Rare earth catalyst composition, rare earth catalyst and butadiene polymer and preparation method thereof

Abstract

The present invention relates to the field of rare earth catalysts and discloses a rare earth catalyst composition, a rare earth catalyst, a butadiene polymer, and a preparation method thereof. The rare earth catalyst composition of the present invention comprises a solid neodymium compound, an alkylaluminum compound, a halogenated compound, and a conjugated diene. The solid neodymium compound is obtained by removing the solvent from the reaction product of an aqueous solution of neodymium chloride, an organic phosphonate, an organic solvent, and an alkaline compound, wherein the molar ratio of the organic phosphonate to the neodymium chloride in the aqueous solution of neodymium chloride is 5 or greater. The butadiene polymer obtained using the rare earth catalyst provided by the present invention has a narrow molecular weight distribution and a high cis content.

Description

Technical Field

[0001] The present invention relates to a rare earth catalyst, in particular to a rare earth catalyst composition, a rare earth catalyst and a butadiene polymer and a preparation method thereof. Background Art

[0002] Social development places higher demands on material performance. In the tire sector, the European Union implemented mandatory tire labeling in 2011, categorizing tires' rolling resistance and wet skid resistance into grades A, B, C, E, and F. The China Rubber Industry Association released the "Tire Grading Standard" in 2016, recommending that tire manufacturers clearly label tires' rolling resistance coefficient, wet performance, and noise level, encouraging users to choose tires with better performance. Both the EU tire labeling regulations and China's tire grading standards clearly stipulate that high-grade tires must have lower rolling resistance.

[0003] Butadiene rubber (BR) is one of the raw materials that must be used in the tire manufacturing process. Scholars have conducted relevant research on how to further reduce the rolling resistance of BR. Yan Rong et al. (Special Rubber Products, 2019, 40(01):1-4) found that when the Mooney viscosity and cis-1,4-structure content are similar, the rolling resistance of narrow-distribution BR is lower. This is because at the same Mooney viscosity (i.e., the processing performance is equivalent), compared with the broad distribution, the narrow distribution BR has a lower weight-average molecular weight and a higher number-average molecular weight. The lower weight-average molecular weight helps to improve the extrusion performance of the rubber; the higher number-average molecular weight can reduce the end effect, improve the dynamic mechanical properties of the rubber, and reduce the hysteresis loss. In addition, the narrow distribution BR is superior to the broad distribution in terms of rebound resilience, tear strength, and heat generation performance.

[0004] To reduce the molecular weight distribution of BR, researchers have attempted to add modifiers to the catalyst. Gwanghoon Kwag (Gwanghoon Kwag. A Highly Reactive and Monomeric Neodymium Catalyst [J]. Macromolecules, 2002, 35: 4875-4879) complexed neodecanoic acid with neodymium neodecanoate to produce a tetraligand neodymium neodecanoate. This catalyst reduced the polymer's molecular weight distribution from over 5.0 to around 3.4, still not meeting the requirement of less than or equal to 2.3.

[0005] Cis content is also crucial for polybutadiene. A slight increase in the cis structure content can significantly improve the performance of polyconjugated dienes. Currently available technologies require complex catalyst structures and / or harsh conditions to achieve a cis orientation exceeding 99% in a catalyst. CN1479754A utilizes a heterogeneous catalyst system of neodymium phosphate / alkylaluminum / alkylaluminum chloride / dienes for isoprene polymerization, producing polyisoprene with a cis structure content exceeding 99%. However, the polymerization reaction must be conducted at 0-55°C and for 18-64 hours to achieve a relatively high conversion rate. The complex cyclopentadienyl neodymium / organoboron salt / alkylaluminum system can be used to prepare polybutadiene or polyisoprene with a cis-structure content exceeding 99%, and the polymerization reaction must also be carried out at 0-78°C (see Macromol Rapid Commun, 2003, 24:179-184 and Macromolecules, 2004, 37:5860-5862). The complex PNP-type rare earth compound / organoboron salt system can produce polyisoprene with a cis-structure content exceeding 99% at room temperature, but the polymer has a number-average molecular weight of 5,000-23,000 and poor mechanical properties (see Angew Chem Int Ed, 2007, 46:1909-1913). Summary of the Invention

[0006] The purpose of the present invention is to overcome the problems of the prior art such as too wide molecular weight distribution and low cis content, and to provide a rare earth catalyst composition, a rare earth catalyst prepared from the rare earth catalyst composition, a method for preparing a butadiene polymer using the rare earth catalyst, and a butadiene polymer prepared therefrom. The butadiene polymer obtained using the rare earth catalyst provided by the present invention has a narrow molecular weight distribution and a high cis content.

[0007] In order to achieve the above-mentioned object, the present invention provides a rare earth catalyst composition on the one hand, wherein the rare earth catalyst composition comprises a solid neodymium compound, an alkyl aluminum compound, a halogenated compound and a conjugated diene, and the solid neodymium compound is obtained by removing the solvent from the reaction product of an aqueous solution of neodymium chloride, an organic phosphonate, an organic solvent and an alkaline compound, wherein the molar ratio of the organic phosphonate to the neodymium chloride in the aqueous solution of neodymium chloride is greater than 5.

[0008] Preferably, the molar ratio of the alkaline compound to the neodymium chloride in the neodymium chloride aqueous solution is 3.0-3.5:1.

[0009] Preferably, the neodymium chloride content in the neodymium chloride aqueous solution is 0.1-0.5 mol / L.

[0010] Preferably, the organic phosphonate is a structure shown in formula (1), wherein Rd1 、R d2 and R d3 Each independently is hydrogen, hydroxyl, C1-C 20 Alkyl or C1-C 20 Alkoxy, and R d1 、R d2 and R d3 At least one of them is C1-C 20 Alkyl or C1-C 20 Alkoxy,

[0011]

[0012] Preferably, in formula (1), R d1 is hydroxyl group, R d2 and R d3 All are 2-ethylhexyloxy.

[0013] Preferably, in formula (1), R d1 is hydroxyl group, R d2 and R d3 All are 2-ethylhexyl.

[0014] Preferably, in formula (1), R d1 is hydroxyl group, R d2 is ethylhexyl, and R d3 It is ethylhexyloxy.

[0015] Preferably, the organic solvent is C5-C 10 Alkanes, C5-C 10 Cycloalkanes and C6-C 12 One or more aromatic hydrocarbons.

[0016] Preferably, the organic solvent is one or more of hexane, cyclohexane, heptane, pentane, isopentane, octane, methylcyclohexane, benzene, toluene, xylene and cumene.

[0017] Preferably, the amount of the organic solvent used is such that the volume of the organic phase to the volume of the aqueous phase is 0.3-2:1.

[0018] Preferably, the alkaline compound is used in the form of an aqueous solution, and the content of the alkaline compound in the aqueous solution is 0.1-5.0 mol / L.

[0019] Preferably, the alkaline compound is one or more of hydroxide and ammonia water.

[0020] Preferably, the molar ratio of the solid neodymium compound to the alkyl aluminum compound, calculated as neodymium element, is 1:5-14, more preferably 1:7-14.

[0021] Preferably, the molar ratio of the solid neodymium compound to the halogenated compound is 1:2-5, calculated as neodymium element.

[0022] Preferably, the molar ratio of the solid neodymium compound to the conjugated diene is 1:10-80, preferably 1:20-60, calculated as neodymium element.

[0023] Preferably, the alkyl aluminum compound is one or more of the compounds represented by the formula Al(R)3 and the compounds represented by Al(R)2H, and R is selected from a C1-C6 alkyl group; more preferably, the alkyl aluminum compound is one or more of triethylaluminum, triisobutylaluminum, diethylaluminum monohydrogen and diisobutylaluminum monohydrogen.

[0024] Preferably, the halogenated compound is of the formula Al(R 1 )2X represented by the compound of formula Si(R 1 ) 4-n X n The compound shown and the formula Al2(R 1 ) One or more compounds represented by 3X3, each R 1 Each is independently selected from C1-C6 alkyl, benzyl and allyl, each X is independently selected from halogen, and n is an integer of 1-4; more preferably, the halogenated compound is one or more of diethylaluminum chloride, diisobutylaluminum chloride, sesquiethylaluminum chloride, sesquiisobutylaluminum chloride, monochlorosilane, dichlorosilane, trichlorosilane and silicon tetrachloride.

[0025] Preferably, the conjugated diene is isoprene or butadiene.

[0026] According to a second aspect of the present invention, a rare earth catalyst is provided, which is obtained by mixing the components of the rare earth catalyst composition of the present invention.

[0027] According to a third aspect of the present invention, a method for preparing a rare earth catalyst is provided, wherein the rare earth catalyst is obtained by mixing the components of the rare earth catalyst composition of the present invention.

[0028] Preferably, the solid neodymium compound is first mixed with the conjugated diene, and then the alkyl aluminum compound and the halogenated compound are mixed.

[0029] According to a fourth aspect of the present invention, a method for preparing a butadiene polymer is provided, the method comprising: polymerizing butadiene in the presence of an organic solvent and a catalyst to obtain a butadiene polymer, wherein the catalyst is the rare earth catalyst described in the present invention or the rare earth catalyst prepared by the preparation method of the present invention.

[0030] Preferably, the polymerization reaction conditions include: temperature of 0-90° C. and time of 1-5 h.

[0031] According to a fifth aspect of the present invention, a butadiene polymer prepared by the method for preparing a butadiene polymer of the present invention is provided.

[0032] According to the present invention, the obtained butadiene polymer has ultra-narrow distribution and ultra-high cis content, with a molecular weight distribution index as low as below 1.8 and a cis content greater than 99.0 mol%. DETAILED DESCRIPTION

[0033] The endpoints of the ranges and any values 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 endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0034] According to a first aspect of the present invention, a rare earth catalyst composition is provided, wherein the rare earth catalyst composition comprises a solid neodymium compound, an alkyl aluminum compound, a halogenated compound and a conjugated diene, and the solid neodymium compound is obtained by removing the solvent from the reaction product of an aqueous solution of neodymium chloride, an organic phosphonate, an organic solvent and an alkaline compound, wherein the molar ratio of the organic phosphonate to the neodymium chloride in the aqueous solution of neodymium chloride is greater than 5.

[0035] In the present invention, the solid neodymium compound is a solid neodymium compound obtained by removing the solvent from a reaction product of an aqueous solution of neodymium chloride, an organic phosphonate, an organic solvent and an alkaline compound, wherein the molar ratio of the organic phosphonate to the neodymium chloride in the aqueous solution of neodymium chloride is 5 or more.

[0036] According to the present invention, the aqueous solution of neodymium chloride can be obtained by reacting neodymium oxide with hydrochloric acid, or by dissolving anhydrous neodymium chloride or neodymium chloride containing crystalline water in water. There is no particular limitation on the concentration of the neodymium chloride, as long as the neodymium chloride is completely dissolved. For example, the concentration of the aqueous solution of neodymium chloride can be 0.1-0.5 mol / L.

[0037] According to the present invention, preferably, the molar ratio of the organic phosphonate to the neodymium chloride in the aqueous solution of neodymium chloride is 5-8: 1. By making the molar ratio of the organic phosphonate to the neodymium chloride in the aqueous solution of neodymium chloride within the above range, the activity of the catalyst can be further improved.

[0038] According to the present invention, preferably, the organic phosphonate is a structure shown in formula (1), wherein R d1 、Rd2 and R d3 Each independently is hydrogen, hydroxyl, C1-C 20 Alkyl or C1-C 20 Alkoxy, and R d1 、R d2 and R d3 At least one of them is C1-C 20 Alkyl or C1-C 20 Alkoxy; preferably R d1 、R d2 and R d3 Each independently is hydroxyl, C4-C 12 Alkyl or C4-C 12 Alkoxy, and R d1 、R d2 and R d3 At least one of them is C4-C 12 Alkyl or C4-C 12 More preferably, R d1 is hydroxyl group, R d2 and R d3 At least one of them is an alkyl group or an alkoxy group, and R d2 and R d3 Each is independently selected from n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylpentyl, 2-ethylpentyl, n-hexyl, 2-methylhexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentyloxy, 2-methylpentyloxy, 2-ethylpentyloxy, n-hexyl, 2-methylhexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyloxy or n-dodecyloxy.

[0039]

[0040] Specific examples of the organic phosphonate may be selected from one or more compounds shown in the following formula:

[0041] In formula (1), R d1 is hydroxyl group, R d2 and R d3 All are 2-ethylhexyloxy (i.e. di(2-ethylhexyl)phosphonate);

[0042] In formula (1), R d1 is hydroxyl group, R d2 and R d3 All are 2-ethylhexyl (i.e. di(2-ethylhexyl)phosphinate);

[0043] In formula (1), Rd1 is hydroxyl group, R d2 is 2-ethylhexyl, R d3 It is 2-ethylhexyloxy (ie, (2-ethylhexyl) mono-2-ethylhexyl phosphate).

[0044] According to the present invention, the organic phosphonate compound can be obtained by conventional methods in the art, for example, it can be a commercial product, or prepared by conventional methods in the art, and the present invention has no particular limitation on this.

[0045] According to the present invention, the organic solvent is a compound capable of dissolving organic neodymium phosphonate, for example, C5-C 10 Alkanes, C5-C 10 Cycloalkanes and C6-C 12 One or more of the aromatic hydrocarbons, preferably one or more of hexane, cyclohexane, heptane, pentane, isopentane, octane, methylcyclohexane, benzene, toluene, xylene and cumene.

[0046] The amount of the organic solvent is not particularly limited. Preferably, the amount of the organic solvent is such that the volume ratio of the organic phase to the aqueous phase is 0.3-2:1, more preferably 0.5-1:1.

[0047] According to the present invention, the contacting may be performed by mixing the aqueous neodymium chloride solution, the organic phosphonate, the organic solvent, and the alkaline compound together, or by mixing two or more of the above ingredients and then mixing them with the other ingredients. To achieve a lower viscosity and lower impurity content in the resulting neodymium phosphonate solution, the contacting preferably includes: first contacting the aqueous neodymium chloride solution with the organic phosphonate and the organic solvent, followed by second contacting the product of the first contact with the alkaline compound.

[0048] In the present invention, the first contact is used to fully dissolve the reaction raw materials. Preferably, the temperature of the first contact can be, for example, 5-80°C. From the perspective of energy conservation, the first contact is preferably performed at 10-50°C. Furthermore, the time of the first contact is not particularly limited, as long as it sufficiently dissolves the reaction raw materials. For example, it can be 1 minute or longer, preferably 1-5 minutes.

[0049] According to the present invention, preferably, the molar ratio of the alkaline compound to the neodymium chloride in the aqueous solution of neodymium chloride is 3.0-3.5:1.

[0050] According to the present invention, the alkaline compound is a substance having a pH value greater than 7 either by itself or after being prepared into an aqueous solution, preferably one or more of hydroxide and ammonia, more preferably one or more of sodium hydroxide, potassium hydroxide and ammonia. For solid alkaline compounds, they are usually prepared into an aqueous solution for use. There is no particular limitation on the concentration of the aqueous solution, as long as it is sufficiently soluble, and for example, it can be 0.1-5.0 mol / L.

[0051] Preferably, the alkaline substance aqueous solution is added dropwise, and the dropping speed can be 2.0-20.0 mL / min, preferably 5.0-10.0 mL / min.

[0052] According to the present invention, preferably, the second contact temperature is 30-80°C, more preferably 30-55°C, more preferably 45-55°C, and particularly preferably 50°C. By carrying out the reaction at 50°C, both reaction rate and energy saving can be taken into account.

[0053] Furthermore, the second contact time may be any time that ensures sufficient reaction, for example, it may be more than 1 hour, preferably 1-6 hours, and more preferably 1-2 hours.

[0054] According to the present invention, the method for removing the solvent from the reaction product to obtain a solid neodymium compound is preferably to first delaminate the reaction product and separate the aqueous phase, and then dry the organic phase. The drying method is well-known, such as evaporating the solvent followed by heating and drying. Alternatively, the neodymium compound can be precipitated with a precipitant and then heated and dried. The precipitant can be acetone, butanone, ethanol, etc. There are no particular restrictions on the heating and drying conditions, as long as sufficient drying is ensured. For example, heating at 80°C under vacuum for 6 hours can be used. Thorough drying can be determined by weighing the material after a period of heating and drying, recording the weight, and continuing to dry for at least 30 minutes before weighing again. If the difference between the two weighings is less than 0.02% of the total mass, it is considered sufficient drying.

[0055] In the present invention, preferably, the alkyl aluminum compound is one or more of the compounds represented by the formula Al(R)3 and the compounds represented by Al(R)2H, and R is selected from a C1-C6 alkyl group; more preferably, the alkyl aluminum compound is one or more of triethylaluminum, triisobutylaluminum, diethylaluminum monohydrogen and diisobutylaluminum monohydrogen.

[0056] Examples of the C1-C6 alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a n-pentyl group, an isopentyl group, and a neopentyl group.

[0057] In the present invention, preferably, the halogenated compound is of the formula Al(R 1 )2X represented by the compound of formula Si(R 1) 4-n X n The compound shown and the formula Al2(R 1 ) One or more compounds represented by 3X3, each R 1 Each is independently selected from C1-C6 alkyl, benzyl and allyl, each X is independently selected from halogen, and n is an integer of 1-4; more preferably, the halogenated compound is one or more of diethylaluminum chloride, diisobutylaluminum chloride, sesquiethylaluminum chloride, sesquiisobutylaluminum chloride, monochlorosilane, dichlorosilane, trichlorosilane and silicon tetrachloride.

[0058] The above-mentioned C1-C6 alkyl group is the same as that exemplified for the halogenated compound.

[0059] In the present invention, the conjugated diene mainly plays the role of stabilizing the active center of the catalyst and improving the catalytic activity.

[0060] Preferably, the conjugated diene is isoprene or butadiene.

[0061] According to the present invention, the amount of the alkylaluminum compound can be selected based on the solid neodymium compound. Preferably, the molar ratio of the solid neodymium compound to the alkylaluminum compound, calculated as neodymium element, is 1:5-14, more preferably 1:7-14. By adopting a molar ratio within this range, a narrow molecular weight distribution of butadiene can be obtained under relatively high catalytic activity conditions.

[0062] According to the present invention, the amount of the halogenated compound can be selected based on the amount of the solid neodymium compound. Preferably, the molar ratio of the solid neodymium compound to the halogenated compound, calculated as neodymium element, is 1:2-5, more preferably 1:2.8-3.3. By employing a molar ratio within this range, the catalyst activity and stability can be further improved.

[0063] According to the present invention, the amount of the conjugated diene can also be selected based on the solid neodymium compound. Preferably, the molar ratio of the solid neodymium compound to the conjugated diene, calculated as neodymium element, is 1:10-80, preferably 1:20-60, and more preferably 1:30-45. By adopting a molar ratio within this range, the catalyst activity and stability can be further improved.

[0064] According to a second aspect of the present invention, a rare earth catalyst is provided, which is obtained by mixing the components of the rare earth catalyst composition of the present invention.

[0065] According to a third aspect of the present invention, a method for preparing a rare earth catalyst is provided, wherein the rare earth catalyst is obtained by mixing the components of the rare earth catalyst composition of the present invention.

[0066] According to the second and third aspects of the present invention, there is no particular limitation on the mixing method, but it is preferred that the solid neodymium compound and the conjugated diene are mixed first, and then the alkyl aluminum compound and the halogenated compound are mixed.

[0067] In a preferred embodiment of the present invention, the mixing is carried out in the following manner: (1) a solid neodymium compound and a conjugated diene are first mixed to obtain a first mixture. There are no special requirements for the mixing conditions in this step, as long as they are fully mixed (for example, they can be mixed at room temperature); (2) an alkyl aluminum compound is added to the first mixture, and the mixture is mixed at 10-50°C for 10-200 minutes to obtain a second mixture; (3) a halogenated compound is added to the second mixture, and the mixture is mixed at 40-80°C for 30-300 minutes to obtain a rare earth catalyst.

[0068] According to the present invention, the catalyst of the present invention can be dissolved in an organic solvent to obtain a solution in a homogeneous state. Preferably, the solvent used in the homogeneous solution is C5-C 10 Alkanes, C5-C 10 Cycloalkanes and C6-C 12 One or more aromatic hydrocarbons, preferably one or more of pentane, cyclopentane, hexane, cyclohexane, methylcyclohexane, heptane, octane, benzene, toluene, xylene, and cumene. The amount of the solvent used can vary within a wide range. Preferably, in the homogeneous solution, the amount of the solvent used is such that the concentration of the solid neodymium compound, calculated as neodymium element, is 0.01-0.5 mmol / mL, preferably 0.01-0.1 mmol / mL, and more preferably 0.01-0.02 mmol / mL.

[0069] According to a fourth aspect of the present invention, a method for preparing a butadiene polymer is provided, comprising the steps of polymerizing a conjugated diene in the presence of an organic solvent and a catalyst to obtain a butadiene polymer, wherein the catalyst is the rare earth catalyst described in the present invention or the rare earth catalyst prepared by the preparation method of the third aspect of the present invention.

[0070] The rare earth catalyst is as described above and will not be described in detail here.

[0071] According to the present invention, the amount of the rare earth catalyst is: the molar ratio of neodymium to monomer is 1.50×10 -5 -4.0×10 -5 .

[0072] According to the present invention, the polymerization reaction conditions include: temperature of 0-90° C., time of 1-5 hours. Preferably, the polymerization reaction conditions include: temperature of 50-90° C., time of 1-5 hours.

[0073] According to the present invention, in order to overcome the damage of oxygen to the active centers of the catalyst, the polymerization reaction can be carried out in an inert atmosphere. The method of maintaining the inert atmosphere is to evacuate the reaction vessel and then introduce a gas selected from nitrogen, argon, helium, etc.

[0074] According to the present invention, the organic solvent can be any hydrocarbon solvent that is inert to the polymerization reaction, and the organic solvent can be, for example, C5-C 10 Alkanes, C5-C 10 Cycloalkanes and C6-C 12 One or more aromatic hydrocarbons, preferably one or more of hexane, cyclohexane, heptane, pentane, isopentane, octane, methylcyclohexane, benzene, toluene, xylene, and cumene. The amount of the organic solvent can vary within a wide range. Preferably, the amount of the organic solvent is 300-1200 parts by weight relative to 100 parts by weight of the conjugated diene.

[0075] According to a fifth aspect of the present invention, a butadiene polymer prepared by the preparation method of the present invention is provided.

[0076] According to the present invention, the molecular weight distribution of the butadiene polymer is less than 1.8, and the content of cis-1,4-polymerization structure is greater than 99.0 mol%.

[0077] The present invention will be described in detail below through examples, but the present invention is not limited to the following examples.

[0078] In the following examples and comparative examples, molecular weight and molecular weight distribution were determined using a Tosoh HLC-8320 gel permeation chromatograph (GPC) equipped with two TSKgel SuperMultipore HZ-H analytical columns, THF as the mobile phase, and narrow-distribution polystyrene as the standard, at 40°C. The cis-1,4-polymer structure content was determined using a Nicolet iS5 mid-infrared spectrometer.

[0079] Example 1

[0080] To a 500mL beaker, add 100mL of n-hexane, 77g of di(2-ethylhexyl)phosphonate, and 210mL of a 0.50mol / L sodium hydroxide aqueous solution, mix, and set aside. To a 1000mL three-necked flask, add 120mL of a 0.25mol / L neodymium chloride aqueous solution and 400mL of n-hexane. Heat to 50°C in a water bath. Stirring is initiated, and the contents of the beaker are then added dropwise to the flask via a constant pressure funnel. The addition takes 30 minutes, and the reaction is continued for 30 minutes after the addition is complete. The molar ratio of di(2-ethylhexyl)phosphonate to neodymium chloride is 8.0, and the molar ratio of sodium hydroxide to neodymium chloride is 3.5. After the reaction is complete, stirring is stopped, the aqueous phase is separated, and then washed three times with 200mL of water. The separated organic phase is evaporated, the solvent evaporated, and dried in a vacuum oven at 80°C for 6 hours to obtain a solid neodymium compound.

[0081] To a 50ml dry glass bottle, add 0.2g of the above-mentioned neodymium compound. After three cycles of vacuum evacuation and nitrogen refilling, add 8ml of n-hexane and 0.4g of butadiene, mix, and stir at 30°C for 30 minutes. Then, add 2.6ml of a 0.5mol / L n-hexane solution of diisobutylaluminum monohydrogen. After reacting for 30 minutes, add 1.2ml of a 0.5mol / L n-hexane solution of diethylaluminum monochloride at 60°C. After reacting for 2 hours, the catalyst is obtained. The molar ratio of the above-mentioned neodymium compound, butadiene, diisobutylaluminum monohydrogen, and diethylaluminum monochloride, calculated as neodymium element, is 1:41:7.2:3.3.

[0082] Under nitrogen protection, 2000 g of hexane and 350 g of butadiene were added to a 5 L stainless steel reactor, stirred evenly, and then the above catalyst (neodymium / monomer molar ratio was 3.1×10 -5 ), and the polymerization reaction was carried out at 40°C for 5 hours to obtain the corresponding polybutadiene. The monomer conversion rate and the properties of the polybutadiene are shown in Table 1.

[0083] Example 2

[0084] The preparation of solid neodymium compound is the same as that in Example 1.

[0085] To a 50ml dry glass bottle, add 0.12g of the above-mentioned neodymium compound. After three cycles of vacuum evacuation and nitrogen refilling, add 8ml of n-hexane and 0.2g of butadiene, mix, and stir at 30°C for 30 minutes. Then, add 2.6ml of a 0.5mol / L n-hexane solution of diisobutylaluminum monohydride. After reacting for 30 minutes, add 0.6ml of a 0.5mol / L n-hexane solution of diethylaluminum monochloride at 60°C. After reacting for 2 hours, the catalyst is obtained. The molar ratio of the above-mentioned neodymium compound, butadiene, diisobutylaluminum monohydride, and diethylaluminum monochloride, calculated as neodymium element, is 1:34:12.0:2.8.

[0086] Under nitrogen protection, 2000 g of hexane and 350 g of butadiene were added to a 5 L stainless steel reactor, stirred evenly, and then the above catalyst (neodymium / monomer molar ratio was 1.9×10 -5 ), and the polymerization reaction was carried out at 30°C for 8 hours to obtain the corresponding polybutadiene. The monomer conversion rate and the properties of the polybutadiene are shown in Table 1.

[0087] Example 3

[0088] To a 500mL beaker, add 100mL of n-hexane, 60g of di(2-ethylhexyl)phosphonate, and 210mL of a 0.50mol / L sodium hydroxide aqueous solution, mix, and set aside. To a 1000mL three-necked flask, add 120mL of a 0.25mol / L neodymium chloride aqueous solution and 400mL of n-hexane. Heat the mixture to 50°C in a water bath. Stirring is initiated, and the contents of the beaker are then added dropwise to the flask via a constant pressure funnel. The addition takes 30 minutes, and the reaction is continued for 30 minutes. The molar ratio of di(2-ethylhexyl)phosphonate to neodymium chloride is 6.2, and the molar ratio of sodium hydroxide to neodymium chloride is 3.5. After the reaction is complete, stirring is stopped, the aqueous phase is separated, and then washed three times with 200mL of water. The separated organic phase is evaporated, the solvent is evaporated, and the organic phase is dried in a vacuum oven at 80°C for 6 hours to obtain a solid neodymium compound.

[0089] To a 50ml dry glass bottle, add 0.16g of the above-mentioned neodymium compound. After three cycles of vacuum evacuation and nitrogen refilling, add 8ml of n-hexane and 0.3g of butadiene, mix, and stir at 30°C for 30 minutes. Then, add 3.0ml of a 0.5mol / L n-hexane solution of diisobutylaluminum monohydride. After reacting for 30 minutes, add 0.8ml of a 0.5mol / L n-hexane solution of diethylaluminum monochloride at 60°C. After reacting for 2 hours, the catalyst is obtained. The molar ratio of the above-mentioned neodymium compound, butadiene, diisobutylaluminum monohydride, and diethylaluminum monochloride, calculated as neodymium element, is 1:38:10.4:2.8.

[0090] Under nitrogen protection, 2000 g of hexane and 350 g of butadiene were added to a 5 L stainless steel reactor, stirred evenly, and then the above catalyst (neodymium / monomer molar ratio was 2.5×10 -5 ), and the polymerization reaction was carried out at 40°C for 5 hours to obtain the corresponding polybutadiene. The monomer conversion rate and the properties of the polybutadiene are shown in Table 1.

[0091] Example 4

[0092] The preparation of solid neodymium compound is the same as that in Example 3.

[0093] To a 50ml dry glass bottle, add 0.12g of the above-mentioned neodymium compound. After three cycles of vacuum evacuation and nitrogen refilling, add 8ml of n-hexane and 0.2g of butadiene, mix, and stir at 30°C for 30 minutes. Then, add 2.6ml of a 0.5mol / L n-hexane solution of diisobutylaluminum monohydride. After reacting for 30 minutes, add 0.6ml of a 0.5mol / L n-hexane solution of diethylaluminum monochloride at 60°C. After reacting for 2 hours, the catalyst is obtained. The molar ratio of the above-mentioned neodymium compound, butadiene, diisobutylaluminum monohydride, and diethylaluminum monochloride, calculated as neodymium element, is 1:34:12.0:2.8.

[0094] Under nitrogen protection, 2000 g of hexane and 350 g of butadiene were added to a 5 L stainless steel reactor, stirred evenly, and then the above catalyst (neodymium / monomer molar ratio was 1.9×10 -5 ), and the polymerization reaction was carried out at 30°C for 8 hours to obtain the corresponding polybutadiene. The monomer conversion rate and the properties of the polybutadiene are shown in Table 1.

[0095] Example 5

[0096] To a 500mL beaker, add 100mL of n-hexane, 48g of di(2-ethylhexyl)phosphonate, and 180mL of a 0.50mol / L sodium hydroxide aqueous solution, mix, and set aside. To a 1000mL three-necked flask, add 120mL of a 0.25mol / L neodymium chloride aqueous solution and 400mL of n-hexane. Heat the mixture to 50°C in a water bath. Stirring is initiated, and the contents of the beaker are then added dropwise to the flask via a constant pressure funnel. The addition takes 30 minutes, and the reaction is continued for 30 minutes after the addition is complete. The molar ratio of di(2-ethylhexyl)phosphonate to neodymium chloride is 5.0, and the molar ratio of sodium hydroxide to neodymium chloride is 3.0. After the reaction is complete, stirring is stopped, the aqueous phase is separated, and then washed three times with 200mL of water. The separated organic phase is evaporated, the solvent evaporated, and dried in a vacuum oven at 80°C for 6 hours to obtain a solid neodymium compound.

[0097] To a 50ml dry glass bottle, add 0.16g of the above-mentioned neodymium compound. After three cycles of vacuum evacuation and nitrogen refilling, add 8ml of n-hexane and 0.3g of butadiene, mix, and stir at 30°C for 30 minutes. Then, add 3.0ml of a 0.5mol / L n-hexane solution of diisobutylaluminum monohydrogen. After reacting for 30 minutes, add 0.8ml of a 0.5mol / L n-hexane solution of diethylaluminum monochloride at 60°C. After reacting for 2 hours, set aside. The ratio of the above-mentioned neodymium compound, butadiene, diisobutylaluminum monohydrogen, and diethylaluminum monochloride is 1:38:10.4:2.8.

[0098] Under nitrogen protection, 2000 g of hexane and 350 g of butadiene were added to a 5 L stainless steel reactor, stirred evenly, and then the above catalyst (neodymium / monomer molar ratio was 2.5×10 -5 ), and the polymerization reaction was carried out at 40°C for 5 hours to obtain the corresponding polybutadiene. The monomer conversion rate and the properties of the polybutadiene are shown in Table 1.

[0099] Example 6

[0100] The preparation of solid neodymium compound is the same as that in Example 5.

[0101] To a 50ml dry glass bottle, add 0.12g of the above-mentioned neodymium compound. After three cycles of vacuum evacuation and nitrogen refilling, add 8ml of n-hexane and 0.2g of butadiene, mix, and stir at 30°C for 30 minutes. Then, add 2.6ml of a 0.5mol / L n-hexane solution of diisobutylaluminum monohydride. After reacting for 30 minutes, add 0.6ml of a 0.5mol / L n-hexane solution of diethylaluminum monochloride at 60°C. After reacting for 2 hours, the catalyst is obtained. The molar ratio of the above-mentioned neodymium compound, butadiene, diisobutylaluminum monohydride, and diethylaluminum monochloride, calculated as neodymium element, is 1:34:12.0:2.8.

[0102] Under nitrogen protection, 2000 g of hexane and 350 g of butadiene were added to a 5 L stainless steel reactor, stirred evenly, and then the above catalyst (neodymium / monomer molar ratio was 1.9×10 -5 ), and the polymerization reaction was carried out at 30°C for 8 hours to obtain the corresponding polybutadiene. The monomer conversion rate and the properties of the polybutadiene are shown in Table 1.

[0103] Example 7

[0104] The synthesis of the solid neodymium compound is the same as in Example 1.

[0105] To a 50ml dry glass bottle, add 0.15g of the above-mentioned neodymium compound. After three cycles of vacuum evacuation and nitrogen refilling, add 8ml of n-hexane and 0.3g of butadiene, mix, and stir at 30°C for 30 minutes. Then, add 2.8ml of a 0.5mol / L triisobutylaluminum solution in n-hexane. After 30 minutes of reaction, add 0.8ml of a 0.5mol / L diethylaluminum chloride solution in n-hexane at 60°C. After 2 hours of reaction, the catalyst is obtained. The molar ratio of the above-mentioned neodymium compound, butadiene, triisobutylaluminum, and diethylaluminum chloride, calculated as neodymium element, is 1:41:10.3:3.0.

[0106] Under nitrogen protection, 2000 g of hexane and 350 g of butadiene were added to a 5 L stainless steel reactor, stirred evenly, and then the above catalyst (neodymium / monomer molar ratio was 2.3 × 10 -5), and the polymerization reaction was carried out at 30°C for 8 hours to obtain the corresponding polybutadiene. The monomer conversion rate and the properties of the polybutadiene are shown in Table 1.

[0107] Example 8

[0108] The synthesis of the neodymium compound is the same as in Example 1.

[0109] To a 50ml dry glass bottle, add 0.25g of the above-mentioned neodymium compound. After three cycles of vacuum evacuation and nitrogen refilling, add 8ml of n-hexane and 0.5g of butadiene, mix, and stir at 30°C for 30 minutes. Then, add 5.4ml of a 0.5mol / L triisobutylaluminum solution in n-hexane. After 30 minutes of reaction, add 1.4ml of a 0.5mol / L diethylaluminum chloride solution in n-hexane at 60°C. After 2 hours of reaction, the catalyst is obtained. The ratio of the above-mentioned neodymium compound, butadiene, triisobutylaluminum, and diethylaluminum chloride, calculated as neodymium element, is 1:41:12.0:3.1.

[0110] Under nitrogen protection, 2000 g of hexane and 350 g of butadiene were added to a 5 L stainless steel reactor, stirred evenly, and then the above catalyst (neodymium / monomer molar ratio was 3.9 × 10 -5 ), polymerization reaction was carried out at 50°C for 5h to obtain the corresponding polybutadiene. The monomer conversion rate and properties of the polybutadiene are shown in Table 1.

[0111] Comparative Example 1

[0112] The same conditions were used as in Example 1, except that 44 g of di(2-ethylhexyl)phosphonate was added instead of 77 g. The molar ratio of di(2-ethylhexyl)phosphonate to neodymium chloride was 4.5, and the molar ratio of sodium hydroxide to neodymium chloride was 3.5. The resulting monomer conversion and properties of the polybutadiene are shown in Table 1.

[0113] Comparative Example 2

[0114] The same conditions were used as in Example 1, except that the organic phase of the neodymium compound was not dried to form a solid neodymium compound, but instead was distilled to remove water to obtain a neodymium acid ester solution (water content: 228 μg / g). The monomer conversion and properties of the resulting polybutadiene are shown in Table 1.

[0115] Table 1

[0116]

[0117] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A rare earth catalyst composition, characterized in that: The rare earth catalyst composition comprises a solid neodymium compound, an alkyl aluminum compound, a halogenated compound and a conjugated diene. The solid neodymium compound is obtained by removing the solvent from a reaction product of an aqueous solution of neodymium chloride, an organic phosphonate, an organic solvent, and an alkaline compound, wherein the molar ratio of the organic phosphonate to the neodymium chloride in the aqueous solution of neodymium chloride is 5 or more, The molar ratio of the solid neodymium compound to the alkyl aluminum compound is 1:5-14, calculated as neodymium element; The molar ratio of the solid neodymium compound to the halogenated compound is 1:2-5, calculated as neodymium element; The molar ratio of the solid neodymium compound to the conjugated diene is 1:10-80, calculated as neodymium element.

2. The rare earth catalyst composition according to claim 1, wherein The molar ratio of the alkaline compound to the neodymium chloride in the neodymium chloride aqueous solution is 3.0-3.5:

1.

3. The rare earth catalyst composition according to claim 1, wherein The neodymium chloride content in the neodymium chloride aqueous solution is 0.1-0.5 mol / L.

4. The rare earth catalyst composition according to claim 1, wherein The organic phosphonate has a structure shown in formula (1), wherein R d1 、R d2 and R d3 Each independently is hydrogen, hydroxyl, C1-C 20 Alkyl or C1-C 20 Alkoxy, and R d1 、R d2 and R d3 At least one of them is C1-C 20 Alkyl or C1-C 20 Alkoxy, 5. The rare earth catalyst composition according to claim 4, wherein In formula (1), R d1 is hydroxyl group, R d2 and R d3 All are 2-ethylhexyloxy.

6. The rare earth catalyst composition according to claim 4, wherein In formula (1), R d1 is hydroxyl group, R d2 and R d3 All are 2-ethylhexyl.

7. The rare earth catalyst composition according to claim 4, wherein In formula (1), R d1 is hydroxyl group, R d2 is 2-ethylhexyl, R d3 It is 2-ethylhexyloxy.

8. The rare earth catalyst composition according to claim 1, wherein The organic solvent is C5-C 10 Alkanes, C5-C 10 Cycloalkanes and C6-C 12 One or more aromatic hydrocarbons.

9. The rare earth catalyst composition according to claim 8, wherein The organic solvent is one or more of hexane, cyclohexane, heptane, pentane, isopentane, octane, methylcyclohexane, benzene, toluene, xylene and cumene.

10. The rare earth catalyst composition according to claim 8, wherein The amount of the organic solvent used is such that the volume of the organic phase and the volume of the aqueous phase are 0.3-2:

1.

11. The rare earth catalyst composition according to claim 1, wherein The alkaline compound is used in the form of an aqueous solution, and the content of the alkaline compound in the aqueous solution is 0.1-5.0 mol / L.

12. The rare earth catalyst composition according to claim 11, wherein The alkaline compound is one or more of hydroxide and ammonia water.

13. The rare earth catalyst composition according to claim 1, wherein The molar ratio of the solid neodymium compound to the alkyl aluminum compound is 1:7-14, calculated based on neodymium element.

14. The rare earth catalyst composition according to claim 1, wherein The molar ratio of the solid neodymium compound to the conjugated diene is 1:20-60, calculated as neodymium element.

15. The rare earth catalyst composition according to any one of claims 1 to 14, wherein: The alkyl aluminum compound is one or more compounds represented by the formula Al(R)3 and Al(R)2H, and R is selected from a C1-C6 alkyl group.

16. The rare earth catalyst composition according to claim 15, wherein The alkyl aluminum compound is one or more of triethyl aluminum, triisobutyl aluminum, diethyl aluminum monohydrogen and diisobutyl aluminum monohydrogen.

17. The rare earth catalyst composition according to any one of claims 1 to 14, wherein: The halogenated compound is of the formula Al(R 1 )2X represented by the compound of formula Si(R 1 ) 4-n X n The compound shown and the formula Al2(R 1 ) One or more compounds represented by 3X3, each R 1 Each X is independently selected from C1-C6 alkyl, benzyl and allyl, each X is independently selected from halogen, and n is an integer of 1-4.

18. The rare earth catalyst composition according to claim 17, wherein The halogenated compound is one or more of diethylaluminum chloride, diisobutylaluminum chloride, sesquiethylaluminum chloride, sesquiisobutylaluminum chloride, monochlorosilane, dichlorosilane, trichlorosilane and silicon tetrachloride.

19. The rare earth catalyst composition according to any one of claims 1 to 14, wherein: The conjugated diene is isoprene or butadiene.

20. A rare earth catalyst, characterized in that The rare earth catalyst is obtained by mixing the components of the rare earth catalyst composition according to any one of claims 1 to 19.

21. A method for preparing a rare earth catalyst, characterized in that: The rare earth catalyst is obtained by mixing the components of the rare earth catalyst composition according to any one of claims 1 to 19.

22. The method according to claim 21, wherein The solid neodymium compound is first mixed with the conjugated diene, and then the alkyl aluminum compound and the halogenated compound are mixed.

23. A method for preparing a butadiene polymer, the method comprising: The step of polymerizing butadiene in the presence of an organic solvent and a catalyst to obtain a butadiene polymer is characterized in that the catalyst is the rare earth catalyst according to claim 20 or the rare earth catalyst prepared according to claim 21 or 22.

24. The method according to claim 23, wherein The polymerization reaction conditions include: temperature of 0-90° C. and time of 1-5 h.

25. The butadiene polymer prepared by the method for preparing a butadiene polymer according to claim 23 or 24.

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