BIPB vulcanized ethylene propylene diene monomer and preparation method thereof

Abstract

The invention belongs to the technical field of ethylene propylene diene monomer, and discloses BIPB vulcanized ethylene propylene diene monomer and a preparation method thereof. The BIPB vulcanized ethylene propylene diene monomer comprises the following raw material components: a rubber base material, a vulcanizing agent, a vulcanization accelerator and a vulcanization activator, the vulcanizing agent is BIPB and sulfur, and the vulcanization accelerator is prepared from triallyl isocyanurate, 2-mercaptobenzothiazole and divinyl benzene; the vulcanizing activator is polyethylene glycol. The BIPB vulcanized ethylene propylene diene monomer prepared by taking a BIPB peroxide vulcanization system as a main material and a sulfur vulcanization system as an auxiliary material and by selecting vulcanization accelerators and vulcanization activators and controlling the proportion of the vulcanization accelerators and the molecular weight of polyethylene glycol as the vulcanization activators has the advantages of no blooming phenomenon, high temperature resistance and high temperature resistance. In addition, the strength and the compression set resistance of the ethylene propylene diene monomer can be further improved, and the industrial requirements can be better met.

Description

Technical Field

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

[0002] Ethylene propylene diene monomer (EPDM) is a polymer obtained by copolymerization of 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, wires and cables, etc.

[0003] The commonly used vulcanization system of EPDM includes sulfur vulcanization system and peroxide vulcanization system. Using sulfur vulcanization system, although the dynamic mechanical properties are excellent, because EPDM is a low unsaturation rubber, the double bond content is less, there are shortcomings such as low crosslinking degree and slow vulcanization speed in vulcanizing EPDM with sulfur vulcanization system, and the amount of EPDM soluble sulfur is less, so it is easy to spray bloom. Using peroxide vulcanization system, the obtained vulcanized rubber has excellent heat resistance and less compression (tensile) permanent deformation. At present, commonly used peroxide vulcanizing agents are diisopropylbenzene peroxide (DCP) and di-tert-butyl peroxide isopropylbenzene (BIPB), wherein in the DCP vulcanization process, a large amount of gases with pungent odors will be produced, and the odor is difficult to eliminate in subsequent production and use, and the environmental pollution is large and the safety is low. In addition, DCP has reproductive toxicity and has been gradually restricted. 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 for its strength, compression resistance (tensile strength, etc.). 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 returned to its original shape, gaps will be generated at the sealing interface or it will not provide good support. The EPDM rubber currently obtained by BIPB vulcanization still needs to be further improved. Studies have shown that the compression set of the peroxide vulcanization system decreases with the increase of peroxide dosage, but as the amount of peroxide increases, the risk of "blooming" on the surface of the EPDM rubber obtained by BIPB vulcanization increases.

[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 solve 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 preparation method thereof. The BIPB vulcanized EPDM rubber provided by the present invention does not produce "blooming" and has excellent strength and resistance to compression permanent deformation.

[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 comprises 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 weight, 2-10 parts of zinc oxide, 30-100 parts of carbon black, and 2-10 parts of paraffin oil; further preferably, the rubber base material further comprises, by weight, 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 0.5-2 parts by mass.

[0020] The invention also provides a method for preparing BIPB vulcanized ethylene propylene diene monomer 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 a 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 thin pass is performed 5-10 times and the mixture is left to stand for 18-24 hours after the thin pass.

[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, thin it for 5-10 times, place it for 18-24 hours, and then vulcanize it at 145-165° C. for 20-60 minutes to obtain BIPB vulcanized EPDM rubber.

[0031] The BIPB vulcanized EPDM rubber provided by the present invention is mainly based on the BIPB peroxide vulcanization system, supplemented by the sulfur vulcanization system, and the mass ratio of the vulcanizing agent BIPB to the sulfur is controlled to be (5-12):1. Because the double bond content in the EPDM rubber is relatively small, the use of a small amount of sulfur in combination with BIPB will not only not reduce the cross-linking degree and vulcanization speed of the rubber, but on the contrary, under a specific proportion of vulcanization accelerators, it can increase the stability and density of the cross-linking structure, thereby improving the strength and compression permanent deformation resistance of the EPDM rubber product. Studies have found that when triallyl isocyanurate, 2-mercaptobenzothiazole, and divinylbenzene are selected as vulcanization accelerators and their proportions are controlled, the cross-linking of the rubber molecular chains in the above-mentioned vulcanization system can be effectively promoted, so that the strength and compression permanent deformation resistance of the vulcanized rubber are significantly improved. Specifically, triallyl isocyanurate contains multiple allyl functional groups. The free radicals generated by the decomposition of peroxide BIPB trigger the allyl groups in the triallyl isocyanurate molecules to react, and then combine with the active sites on the EPDM molecular chain to form a cross-linked structure. 2-Mercaptobenzothiazole can activate sulfur, promote the cross-linking reaction between sulfur and rubber molecules, form a three-dimensional network structure, and control the speed of the vulcanization reaction. The two vinyl groups of divinylbenzene become active under the action of free radicals generated by peroxide, and can undergo cross-linking reactions with the active points on the EPDM molecular chain; due to the particularity of its molecular structure, it can form a stable cross-linked structure between EPDM molecular chains, and work together with triallyl isocyanurate and 2-mercaptobenzothiazole to further improve the elastic recovery properties of EPDM after vulcanization and reduce compression set. In addition, the study found that the use of polyethylene glycol with a molecular weight of 5000-10000 can further improve the strength, compression set resistance and light stability of EPDM products, and reduce 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 is supplemented by 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 prepared BIPB vulcanized EPDM rubber not only does not have a "blooming" phenomenon, but also can further improve the strength and compression permanent deformation resistance of the EPDM rubber, and can better meet industrial needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a diagram showing the blooming 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 frosting 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 frosting 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 frosting of the BIPB vulcanized EPDM rubber provided in Comparative Example 4 after light treatment;

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

[0043] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be pointed out that the following embodiments do not limit the protection scope of 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 material: 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] Vulcanizing agent: 2.8 parts of BIPB, 0.4 parts of sulfur;

[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 draining 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 being thin-passed 6 times, the rubber compound was left to stand 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] Vulcanizing agent: 1.8 parts of BIPB, 0.2 parts of sulfur;

[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 10000;

[0061] 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 draining 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 being thin-passed 6 times, the rubber compound was left to stand 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, 5 parts of sodium aluminum silicate;

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

[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, with a molecular weight of 8000;

[0071] 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 draining 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 being thin-passed 6 times, the rubber compound was left to stand 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 material: 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] Vulcanizing agent: 2.8 parts of BIPB, 0.4 parts of sulfur;

[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] 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 draining 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 being thin-passed 6 times, the rubber compound was left to stand 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 material: 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 draining 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 being thin-passed 6 times, the rubber compound was left to stand 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 material: 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] Vulcanizing agent: 2.2 parts of BIPB, 1.0 parts of sulfur;

[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 draining 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 being thin-passed 6 times, the rubber compound was left to stand 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 material: 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] Vulcanizing agent: 2.8 parts of BIPB, 0.4 parts of sulfur;

[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 draining 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 being thin-passed 6 times, the rubber compound was left to stand 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 material: 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] Vulcanizing agent: 2.8 parts of BIPB, 0.4 parts of sulfur;

[0119] Vulcanization accelerator: 1.8 parts of triallyl isocyanurate, 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 draining 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 being thin-passed 6 times, the rubber compound was left to stand 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 material: 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] Vulcanizing agent: 2.8 parts of BIPB, 0.4 parts of sulfur;

[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 draining 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 being thin-passed 6 times, the rubber compound was left to stand 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 frost 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. The test method shall 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 x 500 h x 95% humidity) and observe the blooming.

[0140] (4) Blooming experiment 2 (sunlight irradiation): OSRAM sunlamp (300W) was used to irradiate continuously 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 permanent deformation of the BIPB vulcanized EPDM rubber prepared in the embodiment of the present invention is less than 24.1%, as low as 20.56%; the tensile strength is not less than 17.9, reaching 19.8%; the elongation is greater than 430%, reaching 465.9%. The compression permanent deformation, tensile strength and elongation of the BIPB vulcanized EPDM rubber prepared in the embodiment of the present invention are better than those of the EPDM rubber prepared in the comparative example. By comparing Example 1 and the comparative example, it can be seen that the BIPB vulcanized EPDM rubber prepared in Comparative Example 1 only uses the vulcanizing agent BIPB, and although it has a high elongation, its compression permanent deformation and tensile strength are significantly reduced. Comparative Example 2 uses more vulcanizing agent sulfur, which not only causes more serious frosting, but also affects the degree of crosslinking, thereby affecting the compression permanent deformation and tensile strength of the EPDM rubber. In Comparative Example 3 and Comparative Example 4, when only one or two accelerators are used, the compression permanent deformation and strength of the prepared BIPB vulcanized EPDM rubber will be 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 will be 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, and slight light spots were observed under lighting, but the overall condition was good and had relatively little impact on subsequent processing and use. Figure 2 ) and OSRAM solar light treatment, the crystals were visible to the naked eye. Comparative Example 2 used more sulfur as a vulcanizing agent, and after being placed under high temperature and high humidity conditions, obvious crystal precipitation was observed with the naked eye (see Figure 3 ), after being treated with light, obvious crystal precipitation can be seen under the condition of illumination (see Figure 4This is because EPDM 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 work well with the BIPB, but will have the opposite effect. Comparative Example 3: When only one accelerator is used, the BIPB-vulcanized EPDM rubber prepared under high temperature, high humidity and OSRAM solar light conditions will have obvious crystal precipitation visible to the naked eye (see Figure 3 and Figure 3, respectively). Figure 5 and Figure 6 ). Comparative Example 4: In the case of using only two accelerators, the BIPB vulcanized EPDM rubber prepared was placed under high temperature and high humidity conditions and slight crystal precipitation was observed with the naked eye (see Figure 7 ); after being treated with light, obvious crystal precipitation can be seen under the condition of lighting (see Figure 8 ). Comparative Example 5 uses low molecular weight polyethylene glycol as a vulcanization activator. Although no blooming occurs after being placed under high temperature and high humidity conditions, crystal precipitation is observed under light treatment (see Fig. 9 ), its light stability decreases.

[0147] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A BIPB vulcanized ethylene propylene diene monomer rubber, characterized in that: The invention 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 comprises 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 weight, 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 weight, 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, and the vulcanizing agent 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 the BIPB vulcanized ethylene propylene diene monomer 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 a 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.

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