Method for preparing hydrogenated rubber latex based on water-soluble rhodium-containing catalyst emulsion polymerization hydrogenation method

Abstract

The invention discloses a method for preparing hydrogenated rubber latex based on an emulsion polymerization hydrogenation method of a rhodium-containing catalyst dissolved in water, which simplifies two processes of nitrile butadiene rubber (NBR) emulsion polymerization and NBR latex hydrogenation in the existing HNBR latex preparation method, and has the advantages of short process flow, high efficiency, low energy consumption, greenness and the like. The preparation method comprises the following steps: carrying out polymerization reaction on a diene monomer and a copolymerizable monomer at high temperature by using at least one hydrogenation catalyst, an initiator, a surfactant and other auxiliaries, and then directly introducing hydrogen to carry out hydrogenation reaction, thereby obtaining the hydrogenated rubber latex. According to the invention, the processes of post-treatment of NBR latex, oxygen removal before hydrogenation and addition of a catalyst are reduced, and pollution to the environment after volatilization of unreacted monomers is prevented.

Description

Technical Field

[0001] The present invention belongs to the technical field of special rubber latex synthesis, and relates to a method for preparing hydrogenated rubber latex by emulsion polymerization hydrogenation based on a rhodium-containing catalyst soluble in water. In particular, it relates to a method for polymerizing a diene monomer and a comonomer at a high temperature using at least one rhodium-containing catalyst soluble in water, a cocatalyst insoluble in water, a polymerization initiator, and at least one surfactant, and then raising the temperature and introducing hydrogen for direct hydrogenation to prepare hydrogenated rubber latex. Background Art

[0002] Hydrogenation of unsaturated polymers is an important process in polymer chemical modification. It not only provides a targeted method for improving the mechanical, chemical, physical, and thermal properties of unsaturated polymers, but also provides a convenient way to synthesize polymers with desired microstructures and unique stereochemical properties.

[0003] Selective hydrogenation of unsaturated olefin groups in nitrile rubber (NBR) is a commercially successful hydrogenation process in the industry. Hydrogenated nitrile rubber (HNBR) retains the elastomeric properties of nitrile rubber, has excellent resistance to thermal oxidative degradation, and shows significant improvement in mechanical properties such as tensile strength, elongation at break, abrasion resistance, and hardness. Due to these superior physicochemical properties, HNBR has found important applications in automotive, oil well, aerospace, and various applications with high performance requirements. Since 1977, hydrogenated nitrile rubber has become the most important member of hydrogenated elastomers and is the main force in high-performance elastomer applications.

[0004] The traditional preparation process of HNBR is divided into two steps: 1. Emulsion copolymerization of acrylonitrile and butadiene to prepare NBR latex; 2. Hydrogenation of NBR to prepare HNBR. At present, NBR latex is usually prepared by reacting acrylonitrile-butadiene emulsion monomers, initiators, surfactants and other auxiliaries in an aqueous medium to produce NBR. However, a large amount of unreacted monomers exist in the NBR latex prepared by the above method, resulting in a high content of VOC (volatile organic compounds) in the product, which will cause certain harm to the environment; and the content of residual monomers will also affect the subsequent hydrogenation process. For the hydrogenation step, the existing processes for preparing HNBR using NBR latex are divided into catalytic hydrogenation and non-catalytic hydrogenation, among which catalytic hydrogenation is further divided into emulsion hydrogenation and solution hydrogenation; non-catalytic hydrogenation refers to the hydrazine hydrate hydrogenation method. Among them: (1) The hydrazine hydrate hydrogenation method is that NBR latex directly generates HNBR latex under the action of hydrazine hydrate, oxidants such as oxygen or hydrogen peroxide, and metal ion initiators such as copper and iron. The main advantage of the hydrazine hydrate hydrogenation method is that the hydrogenation reaction is carried out under normal pressure, the reaction conditions are mild, and the equipment is simple. The disadvantage is that cross-linking side reactions are likely to occur on the unhydrogenated double bonds. If the cross-linking is severe, it will lead to difficult plasticization, so there is no industrial production for the time being. (2) NBR solution hydrogenation method: The NBR solution hydrogenation method is currently the main method for industrial production of HNBR. During operation, the NBR latex needs to be flocculated into solid rubber first, and then crushed and dissolved in a large amount of organic solvents. The organic solvents mainly include cyclohexanone, xylene and chloroform, etc., which will not only cause environmental pollution, but also have a long reaction time, a high reaction temperature, a large energy consumption, and require a large amount of cost and time. According to different catalysts, the NBR solution hydrogenation method is divided into heterogeneous solution hydrogenation method and homogeneous solution hydrogenation method. Among them, the catalyst for the homogeneous solution hydrogenation method includes an inorganic carrier and a Group VIII metal coated on the inorganic carrier, and the catalyst for the heterogeneous solution hydrogenation method includes an inorganic carrier and rhodium-based, ruthenium-based and palladium-based metals coated on the inorganic carrier. The inorganic carrier includes alumina, silica, activated carbon, carbon black, alkaline earth metal carbonates, etc. After the heterogeneous solution hydrogenation reaction is completed, the hydrogenation product and the catalyst are usually separated directly by filtration or centrifugation. For example, Zeon Corporation of Japan first used supported catalysts for NBR hydrogenation reaction in the 1980s. The heterogeneous carrier catalyst it used was a palladium / carbon catalyst with carbon as the carrier. The selectivity of this catalyst is high, and the highest hydrogenation rate can reach 95.6%. However, in the hydrogenation reaction, since carbon is easy to adsorb rubber molecules and cause agglomeration, the product performance is affected. In addition, most of the active components of the supported catalyst prepared by the traditional method are distributed inside the pores. Therefore, NBR molecules must diffuse into the pores to carry out the hydrogenation reaction. To improve the reaction rate, the reaction must be carried out under the conditions of high pressure and strong stirring, and the reaction time is long, the process energy consumption is high, and the polymer performance is likely to deteriorate.

[0005] In order to avoid the cumbersome hydrogenation steps in solution hydrogenation and avoid the use of a large amount of toxic solvents, the emulsion hydrogenation method was proposed. The emulsion hydrogenation method is a method of directly adding a catalyst to the NBR emulsion and then preparing the HNBR emulsion through a hydrogen reduction reaction. Compared with the organic solution catalytic hydrogenation method, the aqueous-phase NBR emulsion catalytic hydrogenation has very obvious advantages: such as relatively mild reaction conditions compared to solution hydrogenation, fewer reaction processes, no need to use organic solvents, which can save energy and reduce pollution. The emulsion catalytic hydrogenation method greatly reduces the preparation cost of HNBR, and the hydrogenated product can be directly applied to industries with demand for HNBR emulsion. In this field, the research group led by Professor Garry L. Rempel has carried out a large amount of work and achieved quite excellent research results. However, due to factors such as fewer NBR latex grades that can achieve emulsion hydrogenation with existing polymerization technologies and the further introduction of a large amount of surfactants during the hydrogenation process, the emulsion catalytic hydrogenation technology has not yet met the requirements of industrial production.

[0006] To sum up, the existing methods for producing HNBR are carried out in two steps: that is, in the first step, NBR latex is generated through emulsion polymerization, and then NBR is hydrogenated to obtain HNBR. Currently, the manufacture of NBR generally adopts the emulsion polymerization process, that is, a process of adding monomers, initiators, surfactants and other auxiliaries in an aqueous medium to react to generate NBR. After the polymerization is completed, the NBR latex needs to be post-treated before the second-step hydrogenation reaction, and deoxygenation also needs to be continued before hydrogenation; the second-step hydrogenation process includes: 1. Traditional catalytic hydrogenation, including catalytic emulsion hydrogenation and catalytic solution hydrogenation; 2. Non-catalytic hydrogenation, which also requires the preparation of NBR latex first, and then non-catalytic means are used, and diimide is used to participate in the redox reaction to generate a hydrogen source. At present, in order to obtain a fast hydrogenation reaction rate, high conversion rate and eliminate the formation of gels, and save time, cost and reduce environmental pollution, the above two-step polymerization hydrogenation methods have encountered great obstacles. Therefore, it is necessary to further improve the technology for producing HNBR. Summary of the Invention

[0007] To address the above technical problems, the present invention provides a method for preparing hydrogenated rubber latex by emulsion polymerization hydrogenation combined with a rhodium-containing catalyst soluble in water, and also provides the hydrogenated rubber latex prepared by the method and its applications. The present invention integrates and simplifies the existing rubber emulsion polymerization and emulsion hydrogenation, aiming to solve the drawbacks of the existing technology such as cumbersome process flow, low efficiency, high energy consumption, and large pollution. In the method of the present invention, a diene monomer and a comonomer are used to synthesize HNBR. A hydrogenation catalyst is added before polymerization. After the polymerization reaction is completed, hydrogen is directly introduced for hydrogenation, reducing the post-treatment of NBR latex and eliminating the processes of adding the hydrogenation catalyst and deoxygenation before hydrogenation. Therefore, it has the advantages of saving time, cost, and being environmentally friendly. In addition, the hydrogenated rubber latex prepared by the method of the present invention has a higher hydrogenation degree and a faster hydrogenation rate than the hydrogenated rubber latex synthesized by the traditional method.

[0008] To achieve the above invention objectives, the present invention provides the following technical solutions:

[0009] A method for preparing hydrogenated rubber latex, the method comprising the following steps:

[0010] The diene monomer and the comonomer are first subjected to a polymerization reaction in the presence of a polymerization initiator, a surfactant, a rhodium-containing catalyst soluble in water, and a cocatalyst. After the polymerization reaction is completed, a terminator is added, and then the temperature is raised and hydrogen is introduced directly for a hydrogenation reaction to obtain a hydrogenated rubber latex.

[0011] According to an embodiment of the present invention, the method comprises the following steps:

[0012] S1. Mix a surfactant, a polymerization initiator, a rhodium-containing catalyst soluble in water, a cocatalyst, a comonomer, a diene monomer, and an optionally added or not added auxiliary agent with water and emulsify.

[0013] S2. After the emulsification is completed, raise the temperature to the polymerization temperature for a polymerization reaction, and add a terminator after the reaction is completed.

[0014] S3. After raising the temperature to the hydrogenation reaction temperature, introduce high-pressure hydrogen for a hydrogenation reaction to obtain a hydrogenated rubber latex.

[0015] According to an embodiment of the present invention, the method comprises the following steps:

[0016] S1. Mix 3 - 8 parts of a surfactant, 0.5 - 3 parts of a polymerization initiator, 0.01 - 0.1 part of a rhodium-containing catalyst soluble in water, 0.2 - 1 part of a cocatalyst, 10 - 60 parts of a comonomer, 40 - 90 parts of a diene monomer, 0.3 - 3 parts of an auxiliary agent with 600 - 1000 parts of water by mass and emulsify.

[0017] S2. Raise the temperature to 40 - 100 °C, carry out the polymerization reaction for 0.5 - 15 h, and then add a terminator to stop the reaction;

[0018] S3. Raise the temperature to 70 - 180 °C, introduce hydrogen until the pressure reaches 6 - 15 MPa, and carry out the hydrogenation reaction for 0.5 - 20 h to obtain a hydrogenated rubber latex.

[0019] The present invention also provides a hydrogenated rubber latex prepared by the above method.

[0020] According to the embodiments of the present invention, the hydrogenation degree of the hydrogenated rubber latex is 50 - 100%, the acrylonitrile content is 10 - 60 mol%, and the solid content of the hydrogenated rubber latex is 10 - 70 wt%.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] For the hydrogenated rubber latex prepared by the method of the present invention, the performance of the nanoparticles in the latex is stable, the size uniformity of the nanomicelles is good, the particle size distribution range is small, and it is not easy to demulsify.

[0023] In addition, the preparation method of the present invention is simple, easy to operate, and easy to industrialize; during the synthesis process, a rhodium metal hydrogenation catalyst dissolved in water is added before polymerization, and hydrogen is directly introduced for the hydrogenation reaction after the polymerization ends. The hydrogenation efficiency is high and the hydrogenation degree is high; the conversion rate of the monomer is extremely high. The present invention reduces the post-treatment of NBR latex and the processes of deoxidation and catalyst addition before hydrogenation, preventing environmental pollution caused by the volatilization of unreacted monomers; furthermore, it uses a rhodium-containing catalyst dissolved in water for the hydrogenation reaction, can avoid using any organic solvents, the reaction conditions are milder, and the reaction can be carried out at a lower temperature and pressure, which not only reduces the industrial cost but also is beneficial to green chemistry. Specific Embodiments

[0024] [A Method for Preparing Hydrogenated Rubber Latex by Emulsion Polymerization Hydrogenation with a Rhodium-Containing Catalyst Dissolved in Water]

[0025] As described above, the present invention provides a method for preparing a hydrogenated rubber latex, and the method includes the following steps:

[0026] The diene monomer and the comonomer are first subjected to a polymerization reaction in the presence of a polymerization initiator, a surfactant, a rhodium-containing catalyst dissolved in water, and a cocatalyst, and then hydrogen is introduced directly for the hydrogenation reaction to obtain a hydrogenated rubber latex.

[0027] In the presence of a rhodium catalyst soluble in water, a polymerization reaction occurs first, and then hydrogen is introduced to directly carry out a hydrogenation reaction to prepare a hydrogenated rubber latex. Without using any organic solvents, the reaction conditions are milder, and the reaction can be carried out at a lower temperature and pressure, which not only reduces industrial costs but also is beneficial to green chemistry.

[0028] According to an embodiment of the present invention, the method comprises the following steps:

[0029] S1. Mix a surfactant, a polymerization initiator, a rhodium catalyst soluble in water, a cocatalyst, a comonomer, a diene monomer, and an optionally added or non-added auxiliary agent with water and emulsify.

[0030] S2. After the emulsification is completed, raise the temperature to the polymerization temperature to carry out a polymerization reaction, and add a terminator after the reaction is completed.

[0031] S3. Raise the temperature to the hydrogenation reaction temperature and then introduce high-pressure hydrogen to carry out a hydrogenation reaction to obtain a hydrogenated rubber latex.

[0032] According to an embodiment of the present invention, the method specifically comprises the following steps:

[0033] S1. By mass, mix 3-8 parts of a surfactant, add 0.5-3 parts of a polymerization initiator, 0.01-0.1 part of a rhodium catalyst soluble in water, 0.2-1 part of a cocatalyst, 10-60 parts of a comonomer, 40-90 parts of a diene monomer, 0.3-3 parts of an auxiliary agent with 600-1000 parts of water and emulsify.

[0034] S2. Raise the temperature to 40-100 °C, carry out a polymerization reaction for 0.5-15 h, and then add a terminator to stop the reaction.

[0035] S3. Raise the temperature and introduce high-pressure hydrogen to carry out a hydrogenation reaction to obtain a hydrogenated rubber latex.

[0036] According to an embodiment of the present invention, the auxiliary agent includes a chain transfer agent and / or a pH regulator.

[0037] According to an embodiment of the present invention, the amount of the chain transfer agent is 0.25-2 parts, preferably 0.5-1.5 parts.

[0038] According to an embodiment of the present invention, the amount of the pH regulator is 0.05-1.0 part, preferably 0.1-0.6 part.

[0039] According to an embodiment of the present invention, the amount of the terminator is 0.01-0.1 part, preferably 0.02-0.1 part, for example, 0.05 part.

[0040] According to an embodiment of the present invention, in step S1, the temperature of emulsification is room temperature; the emulsification time is 0.5 to 1.5 h, preferably 0.5 to 1 h.

[0041] According to an embodiment of the present invention, step S1 includes the following steps:

[0042] S1-a. First, dissolve the surfactant in a part of water to obtain a surfactant solution;

[0043] S1-b. Add the polymerization initiator, comonomer, rhodium-containing catalyst dissolved in water, cocatalyst, and auxiliary agent and the remaining water to the surfactant solution and mix;

[0044] S1-c. Pass in an inert gas for degassing, add the diene monomer, and emulsify.

[0045] According to an embodiment of the present invention, step S1-b specifically includes the following steps: Add the polymerization initiator, comonomer, rhodium-containing catalyst (i.e., hydrogenation catalyst) dissolved in water, cocatalyst, chain transfer agent, pH regulator, and the remaining water to the surfactant solution and mix.

[0046] According to an embodiment of the present invention, step S1-b specifically includes the following steps: Add 0.5 to 3 parts of the polymerization initiator, 10 - 60 parts of the comonomer, 0.01 - 0.1 part of the rhodium-containing catalyst dissolved in water, 0.2 - 1 part of the cocatalyst, 0.25 - 2 parts of the chain transfer agent, 0.05 - 1.0 part of the pH regulator, and the remaining water to the surfactant solution and mix.

[0047] According to an embodiment of the present invention, in step S1-c, 40 - 90 parts of the diene monomer are added.

[0048] According to an embodiment of the present invention, the degassing in step S1-c is carried out under stirring conditions, and the inert gas is selected from at least one of helium, argon, and nitrogen; preferably, the pressure of the inert gas is 0.1 - 1 MPa, for example, 0.5 MPa.

[0049] According to an embodiment of the present invention, in step S1-a, fully dissolving the surfactant in a part of water can effectively maintain the stability of the emulsion interface, and then significantly improve the particle stability of the polymer nanoemulsion. Moreover, using an excessive amount of surfactant can also prepare a nanoemulsion with a smaller particle size to increase the specific surface area of the micelles.

[0050] According to an embodiment of the present invention, in step S1-b, during the reaction process, the acidity and alkalinity in the system cannot be automatically maintained constant but are in a dynamic change. Adding a pH regulator can effectively maintain the pH in the system within a small range, so that the surfactant can effectively maintain the liquid surface stability, which is beneficial to the reaction to proceed in stable micelles.

[0051] According to an embodiment of the present invention, in step S1-b, an appropriate amount of chain transfer agent is added, which can effectively control the degree of polymerization and molecular weight, thereby ensuring the chemical and physical properties of the latex or dry rubber.

[0052] According to an embodiment of the present invention, in step S1-c, an inert gas is introduced to displace the air in the reaction kettle, ensuring the purity of the gas in the kettle and eliminating the influence of air on the hydrogenation effect of the system. Before the reaction, the comonomer and diene monomer are first emulsified. Under the action of the surfactant, the surface tension of water is reduced, and the comonomer and diene monomer are wrapped in the micelles, forming uniform-sized oily monomer droplets, thereby ensuring sufficient monomer concentration in the system during the reaction and the stability of the monomer droplets.

[0053] According to an embodiment of the present invention, step S2 specifically includes the following steps: After the emulsification is completed, the temperature is raised with stirring to carry out the polymerization reaction, and a terminator is added after the polymerization reaction is completed. For example, the temperature of the polymerization reaction is 40-100°C, preferably 60-80°C, and exemplarily 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or 100°C; the time of the polymerization reaction is 0.5-15 h, preferably 2-10 h, further preferably 3-6 h, and exemplarily 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h.

[0054] According to an embodiment of the present invention, step S3 specifically includes the following steps: High-pressure hydrogen is introduced into the reaction kettle, and at this time, the hydrogenation reaction starts. The temperature and pressure in the reaction kettle are kept constant, and continuous stirring is carried out to carry out the hydrogenation reaction to obtain a hydrogenated rubber latex. For example, the temperature of the hydrogenation reaction is 70-180°C, and exemplarily 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C or 180°C; the time of the hydrogenation reaction is 0.5-20 h, preferably 1-10 h, and exemplarily 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 12 h, 15 h or 20 h.

[0055] According to an embodiment of the present invention, in step S3, the pressure of the high-pressure hydrogen is 3-15 MPa, preferably 4-12 MPa, for example 8 MPa.

[0056] According to an embodiment of the present invention, in step S2, the reaction is carried out under stirring conditions, and the stirring speed is 300-900 rpm, preferably the stirring speed is 450-650 rpm, for example 450 rpm.

[0057] According to an embodiment of the present invention, the reaction kettle is selected from high-pressure reaction kettles, such as high-temperature and high-pressure stainless steel reaction kettles.

[0058] According to an embodiment of the present invention, the high-temperature and high-pressure stainless steel reaction kettle includes a kettle body and at least two high-pressure resistant hoses. One end of the high-pressure resistant hose is connected to the kettle body, and the other end is connected to high-pressure gas, and the high-pressure gas is, for example, inert gas and hydrogen.

[0059] According to an embodiment of the present invention, the high-temperature resistant hose includes a stainless steel high-temperature resistant hose and a plastic high-temperature resistant hose. The stainless steel high-temperature resistant hose is used to introduce hydrogen into the kettle body, and the plastic high-temperature resistant hose is used to introduce inert gas into the kettle body.

[0060] According to an embodiment of the present invention, an exhaust port is further provided on the kettle body.

[0061] According to an embodiment of the present invention, a pressure sensor is further provided in the kettle body, and the measuring range of the pressure sensor is -1 to 30 MPa.

[0062] According to an embodiment of the present invention, a temperature sensor is further provided in the kettle body, and the measuring range of the temperature sensor is 0 to 180 °C.

[0063] According to an embodiment of the present invention, a stirring device is further provided in the kettle body for fully mixing the materials in the system, and the stirring speed of the stirring device is 0 to 800 rpm.

[0064] [Comonomer and diene monomer]

[0065] According to an embodiment of the present invention, the comonomer is selected from at least one of acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, propyl acrylate, butyl acrylate, propyl methacrylate, butyl methacrylate, fumaric acid, maleic acid, acrylic acid, and unsaturated carboxylic acids such as methacrylic acid.

[0066] According to an embodiment of the present invention, the diene monomer is a conjugated monomer, and the conjugated monomer is selected from at least one of C4-C6 conjugated dienes. Preferably, the diene monomer is selected from at least one of 1,3-butadiene, isoprene, 1-methylbutadiene, 2,3-dimethylbutadiene, piperylene, and chloroprene.

[0067] [Surfactant]

[0068] According to an embodiment of the present invention, the surfactant is selected from fatty acids, alkyl sulfates, sulfuric acid monoesters of ethoxylated alkanols, ethoxylated alkylphenols, alkali metal salts or ammonium salts of alkyl sulfonic acids and alkyl aryl sulfonic acids, ethoxylated monoalkylphenols, dialkylphenols and trialkylphenols, ethoxylated fatty alcohols, single C4 to C of bis(phenylsulfonic acid) ethers 24An alkali metal salt or ammonium salt of an alkyl derivative, a di-C4 to C of bis(benzenesulfonic acid) ether 24 At least one of an alkali metal salt or ammonium salt of an alkyl derivative, an alkylarylsulfonic acid, an alkylsulfonic acid, an alkali metal salt or ammonium salt of a sulfuric acid monoester of an ethoxylated alkanol, and a gemini surfactant.

[0069] According to an exemplary embodiment of the present invention, the fatty acid surfactant is selected from alkali metal salts or ammonium salts of fatty acids having an alkyl group of C 12 to C 23 Preferably sodium oleate (NaO) or potassium oleate (KO).

[0070] According to an exemplary embodiment of the present invention, the alkali metal salt or ammonium salt surfactants of alkyl sulfates, sulfuric acid monoesters of ethoxylated alkanols, ethoxylated alkylphenols, alkylsulfonic acids, and alkylarylsulfonic acids are the following emulsifiers: such as alkyl sulfates (alkyl: C8 to C 22 ), ethoxylated alkanols (degree of ethylene oxide: 4 to 30, alkyl: C8 to C 22 ), sulfonic acid monoesters of ethoxylated alkylphenols (degree of ethylene oxide: 3 to 50, alkyl: C4 to C 20 ), alkali metal salts or ammonium salts of alkylsulfonic acids (alkyl: C8 to C 22 ) and alkali metal salts or ammonium salts of alkylarylsulfonic acids (alkyl: C4 to C 18 ). For example, the surfactant is sodium dodecyl sulfate (SDS) or sodium dodecylbenzenesulfonate (SDBS).

[0071] According to an exemplary embodiment of the present invention, the ethoxylated monoalkylphenol, dialkylphenol, trialkylphenol or ethoxylated fatty alcohol surfactants are the following emulsifiers: ethoxylated mono-, di- or trialkylphenols (degree of ethylene oxide: 3 to 50; alkyl C4 to C9) or ethoxylated fatty alcohols (degree of ethylene oxide: 3 to 50; alkyl C4 to C9).

[0072] According to an exemplary embodiment of the present invention, the alkali metal salt or ammonium salt surfactants of alkylarylsulfonic acids, alkylsulfonic acids, and sulfuric acid monoesters of ethoxylated alkanols are the alkali metal salts or ammonium salts, especially sodium salts, of the following: alkylarylsulfonic acids, alkylsulfonic acids (such as sulfonated C 12 to C 18 paraffin), alkyl sulfates (such as sodium lauryl sulfate), and sulfuric acid monoesters of ethoxylated alkanols (such as subsulfated ethoxylates of lauryl alcohol having 2 to 3 ethylene oxide units).

[0073] According to an embodiment of the present invention, the gemini surfactant is at least one selected from cationic gemini surfactants, anionic gemini surfactants, nonionic gemini surfactants, and asymmetric gemini surfactants.

[0074] According to an exemplary embodiment of the present invention, the anionic gemini surfactant is at least one anionic gemini surfactant selected from phosphate ester salts, sulfonates, carboxylates, and sulfate ester salts.

[0075] In some embodiments of the present invention, the cationic gemini surfactant has the structure shown in formula (1):

[0076]

[0077] In formula (1), R1, R2, Y, x, and y have the definitions described in A1 - A8:

[0078] A1: R1 = R2 = C m H 2m+1 ; Y = CH2; x + y + 1 = s; m - s - m surfactants;

[0079] A2: R1 = R2 = C m H 2m+1 ; Y = CH2, O, S, N(CH3), x = y = 2;

[0080] A2: R1 = R2 = C m H 2m+1 ; Y = CHOH, (CHOH)2; x = y = 1;

[0081] A3: R1 = R2 = C m H 2m+1 ; Y = (OCH2CH2) z , x = 2; y = 0; m - EOz - m surfactants;

[0082] A4: R1 = R2 = C m H 2m+1 ; Y = C≡C; x = y = 1;

[0083] A5: R1 = R2 = C m H 2m+1 ; Y = a phenylene group; x = y = 1;

[0084] A6: R1 = R2 = C m H 2m+1 OC(O)CH2; no Y; x = y = 1; counterion = chloride;

[0085] A7: R1 = R2 = C m F 2m C4H8; no Y; x = y = 1;

[0086] A8: R1 = C m H 2m+1 ; R2 = C n H 2n+1 ; no Y; x = y = 1; s; m - 2 - n surfactants (m not equal to

[0087] n),

[0088] Among A1 - A8, m, n, z are independently 1 - 60,

[0089] Br - can be replaced by any other anion, preferably F in Group VIIA of the periodic system - 、Cl - 、I - 、At - 、Ts - 。

[0090] In some embodiments of the present invention, the gemini surfactant is selected from at least one of the following:

[0091] C 12 H 25 N + (CH3)2-(CH2) n -N + (CH3)2C 12 H 25 2Br – (n = 3–8),

[0092] C 12 H 25 N + (CH3)2-(CH2) 16 -N + (CH3)2C 12 H 25 2Br – 、

[0093] C 16 H 33 N + (CH3)2-(CH2)2-N + (CH3)2C 16 H 33 2Br – 、

[0094] C8H 17 N+ (CH3)2-(CH2)3-N + (CH3)2C8H 17 2Br – 、

[0095] C 12 H 25 N + (CH3)2-(CH2)2-O-(CH2)2-N + (CH3)2C 12 H 25 2Cl – 、

[0096] C 16 H 33 N + (CH3)2-(CH2)5-N + (CH3)2C 16 H 33 2Br – 、

[0097] C 16 H 33 N + (CH3)2-(CH2)2-O-(CH2)2-N + (CH3)2C 16 H 33 2Br – 、

[0098] C 16 H 33 N + (CH3)2-CH2-(CH2-O-CH2)3-CH2-N + (CH3)2C 16 H 33 2Br – 、

[0099] C 12 H 25 N + (CH3)2-CH2-CH(OH)-CH2-N + (CH3)2C 12 H 25 2Br – 、

[0100] C 12 H 25 N + (CH3)2-CH2-C6H4-CH2-N + (CH3)2C 12 H 25 2Br– ,

[0101] C 12 H 25 N + (CH3)2-CH2-CH(OH)-CH(OH)-CH2-N + (CH3)2C 12 H 25 2Br – ,

[0102] C 12 H 25 N + (CH3)2-CH2-CH(OH)-CH2-N + (CH3)2-CH2-CH(OH)-CH2-N + (CH3)2C 12 H 25 3Cl – ,

[0103] C 12 H 25 OPO2 – -O-(CH2)6-OPO2 – -OC 12 H 25 2Na + ,

[0104] C 10 H 21 O-CH2-CH(OSO3 – )-CH2-O-(CH2)2-O-CH2-CH(OSO3 – )-CH2-OC 10 H 21 2Na + 。

[0105] According to an embodiment of the present invention, the surfactant is selected from at least one of potassium oleate (KO), sodium dodecylbenzenesulfonate (SDBS), and didodecyldimethylammonium bromide.

[0106] In the examples of the present invention, the surfactants used include: anionic surfactants and gemini surfactants. The anionic surfactants generate latex particles with a smaller particle size, good latex stability, and are not prone to generating agglomerates during the polymerization process, and a latex with a high solid content and stability can be obtained; the gemini surfactants have good chemical stability to electrolytes, but the polymerization reaction rate is gentle, the particle size of the obtained latex particles is larger, and agglomerates are easily generated during the polymerization process.

[0107] [Polymerization initiator]

[0108] According to an embodiment of the present invention, the polymerization initiator of the hydrogenated rubber latex is at least one free radical initiator, including oil-soluble initiators: azobisisobutyronitrile, benzoyl peroxide, cumene hydroperoxide, etc.; water-soluble initiators: potassium persulfate, azodiisobutyramidine hydrochloride, azodiisobimidazoline hydrochloride, ammonium persulfate, etc.

[0109] According to an exemplary embodiment of the present invention, the initiator is any one or more of ammonium persulfate, potassium persulfate, and sodium persulfate. The persulfide initiator has strong thermal decomposition ability, fast reaction speed, and the concentration of free radicals generated can reach the highest concentration for the reaction at room temperature.

[0110] [Auxiliary agent]

[0111] According to an embodiment of the present invention, the chain transfer agent is selected from at least one of n-dodecyl mercaptan, tert-dodecyl mercaptan, tert-butyl mercaptan, and n-butyl mercaptan.

[0112] In the examples of the present invention, the chain transfer agent is selected from dodecyl mercaptan, and dodecyl mercaptan has good performance and can effectively reduce the molecular weight of the latex.

[0113] According to an embodiment of the present invention, the pH regulator is selected from at least one of sodium phosphate, tetrasodium diphosphate, trisodium phosphate, sodium hexametaphosphate, and sodium bicarbonate.

[0114] [Terminator]

[0115] According to an embodiment of the present invention, the terminator is selected from substances having the following structure or capable of forming the following structure: quinone, nitro, nitroso, aryl polyhydroxy compounds, and sulfur-containing compounds.

[0116] According to an exemplary embodiment of the present invention, the terminator is selected from N,N-diethylhydroxylamine.

[0117] [Rhodium-containing catalyst soluble in water]

[0118] According to an embodiment of the present invention, the rhodium-containing catalyst soluble in water has the structure shown in Formula I:

[0119] RhQL x Formula I,

[0120] Wherein,

[0121] Q is a hydride or an anion other than hydride,

[0122] L is a ligand soluble in water,

[0123] x is an integer from 1 to 10, for example, x = 1, 2, 3, or 4.

[0124] It must be emphasized that the structure of the water-soluble ligand L is not particularly limited. Such a water-soluble ligand can be, for example, mono- or bidentate. In the case of a monodentate ligand, in general formula (I), x is typically 2, 3 or 4; in the case of a bidentate ligand, x is typically 1 or 2.

[0125] According to an embodiment of the present invention, L has the structure shown in formula II:

[0126] R 1 m Formula II

[0127] wherein R 1 are the same or different and are independently selected from alkyl, cycloalkyl, aryl or aralkyl, and at least one of the R 1 groups is sulfonated one or more times; preferably, R 1 are the same or different and are independently selected from C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 aryl or C7-C 15 aralkyl, and at least one of the R 1 groups is sulfonated one or more times; for example, at least one of the R 1 groups is sulfonated once, twice or three times;

[0128] G is phosphorus, arsenic, sulfur or the sulfoxide group S=O;

[0129] m is 2 or 3;

[0130] In some embodiments of the present invention, Q is a halide and x is preferably 3.

[0131] In some embodiments of the present invention, Q is a hydride and x is preferably 4.

[0132] In some embodiments of the present invention, Q is a halide, preferably chloride or bromide.

[0133] In one embodiment of the present invention, more than one (such as two or three) of the R 1 groups are sulfonated one or more times; for example, each R 1 group is sulfonated once, twice or three times.

[0134] In one embodiment of the present invention, the water-soluble rhodium catalyst is selected from RhCl(TPPMS)3 (TPPMS represents monosulfonated triphenylphosphine, such as P(C6H5)2(m-C6H4SO3 - )) or RhCl(TPPTS)3 (TPPTS represents trisulfonated triphenylphosphine, such as tris(3-sulfophenyl)phosphine, P(C6H4-3-SO3 - )3).

[0135] The rhodium-containing catalyst soluble in water according to the present invention is soluble in water at room temperature, i.e., (24 ± 2)°C. R 1 The counter ion of the sulfonate group used for sulfonating the R + group is an alkali metal ion, such as Na + .

[0136] In one embodiment of the present invention, L has the structure shown in Formula III:

[0137] R 2 n Z-A-ZR 3 n Formula III

[0138] Wherein, R 2 , R 3 are the same or different and are independently selected from alkyl, cycloalkyl, aryl or aralkyl, and at least one of the R 2 or R 3 groups is sulfonated one or more times; preferably, R 2 , R 3 are the same or different and are independently selected from C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 aryl or C7-C 15 aralkyl, and at least one of the R 2 or R 3 groups is sulfonated one or more times; for example, at least one of the R 2 or R 3 groups is sulfonated once, twice or three times;

[0139] Z is phosphorus or arsenic;

[0140] A represents a spacer group, preferably a phenylene group or a C1-C 20 alkylene group or a single bond;

[0141] n is 2;

[0142] x is 1 or 2.

[0143] In one embodiment of the present invention, one or both of the R 2 , R 3 groups are sulfonated once, twice or three times.

[0144] In one embodiment of the present invention, one or both of the R 2 groups and one or both of the R 3 groups are simultaneously sulfonated once, twice or three times.

[0145]

Term Definitions and Explanations

[0146] The term "alkyl" shall mean any branched or unbranched hydrocarbon residue and, unless otherwise specified, shall include C1-C 20 alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, 1-ethylpropyl, n-hexyl, n-heptyl, n-octyl, n-decyl or n-dodecyl.

[0147] The term "cycloalkyl" shall include C3-C 10 cycloalkyl, such as, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl.

[0148] The term "aryl" includes aromatic groups having from 6 to 24 skeletal carbon atoms. Preferred monocyclic, bicyclic or tricyclic carbocyclic aromatic groups having from 6 to 10 skeletal carbon atoms are, for example, phenyl, biphenyl, naphthyl, phenanthryl and anthracenyl.

[0149] The term "substituted" means that a hydrogen atom on a specified group has been replaced by one of the groups specified in each case, provided that the valence of the specified atoms is not exceeded and the substitution results in a stable compound.

[0150] For the purposes of this patent application and invention, all definitions of groups, parameters or explanations given above or below in general terms or in preferred ranges may be combined with each other in any way, i.e., including combinations of the corresponding ranges and preferred ranges.

[0151] [[Promoter]]

[0152] According to an embodiment of the present invention, the promoter is insoluble in water.

[0153] In one embodiment, the promoter has the structure shown in Formula IV:

[0154] R 4 oD Formula IV

[0155] Wherein,

[0156] R 4 are the same or different and are independently selected from alkyl, cycloalkyl, aryl or aralkyl, preferably, R 4 are the same or different and are independently selected from C1-C8 alkyl, C6-C 15 aryl, C4-C8 cycloalkyl or, C7-C 15 aralkyl;

[0157] D is phosphorus, arsenic, sulfur or a sulfoxide group S=O; preferably phosphorus;

[0158] o is 2 or 3.

[0159] In one embodiment, the cocatalyst is a phosphine of triaryl, trialkyl, tricycloalkyl, diaryl - monoalkyl, dialkyl monoaryl, diaryl monocycloalkyl, dialkyl monocycloalkyl, dicycloalkyl monoaryl or dicycloalkyl monoaryl.

[0160] In one embodiment of the present invention, the cocatalyst has the structure shown in Formula V:

[0161] R 5 pE - A - ER 6 pFormula V

[0162] Wherein,

[0163] R 5 、R 6 are the same or different and are independently selected from alkyl, cycloalkyl, aryl or aralkyl; preferably, R 5 、R 6 are the same or different and are independently selected from C1 - C8 alkyl, C6 - C 15 aryl, C4 - C8 cycloalkyl or C7 - C 15 aralkyl;

[0164] E is phosphorus or arsenic;

[0165] A represents a spacer group, preferably phenylene or C1 - C 20 alkylene or a single bond,

[0166] p is 2.

[0167] In one embodiment of the present invention, the cocatalyst is triphenylphosphine. The amount of the rhodium - containing catalyst soluble in water to be used is not critical. A very small amount of this catalyst can be used. Based on the weight of the polymer solids content in the latex, an amount in the range of from 0.01% to 5.0% by weight, preferably in the range of from 0.02% to 1.0% by weight is typically used.

[0168] Based on the weight of the catalyst soluble in water, the water - insoluble cocatalyst is typically used in an amount up to 5000% by weight, preferably in a range of from 500% to 3000% by weight.

[0169] [Hydrogenated rubber]

[0170] The present invention also provides a hydrogenated rubber latex prepared by the above - mentioned method.

[0171] According to the embodiment of the present invention, the degree of hydrogenation of the hydrogenated rubber latex is 50 - 100%, the acrylonitrile content is 10 - 60 mol%, and the solid content of the hydrogenated rubber latex is 10 - 70 wt%.

[0172] According to an embodiment of the present invention, the hydrogenation degree of the hydrogenated rubber latex is greater than or equal to 75%, preferably the hydrogenation degree of the hydrogenated rubber latex is 95%, and further preferably, the hydrogenation degree of the hydrogenated rubber latex is 97%, such as 78%, 84.3%, 97.5%, 97.9%, 99.4%, 99.5%, 99.6%.

[0173] According to an embodiment of the present invention, the acrylonitrile content is 20 - 50 mol%.

[0174] According to an embodiment of the present invention, the particle size of the hydrogenated rubber latex is 50 - 130 nm, preferably the particle size of the hydrogenated rubber latex is 100 - 130 nm. The inventors found that the polymerization system, the emulsification system of the present invention and the rhodium-containing catalyst and cocatalyst dissolved in water have a combined effect, and can also achieve the effect of significantly improving the hydrogenation reaction efficiency and reducing the amount of catalyst used.

[0175] Hereinafter, the technical solutions of the present invention will be clearly and completely described in conjunction with specific embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0176] Example 1

[0177] A preparation method for preparing HNBR latex includes the following steps:

[0178] 1) Dissolve 7 g of surfactant didodecyldimethylammonium bromide in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0179] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(TPPMS)3, 0.5 g of cocatalyst triphenylphosphine, 0.3 g of chain transfer agent tert-dodecyl mercaptan, and 0.05 g of pH regulator sodium phosphate to the reaction kettle;

[0180] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, perform a 0.5-hour degassing treatment while stirring at 200 rpm, and then add 70 g of butadiene in liquid form to the degassed reaction kettle, mix, and emulsify the monomers with stirring at room temperature for 1 hour;

[0181] 4) After the emulsification is completed, raise the temperature to 40 °C and then start the polymerization reaction. After the polymerization conversion rate reaches 80%, add 0.05 g of terminator N,N-diethylhydroxylamine;

[0182] 5) Then adjust the rotation speed to 450 rpm and raise the temperature of the reaction kettle to 90 °C. Introduce high-pressure hydrogen gas at 8 MPa for the hydrogenation reaction. After reacting for 5 h, HNBR latex is obtained.

[0183] Example 2

[0184] A preparation method for preparing HNBR latex, comprising the following steps:

[0185] 1) Dissolve 7 g of surfactant sodium dodecylbenzenesulfonate in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle.

[0186] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(TPPMS)3, 0.5 g of cocatalyst triphenylphosphine, 0.3 g of chain transfer agent tert-dodecyl mercaptan, and 0.05 g of pH regulator sodium phosphate into the reaction kettle.

[0187] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle. While stirring at a rotation speed of 200 rpm, perform a degassing treatment for 0.5 h. Then add 70 g of butadiene in liquid form to the degassed reaction kettle, mix, and stir to emulsify the monomers at room temperature for 1 h.

[0188] 4) After the emulsification is completed, raise the temperature to 40 °C and then start the polymerization reaction. After the polymerization conversion rate reaches 80%, add 0.05 g of terminator N,N-diethylhydroxylamine.

[0189] 5) Then adjust the rotation speed to 450 rpm and raise the temperature of the reaction kettle to 90 °C. Introduce high-pressure hydrogen gas at 8 MPa for the hydrogenation reaction. After reacting for 5 h, HNBR latex is obtained.

[0190] Example 3

[0191] A preparation method for preparing HNBR latex, comprising the following steps:

[0192] 1) Dissolve 7 g of surfactant oleic acid potassium in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle.

[0193] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(TPPMS)3, 0.5 g of cocatalyst triphenylphosphine, 0.3 g of chain transfer agent tert-dodecyl mercaptan, and 0.05 g of pH regulator sodium phosphate into the reaction kettle.

[0194] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, perform degassing treatment for 0.5 hours while stirring at a speed of 200 rpm, then add 70 g of butadiene in liquid form to the degassed reaction kettle, mix, and stir the emulsified monomers at room temperature for 1 hour;

[0195] 4) After the emulsification is completed, raise the temperature to 40 °C and then start the polymerization reaction. After the polymerization conversion rate reaches 80%, add 0.05 g of terminator N,N - diethylhydroxylamine;

[0196] 5) Then adjust the speed to 450 rpm and raise the temperature of the reaction kettle to 90 °C, introduce 8 MPa of high - pressure hydrogen for hydrogenation reaction, and obtain HNBR latex after reacting for 5 h.

[0197] Example 4

[0198] A preparation method of HNBR latex, comprising the following steps:

[0199] 1) Dissolve 10 g of surfactant oleate potassium in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0200] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(TPPMS)3, 0.5 g of cocatalyst triphenylphosphine, 0.3 g of chain transfer agent tert - dodecyl mercaptan, 0.05 g of pH regulator sodium phosphate to the reaction kettle;

[0201] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, perform degassing treatment for 0.5 hours while stirring at a speed of 200 rpm, then add 70 g of butadiene in liquid form to the degassed reaction kettle, mix, and stir the emulsified monomers at room temperature for 1 hour;

[0202] 4) After the emulsification is completed, raise the temperature to 40 °C and then start the polymerization reaction. After the polymerization conversion rate reaches 80%, add 0.05 g of terminator N,N - diethylhydroxylamine;

[0203] 5) Then adjust the speed to 450 rpm and raise the temperature of the reaction kettle to 90 °C, introduce 8 MPa of high - pressure hydrogen for hydrogenation reaction, and obtain HNBR latex after reacting for 5 h.

[0204] Example 5

[0205] A preparation method of HNBR latex, comprising the following steps:

[0206] 1) Dissolve 7 g of surfactant oleate potassium in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0207] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.055 g of hydrogenation catalyst RhCl(TPPMS)3, 0.5 g of cocatalyst triphenylphosphine, 0.3 g of chain transfer agent tert-dodecyl mercaptan, and 0.05 g of pH regulator sodium phosphate into the reaction kettle;

[0208] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, while stirring at a speed of 200 rpm, conduct degassing treatment for 0.5 hours, then add 70 g of butadiene in liquid form into the degassed reaction kettle, mix, and stir the emulsified monomers at room temperature for 1 hour;

[0209] 4) After the emulsification is completed, raise the temperature to 40 °C and then start the polymerization reaction. After the polymerization conversion rate reaches 80%, add 0.05 g of terminator N,N-diethylhydroxylamine;

[0210] 5) Then adjust the speed to 450 rpm and raise the temperature of the reaction kettle to 90 °C, introduce 8 MPa of high-pressure hydrogen for hydrogenation reaction, and obtain HNBR latex after reacting for 5 h.

[0211] Example 6

[0212] A preparation method for preparing HNBR latex, comprising the following steps:

[0213] 1) Dissolve 7 g of surfactant oleic acid potassium in 300 g of deionized water to obtain a surfactant aqueous solution and add it into the reaction kettle;

[0214] 2) Add 3 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(TPPMS)3, 0.5 g of cocatalyst triphenylphosphine, 0.3 g of chain transfer agent tert-dodecyl mercaptan, and 0.05 g of pH regulator sodium phosphate into the reaction kettle;

[0215] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, while stirring at a speed of 200 rpm, conduct degassing treatment for 0.5 hours, then add 70 g of butadiene in liquid form into the degassed reaction kettle, mix, and stir the emulsified monomers at room temperature for 1 hour;

[0216] 4) After the emulsification is completed, raise the temperature to 40 °C and then start the polymerization reaction. After the polymerization conversion rate reaches 80%, add 0.05 g of terminator N,N-diethylhydroxylamine;

[0217] 5) Then adjust the speed to 450 rpm and raise the temperature of the reaction kettle to 90 °C, introduce 8 MPa of high-pressure hydrogen for hydrogenation reaction, and obtain HNBR latex after reacting for 5 h.

[0218] Example 7

[0219] A preparation method of HNBR latex, comprising the following steps:

[0220] 1) Dissolve 7 g of surfactant oleate potassium in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0221] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(TPPTS)3, 0.5 g of cocatalyst triphenylphosphine, 0.3 g of chain transfer agent tert-dodecyl mercaptan, and 0.05 g of pH regulator sodium phosphate to the reaction kettle;

[0222] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, perform degassing treatment for 0.5 hours while stirring at a speed of 200 rpm, and then add 70 g of butadiene in liquid form to the degassed reaction kettle, mix, and stir and emulsify the monomers at room temperature for 1 hour;

[0223] 4) After the emulsification is completed, raise the temperature to 50 °C and then start the polymerization reaction. After the polymerization conversion rate reaches 80%, add 0.05 g of terminator N,N-diethylhydroxylamine;

[0224] 5) Then adjust the speed to 450 rpm and raise the temperature of the reaction kettle to 100 °C, introduce 8 MPa of high-pressure hydrogen for hydrogenation reaction, and obtain HNBR latex after reacting for 5 h.

[0225] After the reaction is completed, samples of the products of Examples 1-7 are taken, and the solid content of the polymer is measured by gel permeation chromatography to calculate the conversion rate. The results are shown in Table 1 below.

[0226] Monomer conversion rate = (system solid content * total system mass - mass of raw material non-volatile components) / total mass of raw material monomers.

[0227] The particle size and particle size distribution of the nanoparticles were measured by dynamic light scattering (DLS) using a Nano ZS 3500 nanoparticle size analyzer.

[0228] The structure of the polymer was determined by FT-IR (BRUKER II, BRUKER instrument, Karlsruhe, Germany). FT-IR method: First, separate the latex sample with ethanol to obtain the polymer solid. Then, dissolve a small amount of dry NBR solid in MEK to form a homogeneous solution. Finally, drop the solution onto a potassium bromide wafer and dry it to form a polymer film, and then perform infrared analysis.

[0229] The calculation of the hydrogenation degree is based on the corresponding absorbances of the characteristic peaks at 2236 cm -1 、970 cm -1 and 723 cm -1 in the FT-IR spectrum.

[0230] 2236 cm -1 is the characteristic peak of cyano group (-C≡N), 970 cm -1 is the characteristic peak of -C=C- (trans 1,4 structure), 723 cm -1 is (-CH2) n , where n > 4.

[0231]

[0232] K(723) = 0.255, K(970) = 2.3 are the unique constants of HNBR

[0233] Then the relative amount of -C=C- in HNBR is:

[0234]

[0235] The relative amount of methylene formed by hydrogenation of -C=C- in NBR is:

[0236]

[0237] Finally, the hydrogenation degree calculation formula is:

[0238]

[0239] The acrylonitrile content is determined by elemental analysis of the N atom content to obtain the acrylonitrile content.

[0240] Table 1 Experimental conditions of Examples 1 - 7 and performance test results of hydrogenated nitrile rubber latex

[0241]

[0242] As can be seen from the above table, the HNBR latex prepared by the emulsion polymerization hydrogenation method based on a rhodium-containing catalyst soluble in water according to the present invention has a small particle size distribution, is not easily demulsified, the preparation method is simple, the operation is convenient, and it is easy to realize industrialization; during the synthesis process, the hydrogenation degree is about 80%, and the highest can reach 99.3%. This shows that the hydrogenation effect of the HNBR latex of the present invention is good and the hydrogenation degree is high.

[0243] Compared with the prior art, the hydrogenated nitrile rubber latex prepared by the emulsion polymerization hydrogenation method using a rhodium-containing catalyst soluble in water according to the present invention has stable performance, good size uniformity of nano-micelles, a small particle size distribution range, is not easily demulsified, the preparation method is simple, the operation is convenient, and it is easy to realize industrialization; and during the synthesis process, a rhodium metal hydrogenation catalyst soluble in water is added before polymerization, and hydrogen is directly introduced for hydrogenation reaction after polymerization, with high hydrogenation efficiency and high degree of hydrogenation; and the conversion rate of the monomer is extremely high. The present invention reduces the post-treatment of NBR latex, the deoxygenation before hydrogenation and the addition process of the catalyst, and prevents the pollution of the environment caused by the volatilization of unreacted monomers. At the same time, the use of a rhodium-containing catalyst soluble in water for the hydrogenation reaction according to the present invention can not use any organic solvents, the reaction conditions are milder, and the reaction can be carried out at a lower temperature and pressure, which not only reduces the industrial cost, but also is beneficial to the development of green chemistry.

[0244] As described above, the embodiments of the present invention have been exemplarily described. However, the protection scope of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a hydrogenated rubber latex, characterized in that, The method includes the following steps: First, a polymerization reaction occurs between a diene monomer and a comonomer in the presence of a polymerization initiator, a surfactant, a rhodium-containing catalyst dissolved in water, and a cocatalyst. After the polymerization reaction ends, a terminator is added, and then the temperature is raised and hydrogen gas is introduced to carry out a hydrogenation reaction to obtain a hydrogenated rubber latex.

2. The method according to claim 1, characterized in that, The method includes the following steps: S1. Mix a surfactant, a polymerization initiator, a rhodium-containing catalyst dissolved in water, a cocatalyst, a comonomer, a diene monomer, and an optional additive or non-additive with water and emulsify them. S2. After emulsification, raise the temperature to the polymerization temperature to carry out a polymerization reaction, and add a terminator after the reaction ends. S3. After raising the temperature to the hydrogenation reaction temperature, introduce high-pressure hydrogen gas to carry out a hydrogenation reaction to obtain a hydrogenated rubber latex.

3. The method according to claim 2, characterized in that, The additive includes a chain transfer agent and / or a pH regulator. The dosage of the chain transfer agent is 0.25 - 2 parts, and the dosage of the pH regulator is 0.05 - 1.0 part.

4. The method according to claim 2, characterized in that, Step S1 includes the following steps: S1-a. First, dissolve the surfactant in a part of water to obtain a surfactant solution. S1-b. Add the polymerization initiator, comonomer, rhodium-containing catalyst dissolved in water, cocatalyst, and additive to the surfactant solution together with the remaining water and mix them. S1-c. Purge with an inert gas to remove air, add the diene monomer, and emulsify.

5. The method according to claim 2, wherein In step S2, the temperature of the polymerization reaction is 40 - 100 °C; the time of the polymerization reaction is 0.5 - 15 h. And / or, in step S3, the temperature of the hydrogenation reaction is 70 - 180 °C; the time of the hydrogenation reaction is 0.5 - 20 h. And / or, in step S3, the pressure of the high-pressure hydrogen gas is 3 - 15 MPa, preferably 4 - 12 MPa.

6. The method according to any one of claims 1-5, characterized in that, The comonomer is selected from at least one of acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, propyl acrylate, butyl acrylate, propyl methacrylate, butyl methacrylate, fumaric acid, maleic acid, acrylic acid, and methacrylic acid.

7. The method according to any one of claims 1-6, characterized in that, The surfactant is selected from fatty acids, alkyl sulfates, sulfuric acid monoesters of ethoxylated alkanols, ethoxylated alkylphenols, alkali metal salts or ammonium salts of alkyl sulfonic acids, alkali metal salts or ammonium salts of alkyl aryl sulfonic acids, ethoxylated monoalkylphenols, dialkylphenols, trialkylphenols, ethoxylated fatty alcohols, alkali metal salts or ammonium salts of mono-C4-C 24 alkyl derivatives of bis(benzenesulfonic acid) ethers, di-C4-C 24 alkyl derivatives of bis(benzenesulfonic acid) ethers, alkyl aryl sulfonic acids, alkyl sulfonic acids, alkali metal salts or ammonium salts of sulfuric acid monoesters of ethoxylated alkanols, at least one of gemini surfactants.

8. The method according to any one of claims 1-7, characterized in that, The rhodium-containing catalyst dissolved in water has a structure shown in formula I: RhQLx Formula I Wherein, Q is a hydride or an anion other than a hydride. L is a ligand dissolved in water. x is an integer from 1 to 10.

9. The method according to claim 8, wherein L has a structure shown in formula II: R 1 m Type G II wherein, R 1 which are the same or different and are each independently selected from alkyl, cycloalkyl, aryl or aralkyl, and wherein at least one R 1 group is sulfonated one or more times; G is phosphorus, arsenic, sulfur, or a sulfoxide group S=O. m is 2 or 3. Or, L has a structure shown in formula III: R 2 n Z-A-ZR 3 n Formula III Wherein, R 2 and R 3 are the same or different and are each independently selected from alkyl, cycloalkyl, aryl or aralkyl, and at least one of the R 2 or R 3 groups is sulfonated once or more times; Z is phosphorus or arsenic. A represents a spacer group, preferably a phenylene group or a C1-C 20 alkylene group or a single bond; n is 2. x is 1 or 2. Preferably, the rhodium-containing catalyst dissolved in water is selected from RhCl(TPPMS)3 or RhCl(TPPTS)3.

10. A hydrogenated rubber latex prepared by the method according to any one of claims 1-9, characterized in that, The hydrogenation degree of the hydrogenated rubber latex is 50 - 100%, the content of the comonomer is 10 - 60 mol%, the content of the diene monomer is 40% - 90%, and the solid content of the hydrogenated rubber latex is 10 - 70 wt%.

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