JP3368049B2 - Glass having light scattering effect and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Glass having a light-scattering effect has excellent designability as compared with transparent glass and is used as a high-value-added glass in various fields such as containers and building materials. By the way, conventionally, a so-called frost processing has been used as a method for producing a light-scattering glass. There are two methods, a method of chemically corroding the glass surface and a method of mechanically scraping the glass surface. However, these manufacturing methods have a big problem for the following reasons. That is, there is surface etching with a solution containing hydrofluoric acid as a typical example of the former, but this method not only reduces productivity due to complication of the manufacturing process, but also uses chemicals extremely harmful to the human body. Therefore, it is necessary to pay sufficient attention to ensuring manufacturing safety and environmental protection. A sandblasting process is a typical example of the latter method, but this method has extremely poor productivity. Therefore, a large increase in manufacturing cost cannot be avoided regardless of which manufacturing method is used.

As a manufacturing method for solving such a problem, Japanese Patent Laid-Open No. 175749/1982 discloses
A method of manufacturing frosted glass products has been devised. This is a method in which a metal oxide film is formed on the glass surface and then heated to a temperature near the glass softening point to form fine pores in the metal oxide film. According to this method
It is said that it is possible to manufacture frosted glass that is exactly the same as the above two methods. However, this method also has the following problems. Since it needs to be heated up to the softening point of the glass, the glass is likely to be greatly deformed, and it is extremely difficult to obtain a desired product shape in a constant manner.

As described above, none of the conventional methods can industrially produce a light-scattering glass. Further, the frosted glass obtained by these is a so-called ground glass shape, and is not sufficiently satisfactory in terms of designability.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above points, and provides a novel glass having a light-scattering property which is excellent in designability and a method capable of industrially producing the same. Is to provide.

[0006]

The glass having a light scattering effect according to the present invention has a metal oxide film with a film thickness of 3 nm or more and 100 nm or less on the surface, and the average height difference between adjacent irregularities is 0.4 μm or more and 5 μm. Hereinafter, it is characterized in that the surface has fine irregularities having an average height difference of adjacent irregularities / an average interval between adjacent convex portions of 0.01 or more and 0.2 or less.

Further, in the method for producing a glass having a light scattering effect according to the present invention, a glass having a metal oxide film with a film thickness of 3 nm or more and 100 nm or less is formed on the surface of the glass, and the metal oxide film is formed in one direction along the surface. 0.3% from the latter dimension
By shrinking in the range of 6% or less, the average height difference between the concavities and convexities adjacent to the shrinking surface is 0.4 μm or more and 5
It is characterized in that fine unevenness having an average height difference of 0.01 μm or less and an average interval between adjacent convexities of 0.01 or more and 0.2 or less is formed. The average height difference between the adjacent irregularities, the average height difference between the adjacent irregularities / the average interval between the adjacent convex portions is such that one side is substantially parallel to the concave portion or the convex portion on the surface on which fine irregularities are formed ( (Corresponding to the direction orthogonal to the shrinking direction of the glass surface), the height difference between adjacent irregularities and the interval between adjacent convex portions are measured for a square portion of 1 cm ² arbitrarily selected so that the measured value is The average value calculated by using.

[0008]

The glass having a light-scattering effect according to the present invention exhibits light-scattering characteristics having the following three features, which are different from those of conventional frosted glass, due to the fine irregularities on the surface and the metal oxide film. One is that, unlike the conventional frost processing, it has an unprecedented design property that has both light scattering properties and subtle gloss. The second is that the light scattering property can be adjusted in a wide range by changing the average height difference of the unevenness and the average height difference of the unevenness / the average interval between the adjacent convex portions within a predetermined range. The other is that by changing the thickness of the metal oxide film within a predetermined range, it is possible to impart a brilliance with high designability.

The glass used in the present invention is not particularly limited. Further, the material of the metal oxide film on the glass surface should be determined from the compatibility with the glass material used. SnO ₂ , TiO ₂ , Al ₂ O _{3 and the} like can be used alone or in combination. In particular, SnO ₂ is a particularly preferable material considering the ease of film formation. There is no particular limitation on the method for forming the metal oxide film, and CV
Both method D and sol-gel method can be used, but CV
Method D is preferable because it is superior in productivity. Conventionally, in the glass bottle industry, a hot end coating method has been adopted in which a high temperature glass bottle immediately after molding is reacted with organotin halide to form a tin oxide film. In the present invention, the method can be applied as it is.

The thickness of the metal oxide film on the glass surface is 3n.
m to 100 nm, preferably 5 to 50 nm. Generally, when the shrinkage rate after forming the metal oxide film is the same,
The light scattering effect tends to increase as the film thickness increases. However, when the film thickness is 50 nm or more, a large increase in the light scattering effect is not recognized, and in particular, the film thickness exceeding 100 nm is more economically disadvantageous. On the contrary, when the film thickness is less than 5 nm, a sufficient light scattering effect cannot be obtained unless the shrinkage rate after forming the metal oxide film is extremely large.
This is not preferable because it causes a large deformation of the molded glass.

In the present invention, when the average height difference between adjacent irregularities is less than 0.4 μm on the glass surface 1 cm ² arbitrarily selected as described above, or the average height difference between adjacent irregularities / between adjacent convex portions is small. If the average distance between the two is less than 0.01, a sufficient light-scattering effect cannot be obtained. Conversely, if the average height difference between adjacent irregularities exceeds 5 μm, or if the average height difference between adjacent irregularities / adjacent convex portions is When the average interval between the two exceeds 0.2, the light scattering effect is exhibited, but the delicate gloss is lost and the designability tends to be lost.

The unevenness is formed by shrinking the glass after forming the metal oxide film on the surface at a predetermined shrinkage ratio. The optimum value of the shrinkage ratio varies depending on the film thickness of the metal oxide film, but is 0.
It must be 3% or more and 6% or less. When the glass is bottle-shaped, the one direction along the surface refers to the vertical direction, or the direction substantially parallel to the circumference of the bottle. When the shrinkage ratio is less than 0.3%, the unevenness in the above range cannot be obtained, and it is difficult to obtain a sufficient light scattering property. On the other hand, when the shrinkage ratio exceeds 6%, although a sufficient light scattering effect is exhibited, it is accompanied by a large deformation due to the shrinkage, which makes it difficult to obtain a desired product size, which is not preferable. In addition, the correlation between the shrinkage ratio and the average height difference of the concavities and convexities adjacent to each other, which was measured on the glass having the SnO ₂ film with the film thickness of 8 to 29 nm provided on the surface, is shown in FIG.
FIG. 4 shows the correlation between the shrinkage ratio and the average height difference between the adjacent irregularities / the average interval between the adjacent convex portions.

The shrinkage of the glass after forming the metal oxide film is preferably performed by an appropriate temperature history. For example, a method such as heat shrinkage by cooling after forming a metal oxide film at high temperature, or a method of shrinking the glass by its own weight by reheat treatment is used. Especially the latter reheat treatment,
It is preferable in that the shrinkage ratio can be set freely. In the case of the reheating treatment, the heating temperature is preferably around the intermediate temperature between the softening point and the slow cooling point of the glass. Here, the softening point means that the viscosity of glass is 4.
The temperature is 5 × 10 ⁷ poise, and the annealing point is the temperature at which the viscosity of glass is 2.5 × 10 ¹³ poise.

Due to the shrinkage, concave portions and convex portions are alternately formed in a wavy shape along the shrinking direction on the glass surface, and the concave portions and the convex portions are formed so as to extend in a direction substantially perpendicular to the shrinking direction. In the case of shrinking by the reheating treatment, the height difference of the unevenness and the length of the convex portion tend to increase as the heating time increases.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited by the description of the following examples.

(Example 1) 0.3 ml of butyltrichlortin was poured into a stainless steel container having an internal capacity of 5 liter and containing a soda-lime glass bottle kept at 450 ° C.
After reacting at 450 ° C. for 30 minutes, it was gradually cooled. Then, after washing the powder (mainly NaCl) attached to the bottle,
When the SnO ₂ film formed on the outer surface of the glass bottle was measured using a hot end coating meter (AGR), the film thickness was 13 nm. Then, place this bottle in an electric furnace at 400 ° C and 63 at a rate of 10 ° C / min.
The temperature was raised to 0 ° C., and the temperature was maintained at 630 ° C. for 5 minutes, during which time it contracted in the height direction by its own weight and then gradually cooled. When the height of the glass bottle was measured after cooling to room temperature, it shrank by 1.4% as compared with that before heating (after forming the SnO ₂ film). The thickness of the SnO ₂ film existing on the outer surface of the bottle after shrinkage was measured and found to be 12 nm.

When the surface of the obtained bottle was visually observed, it exhibited a light scattering effect and had a delicate gloss.
When observing a part of the outer surface of the bottle with a scanning electron microscope, there were wavy fine irregularities in the height direction of the bottle,
The unevenness extends in a direction substantially parallel to the circumference of the bottle. FIG. 1 is a schematic view showing the surface of glass observed by the scanning electron microscope. In the figure, 1 and 1a are adjacent convex portions, 3 is a concave portion, and the arrow direction is the contracting direction. Note that the convex portion 1 and the concave portion 3 are in a relationship of concavity and convexity adjacent to each other.

A glass surface of 1 cm ² in which the height difference of the irregularities and the length of the convex portions are arbitrarily selected by using a diamond probe type surface roughness measuring device (manufactured by Karl Marl)
The average height difference between adjacent irregularities was 0.67 μm, and the average spacing between adjacent convex portions was 12.1 μm.
m, the average height difference between the adjacent irregularities / the average interval between the adjacent convex portions was 0.055. FIG. 2 schematically shows a part of the chart measured by the diamond probe type surface roughness measuring device. This figure is the result of measurement in the shrinking direction, that is, the height direction of the bottle. The vertical axis represents height and the horizontal axis represents the distance in the height direction of the glass surface. The shape, glass composition, softening point and annealing point of the soda lime glass bottle used are shown in the following table.

[0019]

Comparative Example 1 A glass bottle having the same shape and composition as that used in Example 1 was subjected to S in the same manner on the outer surface thereof.
An nO ₂ film was formed. The film thickness was 12 nm. Then, Example 1 is repeated except that the holding time at 630 ° C. is set to 1 minute.
This bottle was heat-treated and gradually cooled in the same manner as in, and contracted in the height direction by its own weight. After cooling to room temperature, the height of the bottle was measured, and it was found to shrink by 0.6% as compared with that before heating. After washing, the thickness of the SnO ₂ film on the outer surface of the bottle was measured and found to be 11 nm.

The light scattering effect of this bottle was worse than that of Example 1. Further, when the surface roughness was measured by the same method as in Example 1, the average height difference between the adjacent irregularities was 0.33 μm.
m, the average interval between the adjacent convex portions is 8.8 μm, the average height difference between the adjacent irregularities / the average interval between the adjacent convex portions is 0.0
38 wavy irregularities were formed.

Comparative Example 2 A glass bottle having the same shape and composition as that used in Example 1 was subjected to S by the same method on the outer surface thereof.
An nO ₂ film was formed. The film thickness was 11 nm. Then, this bottle was heat-treated and gradually cooled in the same manner as in Example 1 except that the holding temperature was 620 ° C. and the holding time was 1 minute, during which the bottle was shrunk in the height direction. When the height of the bottle was measured after cooling to room temperature, it was 0.
It had shrunk by 13%. After washing, the film thickness of the SnO ₂ film on the outer surface of the bottle was measured and found to be 11 nm. This bottle showed almost no light scattering effect. When the roughness of the outer surface of the bottle was measured by the same method as in Example 1, the average height difference between the adjacent irregularities was 0.13 μm, the average interval between the adjacent convex portions was 6.5 μm, and the average height of the adjacent irregularities was high. Differences / concavities and convexities having an average spacing between adjacent convex portions of 0.020 were present.

(Comparative Example 3) A bottle having the same shape and composition as those used in Example 1 was heat-treated in the same manner as in Example 1 without coating, and then gradually cooled to room temperature. After shrinking in the height direction, the height of the bottle was measured, and it was found to shrink 1.5% compared to before heating. When this bottle was observed after washing, no light scattering effect was observed. Also, when the surface roughness of the outer surface of the bottle was measured,
On its surface, the average height difference between adjacent irregularities is 0.5 μm,
The average interval between the adjacent convex portions is 310 μm, the average height difference between the adjacent irregularities / the average interval between the adjacent convex portions is 0.002.
The surface was almost smooth.

COMPARATIVE EXAMPLE 4 A glass bottle having the same shape and composition as used in Example 1 was subjected to S in the same manner on the outer surface thereof.
A nO ₂ film was formed and the bottle was annealed without reheat treatment. The film thickness was 11 nm. No light scattering effect was observed on the washed bottle. As a result of measuring the surface roughness of the outer surface of the bottle, the average height difference between adjacent irregularities is 0.2,
The average spacing between the adjacent convex portions was 86 μm, and the average height difference between the adjacent irregularities / the average spacing between the adjacent convex portions was 0.002, which was a substantially smooth surface.

[0025]

As described above, according to the present invention, it is possible to obtain a glass having a light-scattering effect which has an unprecedented design and is excellent in design. Moreover, since the light-scattering glass according to the present invention is coated with a metal oxide film, the glass itself has a feature that the glass itself is unlikely to be scratched and the strength is less likely to decrease. Therefore, by applying the present invention to a glass bottle, it is possible to manufacture a highly recyclable bottle that can withstand repeated use. Further, according to the production method of the present invention, continuous production is also easy, and since no chemicals such as hydrofluoric acid that are extremely harmful to the human body are used during the production process, it can be produced industrially advantageously. it can.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a surface state of glass having a light scattering effect according to the present invention.

FIG. 2 is a diagram showing an outline of a diamond probe type surface roughness measurement chart of glass having a light scattering effect shown in Example 1.

FIG. 3 shows the correlation between the shrinkage rate and the average height difference between adjacent irregularities.

FIG. 4 shows the correlation between the shrinkage ratio and the average height difference between adjacent projections / recesses / the average spacing between adjacent projections.

[Explanation of symbols]

1 convex part 3 recess

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-85773 (JP, A) Actual development Sho 62-170733 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) C03C 17/00-17/34

Claims (2)

(57) [Claims] 1. A metal oxide film having a film thickness of 3 nm or more and 100 nm or less on the surface, and an average height difference between adjacent irregularities of 0.4 μm or more and 5 μm or less, an average height difference between adjacent irregularities / between adjacent convex portions. A glass having a light-scattering effect, which has fine irregularities with an average interval of 0.01 or more and 0.2 or less on the surface. 2. A glass having a metal oxide film with a film thickness of 3 nm or more and 100 nm or less formed on the surface thereof in a range of 0.3% or more and 6% or less from the dimension after the metal oxide film is formed in one direction along the surface. The average height difference between the concavities and convexities on the contracted surface is 0.4 μm or more and 5 μm or less.
Hereinafter, a method for producing glass having a light-scattering effect, characterized in that fine irregularities having an average height difference between adjacent irregularities / an average interval between adjacent convex portions of 0.01 to 0.2 are formed.