WO2022136797A1

WO2022136797A1 - Method for producing decorative glazing, and corresponding decorative glass

Info

Publication number: WO2022136797A1
Application number: PCT/FR2021/052421
Authority: WO
Inventors: François GUILLEMOT; François COMPOINT
Original assignee: Saint-Gobain Glass France
Priority date: 2020-12-24
Filing date: 2021-12-21
Publication date: 2022-06-30
Also published as: FR3118460A1

Abstract

The invention relates to the field of decorative glazing. The invention relates to a method for producing decorative glazing, using a roller located above a glass conveyor, said roller rotating and comprising cavities filled with fluid enamel. The fluid enamel is partially transferred to the glass, followed by a hardening step involving a heat treatment or an ultraviolet or electron-beam treatment.

Description

DESCRIPTION

TITLE: METHOD FOR MANUFACTURING DECORATIVE GLAZING AND SUCH DECORATIVE GLAZING

The invention relates to the field of decorative glazing.

It is known to texture glasses by rolling the glass, that is to say by passing the hot glass between rollers which are themselves textured, which imprint the surface of the glass and create a relief. This process has several disadvantages:

- lack of flexibility in the design: impossibility to reach very small or specific textures

- constraints on the thickness of the glass: impossibility of texturing glass that is too thin, etc.

The invention relates to an alternative process to the manufacture of decorative glazing without the aforementioned drawbacks.

Thus the subject of the invention is a process for manufacturing decorative glazing (by depositing liquid material in a discontinuous manner) which comprises the formation of a glazing with a set of dry enamel patterns (hardened, solid) comprising the following steps:

- a supply of a fluid enamel composition, often called enamel paste, in particular shear thinning, comprising (and even consisting of) a glass frit, an organic medium which comprises an organic resin, an optional organic solvent, in particular composition capable of forming a transparent enamel after firing or an opaque and/or mass-diffusing enamel (with pigments and/or diffusing particles)

- a scrolling in translation of a sheet of glass (plane), in particular of given thickness E in particular of at most 12mm or 10mm and even of at least 0.3mm, on a conveyor (with a system of rollers), at a given translation speed Vc, sheet of glass with a first main face opposite the conveyor

- a supply of a roller above the conveyor (with an axis parallel to the conveyor and/or to the glass sheet) and having a structured (polymer) surface forming a set of disjoint cavities defined by a cavity width W0 ( on the upper surface), possibly a cavity length LO (on the upper surface), by a cavity depth PO and an intercavity distance DO (on the upper surface), preferably the roller being made of polymer material or having at least one surface layer with the surface structured in polymer material and being spaced from the conveyor by a non-zero distance Hg (Hg less than E in particular greater than E-1) - (during and/or after the rotation of the roller) filling with the fluid enamel composition of said cavities, preferably filling at room temperature and/or at most 60° C., preferably without activation or heating, without hardening or cross-linking of the fluid composition

- a rotation of the roller which is accompanied by scraping of the metal doctor blade, polymer for example), at ambient temperature and/or at most 60° C., preferably without activation or heating, without hardening or crosslinking of the composition fluid

- (by contact with the first face) a partial transfer of the fluid enamel composition on the first main face (directly on the first face or on an underlayer coating the first face) between the roller and the conveyor, the speed tangential of the roller Vt (at the point of contact) having the same direction as the speed of translation Vc of the glass sheet,

The cavities are defined by:

- W0 in a range from 0.5pm to 10000pm

- DO in a range from 0.5 to 10000pm

- PO in a range from 0.5pm to 1500pm or 1000pm or 500pm

- possibly L0 in a range from 0.5pm to 10000pm

- optionally an L0/W0 ratio ranging from 0.01 to 100, in particular from 0.1 to 10, (0.2 to 5 and if necessary from 0.95 to 1.05 (L0 or W0 preferably being in the direction scrolling of the conveyor or even of the glass sheet).

Vc is at least 1 m/min

Vc / Vt is in a range from 0.9 to 1.1 and even from 0.95 to 1.05 and the partial transfer leading to the formation of a set of fluid enamel patterns (at least partially disjoint ), in particular in the form of studs (rounded, with a convex surface) for example defined by a height Hf.

The method comprises, after formation of said set of fluid enamel patterns, a step of hardening (solidification) of the fluid composition by a (first) treatment in particular capable of removing any organic solvent and/or hardening (in particular crosslinking) the organic resin, in particular heat treatment at a temperature of at most 250° C., better still at most 200° C. or by ultraviolet (UV) treatment or by electronic beam ('Ebeam' in English), leading to said set of dry enamel patterns (hardened), in particular with a convex surface, in particular defined by:

- a first lateral dimension of dry enamel pattern W1, called first width, preferably parallel to the roller, W1 in a range going from 0.3 μm to 10000 μm - possibly a second lateral dimension of dry enamel pattern L1 called second width, preferably perpendicular to W1 and even to the roller in a range going from 0.3 pm to 10000 pm

- a height of dry enamel patterns H1 in a range from 0.3pm to 500pm, even from 1 m or 2pm to 300pm or 150pm

- and a distance to the interpattern vertex D1 in a range from 0.5pm to 10000pm

- possibly an H1/W1 aspect ratio in a range from 1/10 to 1/150, even from 1/15 to 1/60.

And possibly the dry enamel composition is present between the dry enamel patterns (with a convex surface) in particular in the form of secondary spots of dry enamel.

The decorative glazing with enamel patterns according to the invention is manufactured by localized deposition of a suitable fluid enamel composition by polymer etched roller. This glass has enamel patterns on its surface (transparent, colorless or colored, opaque, mass-diffusing) giving the glass an overall texture.

The chemical composition of the glass frit may be different from that of the glass sheet, glass frit in particular of Zn and/or Bi borosilicate type.

All or part of the cavities may be lines (without length or orientation constraints, for example over all or part of the circular perimeter of the roller) and/or all or part of the cavities may have a limited length LO in a range going from 0 .5 pm to 10000 pm optionally with an L0/W0 ratio ranging from 0.01 to 100, in particular from 0.1 to 10, (0.2 to 5 and if necessary from 0.95 to 1.05

The more punctual lines or patterns can be close enough for there to be a total coalescence between two fluid lines or patterns deposited (forming a solid area).

Patterns (lines or more punctual) can be created at least partially disjoint and cumulatively patterns obtained by coalescence of one or more patterns (lines or more punctual).

If necessary, the composition is chosen so that the baked enamel patterns are as transparent and as mass-diffusing as possible. We limit the absorption, the backscattering of incident light by the patterns so that the light transmission is as high as possible.

The presence of dry or baked enamel patterns with slopes creates blurring.

The patterns of dry or fired enamel do not necessarily all have the same distribution of slopes nor the same average slope. If necessary, the fluid composition is optimized in terms of grain size distribution (sinter), as well as the organic (resin and possible solvent) / inorganic (sinter) ratio, to be as transparent as possible after firing (heat treatment, etc.) . Patterns deposited dry or baked may be very close to each other, but not completely touching. Otherwise there is total coalescence and loss of slopes. There may be partial coalescence, with possible contact points.

The roller is preferably with a surface or completely made of rubber (EPDM). The roller is smooth non-textured at the micron scale

- between the cavities,

- at the level of the walls delimiting the cavities.

Different roller settings can change the final pattern (dry or baked):

- the deposition speed (speed of the roller and that of the glass): it changes the capillary number which modifies the rate of filling and emptying of the cavities

- the pressure of the blade: it modifies the filling of the cavities.

The fluid composition is sufficiently viscous not to creep significantly after deposition when the shear is stopped.

The filling and emptying of the cavities not being done at 100%, the volume of the cavities is much greater than that of the deposited patterns.

Since the fluid composition is not frozen (dried) in the cavities or even instantaneously frozen (dried) on the surface during transfer, it has a flow (limited, controlled by the adapted viscosity and/or a surface tension) , the width and length of the cavities are less than the width and length of the final patterns (dry or cooked).

The dried or fired deposited patterns are rounded studs, with a convex surface. The section of the patterns (deposited, dried or fired) does not reproduce the section of the cavities.

The hardening step leads to a loss of material (elimination of any solvent) in particular a reduction in height. The hardening step, in particular by heat treatment (oven, etc.) can last up to 30 min, in particular a treatment between 80°C and 180° C for at most 30 min and in particular for 5 min to 30 min.

The process preferably comprises, after the hardening step, a baking - preferably a (second, last) heat treatment (melting) of at least 500°C, better still at 600°C for at least 80s, better still 120s -, leading to the formation of a set of baked enamel patterns which may be transparent (in particular colorless), patterns defined in particular by:

- a first lateral dimension of baked enamel pattern W2, called first width, parallel to the roller, W2 in a range going from 0.2 μm to 10000 μm - optionally a second lateral dimension of baked enamel pattern L2 called second width, perpendicular to the roller, L2 in a range from 0.2 μm to 10000 μm

- a height of baked enamel pattern H2 in a range from 0.2 pm to 300 pm and even from 0.5 pm or 1 pm to 300 pm or 150 pm

- a distance to the interpattern vertex D2 in a range from 0.5pm to 10000pm

- optionally an H2/W2 aspect ratio in a range from 1/10 to 1/150, better still from 1/15 to 1/60 and optionally the transparent baked enamel composition is also present between the patterns and has a thickness less than H2/5.

Baking is preferably a heat treatment which is followed by a quenching operation.

Baking can be done following hardening (in the line of deposition, drying) or in another line (after transport and cutting shaping). The glazing with dry enamel patterns supports transport. Firing can last from 1 min to 10 min depending on the thickness of the glass, in particular about 45s /mm of glass, and/or be at a temperature in particular of 650°C to 730°C.

The possible cooking step also leads to a loss of material (elimination of the organic resin). The height of the baked enamel patterns H2 is lower than that of the dry enamel patterns H1, in particular H2/H1 is at most 0.9, even 0.8, or 0.75 and in particular ranges from 0.4 or 0, 51-11 to 0.71-11. The width and length of the baked enamel patterns may be the same or similar to the width and length of the dry enamel patterns.

The method may include the deposition of the fluid composition directly on the first face (floated, smooth) or on a functional sub-layer, for example mineral (suitable for cooking) and/or of submicron thickness.

The method may include a step of cutting, shaping, and/or storing, and/or transporting the glazing with the dry enamel patterns.

The shape, the distribution of the cavities depends on the desired final patterns and the desired arrangement. The cavities can be asymmetrical or symmetrical, isotropic (same width and length), of geometric section or any other shape. The spacing can be varied.

The cavities have for example a limited length or not, are disjointed and the patterns (deposited, dried cooked) can be disjointed or at least partially disjointed or coalesce (partial totally, by zone or according to their spacing which can be adjusted, variable ). There is for example a plurality of separate cavities from one end to the other of the roller (along the axis of the roller, the length of the roller), for example at least 500 motifs, preferably 2000 separate cavities.

The roller can be of width greater than or equal to the width of the conveyor. The width is for example at least 50cm or 1 m and for example 3m20.

The glass sheet, smooth, untextured, in particular floated (solid, unsoftened) can move with edges parallel to the conveyor (and/or to the roller).

The glass sheet can scroll with oblique edges in relation to the axis of the roller.

The subsequent cutting can be custom.

The roller is preferably of a diameter such that on a circumference there are at least 100 motifs, preferably 500 motifs, for example its diameter is at least 50 cm.

The length of the cavity can be greater than or equal to the width of the cavity. The length as the width of the cavity can vary between the high surface and the low surface.

The width of the cavity is preferably measured perpendicular to the length.

The cavities (and resulting patterns) can be distributed according to a regular, periodic (cubic, hexagonal, etc.) pseudo-periodic or random mesh. It is possible to mix the shapes, dimensions of the cavities and/or their spacing.

Different shapes of cavity volume are possible: flared truncated pyramid, parallelepipedic with square or rectangular base, straight prism with hexagonal base or any other polygonal shape...

The cavities have for example a hexagonal base and with a hexagonal mesh arrangement. The patterns (deposited, dry or fired) retain the hexagonal mesh arrangement but have a circular type base or shape.

The hexagonal mesh makes it possible to have all the cavities (and the resulting patterns) at the same distance in all directions. This mesh is the most compact mesh, so with it we can have the maximum of patterns per unit area, and consequently a maximum of % of area with slopes

For a square mesh, the diagonal cavities are further away than the horizontal or vertical ones.

The cavities (or resulting patterns) can be all identical, some identical or all different (pseudo-random distribution) in terms of shape / width / height / spacing / aspect ratio...

On the first main face, the fluid composition may also possibly be partially present between said fluid enamel patterns, in particular in the form of secondary studs (rounded, with a convex surface), the fluid enamel patterns possibly being connected locally. The scraping can have an influence on the fact that the fluid composition is present between the cavities.

Thus, most often, the scraping is such that the fluid composition is (remains) present (between the cavities then after transfer is present) partially between the said fluid enamel patterns, in particular in the form of fluid secondary studs (rounded, with a surface convex) more or less extensive.

The thickness Ei of the fluid local composition between the dry enamel patterns is preferably less than Hf, in particular Hf/5 or even Hf/10. The thickness of the local dry composition between the dry enamel patterns is preferably less than H1, in particular H1/5 or even H1/10. The thickness of the baked local composition between the baked enamel patterns is preferably less than H2, in particular H2/5 or even H2/10.

In addition, due to the viscosity and/or the spacing of the cavities and possibly the scraping, the process may be such that neighboring fluid enamel patterns are optionally partially connected to each other (partial, local coalescence, reproduced on several patterns in particular along the direction of scrolling), with a thickness less than H1 and even H 1/5.

The coalescence is partial in the sense that any pattern is not connected to a neighboring pattern over its entire contour. We can still distinguish the base (the general shape of the section) from the pattern. There may be partial coalescence, that is to say in one or more given directions, in particular along the direction of scrolling, the patterns are connected by the fluid composition at a lower height.

There may be local partial coalescence, i.e. between two neighboring patterns among a set of disjoint patterns (manufacturing tolerance, etc.).

This can be a defect obtained regularly, an acceptable defect (optically) and useful because it is easier to achieve.

For example, the partial coalescence width between two neighboring dry enamel patterns is less than 2L1/3 or L1/2 or L1/3 or even L1/5.

For example, the partial coalescence width between two neighboring fired enamel patterns is less than 2L2/3 or L2/2 or L2/3 or even L2/5.

To quantify the partial coalescence, on a surface of 10mm ² we can have:

- at least 50% or 80% of patterns are partially contiguous with one or two neighboring patterns (in particular coalescence along one direction if the patterns are aligned)

- or less than 50% and even at most 25% or 10% or 5% of patterns are partially contiguous with one or two neighboring patterns (in particular process defects). The fluid enamel composition may include (essentially) in particular, and even consists of, in % relative to the total weight of the fluid enamel:

- from 40% to 60% glass frit, in particular based on zinc borosilicate and/or bismuth

- from 20 to 40% of the organic medium preferably comprising from 2% to 15% by weight of organic medium of organic resin and from 85% to 98% by weight of organic medium of organic solvent

- no more than 20% pigments and/or diffusing particles the cumulative % in glass frit, organic medium and pigments, diffusing particles being at least 95% or 98% or even 100%.

If necessary, the composition is adapted (formulated) so that the enamel is transparent (not opaque and even slightly diffusing in volume) after firing and even colorless.

The absorption and even the diffusion of the patterns are then limited so that the light transmission is as high as possible.

The composition of fluid enamel can include (essentially) in particular and even consist of:

- from 45% to 80% glass frit, preferably 55% to 80%, capable of being transparent after firing, in particular based on zinc borosilicate and/or bismuth,

- from 20 to 55%, preferably 20% to 45% of the organic medium, preferably comprising from 2%, preferably 5% to 15% of organic resin and from 85% to 95% or 98% of organic solvent, in particular solvent with boiling temperature high enough for transfer, the cumulative % in glass frit and organic medium being at least 95% or 98% or even 99% or 100%.

In particular, the fluid enamel composition comprises at most 2% or 1% of mineral pigment and/or diffusing or reflecting particles and preferably is free of mineral pigment and/or diffusing or reflecting particles, in particular mineral, in particular crystals or oxide particles. metallic. Preferably, it is free of mineral pigment and/or of diffusing or reflecting particle.

The glass frit capable of being transparent after firing is notably devoid of or reduced in Fe, Co or Cr oxide content.

The glass frit can be silicated, in particular with alkaline elements such as Na, K or Li, and metal oxides such as Zn, Zr, Ti, Bi. It is in particular based on zinc and/or bismuth borosilicate.

In particular, it has a softening point that is sufficiently low compared to the cooking temperature, in particular a softening temperature below 590° C. measurable by differential scanning calorimetry (also called DSC - for Differential Scanning Calorimetry), and has a D90 (obtained by laser granulometry) of 5 to 20 μm and preferably of 5 to 18 μm. To reduce blurring and increase transparency, the enamel composition (deposited, dry or baked) is devoid of or comprises a very low content of particles - solid and possibly even hollow particles - in particular diffusing or more broadly any type of particles (unmelted , crystals, white or colored pigments etc). In particular, it contains few or no (solid) particles chosen from particles of alumina, zirconia, silica, titanium dioxide, calcium carbonate, barium sulphate. In particular, the baked enamel is preferably devoid of any devitrified zone. In particular, adding (in addition to the frit) crystals or metallic or metallic oxide particles is avoided.

The glass frit and even the baked enamel can be a vitreous matrix based on zinc borosilicate and/or bismuth, preferably based on zinc borosilicate.

Preferably, the glass frit of the dry or fired enamel has a chemical composition according to at least one of the following characteristics (preferably cumulative): the content by weight of ZnO + B2O3 + Bi2O3 + SiO2 + Na2O is at least 80%, 90% or 95% of the total weight of vitreous material (enamel).

It is also preferred to avoid transition metal oxides from column 5 to 11 and even 12 -except zinc- of the periodic table of the elements (or with a weight content of less than 1% of the total weight of the enamel) . It is preferable to avoid lead, cadmium and mercury oxide as well as chromium if the latter is in the +VI oxidation state (or with a weight content of less than 0.1% of the total weight of the enamel for lead, mercury as well as Chromium VI and with a content by weight of less than 0.01% of the total weight of the enamel for cadmium).

The total content of alkali oxides other than Na2O (such as Li2O, K2O) is preferably at most 3% by weight of the glass frit of the dry or baked enamel (and even of the dry or baked enamel), notably 2% and even 1% or 0.5%.

It is possible to limit to 5% 2%, 1% or 0.5% by weight of the glass frit of the dry or baked enamel (and even of the dry or baked enamel), the weight content of cumulative metal oxides alkaline earth Mg, Ca, or even Mg, Ca and Ba.

Preferably, concerning the constitution of the enamel layer, one or more of the following alternative or cumulative characteristics is provided:

- the content by weight of (solid) diffusing particles is preferably at most 1% of the total weight of the enamel deposited, dry or baked, in particular 0.5% and even 0.1%, or even zero - and/or the weight content of pigments is preferably at most 1% of the total weight of the enamel deposited, dry or baked, in particular 0.5% and even 0.1%, or even zero

- more broadly, the content by weight of particles (in particular unmelted, crystals, pigments, and which may be diffusing particles, etc.) is preferably at most 1% of the total weight of the enamel deposited, dry or baked, in particular 0.5% and even 0.1%, or even zero

- to be colorless, the total weight content of coloring elements (Fe2Os, CuO, CoO, O2O3, MnC>2, Se, Ag, Cu, Au, Nd2Û3, E^Os) is at most 0.5% and even 0.1% of the total weight of the vitreous matrix and even of the baked enamel and preferably zero (except for unavoidable impurities)

- the weight content of the vitreous matrix is at least 80%, 90%, 95% and even 100% of the total weight of the baked enamel

- dry or baked enamel has a weight content of impurities of at most 0.5% of the total weight of the enamel.

For each of the aforementioned oxides or groups of oxides, each of the lower limits can be combined with each of the upper limits, all the possible ranges not being recalled here for the sake of conciseness. Likewise, each range for a given oxide can be combined with any other range for the other oxides. Here again, not all combinations can be indicated so as not to make this text unnecessarily heavy.

Preferably, the glass frit of the dry or baked enamel (and even the dry or baked enamel) has a coefficient of thermal expansion and a glass transition temperature adapted to those of the glass sheet, and a low aptitude for devitrification.

The glass transition temperature Tg1 of the glass frit is low enough to be able to fire at temperatures at which the glass sheet cannot deform. At the same time, the frit must not crystallize (devitrify) during firing, which would have the effect of generating excessive roughness and high optical absorption.

Advantageously, the glass frit has a glass transition temperature Tg lower than that of the first sheet of glass, in particular lower than 590°C.

We consider here the beginning of the curve (“onset temperature”) for the determination of the Tg.

The coefficient of linear thermal expansion of the glass frit can also be matched to that of the glass sheet, usually be close to the latter, or slightly lower, in order to avoid during cooling the appearance in the vitreous material of mechanical stresses likely to damage it.

The coefficient of linear thermal expansion CT 1 between 20 and 300°C of the glass constituting the glass frit is preferably within a range ranging from 70 to 100×10′ ⁷ /°C, in particular 70 to 90×10′ ⁷ /°C. In particular, the first sheet of glass has a coefficient of linear thermal expansion CTO between 20 and 300° C. tq CTO- CT 1 is positive and is at most 10.10 ⁷ /°C.

The solvent serves to dilute if necessary to adjust the viscosity for the transfer generating at least partially disjoint patterns. It is also used to reduce the dry extract and therefore to reduce the thickness deposited.

The organic resin can be of the acrylate or polyacrylate resin, alkyd resin, epoxy resin, polyurethane resin, amino resin, acrylic resin, polyester resin, polyamide resin, phenolic resin, and/or cellulosic resin type.

For the choice of solvent, it is chosen such that the boiling temperature is high enough for it not to evaporate during the transfer (for the stability of the deposit). Preferably it is at least 190°C, 200°C or even 210°C.

Solvents (with low evaporation) are, for example, tripropylene glycol methyl ether (CAS number 25498-49-1) with a boiling point of 243°C.

The medium, the fluid composition, can be water-soluble or oil-compatible. An alternative organic medium comprises (essentially) or even consists of a crosslinkable resin (with UV) without the addition of solvent. Curing then involves the cross-linking of the resin.

Advantageously, Vc is at least 3 or even 6 m/min and preferably at most 20 m/min or 15 m/min.

These are speeds compatible with industrial rates.

Preferably, the fluid enamel has:

- a viscosity between 1 and 500Pa.s at a shear rate of 0.1 s-, preferably 10 to 300Pa.s, preferably 10 to 200Pa.s ¹ ,

- And a viscosity between 0.1 to 100Pa.s, a viscosity between 1 to 50 Pa.s at a shear rate of 10s ^-1 .

In particular, the fluid enamel has a viscosity which is in a range from 100Pa.s to 200Pa.s at a shear rate of 0.1 s ^-1

This range is chosen in order to favor patterns with higher slopes, by limiting the spreading after transfer.

In particular, the fluid enamel has a viscosity which is in a range from 10Pa.s to 50Pa.s at a shear rate of 0.1 s ^-1 This range is chosen in order to favor patterns with lower slopes, with spreading after transfer. And by being less viscous, it is less necessary to scrape heavily, therefore easier to deposit.

Concerning the dimensions and the distribution of the cavities, it is possible to have at least one of the following characteristics:

- DO is at least 0.5pm

- and/or: L0 is in a range from 0.5pm to 10000pm, W0 is in a range from 0.5pm to 10000pm, DO is in a range from 0.5pm to 10000pm

- and/or the cavities are defined by a L0/W0 ratio of between 0.01 and 100

- and/or the ratio PO to W0 and/or PO to L0 is at most 1 and better still at most 0.5

- And/or the degree of coverage of the cavities on the roller is in a range going from 10% to 60%, in particular from 20% to 40%.

We cap the PO ratio on W0 and/or PO on L0 because it is useless to have too deep cavities because we do not fill / evacuate more. And it is more complicated for cleaning to have cavities that are too deep.

The invention also relates to decorative glazing, in particular obtained by the manufacturing process defined above, comprising a sheet of glass (silico-sodium-lime, float, clear or extra-clear, smooth) comprising on a first main face a set of dry enamel patterns, in particular capable of being transparent after firing, comprising a glass frit and an organic resin or baked enamel, in particular transparent, comprising a molten glass frit forming a vitreous matrix, in particular rounded studs (with a convex surface, curved outwards), defined by: a first lateral dimension of pattern, called first width, along a first given direction X, in particular width of the glazing, in a range going from 0.2 μm to 10000 μm,

- optionally a second lateral pattern dimension called second width, along a second given direction Y perpendicular to X: in a range from 0.2 pm to 10000 pm,

- a dry enamel pattern height in a range from 0.2pm to 300pm, even from 1pm or 2pm to 300pm or 150pm,

- and a distance to the interpattern vertex in a range from 0.5pm to 10000pm

- possibly a height to first width aspect ratio in a range from 1/10 to 1/150, better still from 1/15 to 1/60.

Traditionally known enamelled glazing is produced by screen printing and is widely used in the following applications: - as a decorative opaque layer or forming a masking frame, with a black enamel, and possibly a gradation of patterns in the direction of the glass clear

- as a diffusing opaque layer for optical functions such as video projection of images or for the extraction of light from a light guide, forming a layer forming for example a set of discrete white patterns.

Their opacity and dimensions are not suitable for decorative glazing.

In one embodiment, the invention relates in particular to decorative glazing, in particular obtained by the manufacturing process defined above, comprising a sheet of glass (soda-lime, float, clear or extra-clear, smooth) comprising on a first main face a set of patterns of dry enamel, in particular capable of being transparent after firing, comprising a glass frit and an organic resin, in particular rounded studs (with a convex surface, curved outwards), defined by:

- a first lateral dimension of dry enamel pattern W1, called first width, along a first given direction X, in particular width of the glazing, W0 in a range going from 0.3 pm to 10000 pm

- possibly a second lateral dimension of dry enamel pattern L1 called second width, along a second given direction Y perpendicular to X: in a range from 0.3 pm to 10000 pm

- a dry enamel pattern height H1 in a range from 0.3pm to 700pm or 500pm

- and a distance to the interpattern vertex D1 in a range from 0.5pm to 10000pm, better from 1pm or 2pm to 1000pm

- an H1/W1 aspect ratio in a range from 1/10 to 1/150, better still from 1/15 to 1/60n.

And possibly the dry composition is partially present between said dry enamel patterns with a thickness less than H1 and even H1/5,

In one embodiment, the invention relates in particular to decorative glazing, in particular obtained by the manufacturing process defined above, comprising a sheet of glass (soda-lime, float, clear or extra-clear, smooth) comprising on a first main face a set of patterns of baked enamel, in particular transparent, comprising a molten glass frit forming a vitreous matrix, in particular rounded studs (with a convex surface, curved outwards), defined by:

- a first lateral dimension of baked enamel pattern W2, called first width, along a first given direction X, in particular width of the glazing, W2 in a range going from 0.2 μm to 10,000 μm - possibly a second lateral dimension of fired enamel pattern L2 called second width, preferably perpendicular to the first width, in a range going from 0.2 μm to 10000 μm

- a baked enamel pattern height H2 in a range from 0.2pm to 500pm or 300pm

- and a distance to the interpattern top of baked enamel D2 in a range from 0.5 pm to 10000 pm

- an H2/W2 aspect ratio in a range from 1/10 to 1/150, better still from 1/15 to 1/60.

And possibly the baked composition is partially present between said baked enamel patterns with a thickness less than H2 and even H2/5.

The preferred ranges of dry or baked enamel patterns are: the first width (W1 or W2) is in a range from 0.2pm to 10000pm

- the second width (L1 or L2) is in a range from 0.2pm to 10000pm

- the height H1 of dry enamel pattern is in a range from 0.3pm to 500pm, the height H2 of fired enamel pattern is in a range from 0.2pm to 300pm

- the distance to the interpattern vertex (D1 or D2) in a range from 0.5pm to 10000pm

- the aspect ratio height on first width -H1/W1 or H2/W2- (and even on first length) is in a range going from 1/10 to 1/150, even from 1/15 to 1/60.

Preferably, the dry enamel composition comprises in % relative to the total weight of the dry enamel:

- 65% to 75% glass frit

- from 5% to 20% organic resin

- from 15% to 20% of pigments and/or diffusing particles, the cumulative % in glass frit, organic resin, pigments, diffusing particles preferably being at least 95% or 98% or even 100%.

Preferably, the baked enamel composition comprises, in % relative to the total weight of the enamel, at least 80%% of molten glass frit forming a vitreous matrix and at most 20% of pigments and/or diffusing particles.

The scattering particles according to the invention can be submicron, of metal oxide for example TiO2.

Enamel can be transparent and even colorless. The glazing with the fired transparent enamel patterns according to the invention preferably has in the international colorimetry system L, a*, b* calculated in transmission (with D65 illumination): - an absolute value of a* which is less than 10 or even 5 and preferably is less than 3

- and an absolute value of b* which is less than 10 or else 5 and preferably is less than 3.

- 87.5% or 89% to 91% of glass frit capable of being transparent after firing

- from 7.5% or 9% to 11% of organic resin and the cumulative % of glass frit and organic resin being at least 98% or even 99% or 100%.

In particular, the dry enamel composition comprises at most 2% or 1% or 0% of mineral pigment and/or diffusing or reflecting particles.

Preferably, the baked enamel composition comprises, in % relative to the total weight of the enamel, at least 98% or even 99% of molten glass frit forming a transparent vitreous matrix (and even consists of the transparent vitreous matrix). In particular, the baked enamel composition comprises at most 2% or 1% of mineral pigment and/or diffusing or reflecting particles and preferably is free of mineral pigment and/or diffusing or reflecting particles.

The transparent baked enamel preferably has at most 5% by volume of porosities (open and/or closed) and preferably at most 3% by volume. In particular, the porosities are in lower concentration at the heart of the patterns.

Baked enamel chosen transparent may exhibit an intrinsic haze of at most 20% or even at most 10%. Intrinsic haze is the haze value when the baked enamel is a continuous layer at thickness H2. The haze or Haze parameter is a standardized parameter, measured with a BYK Hazeguard device and described in ASTM D1003-C: Test Method for Haze and Luminous Transmittance of T ransparent Plastics (Haze at 2.5°). The blur can also go from 5 to 99%

The sheet of glass, in particular float, smooth, is clear or extra-clear and the glazing with the patterns of transparent baked enamel has, for example, a light transmission within the meaning of standard EN410 of at least 70%, and even of at least 80% or 85%.

The transfer of the composition can therefore be local to a region of the glass sheet, with a width of at least, said roller being provided with cavities over the entire length.

It is possible to have colored and/or opaque and/or transparent, colorless and low-diffusing patterns on the same zone or distinct zones.

The glazing can have a plurality of distinct enamel patterns in distinct or interlocking regions, in particular forming a design, etc. For example, after the first deposition and curing, a new transfer can be provided using a second roller with distinct cavities and even a distinct enamel composition.

It is useful to characterize the enamel patterns optically in particular the diffusion given by the overall texture.

Decorative glazing can have several areas with dry or baked enamel patterns of different sizes and/or compositions.

The decorative glazing may include dry or baked enamel patterns of different dimensions and/or compositions within a zone.

In one embodiment, the glazing (with the dry enamel or the baked enamel) has an average slope which is less than or equal to 12°, better still 10°, calculated in a zone of the glazing surface, called surface of analysis, square including at least 10 of said dry enamel or transparent baked enamel patterns and better still at least 50 patterns of said dry enamel or transparent baked enamel patterns or 100 patterns of said dry enamel or clear baked enamel

The percentage of textured surface with a slope beyond 2.5° or 1.5° contributes to the value of the blur.

The invention finally relates to a decorative double glazing comprising an external glazing and an internal glazing spaced apart and connected by a seal at the periphery, one of the external or internal glazing being said glazing with the transparent baked enamel patterns already defined above, of preferably the enamelled main face being the external face F1 or the face F2 of the external glazing.

The double glazing comprising sealing means, in particular against water and/or gas and water vapour, which are formed by means for fixing and/or sealing the spacer to the main faces of the two glazing. In particular, the sealing means comprise on the one hand means for fixing the spacer by bonding (the means for fixing by bonding being arranged at the interface between the spacer and the internal faces of the glazing), said means fixing forming a barrier to gas and water vapor such as butyl, and on the other hand a waterproof sealant, such as polyurethane, or polysulphide or silicone, arranged between the glazing (their inner face) and on the outer face of the spacer opposite the gas gap.

An example of a spacer has a rigid base body consisting of a thermoplastic material, of the styrene acrylonitrile (SAN) or polypropylene type, and reinforcing fibers, of the glass type, which are mixed with the thermoplastic material, as well as a sheet sealing gas and water vapor bonded to the face intended to be the outer face of the spacer in the mounted position in the glazing (arranged opposite the gas gap). The base body is hollow and additionally accommodates a desiccant. Such a spacer, based on SAN and glass fibers, is known for example under the trade name SWISSPACER® by the applicant when the sealing sheet of the base body is made of aluminum, and under the name SWISSPACER V® when the Base body sealing sheet is made of stainless steel. Another example of a spacer is a flexible spacer made of solid material and incorporating desiccant.

Figures 1 to 3 show the general steps in the manufacture of decorative glazing with fluid, then dry and finally baked enamel patterns according to the invention by an engraved roller placed above a conveyor.

Some figures show photos under an optical microscope at different magnifications of decorative glazing with dry or baked enamel patterns according to the invention by engraved roller.

Some figures show surface or distribution maps of the slopes of decorative glazing with dry or baked enamel patterns according to the invention by engraved roller.

Some figures show graphs of angular distribution of the slopes of decorative glazing with patterns of dry or baked enamel according to the invention by engraved roller.

Figures 1 to 3 schematically show the general stages of manufacture of decorative glazing with dry or baked enamel patterns according to the invention by engraved roller placed above a conveyor.

Figures 1 and 2 are schematic elevational and side views of the manufacture of decorative glazing with fluid enamel patterns 20 by etched roller arranged above a conveyor. Figure 3 is a schematic side view which show the general stages of manufacture of the decorative glazing with dry and then fired enamel patterns according to the invention by engraved roller placed above a conveyor, stages consecutive to the stages described in relation to FIGS. 1 and 2.

The formation of a glazing with a set of dry enamel patterns first involves the following steps (see Figure 1 and Figure 2):

- a supply of a fluid enamel composition 2 comprising a glass frit, an organic medium which comprises an organic resin, an optional organic solvent, composition capable of forming a transparent enamel after firing

- a movement in translation of a sheet of glass 1 flat on a conveyor 5, at a given translational speed Vc, with a first main face 11 opposite the conveyor - a supply of a roller 3 above the conveyor and having a structured surface 31 forming a set of disjoint cavities 30, 3D and/or lines, defined by a cavity width W0, possibly a cavity length L0, a depth of cavity PO and a distance between cavities DO,

- filling of said cavities 30 with the fluid enamel composition,

- a rotation of the roller which is accompanied by a scraping of the roller with a doctor blade 4,

- a partial transfer of the fluid enamel composition on the first main face 11 between the roller and the conveyor, the tangential speed of the roller Vt having the same direction as the speed of translation Vc of the glass sheet, the transfer leading to the formation of a set of fluid enamel patterns 20.

The scraping is such that a portion 20' of the fluid composition is partially present between said fluid enamel patterns 20.

Due to the viscosity and/or the spacing of the cavities and possibly the scraping, the process is such that neighboring fluid enamel patterns are possibly partially connected to each other, with a partial coalescence width between two neighboring dry enamel patterns. is less than LO/2 and with a thickness less than H1 and even H1/5.

Vc is at least 1 m/min and even 3 or 6 m/min and preferably at most 20 m/min or 15 m/min.

Vc/Vt is in a range from 0.9 to 1.1.

The deposition of the fluid composition is directly on the first face or on a functional sub-layer on the first face.

As shown in FIG. 3, the method comprises, after the formation of said set of fluid enamel patterns, a step of hardening the fluid composition by treatment, in particular heat, at a temperature of at most 250° C. or by ultraviolet treatment or by electron beam, leading to said set of dry enamel patterns 21.

After curing, a part 21′ of the dry composition is partially present between said dry enamel patterns 21 with a thickness E1 less than the height H1 of the dry enamel patterns and even less than H 1/5.

After the hardening step, a firing of at least 500° C., better at 600° C., takes place, leading to the formation of a set of transparent baked enamel patterns 22, the firing being a heat treatment followed by a quenching operation. After firing, a portion 22' of the fired composition is partially present between said fired enamel patterns 22 with a thickness E2 less than the height H2 of the baked enamel patterns and even less than H2/5.

EXAMPLES

Several series of examples illustrate the range of possibilities in terms of dimensioning, distribution of slopes, arrangement or deformation of dry or fired patterns and also the influence of process parameters and the choice of cavities.

The following tables bring together the main process data and the sizing characteristics of the cavities, the patterns and the optical characteristics of the enamelled glazing.

The fluid enamel composition consists of glass frit, an organic resin and a tripropylene glycol methyl ether solvent.

The roller is in EPDM, hardness is 45 shA.

The patterns on the roll here are identical with a regular arrangement.

The surface coverage is the ratio between the area of the cavities and the total area of the roller The Hgap is the distance between the conveyor and the roller. It is a value in mm.

The speed is both that of the conveyor and that of the roller, since they are preferably identical so as not to distort the patterns.

For ZTL haze measurements, for each sample, the measurement is made at five points (the 4 corners and the middle) and the value communicated is the average of these five measurements.

The sample surface topography measurement parameters with an optical profilometer are:

-1000um optical pen depth of field

- acquisition frequency: 400 Hz.

Series 1 and 1 ’

Series n°1 concerns six tests 1a to 1f with different basic cavities (S1 to S6) or variable 3D shape with an enamel paste (comprising glass frit, organic resin, organic solvent) diluted by adding the solvent.

Series n°1’ concerns six trials 1’a to 1’f and differs from series 1 in that the enamel paste is pure, without dilution.

Figure 4 shows the six cavities S1 to S6 and the six photos by optical microscopy (common scale of 1 mm) showing the dry enamel patterns, six photos for series 1 in the left column and six photos for series 1' in the column of right.

Tables 1 and 2 gather the manufacturing parameters respectively for series 1 and series 1'. [Table 1]

[Table 2]

To study the impact of changing the shape of the cavity S2 and S3 have the same area, but a different cavity volume. It is clear that the change in cavity volume and shape between S2 and S3, even if the area on the roller is the same, leads to a difference in pattern width. Concerning the series 1, we see that (with cavity S1 of square base) the dilution can lead to a partial coalescence here directional in particular along the axis of scrolling.

On the other hand (with S2 or S5 cavities of hexagonal base) the coalescence can be more punctual with a reduced width of coalescence.

We also see that whatever the shape of the base, the dry enamel patterns have a round shape.

The size and shape of the cavities can be custom adjusted. To simplify, cavities of straight section may be preferred.

Regarding the 1 'series, the patterns fluent less. It is clear that all the patterns of the diluted enamel have a larger diameter than that of the pure enamel. This leads to lower slopes in the case of diluted enamel. There may be a coalescence between two patterns (tolerated defect) as with the cavity S4.

The shape of the final pattern was slightly varied by varying the shape of the cavity: square S1 versus hexagonal S2, with the same enamel, the same deposition parameters, the same cavity volume and the same area. Two different shapes of dry enamel patterns are obtained round for S2 and deformed square for S1.

Through the patterns obtained in S6 (Series 1 or 1 ') we show the possibility of obtaining smaller elements while keeping the same height to width ratio.

Smaller shapes are more advantageous for several reasons:

- reduction in the quantity of enamel deposited and therefore in the cost of the product

- reduction in the thickness of the enamel, therefore more transparent.

Small patterns make it possible to have interesting slopes while maintaining great transparency.

Series 2

Series 2 shows through two examples 2a to 2b the effect of dilution on the baked enamel patterns, all other things being equal. Table 3 gathers the manufacturing parameters of series 2. [Table 3]

Table 4 collates the data on the enamelled glazings 2a and 2b. [Table 4]

Table 5 below indicates for different shear rates the viscosity as a function of the possible dilution.

[Table 5]

Figures 5 and 6 show photos by optical microscopy (200 μm scale, in white line) showing the baked enamel patterns for examples 2a and 2b.

Patterns of larger diameter are found if the dilution is increased.

The crushing of the roller causes the patterns to be deformed in the direction of travel, of the ovaloid type and can lead to two neighboring patterns being partially in contact (figure 6).

Figures 7 and 8 show Dektak contact profile measurements to assess the height of enamel residue between the studs for example 2a.

On 5 profiles, we find heights between 50 nm and 2.3 μm, for enamel blocks which are 22 μm.

FIG. 9 is a set of graphs showing the angular distribution of the slopes (on the ordinate number of normalized strokes on the abscissa, angle in degrees) for examples 2a (curve 1) and 2b (curve 2). We observe for each a local maximum at less than 10°.

Series 3

Series 3 concerns two examples 3a and 3b obtained with different shapes of the cavities. Table 6 summarizes the manufacturing parameters of series 3 and following 4. [Table 6]

Table 7 summarizes the parameters of the enamelled glazing of series 3 and the following series 4 .

[Table 7]

Series 3 shows through these two examples 3a and 3b the negligible impact of the shape of the cavities on the shape of the fired enamel patterns, all other things being equal.

Figures 10 and 11 show photos by optical microscopy (200 μm scale in white line) showing the baked enamel patterns for examples 3a and 3b. FIG. 12 is a set of graphs showing the angular distribution of the slopes (on the ordinate number of strokes in arbitrary units and on the abscissa angle in degrees) for examples 3a (curve 1) and 3b (curve 2). We observe for each a local maximum at less than 13°. Series 4

Series 4 relates to five examples 4a to 4e of the manufacture of glazing with different sizes of fired enamel patterns.

Figure 13 shows two optical microscopy photos (200 μm scale, white line) showing the baked enamel patterns for examples 4a (left) and 4b (right). Figure 14 shows two optical microscopy photos (200 μm scale, white line) showing the baked enamel patterns for examples 4c (left) and 4d (right). Figure 15 shows an optical microscopy photo (200 μm scale, white line) showing the baked enamel patterns for example 4e.

This illustrates the wide range of sizes of baked enamel patterns possible especially for the same coverage rate on the roll (except 4th).

Figure 16 is a set of graphs showing the angular distribution of the slopes (on the ordinate number of strokes in arbitrary units on the abscissa angle in degrees) for examples 4a (curve 1) and 4b (curve 2) 4c (curve 3) 4d ( curve 4) and 4th (curve 5). We observe for each a local maximum at less than 10° but a great variability of width at mid-height.

Series 5

Series 5 concerns three examples 5a to 5c of the manufacture of glazing obtained with different roller speeds.

Table 8 gathers the manufacturing parameters of series 5.

[Table 8]

Table 9 gathers the parameters of the enamelled glazing of the 5 series.

[Table 9]

Series 5 shows the influence of roller speed.

Figure 17 shows two optical microscopy photos (200 μm scale, white line) showing the baked enamel patterns for examples 5a (left) and 5b (right). Figure 18 shows an optical microscopy photo (200 μm scale, white line) showing the baked enamel patterns for Example 5c.

Speed is a key parameter among the deposition parameters. The velocity modifies the capillary number (Ca = Viscosity x Velocity / Surface tension). As it has been shown in the literature, the capillary number modifies the rate of filling and emptying of the cavities. The greater the speed, the less the cavities are filled and the less the cavities are emptied.

We see that the faster we go:

- the more frit there is between the patterns

- the less the patterns are deformed in the direction of scrolling (larger average width in the direction of scrolling) - and that the speed does not generate strong variations in thickness.

Series 6

Series 6 shows three examples of enamelled glasses 6a, 6b, 6c obtained with cavities of different depths.

Table 10 gathers the manufacturing parameters of series 6 and the following series 7.

[Table 10]

Table 11 gathers the parameters of the enamelled glazing of the 6 series.

[Table 11]

Series 6 illustrates the impact of cavity depth.

Figures 19, 20, 21 show photos by optical microscopy (200 μm scale, in white line) showing the enamel patterns fired for examples 6a; 6b and 6c.

The deeper the cavity, the greater the quantity deposited.

The impact is greater for narrow patterns.

Series 7

Series 7 is an example 7 of enamelled glazing with a transparent baked pattern according to the invention Figure 22 shows a photo by optical microscopy (200 μm scale, in white line) showing the baked enamel patterns for example 7.

The point coalescence tolerated is diagonal and in the direction of travel.

Series 8

Furthermore, the pressure of the doctor blade also influences the shape of the pattern deposited: the greater the pressure of the doctor blade, the lower the quantity of enamel deposited and the less residue there is.

Series 8 shows four examples of clear baked enamel patterns 8a to 8d with a high density of enamel residue with moderate squeegee pressure.

Table 12 gathers the manufacturing parameters of series 8.

[Table 12]

Figure 23 shows two photos by optical microscopy (200 μm scale, in white line) showing the enamel patterns fired for examples 8a (left); 8b (right).

Figure 24 shows an optical microscopy photo (200 μm scale, white line) showing the baked enamel patterns for example 8c.

Figure 25 shows an optical microscopy photo (200 μm scale, white line) showing the baked enamel patterns for Example 8d.

Claims

1. A method of manufacturing decorative glazing characterized in that it comprises the formation of a glazing with a set of dry enamel patterns comprising the following steps:

- a supply of a fluid enamel composition, in particular shear thinning, comprising a glass frit, an organic medium which comprises an organic resin, a possible organic solvent,

- a translational scrolling of a flat glass sheet on a conveyor, at a given translational speed Vc, with a first main face opposite the conveyor

- supply of a roller above the conveyor and having a structured surface forming a set of disjoint cavities defined by a cavity width W0, a cavity depth PO and an intercavity distance DO,

- filling said cavities with the fluid enamel composition,

- a rotation of the roller which is accompanied by a scraping of the roller,

- a partial transfer of the fluid enamel composition on the first main face between the roller and the conveyor, the tangential speed of the roller Vt having the same direction as the speed of translation Vc of the glass sheet, characterized in that:

- the cavities are defined by

- W0 in a range from 0.5pm to 10000pm

- DO in a range from 0.5 to 10000pm,

- PO in a range from 0.5pm to 1500pm, in that:

- Vc is at least 1 m/min

- Vc / Vt is in a range from 0.9 to 1.1 the transfer leading to the formation of a set of fluid enamel patterns and in that it comprises after the formation of said set of patterns of fluid enamel, a step of hardening the fluid composition by treatment, in particular heat, at a temperature of at most 250° C. or by ultraviolet treatment or by electron beam, leading to said set of dry enamel patterns.

2. A method of manufacturing decorative glazing according to claim 1, characterized in that the scraping is such that the fluid composition is partially present between said fluid enamel patterns, and after hardening, the dry composition is present.

32 partially between said dry enamel patterns with a thickness less than H1 and even H 1/5.

3. A method of manufacturing decorative glazing according to one of the preceding claims, characterized in that due to the viscosity and/or the spacing of the cavities and possibly the scraping, the method is such that neighboring fluid enamel patterns are partially connected to each other, with a width of partial coalescence between two neighboring dry enamel patterns being less than L1/2 and even with a thickness less than H1 and even H 1/5.

4. A method of manufacturing decorative glazing according to one of the preceding claims, characterized in that the fluid enamel composition comprises, in % relative to the total weight of the fluid enamel:

- from 40% to 60% glass frit

- no more than 20% pigments and/or diffusing particles, the cumulative % in glass frit, organic medium pigments and diffusing particles being at least 95% or 98% or even 100%.

5. A method of manufacturing decorative glazing according to one of claims 1 to 3 characterized in that the fluid enamel composition comprises, in% relative to the total weight of the fluid enamel:

- from 45% to 80% of glass frit capable of being transparent after firing

- from 20 to 55% of the organic medium preferably comprising from 2% to 15% by weight of organic medium of organic resin and from 85% to 98% by weight of organic medium of organic solvent the cumulative % in glass frit and medium organic being at least 95% or 98% or even 100%.

6. A method of manufacturing decorative glazing according to one of the preceding claims, characterized in that the organic medium comprises an organic solvent having a boiling point of at least 190°C.

7. A method of manufacturing decorative glazing according to one of the preceding claims, characterized in that it comprises depositing the fluid composition directly on the first face or on a functional undercoat on the first face.

8. A method of manufacturing decorative glazing according to one of the preceding claims, characterized in that all or part of the cavities are lines and/or all

33 or part of the cavities have a length LO in a range ranging from 0.5 μm to 10,000 μm, possibly certain cavities having a ratio L0/W0 ranging from 0.01 to 100, in particular from 0.1 to 10.

9. A method of manufacturing decorative glazing according to one of the preceding claims, characterized in that the fluid enamel has:

- a viscosity between 1 and 500Pa.s at a shear rate of 0.1s ^-1 , preferably 10 to 300Pa.s, and even preferably 10 to 200Pa.s ¹ ,

- And a viscosity between 0.1 to 100Pa.s, at a shear rate of 10s ^-1 .

10. A method of manufacturing decorative glazing according to one of the preceding claims, characterized in that D0 is at least 0.5 μm, and the cavities are defined by a L0/W0 ratio of between 0.01 and 100 .

11. A method of manufacturing decorative glazing according to one of the preceding claims, characterized in that the PO to W0 ratio and/or the PO to L0 ratio is at most 1 and better still at most 0.5.

12. A method of manufacturing decorative glazing according to one of the preceding claims, characterized in that it comprises, after the hardening step, a firing of at least 500° C., better still at 600° C. leading to the formation of a set of transparent baked enamel patterns, preferably the baking being a heat treatment followed by a quenching operation.

13. Decorative glazing, in particular obtained by the manufacturing method according to one of the preceding claims, characterized in that it comprises a sheet of glass comprising on a first main face carrying a set of dry enamel patterns, comprising a glass frit and an organic resin, or fired enamel comprising a molten glass frit forming a vitreous matrix, patterns, in particular of convex surface, defined by: a first lateral dimension of the enamel pattern, called first width, along a first given direction X, in particular width of the glazing, in a range going from 0.2 pm to 10000 pm,

- optionally a second lateral dimension of enamel pattern called second width, along a second given direction Y perpendicular to X, in a range from 0.2 pm to 10000 pm,

- a height H1 of dry enamel pattern in a range from 0.3 μm to 700 μm or a height H2 of baked enamel pattern in a range from 0.2 μm to 500 μm

- and a distance to the interpattern vertex in a range from 0.5pm to 10OOOprn.

14. Decorative glazing according to one of the preceding glazing claims characterized in that the dry enamel composition is present between the enamel patterns dry and has a thickness less than the height H1 and even less than a fifth of the height H1 or the baked enamel composition is present between the baked enamel patterns and has a thickness less than the height H2 and even less than a fifth of the height H2.

15. Decorative glazing according to one of the preceding glazing claims characterized in that the dry enamel composition comprises, in % relative to the total weight of the dry enamel:

- 65% to 75% glass frit

- from 5% to 20% organic resin

- no more than 20% of pigments and/or diffusing particles, the cumulative % of glass frit, organic resin, pigments, diffusing particles being at least 95% or 98% or even 100%.

16. Decorative glazing according to one of claims 13 or 14 characterized in that the dry enamel composition comprises, in% relative to the total weight of the dry enamel:

- from 87.5% to 91% of glass frit capable of being transparent after firing

- from 7.5% to 11% organic resin. the cumulative % of glass frit and organic resin preferably being at least 98% or even 100%.

17. Decorative glazing according to one of the preceding glazing claims characterized in that the baked enamel composition comprises in % relative to the total weight of the enamel from 98% to 100% of transparent glass frit.