Composition for forming vulcanized rubber, vulcanized rubber as well as preparation method and application of vulcanized rubber

Abstract

The invention provides a composition for forming vulcanized rubber, the vulcanized rubber as well as a preparation method and application of the vulcanized rubber. The composition for forming vulcanized rubber comprises the following components in parts by weight: 100 parts of matrix rubber, 50-70 parts of filler, 1-3 parts of bonding resin, 2.7-7.5 parts of a bonding agent, 1.5-5 parts of an anti-aging agent, 5-13 parts of zinc oxide and 2.5-10 parts of a vulcanizing agent, wherein the matrix rubber comprises natural rubber and epichlorohydrin rubber; the vulcanizing agent comprises ethylene thiourea. Through the synergistic effect of the epichlorohydrin rubber, the ethylene thiourea and the zinc oxide, the modulus and the aging resistance of the prepared vulcanized rubber can be remarkably improved, the bonding strength of the rubber and a tire carcass steel wire is enhanced, and the high bonding strength can be maintained even under the harsh thermo-oxidative aging and damp-heat aging conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tire production, in particular to a composition for forming vulcanized rubber, vulcanized rubber and a preparation method and application thereof. BACKGROUND

[0002] The adhesion performance of the tire carcass is a key performance indicator in tire manufacturing, which directly affects the safety and service life of the tire. The tire bears complex stress during driving, including bending, stretching, compression, shearing, centrifugal force, etc., and good adhesion performance of the tire carcass is the premise of resisting the peeling of the steel wire and rubber in the tire carcass. During rolling, the tire carcass part is prone to fatigue failure due to continuous bending deformation, and micro-cracks are generated at the adhesion interface. Good adhesion performance of the tire carcass can effectively delay the initiation and expansion of micro-cracks at the interface, significantly improve the flex fatigue resistance of the tire, and prolong its service life. When the adhesion performance is poor, the micro-gap or delamination area formed by poor adhesion will become a channel for water and oxygen to penetrate, thereby accelerating the corrosion of the steel wire skeleton material and the aging degradation of the rubber, causing the adhesion strength between the steel wire and the rubber in the tire carcass to further decrease, forming a vicious cycle, and eventually leading to rapid degradation of the tire performance and tire damage failure.

[0003] During the use of the tire, the internal inflation pressure of the tire is large, and the high-pressure environment makes the oxygen and water in the gas inside the tire more easily penetrate the air barrier layer and penetrate into the tire carcass, thereby causing the adhesion performance of the tire carcass to decrease. In addition, under the conditions of long-time high-speed driving or overloading driving, the internal heat of the tire is extremely high, but due to the poor thermal conductivity of the rubber, the heat inside the tire is difficult to dissipate in time, causing the temperature of the tire carcass part to be extremely high, further aggravating the thermal aging of the tire carcass, and thus causing the adhesion performance of the tire carcass to decrease.

[0004] At present, the industry generally adopts the introduction of resorcinol white system (including resorcinol, formaldehyde resin and white carbon black), cobalt salt system and resin tackifier to enhance the adhesion strength between the steel wire and the rubber of the tire. By adjusting the appropriate mixing ratio, it can indeed provide good initial adhesion performance, but when the tire is required to be refurbished several times, the adhesion strength of such tire will decrease significantly after the processes of thermal and oxidative aging and hygrothermal aging, and it is difficult to meet the performance requirements for re-refurbishment.

[0005] Therefore, it is of great significance to research and develop a composition for forming vulcanized rubber with high modulus and good aging resistance, vulcanized rubber and a preparation method thereof to improve the adhesion strength between the steel wire and the rubber of the tire. SUMMARY

[0006] The main objective of this invention is to provide a composition for forming a vulcanizate, the vulcanizate, a method for preparing the vulcanizate, and its application, in order to solve the problem of low bonding strength between tire carcass steel wires and rubber caused by low tire carcass rubber modulus and poor aging resistance in the prior art.

[0007] To achieve the above objectives, the present invention provides a composition for forming a vulcanizate, comprising, by weight: 100 parts of a base rubber, 50-70 parts of filler, 1-3 parts of adhesive resin, 2.7-7.5 parts of binder, 1.5-5 parts of antioxidant, 5-13 parts of zinc oxide, and 2.5-10 parts of vulcanizing agent; wherein the base rubber includes natural rubber and chloroprene rubber; and the vulcanizing agent includes ethylene thiourea.

[0008] Further, by weight, the composition used to form the vulcanizate includes: 100 parts of base rubber, 55 to 70 parts of filler, 1 to 2.5 parts of adhesive resin, 2.7 to 6.5 parts of adhesive, 0.2 to 1.5 parts of cobalt decanoate, 1.8 to 5 parts of antioxidant, 7 to 11 parts of zinc oxide and 5 to 9 parts of vulcanizing agent.

[0009] Further, in the base rubber, the weight ratio of natural rubber to chlorohydrin rubber is (60-100):(5-20), preferably (65-100):(8-17); preferably, the base rubber comprises 80-95 wt% natural rubber, with the balance being chlorohydrin rubber.

[0010] Furthermore, the weight-average molecular weight of natural rubber is 400,000 to 650,000.

[0011] Further, the weight-average molecular weight of the chlorohydrin rubber is 800,000 to 1,700,000; preferably, the chlorine content in the chlorohydrin rubber is 25 to 35 wt% by weight; preferably, the chlorohydrin rubber is selected from homopolymer chlorohydrin rubber and / or copolymer chlorohydrin rubber; preferably, the polymeric monomer of the homopolymer chlorohydrin rubber is epichlorohydrin; preferably, the copolymer chlorohydrin rubber is a copolymer of epichlorohydrin, ethylene oxide, and / or propyl glycidyl ether.

[0012] Further, the vulcanizing agent includes ethylene thiourea and sulfur; preferably, by weight, the vulcanizing agent includes 0.5 to 4 parts of ethylene thiourea and 2 to 6 parts of sulfur; more preferably, it is 2 to 3 parts of ethylene thiourea and 3 to 6 parts of sulfur.

[0013] Furthermore, the specific surface area of ​​the packing is 70–220 m². 2 / g, with an average particle size of 10-30nm; preferably, the filler is selected from carbon black and / or silica.

[0014] Furthermore, the adhesive resin is resorcinol-formaldehyde resin.

[0015] Further, the adhesive includes cobalt decanoate and adhesive RA-65; preferably, the adhesive includes 0.2 to 1.5 parts by weight of cobalt decanoate and 2.5 to 6 parts by weight of adhesive RA-65.

[0016] Further, the antioxidant is selected from antioxidant RD and / or antioxidant 4020; preferably, the antioxidant is a mixture of antioxidant RD and antioxidant 4020; preferably, the antioxidant includes 0.5 to 2 parts by weight of antioxidant RD and 1 to 3 parts by weight of antioxidant 4020.

[0017] Furthermore, the composition for forming the vulcanizate also includes a vulcanization accelerator; preferably, the composition for forming the vulcanizate further includes 0.8 to 2.8 parts by weight of a vulcanization accelerator, more preferably 0.8 to 2.5 parts by weight; preferably, the vulcanization accelerator is N,N-dicyclohexyl-2-benzothiazole sulfenamide.

[0018] To achieve the above objectives, another aspect of the present invention provides a vulcanizate obtained by mixing and vulcanizing the composition for forming vulcanizates provided by the present invention.

[0019] Another aspect of the present invention provides a method for preparing the above-mentioned vulcanizate provided by the present invention, the method comprising: step S1, performing a first mixing of a base rubber, filler, adhesive resin and a portion of the adhesive to obtain a first masterbatch; wherein the base rubber includes natural rubber and chloroprene rubber; step S2, performing a second mixing of the first masterbatch and an antioxidant to obtain a second masterbatch; step S3, performing a third mixing of the second masterbatch, the remaining portion of the adhesive, zinc oxide and a vulcanizing agent to obtain a final compound; wherein the vulcanizing agent includes ethylene thiourea; and step S4, vulcanizing the final compound to obtain a vulcanizate.

[0020] Further, in step S1, the rotation speed of the first mixing is 40-50 r / min, and the time is 60-105 s; preferably, in step S1, a first debinding is performed after the first mixing to obtain a section of masterbatch; more preferably, the debinding temperature of the first debinding is 155-160℃; preferably, part of the binder in step S1 is cobalt decanoate, and the remaining part of the binder in step S3 is binder RA-65; more preferably, the weight parts of cobalt decanoate are 0.2-1.5 parts, and the weight parts of binder RA-65 are 2.5-6 parts.

[0021] Further, in step S2, the rotation speed of the second mixing is 32-47 r / min and the time is 60-90 s; preferably, in step S2, a second degreasing is performed after the second mixing to obtain two-stage masterbatch; more preferably, the degreasing temperature of the second degreasing is 150-155℃.

[0022] Further, in step S3, the rotation speed of the third mixing is 28-35 r / min and the time is 60-105 s; preferably, in step S3, a third debinding is performed after the third mixing to obtain the final rubber; more preferably, the debinding temperature of the third debinding is 100-110℃; preferably, in step S3, a vulcanization accelerator is introduced during the third mixing process.

[0023] Furthermore, in step S4, the vulcanization temperature is 145–175°C, and the time is 25–60 min.

[0024] The fourth aspect of the present invention also provides a composition for forming a vulcanizate provided by the present invention, or the application of the vulcanizate provided by the present invention in a tire.

[0025] The present invention provides a composition for forming a vulcanizate, wherein the base rubber includes natural rubber and chlorohydrin rubber. Chlorohydrin rubber has a saturated ether bond structure; its introduction into the composition improves the heat aging resistance of the vulcanizate and reduces the decrease in adhesive strength caused by heat aging. Furthermore, the flexible segments of chlorohydrin rubber have weak polarity, enabling them to adsorb free water from the environment, thereby improving the resistance of the vulcanizate to humid heat aging and enhancing the adhesion between the vulcanizate and steel wire or other metal substrates in humid environments. The vulcanizing agent in the above-mentioned composition for forming the vulcanizate includes ethylene thiourea. The S and N atoms in ethylene thiourea can undergo nucleophilic substitution reactions with the C atoms directly bonded to Cl atoms in the chlorohydrin rubber molecular chain, thereby introducing the heterocyclic structure of ethylene thiourea into the chlorohydrin rubber molecular chain and forming a cross-linked network structure with carbon-carbon single bonds as the main cross-linking bonds. This significantly increases the modulus of the vulcanizate, thereby improving its aging resistance and adhesion strength to the tire carcass steel wire. The reaction of ethylene thiourea with chlorohydrin rubber produces the byproduct HCl. Zinc oxide acts as an acid acceptor, neutralizing the HCl and promoting the forward nucleophilic substitution reaction between ethylene thiourea and chlorohydrin rubber, thereby fostering a more stable and dense cross-linked network structure. Furthermore, the presence of zinc oxide improves vulcanization efficiency and cross-linking density, thus enhancing the overall properties of the resulting vulcanizate, including its aging resistance, tensile strength, and elongation at break, and improving the adhesion strength between the vulcanizate and steel wire or other metal substrates. The introduction of adhesive resins and binders can further improve the adhesion strength between the vulcanizate and steel wire or other metal substrates.

[0026] Compared to other ranges, limiting the weight parts of each component in the composition used to form the vulcanizate to the above-mentioned specific range can effectively improve the synergistic effect between the components, improve the modulus, heat aging resistance and damp heat aging resistance of the obtained vulcanizate, thereby improving the adhesion strength between the vulcanizate and the tire carcass steel wire or other metal substrates.

[0027] In summary, the composition for forming vulcanizates provided by this invention significantly improves the modulus and aging resistance of the resulting vulcanizate through the synergistic effect of chlorohydrin rubber, ethylene thiourea, and zinc oxide. It also enhances the adhesion strength between the rubber and the tire carcass steel wires, maintaining high adhesion strength even under harsh thermo-oxidative and humid aging conditions. Furthermore, the vulcanizates prepared from the composition provided by this invention are also suitable for use in retreaded tires, meeting the high standards for tire carcass adhesion performance required in retreaded tires, improving tire driving safety, and extending their service life. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0029] As described in the background section, existing tire carcass rubbers suffer from low rubber modulus and poor aging resistance, resulting in low bonding strength between the tire carcass steel wires and the rubber. To address these technical problems, a first aspect of this application provides a composition for forming a vulcanizate, comprising, by weight: 100 parts of a base rubber, 50-70 parts of filler, 1-3 parts of adhesive resin, 2.7-7.5 parts of binder, 1.5-5 parts of antioxidant, 5-13 parts of zinc oxide, and 2.5-10 parts of vulcanizing agent; wherein the base rubber includes natural rubber and chloroprene rubber; and the vulcanizing agent includes ethylene thiourea.

[0030] In the composition for forming vulcanizates provided in this application, the base rubber includes natural rubber and chlorohydrin rubber. Chlorohydrin rubber has a saturated ether bond structure. Introducing it into the composition can, on the one hand, improve the heat aging resistance of the obtained vulcanizate and reduce the decrease in adhesive strength caused by heat aging; on the other hand, the flexible segments of chlorohydrin rubber have weak polarity and can adsorb free water in the environment, thereby improving the damp heat aging resistance of the obtained vulcanizate and improving the adhesion between the vulcanizate and steel wire or other metal substrates in damp heat environments.

[0031] The vulcanizing agent in the above-mentioned composition for forming the vulcanizate includes ethylene thiourea. The S and N atoms in ethylene thiourea can undergo nucleophilic substitution reactions with the C atoms directly bonded to Cl atoms in the chlorohydrin rubber molecular chain, thereby introducing the heterocyclic structure of ethylene thiourea into the chlorohydrin rubber molecular chain and forming a cross-linked network structure with carbon-carbon single bonds as the main cross-linking bonds. This significantly increases the modulus of the obtained vulcanizate, thus improving its aging resistance and adhesion strength to the carcass steel wire. During the reaction of ethylene thiourea with chlorohydrin rubber, the byproduct HCl is generated. Zinc oxide acts as an acid acceptor, neutralizing the byproduct HCl and promoting the forward nucleophilic substitution reaction between ethylene thiourea and chlorohydrin rubber, thereby promoting the formation of a more stable and dense cross-linked network structure. Furthermore, the presence of zinc oxide can also improve vulcanization efficiency and cross-linking density, thereby improving the overall properties of the obtained vulcanizate, such as aging resistance, tensile strength, and elongation at break, and enhancing the adhesion strength between the vulcanizate and the steel wire or other metal substrates.

[0032] It should be noted that the chemical structural formula of ethylene thiourea is: .

[0033] The introduction of adhesive resins and adhesives can further improve the bonding strength between the prepared vulcanizate and steel wire or other metal substrates.

[0034] Compared to other ranges, limiting the weight parts of each component in the composition used to form the vulcanizate to the above-mentioned specific range can effectively improve the synergistic effect between the components, improve the modulus, heat aging resistance and damp heat aging resistance of the obtained vulcanizate, thereby improving the adhesion strength between the vulcanizate and the tire carcass steel wire or other metal substrates.

[0035] In summary, the composition for forming vulcanizates provided in this application significantly improves the modulus and aging resistance of the resulting vulcanizate through the synergistic effect of chlorohydrin rubber, ethylene thiourea, and zinc oxide. It also enhances the adhesion strength between the rubber and the tire carcass steel wires, maintaining high adhesion strength even under harsh thermo-oxidative and humid aging conditions. Furthermore, the vulcanizates prepared from the composition provided in this application are also suitable for use in retreaded tires, meeting the high standards for tire carcass adhesion performance required for retreaded tires, improving tire driving safety, and extending their service life.

[0036] In a preferred embodiment, the composition for forming the vulcanizate, by weight, comprises: 100 parts of base rubber, 55-70 parts of filler, 1-2.5 parts of adhesive resin, 2.7-6.5 parts of binder, 1.8-5 parts of antioxidant, 7-11 parts of zinc oxide, and 5-9 parts of vulcanizing agent. Limiting the weight percentages of each component in the composition for forming the vulcanizate to the above range, compared to other ranges, is beneficial for improving the synergistic effect between the components, and for improving the modulus, heat aging resistance, and damp heat aging resistance of the resulting vulcanizate, thereby improving the bonding strength between the vulcanizate and the tire carcass steel wires.

[0037] Natural rubber possesses excellent abrasion resistance and tear resistance. In a preferred embodiment, the weight ratio of natural rubber to chlorohydrin rubber in the matrix rubber is (60-100):(5-20). This weight ratio of natural rubber to chlorohydrin rubber includes, but is not limited to, the range described above. Limiting it to this range facilitates the introduction of a more suitable amount of chlorohydrin rubber, which helps to improve the modulus and aging resistance of the vulcanizate while maintaining its good mechanical properties, thereby improving the adhesion strength between the vulcanizate and the tire carcass steel wires.

[0038] In order to further promote a better balance between the mechanical properties, modulus and aging resistance of the vulcanizate, thereby further improving the bonding strength between the vulcanizate and the tire carcass steel wire, preferably, the weight ratio of natural rubber to chlorohydrin rubber is (65-100):(8-17).

[0039] In a preferred embodiment, the base rubber comprises 80-95 wt% natural rubber, with the balance being chlorohydrin rubber. Compared to other ranges, limiting the amounts of natural rubber and chlorohydrin rubber to the above range facilitates the introduction of more suitable amounts of natural rubber and chlorohydrin rubber, which helps to improve the modulus and aging resistance of the vulcanizate while maintaining its good mechanical properties, thereby improving the adhesion strength between the vulcanizate and the tire carcass steel wires.

[0040] In order to improve the processability of the composition used to form the vulcanizate and to improve the abrasion resistance and tear strength of the obtained vulcanizate, in a preferred embodiment, the weight-average molecular weight of the natural rubber is 400,000 to 650,000.

[0041] In a preferred embodiment, the weight-average molecular weight of the chlorohydrin rubber is 800,000 to 1,700,000; the chlorine content in the chlorohydrin rubber is 25 to 35 wt%. Compared to other ranges, limiting the weight-average molecular weight of the chlorohydrin rubber and the weight percentage of chlorine content within the above ranges is beneficial for forming a more stable and dense cross-linked network structure, thereby improving the modulus and aging resistance of the obtained vulcanizate, and further improving the adhesion strength between the obtained vulcanizate and the tire carcass steel wires.

[0042] To promote the formation of a more stable and dense cross-linked network structure, further improve the modulus and aging resistance of the obtained vulcanizate, and thus further improve the bonding strength between the obtained vulcanizate and the tire carcass steel wire, in a preferred embodiment, the chlorohydrin rubber includes, but is not limited to, homopolymer chlorohydrin rubber and / or copolymer chlorohydrin rubber; preferably, the polymer monomer of the homopolymer chlorohydrin rubber is epichlorohydrin; preferably, the copolymer chlorohydrin rubber is a copolymer of epichlorohydrin, ethylene oxide and / or propyl glycidyl ether.

[0043] Ethylene thiourea can undergo a nucleophilic substitution reaction with chlorohydrin rubber to form a cross-linked network structure with carbon-carbon single bonds as the main cross-linking bonds. In a preferred embodiment, the vulcanizing agent includes ethylene thiourea and sulfur.

[0044] In a preferred embodiment, the vulcanizing agent comprises 0.5 to 4 parts by weight of ethylene thiourea and 2 to 6 parts by weight of sulfur. The weight percentages of ethylene thiourea and sulfur include, but are not limited to, the ranges described above. Limiting these percentages to the ranges improves the efficiency and controllability of vulcanization, enhances the reaction efficiency between chlorohydrin rubber and ethylene thiourea, and facilitates the formation of a cross-linked network structure with carbon-carbon single bonds as the main cross-linking bonds. This increases the modulus of the resulting vulcanized rubber and, consequently, improves the bonding strength between the vulcanized rubber and the tire carcass steel wires.

[0045] To further improve the efficiency and controllability of vulcanization, promote the formation of a more stable and dense cross-linked network structure, thereby further improving the modulus of the obtained vulcanized rubber and further improving the bonding strength between the vulcanized rubber and the tire carcass steel wire, preferably, by weight, the vulcanizing agent includes 2 to 3 parts of ethylene thiourea and 3 to 6 parts of sulfur.

[0046] In a preferred embodiment, the specific surface area of ​​the packing is 70–220 m². 2 / g, with an average particle size of 10–30 nm. The specific surface area and average particle size of the filler include, but are not limited to, the above ranges. Limiting them to the above ranges is beneficial to improving the dispersibility of the filler and the processability of the composition used to form vulcanizates.

[0047] In order to improve the reinforcing effect of the filler and further improve the mechanical properties such as tensile strength and elongation at break of the obtained vulcanizate, in a preferred embodiment, the filler includes, but is not limited to, carbon black and / or silica.

[0048] To further improve the reinforcing effect of inorganic fillers, the filler is preferably carbon black, and the carbon black grades include, but are not limited to, one or more of N330, N347, N375, N326, N339 and N220 produced by Cabot Corporation.

[0049] In a preferred embodiment, the adhesive resin includes, but is not limited to, resorcinol-formaldehyde resin (SL-3200). The types of adhesive resins include, but are not limited to, those described above; limiting them to these ranges is beneficial for improving the adhesion between the resulting vulcanizate and the tire carcass steel wires.

[0050] To further enhance the adhesion between the prepared vulcanized rubber and the tire carcass steel wires, in a preferred embodiment, the adhesive includes cobalt decanoate and adhesive RA-65.

[0051] To further enhance the adhesion between the obtained vulcanizate and the tire carcass steel wires, preferably, the adhesive comprises 0.2 to 1.5 parts by weight of cobalt decanoate and 2.5 to 6 parts by weight of adhesive RA-65.

[0052] The antioxidants used in this application can be selected from commonly used types in the art. In a preferred embodiment, the antioxidants include, but are not limited to, antioxidant RD and / or antioxidant 4020. Using the above-mentioned types of antioxidants helps to improve the aging resistance of the obtained vulcanizate, inhibit its erosion by aging factors such as oxygen, ultraviolet light, ozone, heat, and humidity, thereby helping to improve the bonding strength between the vulcanizate and the tire carcass steel wires.

[0053] To further improve the aging resistance of the obtained vulcanizate and further improve the bonding strength between the vulcanizate and the tire carcass steel wire, preferably, the antioxidant is a mixture of antioxidant RD and antioxidant 4020; more preferably, the antioxidant includes 0.5 to 2 parts by weight of antioxidant RD and 1 to 3 parts by weight of antioxidant 4020.

[0054] In a preferred embodiment, the composition for forming the vulcanizate further includes a vulcanization accelerator. Introducing a vulcanization accelerator into the above composition helps improve the vulcanization efficiency and controllability of the vulcanization process, promotes the formation of a more stable and dense cross-linked network structure, and thus helps improve the modulus of the obtained vulcanizate.

[0055] To further improve the vulcanization efficiency and controllability of the vulcanization process and promote the formation of a more stable and dense cross-linked network structure, in a preferred embodiment, the composition used to form the vulcanizate further includes 0.8 to 2.8 parts by weight of a vulcanization accelerator, preferably 0.8 to 2.5 parts by weight.

[0056] In a preferred embodiment, the vulcanization accelerator includes, but is not limited to, N,N-dicyclohexyl-2-benzothiazole sulfenamide (DZ), N-cyclohexyl-2-benzothiazole sulfenamide (CZ), and N-tert-butyl-2-benzothiazole sulfenamide (NS). Compared to other types, using the above-mentioned vulcanization accelerators is beneficial to improving the vulcanization efficiency and controllability of the vulcanization process, promoting the formation of a more stable and dense cross-linked network structure, thereby improving the modulus of the obtained vulcanized rubber.

[0057] The second aspect of this application also provides a vulcanizate, which is obtained by mixing and vulcanizing the composition for forming the vulcanizate provided in this application. The composition provided in this application incorporates chlorohydrin rubber, which not only improves the heat aging resistance and damp heat aging resistance of the obtained vulcanizate, but also interacts with ethylene thiourea and zinc oxide to form a cross-linked network structure with carbon-carbon single bonds as the main cross-linking bonds under vulcanization conditions. This significantly increases the modulus of the obtained vulcanizate, thereby effectively improving the adhesion strength between the vulcanizate and the tire carcass steel wires. The vulcanizate obtained from the composition for forming the vulcanizate provided in this application has a high modulus and excellent heat aging resistance and damp heat aging resistance, significantly enhancing the adhesion strength between the vulcanizate and the tire carcass steel wires. Even under harsh thermo-oxidative aging and damp heat aging conditions, it can maintain high adhesion strength. Furthermore, the above-mentioned vulcanizate is more suitable for use in retreaded tires, meeting the high standards required for tire carcass adhesion performance in retreaded tires, improving tire driving safety, and extending its service life.

[0058] A third aspect of this application also provides a method for preparing the above-mentioned vulcanized rubber provided in this application. The method includes: step S1, performing a first mixing of a base rubber, filler, adhesive resin and a portion of the adhesive to obtain a masterbatch; wherein the base rubber includes natural rubber and chloroprene rubber; step S2, performing a second mixing of the masterbatch and an antioxidant to obtain a second masterbatch; step S3, performing a third mixing of the second masterbatch, the remaining portion of the adhesive, zinc oxide and a vulcanizing agent to obtain a final compound; wherein the vulcanizing agent includes ethylene thiourea; and step S4, vulcanizing the final compound to obtain the vulcanized rubber.

[0059] In step S1 of the preparation method provided in this application, the matrix rubber containing natural rubber and chlorohydrin rubber, fillers, adhesive resin, and a portion of the adhesive are firstly mixed to obtain a more uniformly dispersed masterbatch. The introduction of chlorohydrin rubber during the first mixing process, with its saturated ether bond structure exhibiting good stability at high temperatures, improves the heat aging resistance of the resulting vulcanizate and reduces the decrease in adhesive strength caused by heat aging. Furthermore, the flexible segments of chlorohydrin rubber have weak polarity, enabling them to adsorb free water from the environment, thereby improving the humid heat aging resistance of the resulting vulcanizate and enhancing the adhesion between the vulcanizate and steel wire or other metal substrates in humid environments. In step S2, the masterbatch and antioxidant are secondly mixed to improve the uniformity of antioxidant dispersion, resulting in a second-stage masterbatch. The introduction of the antioxidant further enhances the aging resistance of the resulting vulcanizate. In step S3, the second-stage masterbatch, the remaining adhesive, zinc oxide, and the vulcanizing agent containing ethylene thiourea are thirdly mixed to obtain a final compound with uniformly dispersed components. In the third mixing process, ethylene thiourea and zinc oxide are introduced. Ethylene thiourea can undergo a crosslinking reaction with chlorohydrin rubber during subsequent vulcanization, while zinc oxide can improve vulcanization efficiency and crosslinking density during subsequent vulcanization. Simultaneously, it can act as an acid acceptor to neutralize the byproduct HCl generated from the reaction between chlorohydrin rubber and ethylene thiourea, thereby promoting the forward crosslinking reaction and forming a more stable and dense crosslinked network structure. In step S4, the final compound is vulcanized, allowing ethylene thiourea to undergo a nucleophilic substitution reaction with chlorohydrin rubber under vulcanization conditions. This introduces the heterocyclic structure of ethylene thiourea into the molecular chain of chlorohydrin rubber, forming a crosslinked network structure with carbon-carbon single bonds as the main crosslinking bonds. This significantly improves the modulus of the obtained vulcanized rubber, thereby improving the aging resistance of the vulcanized rubber and its adhesion strength to the tire carcass wire.

[0060] Compared to other methods, the vulcanizate prepared by the above method has a higher modulus and excellent heat aging resistance and damp heat aging resistance. It can significantly enhance the bonding strength between the vulcanizate and the tire carcass steel wires, and can maintain a high bonding strength even under harsh thermo-oxidative aging and damp heat aging conditions.

[0061] In a preferred embodiment, in step S1, the rotation speed of the first mixing is 40-50 r / min, and the time is 60-105 s. The rotation speed and time of the first mixing include, but are not limited to, the above range. Limiting them to the above range is beneficial to improving the efficiency and effect of the first mixing, and to improving the dispersion uniformity and stability of the materials in the masterbatch.

[0062] In order to further improve the stability and dispersion uniformity of the masterbatch and facilitate its subsequent processing, in a preferred embodiment, after the first mixing in step S1, a first discharge is performed to obtain a masterbatch. Preferably, the discharge temperature of the first discharge is 155-160°C.

[0063] In order to improve the dispersibility of cobalt decanoate and further enhance the adhesion between the obtained vulcanizate and the tire carcass steel wire, in a preferred embodiment, part of the adhesive in step S1 is cobalt decanoate, and the remaining part of the adhesive in step S3 is adhesive RA-65; preferably, the weight parts of cobalt decanoate are 0.2 to 1.5 parts, and the weight parts of adhesive RA-65 are 2.5 to 6 parts.

[0064] In a preferred embodiment, in step S2, the rotation speed of the second mixing is 32–47 r / min, and the time is 60–90 s. The rotation speed and time of the second mixing include, but are not limited to, the above ranges. Limiting them to the above ranges is beneficial to improving the efficiency and effect of the second mixing, to improving the dispersion uniformity of the primary masterbatch and antioxidant, and also to improving the stability of the obtained secondary masterbatch.

[0065] To further improve the stability and dispersion uniformity of the second-stage masterbatch and facilitate its subsequent processing, in a preferred embodiment, in step S2, a second dispensing is performed after the second mixing to obtain the second-stage masterbatch; preferably, the dispensing temperature of the second dispensing is 150-155℃.

[0066] In a preferred embodiment, in step S3, the rotation speed of the third mixing is 28–35 r / min, and the time is 60–105 s. The rotation speed and time of the third mixing include, but are not limited to, the above range. Limiting them to the above range is beneficial to improving the dispersion uniformity of each material in the final rubber compound, thereby improving the efficiency of subsequent vulcanization, promoting the formation of a more stable and dense cross-linked network structure, improving the modulus and aging resistance of the obtained vulcanized rubber, and further improving the adhesion strength between the vulcanized rubber and the tire carcass steel wire.

[0067] In order to improve the vulcanization efficiency and controllability of the vulcanization process and suppress scorching, in a preferred embodiment, in step S3, a third debinding is performed after the third mixing to obtain the final rubber; preferably, the debinding temperature of the third debinding is 100-110°C.

[0068] To further improve the vulcanization efficiency and controllability of the vulcanization process, in a preferred embodiment, a vulcanization accelerator is also introduced in the third mixing process in step S3.

[0069] In a preferred embodiment, in step S4, the vulcanization temperature is 145–175°C, and the time is 25–60 min. The vulcanization temperature and time include, but are not limited to, the above ranges. Limiting them to these ranges is beneficial for improving the efficiency and controllability of vulcanization, and for increasing the reaction efficiency between chlorohydrin rubber and ethylene thiourea. This facilitates the formation of a cross-linked network structure with carbon-carbon single bonds as the main cross-linking bonds, increases the modulus of the obtained vulcanized rubber, and further improves the adhesion strength between the vulcanized rubber and the tire carcass steel wires.

[0070] The fourth aspect of this application also provides the composition for forming a vulcanizate provided in this application, or the application of the vulcanizate provided in this application in a tire. The composition for forming a vulcanizate provided in this application incorporates chlorohydrin rubber, which not only improves the heat aging resistance and damp heat aging resistance of the obtained vulcanizate, but also interacts with ethylene thiourea and zinc oxide to form a cross-linked network structure with carbon-carbon single bonds as the main cross-linking bonds under vulcanization conditions, significantly improving the modulus of the obtained vulcanizate. The vulcanizate provided in this application has a high modulus and excellent heat aging resistance and damp heat aging resistance. Its application in tires can significantly enhance the adhesion strength between the vulcanizate and the tire carcass steel wires, maintaining high adhesion strength even under harsh thermo-oxidative aging and damp heat aging conditions. This adhesive is particularly suitable for use on copper-plated steel wire surfaces. The oxygen atoms in the chlorohydrin rubber molecular chain and the nitrogen atoms in the ethylene thiourea heterocyclic structure possess lone pairs of electrons, enabling them to form coordinate bonds with copper atoms on the copper-plated steel wire surface. This significantly improves the adhesion between the copper-plated steel wire and the vulcanizate. Furthermore, the vulcanizate provided in this application is also suitable for use in retreaded tires, meeting the high standards for tire carcass adhesion performance required in retreaded tires, improving tire driving safety, and extending their service life.

[0071] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0072] Examples 1 to 6

[0073] A method for preparing vulcanizate specifically includes the following steps:

[0074] (1) Prepare each raw material according to the type and amount of each component in Table 1;

[0075] (2) Place natural rubber, chlorohydrin rubber, carbon black, adhesive resin and cobalt decanoate in a mixer (Yiyang Rubber & Plastics Machinery Group Co., Ltd., GK255), set the speed of the mixer to 46 r / min, press the top plug and mix for 25s, raise the top plug to the position, press the top plug and continue mixing for 24s, then raise the top plug and press the top plug to continue mixing for 28s, then open the discharge door, control the discharge temperature between 155 and 160℃ for the first discharge, open the mill to sheet, cool and collect the rubber to obtain a section of masterbatch;

[0076] (3) Set the speed of the internal mixer (model same as step (2)) to 38 r / min, add the first stage of masterbatch and antioxidant obtained in step (2), press the top bolt and mix for 25s, raise the top bolt to the position, press the top bolt and mix for 28s, raise the top bolt, press the top bolt and continue mixing for 25s, then raise the top bolt, open the discharge door, control the discharge temperature between 150 and 155℃ for the second discharge, open the mill to remove the sheet, cool and collect the rubber to obtain the second stage of masterbatch;

[0077] (4) Set the speed of the internal mixer (same model as step (2)) to 32 r / min, add the second-stage masterbatch, adhesive, zinc oxide, vulcanization accelerator and vulcanizing agent obtained in step (3), press the top plug and mix for 25s, raise the top plug, then press the top plug and continue mixing for 25s, raise the top plug again, press the top plug and mix for 30s, then open the discharge door, control the discharge temperature between 100 and 110℃ for the third discharge, open the mill to remove the sheet, cool and collect the rubber to obtain the final rubber;

[0078] (5) The final compound obtained in step (4) is vulcanized in a flat vulcanizing machine to obtain vulcanized rubber; wherein, the vulcanization conditions for the vulcanized rubber sample for tensile property testing are: vulcanization at 150℃ for 30 min; the vulcanization conditions for the vulcanized rubber sample for adhesive strength testing are: vulcanization at 150℃ for 40 min.

[0079] In Examples 1 to 6, the types and amounts of each component used to form the vulcanizate are shown in Table 1.

[0080] Table 1

[0081]

[0082] Examples 7 to 11

[0083] The difference from Example 3 is that the specific component amounts of the compositions used to form vulcanizates in Examples 7 to 11 are different from those in Example 3, as shown in Table 2; the remaining steps are the same as in Example 3.

[0084] Table 2

[0085]

[0086] The sources of each component in the compositions used to form vulcanizates in Tables 1 and 2 above are as follows: (1) The natural rubber is of type STR20# with a weight-average molecular weight of 550,000; (2) The homopolymer chlorohydrin rubber has a weight-average molecular weight of 1,130,000 and a chlorine content of 33 wt%; (3) The carbon black is N330 produced by Cabot Corporation, with a specific surface area of ​​75 m². 2 / g, with an average particle size of 28nm; (4) Adhesive resin SL-3200 was purchased from Huachi (China) Chemical Co., Ltd.; (5) Adhesive RA-65 was purchased from Jiaozuo Yipeng New Materials Co., Ltd.; (6) Cobalt decanoate was graded CN20.5; (7) Insoluble sulfur HDOT20 was purchased from Shandong Shangshun Chemical Co., Ltd.

[0087] Comparative Examples 1 to 4

[0088] The difference from Example 3 is that the specific amounts of the components used to form the vulcanizate in Comparative Examples 1 to 4 are different from those in Example 3. Specifically, chlorohydrin rubber and ethylene thiourea were not introduced in Comparative Example 1, chlorohydrin rubber was not introduced in Comparative Example 2, and ethylene thiourea was not introduced in Comparative Example 3. The amount of zinc oxide used in Comparative Example 4 is less, as shown in Table 3. The remaining steps are the same as in Example 3.

[0089] Table 3

[0090]

[0091] The sources of each component in the composition used to form the vulcanizate in Table 3 above are the same as those in Tables 1 and 2.

[0092] The following performance tests were performed on the vulcanizates prepared in all the above embodiments and comparative examples of this application:

[0093] (1) Tensile strength, elongation at break, and stress at 100% elongation: measured according to the methods described in the national standard GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber";

[0094] (2) Hardness (Shore A hardness): Measured according to the method described in the national standard GB / T 531.1-2008 "Test method for indentation hardness of vulcanized rubber or thermoplastic rubber - Part 1: Shore hardness tester method (Shore hardness)";

[0095] (3) Adhesion strength: The adhesion strength between vulcanized rubber and copper-plated steel wire cord was tested according to the method described in the national standard GB / T 16586-2014 "Determination of adhesion strength between vulcanized rubber and steel wire cord". The larger the test value, the better the adhesion performance.

[0096] The test results are shown in Table 4.

[0097] Table 4

[0098]

[0099] As shown in Table 4, the tensile strength, elongation at break, and adhesive strength of the vulcanizate prepared in Example 3 are significantly higher than those of Comparative Examples 1 to 4. This indicates that the vulcanizate prepared using the specific components and dosages provided in this application can significantly improve the adhesive strength between the vulcanizate and the copper-plated steel cord while maintaining good tensile strength and elongation at break. In Example 7, the amounts of natural rubber and chloroprene rubber are outside the aforementioned preferred range defined in this application. Due to the insufficient amount of chloroprene rubber, the adhesive strength decreased significantly. Therefore, compared to other ranges, limiting the amounts of natural rubber and chloroprene rubber to the aforementioned preferred range is beneficial for maintaining good mechanical properties of the vulcanizate while improving the adhesive strength between the vulcanizate and the tire carcass steel wire.

[0100] The vulcanizates prepared in all the above-described embodiments and comparative examples of this application were placed in a nitrogen atmosphere at 100°C for 48 hours for heat aging in an airless state. Subsequently, the tensile strength, elongation at break, 100% tensile stress, and hardness (Shore A hardness) of the vulcanizates after heat aging were tested, using the same testing methods as those for the vulcanizates before aging. The tensile volume retention rate was calculated according to formula (I): Tensile volume retention rate % = (tensile strength after heat aging × elongation at break after heat aging) / (initial tensile strength before aging × initial elongation at break before aging) × 100% (I). The test results are shown in Table 5.

[0101] Table 5

[0102]

[0103] As can be seen from Table 5, the tensile strength, elongation at break, and adhesive strength of the vulcanizate prepared in Example 3 are all significantly higher than those of Comparative Examples 1 to 4. Therefore, it can be concluded that the vulcanizate prepared using the composition with the specific components and dosages provided in this application can significantly improve the adhesive strength between the vulcanizate and the copper-plated steel wire cord while maintaining good tensile strength and elongation at break.

[0104] The vulcanizates prepared in all the above-described embodiments and comparative examples of this application were subjected to thermo-oxidative aging treatment in hot air at 100°C. The adhesive strength of the vulcanizates after 72 hours and 168 hours of thermo-oxidative aging was tested, respectively. The adhesive strength test method was the same as that for the adhesive strength test of the vulcanizates before aging described above. Combined with the initial adhesive strength of the vulcanizates before aging in Table 4, the adhesive strength retention rate was calculated. The test results are shown in Table 6.

[0105] Table 6

[0106]

[0107] As shown in Table 6, the adhesive strength retention rate of Example 3 after 168 hours of thermo-oxidative aging treatment in hot air at 100°C was 83.4%, which is much higher than that of Comparative Examples 1 to 4. This indicates that the vulcanizate prepared in Example 3 has superior thermo-oxidative aging resistance. Therefore, the composition provided in this application for forming vulcanizates can significantly improve the modulus of the vulcanizate through the synergistic effect between chlorohydrin rubber, ethylene thiourea, and zinc oxide, thereby improving the thermo-oxidative aging resistance of the vulcanizate. In Example 7, the amounts of natural rubber and chlorohydrin rubber are outside the preferred range defined in this application. Because the amount of chlorohydrin rubber is too small, the modulus and crosslinking density of the vulcanizate are not effectively improved; therefore, the thermo-oxidative aging resistance of the vulcanizate prepared in Example 7 is poor.

[0108] The vulcanizates prepared in all the above-described embodiments and comparative examples of this application were subjected to airless thermal aging treatment in a nitrogen atmosphere at 100°C. The adhesive strength of the vulcanizates after 72 hours and 168 hours of thermal aging was tested (the test method is the same as the adhesive strength test method of the vulcanizates before aging described above). Combined with the initial adhesive strength of the vulcanizates before aging in Table 4, the adhesive strength retention rate was calculated. The test results are shown in Table 7.

[0109] Table 7

[0110]

[0111] As shown in Table 7, the adhesive strength retention rate of Example 3 after heat aging in a nitrogen atmosphere at 100°C for 168 hours was 87.7%, which is much higher than that of Comparative Examples 1 to 4. This indicates that the vulcanizate prepared in Example 3 has superior heat aging resistance. Therefore, the composition provided in this application for forming vulcanizates can significantly improve the modulus of the vulcanizate through the synergistic effect between chlorohydrin rubber, ethylene thiourea, and zinc oxide, thereby improving the heat aging resistance of the vulcanizate. In Example 7, the amounts of natural rubber and chlorohydrin rubber are outside the preferred range defined in this application. Because the amount of chlorohydrin rubber is too small, the modulus and crosslinking density of the vulcanizate are not effectively improved; therefore, the heat aging resistance of the vulcanizate prepared in Example 7 is poor.

[0112] The vulcanizates prepared in all the above-described embodiments and comparative examples of this application were subjected to damp heat aging treatment at 93°C and 95% relative humidity. The adhesive strength of the vulcanizates after 7 days of damp heat aging was tested (the test method is the same as the adhesive strength test method of the vulcanizates before aging described above). Combined with the initial adhesive strength of the vulcanizates before aging in Table 4, the adhesive strength retention rate was calculated. The test results are shown in Table 8.

[0113] Table 8

[0114]

[0115] As shown in Table 8, the adhesive strength retention rate of Example 3 after 7 days of damp heat aging at 93°C and 95% relative humidity was 86.6%, which is much higher than that of Comparative Examples 1 to 4. This indicates that the vulcanizate prepared in Example 3 has superior resistance to damp heat aging. Therefore, the composition provided in this application for forming vulcanizates can significantly improve the modulus of the vulcanizate through the synergistic effect between chlorohydrin rubber, ethylene thiourea, and zinc oxide, thereby improving the resistance to damp heat aging. In Example 7, the amounts of natural rubber and chlorohydrin rubber were outside the preferred range defined in this application. Because the amount of chlorohydrin rubber was too small, the modulus and crosslinking density of the vulcanizate were not effectively improved; therefore, the vulcanizate prepared in Example 7 had poor resistance to damp heat aging.

[0116] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0117] Introducing chlorohydrin rubber with a saturated ether bond structure into the composition used to form vulcanizates can, on the one hand, improve the heat aging resistance of the obtained vulcanizates and reduce the decrease in adhesive strength caused by heat aging; on the other hand, the flexible segments of chlorohydrin rubber have weak polarity and can adsorb free water in the environment, thereby improving the damp heat aging resistance of the obtained vulcanizates and improving the adhesion between the vulcanizates and steel wires or other metal substrates in damp heat environments.

[0118] The vulcanizing agent in the above-mentioned composition for forming vulcanizates includes ethylene thiourea. The S and N atoms in ethylene thiourea can undergo nucleophilic substitution reactions with the C atoms directly bonded to Cl atoms in the chlorohydrin rubber molecular chain, thereby introducing the heterocyclic structure of ethylene thiourea into the chlorohydrin rubber molecular chain and forming a cross-linked network structure with carbon-carbon single bonds as the main cross-linking bonds. This significantly increases the modulus of the obtained vulcanizate, thereby improving its aging resistance and adhesion strength to the carcass steel wire. During the reaction of ethylene thiourea with chlorohydrin rubber, HCl byproducts are generated. Zinc oxide acts as an acid acceptor, neutralizing the HCl byproducts and promoting the forward nucleophilic substitution reaction between ethylene thiourea and chlorohydrin rubber, thus promoting the formation of a more stable and dense cross-linked network structure. Furthermore, the presence of zinc oxide can also improve vulcanization efficiency and cross-linking density, thereby improving the overall properties of the obtained vulcanizate, such as aging resistance, tensile strength, and elongation at break, and enhancing the adhesion strength between the vulcanizate and steel wire or other metal substrates. The introduction of adhesive resins and binders can further improve the bonding strength between the resulting vulcanizate and steel wire or other metal substrates.

[0119] Compared to other ranges, limiting the weight parts of each component in the composition used to form the vulcanizate to the above-mentioned specific range can effectively improve the synergistic effect between the components, improve the modulus, heat aging resistance and damp heat aging resistance of the obtained vulcanizate, thereby improving the adhesion strength between the vulcanizate and the tire carcass steel wire or other metal substrates.

[0120] In summary, the composition for forming vulcanizates provided in this application significantly improves the modulus and aging resistance of the resulting vulcanizate through the synergistic effect of chlorohydrin rubber, ethylene thiourea, and zinc oxide. It also enhances the adhesion strength between the rubber and the tire carcass steel wires, maintaining high adhesion strength even under harsh thermo-oxidative and humid aging conditions. Furthermore, the vulcanizates prepared from the composition provided in this application are also suitable for use in retreaded tires, meeting the high standards for tire carcass adhesion performance required for retreaded tires, improving tire driving safety, and extending their service life.

[0121] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those described herein.

[0122] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composition for forming vulcanizates, characterized in that, The composition for forming the vulcanizate, by weight, comprises: 100 parts of base rubber, 50-70 parts of filler, 1-3 parts of adhesive resin, 2.7-7.5 parts of adhesive, 1.5-5 parts of antioxidant, 5-13 parts of zinc oxide, and 2.5-10 parts of vulcanizing agent; wherein the base rubber comprises natural rubber and chlorohydrin rubber; and the vulcanizing agent comprises ethylene thiourea.

2. The composition for forming vulcanizates according to claim 1, characterized in that, The composition for forming the vulcanizate, by weight, comprises: 100 parts of the base rubber, 55 to 70 parts of the filler, 1 to 2.5 parts of the adhesive resin, 2.7 to 6.5 parts of the adhesive, 1.8 to 5 parts of the antioxidant, 7 to 11 parts of the zinc oxide, and 5 to 9 parts of the vulcanizing agent.

3. The composition for forming a vulcanizate according to claim 1 or 2, characterized in that, In the base rubber, the weight ratio of the natural rubber to the chlorohydrin rubber is (60-100):(5-20), preferably (65-100):(8-17). Preferably, the base rubber comprises 80-95 wt% natural rubber, with the balance being chlorohydrin rubber; Preferably, the weight-average molecular weight of the natural rubber is 400,000 to 650,000; Preferably, the weight-average molecular weight of the chlorohydrin rubber is 800,000 to 1,700,000; preferably, the chlorine content in the chlorohydrin rubber is 25% to 35% by weight. More preferably, the chlorohydrin rubber is selected from homopolymer chlorohydrin rubber and / or copolymer chlorohydrin rubber; even more preferably, the polymeric monomer of the homopolymer chlorohydrin rubber is epichlorohydrin; even more preferably, the copolymer chlorohydrin rubber is a copolymer of epichlorohydrin, ethylene oxide and / or propyl glycidyl ether.

4. The composition for forming a vulcanizate according to any one of claims 1 to 3, characterized in that, The vulcanizing agent includes the ethylene thiourea and sulfur; Preferably, the vulcanizing agent comprises 0.5 to 4 parts of the ethylene thiourea and 2 to 6 parts of the sulfur by weight; more preferably, it comprises 2 to 3 parts of the ethylene thiourea and 3 to 6 parts of the sulfur. Preferably, the specific surface area of ​​the filler is 70–220 m². 2 / g, with an average particle size of 10–30 nm; Preferably, the filler is selected from carbon black and / or silica.

5. The composition for forming a vulcanizate according to claim 1, characterized in that, The adhesive resin is resorcinol-formaldehyde resin; Preferably, the adhesive comprises cobalt decanoate and adhesive RA-65; more preferably, the adhesive comprises 0.2 to 1.5 parts by weight of the cobalt decanoate and 2.5 to 6 parts by weight of the adhesive RA-65; Preferably, the antioxidant is selected from antioxidant RD and / or antioxidant 4020; more preferably, the antioxidant is a mixture of antioxidant RD and antioxidant 4020; even more preferably, the antioxidant comprises 0.5 to 2 parts by weight of antioxidant RD and 1 to 3 parts by weight of antioxidant 4020. Preferably, the composition for forming the vulcanizate further includes a vulcanization accelerator; more preferably, the composition for forming the vulcanizate further includes 0.8 to 2.8 parts by weight of the vulcanization accelerator, more preferably 0.8 to 2.5 parts by weight; preferably, the vulcanization accelerator is N,N-dicyclohexyl-2-benzothiazole sulfenamide.

6. A vulcanizate, characterized in that, The vulcanizate is obtained by mixing and vulcanizing the composition for forming vulcanizates according to any one of claims 1 to 5.

7. A method for preparing the vulcanizate according to claim 6, characterized in that, The preparation method includes: Step S1 involves first mixing the base rubber, filler, adhesive resin, and a portion of the adhesive to obtain a masterbatch; wherein the base rubber includes natural rubber and chlorohydrin rubber. Step S2: The first stage masterbatch and antioxidant are mixed for a second time to obtain the second stage masterbatch; Step S3 involves a third mixing of the second-stage masterbatch, the remaining adhesive, zinc oxide, and vulcanizing agent to obtain the final compound; wherein the vulcanizing agent includes ethylene thiourea. Step S4: Vulcanize the final compound to obtain the vulcanized rubber.

8. The method for preparing vulcanized rubber according to claim 7, characterized in that, In step S1, the rotation speed of the first mixing is 40-50 r / min, and the time is 60-105 s; Preferably, in step S1, after the first mixing, a first degreasing is performed to obtain the first section of masterbatch; more preferably, the degreasing temperature of the first degreasing is 155-160℃. Preferably, the adhesive in step S1 is cobalt decanoate, and the remaining adhesive in step S3 is adhesive RA-65; more preferably, the weight percentage of cobalt decanoate is 0.2 to 1.5 parts, and the weight percentage of adhesive RA-65 is 2.5 to 6 parts. Preferably, in step S2, the rotation speed of the second mixing is 32-47 r / min, and the time is 60-90 s; Preferably, in step S2, a second debinding is performed after the second mixing to obtain the two-stage masterbatch; more preferably, the debinding temperature of the second debinding is 150-155℃.

9. The method for preparing vulcanizate according to claim 7 or 8, characterized in that, In step S3, the rotation speed of the third mixing is 28-35 r / min, and the time is 60-105 s; Preferably, in step S3, a third debinding is performed after the third mixing to obtain the final rubber; more preferably, the debinding temperature of the third debinding is 100-110℃. Preferably, in step S3, a vulcanization accelerator is also introduced during the third mixing process; Preferably, in step S4, the vulcanization temperature is 145–175°C and the time is 25–60 min.

10. A composition for forming a vulcanizate according to any one of claims 1 to 5, or the use of the vulcanizate according to claim 6 in a tire.

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