Flame-retardant rubber support material and preparation method thereof

Abstract

The invention discloses a flame-retardant rubber support material and a preparation method thereof in the technical field of flame-retardant materials. The support material is prepared from the following raw materials in parts by weight: 60 to 80 parts of natural rubber, 40 to 60 parts of chloroprene rubber, 5 to 10 parts of flame-retardant filler, 1 to 2 parts of accelerant TMTM and 2 to 3 parts of sulfur. When the support material is combusted, ammonium polyphosphate on the flame-retardant filler is decomposed to generate phosphoric acid and ammonia gas, the phosphoric acid has strong dehydration property and can react with hydroxyl groups in the polymer base material to promote the material to be dehydrated to form a carbonization layer, the ammonia gas can dilute the content of oxygen and reduce the combustion rate, and the stability of the carbonization layer can be improved due to the existence of Si, N and S; and the internal expanded graphene is further physically expanded under the action of high temperature to form a porous carbonized layer, so that the carbon layer forms a composite structure with a compact carbon layer outside and a porous carbon layer inside, oxygen and heat are effectively isolated, and the material can be quickly extinguished without dripping.

Description

Technical Field

[0001] The present invention relates to the technical field of flame retardant material preparation, and in particular to a flame retardant rubber bearing material and a preparation method thereof. Background Art

[0002] Floor rubber elastic bearings are used between the car body and the carriage floor. They not only support the entire carriage floor, but also, through the unique elastic damping effect of rubber, effectively mitigate the vibration transmitted from the car body to the floor during train travel, thereby increasing journey comfort and being an important guarantee for the overall quality of the train. Rubber itself does not have flame retardant properties and cannot meet the various requirements put forward for it during the development of rubber materials. Therefore, flame retardants and other materials must be added to give rubber properties that it does not possess. At present, flame retardant rubber is prepared by mixing rubber with a large amount of inorganic flame retardants, which has a general flame retardant effect. Some organic flame retardants are used, but organic flame retardants have a small molecular weight and are easily migrated to the rubber surface, resulting in a decrease in the flame retardant effect of the rubber and affecting the safety of the bearings. Summary of the Invention

[0003] In view of the deficiencies in the prior art, the present invention provides a flame-retardant rubber bearing material and a preparation method thereof, which solves the problem that the current rubber materials used for bearings have poor flame retardancy.

[0004] The object of the present invention is achieved as follows: A method for preparing a flame retardant rubber bearing material, specifically comprising the following steps: Step A1: uniformly mixing a modified filler, a palladium-carbon catalyst, triethylamine, and toluene, introducing hydrogen to maintain a pressure of 0.5-1 MPa, and reacting at a speed of 120-150 r / min and a temperature of 40-50° C. for 3-5 hours to obtain an amino filler; uniformly mixing an amino filler, ammonium polyphosphate, deionized water, and ethanol, and reacting at a speed of 200-300 r / min and a temperature of 75-80° C. for 3-4 hours, filtering, and drying to obtain a flame-retardant filler; Step A2: Weigh the following parts by weight of fillers: 60-80 parts of natural rubber, 40-60 parts of chloroprene rubber, 5-10 parts of flame retardant filler, 1-2 parts of accelerator TMTM, and 2-3 parts of sulfur, mix the natural rubber and chloroprene rubber, mix at a speed of 60-80 r / min and a temperature of 55-60° C. for 3-5 minutes, add the flame retardant filler, heat to 90-95° C., mix for 3-5 minutes, cool to 65-70° C., discharge the rubber onto an open mill, add accelerator TMTM and sulfur, pass the thin film 6 times, and then vulcanize at room temperature for 20-25 hours at 150° C. for 8-10 minutes to obtain a flame retardant rubber bearing material.

[0005] Furthermore, the amount ratio of the nitro group, palladium carbon catalyst, triethylamine and toluene on the modified filler described in step A1 is 10 mmol:200 mg:1 mg:60 mL, and the mass ratio of the amino filler and ammonium polyphosphate is 1:1.

[0006] Furthermore, the modified filler is prepared by the following steps: Step B1: flake graphite, ammonium persulfate and concentrated sulfuric acid are mixed, stirred at a speed of 200-300 r / min and a temperature of 35-45°C for 3-4 hours, and the filtrate is removed by filtration. The substrate is added to hydrogen peroxide, stirred at a speed of 300-500 r / min and a temperature of 50-55°C for 40-50 minutes, and the filtrate is removed by filtration. The mixture is then kept at a temperature of 1000-1050°C for 30-40 seconds to obtain expanded graphite; Step B2: Dispersing the expanded graphene in ethanol, stirring and adding KH570 and deionized water at a speed of 300-500 r / min and a temperature of 70-75°C, and reacting for 3-5 hours to obtain pretreated graphite, and mixing the pretreated graphite, trichlorosilane, chloroplatinic acid and DMF, passing nitrogen protection, and reacting at a speed of 120-150 r / min and a temperature of 80-85°C for 6-8 hours to obtain modified graphite; Step B3: Dimethylvinylsilanol lithium and tetrahydrofuran are mixed evenly, stirred and added with modified monomer at a speed of 120-150 r / min and a temperature of 0°C, the temperature is raised to 25-30°C, and the reaction is carried out for 7-9 hours. Modified graphite is added and the reaction is continued for 1-1.5 hours to obtain a pretreated filler. The pretreated filler, 4-nitrobenzene mercaptan, benzophenone and DMF are mixed evenly, and the reaction is carried out at a speed of 60-80 r / min and 365 nm ultraviolet light irradiation for 10-15 minutes to obtain a modified filler.

[0007] Furthermore, the amount ratio of the flake graphite, ammonium persulfate, concentrated sulfuric acid and hydrogen peroxide described in step B1 is 2g:1g:10mL:2mL, the mass fraction of concentrated sulfuric acid is 98%, and the mass fraction of hydrogen peroxide is 30%.

[0008] Furthermore, the amount ratio of expanded graphene, ethanol, KH570 and deionized water in step B2 is 1g:80mL:6mL:20mL, the molar ratio of double bonds on the pretreated graphite to trichlorosilane is 1:1, and the amount of chloroplatinic acid is 1‰ of the mass of trichlorosilane.

[0009] Furthermore, the amount ratio of lithium dimethylvinylsiliconol, modified monomer and modified graphite described in step B3 is 100mmol:400mmol:1g, the molar ratio of the double bond on the pretreated filler and 4-nitrobenzene mercaptan is 1:1, and the amount of benzophenone is 2% of the mass of 4-nitrobenzene mercaptan.

[0010] Furthermore, the modified monomer is prepared by the following steps: 4-hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide, triethylamine, acryloyl chloride and tetrahydrofuran are uniformly mixed, nitrogen is introduced for protection, and the reaction is carried out for 2-3 hours at a speed of 200-300 r / min and a temperature of 40-50°C to obtain a modifier. Tetramethylcyclotetrasiloxane, the modifier, chloroplatinic acid and DMF are mixed, nitrogen is introduced for protection, and the reaction is carried out for 3-5 hours at a speed of 120-150 r / min and a temperature of 80-85°C to obtain a modified monomer.

[0011] Furthermore, the molar ratio of 4-hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide, triethylamine and acryloyl chloride is 1:1.2:1, the molar ratio of tetramethylcyclotetrasiloxane and modifier is 1:4, and the amount of chloroplatinic acid is 1‰ of the mass of tetramethylcyclotetrasiloxane.

[0012] Compared with the prior art, the beneficial effect of the present invention is that: a flame-retardant rubber bearing material prepared by the present invention includes the following raw materials: natural rubber, chloroprene rubber, flame-retardant filler, accelerator TMTM and sulfur, the flame-retardant filler is reduced with the modified filler as raw material, so that the surface nitro group is converted into amino group, and then reacted with ammonium polyphosphate, so that the amino group on the surface of the amino filler and the phosphate group on the ammonium polyphosphate are dehydrated and condensed to obtain the flame-retardant filler.

[0013] The modified filler is prepared by using flake graphite as a raw material, oxidizing and intercalating with ammonium persulfate and concentrated sulfuric acid, then stabilizing the intercalation with hydrogen peroxide, and finally subjecting the material to high-temperature expansion to obtain expanded graphite. The expanded graphite is treated with KH570 to graft double bonds on the surface to obtain pretreated graphite. The pretreated graphite is reacted with trichlorosilane to react the double bonds on the pretreated graphite with the Si-H bonds on the trichlorosilane to obtain modified graphite. Dimethylvinylsilanol lithium is used as an initiator and a modified monomer is used as a polymerization monomer, and then the modified graphite is added to react the lithium siliconate with the Si-Cl bonds on the modified graphite to obtain a pretreated filler. The pretreated filler is reacted with 4-nitrobenzene mercaptan to react the double bonds on the pretreated filler with the sulfhydryl groups on the 4-nitrobenzene mercaptan to obtain a modified filler.

[0014] The modified monomer is prepared by using 4-hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide and acryloyl chloride as raw materials, so that the hydroxyl group on 4-hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide reacts with the acyl chloride on the acryloyl chloride to prepare a modifier, and tetramethylcyclotetrasiloxane and the modifier react so that the Si-H bond on the tetramethylcyclotetrasiloxane reacts with the double bond on the modifier to prepare the modified monomer.

[0015] When the support material burns, the ammonium polyphosphate on the flame retardant filler decomposes to produce phosphoric acid and ammonia. Phosphoric acid has strong dehydrating properties and can react with hydroxyl groups in the polymer matrix to promote the dehydration of the material to form a carbonized layer. Ammonia can dilute the oxygen content and reduce the combustion rate. The presence of Si, N and S can increase the stability of the carbonized layer and increase the density of the carbonized layer. The internal expanded graphene further physically expands under the action of high temperature to form a porous carbonized layer, so that the carbon layer forms a composite structure with a dense carbon layer on the outside and a porous carbon layer on the inside, thereby effectively isolating oxygen and heat, allowing the material to be extinguished quickly without dripping. DETAILED DESCRIPTION

[0016] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0017] Example 1, a method for preparing a flame retardant rubber bearing material, specifically comprising the following steps: Step A1: uniformly mixing a modified filler, a palladium-carbon catalyst, triethylamine, and toluene, introducing hydrogen to maintain a pressure of 0.5 MPa, and reacting at a speed of 120 r / min and a temperature of 40° C. for 3 h to obtain an amino filler; uniformly mixing an amino filler, ammonium polyphosphate, deionized water, and ethanol, and reacting at a speed of 200 r / min and a temperature of 75° C. for 3 h, filtering, and drying to obtain a flame-retardant filler; Step A2: Weigh the following parts by weight of fillers: 60 parts of natural rubber, 40 parts of chloroprene rubber, 5 parts of flame retardant filler, 1 part of accelerator TMTM and 2 parts of sulfur, mix the natural rubber and chloroprene rubber, mix at a speed of 60 r / min and a temperature of 55°C for 3 minutes, add the flame retardant filler, heat to 90°C, mix for 3 minutes, cool to 65°C, discharge the rubber onto an open mill, add accelerator TMTM and sulfur, pass the thin film 6 times and thicken the film, leave it at room temperature for 20 hours, and then vulcanize it at a temperature of 150°C for 8 minutes to obtain a flame retardant rubber bearing material.

[0018] The amount ratio of the nitro group, palladium carbon catalyst, triethylamine and toluene on the modified filler described in step A1 is 10 mmol:200 mg:1 mg:60 mL, and the mass ratio of the amino filler and ammonium polyphosphate is 1:1.

[0019] The model of the natural rubber described in step A2 is SMR20, and the model of the chloroprene rubber is CR322.

[0020] The modified filler is prepared by the following steps: Step B1: flake graphite, ammonium persulfate and concentrated sulfuric acid are mixed, stirred at a speed of 200 r / min and a temperature of 35°C for 3 hours, and the filtrate is removed by filtration. The substrate is added to hydrogen peroxide, stirred at a speed of 300 r / min and a temperature of 50°C for 40 minutes, the filtrate is removed by filtration, and then kept at a temperature of 1000°C for 30 seconds to obtain expanded graphite; Step B2: The expanded graphene was dispersed in ethanol, stirred at a speed of 300 r / min and a temperature of 70°C, and KH570 and deionized water were added for a reaction of 3 hours to obtain pretreated graphite. The pretreated graphite, trichlorosilane, chloroplatinic acid, and DMF were mixed, nitrogen was introduced, and the reaction was carried out at a speed of 120 r / min and a temperature of 80°C for 6 hours to obtain modified graphite; Step B3: Dimethylvinylsiliconol lithium and tetrahydrofuran were mixed evenly, stirred and added with modified monomer at a speed of 120 r / min and a temperature of 0°C, the temperature was raised to 25°C, and the reaction was carried out for 7 hours. Then, modified graphite was added and the reaction was continued for 1 hour to obtain a pretreated filler. The pretreated filler, 4-nitrobenzene mercaptan, benzophenone and DMF were mixed evenly, and the reaction was carried out at a speed of 60 r / min and 365 nm ultraviolet light irradiation for 10 minutes to obtain a modified filler.

[0021] The amount ratio of the flake graphite, ammonium persulfate, concentrated sulfuric acid and hydrogen peroxide described in step B1 is 2g:1g:10mL:2mL, the mass fraction of the concentrated sulfuric acid is 98%, and the mass fraction of the hydrogen peroxide is 30%.

[0022] The amount ratio of expanded graphene, ethanol, KH570 and deionized water in step B2 is 1g:80mL:6mL:20mL, the molar ratio of double bonds on the pretreated graphite to trichlorosilane is 1:1, and the amount of chloroplatinic acid is 1‰ of the mass of trichlorosilane.

[0023] The amount ratio of lithium dimethylvinylsiliconol, modified monomer and modified graphite described in step B3 is 100mmol:400mmol:1g, the molar ratio of the double bond on the pretreated filler to 4-nitrobenzene mercaptan is 1:1, and the amount of benzophenone is 2% of the mass of 4-nitrobenzene mercaptan.

[0024] The modified monomer is prepared by the following steps: 4-Hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide, triethylamine, acryloyl chloride and tetrahydrofuran were mixed evenly, nitrogen was introduced for protection, and the reaction was carried out at a speed of 200 r / min and a temperature of 40°C for 2 hours to obtain a modifier. Tetramethylcyclotetrasiloxane, the modifier, chloroplatinic acid and DMF were mixed, nitrogen was introduced for protection, and the reaction was carried out at a speed of 120 r / min and a temperature of 80°C for 3 hours to obtain a modified monomer.

[0025] The molar ratio of 4-hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide, triethylamine and acryloyl chloride is 1:1.2:1, the molar ratio of tetramethylcyclotetrasiloxane and modifier is 1:4, and the amount of chloroplatinic acid is 1‰ of the mass of tetramethylcyclotetrasiloxane.

[0026] Example 2, a method for preparing a flame-retardant rubber bearing material, specifically comprising the following steps: Step A1: uniformly mixing a modified filler, a palladium-carbon catalyst, triethylamine, and toluene, introducing hydrogen to maintain a pressure of 0.8 MPa, and reacting at a speed of 120 r / min and a temperature of 45° C. for 4 hours to obtain an amino filler; uniformly mixing an amino filler, ammonium polyphosphate, deionized water, and ethanol, and reacting at a speed of 200 r / min and a temperature of 80° C. for 4 hours, filtering, and drying to obtain a flame-retardant filler; Step A2: Weigh the following parts by weight of fillers: 70 parts of natural rubber, 50 parts of chloroprene rubber, 8 parts of flame retardant filler, 1.5 parts of accelerator TMTM and 2.5 parts of sulfur, mix the natural rubber and chloroprene rubber, mix at a speed of 60 r / min and a temperature of 60°C for 4 minutes, add the flame retardant filler, heat to 90°C, mix for 4 minutes, cool to 70°C, discharge the rubber onto an open mill and add accelerator TMTM and sulfur, pass the thin film 6 times and thicken it, leave it at room temperature for 20 hours, and then vulcanize it at a temperature of 150°C for 9 minutes to obtain a flame retardant rubber bearing material.

[0027] The amount ratio of the nitro group, palladium carbon catalyst, triethylamine and toluene on the modified filler described in step A1 is 10 mmol:200 mg:1 mg:60 mL, and the mass ratio of the amino filler and ammonium polyphosphate is 1:1.

[0028] The model of the natural rubber described in step A2 is SMR20, and the model of the chloroprene rubber is CR322.

[0029] The modified filler is prepared by the following steps: Step B1: flake graphite, ammonium persulfate and concentrated sulfuric acid were mixed, stirred at a speed of 300 r / min and a temperature of 40°C for 3.5 hours, and the filtrate was removed by filtration. The substrate was added to hydrogen peroxide, stirred at a speed of 300 r / min and a temperature of 55°C for 45 minutes, and the filtrate was removed by filtration. The mixture was then kept at a temperature of 1025°C for 35 seconds to obtain expanded graphite; Step B2: The expanded graphene was dispersed in ethanol, stirred at a speed of 500 r / min and a temperature of 70°C, and KH570 and deionized water were added for a reaction of 4 h to obtain pretreated graphite. The pretreated graphite, trichlorosilane, chloroplatinic acid, and DMF were mixed, nitrogen was introduced, and the reaction was carried out at a speed of 150 r / min and a temperature of 80°C for 7 h to obtain modified graphite; Step B3: Dimethylvinylsiliconol lithium and tetrahydrofuran were mixed evenly, stirred and added with modified monomer at a speed of 120 r / min and a temperature of 0°C, the temperature was raised to 30°C, and the reaction was carried out for 8 hours. Then, modified graphite was added and the reaction was continued for 1.2 hours to obtain a pretreated filler. The pretreated filler, 4-nitrobenzene mercaptan, benzophenone and DMF were mixed evenly, and the reaction was carried out at a speed of 60 r / min and 365 nm ultraviolet light irradiation for 13 minutes to obtain a modified filler.

[0030] The amount ratio of the flake graphite, ammonium persulfate, concentrated sulfuric acid and hydrogen peroxide described in step B1 is 2g:1g:10mL:2mL, the mass fraction of the concentrated sulfuric acid is 98%, and the mass fraction of the hydrogen peroxide is 30%.

[0031] The amount ratio of expanded graphene, ethanol, KH570 and deionized water in step B2 is 1g:80mL:6mL:20mL, the molar ratio of double bonds on the pretreated graphite to trichlorosilane is 1:1, and the amount of chloroplatinic acid is 1‰ of the mass of trichlorosilane.

[0032] The amount ratio of lithium dimethylvinylsiliconol, modified monomer and modified graphite described in step B3 is 100mmol:400mmol:1g, the molar ratio of the double bond on the pretreated filler to 4-nitrobenzene mercaptan is 1:1, and the amount of benzophenone is 2% of the mass of 4-nitrobenzene mercaptan.

[0033] The modified monomer is prepared by the following steps: 4-Hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide, triethylamine, acryloyl chloride and tetrahydrofuran were mixed evenly, nitrogen was introduced for protection, and the reaction was carried out at a speed of 200 r / min and a temperature of 45°C for 2.5 hours to obtain a modifier. Tetramethylcyclotetrasiloxane, the modifier, chloroplatinic acid and DMF were mixed, nitrogen was introduced for protection, and the reaction was carried out at a speed of 150 r / min and a temperature of 80°C for 4 hours to obtain a modified monomer.

[0034] The molar ratio of 4-hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide, triethylamine and acryloyl chloride is 1:1.2:1, the molar ratio of tetramethylcyclotetrasiloxane and modifier is 1:4, and the amount of chloroplatinic acid is 1‰ of the mass of tetramethylcyclotetrasiloxane.

[0035] Example 3, a method for preparing a flame-retardant rubber bearing material, specifically comprising the following steps: Step A1: uniformly mixing a modified filler, a palladium-carbon catalyst, triethylamine, and toluene, introducing hydrogen to maintain a pressure of 1 MPa, and reacting at a speed of 150 r / min and a temperature of 50° C. for 5 hours to obtain an amino filler; uniformly mixing an amino filler, ammonium polyphosphate, deionized water, and ethanol, and reacting at a speed of 300 r / min and a temperature of 80° C. for 4 hours, filtering, and drying to obtain a flame-retardant filler; Step A2: Weigh the following parts by weight of fillers: 80 parts of natural rubber, 60 parts of chloroprene rubber, 10 parts of flame retardant filler, 2 parts of accelerator TMTM and 3 parts of sulfur, mix the natural rubber and chloroprene rubber, mix at a speed of 80 r / min and a temperature of 60°C for 5 minutes, add the flame retardant filler, heat to 95°C, mix for 5 minutes, cool to 70°C, discharge the rubber onto an open mill and add accelerator TMTM and sulfur, pass the thin film 6 times and thicken the film, leave it at room temperature for 25 hours, and then vulcanize it at a temperature of 150°C for 10 minutes to obtain a flame retardant rubber bearing material.

[0036] The amount ratio of the nitro group, palladium carbon catalyst, triethylamine and toluene on the modified filler described in step A1 is 10 mmol:200 mg:1 mg:60 mL, and the mass ratio of the amino filler and ammonium polyphosphate is 1:1.

[0037] The model of the natural rubber described in step A2 is SMR20, and the model of the chloroprene rubber is CR322.

[0038] The modified filler is prepared by the following steps: Step B1: flake graphite, ammonium persulfate and concentrated sulfuric acid were mixed, stirred at a speed of 300 r / min and a temperature of 45°C for 4 hours, and the filtrate was removed by filtration. The substrate was added to hydrogen peroxide, stirred at a speed of 500 r / min and a temperature of 55°C for 50 minutes, and the filtrate was removed by filtration. The mixture was then kept at a temperature of 1050°C for 40 seconds to obtain expanded graphite; Step B2: The expanded graphene was dispersed in ethanol, stirred at a speed of 500 r / min and a temperature of 75°C, and KH570 and deionized water were added for a reaction of 5 hours to obtain pretreated graphite. The pretreated graphite, trichlorosilane, chloroplatinic acid and DMF were mixed, nitrogen was introduced, and the reaction was carried out at a speed of 150 r / min and a temperature of 85°C for 8 hours to obtain modified graphite; Step B3: Dimethylvinylsiliconol lithium and tetrahydrofuran were mixed evenly, stirred and added with modified monomer at a speed of 150 r / min and a temperature of 0°C, the temperature was raised to 30°C, and the reaction was carried out for 9 hours. Then, modified graphite was added and the reaction was continued for 1.5 hours to obtain a pretreated filler. The pretreated filler, 4-nitrobenzene mercaptan, benzophenone and DMF were mixed evenly, and the reaction was carried out at a speed of 80 r / min and 365 nm ultraviolet light irradiation for 15 minutes to obtain a modified filler.

[0039] The amount ratio of the flake graphite, ammonium persulfate, concentrated sulfuric acid and hydrogen peroxide described in step B1 is 2g:1g:10mL:2mL, the mass fraction of the concentrated sulfuric acid is 98%, and the mass fraction of the hydrogen peroxide is 30%.

[0040] The amount ratio of expanded graphene, ethanol, KH570 and deionized water in step B2 is 1g:80mL:6mL:20mL, the molar ratio of double bonds on the pretreated graphite to trichlorosilane is 1:1, and the amount of chloroplatinic acid is 1‰ of the mass of trichlorosilane.

[0041] The amount ratio of lithium dimethylvinylsiliconol, modified monomer and modified graphite described in step B3 is 100mmol:400mmol:1g, the molar ratio of the double bond on the pretreated filler to 4-nitrobenzene mercaptan is 1:1, and the amount of benzophenone is 2% of the mass of 4-nitrobenzene mercaptan.

[0042] The modified monomer is prepared by the following steps: 4-Hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide, triethylamine, acryloyl chloride and tetrahydrofuran were mixed evenly, nitrogen was introduced for protection, and the reaction was carried out at a speed of 300 r / min and a temperature of 50°C for 3 hours to obtain a modifier. Tetramethylcyclotetrasiloxane, the modifier, chloroplatinic acid and DMF were mixed, nitrogen was introduced for protection, and the reaction was carried out at a speed of 150 r / min and a temperature of 85°C for 5 hours to obtain a modified monomer.

[0043] The molar ratio of 4-hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide, triethylamine and acryloyl chloride is 1:1.2:1, the molar ratio of tetramethylcyclotetrasiloxane and modifier is 1:4, and the amount of chloroplatinic acid is 1‰ of the mass of tetramethylcyclotetrasiloxane.

[0044] Comparative Example 1: Compared with Example 1, this comparative example uses amino filler instead of flame retardant filler, and the other steps are the same.

[0045] Comparative Example 2: Compared with Example 1, this comparative example uses graphite oxide instead of expanded graphite, and the remaining steps are the same.

[0046] Comparative Example 3: Compared with Example 1, this comparative example uses octamethylcyclotetrasiloxane instead of the modified monomer, and the remaining steps are the same.

[0047] The support materials prepared in Examples 1-3 and Comparative Examples 1-3 were made into 125mm×13mm×10mm specimens according to the standard of GB / T2408-2008, and the vertical burning level was tested. The support materials were made into 130mm×10mm×10mm specimens according to the standard of GB / T2406.2-2009, and the limiting oxygen index was tested. The test results are shown in Table 1 below.

[0048] Table 1 It can be seen from the above table that this application has a good flame retardant effect.

[0049] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a flame-retardant rubber bearing material, characterized in that: The specific steps include: Step A1: uniformly mixing a modified filler, a palladium-carbon catalyst, triethylamine, and toluene, and reacting them under a hydrogen atmosphere to obtain an amino filler; and mixing the amino filler, ammonium polyphosphate, deionized water, and ethanol to obtain a flame-retardant filler after reaction, filtering, and drying. Step A2: Weigh the following parts by weight of filler: 60-80 parts of natural rubber, 40-60 parts of chloroprene rubber, 5-10 parts of flame retardant filler, 1-2 parts of accelerator TMTM and 2-3 parts of sulfur, mix, open-mill and vulcanize the raw materials to obtain a flame retardant rubber bearing material.

2. The method for preparing a flame-retardant rubber bearing material according to claim 1, characterized in that: The amount ratio of the nitro group, palladium carbon catalyst, triethylamine and toluene on the modified filler described in step A1 is 10 mmol:200 mg:1 mg:60 mL, and the mass ratio of the amino filler and ammonium polyphosphate is 1:

1.

3. The method for preparing a flame-retardant rubber bearing material according to claim 1, characterized in that: The modified filler is prepared by the following steps: Step B1: flake graphite, ammonium persulfate and concentrated sulfuric acid are mixed and stirred, the filtrate is removed by filtration, the substrate is added to hydrogen peroxide, stirred, the filtrate is removed by filtration, and the mixture is kept at high temperature to obtain expanded graphite; Step B2: Dispersing expanded graphene in ethanol, stirring, adding KH570 and deionized water, and reacting for 3-5 hours to obtain pretreated graphite. The pretreated graphite, trichlorosilane, chloroplatinic acid, and DMF are mixed, and nitrogen is passed through to react to obtain modified graphite. Step B3: lithium dimethylvinylsiliconol and tetrahydrofuran are mixed and stirred and a modified monomer is added. After the reaction, modified graphite is added and the reaction is continued to obtain a pretreated filler. The pretreated filler, 4-nitrobenzene mercaptan, benzophenone and DMF are mixed and reacted to obtain a modified filler.

4. The method for preparing a flame-retardant rubber bearing material according to claim 3, characterized in that: The amount ratio of the flake graphite, ammonium persulfate, concentrated sulfuric acid and hydrogen peroxide described in step B1 is 2g:1g:10mL:2mL.

5. The method for preparing a flame-retardant rubber bearing material according to claim 3, characterized in that: The amount ratio of expanded graphene, ethanol, KH570 and deionized water described in step B2 is 1g:80mL:6mL:20mL, and the molar ratio of double bonds on the pretreated graphite to trichlorosilane is 1:

1.

6. The method for preparing a flame-retardant rubber bearing material according to claim 3, characterized in that: The amount ratio of lithium dimethylvinylsiliconol, modified monomer and modified graphite described in step B3 is 100mmol:400mmol:1g, and the molar ratio of double bonds and 4-nitrobenzenethiol on the pretreated filler is 1:

1.

7. The method for preparing a flame-retardant rubber bearing material according to claim 3, characterized in that: The modified monomer is prepared by the following steps: 4-hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide, triethylamine, acryloyl chloride and tetrahydrofuran are uniformly mixed, nitrogen is introduced to protect the reaction, and a modifier is prepared. Tetramethylcyclotetrasiloxane, the modifier, chloroplatinic acid and DMF are mixed, nitrogen is introduced to protect the reaction, and a modified monomer is prepared.

8. The method for preparing a flame-retardant rubber bearing material according to claim 7, characterized in that: The molar ratio of 4-hydroxymethyl-2,6,7-trioxo-1-phosphabicyclo[2.2.2]octane 1-oxide, triethylamine and acryloyl chloride is 1:1.2:1, and the molar ratio of tetramethylcyclotetrasiloxane and modifier is 1:

4.

9. A flame retardant rubber bearing material, characterized by: Prepared according to any one of claims 1 to 8.

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