JPH07223840A - Production of glass having light scattering effect - Google Patents

Abstract

PURPOSE:To economically and safely produce glass having light scattering effect. CONSTITUTION:Glass having a metal oxide film on the surface is heated to a temperature of annealing point or above and softening point or below of this glass.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing glass having a light scattering effect.

[0002]

2. Description of the Related Art Generally, glass having a light scattering effect is
It has superior decorativeness compared to transparent glass and is used as a high-value-added glass in various fields such as containers, works of art, and building materials.

As a method for producing a glass having such a light scattering effect, a method of corroding the glass surface with hydrofluoric acid or the like to chemically form irregularities to give the glass a light scattering effect. Alternatively, there is known a method in which fine particles such as sand are sprayed on the surface of glass to shallowly cut the surface to give a light scattering effect.

However, since the former method uses a chemical which is extremely harmful to the human body, there is a problem in ensuring manufacturing safety and environmental preservation. There is also a problem that the manufacturing process is complicated and the production is not efficient. On the other hand, the latter method requires a long processing time and may increase the cost of the apparatus. Therefore, whichever method is used,
The current situation is that a large increase in manufacturing costs cannot be avoided.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve such problems, and it is an object of the present invention to provide a method capable of economically and safely manufacturing glass having a light scattering effect. To do.

[0006]

That is, the present invention is
The present invention relates to a method for producing a glass having a light-scattering effect, which comprises heating a glass having a metal oxide film on its surface at a temperature not lower than the slow cooling point and not higher than the softening point of the glass.

The glass used in the present invention is not particularly limited, and soda lime glass which is widely and commonly used is preferable, and alkali oxides (NaO ₂ , K ₂₎ are preferable.
A compound having a total content of O and the like of 5 mol% or more, and more preferably 12 mol% or more exhibits a good light scattering effect.

Various metal oxides for forming a film are known, but when soda lime glass is used as a material glass, SiO ₂ , SnO ₂ , TiO ₂ , Al ₂ O _{3 are used.}
One kind or two or more kinds can be selected from the above and used. From the viewpoint of easy film formation, SnO ₂ is preferable.
The method for coating the glass material with the metal oxide is not particularly limited, and a known method such as a CVD method or a sol-gel method can be used. Furthermore, the thickness of the metal oxide film is appropriately determined depending on the use and purpose of the glass, and is preferably 20 nm to 1500 nm, particularly preferably 50 nm to 800 nm. When the thickness of this metal oxide film is less than 50 nm, it is difficult to obtain a sufficient light scattering effect, and when it is thicker than 800 nm, the film forming cost for the light scattering effect becomes high.

The heating temperature of the glass carried out by the manufacturing method of the present invention is not less than the slow cooling point (hereinafter Ta ° C) of the glass but not more than the softening point (hereinafter Ts ° C). Preferably, (Ta +
Ts) / 2 or more and {(Ta + Ts) / 2} + 80 ° C. or less. The slow cooling point is the temperature at which the viscosity of the glass becomes 2.5 × 10 ¹³ poise, and is also known as the temperature at which the strain of a glass product generally manufactured is removed. The softening point is the temperature at which the glass has a viscosity of 4.5 × 10 ⁷ poise.

When the heating temperature is lower than the annealing point,
The metal oxide film on the glass surface does not show a good light scattering effect. Further, when the glass is heated at a temperature higher than the softening point, the glass itself is softened and deformed. The glass may be heated until the surface thereof reaches the heating temperature, but by heating for several minutes to raise the temperature inside the glass, a glass having a stable light scattering effect can be obtained.

[0011]

The present invention will be described in detail below with reference to examples. The present invention is not limited to these embodiments. Example 1 A glass bottle made of soda-lime glass having the composition shown in the table (internal volume: 130 ml, weight: 88 g)
Was placed in a dimethyldichlorotin vapor atmosphere at 450 ° C. for 3 minutes to form a SnO ₂ film on the surface of the glass bottle. The formed film thickness was 150 nm. This glass bottle was heated in air at 700 ° C. for 5 minutes and then gradually cooled to room temperature by cold air or the like. The glass bottle obtained had a good light-scattering effect as judged by visual observation.

Example 2 A piece of soda-lime glass having the composition shown in the table was placed in a dibutyldichlorotin vapor atmosphere at 460 ° C. for 30 seconds to deposit SnO on the surface of the glass piece.
_Two films were formed. The film thickness was 214 nm. The glass piece was heated in air at 700 ° C. for 5 minutes and then gradually cooled to room temperature by cold air or the like. The glass piece obtained had a good light scattering effect.

Example 3 A soda-lime glass piece having the composition shown in the table was placed in a monobutyltrichlorotin vapor atmosphere for 30 seconds to form a SnO ₂ film on the glass surface. The formed film thickness was 347 nm. After heating this glass piece in air at 650 ° C. for 18 minutes, it was gradually cooled to room temperature by cold air or the like. The light scattering effect of the obtained glass piece was good.

[0014]

[Examples 4 to 6] Next, the light scattering effect of the obtained glass piece was changed by changing the treatment time of the soda-lime glass piece used in Example 2 with dibutyldichlorotin vapor and the subsequent heating conditions. I checked. The results are shown in the table below. Light scattering effect: ◎ Very large. ○ Large △ Appearing with the naked eye

[0016]

[0017]

As shown and described above, according to the method for producing a glass having a light-scattering effect of the present invention, chemicals harmful to the human body, such as hydrofluoric acid, are not used. Is also extremely safe. Further, according to this method, the manufacturing process is simplified, and it is possible to perform continuous treatment or to treat a large amount at a time, and it is possible to economically and efficiently obtain such a glass having a high light scattering effect. .

Claims (1)

[Claims] 1. A method for producing glass having a light-scattering effect, which comprises heating a glass having a metal oxide film on its surface at a temperature not lower than the slow cooling point and not higher than the softening point of the glass.