Preparation method and application of nickel homogeneous hydrogenation catalyst

Abstract

The invention discloses a preparation method and application of a nickel-based homogeneous hydrogenation catalyst, and the preparation method comprises the following steps: adding organic alcohol into LiAlH4, and stirring for reaction to generate a third monomer; the preparation method comprises the following steps: dissolving a main catalyst in a solvent, stirring, then adding a cocatalyst, reacting and aging to obtain a hydrogenation catalyst precursor; and adding a third monomer into the hydrogenation catalyst precursor, and continuing aging to obtain the nickel-based homogeneous hydrogenation catalyst. The nickel-based homogeneous hydrogenation catalyst prepared by the preparation method disclosed by the invention still keeps higher activity under the condition of low addition amount, so that metal ions are easier to remove in a glue solution post-treatment process, the residual quantity of the metal ions in a hydrogenated product is lower, the cost of the catalyst and post-treatment is reduced, and the quality and additional value of the product are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry and relates to a preparation method of a nickel-based homogeneous hydrogenation catalyst and application of the catalyst in hydrogenating SBS or SIS to prepare SEBS or SEPS. Background Art

[0002] At present, the preparation method of SEBS and SEPS is mainly to selectively hydrogenate polymers SBS and SIS (collectively referred to as SDS). The so-called selective hydrogenation refers to hydrogenating the diene segment in SDS (the degree of hydrogenation is generally greater than 90%), while the benzene ring of the polystyrene segment is basically not hydrogenated (the degree of hydrogenation is less than 10%). Traditional hydrogenation catalysts include heterogeneous catalytic systems and homogeneous catalyst systems. The heterogeneous catalytic systems such as nickel, molybdenum, palladium, and platinum with diatomaceous earth as the carrier have large catalyst dosage, high hydrogen pressure and reaction temperature, difficult to control the reaction, poor reproducibility, low hydrogenation selectivity, and are prone to benzene ring hydrogenation, polymer decomposition or coking. Therefore, the current SEBS and SEPS hydrogenation catalysts all use homogeneous hydrogenation systems.

[0003] Homogeneous catalyst systems are widely used in SBS and SIS hydrogenation due to their low catalyst dosage, high activity, low hydrogen pressure and reaction temperature, and good selectivity. The main systems of homogeneous hydrogenation catalysts are nickel / cobalt and titanocene. The metallocene hydrogenation catalytic process, represented by dicyclopentadiene titanium dichloride, is currently the most actively studied catalytic system for SBS hydrogenation. Because metallocenes have high activity, low concentration, and low dosage, the residual ash content in the final polymer product is extremely low. In low-end applications, the purification and removal process can be omitted, the process flow can be simplified, and investment can be saved. However, in recent years, with the rapid development of new energy vehicles, especially the shortage of lithium batteries, the price of raw materials lithium has risen sharply, making the cost advantage of titanocene no longer exist. At the same time, when SEBS and SEPS are used in high-end fields, the residual metal ions in the glue must also be removed, which is equivalent to the process of nickel-based catalytic systems. In addition, titanocene is mainly used for SBS hydrogenation. Due to the steric hindrance of the methyl group of the isoprene side chain, titanocene is not suitable for SIS hydrogenation and has poor adaptability. Cobalt-based catalysts are not suitable as SBS and SIS hydrogenation catalysts if some of them remain in the colloid solution. Cobalt is a variable-valence metal and is prone to discoloration at high temperatures, affecting the use and sales of the product.

[0004] Nickel-based catalytic systems have become a popular hydrogenation catalytic system in recent years because they can be used not only for SBS hydrogenation but also for SIS hydrogenation and have a wide range of adaptability.

[0005] Chinese patent CN201710516400.1 discloses a 1,2 structure butadiene block uniformly distributed SBS and its hydride SEBS and preparation and application methods. The preparation process of SBS is that styrene is polymerized with an initiator under the action of an activator, and the second stage polymerization process is to dissolve the structure regulator in butadiene and add it evenly to the polymerization kettle within 16-18 minutes, react for 8-12 minutes, and the third stage polymerization can be polymerized with styrene or coupled with a coupling agent to obtain SBS, which is then hydrogenated. The structure regulator used in the polymerization of SBS is at least one of tetrahydrofurfuryl alcohol ethyl ether, ditetrahydrofurfuryl propane, tetrahydrofurfuryl amine, and tetrahydrofurfuryl alcohol hexyl ether. The hydrogenation catalyst uses nickel isooctanoate-triisobutylaluminum catalyst system.

[0006] Chinese patent CN201210506300.8 discloses a selectively hydrogenated terpolymer and its preparation method and application; butadiene, isoprene and styrene are prepared under anionic polymerization conditions in the presence of an inert gas, alkyl sulfonate and tetrahydrofurfuryl ether composite structure regulator, and then hydrogenated. The main catalyst of the hydrogenation catalyst is nickel cyclohexane acid or nickel octanoate, and the co-catalyst is triisobutyl aluminum or triethyl aluminum.

[0007] Chinese patent CN201310560265.2 discloses a hydrogenation catalyst for random copolymers or block copolymers of butadiene or isoprene and styrene, the catalyst comprising: component (a) is selected from one or more of nickel naphthenate, nickel octanoate, nickel 2-ethylhexanoate, nickel acetylacetonate, cobalt naphthenate, cobalt octanoate and cobalt acetylacetonate. Component (b) is selected from one or more of triisobutylaluminum, triethylaluminum, n-butyllithium and sec-butyllithium.

[0008] Chinese patent CN97119094.1 discloses a method for selectively hydrogenating a conjugated diene polymer, wherein the conjugated diene polymer is polymerized or copolymerized with at least one conjugated diene as a monomer, or copolymerized with at least one conjugated diene and at least one vinyl aromatic hydrocarbon as a monomer, and the method comprises reacting the conjugated diene polymer dissolved in an inert organic solvent with hydrogen in the presence of a hydrogenation catalyst to selectively hydrogenate the unsaturated double bonds of the conjugated diene units in the conjugated diene polymer, wherein the hydrogenation catalyst is composed of a hydrogenation catalyst (a) and at least one hydrogenation catalyst (b), wherein the hydrogenation catalyst (a) is dicyclopentadiene cobalt or dicyclopentadiene nickel, and (b) is n-butyl lithium or isobutyl lithium.

[0009] "Preparation and Small-Scale Process Research of Styrene-Butadiene-Styrene Block Copolymer Hydrogenation Catalyst" systematically studied the SBS hydrogenation reaction system catalyzed by titanocene catalyst. Under the optimal process conditions, the finished SBS colloid was hydrogenated to prepare SEBS using dichlorotitanocene catalyst.

[0010] In the above-mentioned prior art, the hydrogenation catalysts are all two components, and a large amount of catalyst is required to ensure the hydrogenation activity, so as to ensure that the product has a high degree of hydrogenation. However, this will also make the post-processing process cumbersome, requiring the use of a large amount of reagents, and it will also become more difficult to achieve a low product metal ion residue. This has limited the high-end development of SEBS and SEPS products to a certain extent. In addition, these catalysts are mainly used for SBS hydrogenation, and there is no mention of whether they can be used for SIS hydrogenation, so their adaptability is relatively narrow. Summary of the invention

[0011] The purpose of the present invention is to provide a highly active nickel-based homogeneous hydrogenation catalyst, which can maintain high activity under low addition conditions, so that SBS and SIS can reach a high degree of hydrogenation. A third monomer is introduced on the basis of the nickel-based catalytic system, so that metal ions can be removed more easily during the post-treatment of the gel solution, the residual amount of metal ions in the hydrogenated product is lower, the cost of the catalyst and post-treatment is reduced, the product quality and added value are improved, and the hydrogenated polymer can be applied in high-end fields such as medicine and food.

[0012] To achieve the above object, the present invention provides a method for preparing a nickel-based homogeneous hydrogenation catalyst, the preparation method comprising the following steps:

[0013] Step 1: Add organic alcohol to LiAlH 4 , stirring the reaction to generate a third monomer;

[0014] Step 2: dissolving the main catalyst in a solvent, stirring, then adding a co-catalyst, reacting and aging to obtain a hydrogenation catalyst precursor;

[0015] Step 3: adding the third monomer in step 1 to the hydrogenation catalyst precursor in step 2, and continuing aging to obtain a nickel-based homogeneous hydrogenation catalyst;

[0016] The organic alcohol is selected from at least one of methylphenylsilanol, methyldiphenylsilanol, dimethylphenylsilanol, 1,4-bis(dimethylhydroxysilyl)benzene and unsubstituted C4-C10 monohydric and polyhydric alcohols;

[0017] The main catalyst is at least one of nickel naphthenate, nickel isooctanoate, nickel 2-ethylhexanoate, nickel acetylacetonate, and nickel carbonyl;

[0018] The co-catalyst is at least one of n-butyl lithium, sec-butyl lithium, ethyl magnesium bromide, benzyl magnesium chloride, phenyl magnesium bromide, triethyl aluminum, triisobutyl aluminum, and diethyl zinc.

[0019] The preparation method of the nickel-based homogeneous hydrogenation catalyst of the present invention comprises the following steps: 4The molar ratio of the main catalyst to the co-catalyst is 0.1-0.8. In the preparation method of the nickel-based homogeneous hydrogenation catalyst of the present invention, the molar ratio of the main catalyst to the co-catalyst is 1:2-6.

[0020] In the method for preparing a nickel-based homogeneous hydrogenation catalyst of the present invention, the molar ratio of the added amount of the main catalyst to the co-catalyst is 1:3-4.

[0021] In the method for preparing the nickel-based homogeneous hydrogenation catalyst of the present invention, the volume ratio of the mass of the main catalyst to the solvent is 10-40 g:1 L, preferably 20-30 g:1 L.

[0022] In the method for preparing the nickel-based homogeneous hydrogenation catalyst of the present invention, the molar ratio of the added amount of the main catalyst to the third monomer is 1:1-3.

[0023] In the method for preparing the nickel-based homogeneous hydrogenation catalyst of the present invention, the solvent comprises at least one of aromatic hydrocarbons, aliphatic alkanes and cycloalkanes.

[0024] Preferably, the aromatic hydrocarbon includes at least one of benzene, toluene and ethylbenzene.

[0025] Preferably, the aliphatic alkane includes at least one of pentane, hexane, heptane and octane.

[0026] Preferably, the cycloalkane includes at least one of cyclopentane and cyclohexane.

[0027] In the method for preparing the nickel-based homogeneous hydrogenation catalyst of the present invention, in step 1, the reaction time is 5-120 minutes.

[0028] In the preparation method of the nickel-based homogeneous hydrogenation catalyst of the present invention, in step 2, the reaction aging temperature is 40-60° C., preferably 45-55° C., the pressure is 0.1-0.60 MPa, preferably 0.2-0.4 MPa, and the time is 10-30 min, preferably 20-25 min.

[0029] In the method for preparing the nickel-based homogeneous hydrogenation catalyst of the present invention, in step 3, the time for continuing aging is 30-120 minutes.

[0030] The present invention also provides a method for preparing SEBS or SEPS, which comprises: using the above-mentioned nickel-based homogeneous hydrogenation catalyst.

[0031] The preparation method of SEBS or SEPS of the present invention specifically comprises the following steps: adding a polymer solution containing 3-15wt% SBS or SIS, hydrogen and a nickel-based homogeneous hydrogenation catalyst into a polymerization kettle, and then performing a hydrogenation reaction to obtain SEBS or SEPS.

[0032] In the preparation method of SEBS or SEPS of the present invention, the temperature of the hydrogenation reaction is 50-100° C., the pressure is 1.5-4 MPa, and the time is 2-4 hours.

[0033] In the method for preparing SEBS or SEPS of the present invention, based on the mass of the metal contained in the nickel-based homogeneous hydrogenation catalyst, 0.001 to 0.06 g of the nickel-based homogeneous hydrogenation catalyst is added per 100 g of the SBS / SIS.

[0034] The preparation method of SEBS or SEPS of the present invention, the SBS or SIS is a block copolymer, which is prepared by polymerization of styrene and butadiene or isoprene under the action of an initiator and a structure regulator, the styrene content can be 10-90wt%, and the butadiene or isoprene segment content can be 10-90wt%.

[0035] In the method for preparing SEBS or SEPS of the present invention, the solvent in the polymer solution includes at least one of aromatic hydrocarbons, aliphatic alkanes and cycloalkanes.

[0036] Preferably, the aromatic hydrocarbon includes at least one of benzene, toluene and ethylbenzene.

[0037] Preferably, the aliphatic alkane includes at least one of pentane, hexane, heptane and octane.

[0038] Preferably, the cycloalkane includes at least one of cyclopentane and cyclohexane.

[0039] In the preparation method of SEBS or SEPS of the present invention, the added amount of the solvent is 300-1000wt% of the total weight of styrene and butadiene monomers, and the solvent is preferably cyclopentane and cyclohexane.

[0040] In the preparation method of SEBS or SEPS of the present invention, the initiator is at least one of n-butyl lithium, sec-butyl lithium, tert-butyl lithium and hexyl lithium, preferably n-butyl lithium.

[0041] In the preparation method of SEBS or SEPS of the present invention, the amount of the initiator is 0.2-3 mmol per 100 grams of total monomers.

[0042] The preparation method of SEBS or SEPS of the present invention, the structure regulator is a nitrogen-, oxygen- and other heterocyclic organic compound with a certain polarity, and is selected from at least one of tetrahydrofuran, ethyl tetrahydrofurfuryl ether, tetramethyl divinyl diamine, tetrahydrofuran methanol and diethylene glycol dimethyl ether (2G).

[0043] In the preparation method of SEBS or SEPS of the present invention, the amount of the structure regulator added is 20-2000wt% of the initiator. The structure regulator can adjust the vinyl content of butadiene to between 25-65%, and can also cause the alkyl lithium initiator to produce a polarization or solvation effect, reduce its association degree, and increase the initiation reaction speed of the initiator such as n-butyl lithium. The present invention does not particularly limit the source of the structure regulator, which can be commercially available or prepared by conventional methods in the art.

[0044] The preparation method of SEBS or SEPS of the present invention, the SBS or SIS is a linear triblock copolymer prepared by a three-step method, or a linear diblock copolymer prepared by a two-step method followed by linear coupling, or a star-shaped diblock copolymer prepared by a two-step method followed by star-shaped coupling.

[0045] In the preparation method of SEBS or SEPS of the present invention, the coupling agent used in the coupling process is at least one of polyvinyl compounds, halides, ethers, aldehydes, ketones and esters.

[0046] The coupling agent is at least one of divinylbenzene, tetravinylsilane, tetrachloromethane, silicon tetrachloride, tin tetrachloride and dimethyl terephthalate, preferably divinylbenzene, silicon tetrachloride or tin tetrachloride.

[0047] The molar ratio of the coupling agent to the initiator is 0.1-2.

[0048] In the preparation method of SEBS or SEPS of the present invention, the residual olefin double bond rate of the product obtained after the hydrogenation reaction is not more than 5wt%, preferably not more than 3wt%, and the content of unsaturated benzene rings is not less than 95wt%, preferably not less than 98wt%.

[0049] In the method for preparing SEBS or SEPS of the present invention, the product of the hydrogenation reaction is transferred to a chemical treatment kettle, an antioxidant is added, and then SEBS or SEBS is obtained by separation.

[0050] In the preparation method of SEBS or SEPS of the present invention, the antioxidant is at least one of 1520L, 1076, 1010, 264, TNPP and triisopropanolamine, preferably 1520L, and the added amount is 0.5-5wt%, preferably 0.5-2wt%.

[0051] In the preparation method of SEBS or SEPS of the present invention, the separation can be carried out by a conventional steam stripping and condensation method or by a devolatilization screw extruder.

[0052] The nickel-based homogeneous hydrogenation catalyst of the present invention introduces LiAlH 4The third monomer prepared with organic alcohol can greatly increase the activity of the catalyst, reduce the use of metal compounds on the one hand, and reduce costs. On the other hand, the SEBS and SEPS colloids prepared after hydrogenation are conducive to the removal of metal ions, further reducing costs, improving product quality and added value, and broadening the scope of application of the product. The nickel-based homogeneous hydrogenation catalyst obtained by the preparation method of the present invention has high activity and good stability, so the amount added in the hydrogenation polymerization reaction is small, which can reduce the cost of the catalyst, and at the same time make the subsequent metal ion removal process simple, the removal conditions are mild, and the amount of removal reagents is small, which further reduces the cost of metal ion removal. The nickel-based homogeneous hydrogenation catalyst obtained by the preparation method of the present invention has a low residual metal ion content, which can expand the application of SEBS and SEPS to high-end fields such as medical care, food, and wear; the nickel-based homogeneous hydrogenation catalyst of the present invention can be used not only for the hydrogenation of SBS to prepare SEBS, but also for the hydrogenation of SIS to prepare SEPS, and has strong applicability. In the future, a set of hydrogenation catalyst devices can be used to produce a variety of thermoplastic elastomers when used in industrial devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is the SBS nuclear magnetic hydrogen spectrum of Example 1 of the present invention.

[0054] Figure 2 This is the SEBS H-NMR spectrum of Example 1 of the present invention. DETAILED DESCRIPTION

[0055] The following examples are selected to further illustrate the method of the present invention, but should not be limited thereto in practical applications.

[0056] The polymers in the examples were characterized using the following instruments: US Varian INOVA400 NMR nuclear magnetic resonance 1H-NMR was used to qualitatively and quantitatively analyze the copolymer composition sequence distribution, microstructure and degree of hydrogenation, and the TDA302 gel permeation chromatography (GPC) of Viscotek Company of the United States was used to analyze the molecular weight and molecular weight distribution of the copolymer. Varian Vista MPX was used to test the metal ion content.

[0057] Example 1

[0058] Step 1: In a polymerization reactor that was evacuated and replaced with argon, add 18.9 g of LiAlH 4 Then, 0.1 mol of dimethylphenylsilanol was slowly added into the polymerization kettle. After the addition was completed, the reaction was stirred at room temperature for 30 minutes. After the reaction was completed, the third monomer was obtained.

[0059] Step 2: In an aging bottle that has been evacuated and replaced with argon, add 14.16 mL of 30 g / L nickel cyclohexane solution (metal Ni content is 12%), then slowly add 2.39 mL of triethylaluminum (1.1 mol / L), mix and transfer to a 40°C water bath for aging for 15 min to obtain a hydrogenation catalyst precursor.

[0060] Step 3: Add the third monomer in step 1 to the hydrogenation catalyst precursor obtained in step 2 at 50° C. and continue aging for 60 minutes to obtain a nickel-based homogeneous hydrogenation catalyst C1.

[0061] Step 4: Add the obtained catalyst C1 to 1700mL of SBS glue (single concentration 10g / 100mL, Mn=100000, St%=30, vinyl 30%), start stirring, and when the temperature rises to 60°C, introduce hydrogen and maintain the pressure at 2.0MPa. React for 3h to obtain SEBS glue L1.

[0062] Step 5: The obtained SEBS glue L1 is subjected to a metal ion removal process (adding 10 mL of an oxidant, 200 mL of an acid aqueous solution (concentration of 2%), layered filtration, and removal time of 2 h), followed by coagulation, devolatilization, and drying to obtain SEBS dry glue S1.

[0063] The results of hydrogenation and metal ion removal are shown in Table 1.

[0064] Comparative Example 1

[0065] Step 1: In an aging bottle that has been evacuated and replaced with argon, add 14.16 mL of 30 g / L nickel cyclohexane solution (metal Ni content is 12%), then slowly add 2.39 mL of triethylaluminum (1.1 mol / L), mix and transfer to a 40°C water bath for aging for 15 min to obtain a hydrogenation catalyst precursor.

[0066] Step 2: Add the hydrogenation catalyst precursor obtained in step 1 to 1700 mL of SBS glue (single concentration 10 g / 100 mL, Mn=100000, St%=30, vinyl 30%), start stirring, and when the temperature rises to 60°C, introduce hydrogen and maintain the pressure at 2.0 MPa. React for 3 hours to obtain SEBS glue L2.

[0067] Step 3: The obtained SEBS glue L2 is subjected to a metal ion removal process (adding 10 mL of an oxidant, 200 mL of an acid aqueous solution (concentration of 2%), layered filtration, and removal time of 2 h), followed by condensation, devolatilization, and drying to obtain SEBS dry glue D1.

[0068] The results of hydrogenation and metal ion removal are shown in Table 1.

[0069] Comparative Example 2

[0070] Step 1: In an aging bottle that has been evacuated and replaced with argon, add 14.16 mL of 30 g / L nickel cyclohexane solution (metal Ni content is 12%), then slowly add 2.39 mL of triethylaluminum (1.1 mol / L), and then transfer to a 40°C water bath for aging for 15 minutes to obtain a hydrogenation catalyst precursor.

[0071] Step 2: Add 0.1 mol of dimethylphenylsilanol to the hydrogenation catalyst precursor obtained in step 1 at 50° C. and continue aging for 60 minutes to obtain a nickel-based homogeneous hydrogenation catalyst C2.

[0072] Step 3: Add the obtained catalyst C1 to 1700mL of SBS glue (single concentration 10g / 100mL, Mn=100000, St%=30, vinyl 30%), start stirring, and when the temperature rises to 60°C, introduce hydrogen and maintain the pressure at 2.0MPa. React for 3h to obtain SEBS glue L3.

[0073] Step 4: The obtained SEBS glue L3 is subjected to a metal ion removal process (adding 10 mL of an oxidant, 200 mL of an acid aqueous solution (concentration of 2%), layered filtration, and removal time of 2 h), followed by coagulation, devolatilization, and drying to obtain SEBS dry glue D2.

[0074] The results of hydrogenation and metal ion removal are shown in Table 1.

[0075] Example 2

[0076] The method of Example 1 was followed, except that in step 2, “adding 9.44 mL of 30 g / L nickel cyclohexane solution of nickel cyclohexane (metal Ni content of 12%)” was used instead of “adding 14.16 mL of 30 g / L nickel cyclohexane solution of nickel cyclohexane (metal Ni content of 12%)”, and “subsequently slowly adding 2.39 mL of triethylaluminum (1.1 mol / L)” was used instead of “subsequently slowly adding 1.59 mL of triethylaluminum (1.1 mol / L)” to obtain SEBS dry glue S2.

[0077] The results of hydrogenation and metal ion removal are shown in Table 1.

[0078] Example 3

[0079] The method of Example 1 is followed, except that in step 4, "react for 2 h" is used instead of "react for 3 h" to obtain SEBS dry glue S3.

[0080] The results of hydrogenation and metal ion removal are shown in Table 1.

[0081] Example 4

[0082] The method of Example 1 was followed, except that in step 4, “the pressure was maintained at 1.5 MPa” was used instead of “the pressure was maintained at 2.0 MPa” to obtain SEBS dry adhesive S4.

[0083] The results of hydrogenation and metal ion removal are shown in Table 1.

[0084] Example 5

[0085] The method of Example 2 was followed, except that in step 5, “(add 5 mL of oxidant, 170 mL of acid aqueous solution (concentration of 2%), filter in layers, and remove for 2 h)” was used to replace “(add 10 mL of oxidant, 200 mL of acid aqueous solution (concentration of 2%), filter in layers, and remove for 2 h)” to obtain SEBS dry glue S5.

[0086] The results of hydrogenation and metal ion removal are shown in Table 1.

[0087] Example 6

[0088] The method of Example 1 is followed, except that in step 4, "SIS glue solution (single concentration 10 g / 100 mL, Mn=100000, Ip%=30, 3,4 structure content=30%)" is used to replace "SBS glue solution (single concentration 10 g / 100 mL, Mn=100000, St%=30, vinyl 30%)" to obtain SEPS dry glue S6.

[0089] The results of hydrogenation and metal ion removal are shown in Table 1.

[0090] Example 7

[0091] The method of Example 1 was followed, except that in step 1, "0.1 mol of dimethylphenylsilanol" was used to replace "0.1 mol of methylphenylsilanol" to obtain SEBS dry glue S7.

[0092] The results of hydrogenation and metal ion removal are shown in Table 1.

[0093] Example 8

[0094] The method of Example 1 was followed, except that in step 1, “0.1 mol of dimethylphenylsilanol” was used to replace “0.1 mol of methyldiphenylsilanol” to obtain SEBS dry glue S8.

[0095] The results of hydrogenation and metal ion removal are shown in Table 1.

[0096] Example 9

[0097] The method of Example 1 is followed, except that in step 1, "0.1 mol of 1,4-bis(dimethylhydroxysilyl)benzene" is used to replace "0.1 mol of dimethylphenylsilanol" to obtain SEBS dry glue S9.

[0098] The results of hydrogenation and metal ion removal are shown in Table 1.

[0099] Table 1 Hydrogenation degree and metal ion content in SEBS polymer

[0100]

[0101]

[0102] It can be seen from the results of SI and D1 that when the third monomer is added to the catalyst component, the catalyst activity is greatly improved, and the metal ion removal is relatively easy, and the residual amount is low. It can be seen from the results of S1 and S2 that the catalyst provided by the present invention can still achieve a high degree of hydrogenation when the catalyst content is further reduced. It can be seen from the results of S3 and S5 that the change of hydrogenation conditions still has a certain effect on the degree of hydrogenation, but the effect of the catalyst addition is still the most direct and greatest. It can be seen from the results of S1 and D2 that when LiAlH is not added to the catalyst component, the catalyst activity is greatly improved. 4 When the catalyst activity is reduced, the metal ions are difficult to remove and the residual amount is high. 4 When the third monomer is prepared with organic alcohol, the activity of the obtained catalyst is greatly improved, and the removal of metal ions is relatively easy and the residual amount is low.

[0103] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a nickel-based homogeneous hydrogenation catalyst, It is characterized in that The following steps are involved: Step 1: Add organic alcohol to LiAlH 4 , stirring the reaction to generate a third monomer; Step 2: dissolving the main catalyst in a solvent, stirring, then adding a co-catalyst, reacting and aging to obtain a hydrogenation catalyst precursor; Step 3: adding the third monomer in step 1 to the hydrogenation catalyst precursor in step 2, and continuing aging to obtain a nickel-based homogeneous hydrogenation catalyst; The organic alcohol is selected from at least one of methylphenylsilanol, methyldiphenylsilanol, dimethylphenylsilanol, 1,4-bis(dimethylhydroxysilyl)benzene and unsubstituted C4-C10 monohydric and polyhydric alcohols; The main catalyst is at least one of nickel naphthenate, nickel isooctanoate, nickel 2-ethylhexanoate, nickel acetylacetonate, and nickel carbonyl; The co-catalyst is at least one of n-butyl lithium, sec-butyl lithium, ethyl magnesium bromide, benzyl magnesium chloride, phenyl magnesium bromide, triethyl aluminum, triisobutyl aluminum, and diethyl zinc.

2. The method for preparing the nickel-based homogeneous hydrogenation catalyst according to claim 1, It is characterized in that The organic alcohol and LiAlH 4 The molar ratio is 0.1-0.

8.

3. The method for preparing the nickel-based homogeneous hydrogenation catalyst according to claim 1, It is characterized in that The molar ratio of the main catalyst to the co-catalyst is 1:2-6.

4. The method for preparing the nickel-based homogeneous hydrogenation catalyst according to claim 3, It is characterized in that The molar ratio of the main catalyst to the co-catalyst is 1:3-4.

5. The method for preparing the nickel-based homogeneous hydrogenation catalyst according to claim 1, It is characterized in that The mass ratio of the main catalyst to the volume ratio of the solvent is 10-40g:1L.

6. The method for preparing the nickel-based homogeneous hydrogenation catalyst according to claim 1, It is characterized in that The molar ratio of the main catalyst to the third monomer is 1:1-3.

7. The method for preparing the nickel-based homogeneous hydrogenation catalyst according to claim 1, It is characterized in that The solvent includes at least one of aromatic hydrocarbons, aliphatic alkanes, and cycloalkanes; The aromatic hydrocarbons include at least one of benzene, toluene and ethylbenzene; The aliphatic alkane includes at least one of pentane, hexane, heptane and octane; The cycloalkane includes at least one of cyclopentane and cyclohexane.

8. The method for preparing the nickel-based homogeneous hydrogenation catalyst according to claim 1, It is characterized in that In step 1, the reaction time is 5-120 min; In step 2, the reaction aging temperature is 40-60°C, the pressure is 0.1-0.60MPa, and the time is 10-30min; In step 3, the time for continuing aging is 30-120 minutes.

9. A method for preparing SEBS or SEPS, It is characterized in that include: A nickel-based homogeneous hydrogenation catalyst prepared by the preparation method described in any one of claims 1 to 8.

10. The method for preparing SEBS or SEPS according to claim 9, It is characterized in that The specific steps include: A polymer solution containing 3-15 wt% of SBS or SIS, hydrogen and a nickel-based homogeneous hydrogenation catalyst are added into a polymerization kettle, and then a hydrogenation reaction is carried out to obtain SEBS or SEPS.

11. The method for preparing SEBS or SEPS according to claim 10, It is characterized in that The temperature of the hydrogenation reaction is 50-100° C., the pressure is 1.5-4 MPa, and the time is 2-4 hours.

12. The method for preparing SEBS or SEPS according to claim 10, It is characterized in that The nickel-based homogeneous hydrogenation catalyst is added in an amount of 0.001 to 0.06 g per 100 g of the SBS / SIS, based on the mass of the metal contained in the nickel-based homogeneous hydrogenation catalyst.

13. The method for preparing SEBS or SEPS according to claim 10, It is characterized in that The SBS or SIS is a block copolymer, which is obtained by polymerizing styrene and butadiene or isoprene under the action of an initiator and a structure regulator, wherein the styrene content is 10-90wt%, and the butadiene or isoprene segment content is 10-90wt%.

14. The method for preparing SEBS or SEPS according to claim 10, It is characterized in that The solvent in the polymer solution includes at least one of aromatic hydrocarbons, aliphatic alkanes, and cycloalkanes; The aromatic hydrocarbons include at least one of benzene, toluene and ethylbenzene; The aliphatic alkane includes at least one of pentane, hexane, heptane and octane; The cycloalkane includes at least one of cyclopentane and cyclohexane.

15. The method for preparing SEBS or SEPS according to claim 14, It is characterized in that The amount of the solvent added is 300-1000wt% of the total weight of styrene and butadiene monomers.

16. The method for preparing SEBS or SEPS according to claim 13, It is characterized in that The initiator is at least one of n-butyl lithium, sec-butyl lithium, tert-butyl lithium and hexyl lithium; The initiator is used in an amount of 0.2-3 mmol per 100 grams of total monomers; The structure regulator is selected from at least one of tetrahydrofuran, ethyl tetrahydrofurfuryl ether, tetramethyl divinyl diamine, tetrahydrofuran methanol, and diethylene glycol dimethyl ether; The added amount of the structure regulator is 20-2000wt% of the initiator.

17. The method for preparing SEBS or SEPS according to claim 10, It is characterized in that The SBS or SIS is a linear triblock copolymer prepared by a three-step process, or a linear diblock copolymer prepared by a two-step process followed by linear coupling, or a star-shaped diblock copolymer prepared by a two-step process followed by star-shaped coupling; The coupling agent used in the coupling process is at least one of polyvinyl compounds, halides, ethers, aldehydes, ketones and esters.

18. The method for preparing SEBS or SEPS according to claim 17, It is characterized in that The coupling agent is at least one of divinylbenzene, tetravinylsilane, tetrachloromethane, silicon tetrachloride, tin tetrachloride and dimethyl terephthalate; The molar ratio of the coupling agent to the initiator is 0.1-2.

19. The method for preparing SEBS or SEPS according to claim 10, It is characterized in that The residual rate of olefin double bonds in the product obtained after the hydrogenation reaction is not more than 5wt%, and the content of unsaturated benzene rings is not less than 95wt%.

20. The method for preparing SEBS or SEPS according to claim 10, It is characterized in that The product of the hydrogenation reaction is transferred to a chemical treatment kettle, an antioxidant is added, and then separated to obtain SEBS or SEBS; The antioxidant is at least one of 1520L, 1076, 1010, 264, TNPP and triisopropanolamine, and the added amount is 0.5-5wt%.

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