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CN-121732244-B - Hydrosilylation catalyst and preparation method thereof

CN121732244BCN 121732244 BCN121732244 BCN 121732244BCN-121732244-B

Abstract

The invention relates to the technical field of organosilicon catalysis, and discloses a hydrosilylation reaction catalyst and a preparation method thereof, wherein the catalyst is prepared from platinum complex catalyst solution, maleic anhydride, triphenyl borate, tetraethoxysilane, propylene carbonate and diethylene glycol dibutyl ether; the preparation method involves the steps of solvent dehydration, electronic relay adduct preassembling, active metal introduction, heat-induced aging and the like. The invention constructs electron-deficient coordination center by a stepwise process, reduces electron cloud density of a platinum center by utilizing Lewis acid characteristic of triphenyl borate, improves high temperature tolerance of a catalyst by matching with solvent cage effect of propylene carbonate, effectively inhibits platinum black generation, and solves the compatibility problem of high-polarity components and nonpolar silicone oil matrix by utilizing solubilization bridging effect of diethylene glycol dibutyl ether.

Inventors

  • Hu Yanfa
  • QI GUANJUN
  • WANG HAIJIAN
  • TIAN DAN

Assignees

  • 江西宏柏新材料股份有限公司

Dates

Publication Date
20260508
Application Date
20260227

Claims (8)

  1. 1. A hydrosilylation catalyst, characterized by being prepared from the following raw materials in parts by weight: 10-15 parts of platinum complex catalyst solution; 0.2-0.7 part of maleic anhydride; 0.8-2.0 parts of triphenyl borate; 0.2-0.7 part of tetraethoxysilane; 10-25 parts of propylene carbonate; 15-30 parts of diethylene glycol dibutyl ether; The molar ratio of the maleic anhydride to the triphenyl borate is 1:0.95-1.05, and the molar ratio of the maleic anhydride to the platinum atoms in the platinum complex catalyst solution is 15:1-30:1; The diethylene glycol dibutyl ether is used as an amphiphilic bridging solvent for dispersing a polar catalyst component and providing compatibility with a nonpolar silicone oil matrix; The preparation method of the hydrosilylation catalyst comprises the following steps: s1, mixing propylene carbonate, diethylene glycol dibutyl ether and ethyl orthosilicate under the protection of inert gas, and stirring at 20-30 ℃ for water removal treatment to obtain an anhydrous composite solvent system; s2, heating the system to 40-55 ℃, adding maleic anhydride and triphenyl borate into the anhydrous compound solvent system, and stirring at constant temperature until the solid is completely dissolved and the solution is in a clear and transparent state; S3, stopping heating, cooling the system to 20-30 ℃, dropwise adding a platinum complex catalyst solution in a stirring state, and continuously stirring at a constant temperature after the dropwise adding is finished; And S4, heating the system to 50-65 ℃, aging at constant temperature under the sealed and light-proof condition, and then cooling and filtering to obtain the hydrosilylation catalyst.
  2. 2. A hydrosilylation catalyst according to claim 1, characterized by being prepared from the following raw materials in parts by weight: 13.0-13.5 parts of platinum complex catalyst solution; 0.3-0.6 part of maleic anhydride; 0.8-1.9 parts of triphenyl borate; 0.25-0.6 part of tetraethoxysilane; 12-24 parts of propylene carbonate; 17-27 parts of diethylene glycol dibutyl ether.
  3. 3. A hydrosilylation catalyst according to claim 1 wherein the platinum complex catalyst solution is a solution of 1, 3-divinyl-1, 3-tetramethyldisiloxane-platinum complex in vinyl terminated polydimethylsiloxane with a mass fraction of elemental platinum of 2000 to 5000ppm.
  4. 4. A hydrosilylation catalyst according to claim 1 wherein the hydrosilylation catalyst is free of phosphorus-based ligands or nitrogen-based ligands.
  5. 5. A process for preparing a hydrosilylation catalyst as claimed in any one of claims 1 to 4, comprising the steps of: s1, mixing propylene carbonate, diethylene glycol dibutyl ether and ethyl orthosilicate under the protection of inert gas, and stirring at 20-30 ℃ for water removal treatment to obtain an anhydrous composite solvent system; s2, heating the system to 40-55 ℃, adding maleic anhydride and triphenyl borate into the anhydrous compound solvent system, and stirring at constant temperature until the solid is completely dissolved and the solution is in a clear and transparent state; S3, stopping heating, cooling the system to 20-30 ℃, dropwise adding a platinum complex catalyst solution in a stirring state, and continuously stirring at a constant temperature after the dropwise adding is finished; And S4, heating the system to 50-65 ℃, aging at constant temperature under the sealed and light-proof condition, and then cooling and filtering to obtain the hydrosilylation catalyst.
  6. 6. The method for preparing a hydrosilylation catalyst according to claim 5, wherein in step S1, the stirring time is 30 to 60 minutes, and the inert gas is nitrogen.
  7. 7. The method for preparing a hydrosilylation catalyst according to claim 5, wherein in step S2, the constant temperature stirring is performed for 30 to 50 minutes, so that the maleic anhydride and the triphenyl borate are assembled in coordination with lewis acid base.
  8. 8. The method for preparing a hydrosilylation catalyst according to claim 5, wherein the specific implementation manner of step S3 is as follows: And (3) raising the stirring rotation speed to 400-500rpm, controlling the dripping process to take 10-20 minutes by using a constant-pressure dripping device, continuously stirring for 15-30 minutes at 20-30 ℃ after dripping, and then performing the operation of step S4, wherein the ageing time of step S4 is 2.0-3.0 hours.

Description

Hydrosilylation catalyst and preparation method thereof Technical Field The invention relates to the technical field of organosilicon catalysis, in particular to a hydrosilylation reaction catalyst and a preparation method thereof. Background The hydrosilylation reaction is a core means for constructing a silicon-carbon bond and is widely applied to the processes of organic silicon monomer synthesis, silicone rubber crosslinking and curing, functional silane preparation and the like. Among the numerous catalytic systems, the catalyst of the cassiterite type represented by the platinum complex of vinyl siloxane has been the main choice for industrial application because of its high activity at room temperature and good compatibility with the organosilicon system. However, in the case of high-temperature reactions or long-term storage in actual industrial production, the catalyst system exposes several inherent technical drawbacks, which limit its further high-end applications. The existing Caster catalyst depends on vinyl siloxane as a ligand, the ligand has relatively weak coordination with central metal platinum, and thermodynamic instability exists. Under the high-temperature reaction condition, the weakly coordinated ligand is easy to dissociate, so that bare zero-valent platinum atoms lose protection, irreversible collision agglomeration occurs under the drive of Brownian motion, and finally platinum black precipitate without catalytic activity is generated. The heat inactivation phenomenon not only increases the consumption of noble metal platinum, but also can cause reaction stagnation in the middle and affect the production efficiency. Although the activity can be delayed to a certain extent by adding an alkynyl or alkenyl inhibitor such as maleic anhydride, the inhibition effect of a single ligand at high temperature is greatly reduced due to the reduced binding force, and the severe requirement of the high-temperature rapid curing process on the heat-resistant service life of the catalyst is difficult to meet. Furthermore, unmodified platinum catalytic centers tend to be electronically rich and sterically less hindered. When catalyzing the reaction of long-chain alpha-olefin and hydrogen-containing siloxane, the active center structure is difficult to effectively control the reaction path, and is easy to cause the internal isomerization side reaction of olefin double bonds, so that silicon hydrogen bonds are added to non-terminal carbon atoms to generate non-target products. This lack of regioselectivity directly reduces the yield and purity of the target β -addition product, thereby affecting the physical properties of the final silicone material. In order to solve the above stability problems, there have been attempts in the prior art to introduce highly polar solvents or highly sterically hindered ligands to stabilize the platinum center. However, the organosilicon reaction system is usually composed of nonpolar polysiloxane, and the introduction of high-polarity components damages the solubility parameter matching between the catalyst and the matrix, so that the catalyst is difficult to disperse in silicone oil, and phase separation, turbidity and even precipitation of effective components are extremely easy to occur during storage. This contradiction between compatibility and stability makes it difficult to achieve both heat resistance and long-term dispersion stability in a nonpolar matrix while maintaining high activity of the catalyst. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a hydrosilylation reaction catalyst and a preparation method thereof, and solves the problems of easy agglomeration and deactivation, low regioselectivity and poor compatibility of high-polarity components and nonpolar matrixes of the existing Karster catalyst at high temperature. In order to achieve the above purpose, the invention is realized by the following technical scheme: In a first aspect, the present invention provides a hydrosilylation catalyst, which adopts the following technical scheme: a hydrosilylation catalyst is prepared from the following raw materials in parts by weight: 10 parts to 15 parts of a platinum complex catalyst solution; maleic anhydride 0.2 to 0.7 parts; 0.8 to 2.0 parts of triphenyl borate; 0.2 to 0.7 parts of ethyl orthosilicate; 10 to 25 parts of propylene carbonate; 15 to 30 parts of diethylene glycol dibutyl ether. By adopting the technical scheme, the invention utilizes the synergistic effect of the physical solvation effect and the chemical electronic regulation effect to improve the heat resistance, the storage stability and the regioselectivity of the platinum catalyst. The specific synergy mechanism is described as follows: First, regarding the mechanism of improving thermal stability, the invention constructs an electronic relay stabilizing system. The ability of conventional maleic anhydride ligands to inhibit platinum activity at