Zinc-free rubber composition, tread rubber, and preparation method and application thereof

Abstract

The present invention provides a zinc-free rubber composition, tread rubber, and a preparation method and application thereof. The rubber composition comprises: a diene rubber, an antioxidant, a reinforcing functional filler, and a vulcanization system reagent, wherein the diene rubber comprises a special diene rubber, and the chemical structure of the special diene rubber contains side chains and / or side groups, and the side chains and / or side groups contain alkenyl double bonds and / or aromatic groups. A rubber composition using a certain proportion of special diene rubber can obtain a cross-linking density close to that of a zinc-containing rubber composition, and rubber properties such as hardness, tensile stress, and hysteresis without zinc, thereby meeting the requirements for tire manufacturing performance. The preparation of tread rubber using the zinc-free rubber composition of the present application can be carried out using mature methods and is highly safe.

Description

Technical Field

[0001] The present invention relates to the technical field of tread rubber, and in particular to a zinc-free rubber composition, tread rubber, and a preparation method and application thereof. Background Art

[0002] It's widely known in the industry that zinc oxide or zinc-containing additives are essential as rubber vulcanization activators or functional additives in current tire formulations. Removing zinc from existing rubber compositions results in low tensile stress, modulus, hardness, and crosslinking. In particular, if zinc oxide is omitted from diene rubber compositions containing natural rubber, isoprene rubber, and butyl rubber, the reversion effect can render the rubber completely useless. Therefore, current diene rubber compositions used in tire manufacturing contain at least 2 phr of zinc oxide.

[0003] However, from the perspective of sustainable development and environmental protection, zinc oxide in tires can enter the water cycle along with tire debris, causing water pollution. Both European Commission Directive 2400 / 73 / EC and the 2016 California bill SB1260 propose restrictions on the use of zinc or zinc oxide in tires.

[0004] This has led to a demand for zinc-free production among tire manufacturers. However, if zinc is completely removed from current diene rubber compositions, the degree of crosslinking will be reduced, resulting in lower hardness and modulus of tensile strength, and increased hysteresis loss, significantly reducing the usability of tires made with these compositions.

[0005] In order to achieve environmental protection goals and ensure tire performance at the same time, some attempts to develop zinc-free or low-zinc rubber compositions have been carried out at home and abroad. For example, patent CN109369994B provides a low-zinc rubber composition, which discloses a rubber composition with a zinc content of 0.5 to 1 phr. By replacing zinc oxide with high-specific surface area nano-zinc oxide using zinc hydroxide particles as a carrier, the use of zinc is reduced on the basis of high activity and high dispersion, ensuring good performance of the composition. Patent CN115678038B discloses a method of using a lignin zinc salt complex to replace zinc oxide, taking advantage of its good dispersion characteristics to achieve the purpose of reducing the amount of zinc oxide used, and applying it to tire tread rubber to ensure tire wear resistance and reduce tire rolling resistance, thereby increasing the service life of the tire. Both of the above patents achieve the purpose of reducing the amount of zinc used by improving the dispersion of zinc, and cannot completely eliminate the harm of zinc to the environment. Patent CN102300917B discloses a rubber composition that is zinc-free or contains less than 0.5 phr of zinc and is used in tire manufacturing. The patent uses blocked mercaptosilane to improve the processability of the rubber composition due to its zinc-free state (i.e., reducing viscosity and extending scorch time). Although this patent can reduce the amount of zinc or even exclude zinc, it requires the use of a specific blocked mercaptosilane, which may further react to form mercapto groups during high-temperature mixing, causing certain irritation and odor, and posing safety issues.

[0006] Therefore, there is a need to develop a zinc-free rubber composition that can break through the limitations of specific additives (such as specific silanes) and be used in tire manufacturing without sacrificing rubber compound properties. Summary of the Invention

[0007] The main purpose of the present invention is to provide a zinc-free rubber composition, a tread rubber, and a preparation method and application thereof, so as to solve the problem of performance degradation of the zinc-free rubber composition in the prior art.

[0008] To achieve the above-mentioned object, according to one aspect of the present invention, a zinc-free rubber composition is provided, comprising: a diene rubber, an antioxidant, a reinforcing functional filler, and a vulcanization system reagent, wherein the diene rubber comprises a special diene rubber, the chemical structure of which contains side chains and / or side groups, and the side chains and / or side groups contain alkenyl double bonds and / or aromatic groups.

[0009] Furthermore, the special diene rubber is obtained by polymerizing any one of butadiene and isoprene, or the special diene rubber is obtained by random copolymerization of any two or more of butadiene, isoprene and styrene.

[0010] Furthermore, the special diene rubber has a structure shown in Formula I: wherein a, b, c, d, e and f are each independently an integer greater than or equal to 0, and a, b, c, d, e and f are not 0 at the same time.

[0011]

[0012] Furthermore, the sum of the number of alkenyl double bonds and aromatic groups on the side groups and side chains of the special diene rubber accounts for more than 15% of the sum of the number of alkenyl double bonds and aromatic groups of the special diene rubber;

[0013] Preferably, the molecular weight of the special diene rubber is 10,000 to 4,000,000.

[0014] Furthermore, the special diene rubber accounts for more than 35% of the weight of the diene rubber, and preferably, accounts for more than 60% of the weight of the diene rubber.

[0015] Furthermore, the reinforcing functional filler includes any one or more of a carbon-based filler, a silicon-based filler, and a carbon-silicon dual-phase filler; preferably, the specific surface area of ​​the reinforcing functional filler is 10 to 500 m 2 / g, more preferably 30 to 300 m 2 / g, more preferably 50 to 300 m 2 / g; preferably, the amount of reinforcing functional filler is 20phr-170phr, more preferably 50phr-130phr.

[0016] Furthermore, the vulcanization system reagents include a vulcanizing agent and a vulcanization accelerator. Preferably, the vulcanizing agent includes any one or more of sulfur and sulfur carriers; preferably, the vulcanization accelerator includes any one or more of sulfonamide accelerators, thiazole accelerators and guanidine accelerators.

[0017] Furthermore, the antioxidant includes any one or more of p-phenylenediamines, protective waxes, quinolines, phenols and triazines; and / or, the zinc-free rubber composition also includes other additives, which include any one or more of silane coupling agents, stearic acid, antioxidants, scorch retardants, resins and operating oils.

[0018] Furthermore, the zinc-free rubber composition includes, by weight: 100 parts of diene rubber, 0 to 6 parts of antioxidant, 20 to 170 parts of reinforcing functional filler, 0.5 to 10 parts of vulcanization system reagent and 0 to 100 parts of other additives.

[0019] According to another aspect of the present application, a method for preparing tread rubber is provided, which comprises: mixing the components of any of the above-mentioned zinc-free rubber compositions except the vulcanization system reagent, and separating the components to obtain a masterbatch; and mixing the masterbatch with the vulcanization system reagent, and separating the components to obtain a final mixed rubber.

[0020] According to another aspect of the present application, a tread rubber is provided, which is prepared by any one of the above-mentioned rubber compositions or by the above-mentioned preparation method.

[0021] According to another aspect of the present application, a tire is provided, comprising the above-mentioned tread rubber.

[0022] By applying the technical solution of the present invention, a rubber composition using a certain proportion of special diene rubber can obtain a cross-linking density close to that of a zinc-containing rubber composition, and rubber properties such as hardness, tensile stress, and hysteresis without zinc, thereby meeting the requirements for manufacturing tire performance. The zinc-free rubber composition is used to prepare tread rubber, which has no zinc emissions and is environmentally friendly. Moreover, the rubber composition of the present application does not need to add a specific blocked mercaptosilane (S-octanoylmercaptopropyldihydroxymethylsilane), and can also avoid the reduction in tire performance caused by the low sulfur content of mercaptosilane and the further reaction to generate mercapto groups during high-temperature mixing. The irritation and odor that may occur. The use of the zinc-free rubber composition of the present application to prepare tread rubber can be carried out using mature methods and is highly safe. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0024] As analyzed in the background technology of this application, there is a problem in the prior art that the performance of zinc-free rubber compositions is reduced. In order to solve the problem, this application provides a zinc-free rubber composition, tread rubber, and a preparation method and application thereof.

[0025] According to a typical embodiment of the present application, the present application provides a zinc-free rubber composition, which includes: a diene rubber, an antioxidant, a reinforcing functional filler, and a vulcanization system reagent, wherein the diene rubber includes a special diene rubber, and the chemical structure of the special diene rubber contains side chains and / or side groups, and the side chains and / or side groups contain alkenyl double bonds and / or aromatic groups.

[0026] During the experiment, the researchers of the present application found that the rubber composition using a certain proportion of special diene rubber can obtain a cross-linking density close to that of a zinc-containing rubber composition, and rubber properties such as hardness, tensile stress, and hysteresis in the absence of zinc, meeting the requirements for manufacturing tire performance. The zinc-free rubber composition is used to prepare tread rubber, without zinc emissions, and is environmentally friendly. Moreover, the rubber composition of the present application does not need to add a specific blocked mercaptosilane (S-octanoylmercaptopropyldihydroxymethylsilane), and can also avoid the reduction in the interaction with the filler polymer caused by the low sulfur content of the mercaptosilane, thereby causing a reduction in tire performance, and the possibility of further reaction to generate mercapto groups during high-temperature mixing, and the irritation and odor that may occur. The use of the zinc-free rubber composition of the present application to prepare tread rubber can be carried out using a mature method with high safety.

[0027] The rubber in the rubber composition undergoes the following reaction steps and crosslinking forms during the vulcanization reaction:

[0028]

[0029] Cross-linking form II is an invalid cross-linking and cannot form a network, so it needs to be reduced or avoided. When there are many double bonds in the main chain, carbon-hydrogen free radicals The number is large, the distance between adjacent free radicals is short, there are more opportunities to form cross-linking form II, and the effective cross-linking density is low.

[0030] On the other hand: -S x The longer -, the greater the possibility of cross-linking form II. However, the participation of zinc oxide in the reaction can reduce the -Sx- bond length, reduce the occurrence of cross-linking form II, reduce ineffective cross-linking, and increase the effective cross-linking density.

[0031] RS x -R'+ZnO→RS x-1 -R'+ZnS

[0032] However, when applying special diene rubbers, it was found that by introducing double bonds through side groups or side chains, the number of double bonds on the main chain of the rubber macromolecule was reduced, the active α-H content was reduced, and the generation of S heterocycles (cross-linking form II) could be reduced, thereby increasing the effective cross-linking density.

[0033] In some embodiments of the present application, the above-mentioned special diene rubber is obtained by polymerizing any one of butadiene and isoprene, or the special diene rubber is obtained by random copolymerization of any two or more of butadiene, isoprene and styrene, and the zinc-free rubber composition containing the special diene rubber having such a structure has a higher crosslinking density.

[0034] In some typical embodiments of the present application, when the special diene rubber comprises a structure having the following formula I, the zinc-free rubber composition has a higher crosslinking density and better overall performance:

[0035]

[0036] Wherein, a, b, c, d, e, and f are each independently an integer greater than or equal to 0, and a, b, c, d, e, and f are not all 0. Preferably, at least two of a, b, c, d, e, and f are not 0. The repeating units are randomly distributed. In some preferred embodiments of the present application, in the structural formula of the special diene rubber, a, b, c are 0, and d, e, and f are not 0; or a, b, c are not 0, and d, e, and f are 0; or a, b, c, d are 0, and e, f are not 0. The special diene rubber having such a structure has a higher crosslinking density.

[0037] In some preferred embodiments of the present application, in order to further increase the crosslink density of the rubber composition, the sum of the number of alkenyl double bonds and aromatic groups on the side groups and side chains of the above-mentioned specialty diene rubber accounts for more than 15% of the total number of alkenyl double bonds and aromatic groups in the specialty diene rubber, such as 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 90%, or any range therebetween. It will be understood by those skilled in the art that the molecular structure of the specialty diene rubber may contain only side groups or side chains, or only alkenyl double bonds or aromatic groups on the side groups or side chains, and the number of alkenyl double bonds or aromatic groups on the side groups or side chains accounts for more than 15% of the total number of all alkenyl double bonds and aromatic groups in the molecular structure of the specialty diene rubber.

[0038] In some embodiments of the present application, the molecular weight of the special diene rubber is 10,000 to 4,000,000, which is beneficial to further improve the comprehensive performance of the tread rubber.

[0039] In some embodiments of the present application, in order to further improve the hardness and cross-linking degree of the rubber composition, in the above-mentioned zinc-free rubber composition, the special diene rubber is more than 35% of the weight of the diene rubber, preferably, more than 60% of the weight of the diene rubber. For example, the weight content of the above-mentioned special diene rubber in the diene rubber is 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100%, which has better comprehensive performance.

[0040] The reinforcing functional filler can work together with the special diene rubber of the present application to further improve the crosslinking degree, hardness and tensile strength of the rubber. The specific type of the reinforcing functional filler can be selected from the existing technology. For example, the reinforcing functional filler includes but is not limited to any one or more of carbon-based fillers, silicon-based fillers, and carbon-silicon dual-phase fillers. In some preferred embodiments of the present application, the specific surface area of ​​the reinforcing functional filler is 10 to 500 m 2 / g, more preferably 30 to 300 m 2 / g, more preferably 50 to 300 m 2 / g, the reinforcing functional filler with the above specific surface area has a more prominent effect, which is beneficial to further improve the comprehensive performance of the zinc-free rubber composition.

[0041] In some embodiments of the present application, the amount of the reinforcing functional filler is 20 phr-170 phr, more preferably 50 phr-130 phr, wherein phr represents the weight parts of the reinforcing functional filler or other additives per 100 parts by weight of rubber.

[0042] In some typical embodiments of the present application, the above-mentioned vulcanization system reagents include a vulcanizing agent and a vulcanization accelerator. Preferably, the vulcanizing agent includes any one or more of sulfur and sulfur carriers; preferably, the vulcanization accelerator includes any one or more of sulfonamide accelerators, thiazole accelerators and guanidine accelerators. The use of the above-mentioned vulcanization system reagents can further improve the vulcanization performance of the above-mentioned zinc-free rubber composition.

[0043] The above-mentioned antioxidant can be selected from the existing technology. In some embodiments of the present application, the antioxidant includes any one or more of p-phenylenediamine, protective wax, quinoline, phenol and triazine. The zinc-free rubber composition of the present application has better comprehensive performance.

[0044] The zinc-free rubber composition of the present application may also contain other zinc-free additives known in the art. These additives impart corresponding functionality to the rubber, thereby meeting the requirements of specific usage environments. Exemplary other additives include any one or more of a silane coupling agent, stearic acid, an antioxidant, a scorch retarder, a resin, and a process oil.

[0045] In some embodiments of the present application, the zinc-free rubber composition includes, by weight: 100 parts of diene rubber (calculated as dry rubber), 0 to 6 parts of antioxidant, 20 to 170 parts of reinforcing functional filler, 0.5 to 10 parts of vulcanization system reagent and 0 to 100 parts of other additives, which can better exert the synergistic effect between the components and further improve the comprehensive performance of the rubber composition.

[0046] According to another typical embodiment of the present application, a method for preparing tread rubber is provided, which comprises: mixing the components of any of the above-mentioned zinc-free rubber compositions except the vulcanization system reagent, and separating the components to obtain a masterbatch; and mixing the masterbatch with the vulcanization system reagent, and separating the components to obtain a final mixed rubber.

[0047] The tread rubber prepared by this method, because the raw materials do not contain any zinc reagents, produces no zinc emissions during use, making it environmentally friendly. Furthermore, it possesses similar crosslinking density, hardness, modulus, and hysteresis properties to those of zinc-containing rubber compositions, meeting the performance requirements of tire manufacturing. Furthermore, this method is relatively mature and highly safe.

[0048] In the preparation method of the tread rubber of the present application, the specific mixing process and parameters can refer to the existing technology, and the present application has no special requirements.

[0049] In some typical embodiments of the present application, the above-mentioned zinc-free rubber composition is prepared into rubber according to the following method: (1) rubber, processing aids, reinforcing functional fillers, antioxidants and other reagents except vulcanization system reagents are mixed by kneading once or multiple times, and the mixing temperature reaches 125°C to 200°C for rubber discharge to obtain a first-stage masterbatch; (2) the first-stage masterbatch is thermomechanically kneaded once or multiple times, and the kneading temperature is maintained at 125°C to 180°C, and the rubber discharge is maintained for 0 to 1200s to obtain a second-stage masterbatch; if there are any remaining processing aids, fillers, and antioxidants, they are all added to the second-stage masterbatch at this stage once or in batches; (3) the second-stage masterbatch is mixed with the vulcanization system reagents in an internal mixer, and the mixing temperature is ≤120°C, and the rubber is discharged to obtain the final rubber, i.e., the tread rubber.

[0050] According to another typical embodiment of the present application, a tread rubber is provided, the tread rubber being prepared using any of the aforementioned rubber compositions or any of the aforementioned preparation methods. The tread rubber is zinc-free and, during use, emits no zinc, thus being environmentally friendly. Furthermore, the tread rubber has a crosslink density similar to that of a zinc-containing rubber composition, and rubber properties such as hardness, modulus of tensile stress, and hysteresis, meeting the performance requirements for tire manufacturing.

[0051] According to another typical embodiment of the present application, a tire is provided, comprising the above-mentioned tread rubber. Due to the use of the above-mentioned tread rubber, the tire can effectively solve the environmental problem of zinc emissions and has good safety.

[0052] The following examples and comparative examples will further illustrate the beneficial effects that can be achieved by the present application.

[0053] 1. Rubber composition formula

[0054] The formulations of the rubber compositions of the embodiments and comparative examples of the present application are shown in Tables 1 and 2 below.

[0055] Table 1 (unit: phr)

[0056]

[0057] Table 2 (unit: phr)

[0058]

[0059]

[0060] The sources of the materials in Tables 1 and 2 are as follows:

[0061] SBR-1, Dushanzi Petrochemical SSBR2564S (styrene 25%, vinyl 64%, oil-extended 37.5phr);

[0062] BR-2, Qilu Petrochemical BR9000 (nickel-based high cis-butadiene, cis-1,4-polybutadiene content 97%);

[0063] SBR-3, Qilu Petrochemical ESBR1502 (styrene content 23.5%, vinyl content 15%);

[0064] IR-4, laboratory sample, (catalyst molybdenum pentachloride, polyisoprene rubber with 60% 3,4-(1,2-)polyisoprene content and 40% 1,4-polyisoprene content);

[0065] BR-5, laboratory sample, (catalyst molybdenum pentachloride, randomly branched polybutadiene rubber with 55% 1,2-polybutadiene content and 45% 1,4-polybutadiene content);

[0066] NR-6, Thailand Taihua Rayong 20# standard rubber STR 20 (cis-1,4 polyisoprene content 98% natural rubber);

[0067] Filler-1, Qucheng silica microbeads precipitated silica 165MP (BET 150~190m 2 / g);

[0068] Filler-2, Black Cat Carbon Black Furnace Black N330 (BET 71~85m 2 / g);

[0069] Silane coupling agent, Si69 from Nanjing Shuguang Company;

[0070] Resin, poly α-methylstyrene resin SA85 from Arizona Company, USA;

[0071] TDAE oil, V700 from Hansheng Company, Germany;

[0072] Stearic acid, Malaysian general reagent stearic acid (AR);

[0073] Indirect zinc oxide, Weifang Aolong Zinc Oxide Co., Ltd.

[0074] Antioxidant 6PPD / 4020, Shandong Shangshun Chemical Company;

[0075] Protective wax, Cmax31 from Suzhou Bairuimei Company;

[0076] Sulfur powder, Chaoyang Mingyu Chemical Co., Ltd.;

[0077] Accelerator CZ, Kemai Chemical Co., Ltd.

[0078] Accelerator DPG, Shandong Shangshun Chemical Co., Ltd.

[0079] The rubber compositions of the embodiments and comparative examples were used to prepare tread rubbers in the following manner:

[0080] (1) mixing rubber, filler, silane coupling agent, resin, TDAD oil, stearic acid, indirect zinc oxide (if the content is not zero), antioxidant, and protective wax by kneading, and the mixing temperature reaches 155° C. to prepare a masterbatch;

[0081] (2) subjecting the first stage masterbatch to one or more thermomechanical kneading processes and maintaining the kneading time for 0 to 120 seconds to obtain the second stage masterbatch;

[0082] (3) The second-stage masterbatch is mixed with sulfur powder, accelerator CZ and accelerator DPG in an internal mixer, and the mixing temperature is raised to 115°C for rubber discharge to obtain the final rubber mix.

[0083] (4) vulcanizing the final rubber on a flat vulcanizing machine to obtain vulcanized rubber.

[0084] The final rubber mixes prepared in the above examples and comparative examples and the vulcanized rubbers obtained by vulcanizing the final rubber mixes were subjected to the following tests. The test results are shown in Tables 3 and 4 below.

[0085] The vulcanization characteristics of the rubber compound were determined in accordance with GB / T 16584-1996 Determination of vulcanization characteristics of rubber using a rotorless vulcanizer. The test results are shown in Tables 3 and 4.

[0086] The physical properties of the rubber compound (tensile strength, elongation at break, 100% modulus stress, 300% modulus stress) were measured in accordance with GB / T 528-2009 Vulcanized rubber or thermoplastic rubber - Determination of tensile stress-strain properties. The results are shown in Tables 3 and 4.

[0087] The hardness of the rubber compound was determined in accordance with GB / T 531.1-2008 Test method for indentation hardness of vulcanized or thermoplastic rubber Part 1: Shore hardness method. The test results are shown in Tables 3 and 4.

[0088] The elastic modulus of the rubber compound at 20°C was determined in accordance with GB / T 9870.1-2006 Vulcanized or thermoplastic rubber - Determination of dynamic properties - Part 1: General principles, and the tanδmax of the rubber compound was determined using a rotational rheometer. The test results are shown in Tables 3 and 4.

[0089] Table 3 Physical properties of rubber

[0090]

[0091]

[0092] From the test results in Table 3, it can be seen that the rubber materials prepared from the zinc-free rubber composition of the present invention (Examples 1-4) have similar crosslinking density, modulus, stress, hardness, mechanical properties, and hysteresis properties to those of conventional zinc-containing rubber materials (Comparative Examples 1-4), and can be used to manufacture tires.

[0093] Table 4 Physical properties of rubber

[0094]

[0095] As can be seen from Table 4, the rubber of Comparative Example 5 uses conventional natural rubber and needs to be combined with zinc oxide to promote vulcanization to obtain a rubber compound that can be used in tire manufacturing. However, Examples 5 and 6 use diene rubber with a specific structure without adding zinc oxide, and also achieve rubber compound properties similar to those of Comparative Example 5.

[0096] Since the weight of the special diene rubber in Comparative Examples 6 and 7 is less than 35%, the mechanical properties and hardness thereof are significantly reduced. max The data is almost twice that of Examples 7 and 8, indicating that the hysteresis performance of the rubber compound has been seriously degraded. This proves that a specific ratio of special diene rubber is required to achieve the physical properties of conventional zinc-containing rubber compounds.

[0097] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: when using a special diene rubber, double bonds are introduced through side groups or side chains, reducing the number of double bonds on the rubber macromolecular main chain, reducing the active α-H content, and reducing the formation of S heterocycles (crosslinking form II), thereby increasing the effective crosslink density. Experiments have found that rubber compositions using a certain proportion of special diene rubber can achieve crosslink densities similar to those of zinc-containing rubber compositions, as well as rubber properties such as hardness, tensile stress, and hysteresis, without zinc, meeting the performance requirements of tire manufacturing. This zinc-free rubber composition can be used to prepare tread rubber, eliminating zinc emissions and being environmentally friendly. Furthermore, the rubber composition of the present application does not require the addition of a specific blocked mercaptosilane (S-octanoylmercaptopropyldihydroxymethylsilane), and can also avoid the reduced interaction with the filler polymer caused by the low sulfur content of the mercaptosilane, which can lead to reduced tire performance, as well as the irritation and odor caused by the further reaction to form mercapto groups during high-temperature mixing. The zinc-free rubber composition of the present application can be used to prepare tread rubber using a mature method with high safety.

[0098] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A zinc-free rubber composition, characterized in that include: Diene rubber, an antioxidant, a reinforcing functional filler, and a vulcanization system reagent, wherein the diene rubber includes a special diene rubber, and the special diene rubber accounts for more than 75% of the weight of the diene rubber; the chemical structure of the special diene rubber contains side chains and / or pendant groups, and the sum of the number of alkenyl double bonds and aromatic groups on the side groups and branches of the special diene rubber accounts for more than 15% of the sum of the number of alkenyl double bonds and aromatic groups of the special diene rubber; and the zinc-free rubber composition does not contain blocked mercaptosilane; The zinc-free rubber composition comprises, in parts by weight, 100 parts of diene rubber, 0-6 parts of antioxidant, 20-170 parts of reinforcing functional filler, 0.5-10 parts of vulcanization system reagent, and 0-100 parts of other additives; and the proportions of antioxidant and additives in the zinc-free rubber composition are not 0, and the other additives include a silane coupling agent.

2. The rubber composition according to claim 1, wherein The special diene rubber is obtained by polymerizing any one of butadiene and isoprene, or the special diene rubber is obtained by random copolymerization of any two or more of butadiene, isoprene and styrene.

3. The rubber composition according to claim 2, characterized in that The special diene rubber has a structure shown in Formula I: Formula I Wherein, a, b, c, d, e and f are each independently an integer greater than or equal to 0, and a, b, c, d, e and f are not 0 at the same time.

4. The rubber composition according to claim 1, characterized in that The molecular weight of the special diene rubber is 10,000-4,000,000.

5. The rubber composition according to claim 1, wherein The reinforcing functional filler includes any one or more of a carbon-based filler, a silicon-based filler, and a carbon-silicon dual-phase filler.

6. The rubber composition according to claim 5, characterized in that The specific surface area of ​​the reinforcing functional filler is 10 to 500 m 2 / g.

7. The rubber composition according to claim 5, characterized in that The specific surface area of ​​the reinforcing functional filler is 30 to 300 m 2 / g.

8. The rubber composition according to claim 5, characterized in that The specific surface area of ​​the reinforcing functional filler is 50 to 300 m 2 / g.

9. The rubber composition according to claim 5, characterized in that The amount of the reinforcing functional filler is 20 phr-170 phr.

10. The rubber composition according to claim 5, characterized in that The amount of the reinforcing functional filler is 50 phr-130 phr.

11. The rubber composition according to claim 1, wherein The vulcanization system reagents include a vulcanizing agent and a vulcanization accelerator.

12. The rubber composition according to claim 11, characterized in that The vulcanizing agent includes any one or more of sulfur and sulfur carriers.

13. The rubber composition according to claim 11, characterized in that The vulcanization accelerator includes any one or more of a sulfenamide accelerator, a thiazole accelerator, and a guanidine accelerator.

14. The rubber composition according to claim 1, wherein The antioxidant includes any one or more of p-phenylenediamine, protective wax, quinoline, phenol and triazine; And / or, the other additives further include any one or more of stearic acid, antioxidant, scorch retarder, resin and process oil.

15. A method for preparing tread rubber, characterized in that: include: Mixing the components of the zinc-free rubber composition according to any one of claims 1 to 14 except the vulcanization system reagent, and performing rubber removal to obtain a masterbatch; The masterbatch is mixed with the vulcanization system reagent, and the rubber is discharged to obtain the final rubber. 16 . A tread rubber prepared by the rubber composition according to claim 1 or the method according to claim 15 .

17. A tire comprising the tread rubber according to claim 16.

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