JP2011173764A - Low radiation film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a new barrier layer in which the oxidation of an Ag layer is controlled without spoiling the visible light transmission of a low radiation film, and in addition existing sputtering production equipment can also easily carry out production by low cost, and the low radiation film containing the barrier layer. <P>SOLUTION: The low radiation film formed by a vapor deposition process on a base material, includes: an underlayer and a thin film laminate part on the base material, wherein the thin film laminate part includes: a metal layer; and a barrier layer on the metal layer, and the barrier layer is in contact with the metal layer and comprises a nitride or an oxynitride. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a low radiation film that is suitably used as a window glass for construction.

  A low emission film formed by laminating a dielectric layer such as a metal oxide and a metal layer such as Ag is formed on a transparent substrate such as glass by a thin film forming technique such as a sputtering method. It is used for building window glass.

  Low-emission glass has the property of reflecting solar heat flowing into the room from the outside in the summer through the window glass, and heating heat flowing out from the room to the outside in the winter. Widely used as a window glass to help save energy. Said low radiation glass is a multilayer glass formed by sealing the peripheral part of two opposing glass substrates with a spacer and a sealing material, and between the opposing glass substrates of the multilayer glass, It is filled with dry air or a rare gas such as Ar. The low emission film is often formed on a glass surface in contact with the dry air layer in consideration of durability of the low emission film.

  As a low radiation film used for the above low radiation glass or the like, a laminated structure formed by laminating 2n + 1 layers of a dielectric layer and an Ag layer is disclosed (Patent Document 1).

  Further, as a low radiation film, a film structure in which a barrier layer is inserted immediately above the Ag layer in a laminated structure in which a dielectric layer and an Ag layer are laminated by 2n + 1 layers is disclosed. Or ZnAl alloy (Patent Document 2), Zn or ZnSn alloy (Patent Document 3), Au or Au alloy or Ag alloy (Patent Document 4), FeNiCr alloy or NiCr alloy or FeCr alloy or Nb (Patent Document 5) A metal barrier layer is disclosed. This metal barrier layer is intended to prevent the Ag layer from being oxidized by oxygen plasma when a dielectric layer is formed on the Ag layer.

  On the other hand, a low-emission film that has a laminated structure of transparent conductive layer / metal layer / transparent conductive layer and that does not contain a metal barrier layer, which is formed by using an opposed target sputtering apparatus is disclosed (Patent Document 6). ).

In addition, as a film configuration that does not include a metal barrier layer, an oxide formed in an Ar atmosphere using a lower oxide of TiOx (a lower oxide of TiO ₂ ) or ITO (Sn-doped indium oxide) as a sputtering target. A low emission film using a barrier layer is disclosed (Non-Patent Document 1). Furthermore, a low-emission film that does not contain a barrier layer, in which an ITO layer is formed immediately above the Ag layer while introducing Ar gas and a small amount of oxygen gas using an ITO target, is disclosed (Patent Document 7).

  In addition, low-emission glass has high needs for both excellent daylighting and energy-saving when used in buildings and other buildings, and development of a low-emission film that combines high visible light permeability and high solar radiation shielding is required. ing.

Japanese Patent Laid-Open No. 63-239044 JP 2007-197237 A JP 2007-119303 A JP 2006-505811 A JP 2006-117482 A JP 2006-334787 A JP 2001-226148 A

J. H. Lee et al, Journal of the Korean Physical Society, Vol. 46, June 2005, pp. S154-S158. K. Ishibashi, Y. Shiokawa, Proceedings of the 3rd International Symposium on Sputtering and Plasma Processes, 1995, pp.417-428. D. Severin et al, Applied Physics Letters, Vol. 88 2006 161504.

  As described above, a low radiation film formed by laminating a dielectric layer and an Ag layer is widely used in which a metal barrier layer such as ZnAl is formed immediately above the Ag layer. Generally, a film having a low visible light transmittance is used for the metal barrier layer as described above, but is oxidized by the generated oxygen plasma when a dielectric layer is formed on the metal barrier layer. Thus, the visible light transmittance is supposed to increase. On the other hand, depending on the thickness of the metal barrier layer, the metal barrier layer may not be completely oxidized, and the visible light transmittance of the low emission film may be lowered by the lower oxide or metal remaining in the film.

  In order to completely oxidize the metal barrier layer, the thickness of the metal barrier layer may be adjusted as much as possible, for example, by adjusting the thickness of the barrier layer. However, on the other hand, since it is necessary to adjust the film thickness on the order of several millimeters to reduce the thickness of the barrier layer, technical production is not easy. Furthermore, if the metal barrier layer is made too thin, the Ag layer becomes Not only does it fail to serve as a metal barrier layer, such as being oxidized by oxygen plasma, but it also leads to a decrease in yield. Therefore, it is difficult to say that the conventional metal barrier layer that requires oxidation is preferable from the viewpoint of the visible light transmittance and productivity of the low radiation film.

  Also, by using a counter target type sputtering apparatus, a low radiation film that does not contain a metal barrier layer can be formed, but since a special counter target type sputtering apparatus different from a typical parallel plate sputtering apparatus is required, Large-scale capital investment is required, and there is no track record of forming a low-emission film on a large-area glass with a size of more than 5m, which is the size of a window glass for buildings, using an opposed target sputtering system. It is difficult to say that it has been established as a practically practical technique as a method for forming a low-emission film used.

  In addition, a method using an oxide barrier layer formed using TiOx, ITO, or the like as a sputtering target is preferable from the viewpoint of film formation cost because the oxide target itself is extremely expensive compared to a metal target. Absent. In addition, there is a high possibility that oxygen contained in the target itself oxidizes the Ag layer. Particularly, in a sputtering apparatus for production, high power of the order of several tens of kW is applied to the target in order to achieve high throughput. Presumably, the discharge voltage of the target is inevitably increased, leading to a significant increase in the energy of oxygen negative ions caused by oxygen contained in the target and the atmospheric gas (Non-patent Document 2). Is done.

  Thus, a new barrier layer that suppresses the oxidation of the Ag layer without impairing the visible light transmittance of the low radiation film, and can be easily produced at low cost even with the current sputtering production facility, and the barrier layer are included. The purpose was to obtain a low radiation film.

  As a result of intensive studies by the present applicant, the use of nitride or oxynitride as the barrier layer of the low-emission film does not depend on the oxidation state of the barrier layer, and the visible light transmittance is higher than that of the conventional barrier layer. It was clarified that an increase, a decrease in visible light reflectance, and a decrease in visible light absorptance were observed, indicating that it contributed to an improvement in visible light transmittance.

  That is, the present invention provides a low radiation film formed on a base material by a vapor deposition process, and has a base layer and a thin film laminated portion on the base material, the thin film laminated portion on the metal layer and the metal layer. The barrier layer is a low-emission film made of nitride or oxynitride in contact with the metal layer.

  In addition, when the thin film stack portion of the present invention is formed by stacking 3n (n is an integer of 1 or more) layers, a dielectric layer is formed on the barrier layer.

  Moreover, the film thickness of the said barrier layer of this invention is 1-30 nm, It is characterized by the above-mentioned.

  Further, the barrier layer of the present invention is characterized by having as a main component at least one selected from the group consisting of B, Si, Al, Zn, Sn, In, Ti, Nb, and Bi.

  The dielectric layer according to the present invention is characterized in that it is at least one oxide or oxynitride selected from the group consisting of Zn, Sn, In, Ti, Nb, Bi, B, Al, and Si. .

  Moreover, this invention contains the low emission glass which formed the low emission film | membrane of this invention on glass, and the visible light transmittance computed based on JISR3106 is 50% or more characterized by the above-mentioned It is a double-layer glass.

  The low emission film of the present invention can prevent the deterioration of the Ag layer without impairing the visible light transmittance. In addition, it can be easily produced even with current sputtering production facilities, and has an excellent productivity such as low cost because an inexpensive metal target can be applied. Furthermore, the low radiation film of the present invention has excellent daylighting property, visibility, and clarity that are optimal as architectural window glass due to high visible light transmittance.

It is a cross-sectional schematic diagram showing suitable one Embodiment of the low radiation film | membrane of this invention. It is a figure which shows the outline of a magnetron sputtering device.

  An outline of a preferred embodiment of the low emission film of the present invention is shown in FIG. A preferred low radiation film of the present invention is a low radiation film formed on the substrate 1, and the low radiation film includes the underlayer 2 and the thin film laminated portion 15, and the thin film laminated portion 15 includes: The metal layer 3, the barrier layer 4 formed on the metal layer, and the dielectric layer 14 are laminated on the barrier layer 4 repeatedly by n layers (n is an integer of 1 or more).

  Note that “on the substrate” may be in contact with the substrate, or another film may be interposed between the substrate 1 and the base layer 2. The metal layer 3 is desirably formed on the base layer 2 formed on the substrate, and the metal layer 3 to be further formed is preferably in contact with the base layer 2. And the barrier layer 4 are in contact with each other. In addition to the above, the low emission laminated film of the present invention may be provided with a protective layer or the like as the uppermost layer as long as the low emission property and the visible light transmission property are not impaired.

  In addition, the thin film laminated portion 15 in the low emission film of the present invention includes at least the metal layer 3 and the barrier layer 4 formed on the metal layer 3, and the dielectric layer 14 is formed on the barrier layer 4. It is preferable. One or more dielectric layers may be formed on the barrier layer. However, as described above, when the metal layer, the barrier layer, and the dielectric layer are sequentially laminated, 3n layers are effectively laminated so that the lighting performance, the visibility, and the clarity are improved. It is preferable because it can acquire sex and the like.

  The barrier layer of the present invention is preferably composed mainly of at least one nitride or oxynitride selected from the group consisting of B, Si, Al, Zn, Sn, In, Ti, Nb, and Bi. is there. In particular, B, Si, and Al are preferably used because they can obtain a transparent nitride in the visible light range. In addition, Zn or Sn oxynitride is suitable because the material itself is inexpensive, the film forming speed is relatively high, and the film can be stably formed with a DC power source that is industrially easy to use. Used for. The compound used for the barrier layer may be selected in consideration of adhesion to the dielectric layer laminated thereon.

  Further, when a dielectric is used as the barrier layer used in the low radiation film of the present invention, it can be used as a barrier layer having both the function of the barrier layer and the function of the dielectric layer. In addition, unlike the conventional barrier layer, the barrier layer of the present invention can maintain a suitable visible light transmittance even if the film thickness is not very thin, and thus has a dielectric function with a film thickness of about 30 to 200 nm. It may be used as a barrier layer.

  As described above, as the dielectric barrier layer, boron nitride (BN), silicon nitride (SiN), aluminum nitride (AlN), tin oxynitride (SnNO), zinc oxynitride (ZnNO), titanium oxynitride (TiNO), It is preferable to use silicon oxynitride (SiNO) or aluminum oxynitride (AlNO), and it is particularly preferable to use BN, SiN, or SnNO.

  The dielectric layer used in the low emission film of the present invention is an oxide or oxynitride composed of at least one selected from the group consisting of Zn, Sn, In, Ti, Nb, Bi, B, Al, and Si. Is preferably the main component. In particular, the oxide of Zn or Sn is preferably used because the material itself is inexpensive and can be stably deposited with a DC power source that is industrially easy to use.

  The metal layer used in the low emission film of the present invention is preferably pure Ag or an Ag alloy containing a metal such as palladium, gold, platinum, nickel, copper, etc. containing Ag as a main component. It is preferable to use pure Ag that can achieve both optical properties and thermal properties.

  The underlayer used in the low emission film of the present invention is at least one oxide, nitride, or oxynitride selected from the group consisting of Zn, Sn, In, Ti, Nb, Bi, B, Al, and Si. It is preferable to use a dielectric material containing as a main component.

  The base material on which the low radiation film is formed is preferably used for architectural window glass or the like as double-glazed glass or laminated glass. Moreover, when using the low radiation film | membrane of this invention as a multilayer glass for construction, it is desirable that the visible light transmittance calculated based on JIS R3106 is 50% or more. In addition, when visible light transmittance is less than 50%, visible light transmittance preferable as an architectural window glass cannot be obtained.

  Further, the low emission film of the present invention has a film thickness of the base layer of 5 to 200 nm, a film thickness of the metal layer of 5 to 30 nm, and a film thickness of the barrier layer in order to obtain optical characteristics suitable as a window glass. Is preferably 1 to 30 nm, and the thickness of the dielectric layer is preferably 5 to 200 nm. When the film thickness of each layer is out of the above range, optical characteristics suitable as a window glass cannot be obtained.

  The low radiation film of the present invention is characterized in that the surface resistance is 0.5 to 30Ω / □. When the surface resistance is lower than 0.5Ω / □, it means that the thickness of the metal layer is thick, and the visible light reflectance is increased, so that it is impossible to obtain visible light transmittance suitable as a window glass. . On the other hand, when the surface resistance exceeds 30Ω / □, the emissivity of the low radiation film increases, leading to a decrease in the thermal characteristics of the low radiation glass.

  In addition, the substrate in the present invention is not particularly limited. For example, it is an inorganic material such as a window glass for buildings, a commonly used float plate glass, or a soda-lime glass manufactured by a roll-out method. Transparent plate glass can be used. The plate glass can be used for both colorless glass such as clear glass and high transmission glass, and green colored such as heat ray absorbing glass, and is not particularly limited to the shape of the glass, but visible light. In consideration of the transmittance, it is preferable to use colorless glass such as clear glass and high transmittance glass. In addition to flat glass, bent glass, various glass such as air-cooled tempered glass and chemically tempered glass, netted glass can be used. Furthermore, various glass substrates such as borosilicate glass, low expansion glass, zero expansion glass, low expansion crystallized glass, and zero expansion crystallized glass can be used. Examples of other than the glass substrate include resin substrates such as polyethylene terephthalate resin, polycarbonate resin, and polyvinyl chloride resin.

  The low emission film of the present invention is preferably formed by a vapor deposition process such as a sputtering method. In particular, a magnet is disposed behind the sputtering target, the plasma is confined near the target surface by the generated magnetic field, and sputtering is performed from the target. It is preferable to use a magnetron sputtering method in which a film is formed with the formed particles.

  In the sputtering method, a direct-current power supply, an alternating-current power supply, or a power supply in which alternating current and direct current are superimposed is suitably used as a plasma generation source, but a power source in which alternating current and direct current are superimposed is excellent in continuous productivity, preferable.

  As the sputtering target, a metal or alloy target is preferable because it is inexpensive and can reduce the film formation cost.

  As the film forming apparatus, a magnetron sputtering apparatus as shown in FIG. 2 may be used. After holding the base material 1 on the base material holder 5, the inside of the vacuum chamber 6 is evacuated by the vacuum pump 7, and the vacuum pump 7 is continuously operated during the film formation, and the atmospheric gas in the vacuum chamber is introduced into the gas. It introduce | transduces from the pipe | tube 8, and controls and adjusts the flow volume of gas by a massflow controller (not shown). The substrate holder 5 was rotated to form a film in order to minimize the film thickness distribution. The pressure in the vacuum chamber during film formation is adjusted by controlling the opening of the valve 9 installed between the vacuum chamber and the vacuum pump. A target 11 having a magnet 10 arranged on the back side is used, and the target is turned on from a power source 13 through a power cable 12. Note that the type of vacuum pump, the number and type of targets, selection of a DC power supply and an AC power supply, output power to the target, pressure during film formation, and the like may be appropriately selected and are not particularly limited. Details of FIG. 2 will be described later in the embodiment.

  In the low emission film of the present invention, the barrier layer is formed in an atmosphere containing at least nitrogen. When nitride is formed as the barrier layer, a mixed gas of Ar and nitrogen is preferably used in addition to the nitrogen gas. When an oxynitride film is formed as the barrier layer, oxygen gas may be introduced in addition to nitrogen gas. An appropriate gas introduction amount and gas composition are not particularly limited because they greatly depend on the size of the sputtering apparatus and the size of the target. When a mixed gas of nitrogen and oxygen is used, target oxidation is suppressed (Non-Patent Document 2). Therefore, the generation probability of the negative oxygen ions described above is reduced, and oxidation of the Ag film is suppressed. An oxynitride can also be preferably used.

  Moreover, it is preferable that the dielectric layer in the low radiation film of the present invention is formed under a pressure of 0.1 to 0.5 Pa. When the pressure is lower than 0.1 Pa, it is difficult to maintain a stable discharge. When the pressure exceeds 0.5 Pa, a dielectric layer with a rough surface grows, resulting in deterioration of optical characteristics and thermal characteristics of the low emission film. Connected. Since the pressure during film formation is determined by the balance between the pumping speed of the vacuum pump and the amount of gas introduced, for example, adjusting the opening of a valve installed between the vacuum pump and the film forming chamber, By adjusting, the pressure can be within the above range.

  Moreover, it is preferable that the metal layer in the low radiation film of the present invention is formed with a discharge voltage of 200 to 400V. When the discharge voltage is lower than 200 V, it is difficult to maintain a stable discharge. When the discharge voltage exceeds 400 V, the high energy particles generated in the plasma, for example, Ar gas that bounces off the target and flies toward the base material to the metal layer. The impact is increased, leading to deterioration of optical characteristics and thermal characteristics. Since the discharge voltage in the above range can be easily obtained by the high magnetic field sputtering method in which the magnetic flux density of the magnet disposed behind the target is increased, it is preferably used.

1. Production of low emission film Example 1
Low emission with a ZnO film as a base layer, an Ag film as a metal layer, a nitride silicon nitride film (hereinafter sometimes referred to as SiN) as a barrier layer, and a ZnO film as a dielectric layer on a glass substrate. A membrane was prepared. As the glass substrate, soda lime glass having a thickness of 3 mm was used.

  A low emission film was prepared using a magnetron sputtering apparatus as shown in FIG. Film formation of ZnO as an underlayer was performed by holding the glass substrate 1 on the substrate holder 5 and then evacuating the vacuum chamber 6 with the vacuum pump 7. During film formation, the vacuum pump 7 is continuously operated, and the atmospheric gas in the vacuum chamber is introduced with an oxygen gas from a gas introduction pipe 8 and the flow rate of the oxygen gas is controlled by a mass flow controller (not shown). It was adjusted. A turbo molecular pump was used as the vacuum pump 7. The pressure in the vacuum chamber during film formation was adjusted to 0.2 Pa by adjusting the opening degree of the exhaust valve 9 installed between the vacuum chamber and the vacuum pump. A Zn target was used for the target 11 on which the magnet 10 was arranged on the back side, and the power supplied from the power source 13 through the power cable 12 to the Zn target was 100 W, and a DC power source was used for the power source 10. Further, the film formation time was adjusted so that the thickness of the ZnO film was 37 nm. In addition, about any film | membrane after that, the desired film thickness was obtained by adjusting the film-forming time, and the base material was not heated in particular.

  Next, an Ag film as a metal layer was continuously formed on the ZnO film while maintaining a vacuum. An Ag target was used as the target 8, and the atmospheric gas in the vacuum chamber 6 was introduced with argon from the gas introduction pipe 8, and the pressure was adjusted to 0.5 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the Ag target 11 through the power cable 12 was 50 W, and a DC power source was used as the power source 10. When the maximum magnetic flux density at the center of the target was measured, it was 149 mT, and the discharge voltage applied to the target during film formation was 320 V. The film formation time was adjusted so that the thickness of the Ag film was 10 nm.

  Next, a SiN film as a barrier layer was continuously formed on the Ag film while maintaining a vacuum. Using an Si target as the target 8, nitrogen gas was introduced from the gas introduction pipe 8 as the atmospheric gas in the vacuum chamber 6, and the pressure was adjusted to 0.5 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the Si target 11 through the power cable 12 was 100 W, and the power source 10 was a DC power source on which AC pulses with a frequency of 20 kHz were superimposed. The deposition time was adjusted so that the thickness of the SiN film was 3 nm.

  Next, a ZnO film as a dielectric layer was continuously formed on the SiN film while maintaining a vacuum. A Zn target was used as the target 8, and the atmospheric gas in the vacuum chamber 6 was introduced with oxygen gas from the gas introduction pipe 8, and the pressure was adjusted to 0.2 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the Zn target 11 through the power cable 12 was 100 W, and a DC power source was used as the power source 10. The film formation time was adjusted so that the thickness of the ZnO film was 37 nm.

Example 2
A low radiation film was produced in the same manner as in Example 1 except that the thickness of the SiN film of the barrier layer was changed to 5 nm.

Example 3
A low emission film in which a ZnO film as a base layer, an Ag film as a metal layer, a boron nitride nitride film (hereinafter sometimes referred to as BN) as a barrier layer, and a ZnO film as a dielectric layer are sequentially laminated on a glass substrate Was made. As the glass substrate, soda lime glass having a thickness of 3 mm was used.

  A BN film, which is a barrier layer, was continuously formed immediately above the Ag film while maintaining a vacuum. Using a BN target as the target 8, nitrogen gas was introduced from the gas introduction pipe 8 as the atmospheric gas in the vacuum chamber 6, and the pressure was adjusted to 0.2 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the BN target 11 through the power cable 12 was 200 W, and the power source 10 was an AC power source having a frequency of 13.56 MHz. The film formation time was adjusted so that the thickness of the BN film was 2.6 nm.

  The conditions for forming the dielectric layer and the metal layer other than the barrier layer were the same as in Example 1.

Example 4
A low radiation film was produced in the same manner as in Example 3 except that the thickness of the BN film of the barrier layer was changed to 5 nm.

Example 5
A ZnO film as a base layer on a glass substrate, an Ag film as a metal layer, a tin oxynitride oxynitride film (hereinafter sometimes referred to as SnNO) as a barrier layer, and a ZnO film as a dielectric layer in that order. A radiation film was prepared. As the glass substrate, soda lime glass having a thickness of 3 mm was used.

  An SnNO film, which is a barrier layer, was continuously formed immediately above the Ag film while maintaining a vacuum. An Sn target is used as the target 8, and the atmosphere gas in the vacuum chamber 6 introduces a mixed gas of argon, oxygen, and nitrogen from the gas introduction pipe 8, and the mixing ratio of argon, oxygen, and nitrogen is 3: 7: 3. The pressure was adjusted to 0.5 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the BN target 11 through the power cable 12 was 100 W, and a DC power source was used as the power source 10. The film formation time was adjusted so that the thickness of the BN film was 3.6 nm.

  The film formation conditions for the base layer, dielectric layer, and metal layer other than the barrier layer were the same as in Example 1.

Comparative Example 1
A low-emission film was prepared by sequentially laminating a ZnO film as a base layer, an Ag film as a metal layer, an alloy ZnAl film as a barrier layer, and a ZnO film as a dielectric layer on a glass substrate. As the glass substrate, soda lime glass having a thickness of 3 mm was used.

  A ZnAl film, which is a barrier layer, was continuously formed immediately above the Ag film while maintaining a vacuum. A ZnAl target was used as the target 8, and the atmospheric gas in the vacuum chamber 6 was introduced with argon gas from the gas introduction pipe 8, and the pressure was adjusted to 0.5 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the ZnAl target 11 through the power cable 12 was 20 W, and a DC power source was used as the power source 10. The film formation time was adjusted so that the thickness of the ZnAl film was 3.2 nm.

  The film formation conditions for the base layer, dielectric layer, and metal layer other than the barrier layer were the same as in Example 1.

Comparative Example 2
A low emission film was produced in the same manner as in Comparative Example 1 except that the thickness of the ZnAl film of the barrier layer was 3.8 nm.

Comparative Example 3
A low-emission film was produced in the same manner as in Comparative Example 1 except that the thickness of the barrier layer ZnAl film was 4.4 nm.

Example 6
A ZnO film as a base layer on a glass substrate, an Ag film as a metal layer, a nitride BN film as a barrier layer, a ZnO film as a dielectric layer, an Ag film as a metal layer, a BN film as a barrier layer, and a ZnO film as a dielectric layer A low-emission film was sequentially laminated. As the glass substrate, soda lime glass having a thickness of 3 mm was used.

  A low emission film was prepared using the magnetron sputtering apparatus shown in FIG. Film formation of ZnO as an underlayer was performed by holding the glass substrate 1 on the substrate holder 5 and then evacuating the vacuum chamber 6 with the vacuum pump 7. During film formation, the vacuum pump 7 is continuously operated, and the atmospheric gas in the vacuum chamber is introduced with an oxygen gas from a gas introduction pipe 8 and the flow rate of the oxygen gas is controlled by a mass flow controller (not shown). It was adjusted. A turbo molecular pump was used as the vacuum pump 7. The pressure in the vacuum chamber during film formation was adjusted to 0.2 Pa by controlling the opening degree of the exhaust valve 9 installed between the vacuum chamber and the vacuum pump. A Zn target was used for the target 11 on which the magnet 10 was arranged on the back side, and the power supplied from the power source 13 through the power cable 12 to the Zn target was 100 W, and a DC power source was used for the power source 10. The film formation time was adjusted so that the thickness of the ZnO film was 37 nm.

  Next, an Ag film as a metal layer was continuously formed on the ZnO film while maintaining a vacuum. An Ag target was used as the target 8, and the atmospheric gas in the vacuum chamber 6 was introduced with argon from the gas introduction pipe 8, and the pressure was adjusted to 0.5 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the Ag target 11 through the power cable 12 was 50 W, and a DC power source was used as the power source 10. When the maximum magnetic flux density at the center of the target was measured, it was 149 mT, and the discharge voltage applied to the target during film formation was 320 V. The film formation time was adjusted so that the thickness of the Ag film was 14 nm.

  Next, a BN film as a barrier layer was continuously formed on the Ag film while maintaining a vacuum. Using a BN target as the target 8, nitrogen gas was introduced from the gas introduction pipe 8 as the atmospheric gas in the vacuum chamber 6, and the pressure was adjusted to 0.5 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the BN target 11 through the power cable 12 was 200 W, and the power source 10 was an AC power source having a frequency of 13.56 MHz. The film formation time was adjusted so that the thickness of the BN film was 2.6 nm.

  Next, a ZnO film as a dielectric layer was continuously formed on the BN film while maintaining a vacuum. A Zn target was used as the target 8, and the atmospheric gas in the vacuum chamber 6 was introduced with oxygen gas from the gas introduction pipe 8, and the pressure was adjusted to 0.2 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the Zn target 11 through the power cable 12 was 100 W, and a DC power source was used as the power source 10. The film formation time was adjusted so that the thickness of the ZnO film was 74 nm.

  Next, an Ag film as a metal layer was continuously formed on the ZnO film while maintaining a vacuum. An Ag target was used as the target 8, and the atmospheric gas in the vacuum chamber 6 was introduced with argon from the gas introduction pipe 8, and the pressure was adjusted to 0.5 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the Ag target 11 through the power cable 12 was 50 W, and a DC power source was used as the power source 10. When the maximum magnetic flux density at the center of the target was measured, it was 149 mT, and the discharge voltage applied to the target during film formation was 320 V. The film formation time was adjusted so that the thickness of the Ag film was 14 nm.

  Next, a BN film as a barrier layer was continuously formed on the Ag film while maintaining a vacuum. Using a BN target as the target 8, nitrogen gas was introduced from the gas introduction pipe 8 as the atmospheric gas in the vacuum chamber 6, and the pressure was adjusted to 0.5 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the BN target 11 through the power cable 12 was 200 W, and the power source 10 was an AC power source having a frequency of 13.56 MHz. The film formation time was adjusted so that the thickness of the BN film was 2.6 nm.

  Next, a ZnO film as a dielectric layer was continuously formed on the BN film while maintaining a vacuum. A Zn target was used as the target 8, and the atmospheric gas in the vacuum chamber 6 was introduced with oxygen gas from the gas introduction pipe 8, and the pressure was adjusted to 0.2 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the Zn target 11 through the power cable 12 was 100 W, and a DC power source was used as the power source 10. The film formation time was adjusted so that the thickness of the BN film was 28 nm.

Example 7
A low emission film was produced in the same manner as in Example 6 except that the thickness of the BN film of the barrier layer was changed to 5 nm.

Comparative Example 4
ZnO film as the underlayer on the glass substrate, Ag film as the metal layer, ZnAl film of alloy as the barrier layer, ZnO film as the dielectric layer, Ag film as the metal layer, ZnAl film as the barrier layer, ZnO film as the dielectric layer Low emission films were sequentially stacked. As the glass substrate, soda lime glass having a thickness of 3 mm was used.

  A ZnAl film, which is a barrier layer, was continuously formed immediately above the Ag film while maintaining a vacuum. A ZnAl target was used as the target 8, and the atmospheric gas in the vacuum chamber 6 was introduced with argon gas from the gas introduction pipe 8, and the pressure was adjusted to 0.5 Pa by controlling the exhaust valve 9. The power supplied from the power source 13 to the ZnAl target 11 through the power cable 12 was 20 W, and a DC power source was used as the power source 10. The film formation time was adjusted so that the thickness of the ZnAl film was 3.2 nm.

  The film formation conditions for the base layer, dielectric layer, and metal layer other than the barrier layer were the same as in Example 8.

Comparative Example 5
A low radiation film was produced in the same manner as in Comparative Example 4 except that the thickness of the ZnAl film of the barrier layer was 3.8 nm.

2. Evaluation of low-emission film Optical characteristics of the low-emission film were measured using a self-recording spectrophotometer (U-4000, manufactured by Hitachi, Ltd.). The visible light transmittance of the low radiation film (hereinafter sometimes referred to as Tvis) and the visible light reflectance of the low radiation film surface (hereinafter sometimes referred to as Rvis) were calculated in accordance with JIS R3106. . The visible light absorptivity (hereinafter sometimes referred to as Avis) of the low radiation film was calculated from the following equation.

Avis (%) = 100− (Tvis + Rvis)
Further, the surface resistance of the low radiation film (hereinafter sometimes referred to as Rs) was measured using a surface resistance measuring instrument (Napson, Resistest VIII).

  Table 1 shows the optical characteristics and surface resistances of Examples 1 to 9 and Comparative Examples 1 to 5. In addition, the number of layers in Table 1 represents the total number of layers of the thin film stack portion constituting the low radiation film.

  From Table 1, when the number of layers is 3, Example 3 and Example 4 using a BN film for the barrier layer are about 88.0% Tvis, and Examples 1 and 2 using a SiN or SnNO film for the barrier layer 5 had a Tvis of about 87.0%, while Comparative Examples 1 to 3 had a Tvis of 86.5 ± 0.5%. From the above, it can be said that the low radiation films of Examples 1 to 5 are excellent in daylighting properties when used as window glass.

  In addition, the Rvis of Example 5 using SnNO is about 4.0%, which is the lowest of all the low emission films, and when the low emission film of the present invention is used as a window glass, the reflection of the background It is considered that there is an effect of improving the visibility such as the degree becomes small.

  Further, Avis in Examples 1 to 4 using SiN or BN was 7.5 ± 0.5%, whereas Avis in Comparative Examples 1 to 3 was 9.0 ± 0.5. It was also found that the low emission film of the present invention has high clarity related to the fresh appearance of the window glass.

In addition, the surface resistance Rs and the emissivity ε are considered to have the following correlation (reference: J. Szczyrbowski et al., New low emissivity coating based on TwinMag ^™ sputtered TiO ₂ and Si ₃ N ₄ layers, Thin Solid Films, Vol.351, Issues 1-2, 1999, pp.254-259).

ε = 0.0129 × Rs−6.7 × 10 ⁻⁵ × Rs ²
Since the surface resistances of the low emission films of Examples 1 to 5 were equivalent to those of Comparative Examples 1 to 3, it is estimated that the low emissivity of the window glass was equivalent. Further, it is generally said that the surface resistance tends to increase when the Ag film is oxidized, but the above-mentioned tendency is not observed in the examples of the present invention. Therefore, since it is presumed that the Ag film of the embodiment using the barrier layer of nitride or oxynitride is not oxidized, in the low emission film, the barrier layer of nitride or oxynitride is a dielectric layer. It has been shown to be useful as a barrier layer that prevents the Ag layer from being oxidized when forming.

  When the number of layers is 6, when comparing Avis, Example 6 and Example 7 are 13.5 to 16%, while Comparative Example 4 and Comparative Example 5 are as high as 16.5 to 17.0%. Example 6 and Example 7 were found to be excellent in clarity.

  From these results, it was shown that the low radiation film of the present invention was excellent in daylighting, visibility, and clarity while having low radiation as compared with the prior art.

DESCRIPTION OF SYMBOLS 1 Base material 2 Base layer 3 Metal layer 4 Barrier layer 5 Base material holder 6 Vacuum chamber 7 Vacuum pump 8 Gas introduction pipe 9 Exhaust valve 10 Magnet 11 Target 12 Power cable 13 Power source 14 Dielectric layer 15 Thin film lamination part

Claims (7)

A low-emission film formed on a base material by a vapor deposition process has a base layer and a thin film laminated portion on the base material, and the thin film laminated portion contains a metal layer and a barrier layer on the metal layer. The low-emission film is characterized in that the barrier layer is in contact with the metal layer and is made of nitride or oxynitride. 2. The low radiation film according to claim 1, wherein a dielectric layer is formed on the barrier layer when the thin film stack is formed by stacking 3n (n is an integer of 1 or more) layers. The low emission film according to claim 1, wherein the barrier layer has a thickness of 1 to 30 nm. 4. The barrier layer according to claim 1, wherein the barrier layer has at least one selected from the group consisting of B, Si, Al, Zn, Sn, In, Ti, Nb, and Bi as a main component. 2. The low radiation film according to claim 1. 2. The underlayer is at least one oxide, nitride, or oxynitride selected from the group consisting of Zn, Sn, In, Ti, Nb, Bi, B, Al, and Si. The low radiation film of any one of thru | or 4 thru | or 4. The dielectric layer is at least one oxide or oxynitride selected from the group consisting of Zn, Sn, In, Ti, Nb, Bi, B, Al, and Si. Item 6. The low-emission film according to any one of Items 5. The low radiation glass which formed the low radiation film of any one of Claim 1 thru | or 6 on the plate glass is contained, and the visible light transmittance calculated based on JISR3106 is 50% or more. A double-glazed glass for construction.

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