A kind of fly ash microbead modified rubber composition and preparation method thereof

Abstract

The present invention belongs to the technical field of rubber preparation, and in particular to a rubber composition modified by ceramic microbeads (referred to as fly ash microbeads) prepared from fly ash. The rubber composition includes: by weight, 100.0 parts of synthetic rubber, 50.0-80.0 parts of fly ash microbeads, 5.0-10.0 parts of silane coupling agent, 1.0-10.0 parts of dispersant, 0.5-3.0 parts of antioxidant, 0.8-3.5 parts of accelerator, 0.5-3.5 parts of stearic acid, 2.0-5.0 parts of nano zinc oxide, and 0.75-2.0 parts of sulfur. The present invention adopts a technical solution of preparing a rubber composition by using fly ash microbeads as a reinforcing agent instead of carbon black and white carbon black in a traditional production process, so that the hardness, wear resistance and aging resistance of the rubber composition can be greatly improved. The present invention further proposes a preparation method of the composition.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber preparation, and particularly relates to a rubber composition modified with fly ash microbeads and a preparation method thereof. Background Art

[0002] With the development of the automobile industry, the public's requirements for rubber wear resistance, aging resistance, and impact resistance have increased. During driving, due to the large weight of the vehicle body itself, a large amount of heat will be generated during driving, and there is a possibility of tire rubber deformation, which is likely to affect the performance of the tire. Automobile rubber requires a rubber composition with low density and good rigidity. Currently, most rubber compositions on the market are prepared using white carbon black and carbon black, but white carbon black has poor conductivity and is prone to charge accumulation. As time accumulates, it is likely to cause accidents, and the cost is high, which cannot completely meet market demand.

[0003] There are also methods on the market that use conductive fillers to alleviate the above problems, such as filling graphene, carbon nanotubes, etc. However, due to the large specific surface area of ​​this type of material, although the charge accumulation problem is solved, the heat generation also increases, and the addition of fillers will affect the mechanical properties of rubber. Therefore, adding conductive fillers cannot completely solve the problem.

[0004] The patent with publication number CN 112409657 B provides a conductive rubber composition and a preparation method thereof, using carbon nanotubes and graphene as the main conductive fillers, and using plasticizers to make the fillers more dispersed in the rubber, thereby achieving uniform distribution of the fillers in the rubber. Although the rubber prepared by this preparation method has good conductivity and mechanical properties, and improves the electromagnetic shielding performance in the high-frequency band, the heat generated by the rubber is still high and it is prone to cracking.

[0005] The patent with publication number CN202211597959 provides a rubber composition and a preparation method thereof. The interfacial compatibility of solution-polymerized styrene butadiene rubber and polybutadiene rubber (BR) blends is improved by multiple smelting methods. Although the rubber composition has low rolling resistance, high wear resistance and good tensile strength, the cost is relatively high. Summary of the invention

[0006] The technical problems existing in the prior art are high cost of rubber preparation, poor electrical conductivity, high heat generation, and easy cracking.

[0007] In order to solve the above-mentioned technical problems, a new method of using micro-bead fly ash as a reinforcing agent for tire composition is provided. The method has low raw material cost, good conductivity, less heat generation, and comprehensively solves the problem of easy cracking of rubber products existing in other methods. In addition, this method can effectively reduce the pollution of fly ash to the environment. The application provides the following technical solutions:

[0008] The invention provides a fly ash microbead modified rubber composition. The rubber composition comprises the following raw materials, measured by mass: 100 parts of synthetic rubber, 50-80 parts of fly ash microbeads, 5-10 parts of silane coupling agents, 1-10 parts of dispersants, 0.5-3 parts of antioxidants, 0.8-3.5 parts of accelerators, 0.5-3.5 parts of stearic acid, 2-5 parts of nano zinc oxide and 0.75-2 parts of sulfur.

[0009] Preferably, the synthetic rubber is selected from one or more of solution-polymerized styrene-butadiene rubber (CAS: 9003-55-8), butadiene rubber, cis-polyisoprene, trans-polyisoprene, eucommia gum and nitrile rubber.

[0010] Preferably, the antioxidant is selected from one or more of antioxidant 6PPD, antioxidant 4010, antioxidant RD and antioxidant 4020.

[0011] Preferably, the accelerator is selected from one or more of accelerator NS, accelerator DM, accelerator TMTD, accelerator DPG and accelerator CZ.

[0012] Preferably, the silane coupling agent is one or more of bis(γ-triethoxysilylpropyl)tetrasulfide, bis(γ-triethoxysilylpropyl)disulfide and mercapto-based silane coupling agents.

[0013] Preferably, the particle size of the fly ash microbeads is 0.5-10 μm, and the specific surface area is 0.8-3.7 m 2 / g.

[0014] Preferably, the fly ash microbeads are prepared from industrial waste fly ash.

[0015] Preferably, the fly ash microbeads are prepared by the following preparation method:

[0016] S11: adsorbing fly ash microsphere raw material in a polyelectrolyte solution to obtain adsorbed fly ash microspheres; the fly ash microsphere raw material is obtained by screening industrial waste fly ash and then flotation in boiling water;

[0017] S12: adsorbing the adsorbed fly ash microspheres in a zeolite colloidal solution, washing, and drying to obtain seed-modified microspheres;

[0018] S13: reacting the seed-modified microspheres with an alkaline solution, washing, and drying to obtain the fly ash microspheres; the alkaline solution includes NaOH, NaAlO 2 and water.

[0019] Furthermore, the diameter of the fly ash microsphere raw material is 5-80 μm, and the thickness of the sphere shell is 2-4 μm.

[0020] Furthermore, the polyelectrolyte solution is a polydimethyldiisopropylammonium chloride (PDDA) aqueous solution and a polystyrene sulfonic acid (PSS) aqueous solution.

[0021] Furthermore, in step S13, in the alkaline solution, NaOH and NaAlO 2 The molar ratio is 3-10:1.

[0022] Furthermore, the zeolite colloidal solution is prepared by the following method:

[0023] S21: adding sodium aluminate to an alkaline solution and stirring, adding silica sol and stirring, and performing hydrothermal crystallization to prepare a molecular sieve;

[0024] S22: After the molecular sieve is separated into solid and liquid, the solid is dispersed in water to obtain the zeolite colloidal solution.

[0025] The present invention also provides a method for preparing the above-mentioned fly ash microbead modified rubber composition, comprising the following steps:

[0026] S31: Add synthetic rubber, stearic acid, silane coupling agent and nano zinc oxide into an internal mixer, mix for 20-30 seconds, then add some fly ash microbeads, mix for 20-30 seconds at 105-135° C., raise the plug for 10-30 seconds and then press the plug, mix for 20-30 seconds at 140-155° C., produce a sheet, cool to room temperature (25±5° C.), and obtain a masterbatch; the fly ash microbeads account for 45-70% of the total amount of the fly ash microbeads;

[0027] S32: After mixing the first-stage masterbatch, dispersant and antioxidant for 10-30 seconds, the remaining fly ash microbeads are added, the mixture is pressed and mixed at 105-135° C., the mixture is raised for 10-30 seconds, the mixture is pressed and mixed at 140-155° C., the mixture is discharged, and the mixture is cooled to room temperature to obtain the second-stage masterbatch;

[0028] S33: adding the second-stage masterbatch, sulfur and accelerator into an internal mixer, raising the bolt for 10-30s, pressing the bolt for 1-30s, raising the bolt for 10-30s, lowering the bolt for mixing at 90-115°C, discharging sheets, and cooling to room temperature to obtain the rubber composition.

[0029] Furthermore, the processing interval time between step S31, step S32 and step S33 is 8-16 hours.

[0030] Furthermore, in step S31, step S32 and step S33, a twin-screw extruder is used for sheeting.

[0031] Specifically, the method for preparing the fly ash microbead-modified rubber composition comprises the following steps:

[0032] Step 1, adding synthetic rubber, stearic acid, silane coupling agent and nano zinc oxide into an internal mixer, mixing for 20-30 seconds, then injecting fly ash microbeads accounting for a certain proportion of the total mass, mixing to 105-135° C., maintaining for 20-30 seconds, raising the bolt and maintaining for 10-30 seconds, pressing the bolt and mixing to 140-155° C., maintaining for 20-30 seconds, then using a twin-screw extruder to extrude sheets, and naturally cooling to room temperature to obtain the first stage of masterbatch;

[0033] Step 2, adding the first stage masterbatch, dispersant and antioxidant into an internal mixer, mixing for 10-30 seconds, adding the remaining fly ash microbeads, pressing and mixing to 105-135° C., raising the bolt and keeping for 10-30 seconds, then pressing and mixing again to 140-155° C., extruding through a twin-screw extruder, and cooling to room temperature to obtain a second stage masterbatch;

[0034] Step 3, adding the second masterbatch, sulfur and accelerator into an internal mixer, raising the bolt for 10-30s, pressing the bolt for 10-30s, raising the bolt for 10-30s, lowering the bolt and mixing to 90-115°C, extruding the sheet by a twin-screw extruder again, cooling to room temperature, and obtaining the fly ash microbead modified rubber composition.

[0035] The above technical scheme effectively solves the problem that white carbon black used in the current market has poor conductivity and conductive fillers generate more heat. Fly ash as a raw material is very easy to obtain and can be directly obtained from thermal power plants, which greatly reduces the cost of raw materials. The fly ash microbeads used in this scheme have a size range of 5000-8000 mesh, and the diameter reaches the micro-nano level; when 45%-70% fly ash microbeads are added, the preferred range of smelting temperature is 105-135°C. Dispersants are added in the present invention to make the fly ash microbeads more evenly distributed, so the performance of the rubber composition produced is more stable. Fly ash microbeads have strong rigidity and low density. Using them as a rubber tire reinforcing agent makes the overall performance of the obtained rubber tire far better than the existing combined rubber tires on the market. In addition, the raw materials of this method are mainly prepared from industrial waste fly ash, which reduces the pollution of fly ash to the environment, can greatly reduce costs, and achieve good technical effects.

[0036] The technical solution of the present invention has the following advantages over the prior art:

[0037] The rubber composition provided by the present application contains fly ash microbeads, which can effectively reduce the heat generated by rubber, enhance the bonding force between rubber and the rubber, have higher reinforcement and elasticity, improve the performance of rubber products, and have the advantages of smooth mixed rubber surface, good elasticity of vulcanized rubber, low compression heat rise, and better aging resistance. In addition, the fly ash used in the present application is rich in sources as the main raw material, low in cost, and meets the needs of green development. It can produce higher quality tires at low cost (fly ash microbeads replace white carbon black, which can reduce the production cost of tires by about 50-70%), saving a lot of material costs for enterprises and increasing the profit margin of enterprise products. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a scanning electron microscope image of fly ash microspheres.

[0039] Figure 2 This is a comparison chart of the impact resistance of rubber made from polypropylene.

[0040] Figure 3 The present invention relates to a rubber tire tread modified with fly ash microbeads.

[0041] Figure 4 This is a scanning electron microscope image of micro-nano fly ash microbeads. DETAILED DESCRIPTION

[0042] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0043] Example 1

[0044] A rubber composition with fly ash microbeads as a reinforcing agent and a preparation method thereof. Step 1: Mix synthetic rubber, stearic acid, silane coupling agent and nano zinc oxide and add them to an internal mixer to obtain a mixture I, wherein the mass ratio of synthetic rubber: stearic acid: silane coupling agent: nano zinc oxide is 100: 3.5: 10.0: 5.0, and mix for 30 seconds to obtain a precursor II. Inject 70% fly ash microspheres into the precursor II, wherein the mass ratio of the precursor II to the fly ash microspheres is 118.5:67.5, mix to 105°C, hold for 30 seconds, raise the bolt, hold for 30 seconds, press the bolt, mix to 140°C, hold for 30 seconds, then extruder the sheet using a twin-screw extruder, cool naturally to room temperature, and obtain a masterbatch III; Step 2, add the masterbatch III, dispersant, and antioxidant into an internal mixer, wherein the mass ratio of the masterbatch III: dispersant: antioxidant is 118.5:10.0:3.0, mix for 30 seconds, and then add the remaining Fly ash microspheres, press the bolt and mix to 105°C, raise the bolt and hold it for 30 seconds, then press the bolt and mix to 140°C again, use a twin-screw extruder to extrude sheets, cool to room temperature, and obtain masterbatch IV; step 3, add the masterbatch IV, sulfur and accelerator into an internal mixer, wherein the mass ratio of masterbatch IV: sulfur: accelerator is 131.5:2.0:3.5, raise the bolt and hold it for 30 seconds, press the bolt and hold it for 30 seconds, raise the bolt and hold it for 30 seconds, lower the bolt and mix to 115°C, use a twin-screw extruder to extrude sheets again, cool to room temperature, and obtain the rubber composition.

[0045] Example 2

[0046] According to the method of Example 1, only by changing the mass proportion of fly ash microbeads added in step 1, the mass proportion of fly ash in the total mass and the synthetic rubber component, the properties of the rubber composition can be adjusted to obtain rubber compositions with different elasticity and different wear resistance, as shown in Table 1.

[0047] Table 1: Formula of raw materials for synthetic rubber in Examples 1-5

[0048]

[0049]

[0050] Example 3

[0051] According to the method of Example 1, only by changing the mass proportion of fly ash microbeads added in step 1, the mass proportion of fly ash in the total mass and the synthetic rubber component, the properties of the rubber composition can be adjusted to obtain rubber compositions with different elasticity and different wear resistance, as shown in Table 1.

[0052] Example 4

[0053] According to the method of Example 1, only by changing the mass proportion of fly ash microbeads added in step 1, the mass proportion of fly ash in the total mass and the synthetic rubber component, the properties of the rubber composition can be adjusted to obtain rubber compositions with different elasticity and different wear resistance, as shown in Table 1.

[0054] Example 5

[0055] According to the method of Example 1, only by changing the mass proportion of fly ash microbeads added in step 1, the mass proportion of fly ash in the total mass and the synthetic rubber component, the properties of the rubber composition can be adjusted to obtain rubber compositions with different elasticity and different wear resistance, as shown in Table 1.

[0056] Example 6

[0057] According to the method of Example 1, only by changing the mass proportion of fly ash microbeads added in step 1, the mass proportion of fly ash in the total mass and the synthetic rubber component, the properties of the rubber composition can be adjusted to obtain rubber compositions with different elasticity and different wear resistance, as shown in Table 2.

[0058] Table 2: Formula of raw materials for synthetic rubber in Examples 6-8

[0059]

[0060] Example 7

[0061] According to the method of Example 1, only by changing the mass proportion of fly ash microbeads added in step 1, the mass proportion of fly ash in the total mass and the synthetic rubber component, the properties of the rubber composition can be adjusted to obtain rubber compositions with different elasticity and different wear resistance, as shown in Table 2.

[0062] Example 8

[0063] According to the method of Example 1, only by changing the mass proportion of fly ash microbeads added in step 1, the mass proportion of fly ash in the total mass and the synthetic rubber component, the properties of the rubber composition can be adjusted to obtain rubber compositions with different elasticity and different wear resistance, as shown in Table 2.

[0064] Comparative Example 1

[0065] According to the method of patent CN102171285A, white carbon black, black carbon black and rubber compositions were prepared to obtain samples to be tested. The specific components are shown in Table 3.

[0066] Comparative Example 2

[0067] According to the method of patent CN102171285A, white carbon black, black carbon black and rubber compositions were prepared to obtain samples to be tested. The specific components are shown in Table 3.

[0068] Comparative Example 3

[0069] According to the method of patent CN102171285A, white carbon black, black carbon black and rubber compositions were prepared to obtain samples to be tested. The specific components are shown in Table 3.

[0070] Comparative Example 4

[0071] According to the method of patent CN201210401997.2, a modified silica and rubber composition was prepared using a relatively low pressurization pressure to obtain a sample to be tested, and the specific composition is shown in Table 3.

[0072] Comparative Example 5

[0073] According to the method of patent CN201210401997.2, a modified silica and rubber composition was prepared using a relatively low pressurization pressure to obtain a sample to be tested, and the specific composition is shown in Table 3.

[0074] Comparative Example 6

[0075] According to the method of patent CN202110047833.3, scheme A was used to prepare the sample to be tested in comparative example 6, and the specific components are shown in Table 3.

[0076] Comparative Example 7

[0077] According to the method of patent CN202110047833.3, scheme B was used to prepare the sample to be tested in comparative example 7, and the specific components are shown in Table 4.

[0078] Table 3 Formula of synthetic rubber raw materials in Comparative Examples 1-5

[0079]

[0080]

[0081] Table 4: Formula of synthetic rubber raw materials in Comparative Examples 6 and 7

[0082]

[0083] Effect evaluation 1

[0084] It can be seen from the effect example table that, compared with the current high-performance tire rubber composition, the hardness, Akron loss coefficient and tensile strength of the rubber products obtained in each embodiment are significantly improved.

[0085] This effect example tests the performance of the rubber compositions prepared in Examples 1-8 and Comparative Examples 1-7; the product obtained in Comparative Example 3 is selected as the benchmark in the test (the data obtained in Comparative Example 3 is almost the same as the data of the current high-performance tire rubber composition), and the remaining embodiments and comparative examples are compared with the data obtained in Comparative Example 3; specifically, at 25°C, the tensile strength is measured at a tensile speed of 500 mm / min; at 25°C, the Akron abrasion is measured; at 60°C, the hysteresis of DMA (10 Hz, 0.25%) is measured Loss tanδ; wherein tensile strength index = (tensile strength of each rubber composition) / (tensile strength of comparative example 3) × 100, the larger the tensile strength, the greater the tensile strength; low rolling resistance index = (tanδ of comparative example 3) / (tanδ of each rubber composition) × 100, the larger the low rolling resistance index, the smaller the rolling resistance; wear resistance index = (Akron wear amount of comparative example 3) / (Akron wear amount of each rubber composition) × 100, the larger the wear index, the smaller the wear; the obtained data are shown in Table 5.

[0086] Table 5 Comparison of physical properties of various embodiments and comparative examples

[0087]

[0088] Note: All samples were tested under the same test conditions. “-” means not measured.

[0089] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A rubber composition modified with fly ash microbeads, It is characterized in that The rubber composition comprises the following raw materials by mass: 100 parts of synthetic rubber, 50-80 parts of fly ash microspheres, 5-10 parts of silane coupling agent, 1-10 parts of dispersant, 0.5-3 parts of antioxidant, 0.8-3.5 parts of accelerator, 0.5-3.5 parts of stearic acid, 2-5 parts of nano zinc oxide, and 0.75-2 parts of sulfur; the synthetic rubber is selected from solution-polymerized styrene-butadiene rubber, polybutadiene rubber and epoxidized natural rubber; the fly ash microspheres are prepared by the following preparation method: S11: adsorbing fly ash microsphere raw material in a polyelectrolyte solution to obtain adsorbed fly ash microspheres; the fly ash microsphere raw material is obtained by screening industrial waste fly ash and then flotation in boiling water; S12: adsorbing the adsorbed fly ash microspheres in a zeolite colloidal solution, washing, and drying to obtain seed-modified microspheres; S13: reacting the seed-modified microspheres with an alkaline solution, washing, and drying to obtain the fly ash microspheres; the alkaline solution includes NaOH, NaAlO 2 and water.

2. The fly ash microbead-modified rubber composition according to claim 1, It is characterized in that The silane coupling agent is one or more of bis(γ-triethoxysilylpropyl)tetrasulfide, bis(γ-triethoxysilylpropyl)disulfide and mercapto-based silane coupling agents.

3. The fly ash microbead-modified rubber composition according to claim 1, It is characterized in that The particle size of the fly ash microbeads is 0.5-10 μm, and the specific surface area is 0.8-3.7 m 2 / g.

4. The fly ash microbead-modified rubber composition according to claim 1, It is characterized in that The diameter of the fly ash microsphere raw material is 5-80 μm, and the thickness of the sphere shell is 2-4 μm.

5. The fly ash microbead-modified rubber composition according to claim 1, It is characterized in that The polyelectrolyte solution is a polydimethyl diisopropylammonium chloride aqueous solution and a polystyrene sulfonic acid aqueous solution.

6. The fly ash microbead-modified rubber composition according to claim 1, It is characterized in that In step S13, in the alkaline solution, NaOH and NaAlO 2 The molar ratio is 3-10:

1.

7. The fly ash microbead-modified rubber composition according to claim 1, It is characterized in that The zeolite colloidal solution is prepared by the following method: S21: adding sodium aluminate to an alkaline solution and stirring, adding silica sol and stirring, and performing hydrothermal crystallization to prepare a molecular sieve; S22: After the molecular sieve is separated into solid and liquid, the solid is dispersed in water to obtain the zeolite colloidal solution.

8. A method for preparing the fly ash microbead-modified rubber composition according to any one of claims 1 to 7, It is characterized in that The following steps are involved: S31: adding synthetic rubber, stearic acid, silane coupling agent and nano zinc oxide into an internal mixer, mixing for 20-30 seconds, adding part of fly ash microbeads, mixing at 105-135° C. for 20-30 seconds, mixing at 140-155° C. for 20-30 seconds, cooling to room temperature, and obtaining a masterbatch; the fly ash microbeads are 45-70wt% of the total fly ash microbeads; S32: After mixing the first-stage masterbatch, the dispersant and the antioxidant for 10-30 seconds, the remaining fly ash microbeads are added, mixed at 105-135° C. and then at 140-155° C., and cooled to room temperature to obtain a second-stage masterbatch; S33: mixing the second-stage masterbatch, sulfur and accelerator at 90-115° C. and cooling to room temperature to obtain the rubber composition.

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