A special composite modified rubber for automobile tire and a preparation method thereof

Abstract

The application relates to the field of rubber materials, in particular to a special composite modified rubber for automobile tire and a preparation method thereof. The special composite modified rubber for automobile tire is prepared from the following raw materials in parts by mass: natural rubber 50-70 parts, composite rubber 30-40 parts, amino silane coupling agent 3-5 parts, carbon material 30-50 parts, modified nano-particle 15-25 parts, plasticizer 8-14 parts, activator 3-5 parts, dispersant 2-4 parts, antioxidant 1-1.5 parts, vulcanizing agent 1-3 parts and vulcanizing accelerator 1-2 parts. The special composite modified rubber for automobile tire prepared by the application not only has excellent wear resistance, but also has good aging resistance, temperature stability, waterproofness and skid resistance, and can effectively meet the performance requirements of automobile tire materials in the existing automobile field, and has very excellent market prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rubber materials, in particular to a special composite modified rubber for automobile tire and a preparation method thereof. BACKGROUND

[0002] With the development of the automobile industry, the automobile tire as an important part of the vehicle directly affects the safety and comfort of the automobile. Therefore, developing high-performance automobile tire materials has always been the focus of research. The special composite modified rubber for automobile tire is added with various functional fillers and modifiers to improve the wear resistance, waterproofness, aging resistance, heat stability and tear resistance of the rubber, so as to meet the high-performance requirements of modern automobile tires.

[0003] The traditional automobile tire rubber mainly uses natural rubber (NR) and is assisted with reinforcing agents such as carbon black and white carbon black for performance improvement. However, with the increase of automobile driving speed and the diversification of road conditions, the traditional rubber material cannot fully meet the requirements in some performances. Therefore, researchers have begun to explore new modification technologies and materials to further improve the comprehensive performance of the rubber.

[0004] Although the existing special composite modified rubber for automobile tire improves the performance of the tire to some extent, there are still the following problems. First, because the tire is exposed to ultraviolet light and air oxidation environment for a long time, it is easy to age and wear, which greatly affects the service life of the tire; second, during driving, the tire may encounter sharp objects piercing, and the existing composite modified rubber still needs to be improved in terms of tear resistance; finally, in some harsh environments in China, the existing composite modified rubber for tire has poor waterproofness and skid resistance, which limits its use quality in specific environments. Therefore, in order to effectively solve the above problems, the present application provides a special composite modified rubber for automobile tire and a preparation method thereof. The special composite modified rubber for automobile tire prepared by the present application not only has excellent wear resistance, but also has good aging resistance, temperature stability, waterproofness and skid resistance, etc. It can effectively meet the performance requirements of automobile tire materials in the existing automobile field, and has very excellent market prospect. SUMMARY

[0005] In order to solve the above problems, the first aspect of the present application provides a special composite modified rubber for automobile tire. The raw materials are as follows in terms of mass fraction: natural rubber 50-70 parts, composite rubber 30-40 parts, amino silane coupling agent 3-5 parts, carbon material 30-50 parts, modified nano-particle 15-25 parts, plasticizer 8-14 parts, activator 3-5 parts, dispersant 2-4 parts, antioxidant 1-1.5 parts, vulcanizing agent 1-3 parts, and vulcanization accelerator 1-2 parts.

[0006] As a preferred scheme, the mass ratio of the natural rubber, the composite rubber and the carbon material is (55-65):(32-38):(35-42).

[0007] As a preferred scheme, the mass ratio of the natural rubber, the composite rubber and the carbon material is (58-64):(34-36):(36-40).

[0008] As a preferred scheme, the mass ratio of the natural rubber, the modified nano-particle and the dispersant is (55-65):(18-24):(2.5-3.5).

[0009] As a preferred scheme, the mass ratio of the natural rubber, the modified nano-particle and the dispersant is (58-64):(20-23):(2.5-3).

[0010] As a preferred scheme, the Mooney viscosity of the natural rubber is 85-100, with the condition of ML1+4@100℃.

[0011] As a preferred scheme, the composite rubber is a combination of styrene butadiene rubber and liquid nitrile rubber.

[0012] As a preferred scheme, the mass ratio of the styrene butadiene rubber and the liquid nitrile rubber is (3-4):(1.5-2).

[0013] As a preferred scheme, the mass ratio of the styrene butadiene rubber and the liquid nitrile rubber is (3.5-3.8):(1.6-1.8).

[0014] As a preferred scheme, the kinematic viscosity of the liquid nitrile rubber is 11000-16000 cps, with the condition of 45℃.

[0015] As a preferred scheme, the kinematic viscosity of the liquid nitrile rubber is 12000-14000 cps, with the condition of 45℃.

[0016] As a preferred scheme, the Mooney viscosity of the styrene butadiene rubber is 40-60, with the condition of ML1+4@100℃.

[0017] As a preferred scheme, the Mooney viscosity of the styrene butadiene rubber is 50-55, with the condition of ML1+4@100℃.

[0018] In the present application, by adding the above-mentioned specific composite rubber compound and natural rubber compound, it is possible to ensure the wear resistance of the composite modified rubber while providing excellent aging resistance, temperature stability and waterproof and anti-skid properties. The compounding of the composite rubber compound with the above-mentioned specific viscosity can greatly enhance the wetting effect of the liquid rubber in the system during the mixing, and the modified nanoparticles added in the present application can greatly enhance its dispersion stability in the composite rubber compound, avoiding the segregation and migration of the modified nanoparticles in the rubber system, thereby promoting its stable provision of mechanical connection, waterproof and wear-resistant sites; on the other hand, the added composite rubber compound can greatly improve the fluidity of the early rubber compound, and the appropriate molecular chain length can serve as the connecting molecular chain of the composite rubber compound, while increasing the tightness of the internal colloid and increasing the movement resistance of water molecules and active groups, while increasing the connection movement rate of electrostatic particles and other charges, thereby achieving rapid electron conduction dissipation in long-term ultraviolet light, outdoor and air oxidation environments, and achieving a high absorption conversion of ultraviolet light on the rubber compound surface, thereby obtaining excellent aging resistance and heat stability.

[0019] As a preferred solution, the aminosilane coupling agent is at least one of γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

[0020] As a preferred solution, the aminosilane coupling agent is 3-aminopropyltriethoxysilane.

[0021] As a preferred solution, the carbon material is at least one of carbon black, carbon powder, graphene, graphene oxide and graphite.

[0022] As a preferred solution, the carbon material is carbon black.

[0023] As a preferred solution, the average particle size of the carbon black is 30 to 50 nm.

[0024] As a preferred scheme, the preparation method of the modified nanoparticles comprises the following specific steps: S1: adding titanium dioxide and ammonia water into deionized water, heating to 60-65°C, and adding dropwise a deionized water solution of tetraethyl orthosilicate, triethanolamine and γ-aminopropyltrimethoxysilane at a speed of 60-80 rpm, the dropwise adding time is 0.8-1 h, after the dropwise adding is completed, the reaction is kept for 1.2-1.5 h, after the completion, the pretreated particles are obtained by centrifugal filtration and drying; S2: adding the pretreated particles and anhydrous aluminum chloride into a DMF solution, preheating to 60-80°C for 1-2 h, then heating to 100-110°C, and adding dropwise a DMF solution containing 1,4-benzenedicarboxylic acid and 1,4-benzenedicarboxylic acid-NH2, respectively, the dropwise adding time is 2-3 h; S3: after the dropwise adding is completed, heating to 125-135°C, keeping the temperature for 16-18 h of reflux reaction, after the reaction is completed, naturally cooling to room temperature, collecting the solid product by filtration, and washing with DMF for several times to remove unreacted raw materials and other impurities, placing the filtered product in a vacuum drying oven at 80-90°C to dry overnight to remove residual solvent, and obtaining the modified nanoparticles after the completion.

[0025] As a preferred scheme, the mass ratio of the titanium dioxide, tetraethyl orthosilicate, triethanolamine and γ-aminopropyltrimethoxysilane is (3-3.5):(0.3-0.5):(0.05-0.08):(0.1-0.12).

[0026] As a preferred scheme, the mass ratio of the pretreated particles, anhydrous aluminum chloride, 1,4-benzenedicarboxylic acid and 1,4-benzenedicarboxylic acid-NH2 is (1-1.5):(2-2.2):(1-1.2):(0.8-1).

[0027] As a preferred scheme, the average particle size of the titanium dioxide is 10-20 nm.

[0028] As a preferred scheme, the average particle size of the modified nanoparticles is 400-480 nm.

[0029] The modified nanoparticles can effectively improve the wear resistance, aging resistance, temperature stability and waterproof and antiskid performance of the composite modified rubber. The modified nanoparticles can form a composite particle structure with titanium dioxide as a surface coating and a framework particle as a main body. The existence of the structure can not only form a stable heterojunction electron flow structure, but also ensure the degree of exposure of the main framework particle, thereby ensuring excellent ultraviolet light absorption potential while avoiding the influence of the surface hydroxyl group of titanium dioxide on the waterproof and moisture resistance of the particle. Thus, the ultraviolet and oxygen oxidation resistance can be greatly improved by improving the electron hole recovery resistance, thereby obtaining excellent aging resistance and temperature stability. The surface of the modified nanoparticles can provide excellent wear resistance and antiskid performance, and the rough peak and valley structure of the surface can form a continuous hydration layer to block water molecules on the surface, thereby obtaining excellent surface waterproof resistance.

[0030] As a preferred solution, the plasticizer is at least one of aromatic oil, paraffin oil, naphthenic oil, white oil and silicone oil.

[0031] As a preferred solution, the plasticizer is white oil.

[0032] As a preferred solution, the activator is at least one of magnesium oxide, calcium oxide, barium oxide and aluminum oxide.

[0033] As a preferred solution, the activator is magnesium oxide.

[0034] As a preferred solution, the average particle size of the activator is 0.5-1.5 μm.

[0035] As a preferred solution, the dispersant is at least one of zinc stearate, calcium stearate, tributyl phosphate, triphenyl phosphate and lauryl alcohol polyoxyethylene ether.

[0036] As a preferred solution, the dispersant is zinc stearate.

[0037] As a preferred solution, the antioxidant is at least one of BHT, antioxidant 1010, antioxidant 1076, antioxidant 1135 and antioxidant 245.

[0038] As a preferred solution, the antioxidant is antioxidant 1010 or antioxidant 1076.

[0039] As a preferred solution, the vulcanizing agent is sulfur.

[0040] As a preferred solution, the vulcanization accelerator is a combination of MBTS and DTDM.

[0041] As a preferred solution, the mass ratio of the MBTS and the DTDM is (3-3.5):(1.5-2).

[0042] The second aspect of the application provides a preparation method of the special composite modified rubber for automobile tire, which specifically comprises the following steps: S1: placing natural rubber and composite rubber into a mixing mill, mixing and preheating at 90-95 DEG C for 10-15 min, then adding amino silane coupling agent, carbon material, modified nanoparticles and dispersing agent for mixing for 6-8 min, continuously adding plasticizer, activator and antioxidant for mixing for 8-10 min; S2: adding vulcanizing agent and vulcanizing accelerator for mixing for 5-7 min, taking out the mixed rubber after ensuring uniform dispersion of all components, cooling to room temperature, and extruding the cooled rubber into a shape by an extruder; S3: placing the shaped rubber into a vulcanizing tank, setting the vulcanizing temperature to 130-145 DEG C, the vulcanizing pressure to 1.2-1.6 MPa, and the vulcanizing time to 30-35 min, and taking out the rubber after vulcanization and cooling to room temperature naturally.

[0043] The application has the following beneficial effects:

[0044] 1. The special composite modified rubber for automobile tire provided in the application not only has excellent wear resistance, but also has good aging resistance, temperature stability, waterproofness and skid resistance, and can effectively meet the performance requirements of automobile tire materials in the existing automobile field, and has very excellent market prospects.

[0045] 2. The special composite modified rubber for automobile tire provided in the application can ensure the wear resistance of the composite modified rubber while providing excellent aging resistance, temperature stability and waterproofness and skid resistance by compounding with specific composite rubber and natural rubber; the compounding of the composite rubber with specific viscosity can greatly enhance the wetting effect of the liquid rubber in the system during mixing, and the dispersion stability of the modified nanoparticles in the composite rubber can be greatly enhanced by cooperating with the modified nanoparticles added in the application, thereby avoiding the segregation and migration of the modified nanoparticles in the rubber system, so as to stably provide mechanical connection, waterproofness and wear resistance sites.

[0046] 3. The special composite modified rubber for automobile tire provided in the application can greatly improve the fluidity of the early-stage rubber while the suitable molecular chain length can act as a connecting molecular chain of the composite rubber, which can increase the movement resistance of water molecules and active groups while increasing the connection movement rate of electrostatic particles and other charges, so as to realize rapid electron conduction dissipation in a long-term ultraviolet light, outdoor and air oxidation environment, and achieve high absorption and conversion of ultraviolet light on the surface of the rubber, thereby obtaining excellent aging resistance and heat stability.

[0047] 4、The special composite modified rubber for automobile tire provided in the present application, the modified nano-particles added can form a composite particle structure with titanium dioxide as the surface coating and the framework particle as the main body. The existence of this structure can not only form a stable heterojunction electron flow structure, but also ensure the degree of exposure of the main framework particles, thereby ensuring excellent ultraviolet light absorption potential while avoiding the influence of the surface hydroxyl group of titanium dioxide on the water resistance and moisture resistance of the particles, thereby greatly improving the ultraviolet and oxygen oxidation resistance through the improvement of the electron hole recovery resistance in a long-term ultraviolet light and air oxidation environment, and further obtaining excellent aging resistance and temperature stability. The surface of the modified nano-particles can also provide excellent wear resistance and slip resistance, and the rough peak and valley structure on the surface can form a continuous hydration layer to block water molecules on the surface, thereby obtaining excellent surface water resistance. DETAILED DESCRIPTION

[0048] The technical solutions in the above summary of the present application will be further described and demonstrated in the form of specific embodiments below. The following examples are only actual examples for illustrating and explaining the content of the technical solutions in the specification, and should not limit the scope of the claims to be protected by the present application. Any technical product based on the technical solutions described in the summary of the present application should be covered in the scope to be protected by the present application.

[0049] In the following examples, unless otherwise specified, the raw materials are commercially available products or can be prepared by methods well known to those skilled in the art.

[0050] Example 1

[0051] Example 1 provides a special composite modified rubber for automobile tire, the raw materials are as follows in mass parts: natural rubber 61.6 parts, composite rubber 34.5 parts, amino silane coupling agent 3.8 parts, carbon material 38.8 parts, modified nano-particles 22.5 parts, plasticizer 9.8 parts, activator 3.4 parts, dispersant 2.8 parts, antioxidant 1.2 parts, vulcanizing agent 2.1 parts, and vulcanization accelerator 1.6 parts.

[0052] The Mooney viscosity of the natural rubber is 88, the condition is ML1+4@100℃, and the product is purchased from the RSS-3 model product sold by the Thailand Natural Rubber Public Company.

[0053] The composite rubber is a combination of butadiene styrene rubber and liquid butyl nitrile rubber, and the mass ratio of the two is 3.6:1.6.

[0054] The Mooney viscosity of the butadiene styrene rubber is 52, the condition is ML1+4@100℃, and the product is purchased from the SBR1500 model product sold by Jilin Petrochemical.

[0055] The kinematic viscosity of the liquid nitrile rubber is 12500 cps, conditions: 45℃, and is purchased from the NBR series product with corresponding viscosity sold by Shandong Shengrui Chemical Technology Co., Ltd.

[0056] The amino silane coupling agent is 3-aminopropyl triethoxysilane; the carbon material is carbon black N330, and the average particle size is 30 nm.

[0057] The preparation method of the modified nanoparticles comprises the following specific steps: S1: 3.3 parts of titanium dioxide and 0.2 parts of ammonia water are mixed and added into 100 parts of deionized water, heated to 65℃, and 0.45 parts of tetraethyl orthosilicate, 0.06 parts of triethanolamine and 0.11 parts of 60 parts of deionized water solution of γ-aminopropyl trimethoxysilane are added dropwise at a speed of 80 rpm, the dropwise adding time is 1h, after the dropwise adding is completed, the reaction is kept for 1.2h, after the completion, the centrifugal filtration and drying are carried out, and the pretreated particles are obtained; S2: 1.2 parts of the pretreated particles and 2.1 parts of anhydrous aluminum chloride are mixed and added into 120 parts of DMF solution, preheated to 75℃ for 2h, and then heated to 105℃, and 40 parts of DMF solution containing 1.1 parts of 1,4-benzenedicarboxylic acid and 0.9 parts of 1,4-benzenedicarboxylic acid-NH2 are added dropwise respectively, the dropwise adding time is 2h; S3: after the dropwise adding is completed, the temperature is increased to 125℃, and the reaction is kept for 18h, after the reaction is completed, the natural cooling to room temperature is carried out, the solid product is collected by filtration, and the filtration product is washed several times with DMF to remove the unreacted raw materials and other impurities, the filtered product is placed in a vacuum drying oven at 85℃ for drying overnight to remove the residual solvent, and the modified nanoparticles are obtained after the completion.

[0058] The average particle size of the titanium dioxide is 12nm; and the average particle size of the obtained modified nanoparticles is 424nm.

[0059] The plasticizer is white oil #5; the activator is magnesium oxide, and the average particle size is 0.8μm; the dispersing agent is zinc stearate; and the antioxidant is antioxidant 1010.

[0060] The vulcanizing agent is sulfur; and the vulcanizing accelerator is a combination of MBTS and DTDM, and the mass ratio of the two is 3.2:1.6.

[0061] The second aspect of the embodiment provides a preparation method of the special composite modified rubber for automobile tire, and specifically comprises the following steps: S1: placing natural rubber and composite rubber into a mixing mill, mixing and preheating at 92℃ for 12 min, then adding amino silane coupling agent, carbon material, modified nanoparticles and dispersant and mixing for 6.5 min, continuously adding plasticizer, activator and antioxidant and mixing for 8.5 min; S2: adding vulcanizing agent and vulcanizing accelerator and mixing for 6 min, taking out the mixed rubber after ensuring that all components are uniformly dispersed, cooling to room temperature, and extruding the cooled rubber into a shape by an extruder; S3: placing the shaped rubber into a vulcanization tank, setting the vulcanization temperature to 135℃, the vulcanization pressure to 1.5 MPa, and the vulcanization time to 32 min, and taking out the rubber after vulcanization and naturally cooling to room temperature.

[0062] Example 2

[0063] The specific implementation of the embodiment is basically the same as that of Example 1, and the only difference is that the special composite modified rubber for automobile tire is prepared from the following raw materials in parts by mass: natural rubber 55.2 parts, composite rubber 38 parts, amino silane coupling agent 3.8 parts, carbon material 35.5 parts, modified nanoparticles 18.8 parts, plasticizer 9.8 parts, activator 3.4 parts, dispersant 2.5 parts, antioxidant 1.2 parts, vulcanizing agent 2.1 parts, and vulcanizing accelerator 1.6 parts.

[0064] The composite rubber is a composition of styrene-butadiene rubber and liquid nitrile rubber, and the mass ratio of the two is 3:2.

[0065] The vulcanizing accelerator is a composition of MBTS and DTDM, and the mass ratio of the two is 3.5:1.5.

[0066] Example 3

[0067] The specific implementation of the embodiment is basically the same as that of Example 1, and the only difference is that the special composite modified rubber for automobile tire is prepared from the following raw materials in parts by mass: natural rubber 64.8 parts, composite rubber 32.5 parts, amino silane coupling agent 3.8 parts, carbon material 41.5 parts, modified nanoparticles 24 parts, plasticizer 9.8 parts, activator 3.4 parts, dispersant 3.5 parts, antioxidant 1.2 parts, vulcanizing agent 2.1 parts, and vulcanizing accelerator 1.6 parts.

[0068] The composite rubber is a composition of styrene-butadiene rubber and liquid nitrile rubber, and the mass ratio of the two is 4:1.5.

[0069] The vulcanizing accelerator is a composition of MBTS and DTDM, and the mass ratio of the two is 3:2.

[0070] Comparative Example 1

[0071] The specific implementation of the present comparative example is basically the same as that of Example 1, except that the automobile tire special composite modified rubber has the following raw materials in mass parts: natural rubber 75 parts, composite rubber 20.5 parts, amino silane coupling agent 3.8 parts, carbon material 32 parts, modified nanoparticles 22.5 parts, plasticizer 9.8 parts, activator 3.4 parts, dispersant 2.8 parts, antioxidant 1.2 parts, vulcanizing agent 2.1 parts, and vulcanizing accelerator 1.6 parts.

[0072] Comparative Example 2

[0073] The specific implementation of the present comparative example is basically the same as that of Example 1, except that the automobile tire special composite modified rubber has the following raw materials in mass parts: natural rubber 61.6 parts, composite rubber 34.5 parts, amino silane coupling agent 3.8 parts, carbon material 38.8 parts, modified nanoparticles 10.5 parts, plasticizer 9.8 parts, activator 3.4 parts, dispersant 1.1 parts, antioxidant 1.2 parts, vulcanizing agent 2.1 parts, and vulcanizing accelerator 1.6 parts.

[0074] Comparative Example 3

[0075] The specific implementation of the present comparative example is basically the same as that of Example 1, except that the composite rubber is a combination of butadiene styrene rubber and liquid butadiene nitrile rubber, and the mass ratio of the two is 6:1.

[0076] The liquid butadiene nitrile rubber has a kinematic viscosity of 17500 cps under the condition of 45°C, and is purchased from Shandong Shengrui Chemical Technology Co., Ltd. as a product of NBR series with a corresponding viscosity.

[0077] Comparative Example 4

[0078] The specific implementation of the present comparative example is basically the same as that of Example 1, except that the composite rubber is a combination of butadiene styrene rubber and liquid butadiene nitrile rubber, and the mass ratio of the two is 1:1.

[0079] The liquid butadiene nitrile rubber has a kinematic viscosity of 8500 cps under the condition of 45°C, and is purchased from Shandong Shengrui Chemical Technology Co., Ltd. as a product of NBR series with a corresponding viscosity.

[0080] Comparative Example 5

[0081] The specific embodiment of the comparative example is basically the same as that of Example 1, except that the preparation method of the modified nanoparticles comprises the following specific steps: S1: 4 parts of titanium dioxide and 0.2 parts of ammonia water are mixed and added to 100 parts of deionized water, heated to 65°C, and 0.68 parts of tetraethyl orthosilicate, 0.1 parts of triethanolamine and 0.25 parts of γ-aminopropyltrimethoxysilane in 60 parts of deionized water solution are added dropwise at a speed of 80 rpm, the dropwise time is 1h, after the dropwise addition is completed, the reaction is kept for 1.2h, after completion, centrifugal filtration and drying are carried out to obtain pretreated particles; S2: 1.2 parts of pretreated particles and 2.1 parts of anhydrous aluminum chloride are mixed and added to 120 parts of DMF solution, preheated to 75°C for 2h, then heated to 105°C, and 40 parts of DMF solution containing 1.1 parts of 1,4-benzenedicarboxylic acid and 0.9 parts of 1,4-benzenedicarboxylic acid-NH2 are added dropwise respectively, the dropwise time is 2h; S3: after the dropwise addition is completed, the temperature is raised to 125°C, and the reaction is kept for 18h, after the reaction is completed, the temperature is naturally cooled to room temperature, the solid product is collected by filtration, and washed several times with DMF to remove unreacted raw materials and other impurities, the filtered product is placed in a vacuum drying oven at 85°C for drying overnight to remove residual solvent, and the modified nanoparticles are obtained after completion.

[0082] The average particle size of the titanium dioxide is 30nm; the average particle size of the obtained modified nanoparticles is 644nm.

[0083] Comparative Example 6

[0084] The specific embodiment of the comparative example is basically the same as that of Example 1, except that the preparation method of the modified nanoparticles comprises the following specific steps: S1: 4 parts of titanium dioxide and 0.2 parts of ammonia water are mixed and added to 100 parts of deionized water, heated to 65°C, and 0.68 parts of tetraethyl orthosilicate, 0.1 parts of triethanolamine and 0.25 parts of γ-aminopropyltrimethoxysilane in 60 parts of deionized water solution are added dropwise at a speed of 80 rpm, the dropwise time is 1h, after the dropwise addition is completed, the reaction is kept for 1.2h, after completion, centrifugal filtration and drying are carried out to obtain pretreated particles; S2: 1.2 parts of pretreated particles and 2.1 parts of anhydrous aluminum chloride are mixed and added to 120 parts of DMF solution, preheated to 75°C for 2h, then heated to 105°C, and 40 parts of DMF solution containing 1.1 parts of 1,4-benzenedicarboxylic acid and 0.9 parts of 1,4-benzenedicarboxylic acid-NH2 are added dropwise respectively, the dropwise time is 2h; S3: after the dropwise addition is completed, the temperature is raised to 125°C, and the reaction is kept for 18h, after the reaction is completed, the temperature is naturally cooled to room temperature, the solid product is collected by filtration, and washed several times with DMF to remove unreacted raw materials and other impurities, the filtered product is placed in a vacuum drying oven at 85°C for drying overnight to remove residual solvent, and the modified nanoparticles are obtained after completion.

[0085] The average particle size of the modified nanoparticles obtained was 537 nm.

[0086] Comparative Example 7

[0087] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified nanoparticles comprises the following specific steps: S1: 3.3 parts of titanium dioxide and 0.2 parts of ammonia water are mixed and added to 100 parts of deionized water, the temperature is raised to 65°C, and 60 parts of a deionized water solution of 0.45 parts of ethyl orthosilicate, 0.06 parts of triethanolamine and 0.11 parts of γ-aminopropyltrimethoxysilane are added dropwise at a speed of 80 rpm, the addition time is 1 hour, and after the addition is completed, the temperature is kept for 1.2 hours, and after the completion, the modified nanoparticles are centrifuged, filtered and dried to obtain pretreated particles; S2: 3.5 parts of pretreated particles and 1.5 parts of non- Aluminum chloride solution was mixed and added to 120 parts of DMF solution, and the temperature was raised to 75°C and preheated for 2 hours. The temperature was then raised to 105°C and 40 parts of DMF solution containing 0.8 parts of 1,4-benzenedicarboxylic acid and 0.4 parts of 1,4-benzenedicarboxylic acid-NH2 were added dropwise at the same time, and the addition time was 2 hours. S3: After the addition was completed, the temperature was raised to 125°C, and the mixture was kept under reflux for 18 hours. After the reaction was completed, it was naturally cooled to room temperature. The solid product was collected by filtration and washed several times with DMF to remove unreacted raw materials and other impurities. The filtered product was placed in a vacuum drying oven at 85°C and dried overnight to remove residual solvent. The product was obtained after completion.

[0088] The average particle size of the modified nanoparticles obtained was 533 nm.

[0089] Performance evaluation

[0090] Wear resistance: The composite modified rubbers prepared in the examples and comparative examples were tested for wear resistance with reference to the standard GB / T 1689-2014. The load was 2.5 kg, the rotation speed was 70 r / min, and the test speed was 1000 r. The test values ​​were the average of 10 tests and recorded in Table 1.

[0091] Low temperature resistance test: The composite modified rubber prepared in the embodiment and the comparative example was tested for low temperature shrinkage resistance according to the standard GB / T 7758-2020. The test starting temperature was 23±2°C, the cooling rate was 1.5°C / min, and the values ​​at TR30 and TR50 were taken. The test value was the average of 10 tests and recorded in Table 1.

[0092] Waterproof test: 2 cm × 2 cm × 0.5 cm samples of the composite modified rubber prepared in the examples and comparative examples were taken and tested for moisture permeability. The test was conducted in accordance with the standard GB / T 1037-1988. The test temperature was 25 ± 2°C and the test humidity was 50 ± 5% RH. The test values ​​were the average of 10 tests and recorded in Table 1.

[0093] Aging resistance test: The composite modified rubber prepared by the examples and the comparative examples was taken 2 cm x 2 cm x 0.5 cm sample, and the tensile strength (MPa) was tested. Then the sample was stored in a constant temperature and humidity environment of 65±2℃, 80% relative humidity for 3 months. After 3 months, the sample was taken out and tested again for tensile strength (MPa). The tensile strength retention rate % was calculated and recorded, and the tensile strength retention rate % = tensile strength after test / tensile strength before test x 100%. The test value was the average value of 10 samples.

[0094] Table 1 Performance test results

[0095]

[0096]

[0097] From the data results of the examples and the comparative examples of the present application and Table 1, it can be seen that the examples 1-3 of the present application have obvious advantages in temperature stability, waterproof performance, wear resistance and aging resistance compared with the comparative examples 1-7. This is mainly because the specific rubber material compounding scheme and modified nanoparticles and other technical schemes defined in the present application work together, while the comparative examples 1-7 do not use the technical scheme defined in the present application, resulting in obvious disadvantages in the above performance tests, which further proves the necessity of the technical scheme defined in the present application for the technical effect and solution of the technical problem.

Claims

1. A composite modified rubber for automobile tires, characterized by: Composite modified rubber for automobile tires, the raw materials, by mass, are: 50-70 parts of natural rubber, 30-40 parts of composite rubber, 3-5 parts of 3-aminopropyltriethoxysilane, 30-50 parts of carbon black, 15-25 parts of modified nanoparticles, 8-14 parts of plasticizer, 3-5 parts of activator, 2-4 parts of dispersant, 1-1.5 parts of antioxidant, 1-3 parts of vulcanizing agent, and 1-2 parts of vulcanization accelerator; The Mooney viscosity of the natural rubber is 85-100, under the conditions of ML1+4@100°C; The composite rubber is a composition of styrene-butadiene rubber and liquid nitrile rubber; the mass ratio of the styrene-butadiene rubber to the liquid nitrile rubber is (3-4): (1.5-2); The kinematic viscosity of the liquid nitrile rubber is 11,000 to 16,000 cps at 45°C. The Mooney viscosity of the styrene-butadiene rubber is 40-60, under the conditions of ML1+4@100°C; The preparation method of the modified nanoparticles comprises the following specific steps: S1: titanium dioxide and ammonia water are mixed and added to deionized water, the temperature is raised to 60-65° C., and a deionized water solution of ethyl orthosilicate, triethanolamine and γ-aminopropyltrimethoxysilane is added dropwise at a speed of 60-80 rpm for 0.8-1 hour. After the addition is completed, the reaction is kept warm for 1.2-1.5 hours. After completion, the mixture is centrifuged, filtered and dried to obtain pretreated particles; S2: The pretreated particles and anhydrous aluminum chloride are mixed and added to the DMF solution, the temperature is raised to 60-80°C and preheated for 1-2 hours, and then the temperature is raised to 100-110°C and the DMF solution containing 1,4-benzenedicarboxylic acid and 1,4-benzenedicarboxylic acid-NH2 is added dropwise at the same time, and the addition time is 2-3 hours; S3: After the addition is completed, the temperature is raised to 125-135°C, and the reflux reaction is kept at this temperature for 16-18 hours. After the reaction is completed, it is naturally cooled to room temperature, and the solid product is collected by filtration. It is washed with DMF several times to remove unreacted raw materials and other impurities, and the filtered product is placed in a vacuum drying oven at 80-90°C and dried overnight to remove residual solvent. The product is obtained after completion.

2. The composite modified rubber for automobile tires according to claim 1, characterized in that: The mass ratio of the natural rubber, the composite rubber and the carbon black is (55-65): (32-38): (35-42).

3. The composite modified rubber for automobile tires according to claim 2, characterized in that: The mass ratio of the natural rubber, the modified nanoparticles and the dispersant is (55-65): (18-24): (2.5-3.5).

4. The composite modified rubber for automobile tires according to claim 3, characterized in that: The average particle size of the carbon black is 30-50 nm.

5. The composite modified rubber for automobile tires according to claim 4, characterized in that: The plasticizer is at least one of aromatic oil, paraffin oil, naphthenic oil, white oil and silicone oil; the vulcanizing agent is sulfur; the vulcanization accelerator is a combination of MBTS and DTDM; the mass ratio of MBTS to DTDM is (3-3.5): (1.5-2).

6. The composite modified rubber for automobile tires according to claim 5, characterized in that: The mass ratio of titanium dioxide, ethyl orthosilicate, triethanolamine and γ-aminopropyltrimethoxysilane is (3-3.5): (0.3-0.5): (0.05-0.08): (0.1-0.12).

7. The composite modified rubber for automobile tires according to claim 6, characterized in that: The mass ratio of the pretreated particles, anhydrous aluminum chloride, 1,4-phthalic acid and 1,4-phthalic acid-NH2 is (1-1.5): (2-2.2): (1-1.2): (0.8-1).

8. The composite modified rubber for automobile tires according to claim 7, characterized in that: The average particle size of the titanium dioxide is 10-20 nm; the average particle size of the modified nanoparticles is 400-480 nm.

9. The composite modified rubber for automobile tires according to claim 7, characterized in that: The dispersant is at least one of zinc stearate, calcium stearate, tributyl phosphate, triphenyl phosphate and lauryl alcohol polyoxyethylene ether.

10. A method for preparing the composite modified rubber for automobile tires according to any one of claims 1 to 9, characterized in that: The specific steps include: S1: Put natural rubber and composite rubber into an internal mixer, mix and preheat at 90~95℃ for 10~15min, then add 3-aminopropyltriethoxysilane, carbon black, modified nanoparticles and dispersant and mix for 6~8min, continue to add plasticizer, activator and antioxidant and mix for 8~10min; S2: Add vulcanizer and vulcanization accelerator and mix for 5~7min, ensure that all ingredients are evenly dispersed, then take out the mixed rubber, cool to room temperature, and extrude the cooled rubber into shape using an extruder; S3: Put the molded rubber into a vulcanizing tank, set the vulcanization temperature to 130~145℃, the vulcanization pressure to 1.2~1.6MPa, and the vulcanization time to 30~35min. After the vulcanization is completed, take out the rubber and cool it naturally to room temperature.

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