A kind of BIPB vulcanized EPDM rubber and preparation method thereof

Abstract

The present invention belongs to the technical field of ethylene propylene diene monomer (EPDM) rubber, and discloses a BIPB vulcanized EPDM rubber and a preparation method thereof. The BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base, a vulcanizing agent, a vulcanization accelerator, and a vulcanization activator; the vulcanizing agent is BIPB and sulfur, and the vulcanization accelerator includes triallyl isocyanurate, 2-mercaptobenzothiazole, and divinylbenzene; and the vulcanization activator is polyethylene glycol. The present invention is based on a BIPB peroxide vulcanization system and supplemented with a sulfur vulcanization system. By selecting the vulcanization accelerator and the vulcanization activator, and controlling the ratio of each vulcanization accelerator and the molecular weight of the vulcanization activator polyethylene glycol, the BIPB vulcanized EPDM rubber prepared not only does not exhibit a "blooming" phenomenon, but also further improves the strength and compression set resistance of the EPDM rubber, thereby better meeting industrial needs.

Description

Technical Field

[0001] The invention belongs to the technical field of ethylene propylene diene monomer (EPDM), and in particular relates to BIPB vulcanized EPDM rubber and a preparation method thereof. Background Art

[0002] Ethylene propylene diene monomer (EPDM) is a polymer obtained by copolymerizing ethylene, propylene and a small amount of a third monomer. Due to its low unsaturation, it has excellent resistance to superheated water, water vapor, corrosion, aging, cold, ozone and electrical insulation. Therefore, it is widely used in automotive parts, construction industry, seals, waterproof membranes, hoses and wires and cables.

[0003] The conventional vulcanization system of EPDM comprises sulfur vulcanization system and peroxide vulcanization system.Adopt sulfur vulcanization system, although dynamic mechanical property is excellent, but because EPDM is low unsaturation rubber, double bond content is less, there are shortcomings such as low degree of crosslinking, slow vulcanization rate with sulfur vulcanization system EPDM, and the amount that EPDM can dissolve sulfur is less, so be easy to bloom.Adopt peroxide vulcanization system, gained vulcanized rubber has excellent heat resistance, and resistance to compression (tensile) permanent deformation is less.At present, conventional peroxide vulcanizing agent is dicumyl peroxide (DCP) and di-tert-butyl peroxide isopropyl benzene (BIPB), wherein in the DCP vulcanization process, can produce a large amount of gas with pungent odor, and in subsequent production and use process, odor is difficult to eliminate, environmental pollution is large, and safety is low.In addition DCP has reproductive toxicity, has been progressively restricted to use. BIPB does not produce gases with pungent odor during the vulcanization process, but the EPDM rubber obtained by vulcanization with BIPB is also prone to "frosting" on the surface, that is, a large amount of crystals precipitate and adhere to the surface of the product, affecting subsequent processing and use.

[0004] In addition, EPDM rubber used in seals, supports and other fields is widely used in the fields of strength, compression resistance (tensile strength) and Permanent The deformation requirements are high, such as rubber products cannot recover well after being subjected to compression for a long time If the rubber is not fully cured, it will return to its original shape, creating gaps at the sealing interface or failing to provide adequate support. Currently, EPDM rubber vulcanized using BIPB still needs further improvement. Studies have shown that increasing the amount of peroxide in peroxide-cured systems reduces compression set. However, increasing the amount of peroxide increases the risk of "blooming" on the surface of EPDM rubber vulcanized using BIPB.

[0005] Therefore, there is an urgent need to provide a BIPB vulcanized EPDM rubber that does not produce "blooming" and has excellent strength and resistance to compression permanent deformation. Summary of the Invention

[0006] The present invention aims to address at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a BIPB vulcanized EPDM rubber and a method for preparing the same. The BIPB vulcanized EPDM rubber provided by the present invention exhibits no blooming and exhibits excellent strength and compression set resistance.

[0007] The invention provides a BIPB vulcanized ethylene propylene diene monomer rubber.

[0008] Specifically, a BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator;

[0009] The vulcanizing agent is BIPB and sulfur, and the mass ratio of the BIPB to the sulfur is (5-12):1;

[0010] The vulcanization accelerator includes triallyl isocyanurate (TAIC), 2-mercaptobenzothiazole and divinylbenzene; the mass ratio of the triallyl isocyanurate to the 2-mercaptobenzothiazole and the divinylbenzene is (5-10): (3-5): (0.5-2);

[0011] The vulcanization activator includes polyethylene glycol (PEG), and the molecular weight of the polyethylene glycol is 4500-20000.

[0012] Preferably, in parts by mass, the rubber base material comprises 100 parts of raw rubber, 1.0-6.0 parts of the vulcanizing agent, 1.0-4.5 parts of the vulcanization accelerator, and 0.5-2 parts of the vulcanization activator; further preferably, in parts by mass, the rubber base material comprises 100 parts of raw rubber, 1.5-5.0 parts of the vulcanizing agent, 1.5-3.5 parts of the vulcanization accelerator, and 1.0-2.0 parts of the vulcanization activator; more preferably, in parts by mass, the rubber base material comprises 100 parts of raw rubber, 1.5-3.8 parts of the vulcanizing agent, 1.8-3.0 parts of the vulcanization accelerator, and 1.0-2.0 parts of the vulcanization activator.

[0013] Preferably, the mass ratio of the BIPB to the sulfur is (7-10):1.

[0014] Preferably, the mass ratio of the triallyl isocyanurate to the 2-mercaptobenzothiazole and the divinylbenzene is (6-10):(3-4):(0.8-1.5).

[0015] Preferably, the rubber base material further comprises, by mass, 2-10 parts of zinc oxide, 30-100 parts of carbon black, and 2-10 parts of paraffin oil; further preferably, by mass, the rubber base material further comprises, by mass, 3-6 parts of zinc oxide, 40-80 parts of carbon black, and 3-8 parts of paraffin oil.

[0016] Preferably, the carbon black includes at least one of carbon black N330, carbon black N550 and carbon black N774.

[0017] In some embodiments of the present invention, the rubber base material may further be added with an antioxidant and other processing aids, such as a dispersant, according to actual needs. The dispersant may be sodium aluminum silicate, nano calcium carbonate, etc.

[0018] Preferably, the molecular weight of the polyethylene glycol is 5000-10000.

[0019] Preferably, the raw material components of the BIPB vulcanized EPDM rubber further include a vulcanizing agent, and the vulcanizing agent is bismaleamide. Further preferably, the vulcanizing agent is present in an amount of 0.5-2 parts by mass.

[0020] The present invention also provides a method for preparing BIPB vulcanized EPDM rubber.

[0021] Specifically, a method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0022] After mixing the rubber base material, the rubber is discharged to obtain the rubber compound;

[0023] A vulcanizing agent, a vulcanization accelerator and a vulcanization activator are added to the rubber material, and the rubber material is subjected to thin-pass curing and vulcanization to obtain BIPB vulcanized EPDM rubber.

[0024] Preferably, the mixing temperature is 60-85°C.

[0025] Preferably, the debinding temperature is 130-140°C.

[0026] Preferably, the number of times of thin-passing is 5-10 times, and the mixture is left to stand for 18-24 hours after thin-passing.

[0027] Preferably, the vulcanization temperature is 145-165° C., the vulcanization time is 20-60 min, and the vulcanization pressure is 10-14 MPa.

[0028] More specifically, a method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0029] The rubber base material is mixed at 60-85°C and then discharged at 130-140°C to obtain a rubber compound;

[0030] Add a vulcanizing agent, a vulcanization accelerator and a vulcanization activator to the rubber material, pass it through thin-film 5-10 times, place it for 18-24 hours, and then vulcanize it at 145-165° C. for 20-60 minutes to prepare BIPB vulcanized EPDM rubber.

[0031] The BIPB-vulcanized EPDM rubber provided by the present invention is mainly based on a BIPB peroxide vulcanization system, supplemented by a sulfur vulcanization system, and the mass ratio of the vulcanizing agent BIPB to sulfur is controlled to be (5-12):1. Because the double bond content in EPDM rubber is relatively low, the use of a small amount of sulfur in combination with BIPB not only does not reduce the rubber crosslinking degree and vulcanization speed, but can actually increase the stability and density of the crosslinked structure under a specific ratio of vulcanization accelerators, thereby improving the strength and compression set resistance of EPDM rubber products. Studies have found that when triallyl isocyanurate, 2-mercaptobenzothiazole, and divinylbenzene are selected as vulcanization accelerators and their ratios are controlled, the crosslinking of rubber molecular chains in the above-mentioned vulcanization system can be effectively promoted, significantly improving the strength and compression set resistance of the vulcanized rubber. Specifically, triallyl isocyanurate contains multiple allyl functional groups. The free radicals generated by the decomposition of BIPB peroxide trigger reactions between the allyl groups in the triallyl isocyanurate molecules, which then bind to active sites on the EPDM molecular chains to form a crosslinked structure. 2-Mercaptobenzothiazole activates sulfur, promoting the crosslinking reaction between sulfur and rubber molecules, forming a three-dimensional network structure and controlling the rate of the vulcanization reaction. The two vinyl groups of divinylbenzene become active under the action of the free radicals generated by the peroxide, allowing them to crosslink with active sites on the EPDM molecular chains. Due to its unique molecular structure, it forms a stable crosslinked structure between EPDM chains. This, combined with triallyl isocyanurate and 2-mercaptobenzothiazole, further improves the elastic recovery properties of the vulcanized EPDM and reduces compression set. Furthermore, research has found that using polyethylene glycol with a molecular weight of 5,000-10,000 can further improve the strength, compression set resistance, and light stability of EPDM rubber products, while reducing the risk of blooming.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention mainly uses a BIPB peroxide vulcanization system and supplements it with a sulfur vulcanization system. By selecting a vulcanization accelerator and a vulcanization activator, and controlling the ratio of each vulcanization accelerator and the molecular weight of the vulcanization activator polyethylene glycol, the BIPB vulcanized EPDM rubber prepared not only does not exhibit a "blooming" phenomenon, but also can further improve the strength and compression set resistance of the EPDM rubber, thereby better meeting industrial needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a diagram showing the blooming condition of the BIPB vulcanized EPDM rubber provided in Example 1;

[0035] Figure 2This is a diagram showing the frosting of the BIPB vulcanized EPDM rubber provided in Comparative Example 1 after being treated with high temperature and high humidity;

[0036] Figure 3 This is a diagram showing the frosting of the BIPB vulcanized EPDM rubber provided in Comparative Example 2 after being treated with high temperature and high humidity;

[0037] Figure 4 This is a diagram showing the blooming of the BIPB vulcanized EPDM rubber provided in Comparative Example 2 after light treatment;

[0038] Figure 5 This is a diagram showing the frosting of the BIPB vulcanized EPDM rubber provided in Comparative Example 3 after being treated with high temperature and high humidity;

[0039] Figure 6 This is a diagram showing the blooming of the BIPB vulcanized EPDM rubber provided in Comparative Example 3 after light treatment;

[0040] Figure 7 This is a diagram showing the frosting of the BIPB vulcanized EPDM rubber provided in Comparative Example 4 after being treated with high temperature and high humidity;

[0041] Figure 8 This is a diagram showing the blooming of the BIPB vulcanized EPDM rubber provided in Comparative Example 4 after light treatment;

[0042] Figure 9 This is a diagram of the frosting condition of the BIPB vulcanized EPDM rubber provided in Comparative Example 5 after light treatment. DETAILED DESCRIPTION

[0043] In order to make the technical solution of the present invention more clearly understood by those skilled in the art, the following examples are given for illustration. It should be noted that the following examples do not limit the scope of protection claimed by the present invention.

[0044] Unless otherwise specified, the raw materials, reagents or devices used in the following examples and comparative examples can be obtained from conventional commercial sources or by existing known methods.

[0045] Example 1

[0046] A BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator;

[0047] Rubber base: 100 parts of raw rubber, 5 parts of zinc oxide, 50 parts of carbon black N550, 5 parts of paraffin oil, 5 parts of sodium aluminum silicate;

[0048] Curing agent: BIPB 2.8 parts, sulfur 0.4 parts;

[0049] Vulcanization accelerator: 1.6 parts of triallyl isocyanurate, 0.8 parts of 2-mercaptobenzothiazole and 0.2 parts of divinylbenzene;

[0050] Vulcanization activator: 1.2 parts of polyethylene glycol, with a molecular weight of 8000;

[0051] Co-vulcanizing agent: 0.8 parts of bismaleamide.

[0052] A method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0053] Weighing rubber base raw rubber, zinc oxide, carbon black N550, paraffin oil, and sodium aluminum silicate, then mixing them at 70° C. for 20 minutes, and then debonding at 135° C. to obtain a rubber compound;

[0054] Vulcanizing agent, vulcanization accelerator and vulcanization activator were added to the rubber compound in sequence. After thin-passing 6 times, the rubber compound was placed for 24 hours and then vulcanized at 150°C for 20 minutes to obtain BIPB vulcanized EPDM rubber.

[0055] Example 2

[0056] A BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator;

[0057] Rubber base: 100 parts of raw rubber, 5 parts of zinc oxide, 45 parts of carbon black N550, 6 parts of paraffin oil, 5 parts of sodium aluminum silicate;

[0058] Curing agent: BIPB 1.8 parts, sulfur 0.2 parts;

[0059] Vulcanization accelerator: 1.2 parts of triallyl isocyanurate, 0.48 parts of 2-mercaptobenzothiazole and 0.12 parts of divinylbenzene;

[0060] Vulcanization activator: 1.8 parts of polyethylene glycol, with a molecular weight of 10,000;

[0061] Co-vulcanizing agent: 1.5 parts of bismaleamide.

[0062] A method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0063] Weighing rubber base raw rubber, zinc oxide, carbon black N550, paraffin oil, and sodium aluminum silicate, then mixing them at 70° C. for 20 minutes, and then debonding at 135° C. to obtain a rubber compound;

[0064] Vulcanizing agent, vulcanization accelerator and vulcanization activator were added to the rubber compound in sequence. After thin-passing 6 times, the rubber compound was placed for 24 hours and then vulcanized at 150°C for 20 minutes to obtain BIPB vulcanized EPDM rubber.

[0065] Example 3

[0066] A BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator;

[0067] Rubber base: 100 parts of raw rubber, 3 parts of zinc oxide, 50 parts of carbon black N330, 5.5 parts of paraffin oil, and 5 parts of sodium aluminum silicate;

[0068] Curing agent: BIPB 2.7 parts, sulfur 0.3 parts;

[0069] Vulcanization accelerator: 1.0 part of triallyl isocyanurate, 0.4 part of 2-mercaptobenzothiazole and 0.1 part of divinylbenzene;

[0070] Vulcanization activator: 1.5 parts of polyethylene glycol, its molecular weight is 8000;

[0071] Co-vulcanizing agent: 1.2 parts of bismaleamide.

[0072] A method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0073] Weighing rubber base raw rubber, zinc oxide, carbon black N550, paraffin oil, and sodium aluminum silicate, then mixing them at 70° C. for 20 minutes, and then debonding at 135° C. to obtain a rubber compound;

[0074] Vulcanizing agent, vulcanization accelerator and vulcanization activator were added to the rubber compound in sequence. After thin-passing 6 times, the rubber compound was placed for 24 hours and then vulcanized at 150°C for 20 minutes to obtain BIPB vulcanized EPDM rubber.

[0075] Example 4

[0076] A BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator;

[0077] Rubber base: 100 parts of raw rubber, 5 parts of zinc oxide, 50 parts of carbon black N550, 5 parts of paraffin oil, 5 parts of sodium aluminum silicate;

[0078] Curing agent: BIPB 2.8 parts, sulfur 0.4 parts;

[0079] Vulcanization accelerator: 2.0 parts of triallyl isocyanurate, 0.1 parts of 2-mercaptobenzothiazole and 0.5 parts of divinylbenzene;

[0080] Vulcanization activator: 1.0 part of polyethylene glycol, molecular weight 8000;

[0081] Co-vulcanizing agent: 0.5 parts of bismaleamide.

[0082] A method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0083] Weighing rubber base raw rubber, zinc oxide, carbon black N550, paraffin oil, and sodium aluminum silicate, then mixing them at 70° C. for 20 minutes, and then debonding at 135° C. to obtain a rubber compound;

[0084] Vulcanizing agent, vulcanization accelerator and vulcanization activator were added to the rubber compound in sequence. After thin-passing 6 times, the rubber compound was placed for 24 hours and then vulcanized at 150°C for 20 minutes to obtain BIPB vulcanized EPDM rubber.

[0085] Comparative Example 1

[0086] A BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator;

[0087] Rubber base: 100 parts of raw rubber, 5 parts of zinc oxide, 50 parts of carbon black N550, 5 parts of paraffin oil, 5 parts of sodium aluminum silicate;

[0088] Curing agent: BIPB 3.2 parts;

[0089] Vulcanization accelerator: 1.6 parts of triallyl isocyanurate, 0.8 parts of 2-mercaptobenzothiazole and 0.2 parts of divinylbenzene;

[0090] Vulcanization activator: 1.2 parts of polyethylene glycol, with a molecular weight of 8000;

[0091] Co-vulcanizing agent: 0.8 parts of bismaleamide.

[0092] A method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0093] Weighing rubber base raw rubber, zinc oxide, carbon black N550, paraffin oil, and sodium aluminum silicate, then mixing them at 70° C. for 20 minutes, and then debonding at 135° C. to obtain a rubber compound;

[0094] Vulcanizing agent, vulcanization accelerator and vulcanization activator were added to the rubber compound in sequence. After thin-passing 6 times, the rubber compound was placed for 24 hours and then vulcanized at 150°C for 20 minutes to obtain BIPB vulcanized EPDM rubber.

[0095] Comparative Example 2

[0096] A BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator;

[0097] Rubber base: 100 parts of raw rubber, 5 parts of zinc oxide, 50 parts of carbon black N550, 5 parts of paraffin oil, 5 parts of sodium aluminum silicate;

[0098] Curing agent: BIPB 2.2 parts, sulfur 1.0 part;

[0099] Vulcanization accelerator: 1.6 parts of triallyl isocyanurate, 0.8 parts of 2-mercaptobenzothiazole and 0.2 parts of divinylbenzene;

[0100] Vulcanization activator: 1.2 parts of polyethylene glycol, with a molecular weight of 8000;

[0101] Co-vulcanizing agent: 0.8 parts of bismaleamide.

[0102] A method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0103] Weighing rubber base raw rubber, zinc oxide, carbon black N550, paraffin oil, and sodium aluminum silicate, then mixing them at 70° C. for 20 minutes, and then debonding at 135° C. to obtain a rubber compound;

[0104] Vulcanizing agent, vulcanization accelerator and vulcanization activator were added to the rubber compound in sequence. After thin-passing 6 times, the rubber compound was placed for 24 hours and then vulcanized at 150°C for 20 minutes to obtain BIPB vulcanized EPDM rubber.

[0105] Comparative Example 3

[0106] A BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator;

[0107] Rubber base: 100 parts of raw rubber, 5 parts of zinc oxide, 50 parts of carbon black N550, 5 parts of paraffin oil, 5 parts of sodium aluminum silicate;

[0108] Curing agent: BIPB 2.8 parts, sulfur 0.4 parts;

[0109] Vulcanization accelerator: 2.6 parts of triallyl isocyanurate;

[0110] Vulcanization activator: 1.2 parts of polyethylene glycol, with a molecular weight of 8000;

[0111] Co-vulcanizing agent: 0.8 parts of bismaleamide.

[0112] A method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0113] Weighing rubber base raw rubber, zinc oxide, carbon black N550, paraffin oil, and sodium aluminum silicate, then mixing them at 70° C. for 20 minutes, and then debonding at 135° C. to obtain a rubber compound;

[0114] Vulcanizing agent, vulcanization accelerator and vulcanization activator were added to the rubber compound in sequence. After thin-passing 6 times, the rubber compound was placed for 24 hours and then vulcanized at 150°C for 20 minutes to obtain BIPB vulcanized EPDM rubber.

[0115] Comparative Example 4

[0116] A BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator;

[0117] Rubber base: 100 parts of raw rubber, 5 parts of zinc oxide, 50 parts of carbon black N550, 5 parts of paraffin oil, 5 parts of sodium aluminum silicate;

[0118] Curing agent: BIPB 2.8 parts, sulfur 0.4 parts;

[0119] Vulcanization accelerator: 1.8 parts of triallyl isocyanurate and 0.8 parts of 2-mercaptobenzothiazole;

[0120] Vulcanization activator: 1.2 parts of polyethylene glycol, with a molecular weight of 8000;

[0121] Co-vulcanizing agent: 0.8 parts of bismaleamide.

[0122] A method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0123] Weighing rubber base raw rubber, zinc oxide, carbon black N550, paraffin oil, and sodium aluminum silicate, then mixing them at 70° C. for 20 minutes, and then debonding at 135° C. to obtain a rubber compound;

[0124] Vulcanizing agent, vulcanization accelerator and vulcanization activator were added to the rubber compound in sequence. After thin-passing 6 times, the rubber compound was placed for 24 hours and then vulcanized at 150°C for 20 minutes to obtain BIPB vulcanized EPDM rubber.

[0125] Comparative Example 5

[0126] A BIPB vulcanized EPDM rubber comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator;

[0127] Rubber base: 100 parts of raw rubber, 5 parts of zinc oxide, 50 parts of carbon black N550, 5 parts of paraffin oil, 5 parts of sodium aluminum silicate;

[0128] Curing agent: BIPB 2.8 parts, sulfur 0.4 parts;

[0129] Vulcanization accelerator: 1.6 parts of triallyl isocyanurate, 0.8 parts of 2-mercaptobenzothiazole and 0.2 parts of divinylbenzene;

[0130] Vulcanization activator: 1.2 parts of polyethylene glycol, with a molecular weight of 3000;

[0131] Co-vulcanizing agent: 0.8 parts of bismaleamide.

[0132] A method for preparing BIPB vulcanized EPDM rubber comprises the following steps:

[0133] Weighing rubber base raw rubber, zinc oxide, carbon black N550, paraffin oil, and sodium aluminum silicate, then mixing them at 70° C. for 20 minutes, and then debonding at 135° C. to obtain a rubber compound;

[0134] Vulcanizing agent, vulcanization accelerator and vulcanization activator were added to the rubber compound in sequence. After thin-passing 6 times, the rubber compound was placed for 24 hours and then vulcanized at 150°C for 20 minutes to obtain BIPB vulcanized EPDM rubber.

[0135] Product effect testing

[0136] The properties of the BIPB vulcanized EPDM rubber prepared in Examples 1-4 and Comparative Examples 1-5 were tested, including tensile strength, elongation, compression set, and blooming of the samples under high temperature, high humidity, and light. The details are as follows:

[0137] (1) Compression set (120°C × 24h × 30% compression), test method according to GB / T1683-2018;

[0138] (2) Tensile strength and elongation. Test methods refer to GB / T 528-2009.

[0139] (3) Blooming test 1 (high temperature and high humidity): Place at 70°C and 95% humidity for 500 h (70°C × 500 h × 95% humidity) and observe the blooming situation.

[0140] (4) Blooming experiment 2 (sunlight irradiation): The OSRAM sunlamp (300W) was used for continuous irradiation for 168 h, and the blooming situation was observed.

[0141] The performance test results of the BIPB vulcanized EPDM rubber prepared in the examples and comparative examples are shown in Table 1.

[0142] Table 1

[0143]

[0144]

[0145] As shown in Table 1, the compression set of the BIPB-vulcanized EPDM rubber prepared in the examples of the present invention is less than 24.1%, reaching a low of 20.56%; the tensile strength is no less than 17.9, reaching 19.8%; and the elongation is greater than 430%, reaching 465.9%. The compression set, tensile strength, and elongation of the BIPB-vulcanized EPDM rubber prepared in the examples of the present invention are superior to those of the EPDM rubber prepared in the comparative examples. Comparing Example 1 with the comparative examples, it can be seen that while the BIPB-vulcanized EPDM rubber prepared in Comparative Example 1, which uses only the vulcanizing agent BIPB, exhibits high elongation, its compression set and tensile strength are significantly reduced. The use of a larger amount of sulfur in Comparative Example 2 not only results in severe blooming but also affects the degree of crosslinking, thereby affecting the compression set and tensile strength of the EPDM rubber. The compression set and strength of the BIPB-vulcanized EPDM rubber prepared in Comparative Examples 3 and 4, when using only one or both of the accelerators, are affected to varying degrees. In Comparative Example 5, low molecular weight polyethylene glycol is used as a vulcanization activator. The compression permanent deformation and strength of the prepared BIPB vulcanized EPDM rubber are affected to a certain extent, which is not as good as using polyethylene glycol with a larger molecular weight.

[0146] The blooming conditions of the BIPB vulcanized EPDM rubber prepared in Examples 1-4 and Comparative Examples 1-5 under high temperature, high humidity and light are shown in Tables 1 and Figures 1 to 9 As shown in Table 1 and Figures 1 to 9 It can be seen that the BIPB vulcanized EPDM rubber prepared in Examples 1-3 of the present invention does not show "blooming" phenomenon after being treated under high temperature, high humidity and light conditions, and has a good appearance and is conducive to subsequent processing and use ( Figure 1 The BIPB vulcanized EPDM rubber prepared in Example 4 was placed under high temperature and high humidity conditions. Slight light spots were observed when the BIPB vulcanized EPDM rubber was polished, but the overall condition was good and had relatively little impact on subsequent processing and use. Figure 2 ) and OSRAM solar light treatment, the naked eye can see the crystal precipitation. Comparative Example 2 uses more sulfur as a vulcanizing agent, and after being placed under high temperature and high humidity conditions, the naked eye can see obvious crystal precipitation (see Figure 3 ), after being treated with light, obvious crystal precipitation can be seen under the condition of illumination (see Figure 4). This is because EPDM rubber contains fewer double bonds and can only dissolve a limited amount of sulfur. When the amount of sulfur added exceeds the ratio specified in the present invention, it cannot play a good synergistic role with the vulcanizer BIPB, but will have the opposite effect. Comparative Example 3: When only one accelerator is used, the BIPB-vulcanized EPDM rubber prepared will have obvious crystal precipitation visible to the naked eye after being treated under high temperature and high humidity and irradiated by OSRAM solar light (see Figures 1 and 2). Figure 5 and Figure 6 ). Comparative Example 4: When only two accelerators are used, the BIPB vulcanized EPDM rubber prepared is placed under high temperature and high humidity conditions and slight crystal precipitation is observed with the naked eye (see Figure 7 ); After light treatment, obvious crystal precipitation can be seen under the condition of light (see Figure 8 Comparative Example 5 uses low molecular weight polyethylene glycol as a vulcanizing agent. Although no blooming occurs after being placed under high temperature and high humidity conditions, crystal precipitation is observed after being treated with light (see Figure 9 ), its light stability decreases.

[0147] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A BIPB vulcanized EPDM rubber, characterized in that: The method comprises the following raw material components: rubber base material, vulcanizing agent, vulcanization accelerator and vulcanization activator; The vulcanizing agent is BIPB and sulfur, and the mass ratio of the BIPB to the sulfur is (5-12):1; The vulcanization accelerator includes triallyl isocyanurate, 2-mercaptobenzothiazole and divinylbenzene; the mass ratio of the triallyl isocyanurate to the 2-mercaptobenzothiazole and the divinylbenzene is (5-10): (3-5): (0.5-2); The vulcanization activator is polyethylene glycol, and the molecular weight of the polyethylene glycol is 4500-20000.

2. The BIPB vulcanized EPDM rubber according to claim 1, characterized in that: Calculated by mass, the rubber base material includes 100 parts of raw rubber, 1.0-6.0 parts of the vulcanizing agent, 1.0-4.5 parts of the vulcanization accelerator, and 0.5-2 parts of the vulcanization activator.

3. The BIPB vulcanized EPDM rubber according to claim 1 or 2, characterized in that: The mass ratio of the BIPB to the sulfur is (7-10):

1.

4. The BIPB vulcanized EPDM rubber according to claim 1 or 2, characterized in that: The mass ratio of the triallyl isocyanurate to the 2-mercaptobenzothiazole and the divinylbenzene is (6-10): (3-4): (0.8-1.5).

5. The BIPB vulcanized EPDM rubber according to claim 4, characterized in that: Calculated by mass, the rubber base material further comprises 2-10 parts of zinc oxide, 30-100 parts of carbon black, and 2-10 parts of paraffin oil.

6. The BIPB vulcanized EPDM rubber according to claim 1 or 2, characterized in that: The raw material components also include a vulcanizing agent, which is bismaleamide.

7. The BIPB vulcanized EPDM rubber according to claim 1 or 2, characterized in that: The molecular weight of the polyethylene glycol is 5000-10000.

8. The method for preparing BIPB vulcanized EPDM rubber according to any one of claims 1 to 7, characterized in that: The following steps are involved: After mixing the rubber base material, the rubber is discharged to obtain the rubber compound; A vulcanizing agent, a vulcanization accelerator and a vulcanization activator are added to the rubber material, and the rubber material is subjected to thin-pass curing and vulcanization to obtain BIPB vulcanized EPDM rubber.

9. The preparation method according to claim 8, characterized in that The debinding temperature is 130-140°C.

10. The preparation method according to claim 8 or 9, characterized in that: The vulcanization temperature is 145-165° C., the vulcanization time is 20-60 min, and the vulcanization pressure is 10-14 MPa.

Images