JPH08239240A - Method for forming metal oxide coating film on surface 0f glass vessel - Google Patents

Abstract

PURPOSE: To form a metal oxide coating film having excellent scratch resistance and a uniform and stable film thickness and enabling easy handling of raw materials to improve the safety with a simple apparatus by contacting the mist of an aqueous solution of a metal compound with a heated glass surface. CONSTITUTION: An aqueous solution of one or more kinds of metal compounds selected from tin, titanium and zirconium, e.g. a halogen compound, acetate, sulfate or nitrate such as tin tetrachloride and titanium tetrachloride is placed in a coating apparatus 1 and the mist M of the coating liquid having particle diameter of <=30μm is generated by an ultrasonic transducer 2. The mist is passed through a pipe 4 into a coating hood 6 on a conveyor 5 with a fan 3. A glass bottle G is passed, immediately after the delivery from a molding machine, through the coating hood 6 on the conveyor 5 at the bottle temperature of 450-700 deg.C spending a prescribed time and the surface of the glass is brought into contact with the mist M of the coating liquid. The coated product is transferred through an annealing furnace to form a tough metal oxide layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coating the surface of a glass container such as a glass bottle with a metal oxide for the purpose of preventing strength deterioration and scratches.

[0002]

2. Description of the Related Art Conventionally, in order to further improve the original strength of a glass product or to prevent the surface of the product from being directly scratched, a coating treatment has been widely performed on the surface.

As a first method, a glass obtained by heating and evaporating a solution containing tin tetrachloride, organotin, titanium tetrachloride, and organotitanium as main components is still in a high temperature state immediately after molding. An excellent tin oxide as a substance having scratch resistance by thermal decomposition reaction by spraying on the outer surface of
There is a so-called CVD method (chemical vapor deposition method) for forming a titanium oxide film.

As an example thereof, Japanese Patent Laid-Open No. 3-131547 discloses a base material having an outer surface temperature of 550.degree.
It is disclosed that a scratch-resistant coating film is obtained by bringing into contact a raw material (for example, SnCl ₄ , SnCl ₂ (CH ₃ ) ₂ etc.) capable of forming a film containing O ₂ or TiO ₂ as a main component.

However, according to this method, the thickness of the obtained film is easily influenced by the glass temperature during the process and is unstable,
In addition, SnCl ₄ and TiCl ₄ are easy to hydrolyze the raw materials, so they emit smoke in the air and have a strong irritating odor, which requires careful handling and is very dangerous if leaked.
There was a need for safety measures against it. In addition, the carrier gas requires dry air, and in some cases, heating is required, which makes the device complicated. Further, it is generally known that the film thickness becomes thicker when the surface temperature is raised, and thereby the purpose of improving the scratch resistance can be more achieved. There is a problem that the product itself is likely to be deformed by its own weight or an external factor before the cooling process is completed.

In addition to this, as a vapor deposition method, a PVD method (physical vapor deposition method) is also performed, and a coating type film forming method is also known in which a composition is applied and baked, but these coating films are also known. All of them have insufficient hardness, the film is easily peeled off, or the uniform application is difficult. Therefore, it has been desired to develop a superior coating film that solves these problems.

As another method, a method of dissolving the starting material in an organic solvent and spraying it has been used. However, since this spray method uses a flammable organic solvent, there is a danger of explosion, troubles due to clogging of the nozzle, and cleaning and replacement of the nozzle must be performed regularly. There was a problem such as not becoming. In addition, due to the decrease in the product temperature due to the high pressure gas for spraying, an appropriate film may not be obtained. In addition, problems such as condensation in the exhaust process may occur.

[0008]

SUMMARY OF THE INVENTION Therefore, the present invention solves the above-mentioned problems and, although a relatively simple apparatus is required, it is a film having excellent scratch resistance and the coating amount can be easily controlled. Therefore, it is necessary to obtain a uniform and stable film thickness. Further, it aims to improve safety by facilitating the handling of raw materials.

[0009]

The method of forming a metal oxide film on the surface of a glass container according to the present invention is a method in which an aqueous solution of a metal compound which becomes a metal oxide by thermal decomposition has a particle size of 30 μm or less by an ultrasonic vibrator. Along with generating mist, the mist is blown out by a fan or a blower to be sent into the coating hood provided on the conveyer immediately after glass molding, brought into contact with the glass surface at 450 ° C to 700 ° C, and then gradually cooled. It is characterized by that.

Here, the metal oxide is an oxide of at least one metal selected from tin, titanium and zirconium. The metal compound used as the metal oxide by thermal decomposition at 450 ° C. to 700 ° C. is, for example, a halogen compound such as tin tetrachloride or titanium tetrachloride, or a water-soluble compound such as acetate, sulfate or nitrate. Any metal compound can be used. Further, in the present invention, a solution obtained by dissolving these in water is used. This solution is the coating device 1 in FIG.
It is housed in the
The following mist-like coating liquid M is generated.
Here, the reason why the mist generated is 30 μm or less is that it is difficult to obtain a uniform film if the mist is more than 30 μm, preferably 10 μm or less.

At the same time, the coating liquid M is sent out by the fan 3 through the pipe 4 of the coating apparatus 1 into the coating hood 6 provided on the conveyor 5. Although the pipe 4 is divided into three pipes in the drawing, it goes without saying that it may be divided into one pipe and a plurality of pipes. On the other hand, the glass bottle G immediately after coming out of the molding machine (not shown) will pass through the coating hood 6 on the conveyor 5 for a certain period of time when the bottle temperature is 450 ° C to 700 ° C. Here, the coating solution M in the form of mist comes into contact with the glass surface and the coating process is performed. Then, a strong metal oxide layer is obtained by passing through a conventional annealing furnace (not shown). Further, an exhaust port 7 is separately provided in the coating hood 6 so that the remaining coating liquid M is discharged. The coating amount can be controlled by the ultrasonic vibrator, the strength of the fan, the concentration of the aqueous solution, the surface temperature of the glass container, the coating time (coating hood passage time), and the metal compound. You can control. Especially on normal work, depending on the strength of the ultrasonic transducer and fan,
It is easily controllable. Further, according to the present invention, since a mist-like coating liquid is used, a uniform film thickness can be obtained, which makes it possible to obtain a relatively thick film.

[0012]

EXAMPLE Using the apparatus as described above, a 20% tin tetrachloride aqueous solution was stored in the coating apparatus, the frequency of the ultrasonic oscillator was set to 1.7 MHz, and the output was 60 W and 18
There are two types of 0W, each of which produces a mist with an average particle size of 5μ, is fed into the coating hood through a pipe by a fan, and a glass bottle with an average bottle temperature of 560 ° C immediately after molding (volume 300 ml, weight 150 g bottle) ) Was subjected to coating treatment. The time required for the bottle to pass through the coating hood was set to 1.7 seconds on average. Then, 100 bottles of each bottle product (Example 1, Example 2) were passed through an annealing furnace, and a glass bottle 1 of the same kind coated with a conventional chemical vapor deposition method using organic tin as a comparative example.
The scratch resistance test was performed as follows using 00 pieces. First, the results of measuring the film thickness are shown in Table 1.

[0013]

[Table 1]

Next, with respect to Example 1 and Comparative Example, a line simulator manufactured by AGR was used, and scratching was performed for 0 to 5 minutes by a wet method, and the deterioration rate of internal pressure strength and the state of scratches were examined. The results are shown in Table 2. The state of scratches is
This is a visual inspection.

[0015]

[Table 2]

Further, a scratch resistance tester as shown in FIG. 2 is prepared, the lower sample bottle 1b is fixed on a smooth holding table 2 by a stopper 3, and the upper sample bottle 1a is piled up at a right angle, and the upper part is held. If the upper sample bottle 1a is moved horizontally at a speed not exceeding 8 cm per minute in the direction of 45 degrees with respect to the axes of the bottles 1a and 1b while applying a more specified load, is it scratched? Test whether or not. The load of multiple stages is specified by the platform 4, and the upper and lower sample bottles 1a are
The contact surface of 1b is changed, and the level is sequentially increased to similarly test whether scratches occur. In addition, the display was shown as an SF value (abbreviation of the value of scratch force, also called slip value) by averaging the measured values of three or more times. Table 3 shows the results.

[0017]

[Table 3]

When the amounts of the chemicals used were almost the same, both the average film thickness and the minimum film thickness were higher and the standard deviation was smaller than those obtained by the conventional method. In addition, improvement of strength deterioration prevention and improvement of scratch resistance were confirmed. Since it was confirmed that the film thickness was increased by increasing the output of the ultrasonic transducer, it was found that the film thickness could be controlled by this. In addition,
Although only the tin compound is shown in this embodiment,
Similar results can be expected regardless of whether a metal compound or a mixture thereof is used for titanium and zirconium.

[0019]

As described above, the film formed by the coating method of the present invention can be uniformly applied to the surface of a glass container, and forms a coating film having high scratch resistance. In addition to the above, it is possible to prevent the strength deterioration of the product. In addition, since it is a raw material of an aqueous solution, it is possible to use a commercially available aqueous solution in advance, it has no smoke, irritating odor, and explosive properties, and is highly safe, so it is easy to handle, and compared to conventional products. Are very advantageous. Further, a simple device is sufficient, and according to the device, trouble such as nozzle clogging does not occur. Moreover, since it is a fine mist, a thick film is likely to be formed, which is an advantage for improving scratch resistance. Moreover, it does not require heating and dry air,
Since the scratch resistance of the coating film has been improved, it can be expected to reduce the thickness of the glass container in the future.
This leads to weight reduction of glass products. Therefore, as a coating method that solves the conventional problems, it greatly contributes to the development of industry.

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[Procedure amendment]

[Submission date] July 4, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a scratch resistance test device used in Examples.

[Explanation of Codes] 1 coating device G glass bottle 6 coating hood M coating liquid

Claims (1)

[Claims] 1. A conveyer immediately after glass forming by generating an aqueous solution of a metal compound which becomes a metal oxide by thermal decomposition with an ultrasonic oscillator to generate mist having a particle size of 30 μm or less, and ejecting the mist with a fan or a blower. Into the coating hood provided in the
A method of forming a metal oxide film on the surface of a glass container, which comprises contacting the glass surface at a temperature of ℃ to 700 ℃, and then gradually cooling.