Ceramic material and production method for ceramic material

Abstract

The present disclosure relates to a ceramic material that exhibits superior design properties and has an external appearance like that of a natural material. The ceramic material includes a base material and a design material such that at least some of the design material mixed into the base material is exposed on the surface with a random distribution. The degree of randomness is represented by the expression {(dmax-dmin) / dav} × 100, and is preferably 3% or greater. It is preferable for the ceramic material to further contain a coloring material, for the bulk density of the design material to be 0.02-0.4, and for the bulk density of the coloring material to be 0.3-0.8. The ceramic material exhibits superior design properties, and the random distribution of the design material makes it possible to achieve a substantially uniform design on the surfaces and cross sections thereof.

Description

Ceramic materials and manufacturing methods thereof

[0001] The present disclosure relates to ceramic materials and methods for manufacturing ceramic materials.

[0002] Ceramic materials have been known for use in the exterior and interior walls, roofs, etc. of buildings. In conventional ceramic materials, designs have been formed by molding a pattern using a mold or by painting with paint. However, in recent years, there has been a need for designs with a natural texture, and ceramic materials with designs closer to a natural texture have been proposed (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2002-020157

[0004] The technology disclosed in Patent Document 1 involves impact processing the surface layer of a molded body, removing all or part of the surface layer to expose the interior, thereby obtaining an exterior material with excellent design. However, the technology disclosed in Patent Document 1 requires the skill, effort, and cost of impact processing, as the material that forms the design does not appear on the surface in its natural state. Meanwhile, there has been a demand for the development of ceramic materials with better design that make use of the material's original texture.

[0005] The present disclosure has been made in view of the above, and aims to provide a ceramic material that has an appearance similar to that of natural materials and has excellent design properties.

[0006] The present disclosure relates to a ceramic material comprising a substrate and a decorative material, wherein at least a portion of the decorative material mixed into the substrate is exposed on the surface in a randomly distributed manner.

[0007] The present disclosure relates to a ceramic material comprising a substrate and a decorative material, wherein at least a portion of the decorative material mixed into the substrate is exposed on the surface in a randomly distributed manner, the bulk specific gravity of the decorative material is 0.02 to 0.4, and the bulk specific gravity of the coloring material is 0.3 to 0.8.

[0008] <Ceramic Material> The ceramic material according to this embodiment includes a base material and a decorative material. Portions of the decorative material are randomly distributed and exposed on the surface of the ceramic material, and the color and shape of the material itself used as the decorative material form the design. This allows a design with a natural feel to be realized. The uses of the ceramic material are not particularly limited, but can be used, for example, as decorative panels for the exterior or interior walls of buildings, exterior structural components such as gate sleeves and fences, roofing materials, partitions, etc.

[0009] (Substrate) As the substrate, any material used for ceramic materials can be used without any particular limitation, including, for example, cement, aggregate, pulp, silica sand, coloring material, waste material, etc.

[0010] Examples of cement include, but are not limited to, ordinary Portland cement, high-early-strength cement, alumina cement, magnesia cement, etc. Examples of aggregate include lightweight aggregate and silica stone. Examples of lightweight aggregate include perlite, pumice, and shirasu balloons. Examples of pulp include, but are not limited to, various pulp materials such as wood pulp (N-wood pulp, L-wood pulp, etc.), waste paper pulp, mechanical pulp, and chemical pulp. Examples of silica sand include, but are not limited to, artificial silica sand produced by crushing and classifying quartz, and natural silica sand collected and classified in the form of quartz sand from land, estuaries, coasts, etc. Examples of waste materials include fly ash, blast furnace slag, silica fume, and recycled materials (crushed scraps generated during the hardened body manufacturing process).

[0011] [Coloring Material] The substrate may contain a coloring material as needed. The coloring material is used for the purpose of coloring the substrate. The coloring material is not particularly limited, but it is preferable to include a carbonized material obtained by carbonizing waste materials or biomass materials. This allows the CO ２ can be fixed to the ceramic material. A specific example of the coloring material is bamboo charcoal. The coloring material may be the same as the design material described below. For example, by adjusting the particle size of the design material, it can also be used as a coloring material. One type of coloring material may be used, or two or more types may be used in combination.

[0012] [Water Repellent] The substrate preferably contains a water repellent. Because the ceramic material according to this embodiment contains a decorative material, depending on the quality of the decorative material, it is expected that the water absorption rate of the ceramic material will be higher than that of ceramic materials that do not contain a decorative material. If the water absorption rate of a ceramic material is high, there is a risk of frost damage or changes in the design after thawing. By incorporating a water repellent into the ceramic material, the above-mentioned situations can be prevented. The content of the water repellent is preferably 0.01 to 5 mass% solids mass ratio based on the total weight of the solids of the ceramic material. The content of the water repellent is more preferably 0.1 to 2.5 mass%, and even more preferably 0.2 to 1.2 mass%.

[0013] In addition to the above components, the base material may contain known components that can be contained in ceramic building materials, within the scope that does not impair the effects of the present disclosure. For example, aggregates such as fine aggregate and coarse aggregate other than those described above, mica, reinforcing fibers (such as polypropylene), wood fibers, water-reducing agents, retarders, foaming agents, antifoaming agents, etc.

[0014] (Design Material) At least a part of the design material is exposed on the surface of the ceramic material. The design material is added for the purpose of imparting design to the ceramic material. The design material preferably contains a carbonized material obtained by carbonizing waste material or biomass material. This allows CO ２can be fixed to ceramic materials. Specific examples of carbonizable materials (materials that can be carbonized) used as design materials include smoked charcoal, coconut shells, peanut shells, pine cones, edamame shells, flower petals, cedar, chestnuts, resin, fruit peels, cow and pig manure, mushroom tips and stubs, and plum seeds. Of the above design materials, materials other than those already carbonized do not need to be carbonized. Design materials other than carbonizable materials may also be used, such as vermiculite, eggshells, and seashells. One type of design material may be used, or two or more types may be combined. It is preferable to use at least two types of design materials, a first design material and a second design material, in combination. This allows for a more natural-looking design. The first design material and the second design material may be different materials, or the same type of material with different particle sizes, etc. Alternatively, the coloring material, the first design material, and the second design material may be the same material but with different particle sizes. In the following description, the first design material may be charcoal and the second design material may be vermiculite. In addition to the above, the design material may also have a moisture-regulating function or a fragrance-imparting function.

[0015] In the ceramic material of this embodiment, the decorative material is dispersed almost uniformly inside, so the design of the surface of the ceramic material and the cut surface (sometimes referred to as the side) of the ceramic material can be made almost identical.

[0016] <Particle Size of Design Material> In the ceramic material of this embodiment, the particle size distribution of the design material appearing on the ceramic material surface is preferably 500 to 10,000 μm. The particle size distribution is more preferably 500 to 6,000 μm, and even more preferably 500 to 4,390 μm. When the design material includes a first design material and a second design material, the particle size distribution of the first design material is more preferably 500 to 5,000 μm, and even more preferably 500 to 4,500 μm. The particle size distribution of the second design material is more preferably 500 to 6,000 μm, and even more preferably 600 to 4,537.4 μm. The particle size distribution can be measured using a digital microscope VHX-6000 (manufactured by Keyence Corporation). When determining the particle size using a microscope, for example, three or more particles can be arbitrarily selected and the particle size can be calculated as the average value.

[0017] When the decorative material includes a first decorative material and a second decorative material, the particle size distribution difference between the first decorative material and the second decorative material, that is, the difference in D90 (90% particle size by number) and the difference in D50 (50% particle size by number) (D90 - D50), are preferably both 0 to 9.9 mm. The particle size difference is more preferably 0 to 6.8 mm, and even more preferably 0 to 4.13 mm.

[0018] When comparing the particle sizes of the first and second design materials distributed on the surface of the ceramic material of this embodiment with the particle sizes of the first and second design materials distributed on the cut surface, the difference (D90 - D50) between the D90 (90% particle size by number) and D50 (50% particle size by number) of the surface of the ceramic material and the cut surface of the ceramic material for the first design material is preferably 0 to 8.7 mm. The difference is more preferably 0 to 5.8 mm, and even more preferably 0 to 2.98 mm. The difference (D90 - D50) between the D90 (90% particle size by number) and D50 (50% particle size by number) of the surface of the ceramic material and the cut surface of the ceramic material for the second design material is preferably 0 to 9.3 mm. The difference is more preferably 0 to 6.9 mm, and even more preferably 0 to 4.17 mm. This allows the surface design of the ceramic material and the cut surface design to be almost identical.

[0019] The particle diameters of the decorative material distributed on the surface of the ceramic material in this embodiment are preferably D90 1.40 to 9.61 mm, D50 0.53 to 9.61 mm, and D10 0.24 to 1.52 mm. In this specification and claims, D90, D50, and D10 refer to the 90%, 50%, and 10% cumulative particle diameters based on the number of particles, respectively. D90 is preferably 1.4 to 5.68 mm, and more preferably 1.4 to 2.84 mm. When the decorative material includes a first decorative material and a second decorative material, the D90 of the first decorative material is preferably 1.4 to 9.61 mm, and more preferably 1.4 to 1.60 mm. The D90 of the second decorative material is preferably 2.08 to 5.68 mm, and more preferably 2.08 to 2.84 mm. The D50 of the first decorative material is preferably 0.53 to 3.92 mm, more preferably 0.53 to 1.20 mm. The D50 of the second decorative material is preferably 0.67 to 1.86 mm, more preferably 0.67 to 0.93 mm. The D10 of the first decorative material is preferably 0.25 to 1.52 mm, more preferably 0.25 to 0.60 mm. The D10 of the second decorative material is preferably 0.24 to 0.76 mm, more preferably 0.24 to 0.38 mm.

[0020] When comparing the particle diameter of the design material distributed on the surface of the ceramic material of this embodiment with the particle diameter of the design material distributed on the cut surface, it is preferable that the difference between the D90 of the design material on the surface and the D90 of the design material on the cut surface be 4.0 mm or less. The difference is more preferably 3.26 mm or less, and even more preferably 2.52 mm or less. When the design materials include a first design material and a second design material, the difference in the D90 of the first design material is more preferably 2.25 mm or less, and even more preferably 1.39 mm or less. The difference in the D90 of the second design material is more preferably 3.26 mm or less, and even more preferably 2.52 mm or less. This allows the design on the surface of the ceramic material and the design on the cut surface to be substantially identical.

[0021] When comparing the particle diameter of the design material distributed on the surface of the ceramic material of this embodiment with the particle diameter of the design material distributed on the cut surface, it is preferable that the difference between the D10 of the design material on the surface and the D10 of the design material on the cut surface be 0.6 mm or less. The difference is more preferably 0.36 mm or less, and even more preferably 0.13 mm or less. When the design materials include a first design material and a second design material, the difference in D10 of the first design material is more preferably 0.25 mm or less, and even more preferably 0.10 mm or less. The difference in D10 of the second design material is more preferably 0.36 mm or less, and even more preferably 0.13 mm or less. This allows the design on the surface of the ceramic material and the design on the cut surface to be substantially identical.

[0022] (Standard deviation of particle size) When comparing the standard deviation of the particle size of the design material distributed on the surface of the ceramic material of this embodiment with the standard deviation of the particle size of the design material distributed on the cut surface, the difference between the standard deviation of the design material on the surface and the standard deviation of the design material on the cut surface is preferably 1.00 mm or less. The difference is more preferably 0.62 mm or less, and even more preferably 0.2557 mm or less. When the design material includes a first design material and a second design material, the difference for the first design material is more preferably 0.4 mm or less, even more preferably 0.24 mm or less, and most preferably 0.04 mm or less. The difference for the second design material is more preferably 1.0 mm or less, even more preferably 0.5 mm or less, and most preferably 0.25 mm or less. This allows the design on the surface of the ceramic material and the design on the cut surface to be substantially identical.

[0023] <Randomness of Arrangement of Design Materials> The randomness of the design materials distributed on the surface of the ceramic material according to this embodiment is preferably 3% or more. In this specification and claims, the randomness is expressed by the following formula: {(dmax - dmin) / dav} x 100. In the above formula, dmax, dmin, and dav respectively refer to the maximum center-to-center distance dmax, the minimum center-to-center distance dmin, and the average center-to-center distance dav when three other design materials are identified from a given design material exposed on the surface in order of smallest center-to-center distance. Center-to-center distances can be measured using commercially available equipment, such as a microscope VHX-6000 (manufactured by Keyence Corporation). The randomness is more preferably 4% or more, and even more preferably 5% or more.

[0024] <Color Tone of Ceramic Material> The color difference between the surface and the cut surface of the ceramic material according to this embodiment is L ＊ a ＊ b ＊ Chromaticity of the surface and cut surface according to the color system (L ＊ , a ＊ , b ＊ ) is the difference between ＊ Difference in value ΔL ＊, a ＊ Difference in value Δa ＊ , and b ＊ Difference in value Δb ＊ , and ΔL ＊ , Δa ＊ , and Δb ＊ ΔE calculated from ＊ It can be expressed as ab. ＊ is preferably 0 to 8, more preferably 0 to 5, and even more preferably 0 to 4.24. ＊ is preferably 0 to 1, and more preferably 0 to 0.41. ＊ is preferably 0 to 5, and more preferably 0 to 3.69. ＊ ab is preferably 0 to 15, more preferably 0 to 9, and even more preferably 0 to 5.01. This allows the surface design of the ceramic material and the cut surface design to be substantially the same.

[0025] <Surface appearance frequency of decorative material> The surface appearance frequency, which is the frequency at which the decorative material appears on the surface of the ceramic material according to this embodiment, can be calculated from the area occupancy rate of each decorative material relative to the area of ​​the ceramic material by automatic area measurement through image analysis using a digital microscope VHX-6000 (manufactured by Keyence). The surface appearance frequency of the decorative material is preferably 1.0 to 30.6%. When the decorative material includes a first decorative material and a second decorative material, the surface appearance frequency of the first decorative material is preferably 1.7 to 20.3%, and more preferably 2.4 to 10.2%. The surface appearance frequency of the second decorative material is preferably 3.2 to 17.4%, and more preferably 4.5 to 8.7%.

[0026] The surface appearance frequency of the design material on the surface of the ceramic material according to this embodiment and the surface appearance frequency of the design material on the cut surface are as follows. When the design materials include a first design material and a second design material, the surface appearance frequency of the first design material on the surface is preferably 2.4 to 30.6%, more preferably 2.6 to 20.4%, and even more preferably 2.9 to 10.2%. The surface appearance frequency of the first design material on the cut surface is preferably 2.0 to 12%, more preferably 2.4 to 12%, and even more preferably 2.4 to 9%. The surface appearance frequency of the second design material on the surface is preferably 4.0 to 26.1%, more preferably 4.2 to 17.3%, and even more preferably 4.5 to 8.7%. The surface appearance frequency of the second design material on the cut surface is preferably 3.0 to 18%, more preferably 3.0 to 12%, and even more preferably 3.1 to 6.0%.

[0027] The difference between the frequency of appearance of the decorative material on the surface of the ceramic material according to this embodiment and the frequency of appearance of the decorative material on the cut surface is preferably 26% or less. When the decorative materials include a first decorative material and a second decorative material, the difference for the first decorative material is preferably 0 to 18.7%, and more preferably 0 to 8.76%. The difference for the second decorative material is preferably 17% or less, more preferably 0 to 11.7%, and even more preferably 0 to 5.63%.

[0028] <Specific Gravity of Ceramic Material> The specific gravity of the ceramic material is preferably 0.80 to 1.10, more preferably 0.85 to 1.05, and even more preferably 0.90 to 1.00. The ceramic material according to this embodiment can have a lower specific gravity than conventional ceramic materials. This reduces transportation costs and improves workability.

[0029] <Bulk specific gravity of each component in the ceramic material> The bulk specific gravity of the design material is preferably 0.02 to 0.4, and the bulk specific gravity of the coloring material is preferably 0.3 to 0.8. This allows the design material to be exposed on the surface of the ceramic material simply by mixing it into the ceramic material, resulting in a ceramic material with a desirable design similar to that of natural materials. Furthermore, the specific gravity and porosity of the ceramic material can be adjusted within a suitable range. The bulk specific gravity of smoked charcoal as the design material is preferably 0.05 to 0.25, more preferably 0.08 to 0.13. The bulk specific gravity of vermiculite as the design material is preferably 0.05 to 0.25, more preferably 0.08 to 0.15. The bulk specific gravity of bamboo charcoal as the coloring material is preferably 0.35 to 0.7, more preferably 0.4 to 0.6.

[0030] The ceramic material according to the above embodiment defines its design through the color and shape of the decorative material itself. Therefore, a natural-looking design can be realized. Furthermore, because the decorative material is distributed almost uniformly within the ceramic material, cutting allows the design on the cut surface to be similar to the design on the other surfaces, making it easy to adjust to any shape. Furthermore, because carbonized materials are used as the decorative material, the ceramic material is not only cost-effective and environmentally friendly, but also easily cut and processed. Processing similar to that of wood can be performed, including riveting, mortising, tenoning, drilling, nailing, and screwing. Therefore, for example, shapes that were impossible with conventional ceramic materials can be realized, and shaping can be performed on-site. Furthermore, the maintenance described below can be easily performed at low cost. Furthermore, because the ceramic material according to this embodiment has a natural-looking design on its surface, dirt is less noticeable, reducing the frequency of maintenance.

[0031] <Ceramic material maintenance method> The ceramic material maintenance method according to this embodiment includes at least a polishing step of polishing the surface of the deteriorated ceramic material. The polishing step removes the deteriorated portion of the surface, revealing a new surface. The polishing method used in the polishing step is not particularly limited, and any known method can be used. Because the ceramic material according to this embodiment has decorative material uniformly distributed inside, the design of the new surface is indistinguishable from the design of the ceramic material before deterioration. Therefore, according to the ceramic material maintenance method according to this embodiment, ceramic material can be maintained easily and at low cost.

[0032] The ceramic material according to this embodiment preferably does not have a coating film formed from a paint composition or other articles such as a sheet attached to the surface disposed on its surface. The absence of a coating film or the like on the surface of the ceramic material can improve the maintainability of the ceramic material. Conventional ceramic materials with a coating film or the like disposed on the surface required work such as repainting or replacement when stains, scratches, deterioration, etc. occurred on the surface. In contrast, the ceramic material according to this embodiment does not have a coating film or the like on its surface, and therefore can be easily maintained.

[0033] <Method for Manufacturing Ceramic Material> The method for manufacturing a ceramic material according to this embodiment is not particularly limited, but may include, for example, a slurry production step, a molding step, and a curing step of curing the molded raw material slurry, in this order.

[0034] (Slurry Production Process) The slurry production process is a process for producing a slurry containing the components constituting the base material and the design material. The slurry contains the components and design material, as well as water. The components contained in the slurry are the same as those exemplified in the description of the ceramic material, and may contain components other than those mentioned above. The slurry is produced, for example, by preparing a composition containing the components and design material, adding water to the composition, and kneading. Alternatively, the components constituting the slurry may be directly blended and kneaded. The kneading method in the slurry production process is not particularly limited, and known methods using a mixer or the like can be applied. In the slurry production process, the design material and colorant are dispersed approximately uniformly in the slurry.

[0035] The slurry used in the slurry production process preferably has a slump value of 9.0 to 16.0 cm, as measured in accordance with JIS A 1150. The slump value can be determined by measuring the diameter at which the slurry is expected to spread most and the diameter in the perpendicular direction after the slurry has stopped moving, and then averaging these values. This allows the decorative material to be suitably positioned on the surface of the hardened body (ceramic material) without any special processing, simply by mixing the decorative material into the slurry. The slump value is more preferably 10.0 to 15.0 cm, and even more preferably 11.0 to 14.0 cm.

[0036] (Forming step) The forming step is a step of forming the raw material slurry obtained in the slurry production step. The forming step is not particularly limited, and known methods such as extrusion molding, cast molding, paper molding, and press molding can be applied.

[0037] (Curing Process) The curing process is a process in which the raw material slurry formed in the molding process is cured and hardened to obtain a hardened body (ceramic building material). The curing process forms a hardened body with a surface appearance frequency of the design material of 1.0 to 30.6%. When the design materials include a first design material and a second design material, the surface appearance frequency of the first design material is preferably 1.7 to 20.3%, more preferably 2.4 to 10.2%. The surface appearance frequency of the second design material is preferably 3.2 to 17.4%, more preferably 4.5 to 8.7%. The curing process is not particularly limited except for the use of the raw material slurry, and the curing conditions (temperature, relative humidity, time, pressure, etc.) can be set as desired depending on the properties of the slurry. The surface appearance frequency of the design material can be measured and calculated using the methods described above.

[0038] The above is an example of a method for manufacturing a ceramic material according to the present embodiment, and other steps known in the art for manufacturing ceramic materials may be included as long as they do not impair the effects of the present disclosure. For example, the method may include a cutting step of cutting the hardened body that has undergone the curing step to a predetermined size. The cutting step may include a step of smoothing the cut surface by polishing or the like.

[0039] The method for manufacturing a ceramic material according to this embodiment preferably does not include a step of removing at least a portion of the surface layer of the hardened body that has undergone the curing step by surface processing such as blasting. Even without the step of removing at least a portion of the surface layer of the hardened body, the ceramic material according to this embodiment has a decorative material exposed on the surface of the hardened body, forming a hardened body with a surface appearance frequency of the decorative material of 1.0 to 30.6%. Therefore, the ceramic material according to this embodiment can achieve desirable design properties similar to those of natural materials. Therefore, by not including the removal step in the manufacturing method, the manufacturing process can be simplified, and the manufacturing costs of the ceramic material can be reduced.

[0040] The ceramic material according to the embodiment of the present disclosure has been described above. However, the present disclosure is not limited to the above embodiment and can be modified as appropriate.

[0041] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to the following examples.

[0042] [Preparation of Composition and Raw Material Slurry] The compositions for each Example were prepared by the following method. Smoked charcoal and vermiculite were used as the design materials. Bamboo charcoal was used as the colorant, and the blending ratio was adjusted to obtain the measurement results shown in the tables below. Other components that make up the base material included ordinary Portland cement, silica sand, mica, pulp, and a water repellent. Water was then added and kneaded to obtain the raw material slurry for each Example.

[0043] [Curing] The raw material slurry prepared above was poured into a mold to form it, and if necessary, steam curing or high-temperature, high-pressure curing was carried out to obtain a hardened body according to each example.

[0044] [Surface Particle Diameter of Design Material] As shown in Tables 1 to 5 below, the particle diameters (number basis, D10, D50, D90) of the design material appearing on the surface of each example of ceramic material were measured, and the ceramic material was evaluated for design. A digital microscope VHX-6000 (manufactured by Keyence Corporation) was used to measure 60 particles of each design material. Furthermore, the difference between the particle diameters (number basis, D90) of the first design material and the second design material distributed on the surface of the ceramic material (number basis, D50) was calculated, and the ceramic material's design was evaluated for design. Furthermore, the difference between the particle diameters (number basis, D10, D90) of the design material appearing on the surface and side (cut surface) of the ceramic material was calculated, and the ceramic material's design was evaluated for design. In the tables below, A, B, and C indicate superiority in the design evaluation, in that order. The following design evaluation, "The design material is not very noticeable" means that the color of the design material is not very noticeable against the base color. "Only the design material stands out" means that the color of the design material stands out too much against the base color.

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] [Degree of Randomness of Design Materials] The degree of randomness of the design materials was calculated using the following formula to evaluate the design of the ceramic materials: {(dmax - dmin) / dav} x 100. In the formula, dmax, dmin, and dav represent the maximum center-to-center distance dmax, the minimum center-to-center distance dmin, and the average center-to-center distance dav, respectively, when three other design materials are identified from a given design material exposed on the surface, in order of smallest center-to-center distance. The center-to-center distances were measured using a VHX-6000 microscope (manufactured by Keyence Corporation). Measurements were performed at a magnification of 20x, within a 50mm x 50mm area, with N = 3. The results are shown in Tables 6 to 8. In the design evaluations below, "irregular placement of design materials" means that the placement of the design materials is nearly random, resulting in an appearance that is virtually indistinguishable from natural materials. "The arrangement of decorative materials is irregular" means that the arrangement of decorative materials is not regular, but has an appearance similar to natural materials. "The arrangement of decorative materials is regular" means that the arrangement of decorative materials is regular and unnatural.

[0051]

[0052]

[0053]

[0054] [Standard deviation of particle size of design material] As shown in Tables 9 to 12 below, the standard deviation (mm) of particle size of the design material that appeared on the surface and side (cut surface) of the ceramic material according to each example was determined, and the design of the ceramic material was evaluated. A digital microscope VHX-6000 (manufactured by Keyence Corporation) was used for the measurements. Furthermore, the difference (mm) between the standard deviation of particle size of the design material that appeared on the surface and side (cut surface) of the ceramic material was determined, and the design of the ceramic material was evaluated.

[0055]

[0056]

[0057]

[0058]

[0059] [Color Tone Difference Between Surface and Side (Cut Surface) of Ceramic Material] The color tone difference between the surface and side (cut surface) of the ceramic material according to each example was measured, and the design of the ceramic material was evaluated. The color tone was measured using a color difference meter CR-400 (manufactured by Konica Minolta, Inc., attachment diameter 10 mm, mode: L ＊ a ＊ b ＊ The results are shown in Table 13.

[0060]

[0061] [Particle size of design materials and coloring materials] As shown in Tables 14 to 16 below, the particle size (D90) and particle size difference of the design materials in the ceramic materials of each example were measured, and the design of the ceramic materials was evaluated. A digital microscope VHX-6000 (manufactured by Keyence Corporation) was used for the measurements. Furthermore, as shown in Tables 17 and 18, the difference in particle size distribution of the design materials, i.e., the difference (mm) between D90 and D50, and the difference in particle size distribution between the surface and side (cut surface) of the design materials, i.e., the difference (mm) between D90 and D50, were determined, and the design of the ceramic materials was evaluated. The results are shown in Tables 14 to 18.

[0062]

[0063]

[0064]

[0065]

[0066]

[0067] [Surface appearance frequency of design material] As shown in Tables 19 to 23 below, the surface appearance frequency of the design material in the ceramic material according to each example was calculated using a digital microscope VHX-6000 (manufactured by Keyence) by automatic area measurement through image analysis to calculate the area occupancy rate of each design material relative to the area of ​​the ceramic material, and the design of the ceramic material was evaluated. Furthermore, the surface appearance frequency and difference between the surface and side (cut surface) of the design material were calculated, and the design of the ceramic material was evaluated.

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] [Bulk specific gravity of design materials and coloring materials] The bulk specific gravity of the design materials and coloring materials was changed as shown in Tables 24 to 26 below, and the design of the ceramic materials was evaluated. In addition, the difference in bulk specific gravity between the design material and coloring material, and the difference in bulk specific gravity between two types of design materials was changed as shown in Tables 27 to 29 below, and the design of the ceramic materials was evaluated in the same manner.

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080] [Measurement of Slump Value] The contents of coloring material and design material and the slump value of the slurry were changed as shown in Table 30 below, and design evaluation was performed. The slump value of the slurry was measured in accordance with JIS A 1150. The slump value was calculated by measuring the diameter at which the slurry seemed to spread most and the diameter in the perpendicular direction after the slurry stopped moving, using a vernier caliper or convex, and averaging these values. The results are shown in Table 30.

[0081]

[0082] Preferred aspects of the present disclosure are described below.

[0083] [1] A ceramic material comprising a substrate and a decorative material, wherein at least a portion of the decorative material is exposed on the surface and has a particle size and / or a color tone different from that of the substrate.

[0084] [2] The decorative material includes a first decorative material and a second decorative material, and the difference in the frequency of appearance of the first decorative material between the surface of the ceramic material and the cut surface of the ceramic material is 0 to 26%, and the difference in the frequency of appearance of the second decorative material between the surface and the cut surface is 0 to 17%.

[0085] [3] The ceramic material according to [1] or [2], further comprising a coloring material, and comprising three or more kinds of the design material and the coloring material.

[0086] [4] The decorative material includes a first decorative material and a second decorative material, and further includes a coloring material, wherein the bulk specific gravity of the first decorative material is 0.02 to 0.40, the bulk specific gravity of the second decorative material is 0.02 to 0.40, and the bulk specific gravity of the coloring material is 0.3 to 0.8. A ceramic material according to any one of [1] to [3].

Claims

1. A ceramic material comprising a base material and a decorative material, wherein at least a part of the decorative material mixed in the base material is randomly distributed and exposed on the surface.

2. A ceramic material comprising a base material, a decorative material, and a coloring material, wherein at least a part of the decorative material mixed in the base material is randomly distributed and exposed on the surface, the bulk specific gravity of the decorative material is 0.02 to 0.4, and the bulk specific gravity of the coloring material is 0.3 to 0.

8.

3. The ceramic material according to claim 1 or 2, wherein the decorative material distributed on the surface of the ceramic material has a D90 (90% particle diameter based on the number) of 1.40 to 9.61 mm, a D50 (50% particle diameter based on the number) of 0.53 to 3.92 mm, and a D10 (10% particle diameter based on the number) of 0.24 to 1.52 mm.

4. The randomness degree indicating the random distribution degree of the decorative material distributed on the surface of the ceramic material is represented by the following formula (1): {(dmax - dmin) / dav} × 100 (1) In the formula (1), dmax, dmin, and dav respectively mean the maximum center-to-center distance dmax, the minimum center-to-center distance dmin, and the average center-to-center distance dav among the three center-to-center distances when three other decorative materials are specified in ascending order of the center-to-center distance from one decorative material exposed on the surface. The randomness degree of the decorative material is 3% or more. The ceramic material according to any one of claims 1 to 3.

5. On the surface of the ceramic material and the cut surface of the ceramic material, the difference between the D90 (90% particle diameter based on the number) of the decorative material on the surface of the ceramic material and the D90 (90% particle diameter based on the number) of the decorative material on the cut surface of the ceramic material is 4.0 mm or less, and the difference between the D10 (10% particle diameter based on the number) of the decorative material on the surface of the ceramic material and the D10 (10% particle diameter based on the number) of the decorative material on the cut surface of the ceramic material is 0.6 mm or less. The ceramic material according to any one of claims 1 to 4.

6. On the surface of the ceramic material and the cut surface of the ceramic material, the difference between the standard deviation of the particle diameter of the decorative material on the surface of the ceramic material and the standard deviation of the particle diameter of the decorative material on the cut surface of the ceramic material is 1.00 mm or less. The ceramic material according to any one of claims 1 to 5.

7. The color tone difference between the surface of the ceramic material and the cut surface of the ceramic material is L ＊ a ＊ b ＊ the difference in chromaticity (L ＊ , a ＊ , b ＊ ) between the surface of the ceramic material and the cut surface of the ceramic material in the L ＊ value difference ΔL ＊ , a ＊ value difference Δa ＊ , and b ＊ value difference Δb ＊ , and ΔL ＊ , Δa ＊ , and Δb ＊ when represented by ΔE ＊ ab calculated from, ΔL ＊ is from 0 to 8, Δa ＊ is from 0 to 1, Δb ＊ is from 0 to 5, and ΔE ＊ ab is from 0 to 15. The ceramic material according to any one of claims 1 to 6.

8. The surface appearance frequency of the decorative material on the surface of the ceramic material is 1.0 to 30.6%, and the ceramic material according to any one of claims 1 to 7.

9. In the surface of the ceramic material and the cut surface of the ceramic material, the difference between the surface appearance frequency of the decorative material on the surface of the ceramic material and the surface appearance frequency of the decorative material on the surface of the ceramic material on the cut surface of the ceramic material is 26% or less, and the ceramic material according to any one of claims 1 to 8.

10. The decorative material includes a first decorative material and a second decorative material, and the difference between D90 (90% particle diameter based on the number) of the first decorative material and D50 (50% particle diameter based on the number) of the second decorative material, which is the particle size distribution difference between the first decorative material and the second decorative material, is 0 to 9.9 mm, and the ceramic material according to any one of claims 1 to 9.

11. The decorative material includes a first decorative material and a second decorative material. In the surface of the ceramic material and the cut surface of the ceramic material, the difference between D90 (90% particle diameter based on the number) and D50 (50% particle diameter based on the number) of the first decorative material on the surface and the cut surface of the ceramic material is 0 to 8.7 mm for both, and the difference between D90 (90% particle diameter based on the number) and D50 (50% particle diameter based on the number) of the second decorative material on the surface and the cut surface of the ceramic material is 0 to 9.3 mm for both, and the ceramic material according to any one of claims 1 to 10.

12. The decorative material includes a first decorative material and a second decorative material. In the surface of the ceramic material and the cut surface of the ceramic material, the difference between the particle size deviation of the first decorative material on the surface of the ceramic material and the particle size deviation of the first decorative material on the cut surface of the ceramic material is 0.4 mm or less, and the difference between the particle size deviation of the second decorative material on the surface of the ceramic material and the particle size deviation of the second decorative material on the cut surface of the ceramic material is 0.5 mm or less, and the ceramic material according to any one of claims 1 to 11.

13. The decorative material includes a first decorative material and a second decorative material. On the surface and the cut surface of the ceramic material, the surface appearance frequency of the first decorative material on the surface of the ceramic material is 2.9 to 30.6%, and the surface appearance frequency of the first decorative material on the cut surface of the ceramic material is 2.4 to 12%. The surface appearance frequency of the second decorative material on the surface of the ceramic material is 4.0 to 26.1%, and the surface appearance frequency of the second decorative material on the cut surface of the ceramic material is 3.0 to 18%. The ceramic material according to any one of claims 1 to 12.

14. The decorative material includes a first decorative material and a second decorative material. On the surface and the cut surface of the ceramic material, the difference between the surface appearance frequency of the first decorative material on the surface of the ceramic material and the surface appearance frequency of the first decorative material on the cut surface of the ceramic material is 26% or less. The difference between the surface appearance frequency of the second decorative material on the surface of the ceramic material and the surface appearance frequency of the second decorative material on the cut surface of the ceramic material is 17% or less. The ceramic material according to any one of claims 1 to 13.

15. A method for manufacturing a ceramic material according to any one of claims 1 to 14, comprising a slurry manufacturing step of manufacturing a slurry containing components constituting the base material and the decorative material, a molding step of molding the slurry, and a curing step of curing the slurry molded by the molding step by curing. A method for manufacturing a ceramic material that does not include a step of removing at least a part of the surface layer of the cured body that has undergone the curing step.

16. A method for manufacturing a ceramic material according to any one of claims 1 to 14, comprising a slurry manufacturing step of manufacturing a slurry containing components constituting the base material and the decorative material, a molding step of molding the slurry, and a curing step of curing the slurry molded by the molding step to form a cured body having a surface appearance frequency of the decorative material of 1.0 to 30.6%. A method for manufacturing a ceramic material.

17. The method for manufacturing a ceramic material according to claim 15 or 16, wherein the slurry has a slump value measured in accordance with JIS A 1150 of 9.0 to 16.0 cm.

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