Iodinated hydrocarbon mixture, production method of iodinated hydrocarbon mixture, and iodinated hydrocarbon mixture filling container

Abstract

To provide an iodinated hydrocarbon mixture capable of suppressing quality deterioration even when stored under high temperature, a production method of the iodinated hydrocarbon mixture, and an iodinated hydrocarbon mixture filling container.SOLUTION: An iodinated hydrocarbon mixture contains an iodinated hydrocarbon and water, and concentration of water in the iodinated hydrocarbon mixture is 140 mass ppm or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an iodohydrocarbon mixture, a method for producing an iodohydrocarbon mixture, and a container for filling an iodohydrocarbon mixture. [Background technology]

[0002] Iodohydrocarbons are compounds that are widely used industrially as chemical raw materials and solvents. In recent years, they have also come to be used in various processes in semiconductor manufacturing. Metal containers, such as metal high-pressure vessels (cylinders) or metal canisters, are used as storage containers for these iodinated hydrocarbons used in various processes in semiconductor manufacturing, unlike the resin or glass containers typically used as storage containers for chemical raw materials.

[0003] However, it is known that the purity of iodinated hydrocarbons can decrease depending on factors such as storage conditions, and this property remains a major challenge for the industry. As a solution to this problem, for example, Patent Document 1 listed below discloses a method of arranging a stabilizer for iodinated hydrocarbons in an iodinated hydrocarbon storage container, the stabilizer having a contact surface with the iodinated hydrocarbon liquid and a contact surface with the iodinated hydrocarbon gas made of metallic copper, metallic silver, or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-24073 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, when iodohydrocarbons are used for, for example, semiconductor film formation applications, they are sometimes stored in metal containers at high temperatures (for example, at temperatures of 100°C or higher) in order to increase their vapor pressure and ensure the supply of iodohydrocarbons to semiconductor manufacturing equipment, etc. However, the iodohydrocarbons described in Patent Document 1 have room for improvement in terms of suppressing deterioration of the quality of the iodohydrocarbons, particularly at high temperatures. Since iodocarbons contain trace amounts of water and other impurities, they are not strictly pure substances but mixtures. For this reason, in this specification, "iodocarbons" will be referred to as "iodocarbon mixtures."

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an iodohydrocarbon mixture that can suppress quality deterioration even when stored at high temperatures, a method for producing an iodohydrocarbon mixture, and a container filled with an iodohydrocarbon mixture. [Means for solving the problem]

[0007] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by reducing the water concentration in an iodinated hydrocarbon mixture to a specific value or less, and have thus completed the present invention.

[0008] That is, one aspect of the present invention provides an iodohydrocarbon mixture containing an iodohydrocarbon and moisture, wherein the concentration of the moisture in the iodohydrocarbon mixture is 140 ppm by mass or less. This iodinated hydrocarbon mixture can suppress quality deterioration even when stored at high temperatures.

[0009] Another aspect of the present invention provides a method for producing the above-mentioned iodohydrocarbon mixture, the method comprising a dehydration step of dehydrating a raw material containing iodohydrocarbon and water. According to this method for producing an iodinated hydrocarbon mixture, it is possible to produce an iodinated hydrocarbon mixture that can suppress deterioration in quality even when stored at high temperatures.

[0010] Yet another aspect of the present invention provides an iodohydrocarbon mixture-filled container comprising a container and an iodohydrocarbon mixture filled in the container, the iodohydrocarbon mixture containing an iodohydrocarbon and moisture, wherein the moisture concentration in the iodohydrocarbon mixture is 140 ppm by mass or less. This container filled with an iodohydrocarbon mixture can prevent deterioration in the quality of the iodohydrocarbon mixture even when the container is filled with the iodohydrocarbon mixture and stored at high temperatures.

[0011] In the above iodinated hydrocarbon, the hydrocarbon group may have 1 to 4 carbon atoms and 1 to 3 iodines.

[0012] The iodinated hydrocarbon may be an iodinated saturated hydrocarbon.

[0013] The iodinated hydrocarbon may be diiodomethane.

[0014] In the present invention, an iodinated hydrocarbon refers to a compound represented by RI (R represents a hydrocarbon group, and I represents iodine), or a compound in which some of the hydrogen atoms contained in R of this compound are substituted with iodine. [Effects of the Invention]

[0015] According to the present invention, there are provided an iodohydrocarbon mixture that can suppress quality deterioration even when stored at high temperatures, a method for producing an iodohydrocarbon mixture, and a container filled with an iodohydrocarbon mixture. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described in detail.

[0017] <Iodohydrocarbon mixture> First, an embodiment of an iodinated hydrocarbon mixture according to one aspect of the present invention will be described. The iodohydrocarbon mixture contains an iodohydrocarbon and water, and the concentration of water in the iodohydrocarbon mixture is 140 ppm by mass or less. This iodinated hydrocarbon mixture can suppress quality deterioration even when stored at high temperatures.

[0018] Hereinafter, the iodocarbon and water will be described in detail.

[0019] (iodinated hydrocarbons) Although the iodohydrocarbon is not particularly limited, for example, when the iodohydrocarbon is used for semiconductor film formation, it is preferable that the iodohydrocarbon be an iodohydrocarbon having a high vapor pressure from the viewpoint of ease of handling. As the iodohydrocarbon having a high vapor pressure, an iodohydrocarbon having a hydrocarbon group with 1 to 8 carbon atoms and 1 to 4 iodines is preferred, and an iodohydrocarbon having a hydrocarbon group with 1 to 4 carbon atoms and 1 to 3 iodines is more preferred. These iodohydrocarbons exist in a liquid or solid state at room temperature, but among the above-mentioned iodohydrocarbons having a high vapor pressure, an iodohydrocarbon that exists in a liquid state at room temperature is preferred from the viewpoint of ease of handling. The iodinated hydrocarbon may be an iodinated saturated hydrocarbon or an iodinated unsaturated hydrocarbon, i.e., the hydrocarbon group of the iodinated hydrocarbon may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. An example of the iodinated saturated hydrocarbon is diiodomethane.

[0020] (moisture) The water concentration of the iodinated hydrocarbon may be 140 ppm by mass or less, preferably 100 ppm by mass or less, more preferably 50 ppm by mass or less, and particularly preferably 30 ppm by mass or less. The water concentration of the iodinated hydrocarbon may be 0.1 ppm by mass or more, 0.5 ppm by mass or more, or 1.0 ppm by mass or more.

[0021] Here, the water concentration in the iodinated hydrocarbon mixture is a value measured using a Karl Fischer moisture meter. Specifically, when measuring the water concentration in the iodinated hydrocarbon mixture, a moisture concentration meter sold by a measuring instrument manufacturer can be used. Examples of such moisture concentration meters include a coulometric Karl Fischer moisture meter manufactured by Hiranuma Corporation.

[0022] <Method for producing iodinated hydrocarbon mixture> Next, an embodiment of a method for producing an iodinated hydrocarbon mixture according to another aspect of the present invention will be described.

[0023] The method for producing an iodohydrocarbon mixture according to the present invention is a method for producing an iodohydrocarbon mixture containing an iodohydrocarbon and moisture, the water concentration of which is 140 mass ppm or less, and includes a dehydration step of dehydrating a raw material containing the iodohydrocarbon and moisture.

[0024] (Dehydration process) The raw material may be a mixture containing an iodinated hydrocarbon and water, and the water concentration in the raw material is not particularly limited. The moisture concentration in the raw material may be 1000 ppm by mass or less, or may be 200 ppm by mass or less.

[0025] The dehydration method is not particularly limited as long as it can reduce the water concentration in the raw material iodocarbon mixture before dehydration. Examples of the dehydration method include distillation of the iodocarbon mixture before dehydration and dehydration by contacting the iodocarbon mixture before dehydration with a water adsorbent.

[0026] The type of moisture adsorbent is not particularly limited, but examples of moisture adsorbents include zeolite, activated carbon, and silica gel. The type of zeolite is not particularly limited, and the molar ratio of SiO2 to Al2O3 contained in the zeolite (SiO2 / Al2O3 ratio) and the pore size of the zeolite are also not particularly limited. However, zeolites that do not react with iodohydrocarbons are preferred. Examples of such zeolites include molecular sieve 4A.

[0027] After the dehydration step, the dehydrated raw material may be mixed with water to adjust the water concentration in the iodohydrocarbon mixture.

[0028] The water concentration in the iodohydrocarbon mixture finally obtained by the method for producing an iodohydrocarbon mixture according to the present invention may be 140 ppm by mass or less, but the water concentration is preferably 100 ppm by mass or less, more preferably 50 ppm by mass or less, and particularly preferably 30 ppm by mass or less. The water concentration in the iodinated hydrocarbon mixture may be 0.1 ppm by mass or more, 0.5 ppm by mass or more, or 1.0 ppm by mass or more.

[0029] <Container filled with iodinated hydrocarbon mixture> Next, an embodiment of a container filled with an iodinated hydrocarbon mixture according to yet another aspect of the present invention will be described.

[0030] The container for filling an iodohydrocarbon mixture includes a container and an iodohydrocarbon mixture filled in the container. The iodohydrocarbon mixture contains an iodohydrocarbon and moisture, and the moisture concentration in the iodohydrocarbon mixture is 140 ppm by mass or less. This container filled with an iodohydrocarbon mixture can prevent deterioration in the quality of the iodohydrocarbon mixture even when the container is filled with the iodohydrocarbon mixture and stored at high temperatures.

[0031] The container will now be described. <Container> Although the material constituting the container is not particularly limited, it is preferable to use a material that can ensure airtightness and has excellent pressure resistance, such as alloy steels such as manganese steel, stainless steel, and chromium-molybdenum steel, metals such as carbon steel and aluminum alloys, and composite materials such as fiber-reinforced plastics.

[0032] The container may be made of a single layer or a laminate of two or more layers. The container is preferably pressure-resistant, so that the iodinated hydrocarbon mixture can be stored under pressure.

[0033] <Method for manufacturing containers filled with iodinated hydrocarbons> Next, an embodiment of the method for producing a container filled with an iodinated hydrocarbon mixture of the present invention will be described.

[0034] The method for producing a container filled with an iodohydrocarbon mixture includes the step of filling a container with an iodohydrocarbon mixture to produce a container filled with an iodohydrocarbon mixture.

[0035] In general, iodinated hydrocarbon mixtures are highly reactive. Therefore, the iodinated hydrocarbon mixture is preferably filled in a light-shielded and dehumidified environment to prevent the inclusion of air during filling into a container. For example, the iodinated hydrocarbon mixture is introduced into a container under an inert gas atmosphere, the container is sealed, and the iodinated hydrocarbon mixture is filled into the container. From the viewpoint of preventing the inclusion of air during filling into the container, it is more preferable to connect the iodinated hydrocarbon mixture supply source and the container with a pipe and fill the container with the iodinated hydrocarbon mixture in a closed system that minimizes the possibility of air inclusion. For example, the iodinated hydrocarbon mixture may be connected with a pipe to a container whose pressure has been reduced in advance, and the iodinated hydrocarbon mixture may be filled into the container by utilizing the pressure difference between the container and the iodinated hydrocarbon mixture supply source.

[0036] After filling the container with the iodohydrocarbon mixture, an inert gas may be sealed in the container and the iodohydrocarbon mixture may be stored under normal pressure or under pressure. Alternatively, a supply source of the iodohydrocarbon mixture may be connected via a pipe to a container previously filled with an inert gas, and the iodohydrocarbon mixture may be pressure-fed with the inert gas and filled into the container. [Example]

[0037] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0038] Example 1 The raw material diiodomethane mixture was dehydrated by contacting it with molecular sieve 4A (manufactured by Tosoh Corporation, product name: Zeorum A-4) to prepare a mixture of diiodomethane as an iodinated hydrocarbon and water as a diiodomethane mixture. The water concentration in the diiodomethane mixture was measured using a Karl Fischer moisture meter (manufactured by Hiranuma Corporation, product name: AQ-2200S, coulometric titration method) and was found to be 24 ppm by mass, as shown in Table 1.

[0039] Example 2 The diiodomethane mixture obtained in Example 1 was mixed with water to prepare a diiodomethane mixture having a water concentration of 47 ppm by mass, as shown in Table 1.

[0040] Example 3 The diiodomethane mixture obtained in Example 1 was mixed with water to prepare a diiodomethane mixture having a water concentration of 94 ppm by mass as shown in Table 1.

[0041] (Comparative Example 1) As shown in Table 1, a diiodomethane mixture with a water concentration of 165 mass ppm was prepared.

[0042] <Preparing the test sample> First, a metal container was prepared as follows. First, a cylindrical SUS316L pipe (inner diameter 6.35 mm × length 100 mm × thickness 1.0 mm) with female nuts on both ends was prepared as the cylindrical body, and a SUS316L cap was attached to the bottom end of the pipe using a Swagelok (registered trademark) tube joint, thus obtaining the main body of the metal container. Next, 0.75 mL of the diiodomethane mixture prepared as described above (about half the volume of the container) was poured into the main body of the metal container under a dry N2 atmosphere, and then a SUS316 cap was attached to the top of the piping as a lid for the main body of the metal container using a Swagelok (registered trademark) tube fitting, and the test sample was thus obtained.

[0043] <Test to confirm quality deterioration prevention effect> The test samples were subjected to a test to confirm their effect of inhibiting deterioration in quality caused by a diiodomethane mixture as follows. That is, first, for the above test sample, the purity of the diiodomethane mixture, the concentration of iodomethane in the diiodomethane mixture, and the concentrations of other components (components other than diiodomethane and iodomethane) were measured as the purity or concentration before storage using a GC-FID (manufactured by Shimadzu Corporation, product name: GC-2014). The results are shown in Table 1. Next, the test sample was placed in a thermostatic chamber and stored at 130°C. After storing the test sample for 13 days, it was removed from the thermostatic chamber and allowed to cool to 20-25°C. The purity of the diiodomethane mixture, the concentration of iodomethane in the diiodomethane mixture, and the concentrations of other components (components other than diiodomethane and iodomethane) were measured using the GC-FID. The results are shown in Table 1.

[0044] The purity of the diiodomethane mixture is calculated by the following formula: Purity of diiodomethane mixture (%) = 100% - iodomethane concentration (%) - other component concentration (%) Here, the unit % for purity and concentration is GC area % (area % of the obtained GC chart).

[0045] [Table 1]

[0046] As shown in Table 1, in Examples 1 to 3, the increase in iodomethane concentration was smaller and the decrease in purity of the diiodomethane mixture was smaller before and after storage at high temperatures than in Comparative Example 1, indicating that quality deterioration of the diiodomethane mixture was suppressed even when stored at high temperatures.

[0047] This confirms that the iodinated hydrocarbon mixture of the present invention can suppress quality deterioration even when stored at high temperatures.

Claims

1. An iodohydrocarbon mixture containing an iodohydrocarbon and moisture, An iodinated hydrocarbon mixture, wherein the concentration of the water in the iodinated hydrocarbon mixture is 140 ppm by mass or less.

2. 2. The iodinated hydrocarbon mixture according to claim 1, wherein the hydrocarbon group in the iodinated hydrocarbon has 1 to 4 carbon atoms and 1 to 3 iodines.

3. 2. The iodohydrocarbon mixture of claim 1, wherein the iodohydrocarbon is an iodinated saturated hydrocarbon.

4. 4. The iodinated hydrocarbon mixture of claim 3, wherein the iodinated saturated hydrocarbon is diiodomethane.

5. 10. A method for producing the iodinated hydrocarbon mixture of claim 1, comprising: A method for producing an iodohydrocarbon mixture, comprising a dehydration step of dehydrating a raw material containing an iodohydrocarbon and moisture.

6. 5. The method for producing an iodinated hydrocarbon mixture according to claim 4, wherein the hydrocarbon group in the iodinated hydrocarbon has 1 to 4 carbon atoms and 1 to 3 iodines.

7. 7. The method for producing an iodohydrocarbon mixture according to claim 6, wherein the iodohydrocarbon is an iodinated saturated hydrocarbon.

8. 8. The method for producing an iodinated hydrocarbon mixture according to claim 7, wherein the iodinated saturated hydrocarbon is diiodomethane.

9. A container and an iodohydrocarbon mixture-filled container containing an iodohydrocarbon mixture filled in the container, the iodohydrocarbon mixture containing an iodohydrocarbon and water, A container filled with an iodinated hydrocarbon mixture, wherein the water concentration in the iodinated hydrocarbon mixture is 140 ppm by mass or less.

10. 10. The container filled with an iodinated hydrocarbon mixture according to claim 9, wherein the number of carbon atoms in the hydrocarbon group in the iodinated hydrocarbon is 1 to 4 and the number of iodines in the hydrocarbon group is 1 to 3.

11. 11. The container of claim 10, wherein the iodohydrocarbon is an iodinated saturated hydrocarbon.

12. 12. The iodinated hydrocarbon mixture filled container of claim 11, wherein the iodinated saturated hydrocarbon is diiodomethane.

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