Glazing with an anti-reflective coating

CA 02227031 1998-O1-13 WO 97! 43224 PCTIFR97 / 00857 1 GLASS WITH ANTI-REFLECTIVE COATING The invention relates to transparent substrates, more particularly fes glass substrates, intended to be incorporated into glazing and provided with anti-reflective coatings.

An antireflection coating usually consists of a stack of thin interference layers, in general an alternation of layers based on a dielectric material with high and low refractive indices. Deposited on a transparent substrate, the function of such a coating is to reduce its light reflection, and therefore to increase its light transmission.

A substrate thus coated therefore sees an increase in its transmitted light / reflected light ratio, which improves the visibility of the objects placed behind it.

To obtain a maximum anti-reflective effect, it is recommended to provide each side of the substrate with cE: type of coating.

One of the best-known applications of this type of product is the protection of paintings illuminated by a light placed behind the observer.

Anti-reflective glazing is also very interesting for equipping buildings, for example as a store window, in order to better distinguish what is in the window even when the interior lighting is weak compared to the lighting. exterior, or as a countertop glass.

It would be useful to use this type of product as vehicle glazing, in particular for a car, and more particularly as a windshield, the standards requiring high levels of light transmission.

What currently limits the use of anti-reflective glazing in buildings or to equip vehicles is the level of mechanical and chemical durability which is necessary for such applications.

Indeed, the anti-reflective coating will be placed in the glazing at least on its CA 02227031 2004-09-24 -2face 1, that is to say the face of the glazing turned towards "the exterior of the room or of the window. passenger compartment (conventionally, each of the faces of the glass substrates constituting a given glazing are numbered, starting with the face which is facing outwards).

However, this face of the glazing is subjected to a lot of stresses; thus, in the building, it is subjected to climatic hazards and to cleaning by more or less abrasive means and / or by more or less corrosive chemicals.

The durability problem is perhaps even more glaring for vehicle glazing: the windshield is subjected to the abrasive effect of the wipers to and fro, to various projections of dust or gravel, and all of the side windows of vehicles are subject to repeated friction with the rubber lips of the doors.

However, until now, the majority of anti-reflective coatings proposed are obtained by depositing thin layers using techniques using vacuum, for example techniques of the cathode sputtering type.

This type of deposition technique leads to the production of thin layers of good quality, in particular optical quality, but which often have less durability than that which would be required for the applications envisaged above.

In addition, these techniques are used repeatedly, that is to say discontinuously on the glass trays once cut from the glass ribbon from a float production line.

The aim of the invention is therefore to overcome these drawbacks, by seeking to develop a new type of multilayer coating with an antireflection effect which is optically efficient and which, in addition, has high mechanical and chemical durability.

The subject of the invention is a glazing comprising on at least one of its outer faces an antireflection coating, hereinafter referred to as the “A” coating, and which comprises a stack of layers of materials of alternately strong refractive indices. and weak. The stack is designed so that at least part of the layers which constitute it are pyrolyzed layers, preferably at least the last layer.

For example, provision can be made for the latter to be pyrolyzed and for the first (s) to be deposited under vacuum.

CA 02227031 1998-O1-13 WO 97/43224 PCTlFR.97 / 00857 -3 Advantageously all the layers of the stack are pyrolyzed layers.

In the context of the invention, the expression “outer” faces is understood to mean the faces of the glazing in contact with the atmosphere (to be opposed to the so-called “internal” faces which are in particular those in contact with the intermediate sheet of polymer in a glazing. with a laminated structure).

The advantage of using pyrolyzed layers is triple O on the one hand by pyrolysis, whether in liquid, pulverulent or gaseous phase (the latter often being referred to by the acronym CVD meaning "Chemical Vapor Deposition"), it is possible to obtain a wide choice of materials of the oxide, nitride or carbide type, or a mixture of at least two of these types of compounds, having the refractive indices suitable for being incorporated into an anti-reflective coating, O on the other hand , pyrolyzed layers, and this is of particular interest to the present invention, exhibit generally very high chemical and mechanical durability.

Due to the fact that elves were obtained by decomposition of precursors at very high temperatures on hot glass, elves are particularly solid, dense, strongly adherent to the substrate, and therefore resist well to mechanical attacks such as abrasion / friction or chemical attacks. , in particular by bringing water, polluting gases and aggressive detergents into contact.

What is very advantageous, in order to guarantee the durability of the entire stack of layers, is that the last layer is thus pyrolyzed.

The easiest way is then to deposit all the layers by pyrolysis: in fact, and this is the third advantage of pyrolysis, this type of deposit can be carried out continuously, directly on the hot glass ribbon of a float line. : it is then sufficient to align as many precursor projection nozzles as there are layers to be deposited on the line to obtain the desired stack. However, it is not excluded from the scope of the invention to deposit by pyrolysis only the last or the last “n” layers of the stack, and to deposit the first layer or layers by another deposition technique.

This other technique may for example be a vacuum technique of the c <~ thadic spray type or a sol-gel type technique. It is also not excluded to deposit by pyrolysis, another layer of the stack, in particular CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97 / 00857 -4 the first or the first, and to deposit by a another technique for depositing the last layer (s).

This other technique can for example also be a vacuum technique.

As mentioned above, a partial antireflection effect can be obtained by using only one antireflection coating per glazing. However, it is known that the optimum effect is obtained by providing the glazing not with one but with two anti-reflective coatings, one on each of its outer faces (therefore on faces 1 and 2 if it is a glazing. composed of a single substrate or on faces 1 and 4 if it is a multiple glazing of the laminated glazing type with two glass substrates).

Several choices are therefore offered in the invention to obtain this optimal anti-reflective effect O it is in particular possible to provide the other outer face of the glazing with an anti-reflective coating "A '" similar or even identical to the coating "A", comprising therefore also at least one pyrolyzed layer, in particular at least the last one.

Thus, when the glazing has a laminated structure, it is then sufficient to assemble, using a sheet of polymer, two substrates each provided with a stack of type "A", the two stacks having both been able to be produced directly. on the float glass ribbon.

If it is a monolithic glazing, the first ernpiiement "A" can be obtained on float, and the second in recovery, either also by pyrolysis, or by another technique such as cathodic sputtering or the sol-gel technique. (by masking the anti-reflective coating already deposited).

It is also possible to provide the other face of the glazing with an anti-reflective coating, hereinafter referred to as the “B” coating, which also comprises a stack of layers of materials of alternately strong and weak refractive index, but deposited. by a technique using vacuum such as sputtering.

Having recourse to a second non-pyrolyzed anti-reflective stack can in fact present certain advantages: when the glazing is said to be monolithic, composed of only one glass substrate, it may be advantageous to deposit the first anti-reflection coating of type "A" continuously. on the float glass ribbon, then depositing the second coating CA 02227031 1998-O1-13 WO <37/43224 PCT / FR97l00857 -5 type “B” anti-reflective coating by vacuum deposition without heating the substrate.

It can be emphasized that in this case, the excellent mechanical durability of the anti-reflective stack "A" is very advantageous: the substrate can be moved along a vacuum deposition line on conveyor rollers, with the stack. being in contact with the rollers, without the latter degrading despite the inevitable friction between the substrate and the rollers.

In addition, often one of the two exterior faces of the glazing, in general the face: turned towards (the interior of the room for a building glazing or towards! The interior of the passenger compartment for a vehicle glazing, is less stressed on the chemical or mechanical level: we can therefore "afford" to use a stack: anti-reflective "B" having a durability lower than that of a stack of type "A" but which may nevertheless be sufficient.

As examples of type "B" anti-reflective stacks capable of being deposited by a vacuum technique, reference may advantageously be made to the European patent application filed on February 22, 1996 under number 96 / 400367.7 corresponding to the patent application. French 95/02; 102, which describes an anti-reflective stack having, moreover, the interesting feature of being able to undergo without deterioration heat treatments of the carrier substrate of the bending / tempering or annealing type: this involves in particular "isolating" from the substrate the layers liable to deteriorate at high temperature by migration of alkalis from the glass (such as Nb205, W03, Bi203 or Ce02) using a "screen" layer. forming part of the stack, in particular a low index layer of the Si02, A1203: F type or a mixture of these two coma> daring, or a high index layer such as Si3N4 or AIN, or a layer with an intermediate index in particular based on a mixture of oxide of Si ~~ t Sn, Si and Zn, Si and Ti or else based on SiOXNy.

Reference may also be made advantageously to the French patent application filed on February 22, 1996 under number 96/02194, describing an anti-reflective stack also capable of being deposited by a vacuum technique and using low-index layers of the fluoride type. or aluminum oxyfluoride AlxOyFZ, with y> _ 0.

Mani ~: re general, the so-called low index layers usually deposited by vacuum techniques are chosen for example from Si02, CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97 / 00857 -6 MgF2 and the said layers with a high index, for example from Ta205, Ti02, Nb20 ~, ZrOz, SnOz, ZnO, W03.

Preferably, the anti-reflective coatings of type "A" according to the invention (and also, optionally, the anti-reflective coatings of type "B" which are associated therewith) are designed so that, on the one hand, the layers said low index have a refractive index between 1.35 and 1.70, preferably between 1.38 and 1.65; and on the other hand your so-called high index layers have a refractive index of at least 1.85, in particular between 1.90 and 2.60, preferably between 2.10 and 2.45. The antireflection effect is in fact fully realized only if there is a significant difference in refractive indices between the layers with high and low indices in contact with each other.

According to a particular embodiment of the invention, the first sequence of layers “high index layer / low index layer” of the antireflection coating “A” (and optionally also of the type “B” antireflection coating when it is used ) is replaced by a single layer called "intermediate" index, in particular between 1.70 and 1.85: such a layer has an optical effect very similar to a high index / low index sequence.

The material capable of exhibiting such an index may be chosen based on tin oxide, on silicon oxynitride and / or oxycarbide SiOxCy and / or SiOXNv, or based on a mixture of oxides, for example a mixture of 'oxide of silicon and tin, silicon and zinc, silicon and titanium, the relative proportion of the two types of oxides making it possible to adjust the refractive index to the desired value.

To produce the anti-reflection coating "A" according to the invention, pyrolyzed layers with a low refractive index are preferably chosen consisting of a dielectric material or a mixture of dielectric materials chosen from the group comprising silicon oxide, i. 'silicon oxynitride and / or oxycarbide SiOxNy and / or SiOXCy, or else a mixed oxide of silicon and aluminum also comprising at least one third element M facilitating the formation of a homogeneous mixed oxide structure.

This element M is in particular a halogen of the fluorine type, and the layer may also comprise a fourth element, in particular carbon.

For more CA 02227031 1998-O1-13 WO 97/43224 PCTlFR97 / 00857 _7_ details on the composition of this mixed oxide, reference will be made advantageously to the French patent application FR-A-2 727 107 corresponding to the European application 95 /402612.6, which also describes its preferred okay mode, which is a CVD technique.

This layer is preferably used in the invention to constitute the last low index layer of the antireflection coating, because it has proved to be extremely resistant.

The choice of high index pyrolyzed layers can advantageously relate to dilectrical materials or mixtures of dilectrical materials belonging to the group comprising TiO 2, SnO 2, ZnO, ZrO 2 or Ta 2 O 5.

As mentioned above, the glazing of the invention can consist of a single anti-reflective coating on one of its faces, in particular on face 1, and either a coating A 'of the same type, or a coating B on the opposite face, in particular face 2. If it is a usual sheet glazing, with two glass substrates assembled by a sheet of polymeric material of the type PVB (polyvinylbutyral), it preferably has on one of its faces, in particular the face 1. a coating A, and on the other exterior face, in particular the face 4, either a coating A 'of the same type, or a coating of type B.

It may also be noted that the anti-reflective coatings according to the invention can also ~~ 'apply to so-called asymmetric glazing sheets, comprising at least one glass substrate and at least one sheet of polymer properties of energy absorption such as polyurethane.

The choice of the nature of the glass substrate (s) constituting the glazing can also prove to be important: it is possible to combine the optical and / or thermal properties inl; rinsque (s) aulx) glass substrates) with the optical properties 0 of the glass (s). anti-reflective coatings) to obtain a glazing presenting overall :; desired performance.

Thus, the substrates can be chosen from clear glass, for example such as those sold under the trade name Planilux by the company SAINT-GOBAIf \ I VITRAGE. The additional effect of increasing the CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97 / 00857 _g_ light transmission due to) anti-reflective coatings) then makes it possible to obtain extremely transparent glazing.

But it is also possible to choose the substrates constituting the glazing, made of glass having reduced energy transmission properties, in particular tinted glasses in the mass.

At the cost of a certain drop in light transmission, interesting solar protection glazing is obtained, the effect of increasing light transmission obtained by means of antireflection coatings) advantageously making it possible to attenuate this drop in the level of transparency.

Glazing tinted in the mass, in particular adapted to the building, are for example marketed under the name “Parsol” by the company SAINT-GOBAIN VITRAGE. Other types of glass with reduced energy transmission are also of interest in the context of the present invention.

These are in particular bronze-colored glasses, as described in patents US-4,190,542 and US-4,101,705, or glasses whose composition has been adjusted more with a view to an automotive glazing application. These are, for example, glass called TSA + or TSA ++, in which the levels of coloring oxides of the Fe203, Fe0 and Co0 type are adjusted in order to have a selectivity defined by the T ~ / TE ratio of at least 1.30, or even 1.40 to 1.50, and a tint in the greens.

For more details, reference will be made to European patent application EP-A-0 616 883.

The level of the aforementioned coloring oxides in the glass compositions according to the teaching of this patent (weight proportions) is briefly recalled below.

According to a first series Fe203 0.55 to 0.62 Fe0 0.1 1 to 0.16 Co0 0 to 12 ppm, in particular <12 ppm with in particular the FeZ ~ IFe ratio of the order of 0.19 to 0.25 .

According to a second series Fe203 0.75 to 0.90 Fe0 0.1 5 to 0.22 Co0 0 to 17 ppm, in particular <10 ppm with in particular the Fe2 * / Fe ratio of the order of 0.20.

CA 02227031 1998-O1-13 WO 97143224 PCTlFi2i71Q0857 _g_ II can éç ~ aiement be glasses tinted in the mass, in particular in blue-green such as those described in patent application EP-Ao 644 164, whose composition is recalled below Si02 64 to 75 A1203 0 to 5% B2 ~ 3 0 to 5 Ca0 2 to 15 Mg0 0 to 5 Na20 9 to 18 K20 0 to 5 Fe203 0.75 to 1.4 (total iron expressed in this form) Fe0 0.25 to 0.32 S03 0.10 to 0.35 It can also be glasses such as those described in the PCT application filed; under the corresponding number PCT / FR95100828 on June 22, 1995 to application FR-A-2 721 599, the composition of which, still in weight percentages, is recalled below Si02 f 9 to 75 A1203 0 to 3 BZO3 0 to 5 Ca0 2 to 10% Mg0 0 to 2 Na20 9 to 17 K20 0 to 8 Fe203 (total iron) 0.2 to 4 Se, CoO, Cr203, NiO, Cu0 0 to 0.45 the content of coloring agents other than iron being at least equal to 0.0002% when the Fe203 content is equal to or less than 1.5%, this composition being likely to also contain fluorine, oxides of zinc, zirconium, cerium, titanium and less than 4% barium oxide, CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97 / 00857 10the sum of the percentages of alkaline earth oxides remaining equal to or less than 10%. Still according to the teaching of this patent, it is preferred that the coloring agents other than iron are introduced into the composition of the glasses in alone or in combination, according to weight contents which, preferably, remain lower than (following imitates Se <0.008 Co0 <0.04 Cr203 <0.1 Ni0 <0.07 Cu0 <0.3%. They may also be glasses such as those described in application PCT / FR96 / 00394 filed on March 14, 1996 and corresponding to the French patent application filed on March 16, 1995 under number 95103858, glasses comprising it, expressed in percentages by weight, of 0.85 2% of total iron expressed in the form Fe203, the weight content of Fe0 being between 0.21 and 0.40%. According to this patent, the compositions are, according to a first series, the following SiO2 64 75 A120a 0 5 B20s 0 5 Ca0 2 1 5 Mg0 0 5 Na20 9 18 K20 0 5 Fe203 (total jfer expressed in this form) 0.85 2 Fe0 0.21 0.40 CoO, Cr203, Se, Ti02, MnO, NiO, Cu0 0 0.04 S03 0.08 0.35 and according to a second series, the following Si02 68 75 A1203 0 3 CA 02227031 1998-O1- 13 WO 97/43224 PCT / FR97 / 00857 -1182 ~ 3 0 to 5 Ca0 2 to 10 Mg0 0 to 2 Na20 9 to 18 K20 0 to 8 Fe203 (total fe ~ r expressed in this form) 0.95 to 2 CoO , Cr203, Se, Ti02, MnO, NiO, Cu0 0 to 0.04 Fe0 0.29 to 0.40 SO3 0.08 to 0.35 All of these. Types of tinted glass compositions can therefore be advantageously chosen so that the glazing has energy transmission values ​​of between 30 and 70%, in particular between 35 and 60%, and light transmission values ​​of between 50 and 85%.

The glass substrates carrying the antireflection stack (s) can undergo various heat treatments, in particular bending, tempering or annealing. There are two scenarios: either the coatings are deposited after treatment, which prevents the deposition of the layers on the float line, (and which is difficult for coatings "A" whose deposition requires reheating of the glass) or ies coatings, at least the “A” type coatings, are deposited on the Line and designed so as to be able to undergo these treatments without altering their optical properties.

For stacks of type “B”, a configuration having this type of property has already been mentioned above.

The glazing can also include at least one other type of thin layer or stack of thin layers with a solar protection function. They may be reflective layers such as sufficiently thick silver-based layers.

They can thus be stacks of the dielectric / silver / dielectric or dielectric / silver / dielectric / silver / dielectric type.

For more details on these types of stacks, reference may be made to the dE: European patent mandates EP-A-0 678 484, EP-A-0 645 352 and EP-A-0 638 528.

It is also possible to use stacks comprising a reflecting and / or filtering layer such as a nitride layer, CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97 / 00857 - 1z such as titanium nitride, as described above. in applications EP-A-0 638 527 and EP-A-0 650 938.

It is also possible to provide the glazing according to the invention with at least one electrically conductive coating with an alarm function: it may consist of a conductive layer or a network of conductive wires, for example screen-printed from a paste. conductive silver, which we will connect to a current source by ad hoc leads.

In the event of an attempt to break the glazing, if the current no longer passes, means trigger an audible and / or light alarm.

In fact, we will rather choose either to use tinted glass, or to use this type of solar protection coating, but in both cases it is indeed a question of combining their thermal and optical properties, which are correlated, with the optical properties of anti-reflective coatings to achieve the desired glazing.

A preferred configuration of laminated glazing consists in providing at least one of the internal faces of the glass substrates which constitute it, that is to say the faces 2 and / or 3 of the coatings with a solar protection function and / or with a function of alarm.

The antireflection coating “A” (and / or optionally the antireflection coating “B”) of the glazings according to the invention can be further functionalized, by surmounting it with a coating with photocatalytic properties with an antifouling function, in particular based on sodium oxide. at least partially crystallized titanium which can be obtained by CVD, as described in the French patent application filed on September 15, 1995 under number FR-95/10839.

In the same vein, it is also possible to treat the surface of the last pyrolyzed layer of the “A” type antireflection stack with silanes, in particular by the trickle technique in order to reduce: its coefficient of friction and thus , in particular, to facilitate the sweeping of the windshield wipers in the case of a windshield for example.

In particular in the case where it is envisaged to use the glazing as interior or exterior glazing for buildings, shop windows, store counters or as glazing for motor vehicle type other than the windshield CA 02227031 1998-O1- 13 WO 97/43224 PCTlFR97 / 00857 -13 (side windows, rear glasses, auto roof), the optical thicknesses of the layers constituting the anti-reflection stack (s) are advantageously chosen so as to lower the light reflection of the glazing to values ​​less than 1.5%, in particular less than 1.0% at normal incidence. In general, this is the level of performance expected from anti-reflective glazing.

To obtain such light reflection values, the anti-reflection stacks "A: ~> according to the invention may comprise, starting with the layer located closest to the substrate 1 OO, two layers, including a first layer with a high index of optical thickness between 15 and 50 nm, in particular between 20 and 40 nm, - and a second layer with low optical thickness index between 160 and 200 nm, in particular between 170 and 190 nm, 1 5 O three layers including:

- a first layer of intermediate index of optical thickness between 100 and 1 ~ 40 nm, in particular between 1 10 and 130 nm, - a second layer with a high index, of optical thickness between 210 and 260 nm, in particular between 230 and 250 nm, 20 - and finally a third layer with a low optical thickness index of between 100 and 150 nm, in particular between 110 and 140 nm.

'Particularly in the case where it is envisaged to use the glazing as a windshield, not ~~ even laminated, for a vehicle of the automobile or train type, the selection of the optical thicknesses of the layers of the antireflection stacks will be a not very different, because the criteria will vary: indeed, the current windshields are strongly inclined, an optimization of the light reflection only taking into account measurements at normal incidence proves insufficient.

In addition, windshields must reconcile two properties, that is, present both a very high light transmission for safety concerns - 30 (current standards impose a value of T ~ of at least 75 % at normal incidence) and energy transmission as low as possible, to avoid excessive heating of the passenger compartment in summer: for the specific application of windshields, it is therefore necessary to seek to adjust the value of CA 02227031 1998-O1-13 as high as possible, WO 97/43224 PCTJi'R97 / 00857 -14la selectivity T ~ / TE.

Optical thicknesses of layers are therefore chosen for the windshield application which together make it possible to obtain a value of R ~ less than 7% and even less than 6% at normal incidence, less than 10% at incidence of 60 °, a value of T ~ at normal incidence of at least 75% and a TL / TE selectivity of at least 1.65, in particular of at least 1.70.

To meet all of these criteria, the anti-reflective coatings "A" of the invention can advantageously comprise three layers, including, starting with the layer closest to the substrate O, a first layer of intermediate index of optical thickness between 1 fi0 and 210 nm, in particular between 180 and 200 nm, O a second layer with a high index of optical thickness between 300 and 350 nm, in particular between 320 and 340 nm, O and a third low index layer with an optical thickness of between 120 and 170 nm, in particular between 145 and 165 nm.

A subject of the invention is also the use of the glazing described above for applications other than the building or vehicles already envisaged, in particular applications as glazing for the protection of objects of the table type, for anti-protection screens. - glare for computer, decorative glass, furniture glass furniture or mirror (by adding an opacifying layer for example).

Glazing coated with anti-reflective coatings according to the invention can also be designed and mounted so as to be able to fulfill a fire-resistant function with flame-retardant properties. Reference may be made, for example, advantageously to patent application EP-A-0 635 617 or to patent application EP-A-0 568 458. they can also exhibit fire-resistant properties, and are then usually composed of two glass substrates mounted in a frame at a certain distance from each other, the space separating them being filled with an aqueous gel, as described above. in patent EP-B-442 768 or even patent US-4,983,464.

The details and advantageous characteristics of the invention will now emerge from the following non-limiting examples, with the aid of the appended figures CA 02227031 1998-O1-13 WO 9i143224 PCT / FRg7 / 00857 -15O FIG. 1: a substrate provided with a anti-reflective stacking with two layers (1 a), three layers (1 b) and four layers (1 c), O figure; 2: a monolithic glazing provided with two anti-reflective stacks, O figure. 3: a laminated glazing provided with two anti-reflective stacks.

Figure 1, very schematic, shows in section a glass substrate surmounted by a pyrolyzed anti-reflective coating "A" according to three variants (the proportions between the thickness of the various layers constituting the anti-reflective coating and that of the substrate have not been observed. for easy reading).

A single stack has been shown, even if, as described in Figures 2 and ~ 3, a second anti-reflective stack, pyrolyzed or not, can be deposited on the: substrate on its opposite face.

According to the variant of Figure 1a, is shown a glass substrate 1 which is provided with a two-layer coating A1 comprising a first layer 2 with a high index sun ~ not fitted with a second layer 3 with a low index.

According to the variant of FIG. 1 h, the same substrate 1 is provided with a tri-layer coating A2 comprising a first layer of intermediate index 4 surmounted by a second layer of high index 5 and of a third layer low index 6.

According to the variant of FIG. 1 c, the same substrate 1 is provided with a four-layer coating:> A3 comprising an alternation of two layers with a high index 7, 9 and two layers with a low index 8, 10.

In all the following examples, the layers of coatings A 1, A2 or A3 are obtained by a technique of pyrolysis in the liquid, pulverulent or çiazeuse phase, directly on the float glass ribbon.

Below are indicated, in a non-exhaustive manner, the precursors suitable for obtaining the oxide layers with the desired index O the low index layers of the silica type are deposited by CVD from TEOS tetraorthosilicate or from SiH4, The low index layers of the mixed oxide type of silicon and aluminum E: possibly fluorinated are deposited by CVD from a mixture of a silicon precursor such as TEOS and an aluminum precursor We form an organometallic with an alcoholate function or (3-ketone of t ~~ pe acetylacetonate or methyl-2-heptadione 4,6, optionally fluorinated (fluorinated aluminum precursors are chosen in particular from CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97I00857 -16 hexafluorinated aluminum acetylacetonate or an aluminum trifluoroacetylacetonate, as described in application FR-A -2 727 107 mentioned above, O the layers with an intermediate index of the silicon oxycarbide type SiOxCY are also deposited by CVD from ethylene and from SiH4,.

in accordance with patent application EP-A-0 518 755, O the high index layers based on tin oxide are deposited by pyrolysis of tin dibutyldifluoride (DBTF) powder or by CVD from tetrachloride d 'tin, O the high index layers based on TiO 2 are deposited by liquid pyrolysis from a mixture of alcoholate and titanium chelate in a solvent of the ethyl acetate type (precursors described in patent EP-B -0 465 309) or by CVD from tetraisopropyltitanate, or else by pyrolysis of powder from methyl ethyltitanate or Ti (OCH3) 4.

We will not go into the details of the deposition conditions of each of these layers, which are known to those skilled in the art.

For the anti-reflective products deposited under vacuum, details can in particular be found in the aforementioned European patent application 96 / 400367.7.

FIG. 2 illustrates the configuration of a glazing according to a first example 1: it is a so-called monolithic glazing, comprising only one glass substrate provided on its face 1 with an anti-reflective stack "A" and on its face 2 of an anti-reflection stack “B” made up of thin layers obtained by cathodic sputtering.

The substrate 1 is shown flat, but can also be curved with a variable radius of curvature.

We generally have face 1 facing outwards which then corresponds, in the event of bending, to the convex face (face 2 being concave).

EXAMPLE 1 ~ 1 A first A2 stack is deposited on a float line on a ribbon of glass 4 mm thick and of a silico-soda-lime nature (sold once cut under the name Planilux by the company SAINT-GOBAIN VITRAGE) pyrolyzed comprising (cf. Figure 1 b) O a first layer based on SiOxCy refractive index approximately 1.73 and geometric thickness 71 nm, CA 02227031 1998-O1-13 WO 97/43224 PCTlFR97 / 00857 -17O a second layer based of TiO 2 refractive index 2.45 and geometric thickness 99 nm, O a third low index layer based on mixed oxide SiOAIF, refractive index 1.4f3 and geometric thickness 90 nm.

~ 1 After cutting the tape, is deposited on the other side by re ~~ ctive cathodic sputtering in the presence of oxygen an anti-reflective coating "B" comprising O a first layer of 18 nm geometric thickness of Sn02 index 1 , 9, O a second layer of 35 nm geometrical thickness of SiO 2 of index 1.45, O a third layer of 120 nm of geometrical thickness of Nb 2 O 5 of index 2,1, O a fourth layer of 85 nm of geometrical thickness of SiO 2 of index 1.45.

Table 1 below groups together, for the substrate thus coated and, by way of comparison, for an identical substrate without any coating, the following spectrophotometric values ​​measured under illuminant D65:

T ~ percentage light transmission at normal incidence, TE percentage energy transmission at normal incidence, R ~ percentage light reflection at normal incidence a ~ -b ~ le:> color values ​​in reflection according to the colorimetry system ( LjF, agi, b '~) without unit, TL / TE selectivity without unit TABLE 1 EXAMPLE 1 COMPARATIVE EXAMPLE T ~ 95 - 89 TE 79 83 0.7 7.9 a'x' 3.3 -0.2 b '~ -17.5 -0.5 Tr / TE: ~ 1.2 I - 1.07 CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97 / 00857 - $ 1 It can therefore be seen in the light of these results that the gain in T ~ and in selectivity is very significant, that the value of R ~ of the coated substrate is less than 1%.

The substrate is therefore very suitable for a building application.

A second series of examples 2 to 10 corresponds to glazings having the laminated configuration shown in FIG. 3: the preceding substrate 1 is assembled to a second glass substrate 10 using a sheet 11 of 0.7 PVB. mm thick.

This second substrate is also provided on its outer face with an antireflection stack, either pyrolyzed and identical to that with which the substrate 1 is coated, or deposited under vacuum and of the “B” type.

Examples 2 to 5 use two substrates 1, 10 Planilux glass units 4 mm thick.

EXAMPLE 2 The two antireflection stacks of substrates 1 and 10 are identical and all their layers are pyrolyzed. These are two-layer stacks (cf.

FIG. 1 a), comprising O a first layer of TiO 2 having a geometric thickness of 12 nm, O a second layer of mixed oxide SiOAIFx identical to that of Example 1 with a geometric thickness of 124 nm.

EXAMPLE 3 The two antireflection stacks of substrates 1 and 10 are identical and all their layers pyrolyzed. These are also two-layer stacks comprising O a first layer of SnOZ of 95 nm of geometric thickness, O a second layer of SiOAIFX identical to that of the preceding examples of geometric thickness of 92 nm.

EXAMPLE 4 The two antireflection stacks of substrates 1 and 10 are identical and all their layers pyrolyzed. These are three-layer stacks (cf.

figure x 1 b) structures and layer thicknesses identical to those of Example 1.

EXAMPLE 5 The two antireflection stacks are different: that of substrate 1 is a two-layer stack according to Example 2, that of substrate 10 is a CA 02227031 1998-O1-13 WO 97143224 PCT / F'R97 / 00857 -19 stack of: type "B" deposited under vacuum identical to that described in Example 1.

Table 2 below groups together all the spectrophotometric values ​​already explained for Examples 2 to 4, with, by way of comparison, the values ​​for a laminate assembling two same glass substrates: rs but without any coating.

TABLE 2 EX.2 EX.3 EX.4 EX.S COMPARATIVE T ~ 9fi 95 97 95 86 TE 84 83 78 79 72 R ~ 0.9 1.3 0.4 1.1 7.6 a ~ 44 17, 7 0.7 19.7 -1.0 b '~ -40 -3f, 7 3 -25.4 0.1 TL / TE 1.14 1.14 1.24 1.20 1.18 From this table, it can be seen that all fes examples of the invention, even those with simply two-layer stacks, make it possible to achieve particularly low values ​​of R ~ of at most 1.3%.

One can also note a significant gain in selectivity for Fes Examples 4 and! ~ Compared to the comparative example, and a particularly attenuated residual value in reflection for Example 4.

Examples 6-10 use a 4mm clear substrate the same as that used in Examples 2-5, but a 4mm substrate 1 tinted in the TE coated.

EXAMPLE 6 The antireflection stacks are pyroiysées tri-layer stacks identical to c ~ sux of Example 4.

The glass of the substrate 1 conforms to the teaching of the aforementioned patent EP-A-0 644 164.

Its composition is as follows (in weight percentages) Si02 70.75 AI203 0.62 Ca0 9.50 CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97 / 00857 Mg0 3.90 Na20 13.90 K20 0.09 S03 0.18 5 Fe203 (total iron) 0.95% Fe0 0.285 Fe0 (total iron) 0.30 Taken alone, without coating or laminated assembly, it has a T ~ of 71%, an TE of 43.5% and a T "~ of 18%.

10 COMPARATIVE EXAMPLE 6 It makes it possible to make the comparison with Example 6: the substrates are the same, but devoid of any coating.

EXAMPLE 7 Antireftet stacks are pyrolyzed tri-layer stacks identical to those of Example 4.

The glass of the substrate 1 is 4 mm thick and conforms to the teaching of the aforementioned patent application PCT / FR95 / 00828.

The MgO, Fe203 and Fe0 contents of the glass are as follows (in weight percentages):

M9 ~ 0.3 20 Fe203 0.20 Fe0 0.36 Taken alone, without coating or laminate assembly, it has a T ~ of 81%, a TE of 60% and a T "~ of 51%.

COMPARATIVE EXAMPLE 7 It makes it possible to make the comparison with Example 7: the substrates are the same, but devoid of any coating.

Table 3 below groups together all the spectrophotometric values ​​corresponding to Examples 6, 6 comparative, 7 and 7 comparative:

CA 02227031 1998-O1-13 WO 97/43224 PCT'lFR97 / 0085'7 -21 TABLEAI ~ J 3 EX.6 EX.6 EX.7 EX.7 COMPARATIVE COMPARATIVE T ~ 73 67 88 81 TE 37 37 58 60 R ~ 0.3 6.5 0.4 7.8 a * '-1 -3.3 -0.5 -1.5 b' ~ -1.8 -0.8 -1.5 -0.6 T ~ / TE 1.94 1.8 1.52 1.35 Again, for the examples according to the invention, a net gain in selectivity is observed, with values ​​of R ~ less than 0.5% and very weak reflective colorations The last series of examples 8 10 is more particularly aimed at an application of windshield sheets for automobiles: the two substrates 1, are first fitted with their stacks directly on the float line, then, after cutting ,. are bombs, the substrate 1 having its exterior face 1 convex, and the substrate 10 its exterior face 4 concave. The substrate 1 is 2.6 mm thick and dyed in the mass. The substrate 10 is 2.1 mm thick and clear of the Planilux type.

The 1 sheet 1 of PVB is always 0.7 mm thick. EXAMPLE .B Substrate 1 has a composition in accordance with patent EP-0 644 164, and more precisely the following composition (in weight proportions) Si02 70.8 A1203 0.6 Na20 13.8 K2 ~ 0.10 Ca0 9.50 Mg0 4.10 Fe2O3 (total iron expressed in this form) 0.86 CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97 / 00857 -22 Ti02 0.035 S03 0.17 Fe0 0.28 The two anti-reflective stacks are pyrolyzed , identical, and in the form of a three-layer stack (cf. figure 1 b) with O a first layer based on SiOxCy of index 1.83 and geometric thickness 105 nm, O a second layer based on Ti02 geometric thickness 135 nm, O a third layer in SiOAIFx as above defined, index 1.48 and geometric thickness 107 nm.

COMPARATIVE EXAMPLE 8 It uses the same substrates as in Example 8, but devoid of anti-reflective coatings.

EXAMPLE 9 The only difference from Example 8 is that the substrate 1 is more colored and still meets the teaching of patent EP-O 644 1 5 164 with the composition identical to that indicated for Example 6 .

COMPARATIVE EXAMPLE 9 It uses the same laminated assembly of the substrates identical to Example 9 but without an antireflection coating.

Table 4 below groups together the spectrophotometric values ​​already explained, this time measured as a function of the illuminant “A”.

The values ​​of T ~, TE, RL, a ~ and b ~ at 60 ° incidence are also specified:

CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97 / 00857 -23 TABLE 4 EX.8 EX.8 EX.9 EX.9 COMPARATIVE COMPARATIVE T ~ 81 76 76 71 TE 47 48 44 44 R ~ 1.9 7 1.5 6.7 a ~ '57.8 -2.6 8.9 -3.1 b ~' -73.6 0.1 -45.7 -1.1 T ~ / TE 1.72 1 , 57 1.7 1.61 T ~ (60) 73 66 68 61 TE (60 39 39 37 35) R ~ (60) 6.7 13 5.1 12.7 a '~ (60 5 -3.1 2,4 -3,3) b ~ (60) -17,3 0,3 -5,9 -0,9 From this level, it can be seen that the selection of the thicknesses of the layers of the piles has been modified compared to to the previous series, so as to improve the antireflection effect at oblique incidence, by increasing the value of T ~ significantly at the same time at normal incidence st at 60 °.

The gain in selectivity obtained with the invention is very particularly advantageous in the field of vehicles, for reducing the heating of the passenger compartments.

From Table 4, it can be seen that it is possible, thanks to the invention, to cross the bar of 1.8 for selectivity at oblique incidence.

In addition, the gain in TL obtained by the stacks according to the invention makes it possible to use substrates with reduced energy transmission which hitherto could not be used because they lowered the TL value of the laminate below the threshold value imposed by the standards, of 75%: if we refer to comparative examples 9 and 9, we see that it is the anti-reflective stacks which allow the glazing to cross this limit of 75% of T ~ at normal incidence: the invention therefore allows the use for windshields of fairly strongly colored glazing, which again tends to reduce the heating of the passenger compartments, without being unduly penalized in terms of transparency.

A last example 10 was carried out, similar to example 8.

The only difference lies in the anti-reflective stack placed on face 1 of substrate 1. the three-layer stack comprises a first layer of Si ~ C of index 1.83 and of geometric thickness 102 nm, a second layer CA 02227031 1998-O1-13 WO 97/43224 PCT / FR97 / 00857 -24de TiOz of 1 15 nm, a third layer of SiOAIFX of 80 nm geometric thickness and index 1.48, and, in addition, a last thin layer of 10 nm of TiO2 deposited by CVD and partially crystallized, as described in the aforementioned application FR-95/10839. an additional anti-fouling functionality is thus conferred on the windshield without significantly penalizing its anti-reflection function, since the fourth layer, relatively high index, is confined to a low thickness (in particular at most 20 nm).

Table 5 below groups together the spectrophotometric values ​​of such a glazing at normal incidence as well as at 60 ° incidence EX.10 T ~ 77 TE 4fi R ~ 6 a '~ 21.3 b' ~ -40.9 Tr / T ~ 1.68 T ~ (60) 72 TE (60) 40 R ~ (60) 8 a '~ (60) -7 b'x' (60) -12.4 Lastly, it should be noted that the pyrolyzed stacks according to the invention of all the preceding examples give excellent results in terms of durability, with in particular a resistance to the neutral satin fog test according to the ISO 9227 standard of at least 21 days, and a variation of T ~ of at most 3% when they are subjected to an abrasion test called the operant Taber test, 2000 rotations (test carried out using abrasive powder embedded in an elastomer using a machine manufactured by the company TABER Instrument CA 02227031 1998-O1-13 WO 97/43224 PCTlFR97 / 00857 -25 Corp., machine. referenced under model 174 “Standard Abrasion Tester”, the wheels being of type S10F loaded with 500 grams).