Hydrogenation catalyst for styrene polymers and preparation method therefor, and hydrogenated styrene-butadiene-styrene block copolymer and preparation method therefor

Abstract

The present invention relates to the technical field of catalysts, and in particular to a hydrogenation catalyst for styrene polymers and a preparation method therefor, and a hydrogenated styrene-butadiene-styrene block copolymer and a preparation method therefor. The catalyst comprises a support and an active component supported on the support, wherein the active component contains a non-noble metal phosphide and noble metal clusters deposited on the non-noble metal phosphide. The hydrogenation catalyst for styrene polymers provided by the present invention has excellent hydrogen activation capability.

Description

Hydrogenation catalysts for styrene polymers and their preparation methods, hydrogenated styrene-butadiene-styrene block copolymers and their preparation methods

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411576786.1, filed on November 6, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of catalyst technology, specifically to a styrene-based polymer hydrogenation catalyst and its preparation method, and a hydrogenated styrene-butadiene-styrene block copolymer and its preparation method. Background Technology

[0004] Cyclic block copolymers (CBCs) are a novel type of polymer material obtained by fully hydrogenating a block copolymer of styrene and conjugated diene (typically a triblock styrene-butadiene-styrene block copolymer, SBS). Fully hydrogenated CBCs possess crystallizable polyethylene blocks and amorphous polycyclohexylethylene segments. By adjusting the ratio of soft to hard block structures in the copolymer, the mechanical and physical properties of CBC materials can be effectively controlled, thereby meeting the performance requirements of different products. Furthermore, CBC materials exhibit high transparency, high flowability, low density, low moisture absorption, low impurity content, excellent thermo-oxidative stability, and excellent UV transmittance. They are suitable for processing technologies such as extrusion, injection molding, and blow molding, and have great application potential in optical devices, capacitor separators, medical materials, and IC manufacturing devices.

[0005] [Revised according to Detailed Rule 26, 08.01.2025] Currently, the CBC production process can be broadly divided into two modules: anionic polymerization and catalytic hydrogenation. Anionic polymerization technology has developed rapidly since the concept of active anions was proposed in the 1950s and 60s. Anionic polymerization technology based on non-polar monomers such as styrene and butadiene is already a very mature process in the market. In contrast, full hydrogenation technology is the key challenge in the CBC production process, and a catalyst with excellent hydrogenation performance is the core of the entire technology. Currently, the hydrogenation technology for solution-polymerized styrene-butadiene rubber mainly focuses on achieving hydrogenation saturation of the butadiene fragment. There are very few reports on hydrogenation technology for the benzene ring structure in polymers. Globally, only Taiwan Polymer Co., Ltd. in China has achieved industrial-scale production of SBS full hydrogenation technology, putting into operation a CBC production line with an annual capacity of 5,000 tons in 2018, with the product series named ViviOn. TM .

[0006] [Amended according to Rule 26, 08.01.2025] Polymer hydrogenation catalysts can be divided into homogeneous catalysts and heterogeneous catalysts. Homogeneous catalysts, due to their poor thermal stability, typically have a catalytic temperature range of 60-120℃ and can only be used for the hydrogenation of carbon-carbon double bonds. Heterogeneous catalysts, on the other hand, are currently the mainstream hydrogenation catalysts for aromatic compounds. Related patents include: CN107250188A, CN103665282A, CN116948118A, CN1171913C, TWI660975B, CN101768229B, CN104511295B, EP0378104A2, CN116948063A, CN115364876A, etc. However, these catalysts have complex structural designs, high precious metal content, and high operating costs. Meanwhile, the heterogeneous hydrogenation catalysts currently reported in patents require long reaction times and high reaction temperatures during use, leading to side reactions such as molecular chain breakage, which affect the performance of the final CBC product. Taiwan Polymer's high-efficiency catalase hydrogenation technology, transferred from Dow Chemical, originated in the 1980s and 90s. This technology utilizes specially designed macroporous supports and highly loaded noble metal-based active centers, achieving excellent hydrogenation effects on SBS base gels. However, the preparation process of this type of catalyst is complex and also increases the production cost of CBC.

[0007] Therefore, it is of great significance to research and develop a low-cost, high-performance, low-loading noble metal catalyst for the hydrogenation of styrene polymers. Summary of the Invention

[0008] The purpose of this invention is to overcome the technical difficulties of hydrogenation of benzene ring structures and the problems of complex hydrogenation catalyst structure design, high precious metal content, and high cost in the prior art. This invention proposes a hydrogenation catalyst for styrene polymers and its preparation method. This hydrogenation catalyst has excellent catalytic activity. For example, when used in the hydrogenation of styrene-butadiene-styrene block copolymers, it can achieve a high degree of hydrogenation.

[0009] To achieve the above objectives, a first aspect of the present invention provides a hydrogenation catalyst for styrene-based polymers, the hydrogenation catalyst comprising a support and an active component supported on the support, the active component containing a non-precious metal phosphide and a noble metal atom cluster deposited on the non-precious metal phosphide.

[0010] A second aspect of the present invention provides a method for preparing a hydrogenation catalyst for styrene polymers as described in the first aspect of the present invention, the method comprising:

[0011] S1 contains a solution of a non-precious metal source, a structure modifier, a phosphorus-containing reducing agent, and water. When the solution is brought into contact with a carrier, a first precipitation reaction is carried out to obtain the first material.

[0012] In the presence of a reducing agent, S2 undergoes a second precipitation reaction with a precious metal source;

[0013] S3 involves drying and calcining the solid phase from the second precipitation reaction.

[0014] A third aspect of the present invention provides a hydrogenated styrene-butadiene-styrene block copolymer, the preparation method of which includes: subjecting the styrene-butadiene-styrene block copolymer to a hydrogenation reaction in the presence of a solvent and the hydrogenation catalyst described in the first aspect of the present invention.

[0015] The fourth aspect of the present invention provides a hydrogenated styrene-butadiene-styrene block copolymer, which is prepared by the preparation method described in the third aspect of the present invention.

[0016] Through the above technical solution, the hydrogenation catalyst for styrene polymers provided by the present invention has excellent hydrogen activation ability. Specifically, the hydrogenation catalyst of the present invention can achieve efficient hydrogenation of styrene-butadiene-styrene block copolymers, and the hydrogenation conditions are mild and the structure of the block copolymer is minimally altered, making it suitable for large-scale industrial production. Attached Figure Description

[0017] Figure 1 is a SEM image of the hydrogenation catalyst obtained in Example 1;

[0018] Figure 2 is the H2-TPR spectrum of the hydrogenation catalyst obtained in Example 1;

[0019] Figure 3 shows the hydrogenated polymer obtained in Example 1. 1 H NMR spectrum;

[0020] Figure 4 is a SEM image of the hydrogenation catalyst obtained in Example 2;

[0021] Figure 5 is a SEM image of the hydrogenation catalyst obtained in Example 3. Detailed Implementation

[0022] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0023] The first aspect of the present invention provides a hydrogenation catalyst for styrene-based polymers, the hydrogenation catalyst comprising a support and an active component supported on the support, the active component containing a non-precious metal phosphide and a noble metal atom cluster deposited on the non-precious metal phosphide.

[0024] Compared to traditional noble metal catalysts, the hydrogenation catalyst for styrene polymers in this invention exhibits superior hydrogenation capability for the benzene ring in styrene polymers, achieving a degree of hydrogenation of over 99%, and also demonstrates excellent reusability. This is likely because the non-noble metal phosphide possesses an electronic state distribution similar to that of noble metals, exhibiting both metallic and semiconductor properties. Furthermore, the noble metal in the hydrogenation catalyst is deposited atomically on the non-noble metal phosphide, demonstrating excellent activation ability for hydrogen and exhibiting superior performance in the catalytic hydrogenation of ethylene polymers.

[0025] According to a preferred embodiment of the present invention, the noble metal atom clusters deposited on the non-noble metal phosphide refer to the hydrogenation catalyst specifically in the form of large particles (noble metal atom clusters) deposited and covered on nanoparticles (non-noble metal phosphide).

[0026] According to one embodiment of the present invention, the particle size of the nanoparticles is 1-50 nm, preferably 1-5 nm.

[0027] The microstructure and nanoparticle size of the hydrogenation catalyst in this invention can be observed using a scanning electron microscope.

[0028] Styrene polymers are a class of polymers formed by polymerizing styrene-containing monomers. According to a preferred embodiment of the present invention, the styrene polymer is selected from at least one copolymer produced by copolymerizing at least one styrene comonomer and at least one C4-C8 conjugated diene monomer.

[0029] According to a preferred embodiment of the present invention, the styrene polymer has a block structure.

[0030] In this invention, "block structure" refers to a polymer chain composed of different monomer segments, each segment typically consisting of one or more repeating monomers of the same type, and these segments are spatially interconnected. According to a preferred embodiment of the invention, the structure of the styrene polymer is triblock.

[0031] In this invention, styrene-based polymers include styrene-butadiene-styrene block copolymers and / or styrene-isoprene-styrene block copolymers. The hydrogenation catalyst in this invention exhibits excellent catalytic hydrogenation ability for block copolymers obtained from the polymerization of monomers such as styrene, butadiene, and isoprene. This invention uses styrene-butadiene-styrene block copolymers as an example, but the invention is not limited thereto.

[0032] According to a preferred embodiment of the present invention, the carrier is selected from porous carriers and / or non-porous carriers, preferably non-porous carriers.

[0033] In this invention, a porous support refers to a support with a porous structure, while a non-porous support refers to a support whose internal structure has no pore distribution (i.e., no void structure). The inventors of this invention have discovered that using a non-porous support can enhance the catalytic hydrogenation capacity and cycle life of the hydrogenation catalyst for polymers. This is because polymers are coiled during catalysis, with large free rotation radii and high mass transfer resistance, making it difficult for substrate molecules to contact the active sites of the hydrogenation catalyst. Furthermore, once the substrate molecules have reacted with the catalyst, if the catalyst surface has numerous pores, reaction products are easily trapped in the pores, making timely desorption difficult and masking the active sites. This invention has found that using a non-porous support can, on the one hand, prevent precious metals from settling within the pores and causing activity loss, thus fully exposing the active sites; on the other hand, it can also prevent reaction product deposition, improving the catalyst's cycle life.

[0034] In this invention, hydrogenation catalysts with different particle sizes can be selected according to different application needs, that is, supports with different particle sizes can be selected accordingly. According to a preferred embodiment of this invention, the diameter of the support is 100nm-100μm, for example, the diameter of the support is 100nm, 200nm, 400nm, 800nm, 1000nm, 1500nm, 1800nm, 2μm, 5μm, 10μm, 50μm, 100μm, or any two of the above values, preferably 500nm-50μm.

[0035] In this invention, the specific type of carrier is not particularly limited as long as the purpose of this invention can be achieved. According to a preferred embodiment of this invention, the carrier is selected from at least one of inorganic oxides, natural minerals and carbonaceous materials.

[0036] According to a preferred embodiment of the present invention, the inorganic oxide is selected from at least one of silicon dioxide, aluminum oxide, titanium dioxide, cerium oxide, zirconium oxide and magnesium oxide, preferably titanium dioxide.

[0037] According to a preferred embodiment of the present invention, the natural mineral is selected from at least one of diatomite, clay, diatoms and pumice.

[0038] According to a preferred embodiment of the present invention, the carbon material is selected from activated carbon and / or graphite.

[0039] In this invention, non-precious metals refer to metallic elements other than precious metals. According to a preferred embodiment of this invention, the non-precious metals in the non-precious metal phosphide are selected from transition metal elements and / or lanthanide elements.

[0040] In this invention, transition metal elements refer to a series of metallic elements in the d-block and ds-block of the periodic table. d-block elements include elements of groups IIIB-VIIB and VIII of the periodic table, excluding lanthanides, actinides, and noble metals. The ds-block includes elements of groups IB-IIB of the periodic table. According to a preferred embodiment of the invention, the transition metal elements are selected from group VIB, group VIII, and group IIIB elements.

[0041] In this invention, there are no special restrictions on the types of Group VIB elements as long as the purpose of this invention can be achieved. Group VIB elements that can be listed in this invention include chromium, molybdenum, tungsten, etc. According to a preferred embodiment of this invention, the Group VIB elements are selected from molybdenum and / or tungsten.

[0042] In this invention, there are no special restrictions on the types of Group VIII elements as long as the purpose of this invention can be achieved. The Group VIII elements that can be listed in this invention are at least one of iron, nickel, cobalt, copper and manganese.

[0043] In this invention, there are no special restrictions on the types of Group VIII elements as long as the purpose of this invention can be achieved. The Group IIIB elements that can be listed in this invention include scandium and / or yttrium. According to a preferred embodiment of this invention, the Group IIIB elements are selected from yttrium.

[0044] According to a particularly preferred embodiment of the present invention, the non-precious metal contains at least nickel.

[0045] According to one embodiment of the present invention, the lanthanide element is selected from at least one of cerium, lanthanum and praseodymium.

[0046] According to one embodiment of the present invention, the precious metal is selected from at least one of iridium, ruthenium, rhodium, platinum and palladium.

[0047] According to a particularly preferred embodiment of the invention, the precious metal contains at least platinum.

[0048] According to a preferred embodiment of the present invention, the molar ratio of non-precious metal phosphide to phosphorus on the surface of the hydrogenation catalyst is 2-6:1, for example 2:1, 2.2:1, 2.6:1, 2.9:1, 3.9:1, 4:1, 4.1:1, 4.2:1, 4.5:1, 5:1, 5.1:1, 5.5:1, 6:1, preferably 3.5-4.5:1.

[0049] In this invention, the molar ratio of non-precious metal phosphides to phosphorus on the surface of the hydrogenation catalyst was determined by XPS. The depth measured using conventional XPS in this invention is approximately 5-20 nm. The hydrogenation catalyst of the aforementioned embodiments exhibits better catalytic activity.

[0050] According to a preferred embodiment of the present invention, based on the total mass of the hydrogenation catalyst, the content of non-precious metals, calculated by element, is 5-70 wt%, for example, the content of non-precious metals is 5 wt%, 10 wt%, 18 wt%, 21 wt%, 26 wt%, 28 wt%, 50 wt%, 60 wt%, 70 wt%, or any combination of two of the above values, preferably 10-50 wt%, more preferably 10-40 wt%.

[0051] In this invention, the content of non-precious metals is calculated based on the feeding ratio, wherein non-precious metals refer to the non-precious metals in non-precious metal phosphates.

[0052] In this invention, the content of precious metals in the hydrogenation catalyst is not particularly limited as long as the purpose of this invention can be achieved. According to a preferred embodiment of this invention, based on the total mass of the hydrogenation catalyst, the content of the precious metals is 0.05-2 wt%, for example, the content of precious metals is 0.05 wt%, 0.10 wt%, 0.24 wt%, 0.42 wt%, 0.44 wt%, 0.48 wt%, 0.55 wt%, 0.65 wt%, 0.10 wt%, 0.2 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, or any two of the above values, preferably 0.1-1 wt%, more preferably 0.2-0.5 wt%.

[0053] In this invention, the precious metal content is calculated based on the feed ratio. The hydrogenation catalyst of this invention has a low precious metal loading and highly dispersed precious metals, which is beneficial for the full exposure of the precious metal active sites. In addition, the low precious metal content can also reduce the production cost of the hydrogenation catalyst.

[0054] In this invention, the content of the active component is not particularly limited as long as the purpose of this invention can be achieved. According to a preferred embodiment of this invention, based on the total mass of the hydrogenation catalyst, the content of the active component is 5-95 wt%, for example, the content of the active component is 5 wt%, 10 wt%, 24 wt%, 45 wt%, 48 wt%, 55 wt%, 65 wt%, 70 wt%, 80 wt%, 95 wt%, or any range of two of the above values.

[0055] According to a preferred embodiment of the present invention, based on the total mass of the hydrogenation catalyst, the content of the support is 5-95 wt%, for example, the content of the support is 5 wt%, 10 wt%, 25 wt%, 34 wt%, 45 wt%, 48 wt%, 51 wt%, 76 wt%, 80 wt%, 95 wt%, or any combination of two of the above values, preferably 29-90 wt%, more preferably 49.5-90 wt%.

[0056] A second aspect of the present invention provides a method for preparing a hydrogenation catalyst for styrene polymers as described in the first aspect of the present invention, the method comprising:

[0057] S1 contains a solution of a non-precious metal source, a structure modifier, a phosphorus-containing reducing agent, and water. When the solution is brought into contact with a carrier, a first precipitation reaction is carried out to obtain the first material.

[0058] In the presence of a reducing agent, S2 undergoes a second precipitation reaction with a precious metal source;

[0059] S3 involves drying and calcining the solid phase from the second precipitation reaction.

[0060] The hydrogenation catalyst prepared by this invention has excellent hydrogenation catalytic activity and reusability.

[0061] In this invention, phosphorus-containing reducing agents and reducing agents are selected to reduce metal elements in the solution and cause them to deposit on the surface of the support. The morphology and elemental composition ratio (metal element to phosphorus element ratio) of the deposited layer can be adjusted by structural regulators and solution pH to achieve effective adjustment of the hydrogenation catalyst structure.

[0062] The structure modifier in this invention is used to complex non-noble metal ions. There are no special limitations on the type of structure modifier as long as it achieves the purpose of this invention. According to a preferred embodiment of this invention, in step S1, the structure modifier is selected from compounds containing acid radicals and / or ammonium ions. Preferably, the structure modifier is selected from at least one corresponding alkali metal salt of acetic acid, citric acid, ethylenediaminetetraacetic acid, oxalic acid, lactic acid, malic acid, and tannic acid. The acid radicals and / or ammonium ions, by coordinating and complexing with non-noble metals, change the reduction potential of the non-noble metals, thus affecting their deposition behavior on the carrier surface. Sodium acetate is used as an example of the structure modifier in this invention to illustrate its advantages, but this does not constitute a limitation of the invention.

[0063] According to a preferred embodiment of the present invention, in step S1, the phosphorus-containing reducing agent is selected from at least one of hypophosphite, hypophosphite and phosphite, preferably selected from hypophosphite. The present invention uses sodium hypophosphite as an example to illustrate the advantages of the present invention, but does not represent a limitation of the present invention.

[0064] According to a preferred embodiment of the present invention, in step S2, the reducing agent includes at least one selected from hypophosphite, hypophosphite, phosphite, sodium borohydride, ascorbic acid, ascorbate, and tartrate. The use of sodium hypophosphite as an example of the reducing agent in step S2 of the present invention illustrates the advantages of the invention, but does not represent a limitation thereof.

[0065] According to one embodiment of the present invention, the mass ratio of the structure modifier to the non-precious metal source is 0.3-3:1, for example, 0.3:1, 0.5:1, 0.7:1, 0.9:1, 1.1:1, 1.5:1, 1.8:1, 2:1, 2.2:1, 2.5:1, 2.8:1, 3:1, or any range of two of the above ratios.

[0066] According to a preferred embodiment of the present invention, the non-precious metal source, calculated as non-precious metal element, has a content of 2-100 g / L in the solution, for example, the content of the non-precious metal source is 2 g / L, 5 g / L, 12 g / L, 13 g / L, 17 g / L, 30 g / L, 50 g / L, 70 g / L, 80 g / L, 90 g / L, 100 g / L, or any range of two of the above values.

[0067] According to a preferred embodiment of the present invention, the phosphorus-containing reducing agent, calculated as elemental phosphorus, has a content of 1-50 g / L in the solution, for example, the content of the phosphorus-containing reducing agent is 1 g / L, 5 g / L, 10 g / L, 15 g / L, 16 g / L, 17 g / L, 20 g / L, 24 g / L, 30 g / L, 40 g / L, 50 g / L, or any range of two of the above values.

[0068] According to a preferred embodiment of the present invention, the content of the carrier in the solution is 10-200 g / L, for example, the content of the carrier is 10 g / L, 16 g / L, 20 g / L, 31 g / L, 32 g / L, 40 g / L, 55 g / L, 65 g / L, 75 g / L, 89 g / L, 100 g / L, 120 g / L, 150 g / L, 200 g / L, or any range of two of the above values.

[0069] According to a preferred embodiment of the present invention, the non-precious metal source is calculated as non-precious metal elements, the precious metal source is calculated as precious metal elements, and the mass ratio of the precious metal source to the non-precious metal source is 0.001-0.1:1, for example, 0.001:1, 0.003:1, 0.005:1, 0.008:1, 0.001:1, 0.005:1, 0.008:1, 0.01:1, 0.03:1, 0.05:1, 0.08:1, 0.1:1, or any range of two of the above ratios.

[0070] According to a preferred embodiment of the present invention, the mass ratio of the reducing agent to the precious metal source is 10-15:1, calculated as precious metal element.

[0071] According to a preferred embodiment of the present invention, the reaction conditions for the first precipitate and the second precipitate each independently include: being carried out under an inert atmosphere.

[0072] In this invention, an inert atmosphere refers to an atmosphere that does not contain any substances that affect the corresponding reaction. There are no special restrictions on the type of inert gas as long as the purpose of this invention can be achieved. According to a preferred embodiment of this invention, the inert gas is nitrogen. This invention allows for the stable preparation of hydrogenation catalysts with consistent quality and performance by carrying out the corresponding precipitation reaction under an inert atmosphere.

[0073] According to one embodiment of the present invention, the reaction conditions for the first precipitate and the second precipitate each independently include: a pH of 8-14, preferably a pH of 8-10. In this invention, the pH can be adjusted in any way, for example, by adjusting the pH of the solution with an alkaline solution. In this invention, the morphology and elemental composition ratio (ratio of metal elements to phosphorus elements) of the deposited layer can be adjusted by adjusting the pH.

[0074] According to one embodiment of the present invention, the reaction conditions for the first precipitate and the second precipitate each independently include: a reaction temperature of 20-90°C, for example, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C or 90°C.

[0075] The reaction time for the first precipitation in this invention can be adjusted according to the corresponding temperature. According to a preferred embodiment of this invention, the reaction time for the first precipitation is 30-180 min.

[0076] The reaction time for the second precipitate in this invention can be adjusted according to the corresponding temperature. According to a preferred embodiment of this invention, the reaction time for the second precipitate is 10-120 min.

[0077] According to one embodiment of the present invention, in step S3, the calcination conditions include: being carried out under a reducing atmosphere. The reducing atmosphere in the present invention can be any reducing atmosphere in the art, such as hydrogen. The solid phase obtained from the second precipitation reaction in the present invention can be calcined in a reducing atmosphere (e.g., H2 atmosphere) to obtain the final hydrogenation catalyst.

[0078] According to a preferred embodiment of the present invention, in step S3, the calcination conditions include a temperature of 200-650°C, preferably 400-500°C.

[0079] In this invention, the roasting time can be adjusted according to the corresponding roasting temperature. According to a preferred embodiment of this invention, in step S3, the roasting conditions include: a time of 1-10 hours, preferably 2-4 hours.

[0080] The drying process in step S3 of this invention can be carried out using any method in the art, and will not be described in detail here.

[0081] In one specific embodiment of the present invention for preparing a hydrogenation catalyst: a support is dispersed in water, followed by the addition of a non-precious metal source, a structure modifier, and a phosphorus-containing reducing agent, which are then fully dissolved. The pH of the solution is adjusted using an alkaline solution (e.g., a 20 wt% sodium hydroxide aqueous solution). The mixture is heated under inert gas protection for a certain period of time to obtain a first material. Subsequently, a precious metal source and a reducing agent are added to the system, and the mixture is reacted at a certain temperature for a certain period of time to obtain a solid phase. The solid phase is then filtered, washed, and dried to obtain a catalyst precursor. The catalyst precursor is calcined in a reducing atmosphere at a certain temperature for a certain period of time to obtain the final hydrogenation catalyst.

[0082] In this invention, hydrogenated styrene-butadiene-styrene block copolymer is used as an example to illustrate the advantages of the hydrogenation catalyst for styrene polymers in this invention. Specifically, the third aspect of this invention provides a method for preparing hydrogenated styrene-butadiene-styrene block copolymer, which includes: hydrogenating the styrene-butadiene-styrene block copolymer in the presence of a solvent and the hydrogenation catalyst described in the first aspect of this invention.

[0083] The hydrogenation catalyst of this invention exhibits excellent catalytic hydrogenation capability for styrene-butadiene-styrene block copolymers. It enables highly efficient hydrogenation of styrene-butadiene-styrene block copolymers with minimal alteration to the block polymer structure, making it suitable for large-scale industrial production.

[0084] In this invention, the conditions for the hydrogenation reaction are not particularly limited as long as the purpose of this invention can be achieved. According to a preferred embodiment of this invention, the conditions for the hydrogenation reaction include: the pressure of hydrogen gas is 2-12 MPa, for example, 2 MPa, 4 MPa, 6 MPa, 8 MPa, 10 MPa or 12 MPa.

[0085] According to a preferred embodiment of the present invention, the conditions for the hydrogenation reaction include: a reaction temperature of 100-250°C, for example, 100°C, 140°C, 160°C, 200°C or 250°C.

[0086] In this invention, the hydrogenation reaction time can be adjusted according to the corresponding reaction temperature. According to a preferred embodiment of this invention, the conditions for the hydrogenation reaction include: a reaction time of 0.5-24h, for example, 0.5h, 1h, 3h, 6h, 8h, 12h, 16h, 20h or 23h.

[0087] The preparation of hydrogenated styrene-butadiene-styrene block copolymers using the hydrogenation catalyst of this invention has broad prospects due to its mild hydrogenation reaction conditions, simple process flow, complete hydrogenation of reactants, high product yield, and minimal changes in product structure.

[0088] The styrene-butadiene-styrene block copolymer in this invention can be any styrene-butadiene-styrene block copolymer in the art. According to a preferred embodiment of this invention, the number average molecular weight of the styrene-butadiene-styrene block copolymer is not higher than 100,000, preferably not higher than 100,000, for example, 100,000, 80,000, 60,000, 50,000, etc.

[0089] In this invention, there is no particular limitation on the amount of hydrogenation catalyst used. According to a preferred embodiment of the invention, the mass ratio of the hydrogenation catalyst to the styrene-butadiene-styrene block copolymer is 0.1-3:1, for example, 0.1:1, 0.3:1, 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 2:1 or 3:1.

[0090] According to the present invention, the styrene-butadiene-styrene block copolymer is generally in a solid state. Its solvent can swell and disperse the styrene-butadiene-styrene block copolymer to form a gel, thereby promoting the hydrogenation reaction. As long as the hydrogenation reaction is promoted, the amount of solvent used is not particularly limited. According to a preferred embodiment of the present invention, the mass ratio of the styrene-butadiene-styrene block copolymer to the solvent is 0.02-0.25:1, for example, 0.02:1, 0.05:1, 0.08:1, 0.1:1, 0.15:1, 0.2:1 or 0.25:1.

[0091] The solvent used in this invention is not particularly limited, as long as it can enable the styrene-butadiene-styrene block copolymer to form a liquid. According to a preferred embodiment of the invention, the solvent is selected from C5-C10 alkanes and / or C5-C10 cycloalkanes.

[0092] According to a preferred embodiment of the present invention, the C5-C10 alkane includes at least one selected from n-pentane, n-hexane, isooctane, and hexane.

[0093] According to a preferred embodiment of the present invention, the C5-C10 cycloalkane includes at least one of cyclopentane, cyclohexane, cyclooctane, cycloheptane, and decahydronaphthalene.

[0094] According to a preferred embodiment of the present invention, in preparing hydrogenated styrene-butadiene-styrene block copolymer: a hydrogenation catalyst, styrene-butadiene-styrene block copolymer and solvent are mixed in a hydrogenation reactor. After the reactor is purged with nitrogen several times, hydrogen gas at a certain pressure is introduced. After the reactor is heated to the hydrogenation temperature, the reaction is carried out for several hours to obtain a material containing hydrogenated styrene-butadiene-styrene block copolymer.

[0095] In this invention, the material obtained by hydrogenation reaction contains a solvent. The rubber particles in the hydrogenation product can be aggregated and precipitated using conventional methods in the art, which is beneficial for separating the hydrogenated styrene-butadiene-styrene block copolymer. For example, ethanol coagulation (i.e., using ethanol as a coagulant) can be used to aggregate and precipitate the hydrogenated styrene-butadiene-styrene block copolymer in the material containing the hydrogenated styrene-butadiene-styrene block copolymer. Then, the hydrogenated styrene-butadiene-styrene block copolymer can be separated by methods such as centrifugal sedimentation gravity filtration, pressure filtration, vacuum filtration, and centrifugal filtration.

[0096] The hydrogenation catalyst in this invention has excellent reusability. It can also be recycled and reused, for example, by combining a candle filter with a pressure filtration method to achieve efficient separation and recovery of the hydrogenation catalyst.

[0097] The fourth aspect of the present invention provides a hydrogenated styrene-butadiene-styrene block copolymer, wherein the hydrogenated styrene-butadiene-styrene block copolymer is prepared by the preparation method described in the third aspect of the present invention.

[0098] The present invention will be described in detail below through embodiments. The following embodiments include:

[0099] The hydrogenation catalyst was characterized using the following instruments:

[0100] The phase composition was determined using Cu Kα diffractometer with a Bruker-D2 (30kV, 10mA) instrument.

[0101] The morphology of the hydrogenation catalyst was observed using a Hitachi S4800 field emission scanning electron microscope.

[0102] The atomic distribution of noble metals was observed using a Tecnai G2 F20 S-Twin field emission transmission electron microscope (accelerating voltage 200kV).

[0103] The elemental composition was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) using a Perkin Elmer ICP-8000DV instrument.

[0104] The sample was scanned and recorded using a Scientific Escalab 250Xi spectrometer (Thermo) under vacuum conditions to determine the elemental composition and valence state.

[0105] H2-TPR testing was performed using an AutoChem II 2920 instrument (Micromeritics). First, the instrument was purged at 150°C for 1 hour in an Ar atmosphere for activation. Then, the temperature was lowered and the instrument was cooled. Finally, TPR reduction tests were performed using 5% H2 / Ar gas in the range of room temperature to 750°C.

[0106] The polymer after hydrogenation was characterized using the following instruments: US Varian INOVA 400 NMR nuclear magnetic resonance 1H-NMR was used for qualitative and quantitative analysis of the polymer composition sequence distribution, microstructure, and degree of hydrogenation (calculated as (molar number of benzene rings remaining after hydrogenation * 3 + molar number of carbon-carbon double bonds remaining after hydrogenation) / (molar number of benzene rings remaining before hydrogenation * 3 + molar number of carbon-carbon double bonds remaining before hydrogenation)).

[0107] The molecular weight and molecular weight distribution of the polymers were analyzed using a TDA302 gel permeation chromatography (GPC) system from Viscotek, USA.

[0108] Example 1

[0109] 12 g of non-porous TiO2 (300 nm in diameter) was dispersed in 100 mL of water, and 6.75 g of NiCl2·6H2O, 8.3 g of CH3COONa·3H2O, and 6 g of NaH2PO2·H2O were added and stirred to dissolve. The pH of the system was then adjusted to 8 with a 20 wt% NaOH aqueous solution. The system was then protected with nitrogen and heated to 40 °C for 90 min. Subsequently, 1 mL of a 100 mg / mL H2PtCl6·6H2O solution and 0.5 g of NaH2PO2·H2O were added to the system, and the reaction was continued for another 30 min. After the reaction was complete, the mixture was filtered, washed, and dried to obtain the catalyst precursor. The catalyst precursor was placed in a hydrogen gas flow (50 mL / min) and calcined at 300 °C for 2 hours to obtain the hydrogenation catalyst.

[0110] Hydrogenation test: 200 mL of a 5 wt% SBS base solution (50 ± 3 wt% styrene, 50 ± 3 wt% butadiene, Mn = 63197, solvent: cyclopentane) was added to a 500 mL reactor. Then, 7.5 g of hydrogenation catalyst was added, and the solution was replaced with 1.5 MPa N2 at least three times. H2 was then introduced at 6 MPa at room temperature, and the temperature was raised to 200 °C for 6 hours. After the reaction, the solution was allowed to cool naturally, and the hydrogenated polymer (i.e., hydrogenated SBS) was obtained by condensation with ethanol. The number average molecular weight was 52330, and the molecular weight distribution was 1.02.

[0111] The SEM image of the hydrogenation catalyst is shown in Figure 1, the H2-TPR spectrum of the hydrogenation catalyst is shown in Figure 2, and the hydrogenated polymer obtained after catalysis... 1The H NMR spectrum is shown in Figure 3.

[0112] Figure 1 shows that the catalyst has a uniform non-precious metal phosphide layer covering the surface of the TiO2 support.

[0113] Figure 2 shows that the catalyst has good activation ability for H2 in the low temperature range below 250℃;

[0114] Through Figure 3 1 The H-NMR spectrum showed that the hydrogenated polymer block copolymer (i.e., hydrogenated SBS) did not show any signal peaks in the 6-8 ppm and 4-6 ppm regions, indicating that the SBS base adhesive had been completely hydrogenated and did not have benzene rings or carbon-carbon double bond structures.

[0115] XPS data shows that P and Ni exist in the form of nickel-phosphide, and FE-TEM shows that Pt is deposited on the phosphide in the form of atomic clusters.

[0116] The content of non-precious metal phosphides on the surface of the hydrogenation catalyst / the content of phosphorus (molar ratio) and the hydrogenation test results are shown in Table 1.

[0117] Example 2

[0118] 12 g of non-porous SiO2 (3000 nm in diameter) was dispersed in 100 mL of water. 6.75 g of NiCl2·6H2O, 8.3 g of CH3COONa·3H2O, and 6 g of NaH2PO2·H2O were added and stirred until dissolved. The pH of the system was then adjusted to 8 with a 20 wt% NaOH aqueous solution. The system was then protected with nitrogen and heated to 40 °C for 90 min. Subsequently, 1 mL of a 100 mg / mL H2PtCl6·6H2O solution and 0.5 g of NaH2PO2·H2O were added, and the reaction was continued for another 30 min. After the reaction was complete, the mixture was filtered, washed, and dried to obtain the catalyst precursor. The catalyst precursor was placed in a hydrogen gas flow (50 mL / min) and calcined at 300 °C for 2 hours to obtain the hydrogenation catalyst.

[0119] Hydrogenation test: 200 mL of a 5 wt% SBS base solution (50 ± 3 wt% styrene, 50 ± 3 wt% butadiene, Mn = 63197, solvent: cyclopentane) was added to a 500 mL reactor. Then, 7.7 g of catalyst was added, and the mixture was replaced with 1.5 MPa N2 at least three times. H2 was then introduced at 6 MPa at room temperature, and the temperature was raised to 200 °C for 6 hours. After the reaction, the mixture was allowed to cool naturally, and hydrogenated SBS was obtained by condensation with ethanol. The number average molecular weight was 52372, and the molecular weight distribution was 1.01. The SEM image of the hydrogenation catalyst is shown in Figure 4.

[0120] SEM analysis of the hydrogenation catalyst revealed that the non-precious metal phosphides were extremely unevenly dispersed and not completely deposited on the support surface; some phosphides agglomerated to form particles.

[0121] XPS energy dispersive spectroscopy revealed that P and Ni exist in the form of nickel-phosphide, while FE-TEM showed that Pt is deposited on the phosphide in the form of atomic clusters.

[0122] The content of non-precious metal phosphides on the surface of the hydrogenation catalyst / the content of phosphorus (molar ratio) and the hydrogenation test results are shown in Table 1.

[0123] Example 3

[0124] 12g of diatomaceous earth (approximately 50μm in diameter, with an average pore diameter of approximately 300nm) was dispersed in 100mL of water. 6.75g of NiCl₂·6H₂O, 8.3g of CH₃COONa·3H₂O, and 6g of NaH₂PO₂·H₂O were added and stirred until dissolved. The pH of the system was then adjusted to 8 using a 20wt% NaOH aqueous solution. The system was then protected under nitrogen atmosphere and heated to 40℃ for 90min. Subsequently, 1mL of a 100mg / mL H₂PtCl₆·6H₂O solution and 0.5g of NaH₂PO₂·H₂O were added, and the reaction continued for another 30min. After the reaction was complete, the mixture was filtered, washed, and dried to obtain the catalyst precursor. The catalyst precursor was placed in a hydrogen gas flow (50mL / min) and calcined at 300℃ for 2 hours to obtain the hydrogenation catalyst.

[0125] Hydrogenation test: 200 mL of a 5 wt% SBS base solution (50 ± 3 wt% styrene, 50 ± 3 wt% butadiene, Mn = 63197, solvent: cyclopentane) was added to a 500 mL reactor. Then, 7.5 g of catalyst was added, and the mixture was replaced with 1.5 MPa N2 at least three times. H2 was then introduced at 6 MPa at room temperature, and the temperature was raised to 200 °C and reacted for 6 hours. After the reaction, the mixture was allowed to cool naturally, and hydrogenated SBS was obtained by condensation with ethanol. The number average molecular weight was 53753, and the molecular weight distribution was 1.01.

[0126] The SEM image of the hydrogenation catalyst is shown in Figure 5.

[0127] SEM images of the hydrogenation catalyst revealed that the non-precious metal phosphides did not cover the support surface uniformly, with some phosphides agglomerating to form particles.

[0128] XPS shows that P and Ni exist in the form of nickel-phosphide, while FE-TEM shows that Pt is deposited on phosphide or diatomite in the form of atomic clusters.

[0129] The content of non-precious metal phosphides on the surface of the hydrogenation catalyst / the content of phosphorus (molar ratio) and the hydrogenation test results are shown in Table 1.

[0130] Example 4

[0131] 12 g of non-porous TiO2 (300 nm in diameter) was dispersed in 300 mL of water. 20.25 g of NiCl2·6H2O, 24.9 g of CH3COONa·3H2O, and 18 g of NaH2PO2·H2O were added and stirred until dissolved. The pH of the system was then adjusted to approximately 8 using a 20 wt% NaOH aqueous solution. The system was then protected with nitrogen and heated to 40 °C for 90 min. Subsequently, 3 mL of a 100 mg / mL H2PtCl6·6H2O solution and 1.5 g of NaH2PO2·H2O were added, and the reaction continued for another 30 min. After the reaction was complete, the mixture was filtered, washed, and dried to obtain the catalyst precursor. The catalyst precursor was placed in a hydrogen gas flow (50 mL / min) and calcined at 300 °C for 2 hours to obtain the hydrogenation catalyst.

[0132] Hydrogenation test: 200 mL of a 5 wt% SBS base solution (50 ± 3 wt% styrene, 50 ± 3 wt% butadiene, Mn = 63197, solvent: cyclopentane) was added to a 500 mL reactor. Then, 7.5 g of hydrogenation catalyst was added, and the solution was replaced with 1.5 MPa N2 at least three times. H2 was then introduced at 6 MPa at room temperature, and the temperature was raised to 200 °C and reacted for 6 hours. After the reaction, the solution was allowed to cool naturally, and hydrogenated SBS was obtained by condensation with ethanol. The number average molecular weight was 52218, and the molecular weight distribution was 1.01.

[0133] The SEM of the hydrogenation catalyst is similar to that in Figure 1. The SEM of the hydrogenation catalyst shows that the TiO2 support surface is covered with a uniform layer of non-precious metal phosphide.

[0134] XPS shows that P and Ni exist in the form of nickel-phosphide, and FE-TEM shows that Pt is deposited on the phosphide in the form of atomic clusters.

[0135] The content of non-precious metal phosphides on the surface of the hydrogenation catalyst / the content of phosphorus (molar ratio) and the hydrogenation test results are shown in Table 1.

[0136] Example 5

[0137] 12 g of non-porous TiO2 (300 nm in diameter) was dispersed in 600 mL of water, and 40.5 g of NiCl2·6H2O, 49.8 g of CH3COONa·3H2O, and 36 g of NaH2PO2·H2O were added and stirred to dissolve. The pH of the system was then adjusted to 8 with a 20 wt% NaOH aqueous solution. The system was then protected with nitrogen and heated to 40 °C for 90 min. Subsequently, 6 mL of a 100 mg / mL H2PtCl6·6H2O solution and 3 g of NaH2PO2·H2O were added, and the reaction was continued for another 30 min. After the reaction was complete, the mixture was filtered, washed, and dried to obtain the catalyst precursor. The catalyst precursor was placed in a hydrogen gas flow (50 mL / min) and calcined at 300 °C for 2 hours to obtain the hydrogenation catalyst.

[0138] Hydrogenation test: 200 mL of a 5 wt% SBS base solution (50 ± 3 wt% styrene, 50 ± 3 wt% butadiene, Mn = 63197, solvent: cyclopentane) was added to a 500 mL reactor. Then, 7.5 g of catalyst was added, and the mixture was replaced with 1.5 MPa N2 at least three times. H2 was then introduced at 6 MPa at room temperature, and the temperature was raised to 200 °C and reacted for 6 hours. After the reaction, the mixture was allowed to cool naturally, and hydrogenated SBS was obtained by condensation with ethanol. The number average molecular weight was 52983, and the molecular weight distribution was 1.02.

[0139] SEM analysis of the hydrogenation catalyst revealed severe agglomeration of the non-precious metal phosphide support.

[0140] XPS shows that P and Ni exist in the form of nickel-phosphide, and FE-TEM shows that Pt is deposited on the phosphide in the form of atomic clusters.

[0141] The content of non-precious metal phosphides on the surface of the hydrogenation catalyst / the content of phosphorus (molar ratio) and the hydrogenation test results are shown in Table 1.

[0142] Example 6

[0143] 12 g of non-porous TiO2 (3000 nm in diameter) was dispersed in 300 mL of water. 20.25 g of NiCl2·6H2O, 24.9 g of CH3COONa·3H2O, and 18 g of NaH2PO2·H2O were added and stirred until dissolved. The pH of the system was then adjusted to approximately 9 using a 20 wt% NaOH aqueous solution. The system was then protected with nitrogen and heated to 40 °C for 100 min. Subsequently, 3 mL of a 100 mg / mL H2PtCl6·6H2O solution and 1.5 g of NaH2PO2·H2O were added, and the reaction was continued for another 30 min. After the reaction was complete, the mixture was filtered, washed, and dried to obtain the catalyst precursor. The catalyst precursor was placed in a hydrogen gas flow (50 mL / min) and calcined at 300 °C for 3 hours to obtain the hydrogenation catalyst.

[0144] Hydrogenation test: 200 mL of a 5 wt% SBS base solution (50 ± 3 wt% styrene, 50 ± 3 wt% butadiene, Mn = 63197, solvent: cyclopentane) was added to a 500 mL reactor. Then, 7.5 g of hydrogenation catalyst was added, and the solution was replaced with 1.5 MPa N2 at least three times. Next, 10 MPa H2 was introduced at room temperature, and the temperature was raised to 220 °C for 8 hours. After the reaction, the solution was allowed to cool naturally, and hydrogenated SBS was obtained by condensation with ethanol. The number average molecular weight was 52765, and the molecular weight distribution was 1.02.

[0145] Non-precious metal phosphides were uniformly covered on the surface of TiO2 support by SEM of hydrogenation catalyst.

[0146] XPS shows that P and Ni exist in the form of nickel-phosphide, and FE-TEM shows that Pt is deposited on the phosphide in the form of atomic clusters.

[0147] The content of non-precious metal phosphides on the surface of the hydrogenation catalyst / the content of phosphorus (molar ratio) and the hydrogenation test results are shown in Table 1.

[0148] Example 7

[0149] 12 g of non-porous TiO2 (3000 nm in diameter) was dispersed in 300 mL of water. 20.25 g of NiCl2·6H2O, 3 g of Na2WO4·2H2O, 24.9 g of CH3COONa·3H2O, and 18 g of NaH2PO2·H2O were added and stirred until dissolved. The pH of the system was then adjusted to approximately 10 using a 20 wt% NaOH aqueous solution. The system was then protected with nitrogen and heated to 45 °C for 90 min. Subsequently, 3 mL of a 100 mg / mL H2PtCl6·6H2O solution and 1.5 g of NaH2PO2·H2O were added, and the reaction continued for another 40 min. After the reaction was complete, the mixture was filtered, washed, and dried to obtain the catalyst precursor. The catalyst precursor was placed in a hydrogen gas flow (50 mL / min) and calcined at 320 °C for 2 hours to obtain the hydrogenation catalyst.

[0150] Hydrogenation test: 200 mL of a 5 wt% SBS base solution (50 ± 3 wt% styrene, 50 ± 3 wt% butadiene, Mn = 63197, solvent: cyclopentane) was added to a 500 mL reactor. Then, 7.5 g of catalyst was added, and the mixture was replaced with 1.5 MPa N2 at least three times. Next, 8 MPa H2 was introduced at room temperature, and the temperature was raised to 200 °C and reacted for 7 hours. After the reaction, the mixture was allowed to cool naturally, and hydrogenated SBS was obtained by condensation with ethanol. The number average molecular weight was 51902, and the molecular weight distribution was 1.02.

[0151] Non-precious metal phosphides were uniformly covered on the surface of TiO2 support by SEM of hydrogenation catalyst.

[0152] XPS shows that P, Ni, and W exist in the form of nickel-tungsten-phosphide, while FE-TEM shows that Pt is deposited on the phosphide in the form of atomic clusters.

[0153] The content of non-precious metal phosphides on the surface of the hydrogenation catalyst / the content of phosphorus (molar ratio) and the hydrogenation test results are shown in Table 1.

[0154] Example 8

[0155] 12 g of non-porous TiO2 (3000 nm in diameter) was dispersed in 300 mL of water. 20.25 g of NiCl2·6H2O, 24.9 g of CH3COONa·3H2O, and 27 g of NaH2PO2·H2O were added and stirred until dissolved. The pH of the system was then adjusted to approximately 8 using a 20 wt% NaOH aqueous solution. The system was then protected with nitrogen and heated to 40 °C for 90 min. Subsequently, 3 mL of a 100 mg / mL H2PtCl6·6H2O solution and 1.5 g of NaH2PO2·H2O were added, and the reaction continued for another 30 min. After the reaction was complete, the mixture was filtered, washed, and dried to obtain the catalyst precursor. The catalyst precursor was placed in a hydrogen gas flow (50 mL / min) and calcined at 300 °C for 2 hours to obtain the hydrogenation catalyst.

[0156] Hydrogenation test: 200 mL of a 5 wt% SBS base solution (50 ± 3 wt% styrene, 50 ± 3 wt% butadiene, Mn = 63197, solvent: cyclopentane) was added to a 500 mL reactor. Then, 7.5 g of hydrogenation catalyst was added, and the solution was replaced with 1.5 MPa N2 at least three times. H2 was then introduced at 6 MPa at room temperature, and the temperature was raised to 200 °C for 6 hours. After the reaction, the solution was allowed to cool naturally, and hydrogenated SBS was obtained by condensation with ethanol. The number average molecular weight was 51873, and the molecular weight distribution was 1.02.

[0157] Non-precious metal phosphides were uniformly covered on the surface of TiO2 support by SEM of hydrogenation catalyst.

[0158] XPS shows that P and Ni exist in the form of nickel-phosphide, and FE-TEM shows that Pt is deposited on the phosphide in the form of atomic clusters.

[0159] The content of non-precious metal phosphides on the surface of the hydrogenation catalyst / the content of phosphorus (molar ratio) and the hydrogenation test results are shown in Table 1.

[0160] Comparative Example 1

[0161] 12 g of non-porous TiO2 (3000 nm in diameter) was dispersed in 300 mL of water. 20.25 g of NiCl2·6H2O, 24.9 g of CH3COONa·3H2O, and 18 g of NaH2PO2·H2O were added and stirred until dissolved. Then, 3 mL of a 100 mg / mL H2PtCl6·6H2O solution was added. The pH of the system was then adjusted to approximately 8 using a 20 wt% NaOH aqueous solution. The system was then subjected to nitrogen protection and heated to 40 °C for 90 min. After the reaction, the mixture was filtered, washed, and dried to obtain the catalyst precursor. The catalyst precursor was placed in a hydrogen gas flow (50 mL / min) and calcined at 300 °C for 2 hours to obtain the hydrogenation catalyst.

[0162] Hydrogenation test: 200 mL of a 5 wt% SBS base solution (50 ± 3 wt% styrene, 50 ± 3 wt% butadiene, Mn = 63197, solvent: cyclopentane) was added to a 500 mL reactor. Then, 7.5 g of catalyst was added, and the mixture was replaced with 1.5 MPa N2 at least three times. H2 was then introduced at 6 MPa at room temperature, and the temperature was raised to 200 °C and reacted for 6 hours. After the reaction, the mixture was allowed to cool naturally, and hydrogenated SBS was obtained by condensation with ethanol. The number average molecular weight was 56024, and the molecular weight distribution was 1.02.

[0163] Non-precious metal phosphides were uniformly covered on the surface of TiO2 support by SEM of hydrogenation catalyst.

[0164] XPS showed that P and Ni exist in the form of nickel-phosphide, while FE-TEM showed only a small amount of Pt.

[0165] The content of non-precious metal phosphides on the surface of the hydrogenation catalyst / the content of phosphorus (molar ratio) and the hydrogenation test results are shown in Table 1.

[0166] Table 1

[0167] In Table 1: Hydrogenation catalyst recycling refers to the recycling and reuse of the hydrogenation catalyst. The degree of hydrogenation of SBS is tested when the hydrogenation catalyst is recycled for the 5th time according to the corresponding test method in the hydrogenation test.

Claims

1. A hydrogenation catalyst for styrene-based polymers, characterized in that, The hydrogenation catalyst includes a support and an active component supported on the support, the active component containing a non-precious metal phosphide and a cluster of noble metal atoms deposited on the non-precious metal phosphide.

2. The hydrogenation catalyst according to claim 1, characterized in that, The styrene polymer is selected from at least one copolymer produced by copolymerizing at least one styrene comonomer and at least one C4-C8 conjugated diene monomer.

3. The hydrogenation catalyst according to claim 1, characterized in that, The styrene-based polymer has a block structure.

4. The hydrogenation catalyst according to claim 3, characterized in that, The styrene-based polymer has a triblock structure.

5. The hydrogenation catalyst according to claim 4, characterized in that, The styrene polymers are selected from styrene-butadiene-styrene block copolymers and / or styrene-isoprene-styrene block copolymers.

6. The hydrogenation catalyst according to claim 1, characterized in that, The carrier is selected from porous carriers and / or non-porous carriers; and / or The diameter of the carrier is 100nm-100μm.

7. The hydrogenation catalyst according to claim 6, characterized in that, The carrier is selected from non-porous carriers.

8. The hydrogenation catalyst according to claim 1, characterized in that, The carrier is selected from at least one of inorganic oxides, natural minerals, and carbonaceous materials.

9. The hydrogenation catalyst according to claim 8, characterized in that, The inorganic oxide is selected from at least one of silicon dioxide, aluminum oxide, titanium dioxide, cerium oxide, zirconium oxide, and magnesium oxide; and / or The natural mineral is selected from at least one of diatomite, clay, diatoms, and pumice; and / or The carbonaceous material is selected from activated carbon and / or graphite.

10. The hydrogenation catalyst according to claim 1, characterized in that, The non-precious metal in the non-precious metal phosphate is selected from transition metal elements and / or lanthanide elements; and / or The precious metal is selected from at least one of iridium, ruthenium, rhodium, platinum and palladium.

11. The hydrogenation catalyst according to claim 10, characterized in that, The transition metal element is selected from Group VIB, Group VIII, and Group IIIB elements; and / or The lanthanide elements are selected from at least one of cerium, lanthanum, and praseodymium.

12. The hydrogenation catalyst according to claim 11, characterized in that, The Group VIB element is selected from molybdenum and / or tungsten; and / or The Group VIII elements are selected from at least one of iron, nickel, cobalt, copper, and manganese; and / or The group IIIB element is selected from yttrium.

13. The hydrogenation catalyst according to claim 10, characterized in that, The non-precious metal contains at least nickel; and / or The precious metal contains at least platinum.

14. The hydrogenation catalyst according to any one of claims 1-13, characterized in that, The molar ratio of non-noble metal phosphide to phosphorus on the surface of the hydrogenation catalyst is 2-6:1; and / or Based on the total mass of the hydrogenation catalyst, the content of non-precious metals, calculated as elements, is 5-70 wt%; and / or Based on the total mass of the hydrogenation catalyst, the content of the precious metal is 0.05-2 wt%. and / or Based on the total mass of the hydrogenation catalyst, the content of the active component is 5-95 wt%; and / or Based on the total mass of the hydrogenation catalyst, the content of the support is 5-95 wt%.

15. The hydrogenation catalyst according to claim 14, characterized in that, The molar ratio of non-precious metal phosphide to phosphorus on the surface of the hydrogenation catalyst is 3.5-4.5:1; and / or Based on the total mass of the hydrogenation catalyst, the content of non-precious metals, calculated as elements, is 10-50 wt%; and / or Based on the total mass of the hydrogenation catalyst, the content of the noble metal is 0.1-1 wt%; and / or Based on the total mass of the hydrogenation catalyst, the content of the support is 29-90 wt%.

16. The hydrogenation catalyst according to claim 15, characterized in that, Based on the total mass of the hydrogenation catalyst, the content of non-precious metals, calculated as elements, is 10-40 wt%; and / or Based on the total mass of the hydrogenation catalyst, the content of the noble metal is 0.2-0.5 wt%; and / or Based on the total mass of the hydrogenation catalyst, the content of the support is 49.5-90 wt%.

17. A method for preparing a hydrogenation catalyst for a styrene-based polymer according to any one of claims 1-16, characterized in that, The preparation method includes: S1 contains a solution of a non-precious metal source, a structure modifier, a phosphorus-containing reducing agent, and water. When the solution is brought into contact with a carrier, a first precipitation reaction is carried out to obtain the first material. In the presence of a reducing agent, S2 undergoes a second precipitation reaction with a precious metal source; S3 involves drying and calcining the solid phase from the second precipitation reaction.

18. The preparation method according to claim 17, characterized in that, In step S1, the structure modifier is selected from compounds containing anions and / or ammonium ions; and / or In step S1, the phosphorus-containing reducing agent is selected from at least one of hypophosphite, hypophosphite, and phosphite; and / or In step S2, the reducing agent includes at least one of hypophosphite, hypophosphite, phosphite, sodium borohydride, ascorbic acid, ascorbate, and tartrate.

19. The preparation method according to claim 18, characterized in that, The structure modifier is selected from at least one corresponding alkali metal salt of acetic acid, citric acid, ethylenediaminetetraacetic acid, oxalic acid, lactic acid, malic acid, and tannic acid; and / or The phosphorus-containing reducing agent is selected from hypophosphite.

20. The preparation method according to claim 17, characterized in that, The mass ratio of the structure modifier to the non-precious metal source is 0.3-3:1; and / or The non-precious metal source, calculated as a non-precious metal element, has a content of 2-100 g / L in the solution; and / or The phosphorus-containing reducing agent, calculated as elemental phosphorus, has a concentration of 1-50 g / L in the solution; and / or The solution contains a carrier concentration of 10-200 g / L; and / or The non-precious metal source is calculated as a non-precious metal element, and the precious metal source is calculated as a precious metal element; the mass ratio of the precious metal source to the non-precious metal source is 0.001-0.1:1; and / or The mass ratio of the reducing agent to the precious metal source is 10-15:1, calculated by precious metal element.

21. The preparation method according to any one of claims 17-20, characterized in that, The reaction conditions for the first precipitate and the second precipitate each include independently: Conducted under an inert atmosphere; and / or pH 8-14; and / or The reaction temperature is 20-90℃; and / or The reaction time for the first precipitation is 30-180 min; and / or The reaction time for the second precipitation is 10-120 min.

22. The preparation method according to any one of claims 17-20, characterized in that, In step S3, the calcination conditions include: Performed under a reducing atmosphere; and / or Temperatures range from 200 to 650 degrees Celsius; and / or The time is 1-10 hours.

23. A method for preparing a hydrogenated styrene-butadiene-styrene block copolymer, characterized in that, The preparation method includes: The styrene-butadiene-styrene block copolymer undergoes a hydrogenation reaction in the presence of a solvent and the hydrogenation catalyst described in any one of claims 1-16.

24. The preparation method according to claim 23, characterized in that, The conditions for the hydrogenation reaction include: a hydrogen pressure of 2-12 MPa; and / or a reaction temperature of 100-250 °C; and / or a reaction time of 0.5-24 h; and / or The number average molecular weight of the styrene-butadiene-styrene block copolymer is not higher than 150,000; and / or The mass ratio of the hydrogenation catalyst to the styrene-butadiene-styrene block copolymer is 0.1-3:1; and / or The mass ratio of the styrene-butadiene-styrene block copolymer to the solvent is 0.02-0.25:1; and / or The solvent is selected from C5-C10 alkanes and / or C5-C10 cycloalkanes.

25. The preparation method according to claim 24, characterized in that, The number average molecular weight of the styrene-butadiene-styrene block copolymer is not higher than 100,000; and / or The mass ratio of the styrene-butadiene-styrene block copolymer to the solvent is 0.08-0.15:1; and / or The C5-C10 alkanes include at least one of n-pentane, n-hexane, isooctane, and hexane; and / or The C5-C10 cycloalkanes include at least one of cyclopentane, cyclohexane, cyclooctane, cycloheptane, and decahydronaphthalene.

26. A hydrogenated styrene-butadiene-styrene block copolymer, characterized in that, The hydrogenated styrene-butadiene-styrene block copolymer is prepared by the preparation method according to any one of claims 23-25.

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