Aluminum-silicate composite ceramic material, methods of making the same, and products incorporating the same

Abstract

An aluminum-silicate composite ceramic (ASCC) material is described, the ASCC material including at least 55 wt% silica and no more than 40 wt% aluminum oxide. The silica and the aluminum oxide components of the ASCC are sintered to form a semi-amorphous solid ceramic material. The d50 particle size of the ASCC material is less than 4.5 microns. Methods of preparing the ASCC material are also described.

Description

ALUMINUM-SILICATE COMPOSITE CERAMIC MATERIAL, METHODS OF MAKING THE SAME, AND PRODUCTS INCORPORATING THE SAME CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 568,750, filed March 22, 2024, the entirety of which is hereby incorporated by reference. TECHNICAL FIELD

[0002] The field of the present application relates to the aluminum-silicate composite ceramic (ASCC) materials, methods of making the same, and the incorporation of the ASCC material into titanium dioxide-containing products, such as paints, coatings, and plastics. The inclusion of the ASCC material described herein in titanium dioxide-containing products beneficially allows for a reduction in the amount of titanium dioxide in the product while maintaining the hiding power / opacity performance properties of the product, not diminishing other performance properties of the product, and being compatible with other components of the product. BACKGROUND

[0003] Titanium dioxide (TiO2) is commonly used in various commercial products, such as paints, coatings, and plastics, to provide the product with opacity (hiding power), taking advantage of its high refractive index compared to other raw materials. However, titanium dioxide is a comparatively expensive material, and because it is a synthesized, material, can present environmental issues related to its production. Manufacturers therefore search for other raw materials to include in the product that can also provide hiding power to thereby reduce the amount of titanium dioxide that would otherwise be required to achieve desired opacity.

[0004] One way to reduce the amount of TiO2 used in a product while still achieving a desired level of opacity is to include “extender” or “spacer” particles. Typically, these particles maintain light refraction using less TiO2. Other particles improve the performanceand weight efficiency of the pigment particles and / or the opacity. Other particles are primarily volumetric fillers and / or can improve physical properties of the product. Calcium carbonate and talc are each an example of a typical volumetric filler used across multiple industries. However, extender and spacer particles are limited in the amount of TiO2 they can replace, as they may reduce hiding power function and / or compromise rheology.

[0005] Accordingly, a need exists for new materials that can be used to replace an amount of TiO2in commercial products while maintaining the opacity of the product, not detrimentally impacting other performance characteristics of the product, and providing a more environmentally-friendly solution. SUMMARY

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary, and the foregoing Background, is not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter.

[0007] Various embodiments of an aluminum-silicate composite ceramic (ASCC) material are described herein, with the ASCC material being suitable to replace a quantity of TiO2 in various commercial products that use TiO2 to provide opacity. The ASCC material described herein can be used as an effective spacer providing consistent and typical performance properties in multiple industries, such as paints, coatings, plastics, and other markets. By allowing for the reduction in the amount of TiO2 used in commercial products, the inclusion of ASCC material in the commercial products reduces costs and provides environmental benefits.

[0008] The ASCC material described here is generally a mixture of two or more different materials, each of which may have a silica content and / or an aluminum oxide content. The mixture is subjected to sintering, such as at a temperature in the range of from 800^C to 1400^C, to create a semi-amorphous solid ceramic material. The semi-amorphous solid ceramic material may then be milled to reduce the particle size of the material to within a desired range. In some embodiments, the final ASCC material contains at least 55 wt.%silica and no more than 40 wt.% aluminum oxide, and a d50 particle size of less than 4.5 microns. Once prepared, the ASCC material may be incorporated into a TiO2-containing commercial product, wherein the amount of TiO2present in the product is reduced as compared to the TiO2 content of the product without the ASCC material.

[0009] The ability of ASCC material as described herein to effectively partially reduce TiO2content in commercial products while maintaining the commercial product’s performance is provided by the ASCC material being inert and mostly spherical in shape after being milled (such as to an average particle size of less than 4.5 microns). Increased performance and further substitution of TiO2 may be obtainable when ASCC material with an average particle size less than 2.0 microns is used. The inert and spherical characteristics of ASCC material allows it to be easily incorporated into a wide array of polymer systems used in a variety of different product categories, including paints, coatings, and plastics.

[0010] These and other aspects of the technology described herein will be apparent after consideration of the Detailed Description and Figures herein. It is to be understood, however, that the scope of the claimed subject matter shall be determined by the claims as issued and not by whether given subject matter addresses any or all issues noted in the Background or includes any features or aspects recited in the Summary. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Non-limiting and non-exhaustive embodiments of the disclosed technology, including the preferred embodiment, are described with reference to the following figures wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

[0012] Figure 1 is a flow diagram illustrating a method for manufacturing ASCC material according to various embodiments described herein. DETAILED DESCRIPTION

[0013] Embodiments are described more fully below with reference to the accompanying Figures, which form a part hereof and show, by way of illustration, specificexemplary embodiments. These embodiments are disclosed in sufficient detail to enable those skilled in the art to practice the invention. However, embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense.

[0014] The ASCC material described herein generally includes at least 55 wt.% silica and no more than 40 wt.% aluminum oxide. The ASCC material is in the form of a semi- amorphous ceramic solid due to the sintering step used to prepare the ASCC material. The particle size of the ASCC material is also controlled, and in some embodiments, the d50 particle size of the ASCC material is less than 4.5 microns.

[0015] In some embodiments, the ASCC material includes greater than 60 wt.% silica and no more than 35 wt.% aluminum oxide. In some embodiments, a maximum silica content for the ASCC material is 80 wt.%. In some embodiments, there is a minimum aluminum oxide content in the ASCC material, such as at least 15 wt.% aluminum oxide.

[0016] The source of the silica and aluminum oxide content of the ASCC material is generally from two or more materials that are, in some embodiments, mixed together, sintered, and then milled to form the final ASCC material. Each material used may be a naturally occurring material or a non-naturally occurring material. In some embodiments, at least one material used in the mixture is a naturally occurring material. In some embodiments, at least two materials used in the mixture are naturally occurring material.

[0017] Regardless of whether the material used as part of forming the mixture is naturally occurring or non-naturally occurring, each material used to form the mixture generally includes a content of silica and / or aluminum oxide. In some embodiments, the ASCC material is formed from one naturally occurring material, while the remaining materials used in the ASCC material are non-naturally occurring materials. In some embodiments, the ASCC material is formed from at least two different naturally occurring materials containing silica and / or aluminum oxide. In some embodiments, the ASCC material is formed from a first naturally occurring material that is rich in silica (and which may also contain some aluminum oxide) and a second naturally occurring material that includes a relatively high amount of aluminum oxide (and which may also contain some silica). By using naturallyoccurring materials in the creation of the ASCC material, the ASCC material described herein provides an environmental benefit over the use of TiO2, which is a non-naturally occurring material.

[0018] Exemplary, through non-limiting, naturally occurring materials that can be used as source material for the ASCC material include silica-rich sand, kaolin clay, feldspar, alumina trihydrate, and nepheline syenite. Each of these naturally occurring materials may have variable silica and aluminum oxide content depending on, e.g., from where in the world the naturally occurring material is obtained. For example, silica rich sand from one location may include 85 wt.% silica and 10 wt.% aluminum oxide, while silica rich sand from another location may include 95 wt.% silica and 3 wt.% aluminum oxide. Some silica rich sand can even include 99 wt.% or 100 wt.% silica. Similar compositional variability may exist with respect to any non-naturally occurring material used as a source material for the ASCC material. Accordingly, the specific composition of all source material, whether naturally occurring or non-naturally occurring, must be taken into consideration when preparing the ASCC material in order to obtain an ASCC material with the desired silica and aluminum oxide composition (e.g., greater than 55 wt.% silica and less than 40 wt.% aluminum oxide).

[0019] Non-naturally occurring materials used as a source material for the ASCC material can include those that are made by man, and naturally occurring materials that are modified by man. For example, non-naturally occurring materials suitable for use in embodiments described herein can include modified versions of alumina trihydrate or nepheline syenite.

[0020] In embodiments where the ASCC material is prepared from at least two naturally occurring materials, silica-rich sand, kaolin clay, and / or feldspar may be used as the first naturally occurring material, while kaolin clay, alumina trihydrate, nepheline syenite, and / or feldspar may be used as the second naturally occurring material that includes a relatively high amount of aluminum oxide. In one example, the ASCC material is prepared from a first naturally occurring material that is a silica sand (such as silica sand having 60 wt.% silica and 23 wt.% aluminum oxide) and a second naturally occurring material that is kaolin clay (such kaolin clay having 46 wt.% silica and 38 wt.% alumina oxide). For this example, the ASCC material may further include one or more non-naturally occurring materials, such asaluminum trihydrate that is modified from its naturally occurring form of aluminum ore being almost 100% aluminum oxide. In this example, the mixture may comprise 75 wt.% silica sand, 23 wt.% kaolin clay and 2 wt.% aluminum trihydrate adjusted for losses during calcining.

[0021] The naturally occurring materials and / or the non-naturally occurring materials used in the preparation of the ASCC material may include some amount of impurities, which in this case is considered as any components of the materials that are not silica or aluminum oxide. Typical impurities found in, e.g., silica rich sand and kaolin clay include, but are not limited to, iron, alkali, oxides other than aluminum oxide, and / or other minerals. In some embodiments, these impurities are left in the source materials and therefore become part of the ASCC material, while in other embodiments, processing steps are carried out before or during the formation of the ASCC material to remove at least some of the impurities. In some embodiments, the source materials used and / or the processing steps carried out during manufacture of ASCC material are designed to ensure that the ASCC material includes less than 6 wt.% impurities, such as less than 5 wt.% or less than 3 wt.%. In some embodiments, the impurity content of the ASCC material is less than 1 wt.% to provide for even more improved opacity.

[0022] In some embodiments where the ASCC material is formed from at least a first naturally occurring source material and a second naturally occurring source material, the first naturally occurring source material includes at least 50 wt.% silica (such as at least 70 wt.% silica) and the second naturally occurring material includes at least 10 wt.% aluminum oxide (such as at least 30 wt.% aluminum oxide). The first naturally occurring material having greater than 50 wt.% silica could be, e.g., a silica-rich sand. The second naturally occurring material including at least 10 wt.% aluminum oxide could be, e.g., kaolin clay.

[0023] In some embodiments, the average particle size of the ASCC material is less than 4.5 microns, such as less than 2.0 microns or less than 1.0 microns. Obtaining an average particle size in this range generally requires one or more milling steps, discussed in greater detail below. Typically, an average particle size of 2.0 microns or less for the ASCC material is very versatile in terms of products into which the ASCC material can be incorporated, and also requires lower milling time and cost as compared to smaller averageparticle size. An average particle size of 1.5 microns or less (e.g., 0.5 microns to 0.9 microns) may allow for additional TiO2 substitution, especially for thinner finished product articles, but may cost more to produce. In some embodiments, a broad use average particle size is in the range of 1.0 to 2.0 microns. Such a range is on the order of twice the wavelength range of visible light of 200-700 nanometers where TiO2 is very effective at providing opacity (hiding power).

[0024] Average particle size discussed herein refers to an average of particles in distribution or range of sizes. The distributions can be both narrow and wide. They can also be mono-modal or multi-modal. Mono-modal means that there is one concentration of particle sizes. Multi-modal means that there is more than one concentration of sizes within a distribution. In some embodiment, the most effective partial substitution of TiO2 is achieved with a narrow, mono-modal distribution given that TiO2 has both of these attributes. The narrowness of a distribution is determined most easily by dividing the difference between the d10 and d90 particle sizes by the average particle size (known as d50). The d10 is the particle size in the distribution representing the finest 10% and the d90 is the coarse fraction particle size at 90% of the overall distribution. With TiO2typically having a d50 of 0.3 micron and narrowness Index of less than 1, ASCC material having a narrowness index of less than 10 is most effective for partial substitution of TiO2 and maintaining opacity (hiding power).

[0025] Typically, the d10 for broad based use of ASCC material having a d50 of 1.0 to 2.0 micron is 0.6 to 0.9 micron. For the same broad-based uses of ASCC material, the d90 is in the range of 10-20 micron. These ranges can provide a narrowness index of less than 10.

[0026] Referring now to Figure 1, a method 100 for manufacturing ASCC material generally includes a step 110 of preparing a mixture of materials that provide a mixture having a silica content of greater than 55 wt.% and an aluminum oxide content of no greater than 40 wt.%, a step 120 of calcining the mixture to form a semi-amorphous solid, and a step 130 of milling the semi-amorphous solid to reduce the average particle size. The method 100 shown in Figure 1 further includes optional steps 140, 150, and 160, each of which may be carried out depending on, for example, the manner in which previousprocessing steps are carried out and / or the product into which the ASCC material is to be incorporated. Optional step 140 is a drying step, optional step 150 is a deagglomeration step, and optional step 160 is a surface treatment step.

[0027] With respect to step 110, source material is mixed together to create a mixture having the desired silica and aluminum oxide content, such as greater than 55 wt.% silica and not more than 40 wt.% aluminum oxide. As discussed previously, two or more material sources can be mixed together to achieve these desired mixture content. In some embodiments, at least one of the material sources is a naturally occurring material source. The specific silica content and aluminum oxide content of each source material is factored into determining how much of each source material is mixed together in order to achieve the desired final mixture composition.

[0028] The particle size of the source materials used in step 110 is generally not limited, though the particle size of the source material may dictate whether method 100 requires one or more milling steps. In some embodiments, the particle size of the source materials used in step 110 is relatively large such that one or more milling steps is required in method 100 in order to obtain a final ASCC product with the desired size characteristics. In other embodiments, the particle size of the source materials used in step 110 is relatively small, such that either no milling is required as part of method 100, or only fine milling is required. For example, source material used in step 110 may have a particle size where d50 is less than 5 microns, in which case no milling is required at any point during the method 100, including either before or after the calcining step. Source material may have a relatively low particle size naturally, or the source material may have been subjected to milling prior to being used in step 110.

[0029] The impurity level (e.g., iron content, alkali content, etc.) of the source material may also be a consideration when preparing the mixture in step 110. The desired final impurity content of the mixture is 3 wt.% or less. In embodiments where the impurity content of the source material is relatively high, step 110 may further include processing the source material and / or mixture of source material in order to reduce the impurity content to below the desired maximum. Any manner of reducing impurity levels may be used. In some embodiments, the source material and / or the mixture are subjected to leaching, exposingthe material or a dry or wet magnet, exposing the material to an acid, or any combination thereof. When exposure to an acid is used to reduce impurity content, the acid may be, for example, nitric acid or acetic acid.

[0030] Any manner of mixing together the source materials can be used. In some embodiments, mixing together the source materials provides a relatively homogenous mixture of the source materials.

[0031] With respect to step 120, the mixture prepared in step 110 is subjected to a calcining step in order to produce a semi-amorphous solid material. The semi-amorphous solid material retains the composition of the mixture, such that the semi-amorphous solid material has a silica content greater than 55 wt.% and an aluminum oxide content of not greater than 40 wt.%. The calcining step generally sinters together the silica and aluminum oxide. In other words, the silica and aluminum are fused together without either component becoming a liquid.

[0032] Calcining is carried out in step 120 at a temperature sufficient for silica and aluminum oxide to fuse together. In some embodiments, calcining is carried out at a temperature in the range of 800^C to 1400^C. Generally speaking, the specific temperature used for calcining should be selected to be sufficient to cause fusing while minimizing or avoiding crystallization. If crystallization occurs, the calcining step can lead to the creation of crystalline silica (also referred to as cristobalite), which is a recognized safety hazard.

[0033] The duration of the calcining step 120 is generally not limited and may depend on a variety of factors, including the specific temperature used, the apparatus used to carry out the calcining, and the material / composition of the mixture being calcined. In some embodiments, calcining is carried out for a duration in the range of 0.1 to 3.0 hours.

[0034] With respect to apparatus suitable for use in carrying out calcining step 120, the method may use any of a variety of kilns and refractories. The most common for large volume production is a direct fired rotary kiln. Direct fired rotary kilns are most effective for calcining at temperatures of 1000^C or higher. An indirect kiln can be employed and most likely usable if there is an alkali composition that performs as a flux to promote sintering at a lower temperature. As excess of alkalis has the potential of driving the sinteringtemperature too low such that adequate residence time is not possible to complete the phase change of the silica sand and additional raw materials into a ceramic composite semi- amorphous solid.

[0035] In step 130, milling is carried out on the calcined material in order to reduce the average particle size of the material. In some embodiments, milling step 130 is carried out in order to reduce the average particles size to less than 4.5 microns, such as less than 2.0 microns, or less than 1.0 microns.

[0036] In some embodiments, milling step 130 is carried out in two or more steps, with a first milling step being used to reduce the average particle size to within a first range that is relatively coarse, and the second milling step being used to reduce the average particles size to within a second range that is relatively fine. In some embodiments, the first milling step reduces the average particle size to less than 100 microns, such as less than 50 microns, or less than 10 microns (e.g., 5 to 10 microns). The second milling step is then carried out to reduce the average particle size even further, such as to below 4.5 microns. In such embodiments, the first milling step may be a ball milling step, while the second milling step is fine milling step. Fine milling can be accomplished by dry milling or wet bead milling.

[0037] Given the hardness of the silica sand in the ASCC material, the metallurgy of the milling equipment used in step 130 needs to be considered. All milling equipment used should be very durable to avoid both rapid deterioration of the milling equipment as well as contaminating the ASCC material with eroded material from the milling equipment. In some embodiments, a suitable material for the milling equipment used in step 130 is zirconia.

[0038] Wet bead milling, when used as part of step 130, may be carried out with a solids content in the range of from 20 wt% to 80 wt% in water. Factors to be considered when selecting the specific solids content for the wet bead milling include the material being milled and the objective particle size distribution. Optimizing the solids content is dependent upon the throughput rate, particle size of feed, required final particle size, equipment metallurgy, how the material fractures, the morphology of the fractured material (round like or flat like), and whether any grinding aide is used to facilitate the grinding process by keeping particles separated as well as maintaining stable rheology during the milling process. Stable rheology is beneficial in having a consistent viscosity (both too thick as wellas too thin), as well as avoiding any foaming that may occur. In some embodiments, ASCC being wet milled in the range of 40 wt% to 80 wt% solids in water is workable for wet milling.

[0039] As alluded to above, the use of a grinding aide is an option for wet bead milling. If used, it is preferred to use a grinding aide that is not polar, which can add electrostatic repulsion and attraction forces to milled particles. Grinding aides are also useful in improving the narrowness of the particle size distribution as well as controlling the surface energy caused by fracturing the particles (especially ultra-fines). Surface energy can cause agglomeration, which can compromise performance in end use applications, such as in some paints where the mixing shear forces are not strong enough to break the agglomerates.

[0040] Typical bead sizes in wet bead milling are less than 5 microns, including as low as 0.3 micron. Bead sizing for the most efficient wet milling is determined by the particle size distribution of the feed material and targeted final milling specifications. In some embodiments, the bead size is in the range of 0.8 to 1 micron. With the hardness of ASCC material, a preferred bead material is yttria-stabilized zirconia (YTZ) powder.

[0041] Water is the common liquid used for wet bead milling. It is low cost and can handle temperatures approaching 100^C very well.

[0042] The natural fracking tendency of ASCC material to be ball-like is augmented by use of wet bead milling. The beads serve to round out the fracture surfaces enough to make the particles more spherical (ball-like) or angular and sub-angular in shape. The spherical nature makes incorporation of the ASCC material into water-based, solvent-based and plastics-based articles easier. Having ASCC material extremely well dispersed in an article is also the basis for the partial substitution of TiO2 in order to maintain the opacity, inherent hiding power or TiO2.

[0043] While Figure 1 illustrates milling step 130 being carried out after calcining step 120, it is also possible for some or all of the milling to occur before calcining step 120. In some embodiments, all milling, whether coarse or fine, occurs prior to calcining step 120, and no milling occurs after calcining step 120. In some embodiments, milling occurs bothbefore and after calcining step 120, such as a coarse milling step carried out before calcining step 120 and a fine milling step carried out after calcining step 120.

[0044] With respect to optional step 140, drying of the ASCC material may be carried out, especially in instances where previous steps in the method 100 subject the material to liquid, such as water. Thus, in some embodiments where wet bead milling is carried out as part of step 130, drying step 140 may be beneficial. In some embodiments, drying step 140 is carried out to reduce the moisture content of the ASCC material to less than 5 wt%. In some embodiments, reducing the moisture content of the ASCC material can be accomplished using a spray drier. Spray driers are used extensively in the mineral process industry, and are both high volume and efficient. The wet slurry of fine milled ASCC can be pumped through a nozzle that creates a mist of ASCC and water in a large heated chamber. As the mist falls, the moisture is evaporated, with the solid powder being accumulated in the bottom of the chamber. Often, a mechanical dewatering is used to increase the concentration of the spray drier feed to 80 wt% or higher to minimize the cost of heating and evaporating the remaining water. Typical mechanical dewatering is accomplished with a settling tank where the ASCC material is allowed to sink to the bottom where it is evacuated at a high concentration. Water displaced by the ASCC material is concentrated on top of the settling tank where it is drained and recycled for re-use in wet bead milling again. Residual water evaporated in the spray drier may be discharged to the atmosphere.

[0045] With respect to optional step 150, deagglomeration can be performed on the ASCC material. Deagglomeration may be useful in cases where the particle size distributions is wide (with a large number of particles spread across a range from fine to coarse) or in cases where the particle size distribution is narrow (with a large number of particles having approximately the same size). Typically, the coarser particles are capable of being separated from each other. In contrast, the fines and ultra-fines with a size near or below the d10 have a greater electronic charge on the surface (i.e., surface energy) that function as an attraction force. The higher the surface energy, the higher the probability a particle will attach itself to another particle. If a drying step 140 is carried out, the drying of the ASCC material facilitates the attraction forces between particles beyond any attractionthat occurred during the wet milling process itself. It is these quasi-attached particles that need to be separated via deagglomeration.

[0046] Deagglomeration step 150 can be achieved using high shear equipment that causes the particles to separate. Typical deagglomeration equipment can be a ball mill. Specific deagglomeration equipment can also be used, such as counter-rotating discs or a jet mill. With the hardness of the silica content in the ASCC material, the metallurgy of the deagglomeration equipment has to be sufficiently strong. In some embodiments, yttria- stabilized zirconia (YTZ) is used for the deagglomeration equipment.

[0047] When milling step 130 does not use a wet bead milling step, such as when dry milling is used, this may obviate the need for both drying step 140 and deagglomeration step 150. Fine dry milling incorporates milling and deagglomeration in a single step and no drying is required by default. Dry milling for ASCC material with a D50 of less than 4.5 micron is possible while also maintaining whiteness.

[0048] With respect to optional step 160, applying a hydrophobic surface treatment to the ASCC material may be carried out. Hydrophobic surface treatment may be required when the ASCC material is to be incorporated into plastics, which are inherently hydrophobic. In some embodiments, the surface treatment is treatment of the ASCC material with stearic acid. Stearic acid is inexpensive, readily available both as vegetable and animal based, highly efficient, and universally accepted. In some embodiments, the dosage level is 1.0 wt% stearic acid.

[0049] For Polyvinylchloride (PVC) applications, a hydrophobizing surface treatment is required. A UV light stabilizer could be an additive for the ASCC material or added to the PVC mixture for compounding to offset the reduction in TiO2. TiO2provides both whiteness and UV stability to PVC products. In some embodiments, the light stabilizers used in plastics including PVC are hindered amine light stabilizers (HALS). The most common of these types are benzotriazoles, benzophenones and organic nickel compounds.

[0050] PRODUCT EXAMPLES

[0051] A paint, coating, or plastic with the following composition: from 1 wt.% to 80 wt.% ASCC material; from 1 wt.% to 60 wt.% TiO2; and from 1 wt.% to 80 wt.% solvent or polymeric binder or plastic polymer

[0052] A water-based paint or coating with the following composition: from 1 wt.% to 70 wt.% ASCC material; from 1 wt.% to 30 wt.% TiO2; from 10 wt.% to 60 wt.% water; and from 10 wt.% to 35 wt.% polymeric binder material.

[0053] A solvent-based paint or coating with the following composition: from 1 wt.% to 50. wt% ASCC material; from 1 wt.% to 50 wt.% TiO2 or other pigment; from 1 wt.% to 60 wt.% organic solvent; from 10 wt.% to 75 wt.% polymeric binder material; and from 1 wt.% to 25 wt.% crosslinker.

[0054] A powder coating with the following composition: from 5 wt.% to 50 wt.% ASCC material; from 1 wt.% to 65 wt.% TiO2; from 10 wt.% to 75 wt.% polymeric binder material; and from 1 wt.% to 25 wt.% crosslinker.

[0055] A plastic based on polyethylene, polypropylene, polycarbonate, polystyrene or polyvinyl chloride plastic resin with the following composition: from 20 wt.% to 95 wt.% plastic polymer resin; from 3 wt.% to 60 wt.% titanium dioxide; and from 2 wt.% to 30 wt.% ASCC material.

[0056] A process of making a solid plastic article, the steps being: (a) obtaining a solid plastic concentrate (master batch) with the following composition: (i) from 5 wt.% to 60 wt.% polyethylene or polypropylene; (ii) from 25 wt.% to 75 wt.% titanium dioxide; and (iii) from 10 wt.% to 45 wt.% ASCC material surface treated at 1.0% by weight in polyethylene or polypropylene; (b) mixing the concentrate with plastic polymer; and (c) forming the molten mixture into a solid plastic article prior to cooling.

[0057] A cosmetic, sunscreen, ink, paper or board, paper or board coating or ceramic Glaze with the following composition: from 1 wt.% to 40 wt.% ASCC material; from 1 wt.% to 60 wt.% TiO2, and from 1 wt.% to 80 wt.% solvent or binder material.

[0058] From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that variousmodifications may be made without deviating from the scope of the invention. Accordingly, the invention is not limited except as by the appended claims.

[0059] Although the technology has been described in language that is specific to certain structures and materials, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific structures and materials described. Rather, the specific aspects are described as forms of implementing the claimed invention. Because many embodiments of the invention can be practiced without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.

[0060] Unless otherwise indicated, all number or expressions, such as those expressing dimensions, physical characteristics, etc., used in the specification (other than the claims) are understood as modified in all instances by the term "approximately". At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the claims, each numerical parameter recited in the specification or claims which is modified by the term "approximately" should at least be construed in light of the number of recited significant digits and by applying rounding techniques. Moreover, all ranges disclosed herein are to be understood to encompass and provide support for claims that recite any and all sub-ranges or any and all individual values subsumed therein. For example, a stated range of 1 to 10 should be considered to include and provide support for claims that recite any and all sub-ranges or individual values that are between and / or inclusive of the minimum value of 1 and the maximum value of 10; that is, all sub-ranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less (e.g., 5.5 to 10, 2.34 to 3.56, and so forth) or any values from 1 to 10 (e.g., 3, 5.8, 9.9994, and so forth).

Claims

CLAIMS I / We claim:

1. An aluminum-silicate composite ceramic material, comprising: at least 55 wt% silica; and no more than 40 wt% aluminum oxide; wherein the silica and the aluminum oxide are sintered to form a semi-amorphous solid ceramic material; and wherein the d50 particle size of the aluminum-silicate composite ceramic material is less than 4.5 microns.

2. The aluminum-silicate composite ceramic material of claim 1, comprising: greater than 60 wt% silica; and no more than 35 wt% aluminum oxide.

3. The aluminum-silicate composite ceramic material of claim 1, wherein the silica content and aluminum oxide content of the aluminum-silicate composite ceramic material are provided by at least a first source material and a second source material, wherein the first source material is silica-rich sand, kaolin clay, feldspar, or any combination thereof, and the second source material is kaolin clay, alumina trihydrate, nepheline syenite, feldspar, or any combination thereof.

4. The aluminum-silicate composite ceramic material of claim 1, wherein the d50 particle size of the aluminum-silicate composite ceramic material is less than 2.0 microns.

5. The aluminum-silicate composite ceramic material of claim 1, wherein the d50 particle size of the aluminum-silicate composite ceramic material is less than 1.0 microns.

6. The aluminum-silicate composite ceramic material of claim 1, wherein the aluminum- silicate composite ceramic material is subjected to a hydrophobic surface treatment.

7. The aluminum-silicate composite ceramic material of claim 1, further comprising: a UV light stabilizing additive.

8. The aluminum-silicate composite ceramic material of claim 1, wherein the aluminum- silicate composite ceramic material comprises less than 6 wt.% impurities.

9. A method of making an aluminum-silicate composite ceramic material, comprising: mixing together a first source material comprising silica and / or aluminum oxide and a second source material comprising silica and / or aluminum oxide to form a first mixture, wherein the silica content and the aluminum oxide content in each of the first source material and the second source material, as well as the amount of the first source material and the amount of the second source material, are taken into account when mixing the first source material and the second material such that the first mixture has a silica content of greater than 55 wt% and an aluminum oxide content of less than 40 wt%; and calcining the first mixture at a temperature in the range of 800^C to 1400^C to thereby form a semi-amorphous solid material.

10. The method of claim 9, further comprising: milling the semi-amorphous solid material such that the d50 particle size is less than 4.5 microns.

11. The method of claim 9, wherein the first source material is silica-rich sand, kaolin clay, feldspar, or any combination thereof, and the second source material is kaolin clay, alumina trihydrate, nepheline syenite, feldspar, or any combination thereof.

12. The method of claim 9, wherein calcining the first mixture is carried out in a manner that avoids the formation of crystalline silica.

13. The method of claim 10, wherein milling the semi-amorphous solid material comprises:coarse milling the semi-amorphous solid material; and fine milling the semi-amorphous solid material.

14. The method of claim 13, wherein coarse milling is carried out to reduce the average particle size to less than 100 microns and wherein fine milling is carried out to further reduce the average particle size to less than 4.5 microns.

15. A commercial product containing titanium dioxide for the purpose of providing opacity / hiding power, comprising: a quantity of titanium dioxide; and a quantity of the aluminum-silicate composite ceramic material of claim 1; wherein the quantity of titanium dioxide in the commercial product is reduced relative to the quantity of titanium dioxide in a version of the commercial product that does not contain the quantity of aluminum-silicate composite ceramic material of claim 1, without substantially reducing the opacity / hiding power of the commercial product.

16. The commercial product of claim 15, wherein the commercial product is a plastic, a paint, or a coating.

17. The commercial product of claim 16, wherein the commercial product is a titanium dioxide-containing paint, and the titanium dioxide-containing paint is a water- or solvent- based architectural paint, road marking paint, primer, or industrial coating.

18. The commercial product of claim 17, wherein the titanium dioxide-containing paint has a satin sheen, an egg-shell sheen, a semi-gloss sheen, a gloss sheen, or any other sheen within the spectrum of sheens, and wherein the titanium dioxide-containing paint is configured to be applied via brush, roller, or spray.

19. The commercial product of claim 16, wherein the commercial product is a titanium dioxide-containing coating, and the titanium dioxide-containing coating is a powder coating, water- or solvent-based automotive undercoat or topcoat, or can coating.

20. The commercial product of claim 19, wherein the titanium dioxide-containing coating is configured to be applied via electrostatic deposition spray, flocking, fluidized bed dipping, submersion or curing for powder coatings, via spray or electrodeposition spray for automotive coatings, and via spray, dip, roll, or brush coating for can coatings.

21. The commercial product of claim 16, wherein the commercial product is a titanium dioxide-containing plastic, and the titanium dioxide-containing plastic is a blown or cast polyolefin film or a polyolefin discrete part formed by blow-molding, injection molding, roto- molding, vacuum forming, or compression and transfer molding, and wherein the aluminum-silicate composite ceramic material optionally includes a hydrophobic agent, and wherein the aluminum-silicate composite ceramic material is incorporated into the commercial product in the form of a previously manufactured discrete compound or concentrate.

22. The commercial product of claim 15, wherein the commercial product is a cosmetic, sunscreen, ink, paper, board, paper coating, board coating, ceramic glaze, or polyvinylchloride application wherein the aluminum-silicate composite ceramic material optionally includes a hydrophobic agent and / or light stabilizer.

Images