artificial stone

Abstract

The invention relates to an artificial stone comprising micronized feldspar and to a method for its production.

Description

Technical Field

[0001] This invention relates to materials made of artificial stone for construction, decoration, and building, as well as their manufacture and processing. In particular, the invention falls within the technical field of artificial stone products composed of inorganic fillers selected from stone, stone-like, or ceramic materials and hardened organic resins, manufactured by methods including vacuum vibration compaction and hardening of the unhardened agglomerated mixture. Background Technology

[0002] Artificial stone products that mimic natural stone (also known as engineered stone products) are commonly used in the construction, decoration, architecture, and design fields. Their industrial-scale manufacturing processes are now well-established.

[0003] One of the most popular engineered stone materials is the so-called quartz sintered surface, highly valued for its beauty, hardness, stain resistance, and abrasion resistance. It is widely used in several applications, including countertops, cladding, flooring, sinks, and shower trays. It is more commonly referred to as artificial stone, and its applications partially overlap with those of natural stone such as marble or granite. It can be manufactured to mimic the color and pattern of natural stone, or it can have a completely artificial appearance, such as a bright red or magenta color. Its composition and the technology currently used in its manufacture date back to the late 1970s, developed by companies such as the Italian company Breton SpA, and is now known in the field under the name... Commercially known. For example, its general concept is described in patent US4,204,820. In this production process, quartz granules of different particle sizes (sometimes mixed with synthetic cristobalite and / or other mineral granules) are first mixed with a hardenable binder (usually a liquid organic resin). The resulting mixture is homogenized and dispensed into a temporary mold or onto a sheet of paper, where it is then compacted by vibration under vacuum and subsequently hardened.

[0004] Other combinations of stone granular fillers and binders with varying degrees of commercial success have been proposed. For example, attempts have been made to use marble and granite with organic resins as granular aggregates, but this resulted in materials with significantly lower performance as building materials compared to quartz surfaces, and also led to highly limited potential in terms of appearance. A large number of other mineral and non-mineral granular fillers have been described (mostly in patent literature), such as recycled glass, glass frit, glass beads, feldspar, porphyry, amorphous silica, ceramics, dolomite, basalt, carbonates, metallic silicon, fly ash, shells, corundum, silicon carbide, and so on. On the other hand, inorganic binders such as hydraulic cement have been used instead of organic resins in commercially produced agglomerated artificial stone for building applications.

[0005] Inorganic fillers for artificial stone surfaces, and especially through Those manufactured by this method are typically divided into at least two parts based on their particle size and function: the first part is known to be granular material, and the second part is known to be micronized powder. Granular material is defined by granules with a relatively large particle size, typically ranging from 0.1 mm to 2.0 mm. Granular material forms the product's framework and greatly contributes to the product's mechanical properties. Micronized powder, on the other hand, consists of granules with a smaller particle size, typically less than 100 micrometers, or even <65 micrometers. Micronized powder, together with resin, fills the gaps between the granular material. Sometimes, the mixture of micronized powder and resin is referred to as a "paste." The granular material and micronized powder forming the surface of artificial stone can be made of the same or different materials.

[0006] While quartz stone and synthetic cristobalite are distinct materials, they share several common properties that make them ideal fillers for use as granular particles or micronized powders in the manufacture of durable building / decorative surfaces, such as high abundance and availability, hardness, translucency, whiteness, and chemical inertness. However, they also have at least one significant drawback. The fine fraction of inhalable crystalline silica dust generated during the manufacture of artificial stone containing quartz or cristobalite, or during the machining of this agglomerated material, poses an occupational health risk to workers or manufacturers. For example, long-term or repeated inhalation of the small-particle size fraction of crystalline silica dust is associated with pneumoconiosis (silicosis) and other serious illnesses. To avoid this hazard, workers potentially exposed to high levels of inhalable crystalline silica dust need to wear personal protective equipment (e.g., respirators with particulate filters), work in well-ventilated conditions to effectively refresh the air, and utilize measures to combat dust sources (e.g., handling tools with water supply or dust removal).

[0007] To address this drawback from the perspective of raw materials, abundant natural materials such as feldspar can be proposed as substitutes for quartz in quartz surfaces. In fact, feldspar has been described as a suitable filler in such products, for example in EP2011632A2 Example 1 or 2, EP2216305A1 Example 2, WO2009068714A1, and WO2007014809A1.

[0008] Document WO 2021 / 069464 discloses an artificial stone material comprising a hardened organic resin and feldspar particles as an inorganic filler, in order to reduce the content of crystalline silica in artificial stone.

[0009] The existence of this will further help address the ongoing need for improvement in any shortcomings found in the aforementioned areas or anywhere else. Summary of the Invention

[0010] This invention is based on the inventor's discovery that when micronized feldspar is combined with a small amount of micronized calcium carbonate material, artificial stone containing micronized feldspar can be manufactured more effectively.

[0011] Document WO 2021 / 069464 discloses the use of feldspar as an inorganic filler in the manufacture of artificial stone materials, including its use as a micronized powder. The inventors of this invention have now surprisingly discovered that, in the manufacture of artificial stone materials or articles, a small amount of micronized calcium carbonate material can be advantageously used as an additive to or in combination with feldspar micronized powder. In particular, it has been found that adding a small amount of micronized calcium carbonate material to a micronized mixture containing feldspar micronized powder produces a mixture with an organic resin that exhibits improved miscibility compared to the same mixture without calcium carbonate material, due to a significant reduction in viscosity or a higher flowability.

[0012] The enhanced miscibility of mixtures containing micronized feldspar and micronized calcium carbonate materials facilitates homogenization during the manufacturing process, for example, of artificial stone. It also facilitates more efficient vacuum vibration compaction. Therefore, the produced slabs are less prone to visual defects or mechanical failures, maintain excellent physical properties and appearance, and / or can be manufactured at higher productivity levels.

[0013] Finally, the inventors also discovered a synergistic effect in some embodiments: in addition to improved miscibility and the other advantages mentioned above, adding a small amount of micronized calcium carbonate material together with micronized feldspar in the manufacture of artificial stone results in an increase in the L* (brightness) value of the resulting product's chromaticity. An increase in L* indicates higher whiteness. Therefore, in the case of artificial stone where high whiteness is desired, when using a mixture containing micronized feldspar and micronized calcium carbonate material as a micronized inorganic filler, a smaller amount of whitening pigment (typically TiO2) will be required to achieve the desired whiteness compared to using a mixture containing mostly micronized feldspar but no micronized calcium carbonate material.

[0014] Therefore, in a first aspect, the present invention relates to artificial stone, wherein, based on the weight of the artificial stone, the artificial stone comprises:

[0015] a) 5% to 15% by weight of cured organic resin,

[0016] b) 50% to 90% by weight of inorganic fillers with a particle size of 0.1 mm to 2.0 mm, and

[0017] c) 5% to 32% by weight of micronized inorganic fillers with a particle size of <100 micrometers;

[0018] Based on the weight of the micronized inorganic filler, the micronized inorganic filler comprises:

[0019] c') 50 wt% to 98 wt% feldspar, and

[0020] c”) 2% to 30% by weight of calcium carbonate material.

[0021] In a second aspect, the present invention relates to a method for preparing artificial stone, comprising:

[0022] i) Based on the weight of the composition, mix compositions containing the following components to obtain an uncured mixture:

[0023] a) 5% to 15% by weight of curable organic resin,

[0024] b) 50% to 90% by weight of inorganic fillers with a particle size of 0.1 mm to 2.0 mm, and

[0025] c) 5% to 32% by weight of micronized inorganic fillers with a particle size <100 micrometers, wherein, based on the weight of the micronized inorganic fillers, the micronized inorganic fillers comprise:

[0026] c') 50 wt% to 98 wt% feldspar, and

[0027] c”) 2% to 30% by weight of calcium carbonate material;

[0028] ii) The unhardened mixture obtained in i) is vacuum vibratory compacted to obtain a compacted mixture, and

[0029] iii) Harden the compacted mixture obtained in ii). Detailed Implementation

[0030] The term artificial stone or artificial rock is commonly used and understood in the field of this invention. For clarity, but not intended to be limiting, the term artificial stone or artificial rock herein refers at least to all materials included in the definition contained in European Standard EN 14618:2009.

[0031] As is well known in the art, the term "feldspar" refers to a large class of crystalline minerals found in nature, formed by natural processes (e.g., metamorphism, or crystallization in rocks that have cooled slowly at high Earth depths, or from magma), and found within rocks. They consist of monoclinic and triclinic aluminum silicates with alkali or alkaline earth metals (typically potassium, sodium, and calcium). Minerals in the feldspar group conform to the formula: X(Al,Si)4O8, where X can be an alkali or alkaline earth metal, such as K, Na, Ca, Ba, Rb, and Sr, typically Na, K, and Ca. Examples of minerals belonging to the term feldspar include plagioclase and alkali feldspars, such as andesine, albite, anisoclase, anorthoclase, labradorite, microcline, orthoclase, austenite, sanidine, and terfeldspar.

[0032] Calcium carbonate materials are understood to be materials primarily containing calcium carbonate (CaCO3) or containing at least 80% by weight, preferably at least 90% by weight, of natural, mineral, processed, and / or synthetic materials relative to the weight of the calcium carbonate material. Even more preferably, the CaCO3 content of the calcium carbonate material is at least 95% by weight relative to the weight of the calcium carbonate material. The CaCO3 content can be determined by known analytical methods, such as a Bernard carbonatometer, or by inductively coupled plasma (ICP) optionally coupled with mass spectrometry. The minerals and rocks within the scope of calcium carbonate materials can be selected from those selected from: chalk, limestone, calcite, aragonite, aragonite, marble, travertine, and / or mixtures thereof. Other acceptable natural calcium carbonate materials can be obtained from biological sources (e.g., eggshells, snail shells, seashells). Precipitated calcium carbonate (PCC) produced by a recarbonation method is an example of a suitable synthetic calcium carbonate material.

[0033] The terms "curing organic resin" and "curable organic resin" are well known in the art. According to some embodiments, both organic resin and curable organic resin should be understood as a predominantly organic material formed from compounds or mixtures of compounds optionally together with a solvent. One or more compounds in the mixture of compounds in the resin may be monomeric, oligomeric, or polymeric, optionally having variable molecular weight and degree of crosslinking. At least some of the compounds in the curable organic resin, along with the optional solvent, will have functional reactive groups capable of undergoing curing via a crosslinking or curing reaction that cures the organic resin, resulting in a cured organic resin (or cured adhesive) upon completion of curing.

[0034] "Particle size" (also known as "particle diameter") can be measured, for example, by using known sieving separation with sieves of different mesh sizes. As used herein, the term "particle size" refers to the range in which the diameter of a single particle falls. It can be measured by the retention or passage of a particle on a calibrated sieve with an opening of a measured mesh size, wherein the particle will pass through (and thus be smaller than) a sieve whose size opening is measured and known, or be retained by said sieve (and thus be larger than). Particle size is defined as a specific range of sizes determined by the ability of a particle to pass through a sieve with a larger mesh opening or "hole" but not through a second sieve with a smaller mesh opening. In this specification, where the particle size of the inorganic filler is within a given range, this means that less than 1% of the particles in the total particle population of the filler have a particle size outside the given range. In one embodiment, less than 0.5% of the particles in the total particle population of the filler have a particle size outside the given range. In another embodiment, less than 0.1% of the particles in the total particle population of the filler have a particle size outside the given range. For particles <100 micrometers in size, the particle size distribution of the sample can be measured, for example, by laser diffraction, specifically using known commercial equipment (e.g., the Malvern Panalytical Mastersizer 3000 equipped with a hydrocell). For the measurement, the sample can be dispersed in demineralized water with the assistance of an ultrasonic probe. The laser diffractometer provides a particle distribution curve (particle volume relative to particle size) and statistical values ​​for the D10, D50, and D90 of the sample's particle group (where 10% (D10), 50% (D50), or 90% (D90) of the sample's particle group are below these particle size values, respectively).

[0035] In some implementations, the desired particle size range (particle size) of the inorganic filler can be obtained by grinding and sieving, using methods known in the art, such as grinding with a ball mill or opposing grinding rollers.

[0036] The composition of the inorganic filler can be obtained using X-ray fluorescence (XRF), a well-established technique in the field of mineralogy. The compositions shown herein preferably correspond to the average composition of a sample containing a large amount of filler material (e.g., 1 gram of filler material) calculated from at least three repeated measurements.

[0037] It will be readily understood by those skilled in the art that when a composition or material is defined by the weight percentage values ​​of all its components, the sum of these values ​​can never exceed 100%. The sum of the amounts of all components contained in a material or composition is 100% of the weight of the composition or material.

[0038] In a first aspect, the present invention relates to artificial stone, wherein, based on the weight of the artificial stone, the artificial stone comprises:

[0039] a) 5% to 15% by weight of cured organic resin,

[0040] b) 50% to 90% by weight of inorganic fillers with a particle size of 0.1 mm to 2.0 mm, and

[0041] c) 5% to 32% by weight of micronized inorganic fillers with a particle size of <100 micrometers;

[0042] Based on the weight of the micronized inorganic filler, the micronized inorganic filler comprises:

[0043] c') 50 wt% to 98 wt% feldspar, and

[0044] c”) 2% to 30% by weight of calcium carbonate material.

[0045] The calcium carbonate material used in this invention is preferably a material with a CaCO3 content of 80% to 100% by weight, or 90% to 100% by weight, or more preferably 95% to 100% by weight. Therefore, although the micronized calcium carbonate material used in this invention preferably has high purity, it may contain small amounts of auxiliary minerals or impurities mixed with the main CaCO3.

[0046] As an alternative or addition to the embodiments described herein, the calcium carbonate material is preferably selected from the following minerals or rocks: chalk, limestone, calcite, aragonite, aragonite, marble, travertine and / or mixtures thereof, or selected from the following minerals or rocks: calcite, limestone, marble and / or mixtures thereof.

[0047] In some embodiments, the particle size of the micronized inorganic filler is greater than 0.1 micrometers and less than 100 micrometers, for example, the particle size is from 0.1 micrometers to 99 micrometers, preferably from 0.2 micrometers to 99 micrometers.

[0048] In some embodiments, the micronized inorganic filler may contain 60% to 98% feldspar, preferably 70% to 98% feldspar, based on the weight of the micronized inorganic filler. In another embodiment, the micronized inorganic filler contains 75% to 98% feldspar, more preferably 80% to 95% feldspar, based on the weight of the micronized inorganic filler.

[0049] Based on the weight of the micronized inorganic filler, the micronized inorganic filler may contain 2% to 25% by weight of calcium carbonate material, preferably 5% to 20% by weight of calcium carbonate material; more preferably 7% to 20% by weight of calcium carbonate material.

[0050] In one embodiment, the micronized inorganic filler comprises, based on its weight:

[0051] c') 70 wt% to 98 wt% feldspar, and

[0052] c”) 2% to 30% by weight of calcium carbonate material.

[0053] In one embodiment, the micronized inorganic filler comprises, based on its weight:

[0054] c') 70 wt% to 95 wt% feldspar, and

[0055] c”) 5% to 30% by weight of calcium carbonate material.

[0056] In another embodiment, the micronized inorganic filler comprises, based on its weight:

[0057] c') 75 wt% to 98 wt% feldspar, and

[0058] c”) 2% to 25% by weight of calcium carbonate material.

[0059] In another embodiment, the micronized inorganic filler comprises, based on its weight:

[0060] c') 80 wt% to 95 wt% feldspar, and

[0061] c”) 5% to 20% by weight of calcium carbonate material.

[0062] The particle size of the micronized feldspar is <100 micrometers. In one embodiment, the particle size of the micronized feldspar is <75 micrometers, preferably <65 micrometers, for example, from 0.1 micrometers to 74 micrometers or from 0.5 micrometers to 64 micrometers.

[0063] Preferably, the particle size D90 of the micronized feldspar is <50 micrometers, more preferably <40 micrometers, and even more preferably D90 is 2 to 40 micrometers.

[0064] The particle size of the micronized calcium carbonate material is <100 micrometers. In one embodiment, the particle size of the micronized calcium carbonate material is <30 micrometers, preferably <25 micrometers, for example, from 0.1 micrometers to 29 micrometers or from 0.2 micrometers to 24 micrometers.

[0065] Preferably, the particle size D90 of the micronized calcium carbonate material is <30 micrometers, more preferably <20 micrometers, and even more preferably D90 is 0.2 micrometers to 20 micrometers.

[0066] In one embodiment, the micronized inorganic filler comprises, based on its weight:

[0067] c') 70% to 98% by weight, preferably 75% to 95% by weight feldspar with a particle size <75 micrometers, and

[0068] c”) 2% to 30% by weight, preferably 5% to 25% by weight, of calcium carbonate material with a particle size <30 micrometers.

[0069] In one embodiment, the micronized inorganic filler comprises, based on its weight:

[0070] c') 70% to 98% by weight, preferably 75% to 95% by weight, feldspar with a particle size D90 < 50 micrometers, and

[0071] c”) 2% to 30% by weight, preferably 2% to 25% by weight of calcium carbonate material with a particle size D90 < 20 micrometers.

[0072] Preferably, the micronized feldspar is albite (NaAlSi3O8), and more preferably albite (albite).

[0073] According to one embodiment, based on the weight of the micronized feldspar, the micronized feldspar comprises 60.0 wt% to 73.0 wt% SiO2, 17.0 wt% to 22.0 wt% Al2O3, and 8.0 wt% to 12.0 wt% Na2O. In another related embodiment, the micronized feldspar further comprises 0.0 wt% to 0.5 wt% Fe2O3+TiO2.

[0074] In one embodiment, the micronized feldspar is characterized by comprising a composition of oxides in the following weight percentage range, based on the weight of the micronized feldspar:

[0075] <![CDATA[Al2O3]]> 17.0% by weight to 21.0% by weight <![CDATA[Na2O]]> 9.0% to 12.0% by weight <![CDATA[K2O]]> 0.0% by weight to 2.0% by weight <![CDATA[Fe2O3+TiO2]]> 0.0% by weight to 0.3% by weight

[0076] In another implementation, it includes:

[0077] <![CDATA[Al2O3]]> 17.5% by weight to 20.0% by weight <![CDATA[Na2O]]> 9.3% to 11.9% by weight <![CDATA[K2O]]> 0.0% by weight to 1.0% by weight <![CDATA[Fe2O3+TiO2]]> 0.0% by weight to 0.1% by weight

[0078] Preferably, based on the weight of the micronized feldspar, the micronized feldspar contains 64.0% to 71.0% by weight of SiO2. More preferably, it contains 65.0% to 70.5% by weight of SiO2.

[0079] Preferably, based on the weight of the micronized feldspar, the micronized feldspar contains 17.0% to 21.0% by weight of Al2O3. More preferably, it contains 17.5% to 20.0% by weight of Al2O3.

[0080] Preferably, based on the weight of the micronized feldspar, the micronized feldspar contains 9.0% to 12.0% by weight of Na₂O. More preferably, it contains 9.3% to 11.9% by weight of Na₂O.

[0081] Preferably, based on the weight of the micronized feldspar, the micronized feldspar contains 0.0 wt% to 2.0 wt% K2O, more preferably 0.0 wt% to 1.0 wt%. Even more preferably, 0.01 wt% to 2.0 wt% or 0.01 wt% to 1.0 wt% K2O.

[0082] Preferably, based on the weight of the micronized feldspar, the micronized feldspar contains 0.0% to 0.2% Fe2O3, more preferably 0.0% to 0.1% Fe2O3.

[0083] In one embodiment, the micronized feldspar contains 0.01 wt% to 0.3 wt% or 0.01 wt% to 0.1 wt% of Fe2O3+TiO2, based on the weight of the micronized feldspar.

[0084] When the amount of a component in a composition is given as a range of 0% by weight or 0.0% by weight, it means that the composition may not contain the component or may contain the component in an amount not exceeding the specified upper limit.

[0085] Based on the weight of the micronized feldspar, the sum of the weight percentages of SiO2, Al2O3, and Na2O in the micronized feldspar is preferably at least 85 wt%, or at least 90 wt%, or even at least 93 wt%. Preferably, based on the weight of the micronized feldspar, the sum is in the range of 85.0 wt% to 99.8 wt%, preferably 90.0 wt% to 99.5 wt%, or 93.0 wt% to 99.5 wt%.

[0086] The micronized feldspar may also contain CaO in the composition. In one particular embodiment, based on the weight of the micronized feldspar, it contains 0.0 wt% to 6.0 wt% CaO, preferably 0.0 wt% to 3.0 wt%, more preferably 0.0 wt% to 3.0 wt%. More preferably, 0.01 wt% to 6.0 wt% or 0.05 wt% to 3.0 wt% CaO.

[0087] In one embodiment, the micronized feldspar may contain 0.0% to 0.5% water, more preferably 0.0% to 0.1% water, based on the weight of the micronized feldspar. In another embodiment, the micronized feldspar contains 0.01% to 0.5% or 0.01% to 0.1% water, based on the weight of the micronized feldspar.

[0088] According to one implementation scheme, micronized feldspar comprises:

[0089] <![CDATA[Al2O3]]> 17.0% by weight to 21.0% by weight <![CDATA[Na2O]]> 9.0% to 12.0% by weight CaO 0.0% by weight to 6.0% by weight <![CDATA[K2O]]> 0.0% by weight to 2.0% by weight <![CDATA[Fe2O3+TiO2]]> 0.0% by weight to 0.3% by weight

[0090] In another implementation, it includes:

[0091] <![CDATA[Al2O3]]> 17.5% by weight to 20.0% by weight <![CDATA[Na2O]]> 9.3% to 11.9% by weight CaO 0.0% by weight to 3.0% by weight <![CDATA[K2O]]> 0.0% by weight to 1.0% by weight <![CDATA[Fe2O3+TiO2]]> 0.0% by weight to 0.1% by weight

[0092] Micronized feldspar may contain silica in crystalline form (e.g., as quartz or cristobalite). However, preferably, the concentration of crystalline silica in the micronized feldspar is ≤10 wt%, ≤8 wt%, or even ≤5 wt%, based on the weight of the micronized feldspar. In one embodiment, the concentration of crystalline silica in the micronized feldspar is in the range of 0.0 wt% to 10.0 wt%, or 0.0 wt% to 8.0 wt%, or even 0.0 wt% to 5.0 wt%, based on the weight of the micronized feldspar. In another embodiment, the concentration is in the range of 0.1 wt% to 10.0 wt%, or 0.1 wt% to 8.0 wt%, or even 0.5 wt% to 5.0 wt%, based on the weight of the micronized feldspar.

[0093] The total content of crystalline phase in the micronized feldspar is preferably in the range of 80.0% to 99.0% by weight, or even 81.0% to 97.0% by weight, of the micronized feldspar, with the remainder being amorphous phase. In a preferred embodiment of the invention, the amount of albite (NaAlSi3O8) crystalline phase in the micronized feldspar is 80% to 97.0% by weight, or even 81.0% to 95.0% by weight, of the micronized feldspar.

[0094] The amount of crystalline silica and other crystalline phases in micronized feldspar can be determined by powder X-ray diffraction (XRD) analysis using the Rietveld method (a widely used technique in the field) in conjunction with the use of an internal standard for quantification.

[0095] In one embodiment, the micronized calcium carbonate material may be in the form of micronized marble containing at least 95% by weight of CaCO3 in its composition.

[0096] In one embodiment, the calcium carbonate material may contain other compounds besides CaCO3, which can be determined, for example, by ICP (inductively coupled plasma). Therefore, the calcium carbonate material may preferably contain MgCO3 at a concentration of 0% to 5% by weight, or 0% to 3% by weight, relative to its weight. The calcium carbonate material may preferably contain Al2O3 at a concentration of 0% to 5% by weight, or 0% to 1% by weight. The calcium carbonate material may preferably contain Fe2O3 at a concentration of 0% to 0.2% by weight, more preferably 0% to 0.1% by weight.

[0097] In one embodiment, the micronized calcium carbonate material may contain 0.0% to 0.5% water, preferably 0.0% to 0.1% water, based on the weight of the calcium carbonate material. In another embodiment, the calcium carbonate material contains 0.01% to 0.5% or 0.01% to 0.1% water, based on the weight of the calcium carbonate material.

[0098] According to one embodiment, based on the total weight of the artificial stone, the artificial stone contains 10% to 32% by weight of micronized inorganic filler with a particle size <100 micrometers. In another embodiment, it contains 15% to 32% by weight of the micronized inorganic filler.

[0099] In another embodiment, the artificial stone contains 10% to 25% by weight of micronized inorganic filler with a particle size <100 micrometers, based on the total weight of the artificial stone. In another embodiment, it contains 15% to 25% by weight of the micronized inorganic filler.

[0100] In a preferred embodiment, the weight ratio of micronized feldspar to micronized calcium carbonate material is 75:25 to 97:3; preferably 80:20 to 95:5; more preferably 80:20 to 92:8.

[0101] In some embodiments, the micronized inorganic filler or powder may comprise other inorganic materials with a particle size <100 micrometers, different from feldspar and calcium carbonate materials. In one embodiment, the micronized inorganic filler may further comprise 0% to 20% by weight, preferably 0% to 10% by weight, of other inorganic fillers with a particle size <100 micrometers, different from feldspar and calcium carbonate materials. Other inorganic materials may be selected from stone, stone-like materials, and ceramic materials, such as quartz, silicate glass, silicate glass frit, silica sand, feldspar sand, mica (mirror), granite, basalt, cristobalite, dolomite, ceramics, and mixtures thereof; or quartz, silicate glass, glass frit, quartz sand, feldspar sand, cristobalite, and mixtures thereof. In some embodiments, the micronized inorganic filler with a particle size <100 micrometers, different from feldspar and calcium carbonate materials, comprises 0% to 5% by weight, or 0% to 1% by weight, of inorganic granular material with a crystalline silica content >15% by weight, or >10% by weight.

[0102] In other or alternative embodiments, preferably, the micronized inorganic filler with a particle size <100 micrometers, unlike feldspar and calcium carbonate materials, is selected from silicate glass granules, silicate glass granules, silicate glass frit granules, synthetic silicate granules, ceramic granules, or mixtures thereof. The synthetic silicate granules according to these embodiments may be those described in WO 2021019020 A1 or WO 2021018996A1.

[0103] Based on the total weight of the artificial stone, the artificial stone of the present invention contains 50% to 90% by weight of inorganic filler with a particle size of 0.1 mm to 2.0 mm, preferably 0.1 mm to 1.5 mm. In a particular embodiment, it contains 60% to 90% by weight, or 70% to 90% by weight of the inorganic filler.

[0104] The inorganic filler with a particle size of 0.1 mm to 2.0 mm, preferably 0.1 mm to 1.5 mm, can be stone, stone-like or ceramic materials, such as quartz, feldspar, silicate glass, silicate glass material, silica sand, feldspar sand, mica, granite, basalt, cristobalite, dolomite, marble, ceramics and mixtures thereof.

[0105] Artificial stone with a low crystalline silica content is preferred. Therefore, it is preferred that at least 50% by weight, more preferably at least 75% by weight, more preferably at least 90% by weight, and even more preferably at least 95% by weight of all inorganic fillers (including micronized inorganic fillers and inorganic fillers with a particle size of 0.1 mm to 2.0 mm) have a low crystalline silica content, preferably with a crystalline silica (quartz, cristobalite, or other crystalline polymorphs) content of 0% to 30% by weight, or 0% to 20% by weight, or 0% to 10% by weight relative to the weight of the inorganic fillers. Preferably, at least 75% by weight, more preferably at least 90% by weight of other inorganic fillers in the artificial stone have a crystalline silica content of 0% to 10% by weight relative to the weight of the inorganic fillers.

[0106] In a particularly preferred embodiment, the artificial stone does not contain more than 25% by weight, or even more than 10% by weight, of inorganic fillers (including micronized inorganic fillers and inorganic fillers with a particle size of 0.1 mm to 2.0 mm) with a crystalline silica content of more than 30% by weight, or more than 20% by weight relative to the weight of the inorganic filler.

[0107] Preferably, the artificial stone contains at most 0% to 20% by weight, and more preferably at most 0% to 5% by weight, inorganic fillers (including micronized inorganic fillers and inorganic fillers with a particle size of 0.1 mm to 2.0 mm) of crystalline silica relative to the weight of the inorganic fillers.

[0108] In some embodiments of the invention, the artificial stone does not contain inorganic fillers with a content of >30% by weight or >15% by weight of crystalline silica based on the weight of the inorganic filler.

[0109] The crystalline silica content of artificial stone relative to its weight can be ≤50% by weight, or ≤40% by weight, or ≤25% by weight, or even ≤10% by weight. Alternatively, the crystalline silica content of artificial stone can be from 0% by weight to 50% by weight, or from 0% by weight to 25% by weight, or even from 0% by weight to 10% by weight.

[0110] In one preferred embodiment, the artificial stone contains at least 10% by weight feldspar, preferably at least 25% by weight, and more preferably at least 50% by weight feldspar (including micronized and non-micronized feldspar), based on its weight. In another embodiment, the artificial stone contains from 10% to 90% by weight feldspar, preferably from 20% to 90% by weight, and more preferably from 40% to 90% by weight feldspar (including micronized and non-micronized feldspar), based on its weight.

[0111] Preferably, based on the total weight of the artificial stone, the total amount of micronized inorganic filler with a particle size of <100 micrometers plus inorganic filler with a particle size of 0.1 mm to 2.0 mm is 85% to 95% by weight, more preferably 90% to 95% by weight.

[0112] Based on the total weight of the artificial stone, the artificial stone of the present invention contains 5% to 15% by weight of organic resin. In a preferred embodiment, the amount of organic resin is 5% to 12% by weight based on the weight of the artificial stone.

[0113] The cured (reactive or polymerized) organic resin is preferably a cured organic thermosetting resin, suitably liquid in its uncured state, and can be selected from unsaturated polyester resins, acrylate-based and methacrylate-based resins, vinyl resins, and epoxy resins. In embodiments, the organic resin can be an unsaturated polyester resin, an acrylate-based resin or a methacrylate-based resin, an epoxy resin, or a mixture thereof. The curable organic resin is preferably reactive and can be cured in a curing (or crosslinking) reaction.

[0114] In a preferred embodiment, the organic resin is an unsaturated polyester resin.

[0115] Unsaturated polyester resins can be obtained by polymerizing unsaturated dicarboxylic acids (or anhydrides) with glycols. For example, this can be achieved by condensing an acid or anhydride, such as maleic acid or anhydride, fumaric acid, phthalic acid or anhydride, isophthalic acid, terephthalic acid, adipic acid, succinic acid or anhydride, sebacic acid, or mixtures thereof, with a glycol, such as ethylene glycol, diethylene glycol, propylene glycol, butanediol, neopentyl glycol, hydrogenated bisphenol A, or mixtures thereof. The unsaturated polyester resin may also preferably contain an olefinically unsaturated monomer, such as styrene, in an amount of 25% to 45% by weight based on the weight of the resin.

[0116] In one particular embodiment, the unsaturated polyester resin is obtained by polymerization comprising a mixture of maleic acid or anhydride, phthalic acid or anhydride, and propylene glycol.

[0117] In one embodiment, based on the weight of the unsaturated polyester prepolymer, the unsaturated polyester resin comprises an unsaturated polyester prepolymer containing the following monomer units: 20% to 35% by weight of phthalic anhydride, isophthalic acid, or mixtures thereof; 5% to 20% by weight of maleic anhydride, fumaric acid, or mixtures thereof; 10% to 25% by weight of propylene glycol; 0% to 15% by weight of ethylene glycol; and 0% to 15% by weight of diethylene glycol; diluted in 25% to 45% by weight of styrene.

[0118] Artificial stone may also contain additives such as colorants or pigments, accelerators or catalysts for curing or hardening the resin, accelerators (e.g., silanes) for bonding between the filler and the resin, antimicrobial agents, UV stabilizers, or mixtures thereof. These types of additives and their proportions are known in the prior art. Preferably, these additives may be present in the artificial stone in an amount from 0.01% to 5.0% by weight, based on the weight of the artificial stone.

[0119] Artificial stone products preferably have a strength of 2000 kg / m³. 3 Up to 2600 kg / m 3 or 2100kg / m 3 Up to 2500 kg / m 3 The apparent density is within the range specified. Apparent density can be measured according to EN 14617-1:2013-08.

[0120] Artificial stone can be in the form of blocks, slabs, bricks, sheets, boards, or plates. In one embodiment, the artificial stone has dimensions of at least 1500 mm in length, at least 1000 mm in width, and a thickness of 4 mm to 40 mm; preferably, it has a length of 2000 mm to 3500 mm, a width of 1000 mm to 1800 mm, and a thickness of 4 mm to 40 mm.

[0121] Artificial stone materials can be used for construction or decoration, and are used to manufacture countertops, kitchen countertops, sinks, shower trays, wall or floor coverings, stairs or the like.

[0122] The artificial stone of the present invention can be obtained by a method including the following steps:

[0123] i) Based on the weight of the composition, mix compositions containing the following components to obtain an uncured mixture:

[0124] a) 5% to 15% by weight of curable organic resin,

[0125] b) 50% to 90% by weight of inorganic fillers with a particle size of 0.1 mm to 2.0 mm, and

[0126] c) 5% to 32% by weight of micronized inorganic fillers with a particle size <100 micrometers, wherein, based on the weight of the micronized inorganic fillers, the micronized inorganic fillers comprise:

[0127] c') 50 wt% to 98 wt% feldspar, and

[0128] c”) 2% to 30% by weight of calcium carbonate material;

[0129] ii) The unhardened mixture obtained in i) is vacuum vibratory compacted to obtain a compacted mixture, and

[0130] iii) Harden the compacted mixture obtained in ii).

[0131] Suitable embodiments of artificial stone, organic resin, inorganic fillers with particle sizes from 0.1 mm to 2.0 mm, micronized inorganic fillers, feldspar, and calcium carbonate materials are as defined herein with respect to the artificial stone of the present invention.

[0132] To manufacture artificial stone, a curable organic resin, such as a liquid organic resin, is mixed with inorganic fillers (micronized and non-micronized organic fillers) to form an uncured agglomerated mixture.

[0133] In a preferred embodiment, the micronized feldspar and calcium carbonate material are mixed in a step prior to mixing with the resin to achieve a homogeneous solid mixture.

[0134] For example, mixing can be achieved by stirring using a conventional mixer in a manner known in the art. The curable organic resin can be a resin that, after curing, is used to achieve cohesion and adhesion between inorganic fillers in the produced article or material. The organic resin is preferably thermosetting, liquid, and can be selected from, for example, unsaturated polyester resins, acrylate-based resins, methacrylate-based resins, vinyl resins, and epoxy resins. In embodiments, the organic resin can be an unsaturated polyester resin, an acrylate-based resin, a methacrylate-based resin, an epoxy resin, or a mixture thereof. These resins are preferably reactive and cure in a curing or crosslinking reaction.

[0135] Depending on the organic resin used, the curing of the organic resin can ultimately be accelerated by increasing the temperature and / or by using suitable catalysts and accelerators known in the art, and thus the curing of the mixture after compaction.

[0136] Furthermore, the composition of step i) may contain additives, such as colorants or pigments, curing catalysts, curing accelerators, adhesion promoters (e.g., silanes), antimicrobial agents, UV stabilizers, or mixtures thereof. These types of additives and their proportions are known in the prior art. Preferably, these additives may be present in the composition of step i) in an amount from 0.01% to 5.0% by weight, based on the weight of the composition.

[0137] Inorganic fillers (micronized and non-micronized inorganic fillers) can be incorporated into agglomerated mixtures at different particle sizes and can be obtained by crushing and / or grinding natural or artificial materials. These inorganic fillers can be sourced from, for example, specialized companies that have commercially dried and classified them according to their particle size.

[0138] The uncured agglomerated mixture obtained in step i) can then be conveyed to a distributor device. Suitable distributors are known, for example, those used in the manufacture of quartz agglomerated surfaces for distributing the (uncured) agglomerated mixture. This distributor device is preferably movable along the length of a temporary mold or support sheet. The support sheet, in its simplest form, can be made of kraft paper or plastic sheet. Alternatively, it can be a more complex elastic molded tray. The distributor device preferably consists of a feed hopper that receives the mixture in its top opening and a conveyor belt located below the bottom outlet opening of the hopper, which collects or extracts the mixture from the hopper and deposits it onto or in the mold or support plate. Other distributor devices within the general conception of the invention are also possible.

[0139] The unhardened agglomerated mixture, already distributed in a mold or on a support plate, is preferably covered on its top surface with a protective sheet and subjected to vacuum vibration compaction. For this purpose, in one example, the mixture is fed into the compaction zone of a press, where it is inserted into a sealable chamber. The chamber is then sealed, and a vacuum is created using a suitable gas evacuation pump. Once the desired vacuum level (e.g., 5 mbar to 40 mbar) is reached, the press head applies compaction pressure while simultaneously applying vertical vibration of the piston (e.g., at 2,000 Hz to 4,000 Hz). During vacuum vibration compaction, air entrained in the agglomerated mixture is substantially evacuated.

[0140] The compacted mixture then enters the hardening or curing stage. In this stage, depending on the type of resin and whether any suitable catalysts or accelerators are used, the mixture is appropriately subjected to temperature in a curing oven, typically heated to 80°C to 120°C, with a residence time in the oven generally between 20 and 60 minutes. After curing, the hardened compacted mixture is cooled to a temperature equal to or below 40°C.

[0141] After hardening, the resulting artificial stone (which can be shaped into blocks, slabs, boards, plates, bricks, or sheets) can be cut and / or calibrated to the desired final size, depending on the intended application, and can be finished (polished, honed, etc.) on one or both of its larger surfaces.

[0142] In another aspect, the present invention relates to artificial stone obtainable by the method defined above, the method comprising:

[0143] i) Based on the weight of the composition, mix compositions containing the following components to obtain an uncured mixture:

[0144] a) 5% to 15% by weight of curable organic resin,

[0145] b) 50% to 90% by weight of inorganic fillers with a particle size of 0.1 mm to 2.0 mm, and

[0146] c) 5% to 32% by weight of micronized inorganic fillers with a particle size <100 micrometers, wherein, based on the weight of the micronized inorganic fillers, the micronized inorganic fillers comprise:

[0147] c') 50 wt% to 98 wt% feldspar, and

[0148] c”) 2% to 30% by weight of calcium carbonate material;

[0149] ii) The unhardened mixture obtained in i) is vacuum vibratory compacted to obtain a compacted mixture, and

[0150] iii) Harden the compacted mixture obtained in ii).

[0151] It should be understood that the scope of this disclosure includes all possible combinations of the embodiments disclosed herein.

[0152] Example

[0153] Test method:

[0154] XRF: Oxide and elemental analysis can be performed using X-ray fluorescence in a commercial XRF spectrometer. For example, a disk containing approximately 1 g of sample is mixed with lithium tetraborate and calcined in air at 1.050 °C for 25 minutes, followed by analysis in the spectrometer. Results are reported as the relative weight percentage of oxides (SiO2, Al2O3, etc.) and the weight "loss on ignition" during calcination (evaporation / desorption of volatiles, decomposition of organic matter). The spectrometer is pre-calibrated using multi-point calibration curves with standards of known concentrations. For XRF analysis, the international standard ISO 12677:2011 can be followed.

[0155] XRD: As an example, crystalline phases can be identified and quantified using powder X-ray diffraction (XRD) and the Rietveld method, in conjunction with the use of internal standards. This method also allows for the quantification of all amorphous phases. The internal standard method requires thorough mixing and homogenization of a known amount of a reference standard (e.g., corundum) with each sample to be analyzed, optionally using a small amount of isopropanol or other mixing / homogenizing adjuvant. A Ge(111) monochromator that generates CuKα1 radiation and a commercially available X'Celerator detector (e.g., a PANalytical X'Pert Pro automated diffractometer) can be used. X-ray diffraction patterns of the powder can be recorded in 2θ at 60 sec / steps within 4° to 70°, while rotating to increase the statistical distribution of the particles. After obtaining the X-ray powder diffraction data, the crystalline phase can be identified using software (e.g., Brucker's DIFFRAC.EVA) by comparison with a cataloged diffraction pattern. The quantification of crystalline and amorphous phases can be performed, for example, using TOPAS software (via Coelho Software) with the Rietveld refinement method. After subtracting the amount of internal standard used, the contents of the crystalline phase and all amorphous phases are calculated as a weight percentage of the analyzed sample.

[0156] Particle size determination: Particle size, also known as particle diameter, can be measured by sieving using sieves of known mesh sizes. For particles <200 micrometers, particle size distribution can be measured using commercial equipment (e.g., the Malvern Panalytical Mastersizer 3000 with a Hydrocell) via laser diffraction. For measurement, the sample can be dispersed in demineralized water with the assistance of an ultrasonic probe. The laser diffractometer provides particle distribution curves (particle volume relative to particle size) and statistical values ​​for the D10, D50, and D90 of the particle group (where 10%, 50%, or 90% of the sample particle group are below this value, respectively).

[0157] The chromaticity of the cured mixture of micronized powder and unsaturated polyester resin (UPR resin) was determined as follows: 50 g of activated UPR resin (UPR resin + 0.125 wt% cobalt accelerator) and 50 g of micronized powder were mixed until homogenized, and then 0.75 g of peroxide catalyst was added at room temperature with stirring. The mixture was then poured into a mold and cured in a convection oven set to 70 °C for 30 minutes. After separation from the mold, the chromaticity of the cured mixture was measured on the face-down surface during curing using a Konica Minolta CM-3600d spectrophotometer. The average of three measurements is given in the CIE Lab color space with coordinates L*, a*, and b*.

[0158] The resin absorption of the micronized powder was evaluated as follows: 25.0 g of powder was placed in a graduated burette containing commercially available UPR resin of a precisely known density. Small amounts of resin were slowly added to the powder mixture, incorporated by rubbing and mixing with a spatula and / or a core, until just enough resin was added to achieve the consistency of a hard, putty paste that would not break or separate during handling. This point, known as the saturation point, is reached when the paste can be formed into balls by rubbing it between protected fingers without visible cracks and exhibits a matte, solid surface (i.e., no shine or a soft touch). The volume of resin used to reach this saturation point is noted, and the value of the absorbed resin is reported as the grams of resin absorbed by 100 g of micronized powder.

[0159] Material:

[0160] Three different high-purity commercial calcium carbonate materials were used: C1 and C2 from the same supplier, and C3 from a different supplier. All materials had a moisture content <0.1% by weight, in accordance with ISO 787 / 2.

[0161] C1 and C2 are micronized calcium carbonate from white marble, containing, as determined by ICP, 97.5 wt% CaCO3, 2.2 wt% MgCO3, 0.1 wt% Fe2O3, and <0.1 wt% Al2O3. C3 is micronized calcium carbonate from white marble, containing, as determined by ICP, 98.8 wt% CaCO3, 0.9 wt% MgCO3, 0.06 wt% Al2O3, and 0.1 wt% Fe2O3.

[0162] Feldspar (FD) is micronized albite, composed of 68.4 wt% SiO2, 18.6 wt% Al2O3, 10.6 wt% Na2O, 0.6 wt% CaO, 0.2 wt% K2O, 0.02 wt% TiO2, and 0.01 wt% Fe2O3. The crystalline phases in this albite are approximately 83 wt% albite and 7 wt% quartz.

[0163] The particle size distributions of C1, C2, C3, and FD are shown in Table 1:

[0164] D10 0.88 0.86 0.36 3.4 D50 2.21 2.1 2.0 11.1 D90 4.74 9.4 12.0 26.8

[0165] Table 1

[0166] Compared to C2 and C3, C1 has a narrower particle size distribution, with D90 less than 5 micrometers, while C2 and C3 have a wider particle size distribution, with D90 close to or exceeding 10 micrometers.

[0167] UPR resin 1, UPR resin 2, UPR resin 3, and UPR resin 4 are different commercial resins of unsaturated polyester prepolymers diluted in approximately 35% styrene.

[0168] experiment:

[0169] Micronized powders containing different amounts of feldspar and calcium carbonate were mixed with commercial liquid UPR resin 1. The amounts of various materials in each embodiment are shown in Table 2 below:

[0170]

[0171]

[0172] Table 2

[0173] The mixture was thoroughly mixed using a mechanical stirrer until homogenized. The viscosity was then measured at 25°C using a laboratory Brookfield viscometer operating within a torque range of 10% to 90%. The viscosities of the mixtures from Examples 1 to 6 are shown in Table 3.

[0174] 1 (Comparison) 2380 2 9980 3 7200 4 9880 5 7340 6 (Comparison) 11060

[0175] Table 3

[0176] In a very simple way, a mixture with low viscosity (cP) will flow and move easily and quickly under force (or in other words, it exhibits low flow resistance), while high viscosity (cP) indicates that the mixture flows or moves more slowly under the same force (higher flow resistance). As can be seen from the values ​​listed in Table 3, the mixtures of Examples 2 to 5, which combine small amounts of C1 or C2 with FD, exhibited significantly reduced viscosity in all cases compared to the mixture without any calcium carbonate material (Example 6).

[0177] In another series of experiments, micronized powders containing varying amounts of C1 and FD were thoroughly mixed with commercial UPR resin 2, and their viscosity was measured as described above. The amounts of various materials and their corresponding viscosities in these examples are shown in Table 4.

[0178] 7 (Comparison) 100 - - 900 8 100 20 80 6300 9 100 18 82 6870 10 100 15 85 7423 11 (Comparison) 100 - 100 9380

[0179] Table 4

[0180] The viscosity values ​​in Table 4 confirm the above conclusions; that is, when compared with a mixture containing no calcium carbonate material (Example 11), the mixtures of Examples 8 to 10, which combine small amounts of C1 with FD, exhibited significantly reduced viscosity in all cases. Furthermore, it also demonstrates the correlation between the viscosity reduction of the mixtures in the examples and the amount of calcium carbonate material in the micronized powder. Specifically, Example 8, with the highest amount of calcium carbonate, showed a lower viscosity than those examples with lower amounts of calcium carbonate (e.g., Examples 9 and 10).

[0181] The chromaticity of three different hardened mixtures comprising micronized powder and UPR resin 3 was measured as described above. The contents of FD, C2, and C3 in the micronized powder mixtures in these embodiments are shown in Table 5 as weight percentages, along with the chromaticity in CIELAB coordinates.

[0182] 12 100 - - 57.7 1.3 2.5 13 90 10 - 64.9 1.1 2.8 14 90 - 10 65.0 1.1 3.3

[0183] Table 5

[0184] The CIELAB chromaticity coordinates represent color as three values: L* represents perceived brightness, and a* and b* represent the four distinct colors of human vision: red, green, blue, and yellow. For perceived brightness L*, black is defined as 0, and white as 100. The a* axis is the opposite color to green-red, with negative values ​​tending towards green and positive values ​​towards red. The b* axis represents the opposite color to blue-yellow, with negative values ​​tending towards blue and positive values ​​towards yellow. In Table 5, the CIELAB chromaticity coordinates of Examples 13 and 14 show greater whiteness on the perceived brightness L* scale compared to Example 12. Furthermore, Examples 13 and 14 show different positions between red and green, and between yellow and blue. These results indicate a synergistic effect when calcium carbonate material is incorporated into a mixture with FD. When calcium carbonate material (C2 or C3) is added, in addition to the reduced viscosity of the uncured mixture described above, the cured mixture is also synergistically whiter (Examples 13 and 14, compared to Example 12). For example, when seeking high-whiteness artificial stone, increased perceived brightness L* can be very beneficial, potentially reducing the need for commonly used whitening dyes or pigments.

[0185] In Examples 15 through 17, the resin absorption of three micronized powder mixtures containing FD, C2, and C3 was measured as described above (using UPR resin 4). Table 6 describes the content of each component and the values ​​obtained. A higher absorption value per 100g of powder indicates a higher amount of resin required to achieve the same paste consistency. From these values, it can be concluded that, compared to using only FD as the micronized powder, the micronized powder containing 10% by weight of calcium carbonate material in addition to micronized feldspar requires approximately 12% less resin to reach the saturation point.

[0186]

[0187]

[0188] Table 6

[0189] Industrial trials

[0190] The product is compacted by vacuum vibration (using...) Artificial stone slab blanks manufactured using [technology], and commercialized by the Spanish company Cosentino SAU. The product contains 50% to 90% by weight of inorganic fillers with a particle size of 0.1 mm to 2.0 mm and 5% to 32% by weight of micronized inorganic fillers (or micronized powders) with a particle size of <100 micrometers, as well as 5% to 15% by weight of unsaturated polyester resin.

[0191] exist Three different types were manufactured on the production line. Product References. For each of the three references, in Example 18 (Comparative), the slab was produced using a micronized powder of albite as described in the embodiments herein, while in Example 19, the micronized powder was formed from a mixture of 90 wt% albite and 10 wt% C2, while keeping all other parameters constant. In both Examples 18 and 19, the slab could be produced without problems, although it was observed that the mixture in Example 18 required a longer time to homogenize than that in Example 19. Compared to Example 18, the mixture in Example 19 appeared to be “wetter,” exhibiting a significantly higher flow tendency and being easier to mix, and even the resin content of the mixture could be slightly reduced without affecting the properties of the obtained slab.

[0192] The properties of the slabs obtained in Examples 18 and 19 were examined and compared, and they provided similar results in terms of impact resistance, flexural strength, thermal degradation resistance, abrasion resistance, hydrolysis resistance, and UV degradation resistance. Furthermore, in Examples 18 and 19, the slab surface's resistance to chemical attack by acids, alkalis, solvents, or pigments remained unchanged.

Claims

1. An artificial stone comprising: a) Based on the weight of the artificial stone, 5% to 15% by weight of a hardened organic resin, b) Based on the weight of the artificial stone, 50% to 90% by weight of inorganic fillers with a particle size of 0.1 mm to 2.0 mm, and c) Based on the weight of the artificial stone, 5% to 32% by weight of micronized inorganic fillers with a particle size of <100 micrometers; The micronized inorganic filler comprises: c') Based on the weight of the micronized inorganic filler, 50% to 98% feldspar, and c'') Based on the weight of the micronized inorganic filler, 2% to 30% by weight of calcium carbonate material.

2. The artificial stone according to claim 1, wherein the micronized inorganic filler comprises: c') Based on the weight of the micronized inorganic filler, 70% to 95% feldspar, and c'') Based on the weight of the micronized inorganic filler, 5% to 30% by weight of calcium carbonate material.

3. The artificial stone according to claim 2, wherein the micronized inorganic filler comprises: c') 80% to 95% feldspar based on the weight of the micronized inorganic filler.

4. The artificial stone according to any one of claims 1 to 3, wherein the particle size D90 of the micronized feldspar (c') is <50 micrometers.

5. The artificial stone according to any one of claims 1 to 3, wherein the particle size D90 of the micronized feldspar (c') is <40 micrometers.

6. The artificial stone according to any one of claims 1 to 3, wherein the particle size D90 of the micronized feldspar (c') is 2 micrometers to 40 micrometers.

7. The artificial stone according to any one of claims 1 to 3, wherein the particle size D90 of the micronized calcium carbonate material (c'') is <30 micrometers.

8. The artificial stone according to any one of claims 1 to 3, wherein the particle size D90 of the micronized calcium carbonate material (c'') is < 20 micrometers.

9. The artificial stone according to any one of claims 1 to 3, wherein the particle size D90 of the micronized calcium carbonate material (c'') is 0.2 micrometers to 20 micrometers.

10. The artificial stone according to any one of claims 1 to 3, wherein the micronized feldspar (c') is albite.

11. The artificial stone according to any one of claims 1 to 3, wherein, based on the weight of the micronized feldspar (c'), the micronized feldspar (c') comprises 60.0 wt% to 73.0 wt% of SiO2, 17.0 wt% to 22.0 wt% of Al2O3 and 8.0 wt% to 12.0 wt% of Na2O.

12. The artificial stone according to any one of claims 1 to 3, wherein, based on the weight of the micronized feldspar (c'), the micronized feldspar (c') comprises a combination of the following oxides: 。 13. The artificial stone according to any one of claims 1 to 3, wherein the weight ratio of micronized feldspar (c') to micronized calcium carbonate material (c'') is 75:25 to 97:

3.

14. The artificial stone according to any one of claims 1 to 3, wherein the weight ratio of micronized feldspar (c') to micronized calcium carbonate material (c'') is 80:20 to 95:

5.

15. The artificial stone according to any one of claims 1 to 3, wherein the inorganic filler b) having a particle size of 0.1 mm to 2.0 mm is selected from stone, stone-like materials, ceramic materials, or mixtures thereof.

16. The artificial stone according to any one of claims 1 to 3, wherein the inorganic filler b) having a particle size of 0.1 mm to 2.0 mm is selected from quartz, feldspar, silicate glass, silica sand, mica, granite, basalt, dolomite, marble, ceramics, or mixtures thereof.

17. The artificial stone according to any one of claims 1 to 3, wherein the inorganic filler b) having a particle size of 0.1 mm to 2.0 mm is selected from feldspar sand or cristobalite.

18. The artificial stone according to any one of claims 1 to 3, wherein the CaCO3 content of the calcium carbonate material is at least 80% by weight, based on the weight of the calcium carbonate material.

19. The artificial stone according to any one of claims 1 to 3, wherein the CaCO3 content of the calcium carbonate material is at least 90% by weight, based on the weight of the calcium carbonate material.

20. The artificial stone according to any one of claims 1 to 3, wherein the total amount of inorganic fillers b) and c) is 85% to 95% by weight based on the weight of the artificial stone.

21. The artificial stone according to any one of claims 1 to 3, comprising 5% to 12% by weight of organic resin.

22. The artificial stone according to any one of claims 1 to 3, wherein the hardened organic resin is selected from unsaturated polyester resins, acrylate-based resins, methacrylate-based resins, epoxy resins, or mixtures thereof.

23. The artificial stone according to any one of claims 1 to 3, wherein the hardened organic resin is an unsaturated polyester resin.

24. The artificial stone according to any one of claims 1 to 3, wherein the content of crystalline silica in the artificial stone is ≤50% by weight relative to the weight of the artificial stone.

25. The artificial stone according to any one of claims 1 to 3, wherein the content of crystalline silica in the artificial stone is ≤40% by weight relative to the weight of the artificial stone.

26. A method for preparing artificial stone according to any one of claims 1 to 25, comprising: i) Mixing a composition containing the following ingredients to obtain an uncured mixture: a) 5% to 15% by weight of a curable organic resin, based on the weight of the composition. b) Based on the weight of the composition, 50% to 90% by weight of inorganic fillers with a particle size of 0.1 mm to 2.0 mm, and c) Based on the weight of the composition, 5% to 32% by weight of micronized inorganic fillers with a particle size of <100 micrometers; The micronized inorganic filler comprises: c') Based on the weight of the micronized inorganic filler, 50% to 98% feldspar, and c'') Based on the weight of the micronized inorganic filler, 2% to 30% by weight of calcium carbonate material; ii) The unhardened mixture obtained in i) is subjected to vacuum vibration compaction to obtain a compacted mixture, and iii) Harden the compacted mixture obtained in ii).

27. The method of claim 26, wherein the curable organic resin is selected from unsaturated polyester resins, acrylate-based resins or methacrylate-based resins, epoxy resins or mixtures thereof.

28. The method according to claim 26 or 27, wherein the curable organic resin is an unsaturated polyester resin.

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