JPH01201048A - Method for modifying surface of glass container - Google Patents

Abstract

PURPOSE:To obtain a glass container capable of preventing migration of components in the container to filled contents without requiring a special apparatus and affecting productivity, by bringing the inner surface of the glass container into contact with water optionally containing a specific substance and heat-treating the inner surface. CONSTITUTION:An adequate amount (e.g., tens of g - several g) of water, such as pure water or distilled water, or water containing a substance, such as an inert gas or alcohol, having no interaction with glass without eliminating glass components from the glass surface is added through a suitable filling machine, e.g., dispenser, to the inner surface of a glass container and in the liquid or gaseous state brought into contact therewith in the course of forming and processing or after completing the forming thereof. The resultant container is then heated to 400-900 deg.C, kept at the temperature for a prescribed time (e.g., tens of sec - several hr) and heat-treated to form a modified layer with hardly any content of constituent components readily dissolving and migrating into filled contents of the glass container on the inner surface thereof.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for modifying the surface (inner surface) of a glass container for producing a glass container that has little interaction with the filled contents. [Prior Art and Problems to be Solved] Glass is widely used as a material for containers due to its characteristics, but constituent components of glass often desorb and migrate into the filled contents. For glass containers filled with pharmaceuticals, cosmetics, or foods, where the safety and stability of the filled contents must be particularly strictly ensured, it is particularly desirable to minimize the amount of components that can be eliminated and migrated. borosilicate glass (i.e. Si0.5Q~85%)
, [31035-16%, AQt032-25%, Na
In addition, in the molding process, the phase separation phenomenon that occurs during the melting and solidification process may cause unevenness in the material composition on the container surface layer. In order to suppress this, methods are used to lower the melting temperature and shorten the melting time as much as possible, and in addition, after forming the container, a process is carried out to actively exclude components that are easily desorbed and transferred, for example, molded products are heated to 600 to 900 at least 30 °C
A method of reheating for more than a minute to volatilize the migrated components, a method of cleaning the migrated components by contacting the molded product with a strong acid solution such as butic acid or sulfuric acid, or a strong alkaline solution such as sodium hydroxide or potassium hydroxide, or A commonly used method is to add a substance that easily forms a reaction product with a migrating component, such as sulfur dioxide gas, ammonium sulfate, or ammonium chloride, react by heating, and then clean the reaction product on the surface layer of the molded article. However, the method of molding at low temperatures and in a short time increases shape variations, reduces production per unit time, and has a small reforming effect. Reheating or cleaning the molded product with an acid or alkaline solution requires an additional process, which significantly increases costs and can also make the molded product brittle. In addition, the method of adding a substance that easily reacts with the transitional component and the reaction product by heating requires an additional process, and it is difficult to purify the additive substance, causing the additive substance or its related substances to diffuse into the surrounding process environment. It is difficult to construct processing equipment that will prevent the formation of molded products, resulting in an extremely large increase in costs, and extensive cleaning is required to completely remove the reaction products that adhere to the surface of the molded product in the form of a fine film. As described above, the conventional reforming technology has many problems, and the present situation has no choice but to limit the scope of application or the degree of application. [Means for Solving the Problems] The present invention provides a method for modifying the surface of a glass container, which comprises heating the surface of the glass container by bringing water containing a substance that does not remove glass components from the surface into contact with the surface. On the inner surface of the glass container, a modified layer with a low content of constituent components that are easily dissolved and transferred to the filled contents is formed, making it possible to largely prevent the glass components from transferring to the filled contents. For water that contains substances that do not release glass components from the water or glass surface, pure water, distilled water, inert gases (nitrogen gas, carbon dioxide gas, etc.), organic substances such as alcohol, electrolyte ions, etc. Use water that contains trace amounts of non-interacting substances.A method of bringing water into contact with the surface of a glass container without causing glass components to separate from the water or glass surface is to fill the container with a suitable filling machine, such as a dispenser that can fill a small amount. This is done by adding an appropriate amount (several tens of milligrams to several grams) during the molding process (including the strain removal process) or after the molding process is complete.At this time, the additive is added in the form of a liquid or gas such as water vapor. Furthermore, in cases where the container is molded using a gas combustion burner during the molding process, it is also possible to cause the gas mainly composed of water vapor produced by the combustion to condense and react within the container. The reaction with the glass container (heat treatment step) involves raising the temperature of the container to a high temperature (400 to 900°C) and maintaining it for a certain period of time (several tens of seconds to several hours, preferably tens of seconds to several tens of minutes). At this time, migratory components on the surface of the glass container are selectively removed in the presence of water, and the surface of the glass container is modified to a highly stable state.The method of heating the container is as follows: If there is an annealing furnace for removing distortion during the molding process, it can be carried out simultaneously with the annealing process.Of course, it is also possible to use a dedicated heat treatment oven. In addition to the method of forcibly injecting water or water containing a substance that does not cause glass components to separate from the glass surface, in the heat treatment process, the atmosphere of the heat treatment equipment or the atmosphere inside the glass container contains high concentration of water vapor. It is also possible to perform reforming by filling it with gas to create a high moisture environment. In carrying out the present invention, the amount of water to be added or water containing a substance that does not separate glass components from the glass surface may vary depending on the heating temperature and reaction time. The amount of water to be added or water containing a substance that does not separate glass components from the glass surface varies depending on the shape and volume of the molded product and the composition of the glass, but in the case of a borosilicate glass ampoule container with a capacity of about 10 precepts, it is about 50 to 100 looms. It is. The amount of m added at this time should be within the range that can be completely consumed during the reaction; if it is added in excess, when the molded product is cooled, if the cooling rate after heating is rapid, moisture will be exposed in the container. I don't like it. Furthermore, if the reaction time is too long, cristobalite crystals will grow on the modified surface of the container. The reaction time is determined based on the target modification 1. The method of the present invention is particularly effective for modifying the inner surface of borosilicate glass containers (eg, glass containers for pharmaceuticals, granulated products, and foods such as ampoules and tube bottles). [Example] As an example of the present invention, a pharmaceutical ampoule formed by molding a glass tube for ampules (trade name: BS tube) manufactured by Nippon Electric Glass Co., Ltd. will be specifically described below.

[Example 1] For an ampoule with a content of ff11Od, 50mg of distilled water was injected during the molding process and after the completion of the shaping process, and the temperature was 700~800°C, which is 50~100°C higher than the temperature normally used.
A heat treatment was carried out for about 70 seconds at a temperature of 70 seconds, which also served as a slow cooling step, and a reforming operation was carried out. To evaluate the modified container, add distilled water to this ampoule.
After filling and melt-sealing, sterilization was performed at 121° C. for 30 minutes using an autoclave, and components migrated from the glass were eluted into the filled distilled water, and Na and A12 were measured by atomic absorption spectrometry. The results are shown in Table 1. In addition, for comparison purposes, the same elution operation was performed on a conventional product that was not subjected to the modification operation, and the eluted components were measured. The results are shown in Table 2. Table 2 As shown here, the amount of Na elution from the modified product was approximately 1/2, and the amount of A (elution amount was approximately 1/10). In the molding process, after completing the shape process, the ampoule was filled with steam by injecting steam generated from a boiler into the ampoule for approximately 0°5 seconds through a conduit and a syringe needle. The amount of insects corresponds to about 50 to loomg of water.The ampoule, whose interior was filled with water vapor, was heat-treated at a temperature of 700 to 800°C for about 70 seconds, also serving as a slow cooling process, in the same manner as in Example 1. The modified container was evaluated in the same manner as in Example 1. The results are shown in Table 3. Table 3 As shown here, the amount of Na eluted from the modified product was approximately 172, and A (the elution amount was about 171 O. [Example 3] In the same ampoule forming process as in Example 1, a boat was installed in the slow cooling furnace for heat treatment, and filled with distilled water to
The heat treatment was performed at 0 to 800° C. to create a high-temperature steam environment inside the heat treatment device, and the ampoule was passed through the environment to perform reforming. The modified container was evaluated in the same manner as in Example 1. The results are shown in Table 4. Table 4 As shown here, the amount of Na eluted from the modified product was about 1/2, and the amount of AC eluted was about 1/10. Functions and Effects of the Invention] In the glass container modified by the method of the invention, components transferred from the glass container to the filled contents are greatly reduced. The implementation of the present invention can be easily incorporated into the molding process without affecting productivity in any way. Furthermore, even in cases where it cannot be incorporated into the process, the desired modification effect can be obtained without requiring any special equipment. Furthermore, the quality of the appearance and shape of the modified products obtained by this modification method was equal to or higher than that of conventional products. Furthermore, there were no problems with the amount of residual strain, compressive strength, and other characteristic values, and the characteristic values were comparable to those of conventional products. Patent source Director of the Agency of Industrial Science and Technology Takeda Pharmaceutical Co., Ltd. Daiwa Special Glass Co., Ltd.

Claims (2)

[Claims] (1) A method for modifying the surface of a glass container, which comprises heating the surface of the glass container by bringing water or water containing a substance that does not remove glass components from the glass surface into contact with the surface of the glass container. (2) A claim in which water or water containing a substance that does not separate glass components from the glass surface is brought into contact with the surface of the glass container and heat-treated in the molding process or strain removal process of the glass container, or in a subsequent treatment process. The method described in 1.