JP2000226235A - Low-emissivity glass and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To scarcely change a color tone at a viewing angle without reddening color when viewed from an oblique direction, remarkably improve the moisture resistance of a film, reduce the resistance of the film and impart excellent heat insulating characteristics by providing a low-emissivity glass having a specific value or above of the density of an Ag layer by a sputtering method. SOLUTION: This glass is obtained by regulating the density of an Ag layer to >=8.5 g/cm3. When a low-emissivity film is formed by a sputtering method, the film is obtained by installing a freezing coil for adsorbing steam or various kinds of gases by a cold trap method near an Ag target, regulating the surface temperature of the freezing coil to -120 to -140 deg.C, locally keeping the periphery of the target in a high vacuum state and forming the Ag layer on the glass surface. The glass is preferably composed of a glass/transparent oxide or a nitride layer having 10-50 nm thickness/Ag layer having 8-50 nm thickness/metal barrier layer having <=8.0 nm thickness/transparent oxide or nitride layer having 70-150 nm thickness/Ag layer having 8-50 nm thickness/metal barrier layer having <=8.0 nm thickness/transparent oxide or nitride layer having 10-50 nm thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low emissivity glass useful as a window glass for a vehicle as well as a building, such as a house or an office, and also as various glass articles such as a window glass for a ship or an aircraft.

[0002]

2. Description of the Related Art Recently, for example, in offices and houses, low-emissivity glass having excellent heat insulating properties, heat retaining properties and heat shielding properties has been used mainly in cold regions. This glass is 2
In a double-glazing unit configured by sealing dry air between sheets of glass, a so-called low-emission film, which transmits visible light but reflects infrared light on the intermediate air layer side, is coated on the glass. The main component of these coatings is that Ag is used as a metal layer, and the upper and lower layers of the Ag layer are formed of ZnO or Sn.
It is coated with a non-metallic layer such as O ₂ are generally known.
Among them, as a film having a particularly low emissivity, an Ag layer is generally provided in two layers, and ZnO ₂ , SnO ₂ , TiO ₂ , ITO, Si
_A laminate of transparent oxides such as 2N ₃ and AI ₂ N ₃ , for example, a low-emissivity glass having a high transmittance with a silver layer having a thickness of 110 ° or less and a visible light transmittance of 70% or more. The metal oxide layer is composed of one or both of tin oxide and zinc oxide, the thickness of the third metal oxide layer is 65 to 80 nm, and the thickness of the second silver layer is Japanese Patent Application Laid-Open No. H8-104547, in which the thickness of the fourth metal oxide layer is more than 11 nm and not more than 14 nm.

[0003] Conventionally, it has been generally practiced to combine a mechanical pump, an oil diffusion pump, and a turbo-molecular pump to make the pressure in the entire vacuum chamber high.

[0004]

The low-emissivity glass in which the Ag layer and the transparent oxide layer are laminated can have a high transmittance and a high heat insulating performance. Various changes in the reflection color tone have resulted in very high requirements for the mounting angle of the glass. In addition, when it is attached to a building or the like, if the angle at which a person looks at the glass surface becomes 45 degrees or more, the reflection color becomes very dark, such as red, which is very problematic in appearance quality. As a method of making red less noticeable when the glass surface is viewed obliquely, a method of changing the color from the front to green, which is a complementary color of red, to reduce the color when viewed obliquely, and the like are taken. However, this method is not a fundamental solution because the reflectance from the front is high and the color tone is not neutral.

Further, the conventional low-emissivity glass provided with an Ag layer is liable to cause clouding defects due to oxidation of the Ag film when left in the air. Is necessary.

[0006] Further, the equipment that combines a mechanical pump, an oil diffusion pump, and a turbo molecular pump used in a conventional sputtering apparatus is for increasing the pressure of the entire vacuum chamber to a high vacuum. It is difficult to achieve a high vacuum state in combination with other high-performance pumps (cryopumps or ion pumps), especially when gases are introduced from outside the system with glass, carriers, etc., and gas is desorbed. Had little effect on water vapor and the like which required a long time.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and as a result of intensive studies,
The cryo coil cooling device by the cold trap method is installed near the Ag target in the sputtering device,
By constantly controlling and maintaining the atmosphere around the coil in a clean vacuum state, the Ag film sputter-deposited in this state has very little impurities, and is densely and regularly laminated. The low-emissivity glass using the Ag film has a small change in color tone depending on the viewing angle, the color of the front does not become red even when the front color is neutral, and the moisture resistance is significantly improved compared to the conventional film. It was found that the resistance was low and the heat insulating property was excellent.

That is, according to the present invention, at least one Ag layer is formed.
The present invention relates to a low-emissivity glass obtained by a sputtering method having a layer, wherein the Ag layer has a density of 8.5 g / cm ³ or more.

The low emissivity glass of the present invention is a glass
/ First layer made of transparent oxide or nitride / second layer made of Ag / third layer made of metal barrier / fourth layer made of transparent oxide or nitride / fifth layer made of Ag / metal barrier The first layer has a thickness of 10 to 50 nm, and the second and fifth layers have a thickness of 8 n.
Preferably, the thickness of the third layer and the sixth layer is 8.0 nm or less, the thickness of the fourth layer is 70 to 150 nm, and the thickness of the seventh layer is 10 to 50 nm.

Further, in the L *, a *, b * color system,
The specular color at an incident angle of 8 ° is a * (8 degrees) and the a * (45 degrees) of specularly reflected light at 45 degrees has the following relationship: a * (8 degrees) −a * (45 degrees) )>-2.0 The glass surface reflection characteristic value of the low-emissivity film preferably has the following relationship.

When the incident angle is 8 °; reflectance = 4 to 15
(%) A * (8 degrees) = 0 to -10 at an incident angle of 45 °; reflectance = 4 to 15 (%) a *
(45 degrees) = 2 to -15 Further, it is preferable that the visible light transmittance is 65% to 85% and the surface resistance is 6.0 Ω / □ or less.

Further, the present invention provides a method for forming a low-emission film by sputtering, wherein a refrigeration coil for adsorbing water vapor and various gases by a cold trap method is provided near an Ag target, and the surface temperature of the refrigeration coil is controlled. From -120 to
A method for producing a low-emissivity glass, characterized in that the target is kept at a high vacuum locally at -140 ° C. to form an Ag layer on the glass surface. Also,
The density of Ag is preferably 8.5 g / cm ³ or more.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, when a film is formed by a sputtering method, water vapor brought into a vacuum chamber by an inner wall of a chamber, glass, a carrier for conveying glass, or oil flowing backward from an oil diffusion pump is used. Alternatively, impurities contained in a process gas such as oxygen, argon, or nitrogen during film formation are removed to prevent these gases from being mixed into a film formed.

According to the present invention, in order to prevent water vapor, oil, impurities and the like from being mixed in the formed film, the film is placed on a carrier in a vacuum chamber for coating an Ag layer as shown in FIG. A refrigeration coil is provided immediately below the glass substrate to be conveyed, a high voltage is applied between the Ag target and the anode, and when silver particles are sputtered on the glass substrate, the gas such as water vapor, oil, gas impurities, etc. It is adsorbed by a refrigeration coil by the cold trap method. It is particularly preferable that the surface temperature of the refrigeration coil be -120 to -140 ° C and the degree of vacuum around the Ag target be 10 ^-4 Pa or less in order to remove these gases. The refrigeration coil is formed by arranging a coil (refrigerant flowing in the coil) piped to the refrigerator on the lower surface of a glass plate conveyed through the Ag film forming chamber in a planar manner over the width of the glass. Is preferred. Further, the arrangement of the target, glass, anode electrode, refrigeration coil and the like is not particularly limited. In particular, regarding the disposition of the refrigeration coil, if it is a place where impurities such as water vapor contained in a process gas or the like during film formation can be removed by installing the refrigeration coil as close as possible to a very clean vacuum state. Although not particularly limited, it is not preferable to install the device in a place where plasma is directly emitted or a place where sputtered powder adheres.

In the conventional method, as shown in FIG. 2, the impurity atoms and molecules which existed in a vacuum before the Ag atoms protruded from the Ag target and were deposited on the glass were converted to A atoms.
Although g atoms collided and the direction of ejection was shifted or the speed was changed, a porous Ag film was formed. However, the present invention provides an Ag film by installing a refrigeration coil near the target. The probability that Ag atoms will collide with impurity atoms and molecules that existed in vacuum in the past from when the atoms jumped out of the Ag target to when they were stacked on the glass, causing the direction of the jumping out or a change in velocity. As shown in FIG. 3, a dense, regular thin Ag particle layer having excellent crystallinity is regularly laminated on the glass surface. The Ag density in the Ag layer of the present invention is preferably 8.5 g / cm ³ or more, and if it is less than this density, the Ag layer for forming a low-emissivity glass having the same emissivity may be used. The film thickness becomes thick, and the color tone differs between when the applied glass is viewed obliquely and when viewed from the front, which is not preferable.

Further, the color tone of the low emissivity film greatly depends on the thickness of Ag, and when the thickness of the Ag layer formed by the conventional method is large, the absolute value of the optical path length when viewed obliquely is considered. Change becomes large, and is easily affected by the angle. However, the film formed by the method of the present invention has a density of about 35% higher than the film formed by the conventional method and is densely laminated, so that the film thickness can be reduced and the color tone can be easily improved. It is considered that a change in color tone due to an angle can be suppressed.

The glass substrate used in the present invention includes:
It is ordinary plate glass or so-called float plate glass which is usually used for automotive and architectural glass, etc., and various colored glass such as clear, green and bronze, various functional glass, tempered glass and similar glass, laminated glass Needless to say, it can be used as various kinds of sheet glass products such as double-glazed glass, flat and bent sheets. Further, the glass may be a laminate with a transparent plastic plate or the like. The composition of the glass is soda-lime glass, aluminosilicate glass or the like, but it goes without saying that the glass is not limited to these.

In the low emissivity glass of the present invention, the number of Ag layers laminated is not particularly limited, but the color tone is obtained when the transparent oxide layer or the nitride layer and the Ag layer are repeated two or more Ag layers. Is remarkable, and it is particularly preferable.
When the Ag layer is composed of two layers, the optimum film composition is as follows: glass / transparent oxide or nitride first layer / Ag second layer / metal barrier third layer / transparent oxide or nitride This is a film configuration including a fourth layer made of Ag / a fifth layer made of Ag / a sixth layer made of a metal barrier / a seventh layer made of a transparent oxide or nitride.

The first, fourth, and seventh layers include:
As the transparent oxide, ZnO ₂ , SnO ₂ , TiO _2, IT
Examples of transparent nitrides such as O and SiO ₂ include Al ₂ N ₃ and Si ₂
N ₃ or the like can be used as a single-layer film or a multilayer film. The second and fifth Ag layers have a purity of 100%,
Alternatively, Ti, Zr, V, Nb, Ta, Cr, Ni, P
Ag containing at least one element of d, Pt, Zn, In, and Sn in an amount of 0.0 to 10.0% by weight can be used. As the third and sixth metal barrier layers, Zn,
Sn, Ti, Al, NiCr, Cr, Zn, and Sn alloys (each metal containing 0.0 to 10.0% by weight of Al and Sb metals) can be used.

As for the thickness of each layer, the thickness of the first layer is 1
0 to 50 nm, and each of the second and fifth layers has a thickness of 8 n.
m to 50 nm, and the thickness of each of the third and sixth layers is 8.
Preferably, the thickness of the fourth layer is 70 nm to 150 nm, and the thickness of the seventh layer is 10 nm to 50 nm.

The amorphous film composed of a tin oxide layer and / or a titanium oxide layer as a typical transparent oxide is chemically and mechanically strong and has an amorphous loose structure. Therefore, the adhesive strength with glass is strong and internal stress is hardly generated. Therefore, the first layer coating directly over the glass is preferably a tin oxide layer and / or a titanium oxide layer. The thickness of the first tin oxide layer and / or titanium oxide layer for enhancing adhesion to glass and cutting off the influence of alkali ions is at least 5
nm is required. However, the tin oxide layer and / or the titanium oxide layer have poor adhesion to metals, particularly Ag, and are likely to peel off at the tin oxide layer, the titanium oxide layer / silver layer interface. Also, tin oxide has a weak bond with oxygen, as can be seen from its ionization tendency, and the chemical potential of oxygen in the coating is high,
Oxygen easily diffuses into the Ag layer. For this reason, the electrical resistance of the Ag layer increases and it is difficult to achieve a low emissivity. From the above, it is preferable that the layer composed of the tin oxide layer and / or the titanium oxide layer is not brought into contact with the silver layer. Note that the tin oxide layer and / or the titanium oxide layer may contain an element as an amorphous coating component that improves chemical and mechanical properties and enhances adhesion to glass.

Further, the zinc oxide layer has a high adhesion to the Ag layer, and has a low oxygen potential in the layer due to a high bonding force with oxygen, so that oxygen is hardly diffused into the silver layer, and a low emissivity is obtained. Easy to achieve. Therefore, a layer immediately below the Ag layer is preferably a zinc oxide layer. The thickness of the second zinc oxide layer is required to be at least 3 nm in order to prevent diffusion of oxygen from the underlying tin oxide layer and to obtain a strong adhesion to the Ag layer. In addition,
The zinc oxide layer may contain a known element as a component of the coating that does not decrease the adhesion to the silver layer and makes it difficult for oxygen to diffuse into the silver layer. It is important to keep the chemical potential of oxygen in the oxide layer in contact with the Ag layer as low as possible, and it is desirable to add as much argon as possible together with oxygen to the atmosphere during the formation of zinc oxide. Desirable addition rates of argon vary depending on the equipment, but are generally in the range of 10 to 30.
%. This value is obtained by gradually adding argon from the oxygen atmosphere and suddenly increasing the voltage applied to the target,
It is determined by observing a sudden drop in the current and then slightly reducing the argon.

Further, the thickness of the transparent oxide and the transparent nitride of the first layer formed between the glass and the silver layer ensures a high visible light transmittance, especially 70% or more visible light transmittance, and reflects light. In order to keep the color tone as neutral as possible, 10
~ 50 nm is preferred. Above or below this range, the reflectance will be high and the transmittance will be low.

The thickness of the third and sixth Ag layers affects the emissivity, visible light transmittance and reflection color tone, and is at least 8 nm for low emissivity glass having an emissivity of about 0.1 or less. is necessary.

Further, the third and sixth metal barrier layers formed immediately above the Ag layer are made of zinc or an alloy containing zinc as a main component, which has high adhesion to both the silver layer and the oxide layer. Layers are preferred. Note that the metal barrier layer referred to here is a metal layer immediately after the metal barrier layer of the fourth layer and / or the seventh layer is formed immediately above the silver layer. When forming the fourth or seventh oxide layer on the substrate, an oxidizing atmosphere (for example, oxygen 80%, argon 2
0%), a part of the upper layer portion of the metal layer is converted to an oxide, but this upper layer portion is referred to as a metal barrier layer including the oxidized oxide layer and the remaining metal layer. . The function of the metal barrier layer is to interpose the metal barrier layer so that the oxidizing atmosphere does not affect the lower silver layer when the fourth or seventh oxide layer is formed. To protect the silver layer from being oxidized. As the metal barrier layer, a zinc alloy containing 2 to 10 atomic% of aluminum is particularly preferable because it has a high bonding force with oxygen and most effectively traps oxygen and other corrosive ions diffused into the silver layer. It goes without saying that the thicker the metal barrier layer is, the longer the strong effect lasts. However, if the metal barrier layer is too thick, the visible light transmittance is reduced. However, when the next oxide film is formed, a part of the metal barrier layer is oxidized, so that if the thickness of the first metal layer before the oxidation is 8.0 nm or less, a high transmittance can be obtained.

Here, one of the differences between the oxidized metal barrier layer, especially the oxidized zinc alloy layer, especially the zinc alloy layer containing 2 to 10 atomic% of oxidized aluminum (ZnAlO) and the zinc oxide layer (ZnO) Is that the latter strongly absorbs the ultraviolet rays contained in the sunlight, whereas the former is weak in the absorption. This is because the band gap of zinc oxide is widened by the addition of the impurity, and the absorption region shifts to the short wavelength side. Another difference is that
That is, the film forming rate of the former is reduced to about 70% as compared with the latter. This is due to the former, especially aluminum
This is because the melting point of the zinc alloy containing 0 atomic% is lower by about 20 ° C. than 420 ° C. of zinc, so that the power required for film formation cannot be sufficiently provided to the target. Therefore, it is preferable that the zinc oxide layer be a pure zinc oxide layer which does not contain at most 2 atomic% or more of the impurity metal element except for the portion where the metal barrier layer is oxidized.

The zinc oxide layer is dense and has an effect of preventing the diffusion of corrosive gas in the atmosphere, and has a function of absorbing ultraviolet rays contained in sunlight, but has low chemical durability. When used as the uppermost layer, it is preferable to further provide a tin oxide layer and / or a titanium oxide layer, which are amorphous oxides, on the zinc oxide layer. The thickness of the tin oxide and / or titanium oxide layer is preferably 1 nm or more.

The thickness of the fourth layer is preferably in the range of 70 to 150 nm in order to obtain preferable optical characteristics.

The total thickness of the seventh layer is suitably in the range of 10 to 50 nm in order to keep the visible light transmittance and the reflection color tone as neutral as possible. Higher, thus lowering the transmittance.

The optical properties of the low emissivity glass of the present invention are as follows:
In the *, a *, b * color system, the specular color at an incident angle of 8 ° may have the following relationship with the a * (45 °) of specularly reflected light at 45 ° with respect to a * (8 °). Preferably, (a * (8 degrees) -a *
If (45 degrees)) is smaller than -2.0, it is not preferable because achromatic color is not obtained.

A * (8 degrees) -a * (45 degrees)>-2.0 Further, in the L *, a *, b * color system, the glass surface reflection characteristic value of the low-emission film has the following relationship. It is preferable that the ratio be outside the above range.

When the incident angle is 8 °; reflectance = 4 to 15
(%) A * (8 degrees) = 0 to -10 at an incident angle of 45 °; reflectance = 4 to 15 (%) a *
(45 degrees) = 2 to -15 Further, it is preferable that the visible light transmittance is 65% to 85% and the surface resistance value is 6.0Ω / □ or less.

[0033]

The reason why the placement of the refrigeration coil in the vicinity of the intended target is effective for the Ag film formed by this method is considered as follows.

The Ag film formed by the conventional manufacturing method has an Ag atom of A
The probability that Ag atoms collide with impurity atoms and molecules existing in the vacuum from the time when the target is ejected to the time when the target is laminated on the glass will increase the probability that the ejecting direction will shift or the speed will change. The film is randomly stacked on the glass and becomes a porous film, and the apparent film thickness becomes large. The color tone of the low emissivity film largely depends on the thickness of the Ag film. When the film thickness is large, the change in the absolute value of the optical path length when viewed obliquely becomes large, and the film is easily affected by the angle. However, the film formed by this method is denser (about 3 times) than the film formed by the conventional method.
It is considered that the change of the color tone due to the angle can be suppressed by stacking (5% reduction).

Naturally, the structure of the dense Ag film also affects the performance of the resistance value, and the contact electric resistance between each Ag atom is reduced, and a low resistance characteristic is obtained. As a result, the heat insulating performance is improved. It is a well-known fact that there is a correlation between the resistance value and the value of the hemispherical emissivity representing the performance of the heat insulating property.

Also, the moisture resistance performance is improved as compared with the conventional method. In the conventional method, Ag is oxidized when Ag atoms collide with water vapor molecules, and the oxidized Ag film is taken into normal Ag as it is. It is considered that the oxidation of Ag is spread based on the Ag oxide. Therefore, the Ag film formed by the method of the present invention has less defects of the Ag oxide and is prevented from deteriorating.

[0037]

The present invention will be described below in detail with reference to examples. The film was formed by DC magnetron sputtering. However, the present invention is not limited to such an embodiment.

Example 1 A coating was formed on a float glass measuring 1800 mm × 24000 mm × about 3 mm in the following order. The sputtering apparatus previously provided Sn, Z in each cathode in each chamber.
After attaching each metal target of n (3 units), Ag, and ZnAl (Al content: 4 atomic%), the pressure before film formation was 1
The vacuum chamber was sufficiently evacuated until the pressure became 0 ^-4 Pa or less. In this method, a transport roll is installed below an Ag target in a vacuum chamber, and when a glass plate placed on the roll reciprocates, a predetermined metal layer or metal oxide layer is applied from a target to which power is applied. Is formed on a glass plate.

As shown in FIG. 1, a refrigeration coil (model: PFC-1100, manufacturer; below the glass plate in the Ag film forming chamber (within 5 m from the Ag target))
US POLYCOLD SYSTEMS INTERN
5/8 inch (coil outer diameter) 20 m (coil length) Surface area: 10,000
0 cm ² (surface area) −120 ° C. to −140 ° C. (coil surface temperature)) was disposed over the width of the glass plate.

First, as the first pass, the atmosphere in the deposition chamber is kept in an oxidizing atmosphere (O ₂ : Ar = 8: 2), and the SnO layer as the first layer of the first layer is deposited. 12.5
nm, the ZnO layer as the second layer of the first layer is 20.1 n
m was formed. Next, as the second pass, the atmosphere is Ar 100%.
, And the Ag layer as the second layer is
A third ZnAl alloy layer having a thickness of 0.0 nm and a thickness of 6.5 nm was formed. In the third pass, the atmosphere in the film forming chamber is again kept in the oxidizing atmosphere (O ₂ : Ar = 8: 2), the SnO layer as the first layer of the fourth layer is 12.0 nm, and the second layer is the second layer. Z
A 51.3 nm nO layer is sequentially formed, and the fourth pass is 7.1 nm in SnO layer as the third layer and 3.0 nm in ZnO layer as the fourth layer in the same atmosphere as the third pass.
A film was formed. Next, the atmosphere was Ar100 as the fifth pass.
% Of the Ag layer as the fifth layer.
A ZnAl alloy layer of 2.0 nm and a sixth layer of 6.7 nm were formed. Further, as the sixth pass, the atmosphere in the film forming chamber is again kept in the oxidizing atmosphere (O ₂ : Ar = 8: 2), the SnO layer as the first layer of the seventh layer is 5.5 nm, and the second layer is the second layer. A ZnO layer as an eye was sequentially formed to a thickness of 17.8 nm, and a second SnO layer as a third layer of a thickness of 2 nm was formed as an eighth pass in the same atmosphere as in the seventh pass. Next, the glass was discharged from the film forming chamber. The fourth layer ZnAl on the silver layer
Alloy layer 6.5 nm and seventh layer ZnAl alloy layer 6.7 n
m is oxidized, and each ZnAl alloy layer is about 5 n
m was changed to an oxide layer. The total thickness of the oxide layer between the third Ag layer and the ninth Ag layer is 78.4 nm, and the thickness of the oxide layer above the ninth layer is 30.4 nm.
Met.

The Ag layer had a density of 9.0 g / cm ³ . The density of silver was determined from the results of wet analysis and film thickness measurement. Table 1 shows the film configuration.

[0042]

[Table 1]

The film thickness D of each film is adjusted by the transport speed and the cathode power, and the value is previously removed to a thickness of about 100 nm by partially etching the film formed at the power E ₀ and the transport speed V _0. Then, the step was measured with a stylus type surface roughness meter to determine the thickness D _0, and the cathode power E and the transport speed were V in the example, and D = D ₀ × E / E ₀ × V ₀ / V. It was determined according to the formula. The numbers in the column of the film configuration in Table 1 indicate the thickness (nm) of each film.

The optical characteristics of the obtained low-emissivity glass were further radiated by a spectrophotometer (model: U-4000, manufactured by Hitachi), and the resistance was further measured by a four-probe probe ohmmeter (manufactured by Epson). The rate was measured using an infrared spectrophotometer (model: 270
-30, manufactured by Hitachi). Table 3
The performance evaluation of the double glazing shown in JIS 3209 (double glazing) and JIS 3106 (transmittance of flat glass,
(Reflectance, solar heat acquisition rate test method).

The evaluation results are shown in Table 2 for the optical characteristics.
As shown in Table 3, all of the results show good results. Regarding the thermal characteristics, the shielding coefficient (SC value (summer);
The value of the solar heat removal rate (1-η; the ability to remove solar heat in the summer) is high, and the value of the heat transfer rate (insulation performance) is also low. It was low, and all showed good results.

[0046]

[Table 2]

[0047]

[Table 3]

The moisture resistance was evaluated as 100 × 100 m
m glass sample (n = 3) at 30 ° C.-RH 90%
After exposure for 2 weeks and 3 weeks in an environmental tester, the number of pinholes generated on the film surface was counted. Table 4 shows the results.
As shown in Fig. 7, even after exposure for 3 weeks, there was no pinhole of 0.5 mm or more, and the number of generated pinholes was small and good.

[0049]

[Table 4]

The incident angle of low emissivity glass is 8 °, 3 °
The reflection color tone at each angle of 0 ° and 45 ° shifted to a green tone as shown in Table 5 and FIG. In addition, the reflection color tone by angle is photoal (model; M
The measurement was performed using C-850A (control), MCPD100 (spectromultichannel), UV-VIS (photodetector, manufactured by Otsuka Electronics).

[0051]

[Table 5]

Example 2 In the same manner as in Example 1, as shown in Table 1,
78.6 n of the oxide layer between the first Ag layer and the ninth Ag layer
m, a film was formed in the same manner as in Example 1 except that the thickness of the oxide layer above the ninth layer was changed to 29.6 nm. Note that A
The density of the g layer was 8.8 g / cm ³ . The evaluation result is
As shown in Tables 2, 3, and 4, the optical properties, thermal properties, and moisture resistance were as good as in Example 1.

Example 3 By the same method as in Example 1, as shown in Table 1,
The oxide layer between the Ag layer of the first layer and the Ag layer of the ninth layer is 77.0 n.
m, a film was formed in the same manner as in Example 1 except that the thickness of the oxide layer above the ninth layer was changed to 29.6 nm. Note that A
The density of the g layer was 9.0 g / cm ³ . The evaluation result is
As shown in Tables 2, 3, and 4, the optical properties, thermal properties, and moisture resistance were as good as in Example 1.

Comparative Example 1 A film was formed in the same manner as in Example 1 except that a film was formed without installing a refrigeration coil below the glass plate and the film configuration was changed as shown in Table 1. The density of the Ag layer was 7.3 g / c.
m ³ . As shown in Table 3, as shown in Table 3, the heat insulation performance (shielding coefficient (SC value)) at the time of the multi-layer was not preferable, and in the moisture resistance test, as shown in Table 3, there were many large pinholes of 0.4 mm or more. Occurred. In addition, as shown in Table 4 and FIG. 4, the reflection color tone by angle was redder as the viewing angle became oblique, and was not preferable.

Comparative Example 2 A film was formed in the same manner as in Example 1 except that a film was formed without a refrigeration coil under the glass plate and the film configuration was changed as shown in Table 1. The density of the Ag layer was 7.3 g / cm ^3, which was the same as that of Comparative Example 1. As shown in Table 3, as shown in Table 3, the heat insulation performance (shielding coefficient (SC value)) at the time of the multilayer was not preferable, and in the moisture resistance test, as shown in Table 4, many large pinholes of 0.4 mm or more were found. Occurred. Further, as shown in Table 5 and FIG. 4, the reflection color tone by angle was redder as the viewing angle became oblique, which was not preferable.

Comparative Example 3 A film was formed in the same manner as in Example 1 except that a film was formed without installing a refrigeration coil below the glass plate and the film configuration was changed as shown in Table 1. The density of the Ag layer was 7.3 g / cm ^3, which was the same as that of Comparative Example 1. As shown in Table 3, as shown in Table 3, the heat insulation performance (shielding coefficient (SC value)) at the time of the multilayer was not preferable, and in the moisture resistance test, as shown in Table 4, many large pinholes of 0.4 mm or more were found. Occurred. Further, as shown in Table 5 and FIG. 4, the reflection color tone by angle was redder as the viewing angle became oblique, which was not preferable.

[0057]

The low-emissivity glass of the present invention has a small change in color tone depending on the viewing angle, and does not turn red obliquely even when the front color is neutral. And the heat resistance is low and the heat insulation properties are excellent.

[Brief description of the drawings]

FIG. 1 is a layout diagram of a refrigeration coil in a sputtering chamber according to the present invention.

FIG. 2 is a diagram showing a conventional sputtering situation.

FIG. 3 is a diagram showing the state of sputtering according to the present invention.

FIG. 4 is a diagram showing a reflection color tone on a glass surface according to an angle (Example 1).

FIG. 5 is a graph showing a reflection color tone of a glass surface at different angles (Comparative Example 1).

Claims (6)

[Claims] 1. A low-emissivity glass obtained by sputtering having at least one Ag layer, wherein the density of the Ag layer is 8.5 g / cm ³ or more. 2. A first layer made of glass / transparent oxide or nitride / a second layer made of Ag / a third layer made of metal barrier / a fourth layer made of transparent oxide or nitride / A
g of a fifth layer / a sixth layer of a metal barrier / a coating of a seventh layer of a transparent oxide or nitride. The first layer has a thickness of 10 to 50 nm,
Each of the layer and the fifth layer has a thickness of 8 nm to 50 nm,
Each of the layer and the sixth layer has a thickness of 8.0 nm or less, the fourth layer has a thickness of 70 to 150 nm, and the seventh layer has a thickness of 10 to 50.
2. The low-emissivity glass according to claim 1, wherein 3. An incident angle of 8 in the L *, a *, b * color system.
The a * (45 degrees) of the specular reflection light of 45 degrees has the following relationship with the a * (8 degrees) of the specular reflection color of degree: a * (8 degrees) -a * (45 degrees)> -2.0 Low emissivity glass according to claim 1 or 2, wherein the glass surface reflection characteristic value of the low emissivity film has the following relationship. At an incident angle of 8 °; reflectance = 4 to 15% a * (8
Degree) = 0 to -10 at an incident angle of 45 °; reflectance = 4 to 15% a * (4
5 degrees) = 2 to -15 4. The method according to claim 1, wherein the visible light transmittance is 65% to 85% and the surface resistance is 6.0 Ω / □ or less.
4. A low-emissivity glass according to any one of claims 1 to 3. 5. A method of forming a low-emission film by a sputtering method, wherein a refrigeration coil for adsorbing water vapor or various gases by a cold trap method is provided near an Ag target,
By setting the surface temperature of the refrigeration coil to −120 to −140 ° C., the surroundings of the target are locally kept in a high vacuum state, and an Ag layer is formed on the glass surface. Glass manufacturing method. 6. The method for producing a low-emissivity glass according to claim 5, wherein the density of Ag is 8.5 g / cm ³ or more.