JP2005088463A - Colored inorganic decorative plate and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent stain-like unevenness of color from arising on a colored surface portion in a colored inorganic decorative plate while keeping effects such as light weight, reinforcement and good fabrication of an inorganic mat. <P>SOLUTION: Coloring pigment and bleached pulp as a wooden material are mixed in a half-dry composition constituting at least the surface portion. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a colored inorganic decorative board in which at least a surface layer of a substrate is formed on a colored surface layer and a method for producing the same, and more particularly to a technique for preventing stain-like coloring unevenness from occurring in a colored surface layer during production.

  Conventionally, a semi-dry composition mainly composed of cement and wood material is semi-dry molded to form an uncured inorganic mat, and the uncured inorganic mat is press-molded with a flat plate or an uneven embossed mold. It is well known how to produce an inorganic decorative board by curing the cured uncured inorganic board by autoclaving, and applying the base coating, coloring coating, pattern printing, transparent top coating, etc. to the surface of this inorganic board. Such inorganic decorative boards are used as exterior materials for houses.

  However, since such an inorganic decorative board gives a desired color to the surface by coloring painting or pattern printing, for example, when making a stone pattern, ceramic tile pattern, brick pattern, etc. appear on the surface, It has been difficult to sufficiently express the natural feeling and texture by the above-mentioned painting and printing. In addition, if exposed to wind and rain or sunlight for a long time, it has sufficient durability, such as poor adhesion between the colored coating film and the base material, peeling of the coating film, or fading color, and reducing the surface appearance. I couldn't say that. Furthermore, in order to perform color painting and pattern printing, a series of painting facilities and printing facilities are required, and it takes time and effort to change colors and patterns, resulting in poor productivity.

In order to solve such a problem of colored coating, Patent Document 1 and Patent Document 2 describe that a desired color surface layer is formed by mixing a color pigment into a composition for forming a surface layer of an inorganic plate to mix the surface of the inorganic plate with a desired color surface layer. And the manufacturing method of the inorganic decorative board which omits a coloring painting process is described.
JP 56-162606 A JP 2001-207584 A

  However, the present inventors obtained an inorganic board by semi-dry molding a composition mixed with cement, a woody material and a coloring pigment, and when this inorganic board was cured and cured in an autoclave, coloring was performed after the autoclave treatment. It has been found that uneven coloring such as a stain may partially occur in the surface layer, and when the conventional colored coating process is omitted, the uneven coloring remains on the surface and significantly reduces the surface appearance.

  The present invention has been made in view of such knowledge, and while maintaining the effects of weight reduction, reinforcement, and good formability of the inorganic mat, which are the merits of mixing a wood material into cement, the above-mentioned stain-like pattern is formed on the colored surface layer. An object of the present invention is to provide a colored inorganic decorative board capable of preventing the occurrence of uneven coloring and a method for producing the same.

  In order to achieve the above object, a colored inorganic decorative board according to the invention of claim 1 is formed by semi-dry molding a semi-dry composition mainly composed of cement and wood material, and then curing by autoclave. A coloring pigment and bleached pulp as a woody material are mixed in a semi-dry composition which is intended for a board and constitutes at least a surface portion.

In the colored inorganic decorative board according to the invention of claim 2, the length of the bleached pulp is 0.1 mm to 2 mm, and the bleached pulp is mixed in 5 to 25 parts by weight with respect to 50 parts by weight of cement. The method for producing a colored inorganic decorative board according to the invention of claim 3 includes a first step of mixing a semi-dry composition mainly composed of cement and wood material, and semi-dry molding of the semi-dry composition. Including a second step and a third step of autoclaving the semi-dry molded uncured inorganic board to create a colored inorganic decorative board, wherein the first process comprises at least a surface portion of the colored inorganic decorative board In the semi-dry composition, the coloring pigment and the bleached pulp as the wood material are mixed and mixed.

  According to the first aspect of the present invention, since bleached pulp is used as the woody material, no stain-like uneven coloring occurs on the colored surface portion (colored surface layer) even under high temperature and high pressure during autoclave curing. In addition, the colored inorganic decorative board obtained has good weather resistance and warm water resistance, the color tone of the colored surface layer is stable even when exposed to light and wind and rain for a long time, and the conventional unbleached woody material In this way, it is possible to prevent color unevenness due to decolorization of the wood material of the colored surface portion.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1 above, the weight saving property, the reinforcing property, and the mixability of the semi-dry composition and the molding of the inorganic mat, which are the merits of mixing the wood material into the cement The property can be further improved.

  According to the invention of claim 3, the same effect as that of the invention of claim 1 can be obtained.

  The colored inorganic decorative board according to this embodiment has a multilayer structure in which a surface layer, a core layer and a back layer are laminated, and the semi-dry composition constituting each layer is a surface layer, a core layer, and a back surface. It consists of each composition for layers.

  The composition for the surface layer contains cement, siliceous material, bleached pulp as a wood material, inorganic foam, color pigment and water, and if necessary, hardening accelerator, efflorescence inhibitor, water resistance imparting What added chemicals, such as an agent, can be used.

  The composition for the back surface layer may be the same as the composition for the surface layer, and the composition for the surface layer, such as one in which the color pigment is not mixed or one using a woody material other than bleached pulp It may be different from the object.

  The core layer composition does not need to be added in particular with a color pigment, and includes a cement, a siliceous material, a woody material, an inorganic foam and water, and if necessary, a curing accelerator, an efflorescence inhibitor, What added chemicals, such as a water-resistance imparting agent, can be used.

  Examples of cement include Portland cement, slag cement, alumina cement, silica cement, fly ash cement, etc., and these cements mixed with siliceous materials such as quartz sand, shirasu, and quartzite powder, and gypsum can be used. it can. Further, a pulverized product of cement-based building material waste such as wood cement board waste can be added as a filling substance.

  As described above, bleached pulp is mainly used for the surface layer as described above, and for the core layer or the back layer, wood pieces such as wood flakes, wood fiber bundles, waste paper fibers, pulp, bleached pulp, Sawdust, wood flour, or recycled wood fragments from wood cement board waste can be used. The wood material used for the core layer is preferably a rough wood material such as wood flakes for weight reduction, and the wood material used for the back layer is a finer wood flake or wood fiber than the core layer, It is preferable to use pulp or the like in terms of strength, surface smoothness, and the like.

  The bleaching pulp used for the surface layer has a length of 0.1 mm to 2 mm, preferably about 0.2 mm to 0.6 mm. If it is less than 0.1 mm, the reinforcing effect is poor, and if it exceeds 2 mm, it becomes expensive and the mixing property is deteriorated, so there is no merit of addition.

  As the inorganic foam, pearlite, shirasu balloon or the like can be used.

  As the coloring pigment, an inorganic pigment is preferable in terms of excellent weather resistance, and natural and synthetic iron oxides such as Bengala, titanium oxide, carbon black, chromium oxide, and the like can be used. It is also possible to add a part of the organic pigment to the organic pigment.

  The blending ratio of the semi-dry composition composed of the above materials is as follows. For each layer, approximately 10 to 25 parts by weight of siliceous material, 5 to 25 parts by weight of wood material, and 10 to 25 parts by weight of inorganic foam with respect to 50 parts by weight of cement. Selected from the range of 35 to 45 parts by weight of water. The blending ratio of the color pigment added to the surface layer or front and back layer composition is about 0.5 to 5 parts by weight with respect to 50 parts by weight of cement.

  If the bleached pulp mixed in the surface layer is less than 5 parts by weight, the reinforcing effect and the light weight effect are lowered, and the moldability by the semi-dry method is also deteriorated. On the other hand, if it exceeds 25 parts by weight, it becomes expensive and the fire resistance is lowered, which is not preferable.

  Next, the production procedure of the colored inorganic decorative board will be described. First, the above composition is mixed well by a mixing device to obtain a semi-dry composition for the surface layer, the core layer, and the back layer. According to a conventional method, a predetermined amount of this semi-dry composition is transferred from a forming head of a semi-dry molding apparatus onto a support plate placed on a conveyor that moves downward, for the back layer, the core layer, and the surface layer. It is dropped in order and is semi-dry molded to form an uncured inorganic mat having a colored surface layer.

  Next, after supplying decorative particles such as colored silica sand to the surface of the uncured inorganic mat as necessary, an embossing mold material made of FRP or the like is placed on the support plate, uncured inorganic mat, emboss A plurality of sets of forming molds are deposited and cold-pressed to form an uncured inorganic plate having an embossed pattern engraved on the colored surface layer.

  Next, the uncured inorganic plate is primarily cured in a thermostatic chamber at about 60 ° C. for about 8 to 15 hours to obtain a semi-cured state. If necessary, a transparent base coating such as a sealer coating may be applied to the surface of the inorganic plate after the primary curing.

  Next, the inorganic plate after the primary curing is subjected to secondary curing with an autoclave. In the autoclave curing, the temperature is raised and lowered so that the maximum temperature is around 170 ° C., and steam heating is performed. The inorganic plate after the secondary curing is subjected to transparent coating such as undercoating, intermediate coating, top coating, etc., if necessary, to form a colored inorganic decorative plate in which the color tone of the colored surface layer appears on the surface.

  Next, specific examples will be described. First, as an example, a colored inorganic decorative board was prepared according to the following procedure using a semi-dry composition having the following composition. That is, a semi-dry type for front and back layers comprising 50 parts by weight of cement, 18 parts by weight of silica powder, 15 parts by weight of hardwood bleached pulp having an average fiber length of 0.25 mm, 15 parts by weight of pearlite, 2 parts by weight of color pigment, and 38 parts by weight of water. The composition was mixed well with a semi-dry composition for a core layer consisting of 50 parts by weight of cement, 20 parts by weight of silica powder, 15 parts by weight of wood flakes, 15 parts by weight of pearlite and 42 parts by weight of water, and then semi-dry molding. A predetermined amount was dropped in the order of the back surface layer, the core layer, and the front surface layer onto the support plate that was placed on the lower belt conveyor and moved from the forming head of the apparatus to form an uncured inorganic mat.

  Next, an FRP embossing mold material is placed on the surface of the uncured inorganic mat, and a plurality of sets including the support plate, the uncured inorganic mat, and the embossing mold material are stacked and pressure pressed. Then, this terraced product was brought into a constant temperature room at 60 ° C. and subjected to primary curing for about 11 hours. Thereby, the surface was formed in the colored layer and the inorganic board by which the embossed pattern was engraved in this colored surface layer was obtained.

  After applying a water-based transparent sealer coating on the entire surface of this inorganic board, it is carried into an autoclave and subjected to autoclave curing for about 10 hours at a maximum temperature of 170 ° C. As well as top coating, a colored inorganic decorative board was obtained. In this colored inorganic decorative board, the color tone of the colored surface layer appeared on the surface, and there was no color unevenness such as a stain on the colored surface layer. Moreover, as a result of subjecting this colored inorganic decorative board to an accelerated weather resistance test (metal weather test), even after 500 hours (equivalent to 10 years of outdoor exposure), the color difference is 1.5 level, and there is no sense of incongruity. Had a good appearance.

Then, the coloring inorganic decorative board as a comparative example was created. This colored inorganic decorative board was prepared in the same manner as in the example except that relatively fine wood flakes were used as the wood material instead of the bleached pulp in the above example. In the colored inorganic decorative board of this comparative example, dark colored unevenness such as a stain occurred mainly in the colored surface layer near the edge of the inorganic decorative board. Further, as a result of being subjected to the same accelerated weather resistance test as described above, after 100 hours (corresponding to 2 years of outdoor exposure), the color difference was 6.5 level, and the color tone had a strange feeling.

Claims (3)

A colored inorganic decorative board formed by semi-dry molding a semi-dry composition composed mainly of cement and woody material, followed by autoclave curing,
A colored inorganic decorative board, wherein a colored pigment and bleached pulp as a wood material are mixed in a semi-dry composition constituting at least a surface portion. The colored inorganic decorative board according to claim 1,
The length of the bleached pulp is 0.1 mm or more and 2 mm or less,
A colored inorganic decorative board, wherein the bleached pulp is mixed in an amount of 5 to 25 parts by weight per 50 parts by weight of cement. A first step of mixing a semi-dry composition composed mainly of cement and wood material;
A second step of semi-dry molding the semi-dry composition;
A third step of preparing a colored inorganic decorative board by curing the semi-dry molded uncured inorganic board by autoclave,
The first step is a step of mixing and mixing a coloring pigment and bleached pulp as a woody material in the semi-dry composition constituting at least the surface portion of the colored inorganic decorative board. A method for producing a colored inorganic decorative board.