Method for directly preparing hydrogenated rubber latex based on rhodium-based catalyst high-temperature emulsion polymerization hydrogenation method

Abstract

The invention discloses a method for directly preparing hydrogenated rubber latex based on a rhodium-based catalyst high-temperature emulsion polymerization hydrogenation process, 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 surfactant, a water-insoluble rhodium metal catalyst and a cocatalyst; and after the polymerization reaction is finished, adding a terminator, raising the temperature, introducing hydrogen, and directly carrying out hydrogenation reaction to obtain the 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. The synthesized HNBR is small in particle size distribution, higher in hydrogenation degree, higher in hydrogenation speed, high in stability, not prone to demulsification and extremely low in gel content; and the conversion rate of the HNBR latex is higher than that of HNBR latex synthesized by a traditional method.

Description

Technical Field

[0001] The present invention belongs to the technical field of the synthesis of special rubber latex, and relates to a method for directly preparing hydrogenated rubber latex by high-temperature emulsion polymerization hydrogenation method based on a rhodium-based catalyst, in particular to a method for directly hydrogenating a diene monomer and a copolymerizable monomer by a rhodium metal catalyst insoluble in water, a cocatalyst and at least one surfactant at high temperature and then introducing hydrogen to prepare HNBR latex. Background Art

[0002] Hydrogenation of unsaturated polymers is an important process for 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 has significant improvements in mechanical properties such as tensile strength, elongation at break, abrasion resistance and hardness. Due to these superior physical and chemical properties, HNBR has important applications in the fields of automobiles, oil wells, aerospace and various fields with high performance requirements. Since 1977, hydrogenated nitrile rubber has become the most important member of hydrogenated elastomers and is the main force in the application of high-performance elastomers.

[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, preparing NBR latex usually involves reacting acrylonitrile-butadiene emulsion monomers, initiators, surfactants and other additives in an aqueous medium to generate NBR. However, a large amount of unreacted monomers exist in the NBR latex prepared by the above method, resulting in a relatively high content of VOC (volatile organic compounds) in the product, which will cause certain harm to the environment. At the same time, the content of residual monomers will also affect the subsequent hydrogenation process. Currently, the 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, and 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. Therefore, there is currently no industrial production. (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 used include cyclohexanone, xylene, chloroform, etc., which will not only cause environmental pollution, but also have a long reaction time, a relatively high reaction temperature, high energy consumption, and require a large amount of raw materials and time costs. 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. Inorganic carriers include alumina, silica, activated carbon, carbon black, alkaline earth metal carbonates, etc.; after the heterogeneous solution hydrogenation method 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. This catalyst has high selectivity, 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, it 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 high-pressure stirring conditions, and the reaction time is relatively long, and the process energy consumption is high, resulting in easy deterioration of the polymer performance.

[0005] In order to avoid the cumbersome hydrogenation steps in solution hydrogenation and avoid the use of a large amount of organic solvents, the emulsion hydrogenation method was proposed. The emulsion hydrogenation method is a method of directly adding a catalyst to an NBR emulsion and then preparing an 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 milder reaction conditions, fewer reaction processes, and no need to use organic solvents, thereby saving energy and reducing pollution. Therefore, 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 need to further introduce a large amount of surfactants during the hydrogenation process, the emulsion catalytic hydrogenation technology has not yet reached the requirements of industrial production.

[0006] In short, 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. The manufacture of NBR generally uses the emulsion polymerization process at present, 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 process, and deoxygenation is also required 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, the existing HNBR production technology needs to be further improved. Summary of the Invention

[0007] To improve the deficiencies of the existing technology, the present invention provides a method and application for preparing hydrogenated nitrile rubber latex by high-temperature emulsion polymerization hydrogenation using a rhodium-based catalyst. The present invention integrates and simplifies the existing NBR emulsion polymerization and emulsion hydrogenation, aiming to solve the problems of cumbersome process flow, low efficiency, high energy consumption, and large pollution in the existing technology. In the present invention, a diene monomer and a copolymerizable monomer are used to synthesize HNBR, and a rhodium metal hydrogenation catalyst insoluble in water is added before polymerization. After the polymerization reaction is completed, hydrogen is directly introduced for hydrogenation to obtain hydrogenated nitrile rubber. The present invention reduces the post-treatment of NBR latex and omits the processes of adding a hydrogenation catalyst and removing oxygen before hydrogenation, thus having the advantages of saving time, cost, and being environmentally friendly. In addition, the HNBR prepared by the present invention has a higher hydrogenation degree and a faster hydrogenation rate than the HNBR synthesized by traditional emulsion polymerization.

[0008] To achieve the above-mentioned 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 surfactant, a rhodium metal catalyst insoluble 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 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 metal catalyst insoluble in water, a cocatalyst, a comonomer, a diene monomer, and an optional additive or non-additive 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 polymerization is completed.

[0014] S3. Raise the temperature to the hydrogenation reaction temperature and then introduce high-pressure hydrogen for a hydrogenation reaction to obtain 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, 0.5-3 parts of a polymerization initiator, 0.01-0.1 part of a rhodium metal catalyst insoluble 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 additive with 150-1500 parts of water and emulsify at room temperature for 0.2-1 h;

[0017] S2. Raise the temperature to 20 - 100 °C for polymerization reaction for 0.5 - 8 h, then add a terminator to stop the reaction;

[0018] S3. Raise the temperature to 70 - 180 °C, then introduce hydrogen until the pressure reaches 6 - 15 MPa for 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 75 - 100%, the content of the comonomer is 25 - 40 mol%, and the conversion rate is 60 - 95 wt%.

[0021] According to the embodiments of the present invention, the particle size of the hydrogenated rubber latex is 60 - 90 nm, preferably 65 - 85 nm, such as 60 nm, 65 nm, 67 nm, 69 nm, 70 nm, 72 nm, 73 nm, 75 nm, 80 nm, 82 nm, 84 nm, 86 nm, 89 nm or 90 nm.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1) In the present invention, a diene monomer and a copolymerizable monomer are synthesized into HNBR. Before polymerization, a rhodium metal catalyst insoluble in water is added. 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. At the same time, it avoids the emission of toxic butadiene gas and the process of deoxidation before hydrogenation. Moreover, the conversion rate of the monomer into rubber in the present invention is high, and the gel is less, having the advantages of saving time, cost, and being environmentally friendly.

[0024] 2) The HNBR prepared by the present invention has a smaller particle size distribution, a higher hydrogenation degree, a faster hydrogenation rate, and high stability, is not easily demulsified, and has a very low gel content compared with the HNBR synthesized by traditional hydrogenation methods; the conversion rate of the HNBR latex synthesized by the present invention is higher. Furthermore, the rhodium metal catalyst insoluble in water in the present invention has high hydrogenation activity, can be used without any organic solvents, the reaction conditions are milder, and the reaction can be carried out at lower temperature and pressure, not only reducing the industrial cost, but also contributing to green chemical industry. Detailed implementation manners

[0025] [Method for preparing hydrogenated rubber latex by high-temperature emulsion polymerization hydrogenation method based on rhodium-based catalyst]

[0026] As described above, the present invention provides a method for preparing hydrogenated rubber latex by high-temperature emulsion polymerization hydrogenation method based on rhodium-based catalyst, including the following steps:

[0027] The comonomer and the diene monomer are first subjected to a polymerization reaction in the simultaneous presence of a polymerization initiator, a surfactant, a water-insoluble rhodium metal catalyst, and a cocatalyst, and then a hydrogenation reaction is carried out under high-pressure hydrogen and high-temperature conditions to obtain a hydrogenated rubber latex.

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

[0029] S1. Mix a surfactant, a polymerization initiator, a water-insoluble rhodium metal catalyst (hydrogenation catalyst), a cocatalyst, a comonomer, a diene monomer, and an optional additive or non-additive with water and emulsify.

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

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

[0032] According to an embodiment of the present invention, the dosage of the surfactant is 2 to 15 parts, preferably 3 to 8 parts.

[0033] According to an embodiment of the present invention, in step S1, the dosage of the water is 150 to 1500 parts, preferably 150 to 500 parts.

[0034] According to an embodiment of the present invention, the dosage of the initiator is preferably 0.5 to 3 parts, for example, 1.5 parts.

[0035] According to an embodiment of the present invention, the dosage of the water-insoluble rhodium metal catalyst is 0.01 - 0.1 part, preferably 0.02 to 0.1 part, for example, 0.02 part, 0.05 part.

[0036] According to an embodiment of the present invention, the dosage of the cocatalyst is 0.2 - 1 part, for example, 0.5 part.

[0037] According to an embodiment of the present invention, the additive includes a chain transfer agent and / or a pH regulator.

[0038] According to an embodiment of the present invention, the dosage of the chain transfer agent is 0.25 to 2 parts, preferably 0.5 to 1.5 parts.

[0039] According to an embodiment of the present invention, the dosage of the pH regulator is 0.05 to 1.5 parts, preferably 0.1 to 0.6 parts.

[0040] According to an embodiment of the present invention, the dosage of the terminator is 0.01 - 0.1 part, preferably 0.02 to 0.1 part, for example, 0.05 part.

[0041] According to an embodiment of the present invention, the temperature of the emulsification is room temperature.

[0042] According to an embodiment of the present invention, the emulsification time is 0.2 - 1 h, preferably 0.5 - 1 h.

[0043] According to an embodiment of the present invention, step S1 includes the following steps:

[0044] S1-a. First, dissolve 2 - 15 parts of a surfactant in a part of water to obtain a surfactant solution;

[0045] S1-b. Add 0.5 - 3 parts of a polymerization initiator, 10 - 60 parts of a copolymerizable monomer, 0.01 - 0.1 part of a rhodium metal catalyst insoluble in water, 0.2 - 1 part of a cocatalyst, 0.25 - 2 parts of a chain transfer agent, 0.01 - 0.6 part of a pH regulator and the remaining water to the surfactant solution and mix;

[0046] S1-c. Introduce an inert gas into the reaction kettle for degassing, add 40 - 90 parts of a diene monomer, and emulsify for 0.2 - 2 h at room temperature to obtain an emulsified product.

[0047] According to an embodiment of the present invention, in step S1-a, dissolving the surfactant in a part of water can effectively maintain the stability of the emulsion interface, thereby significantly improving 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.

[0048] 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 for the reaction to proceed in stable micelles; in step S1-b, adding an appropriate amount of a 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.

[0049] According to an embodiment of the present invention, in step S1-c, introducing an inert gas replaces the air in the reaction kettle to ensure the purity of the gas in the kettle and eliminate the influence of air on the polymerization and hydrogenation effects of the system; before the reaction, first emulsify the copolymerizable monomer and the diene monomer. Under the action of the surfactant, the surface tension of water decreases, and the copolymerizable monomer and the diene monomer are wrapped in the micelles, forming uniformly sized oily monomer droplets, thereby ensuring sufficient monomer concentration in the system during the reaction and the stability of the monomer droplets.

[0050] According to an embodiment of the present invention, the inert gas in step S1-c is selected from at least one of helium, argon, and nitrogen. Preferably, the pressure of the inert gas is 0.1 to 1 MPa, for example, 0.5 MPa.

[0051] According to an embodiment of the present invention, the degassing in step S1-c is carried out under stirring conditions, and the stirring speed is 100 to 600 rpm, preferably 160 to 360 rpm. Further preferably, the stirring speed is constant.

[0052] According to an embodiment of the present invention, the temperature of the polymerization reaction in step S2 is 40 to 100 °C, preferably the temperature of the polymerization reaction is 40 to 70 °C.

[0053] According to an embodiment of the present invention, the stirring speed in step S2 is 200 to 900 rpm, preferably the stirring speed is 200 to 650 rpm, and preferably the stirring speed is constant.

[0054] According to an embodiment of the present invention, step S2 specifically includes the following steps: after emulsification is completed, stir and raise the temperature to carry out the polymerization reaction, and add a terminator after the polymerization reaction is completed. For example, the temperature of the polymerization reaction is 20 to 100 °C, preferably 20 to 60 °C, and exemplarily 20 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, 90 °C or 100 °C; the time of the polymerization reaction is 0.5 to 8 h, preferably the time of the polymerization reaction is 2 to 6 h, and exemplarily 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h or 8 h.

[0055] According to an embodiment of the present invention, the reaction in step S3 is carried out under stirring conditions, and the stirring speed is 300 to 900 rpm, preferably the stirring speed is 450 to 650 rpm, for example, 500 rpm.

[0056] According to an embodiment of the present invention, step S3 specifically includes the following steps: introduce high-pressure hydrogen into the reaction kettle, and at this time, start the hydrogenation reaction. Keep the temperature and pressure constant in the reaction kettle, continuously stir, and carry out the hydrogenation reaction to obtain hydrogenated rubber latex. For example, the temperature of the hydrogenation reaction is 70 to 180 °C, preferably 70 to 100 °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 2 to 10 h, preferably the time of the hydrogenation reaction is 3 to 6 h, for example, 5 h.

[0057] According to an embodiment of the present invention, in step S3, the pressure of the high-pressure hydrogen is 3 to 15 MPa, preferably 4 to 12 MPa, for example, 8 MPa.

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

[0059] S1. By mass, mix 2 - 15 parts of a surfactant, 0.5 - 3 parts of a polymerization initiator, 0.01 - 0.1 part of a rhodium metal catalyst insoluble in water, 0.2 - 1 part of a co-catalyst, 10 - 60 parts of a comonomer, 40 - 90 parts of a diene monomer, 0.3 - 3 parts of an auxiliary agent with 150 - 1500 parts of water, and emulsify at room temperature for 0.2 - 1 h;

[0060] S2. Raise the temperature to 20 - 100 °C for polymerization reaction for 0.5 - 8 h, and then add a terminator to stop the reaction;

[0061] S3. Raise the temperature to 70 - 180 °C, then introduce hydrogen until the pressure is 6 - 15 MPa for hydrogenation reaction for 0.5 - 10 h to obtain a hydrogenated rubber latex.

[0062] [Comonomer and diene monomer]

[0063] 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.

[0064] 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 C 4 -C 6 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.

[0065] [Surfactant]

[0066] According to an embodiment of the present invention, the surfactant is selected from at least one of 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, alkali metal salts or ammonium salts of mono C 4 to C 24 alkyl derivatives of bis(phenylsulfonic acid) ether, alkali metal salts or ammonium salts of di C 4 to C 24 alkyl derivatives of bis(phenylsulfonic acid) ether, alkyl aryl sulfonic acids, alkyl sulfonic acids, alkali metal salts or ammonium salts of sulfuric acid monoesters of ethoxylated alkanols, and gemini surfactants.

[0067] 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).

[0068] According to an exemplary embodiment of the present invention, the alkyl sulfate, sulfuric acid monoester of ethoxylated alkanol, ethoxylated alkylphenol, alkali metal salt or ammonium salt of alkyl sulfonic acid, and alkali metal salt or ammonium salt of alkyl aryl sulfonic acid surfactants are the following emulsifiers: such as alkyl sulfate (alkyl: C 8 to C 22 ), ethoxylated alkanol (degree of ethylene oxide: 4 to 30, alkyl: C 8 to C 22 ), sulfuric acid monoester of ethoxylated alkylphenol (degree of ethylene oxide: 3 to 50, alkyl: C 4 to C 20 ), alkali metal salt or ammonium salt of alkyl sulfonic acid (alkyl: C 8 to C 22 ) and alkali metal salt or ammonium salt of alkyl aryl sulfonic acid (alkyl: C 4 to C 18 ). For example, the surfactant is sodium dodecyl sulfate (SDS) or sodium dodecylbenzenesulfonate (SDBS).

[0069] 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 trialkylphenol (degree of ethylene oxide: 3 to 50; alkyl C 4 to C 9 ) or ethoxylated fatty alcohol (degree of ethylene oxide: 3 to 50; alkyl C 4 to C 9 ).

[0070] According to an exemplary embodiment of the present invention, the alkali metal salt or ammonium salt surfactants of alkyl aryl sulfonic acid, alkyl sulfonic acid, and sulfuric acid monoester of ethoxylated alkanol are the alkali metal salts or ammonium salts, especially sodium salts, of the following: alkyl aryl sulfonic acid, alkyl sulfonic acid (e.g., sulfonated C 12 to C 18 paraffin), alkyl sulfate (e.g., sodium lauryl sulfate), and sulfuric acid monoester of ethoxylated alkanol (e.g., subsulfated ethoxylate of lauryl alcohol having 2 to 3 ethylene oxide units).

[0071] 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.

[0072] According to an exemplary embodiment of the present invention, the anionic gemini surfactant is at least one anionic gemini surfactant selected from phosphate salts, sulfonates, carboxylates, and sulfate esters.

[0073] In some embodiments of the present invention, the cationic gemini surfactant has a structure as shown in formula (1):

[0074]

[0075] In formula (1), R 1 , R 2 , Y, x, and y have the definitions described in A1 - A8:

[0076] A1: R 1 = R 2 = C m H 2m+1 ; Y = CH 2 ; x + y + 1 = s; m - s - m surfactants;

[0077] A2: R 1 = R 2 = C m H 2m+1 ; Y = CH 2 , O, S, N(CH 3 ), x = y = 2;

[0078] A2: R 1 = R 2 = C m H 2m+1 ; Y = CHOH, (CHOH) 2 ; x = y = 1;

[0079] A3: R 1 = R 2 = C m H 2m+1 ; Y = (OCH 2 CH 2 ) z , x = 2; y = 0; m - EOz - m surfactants;

[0080] A4: R 1 = R 2 = C m H 2m+1 ; Y = C≡C; x = y = 1;

[0081] A5: R 1 = R 2 = C m H2m+1 ; Y = a phenylene group; x = y = 1;

[0082] A6: R 1 = R 2 = C m H 2m+1 OC(O)CH 2 ; no Y; x = y = 1; counterion = chloride;

[0083] A7: R 1 = R 2 = C m F 2m C 4 H 8 ; no Y; x = y = 1;

[0084] 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 not equal to n),

[0085] wherein, in A1 - A8, m, n, z are independently 1 - 60,

[0086] Br - can be replaced by any other anion, preferably F in Group VIIA of the periodic system - , Cl - , I - , At - , Ts - .

[0087] In some embodiments of the present invention, the gemini surfactant is selected from at least one of the following:

[0088] C 12 H 25 N + (CH 3 ) 2 -(CH 2 ) n -N + (CH 3 ) 2 C 12 H 25 2Br – (n = 3–8),

[0089] C 12 H 25 N+ (CH 3 ) 2 -(CH 2 ) 16 -N + (CH 3 ) 2 C 12 H 25 2Br – 、

[0090] C 16 H 33 N + (CH 3 ) 2 -(CH 2 ) 2 -N + (CH 3 ) 2 C 16 H 33 2Br – 、

[0091] C 8 H 17 N + (CH 3 ) 2 -(CH 2 ) 3 -N + (CH 3 ) 2 C 8 H 17 2Br – 、

[0092] C 12 H 25 N + (CH 3 ) 2 -(CH 2 ) 2 -O-(CH 2 ) 2 -N + (CH 3 ) 2 C 12 H 25 2Cl – 、

[0093] C 16 H 33 N + (CH 3 ) 2 -(CH 2 ) 5 -N +(CH 3 ) 2 C 16 H 33 2Br – 、

[0094] C 16 H 33 N + (CH 3 ) 2 -(CH 2 ) 2 -O-(CH 2 ) 2 -N + (CH 3 ) 2 C 16 H 33 2Br – 、

[0095] 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 – 、

[0096] C 12 H 25 N + (CH 3 ) 2 -CH 2 -CH(OH)-CH 2 -N + (CH 3 ) 2 C 12 H 25 2Br – 、

[0097] C 12 H 25 N + (CH 3 ) 2 -CH 2 -C 6 H 4 -CH 2 -N +(CH 3 ) 2 C 12 H 25 2Br – 、

[0098] 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 – 、

[0099] 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 – 、

[0100] C 12 H 25 OPO 2 – -O-(CH 2 ) 6 -OPO 2 – -OC 12 H 25 2Na + 、

[0101] C 10 H 21 O-CH 2 -CH(OSO 3 – )-CH 2 -O-(CH 2 ) 2 -O-CH 2 -CH(OSO3 – )-CH 2 -OC 10 H 21 2Na + 。

[0102] 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.

[0103] 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 stability; the gemini surfactants have good chemical stability to electrolytes, but the polymerization reaction rate is gentle, the particle size of the resulting latex particles is larger, and agglomerates are easily generated during the polymerization process.

[0104] [Polymerization initiator]

[0105] According to an embodiment of the present invention, the polymerization initiator is at least one free radical initiator, including oil-soluble initiators: azobisisobutyronitrile, benzoyl peroxide, cumene hydroperoxide, etc.; water-soluble initiators: potassium persulfate, azobis(isobutyramidine) dihydrochloride, azobis(2-methylpropionamidine) dihydrochloride, ammonium persulfate, etc.

[0106] 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 generated free radicals can reach the highest concentration for the reaction at room temperature.

[0107] [Auxiliary agent]

[0108] 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.

[0109] 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.

[0110] 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.

[0111] [Terminator]

[0112] 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 compound, and sulfur-containing compound.

[0113] According to an exemplary embodiment of the present invention, the terminator is selected from N,N-diethylhydroxylamine.

[0114] [Hydrogenation catalyst]

[0115] According to a specific implementation of the present invention, the water-insoluble rhodium metal catalyst has a structure as shown in formula (I):

[0116] RhQL x

[0117] Formula (I)

[0118] Wherein,

[0119] Q is hydrogen or a halide ion, preferably a halide ion, such as chloride ion or bromide ion;

[0120] L is a ligand compound having a structure as shown in formula (II):

[0121] R m G

[0122] Formula (II)

[0123] Wherein: R is the same or different and is independently selected from C 1 -C 8 -alkyl, C 4 -C 8 -cycloalkyl, C 6 -C 15 -aryl or C 7 -C 15 -aralkyl;

[0124] G is phosphorus, arsenic, sulfur or sulfoxide group,

[0125] m is 2 or 3,

[0126] x is an integer from 1 to 10, for example, x = 2, 3 or 4.

[0127] In some embodiments of the present invention, G is sulfur or sulfoxide group and m is 2.

[0128] In some embodiments of the present invention, G is phosphorus or arsenic and m is 3.

[0129] In some embodiments of the present invention, Q is halogen and x is 3.

[0130] In some embodiments of the present invention, Q is hydrogen and x is 4.

[0131] In one embodiment of the present invention, the water-insoluble rhodium metal catalyst is selected from tris(triphenylphosphine)rhodium(I) chloride (RhCl(PPh 3 ) 3 ), tris(triphenylphosphine)rhodium(III) chloride, tris(dimethylsulfoxide)rhodium(III) chloride, tetrakis(triphenylphosphine)rhodium hydride, and the corresponding compounds in which the triphenylphosphine moiety is replaced by a tricyclohexylphosphine moiety.

[0132]

Term Definitions and Explanations

[0133] The term "alkyl" shall mean any branched or unbranched hydrocarbon residue and, unless otherwise specified, shall include C 1 -C 20 alkyls, 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.

[0134] The term "cycloalkyl" shall include C 3 -C 10 cycloalkyls, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.

[0135] 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.

[0136] 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.

[0137] 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 one another in any manner, i.e., including combinations of the corresponding ranges and preferred ranges.

[0138] According to an embodiment of the present invention, the cocatalyst has a structure represented by Formula III or Formula IV:

[0139] Ag(PPh 3 ) n X, Formula III

[0140] wherein n = 1, 2, or 3; X is Cl, Br, or I;

[0141] Ph 3 PX, Formula IV

[0142] Wherein, X is O, S or Se.

[0143] In one embodiment, the cocatalyst can be a sulfonic acid group monosubstituted ((TPPMS = PPh 2 (C 6 H 4 -m-SO 3 Na), monosulfonated triphenylphosphine)), sulfonic acid group disubstituted ((TPPDS = PPh(C 6 H 4 -m-SO 3 Na) 2 , disulfonated triphenylphosphine) or sulfonic acid group trisubstituted (P(C 6 H 4 -m-SO 3 Na) 3 , trisulfonated triphenylphosphine) of triphenylphosphine.

[0144] By adopting the cocatalyst with the above structure, the catalytic activity of the water-insoluble rhodium metal catalyst can be specifically and significantly improved, and further the catalytic hydrogenation efficiency of the catalyst can be significantly improved.

[0145] In one embodiment, the cocatalyst is an RG ligand compound with the structure shown in formula (II), wherein R, m and G are as defined above. m

[0146] The amount of the water-insoluble rhodium metal catalyst 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 typically from 0.01% to 5.0% by weight, preferably in the range of from 0.02% to 1.0% by weight is used.

[0147] Based on the weight of the water-insoluble catalyst, the cocatalyst is typically used in an amount up to 5000% by weight, preferably in a range of 500% to 3000% by weight.

[0148] According to an exemplary embodiment of the present invention, the cocatalyst can be a phosphine of triaryl, trialkyl, tricycloalkyl, diaryl-monalkyl, dialkylmonoaryl, diarylmonocycloalkyl, dialkylmonocycloalkyl, dicycloalkylmonoaryl or dicycloalkylmonoaryl, and an example is triphenylphosphine.

[0149] [Hydrogenated nitrile latex]

[0150] Water-insoluble rhodium metal catalyst [Hydrogenated rubber latex]

[0151] ​The present invention also provides a hydrogenated rubber latex prepared by the above method. The degree of hydrogenation of the hydrogenated rubber latex is 75-100%, the content of the comonomer is 25-40 mol%, and the conversion rate is 60-95 wt%.

[0152] 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 85%, and further preferably, the degree of hydrogenation of the hydrogenated rubber latex is greater than or equal to 97%, for example, 76.2%, 80.3%, 86.5%, 87.5%, 98.5%, 98.6%, 99%, 99.2%, 99.5%, 99.6%, 99.9%.

[0153] According to an embodiment of the present invention, the content of the comonomer is 30-35 mol%, for example, 32 mol%, 33 mol%, 34 mol%, 35 mol%.

[0154] According to an embodiment of the present invention, the particle size of the hydrogenated rubber latex is 60-90 nm, preferably 65-85 nm, for example, 60 nm, 65 nm, 67 nm, 69 nm, 70 nm, 72 nm, 73 nm, 75 nm, 80 nm, 82 nm, 84 nm, 86 nm, 89 nm or 90 nm.

[0155] According to an embodiment of the present invention, the conversion rate of the hydrogenated rubber latex is 60-85 wt%, preferably 65-85 wt%, for example, the conversion rate of the hydrogenated rubber latex is 60.2%, 61%, 62%, 63.6%, 76.5%, 70.3%, 73.2%, 75.3%, 75.5%, 76.2%, 77%, 78%, 79%, 80%, 81.3%, 82%, 83.2%, 84% or 85%.

[0156] According to an embodiment of the present invention, in the hydrogenated rubber latex, the hydrogenated rubber molecules are distributed in the nano micelles and exist in the form of latex.

[0157] According to an embodiment of the present invention, the hydrogenated rubber solid rubber can be obtained by first flocculating the hydrogenated rubber latex and then performing post-treatment such as washing and drying on the flocculated product. Detailed Embodiments

[0159] The preparation method of the present invention will be further described in detail below with reference to specific examples. It should be understood that the following examples are only for illustrative explanation of the present invention and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection of the present invention.

[0160] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

[0161] Example 1

[0162] A preparation method of HNBR latex, comprising the following steps:

[0163] 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;

[0164] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(PPh 3 ) 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;

[0165] 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.

[0166] 4) After the emulsification is completed, adjust the speed to 450 rpm and raise the temperature of the reaction kettle to 40 °C for polymerization reaction for 5 hours, and then add 0.05 g of terminator N,N-diethylhydroxylamine.

[0167] 5) Raise the temperature to 70 °C and introduce 8 MPa of high-pressure hydrogen. At this time, start the hydrogenation reaction. Keep the temperature and pressure constant in the reaction kettle and keep the stirring speed constant. After reacting for 5 h, HNBR latex is obtained.

[0168] Example 2

[0169] A preparation method of HNBR latex, comprising the following steps:

[0170] 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;

[0171] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(PPh 3 ) 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;

[0172] 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 stir and emulsify the monomers at room temperature for 1 hour.

[0173] 4) After the emulsification is completed, adjust the rotation speed to 450 rpm and raise the temperature of the reaction kettle to 40 °C for polymerization reaction for 5 hours, and then add 0.05 g of terminator N,N - diethylhydroxylamine.

[0174] 5) Raise the temperature to 70 °C and introduce 8 MPa of high - pressure hydrogen gas. At this time, start the hydrogenation reaction. Keep the temperature and pressure constant in the reaction kettle, and keep the stirring speed constant. After reacting for 5 h, obtain HNBR latex.

[0175] Example 3

[0176] A preparation method of HNBR latex, comprising the following steps:

[0177] 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;

[0178] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(PPh 3 ) 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;

[0179] 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 stir and emulsify the monomers at room temperature for 1 hour.

[0180] 4) After the emulsification is completed, adjust the rotation speed to 450 rpm and raise the temperature of the reaction kettle to 40 °C for polymerization reaction for 5 hours, and then add 0.05 g of terminator N,N - diethylhydroxylamine.

[0181] 5) After the polymerization reaction for 5 hours, add the terminator, raise the temperature to 70 °C and introduce 8 MPa of high - pressure hydrogen gas. At this time, start the hydrogenation reaction. Keep the temperature and pressure constant in the reaction kettle, and keep the stirring speed constant. After reacting for 5 h, obtain HNBR latex.

[0182] Example 4

[0183] A preparation method of HNBR latex, comprising the following steps:

[0184] 1) Dissolve 7 g of surfactant potassium oleate in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0185] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst tetrakis(triphenylphosphine)rhodium hydride, 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;

[0186] 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, and 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 hour.

[0187] 4) After the emulsification is completed, adjust the speed to 450 rpm and raise the temperature of the reaction kettle to 40 °C for polymerization reaction for 5 hours, and then add 0.05 g of terminator N,N-diethylhydroxylamine.

[0188] 5) Raise the temperature to 70 °C and introduce 8 MPa of high-pressure hydrogen. At this time, start the hydrogenation reaction, keep the temperature and pressure constant in the reaction kettle, and keep the stirring speed constant. After reacting for 5 h, obtain HNBR latex.

[0189] Example 5

[0190] A preparation method for preparing HNBR latex, comprising the following steps:

[0191] 1) Dissolve 7 g of surfactant potassium oleate in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0192] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst tris(dimethyl sulfoxide)rhodium chloride, 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;

[0193] 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, and 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 hour.

[0194] 4) After the emulsification is completed, adjust the speed to 450 rpm and raise the temperature of the reaction kettle to 40 °C for polymerization reaction for 5 hours, and then add 0.05 g of terminator N,N-diethylhydroxylamine.

[0195] 5) Raise the temperature to 70 °C and introduce high-pressure hydrogen gas at 8 MPa. At this time, the hydrogenation reaction starts. Keep the temperature and pressure constant in the reaction kettle, and keep the stirring speed constant. After reacting for 5 h, HNBR latex is obtained.

[0196] Example 6

[0197] A preparation method for preparing HNBR latex, comprising the following steps:

[0198] 1) Dissolve 7 g of surfactant potassium oleate in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0199] 2) Add 3 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(PPh 3 ) 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;

[0200] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle. While stirring at a speed of 200 rpm, perform a degassing treatment for 0.5 h, 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 h.

[0201] 4) After the emulsification is completed, adjust the speed to 450 rpm and raise the temperature of the reaction kettle to 40 °C for a polymerization reaction for 5 h, and then add 0.05 g of terminator N,N-diethylhydroxylamine.

[0202] 5) Raise the temperature to 70 °C and introduce high-pressure hydrogen gas at 8 MPa. At this time, the hydrogenation reaction starts. Keep the temperature and pressure constant in the reaction kettle, and keep the stirring speed constant. After reacting for 5 h, HNBR latex is obtained.

[0203] Example 7

[0204] A preparation method for preparing HNBR latex, comprising the following steps:

[0205] 1) Dissolve 7 g of surfactant potassium oleate in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0206] 2) Add 1.5 g of initiator potassium persulfate, 30 g of acrylonitrile, 0.05 g of hydrogenation catalyst RhCl(PPh 3 ) 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;

[0207] 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 stir the emulsified monomer at room temperature for 1 hour.

[0208] 4) After the emulsification is completed, adjust the rotation speed to 450 rpm and raise the temperature of the reaction kettle to 40 °C for polymerization reaction for 5 hours, and then add 0.05 g of terminator N,N - diethylhydroxylamine.

[0209] 5) Raise the temperature to 90 °C and introduce 8 MPa of high - pressure hydrogen gas. At this time, start the hydrogenation reaction. Keep the temperature and pressure constant in the reaction kettle and keep the stirring speed constant. After reacting for 5 h, HNBR latex is obtained.

[0210] Comparative Example 1

[0211] A preparation method for preparing HNBR latex, including the following steps:

[0212] 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.

[0213] 2) Add 30 g of acrylonitrile, 0.3 g of chain transfer agent tert - dodecyl mercaptan, 0.05 g of pH regulator sodium phosphate, and 1.5 g of initiator potassium persulfate to the reaction kettle.

[0214] 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 stir the emulsified monomer at room temperature for 1 hour.

[0215] 4) After the emulsification is completed, adjust the rotation speed to 450 rpm and raise the temperature of the reaction kettle to 40 °C, start the polymerization reaction for 5 hours, and after the polymerization is completed, add 0.05 g of terminator N,N - diethylhydroxylamine;

[0216] 5) Conduct monomer - removal treatment on the emulsion, then add 0.05 g of surfactant oleic acid potassium and 0.05 g of hydrogenation catalyst RhCl(PPh 3 ) 3 , then conduct degassing again, raise the temperature to 70 °C, and introduce 8 MPa of high - pressure hydrogen gas for hydrogenation reaction. After reacting for 5 h, HNBR is obtained.

[0217] After the reaction is completed, samples are taken from the products of Examples 1 - 7 and Comparative Example 1, and gel permeation chromatography is used to measure the solid content of the polymer to calculate the conversion rate. The results are shown in Table 1 below.

[0218] Monomer conversion rate = (solid content of the system * total mass of the system - mass of non-volatile components of the raw materials) / total mass of raw material monomers.

[0219] 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.

[0220] The structure of the polymer was determined by FT-IR (BRUKER II, BRUKER instrument, Karlsruhe, Germany). FT-IR method: First, the latex sample was separated with ethanol to obtain the polymer solid. Then, a small amount of dried NBR solid was dissolved in MEK to form a homogeneous solution. Finally, the solution was dropped onto a potassium bromide wafer and dried to form a polymer film, and then infrared analysis was performed.

[0221] The degree of hydrogenation was calculated 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.

[0222] 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), 723 cm -1 is the characteristic peak of (-CH 2 ) n , n>4.

[0223]

[0224] K(723) = 0.255, K(970) = 2.3 are constants unique to HNBR

[0225] Then the relative amount of -C=C- in HNBR is:

[0226]

[0227] The relative amount of methylene formed by hydrogenation of -C=C- in NBR is:

[0228]

[0229] Finally, the degree of hydrogenation calculation formula is:

[0230]

[0231] The acrylonitrile content was determined by elemental analysis of the N atom content to obtain the acrylonitrile content.

[0232] Table 1 Performance test results of different NBR latexes

[0233]

[0234] Compared with the prior art, the hydrogenated nitrile latex prepared by the high-temperature emulsion polymerization hydrogenation method based on a rhodium-based catalyst in 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; moreover, the hydrogenation effect is good and the hydrogenation degree is high during the synthesis process. And the conversion rate of the monomer is extremely high. The present invention reduces the post-treatment of 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 water-soluble rhodium metal catalyst 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.

[0235] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made 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 the diene monomer and the comonomer to a polymerization reaction in the presence of a polymerization initiator, a surfactant, a water-insoluble rhodium metal catalyst and a co-catalyst, adding a terminator after the polymerization reaction is completed, and then raising the temperature and introducing hydrogen to directly carry out a hydrogenation reaction to obtain a hydrogenated rubber latex.

2. The method according to claim 1, characterized in that The method comprises the following steps: S1. mixing a surfactant, a polymerization initiator, a water-insoluble rhodium metal catalyst, a cocatalyst, a comonomer, a diene monomer, and an optional additive with water and emulsifying; S2. After the emulsification is completed, the temperature is raised to the polymerization temperature for polymerization reaction, 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 amount of the surfactant is 2 to 15 parts, preferably 3 to 8 parts; And / or, in step S1, the amount of water is 150 to 1500 parts, preferably 150 to 500 parts; And / or, the initiator is used in an amount of 0.5 to 3 parts; and / or, the amount of the water-insoluble rhodium metal catalyst is 0.01-0.1 part, preferably 0.02-0.1 part; And / or, the amount of the co-catalyst is 0.2-1 part; 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 the comonomer, the water-insoluble rhodium metal catalyst, the co-catalyst and the auxiliary agent and the remaining water into the surfactant solution and mixing; S1-c, introduce inert gas for degassing, add diene monomer, and emulsify.

5. The method according to claim 2, characterized in that: In step S2, the polymerization reaction temperature is 20 to 100° C.; the polymerization reaction time is 0.5 to 8 hours; And / or, in step S3, the temperature of the hydrogenation reaction is 70 to 180° C.; the time of the hydrogenation reaction is 2 to 10 hours; 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 surfactant is selected from fatty acids, alkyl sulfates, ethoxylated alkanol sulfate monoesters, ethoxylated alkylphenols, alkali metal or ammonium alkylsulfonic acid salts, alkali metal or ammonium alkylarylsulfonic acid salts, 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-insoluble rhodium metal catalyst has a structure as shown in formula (I): QUR x Formula (I) in, Q is hydrogen or a halide ion, preferably a halide ion, such as a chloride ion or a bromide ion; L is a ligand compound having a structure as shown in formula (II): R m B Formula (II) Wherein: R is C1-C8-alkyl, C4-C8-cycloalkyl, C6-C 15 -Aryl or C7-C 15 - aralkyl; B is phosphorus, arsenic, sulfur or sulfoxide, m is 2 or 3, x is 2, 3, or 4.

9. The method according to any one of claims 1 to 8, characterized in that: The co-catalyst has a structure as shown in Formula III or Formula IV: Ag(PPh3) n X, Formula III Wherein, n=1, 2 or 3; X is Cl, Br or I; Ph3PX, Formula IV Wherein, X is O, S or Se.

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 75-100%, the content of the comonomer is 25-40 mol%, and the conversion rate is 60-95 wt%; And / or, the particle size of the hydrogenated rubber latex is 60-90 nm, preferably the particle size of the hydrogenated rubber latex is 65-85 nm.

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