EPDM (ethylene propylene diene monomer) rubber resistant to lean-rich liquid medium and preparation method of EPDM rubber

Abstract

The invention discloses a lean-rich liquid medium resistant ethylene propylene diene monomer and a preparation method thereof, and belongs to the field of rubber materials. The ethylene-propylene-diene monomer rubber comprises the following raw materials in parts by weight: 20-30 parts of common ethylene-propylene raw rubber, 65-85 parts of high-monomer ethylene-propylene raw rubber, 2-6 parts of a processing aid, 1-5 parts of an anti-aging agent, 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 diatomite and 2-6 parts of a vulcanizing agent. According to the invention, the ethylene-propylene raw rubber is taken as a main base material, so that on one hand, the ethylene-propylene rubber has excellent air tightness and waterproofness, and on the other hand, the comprehensive corrosion resistance of the ethylene-propylene-diene monomer rubber is improved by introducing the high-monomer ethylene-propylene raw rubber. The prepared EPDM rubber material has excellent wear resistance, high and low temperature resistance and acid and alkali corrosion resistance, meanwhile, the EPDM rubber is good in mechanical property and aging resistance and long in service life, and the use requirements are met.

Description

Technical Field

[0001] The 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 usually refers to the diethanolamine solution that has been regenerated and has had hydrogen sulfide, mercaptans and sulfides removed; rich liquid usually refers to the diethanolamine solution that has absorbed hydrogen sulfide, mercaptans and sulfides after passing through a 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 resistant to lean and rich liquid media to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, 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 model 6950.

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

[0010] Another object of the embodiment 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: The raw materials in each weight portion are subjected to pressure mixing and kneading treatment, and then extruded to obtain a mixed material; The mixed material is subjected to compression molding and vulcanization treatment to obtain a rubber compound.

[0011] The rubber compound is subjected to secondary vulcanization to obtain EPDM rubber resistant to lean and rich liquid media.

[0012] Preferably, the temperature of the pressure mixing treatment is 120-130°C; and the extrusion temperature of the extrusion molding is 105-115°C.

[0013] Preferably, the temperature of the compression vulcanization treatment is 165-175° C., and the compression pressure is 13.5-15.5 MPa.

[0014] Preferably, the temperature of the secondary vulcanization is 145-155°C.

[0015] Another object of the embodiment of the present invention is to provide an EPDM rubber prepared by the above preparation method.

[0016] The present invention provides an EPDM rubber resistant to lean and rich liquid media, which 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 stressed 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, acid and alkali corrosion resistance. At the same time, the EPDM rubber has good mechanical properties, good aging resistance, long product service life, and meets the use requirements. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] It should be noted that the above raw materials are all commercially available commodities. Specifically, ordinary EPDM rubber can be commercially available Mitsui 4045 EPDM rubber; high monomer EPDM rubber can be commercially available Arlanxeo 6950 EPDM rubber; processing aids can be commercially available Honeywell AC617 aids; high structure carbon black can be commercially available carbon black N550; fine particle carbon black can be commercially available Cabot fine particle carbon black; high temperature paraffin oil can be commercially available Sun 2280 paraffin oil; diatomaceous earth can be commercially available Hofmann N85 diatomaceous earth.

[0022] In a preferred embodiment of the present invention, the vulcanizing agent includes a peroxide, a bridging aid and a scorch retarder.

[0023] The peroxide may be a commercially available product of Nouryon DCP; the bridging agent may be a commercially available HVA-2 agent from Zhejiang East; and the anti-scorching agent may be a commercially available anti-scorching agent E from Weilin Chemical.

[0024] In another embodiment of the present invention, a method for preparing the above-mentioned EPDM rubber resistant to lean and rich liquid media is also provided, which comprises the following steps: S1, pressurizing and kneading the above raw materials in parts by weight, and then extruding and molding to obtain a mixed material; S2, subjecting the mixed material to compression molding and vulcanization treatment to obtain a rubber compound.

[0025] S3. The rubber material is subjected to secondary vulcanization to obtain EPDM rubber resistant to lean and rich liquid media.

[0026] 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; and the extrusion temperature of the extrusion molding is 105-115°C.

[0027] 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.

[0028] 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.

[0029] The following embodiments are some specific implementation cases of the present invention in practical applications, but are not limited thereto.

[0030] 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: 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 extrude to obtain a mixture; wherein the temperature of pressurized mixing is 125°C; the extrusion temperature of 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 type ethylene propylene rubber is used; the processing aid is the commercially available Honeywell AC617 type additive; the high structure carbon black is the commercially available carbon black N550; the fine particle carbon black is the commercially available fine particle carbon black of Cabot; the high temperature paraffin oil is the commercially available Sun 2280 type paraffin oil; the diatomaceous earth is the commercially available Hofmann N85 type diatomaceous earth; the vulcanizing agent is composed of peroxide, bridging agent and anti-scorch agent; the peroxide is the commercially available Nouryon DCP type product; the bridging agent is the commercially available Zhedong HVA-2 agent; the anti-scorch agent is the commercially available Weilin Chemical Anti-scorch Agent E.

[0031] S2. Add the mixture obtained above into 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.

[0032] S3. The rubber 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.

[0033] 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: 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 temperature of the pressurized mixing treatment 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 ethylene-propylene rubber of model 6950 was adopted from Arlanxeo; the processing aid was commercially available Honeywell AC617; the high structure carbon black was commercially available carbon black N550; the fine particle carbon black was commercially available Cabot’s fine particle carbon black; the high temperature paraffin oil was commercially available Sun 2280 paraffin oil; the diatomaceous earth was commercially available Hofmann N85 diatomaceous earth; the vulcanizing agent consisted of peroxide, bridging agent and anti-scorch agent; the peroxide was commercially available Nouryon DCP; the bridging agent was commercially available Zhedong’s HVA-2; the anti-scorch agent was commercially available Weilin Chemical’s anti-scorch agent E.

[0034] S2. Add the mixture obtained above into 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.

[0035] S3. The rubber 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.

[0036] 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: 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 for pressurized mixing for 20 minutes, and then extrude to obtain a mixture; wherein the temperature of pressurized mixing is 130°C; the extrusion temperature of extrusion molding is 115°C; the ordinary EPDM rubber adopts commercially available Mitsui 4045 EPDM rubber; the high monomer EPDM rubber adopts The commercially available Arlanxeo 6950 type ethylene propylene rubber is used; the processing aid is the commercially available Honeywell AC617 type additive; the high structure carbon black is the commercially available carbon black N550; the fine particle carbon black is the commercially available fine particle carbon black of Cabot; the high temperature paraffin oil is the commercially available Sun 2280 type paraffin oil; the diatomaceous earth is the commercially available Hofmann N85 type diatomaceous earth; the vulcanizing agent is composed of peroxide, bridging agent and anti-scorch agent; the peroxide is the commercially available Nouryon DCP type product; the bridging agent is the commercially available Zhedong HVA-2 agent; the anti-scorch agent is the commercially available Weilin Chemical Anti-scorch Agent E.

[0037] S2. Add the mixture obtained above into 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.

[0038] S3. The rubber 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.

[0039] 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: 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 temperature of the pressurized mixing treatment is 122°C; the extrusion temperature of the extrusion molding 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 ethylene-propylene rubber of model 6950 was adopted from Arlanxeo; the processing aid was commercially available Honeywell AC617; the high structure carbon black was commercially available carbon black N550; the fine particle carbon black was commercially available Cabot’s fine particle carbon black; the high temperature paraffin oil was commercially available Sun 2280 paraffin oil; the diatomaceous earth was commercially available Hofmann N85 diatomaceous earth; the vulcanizing agent consisted of peroxide, bridging agent and anti-scorch agent; the peroxide was commercially available Nouryon DCP; the bridging agent was commercially available Zhedong’s HVA-2; the anti-scorch agent was commercially available Weilin Chemical’s anti-scorch agent E.

[0040] S2. Add the mixture obtained above into 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.

[0041] S3. The rubber 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.

[0042] 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: 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 for 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 type ethylene propylene rubber is used; the processing aid is the commercially available Honeywell AC617 type additive; the high structure carbon black is the commercially available carbon black N550; the fine particle carbon black is the commercially available fine particle carbon black of Cabot; the high temperature paraffin oil is the commercially available Sun 2280 type paraffin oil; the diatomaceous earth is the commercially available Hofmann N85 type diatomaceous earth; the vulcanizing agent is composed of peroxide, bridging agent and anti-scorch agent; the peroxide is the commercially available Nouryon DCP type product; the bridging agent is the commercially available Zhedong HVA-2 agent; the anti-scorch agent is the commercially available Weilin Chemical Anti-scorch Agent E.

[0043] S2. Add the mixture obtained above into 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.

[0044] S3. The rubber 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.

[0045] 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: 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 temperature of the pressurized mixing treatment 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 The ethylene-propylene rubber of model 6950 was adopted from Arlanxeo; the processing aid was commercially available Honeywell AC617; the high structure carbon black was commercially available carbon black N550; the fine particle carbon black was commercially available Cabot’s fine particle carbon black; the high temperature paraffin oil was commercially available Sun 2280 paraffin oil; the diatomaceous earth was commercially available Hofmann N85 diatomaceous earth; the vulcanizing agent consisted of peroxide, bridging agent and anti-scorch agent; the peroxide was commercially available Nouryon DCP; the bridging agent was commercially available Zhedong’s HVA-2; the anti-scorch agent was commercially available Weilin Chemical’s anti-scorch agent E.

[0046] S2. Add the mixture obtained above into 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.

[0047] S3. The rubber 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.

[0048] 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: 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 for pressurized mixing for 15 minutes, and then extrude to obtain a mixture; wherein the temperature of pressurized mixing is 125°C; the extrusion temperature of 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 type ethylene propylene rubber is used; the processing aid is the commercially available Honeywell AC617 type additive; the high structure carbon black is the commercially available carbon black N550; the fine particle carbon black is the commercially available fine particle carbon black of Cabot; the high temperature paraffin oil is the commercially available Sun 2280 type paraffin oil; the diatomaceous earth is the commercially available Hofmann N85 type diatomaceous earth; the vulcanizing agent is composed of peroxide, bridging agent and anti-scorch agent; the peroxide is the commercially available Nouryon DCP type product; the bridging agent is the commercially available Zhedong HVA-2 agent; the anti-scorch agent is the commercially available Weilin Chemical Anti-scorch Agent E.

[0049] S2. Add the mixture obtained above into 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.

[0050] S3. The rubber 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.

[0051] Comparative Example 1: This comparative example provides a method for preparing EPDM rubber, which comprises the following steps: 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 extrude to obtain a mixture; wherein the temperature of pressurized mixing is 125°C; the extrusion temperature of extrusion molding is 110°C; the ordinary EPDM rubber adopts commercially available Mitsui 4045 type The ethylene propylene rubber is of type 1; 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-scorch agent; the peroxide is the commercially available Nouryon DCP product; the bridging agent is the commercially available Zhedong HVA-2 agent; the anti-scorch agent is the commercially available Weilin Chemical Anti-scorch Agent E.

[0052] S2. Add the mixture obtained above into 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.

[0053] S3. The rubber 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.

[0054] Comparative Example 2: This comparative example provides a method for preparing EPDM rubber, which comprises the following steps: 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 extrude to obtain a mixture; wherein the temperature of the pressurized mixing treatment is 125°C; the extrusion temperature of the extrusion molding is 110°C; the ordinary EPDM rubber adopts commercially available Mitsui 4045 type The ethylene propylene rubber is of type 1; 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-scorch agent; the peroxide is the commercially available Nouryon DCP product; the bridging agent is the commercially available Zhedong HVA-2 agent; the anti-scorch agent is the commercially available Weilin Chemical Anti-scorch Agent E.

[0055] S2. Add the mixture obtained above into 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.

[0056] S3. The rubber 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.

[0057] Comparative Example 3: This comparative example provides a method for preparing EPDM rubber, which comprises the following steps: 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 for pressurized mixing for 15 minutes, and then extrude to obtain a mixture; wherein the temperature of pressurized mixing is 125°C; the extrusion temperature of extrusion molding is 110°C; the ordinary EPDM rubber adopts commercially available Mitsui 4045 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-scorch agent; the peroxide adopts the commercially available Nouryon DCP product; the bridging agent adopts the commercially available Zhedong HVA-2 additive; the anti-scorch agent adopts the commercially available Weilin Chemical Anti-scorch Agent E.

[0058] S2. Add the mixture obtained above into 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.

[0059] S3. The rubber 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.

[0060] Comparative Example 4: This comparative example provides a method for preparing EPDM rubber, which comprises the following steps: 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 for pressurized mixing for 15 minutes, and then extrude to obtain a mixture; wherein the temperature of pressurized mixing is 125°C; the extrusion temperature of extrusion molding is 110°C; the ordinary EPDM rubber adopts commercially available Mitsui 4045 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-scorch agent; the peroxide adopts the commercially available Nouryon DCP product; the bridging agent adopts the commercially available Zhedong HVA-2 additive; the anti-scorch agent adopts the commercially available Weilin Chemical Anti-scorch Agent E.

[0061] S2. Add the mixture obtained above into 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.

[0062] S3. The rubber obtained by the primary vulcanization and shaping is subjected to secondary vulcanization for 2 hours to obtain EPDM rubber; wherein the temperature of the secondary vulcanization is 150°C.

[0063] Comparative Example 5: This comparative example provides a method for preparing EPDM rubber, which comprises the following steps: 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 talcum powder and 4kg of vulcanizing agent into a mixing device for pressurized mixing for 15 minutes, and then extrude to obtain a mixture; wherein the temperature of pressurized mixing is 125°C; the extrusion temperature of extrusion molding is 110°C; the ordinary EPDM rubber adopts commercially available Mitsui 4045 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-scorch agent; the peroxide adopts the commercially available Nouryon DCP product; the bridging agent adopts the commercially available Zhedong HVA-2 additive; the anti-scorch agent adopts the commercially available Weilin Chemical Anti-scorch Agent E.

[0064] S2. Add the mixture obtained above into 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 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] Performance test: 1. The EPDM rubbers prepared in Example 1 and Comparative Examples 1-2 were immersed in a 50% concentration of lean and rich liquid medium, respectively, at 110°C*168h. After immersion, the EPDM rubbers were taken out and dried, and the volume change rate of the EPDM rubbers was measured. The results are 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%. It can be seen from the above results that the present invention can effectively reduce the swelling of the EPDM rubber in lean and rich liquid medium by using high-monomer EPDM raw rubber with a high degree of crosslinking.

[0067] 2. The EPDM rubbers prepared in Example 1 and Comparative Examples 3-5 were immersed in a 50% concentration of lean and rich liquid medium, respectively, at 110°C*168h. After immersion, the EPDM rubbers were taken out and dried, and the volume change rate of the EPDM rubbers was measured. The results are 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%. It can be seen from the above results that the volume change rate of the EPDM rubber prepared by using diatomaceous earth as a filler is the smallest because the flaky structure inside the diatomaceous earth can hinder the medium from penetrating into the rubber. In addition, since calcium carbonate can react with acidic substances in the medium, it is not suitable as a filler for rubber resistant to lean and rich liquid medium.

[0068] Based on the above-mentioned ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above-mentioned description. 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 poor 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 poor 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 poor and rich liquid medium according to any one of claims 1 to 3, characterized in that: The high monomer ethylene propylene rubber adopts ethylene propylene rubber of model 6950.

5. The EPDM rubber resistant to poor and rich liquid medium 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 as claimed in 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 kneading treatment, and then extruded to obtain a mixed material; The mixed material is subjected to compression molding and vulcanization treatment to obtain a rubber compound. The rubber compound is subjected to secondary vulcanization to obtain EPDM rubber resistant to lean and rich liquid media.

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

9. The method for preparing EPDM rubber resistant to poor 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.