Catalyst for synthesizing hydrogenated butadiene-acrylonitrile rubber and preparation method thereof

Abstract

The invention relates to the technical field of catalysts, in particular to a catalyst for synthesizing hydrogenated butadiene-acrylonitrile rubber and a preparation method of the catalyst. The preparation method comprises the following steps: modifying oxide ceramic powder by using a coupling agent, adding a functional polymer, and covering the surface of the oxide ceramic powder with the functional polymer through an anchoring effect to form a shell-core structure carrier; and reacting the carrier with a platinum group metal compound, and loading the functional group of the functional polymer on the surface of the carrier to form the catalyst for synthesizing the hydrogenated nitrile rubber. Anchoring groups on the surface of the obtained catalyst are uniformly distributed, the adsorption effect is strong, a platinum group metal compound can be more uniformly and stably loaded on a carrier, and meanwhile, the surface of the catalyst is non-polar, so that the influence on the activity of the catalyst due to adsorption of high-polarity nitrile rubber can be avoided. Through the specific preparation method and structural design, the performance and stability of the catalyst are improved, the recycling rate of platinum group metal is increased, and the catalyst has important industrial application value and environmental friendliness.

Description

Technical Field

[0001] The present application relates to the technical field of catalysts, and in particular to a catalyst for synthesizing hydrogenated nitrile rubber and a preparation method thereof. Background Art

[0002] Hydrogenated nitrile rubber (HNBR) is an elastic material obtained by partially hydrogenating nitrile rubber (NBR). NBR itself is copolymerized by butadiene and acrylonitrile, and has excellent properties such as oil resistance, high temperature resistance, wear resistance, and chemical corrosion resistance. However, due to the double bond structure of NBR, it is easily oxidized at high temperatures and is sensitive to aging, which limits its application in certain environments. By reducing some of the double bonds of NBR to single bonds to form HNBR, not only its thermal stability and resistance to ozone and UV aging are improved, but also it has stronger chemical resistance and better mechanical properties. Therefore, it is widely used in the fields of automobiles, aviation, and industrial equipment. The hydrogenation reaction, the core of the HNBR production process, usually requires a catalyst to ensure the efficiency and selectivity of the reaction. Therefore, an efficient and stable catalyst has become a crucial factor restricting the large-scale production of HNBR and reducing costs.

[0003] The preparation process of hydrogenated nitrile rubber is divided into two categories: homogeneous solution hydrogenation method and heterogeneous solution hydrogenation method. The process of HNBR homogeneous solution hydrogenation method is described in US Patent 5,298,374. In the process, triphenylphosphine rhodium chloride is dissolved in chlorobenzene solvent together with NBR as a homogeneous catalyst to form a homogeneous solution, and the hydrogenation reaction is catalyzed in a high-pressure reactor to obtain HNBR. The advantage of the homogeneous solution hydrogenation process is that the catalyst and the reactant are dissolved in the same solvent, and the molecules of the two are fully in contact, avoiding the diffusion and mass transfer problem, thereby not requiring a higher reaction pressure and temperature. However, the biggest drawback of the homogeneous catalyst is that it is difficult to recover or reuse, which increases the product cost and causes metal pollution. The process of HNBR heterogeneous solution hydrogenation method is described in US Patent 6,235,795. This process loads platinum or rhodium metal onto inorganic powders such as activated carbon and silica gel as a catalyst, and suspends it in an NBR solution to catalyze the hydrogenation reaction. In contrast, the advantage of the heterogeneous solution hydrogenation process is that the catalyst and reactants are in the solid-liquid phase. After the reaction is completed, the product and the catalyst can be separated by filtration or centrifugal separation technology, and the catalyst is easy to recover and recycle. In addition, the stability of the supported catalytic system to oxygen and water is increased, and the catalyst is not easy to deactivate or poison. However, there are still many problems with heterogeneous catalysts, such as 1) during the hydrogenation process, the catalyst load is very easy to adsorb NBR molecules, causing them to agglomerate; 2) due to steric hindrance, the supported catalyst requires higher pressure and temperature than the homogeneous phase to maintain a certain reaction rate; 3) the degree of hydrogenation is not as good as that of the homogeneous catalyst, usually less than 95%. Therefore, the optimization and improvement of heterogeneous catalysts is of great significance to their application in the hydrogenation of NBR. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present application provides a catalyst for hydrogenated nitrile rubber synthesis and a preparation method thereof, wherein the present application first modifies the oxide ceramic powder with a coupling agent, then adds a functional polymer, and covers it on the oxide ceramic powder surface to form a shell-core structure carrier through an anchoring effect; then the carrier reacts with a platinum group metal compound, and the functional group of the functional polymer is loaded on the carrier surface to form a catalyst for hydrogenated nitrile rubber synthesis. The catalyst surface anchoring groups prepared by the present application for hydrogenated nitrile rubber synthesis are evenly distributed, and the adsorption is strong, which is conducive to the platinum group metal compound being loaded more evenly and stably on the carrier, and the catalyst surface is non-polar, and the adsorption of highly polar nitrile rubber can be avoided to affect the catalyst activity. In addition, the functional polymer as a carrier shell can provide a homogeneous environment, significantly improving the efficiency and degree of hydrogenation of hydrogenation.

[0005] In a first aspect, the present application provides a method for preparing a catalyst for the synthesis of hydrogenated nitrile rubber, using the following technical scheme: A method for preparing a catalyst for synthesizing hydrogenated nitrile rubber comprises the following steps: S1. Surface treatment of oxide ceramics: suspend the oxide ceramic powder in a solvent under the protection of anhydrous and oxygen-free inert gas, dropwise add a coupling agent under stirring, react at a reaction temperature of 20-80°C for 0.5-5 hours, then filter the reaction liquid and wash the filter cake with a solvent to remove the unreacted coupling agent to obtain a modified oxide ceramic powder; S2. Coupling of modified oxide ceramic powder and functional polymer: In anhydrous and oxygen-free environment and under the protection of inert gas, the modified oxide ceramic powder obtained in step S1 is resuspended in a solvent, and then a functional polymer is added. After continuous immersion at a temperature of 20-80° C. for 5-20 hours, the free functional polymer is washed away with a solvent to obtain a spherical granular carrier; S3, platinum group metal compound adsorption loading: in anhydrous and oxygen-free environment and under the protection of inert gas, the carrier obtained in step S2 is resuspended in a solvent, and then a platinum group metal compound is added, and the reaction is carried out at a temperature of 20-80° C. for 1-10 hours, and then the solvent is filtered out and washed with a sufficient amount of solvent to obtain a catalyst for the synthesis of hydrogenated nitrile rubber; The functional polymer is covered on the surface of the oxide ceramic powder through the anchoring effect of the coupling agent to form a core-shell structure carrier; the platinum group metal compound is loaded on the surface of the core-shell structure carrier through the functional group of the functional polymer to form a catalyst for the synthesis of hydrogenated nitrile rubber.

[0006] By adopting the above technical scheme, the surface treatment of oxide ceramics: the main purpose of this step is to modify the oxide ceramic powder by a coupling agent to change its surface properties. The coupling agent can improve the surface properties of the oxide ceramic powder, making it easier to react with other substances or form a stable structure. At the same time, the surface of the oxide ceramic powder modified by the coupling agent can provide anchoring groups, which can be evenly distributed on the catalyst surface in the subsequent steps, which helps the uniform loading of platinum group metal compounds. Coupling of modified oxide ceramic powder with functional polymer: in this step, the modified oxide ceramic powder is coupled with the functional polymer to form a core-shell structure carrier. The functional polymer covers the surface of the oxide ceramic powder through the anchoring effect to form a uniformly distributed anchoring group. This structure not only helps the uniform loading of platinum group metal compounds, but also provides a homogeneous environment, thereby improving the efficiency and degree of hydrogenation. Platinum group metal compound adsorption loading: in this step, the platinum group metal compound is adsorbed and loaded on the carrier through the functional group of the functional polymer. Stable chemical bonding is formed between the functional group of the functional polymer and the platinum group metal compound, ensuring the uniform distribution and stability of the platinum group metal compound on the carrier. At the same time, since the non-polar main chain of the functional polymer can avoid the adsorption of highly polar nitrile rubber on the catalyst surface, the load condensation and agglomeration phenomenon is avoided, and the efficient activity of the catalyst is guaranteed. In summary, the present application realizes the modification treatment of oxide ceramic powder, the coupling of functional polymer and the adsorption load of platinum group metal compound through a three-step reaction process. These steps work together to jointly construct a catalyst that evenly distributes anchoring groups, provides a homogeneous environment and has good catalytic performance. This catalyst not only improves hydrogenation efficiency and hydrogenation degree, but also ensures the stability and recyclability of the catalyst.

[0007] Preferably, in step S1, the oxide ceramic powder is a spherical granular porous oxide ceramic powder, specifically at least one selected from silicon oxide powder, aluminum oxide powder, titanium oxide powder and zirconium oxide powder. The average diameter of the oxide ceramic powder is between 5 and 500 microns.

[0008] Preferably, in step S1, the coupling agent is a silane compound having a coupling effect and containing two or more reactive functional groups, and its chemical formula is L-(CH2)n-Si-R3, wherein: L is urea, amino, isocyanate, hydroxyl or chlorine, n is 0-6, and R is an alkyl or alkoxy group having 1-6 carbon atoms.

[0009] By adopting the above technical scheme, the coupling agent reacts with the surface of the oxide ceramic powder through its two or more reactive functional groups to form a chemical bond connection. This enables the coupling agent to effectively adhere to the surface of the oxide ceramic powder, thereby changing its surface properties. Through the anchoring effect of the coupling agent, the functional polymer can be more firmly attached to the surface of the oxide ceramic powder. This enhanced adhesion helps to ensure that the functional polymer does not fall off easily in subsequent steps. The presence of the coupling agent enables the functional polymer to cover the surface of the oxide ceramic powder through the anchoring effect to form a core-shell structure carrier. This structure helps to improve the uniformity and stability of the platinum group metal compound on the carrier. The coupling agent helps to reduce the loss of active components during the reaction by enhancing the adhesion between the functional polymer and the surface of the oxide ceramic powder. This is very important for improving the stability and reusability of the catalyst. In summary, the coupling agent plays a key role in the catalyst preparation process, not only changing the surface properties of the oxide ceramic powder, but also improving the performance and stability of the catalyst by enhancing adhesion and forming a core-shell structure.

[0010] Preferably, in step S2, the functional polymer is a styrene copolymer functional polymer containing hydroxyl, amide, pyridine, carboxyl, carbonyl, and amino functional groups, specifically selected from one of styrene-acrylamide copolymers, styrene-vinyl alcohol copolymers, styrene-acrylic acid copolymers, styrene-vinyl pyrrolidone copolymers, and styrene-ethyleneimine copolymers; the copolymers include four types: random, alternating, block, and graft copolymers.

[0011] By adopting the above technical scheme, the functional polymer forms an anchoring effect through the interaction between its functional groups and the surface of the oxide ceramic powder. This anchoring effect ensures that the functional polymer can be stably attached to the surface of the oxide ceramic powder to form a core-shell structure carrier. The functional groups on the functional polymer can effectively adsorb platinum group metal compounds. This adsorption effect ensures that the platinum group metal compounds can be uniformly and stably loaded on the carrier. The functional polymer can swell in an organic solvent, providing a homogeneous environment for the loaded platinum group metal compounds. This homogeneous environment helps to improve the efficiency and degree of hydrogenation of hydrogenation. The main chain of the functional polymer is non-polar, which can prevent the highly polar nitrile rubber from being adsorbed on the surface of the catalyst. This characteristic helps to prevent the load from agglomerating and agglomerating, thereby not affecting the activity of the catalyst. Different functional polymers may have different functional groups and chemical properties. There may be a synergistic effect between them, that is, when two or more functional groups act on the platinum group metal compound at the same time, a stronger adsorption effect or a more stable loading structure may be produced than when acting alone. Specifically, the functional polymers, such as styrene-acrylamide copolymers, styrene-vinyl alcohol copolymers, etc., may have different functional group ratios and structural characteristics. These characteristics determine the way and intensity of their interaction with oxide ceramic powders and platinum group metal compounds, thus affecting the final catalyst performance. In summary, functional polymers play a key role in the catalyst preparation process, not only providing anchoring groups and functional group loading, but also affecting the performance and hydrogenation efficiency of the catalyst through their chemical properties and structural characteristics.

[0012] Preferably, in step S3, the platinum group metal compound is a platinum group metal compound with a chemical formula of BmHn, wherein m is 1.0 and n is 0.5-8.0; B is a platinum group metal having hydrogenation catalytic ability, specifically selected from one of ruthenium, rhodium, palladium, osmium, iridium and platinum metal; H is an inorganic or organic acid radical, specifically selected from one of chlorine, bromine, iodine, nitrate, sulfate, phosphate, acetate and propionate.

[0013] By adopting the above technical scheme, the role of the platinum group metal compound is mainly to serve as the main active component of the catalyst. This platinum group metal compound usually has a high catalytic activity and can effectively catalyze the hydrogenation reaction. At the same time, since this compound has a specific chemical formula BmHn, where B represents a platinum group metal with hydrogenation catalytic ability (such as ruthenium, rhodium, palladium, osmium, iridium and platinum, etc.), and H represents an inorganic or organic acid radical (such as chlorine, bromine, iodine, nitrate, sulfate, phosphate, acetate and propionate, etc.), this structural design enables the platinum group metal compound to provide a stable active center and a suitable acidic environment during the catalytic process. The combination of platinum group metals and acid radicals can form a stable metal-acid radical complex, which can provide a specific reaction site during the catalytic process, thereby improving the catalytic efficiency. At the same time, the presence of acid radicals can also regulate the acidic environment on the catalyst surface, which helps to optimize the path and rate of the catalytic reaction. Different platinum group metals have different catalytic properties and selectivity. Selecting a suitable platinum group metal can provide the best catalytic effect for a specific reaction. For example, some metals may be more suitable for certain specific steps or products in a hydrogenation reaction. The stability of platinum group metal compounds is crucial for the long-term use of catalysts. Stable catalysts can maintain their catalytic performance during the reaction and reduce the loss of active components, thereby increasing the service life and efficiency of the catalyst. Since platinum group metal compounds can be removed and recovered from the catalyst surface by mild chemical methods, this not only helps to reduce environmental pollution and resource waste, but also reduces production costs. In summary, platinum group metal compounds play a key role in the catalyst preparation process, not only providing the active centers required for the catalytic reaction, but also optimizing the performance and stability of the catalyst through synergy with functional polymers.

[0014] Preferably, the solvent is one of toluene, xylene, chlorobenzene and methyl pyrrolidone.

[0015] Preferably, in step S1, the mass ratio of the oxide ceramic powder to the coupling agent is 5:1 to 500:1.

[0016] Preferably, in step S2, the mass ratio of the modified oxide ceramic powder to the functional polymer is 1:2 to 20:1.

[0017] Preferably, the carrier contains 5% to 60% of the functional polymer, and the functional groups on its surface are evenly distributed.

[0018] Preferably, in step S3, the mass ratio of the carrier to the platinum group metal compound is 5:1 to 100:1.

[0019] Preferably, in step S3, the loading amount of the platinum group active component in the catalyst for synthesis of hydrogenated nitrile rubber is 0.2% to 20% of the total mass.

[0020] In the second aspect, the present application provides a catalyst for the synthesis of hydrogenated nitrile rubber, adopting the following technical scheme: As a general technical concept, the present application also provides the above-mentioned catalyst for the synthesis of hydrogenated nitrile rubber, which is prepared by the preparation method of the above-mentioned catalyst for the synthesis of hydrogenated nitrile rubber.

[0021] By adopting the above technical scheme, the anchoring groups on the surface of the single oxide ceramic carrier are unevenly distributed, and the local density of the surface area can differ by more than 5 times, which not only makes the loading reaction difficult to carry out, but also may cause the catalyst concentration in the local area to be too large. The catalyst surface of the present application is a functional polymer, so the anchoring groups on the carrier surface are evenly distributed, and the distribution density is adjustable, which is conducive to the platinum group metal compound being loaded more evenly and stably on the carrier, and conveniently designing the catalyst. Most oxide ceramic surfaces only have hydroxyl groups, and the interaction force between the active sites is weak, which may cause the loss of active components during the reaction, and the hydrogenation performance of the recovered catalyst is poor, while the interaction between the functional polymer core active sites is strong, which can effectively improve the loss of active components. The main chain of the functional polymer on the catalyst surface prepared is non-polar, which can avoid the adsorption of highly polar NBR on the surface of the catalyst, so it will not cause the load to condense and agglomerate, thereby affecting the catalyst activity. The functional polymer as the carrier shell can swell in an organic solvent, and can provide a homogeneous environment for the loaded platinum group metal compound, thereby improving the efficiency and degree of hydrogenation of hydrogenation. The preparation of general polymer carriers is relatively complicated, and the obtained polymer carrier particles are unevenly distributed, and the sphericity is very poor. The use of oxide ceramic powder as the core of the carrier can provide suitable strength, surface area and sphericity, so the carrier particle size distribution obtained in this application is uniform and basically spherical. The core-shell structure of the catalyst prepared in this application is conducive to the recycling of the catalyst. Platinum group metals directly loaded on oxide ceramic powders require more stringent processes for recovery. The core-shell structure carrier of the present application can be used to gently acid or alkaline hydrolyze the functional polymer on the surface of the catalyst into an aqueous solution, and then burn it to recover the platinum group metals, greatly improving the recovery rate of platinum group metals.

[0022] In a third aspect, the present application provides an application of a catalyst for synthesizing hydrogenated nitrile rubber in synthesizing hydrogenated nitrile rubber, using the following technical solution: The catalyst for hydrogenated nitrile rubber synthesis obtained in the present application is used to partially hydrogenate nitrile rubber (NBR) to obtain hydrogenated nitrile rubber (HNBR). Before catalysis, the catalyst is first dispersed in a solvent, activated under the action of hydrogen, and the platinum group metal compound on the catalyst surface is reduced to obtain nano-level platinum group metal, and finally NBR is added to the solution for hydrogenation reaction.

[0023] In summary, the beneficial technical effects of this application are: 1. Uniformly distributed anchoring groups: The anchoring effect of functional polymers on the surface of oxide ceramic powders forms a core-shell structure carrier, so that the anchoring groups on the catalyst surface are evenly distributed, which is conducive to more uniform and stable loading of platinum group metal compounds on the carrier.

[0024] 2. Improve catalyst activity: The functional polymer has a strong interaction with the active site, which can effectively reduce the loss of active components, thereby improving the activity and stability of the catalyst.

[0025] 3. Avoid loss of catalyst activity: The functional polymer main chain on the catalyst surface is non-polar, which can effectively prevent the highly polar nitrile rubber (NBR) from adsorbing on the catalyst surface, prevent the load from agglomerating, and thus maintain the activity of the catalyst.

[0026] 4. Improve hydrogenation efficiency: Functional polymers can swell in organic solvents, providing a homogeneous environment for platinum group metal compounds, which helps to improve hydrogenation efficiency and hydrogenation degree.

[0027] 5. Uniformity of carrier particles: Using oxide ceramic powder as the core carrier, the obtained carrier particle size distribution is uniform and basically spherical, which is conducive to the uniform distribution and use of the catalyst.

[0028] 6. Catalyst recycling: The core-shell structured carrier can recover the functional polymer on the catalyst surface through mild chemical methods (such as acid hydrolysis or alkaline hydrolysis), and then recover the platinum group metals through burning, which greatly improves the recovery rate of platinum group metals and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings used in the embodiments: Figure 1 This is a schematic diagram of the structure of the catalyst used for the synthesis of hydrogenated nitrile rubber in this application; Figure 2 A schematic diagram of a method for preparing a catalyst for synthesizing hydrogenated nitrile rubber according to the present application; Figure 3 Figure A is a scanning electron microscope image of the silicon dioxide powder of Example 1; Figure 3 Figure B is a scanning electron microscope photograph of the catalyst for hydrogenated nitrile rubber synthesis obtained in Example 1. DETAILED DESCRIPTION

[0030] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0031] Example 1 10.0g of dried oxide ceramic silica (SiO2) powder was added to a water-free and oxygen-free reaction bottle. The entire reaction was carried out under nitrogen protection. 100mL of solvent toluene was added to the reaction bottle, and 2.5g of isocyanate propyl triethoxysilane (IPTS) coupling agent was slowly added to the suspension in the reaction bottle at 20°C, and the temperature was raised to 60°C and the reaction was carried out for 4 hours. Filtered under nitrogen protection, washed with toluene 3 times to remove excess IPTS coupling agent. Then, a toluene solution containing 10g of styrene-ethyleneimine graft copolymer (PS-co-PEI, a functional polymer with a nitrogen content of 5%) was slowly added to the reaction bottle, then heated to 80°C, stirred continuously for 10 hours, filtered under nitrogen protection, and washed with toluene 5 times to remove excess styrene-ethyleneimine graft copolymer to obtain SiO2-coated PS-co-PEI core-shell structure supported catalyst. Then, 0.3 g of platinum acetate was added, reacted at 20°C for 20 hours, washed with toluene three times, and finally the solvent was drained to separate the final supported catalyst to obtain a catalyst for hydrogenated nitrile rubber synthesis. The catalyst is spherical particles containing 2% platinum acetate per gram, the weight content of PS-co-PEI in the carrier is 20%, the average diameter is 5 microns, and the particle size distribution is uniform.

[0032] The scanning electron microscope image of silicon dioxide powder is as follows Figure 3 A; a scanning electron microscope photograph of the catalyst used for the synthesis of hydrogenated nitrile rubber is shown in Figure 3 As shown in B.

[0033] Example 2 10.0g of dried oxide ceramic titanium dioxide (TiO2) powder was added to a water-free and oxygen-free reaction bottle. The entire reaction was carried out under nitrogen protection. 100mL of solvent chlorobenzene was added to the reaction bottle, and 2.0g of chloropropyltrimethoxysilane (CPTMO) coupling agent was slowly added to the suspension in the reaction bottle at 30°C, and the temperature was raised to 50°C and reacted for 5 hours. Filtered under nitrogen protection, washed with chlorobenzene 3 times to remove excess CPTMO coupling agent. Then, a chlorobenzene solution containing 8g of styrene-acrylamide copolymer (PS-co-PAM, a functional polymer with a nitrogen content of 5%) was slowly added to the reaction bottle. Then the temperature was raised to 80°C, stirred continuously for 10 hours, filtered under nitrogen protection, and washed with chlorobenzene 5 times to remove excess styrene-acrylamide copolymer to obtain a core-shell structure supported catalyst coated with SiO2 PS-co-PAM. Then, 0.5 g of platinum chloride was added, reacted at 20°C for 20 hours, washed with chlorobenzene three times, and finally the solvent was drained to separate the final supported catalyst to obtain a catalyst for hydrogenated nitrile rubber synthesis. The catalyst is spherical particles containing 4% platinum chloride per gram, the weight content of PS-co-PAM in the carrier is about 25%, the average diameter is 10 microns, and the particle size distribution is uniform.

[0034] Example 3 10.0g of dried oxide ceramic aluminum oxide (Al2O3) powder was added to a water-free and oxygen-free reaction bottle. The entire reaction was carried out under nitrogen protection. 100mL of solvent xylene was added to the reaction bottle, and 3.0g of aminopropyltriethoxysilane (KH550) coupling agent was slowly added to the suspension in the reaction bottle at 30°C, and the temperature was raised to 50°C and reacted for 5 hours. Filtered under nitrogen protection, washed with xylene 3 times to remove excess KH550 coupling agent. Then, a xylene solution containing 10g of styrene-vinyl pyrrolidone copolymer (PS-co-PVP, a functional polymer with a nitrogen content of 5%) was slowly added to the reaction bottle. Then the temperature was raised to 80°C, stirred continuously for 10 hours, filtered under nitrogen protection, and washed with xylene 5 times to remove excess styrene-vinyl pyrrolidone copolymer to obtain a core-shell structure supported catalyst of SiO2-coated PS-co-PVP. Then, 0.9 g of platinum sulfate was added, reacted at 20°C for 20 hours, washed with xylene three times, and finally the solvent was drained to separate the final supported catalyst to obtain a catalyst for hydrogenated nitrile rubber synthesis. The catalyst is spherical particles containing 8% platinum sulfate per gram, the weight content of PS-co-PAM in the carrier is about 30%, the average diameter is 20 microns, and the particle size distribution is uniform.

[0035] Comparative Example 1 10.0g of dried oxide ceramic aluminum oxide (Al2O3) powder was added to a water-free and oxygen-free reaction bottle. The entire reaction was carried out under nitrogen protection. 100mL of solvent xylene was added to the reaction bottle, and then a xylene solution containing 10g of styrene-vinyl pyrrolidone copolymer (PS-co-PVP, a functional polymer with a nitrogen content of 5%) was slowly added to the reaction bottle. Then the temperature was raised to 80°C, stirred continuously for 10 hours, filtered under nitrogen protection, washed with xylene 5 times to remove excess styrene-vinyl pyrrolidone copolymer, and a shell-core structure supported catalyst of SiO2-coated PS-co-PVP was obtained. Then 0.9g of platinum sulfate was added, reacted at 20°C for 20 hours, washed with xylene 3 times, and finally the solvent was drained to separate the final supported catalyst to obtain a catalyst for the synthesis of hydrogenated nitrile rubber. The catalyst is spherical particles containing 8% platinum sulfate per gram, the weight content of PS-co-PAM in the carrier is about 30%, the average diameter is 20 microns, and the particle size distribution is uniform.

[0036] Comparative Example 2 10.0g of dried oxide ceramic aluminum oxide (Al2O3) powder was added to a water-free and oxygen-free reaction bottle. The entire reaction was carried out under nitrogen protection. 100mL of solvent xylene was added to the reaction bottle, and 3.0g of aminopropyltriethoxysilane (KH550) coupling agent was slowly added to the suspension in the reaction bottle at 30°C, and the temperature was raised to 50°C and reacted for 5 hours. Filtered under nitrogen protection, washed with xylene 3 times to remove excess KH550 coupling agent. Then 0.9g of platinum sulfate was added, reacted at 20°C for 20 hours, washed with xylene 3 times, and finally the solvent was drained to separate the final loaded catalyst to obtain a catalyst for the synthesis of hydrogenated nitrile rubber. The catalyst is spherical particles containing 8% platinum sulfate per gram, with an average diameter of 20 microns and uniform particle size distribution.

[0037] Application Example 1 Add xylene solvent to the high-pressure hydrogenation kettle, replace with nitrogen, then add 0.1g of the catalyst for hydrogenated nitrile rubber synthesis in Example 1, then fill with hydrogen, control the hydrogenation temperature to 95°C, and hydrogen pressure to 5MPa for hydrogenation for 1.0 hour. Then add 10.0g NBR and heat to dissolve, continue stirring and reacting for 4.5 hours, and take samples to test the degree of hydrogenation according to the method specified in standard SH / T1762-2008 "Determination of residual unsaturation of rubber hydrogenated nitrile rubber (HNBR) by infrared spectroscopy". The test results are shown in Table 1.

[0038] Application Example 2 Add xylene solvent to the high-pressure hydrogenation kettle, replace with nitrogen, then add 0.1g of the catalyst for hydrogenated nitrile rubber synthesis in Example 2, then fill with hydrogen, control the hydrogenation temperature to 95°C, and hydrogen pressure to 5MPa for hydrogenation for 1.0 hour. Then add 10.0g NBR and heat to dissolve, continue stirring and reacting for 4.5 hours, and take samples to test the degree of hydrogenation according to the method specified in standard SH / T1762-2008 "Determination of residual unsaturation of rubber hydrogenated nitrile rubber (HNBR) by infrared spectroscopy". The test results are shown in Table 1.

[0039] Application Example 3 Add xylene solvent to the high-pressure hydrogenation kettle, replace with nitrogen, then add 0.1g of the catalyst for hydrogenated nitrile rubber synthesis in Example 3, then fill with hydrogen, control the hydrogenation temperature to 95°C, and hydrogen pressure to 5MPa for hydrogenation for 1.0 hour. Then add 10.0g NBR and heat to dissolve, continue stirring and reacting for 4.5 hours, and take samples to test the degree of hydrogenation according to the method specified in standard SH / T1762-2008 "Determination of residual unsaturation of rubber hydrogenated nitrile rubber (HNBR) by infrared spectroscopy". The test results are shown in Table 1.

[0040] Application Example 4 Add xylene solvent to the high-pressure hydrogenation kettle, replace with nitrogen, then add 0.1g of the catalyst for hydrogenated nitrile rubber synthesis in Comparative Example 1, then fill with hydrogen, control the hydrogenation temperature to 95°C, and hydrogen pressure to 5MPa for hydrogenation for 1.0 hour. Then add 10.0g NBR and heat to dissolve, continue stirring and reacting for 4.5 hours, and take samples to test the degree of hydrogenation according to the method specified in standard SH / T1762-2008 "Determination of residual unsaturation of rubber hydrogenated nitrile rubber (HNBR) by infrared spectroscopy". The test results are shown in Table 1.

[0041] Application Example 5 Add xylene solvent to the high-pressure hydrogenation kettle, replace with nitrogen, then add 0.1g of the catalyst for hydrogenated nitrile rubber synthesis in Comparative Example 2, then fill with hydrogen, control the hydrogenation temperature to 95°C, and hydrogen pressure to 5MPa for hydrogenation for 1.0 hour. Then add 10.0g NBR to heat and dissolve, continue stirring and reacting for 4.5 hours, and take samples to test the degree of hydrogenation according to the method specified in standard SH / T1762-2008 "Determination of residual unsaturation of rubber hydrogenated nitrile rubber (HNBR) by infrared spectroscopy". The test results are shown in Table 1.

[0042] Table 1 Hydrogenation degree test results Analyzing the data in Table 1, we can see that: The catalysts for hydrogenated nitrile rubber synthesis prepared in Examples 1 to 3 are applied to hydrogenated nitrile rubber synthesis, and have the advantages of small addition amount and uniform hydrogenation degree ≥ 96.8%.

[0043] Figure 3 Figure B is a scanning electron microscope photograph of the catalyst for hydrogenated nitrile rubber synthesis obtained in Example 1. It can be seen from Figure B that the catalyst is basically spherical, with an average diameter of 5 microns and a uniform particle size distribution.

[0044] The above embodiments are only used to explain the technical solutions of the present application rather than to limit them. Although the above embodiments provide a specific description of the present application, relevant technical personnel should understand that the specific implementation methods of the present application can still be modified or replaced by equivalents, and any modifications and equivalent replacements that do not depart from the spirit and scope of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a catalyst for the synthesis of hydrogenated nitrile rubber, characterized in that: The following steps are involved: S1. Oxide ceramic surface treatment: In anhydrous and oxygen-free environment, oxide ceramic powder is suspended in a solvent under the protection of inert gas, and a coupling agent is added dropwise under stirring. o C, stirring and reacting for 0.5-5 hours, then filtering the reaction solution and washing the filter cake with a solvent to remove the unreacted coupling agent to obtain a modified oxide ceramic powder; S2. Coupling of modified oxide ceramic powder and functional polymer: In anhydrous and oxygen-free environment and under the protection of inert gas, the modified oxide ceramic powder obtained in step S1 is resuspended in a solvent, and then a functional polymer is added. After continuous immersion at a temperature of 20-80° C. for 5-20 hours, the free functional polymer is washed away with a solvent to obtain a spherical granular carrier; S3, platinum group metal compound adsorption loading: in anhydrous and oxygen-free environment and under the protection of inert gas, the carrier obtained in step S2 is resuspended in a solvent, and then a platinum group metal compound is added, and the reaction is carried out at a temperature of 20-80° C. for 1-10 hours, and then the solvent is filtered out and washed with a sufficient amount of solvent to obtain a catalyst for the synthesis of hydrogenated nitrile rubber; The functional polymer is covered on the surface of the oxide ceramic powder through the anchoring effect of the coupling agent to form a core-shell structure carrier; the platinum group metal compound is loaded on the surface of the core-shell structure carrier through the functional group of the functional polymer to form a catalyst for the synthesis of hydrogenated nitrile rubber.

2. A method for preparing a catalyst for the synthesis of hydrogenated nitrile rubber according to claim 1, characterized in that: In step S1, the oxide ceramic powder is a spherical, granular, porous oxide ceramic powder, specifically selected from at least one of silicon oxide powder, aluminum oxide powder, titanium oxide powder and zirconium oxide powder.

3. A method for preparing a catalyst for the synthesis of hydrogenated nitrile rubber according to claim 1, characterized in that: In step S1, the coupling agent is a silane compound having a coupling effect and containing two or more reactive functional groups, and its chemical formula is L-(CH2)n-Si-R3, wherein: L is urea, amino, isocyanate, hydroxyl or chlorine, n is 0-6, and R is an alkyl or alkoxy group with 1-6 carbon atoms.

4. A method for preparing a catalyst for the synthesis of hydrogenated nitrile rubber according to claim 1, characterized in that: In step S2, the functional polymer is a styrene copolymer functional polymer containing hydroxyl, amide, pyridine, carboxyl, carbonyl, and amino functional groups, specifically selected from one of styrene-acrylamide copolymers, styrene-vinyl alcohol copolymers, styrene-acrylic acid copolymers, styrene-vinyl pyrrolidone copolymers, and styrene-ethyleneimine copolymers; the copolymers include four types: random, alternating, block, and graft copolymers.

5. A method for preparing a catalyst for the synthesis of hydrogenated nitrile rubber according to claim 1, characterized in that: In step S3, the platinum group metal compound is a platinum group metal compound with a chemical formula of BmHn, wherein m is 1.0 and n is 0.5-8.0; B is a platinum group metal having hydrogenation catalytic ability, specifically selected from one of ruthenium, rhodium, palladium, osmium, iridium and platinum metal; H is an inorganic or organic acid radical, specifically selected from one of chlorine, bromine, iodine, nitrate, sulfate, phosphate, acetate and propionate.

6. A method for preparing a catalyst for the synthesis of hydrogenated nitrile rubber according to claim 1, characterized in that: The solvent is one of toluene, xylene, chlorobenzene and methyl pyrrolidone.

7. A method for preparing a catalyst for the synthesis of hydrogenated nitrile rubber according to claim 1, characterized in that: In step S1, the mass ratio of the oxide ceramic powder to the coupling agent is 5:1 to 500:

1.

8. A method for preparing a catalyst for the synthesis of hydrogenated nitrile rubber according to claim 1, characterized in that: In step S2, the mass ratio of the modified oxide ceramic powder to the functional polymer is 1:2 to 20:

1.

9. A method for preparing a catalyst for the synthesis of hydrogenated nitrile rubber according to claim 1, characterized in that: In step S3, the mass ratio of the carrier Z to the platinum group metal compound is 5:1 to 100:

1.

10. A catalyst for the synthesis of hydrogenated nitrile rubber, characterized in that: The catalyst for synthesizing hydrogenated nitrile rubber is prepared by the preparation method of the catalyst for synthesizing hydrogenated nitrile rubber according to any one of claims 1 to 9.

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