Method for preparing hydrogenated rubber latex by emulsion polymerization hydrogenation method

Abstract

The invention provides a method for preparing hydrogenated nitrile butadiene rubber (HNBR) latex by an emulsion polymerization hydrogenation method, which comprises the following steps of: firstly, carrying out polymerization reaction on a diene monomer and a comonomer in the presence of a polymerization initiator, a reducing agent, a surfactant, a water-soluble rhodium-containing catalyst and a water-insoluble cocatalyst; and then introducing hydrogen to directly carry out hydrogenation reaction to obtain hydrogenated rubber latex. According to the method disclosed by the invention, the two processes of NBR emulsion polymerization and NBR latex hydrogenation in the existing HNBR latex preparation method are simplified, and the method has the advantages of short process flow, high efficiency, low energy consumption, greenness and the like.

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. In particular, it relates to a method for polymerizing a diene monomer and a copolymerizable monomer at a high temperature using at least one rhodium catalyst soluble in water, a promoter insoluble in water, a polymerization initiator, and at least one surfactant, and then directly hydrogenating the resulting polymer by raising the temperature and introducing hydrogen 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 offers a convenient approach for synthesizing polymers with desired microstructures and unique stereochemical properties.

[0003] Selective hydrogenation of unsaturated olefin groups in nitrile butadiene rubber (NBR) is a commercially successful hydrogenation process in the industry. Hydrogenated nitrile butadiene rubber (HNBR) retains the elastomeric properties of NBR, has excellent resistance to thermal oxidative degradation, and shows significant improvements 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 high-performance applications. Since 1977, hydrogenated nitrile butadiene rubber has become the most important member of hydrogenated elastomers and is the mainstay of high-performance elastomer applications.

[0004] The traditional preparation process of HNBR is divided into two steps: 1. Emulsion copolymerization of acrylonitrile-butadiene to prepare NBR latex; 2. Hydrogenation of NBR to prepare HNBR. Currently, NBR latex is usually prepared by reacting acrylonitrile-butadiene emulsion monomers, initiators, surfactants and other additives in an aqueous medium to form 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 them, 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 forms 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 serious, it will lead to difficult plasticization. Therefore, 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, 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 in 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, carbon is easy to adsorb rubber molecules and cause agglomeration, which affects the product performance. 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 easily deteriorated.

[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 with 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 HNBR emulsion requirements. In this field, the research group led by Professor Garry L. Rempel has carried out a lot 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 by 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 additives in an aqueous medium to react to generate NBR. After polymerization, the NBR latex needs to be post-treated before the second-step hydrogenation reaction, and deoxygenation 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 uses non-catalytic means, using diimide 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 disadvantages 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 copolymerizable monomer 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 process of adding a hydrogenation catalyst and the deoxygenation process 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 object, 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 reducing agent, a surfactant, a rhodium-containing catalyst soluble in water, and a promoter insoluble in water, and then 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 reducing agent, a rhodium-containing catalyst soluble in water, a promoter, a comonomer, a diene monomer, and an optionally added or non-added auxiliary agent with water, and emulsify at a low temperature;

[0013] S2. After the emulsification is completed, add a polymerization initiator, raise the temperature to the polymerization temperature, and then carry out a polymerization reaction. After the reaction is completed, add a terminator;

[0014] S3. Raise the temperature to the hydrogenation reaction temperature and then 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. By mass, mix 2-15 parts of a surfactant, 0.001-0.05 parts of a reducing agent, 0.01-0.2 parts of a rhodium-containing catalyst soluble in water, 0.1-2 parts of a promoter insoluble in water, 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 at a low temperature;

[0017] S2. Raise the temperature to 2 - 40 °C, add 0.5 - 3 parts of polymerization initiator, carry out polymerization reaction for 0.5 - 6 h, and then add terminator to stop the reaction;

[0018] S3. Raise the temperature to 60 - 180 °C, introduce hydrogen until the pressure reaches 3 - 15 MPa, carry out hydrogenation reaction for 0.5 - 10 h to obtain hydrogenated rubber latex.

[0019] The present invention also provides the 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 properties of the nanoparticles in the latex are 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 after the polymerization ends for hydrogenation reaction, with high hydrogenation efficiency and high hydrogenation degree; 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 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] [Method for Preparing Hydrogenated Rubber Latex by Emulsion Polymerization Hydrogenation Method]

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

[0026] First, carry out polymerization reaction on the diene monomer and comonomer in the presence of a polymerization initiator, a reducing agent, a surfactant, a rhodium-containing catalyst dissolved in water, and a cocatalyst, and then directly introduce hydrogen for hydrogenation reaction to obtain 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 includes the following steps:

[0029] S1. Mix a surfactant, a reducing agent, a rhodium catalyst soluble in water, a co-catalyst, a comonomer, a diene monomer, and an optionally added or not added auxiliary agent with water, and emulsify at a low temperature;

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

[0031] S3. After raising the temperature to the hydrogenation reaction temperature, introduce high-pressure hydrogen to carry out a hydrogenation reaction to obtain a hydrogenated rubber latex.

[0032] In the present invention, the amounts of all components such as the surfactant are based on the amount of the monomer (100 parts).

[0033] According to an embodiment of the present invention, in step S1, the amount of the surfactant is 2-15 parts, preferably 3-8 parts.

[0034] According to an embodiment of the present invention, in step S1, the amount of water is 300-1500 parts, preferably 600-1000 parts.

[0035] According to an embodiment of the present invention, in step S1, the amount of the reducing agent is 0.001-0.05 parts, preferably 0.005-0.01 parts.

[0036] According to an embodiment of the present invention, the amount of the rhodium catalyst soluble in water is 0.01-0.2 parts, preferably 0.02-0.1 parts.

[0037] According to an embodiment of the present invention, the amount of the co-catalyst insoluble in water is 0.1-2 parts, preferably 0.2-1 part.

[0038] According to an embodiment of the present invention, the auxiliary agent includes a chain transfer agent and / or a pH regulator.

[0039] 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.

[0040] According to an embodiment of the present invention, the amount of the pH regulator is 0.05-1.0 parts, preferably 0.1-0.6 parts.

[0041] According to an embodiment of the present invention, in step S1, the temperature of emulsification is 2 to 20 °C, preferably 5 to 10 °C; the time of emulsification is 0.2 to 2 hours, preferably 0.5 to 1 hour.

[0042] According to an embodiment of the present invention, in step S2, the dosage of the initiator is 0.01 to 2 parts, preferably 0.05 to 1.5 parts.

[0043] According to an embodiment of the present invention, the dosage of the terminator is 0.01 - 0.1 part, preferably 0.02 - 0.05 part.

[0044] According to an embodiment of the present invention, step S1 includes the following steps:

[0045] S1-a. First, dissolve the surfactant in a part of water to obtain a surfactant solution;

[0046] S1-b. Add the reducing agent, comonomer, rhodium-containing catalyst dissolved in water, cocatalyst insoluble in water, and additives to the surfactant solution and mix;

[0047] S1-c. Pass in an inert gas for degassing, add the diene monomer, and perform emulsification at a low temperature.

[0048] According to an embodiment of the present invention, step S1-b specifically includes the following steps: Add the reducing agent, comonomer, rhodium-containing catalyst (i.e., hydrogenation catalyst) dissolved in water, cocatalyst, chain transfer agent, and pH regulator to the surfactant solution and mix.

[0049] According to an embodiment of the present invention, step S1-b specifically includes the following steps: Add 0.001 to 0.05 part of the reducing agent, 10 - 60 parts of the comonomer, 0.01 - 0.2 part of the rhodium-containing catalyst dissolved in water, 0.1 - 2 parts of the cocatalyst insoluble in water, 0.25 - 2 parts of the chain transfer agent, and 0.05 - 1.0 part of the pH regulator to the surfactant solution and mix.

[0050] According to an embodiment of the present invention, in step S1-c, 40 - 90 parts of the diene monomer are added.

[0051] 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.

[0052] According to an embodiment of the present invention, in step S1-a, the surfactant is fully dissolved in a part of water, which can effectively maintain the stability of the emulsion interface, and then significantly improve the particle stability of the polymer nanoemulsion. Moreover, an excessive amount of surfactant can also be used to prepare a nanoemulsion with a smaller particle size to increase the specific surface area of the micelles.

[0053] According to an embodiment of the present invention, in step S1-b, during the reaction, the pH value in the system cannot be automatically maintained constant but is 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 for the reaction to proceed in stable micelles.

[0054] According to an embodiment of the present invention, in step S1-b, adding an appropriate amount of chain transfer agent can effectively control the degree of polymerization and molecular weight, thereby ensuring the chemical and physical properties of the latex or dry rubber.

[0055] 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 to ensure the purity of the gas in the kettle and eliminate the influence of air on the hydrogenation effect of the system. Before the reaction, the comonomer and the diene monomer are first emulsified. Under the action of the surfactant, the surface tension of water is reduced, and the comonomer and the diene monomer are wrapped in the micelles, forming uniform-sized oily monomer droplets, thus ensuring sufficient monomer concentration in the system during the reaction and the stability of the monomer droplets.

[0056] 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 for the polymerization reaction, and a terminator is added after the polymerization reaction is completed. For example, the temperature of the polymerization reaction is 2 to 40 °C, preferably 5 to 20 °C, and exemplary values are 2 °C, 5 °C, 7 °C, 10 °C, 20 °C, 25 °C, 30 °C or 40 °C; the time of the polymerization reaction is 0.5 to 6 hours, preferably 2 to 4 hours, and exemplary values are 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h or 6 h.

[0057] According to an embodiment of the present invention, step S3 specifically includes the following steps: introducing high-pressure hydrogen 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 hydrogenated rubber latex. For example, the temperature of the hydrogenation reaction is 60-180°C, preferably 70-150°C; 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 0.5-10 h, preferably 2-6 h, 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. 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.

[0058] According to an embodiment of the present invention, the method specifically includes the following steps:

[0059] S1. By mass, mix 2-15 parts of surfactant, 0.001-0.05 parts of reducing agent, 0.01-0.2 parts of rhodium-containing catalyst dissolved in water, 0.1-2 parts of co-catalyst, 10-60 parts of comonomer, 40-90 parts of diene monomer, 0.3-3 parts of auxiliary agent with 600-1000 parts of water, and emulsify at low temperature;

[0060] S2. Raise the temperature to 2-40°C, add 0.5-3 parts of polymerization initiator to carry out the polymerization reaction for 0.5-6 h, and then add a terminator to stop the reaction;

[0061] S3. Raise the temperature to 60-180°C, introduce hydrogen until the pressure is 3-15 MPa to carry out the hydrogenation reaction for 0.5-10 h to obtain hydrogenated rubber latex.

[0062] 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.

[0063] According to an embodiment of the present invention, the reaction kettle is selected from high-pressure reaction kettles, for example, a high-temperature and high-pressure stainless steel reaction kettle.

[0064] 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. The high-pressure gas is, for example, inert gas and hydrogen.

[0065] 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.

[0066] According to an embodiment of the present invention, an exhaust port is further provided on the kettle body.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] [Comonomer and diene monomer]

[0071] 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.

[0072] According to an embodiment of the present invention, the diene monomer is a conjugated monomer, and the conjugated monomer is selected from C 4 -C 6 at least one of 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.

[0073] [Reducing agent]

[0074] According to an embodiment of the present invention, the reducing agent is selected from at least one of potassium borohydride, sodium borohydride, stannous chloride, sodium sulfate, ferrous sulfate, etc.

[0075] [Surfactant]

[0076] 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, mono C of bis(phenylsulfonic acid) ether 4 to C 24 alkyl derivatives of alkali metal salts or ammonium salts, di C of bis(phenylsulfonic acid) ether4 to C 24 at least one of an alkali metal salt or ammonium salt of an alkyl derivative, an alkyl aryl sulfonic acid, an alkyl sulfonic acid, an alkali metal salt or ammonium salt of a sulfuric acid monoester of an ethoxylated alkanol, and a gemini surfactant.

[0077] 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).

[0078] According to an exemplary embodiment of the present invention, the surfactants of alkali metal salts or ammonium salts of alkyl sulfates, sulfuric acid monoesters of ethoxylated alkanols, ethoxylated alkylphenols, alkyl sulfonic acids, and alkyl aryl sulfonic acids are the following emulsifiers: such as alkyl sulfates (alkyl: C 8 to C 22 ), ethoxylated alkanols (degree of ethylene oxide: 4 to 30, alkyl: C 8 to C 22 ), sulfuric acid monoesters of ethoxylated alkylphenols (degree of ethylene oxide: 3 to 50, alkyl: C 4 to C 20 ), alkali metal salts or ammonium salts of alkyl sulfonic acids (alkyl: C 8 to C 22 ) and alkali metal salts or ammonium salts of alkyl aryl sulfonic acids (alkyl: C 4 to C 18 ). For example, the surfactant is sodium dodecyl sulfate (SDS) or sodium dodecylbenzenesulfonate (SDBS).

[0079] According to an exemplary embodiment of the present invention, the surfactants of ethoxylated monoalkylphenols, dialkylphenols, trialkylphenols, or ethoxylated fatty alcohols are the following emulsifiers: ethoxylated mono-, di- or trialkylphenols (degree of ethylene oxide: 3 to 50; alkyl C 4 to C 9 ) or ethoxylated fatty alcohols (degree of ethylene oxide: 3 to 50; alkyl C 4 to C 9 ).

[0080] According to an exemplary embodiment of the present invention, the surfactants of alkali metal salts or ammonium salts of alkyl aryl sulfonic acids, alkyl sulfonic acids, and sulfuric acid monoesters of ethoxylated alkanols are alkali metal salts or ammonium salts, especially sodium salts, of the following: alkyl aryl sulfonic acids, alkyl sulfonic acids (e.g., sulfonated C 12 to C 18 paraffin), alkyl sulfates (e.g., sodium lauryl sulfate), and sulfuric acid monoesters of ethoxylated alkanols (e.g., subsulfated ethoxylates of lauryl alcohol having 2 to 3 ethylene oxide units).

[0081] 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.

[0082] 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.

[0083] In some embodiments of the present invention, the cationic gemini surfactant has a structure shown in formula (1):

[0084]

[0085] In formula (1), R 1 , R 2 , Y, x, and y have the definitions described in A1 - A8:

[0086] A1: R 1 = R 2 = C m H 2m+1 ; Y = CH 2 ; x + y + 1 = s; m - s - m surfactants;

[0087] A2: R 1 = R 2 = C m H 2m+1 ; Y = CH 2 , O, S, N(CH 3 ), x = y = 2;

[0088] A2: R 1 = R 2 = C m H 2m+1 ; Y = CHOH, (CHOH) 2 ; x = y = 1;

[0089] A3: R 1 = R 2 = C m H 2m+1 ; Y = (OCH 2 CH 2 ) z , x = 2; y = 0; m - EOz - m surfactants;

[0090] A4: R 1 = R 2 = Cm H 2m+1 ; Y = C≡C; x = y = 1;

[0091] A5: R 1 = R 2 = C m H 2m+1 ; Y = a pHenylene group; x = y = 1;

[0092] A6: R 1 = R 2 = C m H 2m+1 OC(O)CH 2 ; no Y; x = y = 1; counterion = chloride;

[0093] A7: R 1 = R 2 = C m F 2m C 4 H 8 ; no Y; x = y = 1;

[0094] A8: R 1 = C m H 2m+1 ; R 2 = C n H 2n+1 ; no Y; x = y = 1; s; m-2-n surfactants (m is not equal to

[0095] n),

[0096] Among them, in A1 - A8, m, n, z are independently 1 - 60 respectively,

[0097] Br - can be replaced by any other anion, preferably F in Group VIIA of the periodic system - , Cl - , I - , At - , Ts - .

[0098] In some embodiments of the present invention, the gemini surfactant is selected from at least one of the following:

[0099] C 12 H 25 N + (CH 3 ) 2 -(CH 2 ) n -N + (CH3 ) 2 C 12 H 25 2Br – (n = 3–8),

[0100] C 12 H 25 N + (CH 3 ) 2 -(CH 2 ) 16 -N + (CH 3 ) 2 C 12 H 25 2Br – 、

[0101] C 16 H 33 N + (CH 3 ) 2 -(CH 2 ) 2 -N + (CH 3 ) 2 C 16 H 33 2Br – 、

[0102] C 8 H 17 N + (CH 3 ) 2 -(CH 2 ) 3 -N + (CH 3 ) 2 C 8 H 17 2Br – 、

[0103] C 12 H 25 N + (CH 3 ) 2 -(CH 2 ) 2 -O-(CH 2 ) 2 -N + (CH 3 ) 2 C 12 H 25 2Cl – 、

[0104] C 16 H 33 N + (CH 3 ) 2 -(CH 2 ) 5 -N + (CH 3 ) 2 C 16 H 33 2Br – 、

[0105] C 16 H 33 N + (CH 3 ) 2 -(CH 2 ) 2 -O-(CH 2 ) 2 -N + (CH 3 ) 2 C 16 H 33 2Br – 、

[0106] C 16 H 33 N + (CH 3 ) 2 -CH 2 -(CH 2 -O-CH 2 ) 3 -CH 2 -N + (CH 3 ) 2 C 16 H 33 2Br – 、

[0107] C 12 H 25 N + (CH 3 ) 2 -CH 2 -CH(OH)-CH 2 -N + (CH 3 ) 2 C 12 H 25 2Br – 、

[0108] C12 H 25 N + (CH 3 ) 2 -CH 2 -C 6 H 4 -CH 2 -N + (CH 3 ) 2 C 12 H 25 2Br – 、

[0109] C 12 H 25 N + (CH 3 ) 2 -CH 2 -CH(OH)-CH(OH)-CH 2 -N + (CH 3 ) 2 C 12 H 25 2Br – 、

[0110] C 12 H 25 N + (CH 3 ) 2 -CH 2 -CH(OH)-CH 2 -N + (CH 3 ) 2 -CH 2 -CH(OH)-CH 2 -N + (CH 3 ) 2 C 12 H 25 3Cl – 、

[0111] C 12 H 25 OPO 2 – -O-(CH 2 ) 6 -OPO 2 – -OC 12 H 25 2Na + 、

[0112] C 10H 21 O-CH 2 -CH(OSO 3 – )-CH 2 -O-(CH 2 ) 2 -O-CH 2 -CH(OSO 3 – )-CH 2 -OC 10 H 21 2Na + 。

[0113] 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.

[0114] In the examples of the present invention, the surfactants used include: anionic surfactants and gemini surfactants. The anionic surfactants produce latex particles with smaller particle sizes, good latex stability, and are not prone to generating agglomerates during the polymerization process, enabling the production of a latex with a high solid content and good stability. The gemini surfactants have good chemical stability towards electrolytes, but the polymerization reaction rate is moderate, the resulting latex particles have larger particle sizes, and agglomerates are prone to being generated during the polymerization process.

[0115] [Polymerization initiator]

[0116] According to an embodiment of the present invention, the polymerization initiator for 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, azobis(2-methylpropionamidine) dihydrochloride, azobis(2-methylimidazoline-2-yl) dihydrochloride, ammonium persulfate, etc.

[0117] According to an exemplary embodiment of the present invention, the initiator is any one or several of ammonium persulfate, potassium persulfate, and sodium persulfate. The persulfide initiator has strong thermal decomposition ability, fast reaction rate, and the concentration of free radicals generated can reach the highest concentration for the reaction at room temperature.

[0118] [Auxiliary agent]

[0119] 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.

[0120] In the examples of the present invention, the chain transfer agent is selected from dodecyl mercaptan. Dodecyl mercaptan has good performance and can effectively reduce the molecular weight of the latex.

[0121] 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.

[0122] [Terminator]

[0123] 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.

[0124] According to an exemplary embodiment of the present invention, the terminator is selected from N,N-diethylhydroxylamine.

[0125] [Rhodium-containing catalyst soluble in water]

[0126] According to an embodiment of the present invention, the rhodium-containing catalyst soluble in water has the structure shown in Formula I:

[0127] RhQL x Formula I,

[0128] Wherein,

[0129] Q is a hydride or an anion other than hydride,

[0130] L is a ligand soluble in water,

[0131] x is an integer from 1 to 10, for example, x = 1, 2, 3, or 4.

[0132] It must be emphasized that the structure of the ligand L soluble in water is not particularly limited. Such a ligand soluble in water 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.

[0133] According to an embodiment of the present invention, L has the structure shown in Formula II:

[0134] R 1 m Formula II

[0135] Wherein, R 1 are the same or different and independently selected from alkyl, cycloalkyl, aryl, or aralkyl, and at least one of the R 1 groups is sulfonated once or more; preferably, R 1 are the same or different and independently selected from C 1 -C 8 alkyl, C 4 -C 8 cycloalkyl, C 6 -C 15 aryl, or C 7 -C15 an aralkyl group, and at least one of the R 1 groups is sulfonated once or more; for example, at least one of the R 1 groups is sulfonated once, twice or three times;

[0136] G is phosphorus, arsenic, sulfur or the sulfoxide group S═O;

[0137] m is 2 or 3;

[0138] In some embodiments of the present invention, Q is a halide, and x is preferably 3.

[0139] In some embodiments of the present invention, Q is a hydride, and x is preferably 4.

[0140] In some embodiments of the present invention, Q is a halide, preferably chloride or bromide.

[0141] In one embodiment of the present invention, R 1 more than one (such as two or three) of the groups is sulfonated once or more; for example, each R 1 group is sulfonated once, twice or three times.

[0142] In one embodiment of the present invention, the water-soluble rhodium-containing catalyst is selected from RhCl(TPPMS) 3 (TPPMS represents monosulfonated triphenylphosphine, for example P(C 6 H 5 )) 2 (m-C 6 H 4 SO 3 - )) or RhCl(TPPTS) 3 (TPPTS represents trisulfonated triphenylphosphine, for example tris(3-sulfophenyl)phosphine, P(C 6 H 4 -3-SO 3 - ) 3 ).

[0143] The water-soluble rhodium-containing catalyst of the present invention is soluble in water at room temperature, i.e., (24 ± 2)°C. The counter ion of the sulfonate group used for sulfonating the R 1 group is an alkali metal ion, such as Na + or K + .

[0144] In one embodiment of the present invention, L has the structure shown in Formula III:

[0145] R 2 n Z-A-ZR3 n Formula III

[0146] wherein R 2 and 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 and R 3 are the same or different and are independently selected from C 1 -C 8 alkyl, C 4 -C 8 cycloalkyl, C 6 -C 15 aryl or C 7 -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;

[0147] Z is phosphorus or arsenic;

[0148] A represents a spacer group, preferably a phenylene group or a C 1 -C 20 alkylene group or a single bond;

[0149] n is 2;

[0150] x is 1 or 2.

[0151] In one embodiment of the present invention, one or both of the R 2 and R 3 groups are sulfonated once, twice or three times.

[0152] In one embodiment of the present invention, one or two of the R 2 groups and one or two of the R 3 groups are simultaneously sulfonated once, twice or three times.

[0153]

Term Definitions and Explanations

[0154] The term "alkyl" shall mean any branched or unbranched hydrocarbon residue and shall include C 1 -C 20Alkyl groups 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.

[0155] The term "cycloalkyl" shall include C 3 -C 10 Cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl.

[0156] 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.

[0157] 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.

[0158] 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.

[0159]

Promoter

[0160] According to an embodiment of the present invention, the promoter is insoluble in water.

[0161] In one embodiment, the promoter has a structure as shown in Formula IV:

[0162] R 4 oD Formula IV

[0163] Wherein,

[0164] R 4 are the same or different and independently selected from each other alkyl, cycloalkyl, aryl or aralkyl. Preferably, R 4 are the same or different and independently selected from each other C 1 -C 8 alkyl, C 6 -C 15 aryl, C 4 -C 8 cycloalkyl or C 7 -C 15 aralkyl;

[0165] D is phosphorus, arsenic, sulfur or a sulfoxide group S=O; preferably phosphorus;

[0166] o is 2 or 3.

[0167] In one embodiment, the cocatalyst is a phosphine of triaryl, trialkyl, tricycloalkyl, diaryl - monoalkyl, dialkylmonoaryl, diarylmonocycloalkyl, dialkylmonocycloalkyl, dicycloalkylmonoaryl or dicycloalkylmonoaryl.

[0168] In one embodiment of the present invention, the cocatalyst has a structure as shown in Formula V:

[0169] R 5 pE - A - ER 6 Formula V

[0170] Wherein,

[0171] R 5 and R 6 are the same or different and are independently selected from alkyl, cycloalkyl, aryl or aralkyl; preferably, R 5 and R 6 are the same or different and are independently selected from C 1 - C 8 alkyl, C 6 - C 15 aryl, C 4 - C 8 cycloalkyl or C 7 - C 15 aralkyl;

[0172] E is phosphorus or arsenic;

[0173] A represents a spacer group, preferably a phenylene group or C 1 - C 20 alkylene or a single bond,

[0174] p is 2.

[0175] 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 typically used is in the range from 0.01% to 5.0% by weight, preferably in the range from 0.02% to 1.0% by weight.

[0176] 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 from 500% to 3000% by weight.

[0177] [Hydrogenated rubber]

[0178] The present invention also provides a hydrogenated rubber latex prepared by the above method.

[0179] According to an 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%.

[0180] According to an embodiment of the present invention, the degree of hydrogenation of the hydrogenated rubber latex is greater than or equal to 75%, preferably the degree of hydrogenation of the hydrogenated rubber latex is greater than or equal to 95%, and further preferably, the degree of hydrogenation of the hydrogenated rubber latex is 97%, such as 78%, 84.3%, 97.5%, 97.9%, 99.4%, 99.5%, 99.6%.

[0181] According to an embodiment of the present invention, the acrylonitrile content is 20-50 mol%.

[0182] According to an embodiment of the present invention, the particle size of the hydrogenated rubber latex is 20-70 nm, preferably the particle size of the hydrogenated rubber latex is 30-65 nm.

[0183] The inventors found that the polymerization system, emulsification system of the present invention and the rhodium-containing catalyst and cocatalyst dissolved in water act together, and can also achieve the effect of significantly improving the hydrogenation reaction efficiency and reducing the amount of catalyst used.

[0184] The technical solutions of the present invention will be clearly and completely described below 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 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.

[0185] Example 1

[0186] A method for preparing HNBR latex, comprising the following steps:

[0187] 1) Dissolve 7 g of the surfactant didodecyldimethylammonium bromide in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0188] 2) Add 0.005 g of the reducing agent ferrous sulfate, 30 g of acrylonitrile, 0.05 g of the hydrogenation catalyst RhCl(TPPMS) 3 , 0.5 g of the cocatalyst triphenylphosphine, 0.3 g of the chain transfer agent tert-dodecyl mercaptan, and 0.05 g of the pH regulator sodium phosphate to the reaction kettle;

[0189] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, conduct 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 use a high and low temperature cooling circulation machine to cool down the reaction kettle, and conduct emulsification at 5 °C for 1 hour.

[0190] 4) Add 0.05 g of the emulsion polymerization initiator cumene hydroperoxide to the reaction kettle through the feeding tank, raise the temperature of the reaction kettle to the polymerization reaction temperature of 7 °C, and add 0.05 g of the terminator N,N - diethylhydroxylamine after polymerization for 4 hours.

[0191] 5) Raise the system temperature to 70 °C and introduce 8 MPa of hydrogen. At this time, start the hydrogenation reaction. Keep the temperature and pressure constant in the reaction kettle, and keep the stirring speed constant at 450 rpm. After reacting for 5 hours, obtain HNBR latex.

[0192] Example 2

[0193] A preparation method for preparing HNBR latex, including the following steps:

[0194] 1) Dissolve 7 g of the surfactant potassium oleate in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0195] 2) Add 0.005 g of the reducing agent ferrous sulfate, 30 g of acrylonitrile, 0.05 g of the hydrogenation catalyst RhCl(TPPMS) 3 , 0.5 g of the cocatalyst triphenylphosphine, 0.3 g of the chain transfer agent tert - dodecyl mercaptan, and 0.05 g of the pH regulator sodium phosphate to the reaction kettle;

[0196] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, conduct 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 use a high and low temperature cooling circulation machine to cool down the reaction kettle, and conduct emulsification at 5 °C for 1 hour.

[0197] 4) Add 0.05 g of the emulsion polymerization initiator cumene hydroperoxide to the reaction kettle through the feeding tank, raise the temperature of the reaction kettle to the polymerization reaction temperature of 7 °C, and add 0.05 g of the terminator N,N - diethylhydroxylamine after polymerization for 4 hours.

[0198] 5) Raise the system temperature to 70 °C and introduce 8 MPa of hydrogen. At this time, start the hydrogenation reaction. Keep the temperature and pressure constant in the reaction kettle, and keep the stirring speed constant at 450 rpm. After reacting for 5 hours, obtain HNBR latex.

[0199] Example 3

[0200] A preparation method of HNBR latex, comprising the following steps:

[0201] 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;

[0202] 2) Add 0.005 g of reducing agent ferrous sulfate, 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 into the reaction kettle;

[0203] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, while stirring at a speed of 200 rpm, perform degassing treatment for 0.5 hours, then add 70 g of butadiene in liquid form to the degassed reaction kettle, mix, and use a high and low temperature cooling circulation machine to cool the reaction kettle, and emulsify at 5 °C for 1 hour.

[0204] 4) Add 0.05 g of emulsion polymerization initiator cumene hydroperoxide to the reaction kettle through a feeding tank, raise the temperature of the reaction kettle to the polymerization reaction temperature of 7 °C, and add 0.05 g of terminator N,N-diethylhydroxylamine after polymerization for 4 hours.

[0205] 5) Raise the system temperature to 70 °C and introduce 8 MPa of hydrogen. At this time, start the hydrogenation reaction, keep the temperature and pressure constant in the reaction kettle, and keep the stirring speed constant at 450 rpm. After reacting for 5 hours, HNBR latex is obtained.

[0206] Example 4

[0207] A preparation method of HNBR latex, comprising the following steps:

[0208] 1) Dissolve 10 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;

[0209] 2) Add 0.005 g of reducing agent ferrous sulfate, 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 into the reaction kettle;

[0210] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, conduct 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, use a high and low temperature cooling circulation machine to cool down the reaction kettle, and conduct emulsification at 5°C for 1 hour.

[0211] 4) Add 0.05 g of the emulsion polymerization initiator cumene hydroperoxide to the reaction kettle through a feeding tank, raise the temperature of the reaction kettle to the polymerization reaction temperature of 7°C, and add 0.05 g of the terminator N,N - diethylhydroxylamine after polymerization for 4 hours.

[0212] 5) Raise the system temperature to 70°C and introduce 8 MPa of hydrogen. At this time, start the hydrogenation reaction. Keep the temperature and pressure constant in the reaction kettle, and keep the stirring speed constant at 450 rpm. After reacting for 5 hours, obtain HNBR latex.

[0213] Example 5

[0214] A preparation method of HNBR latex, comprising the following steps:

[0215] 1) Dissolve 7 g of the surfactant potassium oleate in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0216] 2) Add 0.005 g of the reducing agent ferrous sulfate, 30 g of acrylonitrile, 0.07 g of the hydrogenation catalyst RhCl(TPPMS) 3 , 0.5 g of the cocatalyst triphenylphosphine, 0.3 g of the chain transfer agent tert - dodecyl mercaptan, and 0.05 g of the pH regulator sodium phosphate to the reaction kettle;

[0217] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, conduct 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, use a high and low temperature cooling circulation machine to cool down the reaction kettle, and conduct emulsification at 5°C for 1 hour.

[0218] 4) Add 0.05 g of the emulsion polymerization initiator cumene hydroperoxide to the reaction kettle through a feeding tank, raise the temperature of the reaction kettle to the polymerization reaction temperature of 7°C, and add 0.05 g of the terminator N,N - diethylhydroxylamine after polymerization for 4 hours.

[0219] 5) Raise the system temperature to 70°C and introduce 8 MPa of hydrogen. At this time, start the hydrogenation reaction. Keep the temperature and pressure constant in the reaction kettle, and keep the stirring speed constant at 450 rpm. After reacting for 5 hours, obtain HNBR latex.

[0220] Example 6

[0221] A preparation method of HNBR latex, comprising the following steps:

[0222] 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;

[0223] 2) Add 0.005 g of reducing agent ferrous sulfate, 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 into the reaction kettle;

[0224] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, while stirring at a speed of 200 rpm, perform degassing treatment for 0.5 hours, then add 70 g of butadiene in liquid form to the degassed reaction kettle, mix, and use a high and low temperature cooling circulation machine to cool the reaction kettle. Emulsify at 5 °C for 1 hour.

[0225] 4) Add 0.05 g of emulsion polymerization initiator cumene hydroperoxide to the reaction kettle through a feeding tank, and raise the temperature of the reaction kettle to the polymerization reaction temperature of 10 °C. After polymerization for 4 hours, add 0.05 g of terminator N,N-diethylhydroxylamine.

[0226] 5) Raise the temperature of the system to 90 °C and introduce 8 MPa of hydrogen. At this time, start the hydrogenation reaction. Keep the temperature and pressure constant in the reaction kettle, and stir at a constant speed of 450 rpm. After reacting for 5 hours, obtain HNBR latex.

[0227] After the reaction, samples of the products of Examples 1-6 were taken, and the solid content of the polymer was measured by gel permeation chromatography to calculate the conversion rate. The results are shown in Table 1 below.

[0228] Monomer conversion rate = (system solid content * total system mass - mass of raw material non-volatile components) / total mass of raw material monomers.

[0229] 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.

[0230] 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.

[0231] 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.

[0232] 2236 cm -1 is the characteristic peak of the cyano group (-C≡N), 970 cm -1 is the characteristic peak of -C=C- (trans 1,4 structure), and 723 cm -1 is the characteristic peak of (-CH 2 ), n>4. n

[0233]

[0234] K(723) = 0.255, K(970) = 2.3 are the constants unique to HNBR

[0235] Then the relative amount of -C=C- in HNBR is:

[0236]

[0237] The relative amount of methylene formed by the hydrogenation of -C=C- in NBR is:

[0238]

[0239] Finally, the hydrogenation degree calculation formula is:

[0240]

[0241] The acrylonitrile content is determined by the elemental analysis method to measure the N atom content, thereby obtaining the acrylonitrile content.

[0242] Table 1 Performance test results of different NBR latexes

[0243]

[0244] Compared with the prior art, the hydrogenated nitrile rubber latex prepared by the emulsion polymerization hydrogenation method in the present invention has stable performance, good uniformity of the size of the nanomicelles, 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 the hydrogenation effect is good and the hydrogenation degree is high during the synthesis process. Moreover, the conversion rate of the monomer is high. The present invention reduces the post-treatment of the NBR latex and the processes of deoxygenation and catalyst addition before hydrogenation, and prevents environmental pollution caused by the volatilization of unreacted monomers. At the same time, the present invention uses a rhodium-containing catalyst soluble in water for the hydrogenation reaction, 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.

[0245] Above, the embodiments of the present invention have been described by way of example. However, the protection scope of the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing hydrogenated rubber latex, characterized in that: The method comprises the following steps: firstly subjecting diene monomer and comonomer to polymerization reaction in the presence of polymerization initiator, reducing agent, surfactant, water-soluble rhodium-containing catalyst and water-insoluble co-catalyst, then introducing hydrogen to carry out hydrogenation reaction to obtain hydrogenated rubber latex.

2. The method according to claim 1, characterized in that The method comprises the following steps: S1. mixing a surfactant, a reducing agent, a water-soluble rhodium-containing catalyst, a water-insoluble co-catalyst, a comonomer, a diene monomer, and an optional additive with water and emulsifying; S2. After the emulsification is completed, a polymerization initiator is added, the temperature is raised to the polymerization temperature, a polymerization reaction is carried out, and a terminator is added after the reaction is completed; S3. After raising the temperature to the hydrogenation reaction temperature, high-pressure hydrogen is introduced to carry out a hydrogenation reaction to obtain hydrogenated rubber latex.

3. The method according to claim 2, characterized in that The surfactant is used in an amount of 2-15 parts, preferably 3-8 parts; and / or, the amount of water is 300 to 1500 parts, preferably 600 to 1000 parts; and / or, the reducing agent is used in an amount of 0.001 to 0.05 parts, preferably 0.005 to 0.01 parts; and / or, the amount of the rhodium-containing catalyst dissolved in water is 0.01 to 0.2 parts, preferably 0.02 to 0.1 parts; and / or, the amount of the water-insoluble promoter is 0.1-2 parts, preferably 0.2-1 parts; And / or, the auxiliary agent includes a chain transfer agent and / or a pH adjuster, the amount of the chain transfer agent is 0.25 to 2 parts, and the amount of the pH adjuster is 0.05 to 1.0 parts.

4. The method according to claim 2, characterized in that: Step S1 includes the following steps: S1-a, first dissolving a surfactant in a portion of water to obtain a surfactant solution; S1-b, adding a reducing agent, a comonomer, a water-soluble rhodium-containing catalyst, a water-insoluble co-catalyst, and an auxiliary agent into a surfactant solution and mixing; S1-c, introducing inert gas for degassing, adding diene monomer, and emulsifying at low temperature.

5. The method according to claim 2, characterized in that: In step S2, the polymerization temperature is 2 to 40° C.; the polymerization time is 0.5 to 6 hours; And / or, in step S3, the temperature of the hydrogenation reaction is 60 to 180° C.; the time of the hydrogenation reaction is 0.5 to 10 h; And / or, in step S3, the pressure of the high-pressure hydrogen is 3 to 15 MPa, preferably 4 to 12 MPa.

6. The method according to any one of claims 1 to 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 unsaturated carboxylic acids of methacrylic acid.

7. The method according to any one of claims 1 to 6, characterized in that: The reducing agent is selected from at least one of potassium borohydride, sodium borohydride, stannous chloride, sodium sulfate and ferrous sulfate; and / or, the surfactant is selected from fatty acids, alkyl sulfates, sulfuric acid monoesters of ethoxylated alkanols, ethoxylated alkylphenols, alkali metal or ammonium salts of alkylsulfonic acids, alkali metal or ammonium salts of alkylarylsulfonic acids, ethoxylated monoalkylphenols, dialkylphenols, trialkylphenols, ethoxylated fatty alcohols, mono C4-C4 of bis(benzenesulfonic acid) ethers. 24 Alkali metal or ammonium salts of alkyl derivatives, di-C4-C 24 At least one of an alkali metal salt or ammonium salt of an alkyl derivative, an alkylarylsulfonic acid, an alkali metal salt or ammonium salt of a sulfuric acid monoester of an ethoxylated alkanol, and a gemini surfactant.

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

9. The method according to claim 8, characterized in that L has a structure as shown in Formula II: R 1 m G-Formula II, Among them, R 1 are the same or different and are independently selected from alkyl, cycloalkyl, aryl or aralkyl groups, and at least one of them is 1 The group is sulfonated one or more times; G is phosphorus, arsenic, sulfur or a sulfoxide group S=O; m is 2 or 3; Alternatively, L has a structure shown in Formula III: R 2 n Z-A-ZR 3 n Formula III Among them, R 2 , R 3 are the same or different and are independently selected from alkyl, cycloalkyl, aryl or aralkyl groups, and R 2 or R 3 At least one of the groups is sulfonated one or more times; Z is phosphorus or arsenic; A represents a spacer, preferably phenylene or C1-C 20 Alkylene or single bond; n is 2; x is 1 or 2; Preferably, the water-soluble rhodium-containing catalyst 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 to 9, characterized in that: 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%; The particle size of the hydrogenated rubber latex is 20 to 70 nm, preferably 30 to 65 nm.

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