JPS5945913A - Purification of phosphine - Google Patents

Abstract

PURPOSE:To adsorb and remove hydrogenated arsenic compound, selectively and efficiently from crude phosphine containing the compound as an impruity, by contacting the crude phosphine with active carbon in the absence of oxygen. CONSTITUTION:A reaction vessel filled with active carbon is made oxygen- free state by introducing an inert gas into the vessel or evacuating the vessel. A crude phosphine containing 50-300ppm of hydrogenated arsenic compound (e.g. arsine) as an impurity is introduced into the reaction vessel, and made to contact with the active carbon under the pressure of 0-60kg/cm<2> to adsorb the hydrogenated arsenic compound to the active carbon and remove the compound from the system. The weight ratio of the phosphine to the active carbon is <=1. The used active carbon can be regenerated by evacuating at 100-130 deg.C.

Description

[Detailed description of the invention] Yes, and ifrL < so-called arsine (AF3H3
) The arsenic hydride compound is selectively removed from the phosphine (hereinafter referred to as 1 crude phosphine-1) containing impurities such as arsenic hydride compounds represented by (1), and the phosphine contains only substantially pure phosphine and hydrogen. It is an object of the present invention to provide a method for obtaining purified phosphine.

Generally, methods for producing phosphine7 include a method in which alkali is applied to yellow phosphorus, a method in which seedling phosphorus is hydrolyzed at high temperature, and a method in which a metal phosphorus compound such as aluminum phosphide or zinc phosphide is reacted with water or acid. A method for obtaining it, a method using electrolytic reduction of yellow phosphorus, etc., has been proposed.

However, all of these methods use yellow phosphorus as a starting material, but this yellow phosphorus usually contains 40 to 60 I) pm of arsenic, depending on the production area of the phosphate ore. In the produced crude phosphine, there are 11 arsenic hydride compounds represented by arsine with a concentration of 10 to 4 as arsine.
Contains about 0 0 ppm (・ru.

Phosphine is important as a starting material for various phosphorus compound derivatives, as a reducing agent, and as a raw material for semiconductors.When using it, especially as a raw material for semiconductors, if arsenic is contained in the phosphine, l(i. It causes a decline in the quality of the Q body, which is not typical of QT (・.

Therefore, the hydrogenation (di,
Removing J compounds is an important issue in the industry. Phosphate, phosphorus, and arsenic are all elements that belong to Group III of the periodic table.
It is very similar to l'↓ or J1'1;;
116.3゛Cl2 (Solubility in water in Cl2
3 mol/l (1 (l me ) and phosphine (boiling point -877 ° C1 melting point + 33" Cl2 solubility in water at 0 ° C 2 (l mO/! / 100 me
) are very similar, so it is extremely difficult to remove arsine from crude phosphine using either chemical or physical means.

In addition, since it is even more difficult to remove arsine, which is contained in crude phosphine at only several hundred ppm or less, technical literature describing removal methods is limited to νH5.
Voice 1 is also 2, at present, impurities other than arsine are 1
It is only removed as a side effect during purification by adsorption and removal, and depending on the purpose of use, for example, the semiconductors mentioned above, it is difficult to handle very few high-purity hosts other than arsine. .

Therefore, the present inventors have conducted extensive research on the purification method of Japanese-made Bosfin containing hydrogenated arsenic compounds such as 1-1-Harden, and found that Japanese-made Bosfin can be purified by using activated carbon and a specific method. The present invention has been completed based on the discovery that arsenic hydride compounds can be selectively adsorbed and removed very efficiently by a simple and industrial method of just contacting them in weight proportions.

That is, the present invention involves contacting Japanese phosphine containing an arsenic hydride compound as an impurity with activated carbon in a proportion equal to or less than the same weight per unit weight of activated carbon in a substantially oxygen-free state,
This is a method for producing phosphine, which is characterized by adsorbing and removing the arsenic hydride compound.

Here, "substantially anoxic state" refers to a state in which air or oxygen is absent, for example, a state in which the interior of the reaction vessel is replaced with an inert gas such as nitrogen, neon, anongon, etc., or a state in which the reaction vessel is evacuated. In carrying out the present invention, crude phosphine may be brought into contact with activated carbon in a specific weight proportion under such anoxic conditions. Therefore, impurity arsenic hydride compounds are selectively anchored to 1/1 carbon, while phosphine contains almost 7.7% of arsenic hydride compounds from the outlet of the container packed with activated carbon 4. ((Recovered. This contact operation can be carried out in either the batch method or the continuous method.)

- Batch method is a method in which a pressure vessel such as an autoclave is filled with activated carbon, and the crude phosphine is brought into contact with a Japanese-made boss fin for a fixed period of time.

The boss fin may be charged in gaseous or liquid form.

If it is supplied in gaseous form, its vapor L1 will be released under the natural pressure of phosphine.
It can be prepared up to -. When charging in liquid form, it can be easily charged by using a suitable refrigerant such as liquid nitrogen or dry ice/acetone and condensing it into a pressure vessel. Is the processing temperature room temperature? ! r7+] is sufficient. The longer the processing time, the longer it is +”+: fl’
4. The effect of f-coating is large, but it can be prepared in gaseous or liquid form.
I (1 hour or more, preferably 20 hours)
3. Processing pressure is regulated by the amount of charge, and even if the processing pressure is low, arsenic hydride compounds can be removed by contacting with activated carbon for a certain period of time, but the processing capacity will decrease. Therefore, it is only necessary to select the phosphine θ) treatment Il1 conditions according to the processing capacity (・0 Arsenic hydride compounds can be removed very efficiently by simply recovering the 41￥ phosphine treated in this way from the pressure vessel. can do.

Next, the continuous method is a method in which Japanese phosphine is passed through a column packed with activated carbon under normal pressure or increased pressure.3 Needless to say, the operation can be carried out at room temperature. The processing speed of Bosphin gas is not particularly regulated, and the slower it is, the greater the processing effect is, but it goes without saying that the processing speed will decrease.

In terms of processing speed, activated carbon unit type 1)-1 5 to 3
A range of 50 parts by weight/Hr is appropriate. Although it is possible to operate outside this range and the purification effect is sufficient, it is not practical from the point of view of the recovery operation of purified phosphine gas.

In this way, it is possible to remove arsenic hydride compounds using both batch and continuous methods, but in the present invention, arsenic hydride compounds in crude phosphine are selectively activated in one step. 111☆ of the activated carbon used in order to adsorb onto the charcoal: It is essential to treat crude phosphine in an amount equal to or less than the weight of the activated carbon.If more than this amount of phosphine is treated in the batch method, The treatment time becomes extremely long, and in the case of a continuous method, the treatment capacity is lost due to reaching a breakthrough state.The treatment pressure of phosphine on activated carbon is not particularly regulated, and the pressure of phosphine at that temperature ranges from normal pressure. You can arbitrarily select up to the vapor pressure.

Activated carbon is an adsorbent with a high adsorption rate and capacity, but its adsorption capacity increases significantly especially when it is brought into contact with phosphine as an adsorbent under pressure. For example, if the specific adsorption amount of phosphine is expressed as adsorption capacity of phosphine <N-1)/apparent volume of activated carbon (4), the phosphine pressure is 5 kg 7 cm.
2 is 82, ] Okg/cm2 is 107, and 2
At 0 kg//Cm2, it reaches ]/10.

Therefore, when phosphine is brought into contact with activated carbon under pressure, the concentration of phosphine at the contact surface with activated carbon increases, and the contact time becomes longer, resulting in a higher purification effect, but on the other hand, the amount of adsorbed phosphine also increases. During regeneration, the amount of untreated phosphino increases. However, the final stage during regeneration [11 phosphine is placed in a separately prepared live 11-charcoal tower or container... It can be reused by deleting it. Therefore, in the case of a continuous method, phosphine can be purified continuously by using a plurality of purification columns, for example, two, and performing purification and regeneration alternately. Therefore, the working pressure range of the present invention is suitably 0 to 60 kg4□2, preferably 0 to 30 kg/4*t'.

The activated carbon used in the present invention can be in any form, regardless of whether it is granular, crushed or powdered. That thing is so funny. Activated carbon can be used either wet or dry, but if it is used in a wet state, water may get mixed into the purified phosphine, and if it is used in a dry state, the purification effect will be even greater.

In addition, when using activated carbon, sulfur and arsenic,
-Carbon oxides, carbon dioxide, halides.

If an inorganic gas such as nitrogen oxide or an organic gas such as methane or ethane is used in a state where it is used, it may be mixed into the purified phosphine. It is necessary to perform pretreatment such as deaeration.

The used activated carbon in the present invention can be easily regenerated by vacuum degassing at a temperature of 100 to 130°C, and this amphibiotic carbon can be used repeatedly because it fully returns to the same level of processing capacity as the activated carbon before use. I can do it 3
3 The arsenic content in the purified phosphine thus obtained and the Japanese phosphine before purification was determined by completely absorbing a certain amount of the sample gas into an aqueous potassium permanganate solution, and then using the absorbed liquid for arsenic using atomic absorption spectrometry. It is possible to measure with high accuracy by performing a J stiffness analysis).

J: ノ Below, the effects of the present invention are listed.

]) The adsorption method using activated carbon of the present invention is simpler in terms of operation and equipment than the distillation and purification methods using Fhigakusokuwahin 1 because it does not require complicated operations or multiple rows of equipment.

2) Activated carbon has a large adsorption size and capacity (it is suction-cut. These activated carbons are relatively inexpensive and easy to handle, and can be recycled and used repeatedly. 3) The method of the present invention selectively removes arsenic compounds from purified phosphine. Not only can it be adsorbed, but even if impurities such as other inorganic gases and organic gases are mixed in, they can be removed at the same time.

4) Arsenic compound (A・+1I3) by the method of the present invention
By selectively adsorbing arsenic compounds from No. 11 phosphine containing 50 to 300 ppm of phosphine, O to several ppl can be removed to the extent that Q,+ can be seen. .

Next, the present invention will be explained with reference to Examples, but the present invention is not limited thereto.

Example 1 Inside'? i'4)'i Ie #j, tJ', 71'i 'li charcoal','
After filling the system with +50 liters (product name: Tsurumicol 4 CM), repeating pressurization with helium gas and vacuum degassing sufficiently, the system was evacuated, and the crepe was cooled with nitrogen. Crude boss fin 3 (+
(1) was prepared.It was returned to room temperature, and the pressure was increased.
r35k! ? /cm' and left under this pressure for 75 hours. The treated phosphine gas was taken out, 10 ml of it was sampled and absorbed into 50 ml of 1N potassium permanganate aqueous solution, and as a result, it was completely absorbed.This absorbed liquid was analyzed by the original r-absorption method. As a result, the content of arsenic compounds was arunone (ASI+3)
Phosphine (I) H8) as 0.6:3
It was ppm. On the other hand, when phosphine gas before purification was similarly absorbed into a potassium permanganate water bath, it was completely absorbed, but the m content of arsenic was 9:3 p.
It was pm.

Example 2 Activated carbon 3509 was filled in a stainless steel autoclave with content 11 in the same manner as in Example 1, and the arsenic content was 103 at room temperature.
As a result of pressurizing 25 ppm of Japanese phosphine gas until the pressure reached 9/cm2, it was possible to charge 70 ppm of Japanese phosphine. After leaving 1) for 48 hours, the purified phosphino gas was taken out and analyzed, and the arsenic content was 20 yen·tll as As I-13.

Example 3 Secondary adjustment, container, gas outlet 1] flow 1jt in the gas intake section
Activated carbon (Tsurumicol) 174 molded into a stainless steel pressure-resistant column with an inner diameter of 5 cm and a length of 2 m equipped with a regulator.
After sufficiently repeating pressurization with helium gas and vacuum degassing, the system was evacuated and the crude phosphine of 5009 was introduced. At this time, the gas population (C
The pressure of the phosphine gas in the system was adjusted to 20 kg, 7 cm2 by the installed secondary regulator, and the flow rate of the phosphine gas (ii) was adjusted to 150910 r by the flow rate regulator at the outlet. In this way, the purified posphine gas flowing out from the column packed with beef charcoal was collected at regular intervals,
In the same manner as in Example 1, the arsenic content in purified phosphine gas was analyzed. As a result, Asl+, 0.3-0
．． It was 7 ppm.

The used activated carbon treated in this way is 100~+30
The mixture was heated to 7° C. to evacuate the adsorbed phosphine and arsenic hydride compounds, and then subjected to Togaku degassing for an additional hour at that temperature.

Examples 4 to 6 Example: The activated carbon column that had been formed was monitored every month, and the purification and regeneration of phosphine was repeated by changing the treatment meter and flow rate, and the results are shown in Table 1.

No. 1 Representative Yutaka 1) Yuchi Yoshiwa C Sode Tadashi, 1: 11I'1 IO month, 1957 611 Commissioner of the Japan Patent Office Kazuo Wakasugi 1, Indication of Case Patent Application No. 154003 1982, Invention Name of Phosphine Purification Method 3, Relation to the Nagisa Incident to be amended, Special Edition 9-15 Kameido, Koto-ku, Tokyo, Japan Representative Hon Kagaku Kogyo Co., Ltd. Tanahashi φ↑ 4, Agent Tokyo 204, 1 Zugoshin Building, 1-114 Yurakucho, Chiyoda-ku, Miyako
Room No. 501-21385 Column 6 of "Detailed Description of the Invention" of the specification to be amended, contents of the amendment t'1 detailed description of the invention is corrected as follows.

1) Specification power, page 3, line 7 Correct rmo sentence J to "m sentence".

2) // Page 3, line 10 Correct "rmo sentence" to "m sentence".

Claims (1)

[Scope of Claims] ■) In a substantially oxygen-free state, crude phosphine containing an arsenic hydride compound as an impurity is brought into contact with activated carbon in an equal weight or less ratio per unit weight of activated carbon, and the arsenic hydride compound is A method for purifying phosphine, characterized by adsorption and removal. 2) The method for purifying phosphine according to claim 1, wherein used activated carbon is regenerated by vacuum degassing under heating and used repeatedly as the activated carbon.