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CN-121974942-A - Alkyl aluminoxane and preparation method thereof

CN121974942ACN 121974942 ACN121974942 ACN 121974942ACN-121974942-A

Abstract

The present disclosure relates to the technical field of cocatalyst preparation, and in particular, to an alkylaluminoxane and a preparation method thereof. The preparation method of the alkylaluminoxane comprises the steps of mixing metal salt containing crystal water with anhydrous alkali metal halide, grinding to form mixed crystals, and contacting and reacting the mixed crystals with alkylaluminoxane under the protection of inert atmosphere and inert solution to obtain the alkylaluminoxane. The alkyl aluminoxane and the preparation method thereof are used for synthesizing the alkyl aluminoxane with high yield, high safety and high storage stability.

Inventors

  • WEI GUANGYUE
  • CUI WEISONG
  • ZHANG XIAOMING
  • ZHOU WEI
  • LU DONGPO
  • HE WEIYING
  • JIA KE

Assignees

  • 中化学科学技术研究有限公司

Dates

Publication Date
20260505
Application Date
20251210

Claims (10)

  1. 1. A process for the preparation of an alkylaluminoxane, comprising the steps of: Mixing a metal salt containing crystal water with anhydrous alkali metal halide, and grinding to form mixed crystals; And (3) contacting and reacting the mixed crystal with alkyl aluminum under the protection of inert atmosphere and inert solution to obtain the alkyl aluminoxane.
  2. 2. The method for producing an alkylaluminoxane according to claim 1, wherein a molar ratio of crystal water contained in said mixed crystal to said alkylaluminum is (0.1 to 3): 1.
  3. 3. The method for producing an alkylaluminoxane according to claim 1, wherein said mixing of the metal salt containing crystal water with the anhydrous alkali metal halide is followed by grinding to form mixed crystals, comprising: physically mixing a metal salt containing crystal water with anhydrous alkali metal halide according to a molar ratio of (0.01-100): 1; Grinding the mixed materials until mixed crystals with the particle size of 30-500 meshes are obtained.
  4. 4. The method for preparing alkylaluminoxane according to claim 1, wherein said contacting and reacting said mixed crystal with alkylaluminoxane under the protection of inert atmosphere and inert solution to obtain alkylaluminoxane comprises: And adding the mixed crystal into the cooled alkyl aluminum solution under the stirring condition and the protection of inert atmosphere, enabling the mixed crystal to contact with the alkyl aluminum contained in the alkyl aluminum solution and react for 0.5-72 hours at the temperature of-80 ℃ to 150 ℃, and carrying out filtration treatment and concentration treatment on the obtained reaction solution to obtain the alkyl aluminoxane.
  5. 5. The method for producing an alkylaluminoxane according to claim 4, wherein said method further comprises, before said adding said mixed crystal to the cooled alkylaluminum solution: Dissolving alkyl aluminum into an inert solvent to form an alkyl aluminum solution with the mass concentration of 1-70 wt%; the aluminum alkyl solution is cooled to-80 ℃ to 0 ℃.
  6. 6. The method for producing an alkylaluminoxane according to any of claims 1 to 5, wherein said metal salt containing water of crystallization is selected from crystalline hydrates of any salts.
  7. 7. The method for producing an alkylaluminoxane according to claim 6, wherein said metal salt containing crystal water is selected from one or more of an aluminum salt containing crystal water, a copper salt containing crystal water, an iron salt containing crystal water or a zinc salt containing crystal water.
  8. 8. The method for producing an alkylaluminoxane according to any of claims 1 to 5, wherein the anhydrous alkali metal halide is an ionic compound in which alkali metal is combined with halogen.
  9. 9. The method for producing an alkylaluminoxane according to any of claims 1 to 5, wherein the general formula of alkylaluminum is RnAlX 3 -n or R 4 Al 2 X 2 , wherein R is an alkyl group, X is a halogen, and n is 1 to 3.
  10. 10. The alkylaluminoxane according to any of claims 1to 9, which is characterized in that it is produced by a process for producing alkylaluminoxane.

Description

Alkyl aluminoxane and preparation method thereof Technical Field The disclosure relates to the technical field of cocatalyst preparation, in particular to alkyl aluminoxane and a preparation method thereof. Background Alkyl aluminoxane is an indispensable cocatalyst in metallocene and post-transition metal olefin polymerization catalysts, and is widely applied to the synthesis of high-end polyolefin materials such as metallocene polyethylene, polyolefin elastomers and the like. At present, the industrialized preparation method mainly comprises an indirect water method and a direct water method. Among them, the indirect water method uses crystalline hydrate as water source, but the safety is better, but the release of crystalline water is too fast, resulting in lower yield. The direct water method can introduce water in an emulsifying or dispersing mode, and has the advantages of less solid waste generated in the reaction, easier filtering link, intense reaction, high risk and easy blockage of equipment. In addition, the products obtained by the two methods have poor storage stability, are easy to gel or have activity degradation, and influence the use efficiency. Disclosure of Invention The present disclosure has been made in view of the above-described problems. The present disclosure provides an alkylaluminoxane and a preparation method thereof, which can realize the synthesis of the alkylaluminoxane with high yield, high safety and high storage stability, and simultaneously has simple and controllable process and easy industrial implementation. According to a first aspect of the present disclosure, there is provided a method for preparing an alkylaluminoxane, comprising: Mixing a metal salt containing crystal water with anhydrous alkali metal halide, and grinding to form mixed crystals; And (3) contacting and reacting the mixed crystal with alkyl aluminum under the protection of inert atmosphere and inert solution to obtain the alkyl aluminoxane. According to a second aspect of the present disclosure there is provided an alkylaluminoxane prepared according to the method for preparing alkylaluminoxane of the first aspect. In one or more technical schemes provided in the embodiments of the disclosure, firstly, a metal salt containing crystal water is mixed with anhydrous alkali metal halide and then is ground, and crystal water which is easily separated from the metal salt containing crystal water in the metal salt containing crystal water can be locked through the lattice action of the alkali metal halide, so that the technical defect of disordered release of crystal water in the traditional process is effectively overcome. Then, under the protection of inert atmosphere and inert solution, when mixed crystal formed by grinding and alkyl aluminum undergo hydrolysis reaction, the crystal water is not released suddenly in a large amount at the initial stage of the reaction, but gradually participates in the reaction at a stable and controllable rate. The method not only reduces the safety risk of the reaction system caused by local violent reaction, so that the whole preparation process of the alkyl aluminoxane is milder, but also avoids the phenomenon that the aluminoxane excessively reacts with excessive water to generate byproducts from the source, reduces the loss of aluminum element in the reaction system, further improves the reaction yield of the alkyl aluminoxane, and enhances the economic feasibility of the process. Meanwhile, as the release rate of the crystal water is controllable, the regulation and control of the composition structure and polymerization degree distribution of the aluminoxane can be realized, the fluctuation of product performance caused by uneven release of water is avoided, and finally, the alkyl aluminoxane product with higher catalytic activity and more stable quality is obtained, thereby providing cocatalyst guarantee for the subsequent synthesis of high-end polyolefin materials. It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the technology claimed. Drawings The above and other objects, features and advantages of the present disclosure will become more apparent by describing in more detail embodiments thereof with reference to the attached drawings. The accompanying drawings are included to provide a further understanding of embodiments of the disclosure, and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure, without limitation to the disclosure. In the drawings, like reference numerals generally refer to like parts or steps. Fig. 1 shows a preparation flow chart of a preparation method of alkyl aluminoxane provided in an embodiment of the present disclosure. Detailed Description In order to make the objects, technical solutions and