Glass of high-performance, high-durability and low-emissivity and production thereof

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to glass in which a coating film is formed on the surface by sputtering, and a method for producing the same. More specifically, the present invention relates to a sputter-coated glass having high visible light transmittance and high infrared energy reflectance, which is useful as a building glass, and a method for producing the same.

【0002】

[Conventional technology]

For architectural flat glass manufactured by the float method or the like, there is an excellent technique for providing a coating film for controlling sunlight on the flat glass, and two of them are a thermal decomposition method and a magnetron sputtering film forming method. Disadvantages experienced so far in the sputter film forming method are that the film is easily scraped off (that is, lack of durability) and that the polymer seal used when making a multi-faceted glass window partitioned by a lattice or the like. For example, the agent attacks the coating film. This also breaks the seal itself, causing harmful substances to accumulate between the multi-sided glasses. On the other hand, the sputtered coating has the advantages of being able to obtain low emissivity and high transmittance characteristics of visible light as compared with most pyrolysis coatings. These two properties are the most important in obtaining a particular architectural glass.

【0003】

The terms emissivity and transmittance are well known in the art and are used herein in accordance with conventional usage. So, for example, the term transmittance here means the sunlight transmittance consisting of visible light transmittance, infrared energy transmittance, and ultraviolet transmittance. And total solar energy transmission is usually characterized as a weighted average of these other values. Regarding these transmittances, the visible light transmittance is 380-720 nm, infrared rays are 800-2100 nm, ultraviolet rays are 300-400 nm, and total sunlight is 300-2100 nm by the technology using the standard light source C. However, a special infrared range (ie 2500-40000 nm) is used to determine the emissivity, as described below.

【0004】

The visible light transmittance can be measured by using a conventionally known technique. For example, a spectrophotometer such as the Beckmann Sci. Inst. Corp. is used to obtain transmission spectrum curves at each wavelength. Next, the visible light transmission is calculated using ASTM E-308 "Method of calculating the color of an object using the CIE system" (ASTM Standard Yearbook, Vol.14.02). If necessary, a smaller number of wavelength points than those described above can be used. Other visible light transmittance measurement techniques use spectrophotometers such as the Spectraguard spectrophotometer commercially available from Pacific Scientific Corporation. This device directly measures and reports visible light transmission.

【0005】

Emissivity (E) is a unit of measure or characteristic of both light absorptivity and reflectance at a given wavelength. It is usually expressed by the following equation. E- = l- Reflectance (film) [0006]

For architecture, it is important that the emissivity is in the so-called "mid-infrared range" of the infrared spectrum, and sometimes in the "far-infrared range", or about 2500-40000 nm. The term emissivity, as used herein, was proposed by the Primary Glass Manufacturers' Council to "Measure emissivity in flat glass products for construction using radiative analytical measurements and. This red, entitled Test Method for Measuring and Calculating Emittance of Architectural Flat Glass Products Using Radiometric Measurements, as specified by the 1991 ASTM standard for infrared energy measurements to calculate emissivity. It is used for the emissivity measured in the outer range. This standard and its provisions are described as a reference. In this standard, emissivity is divided into two components: hemispherical emissivity (Eh) and normal emissivity (En).

【0007】

The actual accumulation of this emissivity measurement data has been conventionally performed using, for example, a Beckmann model 4260 (Beckmann Sci. Inst. Corp.), which is a spectrophotometer with a VW attachment. This spectrophotometer measures reflectance vs. wavelength, from which emissivity is calculated using the ASTM standard proposed in 1991 above.

【0008】

Another term used herein is sheet resistance. Sheet resistance (Rs) is known in the art and is used based on its known meaning. In general, the term refers to an electrical resistance ohm for an area of a layered structure to an electric current passing through the layered structure on a glass substrate. Sheet resistance is important for many architectural glasses as it is an indicator of how much infrared energy the layer reflects and is therefore often used with emissivity as a measure of this property. Conventionally, sheet resistance is measured using a 4-point probe type ohmmeter. For example, the unrestrained 4-point resistor probe model M-800 with a magnetron instrument head (Signatone Corp., Signaton, Santa Clara, CA).

【0009】

As mentioned above, it is desirable that many architectural glasses have as low radiation as possible and low sheet resistance Rs so that the glass windows reflect most of the infrared rays that hit the glass. Generally, low emissivity (referred to as low E) glass is considered to have a hemispherical emissivity (Eh) of less than about 0.16 and a normal emissivity (En) of less than about 0.12. Desirably, Eh is about 0.13 or less and En is about 0.10 or less. Therefore, at the same time, the sheet resistance (Rs) is preferably less than about 10.5 ohms / square meter. Commercially available glass is usually required to transmit visible light as much as possible, and is approximately 2 mm to 6 mm thick glass using Illuminant C technology (Ill.C) for transmittance measurement, approximately 76. % Or more. From this point of view, the transmittance of visible light is preferably about 78% or more for glass having a thickness of about 2 mm to 6 mm. More preferably, the transmittance of visible light is 80% or more, and most preferably more than 80%.

【0010】

Techniques for producing architectural glass by forming a metal layer and / or a multilayer coating of metal oxides or metal nitrides on a float glass plate by the magnetron sputter film forming method are known and well known metals (eg, Ag, Many combinations and changes of oxides and nitrides (Au, etc.) have been attempted and reported. These techniques use flat or cylindrical targets or a combination thereof within a multi-target zone to achieve the desired effect. An example of a desirable device used in the present invention and the prior art is a magnetron sputter film forming device, which is a product of Airco Corporation. This product is described in US Pat. Nos. 4,356,073 and 4,422,916, which are described as references.

【0011】

In particular, from glass (standard float glass) using the above-mentioned sputter film forming apparatus of Airco, Si₃N₄/ Ni: Cr / Ag / Ni: Cr / Si₃N₄It is known to produce architectural glass having a continuous outward lamination system such as. Here, in reality, the Ni: Cr alloy (ie, nichrome) has a Ni / Cr weight ratio of 80/20, the two nichrome layers are reported to be 7 angstroms thick, and the Ag layer is about 70. Angstrom thickness (especially except when silver is marked 100 angstrom thickness), Si₃N₄The layers are relatively thick (for example, 320 angstroms on the bottom and 450 angstroms on the top). Realistically, the Ag layer is actually only semi-continuity due to its thinness (about 70 angstroms).

【0012】

FIG. 1 is for explaining a sputter film forming apparatus manufactured by Airco Co., Ltd. for manufacturing the above-mentioned products manufactured by Airco Co., Ltd. In the figure, the 1st, 2nd, 4th and 5th zones are made of a cylindrical target t of silicon (Si), and sputtering is performed in a 100% nitrogen atmosphere. The third zone usually uses a planar target P and is used to create three layers of Ni: Cr / Ag / Ni: Cr. Here, a 100% argon atmosphere is used. It has long been believed that nitrogen gas has an adverse effect on silver in sputter film formation techniques, and therefore the third zone was kept out of the influence of nitrogen gas.

【0013】

This coating provides good durability (ie, improved scratch resistance, abrasion resistance, chemical stability, etc.) and this property achieves good levels compared to pyrolysis film formation, but is practical. It was recognized that the other properties above, namely the levels of infrared reflectance and visible light transmittance properties normally required for low reflectance building glass, were not reached. For example, in a glass having a thickness of about 3 mm, the visible light transmittance (Ill.C) is usually about 76%, Eh is about 0.20 to 0.22, and En is about 0.14 to 0.17. Both reflectances are rather high. In addition, the sheet resistance (Rs) is relatively high at 15.8 ohms / square meter. (A more desirable value is about 10.5 or less). Thus, durability is significantly improved, and these coatings are compatible with conventional sealants (thus, the need for "edge removal", which was a problem with multi-faceted windows, can be overcome and is now needed. However, the solar properties have not reached the levels required by many modern buildings.

【0014】

In addition to the layer construction by this Airco device, other coating layers containing silver and / or Ni: Cr have been reported in patent and scientific literature for the purpose of infrared reflection and other ray control. For example, Fabry-Perot filters, other prior art coating and forming techniques, etc. are described in U.S. Pat. Nos. 3,682,528 and 4,799,745 (also described or described herein). Has been done. In addition, many patents such as US Pat. No. 4,179,181; 3,698,946; 3,978,273; 3,901,997 include examples of insulator-metal sandwich structures. Although such coating structures are known or reported, none of the prior art teaches or achieves the ability to use a highly productive sputter coating process, and at the same time, the durability of the pyrolytic coating. No literature mentions obtaining a building glass with an excellent level of solar control characteristics in addition to the characteristics equivalent to or close to those of.

【0015】

The basic Airco equipment and basic methods of operation seem to be fully accepted, but their productivity is inadequate. The cause of the low productivity seems to be the need to isolate silver from nitrogen gas during sputter film formation.

【0016】

[Problems to be Solved by the Invention]

As mentioned above, it is necessary to have the same or similar durability as the pyrolysis coating even in the sputter coating formation system, and to achieve the optimum solar control characteristics, thereby overcoming the problems associated with the usual pyrolysis method. There is. The terms "durable" and "durable" as used herein are used as known in the art and have mechanical and chemical resistance to degradation equivalent to or similar to that obtained by a pyrolytic process. Represents. Further, the film formed by the magnetron sputtering film formation needs to be improved in terms of the transmittance, emissivity, and preferably sheet resistance of the film obtained by the above-mentioned Airco process. Similarly, the productivity of this conventional process needs to be improved. A main object of the present invention is to satisfy the above-mentioned needs. Similarly, other needs can be easily considered by those skilled in the art from the description described below.

【0017】

[Means for solving problems]

In order to achieve the above object, the sputtered film-forming glass product of the present invention has the following constitution. That is, the glass substrate is placed on it from the inside to the outside, and Si₃N₄Lower layer, nickel or nickel alloy first layer, silver layer, nickel or nickel alloy second layer, Si₃N₄It has a layer structure consisting of an upper layer. When the glass substrate has a thickness of about 2 mm to 6 mm, preferably this film-forming glass has a visible light transmittance of about 78% or more (Ill.C), a normal emissivity (En) of less than about 0.12, and a hemispherical emissivity. (Eh) has less than about 0.16.

【0018】

In a desirable embodiment of the present invention, the layer structure is doubled, and the visible light transmittance is about 80% or more, most preferably more than 80% as described above. Also, in other desirable embodiments, the emissivity is about 0.13 or less for Eh and about 0.10 or less for En. In the most desirable embodiment, the emissivity is about 0.12 to 0.13 for Eh and about 0.09 to 0.10. for En. In these examples, the desired range of sheet resistance is 10.5 ohms / square meter or less, most preferably about 9-10 ohms / square meter.

【0019】

In the preferred embodiment of the present invention, the layer structure consists of the above five layers, and nothing else. In another desirable embodiment of the invention, it is possible to increase the layered structure of the invention by providing other conventional coatings that do not compromise the basic quality of the coating of the invention. In one example, this additional layer actually increased the basic quality of this coating. For example, the other layered structure contemplated by the present invention has a seven-layer structure by interposing a nickel-based (for example, nickel-chromium) layer and separating the silver layer into two layers. That is, this layer structure is as follows from the glass substrate to the outside. Si₃N₄/ Ni: Cr / Ag / Ni: Cr / Ag / Ni: Cr / Si₃N₄This 7-layer structure generally has the same high infrared reflectance as that of the above-mentioned 5-layer structure, and exhibits slightly higher durability and scratch resistance characteristics. Further, if necessary, an upper layer for improving scratch resistance can be provided, and an additional lower layer can be provided for improving adhesiveness. However, as described above, the most desirable embodiments of the present invention are a five-layer structure and a seven-layer structure.

【0020】

In the preferred embodiment of the present invention, the thickness of each layer is an important factor in obtaining optimum emissivity and transmittance characteristics. A layer thicker than the above-mentioned conventional Airco 5-layer silver layer thickness of 70 angstroms, that is, when the silver layer is one layer, the continuity of the silver layer is ensured and appropriate infrared reflectance characteristics are ensured. Therefore, use a thickness increased by 20% to 30%. Therefore, in the present invention, a silver layer having a total thickness of about 90 to 105 angstroms, preferably about 95 to 105 angstroms, which is thicker than the silver layer thickness of 70 angstroms having a five-layer structure manufactured by Airco, is used.

【0021】

When the five-layer structure of the present invention, for example, one Ag layer, a thickness of about 95 angstroms is desirable. In an example in which the silver layer is divided into two layers by a nickel-based layer, the total thickness of the two layers is 90 to 105 angstroms, preferably about 50 angstroms for each layer. In this case, the 50 angstrom silver layer is somewhat discontinuous. This discontinuity has been a problem for those manufactured by Airco, but there is no harmful effect from the implementation of the present invention.

【0022】

The nickel-based layer used in the present invention is preferably the same Ni: Cr (80/20) nichrome used by Airco. However, while those made by Airco used a thickness of 10 angstroms (or more), in the present invention they are usually less than about 7 angstroms (eg, less than 6 angstroms, or about 15-20% less). Make it thick.

【0023】

Like the silver layer, the Si of the present invention₃N₄Each of the layers is increased over that of Airco. In the preferred embodiment, the rate of increase is at the same level as the silver layer, i.e. about 20% or more. Therefore, the lower and upper Sis manufactured by Airco₃N₄The layer thickness was about 320 angstroms and 450 angstroms (the lower layer was slightly thinner than the upper layer), whereas in the preferred embodiment of the invention the lower layer Si₃N₄The layer thickness is about 400 angstroms or more, and the upper layer is about 540 angstroms. The most desirable values are 400 angstroms to 425 angstroms in the lower layer and 540 angstroms to 575 angstroms in the upper layer. This Si₃N₄The purpose of the layer is mainly antireflection, color control, chemical resistance, scratch resistance, wear resistance.

【0024】

Multi-sided windows are common in the construction industry, and the layered structure of the present invention is compatible with conventional sealing materials used in multi-sided windows, so the layered structure made by Airco is as good as overcoming problems with multi-sided windows. Can be solved. Therefore, "edge removal" is not necessary in the preferred embodiment of the present invention.

【0025】

The idea of the present invention contradicts the conventional wisdom in the industry. That is, with respect to the desirable layer structure intended here, not only is it not necessary to separate silver from nitrogen when forming a sputter film, but there is also the advantage that both silver and nickel base can be sputtered film formed in the nitrogen atmosphere. is there. There is little loss of silver capacity, and the nickel-based layer contains chromium, which leads to the unexpected effect of a tremendous increase in transmittance when converted to nitrides during sputtering. Therefore, in the preferred embodiment of the invention, the nickel-based target is a Ni: Cr alloy, which during sputtering changes its Cr to a nitride of Cr, at least in part, in the same sputtering zone as silver. It was found that this significantly increased the visible light transmittance of the final product as described above. In addition, making this nitride in the same zone where silver is sputtered will reduce costs and increase productivity.

【0026】

Productivity improvement and cost reduction compared to the Airco process can be obtained empirically as follows. In the airco process (and other processes), Si sputtering must increase the output to the target (cylindrical target in the airco process), and the atmosphere in the sputtering zone is 100% nitrogen gas. It is used and usually difficult due to the limitations of the device. Silver must not be sputtered in a nitrogen-containing environment, and in settings where it is desired to convert chromium to nitride, the Ni: Cr target must be placed in the separation zone, which is costly. Increase. Alternatively, the target may be sputtered in the same nitrogen-containing zone as Si, but this reduces productivity by reducing the number of available Si targets. On the other hand, the method of the present invention has both the advantage of forming a chromium nitride and the advantage that nitrogen gas does not adversely affect silver during sputtering, and two Ni: Cr targets are silver. Since it can be placed in the same zone as the target and sputtered in an argon / nitrogen atmosphere as opposed to the pure argon atmosphere that was conventionally considered necessary, the expensive and unproductive method of the conventional process becomes unnecessary. Therefore, in the preferred embodiment, the atmosphere uses 50% / 50% by volume of argon / nitrogen, but its usable range is 0 to 75% argon and 100% to 25% nitrogen.

【0027】

As mentioned above, the Aeroco process teaches that Si sputtering is performed in 100% nitrogen gas. This is currently one method of sputtering Si according to the present invention, but in a specific environment (for example, small unit, low volume production), when sputtering Si, argon is added to nitrogen and Si is added.₃N₄Although the allowable amount is formed, the sputtering rate of Si is improved.

【0028】

To obtain products with the above properties, the novel method of the present invention sputters Ni: Cr / Ag / Ni: Cr targets in the same zone with an atmosphere containing sufficient nitrogen gas to make chromium nitrides. It is to form a film. Desirably, this atmosphere contains 0-75% by volume of argon and 100-25% by volume of nitrogen. Most preferably, it is 50% by volume of argon and 50% by volume of nitrogen. In one example, the lower and upper sputter coatings are formed in a 100% nitrogen atmosphere, while in the other examples 3-50% by volume argon gas is used with nitrogen to improve productivity.

【0029】

[Example]

A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is an explanatory view of a conventional magnetron sputter film forming apparatus such as an apparatus manufactured by Airco. In the present invention, a 5-zone configuration consisting of 1st zone to 5th zone is used. (The glass substrate advances in the direction of arrow A, and layers are continuously formed.) The first zone is a cylindrical target of silicon (Si) (for example, Si with 3 to 5% by weight of aluminum added to obtain conductivity. ) 6 (t)₁~ t₆) Have. The same target t in the second zone₇~ t₁₂Have. Similarly, the 4th zone and the 5th zone have the same target t.₁₉~ t₂₄, T₂₅~ t₃₀Have.

【0030】

The third zone in the middle has three flat plate targets P to form a five-layer structure as shown in FIG.₁~ P₃It has either (shown in 31, 16 and 33 of FIG. 1, respectively) or 5 to 6 targets (cylindrical or flat) to form a 7-layer structure as shown in FIG. The three flat plate target systems shown can, of course, also be used to create the conventional Airco layered structure shown in FIG. The target arrangement of the third zone for the 7-layer structure shown in FIG. 4 can be appropriately selected by those skilled in the art and is omitted. The utility of the six target positions in Zones 1 to 2 and Zones 4 to 5 is required to form three relatively thin nickel-based (eg nichrome) layers to represent this device. One technology used is Targets 31, 33 (ie, P) as nickel-based targets.₁And P₃), Target 16 (P₂) Instead of P₁And P₃Between t₁₃Is silver, t₁₄Is nickel-based, t₁₅Or t₁₆Use a series of targets, one of which is silver.

【0031】

During operation, the 1st to 5th zones are separated by an appropriate curtain C, which makes it possible to create an atmosphere in which each zone is in a predetermined controlled state by a conventional device known by a sputtering film forming technique. Become. As described above, when silver is used as a target in the sputtering film forming operation, it has been common knowledge from the past that it is important to eliminate nitrogen from the zone (third zone) as much as possible. Therefore, in the process of manufacturing the conventional structure shown in FIG. 2, an atmosphere of 100% argon gas was used. It was also believed that Si sputtering had to be performed in 100% nitrogen gas.

【0032】

Therefore, using this device and atmosphere, the conventional air co-process produced the layered structure shown in FIG. 2 by controlling the speed and power for the sputtering operation. In FIG. 2, the glass substrate is represented by G. The glass substrate is preferably a flat glass with a thickness of 2 to 6 mm and usually has a soda-lime-silica composition produced by a conventional float process. In the 1st and 2nd zones, Si₃N₄A first lower layer 111 consisting of was formed. Its nominal thickness was about 325 angstroms. Zones 1 and 2 were performed in almost 100% nitrogen gas. Next, in Zone 3, a thin layer of 80/20 nichrome 112 (eg, 7 angstroms or higher) is first provided with substantially 100% argon gas, followed by a relatively thick layer of silver 115 (eg, 7 angstroms or higher). For example, about 70 angstroms) was provided. The silver layer 115 is discontinuous, and the discontinuity is shown by a blank portion 117 in FIG. In this same third zone, the silver layer was provided with another relatively thin (eg, 7 angstroms or better) 80/20 nichrome layer 119. Si in the 4th and 5th zones₃N₄The top layer 121 consisting of was provided somewhat thicker than the thickness of the lower layer 111 (eg, about 450 angstroms). This glass is inferior to the desired solar control properties and this example will be referred to below as "standard airco".

【0033】

FIG. 3 shows two examples formed by using the apparatus shown in FIG. 1 of the present invention. This is a five-layer structure formed on a float glass substrate G (thickness 2 to 6 mm). The first layer is Si₃N₄It consists of and is formed in the 1st and 2nd zones of almost 100% nitrogen gas atmosphere. Optionally, under certain conditions (eg, smaller size), some argon gas is introduced (eg, to the second zone) to increase the sputtering of Si. Layers 213 (213'), 215, 219 (219') are then formed in the third zone.

【0034】

In one embodiment of the invention, the atmosphere used in the third zone is substantially 100% argon gas. Target P₁(31) is preferably 80/20 nichrome, but nickel or nickel-based alloys can also be used if desired. To improve solar control properties and overcome the product problems of Figure 2, layer 213, which is a substantially pure metal layer, maintains a thickness of less than about 7 angstroms. This is the target P when making the product shown in Fig. 2.₁Reduce the power consumption to (31) by about 20% or more. In addition, the target P compared to the product in Figure 2.₂The silver layer 215 made from (16) is thicker than the thickness of layer 115 (eg, about 90-105 angstroms), making layer 215 a nearly continuous layer. This is the target P₂It is obtained by increasing the power to 115 by about 20 to 33% compared to when it was formed.

【0035】

Next, another 80/20 nichrome (or nickel-based) pure metal layer 219 is formed in the same way and with the same thickness as when the layer 213 was formed. In addition to this, Si in the next 4th and 5th zones₃N₄The uppermost layer 221 of the above is formed in the same manner as when the lower layer 211 is formed. The top layer 221 is usually somewhat thicker than the bottom layer 211. For example, layer 211 is about 400 angstroms while layer 221 is about 540 angstroms. Si according to the present invention₃N₄The thickness ratio of the upper layer 221 (321) to the lower layer 211 (311) is the same as that of the airco product, but in the preferred embodiment of the present invention, each layer is made thicker than the airco product. This is obtained by increasing the sputtering power in the 1st, 2nd and 4th and 5th zones by about 20% or more. The layered structure thus obtained is slightly inferior to the layered structure of the product of FIG. 2 in scratch resistance, but has almost the same durability, and has extremely excellent emissivity, transmittance, and sheet resistance characteristics. That is, the transmittance approaches the level of 80%, and the emissivity and sheet resistance (Rs) values are quite low.

【0036】

In another desirable embodiment of forming the layered structure of FIG. 3, the apparatus of FIG. 1 is used and a unique method of obtaining better solar control characteristics is used. In this method, contrary to the conventional wisdom, nitrogen gas is used together with argon gas in the third zone, and the nickel-chromium alloy is targeted P.₁(31) and P₃Except that either (33), preferably both, is used to form a chromium metal as its nitride in the Ni: Cr layer (ie, either layer 213', layer 219', or both). For example, it has the same steps as in the first embodiment described above. The ratio of argon to nitrogen can be changed as needed, generally in the range of 0-75% by volume of argon to 100 to 25% by volume of nitrogen, preferably 50% to 50%. 1 Improved properties over the product of the example (eg, transmittance and sheet resistance Rs). In the preferred embodiment of this embodiment, the thickness is the same as the product of the first embodiment. Typical power levels will be described later.

【0037】

The layer structure shown in FIG. 4 is manufactured by the above method of forming a nickel base layer as a substantially pure metal layer, or by using a nitrogen-containing argon atmosphere and a nickel-chromium alloy for one or more targets. Good results are obtained through the generation of chromium nitride in one or more (preferably all) Ni: Cr layers. In this embodiment, the single silver layer 215 of FIG. 3 is further divided into two layers by inserting a nickel base layer in between. Thus, the example of FIG. 4 uses an appropriate number of targets (not shown) in the third zone and Si in the first and second zones.₃N₄Forming the lower layer 311 and Si in the 4th and 5th zones₃N₄Manufactured by forming an upper layer 321. The layer thickness of layers 311, 321 is preferably the same as that of layers 211 and 221.

【0038】

The main difference between the layer structures of FIGS. 4 and 3 is that FIG. 4 shows a nickel-based (preferably 80/20 nichrome) metal layer 313 or its substituted nitride having a thickness of less than about 7 angstroms initially in the third zone. It is to form 313'. It then forms a first silver layer 315A with a thickness of about 50 angstroms, and further forms another nickel-based metal layer 314 with a thickness of less than about 7 angstroms or its substituted nitride 314'. It also forms a second silver layer 315B with a thickness of about 50 angstroms and forms another nickel-based metal layer 319 with a thickness of less than about 7 angstroms or its substituted nitride 319'. In this embodiment, the total thickness of the first and second silver layers is preferably between about 90 and 105 angstroms. And Si₃N₄Completed by forming the upper layer 321.

【0039】

As expected, in the embodiment of FIG. 4, the thickness of each of the silver layers 315A and 315B is only 50 angstroms, and as shown by the blank portion 317, the same discontinuity as that of the blank portion 117 of FIG. 2 occurs. Such a discontinuity was a serious drawback in the product shown in Fig. 2, but it is not a practical defect in the product shown in Fig. 4.

【0040】

The 7-layer structure of FIG. 4 is more durable than the two examples of FIG. 3 and has a lower transmittance (that is, just above the minimum 76% level), but its emissivity and sheet resistance (Rs). The values are better than those in Figure 3. The exact reason for this is unknown, but it is thought that the silver layer was separated into two layers and the Ni-based (Ni: Cr) layer was bonded as an intermediate layer. Therefore, the Ni-based intermediate layer is an important and functional layer that helps to gain great durability. This is especially noticeable in Ni: Cr alloys (eg 80/20 nichrome) in which chromium is converted to its nitride. Next, an example for explaining the present invention in detail is shown below.

【0041】

Example The conventional standard (STD) airco layer structure shown in FIG. 2 and the layer structure according to the two examples of the present invention shown in FIG. 3 were manufactured by the apparatus shown in FIG. Let the first embodiment of the present invention be A type, and the second embodiment (nitride being formed in both layers of 213'and 219') be B type. The target used was Airco's tubular aluminum-added Si target t_1-12And t_19-30Met. Target P₁(31) and P₃(33) was Ni80% by weight and Cr20% by weight. Target P₂(16) was silver (Ag). The glass used was a conventional soda lime silica float glass with a thickness of 3 mm (0.123 inches) manufactured by Guardian Industries Corp. The line speed is 345 inches / minute and the pressure in the 1st, 2nd, 4th and 5th zones is 2.5x10.^-3It was Torr. A 100% nitrogen atmosphere was used in that zone. A 100% argon atmosphere was used for standard airco and type A of the invention. Argon / nitrogen 50% / 50% atmosphere was used for B type. The energy supply for each target is as shown in Attached Tables 1, 2, 3, and 4.

【0042】

[table 1]

<img file="JPH06171984A_D0001.tif" />【0043】

[Table 2]

<img file="JPH06171984A_D0002.tif" />【0044】

[Table 3]

<img file="JPH06171984A_D0003.tif" />【0045】

[Table 4]

<img file="JPH06171984A_D0004.tif" />【0046】

[Table 5]

<img file="JPH06171984A_D0005.tif" />【0047】

[Table 6]

<img file="JPH06171984A_D0006.tif" />【0048】

Two B-type glasses are used so that they can be used for transmittance and infrared energy reflectance in the other two examples of the present invention and in experiments on the effect of layer thickness (especially Ni-based layers). Si in almost the same conditions as the 1st and 2nd zones and the 4th and 5th zones, that is, in a 100% nitrogen atmosphere.₃N₄It was created using the conditions under which the lower and upper layers are formed. The targets in Zones 1, 2 and 4 and 5 are aluminum-added Si targets, P.₁(31) and P₃(33) is 80/20 nichrome and P₂(16) was silver (Ag). The only difference is the use of different power levels within Zone 3, as shown in the table below. The glass was soda lime silica float glass with a thickness of 3 mm.

【0049】

[Table 7]

<img file="JPH06171984A_D0007.tif" />【0050】

As is clear from Table 7, the thickness of the two Ni: Cr (nitride) layers increased slightly, the thickness of the silver layer decreased slightly, and the infrared reflectance and transmittance values decreased. However, both glasses can be used for multi-sided windows in real buildings. In addition, A-type glass samples were made using different power levels in different zones as shown in the table below. The glass thickness was 3 mm, and the same soda lime silica float glass used in Table 7 was used.

【0051】

[Table 8]

<img file="JPH06171984A_D0008.tif" />【0052】

[effect]

The sputtered film-forming glass according to the present invention not only does not need to separate silver from nitrogen when forming a sputtered film, but also has an advantage that both silver and nickel-based can be sputtered film formed in the nitrogen atmosphere. There is little loss of silver capacity, and the nickel-based layer contains chromium, which is more effective than expected when converted to nitrides during sputtering, resulting in a tremendous increase in transmittance. Also, the visible light transmittance of the final product is significantly increased. In addition, making this nitride in the same zone where silver is sputtered will reduce costs and increase productivity.

[Simple explanation of drawings]

[Figure 1]

It is the schematic explanatory drawing which shows the basic structure of the apparatus manufactured by Airco used in this invention.

[Figure 2]

It is a partial cross-sectional view which shows the layer structure by the conventional Airco process.

[Fig. 3]

It is a partial cross-sectional view which shows the layer structure by one Example of this invention.

[Fig. 4]

It is a partial cross-sectional view which shows the layer structure by another Example of this invention.

[Explanation of symbols]

1 ~ 12 Cylindrical target 16 Flat target 19 ~ 30 Cylindrical target 31, 33 Flat plate target 111 Lower layer 113 Nichrome layer 115 silver layer 117 Blank area 119 Nichrome layer 121 Upper layer G glass substrate 211 Lower layer 213, 213'Nickel or nickel-based metal layer 215 silver layer 219, 219'nickel or nickel-based metal layer 221 Upper layer 311 Lower layer 313, 313'nickel or nickel-based metal layer 315A 1st silver layer 314, 314'Nickel-based metal layer 315B 2nd silver layer 317 Blank area 319, 319'Nickel or nickel-based metal layer 321 Upper layer