JPH02296752A - Production of anti-clouding glass - Google Patents

Abstract

PURPOSE:To improve anti-clouding property by forming an Si oxide layer on the surface of glass as a base material and calcining the Si oxide layer in an inert state. CONSTITUTION:An Si oxide layer as a single-layer film or a laminated film having an Si oxide layer as the top layer is formed on the surface of glass such as optical glass or plate glass, e.g. borosilicate crown glass, barium crown glass or lanthanum flint glass as a base material. The formed layer or film is then calcined at >=450 deg.C, preferably 500-1,000 deg.C for >=1min, preferably 30min-3 hr in an atmosphere of an inert gas such as N2 or Ar or in inorg. powder such as Al2O3 powder to obtain anti-clouding glass with a formed Si oxide coating film.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing anti-fog glass having excellent anti-fog properties over a long period of time.

(Prior Art) Generally, when the surface temperature of glass falls below the dew point, minute water droplets adhere to the glass surface, causing fogging. For example, in eyeglass lenses, goggles, car window glass, etc.
It is well known that cloudiness occurs when the surrounding temperature suddenly drops. If the glass fogs up, you won't be able to see what's ahead, which will not only make you feel uncomfortable, but may even lead to a serious accident.

For this reason, the following various techniques have been proposed for preventing glass from fogging, that is, for anti-fogging.

■Unexamined Japanese Patent Publication No. 55-154351 discloses that a thin film containing at least one of molybdenum oxide and tungsten oxide and phosphorus oxide is deposited on the surface of a glass substrate by physical vapor deposition.
A method of obtaining a hydrophilic thin film with excellent antifogging properties by forming it by chemical vapor deposition was proposed, and Japanese Patent Laid-Open No. 54-1051
No. 20 proposes a method of imparting antifogging properties to glass containing P2O by contacting it with liquid or vapor of P2O6; A method has been proposed in which an antifogging film with excellent adhesion is formed by applying a composition containing an activator and an inorganic salt or an acetate to a substrate using a lower alcohol solvent.

(Problems to be Solved by the Invention) In the method (2) above, since the thin film contains phosphorous oxide, there is a problem that the durability is poor, and the surface hardness of the film is also low.

In the method (2) above, P2O5 is easily eluted into water, resulting in poor water resistance.

The above method (2) has low film hardness and lacks long-term sustainability.

As described above, no anti-fog glass with excellent anti-fog properties and durability has been proposed so far.

The present invention has been made by focusing on such actual situation,
An object of the present invention is to provide a method for manufacturing anti-fog glass having excellent durability and anti-fog properties.

(Means for Solving the Problems) The method for producing an anti-fog glass of the present invention includes:
The method is characterized in that after forming the silicon oxide layer, the silicon oxide layer is fired under inert conditions, thereby achieving the above object.

Examples of the glass substrate used in the present invention include silicon crown, crown, flint, heavy flint, barium clan, heavy barium crown, barium flint, heavy barium flint, lanthanum flint, lanthanum crown, heavy lanthanum flint, etc. Examples include inorganic glasses such as optical glass and sheet glass. These optical glasses and sheet glasses are widely used as optical materials for lenses, prisms, etc., and as window glasses.

Methods for forming the silicon oxide layer on the surface of the glass substrate include a sol-gel method, a vacuum evaporation method, and a sputtering method.
Examples include the blowfish method, the CVl method, and the Metsuki method, and the true gel method, which can produce a large amount of hydroxyl groups, which are hydrophilic groups, is particularly preferred. The thickness of the silicon oxide layer may be determined as appropriate depending on the application.

The silicon oxide layer formed on the surface of the glass substrate may be a laminated film of various materials or a single layer film, but
It is essential that at least the top layer contains silicon oxide.

At least the silicon oxide layer of the glass substrate whose surface is thus coated with the silicon oxide layer is fired under an inert condition. Under an inert state means an atmosphere of an inert gas such as nitrogen or argon, or a state buried in inorganic powder. Examples of inorganic powder include Al2O,
Examples include powders such as ZrO2 that have been enlarged and classified to 150 μm or less. The firing conditions vary depending on the type and size of the glass substrate, but are preferably 450°C or higher, more preferably 500°C to 200°C. The firing time is generally preferably 1 minute or more, more preferably 3 minutes.
It is 0 minutes to 3 hours.

If the firing is insufficient, the antifogging property will be reduced.

The surface of the anti-fog glass thus obtained exhibits excellent anti-fog properties. The reason for this has not yet been elucidated, but some of the oxygen atoms that make up the siloxane bonds and silanol bonds on the thin film surface are ruptured and reduced, resulting in an oxygen-deficient state (
This is thought to be because the surface became more active due to silicon's electron-donating properties.

The anti-fog glass of the present invention has excellent durability and water resistance, as well as high film hardness, since the thin film does not contain phosphorus oxides as in the conventional glass.

(Example) The present invention will be specifically described below based on Examples.

A hydrolysis solution was prepared by mixing an ethanol solution of Tetraethylsilicate (manufactured by Colcourt), water, and hydrochloric acid as a catalyst. After coating the surface of borosilicate glass (manufactured by Matsunami) with this solution as a glass base material, 1
Dry in the sun. The obtained silicon oxide layer coated glass is
A film of silicon oxide (SiO□) was formed by heat treatment at 500° C. for 1 hour in a nitrogen gas atmosphere to obtain antifogging glass. The thickness of the film was approximately 0.2 μm.

Further, the pencil hardness of the film was measured according to JIS K 5400 and was found to be 8+1.

Next, the anti-fog properties of this anti-fog glass were evaluated. Anti-fog properties were evaluated on the droplet contact angle of anti-fog glass, anti-fogging properties at high temperatures and anti-fogging properties at low temperatures according to JISS4030. In addition, durability was evaluated by anti-fogging properties (water resistance) after being immersed in distilled water for one month, and anti-fogging properties (moisture resistance) after being left in 60°C and 90% R1+ for one month. Table 1 shows the results.
It was shown to.

The coated glass obtained in the same manner as in Example 1 was
It was buried in Al2O3 powder which had been enlarged and classified to micrometers or less, and heat treated in the atmosphere at 550°C for 30 minutes to form a film of silicon oxide (5f02) to obtain antifogging glass. The thickness of the film was approximately 0.2 μm. Also, Example 1
When the pencil hardness was measured in the same manner as above, it was 8H.

The anti-fog properties and durability of the obtained anti-fog glass were evaluated in the same manner as in Example 1. The results are shown in Table 1.

The coated glass obtained in the same manner as in Example 1 was placed in the atmosphere for 5 minutes.
A film of silicon oxide (Si02) was formed by heat treatment at 00°C for 1 hour to obtain antifogging glass. The thickness of the film was approximately 0.2 μm.

The antifogging properties and durability of the obtained heatproof glass were evaluated in the same manner as in Example 1. The results are shown in Table 1.

The coated glass obtained in the same manner as in Example 1 was used in Example 2.
Similarly, it was buried in Al2O3 powder which had been enlarged and classified to 150 μm or less and heat treated at 400°C for 30 minutes in the atmosphere to form a film of silicon oxide (5i02) to obtain anti-fog glass. The thickness of the film was approximately 0.2 μm.

The anti-fog properties and durability of the obtained anti-fog glass were evaluated in the same manner as in Example 1. The results are shown in Table 1.

A commercially available anti-fog coating agent (manufactured by Matsumoto Yushi Co., Ltd.) was applied to the surface of borosilicate glass and dried, and the anti-fog properties of this glass were evaluated in the same manner as in Example 1. The results are shown in Table 1. In addition, when the pencil hardness was measured in the same manner as in Example 1, it was 2B.0 From the results in Table 1, the commercially available anti-fog coating agent (Comparative Example 3) had an initial anti-fog property. It's good, but I can see that it lacks durability. On the other hand, the anti-fog glasses of Examples 1 and 2 have excellent anti-fog properties both at the initial stage and after one month.

It is thought that the antifogging glass of Comparative Example 2 did not have the same antifogging properties as above because the silicon oxide was insufficiently fired.

(Effects of the Invention) In the present invention, after forming a silicon oxide layer on the surface of a glass substrate, the silicon oxide layer is fired under an inert state, so that excellent antifogging properties can be maintained for a long period of time. able to demonstrate. Therefore, if this anti-fog glass is applied to, for example, eyeglass lenses, goggles, car window glasses, etc., fogging will not easily occur even when the surrounding temperature changes, making it comfortable to use and increasing safety. .

that's all Applicant: Sekisui Chemical Co., Ltd. Representative Hiroshi 1) Kaoru

Claims (1)

[Claims] 1. A method for producing antifogging glass, which comprises forming a silicon oxide layer on the surface of a glass substrate and then firing the silicon oxide layer under an inert condition.