Method for preparing hydrogenated rubber latex by adopting one-step process

Abstract

The invention provides a method for preparing hydrogenated rubber latex by adopting a one-step process, which integrates two processes of rubber emulsion polymerization and latex hydrogenation in the existing hydrogenated rubber latex preparation method into one step, further combines with a rhodium-containing catalyst dissolved in water, and has the advantages of short process flow, high efficiency, low energy consumption, greenness and the like. The hydrogenated rubber latex is prepared from at least one rhodium-containing catalyst dissolved in water, an initiator, a surfactant and other auxiliaries at a certain temperature and a certain hydrogen pressure through a diene monomer and a copolymerizable monomer on the basis of a one-step process. Compared with the hydrogenated rubber latex synthesized by the traditional method, the method disclosed by the invention has the advantages of higher efficiency, higher hydrogenation speed, milder reaction conditions, smaller polymer particle size and greenness and environmental friendliness.

Description

Technical Field

[0001] This invention belongs to the field of specialty rubber latex synthesis technology, and relates to a method for preparing hydrogenated rubber latex using a one-step process. In particular, it relates to a method for prepolymerizing diene monomers and copolymerizable monomers at low temperature and a certain hydrogen pressure using at least one water-soluble rhodium-containing catalyst, an initiator, an insoluble cocatalyst, and at least one surfactant, followed by heating to continue the reaction to produce hydrogenated rubber latex. Background Technology

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

[0003] Selective hydrogenation of unsaturated olefin groups in nitrile butadiene rubber (NBR) is an industrially successful commercial hydrogenation process. Hydrogenated nitrile butadiene rubber (HNBR) retains the elastomer properties of NBR, exhibits excellent resistance to thermal oxidative degradation, and shows significant improvements in mechanical properties such as tensile strength, elongation, abrasion resistance, and hardness. Due to these superior physicochemical properties, HNBR has found important applications in automotive, oil well, aerospace, and various high-performance applications. Since 1977, hydrogenated nitrile butadiene rubber has become the most important member of hydrogenated elastomers and a mainstay in high-performance elastomer applications.

[0004] The traditional HNBR preparation process consists of two steps: 1. Acrylonitrile-butadiene emulsion copolymerization to prepare NBR latex; 2. Hydrogenation of NBR to prepare HNBR.

[0005] The preparation of NBR latex usually involves adding acrylonitrile-butadiene emulsion monomers, initiators, surfactants, and other additives to an aqueous medium to generate NBR. This method has significant drawbacks in terms of process. The prepared NBR latex contains a large amount of unreacted monomers, resulting in high VOC (volatile organic compounds) content in the product, which poses a certain degree of environmental harm. Furthermore, the content of residual monomers can also affect the subsequent hydrogenation process.

[0006] Regarding the hydrogenation step, the existing processes for preparing HNBR using NBR latex are divided into catalytic hydrogenation and non-catalytic hydrogenation. Catalytic hydrogenation is further divided into emulsion hydrogenation and solution hydrogenation, while non-catalytic hydrogenation refers to the hydrogenation of hydrazine hydrate.

[0007] (1) The hydrazine hydrate hydrogenation method is a process in which NBR latex is directly converted into HNBR latex under the action of hydrazine hydrate, 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 at normal pressure, the reaction conditions are mild, and the equipment is simple. The disadvantage is that cross-linking side reactions are prone to occur on the unhydrogenated double bonds. If the cross-linking is severe, it will lead to plasticizing difficulties. Therefore, there is currently no industrial production of this method.

[0008] (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 a solid glue first, and then crushed and dissolved in a large amount of organic solvent. The organic solvents used mainly include cyclohexanone, xylene and chloroform, which not only causes environmental pollution, but also has a long reaction time, high reaction temperature, and high energy consumption, requiring a lot of cost and time.

[0009] Depending on the catalyst, NBR solution hydrogenation is divided into heterogeneous solution hydrogenation and homogeneous solution hydrogenation. The catalyst in homogeneous NBR solution hydrogenation includes an inorganic support and a Group VIII metal coated on the inorganic support. The catalyst in heterogeneous solution hydrogenation includes an inorganic support and a rhodium-based, ruthenium-based, or palladium-based metal coated on the inorganic support. Inorganic supports include alumina, silica, activated carbon, carbon black, and alkaline earth metal carbonates. After heterogeneous solution hydrogenation, the hydrogenated product is usually separated from the catalyst directly by filtration or centrifugation. For example, Zeon Corporation of Japan was the first to use supported catalysts in NBR hydrogenation reactions in the 1980s. The heterogeneous supported catalyst they used was a palladium / carbon catalyst with carbon as the support. This catalyst had high selectivity, with a hydrogenation rate of up to 95.6%. However, during the hydrogenation reaction, carbon easily adsorbed rubber molecules, leading to agglomeration and affecting product performance.

[0010] In addition, the active components of supported catalysts prepared by traditional methods are mostly distributed inside the pores. NBR molecules must diffuse into the pores to carry out the hydrogenation reaction. In order to improve the reaction rate, the reaction must be carried out under high pressure and strong stirring conditions. The reaction time is long and the process consumes a lot of energy, which leads to the degradation of polymer properties.

[0011] (3) Emulsion Hydrogenation: To avoid the cumbersome hydrogenation steps in solution hydrogenation and the use of large amounts of toxic solvents, emulsion hydrogenation has been proposed. Emulsion hydrogenation involves directly adding a catalyst to the NBR emulsion and then preparing HNBR emulsion through a hydrogen reduction reaction. Compared to organic solution catalytic hydrogenation, aqueous NBR emulsion catalytic hydrogenation has significant advantages: the reaction conditions are milder than solution hydrogenation, the reaction process is simpler, organic solvents are not required, and energy and pollution can be saved. Emulsion catalytic hydrogenation greatly reduces the preparation cost of HNBR, and the hydrogenated product can be directly applied to industries requiring HNBR emulsions. Professor Garry L. Rempel's research group has conducted extensive work in this field and achieved remarkable research results. However, due to the limited number of NBR latex grades that can be emulsion hydrogenated using existing polymerization technologies, and the further introduction of large amounts of surfactants in the hydrogenation process, emulsion catalytic hydrogenation technology has not yet met the requirements for industrial production.

[0012] In summary, existing methods for producing HNBR involve two steps, which have drawbacks such as long reaction time, high cost, high energy consumption, and environmental pollution. Further improvements in HNBR production technology are needed. Summary of the Invention

[0013] To address the aforementioned technical problems, this invention provides a one-step process for preparing hydrogenated rubber latex, along with the hydrogenated rubber latex prepared by this method and its applications. The method of this invention aims to overcome the shortcomings of existing technologies, such as cumbersome processes, low efficiency, high energy consumption, and significant pollution. This method offers advantages in terms of time and cost savings, as well as environmental friendliness. Furthermore, the hydrogenated rubber latex prepared by this method exhibits a higher degree of hydrogenation, faster hydrogenation rate, milder reaction conditions, and smaller polymer particle size compared to hydrogenated rubber latex synthesized through traditional emulsion polymerization.

[0014] To achieve the above-mentioned technical problems and objectives, the present invention provides the following technical solution:

[0015] A method for preparing hydrogenated rubber latex, the method comprising the following steps: emulsifying a comonomer and a diene monomer in the presence of a surfactant, a water-soluble rhodium-containing catalyst, a cocatalyst, other auxiliaries and water; lowering the temperature, adding an initiator and introducing hydrogen gas to carry out a prepolymerization reaction; and then raising the temperature to carry out polymerization and hydrogenation reactions to obtain hydrogenated rubber latex.

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

[0017] S1. Mix surfactant, water-soluble rhodium-containing catalyst, cocatalyst, comonomer, diene monomer, optional additives or not, with water, and emulsify at room temperature;

[0018] S2. Lower the temperature to the prepolymerization temperature, add the initiator, and then introduce high-pressure hydrogen to carry out the prepolymerization reaction;

[0019] S3. Increase the temperature to carry out polymerization and hydrogenation reactions to obtain hydrogenated rubber latex.

[0020] The present invention also provides a hydrogenated rubber latex prepared by the above method, specifically, the degree of hydrogenation of the hydrogenated rubber latex is 50-100%, the content of comonomer is 10-60 mol%, the content of diene monomer is 40%-90%, and the solid content of the hydrogenated rubber latex is 10-70 wt%.

[0021] The present invention achieves the following beneficial effects:

[0022] This invention involves prepolymerizing diene monomers and comonomers at low temperature and a certain hydrogen pressure, followed by further reaction at increased temperature to prepare hydrogenated rubber latex. The latex contains stable nanoparticle micelles with good size uniformity, a small particle size distribution, and low emulsion delamination. Using a water-soluble rhodium-containing catalyst for the hydrogenation reaction eliminates the need for any organic solvents, resulting in milder reaction conditions. The reaction can be carried out at lower temperatures and pressures, reducing industrial costs and promoting green chemistry.

[0023] In addition, the preparation method of the present invention is simple, easy to operate, and easy to industrialize.

[0024] Secondly, the method of the present invention incorporates low-temperature prepolymerization and high-temperature polymerization / hydrogenation steps, resulting in a fast hydrogenation rate, excellent product performance, and lower energy consumption.

[0025] Furthermore, in the synthesis process of this invention, polymerization and hydrogenation are carried out simultaneously, resulting in high hydrogenation efficiency and high degree of hydrogenation. The conversion rate of monomers is extremely high, reducing all the steps required from the post-processing of unsaturated rubber latex to the hydrogenation of unsaturated rubber latex, avoiding the use of organic solvents, and preventing environmental pollution from the volatilization of unreacted monomers. Detailed Implementation

[0026] [A one-step process for preparing hydrogenated rubber latex]

[0027] As mentioned above, the present invention provides a method for preparing hydrogenated rubber latex, the method comprising the following steps:

[0028] The comonomer and diene monomer are emulsified in the presence of surfactant, water-soluble rhodium-containing catalyst, cocatalyst, other additives and water. The temperature is lowered, an initiator is added and hydrogen is introduced to carry out a prepolymerization reaction. Then the temperature is raised to carry out polymerization and hydrogenation reactions to obtain hydrogenated rubber latex.

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

[0030] S1. Mix surfactant, water-soluble rhodium-containing catalyst, cocatalyst, comonomer, diene monomer, optional additives or not, with water, and emulsify at room temperature;

[0031] S2. Lower the temperature to the prepolymerization temperature, add the initiator, and then introduce high-pressure hydrogen to carry out the prepolymerization reaction;

[0032] S3. Increase the temperature to carry out polymerization and hydrogenation reactions to obtain hydrogenated rubber latex.

[0033] According to an embodiment of the present invention, the method specifically includes the following steps:

[0034] S1. By weight, mix 2-15 parts of surfactant, 0.01-0.2 parts of water-soluble rhodium-containing catalyst, 0.1-2 parts of co-catalyst, 10-60 parts of comonomer, 40-90 parts of diene monomer, 0.3-3 parts of additives with 300-1500 parts of water, and emulsify at room temperature;

[0035] S2. Lower the temperature to the prepolymerization reaction temperature, add 0.001 to 1 part of initiator to the emulsion product, and carry out the prepolymerization reaction under high pressure hydrogen;

[0036] S3. Heat the prepolymerized product to carry out polymerization and hydrogenation reactions to obtain hydrogenated rubber latex.

[0037] According to an embodiment of the present invention, based on 100 parts by weight of diene monomer, the amount of surfactant is preferably 3 to 8 parts by weight, the amount of water is preferably 600 to 1000 parts by weight, and the amount of initiator is preferably 0.005 to 1 part by weight.

[0038] According to an embodiment of the present invention, the amount of the water-soluble rhodium-containing catalyst is preferably 0.02 to 0.1 parts by weight, for example, 0.05 parts by weight, based on 100 parts by weight of diene monomer.

[0039] According to an embodiment of the present invention, the amount of the co-catalyst is preferably 0.1 to 2 parts by weight, for example 0.5 parts by weight, based on 100 parts by weight of diene monomer.

[0040] According to an embodiment of the present invention, the adjuvant includes a chain transfer agent and / or a pH adjuster.

[0041] According to an embodiment of the present invention, the amount of chain transfer agent is 0.25 to 2 parts by weight, preferably 0.5 to 1.5 parts by weight, based on 100 parts by weight of diene monomer.

[0042] According to an embodiment of the present invention, the amount of the pH adjuster is 0.05 to 1.0 parts by weight, preferably 0.1 to 0.6 parts by weight, based on 100 parts by weight of diene monomer.

[0043] According to an embodiment of the present invention, the emulsification time is 0.2 to 2 hours, preferably 0.5 to 1.5 hours, and more preferably 0.5 to 1 hour.

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

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

[0046] S1-b, The comonomer, water-soluble rhodium-containing catalyst, water-insoluble cocatalyst, chain transfer agent, and the remaining water are added to the surfactant solution and mixed.

[0047] S1-c: Inert gas is introduced into the reactor for degassing, diene monomer is added, and emulsification is carried out at room temperature to obtain an emulsion product.

[0048] According to an embodiment of the present invention, step S1-b specifically includes the following steps: adding the comonomer, water-soluble rhodium-containing catalyst, chain transfer agent, pH adjuster and the remaining water to the surfactant solution and mixing them.

[0049] According to an embodiment of the present invention, step S1-b specifically includes the following steps: adding 10-60 parts of comonomer, 0.01-0.2 parts of water-soluble rhodium-containing catalyst, 0.1-2 parts of cocatalyst, 0.25-2 parts of chain transfer agent, 0.05-1.0 parts of pH adjuster and the balance of water to a surfactant solution and mixing them.

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

[0051] According to an embodiment of the present invention, the degassing in step S1-c is carried out under stirring conditions, and the inert gas is selected from at least one of helium, argon, and nitrogen; preferably, the pressure of the inert gas is 0.1 to 1 MPa, for example, 0.5 MPa.

[0052] According to an embodiment of the present invention, in step S1-a, the surfactant is fully dissolved in water, which can effectively maintain the stability of the emulsion interface and thus significantly improve the particle stability of the polymer nanoemulsion. Moreover, using an excess of surfactant can also prepare nanoemulsions with smaller particle sizes to increase the micelle specific surface area.

[0053] According to an embodiment of the present invention, in step S1-b, the pH of the system cannot be automatically maintained at a constant level during the reaction process, but is in a dynamic state. Adding a pH adjuster can effectively maintain the pH of the system within a small range, thereby enabling the surfactant to effectively maintain the stability of the liquid surface, which is beneficial for the reaction to proceed in stable micelles.

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

[0055] In this invention, a water-soluble rhodium metal catalyst and a water-insoluble co-catalyst are added. The surfactant is compatible with the water-soluble rhodium metal catalyst, thereby effectively catalyzing hydrogenation and greatly accelerating the hydrogenation rate. Moreover, the surfactant also greatly reduces the amount of catalyst used, further reducing costs.

[0056] According to an embodiment of the present invention, in step S1-c, an inert gas is introduced to replace the air in the reactor, ensuring the purity of the gas inside the reactor and eliminating the influence of air on the polymerization and hydrogenation effects of the system. Before the reaction, the comonomer and diene monomer are emulsified. Under the action of the surfactant, the surface tension of water is reduced, and the comonomer and diene monomer are encapsulated in 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.

[0057] According to an embodiment of the present invention, the temperature of the prepolymerization reaction in step S2 is 2 to 40°C, preferably 5 to 20°C, and more preferably, the temperature of the prepolymerization reaction is 6 to 12°C, for example, 5°C, 6°C, 7°C, 8°C, or 9°C.

[0058] According to an embodiment of the present invention, the pressure of the high-pressure hydrogen in step S2 is 3 to 15 MPa, preferably 5 to 12 MPa.

[0059] According to an embodiment of the present invention, the stirring speed in step S2 is 300-900 rpm, preferably 450-650 rpm, and preferably the stirring speed is constant.

[0060] According to an embodiment of the present invention, the prepolymerization reaction time in step S2 is 0.5 to 6 hours, preferably 2 to 4 hours.

[0061] According to an embodiment of the present invention, step S3 specifically includes the following steps: heating the reactor to 60-180°C and continuing the polymerization and hydrogenation reaction for 0.5-10 hours to obtain hydrogenated rubber latex.

[0062] According to an embodiment of the present invention, the reaction temperature in step S3 is 70–150°C, preferably 80–100°C.

[0063] According to an embodiment of the present invention, the reaction in step S3 is carried out under stirring conditions, wherein the stirring speed is 300 to 900 rpm, preferably 450 to 650 rpm, for example 450 rpm.

[0064] According to an embodiment of the present invention, the reaction time in step S3 is 2 to 10 hours, preferably 3 to 6 hours, for example 5 hours.

[0065] According to an embodiment of the present invention, the reactor is selected from high-pressure reactors, such as high-temperature and high-pressure stainless steel reactors.

[0066] According to an embodiment of the present invention, the high-temperature and high-pressure stainless steel reactor includes a reactor body and at least two high-pressure resistant hoses, one end of which is connected to the reactor body and the other end is connected to a high-pressure gas, such as an inert gas and hydrogen.

[0067] According to an embodiment of the present invention, the high-temperature resistant hose includes a stainless steel high-temperature resistant hose and a plastic high-temperature resistant hose, wherein the stainless steel high-temperature resistant hose is used to introduce hydrogen into the reactor, and the plastic high-temperature resistant hose is used to introduce inert gas into the reactor.

[0068] According to an embodiment of the present invention, the vessel body is further provided with an exhaust port.

[0069] According to an embodiment of the present invention, a pressure sensor is further provided inside the vessel, and the pressure sensor has a range of -1 to 30 MPa.

[0070] According to an embodiment of the present invention, a temperature sensor is further provided inside the vessel, and the temperature sensor has a range of 0 to 180°C.

[0071] According to an embodiment of the present invention, the vessel body is further provided with a stirring device for fully mixing the materials in the system, and the stirring speed of the stirring device is 0 to 800 rpm.

[0072] [Comonomers and diene monomers]

[0073] 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 of methacrylic acid.

[0074] According to an embodiment of the present invention, the diene monomer is a conjugated monomer, and the conjugated monomer is selected from at least one of C4-C6 conjugated dienes, preferably selected from at least one of 1,3-butadiene, isoprene, 1-methylbutadiene, 2,3-dimethylbutadiene, pentadiene, and chloroprene.

[0075] [Initiator]

[0076] According to an embodiment of the present invention, the initiator of the rubber latex is at least one free radical initiator, including at least one of peroxide initiators, azo initiators, and redox initiators.

[0077] According to an embodiment of the present invention, the peroxide initiator is an organic peroxide and / or an inorganic peroxide.

[0078] According to an embodiment of the present invention, the azo initiator includes azobisisobutyronitrile, azobisisoheptanenitrile, etc.

[0079] According to an embodiment of the present invention, the redox initiator includes at least one of the following: benzoyl peroxide / sucrose, tert-butyl hydroperoxide / sodium formaldehyde sulfoxylate, tert-butyl hydroperoxide / sodium metabisulfite, benzoyl peroxide / N,N-dimethylaniline, ammonium persulfate / sodium bisulfite, potassium persulfate / sodium bisulfite, hydrogen peroxide / tartaric acid, hydrogen peroxide / sodium formaldehyde sulfoxylate, 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 / tetraethyleneimine, cumene hydroperoxide / ferrous sulfate, etc.

[0080] In this invention, the use of a redox initiator can initiate polymerization at a lower temperature (0-50°C), and can increase the reaction rate, reduce energy consumption, and produce latex with small particle size and narrow particle size distribution.

[0081] [surfactant]

[0082] In some embodiments of the present invention, the surfactant is selected from at least one of fatty acids, alkyl sulfates, ethoxylated alkanol sulfate monoesters, ethoxylated alkylphenols, alkyl sulfonic acids and alkyl aryl sulfonic acids alkali metal salts or ammonium salts, ethoxylated monoalkylphenols, dialkylphenols and trialkylphenols, ethoxylated fatty alcohols, alkali metal salts or ammonium salts of mono-C4 to C24 alkyl derivatives of bis(benzenesulfonic acid) ethers, alkali metal salts or ammonium salts of di-C4 to C24 alkyl derivatives of bis(benzenesulfonic acid) ethers, alkyl aryl sulfonic acids, alkyl sulfonic acids, alkali metal salts or ammonium salts of ethoxylated alkanol sulfate monoesters, and gemini surfactants.

[0083] According to an exemplary embodiment of the present invention, the fatty acid surfactant is selected from those with an alkyl group of C. 12 To C 23 The alkali metal salt or ammonium salt of the fatty acid, preferably sodium oleate (NaO) or potassium oleate (KO).

[0084] According to an exemplary embodiment of the present invention, the alkyl sulfate, ethoxylated alkanol sulfate monoester, ethoxylated alkylphenol, alkali metal salt or ammonium salt of alkyl sulfonic acid, and alkali metal salt or ammonium salt surfactant of alkyl aryl sulfonic acid are emulsifiers such as alkyl sulfates (alkyl: C8 to C9). 22 ), ethoxylated alkanols (ethylene oxide degree: 4 to 30, alkyl: C8 to C9) 22 ), ethoxylated alkylphenols (ethylene oxide degree: 3 to 50, alkyl: C4 to C5) 20 ) sulfonate monoesters, alkyl sulfonates (alkyl: C8 to C9) 22 Alkali metal salts or ammonium salts and alkyl aryl sulfonic acids (alkyl: C4 to C5) 18 The surfactant is an alkali metal salt or ammonium salt. For example, the surfactant is sodium dodecyl sulfate (SDS) or sodium dodecylbenzene sulfonate (SDBS).

[0085] According to an exemplary embodiment of the present invention, the ethoxylated monoalkylphenol, dialkylphenol, trialkylphenol or ethoxylated fatty alcohol surfactant is the following emulsifier: ethoxylated mono, di or trialkylphenol (ethylene oxide degree: 3 to 50; alkyl C4 to C9) or ethoxylated fatty alcohol (ethylene oxide degree: 3 to 50; alkyl C4 to C9).

[0086] According to an exemplary embodiment of the present invention, the alkali metal salt or ammonium salt surfactant of the alkyl aryl sulfonic acid, alkyl sulfonic acid, ethoxylated alkanol sulfate monoester is an alkali metal salt or ammonium salt of the following, especially a sodium salt: alkyl aryl sulfonic acid, alkyl sulfonic acid (e.g., sulfonated C12 to C18 paraffin), alkyl sulfate (e.g., sodium lauryl sulfonate), and ethoxylated alkanol (e.g., a hyposulfonated ethoxylated version of lauryl alcohol having 2 to 3 ethylene oxide units).

[0087] 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.

[0088] According to an exemplary embodiment of the present invention, the anionic gemini surfactant is at least one anionic gemini surfactant selected from phosphate salt type, sulfonate type, carboxylate type and sulfate salt type.

[0089] In some embodiments of the present invention, the cationic gemini surfactant has a structure as shown in formula (1):

[0090]

[0091]

[0092] In equation (1), R1, R2, Y, x, and y have the definitions described in A1-A8:

[0093] A1: R1 = R2 = C m H 2m+1 ;Y=CH2;x+y+1=s;msm surfactants;

[0094] A2: R1 = R2 = C m H 2m+1 ;Y=CH2,O,S,N(CH3),x=y=2;

[0095] A2: R1 = R2 = C m H 2m+1 ;Y=CHOH,(CHOH)2;x=y=1;

[0096] A3: R1 = R2 = C m H 2m+1 Y = (OCH2CH2) z ,x=2;y=0;m-EOz-m surfactants;

[0097] A4: R1 = R2 = C m H 2m+1 ; Y = C ≡ C; x = y = 1;

[0098] A5: R1 = R2 = C m H 2m+1 ;Y=a phenylene group;x=y=1;

[0099] A6: R1 = R2 = C m H 2m+1 OC(O)CH2; no Y; x=y=1; counterion=chloride;

[0100] A7: R1 = R2 = C m F 2m C4H8; no Y; x = y = 1;

[0101] A8:R1=C m H 2m+1 R2 = C n H 2n+1; no Y; x = y = 1; s; m-2-n surfactants (m not equal to

[0102] n),

[0103] In A1-A8, m, n, and z are independently 1-60.

[0104] Br - It can be replaced with any other anion, preferably F from Group VIIA of the periodic table. - Cl - I - At - 、Ts - .

[0105] In some embodiments of the present invention, the gemini surfactant is selected from at least one of the following:

[0106] C 12 H 25 N + (CH3)2-(CH2) n -N + (CH3)2C 12 H 25 2Br – (n = 3–8)

[0107] C 12 H 25 N + (CH3)2-(CH2) 16 -N + (CH3)2C 12 H 25 2Br – ,

[0108] C 16 H 33 N + (CH3)2-(CH2)2-N + (CH3)2C 16 H 33 2Br – ,

[0109] C8H 17 N + (CH3)2-(CH2)3-N + (CH3)2C8H 17 2Br – ,

[0110] C 12 H 25 N +(CH3)2-(CH2)2-O-(CH2)2-N + (CH3)2C 12 H 25 2Cl – 、

[0111] C 16 H 33 N + (CH3)2-(CH2)5-N + (CH3)2C 16 H 33 2Br – 、

[0112] C 16 H 33 N + (CH3)2-(CH2)2-O-(CH2)2-N + (CH3)2C 16 H 33 2Br – 、

[0113] C 16 H 33 N + (CH3)2-CH2-(CH2-O-CH2)3-CH2-N + (CH3)2C 16 H 33 2Br – 、

[0114] C 12 H 25 N + (CH3)2-CH2-CH(OH)-CH2-N + (CH3)2C 12 H 25 2Br – 、

[0115] C 12 H 25 N + (CH3)2-CH2-C6H4-CH2-N + (CH3)2C 12 H 25 2Br – 、

[0116] C 12 H 25 N + (CH3)2-CH2-CH(OH)-CH(OH)-CH2-N + (CH3)2C 12 H25 2Br – ,

[0117] C 12 H 25 N + (CH3)2-CH2-CH(OH)-CH2-N + (CH3)2-CH2-CH(OH)-CH2-N + (CH3)2C 12 H 25 3Cl – ,

[0118] C 12 H 25 OPO2 – -O-(CH2)6-OPO2 – -OC 12 H 25 2Na + ,

[0119] C 10 H 21 O-CH2-CH(OSO3 – )-CH2-O-(CH2)2-O-CH2-CH(OSO3 – )-CH2-OC 10 H 21 2Na + .

[0120] According to an embodiment of the present invention, the surfactant is selected from at least one of potassium oleate (KO), sodium dodecylbenzenesulfonate (SDBS), and bis(dodecyldimethylammonium bromide).

[0121] In this embodiment of the invention, the surfactants used include anionic surfactants and gemini surfactants. Anionic surfactants produce latex microparticles with smaller particle size, better latex stability, and are less prone to agglomeration during polymerization, resulting in latex with high and stable solid content. Gemini surfactants have good chemical stability to electrolytes, but the polymerization reaction rate is slow, resulting in larger latex microparticles with larger particle size, and agglomeration is more likely to occur during polymerization.

[0122] [Additives]

[0123] 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.

[0124] In an embodiment of the present invention, the chain transfer agent is selected from dodecyl mercaptan, which has good performance and can effectively reduce the molecular weight of latex.

[0125] According to an embodiment of the present invention, the pH adjuster is selected from at least one of sodium phosphate, tetrasodium diphosphate, trisodium phosphate, sodium hexametaphosphate, and sodium bicarbonate.

[0126] [Water-soluble rhodium-containing catalysts]

[0127] According to an embodiment of the present invention, the water-soluble rhodium-containing catalyst has a structure as shown in Formula I:

[0128] RhQL x Formula I,

[0129] in,

[0130] Q is a hydride or an anion other than a hydride.

[0131] L is a water-soluble ligand.

[0132] x is an integer from 1 to 10, for example, x = 1, 2, 3 or 4.

[0133] It must be emphasized that the structure of the water-soluble ligand L is not particularly limited. This water-soluble ligand can be, for example, monodentate or bidentate. In the case of a monodentate ligand, x in the general formula (I) is typically 2, 3, or 4; in the case of a bidentate ligand, x is typically 1 or 2.

[0134] According to an embodiment of the present invention, L has a structure as shown in Formula II:

[0135] R 1 m Type G II

[0136] Among them, R 1 They may be the same or different, and are independently selected from alkyl, cycloalkyl, aryl, or aralkyl groups, with at least one of them being R. 1 The group is sulfonated once or multiple times; preferably, R 1 They may be the same or different, and are independently selected from C1-C8 alkyl, C4-C8 cycloalkyl, and C6-C 15 Aryl or C7-C 15 Aryl alkyl group, wherein at least one of the R groups is present. 1 The group is sulfonated once or multiple times; for example, at least one R group is present. 1 The group is sulfonated once, twice, or three times;

[0137] G is a phosphorus, arsenic, sulfur, or sulfoxide group; S=O.

[0138] m is 2 or 3;

[0139] In some embodiments of the present invention, Q is a halide, and x is preferably 3.

[0140] In some embodiments of the present invention, Q is a hydride, and x is preferably 4.

[0141] In some embodiments of the present invention, Q is a halide, preferably a chloride or bromide.

[0142] In one embodiment of the present invention, R 1 One or more of the groups (e.g., two or three) are sulfonated once or multiple times; for example, each R 1 The group is sulfonated once, twice, or three times.

[0143] In one embodiment of the present invention, the water-soluble rhodium-containing catalyst is selected from RhCl(TPPMS)3 (TPPMS represents monosulfonated triphenylphosphine, such as P(C6H5)2(m-C6H4SO3). - )) or RhCl(TPPTS)3 (TPPTS represents trisulfonated triphenylphosphine, such as tris(3-sulfophenyl)phosphine, P(C6H4-3-SO3) - )3).

[0144] The water-soluble rhodium-containing catalyst of the present invention is soluble in water at room temperature, i.e., (24±2) °C. 1 The counter ion of the sulfonate group used in sulfonation is an alkali metal ion, such as Na+. + or K + .

[0145] In one embodiment of the present invention, L has the structure shown in Formula III:

[0146] R 2 n ZA-ZR 3 n Formula III

[0147] Among them, R 2 R 3 They may be the same or different, and are independently selected from alkyl, cycloalkyl, aryl, or aralkyl groups, and R 2 Or R 3 At least one of the groups is sulfonated once or multiple times; preferably, R 2 R 3 They may be the same or different, and are independently selected from C1-C8 alkyl, C4-C8 cycloalkyl, and C6-C 15 Aryl or C7-C 15 Aryl alkyl group, wherein at least one of the R groups is present. 2 Or R 3 The group is sulfonated once or multiple times; for example, at least one R group is present. 2 Or R 3 The group is sulfonated once, twice, or three times;

[0148] Z represents phosphorus or arsenic;

[0149] A represents a spacer group, preferably phenylene or C1-C. 20 alkylene or single bond;

[0150] n is 2;

[0151] x is 1 or 2.

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

[0153] In one embodiment of the invention, one or two R 2 Group and one or two R 3 The groups are sulfonated once, twice, or three times simultaneously.

[0154]

Terminology Definitions and Explanations

[0155] The term "alkyl" should mean any branched or unbranched hydrocarbon residue, and unless otherwise specified, should include C1-C2. 20 Alkyl groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, 1-ethylpropyl, n-hexyl, n-heptyl, n-octyl, n-decyl, or n-dodecyl.

[0156] The term "cycloalkyl" should include C3-C4. 10 Cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.

[0157] The term "aryl" includes aromatic groups having 6 to 24 carbon atoms in their skeleton. Preferred monocyclic, bicyclic, or tricyclic carbocyclic aromatic groups having 6 to 10 carbon atoms in their skeleton are, for example, phenyl, biphenyl, naphthyl, phenanthryl, and anthracene.

[0158] The term "substitution" means that a hydrogen atom on a specified group has been replaced by one of the specified groups in each case, provided that the valence state of the specified atom is not exceeded and the substitution results in a stable compound.

[0159] For the purposes of this patent application and invention, all definitions of groups, parameters or interpretations given above or below in general terms or in preferred ranges may be combined with each other in any way, i.e., including combinations of the corresponding ranges and preferred ranges.

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

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

[0162] R 4 oD-type IV

[0163] in,

[0164] R 4 They may be the same or different, and are independently selected from alkyl, cycloalkyl, aryl, or aralkyl groups, preferably, R 4 They may be the same or different, and are independently selected from C1-C8 alkyl, C6-C 15 Aryl, C4-C8 cycloalkyl or, C7-C 15 Aryl alkyl groups;

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

[0166] o is 2 or 3.

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

[0168] In one embodiment of the invention, the co-catalyst has a structure as shown in Formula V:

[0169] R 5 pE-A-ER 6 p-type V

[0170] in,

[0171] R 5 R 6 They may be the same or different, and are independently selected from alkyl, cycloalkyl, aryl, or aralkyl groups; preferably, R 5 R 6 They may be the same or different, and are independently selected from C1-C8 alkyl, C6-C 15 Aryl, C4-C8 cycloalkyl or, C7-C 15 Aryl alkyl groups;

[0172] E represents phosphorus or arsenic;

[0173] A represents a spacer group, preferably phenylene or C1-C. 20 alkylene or single bond,

[0174] p is 2.

[0175] In one embodiment of the invention, the co-catalyst is triphenylphosphine. The amount of water-soluble rhodium-containing catalyst to be used is not critical. Very small amounts of the catalyst can be used. Typically, it is used in an amount ranging from 0.01% to 5.0% by weight, preferably from 0.02% to 1.0% by weight, based on the weight of the polymer solids content in the latex.

[0176] Based on the weight of the water-soluble catalyst, the water-insoluble co-catalyst is typically used in an amount up to 5000% by weight, preferably in the range of 500% to 3000% by weight.

[0177] The present invention also provides hydrogenated rubber latex prepared by the above method.

[0178] The present invention also provides a hydrogenated rubber latex prepared by the above method, wherein the degree of hydrogenation of the hydrogenated rubber latex is 50-100%, the content of comonomer is 10-60 mol%, the content of diene monomer is 40%-90%, and the solid content of the hydrogenated rubber latex is 10-70 wt%.

[0179] According to an embodiment of the present invention, the degree of hydrogenation of the hydrogenated rubber latex is greater than or equal to 80%, preferably 95%, and more preferably 99%, for example 80.0%, 83.5%, 92.6%, 93.4%, 96.5%, 97.0%, 98.5%, 99.0%, or 99.8%.

[0180] According to an embodiment of the present invention, the particle size of the hydrogenated rubber latex is 50-80 nm, preferably 55-75 nm.

[0181] According to the embodiments of the present invention, the inventors have discovered that the polymerization system and emulsification system of the present invention, together with the water-soluble rhodium-containing catalyst and co-catalyst, can achieve the effect of significantly improving the efficiency of hydrogenation reaction and reducing the amount of catalyst used.

[0182] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0183] Example 1

[0184] The one-step preparation method for HNBR latex includes the following steps:

[0185] 1) Dissolve 7g of surfactant didodecyl dimethyl ammonium bromide in 300g of deionized water to obtain an aqueous surfactant solution, and add it to the reaction vessel;

[0186] 2) Add 30g acrylonitrile, 0.05g catalyst RhCl(TPPMS)3, 0.5g co-catalyst triphenylphosphine, 0.3g chain transfer agent tert-dodecyl mercaptan, and 0.05g pH adjuster sodium phosphate to the reaction vessel;

[0187] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reactor and degas for 0.5 hours while stirring at 200 rpm. Then add 70 g of butadiene in liquid form to the degassed reactor, mix, and emulsify at room temperature for 1 hour.

[0188] 4) Reduce the temperature of the reactor to the prepolymerization reaction temperature of 7°C, add 0.05g of initiator cumene hydroperoxide and 0.05g of initiator ferrous sulfate into the reactor through the feeding tank, and introduce 4MPa high-pressure hydrogen into the reactor for prepolymerization for 4 hours.

[0189] 5) Raise the system temperature to 60℃ to carry out polymerization and hydrogenation reactions. Maintain constant temperature and pressure in the reactor and keep the stirring speed constant at 450 rpm. After 5 hours of reaction, HNBR latex is obtained.

[0190] Example 2

[0191] The one-step preparation method for HNBR latex includes the following steps:

[0192] 1) Dissolve 7g of the surfactant potassium oleate in 300g of deionized water to obtain an aqueous surfactant solution and add it to the reaction vessel;

[0193] 2) Add 30g acrylonitrile, 0.05g catalyst RhCl(TPPMS)3, 0.5g co-catalyst triphenylphosphine, 0.3g chain transfer agent tert-dodecyl mercaptan, and 0.05g pH adjuster sodium phosphate to the reaction vessel;

[0194] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reactor and degas for 0.5 hours while stirring at 200 rpm. Then add 70 g of butadiene in liquid form to the degassed reactor, mix, and emulsify at room temperature for 1 hour.

[0195] 4) Reduce the temperature of the reactor to the prepolymerization reaction temperature of 7°C, add 0.05g of initiator cumene hydroperoxide and 0.05g of initiator ferrous sulfate into the reactor through the feeding tank, and introduce 4MPa high-pressure hydrogen into the reactor for prepolymerization for 4 hours.

[0196] 5) Raise the system temperature to 60℃ to carry out polymerization and hydrogenation reactions. Maintain constant temperature and pressure in the reactor and keep the stirring speed constant at 450 rpm. After 5 hours of reaction, HNBR latex is obtained.

[0197] Example 3

[0198] The one-step preparation method for HNBR latex includes the following steps:

[0199] 1) Dissolve 7g of the surfactant sodium dodecylbenzenesulfonate in 300g of deionized water to obtain an aqueous surfactant solution, and add it to the reaction vessel;

[0200] 2) Add 30g acrylonitrile, 0.05g catalyst RhCl(TPPMS)3, 0.5g co-catalyst triphenylphosphine, 0.3g chain transfer agent tert-dodecyl mercaptan, and 0.05g pH adjuster sodium phosphate to the reaction vessel;

[0201] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reactor and degas for 0.5 hours while stirring at 200 rpm. Then add 70 g of butadiene in liquid form to the degassed reactor, mix, and emulsify at room temperature for 1 hour.

[0202] 4) Reduce the temperature of the reactor to the prepolymerization reaction temperature of 7°C, add 0.05g of initiator cumene hydroperoxide and 0.05g of initiator ferrous sulfate into the reactor through the feeding tank, and introduce 4MPa high-pressure hydrogen into the reactor for prepolymerization for 4 hours.

[0203] 5) Raise the system temperature to 60℃ to carry out polymerization and hydrogenation reactions. Maintain constant temperature and pressure in the reactor and keep the stirring speed constant at 450 rpm. After 5 hours of reaction, HNBR latex is obtained.

[0204] Example 4

[0205] The one-step preparation method for HNBR latex includes the following steps:

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

[0207] 2) Add 30g acrylonitrile, 0.05g catalyst RhCl(TPPTS)3, 0.5g co-catalyst triphenylphosphine, 0.3g chain transfer agent tert-dodecyl mercaptan, and 0.05g pH adjuster sodium phosphate to the reaction vessel;

[0208] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reactor and degas for 0.5 hours while stirring at 200 rpm. Then add 70 g of butadiene in liquid form to the degassed reactor, mix, and emulsify at room temperature for 1 hour.

[0209] 4) Reduce the temperature of the reactor to the prepolymerization reaction temperature of 7°C, add 0.05g of initiator cumene hydroperoxide and 0.05g of initiator ferrous sulfate into the reactor through the feeding tank, and introduce 4MPa high-pressure hydrogen into the reactor for prepolymerization for 4 hours.

[0210] 5) Raise the system temperature to 60℃ to carry out polymerization and hydrogenation reactions. Maintain constant temperature and pressure in the reactor and keep the stirring speed constant at 450 rpm. After 5 hours of reaction, HNBR latex is obtained.

[0211] Example 5

[0212] The one-step preparation method for HNBR latex includes the following steps:

[0213] 1) Dissolve 7g of the surfactant potassium oleate in 300g of deionized water to obtain an aqueous surfactant solution and add it to the reaction vessel;

[0214] 2) Add 30g acrylonitrile, 0.05g catalyst RhCl(TPPMS)3, 0.5g co-catalyst triphenylphosphine, 0.3g chain transfer agent tert-dodecyl mercaptan, and 0.05g pH adjuster sodium phosphate to the reaction vessel;

[0215] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reactor and degas for 0.5 hours while stirring at 200 rpm. Then add 70 g of butadiene in liquid form to the degassed reactor, mix, and emulsify at room temperature for 1 hour.

[0216] 4) Reduce the temperature of the reactor to the prepolymerization reaction temperature of 7°C, add 0.05g of potassium persulfate initiator and 0.05g of ferrous chloride initiator into the reactor through the feeding tank, and introduce 4MPa high-pressure hydrogen into the reactor for prepolymerization for 4 hours.

[0217] 5) Raise the system temperature to 60℃ to carry out polymerization and hydrogenation reactions. Maintain constant temperature and pressure in the reactor and keep the stirring speed constant at 450 rpm. After 5 hours of reaction, HNBR latex is obtained.

[0218] Example 6

[0219] The one-step preparation method for HNBR latex includes the following steps:

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

[0221] 2) Add 30g acrylonitrile, 0.05g catalyst RhCl(TPPMS)3, 0.5g co-catalyst triphenylphosphine, 0.3g chain transfer agent tert-dodecyl mercaptan, and 0.05g pH adjuster sodium phosphate to the reaction vessel;

[0222] 3) Introduce 0.5 MPa inert gas (nitrogen) into the reactor and degas for 0.5 hours while stirring at 200 rpm. Then, add 70 g of butadiene in liquid form to the degassed reactor, mix, and emulsify at room temperature for 1 hour. 4) Lower the reactor temperature to the prepolymerization reaction temperature of 7°C. Add 0.05 g of initiator cumene hydroperoxide and 0.05 g of initiator ferrous sulfate to the reactor through a feeding tank. Introduce 4 MPa high-pressure hydrogen gas into the reactor and prepolymerize for 4 hours.

[0223] 5) Raise the system temperature to 70℃ to carry out polymerization and hydrogenation reactions. Maintain constant temperature and pressure in the reactor and keep the stirring speed constant at 450 rpm. After 5 hours of reaction, HNBR latex is obtained.

[0224] Comparative Example 1

[0225] The one-step preparation method for HNBR latex includes the following steps:

[0226] 1) Dissolve 7g of the surfactant potassium oleate in 300g of deionized water to obtain an aqueous surfactant solution and add it to the reaction vessel;

[0227] 2) Add 30g acrylonitrile, 0.05g water-insoluble catalyst RhCl(PPh3)3, 0.5g co-catalyst triphenylphosphine, 0.3g chain transfer agent tert-dodecyl mercaptan, and 0.05g pH adjuster sodium phosphate to the reaction vessel;

[0228] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reactor and degas for 0.5 hours while stirring at 200 rpm. Then add 70 g of butadiene in liquid form to the degassed reactor, mix, and emulsify at room temperature for 1 hour.

[0229] 4) Reduce the temperature of the reactor to the prepolymerization reaction temperature of 7°C, add 0.05g of initiator cumene hydroperoxide and 0.05g of initiator ferrous sulfate into the reactor through the feeding tank, and introduce 4MPa high-pressure hydrogen into the reactor for prepolymerization for 4 hours.

[0230] 5) Raise the system temperature to 60℃ to carry out polymerization and hydrogenation reactions. Maintain constant temperature and pressure in the reactor and keep the stirring speed constant at 450 rpm. After 5 hours of reaction, HNBR latex is obtained.

[0231] Comparative Example 2

[0232] The one-step preparation method for HNBR latex includes the following steps:

[0233] 1) Dissolve 7g of the surfactant potassium oleate in 300g of deionized water to obtain an aqueous surfactant solution and add it to the reaction vessel;

[0234] 2) Add 30g acrylonitrile, 0.05g catalyst RhCl(PPh3)3, 0.5g co-catalyst triphenylphosphine, 0.3g chain transfer agent tert-dodecyl mercaptan, and 0.05g pH adjuster sodium phosphate to the reaction vessel;

[0235] 3) Introduce 0.5 MPa of inert gas (nitrogen) into the reactor and degas for 0.5 hours while stirring at 200 rpm. Then add 70 g of butadiene in liquid form to the degassed reactor, mix, and emulsify at room temperature for 1 hour.

[0236] 4) Reduce the temperature of the reactor to the prepolymerization reaction temperature of 7°C, add 0.05g of initiator cumene hydroperoxide and 0.05g of initiator ferrous sulfate into the reactor through the feeding tank, and introduce 5MPa high-pressure hydrogen into the reactor for prepolymerization for 4 hours.

[0237] 5) Raise the system temperature to 80℃ to carry out polymerization and hydrogenation reactions. Maintain constant temperature and pressure in the reactor and keep the stirring speed constant at 450 rpm. After 5 hours of reaction, HNBR latex is obtained.

[0238] Comparative Example 3

[0239] The one-step preparation method for HNBR latex includes the following steps:

[0240] 1) Dissolve 7g of the surfactant potassium oleate in 300g of deionized water to obtain an aqueous surfactant solution and add it to the reaction vessel;

[0241] 2) Add 1.5g of potassium persulfate initiator, 30g of acrylonitrile, 0.05g of RhCl(TPPMS)3 catalyst, 0.5g of triphenylphosphine co-catalyst, 0.3g of tert-dodecyl mercaptan chain transfer agent, and 0.05g of sodium phosphate pH adjuster to the reaction vessel;

[0242] 3) Introduce 0.5 MPa inert gas (nitrogen) into the reactor and degas for 0.5 hours while stirring at 200 rpm. Then add 70 g butadiene in liquid form into the degassed reactor, mix, and emulsify the monomer at room temperature for 1 hour.

[0243] 4) After emulsification, adjust the rotation speed to 450 rpm and introduce high-pressure hydrogen gas at 4 MPa.

[0244] 5) Raise the temperature of the reactor to 60°C. At this point, the polymerization and hydrogenation reactions will begin. Maintain constant temperature and pressure inside the reactor and keep the stirring speed constant. After 5 hours of reaction, HNBR latex will be obtained.

[0245] Table 1 Experimental conditions of Examples 1-6 and Comparative Examples 1-3

[0246]

[0247] The particle size and particle size distribution of nanoparticles were determined by dynamic light scattering (DLS) using a Nano ZS 3500 nanoparticle size analyzer.

[0248] The structure of the polymer was determined by FT-IR (BRUKER II, BRUKER Instruments, Karlsruhe, Germany). FT-IR method: First, the latex sample was separated with ethanol to obtain a 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 plate and dried to form a polymer film, which was then analyzed by infrared spectroscopy.

[0249] The degree of hydrogenation is calculated based on the FT-IR spectrum at 2236 cm⁻¹. -1 970cm -1 and 723cm -1 The corresponding absorbance of the characteristic peak at that location.

[0250] 2236cm -1 It is a characteristic peak of the cyano group (-C≡N), at 970 cm⁻¹. -1 It is the characteristic peak of -C=C- (inverse 1,4 structure), 723 cm⁻¹ -1 It is (-CH2) n Characteristic peaks for n>4.

[0251]

[0252] K(723) = 0.255 and K(970) = 2.3 are constants unique to HNBR.

[0253] Then the relative amount of -C = C- in HNBR is:

[0254]

[0255] The relative amount of methylene groups formed by hydrogenation of -C=C- in NBR is:

[0256]

[0257] Finally, the formula for calculating the degree of hydrogenation is:

[0258]

[0259] The acrylonitrile content is obtained by determining the nitrogen atom content using elemental analysis.

[0260] Table 2. Performance test results of hydrogenated nitrile rubber latex in Examples 1-6 and Comparative Examples 1-3

[0261] Particle size (nm) Particle size distribution Acrylonitrile content (%) Degree of hydrogenation (%) Example 1 62 0.021 30 92.6 Example 2 68 0.017 32 98.4 Example 3 65 0.016 31 93.4 Example 4 58 0.009 32 97.0 Example 5 62 0.023 33 96.5 Example 6 71 0.024 34 99.8 Comparative Example 1 69 0.019 28 65.1 Comparative Example 2 65 0.027 33 96.5 Comparative Example 3 126 0.026 32 97.5

[0262] As shown in the table above, the HNBR latex prepared by this invention has a small particle size (less than or equal to 68 nm, with a minimum of 58 nm), is less prone to demulsification, and the preparation method is simple, convenient, and easy to industrialize. During synthesis, the degree of hydrogenation is above 90%, resulting in high conversion rate and good hydrogenation effect. Compared with Comparative Examples 1 and 2, Examples 1-6 utilize a water-soluble rhodium metal catalyst, resulting in milder reaction conditions. Compared with Comparative Example 3, Examples 1-6, prepared using a low-temperature one-step method, produce hydrogenated nitrile butadiene rubber with smaller particle size and a higher degree of hydrogenation.

[0263] Therefore, compared with the prior art, the beneficial effects of the present invention are: the hydrogenated nitrile latex prepared by the present invention in one step has stable latex properties, good uniformity of nanomicelle size, small particle size distribution range, and is not easy to break the emulsion. The preparation method is simple, convenient to operate, and easy to industrialize; the hydrogenation effect is good and the degree of hydrogenation is high during the synthesis process.

[0264] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing a hydrogenated rubber latex, characterized by, The method comprises the following steps: The method comprises the following steps:

2. The method of claim 1, wherein, The method comprises the following steps: S1. mixing the surfactant, the water-soluble rhodium-containing catalyst, the cocatalyst, the comonomer, the diene monomer, the optional additive and water at normal temperature to emulsify; S2. reducing the temperature to the prepolymerization temperature, adding the initiator and then introducing high-pressure hydrogen to perform the prepolymerization reaction; S3. increasing the temperature to perform the polymerization and hydrogenation reaction to obtain the hydrogenated rubber latex.

3. The method of claim 2, wherein, In step S1, the additive comprises a chain transfer agent and / or a pH regulator, the chain transfer agent is used in an amount of 0.25-2 parts, and the pH regulator is used in an amount of 0.05-1.0 parts.

4. The method of claim 2, wherein, Step S1 comprises the following steps: S1-a, dissolving the surfactant in a part of water to obtain a surfactant solution; S1-b, adding the comonomer, the water-soluble rhodium-containing catalyst, the water-insoluble cocatalyst and the chain transfer agent into the surfactant solution to mix; S1-c, introducing inert gas into the reactor to degas, adding the diene monomer and emulsifying at normal temperature to obtain an emulsified product.

5. The process for the preparation of hydrogenated rubber latex in one step according to claim 2, characterized in that, In step S2, the prepolymerization temperature is 2-40℃, the prepolymerization time is 0.5-6h, and the pressure of the high-pressure hydrogen is 3-15MPa. Preferably, step S3 specifically comprises the following steps: increasing the temperature of the reactor to 60-180℃ to continue the polymerization and hydrogenation reaction for 0.5-10h to obtain the hydrogenated rubber latex.

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

7. The method according to any one of claims 1 to 6, characterized in that, the surfactant is selected from the group consisting of fatty acids, alkyl sulfates, sulfuric monoesters of ethoxylated alkanols, ethoxylated alkylphenols, alkali metal or ammonium salts of alkylsulfonic acids, alkali metal or ammonium salts of alkylarylsulfonic acids, ethoxylated monoalkylphenols, dialkylphenols, trialkylphenols, ethoxylated fatty alcohols, mono C4-C 24 alkali metal or ammonium salts of alkyl derivatives, di C4-C 24 alkali metal or ammonium salts of alkyl derivatives, alkylarylsulfonic acids, alkylsulfonic acids, alkali metal or ammonium salts of sulfuric monoesters of ethoxylated alkanols, at least one of the gemini surfactants.

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

9. The method of claim 8, wherein, L has the structure shown in Formula II: R 1 m G Formula II wherein R 1 are the same or different, independently of one another, selected from alkyl, cycloalkyl, aryl or aralkyl, and wherein at least one R1group is sulfonated one or more times; G is phosphorus, arsenic, sulfur or a sulfoxide group S=O; m is 2 or 3; or, L has the structure shown in Formula III: R 2 n Z-A-ZR 3 n Formula III wherein R 2 , R 3 are identical or different and are independently of each other selected from alkyl, cycloalkyl, aryl or aralkyl, and at least one of the R 2 or R 3 groups is sulfonated one or more times; Z is phosphorus or arsenic; A represents a spacer, preferably phenylene or C1-C 20 alkylene or a single bond; n is 2; x is 1 or 2; Preferably, the water-soluble rhodium-containing catalyst is selected from RhCl(TPPMS)3 or RhCl(TPPTS)3.

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

Images