JP2909982B2 - Manufacturing method of plug for high purity chemical container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a stopper of the container for storing a high purity liquid chemicals.

[0002]

2. Description of the Related Art Generally, a glass container or a plastic container is used as a container for storing a solvent or the like.

In particular, in the field of semiconductors and pharmaceuticals, it is required that stored high-purity liquid chemicals can be stored and transported with high purity. Examples of high-purity liquid chemicals include chemicals used for etching and cleaning semiconductor wafers, for example, hydrogen fluoride water, ammonium fluoride water,
Sulfuric acid, hydrochloric acid, nitric acid, aqueous hydrogen peroxide, aqueous ammonia, etc., high-purity solvent-based resists and diluting solvents used for semiconductor processes, liquid crystal displays, etc., for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, isobutyl alcohol, Ethylene glycol, acetone,
Ethyl acetate, ethyl lactate, toluene, dimethylformamide, ethylene glycol acetate, methoxypropyl acetate, butyl cellosolve, and the like, and high-purity solvents used for medicines such as sterilization, disinfection, and drug substances, such as methyl alcohol, ethyl alcohol, and isopropyl There are alcohol and the like.

When these chemicals are stored and transported,
Fine particles are leached out of the container wall due to vibration or the like, thereby impairing the purity of the chemical. For this reason, many studies have been made on the material and manufacturing method of the container in order to have a significant adverse effect on the quality and yield of semiconductors and liquid crystals, and to shorten the storage period of chemicals.

[0005] It is not only containers that impair the purity of chemicals,
The same applies to the stopper because the stopper comes into contact with the contained medicine. The plug includes, for example, a plug 1 having a rib in contact with the inner surface of the mouth of the container (see FIG. 1) and a plug 2 having an inner plug 6 (see FIG. 2).
), A plug 3 having a packing 8 in a portion in contact with a medicine
There is a relatively simple shape of the stopper (see FIG. 3) and a relatively complicated shape of the stopper 4 having the medicine discharge portion 11 as shown in FIG. However, since these plugs have a large role in preventing leakage of the chemical and have a small area in contact with the chemical compared to the container, a plug with minimal leaching of fine particles into the chemical has not been manufactured. Was.

[0006] While the medicine is stored in the container for a long period of time, there is a so-called cleanness as an index indicating the degree of impurity particles leaching from the container and the plug into the contents of the medicine to make the medicine impure. The degree of cleanliness is determined by attaching a stopper to the test container, storing ultrapure water in the test container for a certain period of time, and then adding 0.2 μm particle size to 1 ml of water stored in the test container.
The number of fine particles of m or more is calculated and obtained.
Specifically, it is defined by the following equation.

[0007]

(Equation 1)

In the equation (1), a is the capacity of the container to be inspected, b
Is the amount of ultrapure water sampled from the container to be inspected. Sampling water is collected as follows. First, sampling water for measuring the initial cleanliness is placed in a container to be inspected having a capacity of aml, a half of the volume, a / 2 (m).
l) Ultrapure water is added, shaken for 15 seconds, and 20
Collected after standing for minutes. In addition, the sampling water for measuring the cleanliness after one week, the stopper was attached to the container after the initial cleanliness measurement, left for one week in an inverted position, shaken again for 15 seconds, Water 2
Let stand for 0 minutes. The sampling water is collected after standing for 20 minutes. C is a value obtained by counting fine particles having a particle diameter of 0.2 μm or more contained in the whole amount of the sampling water by a particle counter. Based on the numerical value, the cleanliness at the initial stage and one week later is calculated by the equation (1). When the degree of cleanness is less than 500 cells / ml, the quality and yield of semiconductors and liquid crystals can be improved, and pharmaceuticals can be stably stored.

When a container is used for a high-purity chemical, it cannot be used unless the value of the cleanness is low. In conventional clean containers, recontamination of the container was unavoidable due to the lack of a clean plug. Therefore, the drug maker performs co-washing of the container and the plug with the same drug before filling the drug, which is troublesome, and is an economic burden on the drug maker.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and when storing a high-purity chemical in a high-purity chemical container, the leaching of the impure fine particles into the chemical is small, and the chemical is reduced. Providing a method for manufacturing plugs for high-purity chemical containers that are not contaminated and do not require labor such as co-washing
Is what you do.

[0011]

SUMMARY OF THE INVENTION A method for producing a plug for a high-purity chemical container according to the present invention has been made to achieve the above-mentioned object.
Should be at least in contact with high-purity liquid chemicals.
Among fin-based resins, polyester resins and fluororesins
Molded with at least one material selected from
After that, the contact portion was set to an electric conductivity of 50 μs / c at 25 ° C.
m and pure water with a specific resistance of 10 MΩ · cm or more
Air cleaner measured according to JIS B 9920
Dry in a clean oven of class 6 or less.
And features.

High purity chemical volume obtained by the production method of the present invention
As shown in FIG. 1, at least a high-purity liquid
In accordance with JIS B 9920 at the contact part with body medicine
Surface with a particle size of 1.0 μm or more measured by electron microscopy
The concentration of the attached fine particles becomes 500 particles / cm or less.

In carrying out the molding, JIS B
Class 7 air cleanliness measured according to 9920
It is preferable to carry out in the following clean room.

[0014]

In order to wash the contact portion with pure water, a commercially available washing machine such as an ultrasonic method or an underwater stirring method may be used. Before washing with pure water, preliminary washing with a hydrocarbon solvent or a detergent is performed. You may go.

The polyolefin resin is at least one selected from polyethylene, polypropylene, polybutylene and copolymers thereof, the polyester resin is at least one selected from polyethylene terephthalate and polybutylene terephthalate, the fluororesin Are ethylene tetrafluoride, ethylene tetrafluoride-perfluoroalkyl vinyl ether copolymer, ethylene tetrafluoride-hexafluoropropylene copolymer, ethylene tetrafluoride-ethylene copolymer, ethylene trifluoride chloride, polyfluoroethylene It is at least one selected from vinylidene, polyvinyl fluoride, and ethylene trifluoride-ethylene-ethylene copolymer.

These polymers have a water absorption of 2.0% or less as measured based on ASTM (American Society for Testing and Materials) D570. When a polymer having a water absorption exceeding 2.0% is used, if the chemical stored in the high-purity chemical container dislikes water, the chemical is adversely affected. Further, when the molded high-purity chemical container plug 1 is washed and dried, it takes a long time, which is not preferable.

When a barrier property or a light-shielding property for preventing invasion of an external gas into the stored chemical is required, a portion other than a contact portion with the high-purity chemical is made of a metal material such as aluminum, polyamide, polyvinyl alcohol, or the like. May be freely selected from the above plastic materials to form a multilayer structure.

[0019]

[0020]

[0021]

Embodiments of the present invention will be described below in detail.

Example 1 A particle counter (type: 82-3200 (Dan Kagaku Co., Ltd.)) based on JIS B 9920
In a manufacturing environment in a clean room having a cleanliness of 0.5 μm or more measured at 2.8 × 10 ⁵ pieces / m ³ (class 7),
A polyethylene pellet having a density of 0.951 g / cm ³ and a melt index of 0.15 g / 10 min was injected into an injection molding machine (screw diameter: 36 m / m, clamping force: 80 ton).
(Nissei Plastic Industry Co., Ltd.)) was used by wiping with a detergent, melting at 200 ° C. and having a rib shown in FIG.
Was manufactured.

The concentration of the fine particles attached to the surface of the plug 1 was measured as follows.

The area of the contact portion of the plug 1 with the high-purity chemical is determined to be the effective contact area (cm ² ), and the entire effective contact area is used as a sample. If the entire effective contact area cannot be used as a sample, a part of the sample is cut out without recontamination to obtain a sample. With respect to this sample, the attached fine particles were measured by an electron microscope method among the fine particle concentration measuring methods of JIS B 9920.

First, a vacuum evaporation apparatus (type: E10
2 (manufactured by Hitachi, Ltd.). This sample was subjected to a scanning electron microscope (type: S-2250).
N (manufactured by Hitachi, Ltd.)). After confirming that the distribution of fine particles is not uneven at low magnification throughout the field of view,
The number of particles having a particle size of 1.0 μm or more was measured from a monitor screen and a photograph in a measurement visual field (120 × 80 μm).

From the entire field of view, 100 or more measurement fields of view were scanned uniformly, and the number of particles having a particle size of 1.0 μm or more was determined for each measurement field and totaled to obtain the total number of particles measured.
From the above measurement results, the concentration of the fine particles adhering to the surface was calculated by the following equation (2).
Was calculated. Table 1 shows the results, the material of the contact portion with the content liquid, the manufacturing environment of the contact portion, and the presence / absence of washing and drying of the contact portion.

[0027]

(Equation 2)

Next, the cleanliness of the plug 1 was measured as follows.

First, a clean container to which the plug 1 was attached was manufactured as follows. Weight average molecular weight 250,000, density 0.956 g / cm ³ , melt index 0.02
40 parts by weight of polyethylene pellets of g / 10 minutes and 60 parts by weight of polyethylene pellets having a weight average molecular weight of 150,000, a density of 0.956 g / cm ³ and a melt index of 0.17 g / 10 minutes were dry-blended. This mixed pellet was prepared with a screw diameter of 50 m / m and L / D = 22.
In an extruder (D: screw diameter, L: effective screw length), the mixture was melted at 200 ° C. and extruded into a cylindrical parison. The extruded parison is sandwiched between molds, and compressed air of 6 kg / cm ² is blown from a blow pin, and cooled with a mold cooled to 20 ° C., the capacity is 1000 ml, and the weight is 100 g.
Was manufactured.

Into this clean container, 500 ml of ultrapure water produced by a pure water production apparatus (trade name: Trepure LV-10T (manufactured by Toray Industries, Inc.)) is placed, and a plug 1 is attached to the clean container.
After shaking for 5 seconds and standing for 20 minutes, 5 ml was collected, and the number of fine particles of 0.2 μm or more leached therein was measured with a particle counter (type: KL-22 (manufactured by Lion Corporation)).

The number of fine particles in the water (particles / ml) was calculated by the following equation (3) similar to the equation (1), and was set as the initial cleanliness. Table 1 shows the results.

[0032]

(Equation 3)

Further, this clean container was sealed again with the stopper 1, and left standing at room temperature and in an inverted position for one week. The water that had passed for one week was shaken again for 15 seconds and allowed to stand for another 20 minutes. From the water left for 20 minutes, 5 ml was sampled and the number of fine particles in the water (particles / ml) was calculated in the same manner as above, and the result was taken as the cleanness after one week. Table 1 shows the results.

[0034]

[Table 1]

As shown in Table 1, the number of fine particles adhering to the surface of the plug 1 is as good as 312 / cm ² , the initial cleanness is 50 (pieces / ml) or less, and the cleanness after one week is It was extremely clean at 200 (pieces / ml) or less.

Example 2 In the same manufacturing environment in a clean room of class 7 as in Example 1, polyethylene pellets having a density of 0.920 g / cm ³ and a melt index of 7.0 g / 10 minutes were injected into an injection molding machine (screw diameter: : 36m / m, mold clamping force: 80to
n (manufactured by Nissei Plastic Industry Co., Ltd.) was wiped with a detergent and used, and was melted at 180 ° C. to produce the inner plug 6 of the plug 2 shown in FIG. The cap 5 has a density of 0.940 g / c.
Polyethylene pellets having an m ³ and a melt index of 3.5 g / 10 min were produced by the injection molding machine.

The concentration of the fine particles adhered to the surface of the plug 2, the initial cleanliness, and the cleanliness after one week were measured in the same manner as in Example 1. Table 1 shows the results, the material of the contact portion with the content liquid, the manufacturing environment of the contact portion, and the presence / absence of washing and drying of the contact portion.

As shown in Table 1, the number of fine particles adhering to the surface of the plug 2 is as good as 312 / cm ² , the initial cleanness is 50 (pieces / ml) or less, and the cleanness after one week is It was extremely clean at 300 (pieces / ml) or less.

Example 3 A particle counter (type: 82-3200 (Dan Kagaku Co., Ltd.)) based on JIS B 9920
The density is 0.940 g / cm ³ and the melt index is 3. In a normal production environment in a factory having a cleanliness of 0.5 μm or more and a cleanliness of 1.2 × 10 ⁸ pieces / m ³ (class 8 or more) measured in the above.
The polyethylene pellets of 5 g / 10 min were melted at 180 ° C. using an injection molding machine (screw diameter: 36 m / m, mold clamping force: 80 ton (manufactured by Nissei Plastics Industries, Ltd.)) and the plug 3 shown in FIG. Was manufactured. Next, a packing 8 (type: SSPP, surface material: stretched polypropylene film (manufactured by Dynaga)) was attached to the cap 7.

FIG. 5 shows a shower device for cleaning the plug 3. An upper nozzle 18 and a lower nozzle 19 are arranged above and below a conveyor 20 for feeding the plug 3, and the nozzles 18 and 19 are connected to a pump 16 for pumping ultrapure water 15 through a filter 17.

The plug 3 having the packing 8 was prepared using ultrapure water 15 (electric conductivity 10 μs / c) manufactured by a pure water manufacturing apparatus (trade name: Trepure LV-10T (manufactured by Toray Industries, Inc.)).
m, and the specific resistance was 18 MΩ · cm (25 ° C.)), and the substrate was washed with the shower device for 30 seconds. Then JIS B
The sample was dried in a clean oven (type: DE42 (manufactured by Yamato Scientific Co., Ltd.)) whose air cleanliness measured based on 9920 was class 6 or less.

The concentration of the fine particles adhering to the surface of the plug 3, the initial cleanliness, and the cleanliness after one week were measured in the same manner as in Example 1. Table 1 shows the results, the material of the contact portion with the content liquid, the manufacturing environment of the contact portion, and the presence / absence of washing and drying of the contact portion.

As shown in Table 1, the number of fine particles adhering to the surface of the plug 3 was as good as 104 / cm ² , the initial cleanness was 50 (pieces / ml) or less, and the cleanness after one week was It was extremely clean at 400 (pieces / ml) or less.

Example 4 In a production environment in a normal factory of class 8 or more similar to that in Example 3, polyethylene pellets having a density of 0.940 g / cm ³ and a melt index of 3.5 g / 10 minutes were injected into an injection molding machine ( Screw diameter: 36m / m, mold clamping force: 80 ton
(Nissei Plastic Industry Co., Ltd.)) and melted at 180 ° C. to produce an upper cap 9, a lower cap 10, and a chemical discharge section 11 of the plug 4 shown in FIG. Next, using the perforated packing 12 (type: TSST, surface material: ethylene tetrafluoride film (manufactured by Dynaga Co., Ltd.)), assembling together with the upper cap 9, the lower cap 10, and the chemical discharge section 11, I got

The obtained plug 4 was washed and dried in the same manner as in Example 3.

The concentration of fine particles adhering to the surface of the plug 4, the initial cleanliness, and the cleanliness after one week were measured in the same manner as in Example 1. Table 1 shows the results, the material of the contact portion with the content liquid, the manufacturing environment of the contact portion, and the presence / absence of washing and drying of the contact portion.

As shown in Table 1, the number of fine particles adhering to the surface of the plug 4 was as good as 104 / cm ² , the initial cleanness was 50 (pieces / ml) or less, and the cleanness after one week was It was extremely clean at 200 (pieces / ml) or less.

Comparative Example 1 In a manufacturing environment in a normal factory of class 8 or more similar to that in Example 3, polyethylene pellets having a density of 0.951 g / cm ³ and a melt index of 0.15 g / 10 min were injected into an injection molding machine ( Screw diameter: 36m / m, clamping force: 80 to
n (manufactured by Nissei Plastic Industry Co., Ltd.), and melted at 200 ° C. to produce a plug 1 having a rib shown in FIG.

The concentration of fine particles adhering to the surface of the plug 1, the initial cleanliness, and the cleanliness after one week were measured in the same manner as in Example 1. Table 1 shows the results, the material of the contact portion with the content liquid, the manufacturing environment of the contact portion, and the presence / absence of washing and drying of the contact portion.

As shown in Table 1, the number of fine particles adhering to the surface of the plug 1 was as poor as 3224 / cm ² , the initial cleanness was 612 (particles / ml), and the cleanness after one week was 983. (Pieces / ml) and a large amount of fine particles leached from the plug 1.

Comparative Example 2 In a manufacturing environment in a normal factory of class 8 or more similar to that of Example 3, polyethylene pellets having a density of 0.920 g / cm ³ and a melt index of 7.0 g / 10 minutes were injected into an injection molding machine ( Screw diameter: 36m / m, mold clamping force: 80 ton
(Manufactured by Nissei Plastic Industry Co., Ltd.)) and melted at 180 ° C. to produce an inner plug 6 of the plug 2 shown in FIG. For the cap 5, a polyethylene pellet having a density of 0.940 g / cm ³ and a melt index of 3.5 g / 10 minutes was produced by the injection molding machine.

The concentration of fine particles adhering to the surface of the plug 2, the initial cleanliness, and the cleanliness after one week were measured in the same manner as in Example 1. Table 1 shows the results, the material of the contact portion with the content liquid, the manufacturing environment of the contact portion, and the presence / absence of washing and drying of the contact portion.

As shown in Table 1, the number of fine particles adhering to the surface of the plug 2 was 2704 particles / cm ² , the initial cleanness was 862 (particles / ml), and the cleanness after one week was 1237. (Pieces / ml) and a large amount of fine particles leached from the plug 2.

Comparative Example 3 Using the same plug 3 (see FIG. 3) as used in Example 3, without washing and drying, the concentration of fine particles adhering to the surface of the plug 3 and the initial cleanness The cleanness after one week was measured in the same manner as in Example 1. Table 1 shows the results, the material of the contact portion with the content liquid, the manufacturing environment of the contact portion, and the presence / absence of washing and drying of the contact portion.

As shown in Table 1, the number of fine particles adhering to the surface of the plug 3 was 1976 particles / cm ^2, which was poor, the initial cleanness was 481 (cleanings / ml), and the cleanness after one week was 1016. (Pieces / ml) and a large amount of fine particles leached from the plug 3.

Comparative Example 4 Using the same plug 4 (see FIG. 4) as used in Example 4, without washing and drying, the concentration of fine particles adhering to the surface of the plug 4 and the initial cleanness The cleanness after one week was measured in the same manner as in Example 1. Table 1 shows the results, the material of the contact portion with the content liquid, the manufacturing environment of the contact portion, and the presence / absence of washing and drying of the contact portion.

As shown in Table 1, the number of fine particles adhering to the surface of the plug 4 was 3952 particles / cm ² , the initial cleanness was 2084 (particles / ml), and the cleanness after one week was 2615. (Pieces / ml) and a large amount of fine particles leached from the plug 4.

[0058]

As described above in detail, when the plug for a high-purity chemical container manufactured by the method of the present invention is used, when a high-purity liquid chemical is stored in the high-purity chemical container,
There is little leaching of impure fine particles into the chemicals, the chemicals are not contaminated, and there is no need for labor such as co-washing. If this stopper is attached after manufacturing a high-purity chemical container, the high-purity chemical container can prevent secondary contamination from the external environment until the chemical is filled, and the high-purity chemical container No contamination of the mouth.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a plug for a high-purity chemical container to which the present invention is applied.

FIG. 2 is a sectional view showing another embodiment of the plug for a high-purity chemical container to which the present invention is applied.

FIG. 3 is a sectional view showing another embodiment of the plug for a high-purity chemical container to which the present invention is applied.

FIG. 4 is a sectional view showing another embodiment of the plug for a high-purity chemical container to which the present invention is applied.

FIG. 5 is a schematic view of an apparatus for cleaning a plug in an embodiment of a method for manufacturing a plug for a high-purity chemical container to which the present invention is applied.

[Explanation of symbols]

1, 2, 3, 4 is a plug, 5.7 is a cap, 6 is an inner plug,
8 and 12 are packings, 9 is an upper cap, 10 is a lower cap, 11 is a chemical discharge section, 15 is ultrapure water, 16 is a pump, 17 is a filter, 18 is an upper nozzle, 19 is a lower nozzle, and 20 is a conveyor. is there.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-353409 (JP, A) JP-A-4-330633 (JP, A) JP-A-5-304068 (JP, A) 200649 (JP, A) Japanese Utility Model Showa 63-160498 (JP, U) Japanese Utility Model Showa 64-9644 (JP, U) Japanese Utility Model 2-23354 (JP, U) Japanese Utility Model 4-115154 (JP, U)

Claims (3)

(57) [Claims] 1. A method of manufacturing a stopper of the container for storing a high purity liquid chemicals, the contact portion between at least a high purity liquid chemicals, Po Li olefin resin at least selected from among polyester resins and fluorine resins After molding one type as a raw material, the contact portion is washed with pure water having an electric conductivity of 50 μs / cm or less and a specific resistance of 10 MΩ · cm or more at 25 ° C., and the air cleanliness measured based on JIS B 9920 is measured. A method for producing a plug for a high-purity chemical container, wherein the plug is dried in a clean oven of class 6 or less. 2. In a clean room whose air cleanliness measured according to JIS B 9920 is class 7 or less ,
The method for producing a plug for a high-purity chemical container according to claim 1, wherein the molding is performed . 3. The polyolefin resin is at least one selected from polyethylene, polypropylene, polybutylene and a copolymer thereof, and the polyester resin is at least one selected from polyethylene terephthalate and polybutylene terephthalate. The fluororesin is ethylene tetrafluoride, ethylene tetrafluoride-perfluoroalkyl vinyl ether copolymer, ethylene tetrafluoride-propylene hexafluoride copolymer, ethylene tetrafluoride-ethylene copolymer, ethylene trifluoride chloride, polyvinylidene fluoride, polyvinyl fluoride and trifluoride ethylene chloride - claim 1, characterized in that at least one selected from among ethylene copolymer or
3. The method for producing a plug for a high-purity chemical container according to item 2 or 3.