WO2026003969A1 - Surface treatment method for container, and surface structure of container treated by said method - Google Patents

Abstract

Provided is a glass container having extremely excellent chemical durability. According to the present invention, a cleaning step for cleaning an inner surface of a glass container with a cleaning liquid composed of water, an acid aqueous solution, a surfactant aqueous solution, or an acid aqueous solution to which a surfactant is added, and a distortion removing step for removing distortion by heating and raising the temperature of the glass container cleaned in the cleaning step and then cooling the same are performed. Subsequently, the glass container is disposed in a plasma treatment device, a film-forming surface of the glass container is modified and hydrophilized in a plasma atmosphere formed by a plasma generating part, in a state in which an evaporation source for imparting a hydrophilic group is supplied into a vacuum chamber having a predetermined degree of vacuum in the plasma treatment device, an evaporation source of a precursor material of a SAM film or a self-assembled multilayer film is supplied to the glass container having the hydrophilized film-forming surface, in a state in which an evaporation source for promoting a hydrolysis or nucleophilic reaction of the precursor material of the SAM film or the self-assembled multilayer film is supplied into the vacuum chamber having a predetermined degree of vacuum, a SAM film or a self-assembled multilayer film is formed on the hydrophilized film-forming surface, and finally, bonding in the film-forming surface and the SAM film or the self-assembled multilayer film in the vacuum chamber having a predetermined degree of vacuum is strengthened.

Description

Container surface treatment method and surface structure of container treated by said method

The present invention relates to a surface treatment method for pharmaceutical and laboratory containers, such as ampoules and tube bottles, and the surface structure of containers treated by this method.

Medical containers filled with medicinal liquids, blood, etc. require transparency to allow for checking for contamination by foreign matter or changes due to drug compounding, heat resistance to withstand sterilization processes, flexibility to allow for easy discharge of medicinal liquids, gas barrier properties to prevent deterioration of the quality of medicinal liquids due to the infiltration of water vapor or oxygen into the container, and reduced elution of trace substances from the container surface. Furthermore, after filling these containers with the contents, heat sterilization is generally performed. In particular, infusion preparations that are administered directly into the bloodstream must be kept in a sterile state, and sterilization at 121°C is becoming the global standard.

Traditionally, glass containers have been used as such medical containers, but due to issues such as container breakage due to impact or dropping, plastic containers, which have excellent impact resistance, are also now being used.

Incidentally, glass containers such as ampoules and tube bottles are often manufactured by shaping glass tubes under heat. A typical shaping method is the vertical shaping method. In this method, a glass tube of a certain diameter with both ends open is placed vertically, and the lower end, which becomes the mouth, is heated to soften it and shape it into the desired shape. The glass tube is then cut to the desired length, after which the bottom of the glass container is formed, producing the desired glass container. The remaining glass tube after cutting is shortened by the length of one glass container, and by repeating this process, glass containers can be mass-produced.

However, when a glass container manufactured in this way is used to store, for example, liquid medicine, components of the glass leach out from the glass surface inside the glass container, contaminating the medicine. For example, alkali metals in the glass components can raise the pH value. In some cases, the glass components leach out from the glass surface and react with the liquid inside, causing precipitates, which can impair the quality of the liquid inside.

Conventional methods for solving these problems, such as coating or sulfurizing the glass surface, have complicated the process and increased the manufacturing cost of the glass container, making it impossible to obtain a glass container with excellent chemical durability. Therefore, the present inventors have previously filed a patent application for a method for manufacturing a glass container with excellent chemical durability (Patent Document 1). Patent Document 1 describes a method for manufacturing a glass container that includes a manufacturing process for a glass container in which a glass tube is molded under heat to obtain a glass container, a cleaning process for cleaning the inner surface of the glass container obtained in the manufacturing process with a cleaning solution, and a strain relief process for heating and then cooling the glass container cleaned in the cleaning process to remove strain. However, Patent Document 1 does not fully describe the cleaning process, which takes into account the surface characteristics of the glass, or the strain relief process, which is an important process for obtaining a glass container with excellent chemical durability.
Furthermore, Patent Document 2 describes a chemical vapor deposition method for silicon dioxide films, characterized in that a silicon dioxide film is deposited by a plasma CVD method using tetraisocyanate silane as a raw material gas. However, the method described in Patent Document 2 does not provide a container from which no or only a very small amount of eluted components such as alkaline components are eluted from the surface due to reaction with liquid during storage.

Patent No. 6159304 specification Patent No. 3305826 specification

In the case of pharmaceutical and physicochemical containers, it is desirable to provide containers that do not leach alkaline or other soluble components from the surface, or that leach only a small amount, during the heat sterilization process after filling the manufactured container with a medicinal solution, or during storage due to reactions with the liquid.

The present invention was made in consideration of these problems with conventional technology, and its purpose is to provide a container with extremely excellent chemical durability.

The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result have found that when the lower end of a vertically standing glass tube is heated with, for example, a gas burner to soften it and then formed into a desired shape, the glass quality is altered by the heating, and volatile components of the glass (e.g., Na ₂ O, K ₂ O) are generated from the heated glass, and as the volatile components rise in the space between the open lower and upper ends of the glass tube due to the chimney effect, they adhere to the inner surface of the glass tube to form alkali components, and these adhered alkali components are eluted from the glass surface after the glass container is manufactured.

Furthermore, the inventors discovered that by obtaining a glass container from a glass tube using the above-mentioned vertical molding method and then washing the inner surface of the glass container with a cleaning solution before performing a strain relief operation to remove distortion caused by thermal history, it is possible to produce a glass container with extremely little elution of alkaline components from the inner glass surface.

However, when it comes to cleaning the inner surface of a glass container, there are a wide variety of cleaning methods, and unless the cleaning process takes into account the surface characteristics of the glass, sufficient cleaning effects cannot be achieved. There are many types of glass, more than 700 of which borosilicate low-alkali glass has a small expansion coefficient of 3×10 ⁻⁶ /K, a relatively hard Mohs hardness of about 7, and high corrosion resistance, making it suitable for use in laboratory instruments, medical instruments, and pharmaceutical containers. Borosilicate glass is preferred as the material for the glass container of the present invention.

By the way, glass surfaces are inherently hydrophilic, highly chemically active, and have a strong ability to adsorb moisture and dirt due to intermolecular attractive forces such as hydrogen bonds. They are also poor electrical conductors, and have a strong ability to adsorb dirt. For example, if glass is left in the air, the glass surface will react with the external atmosphere, causing deterioration accompanied by a change in the composition of the surface layer. Therefore, it can be said that it is not easy to achieve the desired level of cleanliness by cleaning glass containers without adversely affecting the glass base material.

Typically, an acid or alkali can be used as a cleaning liquid for such glass containers. Table 1 below shows the weight loss (95°C, 24 hours (mg/ ^cm2 )) of soda-lime glass, borosilicate glass, and quartz glass due to acid and alkali.

As shown in Table 1, borosilicate glass shows the greatest weight loss in response to 5% sodium hydroxide. This is because the main component, silica, dissolves as sodium silicate. On the other hand, what dissolves in 5% hydrochloric acid is mainly the alkali and alkaline earth components contained in the glass, with almost no silica components dissolving. Therefore, unlike dissolution in sodium hydroxide, the amount of dissolution is small. The rate of dissolution in acid is proportional to the square root of time and is significantly slower than the rate of dissolution in alkali. Table 1 shows that acid corrosion is slower than alkali corrosion. Furthermore, it is known that the amount of dissolution in organic acids is smaller than that in hydrochloric acid. Therefore, in the present invention, it is preferable to use organic acids, which corrode glass components relatively slowly, as the cleaning solution.

In addition, hydroxyl groups, such as silanol groups (SiOH), are generally present on glass surfaces, and it is believed that these hydroxyl groups act as adsorption sites for substances. Therefore, if there is a long time between the cleaning process, in which the inner surface of a glass container is washed with a cleaning solution, and the subsequent distortion removal process, the surface characteristics of the glass may change. In other words, it is preferable to keep the time between the cleaning process and the distortion removal process to 30 minutes or less. Furthermore, to improve the cleaning effect, it is preferable to set the spray pressure of the cleaning solution to 0.05 MPa or higher.

Furthermore, when borosilicate glass is heated to a temperature above its glass transition point for a long period of time, it may separate into two phases (phase separation): a polar phase ( _Na2O , _B2O3 , _etc. ) dominated by ionic bonds and a silica phase dominated by covalent bonds. Glass that has separated into two phases has low chemical durability.

Therefore, the present inventors have conducted extensive research into conditions that make phase separation less likely to occur. As a result, they have found that in order to obtain a glass container with excellent chemical durability, in the glass container manufacturing method described in Patent Document 1, the heating temperature in the strain relief step, in which a glass container washed in a washing step is heated to an elevated temperature and then cooled to remove the strain, is extremely important. Based on this finding, the present inventors have found that by appropriately controlling the heating temperature in the strain relief step, a homogeneous coating containing a large amount of chemically stable _SiO2 can be formed on the inner surface of the glass container without causing phase separation or free radicals.

Furthermore, some pharmaceutical and laboratory containers require that the amount of contaminants contained in the container's inner wall be kept below the detection limit (ppm or less). For example, the hydrolytic stability of pharmaceutical glass containers in the European Pharmacopoeia is evaluated based on their resistance to the release of water-soluble inorganic substances into water when the container's inner surface comes into contact with water. The European Pharmacopoeia classifies glass containers into three categories: Type I glass containers, which are suitable for most preparations, regardless of whether they are administered parenterally; Type II glass containers, which are suitable for most acidic and neutral preparations, regardless of whether they are administered parenterally; and Type III glass containers, which are generally suitable for non-aqueous preparations administered parenterally, powders (excluding freeze-dried preparations), and oral preparations. The limit value for surface water resistance testing using flame atomic absorption spectrometry is set at 0.5 for the oxide concentration, expressed as sodium oxide (μg/mL), for Type I and II glass containers with a filled volume of more than 500 mL (milliliters).

To meet these strict requirements, the inner surface of the chamber must be appropriately treated to form a water-resistant thin film. Thin-film formation methods include vacuum deposition, in which metal, oxide, or other film-forming materials are evaporated in a vacuum chamber and then deposited on the opposing substrate surface. Ion plating, which operates on a similar principle, involves passing evaporated particles through plasma, thereby positively charging the deposited material and negatively charging the substrate. The positively charged particles are then attracted to the negatively charged substrate, forming a highly adhesive thin film. In sputtering, the metal to be deposited as a thin film is placed as a target in a vacuum chamber. A high voltage is applied to cause positively ionized rare gas (usually argon) or nitrogen to collide with the negatively charged target, sputtering atoms from the target surface and forming a thin film on the substrate. Chemical vapor deposition, in which a source gas containing the desired thin-film components is supplied to a heated substrate in a quartz or other reaction tube, forming a thin film on the substrate through a gas-phase chemical reaction.

The above-mentioned "vacuum deposition method,""ion plating method," and "sputtering method" belong to the category of physical vapor deposition (hereinafter also referred to as PVD), which is carried out in a high vacuum. This is because if the film-forming precursor frequently collides with other particles, the precursor will not reach the substrate. In the high vacuum in which physical vapor deposition is carried out, the precursor is transported to the substrate in a state almost similar to a molecular beam. Furthermore, since the precursor is often a highly reactive atom, when it flies onto the substrate surface, there is an almost 100% probability that it will adhere to the substrate.
On the other hand, chemical vapor deposition (hereinafter also referred to as CVD) uses gaseous molecules as raw materials. Molecules containing the atoms to be deposited are supplied to a vessel containing a substrate, and some energy is applied to dissociate the molecules (chemical reaction). If the dissociation products containing the atoms to be deposited (precursors) are adhesive, thin film deposition becomes possible. The degree of vacuum required for CVD does not need to be as high as that required for PVD. In other words, CVD is performed in a high-pressure environment. This is because it is not necessary. Higher pressure increases the raw material density, so increasing the pressure appropriately has the advantage of improving the film formation rate. Furthermore, collisions in the gas phase eliminate the directionality of the raw material molecules, making it possible to supply raw material molecules to recesses, which was not possible with PVD.

Furthermore, whereas in PVD no chemical reactions occur during the transport of raw material particles, in CVD many chemical reactions occur simultaneously in addition to the raw material dissociation reaction. Therefore, if the appropriate chemical reactions occur, it is possible to incorporate functional groups from the raw material molecules into the film, making it possible to obtain highly functional films that cannot be obtained with PVD. In this way, because CVD involves complex chemical reactions, it is possible to impart a variety of functions to the film.

The raw materials used in CVD are stable molecules, so they need to be dissociated in some way. Thermal CVD involves heating the substrate and using the resulting thermal energy to heat the raw material molecules. In contrast, in plasma CVD, the electrons in the plasma containing the raw material molecules are the main drivers of decomposition. Therefore, because there is no need to heat the substrate to dissociate the raw material molecules, plasma CVD has the advantage of being able to form films on substrates that are sensitive to heat. Furthermore, in thermal CVD, where heat (vibrational excitation) is the driving force behind all reactions, the reactions that occur and their products are all in a state of thermal equilibrium, whereas plasma CVD, which uses electronic excitation, makes it possible to create materials that are out of thermal equilibrium.

The inventor therefore decided to adopt the plasma CVD method. However, plasma CVD also has a drawback. The ions required to maintain the plasma state damage the deposited film. Therefore, the inventor devised an improved plasma CVD method that overcomes this drawback while at the same time using a different reaction system than the CVD method described in Patent Document 2, which uses tetraisocyanate silane as a raw material.

In other words, the container surface treatment method of the present invention includes a cleaning step in which the inner surface of a glass container is cleaned with a cleaning solution consisting of water, an acid aqueous solution, a surfactant aqueous solution, or an acid aqueous solution containing a surfactant; a distortion-removing step in which the glass container cleaned in the cleaning step is heated to a predetermined temperature and then cooled to remove distortion; the glass container is then placed in a vacuum chamber, and water vapor is supplied into the chamber to a predetermined pressure while an electric discharge is irradiated with plasma to hydrophilize the surface of the glass container. Tetraisocyanate silane or 1H,1H,2H,2H-heptadecafluorodecyltrimethoxysilane is then supplied into the chamber without dissociating, and the reaction is allowed to proceed at a predetermined temperature for a predetermined time to form a thin film on the glass container. Finally, a treatment is performed to strengthen the bond between the glass container surface and the thin film, and in the case of tetraisocyanate silane, surface functional groups are replaced with hydroxy groups. When tetraisocyanate silane is supplied, the surface structure of a container treated by this method is composed of a silicon-based polymer containing urethane bonds, urea bonds, and biuret bonds. Furthermore, when 1H,1H,2H,2H-heptadecafluorodecyltrimethoxysilane is supplied, the surface structure of the container is composed of siloxane bonds.

The container surface treatment method of the present invention also involves placing a resin container in a vacuum chamber, supplying water vapor into the chamber to a predetermined pressure, discharging and irradiating plasma, and after plasma irradiation is complete, supplying tetraisocyanate silane or 1H,1H,2H,2H-heptadecafluorodecyltrimethoxysilane into the chamber and allowing the reaction to proceed at a predetermined temperature for a predetermined time to form a thin film on the resin container. Finally, treatment is performed to strengthen the bond between the resin container surface and the thin film, and when tetraisocyanate silane is supplied, surface functional groups are replaced with hydroxy groups.

The container surface treatment method of the present invention and the surface structure of containers treated using this method result in extremely low amounts of alkaline components leaching from the inner surface of the container, suppressing deterioration of the contents, such as pharmaceuticals, and ensuring that the specified quality is maintained.

FIG. 1(a) is a schematic diagram showing a state in which alkaline elutable components adhere to the inner surface of a glass container, FIG. 1(b) is a schematic diagram showing the glass container after the alkaline elutable components adhered to the inner surface have been removed, and FIG. 1(c) is a schematic diagram showing the state of a glass container having the inner surface shown in FIG. 1(b) after being heated. FIG. 2 is a schematic diagram showing each substep of an example of a method for producing a borosilicate glass container of the present invention. FIG. 3 is a schematic diagram showing an example of a manufacturing apparatus that can be suitably used in the method for manufacturing a borosilicate glass container of the present invention. FIG. 4 is a schematic diagram showing how vials are washed by a washer. FIG. 5 is a schematic cross-sectional view of one embodiment of the borosilicate glass container of the present invention. FIG. 6 is a schematic diagram showing the overall configuration of a plasma processing apparatus according to one embodiment for performing plasma processing on a glass container. FIG. 7 is a cross-sectional view of the vacuum chamber of the plasma processing apparatus shown in FIG. FIG. 8 shows the results of measuring the surface structure of a glass container using a Fourier transform infrared spectrophotometer, with the horizontal axis representing wave number (/cm) and the vertical axis representing absorbance. FIG. 9 is a partial extract of FIG. 8, and shows the results of measuring the surface structure of the glass container with a Fourier transform infrared spectrophotometer, with the horizontal axis representing wave number (/cm) and the vertical axis representing absorbance. FIG. 10 is a partial extract of FIG. 8 and shows the results of measuring the surface structure of the glass container with a Fourier transform infrared spectrophotometer, with the horizontal axis representing wave number (/cm) and the vertical axis representing absorbance. FIG. 11 is a partial extract of FIG. 8 and shows the results of measuring the surface structure of the glass container with a Fourier transform infrared spectrophotometer, with the horizontal axis representing wave number (/cm) and the vertical axis representing absorbance. FIG. 12 is a diagram showing chemical reactions on the surface of a glass container. FIG. 13 is another diagram showing chemical reactions on the surface of a glass container.

There are no particular restrictions on the glass tube used as the material for the glass container of the present invention, but a glass tube made of borosilicate glass is preferred. The cross section of the glass tube is usually circular, but may be elliptical or other shapes. There are no particular restrictions on the diameter of the glass tube, but it is usually about 10 to 100 mm. There are also no particular restrictions on the length of the glass tube, but it is usually about 1 to 5 m. The glass tube may be colorless and transparent, or it may be colored, for example, brown.

Since the method for producing a glass container using such a glass tube has been well established, the glass container of the present invention can be produced in accordance with the method.
For example, a glass tube with a certain diameter and open ends is set up vertically, and the lower end is inserted into a vertical molding machine usually equipped with a heating means. It is heated, for example, with a gas burner at a temperature of about 1500 to 1800°C to form the desired shape of a tube bottle. The formed product and the remaining glass tube extending above are then separated under heat, forming a glass bottle and a bottom. The lower end of the separated glass tube is then reshaped so that its cross section returns to its original perfect circle. The temperature of the glass container after shaping is usually about 300 to 400°C.

By repeating this process, glass containers can be mass-produced. During this process, as described above, it is generally believed that the glass quality is altered by heating, and volatile components of the glass (e.g., _Na2O , _K2O ) rise through the space between the open upper and lower ends of the glass tube due to the chimney effect, adhere to the inner surface of the glass tube, and form alkaline elutable components.

In the present invention, after the above-mentioned glass container manufacturing process, the glass container undergoes a glass container cleaning process, as described in detail below, which removes or reduces alkaline soluble components adhering to the inner surface of the glass tube. Furthermore, by subjecting the glass container to a strain relief process within 30 minutes after the cleaning process and subjecting the glass container to a strain relief treatment controlled at an appropriate heating temperature, it is possible to provide a borosilicate glass container in which no phase separation occurs on the inner surface, no free radicals are present, no flakes or delamination are present, and the silicon and oxygen present on the inner surface are bonded by siloxane bonds.

If necessary, the glass container, which has a temperature of approximately 300-400°C after molding, is allowed to cool, for example to ambient temperature, and is then washed with a cleaning solution, preferably at 150°C or below. The higher the temperature of the glass container, the greater the effect of removing or reducing elutable components adhering to the inner surface of the glass container; however, contacting a hot glass container with a cleaning solution may damage the glass container. Furthermore, taking into consideration cleaning efficiency, the lower limit temperature of the glass container during washing is preferably 30°C or higher. Furthermore, a washing time of less than 10 seconds results in insufficient cleaning, while a time of more than 15 seconds reduces productivity, so a washing time of approximately 10-15 seconds is preferred.

There are no restrictions on the temperature of the cleaning solution used in the cleaning process, but it is preferable to use a cleaning solution at approximately 30 to 100°C, and more preferably a cleaning solution at approximately 40 to 70°C. Within this range, it is possible to obtain glass containers with the extremely excellent chemical durability that is the objective of this invention.

Preferred cleaning solutions are water, an aqueous acid solution, an aqueous solution containing a surfactant, or an aqueous acid solution with added surfactant, with an aqueous acid solution or an aqueous acid solution with added surfactant being more preferred due to their high solubility of alkaline elutable components adhering to the inner surface of the glass container.

Acids used in aqueous acid solutions are broadly divided into organic acids and inorganic acids. Examples of organic acids include formic acid, acetic acid, oxalic acid, phthalic acid, and citric acid, while examples of inorganic acids include hydrochloric acid, sulfuric acid, and nitric acid. These acids may be used alone or in combination. For the reasons mentioned above, organic acids are preferred, and citric acid and oxalic acid are preferred in terms of cleaning effectiveness and ease of handling.

The higher the acid concentration, the greater the solubility of the alkaline component tends to be, but from the perspective of ease of handling, including waste liquid treatment, the acid concentration is usually set to approximately 0.005 to 1.0 mol/L, preferably approximately 0.01 to 0.1 mol/L.

The surfactant used in the surfactant-containing aqueous solution or surfactant-added acid aqueous solution in the above-mentioned cleaning solution is not particularly limited, but preferred surfactants include nonionic surfactants. The concentration of the surfactant may be selected appropriately within a range that does not interfere with the objectives and effects of the present invention.

To clean the inner surface of a glass container with the above-mentioned cleaning solution, the glass container is typically inserted into or suspended from a suitable jig, and the cleaning solution is sprayed upward, typically under pressure, from a nozzle, from the mouth of the glass container toward the bottom. It is preferable to increase the spray pressure of the cleaning solution by, for example, configuring the nozzle's cleaning solution spray outlet so that compressed air can be ejected simultaneously with the cleaning solution (this is also known as jet spray cleaning). Specifically, the spray pressure of the cleaning solution is preferably 0.05 MPa or higher. If the spray pressure is too high, the cleaning effect will saturate, so the upper limit of the spray pressure is around 0.5 MPa.

If a cleaning liquid other than water is used, after cleaning with the cleaning liquid, the cleaning process is completed by rinsing with clean water and then thoroughly draining the water, for example by blowing in air.

In addition, cleaning the inner surface of the glass container with the above cleaning solution may also be performed by ultrasonic cleaning. When using ultrasonic cleaning, the above cleaning solution is usually used to clean not only the inner surface but the entire glass container, followed by rinsing. Whether or not to use ultrasonic cleaning is determined by taking into account the layout of the entire production line, including the vertical molding machine, cleaning machine, and distortion removal furnace, which will be described later.

The strain relief process for glass containers in the present invention involves feeding the glass containers cleaned in the cleaning process into a strain relief furnace controlled to a target maximum atmospheric temperature of 685 to 700°C, heating the glass container to a temperature of 685 to 710°C for one minute, and then cooling the glass container. The total time for the strain relief process, which involves heating the cleaned glass container to a temperature of approximately 30 to 80°C in the strain relief furnace and then cooling it to approximately 300°C, i.e., the time spent in the strain relief furnace (strain relief time), is 3 to 40 minutes. This strain relief process removes residual strain in the glass container due to the thermal history during the molding process of the glass tube into a glass container, and simultaneously forms a homogeneous coating on the inner surface of the glass that does not produce phase separation or contain free radicals and contains a large amount of chemically stable _SiO2 , resulting in a glass container that is free of flakes and delamination and in which silicon and oxygen present on the inner surface are bonded by siloxane bonds.

The process for obtaining the glass container of the present invention can be easily explained as follows:

(1) Adhesion of alkaline elutable components to the inner surface of the glass tube As described above, when a glass tube is heated with a gas burner at a temperature of approximately 1500 to 1800°C and formed into the desired shape of a tube bottle, the glass is altered by the heating, and volatile components of the glass (e.g., Na ₂ O, K ₂ O) rise through the space between the open lower and upper ends of the glass tube due to the chimney effect and adhere to the inner surface of the glass tube, forming alkaline elutable components. Figure 1(a) is a schematic diagram showing a state in which alkaline elutable components 3 have adhered to the inner surface 2 of a glass tube 1.

(2) Removal of alkaline elutable components by washing Although alkaline elutable components can be removed by washing, the washing results in the inner surface 5 of the glass container 4 becoming microscopically uneven, as shown in FIG. 1(b).

(3) Removal of residual strain due to thermal history during molding: Residual strain can be removed by heating the glass container after removing the alkaline eluting components. In addition, atomic diffusion improves the flatness of the inner surface 5 of the glass container 4, as shown in Figure 1(c).

(4) Formation of the inner surface of glass containers Borosilicate glass can undergo phase separation when heated to temperatures above its glass transition point for a long period of time. Furthermore, if the heating temperature is too high, deformation and wrinkles will occur in the glass container. Therefore, the selection of heating conditions is extremely important.

Therefore, the glass container of the present invention can be manufactured by controlling a distortion-removing furnace, which is controlled to a target maximum atmospheric temperature of 685-700°C, so that the actual temperature of the glass container remains at 685-710°C for one minute. If the time at 685-710°C is one minute, no phase separation occurs on the inner surface, no free radicals are present, and the silicon and oxygen present on the inner surface are bonded by siloxane bonds, preventing deformation or wrinkles on the glass surface. Residual distortion due to thermal history is removed, and glass containers with nearly smooth inner and outer surfaces can be manufactured.

If the temperature of the glass container itself exceeds 700°C for a long period of time (10 minutes or more), the glass surface may deform or wrinkles may form. On the other hand, if the maximum ambient temperature of the distortion removal furnace is controlled to less than 650°C, the temperature of the glass container itself is likely to fall below 600°C, which may result in insufficient vitrification.

(5) Plasma Treatment Organic molecules exhibit a unique adsorption phenomenon to solid surfaces, and during the adsorption process, they may form a densely packed, uniformly oriented molecular film. When the adsorbed molecular layer is a single layer, i.e., a monolayer, this is called a self-assembled monolayer (hereinafter sometimes referred to as a SAM film). When the adsorbed molecular layer is two or more layers, it is called a self-assembled multilayer film. Therefore, the glass container manufactured as described above is placed in the vacuum chamber of a plasma processing device, and a SAM film or a self-assembled multilayer film is formed on the surface of the glass container. That is, in a state where an evaporation source that imparts hydrophilic groups is supplied into a vacuum chamber of a plasma processing apparatus having a predetermined vacuum level, a surface hydrophilization mode is executed in which the film formation surface of the glass container is modified to hydrophilize the film formation surface using a plasma atmosphere formed by a plasma generating unit; in a state where an evaporation source that promotes hydrolysis or nucleophilic reaction of a precursor material of a SAM film or a self-assembled multilayer film is supplied into a vacuum chamber of a predetermined vacuum level to the glass container whose film formation surface has been hydrophilized, an evaporation source of a precursor material of a SAM film or a self-assembled multilayer film is supplied to the hydrophilized film formation surface; and finally, in a vacuum chamber of a predetermined vacuum level, a final processing mode is executed in which the bond between the film formation surface of the glass container and the SAM film or the self-assembled multilayer film is strengthened. Note that a similar process can also be performed on a resin container instead of a glass container in the plasma processing apparatus to form a SAM film or a self-assembled multilayer film on the resin container. Examples of such resins include propylene (PP), polyethylene (PE), cycloolefin (COP, COC), polyethylene terephthalate (PET), and polyvinyl chloride (PVC).

The present invention provides a container with extremely low elution of alkaline components and the like.

The following describes an embodiment of the present invention, but it goes without saying that various changes and modifications are possible without departing from the technical scope of the present invention.

A 2 mL vial was obtained using a glass tube made of borosilicate glass with an outer diameter of 16 mm, a length of 1.6 m, and the composition (by weight) shown in Table 2 below, using the following method. First, as shown in Figure 2 (1), the glass tube 11 was inserted into a vertical tube bottle molding machine 12 with the end facing up, and the bottom end was heated with a gas burner to soften the glass, which was then molded into the shape of the bottle opening. The process is explained in more detail below, in order, based on Figure 2.

(1) The lower end of the glass tube 11 was heated to 1200 to 2000° C. by a fishtail burner 13.
(2) A shoulder was formed using a roller 14 and a plunger 15.
(3) The material was heated with a point burner 16 at 1200 to 2000°C.
(4) The mouth was formed using a roller 14 and a plunger 15.
(5) The bottle height was determined using the total height plate 17.
(6) Cutting was performed using a cut burner 18 at a temperature of 1200 to 2000°C.
(7) The bottom was homogenized using point burner 16.
(8) Air 19 was blown in and the bottom of the vial 20 was formed using a point burner 16 at 1200 to 2000°C.

The vials 20 obtained in this manner are inserted into a jig placed on a net conveyor 21 (Figure 3), transported to the washer 22, and left to cool at ambient temperature (cooling step (9) in Figure 2). The inner surfaces of the vials, which are approximately 30°C, are then spray-cleaned with 10 mL of a 25°C cleaning solution (citric acid) using a syringe for 10 seconds (citric acid spray pressure: 0.2 MPa) (cleaning step (10) in Figure 2). They are then further spray-cleaned with purified water for 10 seconds (0.2 MPa), after which air 19 is blown in to thoroughly drain the water (draining step (11) in Figure 2). Although details are omitted in Figure 3, the vials 20 can be transported to the washer 22 and strain relief furnace 24 by the net conveyor 21.

Figure 4 is a schematic diagram showing how vials 20 are washed by washer 22. In Figure 4, 31 is a manifold, 32 is a nozzle, 33 is a needle valve, 34 is a flow meter, 35 is a pressure gauge, 36 is a pump, and 37 is a storage tank for the washing liquid. The spray pressure of the washing liquid can be adjusted by adjusting the opening of needle valve 33.

After washing with citric acid and purified water and draining, the vials 20, which were approximately 25°C, were transported within 30 minutes to a 5-m effective length dewarping furnace 24 equipped with a burner heater 23 (dewarping process (12) in Figure 2). The target maximum ambient temperature in the dewarping furnace was controlled to 670°C, and the dewarping process was carried out for 25 minutes (the ambient temperature remained above 670°C for 108 seconds, the actual temperature of the glass container was 670-700°C, and the actual temperature of the glass container remained at 690-700°C for 1 minute). A borosilicate glass container was obtained, and this glass container was allowed to cool to room temperature. Figure 5 shows a schematic cross-section of the borosilicate glass container 40 obtained in this manner. Note that because the inlet and outlet sides of the dewarping furnace 24 are open, even if the ambient temperature inside the dewarping furnace, as sensed by a thermocouple installed inside the dewarping furnace, is, for example, 670-700°C, the temperatures at the inlet and outlet sides will be lower than this temperature. The ambient temperature inside the distortion removal furnace was measured using thermocouples installed in three locations, and the burner heater 23 was turned on and off so that the temperature measured by one of the thermocouples reached the target temperature. Furthermore, the actual temperature of the glass container was measured using a thermocouple fused to the glass container.

Figure 6 is a schematic diagram showing the overall configuration of one embodiment of a plasma processing apparatus for performing plasma processing on the glass container obtained in this manner to form a SAM film or a self-assembled multilayer film, and Figure 7 is a cross-sectional view of the vacuum chamber of the plasma processing apparatus shown in Figure 6.

As shown in Figure 6, the plasma processing apparatus 51 has a vacuum chamber 52 that houses a glass container V on which a SAM film or self-assembled multilayer film is to be formed, a lower electrode 53 that also serves as a stage for placing the glass container V in the vacuum chamber 52, and an upper electrode 54 that faces the lower electrode 53, with a plasma generation power supply 57 connected to the lower electrode 53. While Figure 6 shows a structure in which the lower electrode 53 supports the glass container V, a structure in which the upper electrode 54 supports the glass container V is also possible, or a structure in which both the lower electrode 53 and the upper electrode 54 support the glass container V is also possible. Furthermore, the plasma generation power supply 57 may be a low-frequency power supply or a high-frequency power supply. Furthermore, a pressure gauge 55 that monitors the pressure within the vacuum chamber 52, an earth 56, and a vacuum pump 59 are connected to the vacuum chamber 52. The system also has a structure in which a gas inlet 60 used for plasma processing, a bubbler 65 for reactant materials required for plasma processing and for forming a SAM film or self-assembled multilayer film, and a raw material chamber 68 for the SAM film or self-assembled multilayer film are connected by piping and introduced into the vacuum chamber 52.

Furthermore, as shown in FIG. 7, the vacuum chamber 52 in this embodiment has an upper chamber 77 and a lower chamber 78, with an O-ring 80 in the lower chamber 78. In this embodiment, the upper chamber 77 and the lower chamber 78 are composed of electrically grounded electrical conductors, and the entire inner wall surface of the vacuum chamber 52 forms a ground potential surface. The electrical conductors that make up the upper chamber 77 and the lower chamber 78 are metallic materials such as transition metals such as copper, nickel, and titanium, alloys of these metals, and refractory metals such as stainless steel, molybdenum, and tungsten. In this embodiment, a gas inlet 71 is provided at the top of the upper chamber 77, and piping connected to the gas inlet 60 used for plasma processing, the bubbler 65 for reactant materials required for plasma processing and the SAM film or self-assembled multilayer film deposition process, and the raw material chamber 68 for the SAM film or self-assembled multilayer film are connected to the gas inlet 71.

In this embodiment, the lower electrode 53 is composed of a current introduction terminal 72 and an electrode stage 73, and insulating members 76 are arranged around the current introduction terminal 72 and below the electrode stage 73. The current introduction terminal 72 is also connected to a plasma generation power supply 57. The upper electrode 54, facing the lower electrode 53, is structured to also function as a gas shower plate 74. In this embodiment, the lower chamber 78 is structured such that an earth ring 75 is provided surrounding the electrode stage 73. Preferably, the difference in height between the electrode stage 73 and the earth ring 75 is approximately 0 mm, but the earth ring 75 may be slightly higher than the electrode stage 73. The earth ring 75 is formed so that the distance between it and the electrode stage 73 is 1 mm or more and 5 mm or less. By forming such a distance, it is possible to control the gas flow and maximize the uniform plasma area. If the distance between the earth ring 75 and the electrode stage 73 is less than 1 mm, the distance will be too narrow to adequately draw gas when using a vacuum pump. Furthermore, abnormal discharge will occur, preventing the desired plasma from being generated. Furthermore, if the distance between the earth ring 75 and the electrode stage 73 is greater than 5 mm, abnormal discharge occurs between the electrode stage 73 and the earth ring 75, making it impossible to generate the desired uniform plasma.

Furthermore, the lower chamber 78 has a vacuum exhaust port 79 connected to a vacuum pump 59 between the current input terminal 72 and the earth ring 75, and the degree of vacuum inside the vacuum chamber 52 can be adjusted using an exhaust flow rate adjustment valve 58. Therefore, by using the device of this embodiment, it is possible to effectively perform hydrophilization treatment using plasma treatment in the pretreatment process for forming a SAM film or self-assembled multilayer film.

In this embodiment, three gas introduction pipes are connected to the vacuum chamber 52: one from the gas inlet 60, which introduces the gas used in plasma processing; one from the bubbler 65 for the reactant materials required for plasma processing and the SAM film or self-assembled multilayer film deposition process; and one from the raw material chamber 68 for the SAM film or self-assembled multilayer film. The gas introduction pipes are surrounded by heat insulating material or a heater (not shown) to prevent the gas from liquefying.

In this embodiment, the gas used in the plasma treatment introduced from the gas inlet 60 is supplied from a gas cylinder (not shown) and introduced into the vacuum chamber 52 via a flow rate adjustment valve/mass flow controller 61. The gas used in the plasma treatment is selected from a gas that imparts hydroxyl groups (OH groups) to the surface of the glass container V, or a pre-treatment gas for the step of imparting OH groups. Examples include water vapor (H ₂ O), oxygen (O ₂ ), and argon (Ar). There are no limitations on the gas used as long as it is a gas that imparts OH groups to the surface, or a gas that can be used for pre-treatment for the step of imparting OH groups.

When the gas used for plasma treatment is supplied to the vacuum chamber 52, the degree of vacuum in the vacuum chamber 52 is controlled by the exhaust flow control valve 58 and vacuum pump 59, and by discharging between the lower electrode 53 and the upper electrode 54, the gas functions as a plasma generating gas, and plasma hydrophilization treatment is performed on the glass container V.

In this embodiment, bubbler 65, into which vapor source 67, a reactant material necessary for plasma processing and for forming a SAM film or a self-assembled multilayer film, is injected, is equipped with a mantle heater 66, and when heated, generates vapor of vapor source 67, a reactant material necessary for plasma processing and for forming a SAM film or a self-assembled multilayer film, which is then supplied to vacuum chamber 52. Bubbler 65 is connected to a pipe through which carrier gas is supplied from carrier gas inlet 62, which carries the vapor from vapor source 67, via a flow control valve/mass flow controller 63, and is configured with a pipe having a bypass valve 64 through which carrier gas passes that can be mixed with the vapor from bubbler 65 without passing through bubbler 65. If carrier gas is not required, it is not necessary to flow carrier gas.

The vapor source 67, which is a reactant material necessary for plasma treatment and for forming the SAM film or self-assembled multilayer film, is selected from an evaporation source that imparts OH groups to the surface of the glass container V or an evaporation source that promotes hydrolysis or nucleophilic reaction of the precursor of the SAM film or self-assembled multilayer film, such as water (H ₂ O).

When vapor from vapor source 67, which is a reactant material necessary for plasma processing and for forming a SAM film or a self-assembled multilayer film, is supplied to vacuum chamber 52, discharge occurs between lower electrode 53 and upper electrode 54, causing the _H2O gas (water vapor) to function as a plasma generating gas and impart OH groups to the surface of glass container V. In the SAM film or self-assembled multilayer film formation process immediately after this, residual components (water vapor) of the plasma generated during discharge promote hydrolysis or nucleophilic reaction with the SAM film or self-assembled multilayer film precursor material. By controlling the degree of vacuum in vacuum chamber 52 with exhaust flow control valve 58 and vacuum pump 59, the subsequent hydrolysis or nucleophilic reaction of the SAM film or self-assembled multilayer film precursor can occur during or after discharge has stopped, as long as the SAM film or self-assembled multilayer film precursor is not decomposed or dissociated.

In this embodiment, the SAM film or self-assembled multilayer film raw material chamber 68, into which a vapor source 70 of the SAM film or self-assembled multilayer film precursor material is injected, is equipped with a mantle heater 69, and by heating with the mantle heater 69, vapor is generated from the SAM film or self-assembled multilayer film raw material chamber 68 and supplied to the vacuum chamber 52. As the vapor source 70 of the SAM film or self-assembled multilayer film precursor material, an evaporation source that undergoes dehydration condensation between OH groups formed by hydrolysis of the SAM film or self-assembled multilayer film precursor material and OH groups formed on the surface of the glass container V, or an evaporation source that undergoes dehydration condensation between the material molecules of the evaporation source of the SAM film or self-assembled multilayer film precursor material themselves and OH groups formed on the surface of the glass container V, is selected. For example, chlorosilanes such as 1H,1H,2H,2H-perfluorodecyldimethylchlorosilane, tetrahydrooctylmethyldichlorosilane (FOMDS), dichlorodimethylsilane (DDMS), 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS), octadecyltrichlorosilane (OTS), and tetrahydrooctyltrichlorosilane (FOTS); dimethyldimethoxysilane, dimethyldiethoxysilane, isobutylmethyldimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, dodecyltriethoxysilane, 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, 1H,1H,2H,2H-tridecafluorooctyl Examples of materials that can form a SAM film or a self-assembled multilayer film include alkoxysilane-based materials such as n-octadecyltrimethoxysilane, n-octadecyltrimethoxysilane, and tetraethoxysilane (TEOS); phosphonic acid-based materials such as octadecylphosphonic acid and 1H,1H,2H,2H-perfluorooctylphosphonic acid; isocyanate-based materials such as tetraisocyanatesilane; alkoxysilane-based and isocyanate-based materials such as triethoxy(3-isocyanatopropyl)silane; and disilazanes such as hexamethyldisilazane (HMDS). These materials are not limited to chlorosilane-based materials, alkoxysilane-based materials, isocyanate-based materials, phosphonic acid-based materials, and disilazanes, as long as they are capable of forming a SAM film or a self-assembled multilayer film.

When the vapor source 70 of the SAM film or self-assembled multilayer film precursor material is supplied to the vacuum chamber 52, it is preferable that no discharge occurs between the lower electrode 53 and the upper electrode 54. In the SAM film or self-assembled multilayer film formation step, if the vapor source 70 of the SAM film or self-assembled multilayer film precursor material is tetraisocyanate silane, residual components of the plasma during the discharge and H ₂ O undergo a nucleophilic reaction with the self-assembled multilayer film precursor material, while unreacted isocyanate groups among the four isocyanate groups react with OH groups attached to the surface of the glass container or resin container to form urethane bonds, thereby forming the first layer of the self-assembled multilayer film. When the vapor source 70 of the SAM film or self-assembled multilayer film precursor material is 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, the residual components of the plasma during discharge and H ₂ O undergo a hydrolysis reaction with the SAM film precursor material, and then the OH groups on the surface of the glass container or resin container and the OH groups of the SAM film precursor material self-assemble through hydrogen bonding, and then a dehydration condensation reaction proceeds to form a SAM film.

As described above, the plasma processing apparatus of this embodiment includes a plasma generating unit that forms a plasma atmosphere in a vacuum chamber, and has modes for performing the following three processes.
(1) A surface hydrophilization mode in which an evaporation source that imparts hydrophilic groups is supplied into a vacuum chamber, and the film-forming surface of a glass container or a resin container is modified by a plasma atmosphere formed by a plasma generating unit to hydrophilize the film-forming surface. (2) A self-assembly mode in which an evaporation source that promotes the hydrolysis or nucleophilic reaction of a precursor material for a SAM film or a self-assembled multilayer film is supplied into a vacuum chamber of a predetermined vacuum degree to a glass container or a resin container whose film-forming surface has been hydrophilized, and an evaporation source for a precursor material for a SAM film or a self-assembled multilayer film is supplied to form a SAM film or a self-assembled multilayer film on the hydrophilized film-forming surface.
(3) A final treatment mode consisting of a heat treatment in a vacuum chamber of a predetermined vacuum level to strengthen the bond between the film formation surface and the SAM film or self-assembled multilayer film, and a silanol treatment of the outermost surface when the self-assembled multilayer film precursor material is tetraisocyanate silane.

In this embodiment, the surface hydrophilization mode, self-assembly mode, and final processing mode are preferably performed within a common vacuum chamber. This allows the transition from the surface hydrophilization mode to the self-assembly mode, and from the self-assembly mode to the final processing mode, to be performed without opening the vacuum chamber to the atmosphere. Note that if the surface hydrophilization mode, self-assembly mode, and final processing mode are performed within separate vacuum chambers, it is preferable that the vacuum chamber be a load-lock type that allows containers to be transported while maintaining a vacuum state.

In this embodiment, it is preferable that the evaporation source that imparts hydroxyl groups to the surface of the container and the evaporation source that promotes hydrolysis of the precursor material of the self-assembled monolayer are both water vapor. Note that the water vapor in the self-assembly mode may be water vapor remaining in the surface hydrophilization mode.

According to this embodiment, by performing vacuum plasma treatment on the substrate surface immediately before forming a SAM film or self-assembled multilayer film on the container, it is possible to impart hydrophilic groups such as hydroxyl groups at a high density, and it is possible to form a high-density SAM film on the container surface without opening the vacuum chamber to the atmosphere and before the hydrophilic properties of the hydrophilic groups imparted to the container change over time.

In addition, the method for forming a SAM film or self-assembled multilayer film in this embodiment includes the steps of: (A) placing a glass container in a vacuum chamber; (B) supplying an evaporation source into the vacuum chamber that imparts hydrophilic groups to the surface of the glass container, and generating plasma from the evaporation source by turning the vacuum chamber into a plasma, thereby hydrophilizing the surface of the glass container; (C) after step (B), supplying an evaporation source of the precursor material of the SAM film or self-assembled multilayer film into the vacuum chamber while the evaporation source that promotes hydrolysis or nucleophilic reaction of the precursor material of the SAM film or self-assembled multilayer film is being supplied, thereby forming a SAM film or self-assembled multilayer film on the surface of the glass container; and (D) strengthening the bond between the glass container surface and the SAM film or self-assembled multilayer film, and silanolizing the outermost surface if the precursor material of the self-assembled multilayer film is a tetrafunctional alkoxysilane such as tetraisocyanate silane or tetraethyl orthosilicate; and at least steps (B) and (C) are performed without opening the vacuum chamber to the atmosphere. Step (D) may be performed in a vacuum chamber as a series of processes without opening to the atmosphere, or may be performed after opening to the atmosphere once.

Then, the borosilicate glass container V obtained as described in paragraphs 0053 to 0058 was placed in the plasma processing apparatus shown in Figure 6, and the surface of the glass container V was subjected to the treatment described below to form a self-assembled multilayer film.

The atmospheric pressure inside the vacuum chamber 52 was reduced to 5-10 Pa. Then, a bubbler 65, into which water had been injected as a vapor source 67, a reactant substance necessary for plasma processing and SAM film formation, was heated to 70°C using a mantle heater 66, and water vapor was introduced into the vacuum chamber 52, maintaining the atmospheric pressure inside the vacuum chamber 52 at 100 Pa. A 13.56 MHz high-frequency power supply was used as the plasma generation power supply 57, and water vapor plasma irradiation was carried out for 3 minutes at a power of 200 W.

The SAM film or self-assembled multilayer film raw material chamber 68, into which 5 cc of tetraisocyanate silane was injected as the vapor source 70 of the SAM film or self-assembled multilayer film precursor material, was heated to 50°C by a mantle heater 69. After plasma irradiation was completed, the valve of the bubbler 65 was closed, and then, without opening the vacuum chamber 52 to the atmosphere, the valve of the SAM film or self-assembled multilayer film raw material chamber 68 was opened to introduce tetraisocyanate silane into the vacuum chamber 52. The glass container V was exposed to the tetraisocyanate silane vapor for 20 minutes, thereby forming a self-assembled multilayer film on the glass container V.

Furthermore, the glass container on which the self-assembled multilayer film was formed was heated to 100-120°C, strengthening the bond between the glass container surface and the self-assembled multilayer film. After that, water vapor plasma was irradiated again, forming silanol groups on the outermost surface, resulting in a hydrophilic surface.

Next, the same treatment as above was performed on a glass container V made of borosilicate glass obtained as described in paragraphs 0053 to 0058 and paragraphs 0078 to 0079, except that 1H,1H,2H,2H-perfluorodecyltrimethoxysilane was used instead of tetraisocyanatesilane as the vapor source 70 of the SAM film or self-assembled multilayer film precursor material. Glass container V, on which a SAM film of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane had been formed, was then heated to 100 to 120°C to strengthen the bond between the glass container surface and the SAM film.

Then, using a Fourier transform infrared spectrophotometer, we identified the molecules formed on the surface of glass container V, which had been treated using the above-mentioned tetraisocyanate silane as a raw material for the self-assembled multilayer film. Because infrared light is absorbed as energy from the vibration and rotational motion of molecular bonds, information on the molecular structure and functional groups can be obtained from the spectrum. Figure 8 shows the results of measuring the surface structure of the glass container using a Fourier transform infrared spectrophotometer, with the horizontal axis representing wavenumber (/cm) and the vertical axis representing absorbance. Figures 9, 10, and 11 are partial excerpts from Figure 8.

By subjecting the surface of glass container V to plasma treatment according to the method of the present invention, urethane bonds (chemical formula 1) are formed on the surface of the glass container, as shown in Figure 12, and urea bonds (chemical formula 2) and biuret bonds (chemical formula 3) are formed on the surface of the glass container, as shown in Figure 13.

Furthermore, a glass container made of borosilicate glass of Comparative Example 1 was obtained through the same steps as those described in paragraphs 0053 to 0058, except that no plasma surface treatment was performed. Furthermore, a glass container made of borosilicate glass of Comparative Example 2 was obtained through the same steps as those described in paragraphs 0053 to 0058, except that no plasma surface treatment was performed and no washing with citric acid and purified water was performed.

Then, as shown in Figure 5, 0.7 mL of purified water 40a was poured into each glass container 40 of a borosilicate glass container (Example 1) that had been surface-treated with tetraisocyanate silane using a plasma treatment device, a borosilicate glass container (Example 2) that had been surface-treated with perfluorocarbon using a plasma treatment device, a borosilicate glass container of Comparative Example 1, and a borosilicate glass container of Comparative Example 2. Then, autoclaving was performed for 2 or 4 hours at 121°C. 41 denotes a rubber stopper. Then, for the purified water in these glass containers, the amount of eluted Na (ppm) was measured using an atomic absorption spectrophotometer, and the amount of eluted B (ppm), eluted Al (ppm), eluted Si (ppm), eluted Ca (ppm), and eluted Ba (ppm) were measured using an inductively coupled plasma optical emission spectrometer. The measurement results, shown in Tables 3 to 8 below, were obtained. Pouring purified water into a glass container serves as an accelerated test to estimate how long it will take for the inner surface of a glass container to deteriorate when a pharmaceutical product (e.g., liquid, freeze-dried, or powder) is stored in the glass container; one hour after pouring the purified water corresponds to 1.6 years.

As shown in Tables 3 to 8, the borosilicate glass containers of Examples 1 and 2 had extremely low elution amounts of all six elements, demonstrating excellent chemical durability. On the other hand, the borosilicate glass container of Comparative Example 1 had approximately the same elution amounts of elements other than Na as the borosilicate glass containers of Examples 1 and 2, but the elution amount of Na was greater than that of the borosilicate glass containers of Examples 1 and 2.
Furthermore, the borosilicate glass container of Comparative Example 2, which was not subjected to a surface treatment, had a large amount of elution of all six elements.

Furthermore, the so-called contact angle, which is the angle between the liquid surface and the solid surface where the free surface of the stationary liquid comes into contact with the solid wall, was measured for the glass container of Example 2, the glass container of Comparative Example 2, the polypropylene container (PP container), and the cycloolefin container (COP container). This contact angle is determined by the magnitude relationship between the cohesive force between liquid molecules and the adhesive force between the liquid and the solid wall, and is expressed by the following equation, where θ is the contact angle, σ _L is the surface tension of the liquid, σ _S is the surface tension of the solid, and σ _SL is the interfacial tension between the solid and the liquid.
COSθ=(σ _S −σ _SL )/σ _LThe PP containers and COP containers were obtained by injection molding so as to have the same external shapes as the glass containers of Examples 1 and 2 and Comparative Examples 1 and 2.

Then, using the sessile drop method, which involves "measuring the coordinates of the droplet contour curve, assuming that the droplet contour shape can be represented by a Young-Laplace theoretical curve, calculating the curve parameters from the contour shape coordinates, determining a specific function that represents the curve, differentiating the function with respect to the endpoint coordinates to find the tangent, and then determining the contact angle from the gradient of the tangent," the contact angles (in degrees) were measured for the four types of containers mentioned above. The liquids used were water, 85% ethanol, acetone, and salad oil. The contact angle (in degrees) measurement results are shown in Tables 9 to 12 below.

As shown in Table 9, the contact angle of the glass container of Example 2 exceeds 90° when the liquid is water, indicating that it has the same water-repellent properties as PP and COP containers. However, the contact angle of the glass container of Comparative Example 2 is less than 90° when the liquid is water, indicating that it is hydrophilic.

When the liquid was 85% ethanol, acetone, or salad oil, as shown in Tables 10 to 12, the glass container of Comparative Example 2 was impossible to measure, and the PP and COP containers were also almost impossible to measure. However, the glass container of Example 2 had a certain contact angle and could not be said to be lipophilic.

The present invention provides containers suitable for use in pharmaceuticals and physicochemical applications.

51 Plasma processing apparatus 52 Vacuum chamber 53 Lower electrode 54 Upper electrode 55 Pressure gauge 56 Earth 57 Plasma generation power supply 58 Exhaust flow rate adjustment valve 59 Vacuum pump 60 Gas inlet 62 Carrier gas inlet 65 Bubbler for reactant material 66, 69 Mantle heater 67 Vapor source of reactant material 68 Raw material chamber for SAM film or self-assembled multilayer film 70 Vapor source of SAM film or self-assembled multilayer film precursor material 71 Gas inlet 72 Current input terminal 73 Electrode stage 74 Gas shower plate 75 Earth ring 76 Insulating member 77 Upper chamber 78 Lower chamber 79 Vacuum exhaust port 80 O-ring

Claims (5)

A container surface treatment method characterized by: a cleaning process in which the inner surface of a glass container is cleaned with a cleaning solution consisting of water, an acid aqueous solution, a surfactant aqueous solution, or an acid aqueous solution containing a surfactant; a distortion removal process in which the glass container cleaned in the cleaning process is heated to a desired temperature and then cooled to remove distortion; subsequently, the glass container is placed in a plasma processing device; an evaporation source that imparts hydrophilic groups is supplied to a vacuum chamber of the plasma processing device with a predetermined vacuum level, and the film-forming surface of the glass container is modified to hydrophilize using a plasma atmosphere formed by a plasma generator; the glass container with the hydrophilized film-forming surface is supplied with an evaporation source that promotes the hydrolysis or nucleophilic reaction of the precursor material of the SAM film or self-assembled multilayer film in a vacuum chamber of the predetermined vacuum level, and a SAM film or self-assembled multilayer film is formed on the hydrophilized film-forming surface; and finally, the bonding between the film-forming surface and the SAM film or self-assembled multilayer film is strengthened in the vacuum chamber of the predetermined vacuum level. A method for treating the surface of a container, comprising: placing a resin container in a plasma processing device; supplying an evaporation source that imparts hydrophilic groups into a vacuum chamber of the plasma processing device; modifying the film-forming surface of the resin container using a plasma atmosphere formed by a plasma generator to make the film-forming surface hydrophilic; supplying an evaporation source that promotes the hydrolysis or nucleophilic reaction of a precursor material for a SAM film or self-assembled multilayer film into the vacuum chamber of the predetermined vacuum level; and supplying an evaporation source of a precursor material for a SAM film or self-assembled multilayer film to the resin container with the hydrophilic film-forming surface to form a SAM film or self-assembled multilayer film on the hydrophilic film-forming surface; and finally strengthening the bond between the film-forming surface and the SAM film or self-assembled multilayer film within the vacuum chamber of the predetermined vacuum level. A surface structure of a container composed of a silicon-based polymer containing urethane bonds, urea bonds, and biuret bonds, obtained by processing using the method of claim 1. A container treated by the method of claim 1 or 2, in which the amount of Na, B, Al, Si, Ca, or Ba eluted from the container surface is less than 1 ppm. A container treated by the method of claim 2, in which the contact angle exceeds 90°.