Method for preparing trimethyl indium by aluminum alkyl method

Abstract

The invention discloses a method for preparing trimethyl indium by an aluminum alkyl method, which comprises the following steps of: mixing an indium source and a solvent according to the molar ratio of the indium source to the solvent of 1: (60-100) to form turbid liquid, and continuously stirring; then, according to the molar ratio of trimethylaluminum to the turbid liquid being 1: (0.8-1.2), trimethylaluminum and the turbid liquid are continuously introduced into the tubular reactor, a reaction is conducted at the temperature of 50-120 DEG C, the theoretical liquid holding time is 10-60 minutes, and a trimethylaluminum crude product is obtained; and then carrying out two-stage continuous distillation purification on the trimethyl indium crude product in a molecular distillation instrument at 0.1-1atm and 100-150 DEG C and at 0.1-1atm and 50-100 DEG C in sequence to obtain trimethyl indium with the indium content of more than 70wt%. According to the invention, the continuous preparation of trimethyl indium can be realized, no solid is generated in the production process, and the phenomena of pipe blockage, backflow and the like are avoided. The reaction process and the product separation and purification process can be synchronous and continuous, and the whole process is continuous, efficient and high in safety coefficient.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical raw material preparation, and particularly relates to a method for preparing trimethylindium. Background Art

[0002] High-purity trimethylindium with a purity of 5N or above is the main raw material for growing optoelectronic materials in the metalorganic chemical vapor deposition (MOCVD) and chemical beam epitaxy (CBE) processes, and is widely used in growing semiconductor thin film materials such as indium phosphide, indium gallium arsenide, and indium gallium phosphide.

[0003] The main methods for preparing high-purity trimethylindium are the indium-magnesium alloy method and the Grignard reagent method. In the indium-magnesium alloy method, impurities such as iron, chromium, and nickel are easily introduced during the alloy preparation process, affecting the purity of the crude trimethylindium. The Grignard method is to drop halogenated methane into a mixed solution of magnesium powder and organic solvent under an inert atmosphere to carry out the Grignard reaction to obtain a solution containing methylmagnesium halide, and then react with indium chloride to obtain trimethylindium complex. This method has harsh reaction conditions and needs to be carried out under anhydrous and anaerobic conditions, otherwise it is prone to explosion, and there are also problems such as many side reactions and low product purity. Summary of the Invention

[0004] The purpose of the present invention is to provide a method that can efficiently prepare high-purity trimethylindium, and the production process is easy to implement, safe and reliable, so as to solve the problems existing in the preparation of trimethylindium in the prior art.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A method for preparing trimethylindium by an alkylaluminum method, comprising the following steps:

[0007] (1) Mix an indium source with a solvent in a ratio of indium source: solvent of 1:60 - 100 by molar ratio to form a suspension, and continuously stir; the indium source is one of anhydrous indium trifluoride, indium trichloride, indium tribromide, and indium trinitrate, and the solvent is one of diethyl ether, tetrahydrofuran, dibutyl ether, and isopropyl ether;

[0008] (2) Continuously introduce trimethylaluminum and the suspension into a tubular reactor respectively in a ratio of trimethylaluminum: suspension of 1:0.8 - 1.2 by molar ratio, and react at 50 - 120 °C with a theoretical holding time of 10 - 60 minutes to obtain crude trimethylindium;

[0009] (3) Continuously distill and purify the crude trimethylindium in a molecular distillation apparatus in two stages at 0.1 - 1 atm and 100 - 150 °C and at 0.1 - 1 atm and 50 - 100 °C to obtain trimethylindium with an indium content of more than 70 wt.%. Continuous distillation is continuous feeding and continuous discharging, and the distillation time is determined according to the amount of material.

[0010] Furthermore, in step (3), the solvent evaporated by the molecular distillation apparatus can be recovered and returned to step (1) for use.

[0011] The present invention adopts an alkyl aluminum method to prepare trimethyl indium, and introduces trimethyl aluminum and an indium source suspension into a tubular reactor in a certain ratio. Under heating conditions, the reaction is continuously stirred to continuously produce a crude trimethyl indium product. No solid is generated during the continuous preparation of trimethyl indium reaction, and pipe blockage and liquid backflow will not occur, thereby avoiding damage to the equipment. The preparation process of the present invention is simple, and the equipment requirements are not high. The reaction and product separation and purification processes can be synchronized and continuous. The entire process is continuously efficient and has a high safety factor. The solvent recovery rate can reach more than 95%, and there is almost no loss of solvent. DETAILED DESCRIPTION

[0012] The present invention is further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the contents described in the embodiments.

[0013] Example 1

[0014] The method for preparing trimethyl indium by alkyl aluminum method comprises the following steps:

[0015] (1) fully mixing anhydrous indium trichloride and diethyl ether at a molar ratio of indium trichloride to diethyl ether of 1:60 to form a suspension, and continuously stirring;

[0016] (2) continuously introducing trimethylaluminum and the suspension into a tubular reactor at a molar ratio of trimethylaluminum to the suspension of 1:0.9, and reacting at 90° C. for 50 minutes to obtain a crude trimethylindium product;

[0017] (3) The crude trimethyl indium product was pumped into a molecular distillation apparatus, first distilled at 1 atm and 150° C., and then continued to be distilled and purified at 1 atm and 50° C. to obtain high-purity trimethyl indium with an indium content of 71.7 wt.%, with a direct yield of 89%.

[0018] The ether evaporated by the molecular distillation apparatus is recovered and reused. The ether recovery rate is 98%.

[0019] Example 2

[0020] The method for preparing trimethyl indium by alkyl aluminum method comprises the following steps:

[0021] (1) indium trinitrate and tetrahydrofuran are fully mixed in a molar ratio of indium trinitrate to tetrahydrofuran of 1:70 to form a suspension, and stirred continuously;

[0022] (2) in a molar ratio of trimethylaluminum to suspension of 1:1, trimethylaluminum and the suspension are respectively introduced into a tubular reactor, and reacted at 100° C. and a holding time of 40 minutes to obtain a crude trimethylindium product;

[0023] (3) The crude trimethyl indium product was first distilled in a molecular distillation apparatus at 0.8 atm and 135° C., and then further distilled and purified at 0.8 atm and 85° C. to obtain high-purity trimethyl indium with an indium content of 71.9 wt.%, with a direct yield of 98%.

[0024] The tetrahydrofuran evaporated by the molecular distillation apparatus is recovered and reused. The recovery rate of tetrahydrofuran is 96%.

[0025] Example 3

[0026] The method for preparing trimethyl indium by alkyl aluminum method comprises the following steps:

[0027] (1) fully mixing anhydrous indium trifluoride and butyl ether in a molar ratio of anhydrous indium trifluoride to butyl ether of 1:90 to form a suspension, and continuously stirring;

[0028] (2) in a molar ratio of trimethylaluminum to suspension of 1:1.1, trimethylaluminum and the suspension were continuously introduced into a tubular reactor, and reacted at 110° C. for 30 minutes to obtain a crude trimethylindium product;

[0029] (3) The crude trimethyl indium product was first distilled in a molecular distillation apparatus at 0.1 atm and 100° C., and then further distilled and purified at 0.1 atm and 50° C. to obtain high-purity trimethyl indium with an indium content of 72.0 wt.%, with a direct yield of 98%.

[0030] The butyl ether evaporated by the molecular distillation apparatus is recovered and reused. The recovery rate of butyl ether is 96%.

[0031] Example 4

[0032] The method for preparing trimethyl indium by alkyl aluminum method comprises the following steps:

[0033] (1) indium tribromide and isopropyl ether are fully mixed in a molar ratio of indium tribromide to isopropyl ether of 1:90 to form a suspension, and stirred continuously;

[0034] (2) continuously introducing trimethylaluminum and the suspension into a tubular reactor at a molar ratio of trimethylaluminum to the suspension of 1:0.8, and reacting at 120° C. for 10 minutes to obtain a crude trimethylindium product;

[0035] (3) The crude trimethyl indium product was first distilled in a molecular distillation apparatus at 0.6 atm and 120° C., and then further distilled and purified at 0.6 atm and 75° C. to obtain high-purity trimethyl indium with an indium content of 71.7 wt.%, with a direct yield of 84%.

[0036] The isopropyl ether evaporated by the molecular distillation apparatus is recovered and reused. The recovery rate of isopropyl ether is 95%.

[0037] Example 5

[0038] The method for preparing trimethyl indium by alkyl aluminum method comprises the following steps:

[0039] (1) indium trichloride and tetrahydrofuran are fully mixed in a molar ratio of indium trichloride to tetrahydrofuran of 1:100 to form a suspension, and stirred continuously;

[0040] (2) continuously introducing trimethylaluminum and the suspension into a tubular reactor at a molar ratio of trimethylaluminum to the suspension of 1:1.2, and reacting at 50° C. for 60 minutes to obtain a crude trimethylindium product;

[0041] (3) The crude trimethyl indium product was first distilled in a molecular distillation apparatus at 0.4 atm and 110° C., and then further distilled and purified at 0.4 atm and 65° C. to obtain high-purity trimethyl indium with an indium content of 72.1 wt.%, with a direct yield of 96%.

[0042] The tetrahydrofuran evaporated by the molecular distillation apparatus is recovered and reused. The recovery rate of tetrahydrofuran is 96%.

[0043] The following table lists the indium content and direct yield of trimethyl indium obtained in 5 examples, and the direct yield is calculated based on the indium source.

[0044] Example Indium content (wt.%) Direct yield (%) 1 71.7％ 89％ 2 71.9％ 98％ 3 72.0％ 98％ 4 71.7％ 84％ 5 72.1％ 96％

[0045] The tubular reactor and molecular distiller used in the method of the present invention are both prior art equipment. The tubular reactor used in this embodiment is a trial-produced equipment of Shandong Weijing Chemical Technology Co., Ltd., and the molecular distiller is the AYAN-F80 model of Hangzhou Anyan Instrument Manufacturing Co., Ltd.

[0046] The raw materials used in the present invention, such as anhydrous indium trifluoride (F3In), indium trichloride (InCl 3 ), indium tribromide (Br3In), indium trinitrate (In(NO 3 ) 3 ), ether, tetrahydrofuran, butyl ether, isopropyl ether, trimethylaluminum (C3H9Al), etc. can be purchased commercially. Among them, the purity of anhydrous indium trifluoride, indium trichloride, indium tribromide, indium trinitrate, and trimethylaluminum is not less than 99.95%.

[0047] Unless otherwise specified, all percentages described in the present invention are by mass percentages.

Claims

1. A method for preparing trimethyl indium by an alkyl aluminum method, characterized in that: The following steps are involved: (1) Mixing the indium source and the solvent at a molar ratio of indium source to solvent of 1:60 to 100 to form a suspension, and continuously stirring; the indium source is one of anhydrous indium trifluoride, indium trichloride, indium tribromide, and indium trinitrate; and the solvent is one of diethyl ether, tetrahydrofuran, butyl ether, and isopropyl ether; (2) at a molar ratio of trimethylaluminum:suspension of 1:0.8-1.2, trimethylaluminum and suspension are continuously introduced into a tubular reactor, respectively, and reacted at 50-120° C. and a theoretical holding time of 10-60 minutes to obtain a crude trimethylindium product; (3) The crude trimethyl indium product is purified by two-stage continuous distillation in a molecular distillation apparatus at 0.1-1 atm, 100-150°C and 0.1-1 atm, 50-100°C, to obtain trimethyl indium with an indium content of more than 70 wt.%.

2. The method for preparing trimethyl indium by an alkyl aluminum method according to claim 1, characterized in that: In step (3), the solvent evaporated by the molecular distillation apparatus is recovered and returned to step (1) for use.