JPS6131329A - Matt glass plate and its production - Google Patents

Abstract

PURPOSE:To produce the titled glass plate having low reflection factor and giving moderate perspective image by allowing a glass plate having an uneven surface prepd. by etching the surface to contact with fluorosilicic acid soln. contg. supersatd. silicon oxide. CONSTITUTION:A glass plate 9 having an uneven surface of 30-60 glossiness of the surface is obtd. by etching the surface by dipping the glass plate 9 in an etching liquid. Then, the glass plate 9 is put in an internal vessel 2 housed in an external vessel 1 contg. water 3 held at a fixed temp. by a heater 4, wherein the glass plate 9 is allowed to contact with 1-2mol concn. fluorosilicic acid soln. contg. supersatd. silicon oxide prepd. by adding 1X10<-2>-40X10<-2>mol boric acid 12 per 1mol fluorosilicic acid, to form silicon oxide film having 400-1,400Angstrom or 2,200-3,000Angstrom thickness on the surface of the glass plate 9. >=3% basing on the whole amt. of the fluorosilic acid soln. is taken out of the rear side 8 of the internal vessel 2 and passed through a filter 11 having <=1.5mum pore size, and circulated from the front side 6 to the inside 7 of the internal vessel 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a frosted glass plate and a method for manufacturing the same.
In particular, the present invention relates to a low-reflectance matte glass plate suitable as a front glass panel of a display device such as a cathode ray tube or an instrument, and a method of manufacturing the same.

[Conventional technology]

Conventionally, as the front glass panel of the display device, a glass plate provided with a multilayer reflective film or a glass plate matted by a physical and/or chemical method has been used.

[Problem that the invention seeks to solve]

However, since the multilayer reflective film described above is created using a vapor phase method, it requires a large number of steps, making it extremely expensive, large in shape, and uniform on substrates with curvature. There were problems such as difficulty in obtaining a suitable film.

Furthermore, glass plates that have been matted by physical and/or chemical methods have the disadvantage that when attempts are made to sufficiently reduce specular reflection, the perspective image deteriorates.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a glass plate having an uneven shape on at least one surface thereof, and provides at least 400 to 1100 ounces of dust r+ -m or G
:lk A matte glass plate provided with a silicon oxide coating having a thickness of 2200 to 3000 angstroms is provided.

In particular, the glossiness of the uneven surface of the glass plate, G5C600
)tt JIS, ZJ74(/ (/962) K
In order to obtain a glass panel with a good perspective image and less specular reflection, it is preferable to set it to 30 to 10j% (measured by Motosuki).

The silicon oxide film that acts as an anti-reflection film on the uneven surface has a thickness of 400 ANGSTROM A.
Also ha 2200~-? The coating is 0.000 angstroms thick, and preferably has a uniform thickness. Films with a thickness of less than 100 angstroms and films with a thickness of <2200 angstroms less than /1I00 angstroms have low antireflection effects.

Further, if the coating is thicker than 3000 angstroms, the productivity of the coating is poor and the coating becomes expensive.

The glass plate used in the present invention may be a commercially available glass plate or any other glass plate other than silica glass, and may be a glass having a curvature in shape. To create irregularities on the surface of the glass plate, conventional methods can be used, such as chemical etching using an etchant made of hydrofluoric acid, ammonium heptafluoride, etc., or etching after sandblasting. .

A method for uniformly forming the surface of a glass plate having an uneven shape while controlling its thickness is a method in which the base material is brought into contact with hydrosilicofluoric acid in a supersaturated state of silicon oxide (abbreviated as precipitation method). .

Here, the supersaturated hydrosilicofluoric acid solution of silicon oxide used in the present invention (hereinafter abbreviated as treatment liquid) refers to a solution containing silicon oxide (silica gel, aerogel, silica glass, other oxidized After dissolving a silicon-containing substance (such as a silicon-containing substance), water or a reagent (boric acid, aluminum chloride, etc.) is added to bring the silicon oxide into a supersaturated state.

The concentration of hydrosilicic acid in the treatment liquid to be brought into contact with the glass plate having an uneven shape is preferably /-2 mol/l;
Among them, a solution in which silicon oxide is saturated in a hydrosilicic acid aqueous solution having a concentration higher than λ mol/l and then diluted with water to a concentration of 1-λ mol/l has a fast film formation rate and can form a film efficiently. 0 When adding a reagent to achieve a supersaturated state, it is preferable to use boric acid as the reagent because it is easy to handle. The amount of acid added must be in the range of /X10-2 to IIo x 1o-2 mol per 1 mol of hydrosilicofluoric acid in the treatment solution, especially /, 2 x l0-2 to 20 ×
10-2 mol is preferred in order to quickly obtain a homogeneous coating.

The method of bringing the treatment liquid into contact with the glass plate having an uneven shape may be a contact method such as flowing the treatment liquid down on the surface of the glass plate, but the glass plate is placed in an immersion bath filled with the treatment liquid. The method of dipping the plate is preferred because it is simple and provides a uniform coating.

In addition, the processing liquid is a processing liquid in which (a) an aqueous boric acid solution is continuously added and mixed even during contact with the glass plate, and (b) a treatment of 3% or more of the total amount of the processing liquid per 7 minutes. This is a processing liquid in which the liquid is filtered and returned.

It is preferable.

Here, it is preferable to continuously add and mix the boric acid aqueous solution during the contact period in order to improve the film formation rate, and to circulate the entire treatment solution of 3% or more in order to continuously obtain a homogeneous film. preferable. In addition, filtering the treatment liquid with a filter is preferred in order to obtain a film with a uniform thickness without unevenness on the silicon oxide film itself, and is usually used as a source of silicon oxide to dissolve and saturate silicon oxide in hydrosilicofluoric acid. When using silica gel, a filter with a pore size of 1.5 μm or less is used, and when using other materials such as silica glass, a filter with a pore size of 7 μm or less is used.
A filter with a diameter of 0 μm or less is preferred.

In addition, when the treatment liquid is placed in an immersion tank and brought into contact with the glass plate, it is necessary to allow the treatment liquid to flow in a laminar flow on the surface of the glass plate during immersion to obtain an even and homogeneous coating. preferred for.

Further, the frosted glass of the present invention has an uneven surface on at least one side of the glass piece, and a silicon oxide coating is provided on at least the uneven surface. It is also possible to provide an uneven shape on both surfaces, and this effect is exhibited as long as an uneven surface and a silicon oxide film covering the uneven shape are present on at least one surface. Among these, it is preferable to provide a glass plate screen with an uneven shape and a silicon oxide coating because it reduces specular reflection. Further, the uneven shape and silicon oxide coating need not be applied to the entire surface of the glass plate, but may be applied to seven portions of the glass plate required for fluoroscopy, etc.

[For production]

According to the present invention, there is provided a frosted glass that simultaneously has the effect of scattering incident light due to the unevenness of the glass plate surface and the effect of reducing reflected light due to the antireflection film. Furthermore, by controlling the contact time between the glass plate and the treatment liquid, a uniform silicon oxide film of any thickness can be deposited and formed on the glass plate.

〔Example〕

Prepare a heat-absorbing glass plate (manufactured by Nippon Sheet Glass ■, product name: Gray Vane) with a length of 10 mm, a width of 100 mm, and a thickness of 3 mm. Half of the glass plate was mixed with 100 g of ammonium heptafluoride, 5 mL of concentrated acid, and 1. 10g aluminum sulfate
When immersed in an etching solution consisting of 100 ml of 1 water and measuring the glossiness and GS (4'°) of both surfaces of the glass plate based on JIS, Z74'/(1962), it was approximately S.
Etching treatment was performed on the uneven surface to give O (%).

The remaining 4' glass plates were thoroughly washed and dried, and then a 10 mm wide masking tape (C, manufactured by Sumitomo 3M Co., Ltd., Sufunochitabe A Q7/) was applied diagonally to one surface of the glass plates.

A silicon oxide film was formed on both surfaces of the glass plate subjected to the above pretreatment using a silicon oxide film manufacturing apparatus shown in FIG.

In FIG. 1, the immersion tank consists of an outer tank (1) and an inner layer (, 2), and water (3) is filled between the inner layer and the outer layer. This water is heated with a heater (4'L) to bring the temperature to 35"C, and is stirred with a stirrer (J) to make the temperature distribution uniform. The inner tank has two parts: a front part (6) and a middle part (7 ), rear fIr
In each part, an aqueous solution of hydrosilicofluoric acid with a concentration of 2.0 mol/l, in which silicon oxide was dissolved and saturated using industrial silica gel powder as a source of silicon oxide, was diluted twice with water. The reaction solution of No. 31 is full. First, the circulation pump (10) is activated to pump out a certain amount of the reaction liquid from the inner tank rear part) and filter it with a filter (l/).
The circulation of the processing liquid was started.

Thereafter, a 0.5 mol/l boric acid aqueous solution (12) was continuously dropped into the rear part of the inner tank and maintained for 70 hours.

In this state, the reaction solution became a treatment solution having an appropriate degree of 5i02 supersaturation.

Here, the absolute removal rate of the filter (/l) was adjusted to 8 sttm and the total circulation of the treatment liquid was adjusted to 2110 ml and 11 minutes (since the total amount of treatment liquid was about 31, the circulation amount was 5% and 7 minutes).

Then, the glass plate (wa) subjected to the surface roughening treatment and masking treatment was immersed vertically in the middle of the inner tank (71K), and under the conditions described above (a 0.5 mol/l boric acid aqueous solution was added at a rate of 2 ml/min, The mixture was circulated for 7 minutes and filtered through an 8 S μm filter.

Then, every 2 hours after immersion, 1 glass plate with surface roughness treatment and 1 glass plate with masking treatment.
Each piece was taken out, washed and dried. In this way, 21 types of samples were created, ranging from a sample soaked for 2 hours to a sample soaked for 2 g hours.

An adherent film was deposited on the surface of each sample, and this adhered film part was analyzed using ESCA (R: 1electron 5pectron
Scopyfor Chemical Analysis
As a result of analysis using s), it was found that most of the components consisted of 8102.

Also, the frosted glass plate sample obtained here/4' type (
A glass plate with a silicon oxide film formed after surface roughening treatment)! The total reflectance for light of j Onm was measured using an integrating sphere method. Furthermore, the masking tape on the masked glass plate was removed, and the level difference between the masked area and the non-masked area was measured. Assuming that the thickness of the silicon oxide film formed on the frosted glass plate is the same as the thickness of the silicon oxide film on the masked glass sampled at the same time, and finding the relationship between the film thickness and total reflectance, The curve was approximately as shown in FIG.

where qoo-rsoo angstrom or 2≦00
+: It can be seen that a matte glass plate with low reflectance was obtained when a film was formed in the range of QOO angstroms.

Also, a matte glass plate soaked for 6 hours (silicon oxide coating is approximately 9
00 angstrom thickness), the glossiness and GS (60°) were approximately 30 (%).

〔Effect of the invention〕

According to the present invention, a frosted glass plate having an appropriate reflectance and an appropriate perspective image can be obtained. Further, according to the manufacturing method of the present invention, a glass plate having a large area, curvature, or unevenness can be frosted, and the number of steps and labor required can be simplified, so that an inexpensive frosted glass plate can be provided.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a circulating silicon oxide film manufacturing apparatus used in an example of the present invention, and Fig. 2 is a diagram showing the relationship between the thickness and reflectance of a silicon oxide film formed on an uneven surface. be. (1) Outer tank (2) Inner tank (3) Water (4')
Heater (, tl Stirrer (6) Inner tank front (7)
Middle part of the inner tank (r) Rear part of the inner tank (ri) Glass plate (10) Circulation pump (//) Filter (l
h) Boric acid aqueous solution Figure 1

Claims (5)

[Claims] (1) A frosted glass plate having a silicon oxide coating having a thickness of 400 to 1400 angstroms or 2200 to 3000 angstroms on at least the uneven surface of a glass plate having an uneven shape on at least one surface. (2) Glossiness of the uneven surface of the glass plate, GS (6
0°) is 30 to 60. The frosted glass plate according to claim 1. (3) After etching the surface of the glass plate with an etchant to form a glass plate having an uneven surface, the glass plate is brought into contact with a supersaturated hydrosilicofluoric acid solution of silicon oxide to at least give the uneven shape. A method for manufacturing a frosted glass plate, which comprises forming a silicon oxide film with a thickness of 400 to 1400 angstroms or 2200 to 3000 angstroms on the side surface. (4) The silicofluoric acid solution in a supersaturated state of silicon oxide is a treatment solution in which boric acid is added to a silicofluoric acid aqueous solution in which silicon oxide is dissolved to make the silicon oxide in a supersaturated state, and the treatment (a) The solution is a processing solution in which an aqueous boric acid solution is continuously added and mixed even during contact with the glass plate, and (b) 3% or more of the total amount of the processing solution is added per minute. 4. The method for producing a frosted glass plate according to claim 3, wherein the treatment liquid is filtered through a filter and returned. (5) The concentration of hydrosilicofluoric acid in the treatment liquid is 1 to 2 mol/
l, and the amount of boric acid added is 1 x 10^-^2 to 40 x 10^-^2 per 1 mole of hydrosilicic acid in the treatment liquid.
5. The method for producing a frosted glass plate according to claim 4, wherein the filter has a pore diameter of 1.5 μm or less.