JP2000072491A - Surface treatment of glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily improve deposition property of liquids or foams on a glass surface at a low cost while keeping transparency of the glass. SOLUTION: In a surface treatment of glass, the glass surface is brought into contact with sulfurous acid gas (SO2), anhydrous sulfuric acid gas (SO3) or chlorine gas (Cl2) to react while heating. The surface temp. of the glass to be in contact and react with the sulfurous acid gas, anhydrous sulfuric acid gas or chlorine gas is preferably 650 to 900 deg.C. Or, after the glass surface is brought into contact and reacted with sulfurous acid gas, anhydrous sulfuric acid gas or chlorine gas at 500 to 800 deg.C, the glass surface is heated again to 650 to 900 deg.C. Reheating may be carried out while the glass is still hot, or after the glass is cooled, the glass may be reheated with flame. Thereby, rather deep recesses are produced on the glass surface, which improves deposition property of liquids and foams.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a glass surface, on which a liquid or bubbles easily adhere to the surface.

[0002]

2. Description of the Related Art In some cases, it is required that liquids and bubbles adhere well to the surface of glass. For example, when drinking beer in a glass, it is said that a beer is delicious if the beer foam remains in a ring shape on the inside of the glass after drinking. Therefore, it is required that bubbles easily adhere to the inner surface of the glass. In such a case, a CFC treatment or a Bloom treatment is performed to make it easier for bubbles to adhere to the inner surface of the glass.

In the process of producing porous glass,
There is a step (dipping) of attaching a treatment liquid such as a metal alkoxide to the surface of a sheet glass to form a sol-gel glass. Also in this case, it is required that the treatment liquid adheres well to the glass surface. In the case of dipping, the surface is roughened by etching with hydrochloric acid, and then the alkali component is removed from the vicinity of the glass surface by a rinsing step of a dealkalizing solution in order to prevent defects in the processing solution thin film caused by impurity ions (such as sodium ions). Work is needed.

[0004]

In the case of the above-mentioned beer glass, since the unevenness formed on the glass surface in the chlorofluorocarbon treatment or the bloom treatment is shallow, the effect of adhering bubbles is weak and the persistence is low.

[0005] In the dipping, the work for removing alkali is troublesome, the rinsing process of hydrochloric acid or dealkalizing solution requires a large amount of a cleaning solution such as deionized water, and the cost is high. No,
The etching of hydrochloric acid has problems that the glass surface has few irregularities and the amount of the treatment liquid adhered is small, and it is difficult to change the irregularity state of the glass surface.

The present invention has been made to solve the above-mentioned problems, and it is possible to obtain relatively deep irregularities on the glass surface easily and at low cost while maintaining the transparency of the glass, without drainage problems, and furthermore, without causing drainage problems. The degree of unevenness can be changed.

[0007]

According to the present invention, sulfuric acid gas (SO2) and sulfuric anhydride gas (SO3)
Alternatively, it is a glass surface treatment method of contacting and reacting with chlorine gas (Cl2). The surface temperature of the glass to be brought into contact with and reacted with sulfurous acid gas, sulfuric anhydride gas or chlorine gas is 650 to 90.
A temperature of 0 ° C. is appropriate. If the temperature is lower than 650 ° C., the reaction hardly occurs. If the temperature exceeds 900 ° C., adverse effects such as deformation of the glass are caused. Further, the present invention is a glass surface treatment method in which a glass surface is reheated to 650 to 900 ° C. after a sulfurous acid gas, a sulfuric anhydride gas or a chlorine gas is contacted and reacted at 500 to 800 ° C. Reheating may be performed while the glass is still hot, or may be performed using a flame or the like after the glass has once cooled.

In the present invention, a sulfurous acid gas, a sulfuric anhydride gas or a chlorine gas may be directly blown onto the glass surface to bring the gas into contact with the glass to cause a reaction, or a substance which generates these gases by heat (for example, ammonium sulfate). May be brought into contact with the glass, and the gas generated thereby may be reacted with the glass.

[0009] The process of bringing sulfur dioxide gas, sulfuric anhydride gas or chlorine gas into contact with and reacting with a heated glass surface (so-called bloom treatment) is known as a dealkalization treatment near the glass surface. By this treatment, the vicinity of the surface of the glass is dealkalized, and a surface layer rich in SiO2 is formed. SO2, SO3 or Cl2 reacts with the high-temperature glass surface and reacts with sodium ions near the glass surface to become Na2SO4 or NaCl and adhere to the glass surface as bloom. The glass surface becomes Si-rich due to scraping of sodium, and becomes a dealkalized state.
After performing this treatment, the glass surface is heated. Then, the Si-rich layer and the glass near the surface expand. Thereafter, the surface shrinks as the glass surface cools, but the Si-rich layer has a smaller expansion coefficient than glass,
Since the degree of shrinkage of the Si-rich layer is smaller than the degree of shrinkage of the glass, the Si-rich layer becomes wrinkled, thereby forming irregularities on the glass surface. The glass surface is 650
The same applies to the reaction of sulfurous acid gas, sulfuric anhydride gas or chlorine gas at a high temperature of 900 ° C.

As the heat treatment after the bloom treatment, a method in which a flame of a burner is brought into contact or a laser beam is scanned is preferable. In this heat treatment, the higher the temperature and the longer the heat treatment time, the larger and deeper the irregularities generated on the glass surface. In the case of the heat treatment by the flame of the burner, a heat treatment time of about 10 to 300 seconds is appropriate.

Further, the present invention provides a method of coating a glass surface with a low-expansion substance, and thereafter coating the glass with 650 to 900.
A glass surface treatment method characterized by heating to ℃ or contacting and reacting a low expansion material with glass heated to 650 to 900 ° C.

[0012] The low expansion material is a material which is thermally decomposed and has a smaller coefficient of thermal expansion than a glass when it reacts with glass. For example, SnO2, Al2O3, B2O
3, TiO2, SiO2 and the like.

[0013] The low expansion material is coated on the glass surface by gas or spray and coated.

On the glass surface coated with the low expansion material, Sn, Ti, S having a lower coefficient of thermal expansion than glass is provided.
An alkali-free layer of a compound such as i, B, or Al is formed. Thereafter, the glass shrinks as the glass surface cools, but this layer has a smaller expansion coefficient than glass, and the degree of shrinkage of this layer is smaller than the degree of shrinkage of the glass, so this layer becomes wrinkled, The wrinkles form irregularities on the glass surface.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION 1 g in a 400 ml glass
Was heated to about 650 ° C. in a firing furnace, and the generated sulfurous acid gas was reacted with the glass surface. Thereafter, the glass was taken out of the firing furnace, and a burner with a diameter of 2 minutes (gas pressure 1 kg / square cm: flow rate air 35 Nl / m)
In, propane (1.4 Nl / min), the inside of the glass was heated for 60 seconds, and the treatment of the example was performed. Thereafter, the glass was left at room temperature, and after the temperature was lowered to room temperature, the glass was washed. The glass treated in this example had the same transparency as the untreated glass. Prepare a glass treated in this example and a glass of another comparative example, pour beer into the glass, aspirate the beer several times with an aspirator from the bottom, and check the state of foam attached to the inner surface of the glass. An experiment was performed. The result is shown in FIG. In FIG. 1, the glass on the left side is not treated at all, the glass in the center is the one on which only sulfur dioxide gas is reacted on the inner surface of the glass and is not subjected to the heat treatment (the one on which only the bloom treatment is performed), and the glass on the right side is This is a result of the processing of the above embodiment.
In the glass on the right side, bubbles were attached stepwise from the mouth in a ring shape, and it was confirmed that the adhesion of the bubbles was good.

The glass surface treated in the above embodiment and the untreated glass surface were observed with an electron microscope. The result is shown in FIG. The one shown above is the treated one, and a hole (recess) having a diameter of 1 to 5 μm can be observed. No such holes are found on the untreated glass surface shown below.

[0017]

According to the glass surface treatment method of the present invention, relatively deep irregularities can be obtained on the glass surface easily and at low cost while maintaining the transparency of the glass. The degree of unevenness of the surface can be changed. The beer glass treated by the treatment method of the present invention has the same transparency as the untreated beer glass and has good adhesion of foam. In the dipping of the glass treated by the treatment method of the present invention, the amount of the treatment liquid attached and the amount pulled up are increased as compared with the conventional etching treatment with hydrochloric acid, so that the film is stabilized.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory diagram of a foam adhesion test result of a beer glass subjected to a process of an example and a beer glass of a comparative example.

FIG. 2 is a photomicrograph of a glass surface that has been treated according to an example and an untreated glass surface.

Continued on the front page (72) Inventor Koichi Sawafuji 1-3-1 Uchisaiwai-cho, Chiyoda-ku, Tokyo F-term in Toyo Glass Co., Ltd. (reference) 4G015 DA01 4G059 AA01 AC01 EA01 EA02 EA04 EA05 EB09

Claims (6)

[Claims] 1. A glass surface treatment method for reacting a sulfurous acid gas, a sulfuric anhydride gas or a chlorine gas with a heated glass surface, wherein the temperature of the glass surface where the sulfurous acid gas, the sulfuric anhydride gas or the chlorine gas is reacted is 650 to 900 ° C. Glass surface treatment method characterized by being 2. A glass surface heated to 500 to 850 ° C. is reacted with sulfurous acid gas, sulfuric anhydride gas or chlorine gas, and immediately thereafter, the glass surface is reheated to 650 to 900 ° C. by a flame or the like. Glass surface treatment method 3. A glass surface heated to 500 to 850 ° C. is reacted with a sulfurous acid gas, a sulfuric acid gas or a chlorine gas, and once cooled to room temperature, the glass surface is reheated using a flame or the like. Glass surface treatment method 4. A glass surface treatment method comprising coating a low expansion material on a glass surface, and thereafter heating the glass to 650 to 900 ° C. 5. A glass surface treatment method comprising reacting a low-expansion substance with glass heated to 650 to 900 ° C. 6. The glass surface treatment method according to claim 4, wherein the low expansion material is SnO2, Al2O3, B2O3, T
Glass surface treatment method characterized by being iO2 or SiO2