High-friction conveying belt material and preparation method thereof

Abstract

The invention relates to a high-friction conveyor belt material and a preparation method thereof, and belongs to the technical field of conveyor belt materials, the high-friction conveyor belt material comprises the following raw materials: 40-60 parts of hydrogenated nitrile rubber, 20-30 parts of a modified bio-based elastomer, 5-15 parts of a plasticizer, 2-5 parts of an anti-aging agent and 2-6 parts of a reinforcing agent; according to the technical scheme, itaconic acid diester, butadiene and epoxidized gutta-percha are combined through an emulsion polymerization method, and the bio-based elastomer is obtained; grafting the silane modified nano composite material onto a bio-based elastomer to obtain a modified bio-based elastomer; and mixing hydrogenated nitrile rubber, a rubber additive and the modified bio-based elastomer, adding a plasticizer, an anti-aging agent and a reinforcing agent for mixing, and carrying out vulcanization molding to finally obtain the high-friction conveyor belt material. The modified bio-based elastomer improves the wear resistance and the mechanical property of the conveying belt material, meanwhile, the environment-friendly property and the aging resistance of the conveying belt material are good, and the comprehensive performance of the high-friction conveying belt material is overall improved.

Description

Technical Field

[0001] The invention belongs to the technical field of conveyor belt materials, and in particular, relates to a high-friction conveyor belt material and a preparation method thereof. Background Art

[0002] Conveyor belt is a commonly used transmission device. It is usually made of rubber and plastic and can realize the function of cyclic rotation transmission through the transmission shaft. High friction conveyor belt is also a common conveyor belt. It is widely used in automatic sorting conveyor lines for postal letters and automatic scanning and resolution conveyor lines for barcodes of small commodity packaging in industries such as food and tobacco. Because the conveyor belt runs very fast, and the scanning and resolution sensors require that the small and light items carried by the conveyor line have good stability and cannot shake, the elastic modulus of the high friction conveyor belt material is required to be as large as possible, and the requirements for its wear resistance and mechanical properties are also high. Traditional ordinary rubber conveyor belts cannot meet the above requirements.

[0003] Existing high-friction conveyor belts are very prone to wear during long-term operation. As the wear increases, the conveyor belts are prone to fatigue fracture, resulting in a reduced service life. Their wear resistance and mechanical properties need to be further improved. Existing high-friction conveyor belt materials also have the defects of poor environmental protection and insufficient aging resistance. In addition, due to the compatibility issues between the components of the conveyor belt materials, their performance stability also needs to be further improved. Summary of the invention

[0004] The purpose of the present invention is to provide a high-friction conveyor belt material and a preparation method thereof. Itaconate diester, butadiene and epoxidized eucommia gum are combined by emulsion polymerization to obtain a bio-based elastomer, which further improves the mechanical properties and wear resistance of the conveyor belt material, and the epoxy groups in the epoxidized eucommia gum can provide reaction sites for subsequent reactions; a silane-modified nanocomposite material is grafted onto the bio-based elastomer to obtain a modified bio-based elastomer, which improves the interface compatibility of the silane-modified nanocomposite material with the bio-based elastomer, and increases the dispersibility of the silane-modified nanocomposite material in the bio-based elastomer; hydrogenated nitrile rubber and a rubber additive are mixed, and then mixed with the modified bio-based elastomer, and then a plasticizer, an antioxidant and a reinforcing agent are added for mixing, and vulcanization molding is performed to finally obtain a high-friction conveyor belt material, and the hydrogenated nitrile rubber and the modified bio-based elastomer can be cross-linked together under the action of the rubber additive to form a double network cross-linked structure, thereby improving the interface compatibility between the hydrogenated nitrile rubber and the modified bio-based elastomer, and the overall performance of the high-friction conveyor belt material is improved, and the environmental protection is good.

[0005] The technical problem to be solved by the present invention is as follows: the existing high-friction conveyor belt is very prone to wear during long-term operation. As the wear increases, the conveyor belt is prone to fatigue fracture, resulting in a reduced service life. Its wear resistance and mechanical properties need to be further improved; the existing high-friction conveyor belt materials also have the defects of poor environmental protection and insufficient aging resistance, and due to the compatibility problems between the components of the conveyor belt material, its performance stability also needs to be further improved.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A high-friction conveyor belt material, comprising the following raw materials in parts by weight: 40-60 parts of hydrogenated nitrile rubber, 20-30 parts of modified bio-based elastomer, 5-15 parts of plasticizer, 2-5 parts of antioxidant and 2-6 parts of reinforcing agent;

[0008] The method for preparing the modified bio-based elastomer comprises the following steps:

[0009] A1: Itaconate diester, butadiene and epoxidized eucommia gum are combined by emulsion polymerization to obtain a bio-based elastomer;

[0010] A2: Grafting the silane-modified nanocomposite onto the bio-based elastomer to obtain the modified bio-based elastomer.

[0011] Furthermore, step A1 is specifically as follows:

[0012] Itaconate diester, butadiene, epoxidized eucommia gum and deionized water are mixed, and then a polymerization aid is added and mixed evenly, diisopropylbenzene is added under a nitrogen atmosphere, and polymerized at 4-8°C for 4.5-5.5h to form a bio-based latex, and the latex is flocculated with ethanol, and finally dried at 45-55°C to obtain a bio-based elastomer.

[0013] In the above reaction process, itaconate diester, butadiene and epoxidized eucommia gum all have carbon-carbon double bonds. Itaconate diester, butadiene and epoxidized eucommia gum can be combined together by emulsion polymerization to finally obtain a bio-based elastomer.

[0014] Furthermore, the itaconate diester is one of dimethyl itaconate, dibutyl itaconate and diethyl itaconate.

[0015] Furthermore, the mass ratio of itaconate diester, butadiene, epoxidized eucommia gum and deionized water is 23-25:15-17:11-13:75-85.

[0016] Furthermore, the polymerization aid is composed of a total emulsifier, a total activator, potassium chloride, tert-dodecyl mercaptan and sodium bisulfite mixed in a mass ratio of 1.44:0.076:0.28:0.048:0.025.

[0017] Furthermore, the total emulsifier is composed of potassium disproportionate rosin acid and sodium fatty acid mixed in a mass ratio of 10:4.4.

[0018] Furthermore, the total activator is composed of ferrous sulfate, bleaching powder and ethylenediaminetetraacetic acid mixed in a mass ratio of 0.08:0.28:0.4.

[0019] Furthermore, the preparation method of the epoxidized eucommia gum comprises the following steps:

[0020] Eucommia gum is added into xylene and stirred at 35-45°C until the Eucommia gum is completely dissolved, and then hydrogen peroxide and formic acid are added and reacted for 2.5-3.5 hours. At the end of the reaction, ethanol is added to precipitate the product, which is filtered, washed with deionized water, and vacuum dried at 45-55°C to obtain epoxidized Eucommia gum.

[0021] In the above reaction process, the eucommia gum has carbon-carbon double bonds, which undergo epoxidation reaction under the action of hydrogen peroxide and formic acid, converting part of the carbon-carbon double bonds on the eucommia gum into epoxy groups, and finally obtaining epoxidized eucommia gum.

[0022] Furthermore, the mass ratio of eucommia gum to xylene is 2-4:50-70.

[0023] Furthermore, step A2 is specifically as follows:

[0024] The silane-modified nanocomposite material is dispersed in anhydrous ethanol, and then the bio-based elastomer is added and stirred in a water bath at 55-65° C. for 9-11 hours. After the reaction is completed, it is washed with anhydrous ethanol and finally dried at 55-65° C. to obtain the modified bio-based elastomer.

[0025] Furthermore, the mass ratio of the silane-modified nanocomposite material to anhydrous ethanol is 4-6:80-120.

[0026] Furthermore, the preparation method of the silane-modified nanocomposite material comprises the following steps:

[0027] Mix montmorillonite and anhydrous ethanol and ultrasonically disperse them for 25-35 minutes, then add tetraethyl orthosilicate and anhydrous ethanol, stir for 25-35 minutes, adjust the pH value of the mixture to 7.8-8.2 with ammonia water, add silane coupling agent, place in a constant temperature water bath at 55-65°C, stir for 11-13 hours, wash with anhydrous ethanol, and finally dry at 75-85°C to obtain a silane-modified nanocomposite material.

[0028] In the above reaction process, montmorillonite has hydroxyl groups, and ethyl orthosilicate generates silica nanoparticles through hydrolysis and condensation under alkaline conditions. The silica nanoparticles can be deposited on the surface of montmorillonite in situ. The silane coupling agent has silanol groups after hydrolysis. The silanol groups on the silane coupling agent can be combined with the hydroxyl groups on the surface of the silica nanoparticles, and the silane coupling agent is grafted onto the surface of the silica nanoparticles, and finally a silane-modified nanocomposite material is obtained.

[0029] Furthermore, the mass ratio of the montmorillonite to anhydrous ethanol is 0.5-1.5:15-25.

[0030] Furthermore, the silane coupling agent is composed of γ-glycidyloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane mixed in a mass ratio of 1:1.

[0031] A method for preparing a high friction conveyor belt material comprises the following steps:

[0032] Weigh the raw materials in parts by mass, add the hydrogenated nitrile rubber and the rubber additive into an internal mixer and mix them evenly to obtain a rubber masterbatch, add the rubber masterbatch into tetrahydrofuran and stir for 10-12 hours to obtain a system A, dissolve the modified bio-based elastomer in tetrahydrofuran to obtain a system B, add the system B into the system A and stir for 1-2 hours, then add a plasticizer, an antioxidant and a reinforcing agent, and mix them in an open rubber mixer to form a strip of rubber, cover the strip of rubber on the cord fabric, and then vulcanize and form it on a flat vulcanizer to obtain a high friction conveyor belt material.

[0033] Furthermore, the rubber additive is composed of zinc oxide, tetramethylthiuram disulfide and 2-mercaptobenzothiazole mixed in a mass ratio of 2.5:0.65:0.8.

[0034] Furthermore, the plasticizer is at least one of dioctyl phthalate, dibutyl phthalate, dinonyl phthalate, butyl benzyl phthalate, and epoxy soybean oil.

[0035] Furthermore, the antioxidant is composed of antioxidant 4010NA, antioxidant ODA and antioxidant RD mixed in a mass ratio of 1:1:1.

[0036] Furthermore, the reinforcing agent is composed of carbon black N330 and white carbon black mixed in a mass ratio of 3:1, and its particle size is 1000-1500 mesh.

[0037] Furthermore, during the mixing, the roller temperature is 60-80° C., and the mixing time is 5-10 min.

[0038] Furthermore, the vulcanization temperature of the vulcanization molding is 140-160° C., the pressure is 10-15 MPa, and the vulcanization time is 20-30 min.

[0039] Beneficial effects of the present invention:

[0040] (1) In the technical scheme of the present invention, itaconic acid diester, butadiene and epoxidized eucommia gum are combined by emulsion polymerization to obtain a bio-based elastomer; itaconic acid diester, butadiene and epoxidized eucommia gum are combined by emulsion copolymerization to form a bio-based elastomer, which has good anti-slip properties and rolling resistance, and can further improve the mechanical properties and wear resistance of the conveyor belt material. At the same time, the epoxidized eucommia gum is introduced into the chains of itaconic acid diester and butadiene, which can not only effectively combine with itaconic acid diester and butadiene, but also the epoxy groups in the epoxidized eucommia gum can provide reaction sites for subsequent reactions, further improving the bonding force between the bio-based elastomer and the silane-modified nanocomposite material; the silane-modified nanocomposite material is grafted onto the bio-based elastomer to obtain a modified Bio-based elastomer; silica particles are in situ deposited on the surface of montmorillonite and then grafted with a silane coupling agent to obtain a silane-modified nanocomposite material. The silane coupling agent is a mixture of γ-glycidyloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane. Both silane coupling agents can combine with the silica particles on the surface of montmorillonite, thereby improving the grafting efficiency of the silane coupling agent. In addition, the amino group on the γ-aminopropyltriethoxysilane can combine with the epoxy group on the bio-based elastomer, thereby improving the interface compatibility of the silane-modified nanocomposite material with the bio-based elastomer and increasing the dispersibility of the silane-modified nanocomposite material in the bio-based elastomer, thereby further improving the wear resistance and mechanical properties of the conveyor belt material.

[0041] (2) In the technical scheme of the present invention, hydrogenated nitrile rubber and rubber additives are mixed, and then mixed with modified bio-based elastomers, and then plasticizers, antioxidants and reinforcing agents are added for kneading, and then vulcanization molding is performed to finally obtain a high-friction conveyor belt material; hydrogenated nitrile rubber and modified bio-based elastomers can be cross-linked together under the action of rubber additives to form a double network cross-linking structure, thereby improving the interface compatibility between hydrogenated nitrile rubber and modified bio-based elastomers, and the modified bio-based elastomer is more environmentally friendly, reducing the use of organic solvents, and further improving the environmental protection, stability, aging resistance and mechanical properties of the high-friction conveyor belt material.

[0042] (3) In the technical scheme of the present invention, itaconate diester, butadiene and epoxidized eucommia gum are combined by emulsion polymerization, and then a silane-modified nanocomposite material is grafted to obtain a modified bio-based elastomer, hydrogenated nitrile rubber and a rubber additive are mixed, and then mixed with the modified bio-based elastomer, a plasticizer, an antioxidant and a reinforcing agent are added for mixing, and vulcanization molding is performed to finally obtain a high-friction conveyor belt material. This can not only improve the wear resistance and mechanical properties of the conveyor belt material, but also enhance the performance stability and aging resistance of the conveyor belt material. At the same time, the obtained high-friction conveyor belt material has good environmental protection, a long service life, and good comprehensive performance. DETAILED DESCRIPTION

[0043] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The specific parameters of the raw materials used in the present invention are as follows:

[0045] Montmorillonite, with a particle size of 16-22 μm, was provided by Shijiazhuang Tengrui Mineral Products Trading Co., Ltd.; hydrogenated nitrile rubber (Lanxess 4369, Germany), with an acrylonitrile content of 43% and a Mooney viscosity (ML 1+4) of 97 at 100°C, was purchased from Meifu New Materials Co., Ltd.

[0046] The raw materials used in the following examples and comparative examples are as follows: the polymerization aid is composed of a total emulsifier, a total activator, potassium chloride, tert-dodecyl mercaptan and sodium bisulfite mixed in a mass ratio of 1.44:0.076:0.28:0.048:0.025; the total emulsifier is composed of a mixture of potassium disproportionate rosin acid and sodium fatty acid in a mass ratio of 10:4.4; the total activator is composed of a mixture of ferrous sulfate, bleaching powder and ethylenediaminetetraacetic acid in a mass ratio of 0.08:0.28:0.4.

[0047] Example 1

[0048] The modified bio-based elastomer is prepared by the following specific steps:

[0049] A1: Dimethyl itaconate, butadiene, epoxidized eucommia gum and deionized water were mixed in a mass ratio of 23:15:11:75, and then a polymerization aid (the mass of the polymerization aid is 11.6wt% of the mass of butadiene) was added and mixed evenly, and diisopropylbenzene (the mass of diisopropylbenzene is 2.3wt% of the mass of butadiene) was added under a nitrogen atmosphere, and polymerized at 4°C for 4.5h to form a bio-based latex, and the latex was flocculated with 95% ethanol (the mass of ethanol is 5 times the mass of butadiene), and finally dried at 45°C for 48h to obtain a bio-based elastomer;

[0050] Wherein, the preparation method of epoxidized eucommia gum comprises the following steps:

[0051] According to the mass ratio of 2:50, eucommia gum is added to xylene, and stirred at 35°C at a speed of 1000 rpm until the eucommia gum is completely dissolved, and then hydrogen peroxide (the mass of hydrogen peroxide is 45wt% of the mass of eucommia gum) and formic acid (the mass of formic acid is 18wt% of the mass of eucommia gum) are added, and the reaction is carried out for 2.5 hours. At the end of the reaction, 50% ethanol is added to precipitate the product (the mass of ethanol is 60wt% of the mass of xylene), filtered, washed with deionized water (the mass of deionized water is 80wt% of the mass of xylene), and vacuum dried at 45°C for 36 hours to obtain epoxidized eucommia gum;

[0052] A2: Disperse the silane-modified nanocomposite in anhydrous ethanol at a mass ratio of 4:80, then add the bio-based elastomer (the mass of the bio-based elastomer is twice the mass of the silane-modified nanocomposite), and stir in a water bath at 55°C for 9 hours. After the reaction is completed, wash with anhydrous ethanol (the mass of anhydrous ethanol is 4 times the mass of the silane-modified nanocomposite), and finally dry at 55°C for 24 hours to obtain a modified bio-based elastomer;

[0053] The preparation method of the silane-modified nanocomposite material comprises the following steps:

[0054] Montmorillonite and anhydrous ethanol are mixed at a mass ratio of 0.5:15, and ultrasonically dispersed for 25 minutes, then tetraethyl orthosilicate (the mass of tetraethyl orthosilicate is twice the mass of montmorillonite) and anhydrous ethanol (the mass of anhydrous ethanol is equal to the mass of the above-mentioned anhydrous ethanol) are added, and stirred for 25 minutes, the pH value of the mixture is adjusted to 7.8 with ammonia water, and then a silane coupling agent (the mass of the silane coupling agent is 5 times the mass of montmorillonite) is added, placed in a constant temperature water bath at 55°C, stirred at a speed of 300 rpm for 11 hours, washed with anhydrous ethanol (the mass of anhydrous ethanol is 30 times the mass of montmorillonite), and finally dried at 75°C for 24 hours to obtain a silane-modified nanocomposite material, wherein the silane coupling agent is composed of γ-glycidyloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane mixed at a mass ratio of 1:1;

[0055] A high-friction conveyor belt material, comprising the following raw materials in parts by weight: 40 parts of hydrogenated nitrile rubber, 20 parts of modified bio-based elastomer, 5 parts of dioctyl phthalate, 2 parts of antioxidant and 2 parts of reinforcing agent;

[0056] The preparation method comprises the following steps:

[0057] Weigh the raw materials by mass, add hydrogenated nitrile rubber and rubber additives into an internal mixer at a mass ratio of 10:0.4 and mix them evenly to obtain a rubber masterbatch, add the rubber masterbatch into tetrahydrofuran at a mass ratio of 1:10, and stir for 10 hours to obtain system A, dissolve the modified bio-based elastomer in tetrahydrofuran at a mass ratio of 1:5 to obtain system B, add system B into system A, and stir for 1 hour, then add dioctyl phthalate, antioxidant and reinforcing agent, and mix them in an open rubber mixer, the roller temperature is 60°C, the mixing time is 5 minutes, a strip of rubber is formed, the strip of rubber is covered on the cord fabric, and then vulcanized on a flat vulcanizer, the vulcanization temperature is 140°C, the pressure is 10MPa, and the vulcanization time is 20 minutes, and finally a high friction conveyor belt material is obtained;

[0058] Among them, the rubber additive is composed of zinc oxide, tetramethylthiuram disulfide and 2-mercaptobenzothiazole mixed in a mass ratio of 2.5:0.65:0.8; the antioxidant is composed of antioxidant 4010NA, antioxidant ODA and antioxidant RD mixed in a mass ratio of 1:1:1; the reinforcing agent is composed of carbon black N330 and white carbon black mixed in a mass ratio of 3:1, and its particle size is 1000 mesh.

[0059] Example 2

[0060] The modified bio-based elastomer is prepared by the following specific steps:

[0061] A1: Dibutyl itaconate, butadiene, epoxidized eucommia gum and deionized water were mixed in a mass ratio of 24:16:12:80, and then a polymerization aid (the mass of the polymerization aid is 11.6wt% of the mass of butadiene) was added and mixed evenly, and diisopropylbenzene (the mass of diisopropylbenzene is 2.3wt% of the mass of butadiene) was added under a nitrogen atmosphere, and polymerized at 6°C for 5h to form a bio-based latex, and the latex was flocculated with 95% ethanol (the mass of ethanol is 5 times the mass of butadiene), and finally dried at 50°C for 48h to obtain a bio-based elastomer;

[0062] Wherein, the preparation method of epoxidized eucommia gum comprises the following steps:

[0063] According to the mass ratio of 3:60, eucommia gum is added to xylene, and stirred at 40°C at a speed of 1000 rpm until the eucommia gum is completely dissolved, and then hydrogen peroxide (the mass of hydrogen peroxide is 45wt% of the mass of eucommia gum) and formic acid (the mass of formic acid is 18wt% of the mass of eucommia gum) are added, and the reaction is carried out for 3 hours. At the end of the reaction, 50% ethanol is added to precipitate the product (the mass of ethanol is 60wt% of the mass of xylene), filtered, washed with deionized water (the mass of deionized water is 80wt% of the mass of xylene), and vacuum dried at 50°C for 36 hours to obtain epoxidized eucommia gum;

[0064] A2: Disperse the silane-modified nanocomposite in anhydrous ethanol at a mass ratio of 5:100, then add the bio-based elastomer (the mass of the bio-based elastomer is twice the mass of the silane-modified nanocomposite), and stir in a water bath at 60°C for 10 hours. After the reaction is completed, wash with anhydrous ethanol (the mass of anhydrous ethanol is 4 times the mass of the silane-modified nanocomposite), and finally dry at 60°C for 24 hours to obtain a modified bio-based elastomer;

[0065] The preparation method of the silane-modified nanocomposite material comprises the following steps:

[0066] Montmorillonite and anhydrous ethanol are mixed in a mass ratio of 1:20, and ultrasonically dispersed for 30 minutes, then tetraethyl orthosilicate (the mass of tetraethyl orthosilicate is twice the mass of montmorillonite) and anhydrous ethanol (the mass of anhydrous ethanol is equal to the mass of the anhydrous ethanol) are added, and stirred for 30 minutes, the pH value of the mixture is adjusted to 8 with ammonia water, and then a silane coupling agent (the mass of the silane coupling agent is 5 times the mass of montmorillonite) is added, placed in a constant temperature water bath at 60°C, stirred at a speed of 300 rpm for 12 hours, washed with anhydrous ethanol (the mass of anhydrous ethanol is 30 times the mass of montmorillonite), and finally dried at 80°C for 24 hours to obtain a silane-modified nanocomposite material, wherein the silane coupling agent is composed of γ-glycidyloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane mixed in a mass ratio of 1:1;

[0067] A high-friction conveyor belt material comprises the following raw materials in parts by weight: 50 parts of hydrogenated nitrile rubber, 25 parts of modified bio-based elastomer, 10 parts of dibutyl phthalate, 3 parts of antioxidant and 4 parts of reinforcing agent;

[0068] The preparation method comprises the following steps:

[0069] Weigh the raw materials by mass, add hydrogenated nitrile rubber and rubber additives into an internal mixer at a mass ratio of 10:0.4 and mix them evenly to obtain a rubber masterbatch, add the rubber masterbatch into tetrahydrofuran at a mass ratio of 1:10, and stir for 11 hours to obtain system A, dissolve the modified bio-based elastomer in tetrahydrofuran at a mass ratio of 1:5 to obtain system B, add system B into system A, and stir for 1.5 hours, then add dibutyl phthalate, antioxidant and reinforcing agent, and mix them in an open rubber mixer, the roller temperature is 70°C, the mixing time is 8 minutes, a strip of rubber is formed, the strip of rubber is covered on the cord fabric, and then vulcanized on a flat vulcanizer, the vulcanization temperature is 150°C, the pressure is 12MPa, and the vulcanization time is 25 minutes, and finally a high friction conveyor belt material is obtained;

[0070] Among them, the rubber additive is composed of zinc oxide, tetramethylthiuram disulfide and 2-mercaptobenzothiazole mixed in a mass ratio of 2.5:0.65:0.8; the antioxidant is composed of antioxidant 4010NA, antioxidant ODA and antioxidant RD mixed in a mass ratio of 1:1:1; the reinforcing agent is composed of carbon black N330 and white carbon black mixed in a mass ratio of 3:1, and its particle size is 1200 mesh.

[0071] Example 3

[0072] The modified bio-based elastomer is prepared by the following specific steps:

[0073] A1: Diethyl itaconate, butadiene, epoxidized eucommia gum and deionized water were mixed in a mass ratio of 25:17:13:85, and then a polymerization aid (the mass of the polymerization aid is 11.6wt% of the mass of butadiene) was added and mixed evenly, and diisopropylbenzene (the mass of diisopropylbenzene is 2.3wt% of the mass of butadiene) was added under a nitrogen atmosphere, and polymerized at 8°C for 5.5h to form a bio-based latex, and the latex was flocculated with 95% ethanol (the mass of ethanol is 5 times the mass of butadiene), and finally dried at 55°C for 48h to obtain a bio-based elastomer;

[0074] Wherein, the preparation method of epoxidized eucommia gum comprises the following steps:

[0075] According to the mass ratio of 4:70, eucommia gum is added to xylene, and stirred at 45°C at a speed of 1000 rpm until the eucommia gum is completely dissolved, and then hydrogen peroxide (the mass of hydrogen peroxide is 45wt% of the mass of eucommia gum) and formic acid (the mass of formic acid is 18wt% of the mass of eucommia gum) are added, and the reaction is carried out for 2.5-3.5h. At the end of the reaction, 50% ethanol is added to precipitate the product (the mass of ethanol is 60wt% of the mass of xylene), filtered, washed with deionized water (the mass of deionized water is 80wt% of the mass of xylene), and vacuum dried at 55°C for 36h to obtain epoxidized eucommia gum;

[0076] A2: Disperse the silane-modified nanocomposite in anhydrous ethanol at a mass ratio of 6:120, then add the bio-based elastomer (the mass of the bio-based elastomer is twice the mass of the silane-modified nanocomposite), and stir in a water bath at 65°C for 11 hours. After the reaction is completed, wash with anhydrous ethanol (the mass of anhydrous ethanol is 4 times the mass of the silane-modified nanocomposite), and finally dry at 65°C for 24 hours to obtain a modified bio-based elastomer;

[0077] The preparation method of the silane-modified nanocomposite material comprises the following steps:

[0078] Montmorillonite and anhydrous ethanol are mixed in a mass ratio of 1.5:25, and ultrasonically dispersed for 35 minutes, then tetraethyl orthosilicate (the mass of tetraethyl orthosilicate is twice the mass of montmorillonite) and anhydrous ethanol (the mass of anhydrous ethanol is equal to the mass of the anhydrous ethanol) are added, and stirred for 35 minutes, the pH value of the mixture is adjusted to 8.2 with ammonia water, and then a silane coupling agent (the mass of the silane coupling agent is 5 times the mass of montmorillonite) is added, placed in a constant temperature water bath at 65°C, stirred at a speed of 300 rpm for 13 hours, washed with anhydrous ethanol (the mass of anhydrous ethanol is 30 times the mass of montmorillonite), and finally dried at 85°C for 24 hours to obtain a silane-modified nanocomposite material, wherein the silane coupling agent is composed of γ-glycidyloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane mixed in a mass ratio of 1:1;

[0079] A high-friction conveyor belt material, comprising the following raw materials in parts by weight: 60 parts of hydrogenated nitrile rubber, 30 parts of modified bio-based elastomer, 15 parts of dinonyl phthalate, 5 parts of antioxidant and 6 parts of reinforcing agent;

[0080] The preparation method comprises the following steps:

[0081] Weigh the raw materials by mass, add hydrogenated nitrile rubber and rubber additives into an internal mixer at a mass ratio of 10:0.4 and mix them evenly to obtain a rubber masterbatch, add the rubber masterbatch into tetrahydrofuran at a mass ratio of 1:10, and stir for 12 hours to obtain system A, dissolve the modified bio-based elastomer in tetrahydrofuran at a mass ratio of 1:5 to obtain system B, add system B into system A, and stir for 2 hours, then add dinonyl phthalate, antioxidant and reinforcing agent, and mix them in an open rubber mixer, the roller temperature is 80°C, the mixing time is 10 minutes, a strip of rubber is formed, the strip of rubber is covered on the cord fabric, and then vulcanized on a flat vulcanizer, the vulcanization temperature is 160°C, the pressure is 15MPa, and the vulcanization time is 30 minutes, and finally a high friction conveyor belt material is obtained;

[0082] Among them, the rubber additive is composed of zinc oxide, tetramethylthiuram disulfide and 2-mercaptobenzothiazole mixed in a mass ratio of 2.5:0.65:0.8; the antioxidant is composed of antioxidant 4010NA, antioxidant ODA and antioxidant RD mixed in a mass ratio of 1:1:1; the reinforcing agent is composed of carbon black N330 and white carbon black mixed in a mass ratio of 3:1, and its particle size is 1500 mesh.

[0083] Comparative Example 1

[0084] The difference between this comparative example and Example 3 is that when preparing the modified bio-based elastomer, the mass of the silane coupling agent in step A2 is replaced by γ-aminopropyltriethoxysilane, and the remaining steps and raw materials are the same as Example 3.

[0085] Comparative Example 2

[0086] The difference between this comparative example and Example 3 is that when preparing the modified bio-based elastomer, the mass of the silane-modified nanocomposite material in step A2 is replaced by the nanocomposite material, and the remaining steps and raw materials are the same as those in Example 3;

[0087] The specific operations of step A2 are:

[0088] The nanocomposite material was dispersed in anhydrous ethanol at a mass ratio of 6:120, and then a bio-based elastomer (the mass of the bio-based elastomer was twice the mass of the silane-modified nanocomposite material) was added, and stirred in a water bath at 65°C for 11 hours. After the reaction was completed, it was washed with anhydrous ethanol (the mass of anhydrous ethanol was 4 times the mass of the silane-modified nanocomposite material), and finally dried at 65°C for 24 hours to obtain a modified bio-based elastomer.

[0089] The method for preparing the nanocomposite material comprises the following steps:

[0090] Montmorillonite and anhydrous ethanol were mixed in a mass ratio of 1.5:25 and ultrasonically dispersed for 35 minutes. Then, tetraethyl orthosilicate (the mass of tetraethyl orthosilicate is twice the mass of montmorillonite) and anhydrous ethanol (the mass of anhydrous ethanol is equal to the mass of the above-mentioned anhydrous ethanol) were added and stirred for 35 minutes. The pH value of the mixture was adjusted to 8.2 with ammonia water, placed in a constant temperature water bath at 65°C, stirred at 300 rpm for 13 hours, washed with anhydrous ethanol (the mass of anhydrous ethanol is 30 times the mass of montmorillonite), and finally dried at 85°C for 24 hours to obtain a nanocomposite material.

[0091] Comparative Example 3

[0092] The difference between this comparative example and Example 3 is that when preparing the modified bio-based elastomer, the mass of epoxidized eucommia gum in step A1 is replaced with eucommia gum, and the remaining steps and raw materials are the same as those in Example 3;

[0093] The specific operations of step A1 are:

[0094] Diethyl itaconate, butadiene, eucommia gum and deionized water are mixed in a mass ratio of 25:17:13:85, and then a polymerization aid is added (the mass of the polymerization aid is 11.6wt% of the mass of butadiene) and mixed evenly. Diisopropylbenzene is added under a nitrogen atmosphere (the mass of diisopropylbenzene is 2.3wt% of the mass of butadiene), and the mixture is polymerized at 8°C for 5.5h to form a bio-based latex. The latex is flocculated with 95% ethanol (the mass of ethanol is 5 times the mass of butadiene), and finally dried at 55°C for 48h to obtain a bio-based elastomer.

[0095] Comparative Example 4

[0096] The difference between this comparative example and Example 3 is that when preparing the modified bio-based elastomer, the mass of epoxidized eucommia gum in step A1 is replaced by glycidyl methacrylate, and the remaining steps and raw materials are the same as those in Example 3;

[0097] The specific operations of step A1 are:

[0098] Diethyl itaconate, butadiene, glycidyl methacrylate and deionized water are mixed in a mass ratio of 25:17:13:85, and then a polymerization aid is added (the mass of the polymerization aid is 11.6wt% of the mass of butadiene) and mixed evenly. Diisopropylbenzene is added under a nitrogen atmosphere (the mass of diisopropylbenzene is 2.3wt% of the mass of butadiene), and the mixture is polymerized at 8°C for 5.5h to form a bio-based latex. The latex is flocculated with 95% ethanol (the mass of ethanol is 5 times the mass of butadiene), and finally dried at 55°C for 48h to obtain a bio-based elastomer.

[0099] Comparative Example 5

[0100] The difference between this comparative example and Example 3 is that when preparing the high friction conveyor belt material, no rubber additive is added, and the components are directly mixed, and the remaining steps and raw materials are synchronized with Example 3;

[0101] A high-friction conveyor belt material, comprising the following raw materials in parts by weight: 60 parts of hydrogenated nitrile rubber, 30 parts of modified bio-based elastomer, 15 parts of dinonyl phthalate, 5 parts of antioxidant and 6 parts of reinforcing agent;

[0102] The preparation method comprises the following steps:

[0103] Weigh the raw materials by mass, put hydrogenated nitrile rubber, modified bio-based elastomer, dinonyl phthalate, antioxidant and reinforcing agent in an open rubber mixer for mixing, the roller temperature is 80°C, the mixing time is 10 minutes, a strip of rubber is formed, the strip of rubber is covered on the cord fabric, and then vulcanized on a flat vulcanizer, the vulcanization temperature is 160°C, the pressure is 15MPa, and the vulcanization time is 30 minutes, and finally a high friction conveyor belt material is obtained;

[0104] Among them, the antioxidant is composed of antioxidant 4010NA, antioxidant ODA and antioxidant RD mixed in a mass ratio of 1:1:1; the reinforcing agent is composed of carbon black N330 and white carbon black mixed in a mass ratio of 3:1, and its particle size is 1500 mesh.

[0105] The high friction conveyor belt materials prepared in Examples 1-3 and Comparative Examples 1-5 were tested for tensile strength, elongation at break, wear resistance and aging resistance; tensile strength and elongation at break were tested according to GB / T 528-2009; wear resistance was tested according to GB / T 9867-2008A; aging resistance was tested according to GB / T3512-2014, the aging temperature was 125°C, the aging time was 7 days, and the change rate of tensile strength was used as the measure. The test results are shown in Table 1 below:

[0106] Table 1 Performance parameters of high friction conveyor belt materials prepared in Examples 1-3 and Comparative Examples 1-5

[0107]

[0108] It can be seen from the data in Table 1 above that, by comparing Comparative Examples 1-2 with Example 3, it can be seen that the test results of the high friction conveyor belt material prepared by replacing the mass of the silane coupling agent in step A2 with γ-aminopropyltriethoxysilane or not adding the silane coupling agent are worse than those of Example 3, indicating that the silane coupling agent composed of γ-glycidyloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane mixed in a mass ratio of 1:1 is grafted onto the nanocomposite material and then combined with the bio-based elastomer to obtain a modified bio-based elastomer, which can better improve the wear resistance, aging resistance and mechanical properties of the conveyor belt material;

[0109] From the comparison between Comparative Examples 3-4 and Example 3, it can be seen that the mass of the epoxidized eucommia gum in step A1 is replaced with eucommia gum or the mass of the epoxidized eucommia gum in step A1 is replaced with glycidyl methacrylate, and combined with diethyl itaconate and butadiene to obtain a bio-based elastomer, and finally prepare a high-friction conveyor belt material. The test result is worse than that of Example 3, indicating that combining diethyl itaconate, butadiene and epoxidized eucommia gum to obtain a bio-based elastomer can not only improve the interface compatibility between the silane-modified nanocomposite material and the bio-based elastomer, but also improve the interface compatibility between the hydrogenated nitrile rubber and the modified bio-based elastomer, thereby further improving the mechanical properties, wear resistance and aging resistance of the conveyor belt material, and having good environmental protection;

[0110] By comparing Comparative Example 5 with Example 3, it can be seen that the high-friction conveyor belt material is prepared by directly mixing the component materials without adding rubber additives, and its test results are worse than those of Example 3, indicating that cross-linking of hydrogenated nitrile rubber and modified bio-based elastomer under the action of rubber additives to form a double network cross-linking structure can further improve the mechanical properties and wear resistance of the conveyor belt material, and improve its aging resistance, while also enhancing the performance stability of the conveyor belt material.

[0111] It can be seen from Table 1 above that the high friction conveyor belt material prepared in Examples 1-3 is compared with the high friction conveyor belt material prepared in Comparative Examples 1-5. The high friction conveyor belt material prepared in Examples 1-3 is prepared by combining itaconate diester, butadiene and epoxidized eucommia gum by emulsion polymerization, and then grafting silane-modified nanocomposite materials to obtain a modified bio-based elastomer, mixing hydrogenated nitrile rubber and rubber additives, and then mixing with the modified bio-based elastomer, adding plasticizers, antioxidants and reinforcing agents for mixing, and vulcanizing to obtain the high friction conveyor belt material, which meets the test performance requirements, while the high friction conveyor belt material prepared in Comparative Examples 1-5 does not meet the performance requirements. This shows that the high friction conveyor belt material prepared by the present invention not only has good wear resistance, aging resistance and mechanical properties, but also has good environmental protection and a long service life.

[0112] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0113] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A high friction conveyor belt material, characterized in that: The invention comprises the following raw materials in parts by weight: 40-60 parts of hydrogenated nitrile rubber, 20-30 parts of modified bio-based elastomer, 5-15 parts of plasticizer, 2-5 parts of antioxidant and 2-6 parts of reinforcing agent; The method for preparing the modified bio-based elastomer comprises the following steps: A1: Itaconate diester, butadiene and epoxidized eucommia gum are combined by emulsion polymerization to obtain a bio-based elastomer; A2: Grafting the silane-modified nanocomposite onto the bio-based elastomer to obtain the modified bio-based elastomer.

2. A high friction conveyor belt material according to claim 1, characterized in that: Step A1 is specifically as follows: Itaconate diester, butadiene, epoxidized eucommia gum and deionized water are mixed, and then a polymerization aid is added and mixed evenly, diisopropylbenzene is added under a nitrogen atmosphere, and polymerized at 4-8°C for 4.5-5.5h to form a bio-based latex, and the latex is flocculated with ethanol, and finally dried at 45-55°C to obtain a bio-based elastomer.

3. A high friction conveyor belt material according to claim 2, characterized in that: The itaconate diester is one of dimethyl itaconate, dibutyl itaconate and diethyl itaconate.

4. A high friction conveyor belt material according to claim 2, characterized in that: The mass ratio of itaconate diester, butadiene, epoxidized eucommia gum and deionized water is 23-25:15-17:11-13:75-85.

5. A high friction conveyor belt material according to claim 2, characterized in that: The preparation method of the epoxidized eucommia gum comprises the following steps: Eucommia gum is added into xylene and stirred at 35-45°C until the Eucommia gum is completely dissolved, and then hydrogen peroxide and formic acid are added and reacted for 2.5-3.5 hours. At the end of the reaction, ethanol is added to precipitate the product, which is filtered, washed with deionized water, and vacuum dried at 45-55°C to obtain epoxidized Eucommia gum.

6. A high friction conveyor belt material according to claim 1, characterized in that: Step A2 is specifically as follows: The silane-modified nanocomposite material is dispersed in anhydrous ethanol, and then the bio-based elastomer is added and stirred in a water bath at 55-65° C. for 9-11 hours. After the reaction is completed, it is washed with anhydrous ethanol and finally dried at 55-65° C. to obtain the modified bio-based elastomer.

7. A high friction conveyor belt material according to claim 6, characterized in that: The mass ratio of the silane-modified nanocomposite material to anhydrous ethanol is 4-6:80-120.

8. A high friction conveyor belt material according to claim 6, characterized in that: The preparation method of the silane-modified nanocomposite material comprises the following steps: Mix montmorillonite and anhydrous ethanol and ultrasonically disperse them for 25-35 minutes, then add tetraethyl orthosilicate and anhydrous ethanol, stir for 25-35 minutes, adjust the pH value of the mixture to 7.8-8.2 with ammonia water, add silane coupling agent, place in a constant temperature water bath at 55-65°C, stir for 11-13 hours, wash with anhydrous ethanol, and finally dry at 75-85°C to obtain a silane-modified nanocomposite material.

9. A high friction conveyor belt material according to claim 7, characterized in that: The silane coupling agent is composed of γ-glycidyloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane mixed in a mass ratio of 1:

1.

10. A method for preparing a high friction conveyor belt material according to any one of claims 1 to 9, characterized in that: The following steps are involved: Weigh the raw materials in parts by mass, add the hydrogenated nitrile rubber and the rubber additive into an internal mixer and mix them evenly to obtain a rubber masterbatch, add the rubber masterbatch into tetrahydrofuran and stir for 10-12 hours to obtain a system A, dissolve the modified bio-based elastomer in tetrahydrofuran to obtain a system B, add the system B into the system A and stir for 1-2 hours, then add a plasticizer, an antioxidant and a reinforcing agent, and mix them in an open rubber mixer to form a strip of rubber, cover the strip of rubber on the cord fabric, and then vulcanize and form it on a flat vulcanizer to obtain a high friction conveyor belt material.

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