steric effect, effectively preventing filler reaggregation and further weakening the filler network. Furthermore, the thiol groups in the modified resin can react with the rubber matrix, similar to the effect of a silane coupling agent, thereby enhancing the interaction between the filler and the polymer.

[0087] Furthermore, the modified resin molecular chains themselves are highly compatible with the rubber matrix, making the filler particles formed after coating more easily dispersed. This reduces the Payne effect of the filler-dispersed rubber compound, thereby reducing the compound's hysteresis loss. Therefore, while increasing the resin dosage may introduce some hysteresis, this hysteresis is attenuated. The reduced hysteresis after modification and the increased hysteresis caused by increasing the amount of modified resin complement each other, ultimately minimizing the increase in hysteresis caused by the modified resin.

[0088] Examples 1 and 8-10 demonstrate that modified resins derived from DCPD resin, C5 petroleum resin, C9 petroleum resin, and terpene resin significantly impact the properties of the rubber compound. However, due to the varying chemical microstructures of the modified resins, the effects on the rubber compound vary. Among the four modified resins, the terpene resin exhibits the most significant improvement in wet skid resistance (tanδ at 0°C) and also increases rolling resistance (tanδ at 70°C). The wear properties of the rubber compounds using all four modified resins are enhanced.

Claims

1. A tire tread rubber composition, characterized in that: The invention comprises styrene-butadiene rubber and a modified resin, wherein the modified resin is a mercapto-containing modified resin, which is obtained by reacting a B resin with a mercapto-containing modifier to undergo a click reaction, and then reacting with a mercapto deprotection auxiliary agent to modify the resin.

2. The tire tread rubber composition according to claim 1, wherein The styrene content of the styrene-butadiene rubber is 15%-35%, and the vinyl content is not less than 30%.

3. The tire tread rubber composition according to claim 1, wherein Calculated by weight, it includes 65-75 parts of styrene-butadiene rubber, 10-40 parts of modified resin, 75-100 parts of white carbon black, 0-10 parts of silane coupling agent, 25-35 parts of natural rubber, 3-4 parts of zinc oxide, 2-3 parts of stearic acid, 3-5 parts of carbon black, 1-4 parts of antioxidant, 1-2.5 parts of protective wax, 10-20 parts of softener, 2-4 parts of cross-linking agent, and 2-6 parts of accelerator.

4. The tire tread rubber composition according to claim 3, characterized in that The silane coupling agent is one of KH580, Si69 and Si75.

5. The tire tread rubber composition according to claim 1, wherein The thiol-containing modifier is 4-methoxythiophenol.

6. The tire tread rubber composition according to claim 5, characterized in that The preparation method of the modified resin comprises the following steps: First stage reaction: Dissolve resin B completely in an organic solvent, add a photoinitiator and a modifier, and react at room temperature under ultraviolet light. After the reaction is completed, add a phosphine ligand to continue the reaction; Preparation of auxiliary agent: Add thiol deprotection auxiliary agent to anhydrous tetrahydrofuran solution and react until the solution changes from colorless to black; Second stage reaction: the intermediate product obtained in the first stage reaction step is dissolved in an organic solvent and added to the solution obtained in the auxiliary agent preparation step for reaction; Third-stage reaction: dissolving the intermediate product obtained in the second-stage reaction step in an organic solvent and adding the solution obtained in the auxiliary agent preparation step to react; Product separation: The intermediate product obtained in the three reaction steps was quenched with hydrochloric acid and reprecipitated with methanol to obtain a modified resin.

7. The tire tread rubber composition according to claim 1, wherein The B resin is one of C5 petroleum resin, C9 petroleum resin, DCPD resin and terpene resin.

8. The tire tread rubber composition according to claim 6, wherein The photoinitiator is one of α-hydroxyisobutyrophenone, α-hydroxyalkylphenone and α-aminoalkylphenone; The organic solvent is at least two of tetrahydrofuran, 1,2-dichloroethane, dichloromethane, and acetonitrile, one of which is tetrahydrofuran; The phosphine ligand is one of triphenylphosphine, tri-o-tolylphosphine, and tricyclohexylphosphine; The thiol deprotection auxiliary agent is a lithium naphthalene composition or a lithium anthracene composition.

9. A method for preparing a tread rubber composition according to any one of claims 1 to 8, characterized in that: The following steps are involved: One-stage mixing: natural rubber, styrene-butadiene rubber, zinc oxide, stearic acid, white carbon black, carbon black, silane coupling agent, modified resin, antioxidant, protective wax, and softener are mixed in an internal mixer, and the mixture is discharged after uniform mixing to obtain a masterbatch; Second stage mixing: the masterbatch, crosslinking agent and accelerator are mixed in an internal mixer, mixed evenly and then discharged to obtain the final rubber; Vulcanization: The final rubber is vulcanized to obtain the rubber compound.

10. A tire, characterized in that The tire is prepared from the tire tread rubber composition according to any one of claims 1 to 8.

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