Method for manufacturing slabs made of agglomerate material and resistant to UV rays and slab thus manufactured, as well as protective composition adapted to be applied onto surfaces of slabs made of agglomerate material.

Abstract

Method for manufacturing slabs made of stone or stone-like agglomerate material and resistant to the UV rays of sunlight, comprising a step of manufacturing a slab from a mix comprising a binding resin and aggregates formed by granules and / or powders of stone or stone-like material, said step comprising at least the compaction and the hardening of the mix distributed beforehand on a temporary support and a step of applying onto at least one surface of the slab at least one layer of a protective composition comprising a functional compound designed to ensure resistance to abrasion and chemical agents. The protective composition comprises at least one inorganic and / or organic compound intended to filter or attenuate the UV rays by means of reflection and diffusion of the UV rays and / or by means of absorption of the UV rays. The present invention also relates to a slab made of agglomerate material and obtained by means of the aforementioned method and a protective composition intended to be applied onto the surfaces of slabs made of agglomerate material.

Description

[0001] “Method for manufacturing slabs made of agglomerate material and resistant to UV rays and slab thus manufactured, as well as protective composition adapted to be applied onto surfaces of slabs made of agglomerate material”

[0002] ★ ★★★★

[0003] The present invention relates to the field for manufacturing articles made of stone or stone-like agglomerate material and in particular relates to a method for manufacturing slabs which are made of stone or stone-like agglomerate material and are resistant to UV rays, in particular solar rays.

[0004] The invention also relates to a protective composition intended to be applied onto at least one surface of a slab made of stone or stone-like agglomerate material and a slab made of stone or stone-like agglomerate material and resistant to UV rays.

[0005] In the technical field for the production of articles and slabs made of stone or stone-like agglomerate material, the agglomerate is obtained preferably, although not exclusively, by means of vibration with simultaneous compression in a vacuum (vacuum vibro-compression) and hardening of a base mix.

[0006] After hardening of the mix, the slabs may be subjected to sizing and smoothing / polishing operations.

[0007] The mix contains mainly a binder and aggregates formed by granules and / or powders of stone or stone-like material.

[0008] In particular, the aggregates generally consist of natural minerals which may be of a siliceous nature, such as quartz, granite, porphyry, basalt, quartzites, siliceous sands, or of a calcareous nature, such as marbles, dolomite, coloured stones, etc. Alternatively, the aggregates may consist of synthetic minerals.

[0009] The granules and powders may have a varied particle size, depending on the aesthetic appearance and the physical / mechanical properties which are to be obtained in the finished slabs.

[0010] Alternatively or in addition, the mix may also contain granules or powders of expanded material, such as expanded glass or expanded clay.

[0011] Furthermore, the binder is preferably of the organic type and consists of a hardening resin chosen from the group comprising polyester resins, acrylic resins, epoxy resins, polyurethane resins, but also resins of natural and plant origin. As an alternative to the organic resin a cementitious binder may be used.

[0012] The mix may also contain fillers, further binders, additives and colouring agents. In particular, the fillers are materials used in combination with the resin in order to form the so-called binding paste.

[0013] The articles may also comprise, on at least one of their surfaces, at least one layer of a functional compound which is designed to ensure a high resistance to abrasion and chemical agents.

[0014] The functional compound is transparent and may consist of a solution of silazane in a solvent; silazane is an organo-metallic compound consisting of silicon hydride and nitrogen having a linear or branched chain of silicon, nitrogen or carbon atoms joined by covalent bonds.

[0015] In the technical field of the present invention the silazane solution allows the slabs to be made more resistance to wear, abrasion, chemical agents, solvents, scratches and adverse weather conditions.

[0016] The use of the functional compound allows the slabs to be used for the construction of flooring, vertical cladding, furnishing elements, kitchen tops or other products which are normally used in for building design.

[0017] One drawback of the articles and the slabs described above consists in the fact that they may be particularly prone to deterioration due to sunlight.

[0018] In fact, the UV rays of sunlight tend to degrade the organic binder, in particular the polyester resins, and cause yellowing thereof, with consequent alteration of the aesthetic appearance of the slabs.

[0019] In this connection, it has been noted that the presence of the functional compound reduces only to a limited degree - and in any case in an unsatisfactory manner - the deterioration caused by sunlight.

[0020] The slabs of agglomerate material, which are made as described above, may also undergo, before or after the sizing and surface smoothing / polishing operations, a step involving the application or printing of at least one ink containing pigments on at least one of the surfaces in order to form decorations and / or chromatic effects.

[0021] For example, the inks used for this purpose may be disperse inks or sublimation inks; in the context of the present description, the expression “disperse inks” is understood as meaning inks in which the pigments are intended to undergo a transition from the solid state to the liquid / gaseous state as a result of the action of a heat source and / or the application of pressure.

[0022] Furthermore, in the context of the present description, the expression “sublimation inks” is understood as meaning inks in which the pigments are intended to undergo sublimation, passing from the solid state to the gaseous state as a result of the action of a heat source and / or the application of a pressure.

[0023] In both aforementioned types of inks, the pigments are dispersed in an aqueous solution and the change in state favours the penetration, by means of diffusion, of the pigments into the surface layer of the slab.

[0024] In particular, following the change in state, the pigments in the inks penetrate by means of diffusion into the binding resin of the mix, namely the organic component of the mix.

[0025] In order to apply the dispersed ink onto the slab or onto the base mix in an effective manner and with an attractive aesthetic effect, the aggregates and / or the slabs must have at least the following characteristics:

[0026] - a light colouring of the aggregates and the pigments, preferably white or light coloured with light shades;

[0027] - small particle size of the granules or powders.

[0028] Furthermore, the application of the disperse ink or sublimation ink onto at least one surface of the slab may be performed in two different ways, namely:

[0029] - using a sheet having, previously printed thereon, the decoration with the inks to be subsequently applied onto the surface of the slab; or

[0030] - directly applying the inks onto the surface of the slab or onto the base mix.

[0031] In particular, the second operating mode involves the formation of the decorations and / or the chromatic effects directly on the surface of the slab or on the base mix by applying the inks, for example, by means of digital inkjet plotters or printers.

[0032] Examples of this second operating method are known, for example, from the patent documents US2020 / 0262101 and WO2021 / 053596.

[0033] The method described in US2020 / 0262101 may comprise a further step of applying onto the article or the slab a coating or layer formed by a protective composition so as to improve the resistance to wear and scratching and provide the article or slab with antimicrobial properties.

[0034] The coating may be formed by a filler, for example corundum, silver or titanium oxide, and by a hardening resin, for example an epoxy resin or acrylic resin.

[0035] One drawback of these latter technical solutions is that the decorations and / or the chromatic effects tend also to deteriorate as a result of the UV rays of sunlight.

[0036] In fact, the UV rays cause the deterioration of the organic base pigments of the inks, which consequently tend to fade. This drawback therefore results in a worsening or at least an alteration of the aesthetic characteristics of the slabs.

[0037] Methods have also been developed for manufacturing slabs having decorations and / or chromatic effects realized using disperse inks, these methods comprising at least one step of applying the functional compound described above onto the surface of the slab on which the chromatic effects and / or the decorations are formed. A method of the aforementioned type is known from WO2023 / 126889.

[0038] In this case, the functional compound also helps confer a greater brightness to the surface of the slab onto which it is applied and protect from abrasion the decorations and / or the chromatic effects.

[0039] This latter technical solution, while being widely favoured in the field, does not help improve substantially the resistance of the slabs to the UV rays of sunlight. The main object of the present invention is to provide a method for manufacturing slabs of stone or stone-like agglomerate material which are more resistant to UV rays, a protective composition intended to be applied onto the slabs, and a slab of stone or stone-like agglomerate material which is more resistant to the UV rays which are therefore able to overcome the aforementioned drawbacks.

[0040] A particular task of the present invention is to provide a method of the type described above which is able to produce slabs able to maintain for a long period of time the original aesthetic characteristics, even when exposed to sunlight.

[0041] Another task of the present invention is to provide a method of the type described above which allows the manufacture of slabs with decorations and / or chromatic effects which last over time.

[0042] A further task of the present invention is to provide a method of the type described above which allows the manufacture of slabs also with a high resistance to abrasion and chemical agents.

[0043] Another task of the present invention is to provide a method of the type described above which allows the manufacture of slabs with a high degree of brightness and with a uniform chromatic effect.

[0044] A further task of the present invention is to provide a protective composition intended to be applied onto at least one surface of the slabs so as to make them more resistant to the UV rays of sunlight as well as to abrasion and the action of chemical agents.

[0045] Another task of the present invention is to provide a slab comprising at least one layer of the aforementioned protective composition and able to maintain for a long period of time its original aesthetic characteristics.

[0046] A further task of the present invention is to provide a slab of the type described above which may be used for the formation of flooring, vertical cladding, furnishing elements, kitchen tops or other products which are normally used for architectural purposes.

[0047] The main tasks and object described above are achieved with a method for manufacturing slabs made of stone or stone-like agglomerate material and resistant to UV rays in accordance with Claim 1 , with a protective composition in accordance with Claim 16, and with a slab made of stone or stone-like agglomerate material and resistant to UV rays in accordance with Claim 21 .

[0048] The present description, provided only by way of a non-limiting illustration of the scope of protection of the invention, relates to a method for manufacturing slabs which are made of stone or stone-like agglomerate material and are resistant to the UV rays of sunlight.

[0049] Conveniently, the slab is obtained from a mix comprising a binding resin and aggregates formed by granules and / or powders of stone or stone-like material, as described further below.

[0050] Advantageously, the material of the granules and powders which form the aggregates of the mix is preferably quartz and / or cristobalite and / or a synthetic mineral containing calcium silicate crystals.

[0051] Furthermore, the aggregates of granules and powders have a particle size preferably of between 0.1 mm and 0.3 mm and volume content equal to 75% of the volume of the slab.

[0052] The binding resin of the mix is of the type described above with reference to the prior art and for this reason will not be further described in the present description.

[0053] Conveniently, the slab of agglomerate material has a basic colouring which is preferably white or light-coloured with light shades.

[0054] Optionally, the slabs may also have decorations and / or chromatic effects which are formed on at least one surface by means of at least one ink containing pigments.

[0055] Preferably, the decorations and the chromatic effects are realized by means of a disperse inks, i.e. inks in which the pigments are intended to undergo a change in state from solid to liquid / gaseous owing to the action of a heat source and / or the application of a predetermined pressure.

[0056] In particular, the decorations and the chromatic effects may also be realized by means of sublimation inks, namely inks in which the pigments are intended to undergo sublimation, changing from the solid state to the gaseous state as a result of the action of a heat source and / or the application of a predetermined pressure.

[0057] The pigments of disperse inks or sublimation inks penetrate by means of diffusion into the slab, in particular in the zones or portions of the slab where the binding resin is present, following the change in state.

[0058] Owing to the aforementioned particular characteristics of the aggregates of granules and powders and consequently of the slab made of agglomerate material it is possible to achieve a clear, pronounced and well-defined effect of the decorations.

[0059] The method comprises mainly the following steps:

[0060] - making a slab from the mix comprising the binding resin and the aggregates formed by granules and / or powders of stone or stone-like material, said step comprising at least the compaction, preferably by means of vacuum vibrocompression, and the hardening of the mix distributed beforehand on a temporary support.

[0061] - applying at least one layer of a protective composition comprising a functional compound onto at least one surface of the slab.

[0062] As mentioned, the functional compound of the protective composition is preferably transparent and consists of a solution of silazane in a solvent, which has mainly the function of providing protection against abrasion, chemical agents, scratching and adverse weather conditions.

[0063] The protective composition, after being applied onto the surface of the slab, is allowed to dry and harden so as to form a layer having a thickness of a few microns; said layer contains particles of quartz bonded covalently with functional groups of the surface of the slab.

[0064] In particular, in the slab according to the present invention obtained from the mix described above, the solution of silazane of the protective composition is stably bonded both to the aggregates, in particular to the granules of silica and calcium silicate, and to the organic component of the resin and the decoration where present.

[0065] The layer of protective composition may also be applied following mounting of the slabs, also several times as needed, in order to restore the intact condition and the aesthetic appearance of the slabs.

[0066] In addition to the optional step of applying at least an ink containing pigments, the method may also comprise a step of machining at least one surface of the slab by means of sizing and / or smoothing and / or polishing performed before the step of applying at least one ink. The operations of sizing and / or polishing and / or smoothing are performed on the hardened slab using machines, devices and tools of the known type, not described further in the present description.

[0067] Furthermore, following the ink application step, the method may comprise a step of drying the inks, a step where the pigments of the inks are allowed to penetrate into the slab or into the hardened mix so as to form the decorations and / or the chromatic effects, a step of removing the excess or residual inks from the at least one surface of the slab and, optionally, a further polishing step.

[0068] The aforementioned steps are performed before the step of applying at least one layer of protective composition onto the surface of the slab.

[0069] As already mentioned, the decorations and the chromatic effects may be realized by means of disperse inks, and preferably by means of sublimation inks.

[0070] The step of applying the disperse inks may be performed by means of inkjet digital plotters or printers, which are generally provided with a series of heads / nozzles supplied with differently coloured inks, and may be carried out on limited portions of the surface of the slab or over the entire surface of the slab to be decorated, depending on the type of decoration to be provided.

[0071] The disperse ink consists preferably of a dispersion of pigments in an aqueous solution and is applied onto the at least one surface of the slab in liquid form.

[0072] The ink application step may be preceded by a primer application step. Preferably, the primer is formed by a solution or dispersion of organic and / or inorganic compounds which are compatible with the process for direct application of the disperse ink onto the slab.

[0073] The primer has the function of favouring adhesion of the ink and preventing the uncontrolled diffusion thereof over the surface of the slab during the penetration step, thus avoiding the loss of chromatic yield and definition of the decoration.

[0074] Conveniently, the drying step is performed preferably in an oven at a temperature of between 85 °C and 95 °C and for a time period of between 2 and 20 minutes.

[0075] The drying step thus performed is able to eliminate the volatile compounds from the - preferably aqueous - solution of disperse inks applied onto the at least one surface of the slab.

[0076] In this way, the dried disperse inks form a kind of film on the surface of the slab to be decorated; this film has a function similar to the sublimation sheet used in traditional methods.

[0077] As already mentioned, the diffusion penetration step is realized by means of the change in state of the disperse ink pigments from solid to liquid / gaseous.

[0078] In the embodiment which involves the use of a sublimation ink, the diffusion penetration step is performed by means of sublimation of the sublimation ink pigments, i.e. the change in state from solid to gaseous.

[0079] Conveniently, the step of sublimation of the dried sublimation ink is performed in an oven, preferably a hot-air oven, at a temperature of between 150 °C and 200 °C for a time period of between 5 and 30 minutes.

[0080] The method involves preferably also a step of cooling the slab downstream of the step of penetration by means of diffusion of the disperse ink pigments; the cooling step must be performed avoiding heat shocks or twisting of the slab. Advantageously, the step of removal of the at least one excess disperse ink is performed after the cooling step and by means of brushing with abrasive tools of the at least one surface of the slab.

[0081] In order to avoid the scuffing or abrasion of the material from the surface of the slab, the abrasive tools must have a hardness less than the hardness of the aggregates indicated above, in particular less than the hardness of the quartz and / or the synthetic mineral containing the calcium silicate crystals.

[0082] However, in order to remove the at least excess or residual disperse ink effectively the hardness of the abrasive tools must be greater than the hardness of components of the disperse ink.

[0083] As mentioned, following the removal of the at least one disperse ink, a further step of polishing the surface of the slab may be performed.

[0084] In accordance with the present invention, the protective composition further comprises at least one compound intended to filter or attenuate the UV rays of the sunlight by means of reflection and diffusion of the UV rays and / or by means of absorption of the UV rays.

[0085] This at least one compound is able to improve the resistance of the slabs to sunlight and consequently limit significantly the deterioration of the aesthetic appearance of the slabs, or of the chromatic effects if present, caused by sunlight.

[0086] In the context of the present description, the resistance to sunlight refers mainly to the properties of colouring agents and pigments to withstand fading when exposed to sunlight.

[0087] In this connection, it is pointed out that various standards for assessing the resistance to sunlight of pigments and colouring agents, such as the Blue Wool Scale, Grey Scale and American Standard Test Measure (ASTM), are known.

[0088] Furthermore, the resistance to sunlight is generally tested by means of the controlled exposure of the materials to the sunlight or to the artificial light generated by a xenon arc lamp. Xenon lamps have a very wide wavelength range and simulate the complete spectrum of sunlight.

[0089] For this purpose, usually a machine which performs the so-called Xenon test is used, i.e. a stability test which is used in various fields in order to verify the durability of materials when exposed to light.

[0090] The reference standard for the aforementioned tests is UNI EN ISO 4892- 2:2013, in accordance with which the materials are exposed to various treatment cycles, by varying the light, dark and humidity conditions; then, the materials are assessed from the aesthetic point of view by means of a visual inspection and / or using instruments such as a colorimeter.

[0091] With reference to the present invention, experimental tests have shown that, in the absence of the protective composition comprising the at least one compound intended to filter or attenuate the UV rays, the organic based pigments of the at least one ink tend to fade after about 70-80 hours of exposure to the Xenon test.

[0092] On the other hand, in the presence of the protective composition comprising the at least one compound intended to filter or attenuate the UV rays, the pigments of the at least one ink did not shown any signs of fading even after 250 hours of exposure to the Xenon test.

[0093] Reference is usually made to the 250 hours as an indication that a material is sufficiently resistant to UV rays in common conditions of use. The amount by weight of the at least one compound intended to filter or attenuate the UV rays of sunlight and present in the protective composition is between about 3% and 25%, and preferably between 6% and 20%, of the weight of the dried functional compound, namely after evaporation of the solvent.

[0094] The compound intended to filter or attenuate the UV rays is an inorganic compound and / or an organic compound. In the technical jargon, the organic compound may be defined as being a physical filter, while the organic compound may also be defined as being a chemical filter.

[0095] Physical filters have the special feature of reflecting and dispersing the UV rays, while chemical filters have the special feature that they absorb UV rays; specifically, chemical filters capture the UV rays and the absorbed energy is emitted in the form of low energy radiation with a greater wavelength energy, or dissipated in the form of heat.

[0096] Generally, inorganic compounds or physical filters keep unchanged their UV ray filtration properties for a longer period of time compared to organic compounds or chemical filters.

[0097] The inorganic compound of the present invention is chosen preferably from the group comprising metal oxides, preferably in the form of nano-particles, such as titanium dioxide (TiO2) and / or zinc oxide (ZnO) and / or silver oxide (Ag2O).

[0098] Moreover, the organic compound of the present invention is chosen preferably from the group comprising oxybenzone, octocrylene, butyl methoxydibenzoylmethane, octinoxate, octisalate and avobenzone.

[0099] The inorganic compound and the organic compound may also consist of different elements or compounds, without thereby departing from the scope of protection of the present invention.

[0100] In accordance with a first embodiment of the invention, the method comprises, before the step of applying the at least one layer of protective composition, a step of applying at least one layer containing solely the functional compound, i.e. the silazane solution, onto the at least one surface of the slab.

[0101] Therefore, the at least one layer of protective composition is applied on top of the at least one layer containing solely the functional compound.

[0102] In this first embodiment, the compound of the protective composition intended for the filtration or attenuation of the UV rays comprises one or more metal oxides, such as titanium dioxide.

[0103] By means of this configuration, the titanium dioxide is prevented from coming into contact with the binding resin of the mix and with the inks of the decorations, where present; in this way, the photocatalytic activity of the titanium dioxide induced by the UV rays does not damage the organic molecules of the binding resin and the inks.

[0104] In accordance with a second embodiment of the invention, the method comprises, following the step of applying the at least one layer of protective composition, a step of applying at least one layer containing solely the functional compound, i.e. the silazane solution.

[0105] Therefore, the at least one layer containing solely the functional compound is applied on top of the at least one layer of protective composition.

[0106] In this second embodiment, the compound of the protective composition intended for filtration or attenuation of the UV rays consists of an organic compound.

[0107] By means of this configuration, the release of the organic compound intended for filtration or attenuation of the UV rays is avoided, this being generally harmful for the health of the user, in particular if ingested.

[0108] In accordance with a third embodiment of the invention, the step of applying the at least one layer of protective composition comprises a first substep of applying a first layer of protective composition comprising the functional compound and a first compound intended for filtration or attenuation of the UV rays and a second substep of applying, on top of the first layer, a second layer of protective composition comprising the functional compound and a second compound intended filtration or attenuation of the UV rays.

[0109] In this third embodiment, the first compound intended for filtration or attenuation of the UV rays consists of an organic compound and the second compound intended for filtration or attenuation of the UV rays comprises one or more metal oxides; preferably this second compound is titanium dioxide.

[0110] With this configuration it is possible to combine the advantages of the first embodiment and the second embodiment described above.

[0111] In accordance with a further alternative embodiment of the invention, a step of applying a single layer of protective composition, comprising the functional compound in combination both with an inorganic compound and with an organic compound for filtration and attenuation of the UV rays, may be envisaged.

[0112] As already mentioned, the present invention also relates to the protective composition used in the method described above and intended to be applied onto the surfaces of slabs made of stone or stone-like agglomerate material. The protective composition has the function of protecting the slabs from abrasion, scratching, adverse weather conditions and the action of chemical agents and of maintaining over time the original aesthetic characteristics even if the slabs are exposed to the UV rays of the sunlight.

[0113] In this respect the protective composition comprises a functional compound and at least one compound intended for filtration or attenuation of the UV rays.

[0114] As mentioned above with reference to the method it may be noted that:

[0115] - the at least one compound intended to filter or attenuate the UV rays is an inorganic compound and / or an organic compound;

[0116] - the at least one inorganic compound is chosen from the group comprising metal oxides, preferably in the form of nanoparticles, such as titanium dioxide and / or zinc oxide and / or silver oxide;

[0117] - the at least one organic compound is chosen from the group comprising oxybenzone, octocrylene, butyl methoxydibenzoylmethane, octinoxate, octisalate and avobenzone;

[0118] - the functional compound is transparent and consists of a solution of silazane in a solvent.

[0119] The weight amount of the at least one compound intended to filter or attenuate the UV rays of the sunlight present in the protective composition is between about 3% and 25%, and preferably between 6% and 20%, of the weight of the dried functional compound, i.e. after evaporation of the solvent.

[0120] The present invention also relates to a slab which is made of stone or stonelike agglomerate material and is resistant to the UV rays of sunlight and which has, on at least one surface, at least one layer of the protective composition described above, i.e. comprising a functional compound and at least one compound intended for filtration or attenuation of the UV rays.

[0121] As indicated above with reference to the method, the at least one surface of the slab may have decorations and / or chromatic effects which are formed using inks containing pigments. In particular, the inks are disperse inks, preferably sublimation inks.

[0122] The at least one layer of protective composition is applied on top of any decorations.

[0123] From the above description it is now clear how the method for manufacturing slabs, the protective composition and the slab according to the present invention are able to achieve advantageously the predefined objects.

[0124] In particular, the application of the protective composition onto the surfaces of the slabs is able to protect the slabs from abrasion and the action of the chemical agents, as well as from the deterioration caused by the UV rays of sunlight.

[0125] In this way it is possible to keep unaltered the aesthetic characteristics of the slabs for a long period of time, in particular in the case where the surfaces of the slabs comprise decorations and / or chromatic effects.

[0126] Obviously, the above description of embodiments applying the innovative principles of the present invention is provided by way of example of these innovative principles and must therefore not be regarded as limiting the scope of the rights claimed herein.

Claims

Claims1. Method for manufacturing slabs made of stone or stone-like agglomerate material and resistant to the UV rays of sunlight, the method comprising at least the following steps:- making a slab from the mix comprising a binding resin and aggregates formed by granules and / or powders of stone or stone-like material, said step comprising at least the compaction and the hardening of the mix distributed beforehand on a temporary support;- applying onto at least one surface of the slab at least one layer of a protective composition comprising a functional compound designed to ensure resistance to abrasion and chemical agents; wherein said protective composition comprises at least one inorganic and / or organic compound intended to filter or attenuate the UV rays by means of reflection and diffusion of the UV rays and / or by means of absorption of the UV rays.

2. Method according to the preceding claim, characterized in that said at least one inorganic compound is chosen from the group comprising metal oxides, preferably in the form of nanoparticles, such as titanium dioxide and / or zinc oxide and / or silver oxide.

3. Method according to Claim 1 , characterized in that said organic compound is chosen from the group comprising oxybenzone, octocrylene, butyl methoxydibenzoylmethane, octinoxate, octisalate and avobenzone.

4. Method according to any one of the preceding claims, characterized in that said functional compound consists of a silazane solution.

5. Method according to any one of the preceding claims, characterizedin that the weight amount of the at least one compound of the protective composition intended to filter or attenuate the UV rays is between 3% and 25%, and preferably between 6% and 20%, of the weight of the dried functional compound.

6. Method according to any one of the preceding claims, characterized in that the method comprises, before the step of applying at least one layer of protective composition, a step of applying at least one further layer of functional compound.

7. Method according to the preceding claim, where dependent on any one of Claims 1 -5, characterized in that the compound of the protective composition intended for the filtration or attenuation of the UV rays is titanium dioxide.

8. Method according to any one of Claims 1-5, characterized in that the method comprises, following the step of applying at least one layer of protective composition, a step of applying at least one further layer of functional compound.

9. Method according to the preceding claim, where dependent on any one of Claims 1 -5, characterized in that the compound of said protective composition intended to filter or attenuate the UV rays is an organic compound.

10. Method according to any one of Claims 1 -5, characterized in that said step of applying at least one layer of protective composition comprises a first substep of applying a first layer of protective composition comprising said functional compound and a first compound intended for filtration or attenuation of the UV rays and a second substep of applying, on top of saidfirst layer, a second layer of protective composition comprising said functional compound and a second compound intended for filtration or attenuation of the UV rays.11 . Method according to the preceding claim, where dependent on any one of Claims 1 -5, characterized in that said first compound intended to filter or attenuate the UV rays is an organic compound and said second compound intended to filter or attenuate the UV rays is titanium dioxide.

12. Method according to any one of the preceding claims, characterized in that the method comprises the following further steps:- machining at least one surface of the slab by means of sizing and / or smoothing and / or polishing;- applying at least one ink containing pigments onto said at least one machined surface;- drying said at least one ink;- penetration of the pigments of said at least one ink into the slab so as to form decorations and / or chromatic effects;- removing the at least one excess or residual ink from the at least one surface of the slab;- where necessary, smoothing / polishing of the at least one surface of the slab; said steps being performed before said step of applying at least one layer of said protective composition.

13. Method according to the preceding claim, characterized in that said at least one ink is a disperse ink and said step of penetration of the ink takes place by means of diffusion of the disperse ink, the pigments of said disperseink during said diffusion penetration step being designed to undergo a change in state from solid to liquid / gaseous.

14. Method according to the preceding claim, characterized in that said at least one disperse ink is a sublimation ink, said step of penetration by means of diffusion being performed by means of sublimation of the pigments of said at least one sublimation ink.

15. Method according to any one of the preceding claims, characterized in that the slab has a base colouring which is white or coloured with light shades.

16. Protective composition designed to be applied onto surfaces of slabs made of stone or stone-like agglomerate material, which protective composition comprises:- a functional compound designed to provide the slab with resistance to abrasion and to chemical agents;- at least one inorganic and / or organic compound intended to filter or attenuate the UV rays by means of reflection and diffusion of the UV rays and / or by means of absorption of the UV rays.

17. Protective composition according to the preceding claim, characterized in that said at least one inorganic compound is chosen from the group comprising metal oxides, preferably in the form of nanoparticles, such as titanium dioxide and / or zinc oxide and / or silver oxide.

18. Protective composition according to Claim 16, characterized in that said at least one organic compound is chosen from the group comprising oxybenzone, octocrylene, butyl methoxydibenzoylmethane, octinoxate, octisalate and avobenzone.

19. Protective composition according to any one of Claims 16-18, characterized in that said functional compound consists of a silazane solution.

20. Protective composition according to any one of Claims 16-19, characterized in that the weight amount of the at least one compound of the protective composition intended to filter or attenuate the UV rays is between 3% and 25%, and preferably between 6% and 20%, of the weight of the dried functional compound.

21. Slab made of stone or stone-like agglomerate material and resistant to the UV rays of sunlight, which slab comprises, on at least one surface, at least one layer of a protective composition comprising a functional compound designed to ensure resistance to abrasion and chemical agents; characterized in that said protective composition comprises at least one inorganic and / or organic compound intended to filter or attenuate the UV rays by means of reflection and diffusion of the UV rays and / or by means of absorption of the UV rays, said protective composition being of the type according to any one of Claims 16-20.

22. Slab according to the preceding claim, characterized in that said at least one surface has decorations and / or chromatic effects realized with at least one ink containing pigments.

23. Slab according to the preceding claim, characterized in that said at least one ink is a disperse ink, preferably a sublimation ink.