Search

JP-7856006-B2 - Storage method for gas-filled containers and (E)-1,1,1,4,4,4-hexafluoro-2-butene

JP7856006B2JP 7856006 B2JP7856006 B2JP 7856006B2JP-7856006-B2

Inventors

  • 谷本 陽祐
  • 鈴木 淳

Assignees

  • 株式会社レゾナック

Dates

Publication Date
20260511
Application Date
20211008
Priority Date
20201015

Claims (13)

  1. A gas-filled container in which (E)-1,1,1,4,4,4-hexafluoro-2-butene is filled into the filled container, A gas-filled container in which the portion of the filled container in contact with the (E)-1,1,1,4,4,4-hexafluoro-2-butene is made of a metal in which the copper concentration is less than 0.5% by mass.
  2. The gas-filled container according to claim 1, wherein the portion of the filled container in contact with the (E)-1,1,1,4,4,4-hexafluoro-2-butene is formed of a metal having a copper concentration of less than 0.4% by mass.
  3. A gas-filled container according to claim 1 or claim 2, wherein the metal is steel.
  4. A gas-filled container according to claim 1 or claim 2, wherein the metal is at least one of manganese steel and chromium-molybdenum steel.
  5. The gas-filled container according to any one of claims 1 to 4, wherein the concentration of copper is measured by X-ray photoelectron spectroscopy.
  6. A gas-filled container according to any one of claims 1 to 5, wherein the filled container comprises a cylinder containing the (E)-1,1,1,4,4,4-hexafluoro-2-butene, and a valve for opening and closing a flow path for the (E)-1,1,1,4,4,4-hexafluoro-2-butene inside the cylinder to the outside.
  7. A gas-filled container according to any one of claims 1 to 6, wherein the purity of the (E)-1,1,1,4,4,4-hexafluoro-2-butene to be filled is 99.90% by volume or more.
  8. A method for storing (E)-1,1,1,4,4,4-hexafluoro-2-butene by filling it into a filled container, A method for storing (E)-1,1,1,4,4,4-hexafluoro-2-butene, wherein the portion of the filled container that comes into contact with the filled (E)-1,1,1,4,4,4-hexafluoro-2-butene is made of a metal with a copper concentration of less than 0.5% by mass.
  9. The method for storing (E)-1,1,1,4,4,4-hexafluoro-2-butene according to claim 8, wherein the portion of the filled container that comes into contact with the filled (E)-1,1,1,4,4,4-hexafluoro-2-butene is made of a metal in which the copper concentration is less than 0.4% by mass.
  10. A method for storing (E)-1,1,1,4,4,4-hexafluoro-2-butene according to claim 8 or 9, wherein the metal is steel.
  11. The method for storing (E)-1,1,1,4,4,4-hexafluoro-2-butene according to claim 8 or 9, wherein the metal is at least one of manganese steel and chromium-molybdenum steel.
  12. The method for storing (E)-1,1,1,4,4,4-hexafluoro-2-butene according to any one of claims 8 to 11, wherein the concentration of copper is measured by X-ray photoelectron spectroscopy.
  13. A method for storing (E)-1,1,1,4,4,4-hexafluoro-2-butene according to any one of claims 8 to 12, wherein the purity of the (E)-1,1,1,4,4,4-hexafluoro-2-butene to be filled is 99.90% by volume or more.

Description

The present invention relates to a gas-filled container and a method for storing (E)-1,1,1,4,4,4-hexafluoro-2-butene. In order to reliably perform fine processing in dry etching, the dry etching gas must be of high purity (for example, 99.9% by volume or higher). Furthermore, since the dry etching gas is stored in a filled container until use, it is necessary that its high purity is maintained over a long period of time within the container. Patent Document 1 discloses a technique for storing 2-fluorobutane, 2-fluoro-2-methylpropane, and 2-fluoropentane, which can be used as dry etching gases, while maintaining high purity over a long period of time. In the technique disclosed in Patent Document 1, the decrease in purity is suppressed by filling a manganese steel container with a small amount of aluminum adhering to its inner surface with 2-fluorobutane, 2-fluoro-2-methylpropane, or 2-fluoropentane. International Publication No. 2016/117464 One embodiment of the present invention is described below. This embodiment is merely an example of the present invention, and the present invention is not limited to this embodiment. Furthermore, various modifications or improvements can be made to this embodiment, and such modified or improved forms may also be included in the present invention. (E)-1,1,1,4,4,4-hexafluoro-2-butene is being considered for use as a dry etching gas in semiconductor manufacturing, but because it is not widely used industrially, its physical properties are not fully understood, and there are currently very few reports on its long-term storage stability or compounds that act as decomposition catalysts. As a result of diligent research, the inventors of the present invention discovered that (E)-1,1,1,4,4,4-hexafluoro-2-butene undergoes reactions such as isomerization, polymerization, and decomposition when in contact with metallic copper, copper alloys, or copper compounds, leading to a decrease in purity, and thus completed the present invention. The present invention specifies the material of the filling container for filling (E)-1,1,1,4,4,4-hexafluoro-2-butene in order to suppress reactions such as isomerization, polymerization, and decomposition of (E)-1,1,1,4,4,4-hexafluoro-2-butene. In other words, the gas-filled container according to this embodiment is a gas-filled container in which (E)-1,1,1,4,4,4-hexafluoro-2-butene is filled into the container, and the portion of the container in contact with the filled (E)-1,1,1,4,4,4-hexafluoro-2-butene is made of a metal in which the copper concentration is less than 0.5% by mass. Furthermore, the storage method for (E)-1,1,1,4,4,4-hexafluoro-2-butene according to this embodiment is a method of storing (E)-1,1,1,4,4,4-hexafluoro-2-butene by filling it into a filled container, wherein the portion of the filled container that comes into contact with the filled (E)-1,1,1,4,4,4-hexafluoro-2-butene is made of a metal with a copper concentration of less than 0.5% by mass. In the filled container, the portion that comes into contact with the filled (E)-1,1,1,4,4,4-hexafluoro-2-butene is made of a metal with a copper concentration of less than 0.5% by mass. Therefore, reactions such as isomerization, polymerization, and decomposition are unlikely to occur in the filled (E)-1,1,1,4,4,4-hexafluoro-2-butene. As a result, even if the gas-filled container according to this embodiment is stored for a long period of time, the purity of the filled (E)-1,1,1,4,4,4-hexafluoro-2-butene is unlikely to decrease. Thus, if a gas-filled container is filled with high-purity (E)-1,1,1,4,4,4-hexafluoro-2-butene, its high purity is likely to be maintained even after long-term storage. The term "copper" above refers to the element copper. If the metal forming the portion of the filled container that comes into contact with the filled (E)-1,1,1,4,4,4-hexafluoro-2-butene contains copper, that copper may be metallic copper, a copper alloy, or a copper compound such as a copper salt. Furthermore, the concentration of copper contained in the above metal must be less than 0.5% by mass, and preferably 0.4% by mass or less. In order to further suppress reactions such as isomerization, polymerization, and decomposition of (E)-1,1,1,4,4,4-hexafluoro-2-butene, it is more preferable that the concentration be 0.1% by mass or less, and even more preferable that it be 0.01% by mass or less. There is no particular lower limit for the concentration of copper, but it may be 0.001% by mass or more. While there are no particular limitations on the method for measuring the concentration of copper, it can be measured by X-ray photoelectron spectroscopy (XPS analysis). [Filling container] The filling container in the gas-filled container according to this embodiment, and the filling container in the storage method for (E)-1,1,1,4,4,4-hexafluoro-2-butene according to this embodiment, preferably comprises a cylinder and a valve. The cylinder is a component that contains (E)-1,1,1,4,4,4-hexafluoro-