JPH07237650A - Stopper structure for container for electronic industrial chemical - Google Patents

Abstract

PURPOSE:To prevent foreign matter and impurity from being mixed into a liquid chemical and keep the liquid chemical highly pure over a long period of time. CONSTITUTION:A structure is composed of an inner stopper 1 and an outer stopper 2, and they are fitted together. The inner stopper 1 has a projection sticking toward a container, and the outside diameter of the projection is larger than the inside diameter (b) of the mouth of the main body of the container. Thus, it can be used, for example, in the packing of car audio-equipment whose depths slightly differ.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stopper for containers of electronic chemicals used for cleaning and etching wafers in the semiconductor manufacturing field.

[0002]

2. Description of the Related Art With the recent remarkable development of the electronic industry field, it is required to highly purify electronic chemicals used therein. The purity required for electronic chemicals is extremely high, for example, the total metal content is 1 ppb or less, and the foreign matter of 0.2 μm or more is 100 pieces / ml or less. Is required. Conventionally, inexpensive general-purpose polyethylene is used as a container material for electronic industrial chemicals from the viewpoint of chemical resistance, impact resistance, etc., but when high-purity electronic industrial chemicals are filled, ions that cause impurities from the material There was a big problem that elution and dust generation occurred, and high purification could not be maintained.
For this reason, polyethylene is known which has improved these problems.

Furthermore, strict standards are also required for stoppers. In a container for electronic industrial chemicals, a stopper is generally shown in FIG.
As shown in (1), it is composed of an inner stopper that comes into contact with a chemical, an outer stopper that holds it, and a packing that maintains the sealing property between the inner stopper and the container spout when the stopper is closed. In general,
In order to prevent the inner plug from falling off from the outer plug, it is fixed to the outer plug so that only the inner plug does not move freely. When the inner plug is opened and closed, dust may be generated by rubbing against the inside of the container pouring mouth, which may contaminate chemicals. Therefore, flatten the inner plug as shown in FIG. When it cannot be made flat, the maximum diameter of the convex portion is smaller than the inner diameter of the spout so that the convex portion of the inner plug does not rub against the spout as shown in FIG.

On the other hand, as the packing material, foamed polyethylene, silicon rubber or the like is used, which is caused by ion elution and dust generation due to this material, and friction between the packing and the spout of the container body and the stopper when tightening. There is concern about dust generation. In this case, the packings and the chemicals come into contact with each other, albeit a small amount, during transportation of the container, and the chemicals are highly likely to be contaminated. However, it has been impossible to prevent foreign substances and ions from being mixed in the chemical liquid due to the shape of the plug and the components forming the plug.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a stopper that suppresses ion elution and dust generation from the stopper structure while maintaining the sealing property with the container body.

[0006]

As a result of earnest efforts, the present inventor has found a method for suppressing the contamination of chemicals with a packing material, foreign matter from a plug constituent, and ion contamination while maintaining the sealing property of a container. Completed the invention. That is, the present invention is
The inner stopper and the outer stopper are fitted together, and further, the inner stopper has a convex portion directed toward the inside of the container, and the outer diameter (length a in FIG. 4) of the convex portion is the inner diameter of the spout of the container body ( FIG. 4 relates to a plug construction larger than length b). Further, preferably, the present invention relates to a container having a structure as shown in FIG. 4 and having a packing attached between the outside of the convex portion of the inner plug and the upper surface of the container body spout. In the present invention, the outer diameter of the convex portion of the inner plug is preferably 0.01 mm or more, more preferably 0.05 to 2 mm, and most preferably 0.1 to 1 mm larger than the inner diameter of the container body pouring opening.

In the present invention, the inner stopper and the outer stopper are fitted together and can move freely without being fixed to the outer stopper. Therefore, when the stopper is closed, the inner stopper is tightly closed without being rotated and pushed. As a result, the inner plug is rotated together with the outer plug as in a normal plug structure in which the inner plug and the outer plug are fixed, and the side surface of the convex portion of the inner plug and the inside of the spout are closely contacted and sealed. Thus, the generation of foreign matter from the contact portion between the inner plug and the inner side surface of the spout can be minimized.

Further, the stopper structure of the present invention is used as a container for electronic industrial chemicals comprising the stopper structure of the present invention and a container body. Further, it is used as a container in which packing is attached as needed between the upper surface of the container main body spout and the inner stopper of this stopper structure. In this case, since the side surface of the convex portion of the inner plug and the inner side surface of the container main body are in close contact with each other,
No foreign matter is mixed into the chemical liquid between the top surface of the container body spout and the inner stopper. The use of packing is not always necessary when the sealing property is high such as in the case of a small container. As the material for the plug structure of the present invention, polyethylene or fluororesin is preferably used for the inner plug and polyethylene is preferably used for the outer plug. The packing material is preferably expanded polystyrene, fluororesin or silicone. The present invention is not limited to the shapes shown in FIGS. 4 and 5 as long as the shape of the inner plug satisfies the requirements of the present invention. Also, the method of fitting the outer stopper and the inner stopper is shown in FIGS.
It is not limited to this.

[0009]

【Example】

Example 1 A 20-liter polyethylene container was filled with ultrapure water, and the container had the structure shown in FIG. 4 and was sealed with a plug structure whose packing material was polyethylene foam. Then, the sample was shaken for 24 hours, and then ultrapure water was taken out from the container, and the concentration of various ions in the ultrapure water and foreign substances with a diameter of 0.2 μm or more were analyzed to measure the increased amount of ions and the increased amount of foreign substances. . The results are shown in Table 1.

Example 2 The same operation as in Example 1 was carried out except that ultrapure 31% hydrogen peroxide water for electronics industry was filled in place of ultrapure water. The results are shown in Table 1. Example 3 The same operation as in Example 1 was carried out except that ultrapure 29% ammonia water for electronics industry was filled in place of ultrapure water. The results are shown in Table 1.

Example 4 The same operation as in Example 1 was carried out except that ultrapure 61% nitric acid for electronics industry was filled in place of ultrapure water. The results are shown in Table 1. Examples 5 to 8 Examples 1 to 8 except that the plug structure has the structure shown in FIG. 4 and the packing material is silicone
The same operation as in 4 was performed. The results are shown in Table 1. Examples 9 to 12 The same operations as in Examples 1 to 4 were performed, except that a 5-liter polyethylene container was sealed with a plug structure having the structure shown in FIG. 5 and a packing material of silicone. The results are shown in Table 1.
Shown in.

Comparative Examples 1 to 4 The same operations as in Examples 1 to 4 were carried out except that the plug structure having the structure shown in FIG. 3 was used as the plug structure and the packing material was foamed polyethylene. The results are shown in Table 2. Comparative Examples 5 to 8 Examples 5 to 8 except that the stopper structure is the structure shown in FIG. 3 and the packing material is silicone
The same operation as in 8 was performed. The results are shown in Table 2.

Comparative Examples 9 to 12 Examples 9 to 12 are the same as the plug structure except that the structure is as shown in FIG. 6 and the packing material is silicone.
The same operation as 12 was performed. The results are shown in Table 2. Comparative Examples 13 to 16 The same operations as in Examples 1 to 4 were performed except that the plug structure was sealed with a plug structure having the structure shown in FIG. 2 and the packing material was foamed polyethylene. The results are shown in Table 2.

[0014]

[Table 1] Filling chemicals Increasing amount of ion Increasing amount of foreign matter (pieces / ml) Example 1 Ultrapure water None 10 Example 2 31% Hydrogen peroxide solution None 20 Example 3 29% Ammonia water None 15 Example 4 61% Nitric acid None 15 Example 5 Ultrapure water None 12 Example 6 31% Hydrogen peroxide solution None 18 Example 7 29% Ammonia water None 15 Example 8 61% Nitric acid None 10 Example 9 Ultrapure water None 5 Example 10 31% Hydrogen peroxide water None 10 Example 11 29% Ammonia water None 10 Example 12 61% Nitric acid None 5

[0015]

[Table 2] Filling chemicals Ion increase amount Foreign matter increase amount (pieces / ml) Comparative example 1 Ultrapure water Cr0.05ppb 200 Comparative example 2 31% Hydrogen peroxide water Cr0.2ppb 300 Comparative example 3 29% Ammonia water Cr0.5ppb 400 Comparative Example 4 61% Nitric Acid Cr0.7ppb 500 Comparative Example 5 Ultrapure Water Ca0.5ppb 500 Comparative Example 6 31% Hydrogen Peroxide Water Ca1.5ppb 800 Comparative Example 7 29% Ammonia Water Ca1.0ppb 700 Comparative Example 8 61% Nitric acid Ca2.0ppb 900 Comparative example 9 Ultrapure water Ca0.3ppb 100 Comparative example 10 31% Hydrogen peroxide solution Ca1.0ppb 150 Comparative example 11 29% Ammonia water Ca0.8ppb 150 Comparative example 12 61% Nitric acid Ca1.4ppb 200 Comparative example Example 13 Ultrapure water Cr0.3ppb 500 Comparative example 14 31% Hydrogen peroxide water Cr0.6ppb 700 Comparative example 15 29% Ammonia water Cr0.8ppb 700 Comparative example 16 61% Nitric acid Cr1.0ppb 800

EFFECTS OF THE INVENTION By using the stopper composition according to the present invention, it is possible to suppress dusting and elution of ions at the time of tightly sealing and to seal the container. In addition, the sealing property of the container is kept extremely high after sealing.
Further, since the side surface of the convex portion of the inner plug and the inner side surface of the spout of the container body are in close contact with each other, it is possible to prevent the packing and the chemical solution from coming into contact with each other. It is possible to prevent the dissolution of ions and the mixture of foreign substances. The present invention provides a container capable of suppressing foreign matter and impurities from being mixed into a chemical liquid derived from a stopper composition and capable of holding a high-purity chemical liquid at high purity for a long period of time.

[Brief description of drawings]

FIG. 1 is a conventional plug structure.

FIG. 2 is a conventional stopper structure.

FIG. 3 is a conventional stopper structure.

FIG. 4 is a stopper structure of the present invention.

FIG. 5 shows the stopper structure of the present invention.

FIG. 6 shows a conventional stopper structure.

[Explanation of symbols]

 Common to all figures :: Inner plug: Outer plug: Packing: Container body: Inner side surface of container body spout: Upper surface of container body spout a: Inner plug convex portion outer diameter length b: Container body spout inner diameter length

Claims (3)

[Claims] 1. An inner stopper and an outer stopper, wherein the inner stopper and the outer stopper are fitted to each other, and the inner stopper has a convex portion facing the container, and the outer diameter of the convex portion is poured into the container body. A stopper structure characterized by being larger than the inner diameter of the mouth. 2. A container for electronic industrial chemicals comprising the stopper structure according to claim 1 and a container body. 3. A container for electronic industrial chemicals according to claim 2, comprising the stopper structure according to claim 1, a container body and a packing, wherein a packing is mounted between the upper surface of the container body spout and the inner plug.