Glazing panel

Description of equivalent WO 2006048462 A2

0001Glazing Panel

0002This invention relates to glazing panels and particularly, but not exclusively, to solar control and/or low emissivity glazing panels and/or glazing panels which may undergo heat treatment following application to the glazing substrate of an optical filter in the form of a coating stack. The invention relates more particularly to cases where a coating stack is applied to the glazing by a vacuum deposition technique, for example by sputtering or magnetron sputtering.

0003Multiple factors must be considered when designing coating stacks for glazing applications. These include not only the desired opto-energetic performance of the coated glazing panel but also, for example, the abrasion resistance of the coating stack (to facilitate handling, transport and processing), the stability and chemical durability of the coating stack (to facilitate storage under various conditions) and the tolerances of the control of the manufacturing process (to facilitate acceptable manufacturing yields and consistency between product runs).

0004It is known to apply a top coat to a coating stack particularly in an attempt to increase the abrasion resistance and/or chemical durability of a coating stack. GB 2,293,179 relates to a protective additional layer for improving chemical and mechanical durability of coated substrates, while minimising any consequential changes in the optical properties. This protective layer is formed of oxides or oxynitrides of silicon, or mixtures of one or more of oxides, nitrides and oxynitrides of silicon, and has a thickness of from 10 to 100 A.

0005However we have found that such protective additional layer like the one described in GB 2,293,179, when deposited on some coating stacks, for example on a coating stack of the type "base antireflective layer / infra-red reflecting layer / top antireflective layer / top coat layer consisting essentially of at least one material selected from the group consisting of titanium, titanium oxide and titanium nitride", was not always offering a good resistance during transport and that scratches might appear at the surface of the coating. Scratches turned out to be even more numerous and visible when the coated glazing panel was heat- treated after its transport. By transport, it is meant herein transfer for example by trucks, in piles or boxes, from, for example, coater to wholesaler or transformer or to tempering furnace.

0006The present invention provides glazing panels, a method of manufacturing glazing panels and use of a top coat layer as defined in the independent claims. Preferred embodiments are defined in the dependent claims.

0007The present invention may provide an advantageous combination of good mechanical resistance, particularly good resistance to scratches during transport, heat treatability, chemical durability, humidity resistance and stability of manufacturing parameters.

0008The topcoat layer may advantageously be a combination of at least Iwo sublayers: the first topcoat sublayer is thought to provide inter alia a "reserve" useful when the glazing panel is to be heat-treated to ensure thermal protection to other parts of the coating stack during heat-treatment; and the second topcoat sublayer is thought to provide inter alia a mechanical protection to the coated glazing panel.

0009It has been found advantageous that the top coat layer comprises a first topcoat sublayer, underneath the second topcoat sublayer, consisting essentially of at least one material selected from the group consisting of titanium, titanium oxide and titanium nitride. One advantage of the first topcoat sublayer of the present invention is that it may provide to the glazing panel a particularly good chemical durability during storage, for example prior to heat treatment and/or assembly, with a facility to control the manufacturing tolerances and production process. This may be combined with an ability to provide thermal protection to other parts of the coating stack during heat treatment. Preferably, the first and second topcoat sublayers are in direct contact with each other, but in other embodiments, a further sublayer may be present between them. Still preferably, the top coat layer consists of Iwo topcoat sublayers. However, in some embodiments, the top coat layer may comprise additional sublayers, for example under the first topcoat sublayer.

0010The first topcoat sublayer may comprise a material other than those cited above, for example, it may consist of, comprise or be based on: ^■ Ti, Zr, Hf, V, Nb, Ta, Cr or their mixtures or a mixture of at least one of those metals with Al and/or B or

0011^■ an oxide, a sub-stoichiometric oxide, a nitride or an oxynitride of Ti, Zr, Hf, V, Nb, Ta, Cr or their mixtures, or an oxide, a sub-stoichiometric oxide, a nitride or an oxynitride which is a mixture of at least one of those metals with Al and/or B.

0012The first topcoat sublayer may have a geometrical thickness in the range 20 to 100 A, preferably in the range 20 to 80 A or 20 to 50 A or 20 to 40 A or 20 to 30 A, and still more preferably in the range 25 to 30 A. Thicknesses of at least 20 A may allow to avoid damages when heat-treating the glazing panel and thicknesses of no more than 100 A, preferably 80 A or 50 A, may avoid a too great decrease in the luminous transmittance of the coated glazing panel.

0013The second topcoat sublayer may consist essentially of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbonitride, silicon oxycarbide, or silicon oxycarbonitride. Preferably, this layer is deposited by a vacuum deposition technique, particularly magnetron sputtering. The target used to deposit such a layer may be made of pure Si or Si doped with for example one or more of Al (for example 8% Al in the Si target), Zr, Ti, NiCr, Ni, B or Sb, as is well-known in the art. The second topcoat sublayer may consequently incoporate relatively small amounts of such doping agent without departing from this invention. Targets of SiC, like target FG90 of Carborundum Company, may also be used.

0014The geometrical thickness of the second topcoat sublayer is advantageously in the range 10 to 50 A, preferably in the range 10 to 40 A, still more preferably in the range 15 to 3θA. Below 10 A, the second topcoat sublayer may not be sufficiently thick to protect the coating stack against scratches, for example during transport. Furthermore, when the coated glazing panel is heat- treated after its formation or after its formation and transport, we have found that thicknesses of the second topcoat sublayer above 50 A may provoke inacceptable scratches. These last scratches, appearing after a heat-treatment of the coated glazing panel, seem to be actually "dendrites" revealing fragility zones in the coating, i.e. a weakness of the coating itself when undergoing a heat-treatment. Such dendrites seem to form along the paths where a mechanical contact has been done prior to heat-treatment, showing, at macroscopic level, "scratches" which render the glazing panel unusable. When the first topcoat sublayer consists of, comprises or is based on Ti or one of its compound cited above, the geometrical thickness of the second topcoat sublayer is advantageously in the range 15 to 30 A, preferably in the range 15 to 25 A.

0015Preferably, when the second topcoat sublayer consists essentially of silicon oxide, this oxide is fully oxidised; this may give optical advantages to the coating stack, a layer of fully oxidised silicon oxide having a lower impact on the colour, for example, of the entire coating stack. Alternatively, the second topcoat sublayer may consist essentially of sub-stoichiometric silicon oxide.

0016Preferably, the second topcoat sublayer is exposed to air, i.e. is the outermost layer of the coating stack. This may provide particularly good results in terms of mechanical resistance and heat-treatability. It is also possible for the second topcoat sublayer to be used without a first topcoat sublayer.

0017In a preferred embodiment, the topcoat layer comprises a first topcoat sublayer consisting essentially of titanium nitride, having a geometrical thickness in the range 20 to 40 A, and a second topcoat sublayer consisting essentially of silicon oxide, having a geometrical thickness in the range 15 to 25 A.

0018The combination of properties that may be provided by the present invention have particular advantages in relation to heat treatable and heat treated glazing panels. Nevertheless, the invention may also be used in respect of glazings which are not heat treated. The term "heat treatable glazing panel" as used herein means that the glazing panel carrying the coating stack is adapted to undergo a bending and/or thermal tempering and/or thermal hardening operation and/or other heat treatment process without the haze of the so treated glazing panel exceeding 0.5, and preferably without the haze exceeding 0.3. Such heat treatment processes may involve heating or exposing the glazing carrying the coating stack or to a temperature greater than about 560⁰C, for example, between 560⁰C and 700⁰C in the atmosphere. Other such heat treatment processes may be sintering of a ceramic or enamel material, vacuum sealing of a double glazing unit and calcination of a wet-coated low reflective coating or anti-glare coating. The heat treatment process, especially when this is a bending and/or thermal tempering and/or thermal hardening operation, may be carried out at a temperature of at least, 600⁰C for at least 10 minutes, 12 minutes, or 15 minutes, at least 620⁰C for at least 10 minutes, 12 minutes, or 15 minutes, or at least 640⁰C for at least 10 minutes, 12 minutes, or 15 minutes.

0019The coating layers are preferably deposited by a vacuum deposition technique, particularly magnetron sputtering. Glazing panels according to the invention may comprise one or more infra-red reflecting layers. These layers, which may be made of silver for example, act to reflect incident infra-red radiation. The dielectric antireflective layers which sandwich the infra-red reflecting layers serve to reduce the reflection of the visible portion of the spectrum which the silver layers would otherwise provoke.

0020Each antireflective dielectric layer may consist of a single layer or may comprise two or more sub-layers which together form the antireflective dielectric layer. The antireflective dielectric layers, or at least portion of the antireflective dielectric layers may comprise an oxide, for example an oxide comprising zinc and tin and/or zinc and aluminium.

0021The coating stack may comprise one or more barrier layers underlying and/or overlying the infra red reflecting layer, as is known in the art.

0022Barriers of, for example, one or more of the following material may be used: Ti,

0023Zn, Cr, "stainless steel", Zr, Nb, Ni, NiCr, NiTi, ZnTi and ZnAl. Such barriers may be deposited as metallic layers, as sub-oxides (i.e. partially oxidised layers) or as fully oxidised oxides. Alternatively, nitrided barrier layers may also be used. Each barrier layer may consist of a single layer or may comprise Iwo or more sub-layers which together form the barrier layer. The barrier layer may comprise a first barrier layer in substantially metallic form, e.g. comprising nickel and chromium, and an overlying second barrier layer of a different composition from the first barrier layer (e.g. comprising titanium) which is in a form selected from the group consisting of oxides, sub-stoichiometric oxides, nitrides, sub-stoichiometric nitrides, oxynitrides and sub-stoichiometric oxynitrides.

0024In one embodiment of the invention, the second topcoat sublayer may have a geometrical thickness in the range 200 to 400 A, preferably 250 to 350 A, or still more preferably, around 300 A. We have surprisingly found that such a range of thicknesses may offer good mechanical properties and may reduce or avoid the apparition of scratches after heat-treatment of the glazing panel. However, such thicknesses may increase the cost of production and may also necessitate that the entire coating stack be reviewed, for examples in terms of thicknesses of layers, to avoid, for example, colour changes.

0025We have observed that the best tool to simulate what a coated glazing panel undergoes when it is transported, is the Automatic Web Rub Test (AWRT). A piston covered with a cotton cloth (reference: CODE 40700004 supplied by ADSOL) is put in contact with the coating and oscillates over the surface. The piston carries a weight in order to have a force of 33N acting on a 17 mm diameter finger. The abrasion of the cotton over the coated surface will damage (remove) the coating after a certain number of cycles. The test is used to define the threshold before the coating discolours (removal of top layer) and before scratches appear in the coating. The test is realised for 10, 50, 100, 250, 500 and 1000 cycles, at separated distances over the sample. The sample is observed under an artificial sky to determine whether discoloration and/or scratches can be seen on the sample. The AWRT score indicates the number of cycles giving no or very light degradation (not visible with naked eye under uniform artificial sky at 80 cm distance from the sample). A "-" or a "+" is indicated after the AWRT score depending respectively if light scratches are appearing or not at all. Preferably, glazing panels according to the invention show AWRT values of at least 250, more preferably at least 500.

0026The coating stack of the glazing panel of the present invention may be such that if applied to a clear sheet of 4 mm glass it would give a TL measured with Illuminant C of greater than about 25%, 30%, 35%, 40%, 45%, 55%, 60%,

002765%, 70%, 75%, 80%, 85% or 90%. Heat treatment may provoke an increase in the luminous transmittance (TL) of the glazing panel. Such an increase in TL may be advantageous in ensuring that TL is sufficiently high for the glazing panel to be used in high light transmittance glazings, for example, in vehicle windscreens or in architectural applications where the monolithic coated glazing panel is desired to have a TL greater than about 25%, 30%, 35%, 40%, 45%, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 90% or in double glazing units where the double glazing unit is desired to have a TL greater than about 55%, 60%, 65%, 70%, 75%, 80% or 85%. TL may increase in absolute terms during heat treatment by, for example, greater than about 2.5%, greater than about 3%, greater than about 4%, greater than about 6%, greater than about 8% or greater than about 10%.

0028Glazing panels according to the invention may be suitable for assembly in a double glazing unit. They may be adapted, for example, for assembly in a double glazing unit with the coating stack in position 3 (interior surface of interior sheet of glass) or in position 2 (interior surface of exterior sheet of glass). At least one of the glazing panels forming the double glazing unit may be heat-treated before its assembly in the double glazing unit.

0029Embodiments of the invention will now be further described, by way of example only, along with comparative examples.

0030Coating stacks have been deposited by magnetron sputtering on glass substrates, according to the tables hereunder. The coating stacks are all described as they exit from the magnetron sputtering coater. Glass thickness is for all examples 6 mm except for example 9, where it is 2.6 mm. Similar results are to be expected on glass of other thickness, for example 4 mm.

0031In examples 1 to 6 and 11 and comparative examples 1 to 11. the coating stack is always the same, except for the topcoat layer. The antireflective layers comprise mixed oxides of zinc and tin in various proportions:

0032Zn(50)Sn(50)Ox meaning a mixed oxide with 50% Zn and 50% Sn and

0033Zn(90)Sn(10)Ox meaning a mixed oxide with 90% Zn and 10% Sn. Actually, the exact composition of the target used to give the Zn(50)Sn(50)Ox layer is Zn:52% Sn:48% by weight of these metals in the target. It corresponds to the composition which allows easily to form a zinc stannate, known in the art for its blocking properties during thermal treatments.

0034Comparative examples 1 and 2 illustrate that a topcoat layer comprising a single sublayer of TiN show poor results in AWRT test, the coating being deteriorated after less than 50 cycles, even when the thickness of the TiN sublayer is higher.

0035Comparative examples 3 to 7 and examples 1 to 3 illustrate the addition of a second topcoat sublayer of SiO2 above a first topcoat sublayer of

0036TiN, this SiO2 sublayers showing different thicknesses. Comparative example 3 shows that the addition of a IOA SiO2 topcoat sublayer does not offer better results in AWRT test. Examples 1 to 3 and comparative examples 4 to 7 show however similar and good AWRT results, with SiO2 topcoat sublayers from 15 to

00373OθA. These coating stacks nevertheless differentiate each other in their ability to be heat-treated, for example tempered, without showing scratches after tempering. Comparative examples 4 to 7, with SiO2 thicknesses between 36 and

0038100 A, show scratches both after tempering, and after transport (simulated by an

0039AWRT test) and tempering. Whereas example 1, 2 and 3, with SiO2 thicknesses of 15, 25 and 300 A, offer the advantage of resisting well to AWRT test, and thus transport, and showing no scratches after tempering. These examples, which are part of this invention, are thus coatings offering a good mechanical resistance, e.g. a good resistance to transport, having the advantage of being heat-treatable. With reference to example 3, note that due to the higher thickness of SiO2, a colour change may appear compared to the coated glazing panel without the SiO2 sublayer. This may be corrected by adjusting the thicknesses of the other layers forming the coating stack, without impairing the advantages of good mechanical resistance and heat-treatability of the stack with the SiO2 topcoat sublayer.

0040Comparative examples 8, 9 and 11 illustrate the advantage of a first topcoat sublayer of TiN for ensuring a good heat-treatability and stability of the coated glazing panel. Comparative example 10 illustrates the advantage of having, in order, the second topcoat sublayer of SiO2 above the first topcoat sublayer of TiN.

0041Examples 4, 5 and 6 illustrate other embodiments of the invention:

00425 a first topcoat sublayer of Ti, or a second topcoat sublayer of SiC. Example 4 shows before heat-treatement a luminous transmittance of 82%, an emissivity of

00430.070 and an electrical resistance of 6 Ω/D, and after heat-treatment, a luminous transmittance of 89%, an emissivity of 0.045 and an electrical resistance of 4.5 Ω/D. Example 6 shows a luminous transmittance of 78% before heat-

0044JO treatement, and of 89% after heat-treatment. Example 11 illustrates a first topcoat sublayer of Zr.

0045Examples 7 to 9 illustrate the application of the invention to double silver coating stacks, with different first topcoat sublayers, i.e. TiN, Ti, TiO2.

0046J 5 Examples 7 and 8 are heat-treatable coatings offering a high selectivity; they show a luminous transmittance of 74% before tempering and of 81% after tempering, an emissivity of 0.018 and an electrical resistance per square of 1.6 Ω/D. A glazing panel according to example 9 may be used in the manufacture of a heatable solar-control windscreen for cars. Such windscreen shows a luminous 0 transmittance of 77% under illuminant A, an energetic transmittance of 44% and an electrical resistance per square of 2.2 Ω/D.

0047Example 10 is a transport test of glazing panels according to the invention (sheets of glass bearing a coating stack according to example 1, except 5 that the thickness of SiO2 was 20 A) and of glazing panels not in accordance with the invention (sheets of glass bearing a coating stack according to comparative example 2). All these sheets of glass were subjected to the following steps: ■ Gathering of the glass sheets into piles of 2.5 T each, with 200 mg of interlaying powder by m² of glass between the sheets of glass. ■ Shipping after 3 -months stocking

0048^■ Loading in trucks with cardboard spacers between the piles

0049^■ Pressure in the cushions of 4 bars

0050^■ Journey of more than 1000 km, passing through the Alps, which is a critical case because of the road curves and the abrupt changes in temperature

0051^■ Inspection of the glass sheets under a spot light: good result (no scratches, no discolouration) for the glass sheets with the SiO2 topcoat sublayer, contrary to the glass sheets without the SiO2 topcoat sublayer

0052^■ Travel back to point of departure, new inspection, and always good result for the glass sheets with the SiO2 topcoat sublayer

0053■ Shipping of the glass sheets with the SiO2 topcoat sublayer which have travel as hereinabove described, to a tempering furnace, 6 months after the glass sheets have been coated

0054■ Handling, cutting, processing of the glass sheets ■ Tempering

0055^■ At the oven exit, no mechanical defect visible at the naked eye.

0056Comp. Example 1 Comp. Example 2 Comp. Example 3 Example 1 Example 2 Comp. Example 4 Comp. Example 5 Comp. Example 6 glass substrate glass 6 mm glass 6 mm glass 6 mm glass 6 mm glass 6 mm glass 6 mm glass 6 mm glass 6 mm base antireflective layer Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A infra-red reflecting layer Ag 107A Ag 107A Ag 107A Ag 107A Ag 107A Ag 107A Ag 107A Ag 107A barrier layer NiCr 10A NiCr 10A NiCr 10A NiCr 10A NiCr 10A NiCr 10A NiCr 10A NiCr 10A TiO2 25A TiO2 25A TiO2 25A TiO2 25A TiO2 25A TiO2 25A TiO2 25A TiO2 25A top antireflective layer Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(90)Sn(10)θx 100A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A Zn(50)Sn(50)θx 275A topcoat layer TiN 25A TiN 35A TiN 36A TiN 36A TiN 36A TiN 36A TiN 36A TiN 36A SiO2 10A SiO2 15A SiO2 25A SiO2 36A SiO2 40A SiO2 60A

0057AWRT result on non heat- treated coated glass¹ 50- 50- 50- 500- 500- 500- 500- 500

0058Observation after tempering² without transport before tempering no scratches no scratches no scratches no scratches no scratches lot of scratches fine scratches fine scratches

0059Observation after AWRT test³ and tempering⁴ scratches scratches scratches no scratches no scratches scratches scratches scratches

0060layers thicknesses are geometrical thicknesses thicknesses given for the first topcoat sublayer comprising TiN or Ti are given as equivalent TiO2 (19A TiO2 correspond to 10A TiN)

00611 : the AWRT score indicates the number of cycles giving no or very light degradation (not visible with naked eye under uniform artificial sky at 80 cm distance from the sample). We indicate a "-" or a "+" depending if light scratches are appearing or not at all.

00622: 660°-670° during 6 min 20

00633: AWRT test 100 cycles

00644: 670° during 10 min 30

0065Comp. Example 7 Example 3 Comp. Example 8 Comp. Example 9 Comp. Example 10 Example 4 \ Example 5 Comp. Example 11 Example 6 glass substrate glass 6 mm glass 6 mm glass 6 mm glass 6 mm glass 6 mm glass 6 mm glass 6 mm glass 6 mm glass 6 mm base antireflective layer Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(90)Sn(10)Ox 100A Zn(90)Sn(10)Ox 100A Zn(90)Sn(10)Ox 100A Zn(90)Sn(10)Ox 100A Zn(90)Sn(10)Ox 100A Zn(90)Sn(10)Ox 100A Zn(90)Sn(10)Ox 100A Zn(90)Sn(10)Ox 100A Zn(90)Sn(10)Ox 100A infra-red reflecting layer Ag 107A Ag 107A Ag 107A Ag 107A Ag 107A Ag 107A Ag 107A Ag 107A Ag 107A bamer layer NiCr 10A NiCr 1θA NiCr 10A NiCr 10A NiCr 10A NiCr 10A NiCr 1θA NiCr 10A NiCr 10A TιO2 25A TιO2 25A TιO2 25A TιO2 25A TιO2 25A TιO2 25A TιO2 25A TιO2 25A TιO2 25A top antireflective layer Zn(90)Sn(10)Ox 100A Zn(90)Sn(10)Ox 1OθA Zn(90)Sn(10)Ox 100A Zn(90)Sn(10)Ox 1OθA Zn(90)Sn(10)Ox 1OθA Zn(90)Sn(10)Ox 1OθA Zn(90)Sn(10)Ox 1OθA Zn(90)Sn(10)Ox 1OθA Zn(90)Sn(10)Ox 1OθA Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A Zn(50)Sn(50)Ox 275A topcoat layer TiN 36A TiN 36A SιO2 <100A SιO2 3OθA SιO2 1OθA Ti 5θA Ti 4θA Sι3N4 <10A TiN 35A SιO2 100A SιO2 300A TiN 30A SιO2 25A SιO2 20A SiC 17A

0066AWRT result on non heat- treated coated glass¹ 500- 500 500+ 250- 500- 500- 500+ 500-

0067Observation after tempenng² no scratches without transport before i Colour shift => tempenng fine scratches review the stack lot of scratches colour shift scratches haze / no scratches no scratches lot of scratches no scratches

0068Observation after AWRT tesf and tempenng⁴ scratches some scratches lot of haze some scratches scratches haze / no scratches no scratches scratches no scratches

0069layers thicknesses are geometrical thicknesses thicknesses given for the first topcoat sublayer comprising TiN or Ti are given as equivalent TiO2 (19A TiO2 correspond to 10A TiN)

00701 : the AWRT score indicates the number of cycles giving no or very light degradation (not visible with naked eye under uniform artificial sky at 80 cm distance from the sample). We indicate a "-" or a "+" depending if light scratches are appearing or not at all.

00712: 660^o-670° during 6 min 20

00723: AWRT test 100 cycles

00734: 670° during 10 min 30

0074Example 7 Example 8 Example 9 Example 11 glass substrate glass 6 mm glass 6 mm glass 2,6 mm glass 6 mm base antireflective layer Zn(50)Sn(50)θx 200A Zn(50)Sn(50)θx 200A Zn(50)Sn(50)θx 180A Zn(50)Sn(50)θx 275A Zn(90)Sn(10)θx 130A Zn(90)Sn(10)θx 130A Zn(90)Sn(10)θx 120A Zn(90)Sn(10)θx 100A

0075Infra-red reflecting layer Ag 110A Ag 110A Ag 130A Ag 107A barrier layer NiCr 10A NiCr 10A Ti 2OA NiCr 10A TiO2 25A TiO2 25A TiO2 25A TiO2 25A central antireflective layer Zn(50)Sn(50)θx 680A Zn(50)Sn(50)θx 680A Zn(50)Sn(50)θx 660A Zn(90)Sn(10)θx 110A Zn(90)Sn(10)θx 110A Zn(90)Sn(10)θx 100A infra-red reflecting layer Ag 155A Ag 155A Ag 155A barrier layer NiCr 10A NiCr 10A Ti 2OA TiO2 25A TiO2 25A TiO2 25A top antireflective layer Zn(90)Sn(10)θx 8θA Zn(90)Sn(10)θx 8θA Zn(90)Sn(10)θx 6OA Zn(90)Sn(10)θx 1OθA Zn(50)Sn(50)θx 200A Zn(50)Sn(50)θx 190A Zn(50)Sn(50)θx 12θA Zn(50)Sn(50)θx 275A topcoat layer TiN 40A Ti 46A TiO2 55A Zr 40A SiO2 21A SiO2 18A SiO2 17A SIO2 2OA

0076AWRT result on non heat- treated coated glass¹ 500- 500- 500- 500-

0077Observation after tempering² without transport before tempering no scratches no scratches no scratches no scratches

0078Observation after AWRT tesf and tempering⁴ no scratches no scratches no scratches no scratches

0079layers thicknesses are geometrical thicknesses thicknesses given for the first topcoat sublayer comprising TiN or Ti, or Zr, are given respectively as equivalent TiO2 (19A TiO2 correspond to 10A TiN), or ZrO2.

00801: t i). We indicate a "-" or a "+" depending if light scratches are appearing or not at all.

00812: 660°-670° during 6 min 20

00823: AWRT test 100 cycles

00834: 670° during 10 min 30