NL1028710C2 - Glass wall coverings. - Google Patents

Description

5

WALL COVERING OF GLASS

The present invention relates to a wall covering of glass, in particular in the form of tiles, intended for covering walls of a home such as the walls, the floors or the ceilings.

The invention relates more particularly to a covering that can be fixed to walls by conventional techniques for applying traditional ceramic tiles.

Glass wall coverings in the form of slabs or tiles are particularly appreciated for their aesthetic quality and ease of maintenance. The total absence of porosity of the glass ensures that the glass is easy to clean, while the light-transmitting and reflecting properties of the glass ensure highly appreciated optical effects, for example the effect of depth when decorations are applied on the back of the 25 plates.

However, its commercial development has been inhibited, and since many years, due to the fact that glass coatings cannot be applied to walls with the help of conventional adhesives used by skilled artisans for placing ceramic tiles. , such as cement adhesives, also called "mortar adhesives". The latter are mixtures of cement and sand to which so-called make-up water is added, to form a paste which is applied to the walls to be coated and which solidifies as a result of the hydration reactions of the cement. The cement is incompatible with conventional types of glass such as soda-lime glass, because its basic nature causes corrosion reactions of the glass which prevent complete adhesion of the glass to the cement and which greatly impair the aesthetic appearance of the glass panel.

Various alternative fasteners for glass coatings are therefore used. These can be mechanical, but then make the manufacture of expensive metal parts (screws, rivets, bolts) necessary. The mechanical connections that are discontinuous also have the disadvantage that they cause a concentration of internal stresses and an irregular distribution of the stiffness which are disadvantageous for a good mechanical strength of the whole. They are also visible, which can be a nuisance from an aesthetic point of view.

The glass coatings can also be attached with the aid of adhesives, for example on the basis of synthetic resins. Due to the high cost of the adhesives used, these are rarely applied over the total surface to be glued, hence a poor distribution of the shear forces and therefore a gluing of a lower quality. Moreover, aging reactions can be expected that will deteriorate its adhesive properties.

Solutions that enable the use of cement adhesives have recently been proposed, but these are not without disadvantages.

The patent US 6 015 622 recommends the use of a very special application method, which comprises in particular the preparation of the mortar with an aqueous dispersion of a polyacrylic acid derivative. The patent DE 100 34 981 demands exclusive rights for a glass tile that has already been coated with a cement with a special composition obtained with the aid of an aqueous dispersion of a styrene / butadiene type resin. EP-A-722 027 also discloses the use of a specific mortar containing 50% of an additive consisting of a diluted aqueous dispersion of a synthetic resin. In these three cases, the use of a mortar with a special composition is indispensable, and the use of mortars commonly used by artisans applying ceramic tiles is not satisfactory.

It also appears that the smooth surface of the glass is detrimental to the good fixing of the glass tile on brick walls. Thus, as early as 1925, the patent FR 599 239 recommended coating the tiles with a layer of paste or varnish derived from synthetic resins to which fragments of glass, metal, sand, gravel, marble, or any other inert material were attached. However, this method necessitates the use of ground fragments, thus obtained with an expensive method.

From the prior art, wall coverings of glass on which a lacquer layer with decorative function has been applied on the side that makes contact with the coated wall are also known. But the type of lacquer used is also incompatible with cement adhesives, and such products must be applied to the walls by other means, for example with the aid of adhesive resins.

The object of the present invention is to eliminate the aforementioned drawbacks by means of a wall covering based on glass, in particular in the form of tiles, which are intended for covering the walls of a house and which are suitable for to be applied to these walls by techniques commonly used for applying ceramic tiles, in particular by using conventional mortar adhesives.

The inventors have discovered that the decisive physico-chemical property in the present case is the water permeability of the lacquer. If this quantity is unsuitable (in this case too high, taking into account the mortar glue used), the make-up water, which has become basic through the hydration reaction of the cement, diffuses through the lacquer layer and reacts this chemically with the surface of the glass, making complete adhesion impossible (in particular the adhesion between glass and lacquer), while affecting the appearance of the glass coating.

In the broadest sense, the coating according to the invention thus comprises a glass substrate which is coated on the side to be applied with a layer based on lacquer, characterized in that the lacquer has such a permeability for water that the coating on Walls can be applied using conventional mortar adhesives or cement adhesives.

The maximum value of the permeability of the varnish in order to be able to achieve a sustainable gluing naturally depends on the type of mortar glue used. The lacquer of the coating according to the invention has a water permeability at 25 ° C, expressed in cm 3. cm. cm -2. s_1. Pa-1 of preferably less than 10 "6, yes, even lower than 5.10" 7, and in particular lower than 10 "7.

In order to ensure perfect adhesion and mechanical stability, in particular a shear resistance for a long time, it is even preferred that the lacquer have a water permeability at 25 ° C of less than 10 ~ 8, more preferably even 10'9 and even 10 -10 cm3 .cm.cm ^ .s ^ .Pa-1. Because coatings according to the invention are intended in certain cases to be applied in places whose environment is moist (for example swimming pools), it is even preferable that the water permeability of the lacquer that is a side of a coating according to the invention covered, less than 10-11, more preferably 10 "12 and even 10'13 cm3 .cm.cm" 2.s_1.Pa "1.

Water permeability is defined as the product of the amount of water vapor that diffuses through a material (in cm3) times the thickness of the material (in cm2) divided by the product of the exposed surface (in cm2) times the exposure time (in seconds) and the pressure difference (in Pascal) between the two planes of the material. The permeability to water can be measured, for example, by measuring the weight increase of a lacquer film after exposure in a climate chamber whose humidity is controlled.

In the case of a polymer in the first order, this quantity depends on the chemical nature of the polymer, and furthermore on the morphology, which depends, for example, on the degree of cross-linking (via, for example, the amount of cross-linking agent and / or the cross-linking temperature), the degree of crystallization, and a possible orientation of the molecules. This quantity may also depend on the nature and amount of mineral fillers.

The lacquer of the coating according to the invention therefore preferably comprises a synthetic resin as binder, preferably in liquid form for depositing and suitable for oven drying. It has been observed that the lacquers that contain binders that have been dried at a high temperature (above 50 ° C, more preferably even above 100 ° C), have generally a much lower permeability than binders that are air dried at ambient temperature, probably as a result of cross-linking reactions that are more descending and lead to much denser three-dimensional networks.

The binder is advantageously a polyurethane resin obtained by crosslinking through an isocyanate or a polyisocyanate of hydroxylated resins, in particular polyester or polyether resins, or preferably acrylic resins (or polyacrylates) that have a higher resistance to ultra-violet radiation. In this case, the hydroxylated acrylic resin is preferably obtained in the polymerization of an acrylic styrene, while the isocyanate (or polyisocyanate) advantageously does not contain an aromatic group. This specific combination makes it possible in particular to obtain a low permeability, good mechanical properties (for example with regard to scratch resistance) and a greater resistance to ultraviolet radiation.

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The binder of the lacquer of the coating according to the invention may also contain or be based on one or more alkyd resins obtained by chemical reaction between at least one polyol, at least one polyacid and at least one fatty acid or oil. These alkyds are preferably low in oil, i.e. the amount of oil or fatty acid in the resin is preferably less than or equal to 40% by weight. The polyols can be, for example, compounds of glycerol or pentaerythritol. The poly-10 acids can be based on phthalic anhydrides. The oils can be siccative (such as linseed oil, wood oil or tung oil), semi-siccative (such as dehydrated soybean oil, tall oil, safflower oil or castor oil) or even non-siccative (such as copra oil or castor oil). To improve their water resistance properties, alkyd binders can also be modified with monomers such as styrene, vinyl toluene or acrylates or with phenolic resins or epoxy resins. Aminoplastic alkyd resins that crosslink under the influence of heat are particularly advantageous binders of the lacquer of the coating according to the invention. The aminoplast crosslinking agent is preferably a urea formol resin or melamine formol resin, which gives good water resistance, in particular when used in an amount of 20 to 30% by weight relative to the dry alkyd binder.

The lacquer can also contain a binder based on thermosetting acrylic resin, which is obtained, for example, by crosslinking a carboxylated acrylic resin with an epoxy resin, formo-phenol resin or melamine-formol resin, an acrylic resin with carboxamide function through an epoxy or alkyd binder or an acrylic resin with epoxy function by acids or polyamines.

The coating according to the invention is advantageously provided with an adhesion promoting layer (also referred to as "adhesion promoter") which is located between the glass and the varnish and which serves to improve the adhesion between the glass and the varnish. This layer is preferably based on silanes which make it possible to avoid the risk of releasing due to moisture. Means for promoting adhesion to the glass, such as silanes, can also be dispersed in the lacquer.

The lacquer advantageously contains inorganic and / or organic pigments, preferably inorganic pigments, in order to obtain the desired aesthetic properties. These pigments are preferably of a type that is resistant to ultraviolet radiation and moisture. Pigments used in the context of the present invention include, for example, titanium oxides or zirconium oxides optionally doped with ions of transition elements or mixed oxides of the zirconium type (Zr-S104). The pigments are preferably free of heavy metals such as cadmium or lead.

The lacquer can also contain mineral liquids intended to optimize the physico-chemical parameters, for example its viscosity. The total content of mineral particles (pigments and fillers) of the lacquer is preferably between 40 and 70% by weight, and even between 50 and 60% by weight.

The lacquer of the coating according to the invention can be applied by any method known to the skilled person! such as curtain casting, pneumatic spraying, screen printing or roll-coating. Screen printing has the advantage that only a part of the substrate can be coated. Roll coating consists of applying the substrate to be coated between two rollers, one of which (generally the top one) is coated with lacquer. For cost reasons, the method used is preferably curtain casting, whereby a stream of lacquer is established on a line that is essentially perpendicular to the direction of travel of the glass substrate, thus allowing the entire surface of to coat the substrate. The flow rate of the lacquer and the run rate of the substrate are controlled such that a deposit of the desired thickness, preferably 100 to 200 μπι in wet conditions, is obtained. The substrate coated with varnish is then subjected to a thermal treatment which allows the hardening of the varnish, more precisely the evaporation of the solvent and the bringing about of polymerization and / or cross-linking reactions of the resins used as binder. The temperature used is preferably between 50 and 250 ° C, in particular between 100 and 200 ° C, in order to give the lacquer a degree of cross-linking suitable for reducing its water permeability. The thickness of the lacquer layer after curing is preferably between 20 and 100 μπι, in particular between 40 and 70 μπι, in order to obtain the desired opacity.

The glass substrate used can be any kind of flat glass (possibly bended by means of bending methods known to those skilled in the art when it comes to coating curved surfaces). It can be monolithic glass, that is to say glass composed of a single glass plate, which can be produced by the "float" process which makes it possible to obtain a perfectly flat and smooth plate, or by drawing or laminating methods. In the latter case and if the laminating rollers have embossed shapes, the glass plate can be pressed in and have patterns (as for example described in the patent EP 493 202) on at least one of the sides, preferably the side that the lacquer bears (or back).

The glass can be clear or have different shades such as blue, bronze, green, gray or pink. The light permeability of the glass can be selected between 10 and 92% for a thickness of 4 mm. A particularly preferred embodiment in the case that the lacquer is white or has an ivory color consists of using a plate of extra clear glass, that is to say glass whose iron oxide content is lower than 250 ppm, preferably lower than or is equal to 200 ppm, 35 or even 150 ppm and of which the transmittance for light under illumination D65 is greater than 89%, in particular 90% for a thickness of 4 mm. It has been found that the optical properties of such a glass enable an excellent display of the white color or ivory color of the lacquer, while the residual green tint of conventional clear glass, the iron oxide content of which is in the order of 1000 ppm, is particularly clear.

The thickness of the glass substrate is preferably between 2 and 19 mm, preferably between 4 and 10 mm, in particular between 5 and 9 mm.

This glass plate can be made mat on at least one of the sides (preferably the front side) by various matting methods, for example matting with hydrofluoric acid or sandblasting. The matting can be performed on the entire surface, or on special zones, thus forming slightly sunken matte patterns. This latter embodiment can be carried out by covering the areas that are not engraved. screens with an acid-resistant coating that is subsequently removed. The matt appearance can also be obtained by depositing an organic or inorganic enamel.

A reflective layer, preferably a silver layer obtained by silvering methods known to those skilled in the art, can also be applied between the glass substrate (optionally provided with adhesion promoters of the silane type) and the lacquer, the latter also having the function of varnish which protects the silver layer against corrosion.

A decoration of one or more colors obtained with screen printing techniques or inkjet techniques is advantageously applied between the glass substrate (possibly provided with adhesion promoters of the silane type) and the lacquer and / or on the front side. For example, applying the decorations on the front and on the back can be combined.

A particularly interesting embodiment relates to a wall covering according to the invention, that is to say coated with a lacquer on the rear side, the rear side of which is subsequently incised by mechanical means (in particular by grinding using grinding stones with a more or more less complex profile) in such a way that, for example, lines with a width of 1 to 30 mm and a depth of 0.5 to 3 mm are formed, where the lacquer is thus completely removed. A decorative layer, preferably a silver layer obtained by known silvering techniques, can then be deposited on the rear side. In the case that the incisions are arranged along straight lines at regular intervals from each other and in two perpendicular directions, one can thus get the visual impression of a number of tiles separated by joints starting from a single glass panel mounted on the wall, an advantage is obtained from a front side which forms a smooth surface, whereby the problem of contamination of the joints is prevented and cleaning is considerably facilitated. This embodiment of the invention moreover makes it possible to shorten the duration of the application of glass tiles by saving on the steps of the jointing.

The glass substrate can also be coated with functional layers such as stacks of anti-reflective layers, layers with self-cleaning function (e.g. layers containing titanium oxide, preferably crystallized in the anatase and / or rutile form, which also have anti-dirt properties, antibacterial anti-fogging properties, anti-fogging properties, or hydrophobic layers. Layers giving anti-slip properties, in particular in the form of enamel, are particularly appreciated for floor covering. Wear-resistant or scratch-resistant layers can also be applied as a coating on the substrate according to the invention.

For reasons of safety or to provide special functions, the glass substrate may advantageously be a laminated glass formed by an assembly of different types of glass, in particular two glass plates separated by a plate of plastic, such as polyvinyl butyral ( PVB). Layers that are electrically conductive and therefore heat through the Joule effect can be integrated on one of the sides of the laminated glass, which makes it possible to obtain heated floors and / or walls, for example. The plastic sheet can also contain liquid crystals which can be directed under the action of an electric field, whereby the transition from a translucent or opaque state to a transparent state is possible, which can, for example, reveal a special decoration located on the rear side .

The glass substrate can also be a light-emitting window, for example a double window filled with a gas, in particular a noble gas such as xenon or neon, which can give luminescent discharges under electric field, as described, for example, in international application WO 2004/015739 which is incorporated herein by reference, whether a laminated or multi-pane is light-emitting diodes that are electrically powered by thin conductive films or by screen-printed tapes or wires, for example based on silver paste.

If the glass covering is in the form of a tiling, the tiles are preferably in the form of rectangles whose dimensions of the sides are multiples of 15 cm, taking into account a joint of a certain dimensions (for example 3 mm). So tiles of 15 x 15 cm 2, 15 x 30 cm 2, 15 x 45 cm 2, 30 x 45 cm 2, 30 x 30 cm 2, 45 x 45 cm 2 and so on can be formed. The fact that a joint of a certain size is taken into account for each of these dimensions makes it possible to combine gels of different sizes on one and the same wall, while an arrangement of the joints that is particularly appreciated on an aesthetic level, preserved.

An advantage of the glass tile over conventional ceramic tiles is precisely the modularity of the possible sizes and the possibility of easily obtaining panels with large dimensions. Namely, the final size is obtained by simply cutting large glass plates whose surface area can be more than 10 m2, while the dimensions of ceramic tiles can only be changed by manufacturing and using shapes of different sizes. Moreover, it is extremely difficult to obtain ceramic parts with large dimensions, for example with an area of more than 1 m 2.

The shape of the edges of the tiles according to the invention is particularly optimized to facilitate the application of joints and to avoid visible joint errors. The inventors have observed that certain edits of the edge, in particular of the "rounded joint" type, make it difficult to apply joints that uniformly cover the entire narrow side of the tile, while the transparency of the glass moreover causes possible joint errors. make the edge visible. The tiles according to the invention therefore preferably have chamfered, possibly ground and / or polished, narrow sides, characterized in that the chamfered width on the front is larger. The rear side is preferably very little affected by the processing, so that the lacquer layer virtually completely covers the surface of the tile. In particular, the width affected by the operation on the back is advantageously less than or equal to 0.5 mm, even less than or equal to 0.3 mm. In general, the lacquered surface is preferably larger than the surface of the front after processing.

Cutting glass tiles according to the invention is particularly simple, and it requires no specific equipment, other than the equipment used for cutting ceramic tiles, in particular vitrified clay material, or for cutting marble or granite. The machining of the edges after cutting can also be carried out with the aid of a polishing sandstone according to methods known to those skilled in the art of applying ceramic tiles.

A number of technical advantages compared to ceramic tiles are mentioned: - the cutting accuracy is generally much higher, hence greater compliance with small dimensional tolerances, - the possibility of finishing paint on large-sized plates setting for cutting tiles allows for better reproducibility of decorations, in particular of the color, - the flatness is excellent, thus allowing the excessive use of mortar glue which is necessary to compensate for any surplus space. between the cladding and the wall.

The present invention will be better understood when reading the following detailed description of non-limiting exemplary embodiments illustrated by the accompanying figures: Figures 1 and 4 illustrate perspective views of the different embodiments of coatings according to the invention,

Figures 2, 3 and 5 illustrate side views of various embodiments of coatings according to the invention,

Figures 6 to 10 illustrate different types of patterns that can be applied to the front of the coating according to the invention by etching with acid.

Figure 1 represents a perspective view of a tile 30 with a square cutting surface. The tile comprises a monolithic plate of clear glass 1 with a thickness of 6 mm, the rear side of which is covered with a layer of lacquer 2 with a thickness of 50 μιη which has been deposited according to the lacquer curtain process. The front side has patterns 3 acid-etched in the form of rectangular parallelepipedes at regular intervals from each other in the two perpendicular directions of the tile.

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After drying, the lacquer 2 comprises the following constituents: - a binder in the form of a polyurethane resin obtained by cross-linking with a non-aromatic isocyanate of hydroxylated acrylic resins, obtained during the polymerization of an acrylic styrene - inorganic materials (pigments and fillers) up to an amount of 55% by weight.

This varnish was obtained by depositing through curtain holes, followed by drying for 5 minutes. The temperature of drying is an important parameter for obtaining a water permeability that is sufficiently low. With these special conditions and at a temperature of drying below 180 ° C, the permeability is much too high and after gluing to a wall with the aid of mortar glue, errors occur after a few days during the drying of the mortar. In the present case, the mixing water of the mortar glue passes through the lacquer layer, which leads to the double effect of peeling off between the glass plate and the lacquer layer and chemically attacking the surface of the glass. On the other hand, at a temperature of drying more than 180 ° C, the stronger crosslinking of the binder of the lacquer leads to a lower permeability to water, whereby no error is caused after gluing with mortar glue.

Figure 2 represents a side view of a tile. The edges of the monolithic glass plate 1 are machined such that they have bevelled narrow sides 4 by trimming the ribs 5 and 6, which step is carried out such that the lacquered surface 2 is smaller than the surface of the front.

Figure 3 also illustrates a side view of a tile. In this embodiment, the rear side of the coating is covered with a silver layer 7 by means of a silvering method. The lacquer layer 2 covers this silver layer 7.

Figure 4 represents a perspective view of a tile formed from a laminated glass pane formed by two glass sheets of 4 mm thickness connected by a sheet of polyvinyl butyral 12 with a thickness of 0.76 mm. The front is etched with acid and has patterns in the form of waves. One of the glass plates is cut off in the drawing to show the presence of light-emitting diodes 11 (LED) on the surface of the polyvinyl butyral 13.

Figure 5 illustrates a side view of a wall covering according to the invention with an incision 12 with a width of 3 mm and a depth of 0.5 mm which is applied after grinding after lacquering. A silver layer 7 is deposited and covers the lacquer layer 2 and incised portion 12. A second lacquer layer 2 (a different composition) is then deposited on the total silver-plated surface. From the front, the silver layer 7 is therefore only visible on the incision 12.

Figures 6 to 10 illustrate different patterns that are technically feasible by acid etching treatment on the front of wall coverings according to the invention. The dark areas represent the etched zones that are deepened relative to the clear ones, which are raised.

The present invention has been described by way of example in the foregoing. It will be clear that a person skilled in the art is able to realize different variants of the invention without, however, going beyond the scope of the invention as defined in the claims.

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Claims (21)

5 1. Glass-based wall covering, in particular in the form of tiles, intended for covering the walls of a dwelling, such as the walls, floors or ceilings, comprising a glass substrate which is coated on the side to be applied with a lacquer layer, characterized in that the lacquer has such a permeability to water that the coating can be applied to the walls with the aid of conventional mortar adhesives or cement adhesives. 2. Wall covering as claimed in claim 1, characterized in that the lacquer has a permeability for water at 25 ° C smaller than 10-6, in particular smaller than 10 "8, even smaller than 10" 13 cm 3. cm. cm -2. s "1. Pa" has 1. 3. Wall covering as claimed in any of the foregoing claims, characterized in that the lacquer contains a synthetic resin as binder. 4. Wall covering as claimed in any of the foregoing claims, characterized in that the binder is based on polyurethane resin, which is obtained in particular by crosslinking a hydroxylated acrylic resin with an isocyanate or a polyisocyanate. 5. Wall covering as claimed in claim 3, characterized in that the binder is based on alkyd resin. 6. Wall covering as claimed in any of the foregoing claims, characterized in that an adhesion-promoting agent is present in the form of a layer which is applied between the lacquer layer and the glass substrate, or is dispersed in the lacquer. 1 02871 0 Wall covering according to claim 6, characterized in that the adhesion promoter is silane based. Wall covering as claimed in any of the foregoing claims, characterized in that a reflective layer, in particular a silver layer for mirrors, and / or a decoration obtained by screen printing or by means of an ink jet is arranged between the lacquer layer and the glass substrate, optionally coated with an adhesion-promoting layer. 9. Wall covering as claimed in any of the foregoing claims, characterized in that the lacquer layer contains pigments that are resistant to ultraviolet radiation. 10. Wall covering as claimed in any of the foregoing claims, characterized in that the lacquer layer contains inorganic fillers in a content expressed in% by weight between 40 and 70%. 11. Wall covering as claimed in any of the foregoing claims, characterized in that the glass substrate is a mono-lithic glass plate. A wall covering according to any one of claims 1 to 10, characterized in that the glass substrate is a multiple pane that comprises a number of glass plates. 13. Wall covering as claimed in any of the foregoing claims, characterized in that the glass substrate has patterns and relief on at least one of its silk which are obtained by laminating and / or matting with acid and / or sandblasting and / or engraving. 14. Wall covering as claimed in any of the foregoing claims, characterized in that the total front side of the glass substrate is matted with hydrofluoric acid or by sandblasting. 15. Wall covering as claimed in any of the foregoing claims, characterized in that the glass substrate on at least one of the sides, preferably the front, at least one functional layer which provides optical properties (stacks of anti-reflective layers). * and / or anti-slip properties, and / or surface properties (in particular soil-resistant properties, antibacterial properties, self-cleaning properties, hydrophobic properties, anti-fogging properties, scratch-resistant properties, wear-resistant properties). 16. Wall covering as claimed in claim 12, characterized in that the glass substrate is a double pane filled with a gas which can give light-emitting discharges under an electric field. 17. Wall covering as claimed in claim 12, characterized in that the glass substrate is a layered pane or multiple pane that contains light-emitting diodes. 18. Wall covering as claimed in any of the foregoing claims, characterized in that the lacquered surface is larger than the surface of the front surface after processing. 19. Wall covering as claimed in any of the foregoing claims, characterized in that a part of the rear side is incised with mechanical means and subsequently covered with a decorative layer, preferably a silver layer, obtained with conventional silvering techniques. 20. Wall covering as claimed in claim 19, characterized in that the incisions are made in the form of lines with a width of 1 to 30 mm and a depth of 0.5 to 3 mm according to straight lines at regular intervals from each other and according to two perpendicular directions. 21. Glass-based wall covering comprising a decoration obtained by screen printing or by means of an ink jet deposited on the rear side of a glass substrate. ***** 1028710