Graphene modified whole-core flame-retardant conveying belt for coal mine and preparation method of graphene modified whole-core flame-retardant conveying belt

Abstract

The invention discloses a graphene modified whole-core flame-retardant conveying belt for a coal mine and a preparation method of the graphene modified whole-core flame-retardant conveying belt, and belongs to the technical field of flame-retardant conveying belts for underground coal mines. Epoxy modification is conducted through (3-glycidoxy) trimethoxysilane, then carbon spheres are generated through glucose pyrolysis, and then the surface is evenly coated with graphene oxide; the preparation method comprises the following steps: firstly, preparing graphene oxide / carbon microspheres, adding the graphene oxide / carbon microspheres to obtain graphene oxide / carbon microspheres, and attacking epoxy groups on the surface of epoxy-modified polyvinyl chloride paste resin through oxygen-containing groups on the surface, so that the graphene oxide / carbon microspheres are uniformly and tightly dispersed in the epoxy-modified polyvinyl chloride paste resin, and stress concentration points are prevented from being formed during agglomeration; the surface of the carbon microspheres is coated with the graphene oxide of the sheet layer, the graphene oxide sheet layer is combined with the carbon microspheres through pi-pi stacking and Van der Waals force to form a multi-level interface, and when subjected to external force, the graphene oxide sheet layer is firstly transmitted through the microsphere interface and then slides between the graphene oxide sheet layers, so that damage to the whole-core flame-retardant conveying belt caused by stress concentration is avoided.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flame-retardant conveying belts for underground coal mines, and particularly relates to a graphene-modified whole-core flame-retardant conveying belt for coal mines and a preparation method thereof. BACKGROUND

[0002] In the modern transportation industry, with the complexification of the conveying environment and the diversification of the materials, the conveying machine is developing towards long distance, large capacity, high speed, high efficiency and multi-function, which forces the conveying belt to develop towards multi-function, multi-variety, light weight, layer reduction and high strength. With the development of the heavy industry such as metallurgy, mining and port in China, the mechanical automation level is continuously improved. Due to the requirements of the conveying operation environment, especially in the coal mining, the materials are not only uneven in size, but also have a large drop, and the impact energy of the materials is very large. Under the working conditions of the mine head breaking, secondary breaking and large drop of the discharge port, the sharp large-diameter ore impacts the conveying belt. The ordinary conveying belt has weak impact resistance and poor tear resistance in the transportation and use process, and is easy to cause damage or breakdown of the cover rubber layer, longitudinal tearing, tearing and other accidents. In addition, the ordinary conveying belt is easy to burn due to the rubber material, which not only affects the production efficiency, but also causes serious economic losses to the using unit. Therefore, higher requirements are put forward for the quality of the conveying belt in the field of coal mining.

[0003] Chinese Patent Application CN119752000A discloses a graphene-modified whole-core flame-retardant conveying belt for coal mines and a preparation method thereof. Chlorobutadiene rubber and hydrogen oxygen butyronitrile rubber are used as main raw materials, and polyester fabric is used as the skeleton structure of the rubber material. Graphene has very high strength and modulus. These characteristics enable graphene to effectively transfer stress. The mechanical strength and tear resistance of the conveying belt are greatly improved by doping graphene composite particles in the raw materials. However, graphene is a non-polar material, and when graphene oxide is directly doped, agglomeration easily occurs, forming stress concentration points, which in turn reduces the tear resistance. SUMMARY

[0004] The purpose of the present application is to provide a graphene-modified whole-core flame-retardant conveying belt for coal mines and a preparation method thereof. Through (3-glycidylpropoxy) trimethoxysilane epoxy modification, an epoxy-modified polyvinyl chloride paste resin is obtained. After the glucose is pyrolyzed to generate carbon spheres, the graphene oxide is uniformly coated on the surface. The graphene oxide / carbon microspheres are obtained. Through the attack of the oxygen-containing groups on the surface of the epoxy-modified polyvinyl chloride paste resin, the graphene oxide / carbon microspheres are uniformly and tightly dispersed in the epoxy-modified polyvinyl chloride paste resin, avoiding the formation of stress concentration points during agglomeration.

[0005] The purpose of the present application can be achieved by the following technical solutions: The application discloses a preparation method of a coal mine graphene modified whole-core flame-retardant conveying belt. Step one: a mixed material is obtained by mixing composite polyvinyl chloride paste resin and hydrogenated nitrile rubber according to a mass ratio of 2:1; the mixed material is added into an open mill, plasticating is carried out at 45-50 DEG C, the roll gap of the plasticating mill is controlled to be 3-4 mm, and plasticated rubber is obtained; dioctyl phthalate, epoxy soybean oil, antimony trioxide, diphenyl phosphate and calcium-zinc composite stabilizer are added into the plasticated rubber, stirring is carried out at 20-25 DEG C and 2500-2600 r / min for 20-40 min, the product is placed into a three-roll grinding machine, grinding is carried out at a rotating speed of 500-600 r / min for 2-3 times, and defoaming is carried out at a vacuum degree of-0.05 Mpa at room temperature for 20 min, and mixed rubber is obtained.

[0006] Step two: the terylene fabric is immersed into the mixed rubber, the terylene fabric is taken out, the excess mixed liquid on the terylene fabric is taken out by using an extrusion roller, then drying is carried out at 73-80 DEG C for 2-3 h, then vulcanization is carried out at a pressure of 6-7 MPa and a temperature of 140-150 DEG C, the vulcanization time is 15-20 min, and a coal mine graphene modified whole-core flame-retardant conveying belt is obtained.

[0007] Further, the amount ratio of dioctyl phthalate, epoxy soybean oil, antimony trioxide, diphenyl phosphate and calcium-zinc composite stabilizer is 1-2 kg:5-6 L:900-950 mL:400-500 g:1-2 kg:200-250 g.

[0008] Further, the composite polyvinyl chloride paste resin is prepared according to the following specific steps: 1-2 kg of graphene oxide / carbon microspheres and 4-6 L of N,N-dimethylformamide are added into a reaction kettle, stirring is carried out at 50-65 DEG C and 400-500 r / min for 20-30 min, then 1-2 kg of epoxy modified polyvinyl chloride paste resin is added, and stirring is continuously carried out for 3-4 h, the filter cake is washed with anhydrous methanol for 2-4 times, and vacuum drying is carried out at 60-70 DEG C for 1-2 h, so as to obtain the composite polyvinyl chloride paste resin.

[0009] Further, the amount ratio of graphene oxide / carbon microspheres, N,N-dimethylformamide and epoxy modified polyvinyl chloride paste resin is 1-2 kg:4-6 L:1-2 kg.

[0010] Further, the epoxy modified polyvinyl chloride paste resin is prepared according to the following specific steps: 4-hydroxybutyl vinyl ether, (3-glycidyl propoxy) trimethoxysilane, anhydrous ethanol, deionized water, 1,4-dioxane, initiator di(2-ethylhexyl) peroxydicarbonate and peroxydilauryl are added into the reaction kettle, and the reaction kettle is sealed, nitrogen is introduced, and chloroethylene is added into the reaction kettle, and stirring is carried out at 57-60 DEG C and 500-600 r / min for 4-5 h; after the reaction is terminated, a 20% methanol solution is added, and after dropwise addition is completed, standing is carried out for 24-26 h; the filter cake is washed with anhydrous methanol for 2-4 times, and vacuum drying is carried out at 60-70 DEG C for 1-2 h, so that the epoxy modified polyvinyl chloride paste resin is obtained.

[0011] Further, the usage ratio of 4-hydroxybutyl vinyl ether, (3-glycidyl propoxy) trimethoxysilane, anhydrous ethanol, deionized water, 1,4-dioxane, di(2-ethylhexyl) peroxydicarbonate, peroxydilauryl, chloroethylene and the methanol solution is 1-2 kg: 800-900 g: 8-9 L: 12-14 L: 6-7 L: 200-220 g: 180-200 g: 7-8 kg: 10-12 L.

[0012] Further, the specific preparation steps of the graphene oxide / carbon microspheres are as follows: Graphene oxide, anhydrous ethanol and deionized water are added into the reaction kettle, stirring is carried out at 30-40 DEG C and 500-600 r / min for 10-12 min, then carbon microspheres are added, and stirring is continued for 8-9 h; the precipitate is washed with deionized water and anhydrous ethanol for 2-4 times, and vacuum drying is carried out at 60-70 DEG C for 1-2 h, so that the graphene oxide / carbon microspheres are obtained.

[0013] Further, the usage ratio of graphene oxide, anhydrous ethanol, deionized water and carbon microspheres is 3-4 kg: 5-6 L: 7-8 L: 1-2 kg.

[0014] Further, the specific preparation steps of the carbon microspheres are as follows: Glucose and glutaric acid are added into the reaction kettle according to the usage ratio of 1-2 kg: 800-900 g, stirring is carried out at 20-25 DEG C and 400-500 r / min for 20-30 min, heating is carried out to 180-190 DEG C, and stirring is continued for 5-6 h; the filter cake is washed with anhydrous ethanol and deionized water for 2-4 times, and vacuum drying is carried out at 60-70 DEG C for 1-2 h, so that the carbon microspheres are obtained.

[0015] The beneficial effects of the present application are as follows: 1.The coal mine graphene modified whole core flame-retardant conveyor belt prepared by the method comprises the following steps: 3-glycidylpropoxy) trimethoxysilane is hydrolyzed to generate silicon hydroxyl, which reacts with the hydroxyl of 4-hydroxybutyl vinyl ether, and then under the action of an initiator, the C=C double bond in the 4-hydroxybutyl vinyl ether containing a vinyl group is opened and chemically reacts with a chloroethylene monomer active center, so that a benzene ring and an epoxy group are grafted into a molecular chain of polyvinyl chloride resin, an epoxy modified polyvinyl chloride paste resin is obtained, long chains and benzene rings are introduced into the polyvinyl chloride chain, the long chains increase the length and flexibility of the molecular chain, and the brittle fracture of the whole core flame-retardant conveyor belt caused by the impregnated glue of the core during low-temperature use is avoided; after the carbon spheres are generated by pyrolysis of glucose, graphene oxide uniformly coats the surface of the carbon spheres to obtain graphene oxide / carbon microspheres, the oxygen-containing groups on the surface of the graphene oxide / carbon microspheres attack the epoxy groups on the surface of the epoxy modified polyvinyl chloride paste resin, the graphene oxide / carbon microspheres are uniformly and closely dispersed in the epoxy modified polyvinyl chloride paste resin, and a composite polyvinyl chloride paste resin is obtained.

[0016] 2.The graphene oxide / carbon microspheres are uniformly and closely dispersed in the epoxy modified polyvinyl chloride paste resin, and after the whole core flame-retardant conveyor belt is prepared, the graphene oxide / carbon microspheres can play a role in dispersing stress through the cooperation of the lamellar and spherical structures, and stress concentration is avoided; the graphene oxide on the surface of the carbon microspheres is combined with the carbon microspheres through π-π stacking and van der Waals force, a multi-level interface is formed, when external force is suffered, the stress is first transmitted through the interface of the microspheres, and then slips between the graphene oxide layers, and damage of the whole core flame-retardant conveyor belt caused by stress concentration is avoided. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0018] Embodiment 1: A preparation method of a coal mine graphene modified whole core flame-retardant conveyor belt comprises the following steps: S1: 1 kg of 4-hydroxybutyl vinyl ether, 800 g of (3-glycidylpropoxy)trimethoxysilane, 8 L of anhydrous ethanol, and 12 L of deionized water were added to a reaction kettle, stirred at 50°C and 400 r / min for 3 h, 6 L of 1,4-dioxane, 200 g of initiator di(2-ethylhexyl) peroxydicarbonate, and 180 g of dilauryl peroxide were added to the reaction kettle, sealed, and protected by nitrogen, then 7 kg of chloroethylene was added to the reaction kettle, stirred at 57°C and 500 r / min for 4 h, after the reaction was terminated, 10 L of a 20% methanol solution was added, after the dropwise addition was completed, it was left to stand for 24 h, filtered, the filter cake was washed with anhydrous methanol twice, and vacuum dried at 60°C for 1 h to obtain an epoxy-modified polyvinyl chloride paste resin.

[0019] S2: 1 kg of glucose and 800 g of glutaric acid were added to a reaction kettle, stirred at 20°C and 400 r / min for 20 min, heated to 180°C, and continued to stir for 5 h, filtered, the filter cake was washed with anhydrous ethanol and deionized water twice, and vacuum dried at 60°C for 1 h to obtain carbon microspheres.

[0020] S3: 3 kg of graphene oxide, 5 L of anhydrous ethanol, and 7 L of deionized water were added to a reaction kettle, stirred at 30°C and 500 r / min for 10 min, then 1 kg of carbon microspheres was added, and continued to stir for 8 h, filtered, the precipitate was washed with deionized water and anhydrous ethanol twice, and vacuum dried at 60°C for 1 h to obtain graphene oxide / carbon microspheres.

[0021] S4: 1 kg of graphene oxide / carbon microspheres and 4 L of N,N-dimethylformamide were added to a reaction kettle, stirred at 50°C and 400 r / min for 20 min, then 1 kg of epoxy-modified polyvinyl chloride paste resin was added, and continued to stir for 3 h, filtered, the filter cake was washed with anhydrous methanol twice, and vacuum dried at 60°C for 1 h to obtain a composite polyvinyl chloride paste resin.

[0022] S5: The composite polyvinyl chloride paste resin and hydrogenated nitrile rubber were mixed in a mass ratio of 2:1 to obtain a mixture, the mixture was added to an open mill, plasticized at 45°C, and the roll gap of the plasticizer was controlled at 3 mm to obtain plasticized rubber; 5 L of dioctyl phthalate, 900 mL of epoxy soybean oil, 400 g of antimony trioxide, 1 kg of diphenyl phosphate, and 200 g of calcium-zinc composite stabilizer were added to the plasticized rubber, stirred at 20°C and 2500 r / min for 20 min, the product was placed in a three-roll mill, milled for 2 passes at a speed of 500 r / min, and vacuum degassed at a vacuum degree of -0.05 Mpa for 20 min at room temperature to obtain a mixed rubber.

[0023] S6: dip the polyester fabric into the mixed rubber, take out the polyester fabric, use an extrusion roller to remove the excess mixed liquid on the polyester fabric, then dry at 73°C for 2h, then vulcanize at a pressure of 6MPa and a temperature of 140°C for 15min, to obtain a graphene modified whole-core flame-retardant conveying belt for coal mines Embodiment 2: a preparation method of a graphene modified whole-core flame-retardant conveying belt for coal mines, comprising the following steps: S1: add 1.5kg of 4-hydroxybutyl vinyl ether, 850g of (3-glycidylpropoxy)trimethoxysilane, 8.5L of anhydrous ethanol, and 13L of deionized water into a reaction kettle, stir at 57.5°C and 450r / min for 3.5h, add 6.5L of 1,4-dioxane, 210g of initiator di(2-ethylhexyl)peroxydicarbonate, and 190g of dilauroyl peroxide into the reaction kettle, seal, and protect by introducing nitrogen, then add 7.5kg of chloroethylene into the reaction kettle, stir at 58.5°C and 550r / min for 4.5h, after the reaction is terminated, add 11L of a methanol solution with a mass concentration of 20%, after dropwise addition is completed, stand for 25h, filter, wash the filter cake with anhydrous methanol for 3 times, and vacuum dry at 65°C for 1.5h, to obtain an epoxy modified polyvinyl chloride paste resin.

[0024] S2: add 1.5kg of glucose and 850g of glutaric acid into a reaction kettle, stir at 22.5°C and 450r / min for 25min, heat to 185°C, and continue to stir for 5.5h, filter, wash the filter cake with anhydrous ethanol and deionized water for 3 times, and vacuum dry at 65°C for 1.5h, to obtain carbon microspheres.

[0025] S3: add 3.5kg of graphene oxide, 5.5L of anhydrous ethanol, and 7.5L of deionized water into a reaction kettle, stir at 35°C and 550r / min for 11min, then add 1.5kg of carbon microspheres, continue to stir for 8.5h, filter, wash the precipitate with deionized water and anhydrous ethanol for 3 times, and vacuum dry at 65°C for 1.5h, to obtain graphene oxide / carbon microspheres.

[0026] S4: add 1.5kg of graphene oxide / carbon microspheres and 5L of N,N-dimethylformamide into a reaction kettle, stir at 57.5°C and 450r / min for 25min, then add 1.5kg of epoxy modified polyvinyl chloride paste resin, continue to stir for 3.5h, filter, wash the filter cake with anhydrous methanol for 3 times, and vacuum dry at 65°C for 1.5h, to obtain a composite polyvinyl chloride paste resin.

[0027] S5: The composite polyvinyl chloride paste resin and hydrogenated nitrile rubber are mixed according to a mass ratio of 2:1 to obtain a mixture, the mixture is added to an open mill, plasticated at 47.5°C, and the roll gap of the plasticator is controlled at 3.5mm to obtain plasticated rubber; 5.5L of dioctyl phthalate, 925mL of epoxy soybean oil, 450g of antimony trioxide, 1.5kg of diphenyl phosphate, and 225g of calcium-zinc composite stabilizer are added to the plasticated rubber, stirred at 22.5°C and 2550r / min for 30min, the product is placed in a three-roll mill, milled for 2 times at a speed of 550r / min, and defoamed at room temperature for 20min under a vacuum degree of-0.05Mpa to obtain mixed rubber.

[0028] S6: The polyester fabric is immersed in the mixed rubber, the polyester fabric is taken out, the excess mixed liquid on the polyester fabric is taken out using a squeeze roller, then dried at 76.5°C for 2.5h, and then vulcanized at a pressure of 6.5MPa and a temperature of 145°C for 17.5min to obtain a graphene modified whole-core flame-retardant conveying belt for coal mines.

[0029] Embodiment 3: A preparation method of a graphene modified whole-core flame-retardant conveying belt for coal mines, comprising the following steps: S1: 1-2kg of 4-hydroxybutyl vinyl ether, 800-900g of (3-glycidylpropoxy)trimethoxysilane, 8-9L of anhydrous ethanol, and 12-14L of deionized water are added to a reaction kettle, stirred at 50-65°C and 400-500r / min for 3-4h, 6-7L of 1,4-dioxane, 200-220g of initiator di(2-ethylhexyl) peroxydicarbonate, and 180-200g of dilauroyl peroxide are added to the reaction kettle, sealed, and protected by nitrogen, then 7-8kg of chloroethylene is added to the reaction kettle, stirred at 57-60°C and 500-600r / min for 4-5h, after the reaction is terminated, 10-12L of a methanol solution with a mass concentration of 20% is added, after the dropwise addition is completed, the mixture is left to stand for 24-26h, filtered, the filter cake is washed with anhydrous methanol for 2-4 times, and vacuum dried at 60-70°C for 1-2h to obtain an epoxy modified polyvinyl chloride paste resin.

[0030] S2: 1-2kg of glucose and 800-900g of glutaric acid are added to a reaction kettle, stirred at 20-25°C and 400-500r / min for 20-30min, heated to 180-190°C, and continuously stirred for 5-6h, the mixture is filtered, the filter cake is washed with anhydrous ethanol and deionized water for 2-4 times, and vacuum dried at 60-70°C for 1-2h to obtain carbon microspheres.

[0031] ; S3: 3-4 kg of graphene oxide, 5-6 L of anhydrous ethanol and 7-8 L of deionized water were added into a reaction kettle, stirred at 30-40℃ and 500-600 r / min for 10-12 min, then 1-2 kg of carbon microspheres were added, and the stirring was continued for 8-9 h, then the precipitate was filtered and washed with deionized water and anhydrous ethanol for 2-4 times, and vacuum dried at 60-70℃ for 1-2 h to obtain graphene oxide / carbon microspheres.

[0032] S4: 1-2 kg of graphene oxide / carbon microspheres and 4-6 L of N,N-dimethylformamide were added into a reaction kettle, stirred at 50-65℃ and 400-500 r / min for 20-30 min, then 1-2 kg of epoxy modified polyvinyl chloride paste resin was added, and the stirring was continued for 3-4 h, then the filter cake was filtered and washed with anhydrous methanol for 2-4 times, and vacuum dried at 60-70℃ for 1-2 h to obtain a composite polyvinyl chloride paste resin.

[0033] S5: The composite polyvinyl chloride paste resin and hydrogenated nitrile rubber were mixed according to a mass ratio of 2:1 to obtain a mixture, the mixture was added into an open mill, and plasticized at 45-50℃, with the roll gap of the plasticizer being controlled at 3-4 mm to obtain plasticized rubber; 5-6 L of dioctyl phthalate, 900-950 mL of epoxy soybean oil, 400-500 g of antimony trioxide, 1-2 kg of diphenyl phosphate and 200-250 g of calcium-zinc composite stabilizer were added into the plasticized rubber, and stirred at 20-25℃ and 2500-2600 r / min for 20-40 min, then the product was placed in a three-roll mill, and ground for 2-3 times at a speed of 500-600 r / min, and defoamed at room temperature for 20 min under a vacuum degree of-0.05 MPa to obtain a mixed rubber.

[0034] S6: The polyester fabric was immersed in the mixed rubber, the polyester fabric was taken out, the excess mixed liquid on the polyester fabric was taken out using a squeezing roller, then dried at 73-80℃ for 2-3 h, and then vulcanized at a pressure of 6-7 MPa and a temperature of 140-150℃ for 15-20 min to obtain a graphene modified whole-core flame-retardant conveyor belt for coal mines.

[0035] Comparative Example 1: On the basis of Example 3, the composite polyvinyl chloride paste resin in step S5 was replaced by the epoxy modified polyvinyl chloride paste resin prepared in step S1.

[0036] Comparative Example 2: On the basis of Example 3, the graphene oxide / carbon microspheres in step S5 were replaced by graphene oxide in step S4.

[0037] Comparative Example 3: On the basis of Example 3, the epoxy modified polyvinyl chloride paste resin in step S2 was replaced by a commercially available polyvinyl chloride resin.

[0038] The graphene-modified flame-retardant whole-core conveyor belt for coal mine obtained from Example 1 to Example 3 and Comparative Example 1 to Comparative Example 3 was subjected to performance testing, with reference to the standard "Flame-retardant whole-core conveyor belt for coal mine" MT914-2008, and the results are shown in Table 1: Table 1 ; As can be seen from Table 1, the tensile strength, abrasion amount and bonding strength of Example 1 to Example 3 are significantly better than those of the comparative examples, indicating that the graphene-modified flame-retardant whole-core conveyor belt for coal mine prepared by the present application has high tensile strength, high toughness, good wear resistance, high bonding strength and is not easy to peel off.

[0039] In Comparative Example 1, the composite polyvinyl chloride paste resin is replaced by epoxy-modified polyvinyl chloride paste resin. The difference between the two lies in that in the composite polyvinyl chloride paste resin, the oxygen-containing groups on the surface of the graphene oxide / carbon microspheres attack the epoxy groups on the surface of the epoxy-modified polyvinyl chloride paste resin, so that the graphene oxide / carbon microspheres are uniformly and closely dispersed in the epoxy-modified polyvinyl chloride paste resin, thereby avoiding the agglomeration of the graphene oxide / carbon microspheres, causing stress point concentration and resulting in a decrease in toughness and strength.

[0040] In Comparative Example 2, the graphene oxide / carbon microspheres are replaced by graphene oxide. The lamellar structure of the graphene oxide is dispersed alone in the polyvinyl chloride paste resin. As can be seen from the experimental data, the performance test is lower than that of the examples, indicating that the lamellar structure of the graphene oxide alone cannot meet the strength requirements of the whole-core flame-retardant conveyor belt in daily use. The graphene oxide lamella coated on the surface of the carbon microspheres can be combined with the carbon microspheres through π-π stacking and van der Waals force, forming a multi-level interface. When subjected to external force, the interface of the microspheres is transmitted first, and then the graphene oxide lamella slips, thereby avoiding damage to the whole-core flame-retardant conveyor belt caused by stress concentration.

[0041] In Comparative Example 3, the epoxy-modified polyvinyl chloride paste resin is replaced by a commercially available polyvinyl chloride resin. The silicon hydroxyl groups produced by the hydrolysis of (3-glycidylpropoxy)trimethoxysilane react with the hydroxyl groups of 4-hydroxybutyl vinyl ether. Then, under the action of an initiator, the C=C double bond in the 4-hydroxybutyl vinyl ether containing a vinyl group is opened and chemically reacts with the active center of the chloroethylene monomer, thereby grafting the benzene ring and the epoxy group to the molecular chain of the polyvinyl chloride resin, obtaining the epoxy-modified polyvinyl chloride paste resin. The introduction of long chains and benzene rings into the polyvinyl chloride chain increases the length and flexibility of the molecular chain, thereby avoiding the brittle fracture of the belt core impregnated rubber during low-temperature use of the whole-core flame-retardant conveyor belt. As can be seen from the experimental data, this comparative example performs the worst in the performance test, indicating that the present application can greatly improve the overall performance of the whole-core flame-retardant conveyor belt through the copolymerization modification of chloroethylene.

[0042] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application.

Claims

1. A method for preparing a graphene-modified solid-core flame-retardant conveyor belt for coal mines, characterized in that, Includes the following steps: Step 1: Mix the composite polyvinyl chloride paste resin and hydrogenated nitrile rubber at a mass ratio of 2:1 to obtain a mixture. Add the mixture to a two-roll mill and plasticize it at 45-50℃, with the roller gap of the plasticizer controlled at 3-4mm, to obtain plasticized rubber. Add dioctyl phthalate, epoxidized soybean oil, antimony trioxide, diphenyl phosphate and calcium-zinc composite stabilizer to the plasticized rubber. Stir for 20-40 minutes at 20-25℃ and 2500-2600r / min. Place the product in a three-roll mill and grind it 2-3 times at a speed of 500-600r / min. Degas it at room temperature for 20 minutes under a vacuum of -0.05Mpa to obtain compounded rubber. Step 2: Immerse the polyester fabric in the compounded rubber, remove the polyester fabric, use a squeeze roller to remove the excess compounded liquid from the polyester fabric, then dry it at 73-80℃ for 2-3 hours, and then vulcanize it at a pressure of 6-7MPa and a temperature of 140-150℃ for 15-20 minutes to obtain a graphene-modified solid core flame-retardant conveyor belt for coal mines.

2. The method for preparing a graphene-modified solid-core flame-retardant conveyor belt for coal mines according to claim 1, characterized in that, The ratio of the amount of graphene oxide / carbon microspheres, dioctyl phthalate, epoxidized soybean oil, antimony trioxide, diphenyl phosphate and calcium-zinc composite stabilizer is 1-2 kg: 5-6 L: 900-950 mL: 400-500 g: 1-2 kg: 200-250 g.

3. The method for preparing a graphene-modified solid-core flame-retardant conveyor belt for coal mines according to claim 1, characterized in that, The specific steps for preparing the composite polyvinyl chloride paste resin are as follows: Add 1-2 kg of graphene oxide / carbon microspheres and 4-6 L of N,N-dimethylformamide to a reactor and stir for 20-30 min at 50-65℃ and 400-500 r / min. Then add 1-2 kg of epoxy-modified polyvinyl chloride paste resin and continue stirring for 3-4 h. Filter the mixture and wash the filter cake 2-4 times with anhydrous methanol. Dry the mixture under vacuum at 60-70℃ for 1-2 h to obtain composite polyvinyl chloride paste resin.

4. The method for preparing a graphene-modified solid-core flame-retardant conveyor belt for coal mines according to claim 3, characterized in that, The ratio of graphene oxide / carbon microspheres, N,N-dimethylformamide, and epoxy-modified polyvinyl chloride paste resin is 1-2 kg: 4-6 L: 1-2 kg.

5. The method for preparing a graphene-modified solid-core flame-retardant conveyor belt for coal mines according to claim 1, characterized in that, The epoxy-modified polyvinyl chloride paste resin is prepared using the following specific steps: 4-Hydroxybutylvinyl ether, (3-glycidylpropoxy)trimethoxysilane, anhydrous ethanol, and deionized water were added to a reaction vessel and stirred for 3-4 hours at 50-65℃ and 400-500 rpm. 1,4-Dioxane, the initiator di(2-ethylhexyl) peroxide dicarbonate, and dilauryl peroxide were then added to the reaction vessel. The vessel was sealed and protected with nitrogen gas. Vinyl chloride was then added to the reaction vessel and stirred for 4-5 hours at 57-60℃ and 500-600 rpm. After the reaction was terminated, a 20% methanol solution was added dropwise. After the addition was complete, the mixture was allowed to stand for 24-26 hours, filtered, and the filter cake was washed 2-4 times with anhydrous methanol and dried under vacuum at 60-70℃ for 1-2 hours to obtain epoxy-modified polyvinyl chloride paste resin.

6. The method for preparing a graphene-modified solid-core flame-retardant conveyor belt for coal mines according to claim 5, characterized in that, The ratio of the amounts of 4-hydroxybutyl vinyl ether, (3-glycidylpropoxy)trimethoxysilane, anhydrous ethanol, deionized water, 1,4-dioxane, di(2-ethylhexyl) peroxydicarbonate, dilauroyl peroxide, vinyl chloride, and methanol solution is 1-2 kg: 800-900 g: 8-9 L: 12-14 L: 6-7 L: 200-220 g: 180-200 g: 7-8 kg: 10-12 L.

7. The method for preparing a graphene-modified solid-core flame-retardant conveyor belt for coal mines according to claim 1, characterized in that, The specific steps for preparing the graphene oxide / carbon microspheres are as follows: Graphene oxide, anhydrous ethanol, and deionized water were added to a reaction vessel and stirred for 10-12 minutes at 30-40℃ and 500-600 r / min. Then carbon microspheres were added and stirring was continued for 8-9 hours. The mixture was filtered, and the precipitate was washed 2-4 times with deionized water and anhydrous ethanol. The precipitate was then dried under vacuum at 60-70℃ for 1-2 hours to obtain graphene oxide / carbon microspheres.

8. The method for preparing a graphene-modified solid-core flame-retardant conveyor belt for coal mines according to claim 7, characterized in that, The ratio of graphene oxide, anhydrous ethanol, deionized water, and carbon microspheres is 3-4 kg: 5-6 L: 7-8 L: 1-2 kg.

9. The method for preparing a graphene-modified solid-core flame-retardant conveyor belt for coal mines according to claim 8, characterized in that, The carbon microspheres are prepared using the following specific steps: Add glucose and glutaric acid to a reaction vessel at a ratio of 1-2 kg: 800-900 g. Stir for 20-30 min at 20-25℃ and 400-500 r / min. Heat to 180-190℃ and continue stirring for 5-6 h. Filter and wash the filter cake 2-4 times with anhydrous ethanol and deionized water. Dry under vacuum at 60-70℃ for 1-2 h to obtain carbon microspheres.

10. A graphene-modified solid-core flame-retardant conveyor belt for coal mines, characterized in that, It is prepared by the preparation method described in any one of claims 1-9.