A rubber composite and a method for producing the same

Abstract

The application discloses a rubber composite material and a preparation method thereof. The raw materials of the rubber composite material include raw rubber, white carbon black, ionic liquid copolymer sulfur, silane coupling agent, antioxidant and vulcanization package. The weight of the white carbon black is 50wt%-100wt% of the raw rubber, the weight of the ionic liquid copolymer sulfur is 0.1wt%-3wt% of the white carbon black, and the weight of the silane coupling agent / the weight of the white carbon black is less than or equal to 10wt%. The rubber composite material can fully utilize the in-situ catalysis of the ionic liquid copolymer sulfur on the silanization reaction of the white carbon black, improve the dispersion of the white carbon black in the rubber matrix, and enhance the interface interaction between the rubber and the white carbon black, so that the rubber composite material has high quasi-static mechanical properties and dynamic fatigue properties.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of tread rubber, and particularly relates to a rubber composite material and a preparation method thereof. BACKGROUND

[0002] White carbon black filled rubber composite material is called "green tire" tread material, which can balance the rolling resistance and wet skid resistance. However, due to the existence of a large number of silicon hydroxyl groups on the surface of white carbon black, white carbon black is prone to self-aggregation in the rubber matrix, thereby affecting the performance of the rubber composite material. Therefore, the uniform dispersion of white carbon black in the rubber matrix and the strong interfacial interaction between rubber and white carbon black are the key to obtaining a rubber composite material with excellent comprehensive performance.

[0003] In order to fully exert the application potential of white carbon black in rubber composite materials, especially in tires, researchers have used various surface treatment techniques to improve the compatibility of white carbon black and rubber, such as using coupling agents or high molecular physical coating or covalent grafting modification of white carbon black, using electron beam or plasma treatment of white carbon black, etc. Patent application file CN106832417B discloses a method of modifying white carbon black with aliphatic polyoxyethylene ether by using chemical combination and physical adsorption to achieve good dispersion of white carbon black in the rubber matrix, and patent application file CN110734653B discloses a method of modifying white carbon black by chemical coating, by controlling the type and content of silane coupling agent to control the surface chemical properties of white carbon black. The above methods usually have the defects of insufficient interfacial interaction between white carbon black and rubber matrix and the need for additional steps to pre-modify white carbon black. In order to further improve the interaction between white carbon black and rubber, patent application file CN104804231A discloses a method of improving the dynamic performance of tread rubber by using small molecule ionic liquid to catalyze the silanization reaction between white carbon black and silane coupling agent. However, the tread rubber modified by the above method has low modulus and low breaking strength, and often fails due to the migration of ionic liquid during processing and storage.

[0004] In the process of implementing the present application, the inventors found that in the process of improving the performance of rubber by in-situ catalyzing the silanization reaction of white carbon black with ionic liquid, due to the large difference in polarity between ionic liquid small molecules and non-polar rubber, the compatibility between ionic liquid and rubber is poor, the ionic liquid acts as a plasticizer, reducing the modulus and breaking strength of the rubber composite material; and the ionic liquid migrates from the inside of the rubber to the surface during processing and storage, resulting in failure. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a rubber composite material and a preparation method thereof, which can solve the above-mentioned problems of the prior art.

[0006] To solve the above-mentioned technical problem, in one aspect, a rubber composite material is provided, raw materials of which include raw rubber, white carbon black, ionic liquid copolymer sulfur, silane coupling agent, antioxidant and vulcanization package, the weight of the white carbon black is 50wt%-100wt% of the raw rubber, the weight of the ionic liquid copolymer sulfur is 0.1wt%-3wt% of the white carbon black, and the weight of the silane coupling agent / the weight of the white carbon black≤10wt%.

[0007] Compared with the prior art, the present application has the following advantages:

[0008] 1. The present application provides a rubber composite material, which has significantly improved quasi-static mechanical properties, significantly reduced rolling resistance and significantly improved wet skid resistance, wherein the tensile strength is increased by about 30%, the 300% modulus is increased by about 33%, the loss factor is reduced by about 35%, and the fatigue temperature rise is reduced by about 51%.

[0009] 2. The rubber composite material of the present application, raw materials of which include raw rubber, white carbon black, ionic liquid copolymer sulfur and silane coupling agent, the sulfur chains in the ionic liquid copolymer sulfur are grafted to the rubber molecules, the compatibility of the rubber and the ionic liquid is increased, the catalytic efficiency of the silane coupling agent and the silanization reaction of the white carbon black is improved, the dispersion degree of the white carbon black in the rubber matrix is improved, and the interfacial interaction between the white carbon black and the rubber is significantly enhanced.

[0010] 3. In the rubber composite material of the present application, the amount of the silane coupling agent can be as low as 4wt% of the mass of the white carbon black, and a rubber composite material with high quasi-static mechanical properties and dynamic fatigue properties can be obtained.

[0011] 4. In the rubber composite material of the present application, the comprehensive performance of the rubber composite material is strongly related to the basicity of the ionic liquid copolymer sulfur, and the modification effect can be adjusted by changing the composition of the ionic liquid copolymer sulfur.

[0012] 5. The method for preparing the above-mentioned rubber composite material of the present application only needs to add the ionic liquid copolymer sulfur in situ during the preparation of the rubber composite material, so that the preparation of the rubber composite material can be realized without additional steps, which is conducive to popularization and application in industry.

[0013] The technical solutions of the present application will be further described in detail below in combination with embodiments. DETAILED DESCRIPTION

[0014] The technical solutions of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0015] In the following description, the term "and / or" is used to describe the association relationship of associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the cases of A alone, B alone and A and B existing at the same time. Wherein A and B can be singular or plural.

[0016] In the following description, the terms "include", "contain", "have" and "contain" and the like are all open terms, that is, they mean to include but not limited to.

[0017] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of the serial numbers does not mean the order of execution, and some or all steps can be executed in parallel or in sequence, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0018] Those skilled in the art should understand that the numerical ranges in the embodiments of the present application should be understood as also specifically disclosing each intermediate value between the upper limit and the lower limit of the range. Each smaller range between any stated value or stated range of values and any other stated value or stated range of values, as well as any other stated value or stated range of values within the stated range, is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.

[0019] Unless otherwise specified, the technical / scientific terms used herein have the same meaning as generally understood by those of ordinary skill in the art to which the present application belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present application. All documents mentioned in the specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of conflict between the content of the specification and any incorporated document, the content of the specification shall prevail.

[0020] The technical principle adopted by the present application is that the ionic liquid copolymer sulfur contains an ionic liquid part and a sulfur chain part, the ionic liquid part can interact with the silicon hydroxyl on the surface of the white carbon black to generate a silicon oxygen negative ion, catalyze the silanization reaction of the silane coupling agent with the white carbon black, the polysulfide bond can be broken under high temperature conditions to generate a sulfur free radical, the ionic liquid part is grafted to the rubber molecular chain to improve the compatibility of the ionic liquid with the rubber, improve the catalytic efficiency of the silanization reaction, the ionic liquid part and the sulfur chain part in the ionic liquid copolymer sulfur cooperate with each other to play a role as a whole, realize the high dispersion of the white carbon black in the rubber matrix, the interface interaction between the rubber and the white carbon black is stronger, the hysteresis loss is lower, and higher quasi-static mechanical properties and dynamic fatigue properties are shown.

[0021] Some embodiments provide a rubber composite material: raw materials include raw rubber, white carbon black, ionic liquid copolymer sulfur, silane coupling agent, antioxidant and curing package; the weight of the white carbon black is 50wt%-100wt% of the raw rubber, the weight of the ionic liquid copolymer sulfur is 0.1wt%-3wt% of the white carbon black, and the weight of the silane coupling agent / weight of the white carbon black≤10wt%. The ionic liquid copolymer sulfur is used to catalyze the silanization of the white carbon black in situ to improve the dispersion characteristics of the white carbon black in the rubber matrix, enhance the interface interaction between the rubber and the white carbon black, and obtain a rubber composite material with high static mechanical properties and dynamic fatigue properties. The weight of the ionic liquid copolymer sulfur is 0.1wt%-3wt% of the white carbon black, and the inventor finds that when the weight of the ionic liquid copolymer sulfur is limited to 0.1wt%-3wt% of the white carbon black, the simultaneous enhancement of the silanization reaction of the silane coupling agent with the white carbon black and the enhancement of the direct interface strength between the rubber and the white carbon black through the polysulfide chain can be realized, the use efficiency of the silane coupling agent and the dispersion degree of the white carbon black in the rubber matrix are both obviously improved, when the amount of the ionic liquid copolymer sulfur is less than 0.1wt% of the white carbon black, the catalytic effect on the silanization reaction between the silane coupling agent and the white carbon black is weak, and the performance of the rubber composite material cannot be well optimized, when the amount is more than 3wt% of the white carbon black, the hysteresis loss of the rubber composite material is obviously increased, and the dynamic performance is reduced, which may be due to the strong polarity of the ionic liquid copolymer sulfur.

[0022] The ionic liquid copolymer sulfur is a kind of copolymer sulfur, which is prepared by free radical addition reaction of sulfur free radicals generated by thermal excitation state sulfur and olefin-containing monomers, and its synthesis method mainly includes the following two kinds: one is that under high temperature conditions, sulfur and ionic liquid containing olefin groups are polymerized by bulk polymerization to directly obtain ionic liquid copolymer sulfur, and the other is that when the ionic liquid is an ionic liquid containing imidazole and other amine compounds and halogen groups, under high temperature conditions, first, sulfur and olefin containing halogen groups are copolymerized by free radical addition, and then imidazole and other amine compounds are added to carry out quaternary ammonium reaction to obtain ionic liquid copolymer sulfur.

[0023] In some embodiments, the structure of the ionic liquid copolymerized sulfur is shown as follows:

[0024]

[0025] wherein x is 2-6; R1 is a fatty chain molecule or an aromatic ring molecule, the fatty chain molecule including a carbon-hydrogen fatty chain molecule and / or a heteroatom-containing fatty chain molecule, the fatty chain molecule including a linear fatty chain molecule and / or a branched fatty chain molecule; the heteroatom including O and / or N;

[0026] R2 is an ionic liquid moiety, the ionic liquid moiety including a cation moiety and an anion moiety, wherein the cation moiety is an alkyl imidazole, an alkyl pyridine or an organic phosphonium salt, and the anion moiety is chloride, bromide, iodide, hexafluorophosphate, tetrafluoroborate, acetate or hydroxide.

[0027] In some embodiments, in the ionic liquid moiety, the cation moiety is an alkyl imidazole, and the anion moiety is hydroxide, acetate or chloride, more preferably, the anion moiety is hydroxide; and in the ionic liquid copolymerized sulfur, the basicity of the cation moiety from strong to weak is as follows: alkyl imidazole, alkyl pyridine, organic phosphonium salt; and the basicity of the anion moiety from strong to weak is as follows: hydroxide, acetate, chloride, bromide, iodide, hexafluorophosphate, tetrafluoroborate. The inventors have found that the basicity of the ionic liquid copolymerized sulfur affects the performance of the rubber composite material, and the stronger the basicity of the ionic liquid copolymerized sulfur, the higher the comprehensive performance of the rubber composite material, and the modulus and rolling resistance performance of the rubber composite material are both significantly improved, which may be due to the stronger basicity of the ionic liquid copolymerized sulfur, the stronger the promotion effect on the silanization reaction between the silane coupling agent and the white carbon black.

[0028] In some embodiments, the silane coupling agent is present in an amount of 4 wt% to 10 wt% of the weight of the white carbon black, and the silane coupling agent is a functional group-containing alkoxysilane. In some preferred embodiments, the silane coupling agent is a sulfur-containing alkoxysilane. In some specific embodiments, the silane coupling agent is silane coupling agent Si69 or Si75. The addition of sulfur-containing silane coupling agents, such as bis-[gamma-(triethoxysilyl)propyl]tetrasulfide (Si69) and / or bis-[3-(triethoxysilyl)propyl]-disulfide (Si75), can achieve in-situ modification of the rubber composite, which is mainly due to the presence of two different functional groups in the silane coupling agent, namely the alkoxyl group and the sulfur-containing organic functional group. The alkoxyl group reacts with the surface silanol groups of the white carbon black, and the sulfur-containing organic functional group reacts with the rubber to couple the rubber and the white carbon black. The reactivity of the silane coupling agent with the white carbon black is low, and a large amount of silane coupling agent needs to be added to improve the modification effect. Typically, the amount of silane coupling agent added is about 10 wt% of the weight of the white carbon black. The inventors have found that increasing the amount of silane coupling agent does not proportionally increase the modification effect, but instead generates a multi-molecular layer on the surface of the white carbon black due to self-condensation or intermolecular condensation, forming an uncontrollable interface structure. The inventors have unexpectedly found that in a rubber composite containing the ionic liquid copolymer sulfur of the above formula and the sulfur-containing silane coupling agent, the silane coupling agent can be coupled with the rubber molecules while the condensation reaction between the alkoxyl group and the surface silanol groups of the white carbon black occurs at the same time, achieving efficient and rapid silanization, and the efficiency of the silane coupling agent is higher. At the same time, it is found that the amount of environmentally harmful products such as alcohols generated during the reaction is significantly reduced.

[0029] In some embodiments, the raw rubber is a diene rubber. The inventors have found that under high temperature conditions, a large amount of sulfur radicals generated by the ionic liquid copolymer sulfur will add to the double bonds in the diene rubber and / or abstract the allylic hydrogen protons, coupling the rubber molecular chains and grafting, achieving specific modification of the diene rubber by the ionic liquid copolymer sulfur modified white carbon black, and improving the overall performance of the rubber.

[0030] In some preferred embodiments, the raw rubber is one or more of styrene-butadiene rubber, natural rubber, and cis-butadiene rubber. In some specific embodiments, the raw rubber is solution-polymerized styrene-butadiene rubber, solution-polymerized styrene-butadiene rubber and cis-butadiene rubber in a mass ratio of 7:3, or solution-polymerized styrene-butadiene rubber and natural rubber in a mass ratio of 7:3.

[0031] In some specific embodiments, the antioxidant is antioxidant 4010NA, and the vulcanization package includes zinc oxide, stearic acid, accelerator CZ, accelerator D, and sulfur. Antioxidants are commonly used raw materials in the rubber industry, and the amount and type will vary depending on the type of raw rubber. The vulcanization package is a commonly used raw material in the rubber industry, and the type of vulcanization package will vary depending on the type of raw rubber.

[0032] In another aspect, provided is a method for preparing a rubber composite material, comprising:

[0033] S1. First-stage mixing: raw rubber, antioxidant, white carbon black, silane coupling agent and ionic liquid copolymerized sulfur are sequentially added into an internal mixer, the rotor speed is 20-40 rpm, and mixing is performed for 3-10 minutes, and the discharge temperature is 50-70 DEG C, to obtain a first-stage mixed rubber; when the mixing time is less than 3 minutes, the raw rubber, white carbon black and the remaining additive components cannot be uniformly mixed, and when the mixing time is more than 10 minutes, the mechanical properties of the rubber compound are obviously decreased, which may be due to the fact that the long mixing time causes the serious chain scission of the rubber molecular chain.

[0034] S2. Second-stage mixing: the first-stage mixed rubber is cooled at room temperature, and the cooled first-stage mixed rubber is mixed in the internal mixer, the rotor speed is 30-70 rpm, mixing is performed for 2-6 minutes, and the discharge temperature is 130-170 DEG C, to obtain a second-stage mixed rubber, and the second-stage mixed rubber is cooled at room temperature; when the second-stage mixing time is less than 2 minutes, the performance of the rubber composite material is poor, which may be due to the fact that the low mixing time cannot significantly promote the silanization reaction and the promotion efficiency is low, and when the mixing time is more than 6 minutes, the rubber compound is heated for a long time at high temperature, which may cause defects such as scorching and oxidation rupture, directly affecting the performance of the rubber composite material.

[0035] S3. The cooled second-stage mixed rubber is added with a curing package on an open mill, a triangle package is punched, and the rubber is placed overnight, vulcanized, to obtain a rubber composite material. The method for preparing the rubber composite material has high matching degree with the traditional rubber mixing process, and only needs to add the ionic liquid copolymerized sulfur in situ to realize the modification of the rubber, without the need of additional steps or special equipment.

[0036] A series of experiments were carried out before the application, and part of the test results are listed below to further describe the application.

[0037] Example 1

[0038] According to the formula in Table 1, raw rubber, antioxidant, white carbon black, silane coupling agent and ionic liquid copolymerized sulfur are sequentially added into an internal mixer for first-stage mixing for 5 minutes, the speed is controlled to discharge at 60 DEG C, to obtain a mixed rubber; the mixed rubber is cooled at room temperature, and the cooled rubber is mixed in the internal mixer for second-stage mixing for 6 minutes, the speed is controlled to discharge at 130 DEG C, and a curing package is added on an open mill after cooling, a triangle package is punched, and the rubber is placed overnight, and then molded and vulcanized at 150 DEG C according to the normal vulcanization time, to obtain a sample, and the corresponding formula and sample are shown as Comparative Sample 1, Sample 1, Sample 2 and Sample 3.

[0039] The raw rubber, antioxidant, white carbon black, silane coupling agent and ionic liquid copolymerized sulfur were sequentially added into a mixing mill according to the formulation in Table 1 to carry out one-stage mixing for 7 min, and the rotation speed was controlled to make the 50℃ discharge glue, to obtain a mixed rubber; then the mixed rubber was cooled at room temperature, and the cooled rubber was placed in the mixing mill to carry out two-stage mixing for 3 min, and the rotation speed was controlled to make the 160℃ discharge glue, and then the vulcanization package was added on the open mill, the triangle package was punched, and then the sample was placed overnight, and the sample was molded and vulcanized at 150℃ according to the normal vulcanization time, to obtain the sample, and the corresponding formulation and sample are shown as Comparative Sample 2, Sample 4 and Sample 5;

[0040] The preparation method of the ionic liquid copolymerized sulfur is as follows:

[0041] 5g of sulfur was melted at 130℃, 5g of 4-vinylbenzyl chloride was added, and the reaction was carried out at the same temperature for 6h to obtain a chlorine-containing copolymer, 2.5g of N-methyl imidazole was added to quaternize the chlorine-containing copolymer, to obtain ionic liquid copolymerized sulfur, and the structural formula is as follows:

[0042]

[0043] The standard for measuring tensile strength, elongation at break and 300% modulus is ISO 37-2005, the test temperature is room temperature, and the tensile rate is 500mm / min; the standard for measuring fatigue heat generation is ISO 4666-3:2016; the rolling resistance (tanδ value at 60℃ under 7% strain and 10Hz frequency) is measured by RPA. The sample test and characterization results are shown in Table 2.

[0044] In Table 1, SSBR is solution polymerized butadiene styrene rubber, the type is VSL5025-2, and the oil filling amount is 37.5phr; BR is butadiene rubber, the type is CB24; NR is natural rubber, the type is 3L; and the raw rubber amount in this embodiment is the sum of the oil-removed part of the oil-filled SSBR, BR and NR;

[0045] Table 1 formulation and process

[0046]

[0047]

[0048] Antioxidant 4010NA 2 parts;

[0049] Vulcanization package: zinc oxide 3 parts, stearic acid 2 parts, accelerator CZ 1.5 parts, accelerator D 2 parts, and sulfur 1.5 parts;

[0050] Table 2 static mechanical properties and dynamic properties

[0051]

[0052] It can be seen from the comparison of the comparative sample 1 and the samples 1-3 that, compared with before modification, the tensile strength and 300% modulus (MPa) of the rubber composite material with the addition of the ionic liquid copolymer sulfur are significantly improved, and the loss factor and the fatigue temperature rise are obviously reduced, wherein the tensile strength is increased by about 30% at most, the 300% modulus is increased by about 33% at most, the loss factor is reduced by about 35% at most, and the fatigue temperature rise is reduced by about 51% at most. It is shown that the introduction of the ionic liquid copolymer sulfur into the rubber composite material can effectively improve the quasi-static mechanical properties and dynamic fatigue properties of the rubber composite material. In addition, with the increase of the amount of the ionic liquid copolymer sulfur, the comprehensive performance of the rubber composite material is further enhanced, which may be due to the fact that the addition of the ionic liquid copolymer sulfur can simultaneously enhance the silanization reaction of the catalytic Si69 and the white carbon black, and the direct interface strength between the rubber and the white carbon black is enhanced through the polysulfide chain, the use efficiency of the silane coupling agent and the dispersity of the white carbon black in the rubber matrix are obviously improved, and the interface adhesion between the materials is stronger.

[0053] It can be seen from the comparison of the comparative sample 2 and the samples 4-5 that, when the amount of the silane coupling agent is reduced, the performance of the rubber composite material with the addition of the ionic liquid copolymer sulfur is still better than that of the rubber composite material without the addition of the ionic liquid copolymer sulfur. It is shown that the method of the present application can reduce the amount of the silane coupling agent while maintaining the comprehensive mechanical properties of the rubber composite material, has a higher modification efficiency, and is conducive to reducing the VOC emission.

[0054] According to the formula in Table 3, the raw rubber, antioxidant, white carbon black, silane coupling agent and ionic liquid copolymer sulfur were sequentially added to a mixing mill for one-stage mixing for 10 minutes, and the rotation speed was controlled to discharge the rubber at 70 ℃ to obtain a mixed rubber; then the mixed rubber was cooled at room temperature, and the cooled rubber was placed in the mixing mill for two-stage mixing for 3 minutes, and the rotation speed was controlled to discharge the rubber at 170 ℃, and then sulfur was added to the rubber on an open mill, and the rubber was wrapped into a triangle bag and then placed overnight, and the rubber was molded and vulcanized at 150 ℃ according to the normal vulcanization time to obtain samples; the corresponding formula and samples are shown in the comparative sample 3, the sample 6, the sample 7, the sample 8, the sample 9 and the sample 10. The sample testing and characterization methods are the same as the above methods, and the results are shown in Table 4. When the cation is butyl imidazole and the anion is hexafluorophosphate, the preparation method of the ionic liquid copolymer sulfur includes: 5 g of sulfur is melted at 165 ℃, 5 g of 1-vinyl-3-butyl imidazole bromide is added, and the reaction is carried out for 3 h to obtain an ionic liquid with a cation of butyl imidazole and an anion of bromine, the ionic liquid is dissolved in water, and 3.2 g of hexafluorophosphoric acid is added to carry out anion replacement reaction to obtain an ionic liquid copolymer sulfur with a cation of butyl imidazole and an anion of hexafluorophosphate; the preparation methods of the remaining ionic liquid copolymer sulfurs are basically the same as the above method.

[0055] Table 3 Formula and process

[0056]

[0057]

[0058] Antioxidant 4010NA 2 parts;

[0059] Vulcanization package: zinc oxide 3 parts, stearic acid 2 parts, accelerator CZ 1.5 parts, accelerator D 2 parts, sulfur 1.5 parts;

[0060] Table 4 Quasi-static mechanical properties and dynamic properties

[0061] Comparative Sample 3 Sample 6 Sample 7 Sample 8 Sample 9 Sample 10 Tensile strength (MPa) 16.4 17.8 18.4 18.7 18.5 18.0 Elongation at break (%) 400 420 413 405 407 410 300% modulus (MPa) 14.6 16.8 17.5 18.3 18.0 17.8 Tan delta value (7%, 10 Hz, 60°C) 0.211 0.162 0.145 0.130 0.132 0.140 Fatigue temperature rise (°C) 25.2 18.6 15.3 14.4 13.1 14.6

[0062] It can be seen from the comparison of Comparative Sample 3 and Samples 6-10 that the rubber composite material added with the ionic liquid copolymerized sulfur of the application has significantly higher tensile strength, 300% modulus, and significantly lower loss factor and fatigue temperature rise compared with the rubber composite material added with the ionic liquid. This is because the small molecular ionic liquid has poor compatibility with the rubber matrix, and its plasticizing property can reduce the modulus and breaking strength of the rubber composite material. The ionic liquid copolymerized sulfur can effectively improve the compatibility of the ionic liquid with the rubber, which is mainly due to the fact that it can be grafted on the molecular chain of the rubber.

[0063] Based on Samples 6-8, it can be seen that when the cationic group in the ionic liquid copolymerized sulfur is unchanged, the tensile strength and rolling resistance performance of the rubber composite material show an increasing trend as the anionic group changes from tetrafluoroborate (Sample 6), hexafluorophosphate (Sample 7) to acetate (Sample 8). According to Samples 8-10, when the anionic group in the ionic liquid copolymerized sulfur is unchanged, the rolling resistance performance of the composite material shows an increasing trend as the cationic group changes from triphenylphosphine (Sample 10), pyridine (Sample 9) to imidazole (Sample 8), indicating that as the basicity of the ionic liquid copolymerized sulfur increases, the comprehensive performance of the rubber composite material improves, which may be due to the fact that the basic ionic liquid copolymerized sulfur has higher promotion efficiency for the silanization reaction.

Claims

1. A rubber composite material, characterized by, The raw materials include raw rubber, white carbon black, ionic liquid copolymer sulfur, silane coupling agent, antioxidant and vulcanization package; the weight of the white carbon black is 50wt%-100wt% of the raw rubber, the weight of the ionic liquid copolymer sulfur is 0.1wt%-3wt% of the white carbon black, and the weight of the silane coupling agent / the weight of the white carbon black is ≤10wt%; the silane coupling agent is sulfur-containing alkoxysilane; in the ionic liquid of the ionic liquid copolymer sulfur, the cation part is alkyl imidazole, alkyl pyridine or organic phosphorus salt, and the anion part is chloride, bromide, iodine, hexafluorophosphate, tetrafluoroborate, acetate or hydroxide; the raw rubber is diene rubber.

2. The rubber composite of claim 1, wherein, The weight of the silane coupling agent is 4wt%-10wt% of the white carbon black.

3. The rubber composite of claim 1, wherein, The cation part is alkyl imidazole, and the anion part is hydroxide, acetate or chloride.

4. A method of preparing the rubber composite of claim 1, characterized in that, It comprises: Raw rubber, antioxidant, white carbon black, silane coupling agent and ionic liquid copolymer sulfur are sequentially added into a mixing mill for mixing to obtain a first-stage mixed rubber; After cooling, the first-stage mixed rubber is placed in the mixing mill for mixing to obtain a second-stage mixed rubber; After cooling, the second-stage mixed rubber is mixed with a vulcanization package, and vulcanized to obtain a rubber composite material.

5. The method of claim 4, wherein, In the first-stage mixing, the rotor speed is 20-40 rpm, the mixing time is 3-10 minutes, and the discharge temperature is 50-70℃.

6. The method of claim 4, wherein, In the second-stage mixing, the rotor speed is 30-70 rpm, the mixing time is 2-6 minutes, and the discharge temperature is 130-170℃.

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