JP2000133987A - Glass with electrically conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a single-plate glass having an electrically conductive film without degradation or deterioration of a conductive film, by coating a glass material thick film comprising low melting point glass the having the value higher than a specified value of film thickness on the surface of the glass having an electrically conductive film. SOLUTION: If glass having an ingredient similar to that of base glass is used as glass material thick film and it is baked at the temperature exceeding its softening point to fuse the glass, the temperature of the base glass exceeds the softening point and the glass is softened deformed too, and a metal film can also be oxidized and deteriorated. Accordingly, low melting point glass having the softening point of 600 deg.C is suitable for use. A glass frit in which a particle diameter is 20 μm or lower is used, it is dispersed in a polymer solution to knead paste, and the paste is applied on a glass plate covered with a conductive film by a means such as a flow coat method or screen printing or the like so as to form a film having thickness of 2 μm after baking. Then, after drying, it is baked at a temperature higher than the softening point of the low melting point glass and lower than the softening point of a glass plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass sheet provided with a conductive film such as a metal film, such as a low-E glass (a glass with a low radiation film) and an electromagnetic shielding glass, and relates to a building, a vehicle, and the like.
The present invention relates to a glass with a transparent conductive film used as a window material or a partition material of a transport machine or the like.

[0002]

2. Description of the Related Art Glass plates coated with a conductive film including a metal film, such as low-E glass and electromagnetic shielding glass, have been widely used as window materials for buildings, vehicles, and transport equipment. I have. The conductive film is usually formed into two or more multilayer thin films by a PVD method such as a sputtering method or a CVD method,
The top layer is metal oxide, metal nitride, metal carbide,
A metal compound film such as a metal nitrogen oxide is provided, which is designed to prevent the metal film from coming into contact with moisture and harmful components in the atmosphere, and to prevent deterioration and deterioration thereof. However, according to the film forming means, it is difficult to form a thick film having a film thickness of more than 1 μm.

[0003] In order to eliminate the above-mentioned adverse effects, a glass plate with a conductive film is usually used as one glass plate and a double-layer glass structure with the other glass plate or a laminated glass structure. Place it inside. However, these multilayer glass structures and laminated glass structures are not
It takes time and effort to manufacture, and its cost is enormous. In addition, especially in the case of double glazing, the construction is also different from the case of single veneer, and the cost (for example, increasing the thickness (front and rear width) of the frame according to the thickness of the double glazing in advance, or applying a so-called attachment frame, further increases the cost). I do.

An object of the present invention is to provide a glass with a transparent conductive film, which solves the above-mentioned disadvantages and can be used without deteriorating or deteriorating the conductive film (metal film) even in a single plate. I do.

[0005]

According to the present invention, a plurality of thin film layers including a metal film are formed on at least one surface of a glass plate,
This is a glass with a conductive film in which a metal compound film is disposed on the outermost layer, and further a glassy thick film made of a low-melting glass having a film thickness of 2 μm or more is applied on the surface thereof.

In the above, it is desirable that the vitreous thick film is an antiglare thick film in which ceramic fine particles are dispersed in low melting point glass.

[0007] In one embodiment of the glass with a conductive film, a thick vitreous film is coated leaving a peripheral portion of the conductive film so that a conductive tape is adhered to the peripheral portion of the conductive film so as to conduct the conductive sash. It can also be used as an electromagnetic shielding glass.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a glass plate, although not specified, a soda-lime-silica-based glass or an alkali-magnesium-lime aluminosilicate-based glass which is inexpensive and mass-produced is suitable.

In the present invention, the thin film refers to a film having a thickness of about 100 nm or less, and the multilayer thin film refers to a film obtained by laminating two or more thin films. As the metal film, for example, a well-known conductive metal film such as gold, silver, copper, platinum, rhodium, palladium, aluminum, zinc, or an alloy thereof can be used. As the metal compound film, metal oxide, metal Nitrides, metal carbides, metal nitrogen oxides and the like, for example, silicon oxide, aluminum oxide, zinc oxide, titanium oxide, zirconium oxide,
Known metal compound films such as tin oxide, indium oxide, composite oxides thereof, silicon nitride, aluminum nitride, titanium nitride, and composite compounds such as silicon nitride oxide can be used.

Examples of the multilayer thin film include: G (glass) ＼silver film＼titanium oxide film G＼silver film＼aluminum-zinc alloy film＼aluminum oxide film G＼zinc oxide film＼silver film＼zinc film＼zinc oxide film珪 素 Silicon nitride film G＼Tin oxide film＼Silver film＼Aluminum-zinc alloy film＼Aluminum-zinc oxide film＼Zinc oxide film＼Silver film＼Aluminum-zinc alloy film＼Aluminum-zinc oxide film＼Zinc oxide film etc. However, not limited to these, there are various combinations.

As a vitreous thick film, ordinary glass has a softening point of 700 ° C. or higher. For example, a soda-lime-silica glass has a softening point of about 720 ° C., whereas a softening point of less than 600 ° C. It is preferable to use a low-melting glass having an expansion coefficient similar to that of the aforementioned substrate glass (approximately 70 to 90 × 10 ⁻⁷ / ° C.), and PbO widely used
Lead-free glass such as Bi ₂ O ₃ and ZnO can be used in addition to the low melting glass.

When a glass having a component composition similar to that of a substrate glass is used for a vitreous thick film, for example, when the glass is baked at a temperature higher than its softening point in order to fuse the glass,
The substrate glass may be softened and deformed beyond the softening point, and the metal film may sometimes be oxidized and deteriorated. Therefore softening point 6
A glass having a low melting point of not higher than 00 ° C. is preferred.

Of course, the low-melting glass is adopted in consideration of weather resistance and durability. For example, in the case of PbO-based glass, SiO _{2 is used.}
To _{10wt%, B 2 O 3 15~25wt%,} Al 2 O 3 10wt% or less, Z
Contains 5 to 15 wt% of nO5, 55 to 75 wt% of PbO, 5 wt% or less of divalent metal oxides such as CaO, MgO, SrO or BaO, and has a softening point.
Those having a thermal expansion coefficient of 500 to 590 ° C and a thermal expansion coefficient of 75 to 90 × 10 ^-7 / ° C can be recommended.

The low-melting glass frit has a particle size of about 20 μm or less, and is dispersed in a polymer solution to prepare a paste. Then, a known method such as flow coating, spin coating, brush coating, or screen printing is used. Means, apply on the glass plate provided with the conductive film so that the film thickness after baking becomes 2 μm or more, preferably 4 μm or more, and then, after drying, the softening point of the low melting point glass or more, Firing at a temperature below the softening point of the plate.

By setting the film thickness to 2 μm or more,
Deterioration of the conductive film, particularly the metal film, during long-term use can be suppressed. On the other hand, if it exceeds 20 μm, no further effect is exhibited, and therefore the upper limit should be 20 μm, preferably 10 μm.

In the case of using an electromagnetic shielding glass, a conductive film is formed on a glass plate, and then a width of a peripheral portion of the film surface of the glass plate is reduced.
About 10 mm is masked with an adhesive tape, a low melting glass frit is applied in the same manner as described above, and after drying, the adhesive tape is peeled off and baked.

It is to be noted that the material may be gradually cooled after firing, or it may be tempered by rapid cooling by air cooling or the like.

The vitreous thick film made of the low melting point glass may contain an inorganic filler such as silica (quartz), alumina (corundum), or zirconia (baddelite).
The weather resistance and durability are further improved by scattering fine powder of about 1 to 1 μm φ, and the surface roughness is thereby improved.
A light-scattering film having a thickness of about 0.1 μm to 1 μm or less can be provided. For example, it can provide antiglare properties and design properties by scattering incident sunlight. If ceria, titania (rutile, anatase) or zinc white is used as a filler, ultraviolet rays can be absorbed and its invasion can be suppressed. If chromium oxide, iron oxide, cobalt oxide, etc. are used, infrared rays can be absorbed and green, Blue, bronze, and other colors can be added to enhance the appearance. The amount of the filler mixed in the vitreous thick film is set to 10 wt% or more with respect to the total of 100 wt% of the filler and the glass in order to exhibit the above-mentioned effect.
The content is set to 30 wt% or less so as not to hinder the adhesion to the vitreous thick glass substrate (conductive film). In consideration of the above, the mixing ratio is set in advance when preparing the paste. Hereinafter, the present invention will be described in detail with reference to specific examples.

[0019]

[Example] A conductive film is formed on the entire surface of a clear soda-lime-silica-based float plate glass, and a low melting point glass frit (or 10% by weight of ceramic fine powder is further mixed in the frit) while leaving a peripheral width of about 10 mm. Is applied), dried, baked, gradually cooled,
Electromagnetic shielding glass having a glassy thick film made of low melting point glass was prepared.

[Formation of Conductive Film] The size is 350 mm × 250 mm (5 mm thick), the transmittance of visible light is common to each of the examples and comparative examples.
90% (haze value is almost 0%) was adopted, and seven conductive films were formed on one surface thereof by a sputtering method. The conductive film is, in order from the glass plate side, a zinc oxide film (thickness 30 nm), a silver film (thickness 40 nm), an aluminum-zinc film (thickness 5 nm), a zinc oxide film (thickness 30 nm), and a silver film (thickness 30 nm). Film thickness
40 nm), an aluminum-zinc film (thickness: 5 nm), and a zinc oxide film (thickness: 30 nm).

The surface resistance is 2.0 Ω / □ measured by a surface resistance measuring element of a four-hand hand,
The average electromagnetic shielding performance at 0.1 MHz to 20 GHz was −35 dB according to the measurement method according to STD 285, and the vertical emissivity was 0.03 according to the measurement method according to JIS R 3106.

In the unit 'dB' indicating the amplification or attenuation rate of the electromagnetic wave, + indicates amplification, and-indicates attenuation (shielding side). The higher the minus value, the higher the attenuation (shielding) performance. .

[Formation of Vitreous Thick Film] As a low melting glass frit, SiO ₂ —B ₂ O ₃ —PbO—
A ZnO-based glass with a softening point of 580 ° C and a coefficient of thermal expansion of about 70
An average particle size of × ¹⁰⁻⁷ / ° C. and an average particle size of 2 μm was employed.

For imparting antiglare properties, silica (quartz) and alumina (corundum) were prepared as ceramic fine powder to be mixed. Silica has an average particle size of 0.3 μm (silica A
), And average particle size 0.5μm (Silica B)
And alumina having an average particle diameter of 1 μm was used.

A low-melting glass frit or a mixture of a low-melting glass frit and a ceramic fine powder in a predetermined ratio is mixed into a paste stock solution comprising a cellulose polymer and an alcohol-based dispersion medium, and the mixture is sufficiently stirred and dispersed by a ball mill to prepare a paste. did.

After attaching an adhesive tape to the peripheral edge width of the conductive film of 10 mm, the paste is cast on the film surface, and the film thickness is adjusted in consideration of the film thickness at the time of baking by a bar coater. It was dried by heating at 150 ° C. for 10 minutes. After the tape was peeled off, it was placed in a baking furnace that was heated and programmed so that the temperature of the glass plate of the substrate was raised to 630 ° C., and was held at 630 ° C. for 10 minutes and then cooled to complete the electromagnetic shielding glass. Table 1 shows the conditions.

[Test Method] As for the optical characteristics of the electromagnetic shielding glass, the visible light transmittance and the haze value were determined based on JIS K 7105 (Test method for optical characteristics of plastics).

Further, based on MIL-STD 285, 0.1 MHz to 1
The electromagnetic shielding performance in GHz was measured, and the average electromagnetic shielding performance without the vitreous thick film was -35 dB. For fluctuations within 2dB, there is a 'slight' change,
For fluctuations beyond that, the change was evaluated as 'significant'.

Further, an accelerated weathering test for 3,000 hours was performed based on JIS A 1415, and those having no discoloration (deterioration or deterioration) of the film on the external appearance were evaluated as “no abnormality” = pass, and the others were rejected. .

The results are shown in Table 1. As is clear from the table, in Example 1 in which no filler was mixed, the visible light transmittance and the electromagnetic shielding performance were not inferior to Comparative Example 1 in which no vitreous thick film was adhered, and no abnormality was observed in the accelerated weathering test. Was. In Examples 2 to 4 in which a filler was mixed,
It can be seen that the haze value is high even though the visible light transmittance is not remarkably reduced, and the antiglare property is rich. In addition, the electromagnetic shielding performance is not inferior to Comparative Example 1, and no abnormality is observed in the accelerated weathering test as in Example 1.

In Comparative Example 2, the thickness of the vitreous thick film was insufficient, and discoloration was observed in a part of the conductive film in the accelerated weathering test. As for Example 2, the emissivity was measured based on JIS R 3106, which was 0.03, which was completely the same as the sample before forming the vitreous thick film (Comparative Example 1). In addition, the electromagnetic shielding performance hardly changed. From this tendency, it is inferred that there is no change in the emissivity in the other examples.

[Table 1] Conditions and measurement results Condition Result Example Low melting point glass layer Visible light Haze value Electromagnetic shielding Accelerated weathering Comparative example Film thickness Roughness Filler type Transmittance Performance test Weight ratio (change: (μm) (μm) (parts by weight) (%) (%) △ dB) Example 1 No filler 2-(Smooth) 88 5 Almost none No abnormality Example 2 Silica A 3 0.3 15 80 70 Almost none No abnormality Example 3 Silica B 3 0.5 15 78 80 Almost none No abnormality Example 4 Alumina 5 0.7 15 70 88 Almost none No abnormality Reference example 1 Only crow plate (5mm thick) 90 ---Comparative Example 1 Only conductive film on glass plate Mottled film Forming 70 0.2 Discolored to the reference state Comparative Example 2 No filler Film is on the periphery 0.7-(smooth) 90 1 Almost none Discoloration

[0033]

According to the present invention, since a thick vitreous film is applied, a conductive film (metal film) can be used without deterioration or deterioration even in a single plate. An effect of being able to impart antiglare properties, or further, ultraviolet blocking properties, coloring properties, and other functionalities can be obtained.

Claims (3)

[Claims] 1. A glass with a conductive film in which a plurality of thin film layers including a metal film are formed on at least one surface of a glass plate, and a metal compound film is disposed on the outermost layer. A glass with a conductive film, comprising a glassy thick film made of a low melting point glass. 2. The glass with a conductive film according to claim 1, wherein the vitreous thick film is an antiglare thick film in which ceramic particles are dispersed in low melting glass. 3. The glass with a conductive film according to claim 1, wherein the glass is a glass for electromagnetic shielding formed by applying a vitreous thick film while leaving a peripheral portion of the conductive film.