A low odor, low heat build-up overcoat rubber composition, mixing method and tire

Abstract

This invention relates to the field of new tire materials technology, and more particularly to a low-odor, low-heat-generating outer rubber composition, a mixing method, and a tire. The low-odor, low-heat-generating outer rubber composition uses a natural rubber composite material to completely or partially replace natural rubber. This natural rubber composite material includes an antibacterial agent that acts on microorganisms before they decompose the non-rubber components, rather than adsorbing or removing the malodorous gases produced after the microorganisms have decomposed the non-rubber components. This fundamentally eliminates the occurrence of natural rubber deterioration, mold growth, and foul odor, thus avoiding the malodorous gases produced by tires made from natural rubber.

Description

Technical Field

[0001] This invention relates to the field of new tire materials technology, and in particular to a low-odor, low-heat-generating outer protective rubber composition, a mixing method, and a tire. Background Technology

[0002] With the rapid development of the automotive industry, automakers are placing increasingly higher demands on tire performance, with requirements for both grip and rolling resistance generally rising. The strong desire for extended driving range in new energy vehicles is also driving up the requirements for tire rolling resistance. Therefore, simply reducing the heat generation of the tread and sidewall rubber is no longer sufficient to meet the low rolling resistance requirements. In response, major tire manufacturers have begun developing low-heat-generating components for the base rubber, gusset rubber, and outer sheath rubber.

[0003] The odor of a car spare tire mainly originates from four components: the tread, sidewall, outer casing, and inner liner. Since the spare tire is mounted on the rim, the inner liner has a relatively small impact on the odor. The odor-causing substances primarily come from rubber, filler oils, antioxidants, and accelerators. Although odor can be optimized by selecting environmentally friendly oils, antioxidants, and accelerators, natural rubber, due to its excellent overall performance, remains the most consumed type of rubber in the tire industry. Natural rubber often refers to Rubber trifoliate orange, a solid natural elastomer material made from latex collected from the Rubber trifoliate orange tree in Brazil through processes such as coagulation, dehydration, and drying. It is also an important strategic material and industrial raw material. Because natural rubber is biosynthesized, it contains small amounts of non-rubber components such as proteins and phospholipids. Under the action of microorganisms or bacteria, these non-rubber components are decomposed into small molecules containing amino and thiol functional groups, which have a foul odor. Therefore, natural rubber emits a foul odor during its production, storage, and use.

[0004] Numerous scholars both domestically and internationally have conducted extensive research on controlling the odor of natural rubber, and existing technologies have disclosed several methods for deodorizing natural rubber. Chinese patent CN113501893A discloses an environmentally friendly natural rubber processing method. This method involves adding a 1:1 to 3 composite bacterial solution of a sterilizing agent and a coagulating agent to fresh latex. After coagulation, the gel block is left to stand and mature, producing a natural rubber raw product. This method utilizes the composite bacteria to decompose non-rubber components in the fresh latex, thereby reducing the odor during the gel block maturation process. Chinese patent CN102558395A discloses a biological deodorization method for natural rubber fresh latex biological blocks. This method involves inoculating a test tube slant culture of strain C1 into water containing 5 wt% sugar, then culturing it in a shaker at 28-35°C for 2-4 days to prepare a biological deodorizing solution. This solution is then mixed into a biological coagulation solution at a weight ratio of 1:10 to 1:1 for coagulating the fresh latex. This method changes the application of the biological deodorizing liquid from the traditional spraying method on the surface of the rubber gel block to mixing the coagulant into the gel block during the latex coagulation stage, coagulating it together with the fresh latex, and then uniformly dispersing it inside the gel block. This is equivalent to adding a long-lasting active deodorant during the coagulation stage of the fresh latex, inhibiting odor generation at the source. This prevents the gel block from emitting odor during processing due to the presence of the active deodorant, and also reduces odor release during the drying process of the standard rubber. Chinese patent CN108164767A discloses an odorless natural rubber and a rubber compound thereof. The preparation method involves adding a modified zeolite molecular sieve dispersion to natural rubber latex, coagulating the natural rubber latex using different coagulation methods, pressing it into sheets, suspending the sheets at room temperature for a period of time, granulating them, soaking them in a deodorant for a certain time, and then drying them in a hot air drying oven to obtain odorless natural rubber. This method utilizes the strong adsorption properties of zeolite molecular sieves modified with coupling agents, which can adsorb the odor generated during rubber processing. At the same time, soaking with deodorant further reduces the odor generated by protein denaturation during the curing of natural rubber. It can effectively remove the odor generated during the initial processing of natural rubber as well as during plasticizing and mixing.

[0005] While the aforementioned technologies disclose methods for preparing odorless natural rubber or deodorizing natural rubber, they only address the technical problem of odor generation during natural rubber production. They do not address the technical issues of natural rubber deterioration, mold growth, and foul odor during long-term storage and use. Therefore, reducing or eliminating odor generation during the storage and use of natural rubber is currently the biggest challenge facing the natural rubber industry. Thus, solving the odor problem of natural rubber can improve the odor level of the outer sheath rubber, thereby reducing the odor level of the spare tire. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a low-odor, low-heat-generating outer rubber composition. This composition uses a natural rubber composite material to completely or partially replace natural rubber. This natural rubber composite material includes an antibacterial agent that acts on microorganisms before they decompose the non-rubber components, rather than adsorbing or removing the malodorous gases produced after the microorganisms have decomposed the non-rubber components. This fundamentally eliminates the occurrence of natural rubber deterioration, mold growth, and odor, and avoids the malodorous gases produced by tires made of natural rubber.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A low-odor, low-heat-generating outer sheath rubber composition is prepared by mixing raw materials comprising the following components;

[0009] Rubber A

[0010] Rubber reinforcing filler A,

[0011] In addition, appropriate amounts of antioxidants, accelerators, activators and sulfur;

[0012] The compounding raw materials for this outer protective rubber composition also include a natural rubber composite material, which is prepared by wet compounding of raw materials comprising the following components, based on 100 parts by weight of rubber B:

[0013] Rubber B 100 parts

[0014] Rubber reinforcing filler B 5.0-20 parts

[0015] 0.05-1.0 parts of 1,3,5-triazine or its derivatives with antibacterial activity;

[0016] In the outer protective rubber composition, rubber A + rubber B are 100 parts by weight, and rubber B is natural rubber; rubber reinforcing filler A + rubber reinforcing filler B are 65-90 parts by weight.

[0017] Preferably, the natural rubber composite material is prepared by wet mixing of raw materials comprising the following components, based on 100 parts by weight of rubber B:

[0018] Rubber B 100 parts

[0019] Rubber reinforcing filler B 8.0-15 parts

[0020] 0.1-0.5 parts of 1,3,5-triazine or its derivatives with antibacterial activity;

[0021] Preferably, the rubber reinforcing filler A + rubber reinforcing filler B is 70-80 parts.

[0022] Preferably, the natural rubber is fresh field latex or concentrated latex.

[0023] Preferably, rubber A is selected from one or more of natural rubber, butadiene rubber, styrene-butadiene rubber and polybutadiene rubber; more preferably, rubber A is selected from one or two of natural rubber and polybutadiene rubber; most preferably, rubber A is polybutadiene rubber, and the amount of rubber A is 40-60 parts and the amount of rubber B is 40-60 parts.

[0024] Preferably, rubber reinforcing filler A and rubber reinforcing filler B are selected from one or more of carbon black or silica;

[0025] Preferably, the BET specific surface area of ​​the carbon black particles is 20-160 m² / g, more preferably 40-130 m² / g, and even more preferably 50-120 m² / g; the average secondary particle size of the carbon black particles is preferably 0.05-3 μm, more preferably 0.1-1.0 μm, and even more preferably 0.2-0.9 μm; most preferably, the carbon black is one or a mixture of N134, N220, N234, N330, N375, and N550.

[0026] Preferably, the BET specific surface area of ​​the silica is 50–250 m². 2 / g, preferably 80-210m 2 / g, more preferably 100-190m2 / g; the average secondary particle size of silica is preferably 0.04-3μm, more preferably 0.1-1μm, and even more preferably 0.2-0.7μm;

[0027] As a further preferred option, N330 carbon black is selected for rubber reinforcing filler B; preferably, the amount of rubber reinforcing filler is 60-75 parts.

[0028] Preferably, the rubber reinforcing filler includes silica, and the natural rubber composite material further includes a surfactant, which is 0.1%-10% of the silica content. The applicant's experiments have shown that when silica is present, a surfactant needs to be added to complete the composite of the rubber reinforcing filler and natural rubber molecular chains in the aqueous phase, achieve co-flocculation with the latex, and uniformly disperse in the rubber matrix. However, for carbon black, the addition of a surfactant is not required.

[0029] More preferably, the surfactant is one or more of octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, decyl methyl sulfoxide, and sodium dodecyl sulfate, and more preferably one or more of octylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, and sodium dodecyl sulfate.

[0030] Preferably, the antioxidant is 0.5-1.5 parts of antioxidant TMQ and 1.0-2.0 parts of antioxidant 6PPD, the activator is 2.0-4.0 parts of zinc oxide and 1.0-3.0 parts of stearic acid, the accelerator is 0.5-1.5 parts of accelerator CZ and 2.0-3.0 parts of sulfur; the rubber composition also includes 3.0-5.0 parts of V700 environmentally friendly oil and 0.5-1.5 parts of microcrystalline wax.

[0031] Preferably, the mixing method for natural rubber composite materials includes the following steps:

[0032] 1) Obtain antibacterial slow-release particles by simultaneously pulverizing the antibacterial agent and the rubber reinforcing filler at high speed;

[0033] 2) Antibacterial sustained-release particles are dispersed in the aqueous phase and prepared into a sustained-release particle dispersion by grinding; or the antibacterial sustained-release particles are directly...

[0034] 3) The slow-release particle dispersion is mixed with natural rubber latex, flocculated, and dried to obtain the long-lasting low-odor natural rubber composite material; or, the antibacterial slow-release particles from step 1) are directly mixed with natural rubber latex, flocculated, and dried to obtain the long-lasting low-odor natural rubber composite material.

[0035] In step (1), high-speed pulverization can be achieved using a high-speed pulverizing mixer; specifically, the antibacterial agent and rubber reinforcing filler are placed into the high-speed pulverizing mixer. Any existing high-speed pulverizing mixer can be used. During high-speed pulverization, excessively low rotation speed will result in poor pulverization effect and uneven mixing and adsorption of the antibacterial agent and carrier; excessively high rotation speed is not very meaningful and will increase energy consumption, equipment wear, and equipment investment, and will also damage the structure of the antibacterial carrier. The rotation speed range of the high-speed pulverizing mixer is 100~5000 r / min, preferably 200-3000 r / min.

[0036] In step (1), during the high-speed pulverization of the antibacterial agent and the rubber reinforcing filler, the antibacterial agent and the rubber reinforcing filler are thoroughly mixed, and the antibacterial agent is adsorbed onto the rubber reinforcing filler. The degree of mixing and adsorption between the antibacterial agent and the rubber reinforcing filler will affect the final antibacterial and low-odor effect. In order to obtain a good antibacterial and low-odor effect, the antibacterial agent and the rubber reinforcing filler should be thoroughly mixed and adsorbed. When using a high-speed pulverizer and mixer, in order to ensure that the mixing and adsorption are sufficient during pulverization, the stirring and pulverization time is 1-120 min, preferably 5-60 min.

[0037] In step (2), the grinding of the aqueous phase can be achieved using grinding equipment. Specifically, a high-shear disperser, ultrasonic crusher, colloid mill, ball mill, or sand mill can be used, with colloid mill, ball mill, or sand mill being preferred. If the grinding time is too short, the grinding effect will be poor, the antibacterial agent will not disperse well in the rubber matrix, and there is a possibility of deterioration in areas without antibacterial agent particles; it will also affect other properties of the rubber product. In order to solve the odor problem while ensuring that the product performance does not decrease or even improves, the grinding time can be 10-300 min, preferably 30-120 min; the grinding temperature can be 25-80℃, preferably 25-60℃.

[0038] In step (2), the solid content of the obtained sustained-release particle nanodispersion is 1%-40%, preferably 3%-20%.

[0039] In step (3), if the mixing time is too short, the antibacterial slow-release particles will not bond well with the rubber, resulting in losses and a deterioration in the effect; if the mixing time is too long, it will lead to energy waste. Therefore, the mixing time can be 10-120 min, preferably 20-60 min.

[0040] In step (3), flocculation is carried out using a flocculant; the flocculant is one or more of formic acid, acetic acid, sodium chloride, calcium chloride, and protease, preferably one or more of formic acid, acetic acid, protease, and calcium chloride.

[0041] Furthermore, the present invention also discloses a low-odor, low-heat tire, characterized in that the outer protective rubber of the tire is prepared by vulcanization of the aforementioned tire rubber composition.

[0042] The present invention uses 1,3,5-triazine as the most preferred solution, but other antibacterial agents can also be used to replace 1,3,5-triazine. Other antibacterial agents are one or more of 1,2-benzisothiazolin-3-one, N-octyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, zinc pyridinethione and sodium benzoate; preferably one or more of 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, triazine and zinc pyridinethione.

[0043] This invention prepares a long-lasting, low-odor natural rubber nanocomposite material by adding appropriate amounts of 1,3,5-triazine and rubber reinforcing filler to natural rubber latex. While 1,3,5-triazine inhibits bacterial and fungal growth, its antibacterial effect is short-lived when added alone. Adding rubber reinforcing filler simultaneously with 1,3,5-triazine allows for sustained-release of the 1,3,5-triazine, similar to a slow-release drug, as the 1,3,5-triazine continuously migrates outward from the pores of the rubber reinforcing filler. Furthermore, the rubber reinforcing filler is uniformly dispersed in the natural rubber, ensuring the overall antibacterial effect of the compound. Since the rubber reinforcing filler is a necessary material for the rubber itself, it does not affect the rubber's properties. In fact, the further dispersion of the rubber reinforcing filler reduces the heat generation of the rubber composition, thereby further reducing tire rolling resistance.

[0044] Compared with the prior art, the present invention reduces the odor level and heat generation of the outer rubber composition by applying a long-lasting antibacterial and low-odor natural rubber composite material without changing the existing mixing, final mixing and vulcanization process, thereby bringing about beneficial improvements in odor and rolling resistance. Detailed Implementation

[0045] The technical solutions of the present invention will be thoroughly reviewed and described below with reference to the embodiments of the present invention, thereby further explaining the invention. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art without creative effort, based on the embodiments of the present invention, are within the scope of protection of the present invention.

[0046] Example 1

[0047] A long-lasting antibacterial and low-odor natural rubber composite material, which is prepared by wet compounding of the following components based on 100 parts by weight of natural rubber:

[0048] 100 parts natural rubber

[0049] Carbon black N330 10 parts

[0050] 0.1 part of 1,3,5-triazine;

[0051] The mixing method for the aforementioned long-lasting antibacterial and low-odor natural rubber composite material is as follows:

[0052] Take 10 parts of carbon black and 0.1 parts of 1,3,5-triazine and mix them in a high-speed mixer at 200 r / min for 10 min to ensure that the carbon black and 1,3,5-triazine are fully mixed and adsorbed, thus obtaining antibacterial slow-release particles. Take the above antibacterial slow-release particles and disperse them in 100 parts of pure water, and grind them in a colloid mill at 25℃ for 30 min to obtain a slow-release particle nano-dispersion. Take the above slow-release particle nano-dispersion and slowly pour it into 100 parts of natural rubber latex (based on dry rubber weight) and stir and mix for 20 min to ensure that the slow-release particles in the slow-release particle nano-dispersion are fully combined with the latex to obtain a mixed rubber solution. Then, mix the mixed rubber solution with 0.8% formic acid solution (based on dry rubber weight), flocculate, dehydrate, and dry to obtain a long-lasting, low-odor natural rubber nanocomposite material, thus obtaining natural rubber composite material A.

[0053] Example 2

[0054] A long-lasting antibacterial and low-odor natural rubber composite material, which is prepared by wet compounding of the following components based on 100 parts by weight of natural rubber:

[0055] 100 parts natural rubber

[0056] Carbon black N330 10 parts

[0057] 0.2 parts of 1,3,5-tris(2-hydroxyethyl)hexahydrotriazine;

[0058] The above-mentioned mixing method for a long-lasting antibacterial and low-odor natural rubber composite material is shown in Example 1, and natural rubber composite material B is obtained.

[0059] Example 3

[0060] A long-lasting antibacterial and low-odor natural rubber composite material, which is prepared by wet compounding of the following components based on 100 parts by weight of natural rubber:

[0061] 100 parts natural rubber

[0062] Carbon black N330 10 parts

[0063] 10 parts of silica

[0064] 0.5 parts of octylphenol polyoxyethylene ether

[0065] 0.5 parts of 1,3,5-triazine;

[0066] The mixing method for the aforementioned long-lasting antibacterial and low-odor natural rubber composite material is as follows:

[0067] Take 10 parts of carbon black N330, 10 parts of silica, and 0.5 parts of 1,3,5-triazine and mix them in a high-speed mixer at 200 r / min for 10 min to ensure thorough mixing and adsorption of the carbon black and 1,3,5-triazine, thus obtaining slow-release antibacterial particles. Disperse the above slow-release antibacterial particles in 100 parts of purified water, add 0.5 parts of octylphenol polyoxyethylene ether, and grind them in a colloid mill at 25°C for 30 min to obtain a slow-release particle nano-dispersion. Slowly pour the above slow-release particle nano-dispersion into 100 parts of natural rubber latex (based on dry rubber weight) and stir for 20 min to ensure thorough compounding of the slow-release particles in the nano-dispersion with the latex, thus obtaining a mixed rubber solution. Subsequently, mix the mixed rubber solution with a 0.8% formic acid solution (based on dry rubber weight), flocculate, dehydrate, and dry to obtain a long-lasting, low-odor natural rubber nanocomposite material, thus obtaining natural rubber composite material C.

[0068] Example 4

[0069] A long-lasting antibacterial and low-odor natural rubber composite material, which is prepared by wet compounding of the following components based on 100 parts by weight of natural rubber:

[0070] 100 parts natural rubber

[0071] Carbon black N330 10 parts

[0072] 0.5 parts of octylphenol polyoxyethylene ether

[0073] 0.1 part of 1,3,5-triazine;

[0074] The mixing method for the aforementioned long-lasting antibacterial and low-odor natural rubber composite material is as follows:

[0075] Ten parts of carbon black N330 and 0.1 parts of 1,3,5-triazine were mixed in a high-speed mixer at 200 r / min for 10 min to ensure thorough mixing and adsorption of the carbon black and 1,3,5-triazine, resulting in slow-release antibacterial particles. These particles were dispersed in 100 parts of purified water, and 0.5 parts of octylphenol polyoxyethylene ether were added. The mixture was then ground in a colloid mill at 25°C for 30 min to obtain a slow-release particle nano-dispersion. This slow-release particle nano-dispersion was slowly poured into 100 parts of natural rubber latex (based on dry rubber weight) and stirred for 20 min to ensure thorough integration of the slow-release particles with the latex, resulting in a mixed solution. The mixed solution was then mixed with a 0.8% formic acid solution (based on dry rubber weight) for flocculation, dehydration, and drying to obtain a long-lasting, low-odor natural rubber nanocomposite material, thus obtaining natural rubber composite material D.

[0076] Comparative Example 1

[0077] Natural rubber solids E were obtained by adding an appropriate amount of formic acid solution to natural latex with a solid content of 25%, followed by flocculation, dehydration, and drying.

[0078] Comparative Example 2

[0079] A natural rubber composite material, which is prepared by wet compounding of the following components based on 100 parts by weight of natural rubber:

[0080] 100 parts natural rubber

[0081] Carbon black N330, 10 parts;

[0082] The mixing method for the aforementioned long-lasting antibacterial and low-odor natural rubber composite material is as follows:

[0083] Take 10 parts of carbon black and add it to 100 parts of natural rubber latex (dry weight). Stir and mix for 20 minutes to fully combine the carbon black and latex to obtain a mixed solution. Then, mix the mixed solution with a 0.8% formic acid solution (dry weight) to form a flocculation, dehydrate and dry to obtain natural rubber nanocomposite material F.

[0084] Comparative Example 3

[0085] A natural rubber composite material, which is prepared by wet compounding of the following components based on 100 parts by weight of natural rubber:

[0086] 100 parts natural rubber

[0087] 0.1 part of 1,3,5-triazine;

[0088] The mixing method for the aforementioned long-lasting antibacterial and low-odor natural rubber composite material is as follows:

[0089] Take 0.1 parts of 1,3,5-triazine and disperse it in 100 parts of purified water. Then slowly pour it into 100 parts of natural rubber latex (based on dry rubber weight) and stir for 20 minutes to fully combine 1,3,5-triazine with the latex to obtain a mixed solution. Subsequently, mix the mixed solution with 0.8% formic acid solution (based on dry rubber weight) for flocculation, dehydration, and drying to obtain a long-lasting, low-odor natural rubber nanocomposite material, thus obtaining natural rubber composite material G.

[0090] Table 1: Sample Odor Rating and Odor Changes After 1 Year of Storage

[0091] Sample number Initial odor level Odor rating after 1 year A 3.0 3.5 B 3.0 3.5 C 3.0 3.5 D 3.0 3.5 E 3.5 4.5 F 3.0 4.5 G 3.0 4.0

[0092] Note: Odor rating is assessed using a 6-level method, referring to SMTC 5 400 012-2011 (V1).

[0093] Application Example 1

[0094] This application example is used for tire outer protective rubber. The reference ratio is conventional natural rubber. Examples 1-4 and Comparative Examples 1-3 use natural rubber composite materials A, B, C, D, E, F, and G after one year of storage, respectively. The specific formulations are shown in Table 1.

[0095] Table 1

[0096]

[0097] The reference, example, and comparative examples were all processed using the same conventional mixing and final mixing processes, and test pieces were prepared by vulcanizing at 160°C for 15 minutes using a flat vulcanizing machine. The dynamic viscoelastic properties of the rubber compositions were characterized using the DMA test method, and the heat generation properties of the rubber compositions were characterized by tanδ at 60°C; the lower the tanδ, the lower the heat generation. Odor was characterized using a 6-level odor test; the lower the value, the lower the odor.

[0098] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A low-odor, low-heat-generating outer sheath rubber composition, the outer sheath rubber composition being prepared by compounding raw materials comprising the following components; Rubber A Rubber reinforcing filler A, The rubber composition also includes appropriate amounts of antioxidants, accelerators, activators, and sulfur; the antioxidants are 0.5-1.5 parts of antioxidant TMQ and 1.0-2.0 parts of antioxidant 6PPD, the activators are 2.0-4.0 parts of zinc oxide and 1.0-3.0 parts of stearic acid, the accelerators are 0.5-1.5 parts of accelerator CZ and 2.0-3.0 parts of sulfur; the rubber composition also includes 3.0-5.0 parts of V700 environmentally friendly oil and 0.5-1.5 parts of microcrystalline wax. Its features are, The compounding raw materials for this outer protective rubber composition also include a natural rubber composite material, which is prepared by wet compounding of raw materials comprising the following components, based on 100 parts by weight of rubber B: Rubber B 100 parts Rubber reinforcing filler B 5.0-20 parts 0.05-1.0 parts of 1,3,5-triazine or its derivatives with antibacterial activity; Rubber reinforcing filler B is selected from carbon black N330; The mixing method for natural rubber composite materials includes the following steps: 1) The antibacterial agent and the rubber reinforcing filler are simultaneously subjected to high-speed pulverization to obtain antibacterial slow-release particles. The pulverization speed is 100~5000r / min and the pulverization time is 1-120min. 2) The antibacterial sustained-release particles are dispersed in the aqueous phase. The solid content of the sustained-release particle nano-dispersion is 1%-40%. The sustained-release particle dispersion is prepared by grinding. The grinding time is 10-300 min and the grinding temperature is 25-80℃. 3) The slow-release particle dispersion is mixed with natural rubber latex, flocculated, and dried to obtain the long-lasting low-odor natural rubber composite material; In the outer protective rubber composition, rubber A + rubber B are 100 parts by weight, and rubber B is natural rubber; rubber reinforcing filler A + rubber reinforcing filler B are 65-90 parts by weight.

2. The low-odor, low-heat-generating outer protective rubber composition according to claim 1, characterized in that, Natural rubber composite materials are prepared by wet compounding of raw materials comprising the following components, with rubber B as 100 parts by weight: Rubber B 100 parts Rubber reinforcing filler B 8.0-15 parts 0.1-0.5 parts of 1,3,5-triazine or its derivatives with antibacterial activity.

3. The low-odor, low-heat-generating outer protective rubber composition according to claim 2, characterized in that, The rubber reinforcing filler A and rubber reinforcing filler B consist of 70-80 parts.

4. A low-odor, low-heat-generating outer protective rubber composition according to claim 1 or 2, characterized in that, Rubber A is selected from one or more of natural rubber, butadiene rubber, styrene-butadiene rubber and polybutadiene rubber.

5. The low-odor, low-heat-generating outer protective rubber composition according to claim 4, characterized in that, Rubber A is selected from one or a mixture of two types of natural rubber and polybutadiene rubber.

6. The low-odor, low-heat-generating outer sheath rubber composition according to claim 4, characterized in that, Rubber A consists of 10-30 parts natural rubber and 50-70 parts polybutadiene rubber, while rubber B consists of 10-30 parts natural rubber.

7. A low-odor, low-heat-generating outer sheath rubber composition according to claim 1 or 2, characterized in that, Rubber reinforcing filler A is selected from one or more of carbon black or silica.

8. The low-odor, low-heat-generating outer protective rubber composition according to claim 7, characterized in that, The BET specific surface area of ​​the carbon black particles is 20–160 m². 2 / g.

9. The low-odor, low-heat-generating outer protective rubber composition according to claim 7, characterized in that, The BET specific surface area of ​​the carbon black particles is 40–130 m². 2 / g.

10. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The BET specific surface area of ​​the carbon black particles is 50-120 m². 2 / g.

11. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The average secondary particle size of the carbon black particles is 0.05–3 μm.

12. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The average secondary particle size of the carbon black particles is 0.1–1.0 μm.

13. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The average secondary particle size of the carbon black particles is 0.2–0.9 μm.

14. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The carbon black is one or a mixture of N134, N220, N234, N330, N375, and N550.

15. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The BET specific surface area of ​​silica is 50–250 m². 2 / g.

16. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The BET specific surface area of ​​silica is 80–210 m². 2 / g.

17. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The BET specific surface area of ​​silica is 100–190 m². 2 / g.

18. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The average secondary particle size of silica is 0.04–3 μm.

19. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The average secondary particle size of silica is 0.1–1 μm.

20. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The average secondary particle size of silica is 0.2–0.7 μm.

21. The low-odor, low-heat-generating outer sheath rubber composition according to claim 7, characterized in that, The rubber reinforcing filler A is selected from N550 carbon black and / or N330 carbon black.

22. The low-odor, low-heat-generating outer sheath rubber composition according to claim 21, characterized in that, N550 carbon black is 25-40 parts.

23. A low-odor, low-heat-generating outer sheath rubber composition according to claim 1 or 2, characterized in that, The rubber reinforcing filler A includes silica, and the natural rubber composite material also includes a surfactant, which is 0.1%-10% of the silica content.

24. The low-odor, low-heat-generating outer sheath rubber composition according to claim 23, characterized in that, The surfactant is one or more of octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, decyl methyl sulfoxide, and sodium dodecyl sulfate.

25. The low-odor, low-heat-generating outer sheath rubber composition according to claim 24, characterized in that, It is one or more of octylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, and sodium dodecyl sulfate.

26. The low-odor, low-heat-generating outer sheath rubber composition according to claim 1, characterized in that, In step (1), the grinding speed is 100~5000 r / min and the grinding time is 1-120 min.

27. The low-odor, low-heat-generating outer sheath rubber composition according to claim 1, characterized in that, In step (1), the grinding speed is 200-3000 r / min and the grinding time is 5-60 min.

28. The low-odor, low-heat-generating outer sheath rubber composition according to claim 1, characterized in that, In step (2), the solid content of the sustained-release particle nano-dispersion is 3%-20%.

29. The low-odor, low-heat-generating outer protective rubber composition according to claim 1, characterized in that, In step (2), the grinding time is 10-300 min and the grinding temperature is 25-80℃.

30. The low-odor, low-heat-generating outer sheath rubber composition according to claim 1, characterized in that, In step (3), the mixing time is 10-120 min.

31. The low-odor, low-heat-generating outer protective rubber composition according to claim 1, characterized in that, In step (3), the mixing time is 20-60 min.

32. The low-odor, low-heat-generating outer protective rubber composition according to claim 1, characterized in that, In step (3), flocculation is carried out using a flocculant; the flocculant is one or more of formic acid, acetic acid, sodium chloride, calcium chloride, and protease.

33. The low-odor, low-heat-generating outer protective rubber composition according to claim 1, characterized in that, In step (3), flocculation is carried out using a flocculant; the flocculant is one or more of formic acid, acetic acid, protease, and calcium chloride.

34. A low-odor, low-heat-generating tire, characterized in that, The outer protective rubber of the tire is prepared by vulcanization of the tire rubber composition according to any one of claims 1-33.

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