JP2009001482A - Improved coated glass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar control glass, particularly a high performance solar control glass exhibiting achromatic color in both reflection and transmission. <P>SOLUTION: The coated glass 1 has a coating comprising a heat absorbing layer 14 and a low emissivity layer 13 of a metal oxide. The preferred heat absorbing layer 14 absorbs preferentially heat at wavelengths above 700 nm, and is composed, for example, of non-stoichiometric or doped tungsten oxide. The preferred low emissivity layer 13 is composed of a semi-conductor metal oxide, for example doped tin oxide or doped indium oxide. The coated glass has an achromatic color. The coating is suitable for deposition on-line on the glass ribbon, during the glass production process, by pyrolytic methods for example chemical vapor deposition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to coated glass, and more particularly to high performance solar control coated glass.

  There is an increasing demand for solar control glasses, particularly high performance solar control glasses that exhibit neutral colors in both reflection and transmission. “High performance” solar control glass means glass that transmits a much higher proportion of incident light than the proportion of total incident radiation energy (total solar heat). Colored glass with iron added can provide high solar control performance, but iron colors the glass green, and green shades are not always acceptable. In addition, including other additives such as, for example, a combination of selenium and a metal oxide such as cobalt oxide can change the green hue more achromatic, but incident heat: transmitted incident light As the percentage increases, some performance is sacrificed.

  British patent application GB 2288818A describes a pyrolytically coated glazing panel having a low solar factor and a high purity reflection color. The GB2288818A includes a first layer containing an oxide of cobalt, iron and chromium and a dielectric second having a specific refractive index, for example, containing aluminum nitride, aluminum oxide, tin oxide or titanium oxide, zirconium oxide or silicon oxide. A coated glass comprising a glass substrate coated with a layer is disclosed. Canadian Patent Specification CA11173383 describes a method for improving the wear resistance of transparent colored metal and metal oxide films on glass. The CA 1117388 describes a method of coating a substrate with a colored layer comprising a mixture of iron, chromium and cobalt oxides and fluorine-doped tin oxide having a thickness in the range of 30 nm to 80 nm.

  A multilayered stack of silver layers combined with a suitable dielectric layer can provide a high performance solar control product and is nearly achromatic in both reflection and transmission but has significant drawbacks. . First, a suitable silver layer will not work with an on-line deposition method in which the coating is applied to the as-manufactured hot glass ribbon, ie, before the ribbon is cut and removed from the production line. Suitable for offline low pressure technology such as magnetron sputtering. Secondly, such silver coatings can be used in coatings in the final product by careful protection and handling during processing, for example by glazing in multiple glazing units with a coating facing the unit space. It has limited physical durability that is required to protect the tempered glass.

UK patent application GB2288818A Canadian Patent Specification CA11173383

  It would be desirable to obtain a coating that provides high performance solar control glazing without the disadvantages of the silver coating described above, and it preferably has a near-achromatic color in reflection and transmission, or at least , Which gives either the green reflection or the transmission color of the above-mentioned characteristics of the high-performance body of colored glass.

  According to the present invention, there is provided a high performance solar control coated glass comprising a glass substrate and a coating comprising a heat absorbing layer and a low emissivity layer comprising a metal compound placed on the heat absorbing layer, The emissivity layer has a thickness of 100 nm to 600 nm, and the coated glass is provided with a coated glass having an emissivity of less than 0.4.

  The present invention is illustrated by the drawings, but is not limited by the attached schematic drawings. Here, FIG. 1 shows a cross-section of a coated glass according to one embodiment of the present invention. FIG. 2 shows a cross section of a coated glass according to a second preferred embodiment of the invention. FIG. 3 shows a cross section of a double glazing glass unit into which the coated glass shown in FIG. 1 is introduced.

  In FIG. 1, a high performance solar control coated glass 1 includes a glass substrate 11, preferably a transparent float glass, and a coating 12 including a heat absorbing layer 14 and a low emissivity layer 13 of a metal compound.

  The embodiment shown in FIG. 2 is the same as the embodiment of FIG. 1, and the coated glass 2 includes a glass substrate 21, preferably a transparent float glass, and a coating 22. However, the coating film 22 is different from the coating film 12 in that, in addition to the heat absorption layer 24 and the low emissivity layer 23, the coating film 22 further includes an iridescence suppression lower layer 25 described below.

  FIG. 3 shows the coated glass plate 1 of FIG. 1 combined with a glazing material 31, typically a second plate of transparent float glass, in a parallel spatial relationship, the plates being spaced apart and spaced. And a double glazing glass unit 3 which is sealed together by a sealing system 32 and has a gap 33 is shown. The coating 12 faces the void 33 of the unit.

  In order to improve performance, it is desirable that the heat-absorbing layer of the coating preferentially absorbs wavelengths above 700 nm, preferably it does not substantially absorb the visible spectrum. The heat-absorbing layer may be a substantially transparent conductive oxide layer, and tungsten oxide is preferred because it exhibits around 900 nm at the characteristic absorption peak.

Tungsten oxide has both conductive and dielectric forms. The stoichiometric tungsten oxide, WO _3, is dielectric and does not substantially absorb near infrared radiation. Non-stoichiometric tungsten oxide, WO _3-x , where x is typically up to about 0.03 (preferably in the range of 0.005 to 0.025) and, for example, hydrogen Doped tungsten oxide containing suitable dopants of different valences, such as fluorine, alkali metals, copper, silver or gold, is electrically conductive and suitable for practical use in the present invention.

  U.S. Pat. No. 5,034,246 describes an organometallic vapor deposition method that adds an alkylamine tungstate salt compound onto a glass substrate having a conductive layer such as indium tin oxide and then the coating. Used to form tungsten oxide by heating the substrate.

  In the present invention, the tungsten oxide layer used as the heat absorption layer under the low emissivity layer may be crystalline or amorphous. If it is crystalline, it is generally preferred to avoid crystals with too large a crystal size. This is because large crystals tend to be cloudy in appearance.

  Other heat absorbing materials that may be used to form the heat absorbing layer include colored transition metal oxides such as chromium oxide, cobalt oxide, iron oxide, molybdenum oxide, niobium oxide and vanadium oxide, and these Mixtures of metal oxides can also be used.

  The heat absorption layer usually has a thickness in the range of 50 nm to 500 nm, in particular 80 nm to 200 nm.

  The low emissivity layer is a layer of a metal compound, typically a metal oxide (since other low emissivity compounds such as metal nitrides and metal silicides tend to have low light transmission), and For example, a transparent semiconductor such as doped indium, tin or zinc oxide. Preferred materials include tin-doped indium oxide and fluorine-doped tin oxide. Low emissivity layers are typically in the range of 100 nm to 600 nm (because the use of thicker layers tends to cause unnecessary reduction in light transmission without making a sufficient reduction in emissivity as compensation). The film thickness is particularly in the range of 200 nm to 500 nm. The low emissivity layer is less than 0.4 (emissivity values referred to in this description and in the appended claims are normal emissivity values measured by ISO 10292: 1994, Annex A) It is preferable to use a low emissivity layer that gives an emissivity of 0.2 or less.

  The low emissivity layer of the coating is usually on top of the heat absorbing layer, and the solar control glass is towards the inner surface of the glazed space (although usually not the building). It is glazed with the facing coating.

  The use of thin films, as in the present invention, can give interference colors and iridescent appearance. In order to avoid or at least mitigate undesired colors resulting from interference effects, a color suppression underlayer (which may itself be a combination of sub-layers), a heat absorbing layer and a low emissivity layer May be applied to the glass before it is deposited. The composition and deposition of the iridescence suppression underlayer is described in GB 2301756B, UK 2115315B, US 5168003 and EP 0275662B previously published. Thus, according to a preferred embodiment of the present invention, the iridescence suppression underlayer or layers thereof are introduced under the coating consisting of the heat absorption layer and the low emissivity layer.

  For example, an additional layer may be introduced over the coating as an anti-reflective layer, but such an upper layer usually leads to loss of low emissivity properties, i.e. increased emissivity, so Is not preferred.

  The heat absorbing layer and low emissivity layer of the present invention may be deposited by known techniques, for example, by sputtering, including reactive sputtering, or by chemical vapor deposition. In fact, it is a significant advantage that both of the above mentioned layers can accept chemical vapor deposition techniques that offer the possibility of applying a coating to a hot ribbon of glass during the glass manufacturing process. A method for depositing the heat absorption layer by chemical vapor deposition is described in, for example, EP0523877A1 and EP0546669B1, but a method for depositing a low emissivity layer of metal oxide by chemical vapor deposition is described in, for example, GB2026454B, US5004490 and EP0365239B. Are listed.

  The present invention will be described but is not limited by the following examples. In the examples, the visible light transmittance described was measured using Illuminant C, as in the following description and claims. The total solar heat transmissivity described is measured by weighting with solar spectral irradiance (ASTME 87-891) representing direct normal radiation incident lines at the surface of the latitude of 37 ° north latitude (air mass 1.5).

Example 1
An iridescence-suppressing underlayer consisting of silicon, carbon and oxygen, having a film thickness of 65 nm and a refractive index of about 1.7 was provided on a ribbon of 3 mm transparent float glass as described in EP 0275662B.

  Thickness of about 100 nm doped with hydrogen, giving a 70% absorption peak on a glass plate cut from a ribbon with a normal reactive magnetron direct current sputtering at a wavelength of 910 nm (measured with a transparent 3 mm float glass without an underlayer) A heat absorbing tungsten oxide layer was overcoated on the lower layer.

An indium tin oxide layer of about 265 nm, which functions as a low emissivity layer and exhibits an electrical resistivity of 4 × 10 ⁻⁴ ohm centimeter, is formed on a tungsten oxide layer by ordinary reactive magnetron direct current sputtering. Deposited using an indium tin target containing 10 atomic percent tin. The indium tin oxide layer has an emissivity of about 0.08.

The resulting coated glass plate had the following properties:
Visible light transmittance 70.4%
Total solar heat transmittance 55.9%

When a coated plate was introduced into a double glazing glass unit having an uncoated transparent float glass plate of 3 mm and an air space of 12 mm, the resulting unit had a visible light transmittance. Is 64%, the total solar heat transmittance is 44%, and under illumination (Illuminant C) shows the following reflection and transmission colors:
a * b * L *
Reflection -5.2 -5.1 46
Transmission -2.9 1.2 84

Example 2
An iridescence-suppressing underlayer consisting of a 25 nm thick undoped tin oxide first layer and a 25 nm thick silica layer was provided on a 3 mm thick transparent float glass ribbon.

  Lithium-doped thickness of about 420 nm giving a 70% absorption peak on a glass plate cut from a ribbon with a normal reactive magnetron direct current sputtering at a wavelength of 910 nm (measured with a transparent 3 mm float glass without an underlayer) A heat absorbing tungsten oxide layer was overcoated on the lower layer.

An indium tin oxide layer of about 85 nm, which functions as a low emissivity layer and exhibits an electrical resistivity of 4 × 10 ⁻⁴ ohm centimeter, is formed on a tungsten oxide layer by ordinary reactive magnetron direct current sputtering. Deposited using an indium tin target containing 10 atomic percent tin.

The resulting coated glass pane had the following properties:
Visible light transmittance 69%
Total solar heat transmittance 54%

When a coated plate was introduced into a double glazing glass unit having an uncoated transparent float glass plate of 3 mm and an air space of 12 mm, the resulting unit had a visible light transmittance. Is 63%, the total solar transmittance is 41%, and under illumination (Illuminant C) shows the following reflection and transmission colors:
a * b * L *
Reflection -3.6 -3.3 90
Transmission -9.3 5.184

Example 3
An iridescence-suppressing lower layer similar to that described in Example 2 was provided on a 3 mm thick float glass ribbon.

A glass plate cut from the ribbon was overcoated with a heat-absorbing non-stoichiometric tungsten oxide layer having a thickness of about 104 nm from the oxide target by magnetron direct current sputtering. The oxidation state of tungsten in tungsten oxide was measured to correspond to the tungsten oxide of formula WO _2.98 .

  An indium tin oxide layer of about 270 nm, functioning as a low emissivity layer, was deposited on the tungsten oxide layer by conventional reactive magnetron direct current sputtering using an indium tin target containing about 10 atomic percent tin. .

When a coated plate was introduced into a double glazing glass unit having a 3 mm plate of uncoated transparent float glass and an air space of 12.5 mm so that the coating was directed to the air space, the resulting unit was visible light The transmittance is 66%, the total solar heat transmittance is 46%, and under illumination (Illuminant C), it shows the following reflection and transmission colors:
a * b * L *
Reflection -7.7 2.25 49
Transmission 1.9 0.61 85

Examples 4-9
In each of this series of examples, it consists of a coated 3 mm transparent float glass, a coated glass plate and a 3 mm uncoated transparent float glass, with a 12.5 mm space and coating facing the space. The optical properties of the double glazing glass unit were calculated from the known optical properties of the glass and the coating layer. Tables 1 and 2 show the structure of the coating and the properties of the coated glass.

  The coating of the present invention provides significant advantages over the prior art. Because they are suitable for production by pyrolysis methods (which have the added benefit of giving them on-line use), they need to pay special attention to handling in a highly reliable form And opens up the possibility of using coatings in free standing glazing without having to protect them in multiple glazing glass units. Compared to colored glass, these are manufactured by applying a more flexible technique (coating) without having to change the composition in the glass melt tank (along with manufacturing-specific losses when changes occur) And the advantage of avoiding the more intense greenish shades that are observed to color as performance increases.

  Furthermore, excellent properties can be achieved with glasses that provide a visible light transmission of greater than 67% and a total solar heat transmission of less than 57%. In general, the solar control glazing of the present invention provides a total solar heat transmission of at least 10% less than the visible light transmission, and the glazing is at least 12% less (with a transparent float glass plate in a double glazing unit). Total solar heat transmission is easily achieved and is preferred (at least 15% in the case of the coated glass used).

A preferred coated glass of the present invention is that the (a ^{* 2} + b ^{* 2} ) ^1/2 of the reflection (when viewed from the coating side) and transmission (when transparent float glass is applied) color is less than 12, In particular, it is a glass with a coating indicating that it is less than 10. In a particularly preferred embodiment, at least one (a ^{* 2} + b ^{* 2} ) ^1/2 of the reflected and / or (preferably and) transmitted color is less than 7.

2 shows a cross section of a coated glass according to one embodiment of the invention. 2 shows a cross section of a coated glass according to a second preferred embodiment of the invention. The cross section of the double glazing glass unit which introduce | transduced the covering glass shown in FIG. 1 is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High performance solar control coating glass 11 Glass substrate 12 Coating 13 Low emissivity layer of metal compound 14 Heat absorption layer 2 Coating glass 21 Glass substrate 22 Coating 23 Low emissivity layer 24 Heat absorption layer 25 Iridescence suppression lower layer 3 Double glazing glass Unit 31 Glazing material 32 Spacing and sealing system 33 Air gap

Claims (19)

  A coated glass comprising a glass substrate and a coating comprising a heat absorption layer and a low emissivity layer of a metal compound placed on the heat absorption layer, the low emissivity layer having a thickness of 100 nm to 600 nm A high performance solar control coated glass, wherein the coated glass has an emissivity of less than 0.4, and the heat absorbing layer is a substantially transparent conductive oxide layer.   The coated glass according to claim 1, wherein the heat absorption layer of the coating is a tungsten oxide layer.   The coated glass according to claim 1 or 2, wherein the heat absorption layer of the coating preferentially absorbs wavelengths exceeding 700 nm.   The coated glass according to any one of claims 1 to 3, wherein the heat absorption layer of the coating is a tungsten oxide layer containing oxygen less than the stoichiometric amount.   The coated glass according to any one of claims 1 to 4, wherein the heat absorption layer of the coating is a tungsten oxide layer doped with hydrogen.   The coated glass according to any one of claims 1 to 5, wherein the heat absorption layer of the coating is a tungsten oxide layer doped with an alkali metal.   The coated glass according to any one of claims 1 to 6, wherein the heat absorption layer of the coating has a thickness in the range of 50 to 500 nm.   The coated glass according to claim 7, wherein the heat absorption layer of the coating has a thickness in the range of 80 to 200 nm.   The coated glass of claim 1 having an emissivity of less than 0.2.   The coated glass according to any one of claims 1 to 9, wherein the low emissivity layer is a semiconductor metal oxide.   The coated glass according to claim 10, wherein the semiconductor metal oxide is doped tin oxide or doped indium oxide.   The coated glass according to claim 1, wherein the low emissivity layer has a thickness in the range of 200 to 500 nm.   The coated glass according to claim 1, wherein the coating further comprises a layer under the iridescence suppression layer or the heat absorption layer.   The coated glass according to any one of claims 1 to 13, which exhibits a total solar heat transmittance of at least 10% less than the visible light transmittance.   15. The coated glass of claim 14, wherein the visible light transmittance is greater than 67% and the total solar heat transmittance is less than 57%. The coating is such that (a ^{* 2} + b ^{* 2} ) ^{1/2 of the} color reflected (when viewed from the coated side) and / or transmitted (when applied to a transparent float glass) ^1/2 is less than 12. The coated glass in any one of 1-15. The coating is such that the (a ^{* 2} + b ^{* 2} ) ^1/2 of the reflection (when viewed from the coating side) and / or transmission (when applied to transparent float glass) color is less than 7. 16. The coated glass according to 16.   A multiple glazing unit comprising the coated glass plate according to claim 1 and a second glazing plate in a spatially parallel relationship.   19. A multiple glazing unit according to claim 18 which exhibits a total solar thermal transmittance of at least 15% less than the visible light transmittance.

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