Method for preparing hydrogenated butadiene-acrylonitrile rubber latex based on water-insoluble rhodium metal catalyst

Abstract

The invention discloses a method for preparing hydrogenated butadiene-acrylonitrile rubber latex based on a water-insoluble rhodium metal catalyst, which comprises the following steps: emulsifying a surfactant, a reducing agent, the water-insoluble rhodium metal catalyst and a cocatalyst, adding a polymerization initiator, and carrying out polymerization reaction at a polymerization temperature, and adding a terminator, raising the temperature, and carrying out hydrogenation reaction under high-pressure hydrogen to obtain the hydrogenated nitrile 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 hydrogenation degree of the hydrogenated rubber latex prepared by the method is 50-100%, the conversion rate is 60-85%, the particle size of the hydrogenated rubber latex is 30-60 nm, nano-particle micelles in the latex are stable in performance, and the nano-micelles are good in size uniformity, small in particle size distribution range and not prone to demulsification.

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 preparing hydrogenated nitrile rubber latex based on a water-insoluble rhodium metal catalyst, specifically to a method for preparing hydrogenated rubber latex by emulsion polymerization hydrogenation using a water-insoluble rhodium metal catalyst, and particularly to a method for polymerizing a diene monomer and a copolymerizable monomer at a low temperature using a water-insoluble rhodium metal catalyst, a co-catalyst and at least one surfactant, and then raising the temperature and introducing hydrogen to directly hydrogenate to prepare HNBR latex. Background Art

[0002] The hydrogenation of unsaturated polymers is an important process in the chemical modification of polymers. 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 the desired microstructure and unique stereochemical properties.

[0003] The 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. At present, the preparation of 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 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.

[0005] At present, 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, so there is no industrial production for the time being. (2) NBR solution hydrogenation method: The NBR solution hydrogenation method is the main method for industrial production of HNBR at present. During operation, it is necessary to first flocculate NBR latex into solid rubber, and then crush and dissolve it in a large amount of organic solvents. The organic solvents used mainly 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 Group VIII metals 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. 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, it will cause agglomeration and affect 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 long, and the process energy consumption is high, resulting in easy deterioration of the polymer performance.

[0006] To avoid the cumbersome hydrogenation steps in solution hydrogenation and 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 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 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 the industries demanding HNBR emulsion. In this field, the research group led by Professor Garry L. Rempel has carried out a large amount of work and achieved quite excellent research results. However, due to factors such as fewer NBR latex grades that can achieve emulsion hydrogenation with existing polymerization technologies and the need to further introduce a large amount of surfactants during the hydrogenation process, the emulsion catalytic hydrogenation technology has not yet met the requirements of industrial production.

[0007] In summary, 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 adopts the emulsion polymerization process at present, that is, a process of adding monomers, initiators, surfactants and other additives 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 also needs to be continued before hydrogenation; the second-step hydrogenation process includes 1. Traditional catalytic hydrogenation, including catalytic emulsion hydrogenation and catalytic solution hydrogenation; 2. Non-catalytic hydrogenation, which also requires preparing NBR latex first, and then using non-catalytic means to use 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, great obstacles have been encountered in the above two-step polymerization hydrogenation method. Therefore, the existing HNBR production technology needs to be further improved. Summary of the Invention

[0008] To improve the deficiencies of the existing technology, the present invention provides a method and application for preparing hydrogenated nitrile butadiene rubber by emulsion polymerization hydrogenation. The present invention integrates and simplifies the existing NBR 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. The present invention synthesizes HNBR from diene monomers and copolymerizable monomers, adds a rhodium metal hydrogenation catalyst insoluble in water before polymerization, carries out a polymerization reaction at a low temperature, and then raises the temperature and directly passes hydrogen for hydrogenation to obtain hydrogenated nitrile butadiene rubber. The present invention reduces the post-treatment of NBR latex and omits the process of adding a hydrogenation catalyst and the process of deoxygenation 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.

[0009] To achieve the above-mentioned invention object, the present invention provides the following technical solutions:

[0010] A method for preparing hydrogenated nitrile rubber latex based on a rhodium metal catalyst insoluble in water, the method comprising the following steps:

[0011] Emulsify a diene monomer and a comonomer in the simultaneous presence of a surfactant, a reducing agent, a rhodium metal catalyst (hydrogenation catalyst) insoluble in water, and a cocatalyst, add a polymerization initiator and carry out a polymerization reaction at a polymerization temperature, add a terminator, then raise the temperature and carry out a hydrogenation reaction under high-pressure hydrogen to obtain hydrogenated nitrile rubber latex.

[0012] According to an embodiment of the present invention, the method specifically comprises the following steps:

[0013] S1. Mix a surfactant, a reducing agent, a rhodium metal catalyst insoluble in water, a cocatalyst, a comonomer, a diene monomer, and an optionally added or non-added auxiliary agent with water and emulsify;

[0014] S2. Add an initiator and carry out a polymerization reaction at a polymerization temperature, add a terminator to stop the reaction;

[0015] S3. Raise the temperature, introduce high-pressure hydrogen to carry out a hydrogenation reaction to obtain hydrogenated nitrile rubber latex.

[0016] According to an embodiment of the present invention, the method comprises the following steps:

[0017] S1. By mass, mix 2-15 parts of a surfactant, 0.001-0.05 parts of a reducing agent, 10-60 parts of a comonomer, 40-90 parts of a diene monomer, 0.02-0.2 parts of a rhodium metal catalyst insoluble in water, 0.2-2 parts of a cocatalyst insoluble in water, 0.3-3 parts of an auxiliary agent with 150-1500 parts of water, and emulsify at room temperature for 0.2-2 h;

[0018] S2. Add 0.001-1 part of a polymerization initiator, carry out a polymerization reaction at a polymerization temperature, add a terminator to stop the reaction;

[0019] S3. Carry out a hydrogenation reaction on the polymerization product at a temperature of 60-180 °C and a hydrogen pressure of 3-15 MPa for 0.5-10 h to obtain hydrogenated nitrile rubber latex.

[0020] The present invention also provides the hydrogenated rubber latex prepared by the above method.

[0021] According to an embodiment of the present invention, the hydrogenation degree of the hydrogenated rubber latex is 50-100%, the content of the comonomer is 10-60 mol%, and the conversion rate is 60-85%.

[0022] According to an embodiment of the present invention, the particle size of the hydrogenated rubber latex is 30 - 60 nm, preferably 35 - 55 nm.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1) The hydrogenated nitrile rubber latex prepared by the present invention based on a rhodium metal catalyst insoluble in water has stable nanoparticle micelle properties in the latex, good size uniformity of the nanomicelles, a small particle size distribution range, is not easily demulsified, has a simple preparation method, is easy to operate, and is easy to industrialize; during the synthesis process, a hydrogenation catalyst is added after polymerization, and hydrogen is directly introduced after polymerization for hydrogenation reaction, with high hydrogenation efficiency and high degree of hydrogenation; the conversion rate of the monomer is extremely high; the post-treatment of NBR latex and the processes of deoxidation before hydrogenation and removal of the added hydrogenation catalyst are reduced, preventing environmental pollution caused by the volatilization of unreacted monomers, and the properties of the flocculated rubber compound are excellent.

[0025] 2) In the preparation method of the present invention, the conversion rate is greater than or equal to 60%, and can reach up to 74.9% at most, while the degree of hydrogenation is greater than 99%, which is significantly higher than the existing preparation methods. Specific Embodiments

[0026] [Method for Preparing Hydrogenated Nitrile Rubber Latex Based on a Rhodium Metal Catalyst Insoluble in Water]

[0027] A method for preparing hydrogenated nitrile rubber latex based on a rhodium metal catalyst insoluble in water includes the following steps:

[0028] Emulsify the comonomer and the diene monomer in the presence of a surfactant, a reducing agent, a rhodium metal catalyst (hydrogenation catalyst) insoluble in water, and a cocatalyst, add a polymerization initiator and carry out a polymerization reaction at the polymerization temperature, add a terminator and then raise the temperature and carry out a hydrogenation reaction under high-pressure hydrogen to obtain the hydrogenated nitrile rubber latex.

[0029] According to an embodiment of the present invention, the method specifically includes the following steps:

[0030] S1. Mix a surfactant, a reducing agent, a rhodium metal catalyst insoluble in water, a cocatalyst, a comonomer, a diene monomer, and optionally added or not added additives with water and emulsify;

[0031] S2. Add an initiator and carry out a polymerization reaction at the polymerization temperature, add a terminator to stop the reaction;

[0032] S3. Raise the temperature, introduce high-pressure hydrogen and carry out a hydrogenation reaction to obtain the hydrogenated nitrile rubber latex.

[0033] According to an embodiment of the present invention, the dosage of the surfactant is 2 to 15 parts, preferably 3 to 8 parts.

[0034] According to an embodiment of the present invention, the dosage of the water is 150 to 1500 parts, preferably 300 to 1500 parts, such as 300 parts.

[0035] According to an embodiment of the present invention, the dosage of the initiator is preferably 0.001 to 1 part, such as 0.05 part.

[0036] According to an embodiment of the present invention, the dosage of the rhodium metal catalyst insoluble in water is preferably 0.02 to 0.1 part, such as 0.05 part.

[0037] According to an embodiment of the present invention, the dosage of the cocatalyst is 0.2 to 1 part, such as 0.5 part.

[0038] According to an embodiment of the present invention, the auxiliary agent includes at least one of a chain transfer agent, a pH regulator or a reducing agent.

[0039] 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.

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

[0041] According to an embodiment of the present invention, the dosage of the reducing agent is 0.001 to 0.05 part, preferably 0.005 to 0.01 part.

[0042] According to an embodiment of the present invention, the dosage of the terminator is 0.02 to 0.1 part, such as 0.05 part.

[0043] According to an embodiment of the present invention, the emulsification temperature is room temperature; the emulsification time is 0.2 to 2 h, preferably 0.5 to 1 h.

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

[0045] S1-a. First, dissolve 2 to 15 parts of the surfactant in a part of water to obtain a surfactant solution;

[0046] S1-b. Add 0.001 to 0.05 part of the reducing agent, 10 - 60 parts of the copolymerizable monomer, 0.02 - 0.2 part of the rhodium metal catalyst insoluble in water, 0.2 - 2 parts of the cocatalyst insoluble in water, 0.25 - 2 parts of the chain transfer agent, 0.05 - 1.0 part of the pH regulator and the balance of water into the surfactant solution and mix.

[0047] S1-c. Introduce inert gas for degassing, add 40 - 90 parts of diene monomer, and emulsify at room temperature for 0.2 - 2 h to obtain an emulsified product.

[0048] According to the embodiments 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.

[0049] According to the embodiments 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; 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. In the present invention, the hydrogenation catalyst used is compatible with the gemini surfactant, and thus can effectively catalyze hydrogenation, greatly accelerating the hydrogenation rate. Moreover, the gemini surfactant also greatly reduces the amount of catalyst used, further reducing the cost.

[0050] According to the embodiments of the present invention, in step S1-c, introduce inert gas 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 polymerization and hydrogenation effects of the system; before the reaction, first emulsify the comonomer and diene monomer. Under the action of the surfactant, the surface tension of water is reduced, and the comonomer and diene monomer are wrapped in the micelles, forming uniform-sized oily monomer droplets, thereby ensuring sufficient monomer concentration in the system during the reaction and the stability of the monomer droplets.

[0051] According to the embodiments 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 - 1 MPa, for example, 0.5 MPa.

[0052] According to the embodiments of the present invention, the degassing in step S1-c is carried out under stirring conditions, and the stirring speed is 100 - 600 rpm, preferably 160 - 360 rpm. Further preferably, the stirring speed is constant.

[0053] According to the embodiments of the present invention, step S2 is specifically as follows:

[0054] S2. Add 0.001 - 1 part of initiator to the emulsified product, raise the temperature to the polymerization reaction temperature, and carry out the polymerization reaction.

[0055] According to an embodiment of the present invention, the temperature of the polymerization reaction in step S2 is 2 to 40 °C, preferably the temperature of the polymerization reaction is 5 to 20 °C, and further preferably, the temperature of the polymerization reaction is 6 to 12 °C, for example, 5 °C, 6 °C, 7 °C, 8 °C, 9 °C.

[0056] According to an embodiment of the present invention, the time of the polymerization reaction in step S2 is 0.5 to 6 h, preferably the time of the prepolymerization reaction is 2 to 4 h.

[0057] According to an embodiment of the present invention, step S3 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 a hydrogenated rubber latex. For example, the temperature of the hydrogenation reaction is 60 to 180 °C, preferably 70 to 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 to 10 h, preferably 2 to 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.

[0058] 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.

[0059] According to an embodiment of the present invention, step S3 specifically includes the following steps: heating the reaction kettle to 60 to 180 °C and carrying out the hydrogenation reaction for 0.5 to 10 h in a hydrogen atmosphere under a pressure of 5 to 15 MPa to obtain an HNBR latex.

[0060] 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, 450 rpm.

[0061] According to an embodiment of the present invention, the method specifically includes the following steps:

[0062] S1. By mass, mix 2 to 15 parts of a surfactant, 0.001 to 0.05 parts of a reducing agent, 10 - 60 parts of a comonomer, 40 - 90 parts of a diene monomer, 0.02 - 0.2 parts of a rhodium metal catalyst insoluble in water, 0.2 - 2 parts of a cocatalyst insoluble in water, 0.3 to 3 parts of an auxiliary agent with 150 to 1500 parts of water, and emulsify at room temperature for 0.2 to 2 h;

[0063] S2. Add 0.001 to 1 part of a polymerization initiator, carry out a polymerization reaction at the polymerization temperature, and add a terminator after the reaction ends;

[0064] S3. The polymerization product is subjected to a hydrogenation reaction at a temperature of 60 to 180 °C and a hydrogen pressure of 3 to 15 MPa for 0.5 to 10 h to obtain a hydrogenated nitrile rubber latex.

[0065] [Copolymer monomer and diene monomer]

[0066] According to an embodiment of the present invention, the copolymer monomer 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.

[0067] 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, and preferably the diene monomer is selected from at least one of 1,3-butadiene, isoprene, 1-methylbutadiene, 2,3-dimethylbutadiene, piperylene, and chloroprene.

[0068] [Reducing agent]

[0069] 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, and ferrous sulfate.

[0070] [Surfactant]

[0071] 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, alkali metal salts or ammonium salts of alkyl aryl sulfonic acids, ethoxylated monoalkylphenols, dialkylphenols, trialkylphenols, ethoxylated fatty alcohols, alkali metal salts or ammonium salts of mono C 4 -C 24 alkyl derivatives of bis(phenylsulfonic acid) ethers, alkali metal salts or ammonium salts of di C 4 -C 24 alkyl derivatives of bis(phenylsulfonic acid) ethers, alkyl aryl sulfonic acids, alkyl sulfonic acids, alkali metal salts or ammonium salts of sulfuric acid monoesters of ethoxylated alkanols, and at least one of gemini surfactants.

[0072] According to an embodiment of the present invention, the fatty acid surfactant is selected from alkali metal salts or ammonium salts of fatty acids with an alkyl group of C 12 -C 23 , and preferably sodium oleate (NaO) or potassium oleate (KO).

[0073] According to an embodiment of the present invention, the surfactant of alkyl sulfate, sulfuric acid monoester of ethoxylated alkanol, ethoxylated alkylphenol, alkali metal salt or ammonium salt of alkyl sulfonic acid, or alkali metal salt or ammonium salt of alkyl aryl sulfonic acid is the following emulsifier: such as alkyl sulfate (alkyl: C 8 to C 22 ), sulfuric acid monoester of 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 ), 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) and sodium dodecylbenzenesulfonate (SDBS).

[0074] According to an embodiment of the present invention, the surfactant of ethoxylated monoalkylphenol, dialkylphenol, trialkylphenol, or ethoxylated fatty alcohol is the following emulsifier: 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 ).

[0075] According to an embodiment of the present invention, the surfactant of alkali metal salt or ammonium salt of alkyl aryl sulfonic acid, alkyl sulfonic acid, or sulfuric acid monoester of ethoxylated alkanol is the alkali metal salt or ammonium salt, especially the sodium salt, of the following: alkyl aryl sulfonic acid, alkyl sulfonic acid (such as sulfonated C 12 to C 18 paraffin), alkyl sulfate (such as sodium lauryl sulfate), and sulfuric acid monoester of ethoxylated alkanol (such as subsulfated ethoxylate of lauryl alcohol with 2 to 3 ethylene oxide units).

[0076] 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.

[0077] According to an embodiment of the present invention, the anionic gemini surfactant is at least one anionic gemini surfactant selected from phosphate ester salt type, sulfonate type, carboxylate type, and sulfate ester salt type.

[0078] In some embodiments of the present invention, the cationic gemini surfactant has a structure represented by formula (I):

[0079]

[0080] In formula (I), R 1 , R 2 , Y, x, and y have the definitions described in A1 - A8:

[0081] A1: R 1 = R 2 = C m H 2m+1 ; Y = CH 2 ; x + y + 1 = s; m - s - m surfactants;

[0082] A2: R 1 = R 2 = C m H 2m+1 ; Y = CH 2 , O, S, N(CH 3 ), x = y = 2;

[0083] A2: R 1 = R 2 = C m H 2m+1 ; Y = CHOH, (CHOH) 2 ; x = y = 1;

[0084] A3: R 1 = R 2 = C m H 2m+1 ; Y = (OCH 2 CH 2 ) z , x = 2; y = 0; m - EOz - m surfactants;

[0085] A4: R 1 = R 2 = C m H 2m+1 ; Y = C≡C; x = y = 1;

[0086] A5: R 1 = R 2 = C m H 2m+1 ; Y = a phenylene group; x = y = 1;

[0087] A6: R 1 = R 2 = C m H2m+1 OC(O)CH 2 ; no Y; x = y = 1; counterion = chloride;

[0088] A7: R 1 = R 2 = C m F 2m C 4 H 8 ; no Y; x = y = 1;

[0089] 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

[0090] n);

[0091] Among A1 - A8, m, n, z are independently 1 - 60;

[0092] Br - can be replaced by any other anion, preferably F from Group VIIA elements - , Cl - , I - , At - , Ts - . In some embodiments of the present invention, the gemini surfactant is selected from at least one of the following:

[0093] C 12 H 25 N + (CH 3 ) 2 -(CH 2 ) n -N + (CH 3 ) 2 C 12 H 25 2Br – (n = 3–8),

[0094] C 12 H 25 N + (CH 3 ) 2 -(CH 2 ) 16 -N + (CH 3 ) 2 C12 H 25 2Br – 、

[0095] C 16 H 33 N + (CH 3 ) 2 -(CH 2 ) 2 -N + (CH 3 ) 2 C 16 H 33 2Br – 、

[0096] C 8 H 17 N + (CH 3 ) 2 -(CH 2 ) 3 -N + (CH 3 ) 2 C 8 H 17 2Br – 、

[0097] C 12 H 25 N + (CH 3 ) 2 -(CH 2 ) 2 -O-(CH 2 ) 2 -N + (CH 3 ) 2 C 12 H 25 2Cl – 、

[0098] C 16 H 33 N + (CH 3 ) 2 -(CH 2 ) 5 -N + (CH 3 ) 2 C 16 H 33 2Br – 、

[0099] C 16 H33 N + (CH 3 ) 2 -(CH 2 ) 2 -O-(CH 2 ) 2 -N + (CH 3 ) 2 C 16 H 33 2Br – 、

[0100] 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 – 、

[0101] C 12 H 25 N + (CH 3 ) 2 -CH 2 -CH(OH)-CH 2 -N + (CH 3 ) 2 C 12 H 25 2Br – 、

[0102] 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 – 、

[0103] C 12 H25 N + (CH 3 ) 2 -CH 2 -CH(OH)-CH(OH)-CH 2 -N + (CH 3 ) 2 C 12 H 25 2Br – 、

[0104] 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 – 、

[0105] C 12 H 25 OPO 2 – -O-(CH 2 ) 6 -OPO 2 – -OC 12 H 25 2Na + 、

[0106] C 10 H 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 +

[0107] 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.

[0108] [Initiator]

[0109] According to an embodiment of the present invention, the initiator is at least one free radical initiator, including at least one of peroxide initiators, azo initiators, and redox initiators.

[0110] According to an exemplary embodiment of the present invention, the peroxide initiator is an organic peroxide and / or an inorganic peroxide.

[0111] According to an exemplary embodiment of the present invention, the azo initiator includes at least one of azobisisobutyronitrile and azobisisoheptonitrile, etc.

[0112] According to an exemplary embodiment of the present invention, the redox initiator includes benzoyl peroxide / sucrose, tert-butyl hydroperoxide / rongalite, tert-butyl hydroperoxide / sodium metabisulfite, and benzoyl peroxide / N,N-dimethylaniline, etc.

[0113] According to an exemplary embodiment of the present invention, the redox initiator is selected from at least one of ammonium persulfate / sodium bisulfite, potassium persulfate / sodium bisulfite, hydrogen peroxide / tartaric acid, hydrogen peroxide / rongalite, ammonium persulfate / ferrous sulfate, hydrogen peroxide / ferrous sulfate, benzoyl peroxide / / N,N-diethylaniline, benzoyl peroxide / ferrous pyrophosphate, potassium persulfate / silver nitrate, persulfate / thiol, cumene hydroperoxide / ferrous chloride, potassium persulfate / ferrous chloride, hydrogen peroxide / ferrous chloride, cumene hydroperoxide / tetraethylenimine, and cumene hydroperoxide / ferrous sulfate, etc.

[0114] Using a redox initiator can initiate a polymerization reaction at a lower temperature (0 - 50 °C), and can increase the reaction rate, reduce energy consumption, and the prepared latex has small particle size and a narrow particle size distribution range.

[0115] [Auxiliary agent]

[0116] 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. For example, it is dodecyl mercaptan, and dodecyl mercaptan has good performance and can effectively reduce the molecular weight of the latex.

[0117] 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.

[0118] [Terminator]

[0119] According to an embodiment of the present invention, the terminator is selected from at least one of quinone, nitro, nitroso, aryl polyhydroxy compound, and sulfur-containing compound.

[0120] According to an exemplary embodiment of the present invention, N,N-diethylhydroxylamine is used as the terminator for the polymerization reaction.

[0121] [Hydrogenation catalyst]

[0122] According to a specific embodiment of the present invention, the water-insoluble rhodium metal catalyst has a structure as shown in formula (I):

[0123] RhQL x

[0124] Formula (I)

[0125] Wherein,

[0126] Q is hydrogen or a halide ion, preferably a halide ion, such as chloride ion or bromide ion;

[0127] L is a ligand compound having a structure as shown in formula (II):

[0128] R m G

[0129] Formula (II)

[0130] 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;

[0131] G is phosphorus, arsenic, sulfur or sulfoxide group,

[0132] m is 2 or 3,

[0133] x is an integer from 1 to 10, for example, x = 2, 3 or 4.

[0134] In some embodiments of the present invention, G is sulfur or sulfoxide group, and m is 2.

[0135] In some embodiments of the present invention, G is phosphorus or arsenic, and m is 3.

[0136] In some embodiments of the present invention, Q is halogen, and x is 3.

[0137] In some embodiments of the present invention, Q is hydrogen, and x is 4.

[0138] 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.

[0139]

Term Definitions and Explanations

[0140] The term "alkyl" shall mean any branched or unbranched hydrocarbon residue and 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.

[0141] The term "cycloalkyl" shall include C 3 -C 10 cycloalkyls, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.

[0142] 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.

[0143] 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.

[0144] For the purposes of this patent application and the invention, all definitions of groups, parameters, or explanations given above or below in general terms or in preferred ranges can be combined with each other in any way, i.e., including combinations of the corresponding ranges and preferred ranges.

[0145] According to an embodiment of the present invention, the cocatalyst has a structure represented by Formula III or Formula IV:

[0146] Ag(PPh 3 ) n X, Formula III

[0147] wherein n = 1, 2, or 3; X is Cl, Br, or I;

[0148] Ph 3 PX, Formula IV

[0149] Among them, X is O, S or Se.

[0150] In one embodiment, the cocatalyst can be a mono-sulfonated sulfonic acid group ((TPPMS = PPh 2 (C 6 H 4 -m-SO 3 Na), mono-sulfonated triphenylphosphine)), bis-sulfonated sulfonic acid group ((TPPDS = PPh(C 6 H 4 -m-SO 3 Na) 2 , bis-sulfonated triphenylphosphine) or tris-sulfonated sulfonic acid group (P(C 6 H 4 -m-SO 3 Na) 3 , tris-sulfonated triphenylphosphine)) of triphenylphosphine.

[0151] 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 thus the catalytic hydrogenation efficiency of the catalyst can be significantly improved.

[0152] In one embodiment, the cocatalyst is an RG ligand compound having the structure shown in formula (II), wherein R, m and G are as defined above. m 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 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.

[0153] 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 from 500% to 3000% by weight.

[0154] According to an exemplary embodiment of the present invention, the cocatalyst can be a phosphine of triaryl, trialkyl, tricycloalkyl, diaryl-monoalkyl, dialkylmonoaryl, diarylmonocycloalkyl, dialkylmonocycloalkyl, dicycloalkylmonoaryl or dicycloalkylmonoaryl, and is exemplified by triphenylphosphine.

[0155] [Hydrogenated nitrile rubber latex]

[0156] [Hydrogenated nitrile rubber latex]

[0157] The present invention also provides a hydrogenated nitrile rubber latex prepared by the above method, wherein the hydrogenation degree of the hydrogenated nitrile rubber latex is 50-100%, the content of the comonomer is 10-60 mol%, and the conversion rate is 60-85%.

[0158] According to an embodiment of the present invention, the hydrogenated nitrile rubber molecules exist in numerous nanoparticles and are in the form of a latex. At the same time, a solid rubber of hydrogenated nitrile rubber can also be obtained by flocculating the hydrogenated nitrile rubber latex and then performing post-treatment methods such as washing and drying.

[0159] According to an embodiment of the present invention, the hydrogenation degree of the hydrogenated nitrile rubber latex is greater than or equal to 70%, preferably greater than or equal to 85%. Further preferably, the hydrogenation degree of the hydrogenated nitrile rubber latex is greater than or equal to 95%, such as 73.9%, 75%, 80%, 85%, 85.4%, 86.9%, 89.1%, 90%, 91%, 92%, 93%, 94%, 95%, 96.2%, 96.9%, 97.6%, 97.9%, 98.2%, 99%, 99.4%, 99.5%, 99.6%, 98.8%, 99.8%, 95.6%.

[0160] According to an embodiment of the present invention, the content of the comonomer is 30-40 mol%, such as 31 mol%, 32 mol%, 33 mol%, 34 mol%.

[0161] According to an embodiment of the present invention, in the hydrogenated nitrile rubber latex, the hydrogenated nitrile rubber molecules are distributed in nano-micelles and are in the form of a latex.

[0162] According to an embodiment of the present invention, the particle size of the hydrogenated rubber latex is 30-60 nm, preferably 35-55 nm, such as 30 nm, 32 nm, 35 nm, 40 nm, 44 nm, 45 nm, 49 nm, 50 nm, 55 nm or 60 nm.

[0163] According to an embodiment of the present invention, the conversion rate of the hydrogenated rubber latex is 60-85%, preferably 65-75 wt%, such as the conversion rate of the hydrogenated rubber latex is 60%, 61%, 62%, 63%, 64.5%, 65%, 66.8%, 70%, 70.5%, 71.2%, 72.3%, 74.9%, 76%, 78%, 79%, 80%, 81%, 82%, 83%, 84% or 85%.

[0164] According to an embodiment of the present invention, a solid rubber of hydrogenated nitrile rubber can be obtained by first flocculating the hydrogenated nitrile rubber latex and then performing post-treatment such as washing and drying on the flocculated product.

[0165] The preparation method and application of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments 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 intended by the present invention.

[0166] Unless otherwise specified, the raw materials and reagents used in the following embodiments are commercially available products or can be prepared by known methods.

[0167] Example 1

[0168] A method for preparing hydrogenated nitrile rubber latex based on a rhodium metal catalyst insoluble in water, comprising the following steps:

[0169] 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;

[0170] 2) Add 0.005 g of the reducing agent ferrous sulfate, 30 g of acrylonitrile, 0.05 g of the hydrogenation catalyst RhCl(PPh 3 ) 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 into the reaction kettle;

[0171] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, perform a 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 circulator to cool down the reaction kettle, and perform emulsification at low temperature for 1 hour.

[0172] 4) Add 0.05 g of the 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 7 °C, carry out polymerization for 4 hours, and then add 0.05 g of the terminator N,N-diethylhydroxylamine.

[0173] 5) Raise the temperature of the system to 70 °C and introduce hydrogen at a pressure of 8 MPa. At this time, the hydrogenation reaction starts. The temperature and pressure in the reaction kettle are kept constant, and the stirring is kept at a constant speed of 450 rpm. After reacting for 5 hours, HNBR latex is obtained.

[0174] Example 2

[0175] A method for preparing hydrogenated nitrile rubber latex based on a rhodium metal catalyst insoluble in water, comprising the following steps:

[0176] 1) Dissolve 7 g of the surfactant sodium dodecylbenzenesulfonate in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0177] 2) Add 0.005 g of the reducing agent ferrous sulfate, 30 g of acrylonitrile, 0.05 g of the hydrogenation catalyst RhCl(PPh 3)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 into the reaction kettle;

[0178] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, conduct a 0.5-hour degassing treatment 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 circulator to cool the reaction kettle, and carry out emulsification at low temperature for 1 hour.

[0179] 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, conduct polymerization for 4 hours, and then add 0.05 g of the terminator N,N-diethylhydroxylamine.

[0180] 5) Raise the temperature of the system to 70 °C and introduce hydrogen at a pressure of 8 MPa. 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.

[0181] Example 3

[0182] A method for preparing hydrogenated nitrile rubber latex based on a rhodium metal catalyst insoluble in water, comprising the following steps:

[0183] 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;

[0184] 2) Add 0.005 g of the reducing agent ferrous sulfate, 30 g of acrylonitrile, 0.05 g of the hydrogenation catalyst RhCl(PPh 3 ) 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 into the reaction kettle;

[0185] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, conduct a 0.5-hour degassing treatment 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 circulator to cool the reaction kettle, and carry out emulsification at low temperature for 1 hour.

[0186] 4) Add 0.05 g of cumene hydroperoxide, an emulsion polymerization initiator, to the reaction kettle through a charging tank; raise the temperature of the reaction kettle to the polymerization reaction temperature of 7 °C, carry out polymerization for 4 hours, and then add 0.05 g of terminator N,N - diethylhydroxylamine.

[0187] 5) Raise the temperature of the system to 70 °C and introduce hydrogen gas at a pressure of 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 at 450 rpm. After reacting for 5 hours, HNBR latex is obtained.

[0188] Example 4

[0189] A method for preparing hydrogenated nitrile - butadiene rubber latex based on a rhodium metal catalyst insoluble in water, comprising the following steps:

[0190] 1) Dissolve 10 g of surfactant potassium oleate in 300 g of deionized water to obtain an aqueous surfactant solution and add it to the reaction kettle;

[0191] 2) Add 0.005 g of reducing agent ferrous sulfate, 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;

[0192] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, carry out 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 - low temperature cooling circulation machine to cool the reaction kettle, and carry out emulsification at low temperature for 1 hour.

[0193] 4) Add 0.05 g of cumene hydroperoxide, an emulsion polymerization initiator, to the reaction kettle through a charging tank; raise the temperature of the reaction kettle to the polymerization reaction temperature of 7 °C, carry out polymerization for 4 hours, and then add 0.05 g of terminator N,N - diethylhydroxylamine.

[0194] 5) Raise the temperature of the system to 70 °C and introduce hydrogen gas at a pressure of 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 at 450 rpm. After reacting for 5 hours, HNBR latex is obtained.

[0195] Example 5

[0196] A method for preparing hydrogenated nitrile - butadiene rubber latex based on a rhodium metal catalyst insoluble in water, including the following steps:

[0197] 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;

[0198] 2) Add 0.005 g of the reducing agent ferrous sulfate, 30 g of acrylonitrile, 0.07 g of the hydrogenation catalyst RhCl(PPh 3 ) 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 into the reaction kettle;

[0199] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, perform a 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 perform emulsification at a low temperature for 1 hour.

[0200] 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, carry out polymerization for 4 hours, and then add 0.05 g of the terminator N,N-diethylhydroxylamine.

[0201] 5) Raise the temperature of the system to 70 °C and introduce hydrogen at a pressure of 8 MPa. 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.

[0202] Example 6

[0203] 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;

[0204] 2) Add 0.005 g of the reducing agent ferrous sulfate, 30 g of acrylonitrile, 0.07 g of the hydrogenation catalyst RhCl(PPh 3 ) 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 into the reaction kettle;

[0205] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, perform a 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 perform emulsification at a low temperature for 1 hour.

[0206] 4) Add 0.05 g of cumene hydroperoxide, an emulsion polymerization initiator, to the reaction kettle through a feed tank; raise the temperature of the reaction kettle to the polymerization reaction temperature of 7 °C, carry out polymerization for 4 hours, and then add 0.05 g of terminator N,N - diethylhydroxylamine.

[0207] 5) Raise the temperature of the system to 90 °C and introduce hydrogen at a pressure of 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 at 450 rpm. After reacting for 5 hours, HNBR latex is obtained.

[0208] Comparative Example 1

[0209] A conventional method for preparing hydrogenated rubber latex includes the following steps:

[0210] 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.

[0211] 2) Add 0.005 g of reducing agent ferrous sulfate, 30 g of acrylonitrile, 0.3 g of chain transfer agent tert - dodecyl mercaptan, and 0.05 g of pH regulator sodium phosphate to the reaction kettle.

[0212] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reaction kettle, carry out 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.

[0213] 4) Add 0.05 g of cumene hydroperoxide, an emulsion polymerization initiator, to the reaction kettle through a feed tank; raise the temperature of the reaction kettle to the polymerization reaction temperature of 7 °C, carry out polymerization for 4 hours, and add 0.05 g of terminator N,N - diethylhydroxylamine;

[0214] 5) After the polymerization reaction is completed; carry out monomer removal treatment on the emulsion, then add 10 g of oleic acid potassium and 0.05 g of catalyst triphenylphosphine rhodium chloride, and then carry out degassing again. After heating to 90 °C, introduce high - pressure hydrogen of 8 MPa for hydrogenation reaction. After reacting for 5 h, HNBR is obtained.

[0215] After the reaction is completed, samples of the products of Examples 1 - 6 and Comparative Example 1 are taken, and the solid content of the polymer is measured by gel permeation chromatography to calculate the conversion rate. The results are shown in Table 1 below.

[0216] Monomer conversion rate = (system solid content * total system mass - mass of raw material non - volatile components) / total mass of raw material monomers.

[0217] 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.

[0218] 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 carried out.

[0219] The calculation of the hydrogenation degree was 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.

[0220] 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>4. n

[0221]

[0222]

[0223] K(723) = 0.255, K(970) = 2.3 are constants unique to HNBR

[0224] Then the relative amount of -C=C- in HNBR is:

[0225]

[0226] The relative amount of methylene formed by hydrogenation of -C=C- in NBR is:

[0227]

[0228] Finally, the hydrogenation degree calculation formula is:

[0229]

[0230] The acrylonitrile content was determined by elemental analysis of the N atom content to obtain the acrylonitrile content.

[0231] Table 1 Performance test results of different NBR latexes

[0232]

[0233] The above results show that: the hydrogenated nitrile rubber latex prepared by the present invention using a rhodium metal catalyst insoluble in water 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; during the synthesis process, the hydrogenation effect is good and the hydrogenation degree is high. Moreover, 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, and prevents environmental pollution caused by the volatilization of unreacted monomers. At the same time, the present invention uses a rhodium metal 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.

[0234] 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 nitrile rubber latex based on a water-insoluble rhodium metal catalyst, characterized in that: The method comprises the following steps: emulsifying a diene monomer and a comonomer in the presence of a surfactant, a reducing agent, a water-insoluble rhodium metal catalyst and a co-catalyst, adding a polymerization initiator to carry out a polymerization reaction at a polymerization temperature, adding a terminator, raising the temperature, and carrying out a hydrogenation reaction under high-pressure hydrogen to obtain a hydrogenated nitrile 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-insoluble rhodium metal catalyst, a cocatalyst, a comonomer, a diene monomer, and an optional additive with water and emulsifying; S2. Add an initiator to carry out the polymerization reaction at the polymerization temperature, and add a terminator to stop the reaction; S3. Raise the temperature and introduce high-pressure hydrogen to carry out hydrogenation reaction to obtain hydrogenated nitrile 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 300 to 1500 parts; And / or, the initiator is used in an amount of 0.001 to 1 part; And / or, the amount of the water-insoluble rhodium metal catalyst is 0.02-0.1 parts; 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; 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 terminator is 0.02 to 0.1 parts.

4. The method according to claim 2, characterized in that: Step S1 includes the following steps: S1-a, first dissolving 2 to 15 parts of a surfactant in a portion of water to obtain a surfactant solution; S1-b, adding 0.001-0.05 parts of a reducing agent, 10-60 parts of a copolymerizable monomer, 0.02-0.2 parts of a water-insoluble rhodium metal catalyst, 0.2-2 parts of a water-insoluble co-catalyst, 0.25-2 parts of a chain transfer agent, 0.05-1.0 parts of a pH adjuster and the balance of water into a surfactant solution and mixing; S1-c, introducing inert gas for degassing, adding 40-90 parts of diene monomer, and emulsifying at room temperature for 0.2-2 hours to obtain an emulsified product.

5. The method according to claim 2, characterized in that: In step S2, the polymerization reaction temperature is 2 to 40° C.; the polymerization reaction 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; 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 Formula B (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 50-100%, the content of the comonomer is 10-60 mol%, and the conversion rate is 60-85%; And / or, the particle size of the hydrogenated rubber latex is 30-60 nm, preferably 35-55 nm.

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