Ethylene propylene rubber and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and particularly provides ethylene propylene rubber and a preparation method thereof.The preparation method comprises the following steps that S100, low migration oil and white carbon black are sequentially added into an ethylene propylene rubber base material, first mixing treatment is carried out, then flame-retardant master batch is added, second mixing treatment is carried out, and master batch is obtained after cooling; s200, sequentially adding a vulcanizing agent and an accelerant or a cross-linking agent into the rubber master batch, uniformly mixing, and reacting to obtain cooked rubber; s300, performing plasma treatment on the cooked rubber to obtain ethylene propylene rubber; wherein the flame-retardant master batch comprises a microcapsule containing a flame retardant. The microencapsulated flame-retardant master batch is introduced, so that the problems that a traditional flame retardant is easy to migrate and lose, uneven in dispersion and the like in the mixing and using processes of the ethylene propylene rubber are effectively solved; through microcapsule packaging, the flame retardant can be stably kept in a rubber matrix, performance degradation caused by direct doping is avoided, controlled release can be achieved under the high-temperature condition, and the flame retardant performance is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular, the present application provides a kind of ethylene-propylene rubber and its preparation method. BACKGROUND

[0002] Ethylene-propylene rubber is widely used in automobile parts, building waterproof materials, wire and cable sheath, heat-resistant rubber tube, adhesive tape and lubricating oil modification fields due to its main chain composed of chemically stable saturated hydrocarbon, excellent aging resistance to ozone, heat, weather, etc., and good chemical resistance, electrical insulation, impact elasticity, low temperature performance, low density and high filling property, as well as heat water resistance and water vapor resistance.

[0003] However, the main chain of ethylene-propylene rubber is composed of chemically stable saturated hydrocarbon, and only a small amount of unsaturated double bond is contained on the side chain. This structure makes it lack of high polarity or aromatic structure, and the cohesive energy between molecular chains is low, with an oxygen index (LOI) of about 19-21, belonging to flammable materials. During combustion, most of the decomposition products are combustible gases, which can easily burn after mixing with oxygen and release a large amount of heat, promoting further thermal decomposition and combustion of the material, forming a vicious cycle.

[0004] In order to improve the flame retardant performance of ethylene-propylene rubber, a flame retardant is usually added during the preparation of ethylene-propylene rubber. However, many flame retardants are polar, while ethylene-propylene rubber is non-polar. This difference in polarity makes the compatibility between the two poor. With the passage of time, the flame retardant molecules are prone to migrate from the inside of the rubber to the surface, which not only causes the surface to stick or affect the appearance, but also reduces the content of the flame retardant inside the rubber, and the flame retardant performance gradually decreases. In order to achieve the desired flame retardant effect, a large amount of flame retardant is often added to the rubber, which seriously affects the physical and mechanical properties of ethylene-propylene rubber, resulting in significant decrease in key indicators such as tensile strength, elongation and elasticity. Therefore, how to enhance the flame retardant performance of ethylene-propylene rubber without affecting its performance has been the goal pursued by experts in the field. SUMMARY

[0005] The present application aims to solve at least one of the above problems.

[0006] The present application provides a preparation method of ethylene-propylene rubber, the preparation method comprising the following steps: S100, sequentially adding low-migration oil and white carbon black to the ethylene-propylene rubber base material, performing first mixing treatment, then adding flame retardant masterbatch, performing second mixing treatment, and obtaining masterbatch after cooling; S200, sequentially adding vulcanizing agent and accelerator or crosslinking agent to the masterbatch, mixing uniformly, then performing reaction, and obtaining cooked rubber; S300, plasma treating the cooked rubber to obtain ethylene-propylene rubber; The flame-retardant masterbatch comprises microcapsules containing a flame retardant.

[0007] In the technical solution, the mass ratio of the ethylene-propylene rubber base material, the low-migration oil and the white carbon black is 1:(0.2-0.35):(0.3-0.5); and / or the mass ratio of the ethylene-propylene rubber base material and the flame-retardant masterbatch is 1:(0.3-0.4); and / or the mass ratio of the ethylene-propylene rubber base material and the vulcanizing agent and the accelerator is 1:(0.005-0.015):(0.001-0.012); and / or the mass ratio of the ethylene-propylene rubber base material and the vulcanizing agent and the cross-linking agent is 1:(0.005-0.015):(0.008-0.03).

[0008] In any of the technical solutions, the oil comprises mineral oil or low-aromatic naphthenic oil; and / or the vulcanizing agent comprises sulfur or peroxide; and / or the accelerator comprises at least one of p-phenylene dithio carbamate, diphenyl disulfide and tetramethyl tetra-thio diurea or a combination thereof; and / or the cross-linking agent comprises TAIC or TAC.

[0009] In any of the technical solutions, the preparation method of the flame-retardant masterbatch comprises: S101, preheating an oil phase, and then adding the oil phase into an aqueous phase containing an emulsifier to uniformly disperse to obtain an emulsion; S102, stirring the emulsion, and then sequentially adding tetraethoxysilane and an alkaline catalyst in the stirring process, and then sequentially performing centrifugal treatment, washing treatment and drying treatment to obtain microcapsules containing a flame retardant; S103, adding the microcapsules containing the flame retardant into low-migration oil to uniformly stir to obtain a flame-retardant masterbatch; In the technical solution, the oil phase comprises carrier oil and a flame retardant; and the aqueous phase comprises deionized water and polyvinyl alcohol.

[0010] In any of the technical solutions, the carrier oil comprises at least one of hydrogenated naphthenic oil, low-aromatic hydrocarbon mineral oil and light paraffin oil or a combination thereof; and / or the flame retardant comprises at least one of DOPO derivatives, ammonium polyphosphate and soluble expanded graphite paste or a combination thereof.

[0011] In any of the technical solutions, S300 comprises: S310, performing plasma treatment on the aged rubber by using oxygen or inert gas as plasma gas under atmospheric pressure; S320, after the plasma treatment, coating a silane solution on the surface after the plasma treatment, and then sequentially performing drying treatment and washing treatment to obtain ethylene-propylene rubber.

[0012] In any of the technical solutions above, the power of the plasma treatment is 100-300 W; and / or the temperature of the drying treatment is 80-120 DEG C; and / or the time of the drying treatment is 10-30 min.

[0013] In any of the technical solutions above, S200 comprises: S210, adding vulcanizing agent and accelerator or crosslinking agent into the masterbatch in sequence, and mixing uniformly; S220, sequentially performing standing treatment, vulcanization treatment and curing treatment to obtain the cured rubber.

[0014] In any of the technical solutions above, the time of the standing treatment is 12-24 h; and / or the temperature of the vulcanization treatment is 150-180 DEG C; and / or the time of the vulcanization treatment is 8-25 min; and / or the temperature of the curing treatment is 120-150 DEG C; and / or the time of the curing treatment is 2-8 h.

[0015] The application also provides an ethylene-propylene rubber, and the chloro-terminated polydimethylsiloxane is prepared by the preparation method in any of the above technical solutions. Thus, the ethylene-propylene rubber has the beneficial effects of any of the above technical solutions, which will not be described herein.

[0016] The technical effects achieved by the technical solutions of the application are as follows: 1. The application effectively solves the problems of easy migration, loss and uneven dispersion of traditional flame retardants in the mixing and use of ethylene-propylene rubber by introducing a microencapsulated flame retardant masterbatch; 2. The flame retardant can be stably maintained in the rubber matrix by microencapsulation, avoiding performance degradation caused by direct incorporation, and can be released under high temperature conditions, improving the flame retardant performance; 3. The purpose of the plasma treatment is to generate stable chemical active sites on the rubber surface and improve the surface energy, so as to firmly fix the silane on the surface through covalent or condensation bond, thereby obtaining an antibacterial surface with long-term wash resistance and aging resistance. DETAILED DESCRIPTION

[0017] In order to more clearly understand the above-mentioned purposes, features and advantages of the application, the application will be further described in detail below with specific embodiments. It should be noted that the embodiments of the application and the features in the embodiments can be combined with each other without conflict.

[0018] In the following description, many specific details are set forth in order to provide a thorough understanding of the application, but the application can also be implemented in other ways different from those described herein, therefore, the protection scope of the application is not limited by the specific embodiments disclosed below.

[0019] In order to make the above-mentioned purposes, features and advantages of the present aspect more apparent and easy to understand, the specific embodiments of the present aspect are described in detail below.

[0020] In the related art, in order to improve the flame retardant performance of the ethylene-propylene rubber, a flame retardant is usually added in the preparation process of the ethylene-propylene rubber, but the compatibility of the flame retardant with the ethylene-propylene rubber is poor, and with the passage of time, the flame retardant molecules are prone to migrate from the inside of the rubber to the surface, which not only causes the surface to be sticky or affects the appearance, but also reduces the content of the flame retardant in the rubber and gradually reduces the flame retardant performance; and in order to achieve the ideal flame retardant effect, a large amount of flame retardant is often added in the rubber, which seriously affects the physical and mechanical properties of the ethylene-propylene rubber, resulting in a significant decrease in the tensile strength, elongation and elasticity and other key indicators of the ethylene-propylene rubber.

[0021] Therefore, the present application provides a preparation method of ethylene-propylene rubber, which effectively solves the problems of easy migration, loss and uneven dispersion of traditional flame retardants in the mixing and use of ethylene-propylene rubber by introducing a microencapsulated flame retardant masterbatch; through microcapsule packaging, the flame retardant can be stably maintained in the rubber matrix, avoiding the performance degradation caused by direct incorporation, and at the same time, it can be released under controlled conditions at high temperatures, improving the flame retardant performance.

[0022] Specifically, the embodiments of the present application provide a preparation method of ethylene-propylene rubber, the preparation method comprising the following steps: S100, sequentially adding low-migration oil and white carbon black to the ethylene-propylene rubber base material, performing first mixing treatment, then adding a flame retardant masterbatch, performing second mixing treatment, and obtaining a masterbatch after cooling; S200, sequentially adding a vulcanizing agent and an accelerator or a crosslinking agent to the masterbatch, mixing uniformly, then performing reaction, and obtaining a cooked rubber; S300, performing plasma treatment on the cooked rubber to obtain the ethylene-propylene rubber.

[0023] Preferably, first, low-migration oil and white carbon black are added to the ethylene-propylene rubber base material. The main role of the low-migration oil is to adjust the flowability and reduce the viscosity of the rubber, which helps the subsequent processing. It can improve the flowability and uniformity during mixing, ensure that the flame retardant and other components can be uniformly dispersed in the matrix, and are not easy to migrate or precipitate. White carbon black is used to improve the mechanical properties, weather resistance and ultraviolet resistance of the rubber, so that the rubber can still maintain its excellent physical properties when exposed to the natural environment for a long time. The mass ratio of the ethylene-propylene rubber base material, oil and white carbon black is 1:(0.2-0.35):(0.3-0.5), which can improve the mixing and processing flowability and provide reinforcement and weather resistance for the ethylene-propylene rubber. The ethylene-propylene rubber base material should at least include two types of ethylene-propylene rubber, which can be selected according to actual conditions and is not limited here. The low-migration oil includes mineral oil or low-aromatic naphthenic oil, because the ethylene-propylene rubber base material is a non-polar matrix, and the mineral oil and low-aromatic naphthenic oil have good compatibility with it and are more environmentally friendly. The first mixing process makes the white carbon black, low-migration oil and ethylene-propylene rubber base material preliminarily mixed uniformly, ensuring the stability of the matrix and avoiding problems such as uneven dispersion or material incompatibility in subsequent steps, which lays the foundation for the uniform dispersion of subsequent vulcanization, cross-linking and other additives. The temperature of the first mixing process is 100-120°C, and the rotation speed is 40-50 rpm. After the temperature drops to 80°C, the flame retardant masterbatch is added and the second mixing process is carried out at a temperature below 80°C. The flame retardant masterbatch mainly contains microcapsules containing flame retardants. The second mixing process at a temperature below 80°C can avoid damaging the microcapsules. The structure of the microcapsules can effectively wrap the flame retardants, avoiding their volatilization or migration during processing, while triggering release under high-temperature conditions to play a flame-retardant role. By adding the microencapsulated flame retardant masterbatch to the matrix, it is ensured that the flame retardant can be stably distributed in the rubber and triggered to release in a high-temperature environment such as a fire, thereby improving the flame-retardant performance of the rubber. In addition, microencapsulation can reduce the mutual reaction of the flame retardant and other chemicals, avoiding performance degradation due to migration or uneven dispersion.

[0024] Further, the preparation method of the flame retardant masterbatch includes: S101, preheat the oil phase, then add the oil phase to the water phase containing an emulsifier, disperse uniformly, and obtain an emulsion; S102, stir the emulsion, and in the process of stirring, sequentially add tetraethoxysilane and an alkaline catalyst, then sequentially perform centrifugal treatment, washing treatment and drying treatment, to obtain microcapsules containing flame retardants; S103, add the microcapsules containing flame retardants to the low-migration oil, stir uniformly, and obtain the flame retardant masterbatch; Wherein, the oil phase includes carrier oil and flame retardant; the water phase includes deionized water and polyvinyl alcohol.

[0025] Preferably, since the oil phase includes a carrier oil and a flame retardant, many high-efficiency flame retardants are low-melting solids or high-viscosity liquids, preheating can reduce the viscosity, facilitate pumping and homogenization, avoid the formation of large aggregates, and be beneficial to subsequent emulsification. The preheating temperature is preferably 50-70°C; the water phase provides a medium for sol-gel hydrolysis and is convenient for subsequent use of alkali catalyst to control shell formation; the carrier oil includes at least one of hydrogenated naphthenic oil, low-aromatic mineral oil, and light paraffin oil, or a combination thereof; the hydrogenated naphthenic oil, low-aromatic mineral oil, and light paraffin oil have good compatibility with the ethylene-propylene rubber matrix, which is beneficial to the weather resistance and low odor requirements of long-term products, and is low in cost; the flame retardant includes at least one of DOPO derivatives, ammonium polyphosphate, and soluble expanded graphite paste, or a combination thereof; the DOPO derivatives (organic phosphorus derivatives) have small volume, can promote carbonization and inhibit flame spread through gas phase or liquid phase action, and can significantly improve the flame retardance and be beneficial to smoke toxicity at low content; the ammonium polyphosphate can form a dense carbon layer and release acidic substances to catalyze carbonization when burning; the soluble expanded graphite paste expands to form a thick heat-insulating carbon layer at high temperature, greatly reducing the heat release rate; the use of these flame retardants as the core of the oil phase in a single or compounded form can take into account both the rapid gas phase inhibition and the solid phase heat insulation / expansion two flame retardant mechanisms, thereby playing a role in different combustion stages.

[0026] Preferably, after the oil phase and the water phase are mixed, tetraethoxysilane (TEOS) and an alkaline catalyst are added. The addition of TEOS can in situ form a silica shell with good heat resistance and strong barrier property at the oil droplet / water interface through hydrolysis and condensation, better isolating the core at the processing temperature and reducing the volatilization and side reactions of the core. Since the condensation of TEOS has a good rate under alkaline conditions and the density of the network structure formed is controllable, an alkaline catalyst is selected to help adjust the pH to 8-9. The alkaline catalyst needs to be added slowly to avoid the generation of free gel. After the formation of the silica shell, the microcapsule particles can be dispersed by centrifugal treatment, and then washed to remove excess TEOS, and dried to obtain microcapsules containing flame retardants.

[0027] Further, in order to reduce the probability of rupture of the microcapsules containing flame retardants caused by mechanical shearing or transient temperature, the microcapsules containing flame retardants need to be masterbatched, i.e., mixed uniformly in a low-migration oil to obtain a flame retardant masterbatch. The flame retardant masterbatch is more easily dispersed in the ethylene-propylene rubber matrix, which can effectively reduce the agglomeration of the flame retardant. Typically, the content of the microcapsules containing flame retardants in the flame retardant masterbatch is 50%, and the mass ratio of the ethylene-propylene rubber matrix to the flame retardant masterbatch in step S100 is 1:(0.3-0.4), which can significantly improve the flame retardance of the prepared ethylene-propylene rubber.

[0028] Further, to further improve the ductility of the shell, impact resistance, and less likely to break under high shear mixing, a small amount of water soluble amine can be added after the TEOS reaction is complete, followed by a small amount of IPDI (isophorone diisocyanate) or MDI (diphenyl methane diisocyanate) ethyl acetate solution, and then a thin layer of polyurea shell is formed by polymerization, followed by centrifugal treatment, washing treatment and drying treatment, to obtain microcapsules containing flame retardants.

[0029] Preferably, in step S200, by adding vulcanizing agent, accelerator or crosslinking agent, crosslinking structure can be formed between rubber molecules, which has higher mechanical strength, elasticity, heat resistance and aging resistance, S200 includes the following steps: S210, adding vulcanizing agent, accelerator and crosslinking agent to the masterbatch in turn, and mixing uniformly; S220, sequentially performing standing treatment, vulcanization treatment and curing treatment to obtain cured rubber.

[0030] Preferably, first, add vulcanizing agent, accelerator or crosslinking agent in sequence, the accelerator will directly affect the vulcanization kinetics, in order to avoid premature activation at high temperature or high shear, the vulcanizing agent includes sulfur or peroxide, sulfur forms C-S-C, C-S n , etc. sulfur-containing bonds on the unsaturated sites of rubber through free radicals or intermediates, the network is more flexible, which gives the ethylene-propylene rubber excellent rebound performance, fatigue resistance and excellent tear resistance, peroxide can generate oxygen free radicals, extract hydrogen and directly form C-C cross-linking, which gives the ethylene-propylene rubber better heat resistance and aging resistance; after the masterbatch is prepared in step S100, if sulfur system is used, sulfur and accelerator are added in the low temperature thin pass stage and added as much as possible in the last stage before discharging, the mass ratio of ethylene-propylene rubber base material to vulcanizing agent and accelerator is 1: (0.005-0.015): (0.001-0.012), the accelerator preferably uses at least one of p-phenylene dithio carbamate, diphenyl disulfide and tetramethyl tetra thiourea; for peroxide system, peroxide and co-crosslinking agent should be added in the thin pass stage and as much as possible to prevent long-term stay at high temperature, the crosslinking agent preferably uses TAIC or TAC, the mass ratio of ethylene-propylene rubber base material to vulcanizing agent and crosslinking agent is 1: (0.005-0.015): (0.008-0.03).

[0031] Further, after adding the vulcanizing agent, accelerator or crosslinking agent, sample testing of the vulcanization curve is required, when the torque = ML+90% x (MH-ML), the discharge can be carried out for subsequent standing treatment and other steps, wherein ML is the minimum torque and MH is the torque peak value.

[0032] Preferably, in step S200, the standing treatment is to let the added vulcanizing agent, accelerator and crosslinking agent fully wet, migrate and disperse in the masterbatch, reduce the internal stress after mixing and thinning, avoid the appearance of pores and internal stress during vulcanization, and avoid apparent defects. In addition, the standing treatment can make the oil in the masterbatch more evenly infiltrate the surface of the microcapsule, reduce the microcapsule rupture rate under instantaneous shear stress, and the standing treatment time is 12-24h, which can obtain better effect; the vulcanization treatment is a key process in rubber processing, which improves the performance of rubber through crosslinking reaction during vulcanization treatment, and the vulcanization treatment temperature is 150-180℃, and the time is 8-25min, which can give the ethylene-propylene rubber a reasonable crosslinking density, and consider strength, elasticity and heat resistance; the aging treatment is used to continue to improve the crosslinking network and complete the delayed reaction, so as to reduce the content of residual accelerators and the like, improve heat aging and compression permanent deformation, stabilize size and eliminate microdefects caused by uneven vulcanization, and the aging treatment at 120-150℃ for 2-8h can continue to promote crosslinking rearrangement and network self-healing under the premise of not damaging the inner core microcapsule shell.

[0033] Preferably, in step S300, the surface is efficiently functionalized without changing the internal structure of the rubber through plasma treatment, thereby giving the ethylene-propylene rubber antibacterial properties and effectively improving the safety and hygiene of the ethylene-propylene rubber; S300 includes: S310, using oxygen or inert gas as plasma gas to treat the aged rubber under atmospheric pressure; S320, after plasma treatment, coating a silane solution on the surface treated by plasma, and sequentially performing drying treatment and washing treatment to obtain the ethylene-propylene rubber.

[0034] Preferably, the purpose of the plasma treatment is to generate stable chemical active sites on the surface of the mature rubber and to increase the surface energy, so as to firmly fix the functional molecules on the surface through covalent or condensation bonds, so as to obtain a long-term wash-resistant, anti-aging and antibacterial surface. The plasma treatment is carried out on the mature rubber under atmospheric pressure by using oxygen or inert gas as the plasma gas. O2 ionization produces active oxygen, which can replace / oxidize s mature rubber surface C-H, introduce polar groups and simultaneously etch / roughen the micro surface, thereby significantly improving the surface polarity and surface energy, providing a large number of surface hydroxyl sites that can condense with silane, facilitating silane chemical bonding, and thereby obtaining firm grafting. The inert gas mainly generates free radicals on the surface through ion bombardment and electron impact, and can clean the surface, break the surface C-H to generate active sites, and simultaneously roughen the micro surface. The inert gas can generate high-density free radicals and does not introduce additional oxidation groups, so that the surface is more easily bonded with organic silane in a free radical type. Preferably, argon or a mixture of argon and oxygen is used for plasma treatment. The power of the plasma treatment is preferably 100-300 W. A power lower than 100 W may result in insufficient activation density, low surface grafting efficiency, and a density after grafting that does not meet the requirements. A power higher than 300 W may result in excessive surface modification depth and energy input, which can easily lead to chain rupture, surface crosslinking or thermal damage.

[0035] Further, after the plasma treatment, a silane solution is coated on the surface after the plasma treatment. To obtain better antibacterial effect, it is preferred to use a quaternary ammonium functional silane for coating. The temperature of the drying treatment is 80-120°C, and the time is 10-30 min. Finally, washing treatment is performed to remove unreacted silane molecules and solvent residues. Preferably, ethanol is used for washing treatment. After washing, further drying is required. Finally, the ethylene-propylene rubber is obtained.

[0036] Example 1 The present embodiment provides an ethylene-propylene rubber, which is prepared by the following preparation method: S100, mineral oil and white carbon black are sequentially added to the ethylene-propylene rubber base material, the mass ratio of the ethylene-propylene rubber base material, the mineral oil and the white carbon black is 1:0.2:0.3, first mixing treatment is performed, then flame retardant masterbatch is added, the mass ratio of the ethylene-propylene rubber base material and the flame retardant masterbatch is 1:0.3, second mixing treatment is performed, and the masterbatch is obtained after cooling; S200, sulfur and p-phenylenedithiocarbamic acid are sequentially added to the masterbatch according to the mass ratio of the ethylene-propylene rubber base material, the vulcanizing agent and the accelerator is 1:0.005:0.001, the mixture is uniformly mixed, and then reacted to obtain the mature rubber; S300, the mature rubber is subjected to plasma treatment to obtain the ethylene-propylene rubber; The flame retardant masterbatch comprises microcapsules containing a flame retardant. The preparation method of the flame retardant masterbatch comprises: S101, preheat the oil phase, then add the oil phase into the water phase containing emulsifier, disperse uniformly, and obtain an emulsion; S102, stir the emulsion, and sequentially add tetraethoxysilane and alkaline catalyst in the stirring process, then sequentially perform centrifugal treatment, washing treatment and drying treatment, and obtain microcapsules containing flame retardant; S103, add the microcapsules containing flame retardant into low-migration oil, stir uniformly, and obtain flame retardant masterbatch; The oil phase comprises hydrogenated naphthenic oil and DOPO derivative; and the water phase comprises deionized water and polyvinyl alcohol.

[0037] Embodiment 2 The embodiment provides an ethylene-propylene rubber prepared by the following preparation method. S100, sequentially add low-aromatic naphthenic oil and white carbon black into the ethylene-propylene rubber base material, the mass ratio of the ethylene-propylene rubber base material, the low-aromatic naphthenic oil and the white carbon black is 1:0.35:0.5, perform first mixing treatment, then add flame retardant masterbatch, the mass ratio of the ethylene-propylene rubber base material and the flame retardant masterbatch is 1:0.4, perform second mixing treatment, and obtain masterbatch after cooling; S200, sequentially add sulfur and dibenzothiazyl disulfide into the masterbatch according to the mass ratio of the ethylene-propylene rubber base material, the sulfur and the dibenzothiazyl disulfide is 1:0.015:0.012, mix uniformly, and perform reaction, and obtain cooked rubber; S300, perform plasma treatment on the cooked rubber, and obtain ethylene-propylene rubber; The flame retardant masterbatch comprises microcapsules containing flame retardant, and the preparation method of the flame retardant masterbatch comprises: S101, preheat the oil phase, then add the oil phase into the water phase containing emulsifier, disperse uniformly, and obtain an emulsion; S102, stir the emulsion, and sequentially add tetraethoxysilane and alkaline catalyst in the stirring process, then sequentially perform centrifugal treatment, washing treatment and drying treatment, and obtain microcapsules containing flame retardant; S103, add the microcapsules containing flame retardant into low-migration oil, stir uniformly, and obtain flame retardant masterbatch; The oil phase comprises low-aromatic hydrocarbon mineral oil and ammonium polyphosphate; and the water phase comprises deionized water and polyvinyl alcohol. S200 comprises: S210, sequentially add sulfur and dibenzothiazyl disulfide into the masterbatch, and mix uniformly; S220, after standing treatment for 12 hours, perform vulcanization treatment at 150 DEG C for 25 minutes, and then perform curing treatment at 120 DEG C for 8 hours, and obtain cooked rubber; S300 comprises: S310, the oxygen is used as the plasma gas to perform plasma treatment on the aged rubber at 100W under atmospheric pressure; S320, after the plasma treatment, a silane solution is coated on the surface after the plasma treatment, and after drying treatment at 80°C for 30min, washing treatment is performed to obtain the ethylene-propylene rubber.

[0038] Embodiment 3 The embodiment provides an ethylene-propylene rubber prepared by the following preparation method. S100, low-aromatic naphthenic oil and white carbon black are sequentially added to the ethylene-propylene rubber base material, the mass ratio of the ethylene-propylene rubber base material, the low-aromatic naphthenic oil and the white carbon black is 1:0.3:0.4, first mixing treatment is performed, then flame retardant masterbatch is added, the mass ratio of the ethylene-propylene rubber base material and the flame retardant masterbatch is 1:0.35, second mixing treatment is performed, and after cooling, a masterbatch is obtained; S200, peroxide and TAC are sequentially added to the masterbatch according to the mass ratio of the ethylene-propylene rubber base material, the peroxide and the TAC is 1:0.01:0.01, after uniform mixing, reaction is performed, and an aged rubber is obtained; S300, the aged rubber is subjected to plasma treatment to obtain an ethylene-propylene rubber; The flame retardant masterbatch comprises microcapsules containing a flame retardant, and the preparation method of the flame retardant masterbatch comprises the following steps: S101, the oil phase is preheated, then the oil phase is added to the water phase containing an emulsifier, and is uniformly dispersed to obtain an emulsion; S102, the emulsion is stirred, and tetraethoxysilane and an alkaline catalyst are sequentially added in the stirring process, and then centrifugal treatment, washing treatment and drying treatment are sequentially performed to obtain the microcapsules containing the flame retardant; S103, the microcapsules containing the flame retardant are added to low-migration oil, and are uniformly stirred to obtain the flame retardant masterbatch; The oil phase comprises light paraffin oil and soluble expanded graphite slurry; and the water phase comprises deionized water and polyvinyl alcohol; S200 comprises: S210, sulfur and dibenzothiazyl disulfide are sequentially added to the masterbatch, and are uniformly mixed; S220, after standing treatment for 24h, vulcanization treatment is performed at 180°C for 8min, and then curing treatment is performed at 150°C for 8h to obtain an aged rubber; S300 comprises: S310, the oxygen is used as the plasma gas to perform plasma treatment on the aged rubber at 300W under atmospheric pressure; S320, after the plasma treatment, a silane solution is coated on the surface after the plasma treatment, and after drying treatment at 120°C for 10min, washing treatment is performed to obtain the ethylene-propylene rubber.

[0039] Performance test Take standard sample size sample, the ethylene propylene rubber in example 1-3 is tested as follows: Limiting oxygen index test: the minimum oxygen concentration required for the ethylene propylene rubber of example 1-3 to burn is tested according to GB / T 2406.2; Antibacterial performance test: the colony log reduction value of the ethylene propylene rubber of example 1-3 relative to ordinary ethylene propylene rubber is tested according to ISO 22196; the colony log reduction value of the ethylene propylene rubber of example 1-3 relative to ordinary ethylene propylene rubber is tested again according to ISO 22196 after the ethylene propylene rubber of example 1-3 is rubbed 10000 times; The test results are shown in table 1.

[0040] Table 1 As can be seen from table 1, the ethylene propylene rubber of example 1-3 requires more oxygen to burn, and the limiting oxygen index of the ethylene propylene rubber of example 1-3 is all greater than 30%, indicating that the ethylene propylene rubber prepared by the preparation method described in the present application has reached the flame-retardant grade; the colony log reduction value of the ethylene propylene rubber of example 1-3 before and after rubbing is not much different, and the colony log reduction value is all greater than 2, indicating that it has good antibacterial performance.

[0041] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "a specific embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are contained in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0042] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, therefore the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A process for the preparation of an ethylene-propylene rubber, characterized in that, The preparation method comprises the following steps: S100, sequentially adding low-migration oil and white carbon black into ethylene-propylene rubber base material, performing first mixing treatment, then adding flame-retardant masterbatch, performing second mixing treatment, and obtaining masterbatch after cooling; S200, sequentially adding vulcanizing agent and accelerator or crosslinking agent into the masterbatch, mixing uniformly, and performing reaction to obtain cooked rubber; S300, performing plasma treatment on the cooked rubber to obtain the ethylene-propylene rubber; The flame-retardant masterbatch comprises microcapsules containing flame retardant.

2. The preparation method according to claim 1, wherein the mass ratio of the ethylene-propylene rubber base material, the low-migration oil and the white carbon black is 1: (0.2-0.35): (0.3-0.5); and / or the mass ratio of the ethylene-propylene rubber base material and the flame-retardant masterbatch is 1: (0.3-0.4); and / or the mass ratio of the ethylene-propylene rubber base material, the vulcanizing agent and the accelerator is 1: (0.005-0.015): (0.001-0.012); and / or the mass ratio of the ethylene-propylene rubber base material, the vulcanizing agent and the crosslinking agent is 1: (0.005-0.015): (0.008-0.03).

3. The preparation method according to claim 2, wherein the oil comprises mineral oil or low-aromatic naphthenic oil; and / or the vulcanizing agent comprises sulfur or peroxide; and / or the accelerator comprises at least one of p-phenylene dithio carbamate, diphenyl disulfide and tetramethyl tetra-thio diurea or a combination thereof; and / or the crosslinking agent comprises TAIC or TAC. The preparation method of the flame-retardant masterbatch comprises: S101, preheating oil phase, then adding the oil phase into water phase containing emulsifier, uniformly dispersing to obtain emulsion; S102, stirring the emulsion, then sequentially adding tetraethoxysilane and alkaline catalyst during the stirring, and then sequentially performing centrifugal treatment, washing treatment and drying treatment to obtain the microcapsules containing flame retardant; S103, adding the microcapsules containing flame retardant into low-migration oil, stirring uniformly to obtain the flame-retardant masterbatch; The oil phase comprises carrier oil and flame retardant; The water phase comprises deionized water and polyvinyl alcohol.

5. The preparation method according to claim 4, wherein the carrier oil comprises at least one of hydrogenated naphthenic oil, low-aromatic hydrocarbon mineral oil and light paraffin oil or a combination thereof; and / or the flame retardant comprises at least one of DOPO derivative, ammonium polyphosphate and soluble expandable graphite paste or a combination thereof. The S300 comprises:

4. The production method according to claim 2, characterized by, S310, performing plasma treatment on the cooked rubber under atmospheric pressure by using oxygen or inert gas as plasma gas; S320, after the plasma treatment, coating silane solution on the surface after the plasma treatment, and sequentially performing drying treatment and washing treatment to obtain the ethylene-propylene rubber.

7. The preparation method according to claim 6, wherein the power of the plasma treatment is 100-300 W; and / or the temperature of the drying treatment is 80-120℃; and / or ​ ​ ​ ​ ​ ​ 6. The method of claim 1, wherein, ​ ​ ​ ​ ​ ​ The drying treatment time is 10-30 min.

8. The method of claim 1, wherein, The S200 comprises: S210, sequentially adding the above curing agent and the above accelerator or the above cross-linking agent into the master batch, and mixing uniformly; S220, sequentially performing standing treatment, vulcanization treatment and curing treatment to obtain the cured rubber.

9. The preparation method according to claim 8, characterized in that, the standing treatment time is 12-24 h; and / or the vulcanization treatment temperature is 150-180 ℃; and / or the vulcanization treatment time is 8-25 min; and / or the curing treatment temperature is 120-150 ℃; and / or the curing treatment time is 2-8 h.

10. An ethylene propylene rubber characterized by, The chloro-terminated polydimethylsiloxane is prepared by the preparation method according to any one of claims 1-9.

Images