EPDM rubber resistant to lean and rich liquid media and preparation method thereof

Abstract

The invention discloses a terpolymer EPDM rubber resistant to poor and rich liquid medium and a preparation method thereof, which belongs to the field of rubber materials, wherein the terpolymer EPDM rubber includes the following raw materials in parts by weight: 20-30 parts of ordinary EPDM rubber, 65-85 parts of high monomer EPDM rubber, 2-6 parts of processing aid, 1-5 parts of antioxidant, 1-5 parts of zinc oxide, 70-90 parts of high-structure carbon black, 5-15 parts of fine particle carbon black, 3-7 parts of high-temperature paraffin oil, 10-20 parts of diatomaceous earth, and 2-6 parts of vulcanizing agent. The present invention is based on EPDM rubber as main base material, on the one hand with excellent air tightness and waterproofness, on the other hand by introducing high monomer EPDM rubber, the comprehensive corrosion resistance of EPDM rubber is improved. The EPDM rubber material made by the present invention has excellent wear resistance, high and low temperature resistance, acid and alkali corrosion resistance, and the mechanical properties of the EPDM rubber are good, aging resistance is good, product service life is long, and meets use requirements.

Description

Technical Field

[0001] The present invention relates to the field of rubber materials, in particular to an EPDM rubber resistant to lean and rich liquid media and a preparation method thereof. Background Art

[0002] In the petrochemical industry, lean and rich liquids are common media in gas desulfurization units. Lean liquid generally refers to the diethanolamine solution that has been regenerated and free of hydrogen sulfide, mercaptans, and sulfides; rich liquid generally refers to the diethanolamine solution that has absorbed hydrogen sulfide, mercaptans, and sulfides after passing through the gas desulfurization unit.

[0003] At present, rubber materials such as EPDM rubber used in gas desulfurization equipment have poor resistance to lean and rich liquid media, are easily corroded, and have problems such as a short service life, so they are in urgent need of improvement. Summary of the Invention

[0004] The object of the present invention is to provide an EPDM rubber that is resistant to lean and rich liquid media, so as to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned objectives, an embodiment of the present invention provides the following technical solution: an EPDM rubber resistant to lean and rich liquid media, comprising the following raw materials in parts by weight: 20-30 parts of ordinary EPDM rubber, 65-85 parts of high-monomer EPDM rubber, 2-6 parts of processing aid, 1-5 parts of antioxidant, 1-5 parts of zinc oxide, 70-90 parts of high-structure carbon black, 5-15 parts of fine-particle carbon black, 3-7 parts of high-temperature paraffin oil, 10-20 parts of diatomaceous earth, and 2-6 parts of vulcanizing agent.

[0006] Preferably, the EPDM rubber includes the following raw materials in parts by weight: 24-26 parts of ordinary EPDM rubber, 70-80 parts of high monomer EPDM rubber, 3-5 parts of processing aid, 2-4 parts of antioxidant, 2-4 parts of zinc oxide, 75-85 parts of high structure carbon black, 8-12 parts of fine particle carbon black, 4-6 parts of high temperature paraffin oil, 14-16 parts of diatomaceous earth, and 3-5 parts of vulcanizing agent.

[0007] Preferably, the EPDM rubber includes the following raw materials in parts by weight: 25 parts of ordinary EPDM rubber, 75 parts of high monomer EPDM rubber, 4 parts of processing aid, 3 parts of antioxidant, 3 parts of zinc oxide, 80 parts of high structure carbon black, 10 parts of fine particle carbon black, 5 parts of high temperature paraffin oil, 15 parts of diatomaceous earth, and 4 parts of vulcanizing agent.

[0008] Preferably, the high monomer EPDM rubber is EPDM rubber of model 6950.

[0009] Preferably, the vulcanizing agent includes a peroxide, a bridging aid and a scorch retarder.

[0010] Another object of the present invention is to provide a method for preparing the above-mentioned EPDM rubber resistant to lean and rich liquid media, which comprises the following steps:

[0011] The raw materials in each weight portion are subjected to pressure mixing and then extrusion molding to obtain a mixed material;

[0012] The mixed material is subjected to molding and vulcanization treatment to obtain a rubber compound.

[0013] The rubber compound is subjected to secondary vulcanization to obtain EPDM rubber that is resistant to lean and rich liquid media.

[0014] Preferably, the temperature of the pressurized mixing treatment is 120-130°C; and the extrusion temperature of the extrusion molding is 105-115°C.

[0015] Preferably, the temperature of the compression vulcanization treatment is 165-175° C., and the compression pressure is 13.5-15.5 MPa.

[0016] Preferably, the temperature of the secondary vulcanization is 145-155°C.

[0017] Another object of the embodiment of the present invention is to provide an EPDM rubber prepared by the above preparation method.

[0018] The present invention provides an EPDM rubber that is resistant to lean and rich liquid media. It uses EPDM rubber as the main base material. On the one hand, it has excellent air tightness and water resistance. On the other hand, by introducing high-monomer EPDM rubber, the comprehensive corrosion resistance of the EPDM rubber is improved. In addition, the present invention can increase the degree of vulcanization and reduce the permanent deformation rate of the EPDM rubber after being subjected to stress by adding a vulcanizing agent containing peroxide to the rubber raw material; by using high-structure carbon black and fine-particle carbon black as raw materials, the physical properties and corrosion resistance of the EPDM rubber can be improved; by using diatomaceous earth as a filler, its internal flaky structure can hinder the penetration of the medium into the rubber. In summary, the EPDM rubber material made by the present invention has excellent wear resistance, high and low temperature resistance, and acid and alkali corrosion resistance. At the same time, the EPDM rubber has good mechanical properties, good aging resistance, a long product life, and meets the use requirements. DETAILED DESCRIPTION

[0019] 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 embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0020] In one embodiment of the present invention, an EPDM rubber resistant to lean and rich liquid media is provided, comprising the following raw materials in parts by weight: 20-30 parts of ordinary EPDM rubber, 65-85 parts of high-monomer EPDM rubber, 2-6 parts of processing aid, 1-5 parts of antioxidant, 1-5 parts of zinc oxide, 70-90 parts of high-structure carbon black, 5-15 parts of fine-particle carbon black, 3-7 parts of high-temperature paraffin oil, 10-20 parts of diatomaceous earth, and 2-6 parts of vulcanizing agent.

[0021] In a preferred embodiment of the present invention, the EPDM rubber includes the following raw materials in parts by weight: 24-26 parts of ordinary EPDM rubber, 70-80 parts of high monomer EPDM rubber, 3-5 parts of processing aid, 2-4 parts of antioxidant, 2-4 parts of zinc oxide, 75-85 parts of high structure carbon black, 8-12 parts of fine particle carbon black, 4-6 parts of high temperature paraffin oil, 14-16 parts of diatomaceous earth, and 3-5 parts of vulcanizing agent.

[0022] In a preferred embodiment of the present invention, the EPDM rubber includes the following raw materials in parts by weight: 25 parts of ordinary EPDM rubber, 75 parts of high monomer EPDM rubber, 4 parts of processing aid, 3 parts of antioxidant, 3 parts of zinc oxide, 80 parts of high structure carbon black, 10 parts of fine particle carbon black, 5 parts of high temperature paraffin oil, 15 parts of diatomaceous earth, and 4 parts of vulcanizing agent.

[0023] It should be noted that the above raw materials are all commercially available commodities. Specifically, ordinary EPDM rubber can be Mitsui 4045; high monomer EPDM rubber can be Arlanxeo 6950; processing aid can be Honeywell AC617; high structure carbon black can be carbon black N550; fine particle carbon black can be Cabot; high temperature paraffin oil can be Sun 2280; and diatomaceous earth can be Hofmann N85.

[0024] In a preferred embodiment of the present invention, the vulcanizing agent includes a peroxide, a bridging aid and a scorch retarder.

[0025] The peroxide may be a commercially available product of Nouryon DCP; the bridging agent may be a commercially available HVA-2 agent from Zhedong; and the anti-scorch agent may be a commercially available anti-scorch agent E from Weilin Chemical.

[0026] In another embodiment of the present invention, a method for preparing the above-mentioned EPDM rubber resistant to lean and rich liquid media is provided, which comprises the following steps:

[0027] S1, pressurizing and mixing the above raw materials in parts by weight, and then extruding to obtain a mixture;

[0028] S2. The mixed material is subjected to a molding and vulcanization treatment to obtain a rubber compound.

[0029] S3. The rubber compound is subjected to secondary vulcanization to obtain EPDM rubber resistant to lean and rich liquid media.

[0030] In a preferred embodiment of the present invention, the temperature of the pressurized mixing treatment is 120-130°C and the time is 10-20 minutes; the extrusion temperature of the extrusion molding is 105-115°C.

[0031] In a preferred embodiment of the present invention, the temperature of the compression vulcanization treatment is 165-175° C., the compression pressure is 13.5-15.5 MPa, and the time is 15-20 min.

[0032] In a preferred embodiment of the present invention, the temperature of the secondary vulcanization is 145-155° C., and the time is 1.5-2.5 hours.

[0033] The following embodiments are some specific implementation cases of the present invention in practical applications, but are not limited thereto.

[0034] Example 1: This example provides a method for preparing the above-mentioned EPDM rubber resistant to lean and rich liquid media, which comprises the following steps:

[0035] S1. Add 25kg of ordinary EPDM rubber, 75kg of high monomer EPDM rubber, 4kg of processing aid, 3kg of antioxidant, 3kg of zinc oxide, 80kg of high structure carbon black, 10kg of fine particle carbon black, 5kg of high temperature paraffin oil, 15kg of diatomaceous earth and 4kg of vulcanizing agent into a mixing device for pressurized mixing for 15 minutes, and then perform extrusion molding to obtain a mixture; wherein the pressure mixing temperature is 125°C; the extrusion temperature of the extrusion molding is 110°C; the ordinary EPDM rubber adopts the commercially available Mitsui 4045 model EPDM rubber; the high monomer EPDM rubber adopts The commercially available ARLANXEO 6950 EPDM rubber was used; the commercially available Honeywell AC617 additive was used as the processing aid; the commercially available carbon black N550 was used as the high-structure carbon black; the commercially available Cabot fine-particle carbon black was used as the fine-particle carbon black; the commercially available Sun 2280 paraffin oil was used as the high-temperature paraffin oil; the commercially available Hofmann N85 diatomaceous earth was used as the diatomaceous earth; the vulcanizing agent consisted of peroxide, bridging agent and anti-scorch agent; the peroxide was the commercially available Nouryon DCP product; the bridging agent was the commercially available Zhedong HVA-2 additive; the anti-scorch agent was the commercially available Weilin Chemical Anti-scorch Agent E.

[0036] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 20 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 170° C. and the compression pressure is 15 MPa.

[0037] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber resistant to lean and rich liquid media; wherein the secondary vulcanization temperature is 150°C.

[0038] Example 2: This example provides a method for preparing the above-mentioned EPDM rubber resistant to lean and rich liquid media, which comprises the following steps:

[0039] S1. Add 20kg of ordinary EPDM rubber, 85kg of high monomer EPDM rubber, 2kg of processing aid, 1kg of antioxidant, 1kg of zinc oxide, 70kg of high structure carbon black, 5kg of fine particle carbon black, 3kg of high temperature paraffin oil, 10kg of diatomaceous earth and 2kg of vulcanizing agent into a mixing device for pressurized mixing for 10 minutes, and then perform extrusion molding to obtain a mixture; wherein the pressure mixing temperature is 120°C; the extrusion temperature of the extrusion molding is 105°C; the ordinary EPDM rubber adopts the commercially available Mitsui 4045 model EPDM rubber; the high monomer EPDM rubber adopts the commercially available The EPDM rubber of model 6950 was sold by Arlanxeo; the processing aid was the commercially available Honeywell AC617; the high-structure carbon black was the commercially available carbon black N550; the fine-particle carbon black was the commercially available fine-particle carbon black of Cabot; the high-temperature paraffin oil was the commercially available Sun 2280 paraffin oil; the diatomaceous earth was the commercially available Hofmann N85 diatomaceous earth; the vulcanizing agent consisted of peroxide, bridging agent and anti-scorch agent; the peroxide was the commercially available Nouryon DCP product; the bridging agent was the commercially available Zhedong HVA-2 agent; the anti-scorch agent was the commercially available Weilin Chemical Anti-scorch Agent E.

[0040] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 15 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 165° C. and the compression pressure is 13.5 MPa.

[0041] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 1.5 hours to obtain EPDM rubber resistant to lean and rich liquid media; wherein the secondary vulcanization temperature is 145°C.

[0042] Example 3: This example provides a method for preparing the above-mentioned EPDM rubber resistant to lean and rich liquid media, which comprises the following steps:

[0043] S1. Add 30kg of ordinary EPDM rubber, 65kg of high monomer EPDM rubber, 6kg of processing aid, 5kg of antioxidant, 5kg of zinc oxide, 90kg of high structure carbon black, 15kg of fine particle carbon black, 7kg of high temperature paraffin oil, 20kg of diatomaceous earth and 6kg of vulcanizing agent into a mixing device and perform pressurized mixing for 20 minutes, and then perform extrusion molding to obtain a mixture; wherein the temperature of the pressurized mixing treatment is 130°C; the extrusion temperature of the extrusion molding is 115°C; the ordinary EPDM rubber adopts the commercially available Mitsui 4045 model EPDM rubber; the high monomer EPDM rubber adopts The commercially available ARLANXEO 6950 EPDM rubber was used; the commercially available Honeywell AC617 additive was used as the processing aid; the commercially available carbon black N550 was used as the high-structure carbon black; the commercially available Cabot fine-particle carbon black was used as the fine-particle carbon black; the commercially available Sun 2280 paraffin oil was used as the high-temperature paraffin oil; the commercially available Hofmann N85 diatomaceous earth was used as the diatomaceous earth; the vulcanizing agent consisted of peroxide, bridging agent and anti-scorch agent; the peroxide was the commercially available Nouryon DCP product; the bridging agent was the commercially available Zhedong HVA-2 additive; the anti-scorch agent was the commercially available Weilin Chemical Anti-scorch Agent E.

[0044] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 20 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 175° C. and the compression pressure is 15.5 MPa.

[0045] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2.5 hours to obtain EPDM rubber resistant to lean and rich liquid media; wherein the secondary vulcanization temperature is 155°C.

[0046] Example 4: This example provides a method for preparing the above-mentioned EPDM rubber resistant to lean and rich liquid media, which comprises the following steps:

[0047] S1. Add 24kg of ordinary EPDM rubber, 80kg of high monomer EPDM rubber, 3kg of processing aid, 2kg of antioxidant, 2kg of zinc oxide, 75kg of high structure carbon black, 8kg of fine particle carbon black, 4kg of high temperature paraffin oil, 14kg of diatomaceous earth and 3kg of vulcanizing agent into a mixing device for pressurized mixing for 15 minutes, and then perform extrusion molding to obtain a mixture; wherein the pressure mixing treatment temperature is 122°C; the extrusion molding extrusion temperature is 108°C; the ordinary EPDM rubber adopts the commercially available Mitsui 4045 model EPDM rubber; the high monomer EPDM rubber adopts the commercially available The EPDM rubber of model 6950 was sold by Arlanxeo; the processing aid was the commercially available Honeywell AC617; the high-structure carbon black was the commercially available carbon black N550; the fine-particle carbon black was the commercially available fine-particle carbon black of Cabot; the high-temperature paraffin oil was the commercially available Sun 2280 paraffin oil; the diatomaceous earth was the commercially available Hofmann N85 diatomaceous earth; the vulcanizing agent consisted of peroxide, bridging agent and anti-scorch agent; the peroxide was the commercially available Nouryon DCP product; the bridging agent was the commercially available Zhedong HVA-2 agent; the anti-scorch agent was the commercially available Weilin Chemical Anti-scorch Agent E.

[0048] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 18 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 168° C. and the compression pressure is 14.5 MPa.

[0049] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber resistant to lean and rich liquid media; wherein the secondary vulcanization temperature is 148°C.

[0050] Example 5: This example provides a method for preparing the above-mentioned EPDM rubber resistant to lean and rich liquid media, which comprises the following steps:

[0051] S1. Add 26kg of ordinary EPDM rubber, 70kg of high monomer EPDM rubber, 5kg of processing aid, 4kg of antioxidant, 4kg of zinc oxide, 85kg of high structure carbon black, 12kg of fine particle carbon black, 6kg of high temperature paraffin oil, 16kg of diatomaceous earth and 5kg of vulcanizing agent into a mixing device and perform pressurized mixing for 15 minutes, and then perform extrusion molding to obtain a mixture; wherein the temperature of the pressurized mixing treatment is 128°C; the extrusion temperature of the extrusion molding is 112°C; the ordinary EPDM rubber adopts the commercially available Mitsui 4045 model EPDM rubber; the high monomer EPDM rubber adopts The commercially available ARLANXEO 6950 EPDM rubber was used; the commercially available Honeywell AC617 additive was used as the processing aid; the commercially available carbon black N550 was used as the high-structure carbon black; the commercially available Cabot fine-particle carbon black was used as the fine-particle carbon black; the commercially available Sun 2280 paraffin oil was used as the high-temperature paraffin oil; the commercially available Hofmann N85 diatomaceous earth was used as the diatomaceous earth; the vulcanizing agent consisted of peroxide, bridging agent and anti-scorch agent; the peroxide was the commercially available Nouryon DCP product; the bridging agent was the commercially available Zhedong HVA-2 additive; the anti-scorch agent was the commercially available Weilin Chemical Anti-scorch Agent E.

[0052] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 15 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 172° C. and the compression pressure is 14 MPa.

[0053] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber resistant to lean and rich liquid media; wherein the secondary vulcanization temperature is 152°C.

[0054] Example 6: This example provides a method for preparing the above-mentioned EPDM rubber resistant to lean and rich liquid media, which comprises the following steps:

[0055] S1. Add 23kg of ordinary EPDM rubber, 77kg of high monomer EPDM rubber, 4kg of processing aid, 3kg of antioxidant, 3kg of zinc oxide, 82kg of high structure carbon black, 8kg of fine particle carbon black, 5kg of high temperature paraffin oil, 15kg of diatomaceous earth and 4kg of vulcanizing agent into a mixing device for pressurized mixing for 15 minutes, and then perform extrusion molding to obtain a mixture; wherein the pressure mixing treatment temperature is 125°C; the extrusion molding temperature is 110°C; the ordinary EPDM rubber adopts the commercially available Mitsui 4045 model EPDM rubber; the high monomer EPDM rubber adopts the commercially available The EPDM rubber of model 6950 was sold by Arlanxeo; the processing aid was the commercially available Honeywell AC617; the high-structure carbon black was the commercially available carbon black N550; the fine-particle carbon black was the commercially available fine-particle carbon black of Cabot; the high-temperature paraffin oil was the commercially available Sun 2280 paraffin oil; the diatomaceous earth was the commercially available Hofmann N85 diatomaceous earth; the vulcanizing agent consisted of peroxide, bridging agent and anti-scorch agent; the peroxide was the commercially available Nouryon DCP product; the bridging agent was the commercially available Zhedong HVA-2 agent; the anti-scorch agent was the commercially available Weilin Chemical Anti-scorch Agent E.

[0056] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 20 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 170° C. and the compression pressure is 15 MPa.

[0057] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber resistant to lean and rich liquid media; wherein the secondary vulcanization temperature is 150°C.

[0058] Example 7: This example provides a method for preparing the above-mentioned EPDM rubber resistant to lean and rich liquid media, which comprises the following steps:

[0059] S1. Add 28kg of ordinary EPDM rubber, 72kg of high monomer EPDM rubber, 4kg of processing aid, 3kg of antioxidant, 3kg of zinc oxide, 78kg of high structure carbon black, 12kg of fine particle carbon black, 5kg of high temperature paraffin oil, 14kg of diatomaceous earth and 4kg of vulcanizing agent into a mixing device and perform pressurized mixing for 15 minutes, and then perform extrusion molding to obtain a mixture; wherein the pressure mixing temperature is 125°C; the extrusion temperature of the extrusion molding is 110°C; the ordinary EPDM rubber adopts the commercially available Mitsui 4045 model EPDM rubber; the high monomer EPDM rubber adopts The commercially available ARLANXEO 6950 EPDM rubber was used; the commercially available Honeywell AC617 additive was used as the processing aid; the commercially available carbon black N550 was used as the high-structure carbon black; the commercially available Cabot fine-particle carbon black was used as the fine-particle carbon black; the commercially available Sun 2280 paraffin oil was used as the high-temperature paraffin oil; the commercially available Hofmann N85 diatomaceous earth was used as the diatomaceous earth; the vulcanizing agent consisted of peroxide, bridging agent and anti-scorch agent; the peroxide was the commercially available Nouryon DCP product; the bridging agent was the commercially available Zhedong HVA-2 additive; the anti-scorch agent was the commercially available Weilin Chemical Anti-scorch Agent E.

[0060] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 20 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 170° C. and the compression pressure is 15 MPa.

[0061] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber resistant to lean and rich liquid media; wherein the secondary vulcanization temperature is 150°C.

[0062] Comparative Example 1: This comparative example provides a method for preparing EPDM rubber, which comprises the following steps:

[0063] S1. Add 25kg of ordinary EPDM rubber, 75kg of commercial 6250 type EPDM rubber, 4kg of processing aid, 3kg of antioxidant, 3kg of zinc oxide, 80kg of high-structure carbon black, 10kg of fine particle carbon black, 5kg of high-temperature paraffin oil, 15kg of diatomaceous earth, and 4kg of vulcanizing agent into a mixing device for pressurized mixing for 15 minutes, and then extrusion molding to obtain a mixture; wherein the pressure mixing treatment temperature is 125°C; the extrusion molding extrusion temperature is 110°C; the ordinary EPDM rubber adopts commercial Mitsui 4045 type The ethylene propylene rubber is of the type of EPDM; the processing aid is the commercially available Honeywell AC617; the high-structure carbon black is the commercially available carbon black N550; the fine-particle carbon black is the commercially available Cabot fine-particle carbon black; the high-temperature paraffin oil is the commercially available Sun 2280 paraffin oil; the diatomaceous earth is the commercially available Hofmann N85 diatomaceous earth; the vulcanizing agent is composed of peroxide, bridging agent and anti-scorching agent; the peroxide is the commercially available Nouryon DCP product; the bridging agent is the commercially available Zhedong HVA-2 agent; the anti-scorching agent is the commercially available Weilin Chemical Anti-scorching Agent E.

[0064] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 20 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 170° C. and the compression pressure is 15 MPa.

[0065] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber; wherein the secondary vulcanization temperature is 150°C.

[0066] Comparative Example 2: This comparative example provides a method for preparing EPDM rubber, which comprises the following steps:

[0067] S1. Add 25kg of ordinary EPDM rubber, 75kg of commercial 6470 type EPDM rubber, 4kg of processing aid, 3kg of antioxidant, 3kg of zinc oxide, 80kg of high-structure carbon black, 10kg of fine particle carbon black, 5kg of high-temperature paraffin oil, 15kg of diatomaceous earth, and 4kg of vulcanizing agent into a mixing device for pressurized mixing for 15 minutes, and then extrusion molding to obtain a mixture; wherein the pressure mixing treatment temperature is 125°C; the extrusion molding extrusion temperature is 110°C; the ordinary EPDM rubber adopts commercial Mitsui 4045 type The ethylene propylene rubber is of the type of EPDM; the processing aid is the commercially available Honeywell AC617; the high-structure carbon black is the commercially available carbon black N550; the fine-particle carbon black is the commercially available Cabot fine-particle carbon black; the high-temperature paraffin oil is the commercially available Sun 2280 paraffin oil; the diatomaceous earth is the commercially available Hofmann N85 diatomaceous earth; the vulcanizing agent is composed of peroxide, bridging agent and anti-scorching agent; the peroxide is the commercially available Nouryon DCP product; the bridging agent is the commercially available Zhedong HVA-2 agent; the anti-scorching agent is the commercially available Weilin Chemical Anti-scorching Agent E.

[0068] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 20 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 170° C. and the compression pressure is 15 MPa.

[0069] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber; wherein the secondary vulcanization temperature is 150°C.

[0070] Comparative Example 3: This comparative example provides a method for preparing EPDM rubber, which comprises the following steps:

[0071] S1. Add 25kg of ordinary EPDM rubber, 75kg of high monomer EPDM rubber, 4kg of processing aid, 3kg of antioxidant, 3kg of zinc oxide, 80kg of high structure carbon black, 10kg of fine particle carbon black, 5kg of high temperature paraffin oil, 15kg of calcium carbonate and 4kg of vulcanizing agent into a mixing device and perform pressurized mixing for 15 minutes, and then perform extrusion molding to obtain a mixture; wherein the pressure mixing temperature is 125°C; the extrusion temperature of the extrusion molding is 110°C; the ordinary EPDM rubber adopts the commercially available Mitsui 4045 type EPDM rubber. The high monomer EPDM rubber adopts the commercially available ARLANXEO 6950 EPDM rubber; the processing aid adopts the commercially available Honeywell AC617 additive; the high structure carbon black adopts the commercially available carbon black N550; the fine particle carbon black adopts the commercially available Cabot fine particle carbon black; the high temperature paraffin oil adopts the commercially available Sun 2280 paraffin oil; the vulcanizing agent consists of peroxide, bridging agent and anti-scorching agent; the peroxide adopts the commercially available Nouryon DCP product; the bridging agent adopts the commercially available Zhedong HVA-2 additive; the anti-scorching agent adopts the commercially available Weilin Chemical Anti-scorching Agent E.

[0072] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 20 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 170° C. and the compression pressure is 15 MPa.

[0073] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber; wherein the secondary vulcanization temperature is 150°C.

[0074] Comparative Example 4: This comparative example provides a method for preparing EPDM rubber, which comprises the following steps:

[0075] S1. Add 25kg of ordinary EPDM rubber, 75kg of high monomer EPDM rubber, 4kg of processing aid, 3kg of antioxidant, 3kg of zinc oxide, 80kg of high structure carbon black, 10kg of fine particle carbon black, 5kg of high temperature paraffin oil, 15kg of kaolin and 4kg of vulcanizing agent into a mixing device and perform pressurized mixing for 15 minutes, and then perform extrusion molding to obtain a mixture; wherein the pressure mixing temperature is 125°C; the extrusion temperature of the extrusion molding is 110°C; the ordinary EPDM rubber adopts the commercially available Mitsui 4045 model EPDM rubber. The high monomer EPDM rubber adopts the commercially available ARLANXEO 6950 EPDM rubber; the processing aid adopts the commercially available Honeywell AC617 additive; the high structure carbon black adopts the commercially available carbon black N550; the fine particle carbon black adopts the commercially available Cabot fine particle carbon black; the high temperature paraffin oil adopts the commercially available Sun 2280 paraffin oil; the vulcanizing agent consists of peroxide, bridging agent and anti-scorching agent; the peroxide adopts the commercially available Nouryon DCP product; the bridging agent adopts the commercially available Zhedong HVA-2 additive; the anti-scorching agent adopts the commercially available Weilin Chemical Anti-scorching Agent E.

[0076] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 20 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 170° C. and the compression pressure is 15 MPa.

[0077] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber; wherein the secondary vulcanization temperature is 150°C.

[0078] Comparative Example 5: This comparative example provides a method for preparing EPDM rubber, which comprises the following steps:

[0079] S1. Add 25kg of ordinary EPDM rubber, 75kg of high monomer EPDM rubber, 4kg of processing aid, 3kg of antioxidant, 3kg of zinc oxide, 80kg of high structure carbon black, 10kg of fine particle carbon black, 5kg of high temperature paraffin oil, 15kg of talc, and 4kg of vulcanizing agent into a mixing device and perform pressurized mixing for 15 minutes, and then perform extrusion molding to obtain a mixture; wherein the pressure mixing temperature is 125°C; the extrusion temperature of the extrusion molding is 110°C; the ordinary EPDM rubber adopts the commercially available Mitsui 4045 model EPDM rubber. The high monomer EPDM rubber adopts the commercially available ARLANXEO 6950 EPDM rubber; the processing aid adopts the commercially available Honeywell AC617 additive; the high structure carbon black adopts the commercially available carbon black N550; the fine particle carbon black adopts the commercially available Cabot fine particle carbon black; the high temperature paraffin oil adopts the commercially available Sun 2280 paraffin oil; the vulcanizing agent consists of peroxide, bridging agent and anti-scorching agent; the peroxide adopts the commercially available Nouryon DCP product; the bridging agent adopts the commercially available Zhedong HVA-2 additive; the anti-scorching agent adopts the commercially available Weilin Chemical Anti-scorching Agent E.

[0080] S2. Add the mixture obtained above to a vulcanization treatment equipment for compression vulcanization treatment for 20 minutes to obtain a rubber compound; wherein the compression vulcanization treatment temperature is 170° C. and the compression pressure is 15 MPa.

[0081] S3. The rubber compound obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber; wherein the secondary vulcanization temperature is 150°C.

[0082] Performance Test: 1. The EPDM rubbers prepared in Example 1 and Comparative Examples 1-2 were immersed in a 50% concentration lean and rich liquid medium at 110°C for 168 hours. After immersion, the EPDM rubbers were removed and air-dried. The volume change rates of the EPDM rubbers were measured. The results were as follows: the volume change rate of the EPDM rubber prepared in Comparative Example 1 was +8.3%, the volume change rate of the EPDM rubber prepared in Comparative Example 2 was +5.6%, and the volume change rate of the EPDM rubber prepared in Example 1 was +2.1%. These results indicate that the present invention, by employing a highly cross-linked, high-monomer EPDM rubber, can effectively reduce the swelling of the EPDM rubber in lean and rich liquid media.

[0083] Second, the EPDM rubbers prepared in Example 1 and Comparative Examples 3-5 were immersed in a 50% concentration lean-rich medium at 110°C for 168 hours. After immersion, the EPDM rubbers were removed and air-dried. The volume change rates of the EPDM rubbers were measured. The results were as follows: the volume change rate of the EPDM rubber prepared in Comparative Example 3 was +18.7%, the volume change rate of the EPDM rubber prepared in Comparative Example 4 was +3.3%, the volume change rate of the EPDM rubber prepared in Comparative Example 5 was +6.7%, and the volume change rate of the EPDM rubber prepared in Example 1 was +2.1%. These results indicate that the EPDM rubber prepared in the present invention using diatomaceous earth as a filler exhibits the lowest volume change rate, as the flaky structure within the diatomaceous earth hinders the penetration of the medium into the rubber. Furthermore, calcium carbonate, which reacts with acidic substances in the medium, is not suitable as a filler for rubber resistant to lean-rich medium.

[0084] Based on the above-mentioned ideal embodiment of the present invention, and through the above description, relevant personnel can make various changes and modifications without departing from the scope of the technical concept of the present invention. The technical scope of the present invention is not limited to the contents of the specification.

Claims

1. An EPDM rubber resistant to lean and rich liquid media, characterized in that: The invention comprises the following raw materials in parts by weight: 20-30 parts of ordinary EPDM rubber, 65-85 parts of high monomer EPDM rubber, 2-6 parts of processing aid, 1-5 parts of antioxidant, 1-5 parts of zinc oxide, 70-90 parts of high structure carbon black, 5-15 parts of fine particle carbon black, 3-7 parts of high temperature paraffin oil, 10-20 parts of diatomaceous earth and 2-6 parts of vulcanizing agent.

2. The EPDM rubber resistant to lean and rich liquid media according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 24-26 parts of ordinary EPDM rubber, 70-80 parts of high monomer EPDM rubber, 3-5 parts of processing aid, 2-4 parts of antioxidant, 2-4 parts of zinc oxide, 75-85 parts of high structure carbon black, 8-12 parts of fine particle carbon black, 4-6 parts of high temperature paraffin oil, 14-16 parts of diatomaceous earth and 3-5 parts of vulcanizing agent.

3. The EPDM rubber resistant to lean and rich liquid media according to claim 2, characterized in that: The invention comprises the following raw materials in parts by weight: 25 parts of ordinary EPDM rubber, 75 parts of high monomer EPDM rubber, 4 parts of processing aid, 3 parts of antioxidant, 3 parts of zinc oxide, 80 parts of high structure carbon black, 10 parts of fine particle carbon black, 5 parts of high temperature paraffin oil, 15 parts of diatomaceous earth and 4 parts of vulcanizing agent.

4. The EPDM rubber resistant to lean and rich liquid media according to any one of claims 1 to 3, characterized in that: The high monomer EPDM rubber is EPDM rubber of model 6950.

5. The EPDM rubber resistant to lean and rich liquid media according to any one of claims 1 to 3, characterized in that: The vulcanizing agent includes peroxide, bridging aid and scorch retarder.

6. A method for preparing EPDM rubber resistant to lean and rich liquid media according to any one of claims 1 to 5, characterized in that: The following steps are involved: The raw materials in each weight portion are subjected to pressure mixing and then extrusion molding to obtain a mixed material; The mixture is subjected to molding and vulcanization treatment to obtain a rubber compound. The rubber compound is subjected to secondary vulcanization to obtain EPDM rubber that is resistant to lean and rich liquid media.

7. The method for preparing EPDM rubber resistant to lean and rich liquid media according to claim 6, characterized in that: The temperature of the pressure mixing treatment is 120-130°C; the extrusion temperature of the extrusion molding is 105-115°C.

8. The method for preparing EPDM rubber resistant to lean and rich liquid media according to claim 6, characterized in that: The temperature of the molding vulcanization treatment is 165-175°C, and the molding pressure is 13.5-15.5MPa.

9. The method for preparing EPDM rubber resistant to lean and rich liquid media according to claim 6, characterized in that: The temperature of secondary vulcanization is 145-155℃.

10. An EPDM rubber prepared by the preparation method according to any one of claims 6 to 9.