Composite rubber material for damping product and preparation method of composite rubber material

Abstract

The invention relates to the technical field of composite materials, in particular to a composite rubber material for damping products and a preparation method thereof.The composite rubber material is prepared from, by weight, 30-40 parts of chlorinated polyethylene rubber, 20-30 parts of fluororubber, 20-30 parts of chloroprene rubber, 10-15 parts of modified nano calcium carbonate, 3-5 parts of filler, 5-8 parts of compatibilizer, 2-4 parts of stearic acid and 3-4 parts of anti-aging agent. 1-3 parts of a flame retardant; the filling agent comprises calcium sulfate whiskers and fumed silica. According to the composite rubber material for the damping product, through matching and combination of the raw materials, the elasticity and aging resistance of the composite rubber material are improved, meanwhile, the composite rubber material has good flame retardance and wear resistance, the use efficiency of the composite rubber material is improved, and the application range is widened.

Description

Technical Field

[0001] This application relates to the field of composite materials technology, specifically to a composite rubber material for shock-absorbing products and its preparation method. Background Technology

[0002] Rubber, due to its good viscoelasticity, strong adaptability to deformation, and easy compounding properties, is an ideal material for shock absorption, cushioning, and sound insulation. It is widely used in automobiles, construction, and household products. Natural rubber, butyl rubber, chloroprene rubber, nitrile rubber, ethylene propylene rubber, and silicone rubber are all commonly used types of rubber.

[0003] However, single rubbers often have significant performance limitations. For example, natural rubber has poor oil resistance, and nitrile rubber has poor cold resistance, failing to meet the higher requirements for rubber materials in reality. Composite rubber materials achieve better performance by blending different rubbers or combining them with other materials. This overcomes the performance limitations of single rubbers and allows them to adapt to higher performance requirements and more application scenarios.

[0004] However, the preparation of composite rubber materials faces many challenges, such as limitations in material selection, complex component matching, and control of the preparation process. General composite rubber materials still cannot achieve a balance between elasticity and comprehensive properties such as flame retardancy and weather resistance. Summary of the Invention

[0005] This application aims to overcome at least one of the deficiencies of the prior art by providing a composite rubber material for shock-absorbing products and a method for preparing the same. This composite rubber material for shock-absorbing products improves the elasticity and aging resistance of the composite rubber material through the combination of raw materials, while also exhibiting good flame retardancy and wear resistance, thereby improving the efficiency of the composite rubber material and expanding its application range.

[0006] In a first aspect, embodiments of this application provide a composite rubber material for shock-absorbing products, achieved through the following technical solution: A composite rubber material for shock-absorbing products comprises the following raw materials in parts by weight: 30-40 parts of chlorinated polyethylene rubber, 20-30 parts of fluororubber, 20-30 parts of chloroprene rubber, 10-15 parts of modified nano-calcium carbonate, 3-5 parts of filler, 5-8 parts of compatibilizer, 2-4 parts of stearic acid, 3-4 parts of antioxidant, and 1-3 parts of flame retardant. The filler includes calcium sulfate whiskers and fumed silica.

[0007] The composite rubber material for shock-absorbing products according to the embodiments of this application has at least the following beneficial effects: The composite rubber material of this application is made by combining chlorinated polyethylene rubber, fluororubber and chloroprene rubber. Fluororubber has good high temperature resistance and corrosion resistance, chlorinated polyethylene rubber has excellent flame retardancy, ozone resistance and weather resistance, and chloroprene rubber has excellent weather resistance, flame retardancy, oil resistance and acid and alkali resistance, and good mechanical strength. The combination of the three can improve the comprehensive performance of the composite rubber material.

[0008] The fumed silica of this application can form a silica coating when the material is burning. This coating has the functions of heat insulation and shielding, which can prevent heat transfer and the escape of combustibles. The addition of fumed silica can also increase the residual carbon content of the material. As the amount of fumed silica increases, the residual carbon content of the composite material gradually increases, and the carbon layer gradually becomes denser and more complete, thereby improving the flame retardant performance.

[0009] The calcium sulfate whiskers of this application, as microfibers, form a stable skeleton in rubber, significantly improving strength, hardness and modulus. Their fiber structure can prevent crack propagation, absorb impact energy, and improve the wear resistance of rubber. At the same time, the calcium sulfate whiskers themselves are resistant to high temperature and non-flammable, enhancing the overall flame retardant effect of rubber. The compatibilizer of this application can accumulate at the interface, reduce the repulsive force between the two phases, prevent the aggregation of dispersed phase particles during the blending process, and improve the compatibility of each component.

[0010] The composite rubber material for shock-absorbing products of this application improves the elasticity and aging resistance of the composite rubber material through the combination of raw materials, while also exhibiting good flame retardancy and wear resistance, thereby improving the efficiency of the composite rubber material and expanding its application range.

[0011] According to some embodiments of this application, the compatibilizer is a silane coupling agent KH550.

[0012] According to some embodiments of this application, the antioxidant is a mixture of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N,N-di-n-butyldithiocarbamate in a weight ratio of (1-2):1.

[0013] According to some embodiments of this application, the flame retardant is at least one of triethyl phosphate, ammonium polyphosphate, and zinc borate. Triethyl phosphate has extremely low viscosity and high phosphorus content, resulting in good flame retardant effect; ammonium polyphosphate is a highly efficient and environmentally friendly inorganic phosphorus-nitrogen flame retardant that forms a dense and robust foamed char layer during combustion through the expansion and flame retardant effects of acid source, char source, and gas source, isolating heat and oxygen, resulting in high flame retardant efficiency and good smoke suppression; zinc borate is a halogen-free and environmentally friendly flame retardant with multiple functions such as flame retardancy, smoke suppression, char formation promotion, and arc prevention, and can synergistically enhance the flame retardant effect with chlorinated polyethylene rubber.

[0014] According to some embodiments of this application, the preparation of the modified nano-calcium carbonate includes the following steps: first, condensed phosphoric acid is continuously added dropwise to treat the surface of the nano-calcium carbonate particles, so that the pH value of the nano-calcium carbonate is reduced to below 8.0; then, titanate coupling agent is continuously added dropwise, and the nano-calcium carbonate particles are dry-coated by high-speed mixing, shearing, and grinding; coarse particles are sieved out to obtain modified nano-calcium carbonate treated with titanate coupling agent.

[0015] Titanate coupling agents can form a monolayer on the surface of nano-calcium carbonate. One end is chemically bonded to the hydroxyl groups on the surface of calcium carbonate, while the long-chain organic groups at the other end are entangled or physically miscible with the composite rubber material matrix. This greatly improves the dispersion and interfacial bonding of nano-calcium carbonate particles in the composite rubber material matrix, thereby enhancing and toughening the material.

[0016] According to some embodiments of this application, the preparation of the filler includes the following steps: S1. Calcium sulfate whiskers were ultrasonically dispersed in a mixed solution of anhydrous ethanol and deionized water in a mass ratio of (8-9):1, and γ-aminopropyltriethoxysilane was added under stirring and mixed evenly. S2. Raise the temperature to 70-80℃, add fumed silica, stir magnetically at a constant temperature for 5-8 hours, and obtain the organosilicon modified filler after centrifugation, washing and drying. S3. Graphene pretreatment: Graphene was ultrasonically dispersed in a mixed solution of sulfuric acid and nitric acid, and then refluxed at 80°C for 4 hours. After the reaction was completed, it was dried and ground. S4. Add the pretreated graphene from step S3 to ethanol and disperse it by ultrasonication. Add the organosilicon-modified filler obtained in step S2, stir rapidly at 25-35℃ to allow it to react fully, centrifuge, wash several times with anhydrous ethanol, vacuum dry, and grind to obtain the filler.

[0017] Calcium sulfate whiskers and fumed silica are used as fillers in composite rubber materials. Due to their large specific surface area and high adsorption capacity, they can enhance the mechanical properties of rubber materials. Organosilicon can increase the dispersion of fillers in composite rubber and improve the anti-aging effect of composite rubber materials. After graphene is acidified, its surface will be oxidized to carboxyl groups, which will combine with organosilicon-modified fillers, reducing the problem of graphene agglomeration. The layered structure of graphene makes the mixing between fillers and composite rubber components more thorough, improving the mechanical strength and durability of composite rubber materials used in shock-absorbing products.

[0018] Furthermore, the calcium sulfate whiskers have a particle size of 1200-1300 mesh.

[0019] Furthermore, the average particle size of the fumed silica is 25-35 nm, for example, the average particle size of the fumed silica is 30 nm. Nanoscale fumed silica can capture free radicals released by combustion reactions and form a dense and uniform barrier layer, thereby enhancing the flame retardant effect.

[0020] Further, the weight ratio of the calcium sulfate whiskers, the anhydrous ethanol and the γ-aminopropyltriethoxysilane in step S1 is 2:(8-12):(0.5-1).

[0021] Furthermore, the weight ratio of the calcium sulfate whiskers to the fumed silica is 2:(1-1.5).

[0022] Secondly, this application provides a method for preparing the aforementioned composite rubber material for shock-absorbing products, achieved through the following technical solution: A method for preparing a composite rubber material for shock-absorbing products includes the following steps: (1) Mixing: Chlorinated polyethylene rubber, fluororubber, chloroprene rubber, modified nano calcium carbonate, filler, compatibilizer, stearic acid, antioxidant, and flame retardant are added to a high-power dispersing mixer according to the weight parts. The mixture is stirred for 30-60 minutes at a temperature of 120-140℃, a vacuum degree of 0.08-0.10Mpa, and a speed of 100-300rpm to obtain the mixed raw materials. (2) Hot pressing: The mixed raw materials obtained in step (1) are added into the mold cavity and hot pressed for 3-5 minutes at a temperature of 145-165℃ and a pressure of 15-20MPa to obtain the rough product; (3) Microwave heat treatment: The crude product obtained in step (2) is placed in a microwave heating device and cured at a temperature of 140-180℃. After cooling to room temperature, a composite rubber material for shock-absorbing products is obtained.

[0023] The method for preparing composite rubber material for shock-absorbing products according to the embodiments of this application has at least the following beneficial effects: The preparation method of this application is simple, does not require complex production equipment, has low cost, is pollution-free in the manufacturing process, emits no toxic substances, does not harm the health of operators, and is suitable for industrial production.

[0024] According to some embodiments of the present invention, the curing heat treatment in step (3) is to keep the temperature at 140°C, 160°C and 180°C for 1h, 1.5h and 2h respectively.

[0025] Furthermore, the heating rate of the curing heat treatment in step (3) is 3-5℃ / min. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, a further detailed description will be provided below in conjunction with specific embodiments. The embodiments described herein are merely some examples of this application and should not be construed as limiting the scope of protection of this application. Example 1

[0027] Preparation of composite rubber materials for shock-absorbing products: (1) Mixing: Add 35 parts of chlorinated polyethylene rubber, 25 parts of fluororubber, 25 parts of chloroprene rubber, 12 parts of modified nano calcium carbonate, 4 parts of filler, 6 parts of silane coupling agent KH550, 3 parts of stearic acid, 3.5 parts of antioxidant, and 2 parts of zinc borate to a high-power dispersing mixer according to the weight. Mix for 45 minutes at a temperature of 130℃, a vacuum degree of 0.09Mpa, and a speed of 200rpm to obtain the mixed raw materials. (2) Hot pressing: The mixed raw materials obtained in step (1) are added into the mold cavity and hot pressed for 4 minutes at a temperature of 155℃ and a pressure of 18MPa to obtain the rough product; (3) Microwave heat treatment: The crude product obtained in step (2) is placed in a microwave heating device and kept at 140℃, 160℃ and 180℃ for 1h, 1.5h and 2h respectively for curing heat treatment. The heating rate is 4℃ / min. After cooling to room temperature, the composite rubber material for shock-absorbing products is obtained. The antioxidant is composed of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N,N-di-n-butyldithiocarbamate in a weight ratio of 1.5:1. The method for preparing the modified nano-calcium carbonate is as follows: first, condensed phosphoric acid is continuously added dropwise to treat the surface of the nano-calcium carbonate particles, so that the pH value of the nano-calcium carbonate is reduced to below 8.0; then, titanate coupling agent is continuously added dropwise, and the nano-calcium carbonate particles are dry-coated by high-speed mixing, shearing, and grinding; coarse particles are sieved out to obtain modified nano-calcium carbonate treated with titanate coupling agent. The filler is prepared by: S1. Calcium sulfate whiskers with a particle size of 1200-1300 mesh are ultrasonically dispersed in a mixed solution of anhydrous ethanol and deionized water at a mass ratio of 8.5:1, and γ-aminopropyltriethoxysilane is added under stirring and mixed evenly. S2. Increase the temperature to 75℃, add fumed silica with an average particle size of 30nm, stir magnetically at a constant temperature for 7h, and obtain the organosilicon modified filler after centrifugation, washing and drying. S3. Graphene pretreatment: Graphene was ultrasonically dispersed in a mixed solution of sulfuric acid and nitric acid, and then refluxed at 80°C for 4 hours. After the reaction was completed, it was dried and ground. S4. Add the pretreated graphene from step S3 to ethanol and disperse it by ultrasonication. Add the organosilicon-modified filler obtained in step S2, stir rapidly at 30°C to allow it to react fully, centrifuge, wash several times with anhydrous ethanol, vacuum dry, and grind to obtain the filler. The weight ratio of the calcium sulfate whiskers, the anhydrous ethanol, and the γ-aminopropyltriethoxysilane in step S1 is 2:10:0.8; The weight ratio of the calcium sulfate whiskers to the fumed silica is 2:1.3. Example 2

[0028] Preparation of composite rubber materials for shock-absorbing products: (1) Mixing: Add 40 parts by weight of chlorinated polyethylene rubber, 20 parts of fluororubber, 30 parts of chloroprene rubber, 10 parts of modified nano calcium carbonate, 5 parts of filler, 5 parts of silane coupling agent KH550, 4 parts of stearic acid, 3 parts of antioxidant, and 3 parts of triethyl phosphate to a high-power dispersing mixer and stir for 60 minutes at a temperature of 120℃, a vacuum degree of 0.10Mpa, and a speed of 100rpm to obtain mixed raw materials; (2) Hot pressing: The mixed raw materials obtained in step (1) are added into the mold cavity and hot pressed for 3 minutes at a temperature of 145℃ and a pressure of 20MPa to obtain the rough product; (3) Microwave heat treatment: The crude product obtained in step (2) is placed in a microwave heating device and kept at 140℃, 160℃ and 180℃ for 1h, 1.5h and 2h respectively for curing heat treatment. The heating rate is 5℃ / min. After cooling to room temperature, the composite rubber material for shock-absorbing products is obtained. The antioxidant is composed of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N,N-di-n-butyldithiocarbamate in a weight ratio of 1:1. The method for preparing the modified nano-calcium carbonate is as follows: first, condensed phosphoric acid is continuously added dropwise to treat the surface of the nano-calcium carbonate particles, so that the pH value of the nano-calcium carbonate is reduced to below 8.0; then, titanate coupling agent is continuously added dropwise, and the nano-calcium carbonate particles are dry-coated by high-speed mixing, shearing, and grinding; coarse particles are sieved out to obtain modified nano-calcium carbonate treated with titanate coupling agent. The filler is prepared by: S1. Calcium sulfate whiskers with a particle size of 1200-1300 mesh are ultrasonically dispersed in a mixed solution of anhydrous ethanol and deionized water in a mass ratio of 9:1, and γ-aminopropyltriethoxysilane is added under stirring and mixed evenly. S2. Increase the temperature to 70℃, add fumed silica with an average particle size of 35nm, stir magnetically at a constant temperature for 5h, and obtain organosilicon modified filler after centrifugation, washing and drying. S3. Graphene pretreatment: Graphene was ultrasonically dispersed in a mixed solution of sulfuric acid and nitric acid, and then refluxed at 80°C for 4 hours. After the reaction was completed, it was dried and ground. S4. Add the pretreated graphene from step S3 to ethanol and ultrasonically disperse it. Add the organosilicon-modified filler obtained in step S2, stir rapidly at 35°C to allow it to react fully, centrifuge, wash several times with anhydrous ethanol, vacuum dry, and grind to obtain the filler. The weight ratio of the calcium sulfate whiskers, the anhydrous ethanol, and the γ-aminopropyltriethoxysilane in step S1 is 2:8:1. The weight ratio of the calcium sulfate whiskers to the fumed silica is 2:1. Example 3

[0029] Preparation of composite rubber materials for shock-absorbing products: (1) Mixing: Add 30 parts by weight of chlorinated polyethylene rubber, 30 parts of fluororubber, 20 parts of chloroprene rubber, 15 parts of modified nano calcium carbonate, 3 parts of filler, 8 parts of silane coupling agent KH550, 2 parts of stearic acid, 4 parts of antioxidant, and 1 part of ammonium polyphosphate to a high-power dispersing mixer and stir for 30 minutes at a temperature of 140℃, a vacuum of 0.08Mpa, and a speed of 300rpm to obtain mixed raw materials; (2) Hot pressing: The mixed raw materials obtained in step (1) are added into the mold cavity and hot pressed for 5 minutes at a temperature of 165℃ and a pressure of 15MPa to obtain the rough product; (3) Microwave heat treatment: The crude product obtained in step (2) is placed in a microwave heating device and kept at 140℃, 160℃ and 180℃ for 1h, 1.5h and 2h respectively for curing heat treatment. The heating rate is 3℃ / min. After cooling to room temperature, the composite rubber material for shock-absorbing products is obtained. The antioxidant is composed of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N,N-di-n-butyldithiocarbamate in a weight ratio of 2:1. The method for preparing the modified nano-calcium carbonate is as follows: first, condensed phosphoric acid is continuously added dropwise to treat the surface of the nano-calcium carbonate particles, so that the pH value of the nano-calcium carbonate is reduced to below 8.0; then, titanate coupling agent is continuously added dropwise, and the nano-calcium carbonate particles are dry-coated by high-speed mixing, shearing, and grinding; coarse particles are sieved out to obtain modified nano-calcium carbonate treated with titanate coupling agent. The filler is prepared by: S1. Calcium sulfate whiskers with a particle size of 1200-1300 mesh are ultrasonically dispersed in a mixed solution of anhydrous ethanol and deionized water at a mass ratio of 8:1, and γ-aminopropyltriethoxysilane is added under stirring and mixed evenly. S2. Raise the temperature to 80℃, add fumed silica with an average particle size of 25nm, stir magnetically at a constant temperature for 8h, and obtain the organosilicon modified filler after centrifugation, washing and drying. S3. Graphene pretreatment: Graphene was ultrasonically dispersed in a mixed solution of sulfuric acid and nitric acid, and then refluxed at 80°C for 4 hours. After the reaction was completed, it was dried and ground. S4. Add the pretreated graphene from step S3 to ethanol and ultrasonically disperse it. Add the organosilicon-modified filler obtained in step S2, stir rapidly at 25°C to allow it to react fully, centrifuge, wash several times with anhydrous ethanol, vacuum dry, and grind to obtain the filler. The weight ratio of the calcium sulfate whiskers, the anhydrous ethanol, and the γ-aminopropyltriethoxysilane in step S1 is 2:12:0.5. The weight ratio of the calcium sulfate whiskers to the fumed silica is 2:1.5. Example 4

[0030] Preparation of composite rubber materials for shock-absorbing products: (1) Mixing: Add 36 parts by weight of chlorinated polyethylene rubber, 24 parts of fluororubber, 22 parts of chloroprene rubber, 13 parts of modified nano calcium carbonate, 4 parts of filler, 6.5 parts of silane coupling agent KH550, 3 parts of stearic acid, 3 parts of antioxidant, and 2 parts of zinc borate to a high-power dispersing mixer and stir for 50 minutes at a temperature of 130℃, a vacuum degree of 0.09Mpa, and a speed of 250rpm to obtain mixed raw materials; (2) Hot pressing: The mixed raw materials obtained in step (1) are added into the mold cavity and hot pressed for 4 minutes at a temperature of 150℃ and a pressure of 16MPa to obtain the rough product; (3) Microwave heat treatment: The crude product obtained in step (2) is placed in a microwave heating device and kept at 140℃, 160℃ and 180℃ for 1h, 1.5h and 2h respectively for curing heat treatment. The heating rate is 4℃ / min. After cooling to room temperature, the composite rubber material for shock-absorbing products is obtained. The antioxidant is composed of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N,N-di-n-butyldithiocarbamate in a weight ratio of 1.6:1. The method for preparing the modified nano-calcium carbonate is as follows: first, condensed phosphoric acid is continuously added dropwise to treat the surface of the nano-calcium carbonate particles, so that the pH value of the nano-calcium carbonate is reduced to below 8.0; then, titanate coupling agent is continuously added dropwise, and the nano-calcium carbonate particles are dry-coated by high-speed mixing, shearing, and grinding; coarse particles are sieved out to obtain modified nano-calcium carbonate treated with titanate coupling agent. The filler is prepared by: S1. Calcium sulfate whiskers with a particle size of 1200-1300 mesh are ultrasonically dispersed in a mixed solution of anhydrous ethanol and deionized water at a mass ratio of 8:1, and γ-aminopropyltriethoxysilane is added under stirring and mixed evenly. S2. Increase the temperature to 76℃, add fumed silica with an average particle size of 32nm, stir magnetically at a constant temperature for 7h, and obtain organosilicon modified filler after centrifugation, washing and drying. S3. Graphene pretreatment: Graphene was ultrasonically dispersed in a mixed solution of sulfuric acid and nitric acid, and then refluxed at 80°C for 4 hours. After the reaction was completed, it was dried and ground. S4. Add the pretreated graphene from step S3 to ethanol and disperse it by ultrasonication. Add the organosilicon-modified filler obtained in step S2, stir rapidly at 30°C to allow it to react fully, centrifuge, wash several times with anhydrous ethanol, vacuum dry, and grind to obtain the filler. The weight ratio of the calcium sulfate whiskers, the anhydrous ethanol, and the γ-aminopropyltriethoxysilane in step S1 is 2:9:0.6; The weight ratio of the calcium sulfate whiskers to the fumed silica is 2:1.2.

[0031] Comparative Example 1 Preparation of composite rubber materials for shock-absorbing products: (1) Mixing: Add 35 parts of chlorinated polyethylene rubber, 25 parts of fluororubber, 25 parts of chloroprene rubber, 12 parts of modified nano calcium carbonate, 4 parts of filler, 6 parts of silane coupling agent KH550, 3 parts of stearic acid, 3.5 parts of antioxidant, and 2 parts of zinc borate to a high-power dispersing mixer according to the weight. Mix for 45 minutes at a temperature of 130℃, a vacuum degree of 0.09Mpa, and a speed of 200rpm to obtain the mixed raw materials. (2) Hot pressing: The mixed raw materials obtained in step (1) are added into the mold cavity and hot pressed for 4 minutes at a temperature of 155℃ and a pressure of 18MPa to obtain the rough product; (3) Microwave heat treatment: The crude product obtained in step (2) is placed in a microwave heating device and kept at 140℃, 160℃ and 180℃ for 1h, 1.5h and 2h respectively for curing heat treatment. The heating rate is 4℃ / min. After cooling to room temperature, the composite rubber material for shock-absorbing products is obtained. The antioxidant is composed of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N,N-di-n-butyldithiocarbamate in a weight ratio of 1.5:1. The method for preparing the modified nano-calcium carbonate is as follows: first, condensed phosphoric acid is continuously added dropwise to treat the surface of the nano-calcium carbonate particles, so that the pH value of the nano-calcium carbonate is reduced to below 8.0; then, titanate coupling agent is continuously added dropwise, and the nano-calcium carbonate particles are dry-coated by high-speed mixing, shearing, and grinding; coarse particles are sieved out to obtain modified nano-calcium carbonate treated with titanate coupling agent. The filler is prepared by: S1. Calcium sulfate whiskers with a particle size of 1200-1300 mesh are ultrasonically dispersed in a mixed solution of anhydrous ethanol and deionized water at a mass ratio of 8.5:1, and γ-aminopropyltriethoxysilane is added under stirring and mixed evenly. S2. Increase the temperature to 75℃, stir magnetically for 7 hours, and obtain the organosilicon modified filler after centrifugation, washing and drying; S3. Graphene pretreatment: Graphene was ultrasonically dispersed in a mixed solution of sulfuric acid and nitric acid, and then refluxed at 80°C for 4 hours. After the reaction was completed, it was dried and ground. S4. Add the pretreated graphene from step S3 to ethanol and disperse it by ultrasonication. Add the organosilicon-modified filler obtained in step S2, stir rapidly at 30°C to allow it to react fully, centrifuge, wash several times with anhydrous ethanol, vacuum dry, and grind to obtain the filler. The weight ratio of the calcium sulfate whiskers, the anhydrous ethanol, and the γ-aminopropyltriethoxysilane in step S1 is 2:10:0.8.

[0032] Comparative Example 2 Preparation of composite rubber materials for shock-absorbing products: (1) Mixing: Add 35 parts of chlorinated polyethylene rubber, 25 parts of fluororubber, 25 parts of chloroprene rubber, 12 parts of modified nano calcium carbonate, 4 parts of filler, 6 parts of silane coupling agent KH550, 3 parts of stearic acid, 3.5 parts of antioxidant, and 2 parts of zinc borate to a high-power dispersing mixer according to the weight. Mix for 45 minutes at a temperature of 130℃, a vacuum degree of 0.09Mpa, and a speed of 200rpm to obtain the mixed raw materials. (2) Hot pressing: The mixed raw materials obtained in step (1) are added into the mold cavity and hot pressed for 4 minutes at a temperature of 155℃ and a pressure of 18MPa to obtain the rough product; (3) Microwave heat treatment: The crude product obtained in step (2) is placed in a microwave heating device and kept at 140℃, 160℃ and 180℃ for 1h, 1.5h and 2h respectively for curing heat treatment. The heating rate is 4℃ / min. After cooling to room temperature, the composite rubber material for shock-absorbing products is obtained. The antioxidant is composed of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N,N-di-n-butyldithiocarbamate in a weight ratio of 1.5:1. The method for preparing the modified nano-calcium carbonate is as follows: first, condensed phosphoric acid is continuously added dropwise to treat the surface of the nano-calcium carbonate particles, so that the pH value of the nano-calcium carbonate is reduced to below 8.0; then, titanate coupling agent is continuously added dropwise, and the nano-calcium carbonate particles are dry-coated by high-speed mixing, shearing, and grinding; coarse particles are sieved out to obtain modified nano-calcium carbonate treated with titanate coupling agent. The filler is prepared by: S1. Prepare a mixed solution by mixing anhydrous ethanol and deionized water at a mass ratio of 8.5:1, and add γ-aminopropyltriethoxysilane under stirring, and mix thoroughly; S2. Increase the temperature to 75℃, add fumed silica with an average particle size of 30nm, stir magnetically at a constant temperature for 7h, and obtain the organosilicon modified filler after centrifugation, washing and drying. S3. Graphene pretreatment: Graphene was ultrasonically dispersed in a mixed solution of sulfuric acid and nitric acid, and then refluxed at 80°C for 4 hours. After the reaction was completed, it was dried and ground. S4. Add the pretreated graphene from step S3 to ethanol and disperse it by ultrasonication. Add the organosilicon-modified filler obtained in step S2, stir rapidly at 30°C to allow it to react fully, centrifuge, wash several times with anhydrous ethanol, vacuum dry, and grind to obtain the filler. The weight ratio of the fumed silica, the anhydrous ethanol, and the γ-aminopropyltriethoxysilane is 2:10:0.8.

[0033] Comparative Example 3 Preparation of composite rubber materials for shock-absorbing products: (1) Mixing: Add 35 parts of chlorinated polyethylene rubber, 25 parts of fluororubber, 25 parts of chloroprene rubber, 12 parts of nano calcium carbonate, 4 parts of filler, 6 parts of silane coupling agent KH550, 3 parts of stearic acid, 3.5 parts of antioxidant, and 2 parts of zinc borate to a high-power dispersing mixer according to the weight. Mix for 45 minutes at a temperature of 130℃, a vacuum degree of 0.09Mpa, and a speed of 200rpm to obtain mixed raw materials; (2) Hot pressing: The mixed raw materials obtained in step (1) are added into the mold cavity and hot pressed for 4 minutes at a temperature of 155℃ and a pressure of 18MPa to obtain the rough product; (3) Microwave heat treatment: The crude product obtained in step (2) is placed in a microwave heating device and kept at 140℃, 160℃ and 180℃ for 1h, 1.5h and 2h respectively for curing heat treatment. The heating rate is 4℃ / min. After cooling to room temperature, the composite rubber material for shock-absorbing products is obtained. The antioxidant is composed of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N,N-di-n-butyldithiocarbamate in a weight ratio of 1.5:1. The filler is prepared by: S1. Calcium sulfate whiskers with a particle size of 1200-1300 mesh are ultrasonically dispersed in a mixed solution of anhydrous ethanol and deionized water at a mass ratio of 8.5:1, and γ-aminopropyltriethoxysilane is added under stirring and mixed evenly. S2. Increase the temperature to 75℃, add fumed silica with an average particle size of 30nm, stir magnetically at a constant temperature for 7h, and obtain the organosilicon modified filler after centrifugation, washing and drying. S3. Graphene pretreatment: Graphene was ultrasonically dispersed in a mixed solution of sulfuric acid and nitric acid, and then refluxed at 80°C for 4 hours. After the reaction was completed, it was dried and ground. S4. Add the pretreated graphene from step S3 to ethanol and disperse it by ultrasonication. Add the organosilicon-modified filler obtained in step S2, stir rapidly at 30°C to allow it to react fully, centrifuge, wash several times with anhydrous ethanol, vacuum dry, and grind to obtain the filler. The weight ratio of the calcium sulfate whiskers, the anhydrous ethanol, and the γ-aminopropyltriethoxysilane in step S1 is 2:10:0.8; The weight ratio of the calcium sulfate whiskers to the fumed silica is 2:1.3.

[0034] Experimental Example The relevant properties of the composite rubber materials for shock-absorbing products prepared in Examples 1-4 and Comparative Examples 1-3 were tested using the following methods: Tensile strength was tested according to GB / T 528-2009 standard. The tensile strength after heat aging was measured after holding at 100℃ for 72 hours.

[0035] The resilience was tested according to the standard GB / T 1681-2009.

[0036] The flame retardancy rating was tested according to the standard GB 8624-2012.

[0037] Performance test data are shown in Table 1 below:

[0038] As can be seen from Table 1, the composite rubber materials for shock-absorbing products in Examples 1-4 of this application have good performance. Under the specific combination of raw material ratios, their elasticity, flame retardancy, tensile strength, and heat aging resistance can all reach a high level.

[0039] The filler in Comparative Example 1 did not contain fumed silica, and all other components were the same as in Example 1. The flame retardancy of the composite rubber material for shock-absorbing products prepared in Comparative Example 1 was significantly worse, indicating that the fumed silica of this application can form a silica coating when the material is burning. This coating has the functions of heat insulation and shielding, which can prevent heat transfer and the escape of combustibles. The addition of fumed silica can also increase the residual carbon content of the material. As its dosage increases, the residual carbon content of the composite material gradually increases, and the carbon layer gradually becomes denser and more complete, thereby improving the flame retardant performance.

[0040] The filler in the raw materials of Comparative Example 2 did not contain fumed silica, and all other components were the same as in Example 1. The elasticity and tensile strength of the composite rubber material for shock-absorbing products prepared in Comparative Example 2 were significantly worse, indicating that the calcium sulfate whiskers of this application, as microfibers, form a stable skeleton in the rubber, significantly improving strength, hardness and modulus. Its fiber structure can prevent crack propagation, absorb impact energy, and improve the wear resistance of the rubber. At the same time, the calcium sulfate whiskers themselves are resistant to high temperature and non-flammable, enhancing the overall flame retardant effect of the rubber.

[0041] The nano-calcium carbonate in the raw materials of Comparative Example 3 was not modified, and the rest were the same as in Example 1. The elasticity, tensile strength and aging resistance of the composite rubber material for shock-absorbing products prepared in Comparative Example 3 were significantly worse, indicating that the titanate coupling agent of this application can form a monolayer on the surface of nano-calcium carbonate. One end is chemically bonded to the hydroxyl groups on the surface of calcium carbonate, while the long-chain organic groups at the other end are entangled or physically miscible with the composite rubber material matrix. This greatly improves the dispersion and interfacial bonding of nano-calcium carbonate particles in the composite rubber material matrix, thereby playing a role in strengthening and toughening.

[0042] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions or alterations can be made to these embodiments without departing from the principles and spirit of this application, and the technical solutions resulting from such changes, modifications, substitutions or alterations will all fall within the protection scope of this application.

Claims

1. A composite rubber material for shock-absorbing products, characterized in that, The preparation materials include the following parts by weight: 30-40 parts of chlorinated polyethylene rubber, 20-30 parts of fluororubber, 20-30 parts of chloroprene rubber, 10-15 parts of modified nano calcium carbonate, 3-5 parts of filler, 5-8 parts of compatibilizer, 2-4 parts of stearic acid, 3-4 parts of antioxidant, and 1-3 parts of flame retardant. The filler includes calcium sulfate whiskers and fumed silica.

2. The composite rubber material for shock-absorbing products according to claim 1, characterized in that, The weight ratio of the calcium sulfate whiskers to the fumed silica is 2:(1-1.5).

3. The composite rubber material for shock-absorbing products according to claim 1, characterized in that, The antioxidant is composed of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N,N-di-n-butyldithiocarbamate nickel in a weight ratio of (1-2):

1.

4. The composite rubber material for shock-absorbing products according to claim 1, characterized in that, The flame retardant is at least one of triethyl phosphate, ammonium polyphosphate, and zinc borate.

5. The composite rubber material for shock-absorbing products according to claim 1, characterized in that, The preparation of the modified nano-calcium carbonate includes the following steps: first, condensed phosphoric acid is continuously added dropwise to treat the surface of the nano-calcium carbonate particles, so that the pH value of the nano-calcium carbonate is reduced to below 8.0; then, titanate coupling agent is continuously added dropwise, and the nano-calcium carbonate particles are dry-coated by high-speed mixing, shearing, and grinding; coarse particles are sieved out to obtain modified nano-calcium carbonate treated with titanate coupling agent.

6. The composite rubber material for shock-absorbing products according to claim 1, characterized in that, The preparation of the filler includes the following steps: S1. Calcium sulfate whiskers were ultrasonically dispersed in a mixed solution of anhydrous ethanol and deionized water in a mass ratio of (8-9):1, and γ-aminopropyltriethoxysilane was added under stirring and mixed evenly. S2. Raise the temperature to 70-80℃, add fumed silica, stir magnetically at a constant temperature for 5-8 hours, and obtain the organosilicon modified filler after centrifugation, washing and drying; S3. Graphene pretreatment: Graphene was ultrasonically dispersed in a mixed solution of sulfuric acid and nitric acid, and then refluxed at 80°C for 4 hours. After the reaction was completed, it was dried and ground. S4. Add the pretreated graphene from step S3 to ethanol and disperse it by ultrasonication. Add the organosilicon-modified filler obtained in step S2, stir rapidly at 25-35℃ to allow it to react fully, centrifuge, wash several times with anhydrous ethanol, vacuum dry, and grind to obtain the filler.

7. The composite rubber material for shock-absorbing products according to claim 6, characterized in that, The average particle size of the fumed silica is 25-35 nm.

8. The composite rubber material for shock-absorbing products according to claim 6, characterized in that, The weight ratio of the calcium sulfate whiskers, the anhydrous ethanol and the γ-aminopropyltriethoxysilane in step S1 is 2:(8-12):(0.5-1).

9. A method for preparing a composite rubber material for shock-absorbing products as described in any one of claims 1 to 8, characterized in that, Includes the following steps: (1) Mixing: Chlorinated polyethylene rubber, fluororubber, chloroprene rubber, modified nano calcium carbonate, filler, compatibilizer, stearic acid, antioxidant, and flame retardant are added to a high-power dispersing mixer according to the weight parts. The mixture is stirred for 30-60 minutes at a temperature of 120-140℃, a vacuum degree of 0.08-0.10Mpa, and a speed of 100-300rpm to obtain the mixed raw materials. (2) Hot pressing: The mixed raw materials obtained in step (1) are added into the mold cavity and hot pressed for 3-5 minutes at a temperature of 145-165℃ and a pressure of 15-20MPa to obtain the rough product; (3) Microwave heat treatment: The crude product obtained in step (2) is placed in a microwave heating device and cured at a temperature of 140-180℃. After cooling to room temperature, a composite rubber material for shock-absorbing products is obtained.

10. The method for preparing a composite rubber material for shock-absorbing products according to claim 9, characterized in that, The curing heat treatment in step (3) involves holding the product at temperatures of 140℃, 160℃, and 180℃ for 1 hour, 1.5 hours, and 2 hours, respectively.

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