Anti-deformation long-life food-grade butterfly valve material and preparation method thereof

Abstract

The invention relates to the technical field of butterfly valves, and particularly discloses an anti-deformation long-life food-grade butterfly valve material and a preparation method thereof.The butterfly valve material is prepared from composite rubber, filler, an activating agent, a softening agent, a vulcanizing agent, a plasticizer, an antioxidant, a processing aid, a bacteriostatic agent, an assistant crosslinker and an anti-aging agent; the preparation method comprises the following steps: S1, mixing the ethylene propylene diene monomer A, the ethylene propylene diene monomer B and the liquid rubber, adding the mixture into an internal mixer, and internally mixing to obtain internally mixed rubber; s2, adding the internal mixed rubber into rubber mixing equipment, adding the rest raw materials, uniformly mixing, mixing, and vulcanizing after mixing; and S3, performing open milling on the vulcanized rubber compound, and performing standing and cooling to obtain the anti-deformation long-life food-grade butterfly valve material. The butterfly valve material prepared by the invention is excellent in mechanical property, high-temperature-resistant, good in wear resistance, long in service life and good in antibacterial performance.

Description

Technical Field

[0001] The present application relates to the technical field of butterfly valves, and more specifically, to an anti-deformation long-life food-grade butterfly valve material and a preparation method thereof. Background Art

[0002] A butterfly valve is a common fluid control device used to regulate the fluid flow in pipelines or equipment. Due to its advantages such as simple structure, small size, light weight, easy and rapid operation, it is widely used in fields such as chemical industry, petroleum, natural gas, food, pharmaceutical, metallurgy, water treatment, etc. In a water dispenser, a butterfly valve is usually used to control the flow of cold and hot water to meet the drinking needs of users. However, the butterfly valves currently used in water dispensers generally have the following problems: (1) Poor sealing performance: The butterfly valves used in existing water dispensers are easily affected by pressure, temperature, and medium, resulting in leakage problems, which not only cause waste of water resources but also bring inconvenience to the user experience.

[0003] (2) Poor corrosion resistance: Existing tap water is mostly disinfected with chlorine, and chlorine will produce disinfection by-products in tap water. The butterfly valves in water dispensers usually come into contact with these disinfection by-products. Prolonged use is extremely likely to cause corrosion and damage to the butterfly valves, resulting in a reduction in the performance of the butterfly valves and even inability to work properly, bringing certain risks to the use of water dispensers.

[0004] (3) Poor fatigue resistance: The usage frequency of butterfly valves in water dispensers is usually high, and they need to be frequently opened and closed. However, the materials of the currently used butterfly valves often have low fatigue resistance. Prolonged frequent opening and closing will cause the performance of the butterfly valves to gradually decline and may pose a risk of fatigue rupture. This will not only affect the normal operation of the water dispenser but also pose a potential threat to the use safety of users.

[0005] Based on the above statements, the present application provides an anti-deformation long-life food-grade butterfly valve material and a preparation method thereof. Summary of the Invention

[0006] To solve the technical problems existing in the background art, the present application provides an anti-deformation long-life food-grade butterfly valve material and a preparation method thereof.

[0007] In a first aspect, the present application provides an anti-deformation long-life food-grade butterfly valve material, adopting the following technical solution: A deformation-proof and long-life food-grade butterfly valve material, characterized by comprising raw materials in the following weight components: 120-160 parts of composite rubber, 20-40 parts of filler, 4-7 parts of activator, 1-5 parts of softener, 1.5-3 parts of vulcanizing agent, 0.5-1.5 parts of plasticizer, 0.5-1.5 parts of antioxidant, 0.5-1.5 parts of processing aid, 0.5-1.5 parts of bacteriostatic agent, 0.5-1.5 parts of co-crosslinking agent, and 0.5-1.5 parts of anti-aging agent.

[0008] Preferably, the composite rubber is a mixture of ethylene propylene diene monomer (EPDM) rubber A, EPDM rubber B and liquid rubber with a mass ratio of 2-6:1-3:1.

[0009] Preferably, the Mooney viscosity of the EPDM rubber A is 30-50 MU, and the ENB content is 8-10 wt%; the Mooney viscosity of the EPDM rubber B is 60-70 MU, and the ENB content is 4-6 wt%.

[0010] Preferably, the liquid rubber is prepared by the following method: A1. Dissolve butadiene in toluene, add azobisisobutyronitrile, and stir and react at a temperature of 50-70 °C for 1-2 h to obtain liquid rubber 1; A2. Mix cashew shell oil diol, alkyl monoisocyanate and polyisocyanate, heat up to 100-120 °C, and react for 3-5 h to obtain liquid rubber 2; A3. Mix liquid rubber 1, liquid rubber 2 and ethanol, stir and react at a temperature of 60-70 °C for 1-2 h, and ultrasonically react at a frequency of 20-30 kHz for 1-2 h to obtain the liquid rubber.

[0011] Preferably, in step A1, the mass ratio of butadiene, toluene, and azobisisobutyronitrile is 1-1.5:3-5:0.05-0.1; in step A2, the mass ratio of cashew shell oil diol, alkyl monoisocyanate and polyisocyanate is 1.5-2:0.8-1.2:0.8-1.2; in step A3, the mass ratio of liquid rubber 1, liquid rubber 2 and ethanol is 1-2:1.5-4:5-8.

[0012] Preferably, the hydroxyl value of the cashew shell oil diol is 65-80 mgKOH / g, and the viscosity (25 °C) is 950-1850 cps.

[0013] Preferably, the filler is carbon black SP5000.

[0014] Preferably, the activator is zinc oxide and stearic acid with a mass ratio of 4-6:0.3-0.9.

[0015] Preferably, the softener is paraffin oil 6030.

[0016] Preferably, the vulcanizing agent is vulcanizing agent BIBP.

[0017] Preferably, the plasticizer is polyethylene glycol - 4000.

[0018] Preferably, the antioxidant is antioxidant 1020.

[0019] Preferably, the processing aid is processing aid WB - 2.

[0020] Preferably, the bacteriostatic agent is prepared by the following method: B1. Put sodium silicate, methyl orthosilicate and polydimethylsiloxane into an aqueous solution of 95% ethanol, add tetra - isopropyl titanate, stir and react at a temperature of 60 - 70 °C for 1 - 2 h, age, dry and grind the reaction product to obtain silica powder; B2. Put the silica powder prepared in step B1 into water, ultrasonically disperse it at a frequency of 20 - 30 kHz for 0.5 - 1 h, then add a silane coupling agent, and continue to ultrasonically disperse it at a frequency of 40 - 50 kHz for 1 - 2 h to obtain a silica powder dispersion; B3. Heat the silica powder dispersion obtained in step B2 to 40 - 50 °C, dropwise add silver nitrate solution to react, then add tea tree oil, ultrasonically disperse it at a frequency of 20 - 30 kHz for 0.5 - 1 h, filter and dry to obtain the required antibacterial agent.

[0021] Preferably, in step B1, the mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, 95% ethanol aqueous solution and tetra - isopropyl titanate is 5 - 8:4 - 6:1 - 2:8 - 10:0.4 - 0.8; in step B2, the mass ratio of silica powder, water and silane coupling agent is 3 - 5:8 - 10:0.1 - 0.3; in step B3, the mass ratio of silica powder dispersion, silver nitrate solution and tea tree oil is 8 - 10:2 - 3:1 - 1.8.

[0022] Preferably, the co - crosslinking agent is triallyl isocyanurate.

[0023] Preferably, the anti - aging agent is anti - aging agent MB.

[0024] In a second aspect, the present application provides a preparation method of a deformation - resistant and long - life food - grade butterfly valve material, adopting the following technical solution: A preparation method of a deformation - resistant and long - life food - grade butterfly valve material, comprising the following steps: S1. Premix the composite rubber to obtain premixed rubber; S2. Add filler, activator, plasticizer, antioxidant, softening agent, processing aid, bacteriostatic agent, co - crosslinking agent, anti - aging agent and vulcanizing agent to the premixed rubber, mix them evenly and then carry out mixing and vulcanization; S3. Open mill the vulcanized mixed rubber to obtain the required anti-deformation long-life food-grade butterfly valve material.

[0025] Preferably, the method of step S1 is as follows: According to the weight ratio, add ethylene propylene diene monomer rubber A, ethylene propylene diene monomer rubber B and liquid rubber into an internal mixer, the plasticizing temperature is 95-100 °C, and plasticize at 240-250 r / min for 45-50 min to obtain the internal mixed rubber.

[0026] Preferably, the method of step S2 is as follows: Add the internal mixed rubber into a rubber mixing equipment, add filler, activator, plasticizer, antioxidant, softening agent, processing aid, bacteriostat, co-crosslinking agent, anti-aging agent, vulcanizing agent according to the weight ratio, mix evenly and then carry out mixing. Mix at 95-100 °C at 200-210 r / min for 50-60 min to obtain the mixed rubber; Let the mixed rubber stand for 6-10 h, then carry out vulcanization, the vulcanization temperature is 168-175 °C, and the vulcanization time is 350-450 s.

[0027] Preferably, the method of step S3 is as follows: Open mill the vulcanized mixed rubber, set the temperature of the open mill to 40-80 °C, the rotation speed is 20-30 r / min, and the roll speed ratio is 22-30:18. Put the internal mixed rubber into the open mill and make 4-8 triangle packages, then thin pass 4-8 times, and finally adjust the thickness to 0.8-1.2 mm to produce a sheet, and let it stand for 20-28 h.

[0028] In summary, the present application has the following beneficial effects: 1. The present application uses ethylene propylene diene monomer rubber A with high ENB content and medium Mooney viscosity, ethylene propylene diene monomer rubber B with medium ENB content and high Mooney viscosity and liquid rubber compounded as the composite rubber, which is non-toxic, odorless and meets the food safety requirements. Among them, ethylene propylene diene monomer rubber A has excellent weather resistance and anti-ultraviolet performance, and ethylene propylene diene monomer rubber B has excellent processing performance and extremely high mechanical strength. In the presence of liquid rubber, the two are mixed and used. Through performance complementarity, it can ensure that the composite rubber has excellent chemical resistance, heat resistance, wear resistance and fatigue resistance, while obtaining excellent elasticity and resilience. It can withstand long-term use and frequent opening and closing operations when used in the preparation of butterfly valves.

[0029] 2. In this application, butadiene is dissolved in toluene and reacts through the initiator azobisisobutyronitrile to generate liquid rubber 1. The conjugated double bonds of butadiene polymerize to form liquid rubber 1 with good flexibility and elasticity. Cardanol diol, alkyl monoisocyanate and polyisocyanate react to generate liquid rubber 2. In this process, more functional groups and crosslinking points are introduced, making the performance of liquid rubber 2 more diverse, with better weather resistance, wear resistance or chemical corrosion resistance. Liquid rubber 1 and liquid rubber 2 are stirred and mixed with ethanol and assisted by ultrasonic treatment to make the mixing of the two liquid rubbers more uniform, promote the interaction and crosslinking between their molecules, and make the performance of the finally prepared liquid rubber more excellent.

[0030] 3. In the preparation process of the bacteriostatic agent in this application, a silicon micropowder dispersion is first prepared as a carrier material. The silicon micropowder dispersion has good biocompatibility and chemical stability. Subsequently, a silver nitrate solution is added dropwise to the silicon micropowder dispersion to react, forming silver-containing nanoparticles attached to the surface of the silicon micropowder. Silver is a broad-spectrum antibacterial agent that has a killing or inhibitory effect on a variety of bacteria, fungi and viruses, and has significant antibacterial properties. Tea tree oil is added to further enhance the antibacterial effect. Tea tree oil itself has natural antibacterial, anti-inflammatory and antioxidant properties, and its synergistic effect with silver can enable the bacteriostatic agent to play a role in a wider range of microorganisms. Specific embodiments

[0031] The following further elaborates on this application with reference to examples.

[0032] The raw materials used in the examples and comparative examples of this application are specifically as follows: Ethylene propylene diene monomer A is EPDM Keltan® 4869C (Mooney viscosity is 48 MU, ENB content is 8.7 wt%), and ethylene propylene diene monomer B is EPDM Keltan® 6470C (Mooney viscosity is 63 MU, ENB content is 4.8 wt%); Cardanol diol is purchased from Guangzhou Haoyi New Materials Technology Co., Ltd.; Titanium tetraisopropoxide is purchased from Merck 87560; Tea tree oil is purchased from Macklin Reagent Company, and the product number is T819562.

[0033] Silicon micropowder is purchased from Macklin Reagent Company, and the product number is M758933.

[0034] Examples 1-3 provide a deformation-proof and long-life food-grade butterfly valve material and its preparation method.

[0035] Example 1 A deformation-proof and long-life food-grade butterfly valve material, including raw materials with the following weight components: 120 parts of compound rubber, 20 parts of filler, 4 parts of activator, 1 part of softener, 1.5 parts of vulcanizing agent, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of processing aid, 0.5 part of bacteriostatic agent, 0.5 part of co-crosslinking agent, 0.5 part of anti-aging agent.

[0036] The compound rubber is a mixture of ethylene propylene diene monomer rubber A, ethylene propylene diene monomer rubber B and liquid rubber with a mass ratio of 2:1:1.

[0037] Among them, the liquid rubber is prepared by the following method: A1. Dissolve butadiene in toluene, add azobisisobutyronitrile, and react at a high speed of 800 rpm at a temperature of 50 °C for 1 h to obtain liquid rubber 1, where the mass ratio of butadiene, toluene, and azobisisobutyronitrile is 1:3:0.05; A2. Mix cardanol shell oil diol, methyl isocyanate and isophorone diisocyanate, heat up to 100 °C, and react for 3 h to obtain liquid rubber 2, where the mass ratio of cardanol shell oil diol, methyl isocyanate and isophorone diisocyanate is 1.5:0.8:0.8; A3. Mix liquid rubber 1, liquid rubber 2 and ethanol, react at a high speed of 800 rpm at a temperature of 60 °C for 1 h, and ultrasonically react at a frequency of 20 kHz for 1 h to obtain liquid rubber, where the mass ratio of liquid rubber 1, liquid rubber 2 and ethanol is 1:1.5:5.

[0038] The bacteriostatic agent is prepared by the following method: B1. Place sodium silicate, methyl orthosilicate and polydimethylsiloxane in an ethanol aqueous solution with a mass fraction of 95%, add tetra-isopropyl titanate, react at a high speed of 800 rpm at a temperature of 60 °C for 1 h, age the reaction product for 2 h, and dry at 80 °C for 2 h to obtain silicon micropowder, where the mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, 95% ethanol aqueous solution and tetra-isopropyl titanate is 5:4:1:8:0.4; B2. Place the silicon micropowder prepared in step B1 in water, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, then add silane coupling agent KH-570, and continue to ultrasonically disperse it at a frequency of 40 kHz for 1 h to obtain a silicon micropowder dispersion, where the mass ratio of silicon micropowder, water, and silane coupling agent KH-570 is 3:8:0.1; B3. Heat the silicon micropowder dispersion obtained in step B2 to 40 °C, dropwise add 0.05 mol / L silver nitrate solution to react, then add tea tree oil, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, filter and dry to obtain the required antibacterial agent, where the mass ratio of silicon micropowder dispersion, 0.05 mol / L nitrate solution, and tea tree oil is 8:2:1.

[0039] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 4:0.3, the softener is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol - 4000, the antioxidant is antioxidant 1020, the processing aid is WB - 2, the co - crosslinking agent is triallyl isocyanurate, and the anti - aging agent is anti - aging agent MB.

[0040] A deformation - resistant and long - life food - grade butterfly valve material, comprising the following steps: S1: According to the weight ratio, add ethylene - propylene - diene monomer A, ethylene - propylene - diene monomer B and liquid rubber to a kneader. The plasticizing temperature is 95 °C, and plasticize at 240 r / min for 45 min to obtain kneaded rubber.

[0041] S2: Add the kneaded rubber to a rubber - refining equipment, and add the filler, activator, plasticizer, antioxidant, softener, processing aid, bacteriostatic agent, co - crosslinking agent, anti - aging agent, and vulcanizing agent according to the weight ratio, mix evenly and then carry out mixing. Mix at 95 °C at 200 r / min for 50 min to obtain the mixed rubber; after standing the mixed rubber for 6 h, carry out vulcanization. The vulcanization temperature is 168 °C and the vulcanization time is 350 s.

[0042] S3: Open - mill the vulcanized mixed rubber. The temperature of the open - mill is set at 40 °C, the rotational speed is 20 r / min, and the roll speed ratio is 22:18. Put the kneaded rubber into the open - mill and make 4 triangle - shaped packages, then thin - pass 4 times, and finally adjust the thickness to 0.8 mm to produce a sheet, and let it stand for 20 h.

[0043] Example 2 A deformation - resistant and long - life food - grade butterfly valve material, comprising raw materials with the following weight components: 140 parts of composite rubber, 30 parts of filler, 6 parts of activator, 3 parts of softener, 2.5 parts of vulcanizing agent, 1 part of plasticizer, 1 part of antioxidant, 1 part of processing aid, 1 part of bacteriostatic agent, 1 part of co - crosslinking agent, 1 part of anti - aging agent.

[0044] The composite rubber is a mixture of ethylene - propylene - diene monomer A, ethylene - propylene - diene monomer B and liquid rubber with a mass ratio of 4:2:1. The liquid rubber is prepared by the following method: A1: Dissolve butadiene in toluene, add azobisisobutyronitrile, and react at a high speed of 800 rpm at 60 °C for 1.5 h to obtain liquid rubber 1, where the mass ratio of butadiene, toluene, and azobisisobutyronitrile is 1.3:4:0.075; A2: Mix cashew shell oil diol, n - butyl isocyanate and hexamethylene diisocyanate, heat up to 110 °C, and react for 4 h to obtain liquid rubber 2, where the mass ratio of cashew shell oil diol, n - butyl isocyanate and hexamethylene diisocyanate is 1.8:1:1; A3. Mix liquid rubber 1, liquid rubber 2 and ethanol, react at a high speed of 800 rpm at a temperature of 65 °C for 1.5 h, and ultrasonically react at a frequency of 25 kHz for 1.5 h to obtain liquid rubber, where the mass ratio of liquid rubber 1, liquid rubber 2 and ethanol is 1.5:2.3:6.5.

[0045] The bacteriostatic agent is prepared by the following method: B1. Place sodium silicate, methyl orthosilicate and polydimethylsiloxane in an ethanol solution with a mass fraction of 95%, add tetra-isopropyl titanate, react at a high speed of 800 rpm at a temperature of 65 °C for 1.5 h, age the reaction product for 2 h, and dry at 80 °C for 2 h to obtain silicon micro-powder, where the mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, ethanol solution with a mass fraction of 95% and tetra-isopropyl titanate is 6:5:1.5:9:0.6; B2. Place the silicon micro-powder prepared in step B1 in water, ultrasonically disperse it at a frequency of 25 kHz for 0.8 h, then add silane coupling agent KH-570, and continue to ultrasonically disperse it at a frequency of 45 kHz for 1.5 h to obtain a silicon micro-powder dispersion, where the mass ratio of silicon micro-powder, water and silane coupling agent KH-570 is 4:9:0.2; B3. Heat the silicon micro-powder dispersion obtained in step B2 to 45 °C, dropwise add 0.05 mol / L silver nitrate solution to react, then add tea tree oil, ultrasonically disperse it at a frequency of 25 kHz for 0.8 h, filter and dry to obtain the required antibacterial agent, where the mass ratio of silicon micro-powder dispersion, 0.05 mol / L nitrate solution and tea tree oil is 9:2.5:1.4.

[0046] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 5:0.6, the softener is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol-4000, the antioxidant is antioxidant 1020, the processing aid is WB-2, the co-crosslinking agent is triallyl isocyanurate, and the anti-aging agent is anti-aging agent MB.

[0047] A kind of anti-deformation long-life food-grade butterfly valve material, comprising the following steps: S1: According to the weight ratio, add ethylene propylene diene monomer A, ethylene propylene diene monomer B and liquid rubber to a mixer, the plasticizing temperature is 98 °C, and plasticize at 245 r / min for 48 min to obtain plasticized rubber.

[0048] S2: Add the kneaded rubber into a rubber kneading device, and add filler, activator, plasticizer, antioxidant, softening agent, processing aid, bacteriostatic agent, co-crosslinking agent, antioxidant, and vulcanizing agent according to the weight ratio. After mixing evenly, conduct kneading. After kneading at 98 °C at 205 r / min for 55 min, obtain the kneaded rubber; after standing the kneaded rubber for more than 8 h, conduct vulcanization. The vulcanization temperature is 171 °C, and the vulcanization time is 400 s.

[0049] S3: Open the vulcanized kneaded rubber. Set the temperature of the open mill to 60 °C, the rotation speed to 25 r / min, and the roll speed ratio to 25:18. Put the kneaded rubber into the open mill and make 6 triangular bales, then thin pass 6 times, and finally adjust the thickness to 1 mm to produce a sheet, and let it stand for 24 h.

[0050] Example 3 A food-grade butterfly valve material with anti-deformation and long life, comprising raw materials with the following weight components: 160 parts of composite rubber, 40 parts of filler, 7 parts of activator, 5 parts of softening agent, 3 parts of vulcanizing agent, 1.5 parts of plasticizer, 1.5 parts of antioxidant, 1.5 parts of processing aid, 1.5 parts of bacteriostatic agent, 1.5 parts of co-crosslinking agent, 1.5 parts of antioxidant.

[0051] The composite rubber is a mixture of ethylene propylene diene monomer A, ethylene propylene diene monomer B and liquid rubber with a mass ratio of 6:3:1.

[0052] Among them, the liquid rubber is prepared by the following method: A1. Dissolve butadiene in toluene, add azobisisobutyronitrile, and react at a high speed of 800 rpm at 70 °C for 2 h to obtain liquid rubber 1, where the mass ratio of butadiene, toluene, and azobisisobutyronitrile is 1.5:5:0.1; A2. Mix cashew shell oil diol, tert-butyl isocyanate and hexamethylene diisocyanate, heat up to 120 °C, and react for 5 h to obtain liquid rubber 2, where the mass ratio of cashew shell oil diol, tert-butyl isocyanate and hexamethylene diisocyanate is 2:1.2:1.2; A3. Mix liquid rubber 1, liquid rubber 2 and ethanol, react at a high speed of 800 rpm at 70 °C for 2 h, and ultrasonicate at a frequency of 30 kHz for 2 h to obtain liquid rubber, where the mass ratio of liquid rubber 1, liquid rubber 2 and ethanol is 2:4:8.

[0053] The bacteriostatic agent is prepared by the following method: B1. Sodium silicate, methyl orthosilicate, and polydimethylsiloxane are placed in an ethanol solution with a mass fraction of 95%. Tetraisopropyl titanate is added, and a high-speed reaction is carried out at 800 rpm for 2 h at a temperature of 70 °C. The reaction product is aged, dried, and ground to obtain silica powder. The mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, the ethanol solution with a mass fraction of 95%, and tetraisopropyl titanate is 8:6:2:10:0.8; B2. The silica powder prepared in step B1 is placed in water and ultrasonically dispersed at a frequency of 30 kHz for 1 h. Then, silane coupling agent KH-570 is added, and ultrasonically dispersed at a frequency of 50 kHz for another 2 h to obtain a silica powder dispersion. The mass ratio of silica powder, water, and silane coupling agent KH-570 is 3:8:0.3; B3. The silica powder dispersion obtained in step B2 is heated to 40 °C, and a 0.05 mol / L silver nitrate solution is added dropwise for reaction. Then, tea tree oil is added, and ultrasonically dispersed at a frequency of 30 kHz for 1 h. After filtration and drying, the required antibacterial agent is obtained. The mass ratio of silica powder dispersion, 0.05 mol / L nitrate solution, and tea tree oil is 10:3:1.8.

[0054] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 6:0.9, the softening agent is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol-4000, the antioxidant is antioxidant 1020, the processing aid is WB-2, the co-crosslinking agent is triallyl isocyanurate, and the anti-aging agent is anti-aging agent MB.

[0055] A food-grade butterfly valve material with anti-deformation and long life includes the following steps: S1: According to the weight ratio, ethylene propylene diene monomer A, ethylene propylene diene monomer B, and liquid rubber are mixed and added to an internal mixer. The plasticizing temperature is 100 °C, and plasticized at 250 r / min for 50 min to obtain plasticized rubber.

[0056] S2: The plasticized rubber is added to a rubber mixing equipment, and the filler, activator, plasticizer, antioxidant, softening agent, processing aid, antibacterial agent, co-crosslinking agent, anti-aging agent, and vulcanizing agent are added according to the weight ratio and mixed evenly for mixing. After mixing at 210 r / min for 60 min at 100 °C, the mixed rubber is obtained; after the mixed rubber is allowed to stand for more than 10 h, vulcanization is carried out. The vulcanization temperature is 175 °C, and the vulcanization time is 450 s.

[0057] S3: The vulcanized mixed rubber is open-milled. The temperature of the open mill is set to 80 °C, the rotational speed is 30 r / min, and the roll speed ratio is 30:18. The plasticized rubber is put into the open mill to make 8 triangular packages, then thin-sliced 8 times, and finally the thickness is adjusted to 1.2 mm for sheet extrusion and allowed to stand for 28 h.

[0058] To verify the comprehensive performance of the anti-deformation long-life food-grade butterfly valve material prepared in Examples 1-3 of this application, the applicant set Comparative Examples 1-10, which are specifically as follows: Comparative Example 1 An anti-deformation long-life food-grade butterfly valve material, comprising raw materials in the following weight components: 120 parts of composite rubber, 20 parts of filler, 4 parts of activator, 1 part of softener, 1.5 parts of vulcanizing agent, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of processing aid, 0.5 part of bacteriostatic agent, 0.5 part of co-crosslinking agent, 0.5 part of anti-aging agent.

[0059] The composite rubber is a mixture of ethylene-propylene-diene monomer rubber A and liquid rubber with a mass ratio of 3:1.

[0060] Among them, the liquid rubber is prepared by the following method: A1. Dissolve butadiene in toluene, add azobisisobutyronitrile, and react at a high speed of 800 rpm at a temperature of 50 °C for 1 h to obtain liquid rubber 1, where the mass ratio of butadiene, toluene, and azobisisobutyronitrile is 1:3:0.05; A2. Mix cashew shell oil diol, methyl isocyanate, and isophorone diisocyanate and heat up to 100 °C, and react for 3 h to obtain liquid rubber 2, where the mass ratio of cashew shell oil diol, methyl isocyanate, and isophorone diisocyanate is 1.5:0.8:0.8; A3. Mix liquid rubber 1, liquid rubber 2, and ethanol, and react at a high speed of 800 rpm at a temperature of 60 °C for 1 h, and ultrasonically react at a frequency of 20 kHz for 1 h to obtain liquid rubber, where the mass ratio of liquid rubber 1, liquid rubber 2, and ethanol is 1:1.5:5.

[0061] The bacteriostatic agent is prepared by the following method: B1. Place sodium silicate, methyl orthosilicate, and polydimethylsiloxane in an aqueous ethanol solution with a mass fraction of 95%, add tetra-isopropyl titanate, and react at a high speed of 800 rpm at a temperature of 60 °C for 1 h. Age the reaction product for 2 h and dry it at 80 °C for 2 h to obtain silicon micro-powder, where the mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, the aqueous ethanol solution with a mass fraction of 95%, and tetra-isopropyl titanate is 5:4:1:8:0.4; B2. Place the silicon micro-powder prepared in step B1 in water, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, then add silane coupling agent KH-570, and continue to ultrasonically disperse it at a frequency of 40 kHz for 1 h to obtain a silicon micro-powder dispersion liquid, where the mass ratio of silicon micro-powder, water, and silane coupling agent KH-570 is 3:8:0.1; B3. Heat the silica powder dispersion obtained in step B2 to 40°C, add 0.05 mol / L silver nitrate solution dropwise for reaction, then add tea tree oil, ultrasonically disperse at a frequency of 20 kHz for 0.5 h, filter and dry to obtain the required antibacterial agent, where the mass ratio of the silica powder dispersion, 0.05 mol / L nitrate solution, and tea tree oil is 8:2:1.

[0062] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 4:0.3, the softener is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol - 4000, the antioxidant is antioxidant 1020, the processing aid is WB - 2, the co - crosslinking agent is triallyl isocyanurate, and the anti - aging agent is anti - aging agent MB.

[0063] A deformation - resistant and long - life food - grade butterfly valve material, comprising the following steps: S1: According to the weight ratio, add ethylene - propylene - diene monomer rubber A and liquid rubber to a mixer, the plasticizing temperature is 95°C, plasticize at 240 r / min for 45 min to obtain plasticized rubber.

[0064] S2: Add the plasticized rubber to a rubber - mixing equipment, add the filler, activator, plasticizer, antioxidant, softener, processing aid, antibacterial agent, co - crosslinking agent, anti - aging agent, and vulcanizing agent according to the weight ratio, mix evenly and then carry out mixing. Mix at 95°C at 200 r / min for 50 min to obtain the mixed rubber; let the mixed rubber stand for 6 h, then carry out vulcanization, the vulcanization temperature is 168°C, and the vulcanization time is 350 s.

[0065] S3: Open - mill the vulcanized mixed rubber, set the open - mill temperature to 40°C, the rotation speed to 20 r / min, and the roll speed ratio to 22:18. Put the plasticized rubber into the open - mill to make 4 triangle packages, then thin - pass 4 times, and finally adjust the thickness to 0.8 mm to produce a sheet, and let it stand for 20 h.

[0066] Comparative Example 2 A deformation - resistant and long - life food - grade butterfly valve material, comprising raw materials with the following weight components: 120 parts of composite rubber, 20 parts of filler, 4 parts of activator, 1 part of softener, 1.5 parts of vulcanizing agent, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of processing aid, 0.5 part of antibacterial agent, 0.5 part of co - crosslinking agent, 0.5 part of anti - aging agent.

[0067] The composite rubber is a mixture of ethylene - propylene - diene monomer rubber B and liquid rubber with a mass ratio of 3:1.

[0068] Among them, the liquid rubber is prepared by the following method: A1. Dissolve butadiene in toluene, add azobisisobutyronitrile, and react at a high speed of 800 rpm at a temperature of 50 °C for 1 h to obtain liquid rubber 1, where the mass ratio of butadiene, toluene, and azobisisobutyronitrile is 1:3:0.05; A2. Mix cardanol shell oil diol, methyl isocyanate, and isophorone diisocyanate and heat up to 100 °C, react for 3 h to obtain liquid rubber 2, where the mass ratio of cardanol shell oil diol, methyl isocyanate, and isophorone diisocyanate is 1.5:0.8:0.8; A3. Mix liquid rubber 1, liquid rubber 2, and ethanol, react at a high speed of 800 rpm at a temperature of 60 °C for 1 h, and ultrasonically react at a frequency of 20 kHz for 1 h to obtain liquid rubber, where the mass ratio of liquid rubber 1, liquid rubber 2, and ethanol is 1:1.5:5.

[0069] The bacteriostatic agent is prepared by the following method: B1. Place sodium silicate, methyl orthosilicate, and polydimethylsiloxane in an aqueous ethanol solution with a mass fraction of 95%, add tetra-isopropyl titanate, react at a high speed of 800 rpm at a temperature of 60 °C for 1 h, age the reaction product for 2 h, and dry it at 80 °C for 2 h to obtain silica powder, where the mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, the aqueous ethanol solution with a mass fraction of 95%, and tetra-isopropyl titanate is 5:4:1:8:0.4; B2. Place the silica powder prepared in step B1 in water, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, then add silane coupling agent KH-570, and continue to ultrasonically disperse it at a frequency of 40 kHz for 1 h to obtain a silica powder dispersion, where the mass ratio of silica powder, water, and silane coupling agent KH-570 is 3:8:0.1; B3. Heat the silica powder dispersion obtained in step B2 to 40 °C, dropwise add 0.05 mol / L silver nitrate solution to react, then add tea tree oil, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, filter and dry to obtain the required antibacterial agent, where the mass ratio of the silica powder dispersion, 0.05 mol / L nitrate solution, and tea tree oil is 8:2:1.

[0070] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 4:0.3, the softener is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol-4000, the antioxidant is antioxidant 1020, the processing aid is WB-2, the co-crosslinking agent is triallyl isocyanurate, and the anti-aging agent is anti-aging agent MB.

[0071] A kind of anti-deformation long-life food-grade butterfly valve material, including the following steps: S1: According to the weight ratio, add ethylene propylene diene monomer rubber B and liquid rubber to a Banbury mixer. The plasticizing temperature is 95 °C, and plasticize at 240 r / min for 45 min to obtain Banbury mix.

[0072] S2: Add the Banbury mix to a rubber mixing equipment, and add filler, activator, plasticizer, antioxidant, softener, processing aid, bacteriostat, co-crosslinking agent, antioxidant, vulcanizing agent according to the weight ratio. After mixing evenly, conduct mixing. Mix at 95 °C at 200 r / min for 50 min to obtain mixed rubber; let the mixed rubber stand for 6 h, then conduct vulcanization. The vulcanization temperature is 168 °C, and the vulcanization time is 350 s.

[0073] S3: Open mill the vulcanized mixed rubber. The temperature of the open mill is set at 40 °C, the rotational speed is 20 r / min, and the roll speed ratio is 22:18. Put the Banbury mix into the open mill to make 4 triangle bales, then thin pass 4 times, and finally adjust the thickness to 0.8 mm to produce a sheet, and let it stand for 20 h.

[0074] Comparative Example 3 A food-grade butterfly valve material with anti-deformation and long life, comprising raw materials with the following weight components: 120 parts of composite rubber, 20 parts of filler, 4 parts of activator, 1 part of softener, 1.5 parts of vulcanizing agent, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of processing aid, 0.5 part of bacteriostat, 0.5 part of co-crosslinking agent, 0.5 part of antioxidant.

[0075] The composite rubber is ethylene propylene diene monomer rubber A and ethylene propylene diene monomer rubber B with a mass ratio of 2.6:1.4.

[0076] The bacteriostat is prepared in the following manner: B1: Place sodium silicate, methyl orthosilicate and polydimethylsiloxane in an aqueous ethanol solution with a mass fraction of 95%, add tetraisopropyl titanate, and react at a high speed of 800 rpm at 60 °C for 1 h. Age the reaction product for 2 h and dry at 80 °C for 2 h to obtain silica powder. The mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, the aqueous ethanol solution with a mass fraction of 95% and tetraisopropyl titanate is 5:4:1:8:0.4; B2: Place the silica powder prepared in step B1 in water, ultrasonically disperse at a frequency of 20 kHz for 0.5 h, then add silane coupling agent KH-570, and continue to ultrasonically disperse at a frequency of 40 kHz for 1 h to obtain a silica powder dispersion. The mass ratio of silica powder, water and silane coupling agent KH-570 is 3:8:0.1; B3. Heat the silica powder dispersion obtained in step B2 to 40°C, add 0.05 mol / L silver nitrate solution dropwise for reaction, then add tea tree oil, ultrasonically disperse at a frequency of 20 kHz for 0.5 h, filter and dry to obtain the required antibacterial agent, where the mass ratio of the silica powder dispersion, 0.05 mol / L nitrate solution, and tea tree oil is 8:2:1.

[0077] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 4:0.3, the softener is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol - 4000, the antioxidant is antioxidant 1020, the processing aid is WB - 2, the co - crosslinking agent is triallyl isocyanurate, and the anti - aging agent is anti - aging agent MB.

[0078] A deformation - resistant and long - life food - grade butterfly valve material, comprising the following steps: S1: According to the weight ratio, mix ethylene - propylene - diene monomer A and ethylene - propylene - diene monomer B and add them to a kneader. The plasticizing temperature is 95°C, and plasticize at 240 r / min for 45 min to obtain kneaded rubber.

[0079] S2: Add the kneaded rubber to a rubber - mixing equipment, add the filler, activator, plasticizer, antioxidant, softener, processing aid, antibacterial agent, co - crosslinking agent, anti - aging agent, and vulcanizing agent according to the weight ratio, mix evenly and then carry out mixing. Mix at 95°C at 200 r / min for 50 min to obtain the mixed rubber; let the mixed rubber stand for 6 h, and then carry out vulcanization. The vulcanization temperature is 168°C, and the vulcanization time is 350 s.

[0080] S3: Open - mill the vulcanized mixed rubber. The temperature of the open - mill is set to 40°C, the rotation speed is 20 r / min, and the roll speed ratio is 22:18. Put the kneaded rubber into the open - mill and make 4 triangle packages, then thin - pass 4 times, and finally adjust the thickness to 0.8 mm to produce a sheet, and let it stand for 20 h.

[0081] Comparative Example 4 A deformation - resistant and long - life food - grade butterfly valve material, comprising raw materials with the following weight components: 120 parts of composite rubber, 20 parts of filler, 4 parts of activator, 1 part of softener, 1.5 parts of vulcanizing agent, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of processing aid, 0.5 part of antibacterial agent, 0.5 part of co - crosslinking agent, 0.5 part of anti - aging agent.

[0082] The composite rubber is a mixture of ethylene - propylene - diene monomer A, ethylene - propylene - diene monomer B, and liquid rubber with a mass ratio of 2:1:1.

[0083] Among them, the liquid rubber is prepared by the following method: A1. Mix cardanol diol, methyl isocyanate and isophorone diisocyanate, heat up to 100 °C and react for 3 h to obtain liquid rubber 1, where the mass ratio of cardanol diol, methyl isocyanate and isophorone diisocyanate is 1.5:0.8:0.8; A2. Mix liquid rubber 1 and ethanol, react at a high speed of 800 rpm at a temperature of 60 °C for 1 h, and ultrasonically react at a frequency of 20 kHz for 1 h to obtain liquid rubber, where the mass ratio of liquid rubber 1 and ethanol is 2.5:5.

[0084] The bacteriostatic agent is prepared by the following method: B1. Place sodium silicate, methyl orthosilicate and polydimethylsiloxane in an aqueous ethanol solution with a mass fraction of 95%, add tetra-isopropyl titanate, react at a high speed of 800 rpm at a temperature of 60 °C for 1 h, age the reaction product for 2 h, and dry at 80 °C for 2 h to obtain silica powder, where the mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, the aqueous ethanol solution with a mass fraction of 95% and tetra-isopropyl titanate is 5:4:1:8:0.4; B2. Place the silica powder prepared in step B1 in water, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, then add silane coupling agent KH-570, and continue to ultrasonically disperse it at a frequency of 40 kHz for 1 h to obtain a silica powder dispersion, where the mass ratio of silica powder, water and silane coupling agent KH-570 is 3:8:0.1; B3. Heat up the silica powder dispersion obtained in step B2 to 40 °C, dropwise add 0.05 mol / L silver nitrate solution to react, then add tea tree oil, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, filter and dry to obtain the required antibacterial agent, where the mass ratio of the silica powder dispersion, 0.05 mol / L nitrate solution and tea tree oil is 8:2:1.

[0085] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 4:0.3, the softener is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol-4000, the antioxidant is antioxidant 1020, the processing aid is WB-2, the co-crosslinking agent is triallyl isocyanurate, and the anti-aging agent is anti-aging agent MB.

[0086] A kind of anti-deformation long-life food-grade butterfly valve material, comprising the following steps: S1: According to the weight ratio, add ethylene propylene diene monomer A, ethylene propylene diene monomer B and liquid rubber to an internal mixer, the plasticizing temperature is 95 °C, and plasticize at 240 r / min for 45 min to obtain internal mixer rubber.

[0087] S2: Add the internal mixer rubber into the rubber mixing equipment, and add filler, activator, plasticizer, antioxidant, softening agent, processing aid, bacteriostatic agent, co-crosslinking agent, anti-aging agent, and vulcanizing agent according to the weight ratio, mix them evenly and then carry out mixing. After mixing at 95 °C at 200 r / min for 50 min, the mixed rubber is obtained; after standing the mixed rubber for 6 h, vulcanization is carried out, the vulcanization temperature is 168 °C, and the vulcanization time is 350 s.

[0088] S3: Open mill the vulcanized mixed rubber, set the temperature of the open mill to 40 °C, the rotational speed to 20 r / min, and the roll speed ratio to 22:18. Put the internal mixer rubber into the open mill and make 4 triangle wraps, then thin pass 4 times, and finally adjust the thickness to 0.8 mm to take out the sheet and stand for 20 h.

[0089] Comparative Example 5 A food-grade butterfly valve material with anti-deformation and long life, comprising raw materials with the following weight components: 120 parts of composite rubber, 20 parts of filler, 4 parts of activator, 1 part of softening agent, 1.5 parts of vulcanizing agent, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of processing aid, 0.5 part of bacteriostatic agent, 0.5 part of co-crosslinking agent, 0.5 part of anti-aging agent.

[0090] The composite rubber is a mixture of ethylene-propylene-diene monomer rubber A, ethylene-propylene-diene monomer rubber B and liquid rubber with a mass ratio of 2:1:1.

[0091] Among them, the liquid rubber is prepared by the following method: A1: Dissolve butadiene in toluene, add azobisisobutyronitrile, and react at a high speed of 800 rpm at 50 °C for 1 h to obtain liquid rubber 1, where the mass ratio of butadiene, toluene, and azobisisobutyronitrile is 1:3:0.05; A3: Mix liquid rubber 1 and ethanol, react at a high speed of 800 rpm at 60 °C for 1 h, and ultrasonicate at a frequency of 20 kHz for 1 h to obtain liquid rubber, where the mass ratio of liquid rubber 1 and ethanol is 2.5:5.

[0092] The bacteriostatic agent is prepared by the following method: B1: Place sodium silicate, methyl orthosilicate and polydimethylsiloxane in an ethanol aqueous solution with a mass fraction of 95%, add tetra-isopropyl titanate, react at a high speed of 800 rpm at 60 °C for 1 h, age the reaction product for 2 h, and dry at 80 °C for 2 h to obtain silicon micropowder, where the mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, 95% ethanol aqueous solution and tetra-isopropyl titanate is 5:4:1:8:0.4; B2. Place the silica powder prepared in step B1 in water, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, then add silane coupling agent KH-570, and continue to ultrasonically disperse it at a frequency of 40 kHz for 1 h to obtain a silica powder dispersion. The mass ratio of silica powder, water, and silane coupling agent KH-570 is 3:8:0.1; B3. Heat the silica powder dispersion obtained in step B2 to 40 °C, add 0.05 mol / L silver nitrate solution dropwise for reaction, then add tea tree oil, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, filter and dry to obtain the required antibacterial agent. The mass ratio of silica powder dispersion, 0.05 mol / L nitrate solution, and tea tree oil is 8:2:1.

[0093] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 4:0.3, the softening agent is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol-4000, the antioxidant is antioxidant 1020, the processing aid is WB-2, the co-crosslinking agent is triallyl isocyanurate, and the anti-aging agent is anti-aging agent MB.

[0094] A deformation-resistant and long-life food-grade butterfly valve material, comprising the following steps: S1: According to the weight ratio, add ethylene propylene diene monomer A, ethylene propylene diene monomer B, and liquid rubber to a kneader, the plasticizing temperature is 95 °C, and plasticize at 240 r / min for 45 min to obtain kneaded rubber.

[0095] S2: Add the kneaded rubber to a rubber mixing equipment, add filler, activator, plasticizer, antioxidant, softening agent, processing aid, bacteriostatic agent, co-crosslinking agent, anti-aging agent, and vulcanizing agent according to the weight ratio, mix evenly and then carry out mixing. Mix at 95 °C at 200 r / min for 50 min to obtain mixed rubber; let the mixed rubber stand for 6 h, then carry out vulcanization, the vulcanization temperature is 168 °C, and the vulcanization time is 350 s.

[0096] S3: Open mill the vulcanized mixed rubber, set the open mill temperature to 40 °C, the rotation speed to 20 r / min, and the roll speed ratio to 22:18. Put the kneaded rubber into the open mill to make 4 triangle packages, then thin pass 4 times, and finally adjust the thickness to 0.8 mm to produce a sheet, and let it stand for 20 h.

[0097] Comparative Example 6 A deformation-resistant and long-life food-grade butterfly valve material, comprising raw materials with the following weight components: 120 parts of composite rubber, 20 parts of filler, 4 parts of activator, 1 part of softening agent, 1.5 parts of vulcanizing agent, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of processing aid, 0.5 part of bacteriostatic agent, 0.5 part of co-crosslinking agent, 0.5 part of anti-aging agent.

[0098] The composite rubber is a mixture of ethylene-propylene-diene monomer rubber A, ethylene-propylene-diene monomer rubber B and liquid rubber with a mass ratio of 2:1:1.

[0099] Among them, the liquid rubber is prepared in the following way: A1. Dissolve butadiene in toluene, add azobisisobutyronitrile, and react at a high speed of 800 rpm at a temperature of 50 °C for 1 h to obtain liquid rubber 1, where the mass ratio of butadiene, toluene, and azobisisobutyronitrile is 1:3:0.05; A2. Mix cashew shell oil diol, methyl isocyanate and isophorone diisocyanate, heat up to 100 °C, and react for 3 h to obtain liquid rubber 2, where the mass ratio of cashew shell oil diol, methyl isocyanate and isophorone diisocyanate is 1.5:0.8:0.8; A3. Mix liquid rubber 1, liquid rubber 2 and ethanol, react at a high speed of 800 rpm at a temperature of 60 °C for 1 h, and ultrasonically react at a frequency of 20 kHz for 1 h to obtain liquid rubber, where the mass ratio of liquid rubber 1, liquid rubber 2 and ethanol is 1:1.5:5.

[0100] The bacteriostatic agent is prepared in the following way: B1. Place silica powder in water, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, then add silane coupling agent KH-570, and continue to ultrasonically disperse it at a frequency of 40 kHz for 1 h to obtain a silica powder dispersion liquid, where the mass ratio of silica powder, water, and silane coupling agent KH-570 is 3:8:0.1; B2. Heat the silica powder dispersion liquid obtained in step B2 to 40 °C, dropwise add 0.05 mol / L silver nitrate solution to react, then add tea tree oil, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, filter and dry to obtain the required antibacterial agent, where the mass ratio of silica powder dispersion liquid, 0.05 mol / L nitrate solution, and tea tree oil is 8:2:1.

[0101] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 4:0.3, the softener is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol-4000, the antioxidant is antioxidant 1020, the processing aid is WB-2, the co-crosslinking agent is triallyl isocyanurate, and the anti-aging agent is anti-aging agent MB.

[0102] A kind of anti-deformation long-life food-grade butterfly valve material, including the following steps: S1: According to the weight ratio, mix ethylene-propylene-diene monomer rubber A, ethylene-propylene-diene monomer rubber B and liquid rubber and add them to an internal mixer. The plasticizing temperature is 95 °C, and plasticize at 240 r / min for 45 min to obtain internal mixer rubber.

[0103] S2: Add the kneaded rubber into a rubber kneading device, and add filler, activator, plasticizer, antioxidant, softening agent, processing aid, bacteriostatic agent, co-crosslinking agent, antioxidant and vulcanizing agent according to the weight ratio, mix them evenly and then carry out kneading. After kneading at 95 °C at 200 r / min for 50 min, the kneaded rubber is obtained; after the kneaded rubber is left standing for 6 h, vulcanization is carried out, the vulcanization temperature is 168 °C, and the vulcanization time is 350 s.

[0104] S3: Open the vulcanized kneaded rubber on an open mill. The temperature of the open mill is set at 40 °C, the rotation speed is 20 r / min, and the roll speed ratio is 22:18. Put the kneaded rubber into the open mill to make 4 triangular bales, then thin pass 4 times, and finally adjust the thickness to 0.8 mm to produce a sheet, and leave it standing for 20 h.

[0105] Comparative Example 7 A kind of anti-deformation long-life food-grade butterfly valve material, comprising raw materials with the following weight components: 120 parts of composite rubber, 20 parts of filler, 4 parts of activator, 1 part of softening agent, 1.5 parts of vulcanizing agent, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of processing aid, 0.5 part of bacteriostatic agent, 0.5 part of co-crosslinking agent, 0.5 part of antioxidant.

[0106] The composite rubber is a mixture of ethylene-propylene-diene monomer rubber A, ethylene-propylene-diene monomer rubber B and liquid rubber with a mass ratio of 2:1:1.

[0107] Among them, the liquid rubber is prepared by the following method: A1. Dissolve butadiene in toluene, add azobisisobutyronitrile, and carry out a high-speed reaction at 50 °C at 800 rpm for 1 h to obtain liquid rubber 1, where the mass ratio of butadiene, toluene and azobisisobutyronitrile is 1:3:0.05; A2. Mix cashew shell oil diol, methyl isocyanate and isophorone diisocyanate, heat up to 100 °C and react for 3 h to obtain liquid rubber 2, where the mass ratio of cashew shell oil diol, methyl isocyanate and isophorone diisocyanate is 1.5:0.8:0.8; A3. Mix liquid rubber 1, liquid rubber 2 and ethanol, carry out a high-speed reaction at 60 °C at 800 rpm for 1 h, and ultrasonicate at a frequency of 20 kHz for 1 h to obtain liquid rubber, where the mass ratio of liquid rubber 1, liquid rubber 2 and ethanol is 1:1.5:5.

[0108] The bacteriostatic agent is prepared by the following method: B1. Sodium silicate, methyl orthosilicate, and polydimethylsiloxane were placed in an ethanol aqueous solution with a mass fraction of 95%. Tetraisopropyl titanate was added, and the mixture was reacted at a high speed of 800 rpm at 60 °C for 1 h. The reaction product was aged for 2 h and dried at 80 °C for 2 h to obtain silica powder. The mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, the ethanol aqueous solution with a mass fraction of 95%, and tetraisopropyl titanate was 5:4:1:8:0.4; B2. The silica powder prepared in step B1 was placed in water and ultrasonically dispersed at a frequency of 20 kHz for 0.5 h. Then, silane coupling agent KH-570 was added, and the mixture was continuously ultrasonically dispersed at a frequency of 40 kHz for 1 h to obtain a silica powder dispersion. The mass ratio of silica powder, water, and silane coupling agent KH-570 was 3:8:0.1; B3. The silica powder dispersion obtained in step B2 was heated to 40 °C, tea tree oil was added, and the mixture was ultrasonically dispersed at a frequency of 20 kHz for 0.5 h. After filtration and drying, the required antibacterial agent was obtained. The mass ratio of the silica powder dispersion to tea tree oil was 9:2.

[0109] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 4:0.3, the softening agent is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol-4000, the antioxidant is antioxidant 1020, the processing aid is WB-2, the co-crosslinking agent is triallyl isocyanurate, and the anti-aging agent is anti-aging agent MB.

[0110] A deformation-proof and long-life food-grade butterfly valve material, comprising the following steps: S1: According to the weight ratio, ethylene propylene diene monomer A, ethylene propylene diene monomer B, and liquid rubber were mixed and added to a mixer. The plasticizing temperature was 95 °C, and the mixture was plasticized at 240 r / min for 45 min to obtain plasticized rubber.

[0111] S2: The plasticized rubber was added to a rubber mixing equipment. According to the weight ratio, filler, activator, plasticizer, antioxidant, softening agent, processing aid, antibacterial agent, co-crosslinking agent, anti-aging agent, and vulcanizing agent were added and mixed evenly, and then kneaded. The kneading was carried out at 95 °C at 200 r / min for 50 min to obtain kneaded rubber; after the kneaded rubber was left standing for 6 h, vulcanization was carried out. The vulcanization temperature was 168 °C, and the vulcanization time was 350 s.

[0112] S3: The vulcanized kneaded rubber was open-milled. The temperature of the open mill was set at 40 °C, the rotation speed was 20 r / min, and the roll speed ratio was 22:18. The plasticized rubber was put into the open mill to make 4 triangle packages, then thin-sliced 4 times, and finally the thickness was adjusted to 0.8 mm to produce a sheet, which was left standing for 20 h.

[0113] Comparative Example 8 A deformation-proof and long-life food-grade butterfly valve material, comprising raw materials with the following weight components: 120 parts of compound rubber, 20 parts of filler, 4 parts of activator, 1 part of softener, 1.5 parts of vulcanizing agent, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of processing aid, 0.5 part of bacteriostatic agent, 0.5 part of co-crosslinking agent, 0.5 part of anti-aging agent.

[0114] The compound rubber is a mixture of ethylene-propylene-diene monomer rubber A, ethylene-propylene-diene monomer rubber B and liquid rubber with a mass ratio of 2:1:1.

[0115] Among them, the liquid rubber is prepared in the following way: A1. Dissolve butadiene in toluene, add azobisisobutyronitrile, and react at a high speed of 800 rpm at a temperature of 50 °C for 1 h to obtain liquid rubber 1, where the mass ratio of butadiene, toluene, and azobisisobutyronitrile is 1:3:0.05; A2. Mix cardanol shell oil diol, methyl isocyanate and isophorone diisocyanate and heat up to 100 °C, react for 3 h to obtain liquid rubber 2, where the mass ratio of cardanol shell oil diol, methyl isocyanate and isophorone diisocyanate is 1.5:0.8:0.8; A3. Mix liquid rubber 1, liquid rubber 2 and ethanol, react at a high speed of 800 rpm at a temperature of 60 °C for 1 h, and ultrasonicate at a frequency of 20 kHz for 1 h to obtain liquid rubber, where the mass ratio of liquid rubber 1, liquid rubber 2 and ethanol is 1:1.5:5.

[0116] The bacteriostatic agent is prepared in the following way: B1. Place sodium silicate, methyl orthosilicate and polydimethylsiloxane in an aqueous ethanol solution with a mass fraction of 95%, add tetra-isopropyl titanate, react at a high speed of 800 rpm at a temperature of 60 °C for 1 h, age the reaction product for 2 h, and dry at 80 °C for 2 h to obtain silica powder, where the mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, aqueous ethanol solution with a mass fraction of 95% and tetra-isopropyl titanate is 5:4:1:8:0.4; B2. Place the silica powder prepared in step B1 in water, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, then add silane coupling agent KH-570, and continue to ultrasonically disperse it at a frequency of 40 kHz for 1 h to obtain a silica powder dispersion, where the mass ratio of silica powder, water and silane coupling agent KH-570 is 3:8:0.1; B3. Heat the silica powder dispersion obtained in step B2 to 40 °C, dropwise add 0.05 mol / L silver nitrate solution to react, ultrasonically disperse it at a frequency of 20 kHz for 0.5 h, filter and dry to obtain the required antibacterial agent, where the mass ratio of the silica powder dispersion and 0.05 mol / L nitrate solution is 8.5:2.5.

[0117] The filler is carbon black SP5000, the activator is zinc oxide and stearic acid with a mass ratio of 4:0.3, the softener is paraffin oil 6030, the vulcanizing agent is BIBP, the plasticizer is polyethylene glycol - 4000, the antioxidant is antioxidant 1020, the processing aid is WB - 2, the co - crosslinking agent is triallyl isocyanurate, and the anti - aging agent is anti - aging agent MB.

[0118] A deformation - resistant and long - life food - grade butterfly valve material, comprising the following steps: S1: According to the weight ratio, ethylene propylene diene monomer A, ethylene propylene diene monomer B and liquid rubber are mixed and added to an internal mixer. The plasticizing temperature is 95 °C, and plasticizing is carried out at 240 r / min for 45 min to obtain a kneaded rubber.

[0119] S2: The kneaded rubber is added to a rubber - refining equipment, and the filler, activator, plasticizer, antioxidant, softener, processing aid, bacteriostatic agent, co - crosslinking agent, anti - aging agent, and vulcanizing agent are added according to the weight ratio. After mixing evenly, mixing is carried out. Mixing is carried out at 95 °C at 200 r / min for 50 min to obtain a mixed rubber; after the mixed rubber is left standing for 6 h, vulcanization is carried out. The vulcanization temperature is 168 °C, and the vulcanization time is 350 s.

[0120] S3: The vulcanized mixed rubber is open - milled. The temperature of the open - mill is set at 40 °C, the rotational speed is 20 r / min, and the roll speed ratio is 22:18. The kneaded rubber is put into the open - mill to make 4 triangle packages, then thin - passed 4 times, and finally the thickness is adjusted to 0.8 mm for sheet - making, and left standing for 20 h.

[0121] Performance testing The comprehensive performances of the deformation - resistant and long - life food - grade butterfly valve materials prepared in Examples 1 - 3 and Comparative Examples 1 - 8 of this application are respectively tested.

[0122] 1. Mechanical property testing: The hardness is tested according to the standard of GB / T531.1 - 2008; the tensile property is tested according to the standard of GB / T528 - 2009; the compression set is tested according to the standard of GB / T7759.1 - 2015.

[0123] High - temperature treatment: Treatment is carried out at 80 °C for 72 h.

[0124] Acid treatment: Treatment is carried out under 10% HCL for 24 h.

[0125] The results of the mechanical property testing are shown in Table 1: Table 1

[0126] It can be seen from the data shown in Table 1 above that the mechanical properties of the anti-deformation and long-life food-grade butterfly valve materials prepared in Examples 1-3 are better than the mechanical properties of the anti-deformation and long-life food-grade butterfly valve materials obtained in Comparative Examples 1-7.

[0127] Compared with Comparative Examples 1-2, Example 1 uses two EPDM rubbers with different ENB contents and Mooney viscosities in the presence of liquid rubber, which improves the mechanical properties of the butterfly valve material and has good high temperature and corrosion resistance. Comparative Example 1 uses only EPDM rubber A, and Comparative Example 2 uses only EPDM rubber B. The mechanical properties of the butterfly valve materials of Comparative Examples 1-2 are significantly reduced, and the high temperature and corrosion resistance are poor. EPDM rubber A has excellent weather resistance and UV resistance, and EPDM rubber B has excellent processing performance and high mechanical strength. In the presence of liquid rubber, the two are mixed and used, and through complementary performance, it can ensure that the composite rubber has excellent chemical resistance, temperature resistance, wear resistance and fatigue resistance, while obtaining excellent elasticity and resilience.

[0128] Compared with comparative examples 3-5, in Example 1, liquid rubber 1 and liquid rubber 2 are prepared in the presence of two EPDM rubbers, and the two liquid rubbers are mixed and cross-linked, which ultimately improves the mechanical properties and high temperature and corrosion resistance of the butterfly valve material. However, in comparative example 3, no liquid rubber is added, liquid rubber 1 is not prepared in comparative example 4, and liquid rubber 2 is not prepared in comparative example 5. The mechanical properties of the butterfly valve materials of comparative examples 3-5 are significantly reduced, and the high temperature and corrosion resistance are deteriorated. Liquid rubber 1 has good flexibility and elasticity, and liquid rubber 2 has better weather resistance, wear resistance or chemical corrosion resistance. Liquid rubber 1 and liquid rubber 2 are stirred and mixed with ethanol and assisted by ultrasonic treatment, so that the two liquid rubbers are mixed more evenly, the interaction and cross-linking between the molecules of the two are promoted, and the performance of the liquid rubber finally obtained is more excellent.

[0129] 2. Antibacterial property: According to ASTM E2149-2010 (Standard Test Method for Determination of Antimicrobial Activity of Fixed Antimicrobial Agents under Dynamic Contact Conditions), the antimicrobial performance test was carried out under the conditions of oscillating contact time of 24h. The test data are shown in Table 2: Table 2

[0130] It can be seen from the data shown in Table 2 above that the antibacterial performance of the anti-deformation and long-life food-grade butterfly valve materials prepared in Examples 1-3 is better than the antibacterial performance of the anti-deformation and long-life food-grade butterfly valve materials obtained in Comparative Examples 6-8.

[0131] Comparing Comparative Example 6 with Example 1, in Example 1, a self-prepared silica powder dispersion was used as the carrier solvent, while in Comparative Example 8, commercially available silica powder was used to prepare a silica powder dispersion as the solvent for the antibacterial agent. When the silver nitrate solution was added dropwise to the silica powder dispersion, silver-containing nanoparticles were formed and adhered to the surface of the silica powder, which helped to disperse the silver nitrate solution, thereby improving the antibacterial performance of the anti-deformation long-life food-grade butterfly valve material.

[0132] Comparing Comparative Example 7 with Example 1, in Example 1, the silver nitrate solution was added dropwise during the preparation of the bacteriostatic agent, so that silver-containing nanoparticles were formed in the silica powder. Silver is a broad-spectrum antibacterial agent with significant antibacterial properties. The addition of silver nitrate during the preparation of the bacteriostatic agent significantly improved the antibacterial performance. In Comparative Example 7, only a single tea tree oil was added as the antibacterial component, which significantly reduced the antibacterial performance.

[0133] Comparing Comparative Example 8 with Example 1, in Example 1, tea tree oil was added during the preparation of the bacteriostatic agent. Tea tree oil itself has natural antibacterial, anti-inflammatory and antioxidant properties, and its synergistic effect with silver can make the antibacterial performance of the antibacterial agent more significant. In Comparative Example 8, only a single silver nitrate was added as the antibacterial component, which significantly reduced the antibacterial performance.

[0134] This specific embodiment is only an explanation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A food-grade butterfly valve material with anti-deformation and long service life, characterized in that, Raw materials including the following weight components: 120 - 160 parts of composite rubber, 20 - 40 parts of filler, 4 - 7 parts of activator, 1 - 5 parts of softener, 1.5 - 3 parts of vulcanizing agent, 0.5 - 1.5 parts of plasticizer, 0.5 - 1.5 parts of antioxidant, 0.5 - 1.5 parts of processing aid, 0.5 - 1.5 parts of bacteriostatic agent, 0.5 - 1.5 parts of co - crosslinking agent, 0.5 - 1.5 parts of anti - aging agent.

2. The anti-deformation long-life food-grade butterfly valve material according to claim 1, wherein The composite rubber is a mixture of ethylene - propylene - diene monomer rubber A (EPDM A), ethylene - propylene - diene monomer rubber B (EPDM B) and liquid rubber with a mass ratio of 2 - 6:1 - 3:

1.

3. The anti-deformation long-life food-grade butterfly valve material according to claim 2, characterized in that, The Mooney viscosity of the EPDM A is 30 - 50 MU, and the ENB content is 8 - 10 wt%; the Mooney viscosity of the EPDM B is 60 - 70 MU, and the ENB content is 4 - 6 wt%.

4. The anti-deformation long-life food-grade butterfly valve material according to claim 2, characterized in that, The liquid rubber is prepared by the following method: A1. Dissolve butadiene in toluene, add azobisisobutyronitrile, and stir - react at a temperature of 50 - 70 °C for 1 - 2 h to obtain liquid rubber 1; A2. Mix cashew shell oil diol, alkyl monoisocyanate and polyisocyanate, heat up to 100 - 120 °C, and react for 3 - 5 h to obtain liquid rubber 2; A3. Mix liquid rubber 1, liquid rubber 2 and ethanol, stir - react at a temperature of 60 - 70 °C for 1 - 2 h, and ultrasonically react at a frequency of 20 - 30 kHz for 1 - 2 h to obtain the liquid rubber.

5. The anti-deformation long-life food-grade butterfly valve material according to claim 4, wherein In step A1, the mass ratio of butadiene, toluene, and azobisisobutyronitrile is 1 - 1.5:3 - 5:0.05 - 0.1; in step A2, the mass ratio of cashew shell oil diol, alkyl monoisocyanate and polyisocyanate is 1.5 - 2:0.8 - 1.2:0.8 - 1.2; in step A3, the mass ratio of liquid rubber 1, liquid rubber 2 and ethanol is 1 - 2:1.5 - 4:5 - 8.

6. The anti-deformation long-life food-grade butterfly valve material according to claim 4, characterized in that, The hydroxyl value of the cashew shell oil diol is 65 - 80 mgKOH / g, and the viscosity (at 25 °C) is 950 - 1850 cps.

7. The anti-deformation and long-life food-grade butterfly valve material according to claim 4, characterized in that, The alkyl monoisocyanate is one of methyl isocyanate, n - butyl isocyanate or tert - butyl isocyanate; the polyisocyanate is one of isophorone diisocyanate or hexamethylene diisocyanate.

8. The anti-deformation long-life food-grade butterfly valve material according to claim 1, characterized in that, The bacteriostatic agent is prepared by the following method: B1. Place sodium silicate, methyl orthosilicate and polydimethylsiloxane in a 95% ethanol aqueous solution, add tetra - isopropyl titanate, stir - react at a temperature of 60 - 70 °C for 1 - 2 h, age, dry and grind the reaction product to obtain silica powder; B2. Place the silica powder prepared in step B1 in water, ultrasonically disperse it at a frequency of 20 - 30 kHz for 0.5 - 1 h, then add a silane coupling agent, and continue to ultrasonically disperse it at a frequency of 40 - 50 kHz for 1 - 2 h to obtain a silica powder dispersion; B3. Heat the silica powder dispersion obtained in step B2 to 40 - 50 °C, drop - add silver nitrate solution to react, then add tea tree oil, ultrasonically disperse it at a frequency of 20 - 30 kHz for 0.5 - 1 h, filter and dry to obtain the required bacteriostatic agent.

9. The anti-deformation and long-life food-grade butterfly valve material according to claim 8, characterized in that In the step B1, the mass ratio of sodium silicate, methyl orthosilicate, polydimethylsiloxane, 95% ethanol aqueous solution and tetra-isopropyl titanate is 5-8:4-6:1-2:8-10:0.4-0.8; in the step B2, the mass ratio of silica powder, water and silane coupling agent is 3-5:8-10:0.1-0.3; in the step B3, the mass ratio of silica powder dispersion, silver nitrate solution and tea tree oil is 8-10:2-3:1-1.

8.

10. A method for preparing the anti-deformation long-life food-grade butterfly valve material according to any one of claims 1-9, characterized in that, It includes the following steps: S1. Pre-mill the composite rubber to obtain milled rubber. S2. Add filler, activator, plasticizer, antioxidant, softener, processing aid, bacteriostat, co-crosslinking agent, anti-aging agent and vulcanizing agent to the milled rubber, mix evenly, and then carry out mixing and vulcanization. S3. Open mill the vulcanized mixed rubber to obtain the required anti-deformation long-life food-grade butterfly valve material.

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