WO2022253692A1

WO2022253692A1 - Glazing for animal enclosures

Info

Publication number: WO2022253692A1
Application number: PCT/EP2022/064346
Authority: WO
Inventors: Stijn Mahieu; Bhadresh PARBHOO; Philippe VANDESTRICK
Original assignee: Agc Glass Europe
Priority date: 2021-06-03
Filing date: 2022-05-25
Publication date: 2022-12-08

Abstract

The present invention concerns a coated article having high ultraviolet light transmittance that may be used in an insulating glazing for animals kept in captivity comprising a first glass substrate and a coating on at least part of one first major surface of the first glass substrate, the coating comprising in sequence starting from the first glass, an undercoating in direct contact with the first glass substrate, a first functional layer in direct contact with the undercoating, an intermediate coating in direct contact with the first functional layer, a second functional layer in direct contact with the intermediate coating, an overcoating in direct contact with the second functional layer, the first and second functional layers being metal layers reflecting infrared light, wherein the coating comprises not more than two functional layers, and no metal layer other than the functional layers and wherein the undercoating, intermediate coating and overcoating each comprise one or more layers comprising oxides, nitrides or oxynitrides of metals, of silicon and/or of mixtures of metals and/or silicon, the metals being selected from Ti, Zr, Nb, Hf, Bi, Al, Zn, Sn, characterized in that the geometrical thickness of the intermediate coating is comprised between 50 and 70 nm, in that the geometrical thickness of the overcoating is comprised between 30 and 40nm and in that the sum of the geometrical thicknesses of the first and second functional layers is comprised between 21 and 26nm.

Description

Glazing for animal enclosures

Technical Field

[0001] The present invention relates to a coated article having high ultraviolet light transmittance that may be used in an insulating glazing for animals kept in captivity.

Background Art

[0002] In zoos and animal parks, animals are frequently kept in glazed, greenhouse-like, enclosures. The glazing used provides light for both animals, plants and the visitors, and is usually provided with insulating and/or solar control coatings so as to avoid overheating during hot days and heat loss during cold days. Such coatings are known in the art for insulating glazing used in buildings. These solar control and or insulating low emissivity (low-E) coatings may be highly performing in their solar control or insulating lowE function and esthetically adapted to their use in buildings, having neutral colors in transmission and reflection. They are however not optimized for plant growth. In particular, they reduce significantly the transmittance of ultraviolet (UV) light, as such UV light may adversely affects ageing of indoor fabrics, colors and such.

[0003] Animals, in particular certain reptiles and birds, however obtain vitamin D through exposure to ultraviolet (UV) light. When they are kept in captivity, such as in zoos or animal parks, the UV absorbing glazing used absorbs a large part of UV light, making it necessary to provide UV lights within the glazed enclosure to avoid vitamin D deficiencies.

[0004] There is therefore a need in the art to provide glazing that may be used in enclosures of spaces where animals are kept, that avoid overheating as and/or heat loss and at the same time provide high UV transmittance for the health of the animals.

Summary of invention

[0005] It is an object of the present is to provide a coated article providing an adequate compromise between, on one hand, solar control, to avoid overheating and/or low emissivity to avoid heat loss and, on the other hand, UV light transmittance to promote animal health.

[0006] It is another object of the present invention to provide a coated article providing an adequate compromise between, on one hand, solar control, to avoid overheating and/or low emissivity to avoid heat loss and, on the other hand, UV light transmittance to promote animal health and that is esthetically pleasing. In particular the coated article may have neutral colors in transmission and/or reflection.

[0007] The coated article, may have neutral colors of transmitted light whether in a single glazing or multiple glazing, that are preferably withing the follow value ranges for L* a*, b*: 86 < L* < 99; -5 < a* < +5; -6 < b* < +6.

[0008] It is another object of the present invention to provide a coated article that may be used in an enclosure for a variety of spaces for keeping animals in captivity, in particular reptiles and birds.

[0009] The inventors have in particular found that the desired optoenergetical properties are obtained by providing a coated article comprising a glass substrate and a coating, the coating comprising, in sequence starting from the glass, an undercoating, a first functional layer, an intermediate coating, a second functional layer and an overcoating.

[0010] Such coatings, in particular not comprising more than two functional layers, may provide optimum optoenergetical compromises for the intended application of the present invention.

[0011] According to the present invention the geometrical thickness of the intermediate coating is comprised between 50 and 70 nm and the sum of the geometrical thicknesses of the two functional layers is comprised between 21 and 26 nm.

[0012] The inventors have found that thereby, in particular by limiting as far as possible coating thicknesses responsible for UV absorption, the following optoenergetical properties, measured according to standard EN410, may be obtained on a substrate of 6 mm thick low-iron glass, such as for example the low iron soda lime glass Clearvision commercialized by AGC: a. Emissivity less than 0.045 b. Visible light transmittance TL greater than 65% c. UV light transmittance Tuv greater than 40% d. Energetical transmittance TE less than 45%

[0013] Advantageously, Visible light transmittance TL is greater than 70% and/or UV light transmittance Tuv greater than 42% and/or Energetical transmittance TE less than 43%. a. The following information is used in the present invention: b. light transmission (LT) is the percentage of incident light flux, illuminant D65/2°, transmitted by the glazing. c. light reflection (LR) is the percentage of incident light flux, illuminant D65/2°, reflected by the glazing. It may be measured from the layer side (LRc) or the substrate side (LRg). d. energy transmission (ET) is the percentage of incident energy radiation transmitted by the glazing calculated in accordance with standard EN410. e. energy reflection (ER) is the percentage of incident energy radiation reflected by the glazing calculated in accordance with standard EN410. It may be measured on the external side of the building or vehicle (ERext) or the internal side of the building or vehicle (ERint). f. solar factor (SF or g) is the percentage of incident energy radiation that is directly transmitted by the glazing, on the one hand, and that is absorbed by the glazing and then radiated in the opposite direction to the energy source in relation to the glazing. It is here calculated in accordance with standard EN410. g. the U value (coefficient k) and emissivity (e) are calculated in accordance with standards EN673 and ISO 10292. h. the CIELAB 1976 values (L*a*b*) are used to define the tints or colors. They are measured with illuminant D65/10°. Description of embodiments

[0014] According to the present invention the functional layers are metal layers reflecting infrared light. In certain advantageous embodiments these functional layers comprise silver, optionally a silver alloy, in particular an alloy of silver and palladium. Advantageously the functional layers essentially consist of silver.

[0015] According to the invention, the undercoating, intermediate coating and overcoating each comprise one or more layers comprising or essentially consisting of oxides nitrides or oxynitrides of metals, of silicon and/or of mixtures of metals and/or silicon. The metals are selected from Ti, Zr, Nb, Hf, Bi, Al, Zn, Sn. In certain advantageous embodiments, one or more dielectric coatings comprise at least one of mixed titanium and zirconium oxides, of mixed zinc and tin oxides or of mixed silicon and aluminum oxides or of silicon nitride. Silicon nitride is particularly advantageous to prevent migration of Na or O during heat treatments. Mixed oxides of titanium and zirconium are particularly interesting as high refractive index material that resists to thermal treatments without generating haze.

[0016] In certain embodiments there is no additional coating over the overcoating. In certain other embodiments there a sacrificial carbon layer deposited on the overcoating, that may be burned off during tempering so that in the final, tempered product there is no additional coating over the overcoating.

[0017] For the purpose of the present invention, the undercoating, intermediate coating and overcoating comprise any wetting layers, contact layers, primer layers generally used in magnetron sputtering of layer stacks comprising functional layers of silver for example.

[0018] According to the present invention, the coated article of the present invention comprises no metal layer other than the functional layers. Such layers tend to increase absorption of UV light.

[0019] Any of the material compositions above may also at least one other element and containing up to at most about 10% by weight of this at least one other element. Some of the other elements are present as impurities in the target material used for magnetron sputtering. Some of these other elements are present in the sputtering target material to avoid problems during the coating deposition process. This is in particular the case for aluminum doping of silicon and zinc targets. For the purposransparent conductive oxides, such as aluminum doped zinc oxide are included as layers of the dielectric coatings.

[0020] In certain embodiments of the present invention the geometrical thickness of the undercoating is comprised between 20 and 50nm, alternately between 30 and 50 nm.

[0021] In certain embodiments of the present invention the geometrical thickness of the third dielectric coating is comprised between 30 and 40 nm.

[0022] In certain embodiments of the present invention the sum of the geometrical thicknesses of the first, second and overcoatings is comprised between 110 and 160nm.

[0023] In certain embodiments of the present invention the sum of the geometrical thicknesses of the functional layers is comprised between 20 and 27 nm. Advantageously the sum of the geometrical thicknesses of the functional layers may be comprised between 21 and 26 nm.

[0024] In certain embodiments of the present invention the geometrical thickness T 1 of the first functional layer is equal or greater to the geometrical thickness T2 of the second functional layer. Advantageously 1.0 ^c T2 < T1 < 1.5 ^c T2. More advantageously 1.1 * T2 < T1 < 1.4 * T2.

[0025] For the calculation of the geometrical thicknesses of the dielectric coatings, any

[0026] In certain embodiments, the present invention concerns a multiple glazing unit, or insulating glazing unit (IGU), comprising two or more glass sheets.

[0027] Because of the particular selection of layers of the coating stack and because of the combination of the selected number and thickness and number of silver layers and geometrical thicknesses of dielectric coatings such glazing units may thus provide one or more of the following advantages, evaluated for when the coating is on a standard 6 mm thick extra-clear low-iron soda-lime float glass sheet incorporated into a double glazing unit with another standard 4 mm thick extra-clear low-iron soda-lime float glass sheet, space between glass sheets of 16 mm filled to 90% with argon, the coating is in position 2, no other coatings being present: a. A high ultraviolet light transmission (Tuv > 35%, advantageously 35% < Tuv < 50%, more advantageously 35% < Tuv < 45%) for the animal health reasons mentioned above; b. a high light transmission (LT > 60%, advantageously LT > 62%, more advantageously LT > 65%) at the same time as a low emissivity (e < 0.038, advantageously e < 0.025) to limit heat losses; c. a low solar factor (SF < 45%, advantageously SF < 43%) to enable reduction of the risk of excess overheating as a result of sunshine; d. a high selectivity (LT/SF > 1.4, advantageously LT/SF > 1.5); e. an insulating property enabling a value U < 1.1 W/(m2K), advantageously U < 1.0 W/(m2K) to be reached; f. a neutrality of tint in transmission and in inside reflection, whether in a single glazing or multiple glazing, with preferred values in double glazing: g. in transmission: 82 < L* < 94; -6 < a* < +1 ; -4 < b* < +2 h. in reflection inside: 35 < L* < 45; -2 < a* < +5; -4 < b* < +3 i. the possibility of being heat treated, the coating being resistant to high temperatures, or of being used without heat treatment; j. an aesthetic appearance without flaw, with an extremely limited or even non-existent haze without or after heat treatment, and the absence of unacceptable spots after heat treatment; k. an adequate chemical stability for use without heat treatment or for the time interval before heat treatment, and in particular a result of the climatic chamber test or the salt spray test according to standard EN1036-2012 that does not give any defect or any discoloration visible to the naked eye after 1 day, preferably after 3 days.

[0028] The properties of an IGU comprising the coating of the present invention depend on the substrates. The IGU performance of a coating may be evaluated or compared using the substrates chosen above, for example the low iron soda lime glass Clearvision commercialized by AGC or any similar low iron soda lime glass, even if the coating is combined with different substrates.

[0029] Any one glass sheet in a glazing comprising a coating of the present invention may be a laminated glass sheet, comprising two glass sheets laminated by a sheet of thermoplastic interlayer. Regular thermoplastic interlayers are highly UV absorbing. For the present invention it is important to choose thermoplastic interlayers having high UV transmittance. The UV transmittance of the interlayer, evaluated as the Tuv of a laminated glazing of two 4mm thick normal soda lime glass sheets may be at least 40%, advantageously at least 46%, more advantageously at least 48%. The interlayer may have a thickness of at least 0.38mm, for example of about or of at least 0.76mm, of about or of at least 0.89mm, or of about 1.52 mm. The interlayer may for example be of polyvinyl butyral (PVB) or ethyl vinyl acetate (EVA).

[0030] In an exemplary embodiment, the present invention concerns an insulating glazing comprising an first glass sheet, bearing on its inner surface, turned towards the space in between glass sheets, a coating according to the present invention the second spaced-apart glass sheet may be a laminated glass sheet. The first glass sheet may be a low-iron glass sheet for example of 8mm thickness, the inner glass sheet may be a laminated glass sheet of two 5mm mid-iron soda lime glass sheets and a 0.76 mm thick thermoplastic PVB interlayer. The low-iron glass may be for example AGC Clearvision glass, the mid-iron glass may be AGC Clearlite glass.

[0031] In certain embodiments of the present invention, the laminated glass sheet may be turned towards the inside or the outside of a building depending on requirements of safety standards for example.

[0032] In certain embodiments of the present invention, Any one of the glass sheets may also be a heat strengthened glass sheet, or a chemically strengthened glass sheet.

[0033] The substrate is preferably a glass sheet made of glass whose matrix composition is not particularly limited and may thus belongs to different glass categories. The glass may be a soda-lime-silicate glass, an alumino silicate glass, an alkali-free glass, a boro-silicate glass, etc. Preferably, the glass sheet of the invention is made of a soda-lime glass or an alumino silicate glass.

[0034] According to an embodiment of the invention, the glass sheet has a composition comprising, in a content expressed in percentages of the total weight of the glass:

Si0₂ 55 85%

AI2O3 0 30%

B2O3 0 20%

Na₂0 0 25%

CaO 0 20%

MgO 0 15%

K₂0 0 20%

BaO 0 - 20%.

[0035] In a preferred manner, the glass sheet has a composition comprising, in a content expressed in percentages of the total weight of the glass:

Si0₂ 55 - 78%

AI2O3 0 - 18%

B2O3 0 - 18%

Na₂0 5 - 20%

CaO 0 - 10%

MgO 0 - 10%

K₂0 0 - 10%

BaO 0 - 5%. [0036] In a more preferred manner, the glass sheet has a composition comprising, in a content expressed in percentages of the total weight of the glass:

Si0₂ 65 - 78%

AI2O3 0 - 6%

B2O3 0 - 4%

CaO 0 - 10%

MgO 0 - 10%

Na₂0 5 - 20%

K₂0 0 - 10%

BaO 0 - 5%.

[0037] Such a soda-lime-type base glass composition has the advantages to be inexpensive even if it is less mechanically resistant as such.

[0038] Ideally, according to this last embodiment, the glass composition does not comprise B2O3 (meaning that it is not intentionally added, but could be present as undesired impurities in very low amounts).

[0039] In an alternative more preferred manner, the glass sheet has a composition comprising, in a content expressed in percentages of the total weight of the glass:

S1O2 55 - 70%

AI2O3 6 - 18%

B2O3 0 - 4%

CaO 0 - 10%

MgO 0 - 10%

Na₂0 5 - 20%

K₂0 0 - 10%

BaO 0 - 5%.

[0040] Such an alumino-silicate-type base glass composition has the advantages to be more mechanically resistant but it is more expensive than soda-lime.

[0041] Ideally, according to this last embodiment, the glass composition does not comprise B2O3 (meaning that it is not intentionally added, but could be present as undesired impurities in very low amounts). [0042] According to an advantageous embodiment of the invention, combinable with previous embodiments on base glass composition, the glass sheet has a composition comprising a total iron content, expressed in terms of FeaC , ranging from 0.002 to 0.06 weight%. Such low iron contents help obtaining a high UV transmittance with the coated glass. A total iron (expressed in the form of FeaC ) content of less than or equal to 0.06 weight% makes it possible to obtain a glass sheet with almost no visible coloration and allowing a high degree of flexibility in aesthetic designs (for example, getting no distortion when white silk printing of some glass elements of smartphones). The minimum value makes it possible not to be excessively damaging to the cost of the glass as such, low iron values often require expensive, very pure, starting materials and also purification of these. Preferably, the composition comprises a total iron (expressed in the form of Fe2C ) content ranging from 0.002 to 0.06 weight%. Alternately, the composition comprises a total iron (expressed in the form of Fe2C ) content ranging from 0.02 to 0.06 weight%, as is considered typical for a mid-iron soda lime glass. More preferably, the composition comprises a total iron (expressed in the form of Fe2C ) content ranging from 0.002 to 0.02 weight%, as is considered typical in a low-iron soda lime glass. In the most preferred embodiment, the composition comprises a total iron (expressed in the form of Fe2C ) content ranging from 0.002 to 0.015 weight%.

[0043] According to another embodiment of the invention, in combination with previous embodiments on Fe2C content, the glass has a composition comprising chromium in a content such as : 0.0001% < C^C £ 0.06%, expressed in percentages of the total weight of glass. Preferably, the glass has a composition comprising chromium in a content such as : 0.002% < 0₂0₃ £ 0.06%. This chromium content allows getting a glass with a higher IR transmission.

[0044] According to a preferred embodiment, the glass sheet of the invention is a float glass sheet. The term “float glass sheet” is understood to mean a glass sheet formed by the float process, which consists in pouring the molten glass onto a bath of molten tin, under reducing conditions.

[0045] The glass sheet according to the invention may have a thickness of from 0.1 to 25 mm substrate thickness may be adapted to different applications as is well known in the art.

[0046] It is noted that the invention relates to all possible combinations of features recited in the claims.

[0047] The present invention in certain embodiments concerns the following items:

Item 1. A coated article comprising a first glass substrate and a coating on at least part of one first major surface of the first glass substrate, the coating comprising in sequence starting from the first glass, an undercoating in direct contact with the first glass substrate, a first functional layer in direct contact with the undercoating, an intermediate coating in direct contact with the first functional layer, a second functional layer in direct contact with the intermediate coating, an overcoating in direct contact with the second functional layer, the first and second functional layers being metal layers reflecting infrared light, wherein the coating comprises not more than two functional layers and no metal layer other than the functional layers and wherein the undercoating, intermediate coating and overcoating each comprise one or more layers comprising oxides, nitrides or oxynitrides of metals, of silicon and/or of mixtures of metals and/or silicon, the metals being selected from Ti, Zr, Nb, Hf, Bi, Al, Zn, Sn, characterized in that the geometrical thickness of the intermediate coating is comprised between 50 and 70 nm , in that the geometrical thickness of the overcoating is comprised between 30 and 40nm and in that the sum of the geometrical thicknesses of the first and second functional layers is comprised between 21 and 26nm.

Item 2. Coated article according to item 1 wherein the geometrical thickness of the undercoating is comprised between 20 and 50nm, alternately between 30 and 50nm.

Item 3. Coated article according to any one preceding item wherein the thickness of the intermediate coating is comprised between 55 and 65 nm, preferably between 57 and 63 nm. Item 4. Coated article according to any one preceding item wherein the sum of the geometrical thicknesses of the undercoating, intermediate coating and overcoating is comprised between 110 and 160nm.

Item 5. Coated article according to any one preceding item further comprising, in sequence starting from a second major surface of the first glass substrate a thermoplastic interlayer in direct contact with the first glass substrate and a second glass substrate in direct contact with the thermoplastic interlayer.

Item 6. Coated article according to item 7 wherein the thermoplastic interlayer has an ultraviolet light transmittance of at least 40%, evaluated as the ultraviolet light transmittance of a laminated glazing of two 4mm thick normal soda lime glass sheets.

Item 7. Coated article according to any one of items 1 to 8 wherein the first and/or second glass substrate has a composition comprising a total iron content, expressed in terms of Fe203, ranging from 0.002 to 0.06 weight%

Item 8. Coated article according to any one of items 1 to 9 wherein the average refractive index at a wavelength of 550nm of the undercoating and/or the intermediate coating and/or the overcoating is comprised between 1.8 and 2.4 .

Item 9. Insulated glazing unit comprising a coated article according to any one of items 1 to 8.

Item 10. Building for keeping animals in captivity comprising a coated article according to any one of items 1 to 8.

Item 11. Method for keeping animals in captivity, wherein the animals produce vitamin D through exposure to ultraviolet light, comprising surrounding at least partly the animals with an enclosure comprising a coated article according to any one of items 1 to 8.

Examples

[0048] Example 1 : The following layer sequence in Table 1 , starting from the glass, is prepared on a 6mm thick Clearvision, low-iron glass sheet. Preferably magnetron sputtering is used with metal and/or ceramic targets and sputtering under Ar or Ar/02 or Ar/N2 mixed atmospheres under vacuum.

[0049] Table 1

[0050] Zn2Sn04 is a mixed oxide of zinc and tin containing 50% by weight of each constituent; a Zn2Sn04 layer may be replaced, or partly replaced by a layer of mixed zinc tin oxide of different composition, for example comprising a weight ratio of ZnO/Sn02 of 90/10.

[0051] TiZrOx is a mixed titanium zirconium oxide deposited from a ceramic target comprising a weight ratio Ti02/Zr02 of 65/35. Y203 is generally present as an impurity;

[0052] ZnO:AI is an aluminium-doped zinc oxide with an aluminium content of between 1 % and 5% by weight of aluminum.

[0053] The refractive index of Zn2Sn04, Si3N4 and ZnO:AI is 2.0 at a wavelength of 550nm. The refractive index of TiZrOx is 2.4 at a wavelength of 550 nm.

[0054] The optoenergetical performance of Example 1 is compared to other commercially available products in Table 1 below for double glazing units of an outer Clearvision 4 mm thick extra-clear low-iron soda-lime float glass sheet, bearing the coating in position 2, a 16mm space filled with 90% Argon in between the glass sheets, and an inner glass sheet of 4mm thickClearvision extra-clear low-iron soda-lime float glass. The comparative products are of AGC’s Energy and Stopray Vision ranges. [0055] Table 2

[0056] Example 2: The following layer sequence, starting from the glass, is prepared on a 6mm thick Clearvision, low-iron glass sheet and then thermally strengthened (tempered). Preferably magnetron sputtering is used with metal and/or ceramic targets and sputtering under Ar or Ar/02 or Ar/N2 mixed atmospheres under vacuum.

[0057]

[0058] The optoenergetical performance of Example 2 is compared to other commercially available products in Table 3 below for double glazing units of an outer Clearvision 4 mm thick tempered extra-clear low-iron soda-lime float glass sheet, bearing the coating in position 2, a 16mm space filled with 90% Argon in between the glass sheets, and an inner glass sheet of 4mm thickClearvision extra-clear low-iron soda-lime float glass. The comparative products are of AGC’s Energy and Stopray Vision ranges.

[0059] Table 3

Claims

Claim 1. A coated article comprising a first glass substrate and a coating on at least part of one first major surface of the first glass substrate, the coating comprising in sequence starting from the first glass, an undercoating in direct contact with the first glass substrate, a first functional layer in direct contact with the undercoating, an intermediate coating in direct contact with the first functional layer, a second functional layer in direct contact with the intermediate coating, an overcoating in direct contact with the second functional layer, the first and second functional layers being metal layers reflecting infrared light, wherein the coating comprises not more than two functional layers and no metal layer other than the functional layers and wherein the undercoating, intermediate coating and overcoating each comprise one or more layers comprising oxides, nitrides or oxynitrides of metals, of silicon and/or of mixtures of metals and/or silicon, the metals being selected from Ti, Zr, Nb, Hf, Bi, Al, Zn, Sn characterized in that the geometrical thickness of the intermediate coating is comprised between 50 and 70 nm , in that the geometrical thickness of the overcoating is comprised between 30 and 40nm and in that the sum of the geometrical thicknesses of the first and second functional layers is comprised between 21 and 26nm.

Claim 2. Coated article according to claim 1 wherein the geometrical thickness of the undercoating is comprised between 20 and 50nm.

Claim 3. Coated article according to any one preceding claim wherein the thickness of the intermediate coating is comprised between 55 and 65 nm, preferably between 57 and 63 nm.

Claim 4. Coated article according to any one preceding claim wherein the sum of the geometrical thicknesses of the undercoating, intermediate coating and overcoating is comprised between 110 and 160nm.

Claim 5. Coated article according to any one preceding claim further comprising, in sequence starting from a second major surface of the first glass substrate a thermoplastic interlayer in direct contact with the first glass substrate and a second glass substrate in direct contact with the thermoplastic interlayer.

Claim 6. Coated article according to claim 7 wherein the thermoplastic interlayer has an ultraviolet light transmittance of at least 40%, evaluated as the ultraviolet light transmittance of a laminated glazing of two 4mm thick normal soda lime glass sheets.

Claim 7. Coated article according to any one of claims 1 to 8 wherein the first and/or second glass substrate has a composition comprising a total iron content, expressed in terms of Fe₂0₃, ranging from 0.002 to 0.06 weight%

Claim 8. Insulated glazing unit comprising a coated article according to any one of claims 1 to 8.

Claim 9. Building for keeping animals in captivity comprising a coated article according to any one of claims 1 to 8.

Claim 10. Method for keeping animals in captivity, wherein the animals produce vitamin D through exposure to ultraviolet light, comprising surrounding at least partly the animals with an enclosure comprising a coated article according to any one of claims 1 to 8.