Glazing comprising a temporary organic protective layer

Abstract

The invention relates to glazing materials comprising a substrate coated with a functional coating and with a temporary organic protective layer deposited on at least a portion of the functional coating. The protective layer is obtained by crosslinking a polymerizable composition comprising (a) (meth)acrylate compounds and (b) optionally a polymerization initiator. The temporary organic protective layer has a weight loss by thermogravimetric analysis (TGA) from 30°C to 450°C at a heating rate of 10°C / min in air of greater than 65%.

Description

Glazing including a temporary organic protective layer

[0001] The invention relates to a material comprising a transparent substrate coated with a functional coating capable of acting on solar radiation and / or infrared radiation. The invention also relates to glazing comprising these materials as well as the use of such materials for manufacturing glazing.

[0002] In the remainder of the description, the term “functional” qualifying “functional coating” means “capable of acting on solar radiation and / or infrared radiation”.

[0003] These functional coatings are used in so-called "solar control" glazing aimed at reducing the amount of incoming solar energy and / or in so-called "low-emissivity" glazing aimed at reducing the amount of energy dissipated to the outside of a building or vehicle due to their advantageous electrical conduction and infrared (IR) radiation reflection properties.

[0004] Functional coatings comprise one or more functional layers. These functional layers can be based on conductive oxide or based on metal layers.

[0005] Conductive oxide-based functional coatings are typically based on ITO (Indium Tin Oxide). These coatings exhibit low emissivity, good chemical durability, and good mechanical strength. However, such functional coatings are relatively expensive.

[0006] Functional coatings comprising one or more silver-based metallic functional layers (hereinafter silver-based functional coatings) are significantly less expensive. However, the corrosion resistance and mechanical strength of these functional coatings is often insufficient. This low resistance results in the short-term appearance of defects such as corrosion spots, scratches, or even total or partial peeling of the coating during its use under normal conditions. Any defects or scratches, whether due to corrosion or mechanical stress, are likely to impair not only the aesthetics of the coated substrate but also the optical and energy performance.

[0007] Applications WO 2015 / 019022 and WO 2018 / 051029 disclose a substrate provided with a functional coating reflecting infrared radiation covered with a temporary protective layer intended to be removed following a heat treatment of the quenching type. These temporary protective layers are organic polymeric layers based on acrylate of 10 to 20 µm thickness. These thick temporary protective layers make it possible to prevent any appearance of scratches in the functional coating which they protect. These layers are removed during the heat treatment.

[0008] The solutions developed in these documents can still be improved. In particular, the following inconveniences are sometimes observed: - the temporary layer is not systematically completely burned, especially when the thermal degradation rate is too low compared to the duration and / or the temperature of the heat treatment, - unpleasant odors are sometimes obtained, especially in the quenching furnace.

[0009] WO 2019 / 123477 discloses a temporary protective layer based on (meth)acrylate compounds comprising solid particles such as polymeric beads or glass beads. The solid particles are used both as a replacement for expensive oligomeric (meth)acrylate compounds and also as a replacement for spacers and / or powders used between two glass substrates to prevent friction or adhesion phenomena, particularly during storage.

[0010] The applicant has surprisingly discovered that the use of a polymeric protective layer based on specific acrylates, including a significant proportion of acrylate compounds of defined molecular weight and functionalities, makes it possible to prevent these disadvantages. This layer has a faster degradation rate and a lower degradation temperature. This layer effectively protects the coated substrate from any defects or scratches while being more easily removed during heat treatment.

[0011] The invention therefore relates to a material comprising a substrate coated with a functional coating and a temporary organic protective layer deposited on at least part of the functional coating, the protective layer comprises a polymer matrix obtained by crosslinking a polymerizable composition comprising (a) (meth)acrylate compounds and (b) optionally a polymerization initiator, characterized in that: the temporary organic protective layer has a weight loss by thermogravimetric analysis (TGA) from 30°C to 450°C at a heating rate of 10°C / min in air greater than 65%, preferably greater than 70%, or even greater than 75%. The polymerizable composition may comprise (meth)acrylate compounds (a1) comprising at least one alkyleneoxy group and a molecular weight of between 100 and 800 g / mol. Preferably, these (meth)acrylate compounds (a1) represent at least 30%, by mass of the total mass of the protective layer.

[0012] The invention also relates to a material comprising a substrate coated with a functional coating and a temporary organic protective layer deposited on at least part of the functional coating, the protective layer comprises a polymer matrix obtained by crosslinking a polymerizable composition comprising (a) (meth)acrylate compounds and optionally (b) a polymerization initiator, characterized in that the polymerizable composition comprises (meth)acrylate compounds (a1) comprising at least one alkylene-oxy group and a molecular mass of between 100 and 800 g / mol, these (meth)acrylate compounds (a1) represent, once crosslinked, at least 30%, by mass of the total mass of the protective layer.

[0013] This is the same temporary organic protective layer defined in two different ways, namely: - by its percentage of degradation by ATG at a temperature, - by the proportion of (meth)acrylate compounds of defined molecular mass.

[0014] The invention also relates to a material comprising a substrate coated with a functional coating and a temporary organic protective layer deposited on at least part of the functional coating, the protective layer is obtained by crosslinking a polymerizable composition comprising (a) (meth)acrylate compounds and optionally (b) a polymerization initiator, characterized in that: at least 50%, at least 60% or at least 70%, by mass of the total mass of the protective layer comprises (meth)acrylate compounds having a molecular mass of between 100 and 800 g / mol, preferably of between 100 and 500 g / mol.

[0015] The organic protective layer is an organic polymeric layer. The organic protective layer is essentially organic in nature. It is obtained from a polymerizable composition. It results from the crosslinking of the polymerizable organic compounds present in the polymerizable composition.

[0016] The (meth)acrylate compounds (a) and optionally (b) the polymerization initiator react with each other and, once crosslinked, form an organic polymer matrix. When considering that the protective layer comprises a certain proportion by mass of (meth)acrylate compounds (a) and optionally (b) of a polymerization initiator, this corresponds to the proportion by mass of this organic polymer matrix. The polymerization initiator, when present, is incorporated into the resulting organic matrix.

[0017] The polymer matrix represents at least 80%, at least 85%, at least 90%, at least 95%, at least 98% or 100% by mass of the total mass of the protective layer. The polymer matrix is ​​obtained by crosslinking a polymerizable composition comprising (a) (meth)acrylate compounds and optionally (b). This means that these percentages can also correspond to the proportions of the compounds (a) and (b) reacted with each other. The compounds (a) and (b) reacted with each other represent at least 80%, at least 85%, at least 90%, at least 95%, at least 98% or 100% by mass of the polymer matrix. The compounds (a) and (b) reacted with each other represent at least 80%, at least 85%, at least 90%, at least 95%, at least 98% or 100% by mass of the organic protective layer.

[0018] The invention also relates to a method for obtaining a material treated at high temperature, the material comprising a substrate coated with a functional coating, said method comprising the following steps: a step of protecting the article comprising: - preparing a polymerizable composition comprising (a) (meth)acrylate compounds and optionally (b) a polymerization initiator, including (meth)acrylate compounds (a1) comprising at least one alkylene-oxy group and a molecular mass of between 100 and 800 g / mol, these (meth)acrylate compounds (a1) represent at least 30%, by mass of the total mass of the protective layer,

[0019] - applying the polymerizable composition to at least part of the functional coating to a thickness of at least 1 micrometer,- crosslinking the composition so as to form a temporary organic protective layer, the same step of heat treatment and deprotection of the article comprising:- removing the temporary protective layer by heat treatment at a temperature above 200°C and sufficient to harden the article.

[0020] The invention also relates to a method for obtaining a material treated at high temperature, the material comprising a substrate coated with a functional coating, said method comprising the following steps: a step of protecting the article comprising: - preparing a polymerizable composition comprising (a) (meth)acrylate compounds and optionally (b) a polymerization initiator, - applying the polymerizable composition to at least part of the functional coating over a thickness of at least 1 micrometer, - crosslinking the composition so as to form a temporary organic protective layer, a same step of heat treatment and deprotection of the article comprising: - removing the temporary protective layer by heat treatment at a temperature above 200 °C and sufficient to achieve the tempering of the article,characterized in that the temporary organic protective layer has a weight loss by thermogravimetric analysis (TGA) from 30°C to 450°C at a rate of 10°C / min in air greater than 65%, preferably greater than 70%, or even greater than 75%.,

[0021] According to these methods, the functional coating is preferably deposited by magnetic field-assisted sputtering and the temporary protective layer is in direct contact with the functional coating.

[0022] (Meth)acrylate means an acrylate or a methacrylate. (Meth)acrylate functions mean an acrylate function (CH2=CH-COO-) or a methacrylate function (CH2=C(CH3)-COO-).

[0023] The (meth)acrylate compounds having reacted with each other represent by mass relative to the total mass of the organic protective layer, in increasing order of preference: - at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, and / or - at most 99%, at most 98%, at most 97%, at most 96%, at most 95%.

[0024] The term "(meth)acrylate compounds" means esters of acrylic or methacrylic acid comprising at least one (meth)acrylate function. The (meth)acrylate compounds used according to the invention may be chosen from monofunctional and polyfunctional (meth)acrylates such as mono-, di-, tri-, poly-functional (meth)acrylates. These esters may be monomers, oligomers, pre-polymers or polymers. These (meth)acrylate compounds, when subjected to polymerization conditions, give a polymer network with a solid structure.

[0025] The (meth)acrylate compounds (a) have a molecular mass or average molecular mass (hereinafter molecular mass) of between 100 and 800 g / mol.

[0026] According to the invention, the (meth)acrylate compounds are chosen from esters of acrylic or methacrylic acid.

[0027] The term "(meth)acrylate compound comprising an alkyleneoxy group" means a (meth)acrylate compound which comprises one or more alkyleneoxy groups. The term "alkyleneoxy group" means a chemical group consisting of an allylene group linked to an oxygen atom of formula -[(C n H2 n )-O]- with preferably with n being from 1 to 6. This definition does not include the group(s) involved in the formation of the ester group(s) of acrylic or methacrylic acid. Preferably, the alkyleneoxy groups are selected from an oxyethylene group -CH2-CH2-O- and oxypropylene group -CH2-CH2-CH2-O-, -CH(CH3)-CH2-O- and -CH2-CH(CH3)-O-.

[0028] The term “(meth)acrylate compounds (a1)” means a (meth)acrylate compound comprising at least one alkyleneoxy group and a molecular mass of between 100 and 800 g / mol.

[0029] The term “(meth)acrylate (a) compounds” includes:

[0030] - (meth)acrylate compounds not comprising an alkyleneoxy group and

[0031] - (meth)acrylate compounds (a1).

[0032] Methacrylate compounds (a1) comprising a low molecular weight alkyleneoxy group have the advantage of having less thermal stability around 400°C than other (meth)acrylate compounds such as trimethylolpropane triacrylate. This lesser stability allows the temporary protective layer to be degraded at a lower temperature and more efficiently during thermal quenching. This lesser thermal stability can be attributed to the presence of "alkyleneoxy" groups in the polymer matrix of the temporary protective layer compared to the simple presence of "alkylene" groups.

[0033] The (meth)acrylate compounds (a1) comprising at least one alkyleneoxy group and a molecular mass of between 100 and 800 g / mol used according to the invention have the following characteristics alone or in combination:

[0034] - they may represent at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65% or at least 70%, by mass of the total mass of the protective layer,

[0035] - the (meth)acrylate compounds (a1) are chosen from the (meth)acrylate compounds comprising:

[0036] - a (meth)acrylate function,

[0037] - two (meth)acrylate functions,

[0038] - three (meth)acrylate functions,

[0039] - four (meth)acrylate functions,

[0040] - advantageously, the (meth)acrylate compounds (a1) are chosen from the (meth)acrylate compounds comprising:

[0041] - two (meth)acrylate functions,

[0042] - three (meth)acrylate functions,

[0043] - the (meth)acrylate compounds (a1) represent at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65% or at least 70%, by mass of the total mass of the protective layer,

[0044] - (meth)acrylate compounds (a1) having 3 (meth)acrylate functions representing at least 40%, at least 50%, at least 60% or at least 70% by mass relative to the total mass of the organic protective layer,

[0045] - the (meth)acrylate compounds (a1) with an alkylene-oxy group are chosen from:

[0046] - (meth)acrylate compounds comprising an ethylene-oxy group,

[0047] - (meth)acrylate compounds comprising a propyleneoxy group,

[0048] - the (meth)acrylate compounds (a1) are chosen from (meth)acrylate compounds comprising at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 alkyleneoxy groups,

[0049] - the (meth)acrylate compounds (a1) have an average molecular mass of between 300 and 800 g / mol, 350 and 800 g / mol or 350 to 500 g / mol,

[0050] - the methacrylate compounds with an alkylene-oxy group are chosen from:

[0051] - polyethylene glycol diacrylate such as:

[0052] - triethylene glycol diacrylate,

[0053] - tetra(ethylene glycol) diacrylate,

[0054] - polyethylene glycol (200) diacrylate,

[0055] - polyethylene glycol (300) diacrylate,

[0056] - polyethylene glycol (400) diacrylate,

[0057] - polyethylene glycol (600) diacrylate,

[0058] - hexanediol ethoxylated (5) diacrylate

[0059] - polypropylene glycol di(meth)acrylate such as

[0060] - dipropylene glycol diacrylate,

[0061] - tripropylene glycol diacrylate,

[0062] - polypropylene glycol neopentyl glycol ether diacrylate,

[0063] - 1,6-Hexanediol ethoxylated diacrylate

[0064] - polyethylene glycol tri(meth)acrylate such as

[0065] - trimethylolpropane ethoxy (3) triacrylate,

[0066] - trimethylolpropane ethoxy (6) triacrylate,

[0067] - trimethylolpropane ethoxy (9) triacrylate,

[0068] - polypropylene glycol tri(meth)acrylate such as

[0069] Polyethylene glycol (PEG) diacrylates have the formula: H2C=CHCOO(CH2CH2)(OCH2CH2)nO2CCH=CH2with n being 1 to 14, preferably 2 to 10 and better still 2 to 5. Their molecular mass is between 200 and 800 g / mol -1in particular 200, 300, 400, 500, 600, 700. We can notably cite triethylene glycol diacrylate (n=2) and tetra(ethylene glycol) diacrylate with (n=3), polyethylene glycol (200) diacrylate, polyethylene glycol (300) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) diacrylate. We usually indicate the average molar mass of PEG after the name, for example polyethylene glycol (200) or PEG-200 (200 g / mol).

[0070] Polypropylene glycol diacrylates have the formula:

[0071] H2C=CHCOO(C3H6)(OC3H6) n O2CCH=CH2 with n being 1 to 10, preferably 2 to 5. Examples include dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol neopentyl glycol ether diacrylate. Their molecular mass is between 200 and 800 g / mol -1 including 200, 300, 400, 500, 600, 700.

[0072] Di-ethoxylated 1,6 hexane diol diacrylate has the CAS number 84170-27-4.

[0073] Polypropylene glycol triacrylates comprise three acrylate functions and at least one alkyleneoxy group. Examples include trimethylolpropane ethoxy (3) triacrylate (TMPEOTA) comprising 3 alkyleneoxy groups, trimethylolpropane ethoxy (6) triacrylate, and trimethylolpropane ethoxy (9) triacrylate.

[0074] The list below includes the preferred alkyleneoxy group (meth)acrylate compounds (a1) and some of their trade names:

[0075] - polyethylene glycol (200) diacrylate (PEG200DA) SR259®,

[0076] - tetraethylene glycol diacrylate (TTEGDA) SR268G®,

[0077] - triethylene glycol diacrylate (TIEGDA) SR272®,

[0078] - tripropylene glycol diacrylate (TPGDA) SR306®,

[0079] - polyethylene glycol (400) diacrylate (PEG400DA) SR344®,

[0080] - polyethylene glycol 600 diacrylate (PEG600DA) SR610®,

[0081] - dipropylene glycol diacrylate (DPGDA)

[0082] - 3-ethoxy bisphenol A diacrylate (BPA3EODA) SR349®, SR508®,

[0083] - 4-ethoxy bisphenol A diacrylate (BPA4EODA) SR601E®,

[0084] - ethoxy 10 bisphenol A diacrylate (BPA10EODA) SR602®,

[0085] - ethoxy 3 trimethylolpropane triacrylate (TMP3EOTA) SR415®,

[0086] - ethoxy 6 trimethylolpropane triacrylate (TMP6EOTA) SR499®,

[0087] - ethoxy 9 trimethylolpropane triacrylate (TMP9EOTA) SR502®,

[0088] - propoxy 3 trimethylolpropane triacrylate (TMP3POTA) SR492®,

[0089] - propoxy 3 glyceryl triacrylate (GPTA) SR9020®,

[0090] - ethoxy glyceryl triacrylates preferably comprising from 1 to 11 ethylene-oxy groups,

[0091] - ethoxy 12 glyceryl triacrylate (G12EOTA) SR9046®,

[0092] - glyceryl propoxy triacrylate.

[0093] The polymerizable composition may comprise (meth)acrylate compounds (a), some of which do not comprise an alkyleneoxy group.

[0094] The (meth)acrylate compounds (a) used according to the invention have the following characteristics alone or in combination:

[0095] - at least 50%, at least 60% or at least 70%, by mass of the total mass of the protective layer comprises (meth)acrylate compounds (a) having a molecular mass of between 100 and 800 g / mol, preferably of between 100 and 500 g / mol, and / or

[0096] - the composition comprises (meth)acrylate compounds (a) having 1 to 3 (meth)acrylate functions, and / or

[0097] - the (meth)acrylate compounds (a) having 1 to 3 (meth)acrylate functions represent in mass relative to the total mass of the organic protective layer:

[0098] - at least 50%, at least 60% or at least 65%, and / or

[0099] - at most 90%, at most 85%, at most 80% or at most 75%, and / or

[0100] - the composition comprises (meth)acrylate compounds (a) having 3 (meth)acrylate functions representing by mass relative to the total mass of the organic protective layer:

[0101] - at least 40%, at least 50% or at least 60%, and / or

[0102] - at most 80%, at most 75%, at most 70% or at most 65%, and / or

[0103] - the composition comprises (meth)acrylate compounds (a) having 1 or 2 (meth)acrylate functions representing by mass relative to the total mass of the organic protective layer:

[0104] - at least 5%, and / or

[0105] - at most 40%, at most 30%, at most 20% or at most 10%, and / or

[0106] - the composition comprises (meth)acrylate compounds (a) having at least 4 (meth)acrylate functions which represent by mass relative to the total mass of the organic protective layer:

[0107] - at least 5%, at least 10% or at least 15%, and / or

[0108] - at most 40%, at most 35%, at most 30%, at most 25% or at most 20%, and / or

[0109] - the compounds (a) and (b) having reacted with each other represent, in order of increasing preference, at least 80%, at least 90%, at least 95%, at least 98% by mass of the organic protective layer.

[0110] The above list includes (meth)acrylate compounds (a) that do not contain an alkyleneoxy group. These compounds can be used in limited proportions so as not to impact the good degradation properties:

[0111] - 1,6-Hexanediol diacrylate,

[0112] - tricyclodecane dimethanol diacrylate (SR833S),

[0113] - decanediol diacrylate

[0114] - esterdiol diacrylate

[0115] - trimethylolpropane triacrylate (TMPTA) SR351®,

[0116] - pentaerythritol triacrylate (PETIA) SR444D®,

[0117] - polybutadiene diacrylate,

[0118] - ethoxy 15 trimethylolpropane triacrylate (TMP15EOTA) SR9035®,

[0119] - trimethylolpropane triacrylate (TMPTA) SR351®.

[0120] The invention also relates to a material further comprising one or more of the following characteristics:

[0121] - the temporary organic protective layer has a weight loss by thermogravimetric analysis (TGA) from 30°C to 450°C at a heating rate of 10°C / min in air greater than 65%, preferably increasing greater than 70%, or even greater than 75% o, and / or

[0122] - the temporary organic protective layer may also advantageously have a weight loss by thermogravimetric analysis (TGA) of 30°C to 400°C at a heating rate of 10°C / min in air of greater than 50%, preferably greater than 60% and / or

[0123] - the temporary organic protective layer may also advantageously have a weight loss by thermogravimetric analysis (TGA) from 30°C to 350°C at a heating rate of 10°C / min in air greater than 25%, preferably greater than 30%, or even greater than 35%, and / or

[0124] - the organic protective layer has a thickness:

[0125] - less than 50 µm, less than 30 µm, less than 20 µm and / or

[0126] - greater than 1 µm, greater than 5 µm, greater than 10 µm, and / or

[0127] - the temporary protective layer is in direct contact with the functional coating, and / or

[0128] - the functional coating comprises a stack of thin layers successively comprising, starting from the substrate, an alternation of n functional metal layers based on silver or a metal alloy containing silver, and (n+1) dielectric coatings, each dielectric coating comprising at least one dielectric layer, so that each functional metal layer is arranged between two dielectric coatings, and / or

[0129] - the functional coating is deposited by magnetic field-assisted sputtering, and / or

[0130] - the substrate bearing the functional coating has not undergone heat treatment at a temperature above 400°C.

[0131] According to advantageous embodiments of the invention, the polymerizable composition has the following characteristics:- it comprises at least one polymerization initiator (or primer), preferably a photoinitiator,- it may comprise at least two different photoinitiators,- the polymerization initiator represents 0.1 to 20%, or 2 to 15%, preferably 5 to 15% and better still 8 to 12% by mass relative to the total mass of the organic protective layer,- the (meth)acrylate compounds a) are chosen from monomers, oligomers, prepolymers or polymers comprising at least one (meth)acrylate function,- the (meth)acrylate compounds a) are chosen from esters of acrylic or methacrylic acid comprising at least two (meth)acrylate functions,- the (meth)acrylate compounds a) do not comprise an aromatic group,- the (meth)acrylate compounds a) comprise at least one oligomer monomer or prepolymer comprising, at least 1, at least 2,at least 3, at least 4, at least 5 (meth)acrylate functions,- the polymerizable composition further comprises at least one additive chosen from adhesion promoters, plasticizers, absorbers, separating agents, heat and / or light stabilizers, thickening agents or surface modifiers,- the sum of all the additives is between 0 and 10%, preferably 0 and 5%, or even 0.05 to 2.00% by mass relative to the total mass of the organic protective layer.,

[0132] According to the invention, polymerization initiators are not considered additives.

[0133] The organic protective layer is continuous. It has a thickness, in order of increasing preference: - less than 50 µm, less than 40 µm, less than 30 µm, less than 20 µm, and / or - greater than 5 µm, greater than 7 µm, greater than 8 µm, greater than 10 µm.

[0134] The organic protective layer according to the invention is preferably applied at the outlet of the production line for substrates bearing functional coatings. The step of depositing the organic protective layer can be easily integrated into the production process for the substrate bearing the functional coating.

[0135] The polymerizable composition has, thanks to the judicious choice of (meth)acrylate compounds and possibly solvent, a viscosity suitable for easily obtaining an organic protective layer with a thickness greater than or equal to 5 µm.

[0136] The chemical nature, the degree of crosslinking, the density of the organic protective layer contribute to obtaining effective protection against abrasion, the appearance of scratches and corrosion.

[0137] The organic protective layer is preferably deposited and crosslinked using suitable means that can be directly integrated into the output of the functional coating deposition chamber. This prevents any contamination of the coated substrates and allows for continuous production of protected materials.

[0138] The polymerizable composition can therefore be applied at room temperature by any known means and in particular by roller coating, by spraying, by dipping, by curtain coating, or by spraying.

[0139] This non-water-soluble organic protective layer provides effective protection even during the washing stage.

[0140] Although the invention is particularly suitable for the protection of substrates bearing mechanically weak functional coatings, the solution of the invention can be applied to the protection of substrates bearing all types of functional coating.

[0141] The functional coating comprises at least one functional layer. The functional layer is preferably a layer capable of acting on solar radiation and / or long-wave infrared radiation. These functional layers are, for example, metallic functional layers based on silver or a metal alloy containing silver. They are deposited between dielectric coatings which generally comprise several dielectric layers making it possible to adjust the optical properties of the stack. These dielectric layers also make it possible to protect the silver layer from chemical or mechanical attack.

[0142] The functional coating therefore advantageously comprises at least one silver-based functional metal layer, at least two dielectric coatings, each dielectric coating comprising at least one dielectric layer, such that each functional metal layer is arranged between two dielectric coatings.

[0143] The substrate may comprise a functional coating comprising a stack of thin layers successively comprising, starting from the substrate, an alternation of n functional metal layers based on silver or a metal alloy containing silver, and (n+1) dielectric coatings, each dielectric coating comprising at least one dielectric layer, such that each functional metal layer is arranged between two dielectric coatings. Preferably, n is 1, 2, 3 or 4. Even more preferably, n is greater than 1, in particular n is 2 or 3.

[0144] The substrate may successively comprise, starting from the substrate, an alternation of two functional metal layers, in particular functional layers based on silver or a metal alloy containing silver, and three dielectric coatings, each dielectric coating comprising at least one dielectric layer, so that each functional metal layer is arranged between two dielectric coatings.

[0145] The substrate may also comprise a functional coating comprising a stack of thin layers successively comprising, starting from the substrate, an alternation of three functional metal layers based on silver or a metal alloy containing silver, and 4 dielectric coatings, each dielectric coating comprising at least one dielectric layer, so that each functional metal layer is arranged between two dielectric coatings.

[0146] The thickness of the functional coating is:- greater than 50 nm, greater than 100 nm, preferably greater than 150 nm, and / or- less than 350 nm or less than 300 nm.

[0147] According to a particularly advantageous embodiment of the invention, the functional coating comprises a non-organic upper protective layer chosen from nitrides, oxides or oxynitrides of titanium and / or zirconium. The upper layer of the functional coating is the layer furthest from the substrate and / or the layer in direct contact with the organic protective layer.

[0148] The thickness of these upper layers is preferably between 1 and 20 nm and better between 1 and 5 nm.

[0149] The top layer of the functional coating, especially when it is based on titanium oxide, is important because it promotes adhesion between the inorganic layers of the functional coating and the organic protective layer.

[0150] The functional coating can be deposited by any known means such as magnetic field assisted sputtering, thermal evaporation, CVD or PECVD, pyrolysis, chemical deposition, sol-gel deposition or wet deposition of inorganic layers.

[0151] The functional coating is preferably deposited by magnetic field-assisted sputtering. According to this advantageous embodiment, all layers of the functional coating are deposited by magnetic field-assisted sputtering. The organic protective layer is advantageously in direct contact with the functional coating.

[0152] The substrate is preferably a glass substrate. The glass substrate may be flat or curved, colorless and / or tinted. The thickness of the substrate is preferably between 1 and 19 mm, more particularly between 2 and 12 mm, or even between 3 and 12 mm.

[0153] The organic protective layer may be deposited:- on each of the main surfaces of the substrate, and / or- on at least one edge of the substrate, and / or- on each of the edges of the substrate.

[0154] The invention also relates to the method for obtaining a material according to the invention. The method of the invention comprises one or more of the following characteristics: - the functional coating is deposited by magnetic field-assisted sputtering and the organic protective layer is in direct contact with the functional coating, - the polymerizable composition is applied to the functional coating, - the organic protective layer is obtained by UV crosslinking.

[0155] Preferably, the functional coating is deposited by magnetic field-assisted sputtering and the organic protective layer is in direct contact with the functional coating.

[0156] The organic protective layer can be formed immediately after the step of depositing the functional coating. According to the invention, it is considered that the organic protective layer can be formed “immediately after”, when the organic protective layer can be formed less than 10 minutes, preferably less than 5 minutes and more preferably less than 1 minute after the step of depositing the functional coating.

[0157] The invention also relates to a glazing comprising a material according to the invention. The glazing can be mounted on a vehicle or a building.

[0158] Glazing according to the invention is particularly suitable for equipping buildings or vehicles, particularly as side windows, sunroofs or even rear windows. It is also suitable for use as a display case or refrigerator door with an anti-fog (anti-condensation) function, particularly for equipping frozen product displays in supermarkets.

[0159] The following examples illustrate the invention. Examples I. Functional substrates and coatings

[0160] The functional coatings defined below are deposited on clear soda-lime glass substrates with a thickness of 6 mm. The functional coating was deposited using a magnetic field-assisted sputtering device (magnetron). The deposition conditions of the sputter-deposited layers (so-called "magnetron sputtering") are summarized in Table 1 below. Table 1 Targets used Deposition pressure Gas Index * Sn Zn Ox Sn:Zn (60:40 wt.%) 1.5 * 10-3 mbar Ar 39 % - O2 61 % 2.09 ZnO:Al Zn:Al (98:2 wt.%) 1.8.10-3 mbar Ar / (Ar + O2) at 63 % 1.95 Ni Cr Ni:Cr (80:20 at.%) 1-5 * 10 -3 mbarAr at 100%-AgAg2-3*10 -3 mbarAr at 100%-TiO2TiOx1.5*10 -3 mbarAr 88% - O212%2.32

[0161] at.: atomic; pds: weight; *: at 550 nm.

[0162] The table below lists the materials and physical thicknesses in nanometers (unless otherwise indicated) of each layer or coating that constitutes the stack according to their positions relative to the substrate carrying the stack.Table 2: GlazingUpper protective layerTiOx2.5Dielectric coatingSnZnOx30ZnO:Al6OB blocking layerNiCr0.4Functional layerAg12UB blocking layerNiCr0.1Dielectric coatingZnO:Al6SnZnOx30Substrate (mm)glass6 II. Organic protective layer 1. Raw materials

[0163] Polymerizable compositions have been prepared. They include (meth)acrylate compounds, polymerization initiators and optionally additives. The various constituents and additives are mixed by mechanical stirring. a) (Meth)acrylate monomers and oligomers

[0164] These (meth)acrylate compounds include oligomers and monomers comprising at least one acrylate function. The following compounds marketed by Sartomer were used:A - Isobornyl acrylate monomer, mono-functional acrylate having a molecular weight of 208.30 g / mol, ((meth)acrylate compound (a)),B1 - Tricyclodecane dimethanol diacrylate (SR833S), di-functional acrylate monomer having a molecular weight of 304 g / mol, ((meth)acrylate compound (a)),B2 - Dipropylene glycol diacrylate, di-functional acrylate monomer having a molecular weight of 242.3 g / mol, ((meth)acrylate compound (a1))C1 - Trimethylolpropane ethoxy triacrylate, tri-functional acrylate monomer having a molecular weight of 428 g / mol, ((meth)acrylate compound (a1))C2 - Trimethylolpropane triacrylate (SR351), tri-functional acrylate monomer having a molecular weight of 296 g / mol,((meth)acrylate compound (a))D - Tetra-functional aliphatic urethane-acrylate oligomer CN9276 (hereinafter 4-functional acrylate oligomer) having a molecular mass of 1000 g / mol, ((meth)acrylate compound (a))E - Dipentaerythritol pentaacrylate, penta-functional acrylate monomer having a molecular mass of 524.5 g / mol, ((meth)acrylate compound (a)), b) Photoinitiator

[0165] The initiator can be chosen from the photoinitiators marketed by BASF under the name Irgacure® such as Iragure 500, by Lambson under the name Speedcure 500, Speedcure 84 or by Lamberti under the name Esacure HB. The photoinitiator can also be 1-hydroxy-1-methylethyl phenyl ketone. c) Additives

[0166] An adhesion promoter can be used. 2. Polymerizable compositions

[0167] The tested compositions are defined in the table below in parts by mass. The polymerizable compositions are liquid. They are filtered to 0.2 µm to avoid aggregates. Their dry extracts can be adapted by adding solvent according to the desired protective layer thicknesses.CompositionsFunctionsCCCICI2A (a)1-7.0-B1 (a)218.1--B2(a1)2--17.0C1(a1)3-65.073C2 (a)319.2--D (a)453.0--E (a)5-18.3-(b) UV initiator-9.59.59.8(c) Adhesion promoter-0.20.20.2Total dry matter-100100100% monomer ≤ 3 acrylate functions by weight relative to the sum of monomers-41%80%100%% by weight relative to the sum of monomers with a molecular mass < 800 g / mol-41%100%100%% by weight of compounds (meth)acrylate (a1) in the protective layer - 0%65%90%

[0168] The compositions are defined as a percentage by mass. The compositions are applied to glass substrates by spin coating or with a Meyer bar. The layers cured by UV irradiation are crosslinked by UV radiation provided by a Light Hammer® lamp with an H+ bulb at a speed of between 10 and 50 m / min. The polymerizable compositions are applied so as to have a thickness after curing of approximately 15 µm. 3. Preparation of tested materials

[0169] The table below lists for each material comprising a substrate coated with a functional coating:- the nature of the organic protective layer,- the polymerizable composition used,- the thickness of the organic protective layer after curing.MaterialsComp.Inv.1Inv.2Comp. polymerizableCCCI1CI2Rev. functionalYesYesYesThickness (µm)151515 III. Characterization

[0170] 1. Evaluation of elimination by heat treatment 1.a. Thermogravimetric analysis

[0171] The thermal stability of the protective layers was determined by thermogravimetric analysis (TGA) at atmospheric pressure in air with a heating rate of 10°C / min for a temperature of 30°C to 700°C. The mass loss curves in % as a function of temperature, after curing: - of the comp. composition (CC), - of the composition according to the invention (CI1). In this figure, we observe a shift of the CI1 curve towards lower temperatures. The composition according to the invention begins to degrade at a significantly lower temperature. Due to its lower thermal stability, the composition degrades more quickly in the hardening furnace.

[0172] Tempering tests using a vertical furnace were carried out. The vertical furnace allows for laboratory simulation of tempering conditions. The glass is held vertically, using a clamp system, on a mobile support. This support is automatically inserted into the furnace located above at the required temperature. Once the tempering time has elapsed, the support descends and the glass is subjected to a jet of cold air on both sides using a nozzle system. The furnace is convection-free and the temperature is regulated using 3 thermocouples located at 3 separate locations. The following parameters are fixed: - Furnace temperature: 670 °C, - Heating time: Variable, - Cooling time: 100 s, - Cold air pressure: 0.7 bar.

[0173] For each material, the shortest tempering times were determined. These times correspond to the minimum times to:- obtain good quality glazing with, in particular, no breakage, no iridescence, no corrosion of the functional coating, good flatness,- obtain glazing with satisfactory fragmentation and- remove the temporary protective layer.MaterialTempering timeComp.330 sInv.1315 s

[0174] With the prior art polymerizable composition (CC), the minimum quenching time is 330 s under our conditions. When these times are shortened, unburned composition is still present on the functional coating.

[0175] With the polymerizable composition of the invention (CI1), we observe for quenching times of 315 s, or even for shorter times, the absence of residue and good fragmentation on breakage.

[0176] 2. Evaluation of odors following heat treatment

[0177] During the heat treatment of the temporary protective layer of the prior art, volatile organic compounds ("VOCs") may be emitted and under certain conditions:- during edge trimming: an abrasive wheel removes the protective layer and the functional coating from the substrate and / or- during the heat treatment at high temperature. It is likely that the emission of these volatile compounds generates unpleasant odors. These negative effects are not observed with the materials according to the invention Inv.1 and Inv.2. It is likely that this is due to the absence of a high molecular mass compound, i.e. approximately 1000 g / mol.

Claims

Material comprising a substrate coated with a functional coating and a temporary organic protective layer deposited on at least part of the functional coating, the protective layer is obtained by crosslinking a polymerizable composition comprising (a) (meth)acrylate compounds and (b) optionally a polymerization initiator, characterized in that: the temporary organic protective layer has a weight loss by thermogravimetric analysis (TGA) from 30°C to 450°C at a heating rate of 10°C / min in air greater than 65%, preferably greater than 70%, or even greater than 75%. Material comprising a substrate coated with a functional coating and a temporary organic protective layer deposited on at least part of the functional coating, the protective layer comprises a polymeric matrix obtained by crosslinking a polymerizable composition comprising (a) (meth)acrylate compounds and optionally (b) a polymerization initiator, characterized in that the polymerizable composition comprises (meth)acrylate compounds (a1) comprising at least one alkylene-oxy group and a molecular mass of between 100 and 800 g / mol, these (meth)acrylate compounds (a1) represent at least 30%, by mass of the total mass of the protective layer. Material according to any one of the preceding claims, characterized in that at least 70%, by mass of the total mass of the protective layer comprises (meth)acrylate compounds (a) having a molecular mass of between 100 and 800 g / mol, preferably of between 100 and 500 g / mol. Material according to any one of the preceding claims, characterized in that the polymerizable composition comprises (meth)acrylate compounds (a1) representing at least 50% by mass of the total mass of the protective layer. Material according to the preceding claim, characterized in that the (meth)acrylate compounds (a1) comprise 1 to 3 (meth)acrylate functions. Material according to any one of the preceding claims, characterized in that the (meth)acrylate compounds (a1) are chosen from (meth)acrylate compounds comprising at least 2 alkylene-oxy groups. Material according to any one of the preceding claims, characterized in that the (meth)acrylate compounds (a1) have an average molecular mass of between 300 and 800 g / mol. Material according to any one of the preceding claims, characterized in that the (meth)acrylate compounds (a1) having 3 (meth)acrylate functions represent at least 40% by mass relative to the total mass of the organic protective layer. Material according to any one of the preceding claims, characterized in that the compounds (a) and (b) having reacted with each other represent at least 90% by mass of the organic protective layer. Material according to any one of the preceding claims, characterized in that the polymerizable composition comprises (meth)acrylate compounds (a) having 1 to 3 (meth)acrylate functions representing at least 50% by mass relative to the total mass of the organic protective layer. Material according to any one of the preceding claims, characterized in that the polymerizable composition comprises (meth)acrylate compounds (a) having 1 or 2 (meth)acrylate functions representing at least 5% by mass relative to the total mass of the organic protective layer. Material according to any one of the preceding claims, characterized in that the polymerizable composition comprises (meth)acrylate compounds (a) having at least 4 (meth)acrylate functions which represent by mass relative to the total mass of the organic protective layer, at least 5%. Material according to any one of the preceding claims, characterized in that the organic protective layer has a thickness:- less than 50 µm, and- greater than 1 µm. Material according to any one of the preceding claims, characterized in that the temporary protective layer is in direct contact with the functional coating. Material comprising a substrate according to any one of the preceding claims, characterized in that the functional coating is deposited by cathodic sputtering assisted by a magnetic field. Material comprising a substrate according to any one of the preceding claims, characterized in that the functional coating comprises at least one silver-based functional metal layer. Material comprising a substrate according to any one of the preceding claims, characterized in that the functional coating comprises a stack of thin layers successively comprising, starting from the substrate, an alternation of n functional metal layers based on silver or a metal alloy containing silver, and (n+1) dielectric coatings, each dielectric coating comprising at least one dielectric layer, so that each functional metal layer is arranged between two dielectric coatings.

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