JP6637127B1 - Method for producing inorganic decorative board and inorganic decorative board - Google Patents

Abstract

The present invention provides a method for producing an inorganic decorative board having a deeply carved and sharp uneven pattern on its surface, and such an inorganic decorative board. A method of manufacturing an inorganic decorative board (50) having an uneven pattern formed on a surface thereof includes at least a surface layer formed by a wet mat formed from a slurry containing mineral fibers, an inorganic powder and a binder as main components by wet papermaking. A wet base material forming step S1 for forming a plate-like wet base material, a drying step S2 for drying the wet base material to form a dry base material, and a softener comprising water on the surface of the dry base material. The method includes a coating step S3 for coating, and after the coating step S3, a heating and compression step S4 of heating and compressing the dry base material with an embossing type to cure the binder to form an uneven pattern on the surface of the dry base material. A surfactant is added to the softener applied in the application step S3. [Selection diagram] FIG.

Description

    The present invention relates to a method for producing an inorganic decorative board used as a decorative material for interior materials, building materials, opening members, furniture and the like of buildings such as houses and an inorganic decorative board.

    Conventionally, as a base material for decorative panels such as interior materials, building materials, opening members, furniture, etc. of buildings such as houses, an uneven pattern is formed on the surface serving as a decorative surface by heating and compressing with an embossing mold. A painted inorganic decorative board is used (see Patent Document 1 below).

    In Patent Literature 1, the inorganic decorative board is manufactured by the following steps. A plate-shaped wet base material is formed with a wet mat (wet mat) formed by wet-making a slurry containing mineral fibers, an inorganic powder, and a binder, and dried under conditions where the binder is not cured. Then, a dry substrate (dry board) is formed. Then, water or a resin aqueous solution is applied to at least the surface of the dried base material to soften it, and then the dried base material is heated and compressed (embossed) with an embossing mold to cure the binder, thereby forming an uneven pattern on the surface. An inorganic decorative plate having a decorative layer formed on the surface on which an uneven pattern is formed is obtained by forming an inorganic plate and applying a coating on the surface of the inorganic plate.

JP 2005-298988 A

    However, in the conventional method of manufacturing an inorganic decorative board, even if a small uneven pattern having a small difference in elevation can be formed on the surface of the inorganic decorative board, the dry base material is embossed when trying to form a large uneven pattern having a large difference in height. The press load when heating and compressing with a mold becomes remarkably large, and even if water or an aqueous resin solution is applied before the heat and compression processing, cracks or cracks may be generated on the surface. In addition, depending on the configuration of the concave and convex pattern, the balance of the press load during the heating and compressing process is deteriorated, and there is a possibility that the edge is not clear and is formed into a blurred concave and convex pattern. For this reason, the conventional method of manufacturing an inorganic decorative board cannot produce an inorganic decorative board having a deeply carved and sharp uneven pattern on the surface.

    The present invention has been made in view of the above, and an object of the present invention is to provide a method for manufacturing an inorganic decorative board having a surface with a deeply carved and sharp uneven pattern, and to provide such an inorganic decorative board. is there.

    The inventors of the present application have conducted intensive studies and found that, in the application step, simply applying a softening agent to the surface of the dry substrate on which the concavo-convex pattern is formed in the subsequent heat compression step softens the vicinity of the surface of the dry substrate. However, it has been found that in the case of forming a deeply carved uneven pattern, a crack or a crack is generated because the embossed projection is pierced deep without being softened during the heating and compressing step.

    From this point, in the present invention, in order to achieve the above object, the softening agent is made to penetrate deep inside the dry base material before the heat compression step.

    Specifically, the first invention is directed to a plate-shaped wet base material having at least a surface layer formed by a wet mat formed by wet papermaking from a slurry containing mineral fibers, an inorganic powder, and a binder as main components. Forming a wet base material, drying the wet base material to form a dry base material, applying a softening agent composed of water to the surface of the dry base material, and after the application process Heating and compressing the dried base material in an embossing mold to cure the binder to form a concavo-convex pattern on the surface of the dried base material, and wherein the concavo-convex pattern is formed on the surface. A method for manufacturing an inorganic decorative board for manufacturing a board, wherein a surfactant is added to the softener.

    In the first invention, a surfactant is added to a softening agent composed of water applied to the surface of the dry base material before the dry base material is heated and compressed by the embossing type. By applying such a softening agent to the surface of the dry base material, the softener easily permeates the dry base material. Therefore, the softener penetrates deeper into the dry base material as compared with the case where a softener containing no surfactant is applied. This softens not only the surface of the dry substrate but also the inside of the substrate. Therefore, even in the case where a sharp engraved pattern with a deep engraving is formed on the surface of the dried base material in the subsequent heating and compressing step, the processing can be performed without generating cracks or cracks. Therefore, according to the method for manufacturing an inorganic decorative board, it is possible to manufacture an inorganic decorative board excellent in design in which a large uneven pattern having a large difference in height is formed on the surface without cracks or cracks.

    According to a second invention, in the first invention, a release agent is added to the softener.

    In the second invention, a release agent is added to the softening agent composed of water applied to the surface of the dry base material, in addition to the surfactant, before the dry base material is heated and compressed by the embossing type. As described above, since the softener penetrates deep inside the dry base material due to the addition of the surfactant, the release agent also penetrates deep inside the dry base material. The release agent that has penetrated deep into the inside of the dried base material in this way improves the releasability of the embossing die in the heat compression step. Therefore, at the time of the heating and compressing step, there is no possibility that dirt (waste of the dried base material) adheres to the side surface of the embossed convex portion, and the heating and compressing step is not performed by the embossed mold having the dirt adhered to the side surface of the convex portion. Therefore, there is no possibility that a part of the concavo-convex pattern may be chipped due to poor mold release. In addition, there is no need to apply a release agent to the embossing die, and the releasability can be easily improved. Therefore, according to the method for manufacturing an inorganic decorative plate, there is no possibility that a part of the concave and convex pattern formed on the surface of the inorganic decorative plate due to poor mold release may be chipped, and a sharp concave and convex pattern without deep engraving may be formed on the surface. The formed inorganic decorative board can be easily manufactured.

    As described above, according to the present invention, before the heating and compressing step, the softening agent is made to penetrate deep inside the dry base material, so that the surface of the inorganic decorative plate having a deeply carved and sharp uneven pattern on the surface is formed. A manufacturing method can be provided.

FIG. 1 is a perspective view showing an inorganic decorative board according to Embodiment 1 of the present invention. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a plan view showing the inorganic decorative plate according to Embodiment 1 of the present invention. FIG. 4 is a flowchart showing a method for manufacturing an inorganic decorative board according to Embodiment 1 of the present invention. FIG. 5A is a process diagram illustrating a process of manufacturing the inorganic decorative board according to Embodiment 1 of the present invention. FIG. 5B is a process diagram illustrating a process of manufacturing the inorganic decorative plate according to Embodiment 1 of the present invention. FIG. 6 is an enlarged perspective view showing a part of the inorganic decorative plate according to Embodiment 2 of the present invention. 7 (A) and 7 (B) are views showing a part of a top coating process of a method for manufacturing an inorganic decorative board according to Embodiment 3 of the present invention, and FIG. FIG. 7B shows a case where the nozzle head is moved while the nozzle head is fixed, and FIG. 7B shows a case where the substrate is moved while the nozzle head is fixed. 8 (A) and 8 (B) are views showing a part of a top coating process of a method for manufacturing an inorganic decorative board according to Embodiment 4 of the present invention, and FIG. FIG. 8B shows a case in which the nozzle head is moved while being fixed, and FIG. 8B shows a case in which the base material is moved while fixing the nozzle head.

    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are merely preferred examples in nature, and are not intended to limit the scope of the present invention, its application, or its use.

<< First Embodiment of the Invention >>
FIG. 1 and FIG. 2 show an inorganic decorative plate 50 having a coating film 30 formed on a surface 1 of a base material 10 according to the first embodiment of the present invention. In the inorganic decorative board 50, the coating film 30 corresponding to the uneven pattern is formed on the surface 1 of the base material 10 on which the uneven pattern is formed by embossing, whereby the uneven surface is formed on the decorative surface. Used as interior materials, building materials, opening members, furniture and other decorative materials for buildings.

-Composition of base material-
In the present embodiment, the base material 10 includes a surface layer (first layer) 11 located on the front side 1 (upper side in FIG. 2) and a back layer (third layer) located on the back side 2 (lower side in FIG. 2). ) 12 and a core layer (second layer) 13 located between the surface layer 11 and the back layer 12 to form a three-layer structure. The surface layer 11 and the back layer 12 are the same as each other, and are layers mainly composed of mineral fibers, inorganic powder, and a binder. On the other hand, the core layer 13 is a layer mainly composed of a lightweight aggregate, a binder and fibers. The surface layer 11, the back layer 12, and the core layer 13 are compositely integrated by curing the binder.

    The substrate 10 is heated and compressed by the embossing die 20 to form an uneven pattern on the surface 1 on the surface layer 11 side. In the present embodiment, the concavo-convex pattern is formed as a deeply carved stone-grained tile pattern. The uneven pattern may be any pattern. In the present embodiment, the uneven pattern is formed so that the thickness of the base material 10 is 6 mm at the thinnest portion and 9 mm at the thickest portion.

<Main components of surface layer and back layer>
[Mineral fiber]
Rock wool, slag wool, mineral wool, glass wool, or the like can be used as the mineral fibers of the surface layer 11 and the back layer 12. These can be used alone or in combination of two or more. Mineral fibers are added to obtain high surface properties while having tenacity and strength, and are added in an amount of 40% by weight or more and 80% by weight or less of the entire solid component. When the amount of the mineral fiber is less than 40% by weight, the entanglement of the mineral fibers is reduced and the flexural strength is reduced, and when the amount exceeds 80% by weight, the addition ratio of the inorganic powder is reduced. For this reason, the compactness of the surface is reduced, and the cosmetic property is impaired.

[Inorganic powder]
As the inorganic powder of the surface layer 11 and the back layer 12, calcium carbonate, micro silica, aluminum hydroxide, slag powder or the like can be used. These can be used alone or in combination of two or more. The inorganic powder is added to ensure fire resistance and hardness, and is added in an amount of 20% by weight or more and 60% by weight or less of the entire solid component. When the amount of the inorganic powdery substance is less than 20% by weight, the denseness of the surface of the inorganic decorative plate 50 to be formed is reduced and the cosmetic property is impaired. This is because the flexural strength is weakened because the addition ratio of the compound is small.

[Binder]
The binder of the surface layer 11 and the back layer 12 is a thermosetting resin binder, and a powdery or aqueous binder such as a phenol resin, a melamine resin, and a urea melamine resin can be used. Further, as the binder, a water-soluble or water-dispersible polymer binder such as polyvinyl alcohol, starch, polyacrylamide, SBR latex, and acrylic resin emulsion can be used in combination with the thermosetting resin. The binder is added to bind the components including the mineral fibers and the inorganic powder, and is contained in an amount of 5% to 20% by weight, preferably 7% to 15% by weight of the entire solid component. Only the following are added. When the amount of the binder is less than 5% by weight, the strength is insufficient. On the other hand, when the amount exceeds 20% by weight, the incombustibility is impaired.

<Main component of core layer>
[Lightweight aggregate]
As the lightweight aggregate of the core layer 13, pearlite, shirasu foam, silica flower, glass foam, or the like can be used. The lightweight aggregate is added to reduce the weight while securing the compressive strength, and is added in an amount of 40% by weight or more and 90% by weight or less of the entire solid component. When the amount of the lightweight aggregate is less than 40% by weight, the weight is insufficiently reduced, and it is difficult to uniformly scatter the material when spraying. On the other hand, when the amount exceeds 90% by weight, the strength is reduced. This is because the pressure at the time of compression becomes too high and the productivity decreases.

[Binder]
The binder of the core layer 13 is a thermosetting resin binder, which can be used for the surface layer 11 and the back layer 12, that is, a powdery or aqueous binder such as a phenol resin, a melamine resin, and a urea melamine resin. Can be used. Further, similarly to the binder of the surface layer 11 and the back layer 12, a water-soluble or water-dispersible polymer binder such as polyvinyl alcohol, starches, polyacrylamide, SBR latex, and acrylic resin emulsion is used as a thermosetting resin. It is also possible to use them together. The binder is added to bind the components including the lightweight aggregate, and is added in an amount of 5% by weight or more and 20% by weight or less, preferably 7% by weight or more and 15% by weight or less of the whole solid components. . When the amount of the binder is less than 5% by weight, the strength is insufficient. On the other hand, when the amount exceeds 20% by weight, the incombustibility is impaired.

[fiber]
As the fibers of the core layer 13, inorganic fibers or organic fibers can be used. Specifically, glass fibers, wollastonite, and the like can be used as the inorganic fibers. In addition, synthetic fibers such as polyester, polypropylene, and vinylon, wood fibers, and pulp can be used as the organic fibers. These can be used alone or in combination of two or more. The fibers are added to impart tenacity and strength, and are added in an amount of 1% by weight to 10% by weight of the entire solid component. When the added amount of the fiber is less than 1% by weight, the stickiness is lost and the reinforcing effect is reduced, and when the added amount is more than 10% by weight, irregularities occur during papermaking, irregularities occur during papermaking, and a good wet mat can be obtained. This is because it will not be possible.

<Uneven pattern>
An uneven pattern is formed on the surface 1 of the substrate 10. The surface 1 of the base material 10 is divided into a plurality of blocks by this uneven pattern.

[groove]
Specifically, in the first embodiment, as shown in FIGS. 1 to 3, a plurality of grooves 3 which are part of a concave and convex pattern are formed on the surface 1 of the base material 10. The plurality of grooves 3 extend vertically and horizontally on the surface 1 of the substrate 10. Specifically, the plurality of grooves 3 include a plurality of lateral grooves 3 extending in the lateral direction on the surface 1 of the base material 10 and a plurality of longitudinal grooves 3 extending between the adjacent lateral grooves 3 and extending perpendicular to the lateral grooves 3. The grooves 3 are formed so as to be joints of the tile pattern. The substrate 10 is partitioned into a plurality of blocks by the plurality of grooves 3.

    Each groove 3 is defined by two opposing side wall surfaces and a bottom surface. The width of the bottom surface of each groove 3 is 0.3 to 1.0 mm. In the present embodiment, the width of the bottom surface of each groove 3 is formed to be 0.5 mm. At least one side wall surface of each groove 3 is formed as a steep slope having an inclination angle α of 65 degrees or more and 90 degrees or less with respect to the back surface 2 of the base material 10. In the first embodiment, the two side wall surfaces of each groove 3 are both formed so that the inclination angle α is about 75 degrees and the angle between the two side wall surfaces is about 30 degrees.

    Each groove 3 is configured to have the same groove bottom depth, and is formed to have a groove bottom depth that is recessed not only to the first surface layer 11 of the base material 10 but also to the second core layer 13. Each groove 3 constitutes the deepest concave portion of the uneven pattern. That is, in the base material 10, the portion where the groove 3 is formed is the thinnest portion. In the present embodiment, the thickness (minimum thickness) of the base material 10 in the groove 3 is 6 mm. On the other hand, in the base material 10, the thickness of the base material 10 at the thickest part (the largest convex part of the uneven pattern) is 9 mm. That is, in the present embodiment, the surface level of the thickest portion of the base material 10 (the height of the front surface 1 with respect to the back surface 2 of the base material 10) and the groove bottom level (the height of the bottom surface of the groove 3 with respect to the back surface 2 of the base material 10) ) Is defined as the groove bottom depth, each groove 3 is formed such that the groove bottom depth is 3 mm. The bottom surface of the groove 3 is a portion of the front surface 1 of the base material 10 having the lowest height relative to the back surface 2.

    On the surface of the plurality of blocks surrounded by the plurality of grooves 3 on the surface 1 of the base material 10, an uneven surface pattern 4 which is a part of the uneven pattern is formed. In the first embodiment, fine wrinkles (grain) are formed on the surface of each block to give a stone-grain finish, and the fine wrinkles constitute a stone-grain surface pattern 4. The surface pattern 4 has a smaller difference in height than the groove 3 (see FIG. 2).

    In addition, in this Embodiment 1, although the surface pattern 4 is comprised by the fine wrinkle for finishing to a stone-grained tone, what kind of thing according to a surface pattern may be sufficient. The surface pattern 4 may be composed of, for example, fine irregularities in a cloth tone for finishing into a cloth pattern.

    As described above, the concavo-convex pattern formed on the surface of the base material 10 extends vertically and horizontally on the surface of the base material 10 and has a groove bottom depth of 3 mm or more and an inclination angle α of 65 degrees or more and 90 degrees or less. And a plurality of deep and sharp grooves 3 having at least one of them, and a surface pattern 4 of a plurality of blocks surrounded by the plurality of grooves 3.

    Due to such a concavo-convex pattern, the base layer 10 has a thickness of the surface layer 11 of 3 mm in the thickest portion (the largest protruding portion of the concavo-convex pattern) of the block body except for the outer edge of the block (the outer edge of the groove 3). The thickness of the core layer 13 is 3.5 mm, and the thickness of the back layer 12 is about 2.5 mm. In addition, the base material 10 is formed such that the thickness of the surface layer 11 is about 1 mm, the thickness of the core layer 13 is about 3 mm, and the thickness of the back layer 12 is about 2 mm at the bottom of the groove 3 which is the thinnest part. Have been. That is, the groove 3 forming a part of the concavo-convex pattern has a groove bottom depth greater than the maximum thickness of the surface layer 11 (the thickness of the surface layer 11 at the thickest part of the block body).

[block]
The plurality of blocks surrounded by the plurality of grooves 3 as described above are constituted by the thick blocks 61 and the thin blocks 62.

    The thick block 61 is a block including only a thick portion in which the height level of the front surface 1 with respect to the back surface 2 is higher than the reference level M, and the thin block 62 has a height level of the front surface 1 with respect to the back surface 2 which is the reference level M. It is a block with a thinner part than the lower part (see FIG. 2). In FIG. 3, the thin portion is indicated by a large number of dots. In the range shown in FIGS. 1 and 3, thirteen thick blocks 61 are formed, and nine thin blocks 62 are formed.

    In the present embodiment, as shown in FIG. 2, the intermediate level between the highest level H and the lowest level L, where the height level of the front surface 1 with respect to the back surface 2 of the base material 10 is highest, is defined as the above-described reference level. Level M.

    In addition, a part of the thin block 62 is configured as an inclined block 63 having not only the thin part but also the thick part, and the rest is configured as a thinnest block 64 including only the thin part.

    As shown in FIG. 2, the inclined block 63 is configured such that the surface of the thick portion where the height level of the surface 1 is higher than the reference level M and the surface of the thin portion where the height level is lower than the reference level M are smoothly and continuously inclined. I have. In the present embodiment, the inclined block 63 is formed such that the ratio of the thin portion to the entirety is 2/3 or less. In the range shown in FIGS. 1 and 3, seven inclined blocks 63 are formed.

    On the other hand, as described above, the thinnest block 64 is entirely formed as a thin portion in which the height level of the surface 1 is lower than the reference level M. In the present embodiment, the thinnest block 64 is formed so as to have a smaller area than the thick block 61 in a plan view shown in FIG.

    The plurality of blocks are arranged such that at least one thick block 61 is adjacent to the thin block 62. In FIG. 3, a thick block 61 shown by white is always adjacent to a thin block 62 having a thin portion indicated by a large number of dots. Also, among the thin blocks 62, a plurality of blocks are arranged in the thinnest block 62 such that two or more thick blocks 61 are adjacent to each other. In the first embodiment, the plurality of blocks are arranged so that the ratio of the thin portion to the entire base material 10 is 1/3 or less. By devising the arrangement of a plurality of types of blocks in this way, a concavo-convex pattern having thin portions scattered is formed.

    As described above, in the base material 10, the groove bottom depth is equal to or more than the maximum thickness of the surface layer 11, and the inclination angle α has at least one side wall surface of 65 degrees or more and 90 degrees or less. By the surface pattern 4 of the plurality of blocks in which the thick blocks 61 and the thin blocks 62 are mixed, the concavo-convex pattern formed on the surface 1 is deeply carved and sharply formed.

-Composition of coating film-
The coating film 30 has an undercoat layer 31 formed directly on the surface 1 of the substrate 10, and an overcoat layer 32 formed on the undercoat layer 31.

    The undercoat layer 31 is formed by applying an aqueous paint containing an aqueous resin as a binder. As the aqueous resin, for example, an acrylic emulsion can be used.

    The overcoat layer 32 is formed by jetting colored ink onto the undercoat layer 31 by an inkjet device. In the overcoat layer 32, the color (ink color) of the coating film in the concave portion is higher than the color (ink color) of the coating film in the convex portion so that the color tone is synchronized with the uneven pattern formed on the surface 1 of the base material 10. Also dark.

    Specifically, in the present embodiment, as shown in FIGS. 1 and 2, the in-groove coating film 30 a formed on the inner surface of the groove 3 is larger than the outer coating film 30 b formed on a portion other than the groove 3. It is formed so as to be dark. Here, the dark color means that the color is at least low in brightness. Although details will be described later, the in-groove coating film 30a is formed by painting so as to have a lower brightness than the outer groove coating film 30b. As a result, the inner surface of the groove 3 looks darker due to the dark-colored inner groove coating 30a, and the portion other than the groove 3 has a lighter color (at least higher brightness) outer groove coating 30b than the inner groove coating 30a. As a result, it looks brighter than the coating film 30a in the groove. In this manner, by forming the overcoat layer 32 having the color tone synchronized with the uneven pattern on the undercoat layer 31, the coating film 30 synchronized with the uneven pattern on the surface 1 of the base material 10 is formed. . In addition, the in-groove coating film 30a formed on the inner surface of the groove 3 is not only lower in brightness but also has a higher saturation than the outer coating film 30b formed in a portion other than the groove 3 by coating. It may be formed.

-Manufacturing method-
Hereinafter, a method for manufacturing the inorganic decorative board 50 according to Embodiment 1 of the present invention (a method for manufacturing the inorganic decorative board) will be described with reference to FIGS. 4, 5A, and 5B.

    The method of manufacturing the inorganic decorative board 50 includes a wet base material forming step S1, a first drying step S2, a coating step S3, a heating / compression step S4, an undercoating step S5, a second drying step S6, and a topcoating step. Step S7.

(1) Wet base material forming step First, a wet base material forming step S1 is performed. In the present embodiment, the wet base material forming step S1 includes a back layer mat forming step, a core layer mat forming step, and a surface layer mat forming step.

<Back layer mat formation process>
In the back layer mat forming step, the material for forming the back layer 12, that is, the mineral fiber, the inorganic powder and the binder are added to water and agitated, and the mineral fiber and the inorganic powder are combined. And a slurry containing the agent as a main component. Then, the resulting slurry is wet-formed by a long-mesh wet-type papermaking apparatus or a round-mesh type wet-type papermaking machine to form a back layer mat 10c (third layer mat). In the present embodiment, the back layer mat 10c is formed to have a uniform thickness of 4 mm.

<Core layer mat forming process>
In the core layer mat forming step, a material for forming the core layer 13, that is, a lightweight aggregate, a binder and fibers are mixed while spraying water to produce a core layer composition. Then, the generated core layer composition is evenly spread on the previously formed back layer mat 10c to form a core layer mat 10b (second layer mat). In the present embodiment, the core layer mat 10b is formed to have a uniform thickness of 5 mm.

<Surface mat formation process>
In the surface layer mat forming step, similarly to the back layer mat forming step, a material for forming the surface layer 11, that is, a mineral fiber, an inorganic powdery substance and a binder are added to water and stirred, and the mineral fiber is formed. And a slurry containing, as main components, an inorganic powder and a binder. The resulting slurry is wet-processed with a fourdrinier wet papermaking apparatus or a round net wet papermaking machine to form a surface mat 10a (first layer mat), and the surface mat 10a is placed on the core layer mat 10b. Laminate. In this embodiment, the surface mat 10a is formed to have a uniform thickness of 5 mm. As described above, in the present embodiment, the thickness (5 mm) of the surface layer mat 10a is formed larger than the thickness (4 mm) of the back layer mat 10c. Also, by forming the surface mat 10a thick in this way, the minimum thickness (thickness in the groove 3) of the surface layer 11 of the base material 10 on which the uneven pattern is formed on the surface 1 in the subsequent heat compression step S4 is reduced. It can be formed to 1 mm or more.

    By performing the wet base material forming step S1 as described above, the surface mat 10a and the back mat 10c made of the wet mat containing the mineral fiber, the inorganic powder, and the binder as main components can be used as a lightweight aggregate. A plate-shaped wet base material 10A having a three-layer structure sandwiching the core layer mat 10b containing a binder and fibers as main components is formed (see FIG. 5A (a)). As described above, in this embodiment, the three-layer wet base material 10A has a thickness of the surface mat 10a of 5 mm, a thickness of the core layer mat 10b of 5 mm, and a thickness of the back layer mat 10c of 4 mm. It is formed so as to have a total thickness of 14 mm.

(2) First drying step (drying step)
Next, a first drying step S2 is performed. In the first drying step S2, the wet base material 10A formed in the wet base material forming step S1 is carried into a hot-air circulation dryer and dried so that the water content is less than 10% by weight, preferably less than 4% by weight. Then, a dry substrate (dry board) 10B is formed (see FIG. 5A (b)). At this time, the wet base material 10A is dried so that the binder (thermosetting resin binder) contained in the wet base material 10A does not reach the pre-cured state, that is, under the condition that the binder is not cured. This is because when the binder reaches the pre-cured state even if the binder is not completely cured, the tissue bound by the binder in the pre-cured state is crushed in the subsequent heating and compressing step S4, so that the obtained inorganic decorative plate 50 is weakened. This is because there is a danger.

    Further, the wet base material 10A may be heated and compressed by a heating roll, a continuous press, a flat plate press or the like before drying by a hot air circulation type dryer. By performing preliminary heating and compression before drying as described above, it is possible to form the dried base material 10B having high strength. This preliminary heat compression is also performed under the condition that the binder in the wet base material 10A does not reach the pre-cured state.

    The conditions under which the binder does not reach the pre-cured state vary depending on the binder.For example, when a powdered phenol resin is used as the binder, drying with a hot-air circulating dryer is performed at a temperature of about 60 ° C. to 140 ° C. The preliminary heat compression can be performed under a temperature condition of about 80 ° C to 180 ° C.

(3) Coating Step Next, a coating step S3 is performed. In the application step S3, a softener composed of water is applied to the front surface 1B and the back surface 2B of the dry base material 10B (see FIG. 5A (c)). As a result, the front surface 1B and the back surface 2B of the dried base material 10B are softened, and cracks and cracks are less likely to occur in the front surface 1B and the back surface 2B of the dried base material 10B in the subsequent heating and compressing step S4. In the present embodiment, a softening agent of 400 g / m ² is applied to the front surface 1B of the dried base material 10B, and a softening agent of 100 g / m ² is applied to the back surface 2B of the dried base material 10B.

    In the first embodiment, a surfactant is added to the softener. By applying such a softening agent to the front surface 1B and the back surface 2B of the dry base material 10B, the softener easily penetrates into the dry base material 10B. Therefore, the softener penetrates deep inside the dry base material 10B as compared with the case where a softener containing no surfactant is applied. This softens not only the front surface 1B and the back surface 2B of the dry base material 10B but also the depth to which the softener has penetrated. Therefore, even if a deeply carved uneven pattern is formed on the surface 1B of the dry base material 10B in the subsequent heating and compressing step S4, no crack or crack is generated on the surface 1B of the dry base material 10B. Further, even if the amount of the softener applied to the back surface 2B of the dry base material 10B is smaller than the amount of the softener applied to the front surface 1B of the dry base material 10B, the softener is dried during the subsequent heat compression step S4. Since a large amount of the softening agent applied to the front surface 1B of the base material 10B becomes vapor and penetrates into the dry base material 10B, even if the amount of the softening agent applied to the back surface 2B is small, cracking of the dry base material 10B Cracking is prevented.

    As the surfactant, a nonionic surfactant such as an ester type, an ether type, and an amide type can be used. The surfactant may be any non-ionic surfactant as long as it promotes penetration of moisture into the dry base material 10B.

In the first embodiment, the addition ratio of the surfactant to the softener (water) is set to 0.5% or more and 2% or less. This is set so as to penetrate at least deeper than the groove 3 from the surface 1B of the dry base material 10B where the deeply carved uneven pattern is formed in the subsequent heat compression step S4. In the first embodiment, each groove 3 is formed so as to be recessed not only to the surface layer 11 but also to the core layer 13, and the groove bottom depth is formed to be equal to or greater than the maximum thickness of the surface layer 11. Therefore, the rate of addition of the surfactant to the softener is such that when the softener of 400 g / m ² is applied to the surface 1B of the dry base material 10B, the softener penetrates at least to the core layer mat 10b of the dry base material 10B. It is set to such an addition rate (0.5 to 2%).

When the addition ratio of the surfactant to the softening agent is lower than 0.5%, even if the softening agent of 400 g / m ² is applied to the surface 1B of the dry base material 10B, it does not penetrate to the desired depth, When a deeply carved uneven pattern is formed on the surface 1B of the dry base material 10B in the subsequent heating and compressing step S4, the dry base material 10B may not be sufficiently softened, particularly at the groove 3, and cracks and cracks may occur. is there. On the other hand, when the addition ratio of the surfactant to the softener is more than 2%, the water absorption performance of the inorganic decorative plate 50 as the final product may be unnecessarily increased. Therefore, in the first embodiment, the addition ratio of the surfactant to the softener (water) is set to 0.5% or more and 2% or less.

    In the first embodiment, a release agent is added to the softener in addition to the surfactant so that the releasability is improved in the subsequent heat compression step S4. As the release agent, a wax-based, silicon-based, or fluorine-based release agent can be used. As the release agent, any other water-soluble release agent may be used, in addition to those described above. This is because a water-soluble release agent is dissolved in water (softening agent) and penetrates with water to the inside deep from the surface 1B of the dry substrate 10B to the convex portion 21 of the embossing mold 20.

In the first embodiment, the rate of addition of the release agent to the softener (400 g / m ² ) is 1 to 5% (1.6 to 8 g / m ² in terms of the solid content of the release agent). When the rate of addition of the release agent to the softener is less than 1%, the releasability deteriorates in the subsequent heating and compressing step S4, and dirt (scrap of the dried base material 10B) is formed on the side surface of the projection 21 of the embossing die 20. When the heating and compressing step S4 is performed with the embossing die 20 having dirt adhered to the side surface of the projection 21, there is a possibility that a part of the concavo-convex pattern may be lost due to poor mold release. On the other hand, when the addition rate of the release agent is higher than 5%, the adhesion of the coating film 30 formed in the undercoating step S5 and the topcoating step S7 after the heat compression step S4 to the surface 1 of the base material 10 is adversely affected. , Peeling may occur. Therefore, in the first embodiment, the addition rate of the release agent to the softener (water) is set to 1 to 5% (1.6 to 8 g / m ² in terms of the solid content of the release agent).

In addition, the application amount of the softening agent to the front surface 1B and the back surface 2B of the dry base material 10B is not limited to the above application amount. The amount of the softener applied to the front surface 1B of the dry base material 10B is preferably 200 g / m ² or more and 600 g / m ² or less, and the amount of the softener applied to the back surface 2B is 50 g / m ² or more and 100 g / m ^2. m ² or less.

When the application amount of the softening agent to the surface 1B of the dried base material 10B is less than 200 g / m ² , the softener does not penetrate from the surface 1B side of the dried base material 10B to a desired depth (reach the core layer mat 10b). In the heating and compressing step S4, cracks and cracks may be generated on the surface 1B. On the other hand, when the amount of the softener applied to the surface 1B of the dried base material 10B exceeds 600 g / m ² , a large amount of water that has been turned into steam and permeated into the dried base material 10B in the subsequent heating and compressing step S4 is dried. There is a problem that the material 10B hardly comes off and the time required for drying becomes long.

    By the way, in the subsequent heating and compressing step S4, since the binder obtains fluidity and spreads throughout the dry base material 10B due to the softening agent that has been vaporized and penetrated into the dry base material 10B, an uneven pattern is formed on the surface 1B. It is formed sharply and the smoothness is improved on the back surface 2B.

Therefore, when the amount of the softener applied to the back surface 2B of the dried base material 10B is less than 50 g / m ² , the binder in the dried base material 10B obtains fluidity in the subsequent heat compression step S4, and the dry base material 10B Since the binder is hardened on the back surface 2B before reaching the inside, the smoothness of the back surface 2 of the completed substrate 10 may not be obtained. On the other hand, if the application amount of the softening agent to the back surface 2B of the dry base material 10B exceeds 100 g / m ² , a large amount of water that has been turned into steam and permeated into the dry base material 10B in the subsequent heating and compressing step S4 will be dried. There is a problem that the material 10B hardly comes off and the time required for drying becomes long.

For the above reasons, the amount of the softener applied to the front surface 1B of the dry base material 10B is preferably 200 g / m ² or more and 600 g / m ² or less, and the softener is applied to the back surface 2B of the dry base material 10B. The amount is preferably 50 g / m ² or more and 100 g / m ² or less.

(4) Heat Compression Step Next, a heat compression step S4 is performed. In the heating and compressing step S4, the dry base material 10B having the softening agent applied to the front surface 1B and the back surface 2B is inserted between hot plates of a heating and compression device such as a multi-stage hot press (see FIG. 5A (d)). Using an embossing mold 20 for forming a predetermined uneven pattern on 1B, heat compression is performed at a temperature equal to or higher than the curing temperature of the binder (thermosetting resin binder) (see FIG. 5B (e)). In the first embodiment, the dry base material 10B is heated and compressed at a temperature of 180 ° C. and a pressure of 2.0 N / mm ² for 6 minutes. When the dry base material 10B configured in the same manner as in the first embodiment is heated and compressed into a flat plate having a pressure of 9 mm, the dry base material 10B needs to be heated and compressed at a pressure of 1.2 N / mm ² for 6 minutes. is there. When the dry base material 10B configured in the same manner as in the first embodiment is heated and compressed into a flat plate having a pressure of 6 mm, it is necessary to heat and compress the dry base material 10B at a pressure of ^2.5 N / mm ² for 8 minutes. is there.

    When the dry base material 10B is heated and compressed, the softener applied to the front surface 1B and the back surface 2B of the dry base material 10B in the previous application step S3, and penetrated to a desired depth to be stored, becomes vapor. It penetrates into the dried substrate 10B. Here, since the binder of the surface layer mat 10a, the core layer mat 10b, and the back layer mat 10c in the dry base material 10B is not pre-cured, the fluidity is reduced by the softener that has penetrated into the dry base material 10B. Obtained and spread in the dry base material 10B together with the softener.

    Further, since the dry base material 10B is heated and compressed by using the embossing die 20, it is compressed, and at the same time, the back surface 2B is deformed smoothly and the front surface 1B is deformed into an uneven pattern shape.

    At this time, in the previous application step S3, the softening agent is applied to the front surface 1B and the back surface 2B of the dry base material 10B to soften. In the first embodiment, since the surfactant is added to the softener, the moisture penetrates deep inside the dry base material 10B. Therefore, not only the front surface 1B and the back surface 2B of the dry base material 10B, but also the softening agent is softened by the depth of penetration. Also, since a larger amount of softening agent is applied to the front surface 1B of the dried base material 10B than to the back surface 2B, the front surface 1B side of the dried base material 10B is softened deeper than the back surface 2B side. Therefore, the surface 1B of the dry base material 10B is deformed into a deeply carved uneven pattern shape without generating cracks or cracks.

    Also, in the wet base material forming step, the thickness (5 mm) of the surface layer mat 10a is formed to be equal to or more than the maximum height difference (groove bottom depth of the groove 3, 3 mm in the first embodiment) of the uneven pattern. For this reason, when the dry base material 10B is heated and compressed by the embossing die 20, the embossing die 20 sharp projection 21 for forming the groove 3 which is a sharp recess penetrates the surface mat 10a and reaches the core layer mat 10b. Without this, an uneven pattern is formed on the surface 1B.

    Also, if the softening agent is not applied at all to the back surface 2B of the dry base material 10B in the application step S3, the binder in the dry base material 10B obtains fluidity and spreads in the dry base material 10B before the back surface 2B. Since the binder hardens, the smoothness of the back surface 2B attached to the base material or the like cannot be obtained, and the inorganic decorative plate 50 may be easily peeled. In the first embodiment, however, in the application step S3, The softening agent is applied to the back surface 2B of the dry base material 10B in a small amount. Therefore, the binder in the back surface 2B does not harden before the binder in the dry base material 10B obtains fluidity and spreads in the dry base material 10B in the heat compression step S4. That is, at the time of the heating and compressing step S4, the softening agent applied and permeated to each of the front surface 1B and the back surface 2B of the dry base material 10B turns into vapor and penetrates into the dry base material 10B. To be spread throughout the dry substrate 10B. Therefore, the back surface 2B can be formed smoothly in the heating and compressing step S4.

    As described above, in a state where the dry base material 10B is deformed, the binder (thermosetting resin binder) spread throughout the dry base material 10B is hardened, so that the surface 1 is deeply carved and sharp. The substrate 10 on which the uneven pattern is formed and the back surface 2 is formed smoothly is formed (see FIG. 5B (f)).

    In the application step S3, a release agent is added to the softening agent that has been applied to the front surface 1B and the back surface 2B of the dry base material 10B and has penetrated. Therefore, in the heating and compressing step S4, it is possible to prevent dirt (waste of the base material 10) from adhering to the side surface of the convex portion 21 of the embossing die 20. Therefore, there is no possibility that a part of the concave and convex pattern of the base material 10 may be chipped due to poor mold release, and the base material 10 having a sharply concave and convex pattern with a deep cut in the surface 1 can be formed.

(5) Undercoating Step Next, an undercoating step S5 is performed. In the undercoat coating step S5, an aqueous paint containing an aqueous resin (for example, an acrylic emulsion) as a binder is applied to the surface 1B of the dry substrate 10B. Thereby, the undercoat layer 31 is formed on the surface 1B of the dried base material 10B (see FIG. 5B (g)).

(6) Second drying step After the undercoat coating step S5, a second drying step S6 is performed. In the second drying step S6, the aqueous paint containing, as a binder, the aqueous resin applied to the surface 1B of the dry base material 10B in the undercoat coating step S5 is dried. In the present embodiment, the dried substrate 10B is dried in an oven at 140 ° C. until there is no more moisture (see FIG. 5B (h)).

(7) Topcoating Step Next, a topcoating step S7 is performed. In the overcoating step S7, colored ink is ejected by an inkjet device onto the undercoat layer 31 formed on the surface 1 of the substrate 10 on which the uneven pattern is formed (see FIG. 5B (i)). Thereby, the overcoat layer 32 is formed further on the undercoat layer 31 formed on the surface 1 of the substrate 10. In the present embodiment, the ink jet apparatus contains four color inks of black, magenta, yellow, and cyan, and a mixture of these is ejected from the nozzle head 40 to the base material 10 as a colored ink. In addition, the ink jet device stores in advance coating data such that the overcoat layer 32 is formed in synchronism with the uneven pattern of the inorganic decorative plate 50. In the ink jet device, each portion has a desired color tone according to the coating data. The color of the colored ink to be ejected is adjusted by appropriately adjusting the mixing ratio of the four colors of ink for each ejection location so that the ink is colored.

    In the present embodiment, when the inner surface of the groove 3 is painted, the ink jet apparatus adjusts the mixing ratio of the four colors of ink so that the ink is colored darker than when painting the portion other than the groove 3. The color of the colored ink to be adjusted. As a result, on the inner surface of the groove 3, an inner groove coating 30a that is darker than the outer groove coating 30b formed on a portion other than the groove is formed. By such an overcoating process, an overcoat layer 32 whose color tone is tuned to an uneven pattern is formed on the undercoat layer 31 formed on the surface 1 of the substrate 10. That is, the coating film 30 in which the color tone is synchronized with the uneven pattern is formed on the surface 1 of the base material 10.

    Note that the type of ink contained in the inkjet apparatus is not limited to black, magenta, yellow, and cyan. Further, the ink contained in the inkjet apparatus is not limited to four colors, but may be three or less, or five or more.

    Through the above steps S1 to S7, an inorganic decorative board 50 on which a decorative pattern is formed on the decorative surface and painted is manufactured.

-Effects of Embodiment 1-
As described above, according to the manufacturing method of the first embodiment, before heating and compressing the dry base material 10B with the embossing die 20, the surfactant is added to the softening agent composed of water applied to the surface 1B of the dry base material 10B. Is added. By applying such a softening agent to the surface 1B of the dry base material 10B, the softener can easily penetrate into the dry base material 10B. Therefore, the softener penetrates deep inside the dry base material 10B as compared with the case where a softener containing no surfactant is applied. Thereby, it softens not only to the surface 1B of the dried base material 10B but also deep inside. Therefore, even when a sharp engraved pattern is formed on the surface 1B of the dry base material 10B in the subsequent heating and compressing step S4, the processing can be performed without causing cracks or cracks. Therefore, according to the method for manufacturing the inorganic decorative board 50 of the first embodiment, it is possible to manufacture the inorganic decorative board 50 having a great design with the surface 1 having a large uneven pattern having a large difference in height without cracking or cracking. .

    In addition, according to the manufacturing method of the first embodiment, before heating and compressing the dry base material 10B with the embossing die 20, the softening agent composed of water applied to the surface 1B of the dry base material 10B, in addition to the surfactant, A release agent has been added. As described above, since the softener penetrates deep inside the dry base material 10B due to the addition of the surfactant, the release agent also penetrates deep inside the dry base material 10B. The release agent that has penetrated deep inside the dry base material 10B in this manner improves the releasability of the embossing die 20 in the heating and compressing step S4. Therefore, at the time of the heating and compressing step S4, there is no possibility that dirt (waste of a dry base material) adheres to the side surface of the convex portion 21 of the embossing die 20. Since S4 is not performed, there is no possibility that a part of the concave and convex pattern is missing due to a mold release failure. In addition, there is no need to apply a release agent to the embossing die 20, and the release property can be easily improved. Therefore, according to the manufacturing method of the inorganic decorative board 50, there is no possibility that a part of the uneven pattern formed on the surface 1 of the inorganic decorative board 50 may be chipped due to poor mold release. The inorganic decorative board 50 formed on the surface can be manufactured.

    Further, in the inorganic decorative board 50 of the first embodiment, the uneven pattern formed on the surface 1 of the base material 10 extends vertically and horizontally on the surface 1 of the base material 10 and has a deep and steep side wall surface with a groove bottom depth. And a plurality of grooves 3 for dividing the base material 10 into a plurality of blocks. When the embossing die 20 heats and compresses the dry base material 10B, the pressing load concentrates on the protrusions 21 of the embossing die 20 that form the deep and sharp grooves 3 as described above. In the first embodiment, a plurality of grooves 3 on which the press load is concentrated as described above are arranged on the entire surface 1 of the substrate 10, and a plurality of blocks are surrounded by the plurality of grooves 3.

    By the way, when the concave portion which is deeply concave in the concave and convex pattern is arranged to be partially biased in the base material 10, the load concentrates on one portion during the heat compression processing, and the load does not work well on the other portion. There is a possibility that the contour of the concavo-convex pattern in the portion of the image becomes blurred.

    However, according to the above configuration, by forming the deep and sharp grooves 3 over the entire surface of the base material 10, a portion where the press load is concentrated on the base material 10 (dry base material 10 </ b> B) during the heat compression processing. Is not biased to a part of the substrate 10, and the portion where the press load is concentrated is dispersed over the entire substrate 10. Therefore, it is possible to form a deeply carved sharp uneven pattern over the entire surface of the base material 10 without blurring the outline of a part of the base material 10 during the heat compression processing. Therefore, according to the first embodiment, it is possible to provide the inorganic decorative plate 50 on which a deeply carved sharp uneven pattern is formed.

    By the way, the more the amount of the softening agent applied to the front surface 1B and the back surface 2B of the dried base material 10B, the more the crack prevention effect of the front surface 1B increases, and even if the engraving is deep and sharp, a crack or a crack is generated. It is possible to form without.

    However, when the amount of the softening agent applied to the front surface 1B and the back surface 2B of the dried base material 10B is increased, a large amount of water that has been turned into steam and permeated into the dried base material 10B during the heating and compressing step S4 becomes uneven. While it plays a role in preventing cracks during the formation of the film, there is a problem that it does not easily come off from the dried base material 10B and the time required for drying becomes longer. In addition, during the heating and compressing step S4, a large amount of moisture evaporates, which may cause the dry base material 10B to expand and deform.

    Therefore, according to the manufacturing method of the first embodiment, before the heating and compressing step S4 of heating and compressing the dry base material 10B with the embossing die 20, a coating in which a softener is applied to the front surface 1B and the rear surface 2B of the dry base material 10B. In step S3, the amount of the softener applied to the dry base material 10B is set to be larger on the front surface 1B where the uneven pattern is formed than on the back surface 2B. By applying a larger amount of a softening agent to the front surface 1B of the dry base material 10B than to the back surface 2B, an uneven pattern is formed by the embossing die 20 in the heating and compressing step S4. The front surface 1B of the base material 10B is softer than the back surface 2B. Therefore, even when a deep and sharp engraving pattern is formed, processing can be performed without causing cracks or cracks.

    In the manufacturing method of the first embodiment, in the application step S3, the amount of the softener applied to the back surface 2B of the dry base material 10B is smaller than the amount of the softener applied to the front surface 1B of the dry base material 10B. In the heating and compressing step, a large amount of the softening agent applied to the front surface 1B of the dry base material 10B becomes vapor and penetrates into the dry base material 10B during the heating and compressing step. However, cracks and cracks of the dried base material 10B can be prevented.

    Further, in the manufacturing method of the first embodiment, in the application step S3, a softening agent is applied to the back surface 2B of the dry base material 10B although the amount is smaller than the amount applied to the front surface 1B. Therefore, as in the case where the softening agent is not applied at all to the back surface 2B of the dry base material 10B, the binder in the dry base material 10B obtains fluidity in the subsequent heat compression step S4 and becomes The binder does not harden on the back surface 2B before going around. That is, at the time of the heating and compressing step, the softener applied to each of the front surface 1B and the back surface 2B of the dry base material 10B turns into vapor and penetrates into the dry base material 10B, whereby the binder obtains fluidity. It will spread throughout the dry substrate 10B. Therefore, at the time of the heating and compressing step, an uneven pattern can be sharply formed on the front surface 1B of the dry base material 10B, and the back surface 2B can be formed smoothly. Therefore, the smoothness of the back surface 2 attached to the base material or the like cannot be obtained, and the inorganic decorative plate 50 does not easily come off.

    Further, in the manufacturing method of the first embodiment, in the application step S3, the application amount of the softening agent applied to the front surface 1B of the dry base material 10B is made smaller than the application amount of the softener applied to the back surface 2B of the dry base material 10B. Have also many. That is, the amount of the softener applied to the back surface 2B of the dry base material 10B is smaller than the amount of the softener applied to the front surface 1B of the dry base material 10B. Therefore, the amount of moisture contained in the dried base material 10B is smaller than when the same amount of softener is applied to the front surface 1B and the back surface 2B of the dried base material. Can be shortened. Further, there is no possibility that a large amount of water applied to the dry base material 10B in the heating and compressing step S4 evaporates at a stretch to deform the dry base material 10B.

    Therefore, according to the manufacturing method of the first embodiment, it is possible to manufacture the inorganic decorative plate 50 on which the engraving is deep and sharp with a concave-convex pattern in a short time without causing cracks, cracks, or deformation.

    Further, in the manufacturing method of the first embodiment, in the application step S3, a softening agent is applied to the front surface 1B of the dry base material 10B at least twice as much as the back surface 2B. In other words, only one-half or less of the softening agent of the front surface 1B is applied to the back surface 2B of the dry base material 10B. With such a ratio, the total amount of the softener applied in the application step S3 can be significantly reduced. Therefore, the time required for drying the dried base material 10B during the heating and compressing step can be significantly reduced.

    By the way, in the application step S3, if the amount of the softener applied to the surface 1B of the dry base material 10B is too small, the softening of the surface 1B of the dry base material 10B on which the concavo-convex pattern is formed is insufficient, and the subsequent heat compression step In S4, cracks and cracks may be generated on the surface 1B. On the other hand, if the amount of the softening agent applied to the surface 1B of the dry base material 10B is too large in the application step S3, a large amount of water that becomes vapor in the subsequent heat compression step S4 and penetrates into the dry base material 10B is dried. It does not easily come off from the base material 10B, and the time required for drying becomes longer.

    In the manufacturing method of the first embodiment, in the application step S3, the amount of the softener applied to the surface 1B of the dry base material 10B is set to 200 g or more and 600 g or less per square meter. By applying such an amount of the softening agent to the surface 1B of the dry base material 10B in the application step S3, the surface of the dry base material 10B to be formed into a decorative surface by forming a concavo-convex pattern in the subsequent heat compression step S4. The generation of cracks and cracks in 1B can be reliably prevented. In addition, by minimizing the amount of moisture contained in the dried base material 10B in the application step S3, the time required for drying the dried base material 10B in the heating compression step S4 can be reduced.

    By the way, in the application step S3, if the amount of the softener applied to the back surface 2B of the dry base material 10B is too small, the binder in the dry base material 10B obtains fluidity in the subsequent heat compression step S4, and the dry base material Since the binder is cured on the back surface 2B before reaching the inside of 10B, there is a possibility that the smoothness of the back surface 2 of the completed inorganic decorative plate 50 may not be obtained. On the other hand, if the applied amount of the softening agent to the back surface 2B of the dry base material 10B is too large, a large amount of water which becomes vapor in the subsequent heating and compressing step S4 and penetrates into the dry base material 10B easily from the dry base material 10B. It does not come off and the time required for drying becomes longer.

    In the manufacturing method of the first embodiment, in the application step S3, a softening agent of 50 g or more and 100 g or less per square meter is applied to the back surface 2B of the dry base material 10B. In the application step S3, by applying such an amount of the softening agent to the back surface 2B of the dry base material 10B, the binder in the dry base material 10B obtains fluidity in the subsequent heat compression step S4, and the dry base material is obtained. Before reaching the inside of the base material 10B, the binder does not harden on the back surface 2B, and the softener becomes vapor and penetrates into the dry base material 10B, whereby the binder obtains fluidity and the dry base material is dried. It is heated and compressed by the embossing die 20 in a state where it extends over 10B. Therefore, an uneven pattern is formed sharply on the front surface 1 and the smooth inorganic decorative plate 50 can be obtained on the back surface 2. Therefore, the smoothness of the back surface 2 attached to the base material or the like cannot be obtained, and the inorganic decorative plate 50 does not easily come off. Further, by applying a small amount of the softening agent as described above to the back surface 2B of the dry base material 10B, the dryness is lower than when the same amount of the softener is applied to the front surface 1B and the back surface 2B of the dry base material 10B. Since the amount of water contained in the base material 10B is reduced, the time required for drying the dried base material 10B in the heating and compressing step S4 can be reduced. Further, it is possible to prevent a large amount of water applied to the dry base material 10B in the heating and compressing step S4 from evaporating at a stretch, thereby preventing the dry base material 10B from being deformed.

    By the way, as described above, in order to form a concavo-convex pattern having a large difference in height on the surface of the inorganic decorative board 50, there is a problem that a pressing load is significantly increased when the dry base material 10B is heated and compressed by the embossing die 20. is there.

    Therefore, in the first embodiment, the base material 10 is divided into a plurality of blocks by a plurality of grooves 3 constituting a part of the uneven pattern formed on the front surface 1 of the base material 10, and a part of the plurality of blocks 3 A thin block 62 having a thin portion whose height level is lower than a predetermined reference level M, and the rest being a thick block consisting only of a thick portion having a front surface height level higher than the reference level M with respect to the back surface. The thin block 62 and the thick block 61 are mixed. Specifically, in the thin block 62 having a thin portion where a large load needs to be applied in the heating and compressing step S4, a thickness consisting of only a thick portion that requires a smaller load to be applied during the heating and compressing process as compared with the thin portion. At least one meat block 61 is made adjacent. With such a configuration, the thin blocks 62 having thin portions that need to apply a large load at the time of heat compression processing are scattered in the base material 10. Therefore, according to the first embodiment, it is possible to provide the inorganic decorative plate 50 in which a large uneven pattern having a large difference in height is formed on the surface serving as the decorative surface without increasing the pressing load in the heating and compressing step S4.

    By the way, since the inorganic decorative board 50 is formed by heat compression, the thin portion has a smaller thickness and a higher density than the thick portion. With such a configuration, even if the thin portion is made thin, the strength is not significantly reduced as compared with the thick portion. Further, in the inorganic decorative plate 50, since the thick portion is always adjacent to the thin portion, even when an uneven pattern having a large difference in height is formed, a decrease in the strength of the entire inorganic decorative plate 50 is suppressed. can do.

    Further, according to the first embodiment, at least one of the thin blocks 62 is formed as the inclined block 63 having not only the thin portion but also the thick portion, and further, the surfaces of the thin portion and the thick portion are smoothly continuous. Configured. By using such an inclined block 63 having both a thin portion and a thick portion, it is possible to form various design irregularities on the surface 1 of the substrate 10. In addition, by forming a thin portion and a thick portion in one block, a thin portion where a large load needs to be applied at the time of heat compression processing is required to be close to a thin portion at which a load applied at the time of heat compression processing is small. A meat portion will be formed. According to such a configuration, even if a concavo-convex pattern having a large difference in height is formed on the surface serving as the decorative surface, the pressing load in the heating and compressing step S4 can be relatively suppressed.

    Further, in the first embodiment, not only the inclined block 63 having both the thin portion and the thick portion but also the thinnest block 64 composed of only the thin portion is used as one of the thin blocks. Thereby, uneven patterns of various designs can be formed on the surface of the inorganic decorative plate 50.

    In the first embodiment, the thinnest block 64 composed of only the thin portion of the thin block 62 is formed smaller than the thick block 61. As the width of the thin portion increases, the press load required during the heat compression processing increases dramatically. Thus, in the first embodiment, the thinnest block 64 requiring a relatively large press load is formed to be small. As a result, the pressing load required at the time of the heat compression processing can be suppressed to be low.

    Further, in the first embodiment, the maximum height difference (groove bottom depth of the groove 3) of the concave and convex pattern is set to be の or more (3 mm or more) of the maximum thickness of the base material 10. By forming such a deeply carved concavo-convex pattern on the surface 1 of the base material 10, the inorganic decorative plate 50 excellent in design can be formed. In addition, the inorganic decorative board 50 having such excellent design can be provided without increasing the pressing load in the heating and compressing step S4 by appropriately arranging the thin blocks 62 and the thick blocks 61.

    Further, in the first embodiment, an overcoat is applied by an inkjet coating on the undercoat layer 31 formed on the surface 1 of the substrate 10 on which the uneven pattern is formed. In ink-jet coating, the position can be adjusted in units of several mm, and the amount of paint sprayed can be controlled with high precision, so that the paint can be applied without filling the recesses of the uneven pattern on the surface 1 of the base material 10 with paint. It can be carried out. Therefore, according to the method for manufacturing an inorganic decorative board of the first embodiment, the inorganic decorative board 50 having excellent design can be manufactured by painting the surface 1 without impairing the design of the sharp uneven pattern applied to the surface 1. can do.

    By the way, in a conventional inorganic decorative board, a sharp uneven pattern can be formed by embossing by including a mineral fiber as a main component.However, how to paint on such a sharp uneven pattern is considered at all. However, the same coating was applied to the concave portions and the convex portions. Therefore, even if a sharp uneven pattern can be formed by embossing, the coloring of the side wall surface of the groove 3 having a large inclination angle α becomes insufficient, or the same coating is applied to the concave portion and the convex portion. In addition, the unevenness of the uneven pattern may be reduced, and the design may be impaired by painting.

    Therefore, in the first embodiment, the undercoat layer 31 formed on the surface 1 of the base material 10 on which the sharp uneven pattern is formed by the embossing process of heating and compressing with the embossing die 20 is applied to the inside of the groove 3 by inkjet coating. The coating film 30 is formed such that the portion is darker than the portion other than the groove 3. In other words, the coating film 30 formed on the surface 1 of the base material 10 on which the uneven pattern is formed is the coating film 30a of the dark color formed in the groove 3 and the coating film 30a formed in the portion other than the groove 3. It is composed of the coating film 30b outside the groove which is lighter in color than the coating film 30a, and the color tone is synchronized with the uneven pattern. By forming the coating film 30 having such a color tone synchronized with the uneven pattern on the surface 1, the sharp unevenness of the sharp uneven pattern formed on the surface 1 by embossing is emphasized by the coating film 30. . Accordingly, it is possible to provide the inorganic decorative plate 50 having the excellent design, in which the surface 1 is coated, without impairing the design of the sharp uneven pattern applied to the surface 1.

    Further, according to the manufacturing method of the first embodiment, the dry base material 10B in which at least the surface layer 11 is formed of the inorganic layer containing the mineral fiber as a main component is heated and compressed by the embossing die 20 to form the uneven pattern on the surface 1. Is to be formed. By such a manufacturing method, it is possible to manufacture the inorganic decorative plate 50 in which the sharp uneven pattern is formed on the surface 1. In addition, on the surface 1 of the substrate 10 on which the sharp uneven pattern including the plurality of grooves 3 is formed by inkjet coating, the inner surfaces of the plurality of grooves 3 are colored darker than portions other than the grooves 3. To be painted. According to such a manufacturing method, the in-groove coating 30a formed in the groove 3 becomes darker than the outer coating 30b formed in a portion other than the groove 3. That is, the color tone of the coating film 30 is synchronized with the uneven pattern, and the unevenness of the sharp uneven pattern formed on the surface 1 by embossing is emphasized by the coating film 30. Therefore, according to the above-mentioned manufacturing method, it is possible to manufacture the inorganic decorative plate 50 having excellent design properties, in which the surface 1 is painted, without impairing the design properties of the sharp uneven pattern applied to the surface 1.

    By the way, when the core layer 13 overlapping the surface layer 11 on which the concavo-convex pattern is formed by embossing is made of a material mainly containing an inorganic foaming agent and a binder as in the first embodiment, a groove is formed in the concavo-convex pattern. In the case where there is a sharp concave portion formed by a steep slope such as 3, when the embossing die 20 is heated and compressed, the sharp convex portion 21 of the embossing die 20 for forming a sharp concave portion breaks through the surface layer 11 and the concave portion. May reach the core layer 13. Since the core layer 13 has low strength due to the low density, the inorganic decorative board 50 including the base material 10 in which the concave portion reaching the core layer 13 is formed has a significantly reduced bending strength at the concave portion. There was a problem.

    Therefore, in the inorganic decorative board 50 of the first embodiment, the surface layer 11 on which the uneven pattern is formed by heating and compression is formed of a material mainly composed of the mineral fiber, the inorganic powder, and the binder. Is formed of a material mainly composed of a lightweight aggregate and a binder. That is, the core layer 13 on the back side of the surface layer 11 having the uneven pattern formed on the surface is formed of a material having a relatively low density. Further, in the inorganic decorative board 50 of the first embodiment, the surface layer 11 on which the uneven pattern is formed by heating and compression is formed so that the minimum thickness (the thickness in the groove 3) is 1 mm or more. . With such a configuration, the surface layer 11 is ensured to have a thickness of 1 mm or more even in a portion where the thinnest sharp concave portion is formed. By forming the surface layer 11 thicker in this way, even if there are sharp concave portions (grooves 3) in the uneven pattern, the concave portions (grooves 3) are made of a material having a relatively low density. It does not reach the layer 13. Therefore, even in the case where a sharp concave portion (groove 3) is formed in the inorganic decorative plate 50 having a concave-convex pattern formed on the surface serving as a decorative surface, a decrease in strength at the sharp concave portion (groove 3) is prevented. Can be suppressed. In other words, it is possible to increase the bending strength of the inorganic decorative board 50 in which an uneven pattern is formed on the surface serving as the decorative surface.

    Further, in the inorganic decorative board 50 of the first embodiment, the surface layer 11 on which the uneven pattern is formed by the heat compression and the back layer 12 on the back side are made of a material mainly composed of mineral fibers, inorganic powder, and a binder. The core layer 13 between the surface layer 11 and the back layer 12 has a three-layer structure made of a material mainly composed of a lightweight aggregate and a binder. Further, the surface layer 11 on which the uneven pattern is formed by heating and compression is formed so that the maximum thickness is larger than the back layer 12 (maximum thickness of the surface layer 3> 3 mm> maximum thickness of the back layer 12). 2.5 mm). Thus, even when the total thickness of the front and back layers is made constant, even if there is a sharp concave portion (groove 3) in the uneven pattern due to the formation of the surface layer 11 thick, the concave portion (groove 3) is formed. ) Does not reach the core layer 13 formed of a material having a relatively low density. Accordingly, it is possible to increase the bending strength of the inorganic decorative plate 50 having the uneven surface formed on the surface serving as the decorative surface.

    According to the method for manufacturing the inorganic decorative board 50 of the first embodiment, at least the surface mat 10a is formed in the wet base material forming step S1 in which the surface mat 10a and the core mat 10b are laminated to form the wet base material 10A. The wet base material 10A is formed so that the thickness (5 mm) is equal to or more than the maximum height difference (3 mm) of the concavo-convex pattern formed by the embossing die 20 in the subsequent heating and compressing step S4. By forming the wet base material 10A so that the thickness of the surface mat 10a is equal to or greater than the maximum height difference of the uneven pattern, the wet base material 10A is dried into a dry base material 10B, and then the embossing die 20 is formed. When the heating and compression are performed, the sharp projections of the embossing mold 20 for forming the sharp recesses (grooves 3) are prevented from breaking through the surface mat 10a and reaching the core layer mat 10b. In other words, when manufacturing the inorganic decorative plate 50 having the uneven surface formed on the surface serving as the decorative surface, even when the sharp concave portion (groove 3) is formed in the base material 10, the sharp concave portion (groove 3) is formed. It is possible to manufacture the inorganic decorative board 50 in which a decrease in strength at a portion is suppressed. In other words, it is possible to manufacture the inorganic decorative board 50 having a high bending strength, which is an inorganic decorative board 50 in which an uneven pattern is formed on a surface serving as a decorative surface.

    Further, according to the method of manufacturing the inorganic decorative board 50 of the first embodiment, the surface mat 10a, the core layer mat 10b, and the back layer mat 10c formed in the same manner as the surface layer mat 10a are sequentially laminated to obtain wetness. The base material 10A is to be formed. The thickness (5 mm) of the surface mat 10a is larger than the thickness (4 mm) of the back layer mat 10c. By increasing the thickness of the surface mat 10a as described above, the wet base material 10A is dried into the dry base material 10B, and then, when heated and compressed by the embossing die 20, a sharp concave portion (groove 3) is formed. The sharp projections of the embossing die 20 for piercing are prevented from breaking through the surface mat 10a and reaching the core layer mat 10b. Accordingly, it is possible to manufacture the inorganic decorative board 50 having the unevenness pattern formed on the surface 1 serving as the decorative surface and having high bending strength.

    Further, according to the method for manufacturing the inorganic decorative board 50 of the first embodiment, the thickness (5 mm) of the surface layer mat 10a is formed to be thicker than the conventional one, while the thickness (5 mm) of the core layer mat 10b is made larger than the conventional one. The wet base material 10A which is formed thinly and laminated on them is formed. As described above, by increasing the mass of the surface layer mat 10a as compared with the conventional case, and reducing the mass of the core layer mat 10b as compared with the conventional case, it is possible to suppress an increase in the compression pressure in the heating and compressing step.

<< Embodiment 2 of the invention >>
In the second embodiment, the configuration of the coating film 30 of the inorganic decorative plate 50 of the first embodiment is partially changed.

    As shown in FIG. 6, among the coating films 30, the coating film 30a in the groove formed in the groove 3 is not monochromatic, but is configured so that the shading changes gradually (gradation). Specifically, among the in-groove coating films 30a, the coating film formed on the bottom surface of the groove 3 is the darkest, and the coating film formed on the side surface of the groove 3 is the groove 3 from the bottom to the top of the groove 3. It is configured such that the color becomes darker stepwise from the dark color equivalent to the coating film on the bottom surface and becomes lighter color equivalent to the outer coating film 30b on the upper portion.

    In the second embodiment, in order to form the coating film 30 as described above, at the time of the top coating process S7 (at the time of ink-jet coating), when the inner surface of the groove 3 is coated, the groove 3 is gradually increased from the top to the bottom. It is painted so that it is colored dark. In other words, the ink jet device uses four colors of ink such that the color (coating color) applied in the order other than the groove 3 on the surface 1 of the substrate 10, the side surface of the groove 3, and the bottom surface of the groove 3 becomes darker. The color of the color ink to be ejected is adjusted by adjusting the mixing ratio. In addition, when the ink jet device paints the side surface of the groove 3, the inks of the four colors are mixed so that the color to be painted (the color of the coating film) gradually becomes darker from the top to the bottom of the groove 3. The color of the colored ink to be ejected is adjusted by adjusting the ratio. The above-described coating film 30 in which the shading changes stepwise in the groove 3 is formed by the overcoating step S7.

    According to the second embodiment, at the time of the top coating process S7 (at the time of ink-jet coating), when the inner surface of the groove 3 is coated, the groove 3 is coated so as to be gradually colored darker from the top to the bottom. Thus, a coating film 30a in the groove 3 is formed on the inner surface of the groove 3 where the color gradually increases in color from the top to the bottom of the groove 3. According to such a configuration and a manufacturing method, the color depth of the in-groove coating film 30a is increased as compared with a case where such a change in shading is not applied to the in-groove coating film 30a formed in the groove 3, and the inorganic material The unevenness of the sharp uneven pattern formed on the surface 1 by embossing in the decorative board 50 is further emphasized. Therefore, it is possible to provide the inorganic decorative plate 50 having more excellent design.

<< Embodiment 3 of the invention >>
In the third embodiment, in the method of manufacturing the inorganic decorative plate 50 of the first embodiment, a device is added to the inkjet coating in the overcoating step S7. Specifically, in the overcoating step S7, the relative movement direction is specified when the base material 10 and the nozzle head 40 of the inkjet device are relatively moved to coat the entire surface 1.

    As shown in FIGS. 7A and 7B, in the third embodiment, in the heating and compressing step S <b> 4, the plurality of grooves 3 extend in parallel, and in each groove 3, one first side surface 3 a is connected to the other side. Is embossed so that the inclination angle with respect to the back surface 2 which is flatter than the second side surface 3b becomes larger. In such a case, the base material 10 and the nozzle head 40 are coated so that the second side surface 3b, the bottom surface 3c, and the first side surface 3a are coated in each groove 3 in the top coating process S7 (at the time of inkjet coating). Are relatively moved in a direction orthogonal to the extending direction of each groove 3.

    Specifically, as shown in FIG. 7A, when the nozzle head 40 is moved while fixing the base material 10, the nozzle head 40 is placed above the base material 10 on the second side surface 3b side (see FIG. It is moved from the left side in FIG. 7A to the first side surface 3a side (the right side in FIG. 7A).

    On the other hand, as shown in FIG. 7B, when moving the substrate 10 while fixing the nozzle head 40, the substrate 10 is moved below the nozzle head 40 on the first side surface 3a side (FIG. 7B). From the right side in FIG. 7) to the second side 3b side (the left side in FIG. 7B).

    By the way, when the inclination angle of the side surface of the groove 3 is large (the first side surface 3a in FIGS. 7A and 7B), the nozzle head 40 above the substrate 10 is more inclined than when the inclination angle is gentle. The attached amount of the ejected coloring ink is reduced, and coloring is difficult.

    On the other hand, on the side surface of the groove 3, the relative movement of the base material 10 and the nozzle head 40 is reversed in such a manner that the colored ink ejected from the nozzle head 40 hits from the bottom side to the upper side of the groove 3 in order. The side surface of the groove 3 is more likely to be colored than to be moved.

    Therefore, in the third embodiment, when the base material 10 and the nozzle head 40 are relatively moved as described above and the entire surface 1 of the base material 10 is coated, the two side surfaces of the groove 3 (the first side surface 3a and the first side surface 3a). The base material 10 is formed such that the first side surface 3a is coated in order from the bottom side of the groove 3 to the upper side during the inkjet coating so that the first side surface 3a that is difficult to be colored out of the second side surface 3b) is easily colored. And the nozzle head 40 are relatively moved in a direction orthogonal to the extending direction of each groove 3. According to such a manufacturing method, the finish of the coating of the first side surface 3a that is difficult to be colored is improved, so that it is possible to provide the inorganic decorative plate 50 having more excellent design.

<< Embodiment 4 of the invention >>
In the fourth embodiment, in the method of manufacturing the inorganic decorative board 50 of the first embodiment, the ink jet coating in the top coat coating step S7 is modified. Specifically, in the overcoating step S7, the relative movement direction is specified when the base material 10 and the nozzle head 40 of the inkjet device are relatively moved to coat the entire surface 1.

    As shown in FIGS. 8A and 8B, in the fourth embodiment, in the heating and compressing step S <b> 4, the plurality of grooves 3 extend in parallel, and the first side surface 3 a on one side of each groove 3 is on the other side. Is embossed so as to have an area larger than that of the second side surface 3b. In such a case, the base material 10 and the nozzle head 40 are coated so that the second side surface 3b, the bottom surface 3c, and the first side surface 3a are coated in each groove 3 in the top coating process S7 (at the time of inkjet coating). Are relatively moved in a direction orthogonal to the extending direction of each groove 3.

    Specifically, as shown in FIG. 8A, when the nozzle head 40 is moved while the base material 10 is fixed, the nozzle head 40 is placed above the base material 10 on the second side surface 3b side (see FIG. (A) to the first side surface 3a side (the right side in FIG. 8A).

    On the other hand, as shown in FIG. 8B, when moving the substrate 10 while fixing the nozzle head 40, the substrate 10 is moved below the nozzle head 40 toward the first side surface 3a (see FIG. 8B). From the right side in FIG. 8B to the second side 3b side (the left side in FIG. 8B).

    When the first side surface 3a on one side has a larger area than the second side surface 3b on the other side of the two side surfaces 3a and 3b of the groove 3, the height of the second side surface 3b is equal to the height of the first side surface 3a. In this case, the first side surface 3a is conspicuous. Therefore, in order to improve the design of the inorganic decorative plate 50, it is necessary to improve the finish of the coating of the first side surface 3a that is conspicuous.

    On the other hand, on the side surface of the groove 3, the relative movement of the base material 10 and the nozzle head 40 is reversed in such a manner that the colored ink ejected from the nozzle head 40 hits from the bottom side to the upper side of the groove 3 in order. The side surface of the groove 3 is more likely to be colored than to be moved.

    Therefore, in the fourth embodiment, when the base material 10 and the nozzle head 40 are relatively moved as described above and the entire surface 1 of the base material 10 is coated, the two side surfaces of the groove 3 (the first side surface 3a and the first side surface 3a) are used. The base material 10 and the second side surface 3b) are so formed that the first side surface 3a is sequentially applied from the bottom side to the top side of the groove 3 at the time of ink jet coating so that the first side surface 3a that is conspicuous is easily colored. The nozzle head 40 and the nozzle head 40 are relatively moved in a direction orthogonal to the extending direction of each groove 3. According to such a manufacturing method, the finish of the coating of the first side surface 3a which is conspicuous in the groove 3 is improved, so that it is possible to provide the inorganic decorative plate 50 having more excellent design.

<< Other embodiments >>
In the first embodiment, the wet base material 10A has a three-layer structure, but the wet base material 10A is not limited to this. It may have a two-layer structure including the surface layer 11 and the core layer 13, or may have a structure having four or more layers by providing an intermediate layer in addition to the core layer 13.

    Further, in the first embodiment, the inorganic decorative board according to the present invention is constituted by the inorganic decorative board 50 in which the coating film 30 is formed on the surface 1 of the base material 10. The inorganic decorative board targeted for the manufacturing method and the inorganic decorative board may be composed of only the base material 10.

    In each embodiment, the overcoating step S7 is performed by inkjet coating. However, the topcoating step S7 is not limited to the above. The overcoating step S7 may be a step of forming the single-color or multicolor overcoat layer 32 by spray coating or roll coater coating.

    In the first embodiment, the softening agent is applied to the front surface 1B and the back surface 2B of the dry base material 10B (coating step S3) before the dry base material 10B is heated and compressed by the embossing type in the heat compression step S4. The surface layers of the front surface 1B and the back surface 2B of the base material 10B were softened. This prevents cracks and cracks from occurring when the dry base material 10B is heated and compressed in the heating and compressing step S4.

    However, as described above, the second drying step S6 may be omitted, and in that case, in the application step S3, a softening agent may be applied only to the back surface 2B of the dry base material 10B. When the second drying step S6 is omitted, the water-based paint is applied to the surface 1B of the dry base material 10B in the undercoating step S5. Therefore, a softener is applied to the surface 1B of the dry base material 10B in the application step S3. Even without this, the surface layer portion of the surface 1B of the dried base material 10B can be softened.

    In the first embodiment, the second drying step S6 of drying the dry base 10B is performed after the undercoating step S5 of coating the surface 1B of the dry base 10B with the aqueous paint. However, the second drying step S6 may be omitted. Even without performing the second drying step S6 of drying the dried base material 10B to which the water-based paint is applied, both the curing of the binder and the drying of the water-based paint are simultaneously performed in the heating compression step S4 of heating and compressing the dried base material 10B It can be carried out. Therefore, in the first embodiment, the method of manufacturing the inorganic decorative board 50 may be simplified by omitting the second drying step S6 after the undercoating.

    Next, a specific example will be described.

(Example 1)
50% by weight of slag wool as mineral fiber, 39% by weight of aluminum hydroxide as inorganic powder, 6% by weight of powdered phenol resin as binder of thermosetting resin, and Starch 4 as binder of water-soluble or water-dispersible. A raw material consisting of 1% by weight, 1% by weight of polyester fiber as a heat fusion fiber, and a coagulant was added to a large amount of water and stirred to obtain a slurry having a solid concentration of 3% by weight. Then, this slurry was wet-formed by a round net wet-making apparatus, and the thickness was adjusted by a wet press to obtain a wet mat (surface layer mat, back layer mat) for the front and back layers having a water content of 80%.

    On the other hand, 55% by weight of pearlite as a lightweight aggregate, 34% by weight of aluminum hydroxide as an inorganic powder, 5% by weight of a powdered phenol resin as a thermosetting resin binder, and starch as a water-soluble or water-dispersible binder. Raw materials consisting of 4% by weight and 1% by weight of polyester fibers as heat-fusible fibers were uniformly mixed in a mixer while spraying water to obtain a core layer composition having a water content of 20%. Then, the composition for a core layer is uniformly dispersed and deposited on a back layer mat (wet mat), and a surface layer mat (wet mat) is laminated on the dispersion surface to form a three-layer wet base material (wet mat). (Laminate) was formed.

    Next, the wet base material having the three-layer structure was temporarily pressed at 130 ° C. for 90 seconds through a distance bar having a thickness of 8 mm, and then was carried into a hot-air circulation dryer to have a surface temperature of 140 ° C. (Primary drying). Thus, a dry substrate (dry board) having a moisture content of 3% was obtained. The dried base material had been dried to the above-mentioned water content in a state where the powder phenol resin of the surface layer had not reached the pre-cured state.

Then, it carries the resultant dried base material in a hot press apparatus, 400 g / ^{m 2} on its surface was coated with water 100 g / ^{m 2} on the rear surface. Thereafter, the dried base material was inserted between hot plates of a hot press device, and was heated and compressed at a temperature of 200 ° C. through an embossing mold to sufficiently cure the phenol resin powder. By performing this heat compression for 3.5 minutes, a large amount of water permeated into the dried base material was removed, and the dried base material was dried (secondary drying). Then, an inorganic decorative plate having an average thickness of 3.2 mm (2.3 to 5.5 mm), a specific gravity of about 1.5 and a sharply embossed pattern with a deeply carved surface was obtained. The dried base material before the heat compression had an average thickness of 8 mm and a specific gravity of about 0.6 to 0.7 (true specific gravity of 2.4). No cracks, cracks, deformation, etc. were observed on the surface of the obtained inorganic decorative plate.

(Comparative Example 1)
A dry substrate (dry board) having the same water content of 3% as that obtained in the above example was carried into a hot press device, and 400 g / m ² of water was applied to the front and back surfaces thereof. Thereafter, the dried base material was inserted between hot plates of a hot press device, and was heated and compressed at a temperature of 200 ° C. through an embossing mold to sufficiently cure the phenol resin powder. In addition, it took about 7 minutes until a large amount of water permeated into the dried base material was removed and the dried base material was dried (secondary drying). Then, an inorganic decorative plate having an average thickness of 3.2 mm (2.3 to 5.5 mm) and a surface with an uneven pattern having a specific gravity of about 1.5 was obtained. No cracks, cracks, deformation, etc. were observed on the surface of the obtained inorganic decorative plate.

(Comparative Example 2)
A dry substrate (dry board) having the same water content of 3% as that obtained in the above example was carried into a hot press apparatus, and 100 g / m ² of water was applied to the front and back surfaces thereof. Thereafter, the dried base material was inserted between hot plates of a hot press device, and was heated and compressed at a temperature of 200 ° C. through an embossing mold to sufficiently cure the phenol resin powder. By performing this heat compression for 3.5 minutes, a large amount of water permeated into the dried base material was removed, and the dried base material was dried (secondary drying). Then, an inorganic decorative plate having an average thickness of 3.2 mm (2.3 to 5.5 mm) and a surface with an uneven pattern having a specific gravity of about 1.5 was obtained. Cracks, cracks, deformation and the like were observed on the surface of the obtained inorganic decorative plate.

(Comparative Example 3)
A dry base material (dry board) having the same water content of 3% as that obtained in the above example was carried into a hot press device, and 400 g / m ² of water was applied only to the front surface, and water was applied to the back surface. Not applied. Thereafter, the dried base material was inserted between hot plates of a hot press device, and was heated and compressed at a temperature of 200 ° C. through an embossing mold to sufficiently cure the phenol resin powder. By performing this heat compression for 3.5 minutes, a large amount of water permeated into the dried base material was removed, and the dried base material was dried (secondary drying). Then, an inorganic decorative plate having an average thickness of 3.2 mm (2.3 to 5.5 mm) and a surface with an uneven pattern having a specific gravity of about 1.5 was obtained. No cracks, cracks or deformations were observed on the surface of the obtained inorganic decorative plate, but the binder was unevenly cured on the back surface, and the back surface was low in smoothness.

    INDUSTRIAL APPLICABILITY As described above, the present invention is useful for an inorganic decorative plate used as a decorative material for an interior material, a building material, an opening member, furniture and the like of a building such as a house, and a method for manufacturing and applying the same.

1 surface
2 Back
3 grooves
4 Surface pattern
10 Substrate
10A wet base
10B Dry substrate
11 Surface
13 core layer
20 Emboss type
21 convex
30 Coating
50 Inorganic decorative board

Claims (2)

A wet base material forming step of forming a plate-like wet base material having at least a surface layer formed by a wet mat formed by wet papermaking from a slurry containing mineral fibers, an inorganic powder and a binder as main components,
A drying step of drying the wet base material to make a dry base material,
An application step of applying a softener composed of water to the surface of the dried substrate,
After the coating step, comprising a heating and compressing step of heating and compressing the dry base material in an embossing mold to cure the binder to form an uneven pattern on the surface of the dry base material,
A method of manufacturing an inorganic decorative board for manufacturing an inorganic decorative board having the uneven pattern formed on a surface thereof,
A method for producing an inorganic decorative board, wherein a surfactant is added to the softener. In claim 1,
A method for producing an inorganic decorative board, wherein a release agent is added to the softener .