JPS5864248A - Surface treatment of glass bottle - Google Patents

Abstract

PURPOSE:To enhance the chemical durability and mechanical strength of a glass bottle by charging a dealkalizing agent into the bottle after molding and by heat treating the bottle under prescribed conditions. CONSTITUTION:A dealkalizing agent such as gaseous SO2 or ammonium sulfate is charged into a glass bottle after molding. The bottle is kept at 580-650 deg.C for 10-40min and rapidly cooled by spraying cooling air on both the inner and outer surfaces of the bottle. Thus, the surface of the glass bottle is dealkalized and coated with a formed compressive stress layer, and the chemical durability and mechanical strength are enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to surface treatment of glass bottles, and in particular, by performing alkalization treatment on the inner and outer surfaces of the base glass bottle and forming a compressive stress layer in an integrated manner, the chemical durability and mechanical durability of the glass bottle are improved. The target strength can be improved to 1 and 4.
! ! It relates to a surface treatment method.

A strengthening method for increasing the mechanical strength of glass products consists in forming a compressive stress layer on the surface of the glass. Typical methods for forming a compressive stress layer on the glass surface include the ion exchange method, in which sodium ions on the glass surface layer are ion-exchanged with potassium ions having a larger ionic radius, creating a compressive stress layer on the surface layer, and heating. There is a method in which the glass surface is rapidly cooled and compressive stress is generated on the glass surface due to the difference in cooling with the inside of the glass. For the latter, general KFi cooling air is blown to rapidly cool it.
This method is called the air-cooling strengthening method or the air-cooling strengthening method, and it has already been put into practical use in the field of sheet glass. This wind cooling reinforcement method is
It is most important to uniformly cool the glass surface.
For example, JP-A-51-122981, JP-A-54-
As described in Japanese Patent No. 102322, a uniform cooling technique for glass products having a complicated shape has been developed and proposed. I learned that it is possible to strengthen the mood and coldness of mourning.

The ζO air-cooling strengthening method is much more advantageous in terms of process and economy than the ion exchange method. The inner surface must undergo main quenching treatment. However, when the inner surface of a glass bottle is rapidly cooled to form a compressive stress layer on the surface layer, the leaching of alkali (sodium) components is accelerated, which has the disadvantage of reducing the chemical durability of the contents filled therein. .

As shown in the graph of FIG. 1, which will be described later, the elution of alkali components from air-cooled tempered bottles is much greater than from untreated bottles. Unlike other glass products, glass bottles are filled with liquid contents as containers and are often stored for long periods of time. The deterioration in the quality of the bottle results in a serious disadvantage that affects the value of the bottle.

Therefore, the inventors of the present invention made extensive efforts and discovered a new method for surface treatment of glass bottles, which can be called an air-cooling strengthening method that also has excellent chemical durability. A detailed explanation will be given below based on examples.

In this invention, nitrogenous acid gas is contained in the base glass bottle after molding.
A dealkalizing treatment step in which a known dealkalizing agent such as ammonium sulfate is introduced and the glass is maintained at a temperature below the softening point and above the strain point, and subsequently, when the glass bottle is at the strain point or above, the glass bottle is removed. The main part is a rapid cooling process in which a single blow of cooling air is applied to both the internal and external surfaces to rapidly cool them.

That is, first, sulfur dioxide gas is introduced into a soda-lime glass bottle after molding, and the bottle is introduced into a furnace whose temperature is controlled at 580 to 650 DEG C., and the bottle is held for about 5 to 40 minutes to perform a dealkalization treatment. Immediately after forming, the internal temperature of the glass bottle reaches over 700°C, and in this case, KFi's dealkalization process 1! A short time of 5 to 10 minutes may be sufficient.

After the dealkalization treatment, the glass bottle is taken out of the furnace, and when it is at a temperature above the strain point, cooling air is blown onto the inner and outer surfaces of the glass bottle to perform a quenching treatment. At this time, compressive stress is generated on the inner and outer surfaces of the glass bottle due to the difference in cooling between the surface layer and the inner layer. however,
Since alkali ions (sodium ions) have been removed from the surface of the glass bottle, especially the inner surface, by the previous dealkalization treatment, leaching of alkaline components is suppressed to the lowest possible level.

Graph of an experiment comparing eluted components (Na20 and 51 oz) and flake generation in glass bottles treated according to Example 1, 9 bottles (air-cooled strengthened bottles) B and untreated bottles C, which were only subjected to quenching treatment is shown in FIG. In this experiment, the values were measured after 12 hours in autoclave 121@c. The elution amount of Ma2O and E1102 in bottle B, which was subjected to only quenching treatment, is the same as that of untreated bottle C.
It can be seen that there are many losses in lc, which can be greatly reduced by the processing method of the present invention. In addition, in the flake generation test, the ratio of the number of flakes generated to the number of samples m)
The bottles processed according to the present invention produced no flakes, and the air-cooled strengthened bottle B produced flakes after 60's of the sample.

FIG. 2 and subsequent graphs are graphs showing the results of comparative experiments in which processing methods proposed in the process leading to the present invention were added.

In Figure tJ2 to Figure 4, the symbol, ? The bottles shown are all obtained by reversing the order of the processing steps of the present invention and subjecting the parent glass bottle to a quenching treatment followed by a dealkalization treatment, and the specific treatment method is as follows.

D: After rapid cooling of the base glass bottle, sulfur dioxide gas was introduced into the bottle, and then heat treatment was performed at 300 - for 30 minutes.

After quenching the E-rich matrix glass, sulfur dioxide gas was introduced into the bottle and then heat treated at 400°C for 30 minutes.

IP = After rapid cooling of the base glass, sulfur dioxide gas was introduced into the bottle, and then heat treated at 450'C for 1 hour, resulting in 9 bottles.

Figure 2 shows an alkali elution amount (ml consumption amount of ^azgo4) test using two methods of the alkali elution test method in the Japanese Pharmacopoeia's glass container test method for injections. It shows a stable and low alkali elution amount regardless of the kit.

@Figures 3 and 4 show the mechanical strength of glass bottles K151
Figure 3 is a graph showing the blank ratio for untreated bottles with 1i and #1JTIII8S+3.
Mechanical impact test by Tsu3, Figure 4 is also JI88
Based on internal pressure strength test at 2502K. Regarding these O mechanically strong fK, the bottle B treated with the present invention is
It has been demonstrated that the strength is almost comparable to that of

As is clear from the treated bottles of No. 1, I, and F in the test examples, even if one quenching treatment is performed and then the dealkalization treatment is performed, the improvement in chemical durability is low and the effect of air cooling reinforcement is also reduced. In conclusion, as in the present invention, when the dealkalization treatment is the first step and the rapid cooling treatment is performed subsequently, it is possible to obtain a bottle that has a low amount of alkali elution and is effectively strengthened by air cooling.

The parent glass bottles treated according to the present invention are generally untreated bottles after molding, but may also be hot-end coated bottles prior to treatment according to the present invention. In other words, it is better to increase the impact strength of the glass surface by applying compounds such as soot and titanium to the hot bottle immediately after it has been manufactured in a bottle making machine to form an oxide film of these metals on the bottle surface. Although this is a hot-end coating treatment, in the treatment method of the present invention, glass pins that have been subjected to such treatment may be selected as the base glass pin.

Furthermore, the ilK
Adding a step of closely applying a coating agent with good slipperiness is extremely effective in maintaining and increasing the mechanical strength of glass bottles.

That is, in the surface treatment process according to the present invention, a glass bottle is cooled appropriately, and a coating agent such as a paraffin-based or fatty acid surfactant with good lubricity, such as plastic emulsion carbonate, is closely applied to the outer surface of the glass bottle. It improves lubricity or abrasion resistance. The former process of improving lubricity is generally referred to as cold-end coating treatment, and glass bottles treated with this treatment are less prone to rubbing against each other due to the lubricity of the coating agent.
It is possible to prevent scratches caused by bending, improve mechanical strength by strengthening wind cooling first, smooth the flow of the production line, and improve the efficiency of packaging and transportation. . In addition, even when the above-mentioned cold-end coating process is added, it is possible to select one in which a metal oxide film is formed on the surface of the base glass bottle by the above-mentioned hot-end coating process. In this case, the surface of the glass bottle undergoes hot-end coating treatment -> [dealkalization treatment - quenching treatment] -> cold-end coating treatment - to give a surface that has excellent mechanical strength and chemical durability. The same applies to the case where a surface coating is formed using the plastic film described above.

As explained above, according to the present invention, the dealkalization process and the formation of the compressive stress layer can be stably performed integrally in a round shape by performing the quenching process subsequent to the dealkalization process. . Therefore, the deterioration of chemical durability, which was the biggest drawback of air-cooling strengthening of glass bottles, has been greatly improved, and this invention is applicable not only to bottles that require strict chemical durability, such as medicine bottles and food bottles. First, it has been praised as paving the way for practical air-cooling strengthening of glass bottles in general.

i9 The treatment according to the present invention can be carried out in a series of steps of bottle molding, alkaline treatment, and rapid cooling treatment, so it does not require any special equipment for the rounding of the invention and has great economic advantages. Then, Jin and K undergo further rapid cooling treatment.
Therefore, in addition to the advantages of improved mechanical strength and chemical durability, such as eliminating the need for a slow cooling step, it is possible to enjoy extremely great advantages in practical operation and implementation.

[Brief explanation of drawings]

Figure 1 is a graph showing the occurrence of nine eluted components and flakes in a comparative test of bottles treated according to the present invention with other bottles, Figure 2 is a graph of the alkali elution amount test, and Figure 3 is a graph of the impact strength test. The graph in Figure 4 is also a glove from the internal pressure test. M・1 Bottles treated with the present invention, B...Air-cooled strengthened bottles, C
・−・Untreated bottle. Agent for patent applicant Nippon Steel Bottle Industry Co., Ltd.

Claims (1)

[Scope of Claims] 1. After introducing a dealkalizing agent such as sulfur dioxide gas or ammonium sulfate into the molded base glass bottle and keeping it at a temperature below the softening point and above the strain point of the glass, both the inside and outside of the glass bottle are removed. A method for surface treatment of glass bottles, characterized in that 4I characteristics include dealkalizing the surface of the glass bottle and forming a compressive stress layer by rapidly cooling the surface by blowing cooling air onto the surface. 2. The method for surface treatment of glass bottles according to claim 1, wherein the dealkalizing agent is added and maintained at a temperature of 580 to 650'a for 10 to 40 minutes. 5. The glass bottle surface treatment method according to claim 1, wherein the base glass bottle has a metal oxide coating on its surface by hot end coating treatment. 4 A dealkalizing agent such as sulfur dioxide gas or ammonium sulfate was added into the glass bottle after molding, and the temperature was maintained at 11 degrees below the softening point and above the strain point of the glass. By spraying and rapidly cooling the glass bottle, a coating agent is applied to the outer surface of the glass bottle to improve lubricity or prevent scratches. 1. A method for surface treatment of glass bottles, comprising the step of improving the lubricity or abrasion resistance of the glass bottle surface by heavily coating the glass bottle. . 5. The method for surface treatment of a glass bottle according to claim 4, wherein the base glass bottle has a metal oxide coating on its surface by hot-end coating treatment.