A novel rare earth neodecanoate catalyst for polymerization, its preparation method and application

Abstract

The present invention relates to the technical field of catalysts, and particularly relates to a rare earth neodecanoate catalyst for polymerization, its preparation method and application. The rare earth neodecanoate catalyst comprises the following components: neodymium neodecanoate, a halogen-containing compound, an alcohol compound, a conjugated diene and an auxiliary agent. The auxiliary agent comprises a mixture of triphenyl(methyl)-tetrakis(pentafluorophenyl)borate and phenyl-dimethylamino-tetraphenylborate, and the molar ratio of the two is 2-4:1. The polybutadiene product prepared by the rare earth catalyst of the present invention has a high cis structure content, molecular weight and yield, and at the same time has a narrow molecular weight distribution, the raw materials are easy to obtain, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and particularly relates to a rare earth neodecanoate catalyst for polymerization, a preparation method thereof, and an application thereof. Background Art

[0002] Butadiene rubber is short for cis-1,4-polybutadiene rubber, and its molecular formula is (C4H6). n Butadiene rubber is a synthetic rubber with a regular structure polymerized from 1,3-butadiene, and its cis structure content is above 95%. Butadiene rubber is particularly suitable for manufacturing automobile tires and cold-resistant products, and can also manufacture buffer materials and various rubber shoes, adhesive tapes, tapes, and sponge rubbers, etc.

[0003] The polymerization reaction of preparing butadiene rubber with 1,3-butadiene as the monomer is a highly stereospecific reaction, which can provide various polybutadienes with different microstructures and affect the basic properties of the rubber. The stereoselectivity of 1,3-butadiene is mainly controlled by adjusting polymerization parameters (i.e., reaction temperature, solvent used, and catalyst system). Butadiene rubber can be divided into nickel-based, cobalt-based, titanium-based, and rare earth-based (neodymium-based) butadiene rubbers according to different catalysts.

[0004] Rare earth catalysts are generally multi-component systems with rare earth compounds as the main catalyst. When the main catalyst is a rare earth compound containing halogen, usually adding alkyl aluminum can form a catalyst with catalytic activity, which is a binary system. When the main catalyst is a rare earth compound without halogen, in addition to adding alkyl aluminum, a Lewis acid that can provide halogen must also be added to form a catalyst with catalytic activity, which is a ternary system. In addition, in order to improve the activity of the catalyst, improve the catalyst phase state, and regulate the molecular weight and microstructure of polymerization, some regulators are usually added, such as dienes, carboxylic acids, and aromatic hydrocarbons, etc.

[0005] However, the rare earth catalyst systems at the present stage have problems such as cumbersome preparation process, complex composition, and high cost. The yield of polybutadiene rubber products is low, and most rare earth catalyst systems have not achieved a 1,4-cis selectivity higher than 98%, resulting in limited practical applications.

[0006] For example, Chinese Patent Application CN113929802A discloses a neodecanoic acid rare earth catalyst, its preparation method and application. The rare earth catalyst includes: a. neodymium phosphate compound; b. conjugated diene; c. alkyl aluminum or alkyl aluminum hydride, or a mixture of both; d. halogen-containing compound; wherein, the molar ratio of each component is a:b:c:d = 1:(2-50):(5-40):(1-20). The cis structure content of the polybutadiene rubber product prepared by the rare earth catalyst provided by this invention is below 98%, and the molecular weight distribution Mw / Mn is above 2. Therefore, the cis structure content needs to be further improved, and the molecular weight distribution needs to be further narrowed.

[0007] Chinese Patent CN117264103B discloses a rare earth catalyst containing neodymium neodecanoate and a preparation method of polybutadiene rubber based on this catalyst. The rare earth catalyst containing neodymium neodecanoate is made of neodymium neodecanoate, alcohol compound, methylaluminoxane, conjugated diene and ionic liquid. The rare earth catalyst provided by this invention has the advantages of high activity and high cis selectivity, and can prepare high-quality polybutadiene rubber products with characteristics such as ultra-high cis content, high molecular weight and narrow molecular weight distribution, and the product has a high yield. However, ionic liquid is used in this catalyst, the preparation process is complex, and the cost is relatively high.

[0008] Therefore, it is very necessary to develop a neodecanoic acid rare earth catalyst and its preparation method and application that can solve the above technical problems. Summary of the Invention

[0009] The purpose of this invention is to overcome the deficiencies of the prior art and provide a neodecanoic acid rare earth catalyst, its preparation method and application. The polybutadiene product prepared by the neodecanoic acid rare earth catalyst of this invention has a relatively high cis structure content, molecular weight and yield, and at the same time has a narrow molecular weight distribution, the raw materials are easy to obtain, and the cost is relatively low.

[0010] This invention is realized through the following technical solutions:

[0011] A neodecanoic acid rare earth catalyst for polymerization, including the following components: neodymium neodecanoate, halogen-containing compound, alcohol compound, conjugated diene and additive. The additive includes a mixture of triphenyl(methyl)-tetrakis(pentafluorophenyl)borate and phenyl-dimethylamino-tetraphenylborate, and the molar ratio of the two is 2-4:1.

[0012] Preferably, the halogen-containing compound includes alkyl aluminum halide.

[0013] More preferably, the alkyl aluminum halide includes at least one of diethylaluminum chloride and diisobutylaluminum trichloride.

[0014] More preferably, the alkylaluminum halide is a mixture of diethylaluminum chloride and diisobutylaluminum trichloride, and the molar ratio of the two is 1-3:1.

[0015] Preferably, the alcohol compound includes at least one of isopropanol and cyclohexanol.

[0016] More preferably, the alcohol compound is a mixture of isopropanol and cyclohexanol, and the molar ratio of the two is 3-5:1.

[0017] Preferably, the conjugated diene is isoprene and / or piperylene.

[0018] Preferably, the molar ratio of neodymium element, halogen-containing compound, alcohol compound, conjugated diene, and additive in neodymium neodecanoate is 1:1-20:5-10:20-80:1-5.

[0019] More preferably, the molar ratio of neodymium element, halogen-containing compound, alcohol compound, conjugated diene, and additive in neodymium neodecanoate is 1:5-15:6-8:30-70:2-4.

[0020] Preferably, the preparation method of the neodymium neodecanoate includes the following steps:

[0021] (1) Dissolve neodymium oxide in hydrochloric acid, control the pH to 4.5-5.0, and remove impurities to obtain a neodymium chloride NdCl3 solution;

[0022] (2) Let the NdCl3 solution obtained in step (1) stand, filter the precipitate, and obtain a clear NdCl3 solution;

[0023] (3) Mix neodecanoic acid and n-hexane, add a sodium hydroxide solution with a concentration of 5 mol / L, and carry out a saponification reaction at 60-65 °C for 30-35 minutes to obtain a reaction solution;

[0024] (4) Add the clear NdCl3 solution to the reaction solution obtained in step (3), mix and react for more than 20 minutes, and let it stand for phase separation;

[0025] (5) Further filter the upper product obtained in step (4) to remove impurities to complete the preparation.

[0026] More preferably, the dosage of neodymium oxide is 23-24 parts by weight, neodecanoic acid is 170-178 parts by weight, n-hexane is 185-195 parts by weight, and the sodium hydroxide solution is 50-55 parts by weight.

[0027] The present invention also relates to a preparation method of the above-mentioned rare earth neodecanoate catalyst, including the following steps:

[0028] 1) Under an inert atmosphere, dissolve neodymium neodecanoate, alcohol compound, additive, and conjugated diene in an organic solvent to obtain a mixed solution A;

[0029] 2) Add a halogen-containing compound to the mixed solution A to obtain a mixed solution B, and age for 15 - 30 min to obtain the product.

[0030] Preferably, the organic solvent in step 1) is an inert organic solvent.

[0031] More preferably, the inert organic solvent includes saturated aliphatic hydrocarbons and / or cycloaliphatic hydrocarbons.

[0032] More preferably, the inert organic solvent includes straight-chain alkanes with 5 - 10 carbon atoms and / or cycloalkanes with 5 - 10 carbon atoms.

[0033] More preferably, the inert organic solvent includes at least one of n-pentane, n-hexane, cyclohexane, and n-heptane.

[0034] Preferably, the dosage of the organic solvent in step 1) is: neodymium neodecanoate: organic solvent = 0.3 - 0.6 mol / L.

[0035] The present invention also relates to the application of the rare earth neodecanoate catalyst described above or the rare earth neodecanoate catalyst prepared by the above preparation method in the preparation of polybutadiene.

[0036] Preferably, the method for preparing polybutadiene is as follows:

[0037] Under an inert atmosphere, mix the rare earth neodecanoate catalyst and 1,3-butadiene monomer in a solvent, and carry out a polymerization reaction at 40 - 70 °C to obtain the product.

[0038] More preferably, the solvent is cyclohexane.

[0039] More preferably, the molar ratio of neodymium neodecanoate in the rare earth neodecanoate catalyst to the 1,3-butadiene monomer is: 2×10 -5 -6×10 -5 : 1.

[0040] More preferably, the dosage ratio of the 1,3-butadiene monomer to the solvent is 1.5 - 2.5 mol / L.

[0041] More preferably, the polymerization reaction time is 1.5 - 2.5 h.

[0042] More preferably, the polymerization reaction is terminated with a terminator commonly used in the art. For example, it can be at least one of ethanol, isopropanol, 2,6-di-tert-butyl-p-hydroquinone methanol.

[0043] The beneficial effects of the present invention are:

[0044] The present invention optimizes the composition of the rare earth catalyst. The synergistic effect of the halogen-containing compound, alcohol compound and additive is significant, which significantly improves the catalytic activity and selectivity of the catalyst. The prepared polybutadiene rubber has a higher cis structure content, a larger molecular weight and a narrower molecular weight distribution, and a high product yield.

[0045] The present invention further optimizes the composition of the additive. The synergistic effect of triphenyl(methyl)-tetrakis(pentafluorophenyl)borate and phenyl-dimethylamino-tetraphenylborate is significant, which further improves the catalytic activity and selectivity of the catalyst. The product yield, molecular weight, molecular weight distribution effect and cis structure stereoselectivity of the polybutadiene rubber are significantly improved. Detailed implementation mode

[0046] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description progresses. However, these embodiments are exemplary only and do not constitute any limitation to the scope of the present invention. Those skilled in the art should understand that the details and forms of the technical solutions of the present invention can be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the protection scope of the present invention.

[0047] Example 1

[0048] A neodecanoic acid rare earth catalyst comprises the following components: neodymium neodecanoate, halogen-containing compound, alcohol compound, conjugated diene and additive. The molar ratio of neodymium element in neodymium neodecanoate, halogen-containing compound, alcohol compound, conjugated diene and additive is 1:1:5:20:1. The additive comprises a mixture of triphenyl(methyl)-tetrakis(pentafluorophenyl)borate and phenyl-dimethylamino-tetraphenylborate, and the molar ratio of the two is 2:1;

[0049] The halogen-containing compound is a mixture of diethylaluminum monochloride and diisobutylaluminum trichloride, and the molar ratio of the two is 1:1;

[0050] The alcohol compound is a mixture of isopropanol and cyclohexanol, and the molar ratio of the two is 3:1;

[0051] The conjugated diene is isoprene.

[0052] The preparation method of the neodymium neodecanoate comprises the following steps:

[0053] (1) Dissolve 23 parts by weight of neodymium oxide with hydrochloric acid, control the pH to 4.5, and remove impurities to obtain a neodymium chloride NdCl3 solution;

[0054] (2) Let the NdCl3 solution obtained in step (1) stand, filter the precipitate to obtain a clear NdCl3 solution;

[0055] (3) Mix 170 parts by weight of neodecanoic acid and 185 parts by weight of n-hexane, add 50 parts by weight of a sodium hydroxide solution with a concentration of 5 mol / L, and carry out a saponification reaction at 60 °C for 35 minutes to obtain a reaction solution;

[0056] (4) Add the clarified NdCl3 solution to the reaction solution obtained in step (3), mix and react for more than 20 minutes, and let it stand for phase separation;

[0057] (5) Further filter the upper-layer product obtained in step (4) to remove impurities to complete the preparation.

[0058] A method for preparing a rare earth catalyst, comprising the following steps:

[0059] (1) Under an inert atmosphere, dissolve neodymium neodecanoate, an alcohol compound, an auxiliary agent, and a conjugated diene in n-pentane, with neodymium neodecanoate:n-pentane = 0.3 mol / L, to obtain a mixed solution A;

[0060] (2) Add a halogen-containing compound to the mixed solution A to obtain a mixed solution B, and age for 15 min to obtain the product.

[0061] Example 2

[0062] A neodecanoic acid rare earth catalyst, comprising the following components: neodymium neodecanoate, a halogen-containing compound, an alcohol compound, a conjugated diene, and an auxiliary agent. The molar ratio of neodymium element in neodymium neodecanoate, the halogen-containing compound, the alcohol compound, the conjugated diene, and the auxiliary agent is 1:20:10:80:5. The auxiliary agent includes a mixture of triphenyl(methyl)-tetrakis(pentafluorophenyl)borate and phenyl-dimethylamino-tetraphenylborate, and the molar ratio of the two is 4:1;

[0063] The halogen-containing compound is a mixture of diethylaluminum chloride and diisobutylaluminum trichloride, and the molar ratio of the two is 3:1;

[0064] The alcohol compound is a mixture of isopropyl alcohol and cyclohexanol, and the molar ratio of the two is 5:1;

[0065] The conjugated diene is piperylene.

[0066] The preparation method of the neodymium neodecanoate comprises the following steps:

[0067] (1) Dissolve 24 parts by weight of neodymium oxide in hydrochloric acid, control the pH to 5.0, and remove impurities to obtain a neodymium chloride NdCl3 solution;

[0068] (2) Let the NdCl3 solution obtained in step (1) stand, filter the precipitate, and obtain a clarified NdCl3 solution;

[0069] (3) Mix 178 parts by weight of neodecanoic acid and 195 parts by weight of n-hexane, add 55 parts by weight of a sodium hydroxide solution with a concentration of 5 mol / L, and carry out a saponification reaction at 65 °C for 30 minutes to obtain a reaction solution;

[0070] (4) Add the clarified NdCl3 solution to the reaction solution in step (3), mix and react for more than 20 minutes, and let it stand for phase separation;

[0071] (5) Further filter the upper-layer product in step (4) to remove impurities to obtain the product.

[0072] A method for preparing a rare earth catalyst, comprising the following steps:

[0073] 1) Under an inert atmosphere, dissolve neodymium neodecanoate, an alcohol compound, an auxiliary agent, and a conjugated diene in n-heptane, with neodymium neodecanoate:n-heptane = 0.6 mol / L, to obtain a mixed solution A;

[0074] 2) Add a halogen-containing compound to the mixed solution A to obtain a mixed solution B, and age for 30 min to obtain the product.

[0075] Example 3

[0076] A neodecanoic acid rare earth catalyst, comprising the following components: neodymium neodecanoate, a halogen-containing compound, an alcohol compound, a conjugated diene, and an auxiliary agent. The molar ratio of neodymium element in neodymium neodecanoate, the halogen-containing compound, the alcohol compound, the conjugated diene, and the auxiliary agent is 1:10:7:50:3. The auxiliary agent includes a mixture of triphenyl(methyl)-tetrakis(pentafluorophenyl)borate and phenyl-dimethylamino-tetraphenylborate, and the molar ratio of the two is 3:1;

[0077] The halogen-containing compound is a mixture of diethylaluminum chloride and diisobutylaluminum trichloride, and the molar ratio of the two is 2:1;

[0078] The alcohol compound is a mixture of isopropyl alcohol and cyclohexanol, and the molar ratio of the two is 4:1;

[0079] The conjugated diene is isoprene.

[0080] The preparation method of the neodymium neodecanoate comprises the following steps:

[0081] (1) Dissolve 24 parts by weight of neodymium oxide in hydrochloric acid, control the pH to 4.5, and remove impurities to obtain a neodymium chloride NdCl3 solution;

[0082] (2) Let the NdCl3 solution in step (1) stand, filter the precipitate, and obtain a clarified NdCl3 solution;

[0083] (3) Mix 175 parts by weight of neodecanoic acid and 190 parts by weight of n-hexane, add 53 parts by weight of a sodium hydroxide solution with a concentration of 5 mol / L, and carry out a saponification reaction at 65 °C for 35 minutes to obtain a reaction solution;

[0084] (4) Add the clarified NdCl3 solution to the reaction solution in step (3), mix and react for more than 20 minutes, and let it stand for phase separation;

[0085] (5) Further filter the upper-layer product in step (4) to remove impurities to obtain the finished product.

[0086] A preparation method of a rare earth catalyst, comprising the following steps:

[0087] 1) Under an inert atmosphere, dissolve neodymium neodecanoate, an alcohol compound, an additive, and a conjugated diene in cyclohexane, with neodymium neodecanoate: cyclohexane = 0.5 mol / L, to obtain a mixed solution A;

[0088] 2) Add a halogen-containing compound to the mixed solution A to obtain a mixed solution B, and age for 20 min to obtain the product.

[0089] Comparative Example 1

[0090] The difference from Example 3 is only the catalyst composition, and the specific molar ratios of each component are as follows:

[0091] Comparative Example 1-1 Comparative Example 1-2 Comparative Example 1-3 Neodymium neodecanoate 1 1 1 Conjugated diene 50 50 50 Halogen-containing compound 0 15.38 11.76 Alcohol compound 14 0 8.24 Auxiliary agent 6 4.62 0

[0092] Comparative Example 2

[0093] The difference from Example 3 is only the additive composition, which is replaced with an equimolar amount of methylaluminoxane.

[0094] Comparative Example 3

[0095] The difference from Example 3 is only the additive composition, and triphenyl(methyl)-tetrakis(pentafluorophenyl)borate is replaced with an equimolar amount of phenyl-dimethylamino-tetraphenylborate.

[0096] Comparative Example 4

[0097] The difference from Example 3 is only the additive composition, and phenyl-dimethylamino-tetraphenylborate is replaced with an equimolar amount of triphenyl(methyl)-tetrakis(pentafluorophenyl)borate.

[0098] Application Example

[0099] A preparation method of polybutadiene: Under a nitrogen atmosphere, mix any one of the neodecanoic acid rare earth catalysts of Examples 1-3 and Comparative Examples 1-4 and 1,3-butadiene monomer in cyclohexane, and the molar ratio of neodymium neodecanoate to 1,3-butadiene monomer is 4×10 -5: 1. The dosage ratio of 1,3-butadiene monomer to cyclohexane is 2 mol / L. The polymerization reaction is carried out at 60 °C for 2 h, and an appropriate amount of ethanol is added to terminate the reaction. After drying, it is obtained.

[0100] Test Example

[0101] The yield, cis-structure content, molecular weight and molecular weight distribution of the polybutadiene prepared in the application example were measured, and the results are shown in Table 1.

[0102] Table 1

[0103]

[0104]

[0105] It can be seen from Comparative Examples 1-1 to 1-3 that only any two of the halogen-containing compounds, alcohol compounds and additives are contained, and the yield of polybutadiene, the stereoselectivity of the cis-structure and the product molecular weight are all significantly reduced, and the molecular weight distribution is significantly broadened. It shows that the synergistic effect between the halogen-containing compounds, alcohol compounds and additives of the present invention is significant, and the effects of the yield of polybutadiene, the stereoselectivity of the cis-structure, the product molecular weight and the molecular weight distribution can be improved simultaneously.

[0106] It can be seen from the comparison between Comparative Example 2 and Example 3 that after the additive of the present invention is replaced by methylaluminoxane, the product yield, the stereoselectivity of the cis-structure and the molecular weight are significantly reduced, especially the molecular weight distribution effect, which is reduced by 56.6%.

[0107] It can be seen from the comparison between Comparative Examples 1-3, 3, 4 and Example 3 that Comparative Examples 3 and 4 added an additive on the basis of Comparative Example 1-3, and the product yield, product molecular weight and molecular weight distribution effect were improved, but the influence on the stereoselectivity of the cis-structure was small. Two additives were added in Example 3, and as a result, the stereoselectivity of the cis-structure was significantly improved, and at the same time, the molecular weight distribution effect, yield and molecular weight were further significantly improved, indicating that the synergistic effect of the two additives is significant.

[0108] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification without departing from the present invention shall be included in the scope of the technical solution of the present invention.

Claims

1. A novel rare earth neodecanoate catalyst for polymerization, characterized in that, It comprises the following components: neodymium neodecanoate, halogen-containing compound, alcohol compound, conjugated diene and auxiliary agent. The auxiliary agent comprises a mixture of triphenyl(methyl)-tetrakis(pentafluorophenyl)borate and phenyl-dimethylamino-tetraphenylborate, and the molar ratio of the two is 2-4:

1.

2. The rare earth neodecanoate catalyst according to claim 1, wherein The halogen-containing compound comprises alkyl aluminum halide.

3. The rare earth neodecanoate catalyst according to claim 2, wherein The alkyl aluminum halide comprises diethylaluminum chloride.

4. The rare earth neodecanoate catalyst according to claim 1, wherein, The alcohol compound comprises at least one of isopropanol and cyclohexanol.

5. The rare earth neodecanoate catalyst according to claim 4, characterized in that, The alcohol compound is a mixture of isopropanol and cyclohexanol, and the molar ratio of the two is 3-5:

1.

6. The rare earth neodecanoate catalyst according to claim 1, wherein The molar ratio of neodymium element in neodymium neodecanoate, halogen-containing compound, alcohol compound, conjugated diene and auxiliary agent is 1:1-20:5-10:20-80:1-5.

7. The rare earth neodecanoate catalyst according to claim 6, wherein The molar ratio of neodymium element in neodymium neodecanoate, halogen-containing compound, alcohol compound, conjugated diene and auxiliary agent is 1:5-15:6-8:30-70:2-4.

8. The preparation method of the rare earth neodecanoate catalyst according to any one of claims 1-7, characterized in that, It comprises the following steps: (1) Under an inert atmosphere, dissolve neodymium neodecanoate, alcohol compound, auxiliary agent and conjugated diene in an organic solvent to obtain a mixed solution A; (2) Add the halogen-containing compound to the mixed solution A to obtain a mixed solution B, and age for 15-30 min to obtain the product.

9. The preparation method according to claim 8, characterized in that, The organic solvent in step (1) is an inert organic solvent.

10. The preparation method according to claim 9, characterized in that, The inert organic solvent comprises saturated aliphatic hydrocarbon and / or alicyclic hydrocarbon.

11. The preparation method according to claim 9, wherein, The inert organic solvent comprises straight-chain alkanes with 5-10 carbon atoms and / or cycloalkanes with 5-10 carbon atoms.

12. The preparation method according to claim 9, characterized in that, The inert organic solvent comprises at least one of n-pentane, n-hexane, cyclohexane and n-heptane.

13. The preparation method according to claim 8, characterized in that, The dosage of the organic solvent in step (1) is: neodymium neodecanoate: organic solvent = 0.3-0.6 mol / L.

14. Application of the rare earth neodecanoate catalyst according to any one of claims 1-7 or the rare earth neodecanoate catalyst prepared by the preparation method according to any one of claims 8-13 in the preparation of polybutadiene.

15. The application according to claim 14, wherein The method for preparing polybutadiene is as follows: Under an inert atmosphere, mix the rare earth neodecanoate catalyst and 1,3-butadiene monomer in a solvent, and carry out a polymerization reaction at 40-70 °C to obtain the product.

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