Catalyst for producing silane through disproportionation of trichlorosilane and preparation method of catalyst

Abstract

The invention relates to the technical field of trichlorosilane disproportionation reaction catalysts, in particular to a catalyst for producing silane through trichlorosilane disproportionation and a preparation method thereof, and the preparation method comprises the following steps: uniformly mixing rosin maleic anhydride acrylate, a cross-linking agent, 2-(dimethylamino) ethyl methacrylate, an organic solvent and an initiator to obtain a first component; adding the surfactant into the pure water, and uniformly stirring to obtain a second component; slowly adding the first component into the second component, and reacting under heating and heat preservation to obtain weakly-alkaline macroporous anion exchange resin; adding a tertiary amine reagent after washing, extracting and purifying after washing, and drying to obtain the catalyst. By adopting the steps, the used rosin maleic anhydride acrylate has better thermal stability and chemical stability, and a main chain structure formed by double-bond polymerization in the catalyst can provide a stable support structure for active sites to promote the trichlorosilane disproportionation reaction.

Description

Technical Field

[0001] The present invention relates to the technical field of trichlorosilane disproportionation reaction catalysts, and particularly to a catalyst for the disproportionation production of silane from trichlorosilane and a preparation method thereof. Background Art

[0002] At present, there are mainly three production methods for silane: sodium hexafluoroaluminate method, silicon-magnesium alloy method, and chlorosilane disproportionation method. The chlorosilane disproportionation method mostly uses trichlorosilane as the raw material, and through multiple steps of disproportionation reactions under the catalysis of a catalyst, silane and silicon tetrachloride are finally produced. The by-products silicon tetrachloride and hydrogen can both be recycled. During the trichlorosilane disproportionation reaction process, the anion exchange resin catalyst for the chlorosilane disproportionation reaction will form some reaction intermediates. The anion exchange resin catalyst can form a relatively stable complex with these intermediates, reduce the energy of the intermediates, and make them exist more stably in the reaction system, thereby increasing the possibility of the reaction proceeding in the direction of generating silane.

[0003] However, in the functionalization reaction for preparing the existing anion exchange resin catalyst, for example, the chloromethylating reagent chloromethyl methyl ether is a highly toxic substance, and the chloromethylation step will generate a large amount of toxic and harmful wastewater, waste gas, and waste residue, which need to be strictly treated environmentally to meet the environmental protection discharge standards. At the same time, during the long-term disproportionation reaction process or under some relatively harsh reaction conditions, its catalytic activity is greatly affected by reaction conditions (such as temperature, pressure, and reactant concentration). In some high-temperature or high-concentration trichlorosilane reaction systems, the activity may decrease and cannot meet the requirements of some industrial high-efficiency reactions. Summary of the Invention

[0004] The object of the present invention is to provide a catalyst for the disproportionation production of silane from trichlorosilane and a preparation method thereof. The rosin maleic anhydride acrylate used has good thermal stability and chemical stability, and the cross-linked structure formed by its polymerization can enhance the overall stability. Under relatively harsh reaction conditions such as high temperature and strong acid-base in the trichlorosilane disproportionation reaction, it can maintain good stability and is not prone to structural damage and activity reduction.

[0005] To achieve the above object, the present invention provides a preparation method for a catalyst for the disproportionation production of silane from trichlorosilane, including the following steps, S1. Uniformly mix rosin maleic anhydride acrylate, a cross-linking agent, 2-(dimethylamino)ethyl methacrylate, an organic solvent, and an initiator to obtain a first component; S2. Add a surfactant to pure water and stir evenly to obtain a second component; S3. Slowly add the first component in S1 to the second component in S2, and react under heating and insulation to obtain a weakly basic macroporous anion exchange resin; After washing the weakly basic macroporous anion exchange resin in S3, a tertiary amine reagent is added, and after washing, extraction and purification are carried out, and the catalyst is obtained after drying.

[0006] Preferably, in S1, the dosage ratio of rosin maleic anhydride acrylate to 2-(dimethylamino)ethyl methacrylate is 1:0.5 - 3.

[0007] Preferably, in S1, the crosslinking agent includes one or more of ethylene glycol dimethacrylate, pentaerythritol triacrylate, trimethylolpropane trimethacrylate, and bisphenol A diglycidyl ether.

[0008] Preferably, in S1, the organic solvent includes one or more of toluene, acetone, benzene, ethanol, and ethyl acetate.

[0009] Preferably, in S1, the initiator includes one or more of azobisisobutyronitrile, benzoyl peroxide, potassium persulfate, and tert-butyl hydroperoxide.

[0010] Preferably, in S2, the surfactant includes one or more of sodium dodecyl sulfate, sodium dodecyl sulfate, cetyltrimethylammonium bromide, and polyoxyethylene lauryl ether.

[0011] Preferably, in S3, the temperature for heating and insulation is 50 - 100 °C, and the time is 0.5 - 8 h.

[0012] Preferably, in S4, the tertiary amine reagent includes one or more of trimethylamine, triethylamine, and N,N-dimethylethanolamine; The dosage ratio of the tertiary amine reagent to rosin maleic anhydride acrylate is 1 - 3:1.

[0013] Preferably, in S4, methanol is used for washing, ethanol is used for extraction and purification, the drying temperature is 50 - 80 °C, and the drying time is 12 - 24 h.

[0014] The above method for preparing a catalyst for the disproportionation production of silane from trichlorosilane, and the prepared catalyst.

[0015] The mechanism of the present invention is as follows: Rosin maleic anhydride acrylate contains a carbon-carbon double bond and an acid anhydride group, and 2-(dimethylamino)ethyl methacrylate contains a carbon-carbon double bond and an amino side chain. The carbon-carbon double bonds of the two can undergo a free radical polymerization reaction to form a crosslinked polymer network structure. At the same time, the acid anhydride group in rosin maleic anhydride acrylate can undergo a ring-opening reaction with the amino group in 2-(dimethylamino)ethyl methacrylate, further promoting the formation of the crosslinked structure.

[0016] The dimethylamino group in ethyl 2-(dimethylamino)acrylate serves as a weakly basic active site. By introducing more tertiary amines through subsequent tertiary amine modification of the crosslinked structure, the active sites interacting with trichlorosilane molecules in the catalyst can be further increased, promoting the disproportionation reaction of trichlorosilane.

[0017] Therefore, the present invention adopts a catalyst for the disproportionation production of silane and its preparation method using the above steps, and its beneficial effects are as follows. 1. The main chain structure formed by the polymerization of double bonds in the catalyst provided by the present invention can provide a stable support structure for the active sites, enabling them to play a better role. Certain pores and voids are formed in the crosslinked network, which is beneficial to the diffusion and adsorption of trichlorosilane molecules inside the catalyst, improving the efficiency of the disproportionation reaction, having better selectivity for silane, reducing the occurrence of side reactions, and thus increasing the yield and quality of silane. 2. The rosin maleic anhydride acrylate used in the present invention has good thermal stability and chemical stability. The crosslinked structure formed by its polymerization can enhance the overall stability. Under relatively harsh reaction conditions such as high temperature and strong acids and bases in the trichlorosilane disproportionation reaction, it can maintain good stability, is not prone to structural damage and activity reduction, avoids decomposition or other side reactions during the disproportionation reaction and loses its catalytic ability, and prolongs the service life of the catalyst. 3. Through tertiary amine modification in the present invention, more tertiary amines are introduced into the crosslinked product, which can further increase the active sites interacting with trichlorosilane molecules in the catalyst and promote the disproportionation reaction of trichlorosilane. 4. Rosin, as a natural renewable resource, is rich in source and relatively low in price, which reduces the production cost of the catalyst to a certain extent. Using rosin maleic anhydride acrylate has better environmental friendliness, is not prone to cause long-term pollution accumulation in the environment, and reduces the production cost.

[0018] Next, through examples, the technical solutions of the present invention will be further described in detail. Specific Embodiments

[0019] Next, in combination with examples, the present invention will be further described. Unless otherwise defined, the technical terms or scientific terms used in the present invention should have the ordinary meaning understood by those with ordinary skills in the field to which the present invention belongs. The above-mentioned features mentioned in the present invention or the features mentioned in the specific examples can be combined arbitrarily. These specific examples are only used to illustrate the present invention and do not limit the scope of the present invention.

[0020] Example 1 A preparation method of a catalyst for the disproportionation production of silane from trichlorosilane includes the following steps. S1. Uniformly mix rosin maleic anhydride acrylate, crosslinking agent ethylene glycol dimethacrylate, 2-(dimethylamino)ethyl methacrylate, organic solvent benzene, and initiator azobisisobutyronitrile to obtain the first component.

[0021] In S1, the dosage ratio of rosin maleic anhydride acrylate to 2-(dimethylamino)ethyl methacrylate is 1:1.

[0022] S2. Add surfactant sodium dodecyl sulfate to pure water and stir evenly to obtain the second component.

[0023] S3. Slowly add the first component in S1 to the second component in S2, and react under heating and insulation at 80 °C for 6 h to obtain a weakly basic macroporous anion exchange resin.

[0024] S4. After washing the weakly basic macroporous anion exchange resin in S3, add tertiary amine reagent trimethylamine, react at 50 °C for 8 h, wash with methanol and then extract and purify with ethanol, and dry at 80 °C for 10 h to obtain the catalyst.

[0025] In S4, the dosage ratio of the tertiary amine reagent to rosin maleic anhydride acrylate is 3:1.

[0026] Example 2 A preparation method of a catalyst for the disproportionation production of silane from trichlorosilane, comprising the following steps: S1. Uniformly mix rosin maleic anhydride acrylate, crosslinking agent pentaerythritol triacrylate, 2-(dimethylamino)ethyl methacrylate, organic solvent toluene, and initiator azobisisobutyronitrile to obtain the first component.

[0027] In S1, the dosage ratio of rosin maleic anhydride acrylate to 2-(dimethylamino)ethyl methacrylate is 1:1.5.

[0028] S2. Add surfactant sodium dodecyl sulfate to pure water and stir evenly to obtain the second component.

[0029] S3. Slowly add the first component in S1 to the second component in S2, and react under heating and insulation at 80 °C for 6 h to obtain a weakly basic macroporous anion exchange resin.

[0030] S4. After washing the weakly basic macroporous anion exchange resin in S3, add tertiary amine reagent triethylamine, react at 50 °C for 8 h, wash with methanol and then extract and purify with ethanol, and dry at 80 °C for 10 h to obtain the catalyst.

[0031] In S4, the dosage ratio of the tertiary amine reagent to rosin maleic anhydride acrylate is 2.5:1.

[0032] Example 3 A preparation method of a catalyst for the disproportionation production of silane from trichlorosilane, comprising the following steps, S1. Uniformly mix rosin maleic anhydride acrylate, crosslinking agent divinylbenzene, 2-(dimethylamino)ethyl methacrylate, organic solvent toluene and initiator azobisisobutyronitrile to obtain a first component.

[0033] In S1, the dosage ratio of rosin maleic anhydride acrylate to 2-(dimethylamino)ethyl methacrylate is 1:2.

[0034] S2. Add surfactant cetyltrimethylammonium bromide to pure water and stir evenly to obtain a second component.

[0035] S3. Slowly add the first component in S1 to the second component in S2, and react for 8 h under heating and insulation at 80 °C to obtain a weakly basic macroporous anion exchange resin.

[0036] S4. After washing the weakly basic macroporous anion exchange resin in S3, add tertiary amine reagent triethylamine, react at 50 °C for 8 h, wash with methanol and then extract and purify with ethanol, and dry at 80 °C for 10 h to obtain the catalyst.

[0037] In S4, the dosage ratio of the tertiary amine reagent to rosin maleic anhydride acrylate is 2:1.

[0038] Test Example 1 At a reaction temperature of 353.15 K and an addition amount of 50 ml of raw material trichlorosilane, 5.0 g of the catalysts in Examples 1-3 and a commercially available tertiary amine-based weakly basic macroporous anion exchange resin were respectively used to react in a high-pressure reaction kettle, and the conversion rates of the disproportionation reaction were obtained as shown in Table 1.

[0039] Table 1. Conversion data table of the catalysts in Examples 1-3 and the commercially available tertiary amine-based weakly basic macroporous anion exchange resin

[0040] As can be seen from Table 1, the catalysts provided in Examples 1-3 have excellent disproportionation reaction conversion rates, which are significantly better than the commercially available tertiary amine-based weakly basic macroporous anion exchange resin.

[0041] Therefore, the present invention adopts a catalyst for the disproportionation production of silane from trichlorosilane and its preparation method with the above steps. More tertiary amines are introduced into the crosslinked product, further increasing the active sites interacting with trichlorosilane molecules in the catalyst. The main chain structure formed by the polymerization of double bonds in the catalyst can provide a stable support structure for the active sites, promoting the progress of the trichlorosilane disproportionation reaction.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions of the present invention or make equivalent replacements, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a catalyst for producing silane by disproportionation of trichlorosilane, characterized in that: The following steps are included: S1, uniformly mixing rosin maleic anhydride acrylate, a crosslinking agent, 2-(dimethylamino)ethyl methacrylate, an organic solvent and an initiator to obtain a first component; S2, adding the surfactant into pure water and stirring evenly to obtain the second component; S3, slowly adding the first component in S1 to the second component in S2, and reacting under heating and heat preservation to obtain a weakly basic macroporous anion exchange resin; S4, after washing the weakly alkaline macroporous anion exchange resin in S3, a tertiary amine reagent is added, and after washing, extraction and purification are performed, and the catalyst is obtained after drying.

2. The method for preparing a catalyst for producing silane by disproportionation of trichlorosilane according to claim 1, characterized in that: In S1, the usage ratio of rosin maleic anhydride acrylate and 2-(dimethylamino)ethyl methacrylate is 1:0.5-3.

3. The method for preparing a catalyst for producing silane by disproportionation of trichlorosilane according to claim 1, characterized in that: In S1, the crosslinking agent includes one or more of ethylene glycol dimethacrylate, pentaerythritol triacrylate, trimethylolpropane trimethacrylate and bisphenol A diglycidyl ether.

4. The method for preparing a catalyst for producing silane by disproportionation of trichlorosilane according to claim 1, characterized in that: In S1, the organic solvent includes one or more of toluene, acetone, benzene, ethanol and ethyl acetate.

5. The method for preparing a catalyst for producing silane by disproportionation of trichlorosilane according to claim 1, characterized in that: In S1, the initiator includes one or more of azobisisobutyronitrile, benzoyl peroxide, potassium persulfate and tert-butyl hydroperoxide.

6. The method for preparing a catalyst for producing silane by disproportionation of trichlorosilane according to claim 1, characterized in that: In S2, the surfactant includes one or more of sodium lauryl sulfate, sodium dodecyl sulfate, hexadecyltrimethylammonium bromide and polyoxyethylene lauryl alcohol ether.

7. The method for preparing a catalyst for producing silane by disproportionation of trichlorosilane according to claim 1, characterized in that: In S3, the heating and insulation temperature is 50-100°C and the time is 0.5-8h.

8. The method for preparing a catalyst for producing silane by disproportionation of trichlorosilane according to claim 1, characterized in that: In S4, the tertiary amine reagent includes one or more of trimethylamine, triethylamine and N,N-dimethylethanolamine; The dosage ratio of the tertiary amine reagent to the rosin maleic anhydride acrylate is 1-3:

1.

9. The method for preparing a catalyst for producing silane by disproportionation of trichlorosilane according to claim 1, characterized in that: In S4, methanol is used for washing, ethanol is used for extraction and purification, the drying temperature is 50-80° C., and the drying time is 5-24 h.

10. A method for preparing a catalyst for producing silane by disproportionation of trichlorosilane as claimed in any one of claims 1 to 9, and the prepared catalyst.

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