A distillation and purification method for electronic grade bis(tert-butylamino)silane

Abstract

The invention discloses a distillation and purification method for electronic-grade bis(tert-butylamino)silane, and belongs to the technical field of bis(tert-butylamino)silane purification. The invention uses a distillation-adsorption-re-distillation method to jointly process a crude bis(tert-butylamino)silane product, wherein some low-boiling-point substances can be removed by distillation-light removal treatment, some high-boiling-point substances can be removed by distillation-heavy removal treatment, and metal impurities and phosphorus-containing non-metallic impurities can be removed by adsorption treatment; and impurities existing in the product are further removed by distillation-light removal and distillation-heavy removal treatment, so as to obtain electronic-grade bis(tert-butylamino)silane with a product purity of 99.99%.

Description

Technical Field

[0001] The invention relates to the technical field of bis(tert-butylamino)silane purification, and in particular to a distillation and purification method for electronic grade bis(tert-butylamino)silane. Background Art

[0002] Precursor materials are widely used in key processes of integrated circuits, such as epitaxy, lithography, chemical vapor deposition and atomic layer deposition. Among them, silicon-based precursors are an important and large-volume branch, and have been one of the research hotspots in the field of advanced integrated circuit materials in recent years.

[0003] Bis(tert-butylamino)silane is one of the more popular advanced silicon-based precursor materials. It is mainly used as the silicon source for BEOL low-temperature Si3N4 / SiO2 in logic circuits and memories. The film mainly acts as a spacer layer and is mainly realized by AMAT's CVD and ALD machines. The main technical nodes are 65nm / 45nm / 28nm in logic circuit processes and multi-layer spacer materials in 3D NAND. It is currently the most advanced silicon source alternative.

[0004] With the continuous development of semiconductor technology, silicon-based precursor materials have become the key to the development of integrated circuit technology. Technical indicators such as material purity and metal impurity content will directly affect the quality and performance of chips. In advanced semiconductor preparation processes, the purity of silicon-based precursor materials needs to reach more than 99.99%. At present, reactive distillation, complex distillation and adsorption distillation are mainly used to separate, refine and purify materials to meet the needs of semiconductor industry development.

[0005] Chinese patent document CN112812134A discloses a method for refining bis(tert-butylamino)silane, which uses a surface-grafted macroporous adsorption resin to first purify and adsorb the crude BTBAS product to remove a small amount of the reaction raw material tert-butylamine contained in the product, and then uses distillation to remove a trace of residual reaction raw material dichlorosilane at low temperature, and then heats up the distillation to obtain a high-purity product. However, the distillation temperature of the patent is 80-150°C, which has a wide temperature range and cannot effectively separate residual impurities. At the same time, the method of using electron beam radiation to activate the macroporous adsorption resin in the patent is relatively complicated and difficult to control the process. Summary of the invention

[0006] The main purpose of the present invention is to provide a distillation and purification method for electronic grade bis(tert-butylamino)silane, by which crude bis(tert-butylamino)silane is treated by a distillation-adsorption-re-distillation method to obtain electronic grade bis(tert-butylamino)silane with a product purity of 99.99%.

[0007] To achieve the above object, the present invention provides a method for preparing electronic grade bis(tert-butylamino)silane, comprising the following steps:

[0008] S1, distillation and light removal: add industrial-grade bis(tert-butylamino)silane to the first distillation tower, perform distillation and light removal treatment to remove low-boiling impurities, and after the treatment, draw out the light-removed product from the bottom of the tower;

[0009] Preferably, the temperature of the bottom of the first distillation tower is 175-180°C, the top temperature is 170-175°C, and the bottom pressure is 0.1MPa-0.2MPa; the theoretical plate number of the first distillation tower is 60-70; in this step, some low-boiling point substances, such as tert-butylamine residual in the reaction, can be removed by distillation and light removal treatment.

[0010] S2, distillation and de-heavy: the product after de-heavy is introduced into the second distillation tower for de-heavy treatment, and the de-heavy product is taken out from the top of the tower after the treatment is completed;

[0011] Preferably, the temperature of the bottom of the second distillation tower is 185-195°C, the top temperature is 175-180°C, the bottom pressure is 0.05MPa-0.1MPa, and the number of theoretical plates of the second distillation tower is 70-80. In this step, some high-boiling point substances, such as some oligomers generated during the reaction process, can be removed by distillation and de-weighting treatment.

[0012] S3, adsorption: introducing the light removal treatment product into an adsorption tank, wherein the adsorption tank is filled with an adsorbent to adsorb impurities;

[0013] Preferably, the preparation method of the adsorbent is as follows:

[0014] (1) adding activated carbon to a potassium permanganate aqueous solution and soaking it, filtering it after the soaking is completed, collecting the solid, washing it until the filtrate is neutral, and drying it to obtain pretreated activated carbon;

[0015] (2) dispersing the pretreated activated carbon in anhydrous ethanol, adding epichlorohydrin and ethylenediamine, heating to react, filtering, collecting the solid, washing and drying, and then dispersing it in chloroform, adding triethylamine, and adding itaconyl chloride dropwise in an ice bath. After the addition is completed, heating to react, after the reaction is completed, filtering and collecting the solid, washing and drying the solid to obtain modified activated carbon;

[0016] (3) Dispersing the modified activated carbon in thionyl chloride, adding 5-amino-2-mercaptobenzimidazole and benzoyl peroxide, heating for reaction, filtering, collecting the solid, washing and drying to obtain the adsorbent.

[0017] Further preferably, the concentration of the potassium permanganate aqueous solution in step (1) is 10-30 wt %, and the soaking time is 2-4 h.

[0018] Further preferably, in the step (2), the mass ratio of pretreated activated carbon, epichlorohydrin, ethylenediamine and itaconyl chloride is 15-25:10-15:5-8:30-50.

[0019] Further preferably, in step (3), the mass ratio of modified activated carbon to 5-amino-2-mercaptobenzimidazole is 3-5:1-1.5.

[0020] S4, distillation and de-lightening: adding the product after the adsorption to the third distillation tower for de-lightening, and performing distillation and de-lightening treatment. After the treatment is completed, the product after de-lightening is drawn out from the bottom of the tower;

[0021] Preferably, the temperature of the bottom of the third distillation tower is 175-180°C, the temperature of the top of the tower is 170-175°C, and the vacuum degree is 0.1MPa-0.2MPa; the theoretical plate number of the third distillation tower is 60-70; in this step, the residual light components in the product can be further removed by distillation and then light removal.

[0022] S5, distillation and de-heavy treatment: the de-heavy product is introduced into the fourth distillation tower for de-heavy treatment, and the de-heavy product is sent to a finished product collection tank to obtain the high-purity bis(tert-butylamino)silane.

[0023] Preferably, the temperature of the bottom of the fourth distillation tower is 205-210°C, the top temperature is 185-190°C, and the bottom pressure is 0.08MPa-0.1MPa; the theoretical plate number of the fourth distillation tower is 80-90; in this step, the heavy components remaining in the product can be further removed by distillation and then de-heavy treatment, thereby ensuring the high purity of the product.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The method for purifying electronic-grade bis(tert-butylamino)silane provided by the present invention comprises treating crude bis(tert-butylamino)silane by a distillation-adsorption-re-distillation method, wherein some low-boiling-point substances, such as tert-butylamine remaining in the reaction, can be removed by distillation and light removal treatment; some high-boiling-point substances, such as some oligomers generated during the reaction, can be removed by distillation and heavy removal treatment; metal impurities and phosphorus-containing non-metallic impurities can be removed by adsorption treatment; impurities present in the product can be further removed by distillation and light removal and distillation and heavy removal treatment; thereby obtaining electronic-grade bis(tert-butylamino)silane with a product purity of 99.99%;

[0026] 2) During the distillation process, the metal impurities and phosphorus-containing non-metallic impurities in the crude bis(tert-butylamino)silane cannot be separated from the bis(tert-butylamino)silane. The present invention adopts an adsorption treatment method to adsorb and separate the phosphorus-containing impurities and metal impurities remaining in the bis(tert-butylamino)silane. The adsorbent of the present invention uses activated carbon as an adsorption carrier. The activated carbon has a high specific surface area and porosity and is a low-cost adsorption material, but its adsorption performance for metal impurities is poor. The present invention first treats the activated carbon with potassium permanganate to increase the surface area of ​​the activated carbon. The oxygen-containing functional groups on the surface of the activated carbon are removed to improve its adsorption performance. Amino groups are then introduced onto its surface to graft itaconyl chloride onto the activated carbon to form an amide bond. The amide bond can coordinate with the phosphorus element, thereby removing the phosphorus-containing impurities in the crude product. Then 5-amino-2-mercaptobenzimidazole reacts with the carbon-carbon double bond in itaconyl chloride, and then 5-amino-2-mercaptobenzimidazole is grafted onto the activated carbon molecule. The amide bond, the amino group and the imidazole group in the 5-amino-2-mercaptobenzimidazole can coordinate with metal impurities, thereby improving the removal performance of the activated carbon for metal impurities. DETAILED DESCRIPTION

[0027] To avoid redundancy, the items used in the following examples are all commercially available products unless otherwise specified, and the methods used are all conventional methods unless otherwise specified.

[0028] The sources of some raw materials used in the present invention are as follows:

[0029] Activated carbon, 200 mesh, coconut shell powder charcoal, was purchased from Dongguan Huahai Carbon Industry Environmental Protection Co., Ltd.

[0030] Example 1

[0031] A method for preparing electronic grade bis(tert-butylamino)silane comprises the following steps:

[0032] S1, distillation and light removal: industrial-grade bis(tert-butylamino)silane is added to the first distillation tower, and distillation and light removal treatment is performed to remove low-boiling impurities. The temperature of the first distillation tower kettle is 178°C, the tower top temperature is 172°C, the tower kettle pressure is 0.13MPa, and the theoretical plate number is 65. After the treatment is completed, the light-removed product is drawn out from the bottom of the tower;

[0033] S2, distillation and de-heavy: the product after de-heavy is introduced into the second distillation tower for de-heavy treatment; the temperature of the second distillation tower kettle is 190 ° C, the tower top temperature is 178 ° C, and the tower kettle pressure is 0.06 MPa; the theoretical plate number of the second distillation tower is 75, and the de-heavy product is drawn out from the top of the tower after the treatment is completed;

[0034] S3, adsorption: the light removal product is introduced into an adsorption tank, in which an adsorbent is contained, and the temperature of the adsorption tank is 36° C., to adsorb impurities;

[0035] The preparation method of the adsorbent is as follows:

[0036] (1) 120 g of activated carbon was added to 200 mL of a 20 wt% potassium permanganate aqueous solution and soaked for 3 h. After the soaking was completed, the solid was filtered, washed until the filtrate was neutral, and dried to obtain pretreated activated carbon;

[0037] (2) 80 g of pretreated activated carbon was dispersed in 400 mL of anhydrous ethanol, 51.2 g of epichlorohydrin and 29.6 g of ethylenediamine were added, and the mixture was heated at 60° C. for reaction for 5 h, filtered, the solid was collected, washed, dried, and then dispersed in chloroform, 65 g of triethylamine was added, and 164 g of itaconyl chloride was added dropwise in an ice bath. After the addition was completed, the mixture was heated to 35° C. for reaction for 1 h. After the reaction was completed, the solid was collected by filtration, filtered, the solid was collected, washed, and dried to obtain modified activated carbon;

[0038] (3) dispersing 32 g of modified activated carbon in 400 mL of thionyl chloride, adding 10.4 g of 5-amino-2-mercaptobenzimidazole and 0.7 g of benzoyl peroxide, heating at 60° C. for reaction for 6 h, filtering after the reaction is completed, collecting the solid, washing and drying to obtain the adsorbent;

[0039] S4, distillation and de-lightening: the product after the adsorption is added to the third distillation tower for de-lightening, and distillation and de-lightening treatment is performed. The temperature of the third distillation tower kettle is 178°C, the tower kettle temperature is 172°C, and the tower kettle pressure is 0.15MPa; the theoretical plate number of the third distillation tower is 66, and the product after de-lightening is drawn out from the bottom of the tower after the treatment is completed;

[0040] S5, distillation and re-de-weighting: the re-de-weighting product is introduced into the fourth distillation tower for re-de-weighting, and distillation and re-de-weighting treatment is carried out. The temperature of the bottom of the fourth distillation tower is 208° C., the bottom temperature is 187° C., and the bottom pressure is 0.09 MPa; the theoretical plate number of the fourth distillation tower is 86; the product of distillation and re-de-weighting enters the finished product collection tank, and the high-purity bis(tert-butylamino)silane is obtained.

[0041] Example 2

[0042] A method for preparing electronic grade bis(tert-butylamino)silane comprises the following steps:

[0043] S1, distillation and light removal: industrial-grade bis(tert-butylamino)silane is added to the first distillation tower, and distillation and light removal treatment is performed to remove low-boiling impurities. The temperature of the first distillation tower kettle is 175°C, the tower top temperature is 170°C, the tower kettle pressure is 0.1MPa, and the theoretical plate number is 60. After the treatment is completed, the light-removed product is drawn out from the bottom of the tower;

[0044] S2, distillation and de-heavy: the product after de-heavy is introduced into the second distillation tower for de-heavy treatment; the temperature of the second distillation tower kettle is 185 ° C, the tower top temperature is 175 ° C, and the tower kettle pressure is 0.05 MPa; the theoretical plate number of the second distillation tower is 70, and the de-heavy product is drawn out from the top of the tower after the treatment is completed;

[0045] S3, adsorption: the light removal product is introduced into an adsorption tank, in which an adsorbent is contained, and the temperature of the adsorption tank is 36° C., to adsorb impurities;

[0046] The preparation method of the adsorbent is as follows:

[0047] (1) 120 g of activated carbon was added to 200 mL of a 20 wt% potassium permanganate aqueous solution and soaked for 3 h. After the soaking was completed, the solid was filtered, washed until the filtrate was neutral, and dried to obtain pretreated activated carbon;

[0048] (2) 80 g of pretreated activated carbon was dispersed in 400 mL of anhydrous ethanol, 51.2 g of epichlorohydrin and 29.6 g of ethylenediamine were added, and the mixture was heated at 60° C. for reaction for 5 h, filtered, the solid was collected, washed, dried, and then dispersed in chloroform, 65 g of triethylamine was added, and 164 g of itaconyl chloride was added dropwise in an ice bath. After the addition was completed, the mixture was heated to 35° C. for reaction for 1 h. After the reaction was completed, the solid was collected by filtration, filtered, the solid was collected, washed, and dried to obtain modified activated carbon;

[0049] (3) dispersing 32 g of modified activated carbon in 400 mL of thionyl chloride, adding 8.2 g of 5-amino-2-mercaptobenzimidazole and 0.8 g of benzoyl peroxide, heating at 60° C. for 6 h, filtering after the reaction is completed, collecting the solid, washing and drying to obtain the adsorbent;

[0050] S4, distillation and de-lightening: the product after the adsorption is added to the third distillation tower for de-lightening, and distillation and de-lightening treatment is performed. The temperature of the third distillation tower kettle is 175°C, the tower kettle temperature is 170°C, and the tower kettle pressure is 0.1MPa; the theoretical plate number of the third distillation tower is 60, and the product after de-lightening is drawn out from the bottom of the tower after the treatment is completed;

[0051] S5, distillation and re-de-weighting: the re-de-weighting product is introduced into the fourth distillation tower for re-de-weighting, and distillation and re-de-weighting treatment is carried out. The temperature of the bottom of the fourth distillation tower is 205° C., the bottom temperature is 185° C., and the bottom pressure is 0.08 MPa; the theoretical plate number of the fourth distillation tower is 80; the product of distillation and re-de-weighting enters the finished product collection tank, and the high-purity bis(tert-butylamino)silane is obtained.

[0052] Example 3

[0053] A method for preparing electronic grade bis(tert-butylamino)silane comprises the following steps:

[0054] S1, distillation and light removal: add industrial-grade bis(tert-butylamino)silane to the first distillation tower, and perform distillation and light removal treatment to remove low-boiling impurities. The temperature of the first distillation tower kettle is 180°C, the tower top temperature is 175°C, the tower kettle pressure is 0.2MPa, and the theoretical plate number is 70. After the treatment is completed, the light-removed product is drawn out from the bottom of the tower;

[0055] S2, distillation and de-heavy: the product after de-heavy is introduced into the second distillation tower for de-heavy treatment; the temperature of the second distillation tower kettle is 195 ° C, the tower top temperature is 180 ° C, and the tower kettle pressure is 0.1 MPa; the theoretical plate number of the second distillation tower is 80, and the de-heavy product is drawn out from the top of the tower after the treatment is completed;

[0056] S3, adsorption: the light removal product is introduced into an adsorption tank, in which an adsorbent is contained, and the temperature of the adsorption tank is 36° C., to adsorb impurities;

[0057] The preparation method of the adsorbent is as follows:

[0058] (1) 120 g of activated carbon was added to 200 mL of a 20 wt% potassium permanganate aqueous solution and soaked for 3 h. After the soaking was completed, the solid was filtered, washed until the filtrate was neutral, and dried to obtain pretreated activated carbon;

[0059] (2) 80 g of pretreated activated carbon was dispersed in 400 mL of anhydrous ethanol, 51.2 g of epichlorohydrin and 29.6 g of ethylenediamine were added, and the mixture was heated at 60° C. for reaction for 5 h, filtered, the solid was collected, washed, dried, and then dispersed in chloroform, 65 g of triethylamine was added, and 164 g of itaconyl chloride was added dropwise in an ice bath. After the addition was completed, the mixture was heated to 35° C. for reaction for 1 h. After the reaction was completed, the solid was collected by filtration, filtered, the solid was collected, washed, and dried to obtain modified activated carbon;

[0060] (3) dispersing 32 g of modified activated carbon in 400 mL of thionyl chloride, adding 12 g of 5-amino-2-mercaptobenzimidazole and 0.6 g of benzoyl peroxide, heating at 60° C. for 6 h, filtering after the reaction is completed, collecting the solid, washing and drying to obtain the adsorbent;

[0061] S4, distillation and de-lightening: the product after adsorption is added to the third distillation tower for de-lightening, and distillation and de-lightening treatment is performed. The temperature of the third distillation tower kettle is 180°C, the tower kettle temperature is 175°C, and the tower kettle pressure is 0.2MPa; the theoretical plate number of the third distillation tower is 70, and the product after de-lightening is drawn out from the bottom of the tower after the treatment is completed;

[0062] S5, distillation and re-de-weighting: the re-de-weighting product is introduced into the fourth distillation tower for re-de-weighting, and distillation and re-de-weighting treatment is carried out. The temperature of the bottom of the fourth distillation tower is 210° C., the temperature of the top of the tower is 190° C., and the pressure of the bottom of the tower is 0.1 MPa; the theoretical plate number of the fourth distillation tower is 90, and the product of distillation and re-de-weighting enters the finished product collection tank to obtain the high-purity bis(tert-butylamino)silane.

[0063] Comparative Example 1

[0064] A method for preparing electronic grade bis(tert-butylamino)silane is similar to Example 1, except that 5-amino-2-mercaptobenzimidazole is not added to the adsorbent, and specifically comprises the following steps:

[0065] S1, distillation and light removal: industrial-grade bis(tert-butylamino)silane is added to the first distillation tower, and distillation and light removal treatment is performed to remove low-boiling impurities. The temperature of the first distillation tower kettle is 178°C, the tower top temperature is 172°C, the tower kettle pressure is 0.13MPa, and the theoretical plate number is 65. After the treatment is completed, the light-removed product is drawn out from the bottom of the tower;

[0066] S2, distillation and de-heavy: the product after de-heavy is introduced into the second distillation tower for de-heavy treatment; the temperature of the second distillation tower kettle is 190 ° C, the tower top temperature is 178 ° C, and the tower kettle pressure is 0.06 MPa; the theoretical plate number of the second distillation tower is 75, and the de-heavy product is drawn out from the top of the tower after the treatment is completed;

[0067] S3, adsorption: the light removal product is introduced into an adsorption tank, in which an adsorbent is contained, and the temperature of the adsorption tank is 36° C., to adsorb impurities;

[0068] The preparation method of the adsorbent is as follows:

[0069] (1) 120 g of activated carbon was added to 200 mL of a 20 wt% potassium permanganate aqueous solution and soaked for 3 h. After the soaking was completed, the solid was filtered, washed until the filtrate was neutral, and dried to obtain pretreated activated carbon;

[0070] (2) 80 g of pretreated activated carbon was dispersed in 400 mL of anhydrous ethanol, 51.2 g of epichlorohydrin and 29.6 g of ethylenediamine were added, and the mixture was heated at 60° C. for reaction for 5 h, filtered, the solid was collected, washed, dried, and then dispersed in chloroform, 65 g of triethylamine was added, and 164 g of itaconyl chloride was added dropwise in an ice bath. After the addition was completed, the mixture was heated to 35° C. for reaction for 1 h. After the reaction was completed, the solid was collected by filtration, filtered, the solid was collected, washed, and dried to obtain modified activated carbon, i.e., the adsorbent;

[0071] S4, distillation and de-lightening: the product after the adsorption is added to the third distillation tower for de-lightening, and distillation and de-lightening treatment is performed. The temperature of the third distillation tower kettle is 178°C, the tower kettle temperature is 172°C, and the tower kettle pressure is 0.15MPa; the theoretical plate number of the third distillation tower is 66, and the product after de-lightening is drawn out from the bottom of the tower after the treatment is completed;

[0072] S5, distillation and re-de-weighting: the re-de-weighting product is introduced into the fourth distillation tower for re-de-weighting, and distillation and re-de-weighting treatment is carried out. The temperature of the bottom of the fourth distillation tower is 208° C., the bottom temperature is 187° C., and the bottom pressure is 0.09 MPa; the theoretical plate number of the fourth distillation tower is 86; the product of distillation and re-de-weighting enters the finished product collection tank, and the high-purity bis(tert-butylamino)silane is obtained.

[0073] Comparative Example 2

[0074] A method for preparing electronic grade bis(tert-butylamino)silane is similar to Example 1, except that itaconyl chloride is not added to the adsorbent, and specifically comprises the following steps:

[0075] S1, distillation and light removal: industrial-grade bis(tert-butylamino)silane is added to the first distillation tower, and distillation and light removal treatment is performed to remove low-boiling impurities. The temperature of the first distillation tower kettle is 178°C, the tower top temperature is 172°C, the tower kettle pressure is 0.13MPa, and the theoretical plate number is 65. After the treatment is completed, the light-removed product is drawn out from the bottom of the tower;

[0076] S2, distillation and de-heavy: the product after de-heavy is introduced into the second distillation tower for de-heavy treatment; the temperature of the second distillation tower kettle is 190 ° C, the tower top temperature is 178 ° C, and the tower kettle pressure is 0.06 MPa; the theoretical plate number of the second distillation tower is 75, and the de-heavy product is drawn out from the top of the tower after the treatment is completed;

[0077] S3, adsorption: the light removal product is introduced into an adsorption tank, in which an adsorbent is contained, and the temperature of the adsorption tank is 36° C., to adsorb impurities;

[0078] The preparation method of the adsorbent is as follows:

[0079] (1) 120 g of activated carbon was added to 200 mL of a 20 wt% potassium permanganate aqueous solution and soaked for 3 h. After the soaking was completed, the solid was filtered, washed until the filtrate was neutral, and dried to obtain pretreated activated carbon;

[0080] (2) 80 g of pretreated activated carbon was dispersed in 400 mL of anhydrous ethanol, 51.2 g of epichlorohydrin and 29.6 g of ethylenediamine were added, and the mixture was heated at 60° C. for 5 h, filtered, and the solid was collected, washed, dried, and then dispersed in chloroform, 10.4 g of 5-amino-2-mercaptobenzimidazole and 0.7 g of benzoyl peroxide were added, and the mixture was heated at 60° C. for 6 h. After the reaction was completed, the mixture was filtered, and the solid was collected, washed, and dried to obtain the adsorbent;

[0081] S4, distillation and de-lightening: the product after the adsorption is added to the third distillation tower for de-lightening, and distillation and de-lightening treatment is performed. The temperature of the third distillation tower kettle is 178°C, the tower kettle temperature is 172°C, and the tower kettle pressure is 0.15MPa; the theoretical plate number of the third distillation tower is 66, and the product after de-lightening is drawn out from the bottom of the tower after the treatment is completed;

[0082] S5, distillation and re-de-weighting: the re-de-weighting product is introduced into the fourth distillation tower for re-de-weighting, and distillation and re-de-weighting treatment is carried out. The temperature of the bottom of the fourth distillation tower is 208° C., the bottom temperature is 187° C., and the bottom pressure is 0.09 MPa; the theoretical plate number of the fourth distillation tower is 86; the product of distillation and re-de-weighting enters the finished product collection tank, and the high-purity bis(tert-butylamino)silane is obtained.

[0083] The bis(tert-butylamino)silane prepared in Example 1-3 and Comparative Example 1-2 was tested for purity. The test results are shown in Table 1:

[0084] Table 1 Bis(tert-butylamino)silane purity test results

[0085]

[0086]

[0087] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A distillation and purification method for electronic grade bis(tert-butylamino)silane, characterized in that: The steps include: S1, distillation and light removal: add industrial-grade bis(tert-butylamino)silane to the first distillation tower, perform distillation and light removal treatment to remove low-boiling impurities, and after the treatment, draw out the light-removed product from the bottom of the tower; S2, distillation and de-heavy: the product after de-heavy is introduced into the second distillation tower for de-heavy treatment, and the de-heavy product is drawn out from the top of the tower after the treatment is completed; S3, adsorption: introducing the light removal treatment product into an adsorption tank, wherein the adsorption tank is filled with an adsorbent to adsorb impurities; S4, distillation and de-lightening: adding the product after the adsorption to the third distillation tower for de-lightening, and performing distillation and de-lightening treatment. After the treatment is completed, the product after de-lightening is drawn out from the bottom of the tower; S5, distillation and de-heavy treatment: the de-heavy product is introduced into the fourth distillation tower for de-heavy treatment, and the de-heavy product is sent to a finished product collection tank to obtain the high-purity bis(tert-butylamino)silane.

2. The rectification and purification method according to claim 1, characterized in that: The temperature of the bottom of the first distillation tower is 175-180°C, the temperature of the top of the tower is 170-175°C, and the pressure of the bottom of the tower is 0.1MPa-0.2MPa; the number of theoretical plates of the first distillation tower is 60-70.

3. The rectification and purification method according to claim 1, characterized in that: The temperature of the bottom of the second distillation tower is 185-195°C, the temperature of the top of the tower is 175-180°C, and the pressure of the bottom of the tower is 0.05MPa-0.1MPa; the number of theoretical plates of the second distillation tower is 70-80.

4. The distillation purification method according to claim 1, characterized in that: The preparation method of the adsorbent is as follows: (1) adding activated carbon to a potassium permanganate aqueous solution and soaking it, filtering it after the soaking is completed, collecting the solid, washing it until the filtrate is neutral, and drying it to obtain pretreated activated carbon; (2) dispersing the pretreated activated carbon in anhydrous ethanol, adding epichlorohydrin and ethylenediamine, heating to react, filtering, collecting the solid, washing and drying, and then dispersing it in chloroform, adding triethylamine, and adding itaconyl chloride dropwise in an ice bath. After the addition is completed, heating to react, after the reaction is completed, filtering and collecting the solid, washing and drying the solid to obtain modified activated carbon; (3) Dispersing the modified activated carbon in dichlorothionyl, adding 5-amino-2-mercaptobenzimidazole and benzoyl peroxide, heating for reaction, filtering, collecting the solid, washing and drying to obtain the adsorbent.

5. The rectification and purification method according to claim 4, characterized in that: In the step (1), the concentration of the potassium permanganate aqueous solution is 10-30 wt %, and the soaking time is 2-4 h.

6. The rectification and purification method according to claim 4, characterized in that: In the step (2), the mass ratio of pretreated activated carbon, epichlorohydrin, ethylenediamine and itaconyl chloride is 15-25:10-15:5-8:30-50.

7. The rectification and purification method according to claim 4, characterized in that: In the step (3), the mass ratio of modified activated carbon to 5-amino-2-mercaptobenzimidazole is 3-5:1-1.

5.

8. The rectification and purification method according to claim 1, characterized in that: The temperature of the kettle of the third distillation tower is 175-180° C., the temperature of the top of the tower is 170-175° C., and the vacuum degree is 0.1 MPa-0.2 MPa; the number of theoretical plates of the third distillation tower is 60-70.

9. The rectification and purification method according to claim 1, characterized in that: The temperature of the bottom of the fourth distillation tower is 205-210°C, the temperature of the top of the tower is 185-190°C, and the pressure of the bottom of the tower is 0.08MPa-0.1MPa.

10. The distillation purification method according to claim 1, characterized in that: The fourth distillation tower has a theoretical plate number of 80-90.

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