JP4870371B2 - Light weight inorganic board and method for producing the light weight inorganic board - Google Patents

Description

  The present invention relates to a lightweight inorganic board used for building boards such as outer wall materials and interior materials, and a method for producing the inorganic board.

BACKGROUND OF THE INVENTION
An inorganic plate obtained by molding and firing ceramic powders such as silica and alumina into a plate shape is excellent in durability, and is frequently used as a building plate having a high-quality design with a sense of beauty and texture.
The inorganic plate is manufactured by adding a binder and water to a ceramic powder and kneading, forming the kneaded product into a plate shape by extrusion molding or casting, and firing the plate-shaped product, It has high hardness and poor machinability, and it is difficult to easily cut to a predetermined size on site. In the case of a large plate, the weight is large and labor is required for transportation and construction work, and when it is attached to a wall frame or the like, the weight load on the wall frame becomes large.

[Conventional technology]
Therefore, as a means for solving the problems of the above-mentioned inorganic board, a mat is formed by spraying a raw material mixture in which a flammable organic material such as blast furnace slag or slaked lime is added with a combustible organic component such as wood chips or wood powder on a substrate. A porous and lightweight inorganic board is formed by forming, pressing and curing the mat to form a green board, firing the green board, and burning off the combustible organic components contained in the green board. It has been proposed to obtain. (For example, refer to Patent Documents 1 to 5).

JP-A-6-345529 JP-A-6-144923 Japanese Patent Laid-Open No. 9-30873 JP 2005-60163 A Japanese Patent Application No. 2003-31856

In the above prior art, the strength of the green plate obtained by press-curing and curing the mat of the raw material mixture is not sufficient, so that it is easily chipped, deformed or collapsed, and there is a problem in handling properties. In addition, when a concavo-convex pattern is formed on the plate surface by embossing, a too deep concavo-convex pattern cannot be formed, and thus the concavo-convex pattern is restricted. Furthermore, there is a problem that the strength required for cutting a real edge or the like on the edge of the plate cannot be obtained, and it is easily chipped during processing.
In order to increase the strength of the green plate, curing may be performed for a long time, but if so, the production efficiency of the inorganic plate is deteriorated.

In the present invention, as means for solving the above-described conventional problems, 15 to 45% by mass of a cement-based inorganic material, 1 to 15% by mass of a vitreous material, 20 to 45% by mass of aggregate, and 15 to 35% by mass of reinforcing fibers The hardened and fired layers of the raw material mixture containing the front and back layers are cement-based inorganic materials 15 to 45% by mass, glassy materials 1 to 15% by mass, aggregates 0 to 30% by mass, reinforcing fibers 20 to 30% by mass, The present invention provides a lightweight inorganic plate having a core layer of a cured and fired layer of a raw material mixture containing a combustible organic component and / or an inorganic lightweight body of 15 to 30% by mass.
As a desirable method for producing the lightweight inorganic board, cement inorganic material 15 to 45% by mass, glassy material 1 to 15% by mass, aggregate 20 to 45% by mass, reinforcing fiber 15 to 35% by mass are included. The raw material mixture for the front and back layers contained is sprinkled on the substrate to form the front layer or the back layer mat. The core layer mat is formed by spraying the raw material mixture for the core layer containing 20 to 30% by mass of the reinforcing fiber, 15 to 30% by mass of the combustible organic component and / or the inorganic lightweight body on the surface layer or the back layer mat. Further, the raw material mixture for the front and back layers is sprayed on the core layer mat to form the back layer or the surface layer mat, and the mat having the three-layer structure thus obtained is pressed and hardened in the presence of moisture. Making a raw plate by Rukoto, firing the organism plate.
The firing temperature is desirably set in a range of 1100 ° C. or higher (including 1100 ° C.) and 1300 ° C. or lower (including 1300 ° C.).

[Action]
In the present invention, a cement-based inorganic material is used as the hydraulic inorganic material. However, since the cement-based inorganic material has a fast hydraulic reaction, in the process of pressing and curing the three-layer structure mat, the cement-based inorganic material is short. Curing proceeds smoothly over time, and a high strength green plate is obtained.

〔effect〕
Therefore, in the present invention, the raw plate is not easily chipped, deformed or collapsed during handling or actual cutting processing, so that handling and workability are improved, and deep uneven patterns are easily formed by embossing. The degree of freedom of the concavo-convex pattern can be increased. Furthermore, the time required for the compression curing and curing is shortened, and the production efficiency is improved.

The present invention is described in detail below.
[Cement-based inorganic materials]
In the present invention, as described above, a cement-based inorganic material is used as the hydraulic inorganic material. Examples of the cement-based inorganic material include ordinary Portland cement, early-strength Portland cement, alumina cement, blast furnace slag cement, silica cement, fly ash cement and the like.
Since the cement-based inorganic material has a high hydraulic reaction rate, the time required for compression biocure is shortened, and the strength of the green plate obtained is improved.

[Glass-containing material]
Furthermore, in this invention, the vitreous content material which fuse | melts by baking and becomes a binder is added. Examples of such a vitreous material include shirasu, fly ash, mine stone, glass powder, and ground glass. What is desirable as the glassy-containing material is a low-melting glass having a softening point of 900 ° C. or lower. As the low-melting glass, a glass having an increased content of low-melting-point components such as PbO, B ₂ O ₃ and ZnO is used. For example, E glass powder having a softening point of 840 ° C. and a melting point of 1200 ° C. is a desirable low-melting glass. E glass, or electrical glass, is a glass fiber powder, the average particle size is 30 μm, the main components are SiO ₂ 54 mass%, Al ₂ O ₃ 15 mass%, CaO 23 mass%, B ₂ O ₃ 7 mass%. Because it contains B ₂ O ₃ , it has a low melting point and enables low-temperature firing at around 1000 ° C.

〔aggregate〕
Furthermore, in the present invention, an aggregate which is melted by firing and becomes a main element of the plate structure is added. Examples of the aggregate include clay minerals such as porcelain stone, feldspar, wax stone, kaolin, halosite, kibushi clay, lacquered clay, sericite, chamotte (ceramic stone powder), dolomite, silica sand, quartzite powder, There are siliceous materials such as diatomaceous earth, glitter, and silica fume. Among the above-mentioned aggregates, silica sand or quartzite powder having a brain value of 3800 and a SiO ₂ purity of 95% by mass or more, or chamotte is preferable.

[Reinforcing fiber]
Furthermore, in the present invention, reinforcing fibers are added to suppress expansion and contraction due to firing. Examples of the reinforcing fibers include mineral fibers such as wollastonite and sepiolite, metal fibers such as steel fibers and stainless fibers, glass fibers, and ceramic fibers. A desirable reinforcing fiber is wollastonite. Wollastonite has a larger aspect ratio (15) than ordinary reinforcing fibers. Wollastonite improves the dispersibility of the raw material mixture, and the dry method in which the raw material mixture is sprayed on the template prevents the formation of agglomerates and lumps in the raw material mixture and improves the spraying workability. . Generally, wollastonite having an average fiber length of 600 μm and an average fiber diameter of 40 μm is used. Further, wollastonite improves shape retention and cutting properties, and facilitates the production of large size plates.

[Flammable organic components]
In the present invention, a flammable organic component may be added together with the inorganic lightweight body or in place of the inorganic lightweight body in order to burn out during firing and form a porous structure in the core layer. Examples of such combustible organic components include wood materials such as wood chips, wood fiber bundles, wood pulp, wood wool, and wood flour, and organic materials such as polyester fibers, polyamide fibers, polyethylene fibers, polypropylene fibers, acrylic fibers, and vinylon fibers. There are synthetic resin components such as fibers, expanded polystyrene beads, expandable polyethylene beads, expandable polypropylene beads, or wood cement board waste.
Wood cement board waste materials used as a source of combustible organic components are wood reinforcing materials such as wood chips, wood fiber bundles, wood pulp, wood wool, wood flour, ordinary Portland cement, early strength cement, alumina cement, blast furnace Using a raw material mixture mainly composed of cements such as slag cement and fly ash cement, limes such as quick lime and slaked lime, or hydraulic inorganic materials such as gypsum and magnesium carbonate, dry method, semi-dry method, wet method The waste material of the wood cement board formed into a plate shape by the extrusion molding method or the like is used to grind and recycle the end material in the manufacturing process and these waste materials generated at the time of extension and reconstruction.
The wood cement board usually contains 10 to 30% by mass of the wood content.

  The wood cement board may further contain organic fibers such as polyester fiber, polyamide fiber, polyethylene fiber, polypropylene fiber, acrylic fiber, and vinylon fiber, and flammable organic components such as expanded polystyrene beads, polyethylene beads, and polypropylene beads. During burning, these combustible organic components are also burned out, contributing to the porous structure of the core layer together with the wood.

  The wood cement board waste is usually pulverized to a particle size of about 10 to 100 μm by an impact type pulverizer or a grinding type pulverizer, and used as a raw material of the present invention.

[Inorganic lightweight body]
In the present invention, in order to form a porous structure in the core layer, an inorganic lightweight body may be added instead of the combustible organic component or together with the combustible organic component. Examples of the inorganic lightweight body include pearlite, fly ash balloon, shirasu balloon, and glass foam, and those having a bulk specific gravity of 0.4 or less and a compressive strength of 10 N / mm ² or more are preferable.

[Raw material mixture for front and back layers]
As the raw material for the front and back layers, the above-mentioned cement-based inorganic material, glassy-containing material, aggregate, and reinforcing fiber are used.
In the raw material mixture for the front and back layers, the cement-based inorganic material is 15 to 45% by mass, the glassy-containing material is 1 to 15% by mass, the aggregate is 20 to 45% by mass, and the reinforcing fiber is about 15 to 35% by mass. It is said. When the aggregate is added in an amount exceeding 45% by mass, the specific gravity of the plate becomes high, and it is difficult to reduce the weight, and the workability also deteriorates. On the other hand, when the aggregate is added in an amount less than 20% by mass, the strength of the plate is lowered and the frost resistance is also deteriorated. Moreover, the combustible organic component and / or inorganic lightweight body which are used for a core layer may be added to the said raw material mixture for front and back layers.

[Raw material mixture for core layer]
As the raw material for the core layer, in addition to the raw material for the front and back layers, the combustible organic component and / or the inorganic lightweight body is used. In the raw material mixture for the core layer, cement-based inorganic material 15 to 45% by mass, glassy material 1 to 15% by mass, aggregate 0 to 30% by mass, reinforcing fibers 20 to 30% by mass, combustible organic component And / or it is set as the ratio of 15-30 mass% of inorganic lightweight bodies.
In the raw material mixture for the core layer, when the amount of the combustible organic component and / or the inorganic lightweight body is less than 15% by mass, the core layer is not sufficiently porous and the weight is not reduced. On the other hand, when the amount of the combustible organic component and / or the inorganic lightweight body is more than 30% by mass, the core layer becomes excessively porous, resulting in poor mechanical strength and frost resistance.

[Method for producing lightweight inorganic board]
As a method for producing the lightweight inorganic board of the present invention, a semi-dry method using a raw material mixture in which a predetermined amount (usually 5 to 20% by mass) of water is added is generally applied, but water is added to the raw material mixture. Alternatively, a dry method in which water is added immediately before or after compression curing biocure may be applied.
That is, in the production method of the present invention, a raw material mixture for front and back layers is formed on a substrate such as a template, a conveyance plate, and a flat plate to form a surface layer or a back layer mat, and a core is formed on the surface layer or the back layer mat. The raw material mixture for the layer is sprayed to form the core layer mat, the raw material mixture for the front and back layers is sprayed on the core layer mat to form the back layer or the surface layer mat, and the three-layer structure thus obtained is formed. The mat is cured by pressing and curing in the presence of moisture, and the resulting inorganic plate green plate is fired to obtain the lightweight inorganic plate of the present invention.

In the above method, a predetermined uneven shade pattern may be formed on the substrate surface. The pressing is usually performed at a surface pressure of 5 to 8 MPa in a pressing apparatus in which a substrate is further stacked on a formed three-layer mat, and the upper surface of the mat is used as a surface to the upper substrate surface. A predetermined uneven shade pattern may be formed.
Curing and curing is performed in the above-mentioned pressed state, and a condition of 6 to 10 hours is usually employed at a temperature of 45 to 65 ° C.
After curing and curing, it is depressurized and desirably dried in an absolutely dry state, and subjected to predetermined processing such as actual processing. Further, if desired, a glaze is applied to at least the surface of the raw inorganic plate. As the glaze used in the present invention, general glazes such as lead yu, frit yu, bristol yu, porcelain yu and the like are used. Thereafter, the raw inorganic plate is introduced into a firing furnace and fired. Desirable firing conditions are 1100 ° C. or higher (including 1100 ° C.) and 1300 ° C. or lower (including 1300 ° C.), preferably 1150 ° C. or higher (including 1150 ° C.) and 1250 ° C. or lower (including 1250 ° C.) for 10 to 20 minutes. The following conditions are adopted.
The lightweight inorganic board thus produced usually has a thickness of 12 to 25 mm, a specific gravity of the front and back layers of 1.5 to 1.8, and a specific gravity of the core layer of about 0.8 to 1.3.

[Examples 1 to 5 , Reference Examples 1 and 2, Comparative Examples 1 to 4]
Spread the raw material mixture for the front and back layers shown in Table 1 on the template, spread the raw material mixture for the core layer on it, and form a mat with a three-layer structure on which the raw material mixture for the front and back layers is further spread, The mat having the three-layer structure is subjected to pressing and curing and curing for 10 hours under the conditions of a surface pressure of 5 MPa and a temperature of 50 ° C. in the presence of moisture, and the resulting inorganic plate green plate is kept in an absolutely dry state at a temperature of 105 ° C. for 24 hours. Examples 1 to 5 , Reference Examples 1 and 2, and Comparative Examples having a three-layer structure that was dried, coated with glaze on the surface, introduced into a baking furnace and baked for 10 minutes at the temperatures shown in the table to a thickness of 18 mm The lightweight inorganic board sample of Examples 1-4 was created, and the following physical-property evaluation was performed. The results are shown in Table 1.

〔Evaluation of the physical properties〕
(1) Shrinkage ratio: Ratio of dimension after molding to dimension after firing (%)
(2) Specific gravity: Absolute dry specific gravity
(3) Bending strength: according to JIS A 1408 (N / mm ² )
(4) High surface design: The following standards are given for a cured product formed by a semi-dry method using a mold plate having a concave convex portion with an embossing depth of 11 mm and an embossing angle of 60 °, set to a plate thickness of 25 mm by a table test. It was evaluated with.
◎: No irregularity ○: Slight burrow in the convex part △: Slightly missing in the convex part ×: Large chipped in the convex part (pattern missing)
(5) Cutability: Can be cut with a hand saw, and can be cut smoothly without cracks or chipping. (If you can cut smoothly ○)
(6) Freezing and thawing resistance: ASTM B method Whether there is any abnormality after 300 cycles. (No abnormality ○)
(7) Impact resistance: According to JIS A 1408, the height at which a 500 g iron ball does not crack when dropped. (M)

Referring to Table 1, in Example 1, the content of the cementitious inorganic material is an optimum value, but the firing temperature is the lowest value within the set range, so the impact resistance is slightly inferior, but within the set range, Other physical properties are good. In Example 2, both the content of the cementitious inorganic material and the firing temperature are within the optimum setting range, the strength of the obtained lightweight inorganic board is high, and the other physical properties are also good. In Example 3, the content of the cementitious inorganic material is an optimum value, but the firing temperature is high within the set range, but the strength of the obtained lightweight inorganic board is high and other physical properties are also good. In Example 4, the content of the cementitious inorganic material is an optimum value, but the firing temperature is the highest value within the set range, but the strength after curing is large, and other physical properties are also good. In Example 5, since the cement-based inorganic material is less within the set range, the bending strength after curing is slightly low and slightly inferior to the high surface design, but it is within the set range and other physical properties are good. In Reference Example 1, since the cement-based inorganic material is larger in the set range, the shrinkage rate is slightly larger, but it is within the set range, and other physical properties are good. In Reference Example 2, there are many cement-based inorganic materials and no aggregate is added to the core layer. Therefore, the shrinkage rate is slightly large, and the freeze-thaw resistance and impact resistance are slightly inferior, but within the set range. Is good.

  Since the comparative example 1 does not use a cement-type inorganic material as a hydraulic inorganic material, the bending strength after hardening is remarkably low, and therefore the surface high designability is remarkably lowered. In Comparative Example 2, a cement-based inorganic material was not used as the hydraulic inorganic material, and the amount of the hydraulic inorganic material was small, so that the bending strength after curing was extremely low, and thus the surface high designability was significantly lowered. In Comparative Example 3, no cement-based inorganic material was used as the hydraulic inorganic material, and the amount of the hydraulic inorganic material was large, but the bending strength after curing was low, and thus the high surface design was also lowered. In Comparative Example 4, the cement-based inorganic material was not used as the hydraulic inorganic material, and the aggregate was not added to the core layer. Therefore, the bending strength after curing was low, and thus the high surface design was also lowered.

  The inorganic board of the present invention has high productivity, is lightweight, has good transportability, workability and workability, is excellent in mechanical properties and freeze-thaw resistance, and has a deep uneven pattern on the surface. It can be used and is useful for exterior wall materials and interior materials.

Claims (3)

Cement-based inorganic material 15 to 45% by mass, E glass powder 1 to 15% by mass containing B ₂ O ₃ as a vitreous material, aggregates 20 to 45% by mass, wollastonite 15 to 35% by mass as reinforcing fibers 1 to 15% by mass of E glass powder containing 15 to 45% by mass of a cement-based inorganic material and B ₂ O ₃ as a vitreous material, and 0 to 30 aggregates. wt%, wollastonite 2 5 weight to 30% by weight as a reinforcing fiber, characterized in that the combustible organic component and / or core layer a cured fired layer of the raw material mixture containing an inorganic lightweight material 15 to 30 wt% Lightweight inorganic board. Cement-based inorganic material 15 to 45% by mass, E glass powder 1 to 15% by mass containing B ₂ O ₃ as a vitreous material, aggregates 20 to 45% by mass, wollastonite 15 to 35% by mass as reinforcing fibers An E glass powder 1 containing 15 to 45% by mass of a cement-based inorganic material and B ₂ O ₃ as a vitreous material is formed by spreading a raw material mixture for front and back layers on the substrate to form a surface layer or a back layer mat. A raw material mixture for a core layer containing 15 to 30% by mass, 0 to 30% by mass of aggregate, 25 to 30% by mass of wollastonite as a reinforcing fiber, and 15 to 30% by mass of a combustible organic component and / or an inorganic lightweight body. The core layer mat is formed by spraying on the front layer or the back layer mat, and the raw material mixture for the front and back layers is further sprayed on the core layer mat to form the back layer or the surface layer mat. Method for producing a lightweight inorganic board according to claim 1, characterized in that to a raw plate by pressing cure cured mat having a three-layer structure obtained in the presence moisture, calcining the organism plate. The said baking is a manufacturing method of the lightweight inorganic board of Claim 2 set to 10 to 20 minutes in the range whose temperature is 1150 degreeC or more (1150 degreeC included) 1300 degrees C or less (1300 degreeC included).