A rubber conveyor belt quick repair material and a preparation method thereof

Abstract

The application discloses a kind of rubber conveyor belt quick repair material and preparation method thereof, it is related to rubber repair material technical field, belongs to patent classification number C08K3 / 00.Preparation method includes the following steps: preheating treatment is carried out to ethylene-propylene-diene rubber and hydrogenated styrene-butadiene block copolymer, then it is added into internal mixer and carries out basic mixing, subsequently paraffin oil is added, and the mixing material is obtained;Trimethylolpropane triacrylate crosslinking agent and organic vermiculite reinforcing filler are added to the mixing material, stir uniformly, then zinc stearate activator and sulfur vulcanizing agent are added, continue to stir uniformly, and the mixture material is obtained;The mixture material is transferred to mould, and is formed under the condition of heating and pressurizing, then vulcanization treatment is carried out to make crosslinking reaction completely, and the rubber conveyor belt quick repair material is obtained.The rubber repair material of the application can be firmly bonded with rubber conveyor belt matrix, the strength after repair is high, and the rubber conveyor belt can be quickly repaired.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rubber repair materials, belongs to the patent classification number C08K3 / 00, and specifically relates to a rubber conveyor belt rapid repair material and a preparation method thereof. BACKGROUND

[0002] The rubber conveyor belt is widely used in mining, port, metallurgy, chemical industry and the like, and is a key equipment for continuous material conveying. In a long-term use process, the rubber conveyor belt is prone to damage due to material impact, wear, scratches and aging. In order to reduce costs and prolong the service life of the conveyor belt, repairing the damaged part is a common and effective method.

[0003] At present, various rubber conveyor belt repair materials exist on the market, such as epoxy resin, polyurethane and chloroprene rubber. These repair materials can repair the damaged part of the rubber conveyor belt to a certain extent, but there are still many problems in actual application. The most prominent problem is that the strength of the repaired material is insufficient, which is difficult to meet the use requirements of the conveyor belt under complex working conditions.

[0004] On the one hand, the bonding strength between the existing repair material and the rubber conveyor belt base is limited. Due to the stable molecular chain structure and low polarity of the rubber surface, it is difficult for the repair material to form firm chemical bonding or physical entanglement with the rubber base. In the process of conveying belt operation, under the action of external forces such as material friction and tensile stress, interface separation is easily generated between the repaired part and the rubber base, and then the repair material is easily separated. On the other hand, the mechanical properties of most repair materials are difficult to match with the rubber conveyor belt. The rubber conveyor belt needs to bear a large tensile stress, bending stress and wear during work, and the elastic modulus, tensile strength and wear resistance of the existing repair material often cannot reach the level close to the original conveyor belt. When the repair material is stressed, stress concentration is easily generated in the internal due to the inability to effectively disperse and transfer stress, which causes the repaired area to crack prematurely. Once the crack is formed, the crack will rapidly expand during the continuous operation of the conveyor belt, and eventually leads to secondary cracking of the repaired part, which seriously affects the normal use of the conveyor belt and production efficiency.

[0005] Secondly, the repair speed of the existing repair material is slow, and the curing process takes a long time. For example, the epoxy resin repair material needs to be cured for several hours or even tens of hours at room temperature, and the curing time of the polyurethane material is shortened, but it still cannot meet the urgent repair demand. For continuous production enterprises, the long repair time will cause the production line to be shut down for a long time, causing huge economic losses. SUMMARY

[0006] The present application aims to provide a rubber conveyor belt quick repair material and a preparation method thereof, so as to solve the technical problems of insufficient mechanical strength and slow curing speed of the rubber repair material in the background art. The rubber repair material can be firmly bonded with the rubber conveyor belt matrix, has excellent mechanical properties, high strength after repair, and is not prone to secondary cracking, and can quickly repair the rubber conveyor belt.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0008] A rubber conveyor belt quick repair material, comprising the following components by weight:

[0009] 60-70 parts of ethylene-propylene-diene rubber, 20-30 parts of hydrogenated styrene-butadiene block copolymer, 3-6 parts of trimethylolpropane triacrylate, 4-8 parts of organic vermiculite, 2-3 parts of zinc stearate, 5-7 parts of sulfur, and 5-8 parts of paraffin oil.

[0010] In the technical solution of the present application, the ethylene-propylene-diene rubber as the main matrix of the rubber repair material provides excellent mechanical properties and weather resistance. The hydrogenated styrene-butadiene block copolymer as a compatibilizer improves the interfacial compatibility. In addition, the maleic anhydride groups on the hydrogenated styrene-butadiene block copolymer undergo esterification with trimethylolpropane triacrylate at the vulcanization temperature, and at the same time, the styrene blocks of the hydrogenated styrene-butadiene block copolymer form an interpenetrating network with the ethylene-propylene-diene rubber through physical entanglement, enhancing the intermolecular forces. The trimethylolpropane triacrylate as a crosslinking agent, under high-temperature sulfur vulcanization conditions, the acrylate groups react with the rubber molecular chains and the active groups (such as amino groups modified by silane coupling agents) on the surface of the organic vermiculite through a free radical mechanism, building a three-dimensional crosslinked network, significantly improving the mechanical strength between the rubber and the rubber repair material and the mechanical strength of the repair material itself. The organic vermiculite has a layered structure, and the rubber molecular chains can be inserted into the interlayer of the vermiculite to form an "intercalation composite" structure, which is equivalent to the physical restriction of the vermiculite on the rubber molecular chains. When the rubber is subjected to external force, this intercalation structure can effectively hinder the relative slipping of the rubber molecular chains, so that the stress can be more evenly dispersed in the entire rubber matrix, thereby improving the mechanical properties such as tensile strength and tear strength of the rubber. In addition, the vermiculite itself has high hardness and rigidity, and after being uniformly dispersed in the rubber, it can enhance the overall rigidity of the rubber like a rigid particle, improving its resistance to deformation. The paraffin oil plays a plasticizing role in the processing process, promoting the uniform dispersion of each component, and at the same time, part of it volatilizes to form a microporous structure in the later stage of vulcanization, which is beneficial to stress buffering. This synergistic effect enables the repair material to form a repair layer combined with the matrix in a short time.

[0011] As a preferred embodiment, the preparation method of the hydrogenated styrene-butadiene block copolymer comprises the following steps:

[0012] (1) using cyclohexane as solvent and n-butyllithium as initiator, the polymerization reaction is carried out by a three-step method of anionic polymerization, first, the first-stage styrene polymerization is initiated, then, the second-stage polymerization is carried out by adding butadiene, and finally, the third-stage polymerization is completed by adding styrene, thereby obtaining a triblock copolymer;

[0013] (2) using tris(triphenylphosphine)rhodium chloride catalyst, the triblock copolymer is hydrogenated, so that the butadiene segment double bond is fully hydrogenated, thereby obtaining a hydrogenated polymer;

[0014] (3) the hydrogenated polymer is mixed with maleic anhydride and dicumyl peroxide initiator, and a melt grafting reaction is carried out in a twin-screw extruder, after the grafting is completed, impurities are removed by Soxhlet extraction with acetone, and finally, vacuum drying is carried out, thereby obtaining a hydrogenated styrene-butadiene block copolymer.

[0015] As preferred, in the step (3), the maleic anhydride is added in an amount of 2-5% of the mass of the hydrogenated polymer.

[0016] As preferred, the dicumyl peroxide initiator is added in an amount of 0.1-0.3% of the mass of the hydrogenated polymer.

[0017] As preferred, the preparation method of the organic vermiculite comprises the following steps:

[0018] (a) after crushing and sieving a natural vermiculite raw ore, vermiculite powder is obtained, and then drying treatment is carried out to remove adsorbed water, thereby obtaining dried vermiculite powder;

[0019] (b) the dried vermiculite powder is mixed with a sodium salt solution, and stirring reaction is carried out at a certain temperature, after the reaction is completed, centrifugal separation is carried out, and washing with deionized water is carried out until neutral, and finally, drying is carried out, thereby obtaining sodium-based vermiculite;

[0020] (c) the sodium-based vermiculite is mixed with cetyltrimethylammonium bromide, deionized water is added, and ultrasonic-assisted reaction is carried out at a certain temperature, after the reaction is completed, suction filtration and washing are carried out, and unreacted cetyltrimethylammonium bromide is removed, and finally, drying is carried out, thereby obtaining organic intercalation vermiculite;

[0021] (d) the organic intercalation vermiculite is mixed with 3-aminopropyltriethoxysilane, and an ethanol / water solution is added as solvent, reflux reaction is carried out under acidic conditions, after the reaction is completed, centrifugal separation is carried out and washing with ethanol is carried out, and finally, drying is carried out, thereby obtaining organic vermiculite.

[0022] In the technical solution of this invention, as described above, the organic vermiculite has a layered structure, and the rubber molecular chains can be inserted into the interlayer of the vermiculite to form an "intercalated composite" structure. This is equivalent to the vermiculite playing a physical constraint role on the rubber molecular chains. When the rubber is subjected to external force, this intercalated structure can effectively hinder the relative slippage of the rubber molecular chains, so that the stress can be more evenly distributed throughout the entire rubber matrix, thereby improving the tensile strength, tear strength and other mechanical properties of the rubber.

[0023] The organic vermiculite prepared in this invention differs from ordinary vermiculite. Ordinary vermiculite has a very small interlayer spacing, preventing rubber molecular chains from inserting into the interlayers and forming an "intercalation composite" structure. To enable the smooth insertion of rubber molecular chains into the vermiculite interlayers, this invention modifies the vermiculite interlayer spacing by widening it. First, vermiculite is mixed and reacted with a sodium salt solution, and sodium-based vermiculite is obtained through ion exchange, improving its swelling and dispersibility, thus facilitating dispersion in the rubber matrix and the subsequent intercalation reaction of hexadecyltrimethylammonium bromide. Then, the sodium-based vermiculite reacts with hexadecyltrimethylammonium bromide under ultrasonic assistance, allowing the surfactant to insert into the vermiculite interlayers, increasing the interlayer spacing and compatibility with rubber, thereby enabling the smooth insertion of rubber molecular chains into the vermiculite interlayers. In addition, by grafting vermiculite onto the surface with a silane coupling agent, the present invention can form stronger chemical bonds or physical interactions with rubber molecules, making the interfacial bond between vermiculite and the rubber matrix more robust and thus improving the mechanical strength of the rubber.

[0024] Preferably, in step (a), the particle size of the vermiculite powder is controlled to be ≤30μm.

[0025] Preferably, in step (b), the sodium salt is sodium carbonate.

[0026] Preferably, in step (c), the mass ratio of sodium vermiculite to hexadecyltrimethylammonium bromide is 10:2-5.

[0027] In the technical scheme of the present application, the sodium-based vermiculite is intercalated by cetyltrimethylammonium bromide to increase the interlayer spacing of the vermiculite, facilitate the insertion of rubber molecular chains into the interlayer of the vermiculite, and improve the mechanical strength of the rubber. In order to maximize the interlayer spacing of the vermiculite, a sufficient amount of cetyltrimethylammonium bromide must be inserted. Therefore, the mass ratio of the sodium-based vermiculite to cetyltrimethylammonium bromide is less than 10 / 2 in the present application. However, the present application team accidentally found that as the amount of cetyltrimethylammonium bromide continues to increase, when the mass ratio of the sodium-based vermiculite to cetyltrimethylammonium bromide is less than 10 / 5, the curing time of the rubber repair material suddenly increases significantly. After research, it is found that this is because cetyltrimethylammonium bromide has long-chain alkyl and polar quaternary ammonium groups. After excessive addition, the polarity of the reaction system changes significantly. The change in polarity affects the interaction between the vulcanizing agent molecules, disrupts the original ordered arrangement and intermolecular force, increases the energy required for the vulcanizing agent to crack, slows down the rate of free radical generation, and thus prolongs the curing time of the rubber.

[0028] Preferably, the mass ratio of the organic intercalated vermiculite to 3-aminopropyl triethoxysilane in step (d) is 1:0.1-0.3.

[0029] A preparation method of a rubber conveyor belt rapid repair material, comprising the following steps:

[0030] The ethylene propylene terpolymer and the hydrogenated styrene-butadiene block copolymer are preheated, then added into a mixing mill for basic mixing, and then paraffin oil is added to obtain a mixed material;

[0031] The trimethylolpropane triacrylate crosslinking agent and the organic vermiculite reinforcing filler are added into the mixed material and stirred uniformly, then the zinc stearate activator and the sulfur vulcanizing agent are added and continuously stirred uniformly to obtain a mixture;

[0032] The mixture is transferred into a mold for molding under heating and pressurizing conditions, and then vulcanization treatment is performed to complete the crosslinking reaction, thereby obtaining the rubber conveyor belt rapid repair material.

[0033] Compared with the prior art, the present application has the following advantages:

[0034] 1. The ethylene propylene terpolymer provides good mechanical properties and weather resistance as the main matrix, the hydrogenated styrene-butadiene block copolymer enhances the intermolecular force through esterification and physical entanglement, the trimethylolpropane triacrylate constructs a three-dimensional crosslinking network, and the organic vermiculite forms an intercalated composite structure and has rigidity as a rigid reinforcing material, which jointly act to significantly improve the mechanical properties such as tensile strength and tear strength of the repair material.

[0035] 2. Hydrogenated styrene-butadiene block copolymer acts as a compatibilizer to improve the interface compatibility of each component, and the interface between the modified organic vermiculite and the rubber matrix is firm, so that the components of the repair material synergize to ensure the stable overall performance of the material. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0037] The specific specifications of the main raw materials used in the specific embodiments of the present application are as follows:

[0038] Ethylene propylene diene rubber (EPDM): ENB type, ethylene content 58-65%, ENB content 4.5-5.5%; trimethylolpropane triacrylate (TMPTA): purity ≥ 99% (HPLC), acid value ≤ 0.5 mg KOH / g; zinc stearate: zinc content 10.5-11.5%, free acid ≤ 0.5%; sulfur: purity ≥ 99.5%; paraffin oil: aromatic hydrocarbon content ≤ 3%.

[0039] Embodiment 1

[0040] A rubber conveyor belt rapid repair material, comprising the following components by weight parts:

[0041] Ethylene propylene diene rubber 68 parts, hydrogenated styrene-butadiene block copolymer 27 parts, trimethylolpropane triacrylate 5 parts, organic vermiculite 7 parts, zinc stearate 2.5 parts, sulfur 6.5 parts, paraffin oil 7 parts.

[0042] Preparation of hydrogenated styrene-butadiene block copolymer:

[0043] (1) Prepare a 1000 mL four-necked flask, add 800 mL of cyclohexane as a solvent to it, and purge nitrogen to exhaust air to maintain the inert environment of the system. Place the flask in a constant temperature water bath, and heat to 50°C. Weigh 20 g of styrene, slowly add it to the flask, and then add 0.5 g of n-butyllithium initiator, continue to stir for 2 h to complete the first stage of styrene polymerization. Then, weigh 30 g of butadiene, add it to the flask under nitrogen protection, and continue to react for 3 h to carry out the second stage of polymerization. Finally, add 20 g of styrene, and react for 2 h to complete the third stage of polymerization, obtaining a triblock copolymer.

[0044] (2) The above-mentioned triblock copolymer is transferred to a high-pressure reactor, 0.3 g of tris(triphenylphosphine)rhodium chloride catalyst is added, hydrogen is introduced, the reaction pressure is controlled at 5 MPa, the temperature is 80°C, and the reaction is carried out for 6 h to fully hydrogenate the butadiene segment double bond to obtain a hydrogenated polymer.

[0045] (3) 100 g of the hydrogenated polymer is weighed into a beaker, 4 g of maleic anhydride and 0.25 g of dicumyl peroxide initiator are added, and stirred uniformly. The mixture is transferred to a twin-screw extruder, the extruder temperature is set to 200°C, and the screw speed is 80 r / min, and a melt grafting reaction is carried out. After the reaction is completed, the product is extracted with acetone in a Soxhlet extractor for 12 h to remove impurities, and finally dried in a vacuum drying oven at 60°C for 8 h to obtain a hydrogenated styrene-butadiene block copolymer.

[0046] Preparation of organically modified vermiculite:

[0047] (a) The natural vermiculite ore is crushed to a particle size of ≤30 μm using a crusher to obtain vermiculite powder. The vermiculite powder is placed in a forced air drying oven and dried at 105°C for 6 h to remove adsorbed water, obtaining dried vermiculite powder;

[0048] (b) A 10% sodium carbonate solution is prepared, 100 g of dried vermiculite powder is added to 800 mL of sodium carbonate solution, and placed in a constant temperature water bath at 60°C for 4 h. After the reaction is completed, the mixture is transferred to a centrifuge and centrifuged at 4000 r / min for 10 min, the supernatant is discarded, the precipitate is washed with deionized water until it is neutral, and finally dried at 110°C for 8 h to obtain sodium-based vermiculite.

[0049] (c) 50 g of sodium-based vermiculite and 22 g of cetyltrimethylammonium bromide are weighed together and added to 500 mL of deionized water, and placed in an ultrasonic reactor at 50°C for 3 h. After the reaction is completed, filtration is performed, and the filter cake is washed with deionized water several times until no cetyltrimethylammonium bromide is detected in the washing liquid, and finally dried at 80°C for 10 h to obtain organically intercalated vermiculite.

[0050] (d) 10 g of organically intercalated vermiculite and 2.5 g of 3-aminopropyltriethoxysilane are weighed and added to 300 mL of an ethanol / water solution (ethanol and water in a volume ratio of 1:1), hydrochloric acid is added dropwise to adjust the pH of the system to 3-4, and refluxed at 80°C for 6 h. After the reaction is completed, the mixture is centrifuged at 4000 r / min for 10 min, the supernatant is discarded, the precipitate is washed with ethanol three times, and finally dried at 80°C for 8 h to obtain organically modified vermiculite.

[0051] A method for preparing a rubber conveyor belt rapid repair material, comprising the following steps:

[0052] The EPDM and hydrogenated styrene-butadiene block copolymer were weighed and preheated in a blast drying oven at 60°C for 2 h. The preheated raw materials were added to the internal mixer, and the internal mixer was set at a speed of 60 r / min and a temperature of 80°C. The raw materials were mixed for 10 min. Then, the paraffin oil was added, and the mixture was mixed for another 5 min to obtain a mixed material.

[0053] The crosslinking agent trimethylolpropane triacrylate and the reinforcing filler organo-montmorillonite were added to the mixed material, and stirred for 10 min to uniformly disperse them. Then, the zinc stearate activator and the sulfur vulcanizing agent were added, and stirred for another 10 min to obtain a mixture.

[0054] The mixture was transferred to a mold, and placed in a flat vulcanizing machine. The mixture was molded at 160°C and a pressure of 15 MPa for 10 min, and then vulcanized at 160°C for another 20 min to complete the crosslinking reaction. After demolding, a rubber conveyor belt rapid repair material was obtained.

[0055] Example 2

[0056] A rubber conveyor belt rapid repair material, comprising the following components by weight:

[0057] 62 parts of EPDM, 23 parts of hydrogenated styrene-butadiene block copolymer, 4 parts of trimethylolpropane triacrylate, 5 parts of organo-montmorillonite, 2.5 parts of zinc stearate, 5.5 parts of sulfur, and 6 parts of paraffin oil.

[0058] Preparation of hydrogenated styrene-butadiene block copolymer:

[0059] (1) A 1000 mL four-necked flask was prepared, and 800 mL of cyclohexane was added as a solvent. Nitrogen was introduced to remove air and maintain an inert environment. The flask was placed in a constant temperature water bath, and the temperature was raised to 50°C. 20 g of styrene was slowly added to the flask, and 0.5 g of n-butyllithium initiator was added. The reaction was continuously stirred for 2 h to complete the first-stage styrene polymerization. Then, 30 g of butadiene was added to the flask under nitrogen protection, and the reaction was continued for 3 h to perform the second-stage polymerization. Finally, 20 g of styrene was added, and the reaction was continued for 2 h to complete the third-stage polymerization, thereby obtaining a triblock copolymer.

[0060] (2) The above-mentioned triblock copolymer was transferred to a high-pressure reaction kettle, and 0.3 g of tris(triphenylphosphine)rhodium chloride catalyst was added. Hydrogen was introduced, and the reaction pressure was controlled at 5 MPa and the temperature was controlled at 80°C. The reaction was continued for 6 h to fully hydrogenate the double bonds in the butadiene segment, thereby obtaining a hydrogenated polymer.

[0061] (3) Weigh 100g of hydrogenated polymer and place it in a beaker. Add 3g of maleic anhydride and 0.15g of dicumyl peroxide initiator and stir until homogeneous. Transfer the mixture to a twin-screw extruder and set the extruder temperature to 200℃ and the screw speed to 80r / min for melt grafting reaction. After the reaction is complete, extract the product with acetone in a Soxhlet extractor for 12h to remove impurities. Finally, dry the product in a vacuum drying oven at 60℃ for 8h to obtain hydrogenated styrene-butadiene block copolymer.

[0062] Preparation of organo-modified vermiculite:

[0063] (a) Take natural vermiculite ore and crush it to a particle size ≤30μm using a pulverizer to obtain vermiculite powder. Place the vermiculite powder in a forced-air drying oven and dry it at 105℃ for 6 hours to remove adsorbed moisture and obtain dried vermiculite powder;

[0064] (b) Prepare a 10% sodium carbonate solution. Add 100g of dried vermiculite powder to 800mL of sodium carbonate solution and place in a constant temperature water bath. Stir and react at 60℃ for 4h. After the reaction is complete, transfer the mixture to a centrifuge and centrifuge at 4000r / min for 10min. Discard the supernatant, wash the precipitate with deionized water until neutral, and finally dry at 110℃ for 8h to obtain sodium-based vermiculite.

[0065] (c) Weigh 50g of sodium-based vermiculite and 15g of hexadecyltrimethylammonium bromide, add them together to 500mL of deionized water, place the mixture in an ultrasonic reactor, and sonicate at 50℃ for 3 h. After the reaction is complete, filter the mixture and wash the filter cake several times with deionized water until no hexadecyltrimethylammonium bromide is detected in the washing liquid. Finally, dry the mixture at 80℃ for 10 h to obtain organic intercalated vermiculite.

[0066] (d) Weigh 10g of organointercalated vermiculite and 1.5g of 3-aminopropyltriethoxysilane, add them to 300 mL of ethanol / water solution (ethanol to water volume ratio 1:1), adjust the pH of the system to 3-4 by adding hydrochloric acid dropwise, and reflux at 80℃ for 6 h. After the reaction is complete, centrifuge the mixture at 4000 r / min for 10 min, discard the supernatant, wash the precipitate three times with ethanol, and finally dry it at 80℃ for 8 h to obtain organointercalated vermiculite.

[0067] A method for preparing a rapid repair material for rubber conveyor belts includes the following steps:

[0068] Weigh out EPDM rubber and hydrogenated styrene-butadiene block copolymer, place them in a forced-air drying oven, and preheat at 60℃ for 2 h. Add the preheated raw materials to a Banbury mixer, set the mixer speed to 60 r / min and the temperature to 80℃, and perform basic mixing for 10 min. Then add paraffin oil and continue mixing for 5 min to obtain the compound.

[0069] The crosslinking agent and the reinforcing filler were added into the mixing material, and stirred for 10 min to make them uniformly dispersed. Then the activator and the vulcanizing agent were added, and stirred for another 10 min to obtain the mixture.

[0070] The mixture was transferred into a mold, and placed into a flat vulcanizing machine to be molded at 160°C and under a pressure of 15 MPa for 10 min, and then vulcanized at 160°C for 20 min to complete the crosslinking reaction, thereby obtaining the rubber conveyor belt rapid repair material.

[0071] Example 3

[0072] A rubber conveyor belt rapid repair material, comprising the following components by weight:

[0073] 65 parts of ethylene-propylene-diene rubber, 25 parts of hydrogenated styrene-butadiene block copolymer, 4.5 parts of trimethylolpropane triacrylate, 6 parts of organic vermiculite, 2.5 parts of zinc stearate, 6 parts of sulfur, and 6 parts of paraffin oil.

[0074] Preparation of hydrogenated styrene-butadiene block copolymer:

[0075] (1) A 1000 mL four-necked flask was prepared, 800 mL of cyclohexane was added as a solvent, and nitrogen was introduced to remove air and maintain an inert environment. The flask was placed in a constant temperature water bath, and the temperature was raised to 50°C. 20 g of styrene was slowly added to the flask, and 0.5 g of n-butyllithium initiator was added, and the reaction was continuously stirred for 2 h to complete the first-stage styrene polymerization. Then, 30 g of butadiene was added to the flask under nitrogen protection, and the reaction was continued for 3 h for the second-stage polymerization. Finally, 20 g of styrene was added, and the reaction was continued for 2 h to complete the third-stage polymerization, thereby obtaining a triblock copolymer.

[0076] (2) The above-mentioned triblock copolymer was transferred to a high-pressure reaction kettle, 0.3 g of tris(triphenylphosphine)rhodium chloride catalyst was added, hydrogen was introduced, the reaction pressure was controlled at 5 MPa, and the temperature was controlled at 80°C, and the reaction was continued for 6 h to fully hydrogenate the double bonds in the butadiene segment, thereby obtaining a hydrogenated polymer.

[0077] (3) 100 g of the hydrogenated polymer was weighed into a beaker, 3.5 g of maleic anhydride and 0.2 g of dicumyl peroxide initiator were added, and stirred uniformly. The mixture was transferred to a twin-screw extruder, the temperature of the extruder was set to 200°C, and the screw rotation speed was set to 80 r / min, and a melt grafting reaction was carried out. After the reaction was completed, the product was extracted with acetone in a Soxhlet extractor for 12 h to remove impurities, and finally dried in a vacuum drying oven at 60°C for 8 h, thereby obtaining the hydrogenated styrene-butadiene block copolymer.

[0078] Preparation of organic vermiculite:

[0079] (a) Take the natural vermiculite ore, crush it to a particle size of ≤30 μm using a crusher, and obtain vermiculite powder. Dry the vermiculite powder in a blast drying oven at 105°C for 6 h to remove adsorbed water, and obtain dry vermiculite powder;

[0080] (b) Prepare a 10% sodium carbonate solution, add 100 g of dry vermiculite powder to 800 mL of the sodium carbonate solution, and place it in a constant-temperature water bath at 60°C for 4 h of stirring reaction. After the reaction is completed, transfer the mixture to a centrifuge and centrifuge it at a speed of 4000 r / min for 10 min, discard the supernatant, wash the precipitate with deionized water until it is neutral, and finally dry it at 110°C for 8 h to obtain sodium-based vermiculite.

[0081] (c) Take 50 g of sodium-based vermiculite and 20 g of cetyltrimethylammonium bromide, add them to 500 mL of deionized water, and place them in an ultrasonic reaction kettle for 3 h of ultrasonic-assisted reaction at 50°C. After the reaction is completed, perform suction filtration, and wash the filter cake with deionized water multiple times until no cetyltrimethylammonium bromide is detected in the washing liquid, and finally dry it at 80°C for 10 h to obtain organic intercalation vermiculite.

[0082] (d) Take 10 g of organic intercalation vermiculite and 2 g of 3-aminopropyltriethoxysilane, add them to 300 mL of an ethanol / water solution (ethanol and water in a volume ratio of 1:1), drop in hydrochloric acid to adjust the pH of the system to 3-4, and reflux at 80°C for 6 h of reaction. After the reaction is completed, centrifuge the mixture at a speed of 4000 r / min for 10 min, discard the supernatant, wash the precipitate with ethanol 3 times, and finally dry it at 80°C for 8 h to obtain organic vermiculite.

[0083] A preparation method of a rubber conveyor belt rapid repair material, comprising the following steps:

[0084] Take the ethylene-propylene-diene rubber and the hydrogenated styrene-butadiene block copolymer, and place them in a blast drying oven for preheating at 60°C for 2 h. Add the preheated raw materials to a banbury mixer, set the banbury mixer speed to 60 r / min and the temperature to 80°C, and perform basic mixing for 10 min. Then add paraffin oil and continue mixing for 5 min to obtain a mixed material.

[0085] Add the trimethylolpropane triacrylate crosslinking agent and the organic vermiculite reinforcing filler to the mixed material, and stir for 10 min to uniformly disperse them. Then add the zinc stearate activator and the sulfur vulcanizing agent, and continue stirring for 10 min to obtain a mixture.

[0086] The mixture is transferred into a mold, placed into a flat plate vulcanizing machine, and molded at 160°C under a pressure of 15 MPa for 10 min, and then vulcanized at 160°C for 20 min to complete the crosslinking reaction, to obtain the rubber conveyor belt rapid repair material after demolding.

[0087] Example 4

[0088] A rubber conveyor belt rapid repair material comprises the following components by weight:

[0089] 70 parts of ethylene-propylene-diene rubber, 30 parts of hydrogenated styrene-butadiene block copolymer, 6 parts of trimethylolpropane triacrylate, 8 parts of organic vermiculite, 3 parts of zinc stearate, 7 parts of sulfur, and 8 parts of paraffin oil.

[0090] Preparation of hydrogenated styrene-butadiene block copolymer:

[0091] (1) A 1000 mL four-necked flask is prepared, 800 mL of cyclohexane is added as a solvent, nitrogen is introduced to remove air, and the system is maintained in an inert environment. The flask is placed in a constant temperature water bath, and the temperature is raised to 50°C. 20 g of styrene is weighed and slowly added to the flask, followed by the addition of 0.5 g of n-butyllithium initiator, and the reaction is continuously stirred for 2 h to complete the first-stage styrene polymerization. Then, 30 g of butadiene is added to the flask under nitrogen protection, and the reaction is continued for 3 h for the second-stage polymerization. Finally, 20 g of styrene is added, and the reaction is carried out for 2 h to complete the third-stage polymerization, obtaining a triblock copolymer.

[0092] (2) The above-mentioned triblock copolymer is transferred to a high-pressure reaction kettle, 0.3 g of tris(triphenylphosphine)rhodium chloride catalyst is added, hydrogen is introduced, the reaction pressure is controlled at 5 MPa, and the temperature is controlled at 80°C, and the reaction is carried out for 6 h to fully hydrogenate the butadiene segment double bonds, obtaining a hydrogenated polymer.

[0093] (3) 100 g of the hydrogenated polymer is weighed and placed in a beaker, 5 g of maleic anhydride and 0.3 g of dicumyl peroxide initiator are added and stirred uniformly. The mixture is transferred to a twin-screw extruder, the temperature of the extruder is set to 200°C, and the screw rotation speed is 80 r / min, and the melt grafting reaction is carried out. After the reaction is completed, the product is extracted with acetone in a Soxhlet extractor for 12 h to remove impurities, and finally dried in a vacuum drying oven at 60°C for 8 h, obtaining the hydrogenated styrene-butadiene block copolymer.

[0094] Preparation of organic vermiculite:

[0095] (a) The natural vermiculite ore is crushed to a particle size of ≤30 μm using a crusher to obtain vermiculite powder. The vermiculite powder is placed in a forced air drying oven and dried at 105°C for 6 h to remove adsorbed water, obtaining dried vermiculite powder;

[0096] (b) A 10% sodium carbonate solution was prepared, 100 g of dry vermiculite powder was added to 800 mL of the sodium carbonate solution, and the mixture was placed in a constant-temperature water bath and stirred at 60°C for 4 h. After the reaction was completed, the mixture was transferred to a centrifuge and centrifuged at 4000 r / min for 10 min, the supernatant was discarded, the precipitate was washed with deionized water until neutral, and finally dried at 110°C for 8 h to obtain sodium-based vermiculite.

[0097] (c) 50 g of sodium-based vermiculite and 25 g of cetyltrimethylammonium bromide were weighed and added to 500 mL of deionized water, and the mixture was placed in an ultrasonic reactor and ultrasonically assisted at 50°C for 3 h. After the reaction was completed, the mixture was filtered, and the filter cake was washed with deionized water until no cetyltrimethylammonium bromide was detected in the washing liquid, and finally dried at 80°C for 10 h to obtain organic intercalation vermiculite.

[0098] (d) 10 g of organic intercalation vermiculite and 3 g of 3-aminopropyltriethoxysilane were weighed and added to 300 mL of an ethanol / water solution (volume ratio of ethanol to water 1:1), hydrochloric acid was added dropwise to adjust the pH of the system to 3-4, and the mixture was refluxed at 80°C for 6 h. After the reaction was completed, the mixture was centrifuged at 4000 r / min for 10 min, the supernatant was discarded, and the precipitate was washed with ethanol three times, and finally dried at 80°C for 8 h to obtain organically modified vermiculite.

[0099] A method for preparing a rubber conveyor belt rapid repair material, comprising the following steps:

[0100] The ethylene-propylene-diene rubber and the hydrogenated styrene-butadiene block copolymer were weighed and placed in a forced air drying oven and preheated at 60°C for 2 h. The preheated raw materials were added to a banbury mixer, the banbury mixer was set to a speed of 60 r / min and a temperature of 80°C, and the raw materials were mixed for 10 min. Subsequently, paraffin oil was added and the mixture was mixed for another 5 min to obtain a mixed material.

[0101] The crosslinking agent trimethylolpropane triacrylate and the organic vermiculite reinforcing filler were added to the mixed material and stirred for 10 min to uniformly disperse them. Then, the zinc stearate activator and the sulfur vulcanizing agent were added and stirred for another 10 min to obtain a mixture.

[0102] The mixture was transferred to a mold and placed in a flat plate vulcanizing machine, and the mixture was molded at 160°C and a pressure of 15 MPa for 10 min, and then vulcanized at 160°C for another 20 min to complete the crosslinking reaction. After demolding, a rubber conveyor belt rapid repair material was obtained.

[0103] Example 5

[0104] A rubber conveyor belt rapid repair material, comprising the following components by weight:

[0105] EPDM 60 parts, hydrogenated styrene-butadiene block copolymer 20 parts, trimethylolpropane triacrylate 3 parts, organo-vermiculite 4 parts, zinc stearate 2 parts, sulfur 5 parts, paraffin oil 5 parts.

[0106] Preparation of hydrogenated styrene-butadiene block copolymer:

[0107] (1) Prepare a 1000 mL four-necked flask, add 800 mL of cyclohexane as a solvent to it, and purge it with nitrogen to remove air and maintain an inert environment. Place the flask in a constant temperature water bath and heat it to 50°C. Weigh 20 g of styrene and slowly add it to the flask, then add 0.5 g of n-butyllithium initiator, and continue stirring for 2 h to complete the first-stage styrene polymerization. Then, weigh 30 g of butadiene and add it to the flask under nitrogen protection, and continue to react for 3 h to carry out the second-stage polymerization. Finally, add 20 g of styrene and react for 2 h to complete the third-stage polymerization, obtaining a triblock copolymer.

[0108] (2) Transfer the above-mentioned triblock copolymer to a high-pressure reaction kettle, add 0.3 g of tris(triphenylphosphine)rhodium chloride catalyst, and introduce hydrogen gas to control the reaction pressure at 5 MPa and the temperature at 80°C, and react for 6 h to fully hydrogenate the butadiene segment double bonds, obtaining a hydrogenated polymer.

[0109] (3) Weigh 100 g of the hydrogenated polymer and place it in a beaker, add 2 g of maleic anhydride and 0.1 g of dicumyl peroxide initiator, and stir uniformly. Transfer the mixture to a twin-screw extruder, set the extruder temperature to 200°C, and the screw rotation speed to 80 r / min, and carry out a melt grafting reaction. After the reaction is completed, extract the product with acetone in a Soxhlet extractor for 12 h to remove impurities, and finally dry it in a vacuum drying oven at 60°C for 8 h, obtaining a hydrogenated styrene-butadiene block copolymer.

[0110] Preparation of organo-vermiculite:

[0111] (a) Take the natural vermiculite ore and crush it to a particle size of ≤30 μm using a crusher, obtaining vermiculite powder. Place the vermiculite powder in a forced air drying oven and dry it at 105°C for 6 h to remove adsorbed water, obtaining dried vermiculite powder;

[0112] (b) Prepare a 10% sodium carbonate solution, take 100 g of dried vermiculite powder and add it to 800 mL of sodium carbonate solution, and place it in a constant temperature water bath and stir at 60°C for 4 h. After the reaction is completed, transfer the mixture to a centrifuge and centrifuge it at a speed of 4000 r / min for 10 min, discard the supernatant, wash the precipitate with deionized water until it is neutral, and finally dry it at 110°C for 8 h, obtaining sodium-based vermiculite.

[0113] (c) Weigh 50 g of sodium-based vermiculite and 10 g of cetyltrimethylammonium bromide together into 500 mL of deionized water, and put into an ultrasonic reactor, and ultrasonic-assisted reaction at 50°C for 3 h. After the reaction is completed, perform suction filtration, and wash the filter cake with deionized water several times until no cetyltrimethylammonium bromide is detected in the washing liquid, and finally dry at 80°C for 10 h to obtain the organic intercalation vermiculite.

[0114] (d) Weigh 10 g of the organic intercalation vermiculite and 1 g of 3-aminopropyl triethoxysilane together into 300 mL of an ethanol / water solution (volume ratio of ethanol to water 1:1), and add hydrochloric acid to adjust the pH of the system to 3-4, and reflux reaction at 80°C for 6 h. After the reaction is completed, centrifuge the mixture at a speed of 4000 r / min for 10 min, discard the supernatant, wash the precipitate with ethanol for 3 times, and finally dry at 80°C for 8 h to obtain the organified vermiculite.

[0115] A preparation method of a rubber conveyor belt rapid repair material, comprising the following steps:

[0116] Weigh the ethylene-propylene-diene rubber and the hydrogenated styrene-butadiene block copolymer, and place them in a forced air drying oven for preheating at 60°C for 2 h. Add the preheated raw materials into a banbury mixer, set the banbury mixer speed to 60 r / min, and the temperature to 80°C, and perform basic mixing for 10 min. Then add paraffin oil, and continue mixing for 5 min to obtain a mixed material.

[0117] Add the trimethylolpropane triacrylate crosslinking agent and the organified vermiculite reinforcing filler to the mixed material, and stir for 10 min to uniformly disperse them. Then add the zinc stearate activator and the sulfur vulcanizing agent, and continue stirring for 10 min to obtain a mixture.

[0118] Transfer the mixture into a mold, and place it into a flat plate vulcanizing machine for mold pressing at 160°C and a pressure of 15 MPa for 10 min, and then continue vulcanizing at 160°C for 20 min to completely perform the crosslinking reaction, and after demolding, obtain the rubber conveyor belt rapid repair material.

[0119] Comparative Example 1

[0120] Comparative Example 1 differs from Example 1 in that the repair material does not add the hydrogenated styrene-butadiene block copolymer, and the remaining steps are the same.

[0121] Comparative Example 2

[0122] Comparative Example 2 differs from Example 1 in that the hydrogenated styrene-butadiene block copolymer does not perform a maleic anhydride grafting reaction in the preparation process, and the remaining steps are the same.

[0123] Comparative Example 3

[0124] Comparative Example 3 differs from Example 1 in that the repair material does not add organic vermiculite, and the rest of the steps are the same.

[0125] Comparative Example 4

[0126] Comparative Example 4 differs from Example 1 in that the organic vermiculite in the repair material is replaced by ordinary vermiculite, and the rest of the steps are the same.

[0127] Comparative Example 5

[0128] Comparative Example 5 differs from Example 1 in that the organic vermiculite is not intercalated with cetyltrimethylammonium bromide during preparation, and the rest of the steps are the same.

[0129] Comparative Example 6

[0130] Comparative Example 6 differs from Example 4 in that the mass ratio of sodium-based vermiculite to cetyltrimethylammonium bromide during the preparation of organic vermiculite is 10:6, and the rest of the steps are the same.

[0131] Comparative Example 7

[0132] Comparative Example 7 differs from Example 4 in that the mass ratio of sodium-based vermiculite to cetyltrimethylammonium bromide during the preparation of organic vermiculite is 10:7, and the rest of the steps are the same.

[0133] Performance Test

[0134] 1. Tensile strength test:

[0135] According to the standard GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized or thermoplastic rubber", the prepared rubber conveyor belt quick repair material is made into dumbbell-shaped samples, 5 samples for each group of examples and comparative examples. Use an electronic universal testing machine, set the tensile speed to 500 mm / min, test at room temperature (23±2) ℃. Record the maximum force value when the sample breaks, and calculate the tensile strength by formula. The calculation results are shown in Table 1.

[0136] 2. Tear strength test:

[0137] According to GB / T529-2008 "Determination of tear strength of vulcanized or thermoplastic rubber (pant, right angle and crescent shaped samples)", right angle samples are used, 5 samples for each group. Install the sample on an electronic universal testing machine, set the tensile speed to 500 mm / min, and test at (23±2) ℃. Read the maximum force value when the sample tears, and calculate the tear strength. The calculation results are shown in Table 1.

[0138] 3. Adhesion strength test:

[0139] The repair material was coated on the rubber conveyor belt substrate and cured according to the actual repair process. According to GB / T 7124-2008 "Determination of Tensile Shear Strength of Adhesives (Rigid on Rigid)", tensile shear samples were prepared, 5 samples per group. An electronic universal testing machine was used to perform tensile testing at a speed of 5 mm / min, and the maximum force value at the time of sample failure was recorded to calculate the bonding strength. The calculation results are shown in Table 1.

[0140] 4. Curing speed test:

[0141] An appropriate amount of repair material was placed in a flat vulcanizing machine under specified temperature (160°C) and pressure (15 MPa) conditions. The sample was removed every 5 min, and its hardness was tested using a Shore hardness tester. When the hardness reached the specified value (Shore A hardness 70±5), the time used was recorded as the curing time. The test results are shown in Table 1.

[0142] 5. Wear resistance test:

[0143] According to GB / T 9867-2008 "Determination of Wear Resistance of Vulcanized or Thermoplastic Rubber (Rotary Roller Abrasion Machine Method)", the sample was installed on a rotary roller abrasion machine, a certain load (5N) was applied, the abrasion machine speed was set to 40 r / min, and the abrasion time was 60 min. After the test was completed, the mass loss of the sample was weighed, and the volume abrasion amount was calculated by the formula. The calculation results are shown in Table 1.

[0144] Tensile strength (MPa) Tear strength (kN / m) Adhesion strength (MPa) Curing time (min) Volume wear (mm 3 ) Example 1 19.1 45 3.5 30 101 Example 2 18.3 42 3.2 33 110 Example 3 18.6 44 3.4 31 106 Example 4 19.5 47 3.9 28 96 Example 5 17.4 39 3.0 35 113 Comparative Example 1 12.6 30 2.1 33 156 Comparative Example 2 14.5 35 2.5 32 135 Comparative Example 3 13.8 33 2.2 33 141 Comparative Example 4 11.6 28 1.8 31 162 Comparative Example 5 14.7 36 2.7 32 133 Comparative Example 6 19.6 48 4.0 53 95 Comparative Example 7 19.8 48 4.2 58 95

[0145] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or make equivalent replacements to part of the technical features, as long as they are within the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the scope of the present application should be included in the protection scope of the present application.

Claims

1. A rapid repair material for rubber conveyor belts, characterized in that, Comprise the following components by weight parts: Ethylene propylene terpolymer 60-70 parts, hydrogenated styrene-butadiene block copolymer 20-30 parts, trimethylolpropane triacrylate 3-6 parts, organic vermiculite 4-8 parts, zinc stearate 2-3 parts, sulfur 5-7 parts, paraffin oil 5-8 parts; The preparation method of the hydrogenated styrene-butadiene block copolymer comprises the following steps: (1) Using cyclohexane as the solvent and n-butyllithium as the initiator, the polymerization reaction is carried out by a three-step anionic polymerization method, that is, first, the first-stage styrene polymerization is initiated, then the second-stage polymerization is carried out by adding butadiene, and finally, the third-stage polymerization is completed by adding styrene, to obtain a triblock copolymer; (2) The triblock copolymer is hydrogenated by using tris(triphenylphosphine) rhodium chloride catalyst to fully hydrogenate the double bonds in the butadiene segment, to obtain a hydrogenated polymer; (3) The hydrogenated polymer is mixed with maleic anhydride and dicumyl peroxide initiator, and a melt grafting reaction is carried out in a twin-screw extruder. After the grafting is completed, impurities are removed by Soxhlet extraction with acetone, and finally, vacuum drying is carried out to obtain the hydrogenated styrene-butadiene block copolymer; The preparation method of the organic vermiculite comprises the following steps: (a) The natural vermiculite ore is crushed and sieved to obtain vermiculite powder, which is then dried to remove adsorbed water, to obtain dry vermiculite powder; (b) The dry vermiculite powder is mixed with a sodium salt solution, stirred at a certain temperature, centrifuged after the reaction is completed, washed with deionized water until neutral, and finally dried to obtain sodium-based vermiculite; (c) The sodium-based vermiculite is mixed with cetyltrimethylammonium bromide, deionized water is added, and ultrasonic-assisted reaction is carried out at a certain temperature. After the reaction is completed, suction filtration and washing are carried out to remove unreacted cetyltrimethylammonium bromide, and finally, drying is carried out to obtain organic intercalated vermiculite; (d) The organic intercalated vermiculite is mixed with 3-aminopropyl triethoxysilane, and an ethanol / water solution is added as the solvent. Reflux reaction is carried out under acidic conditions, centrifugation and ethanol washing are carried out after the reaction is completed, and finally, drying is carried out to obtain the organic vermiculite.

2. A rapid repair material for rubber conveyor belts according to claim 1, characterized in that, In step (3), the addition amount of maleic anhydride is 2-5% of the mass of the hydrogenated polymer.

3. A rapid repair material for rubber conveyor belts according to claim 2, characterized in that, The addition amount of dicumyl peroxide initiator is 0.1-0.3% of the mass of the hydrogenated polymer.

4. The rapid repair material for a rubber conveyor belt according to claim 1, wherein In step (a), the particle size of the vermiculite powder is controlled to be ≤30 μm.

5. The rapid repair material for a rubber conveyor belt according to claim 1, wherein In step (b), the sodium salt is sodium carbonate.

6. A rapid repair material for a rubber conveyor belt according to claim 1, characterized in that, In step (c), the mass ratio of sodium-based vermiculite to cetyltrimethylammonium bromide is 10:2-5.

7. A rapid repair material for a rubber conveyor belt according to claim 1, characterized in that, In step (d), the mass ratio of organic intercalated vermiculite to 3-aminopropyl triethoxysilane is 1:0.1-0.

3.

8. A method for the production of a rapid repair material for rubber conveyor belts according to any one of claims 1 to 7, characterized in that Comprise the following steps: The ethylene propylene terpolymer and the hydrogenated styrene-butadiene block copolymer are preheated and treated, then added into a mixer for basic mixing, then paraffin oil is added to obtain a mixed material; The trimethylolpropane triacrylate crosslinking agent and the organic vermiculite reinforcing filler are added into the mixed material, stirred uniformly, then the zinc stearate activator and the sulfur vulcanizing agent are added, and continue to stir uniformly to obtain a mixture; The mixture is transferred into a mold, and is molded under heating and pressure, and then vulcanization treatment is performed to completely cross-link the reaction, thereby obtaining the rubber conveyor belt rapid repair material.