JPH059086A - Lightweight decorative board and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a lightweight decorative board that does not cause the white flower phenomenon on the surface of natural stone even if it is in contact with air for a long time, and a method for producing the same. [Structure] A natural stone plate is laminated and bonded to an inorganic lightweight plate through a resin layer, and the inorganic lightweight plate is formed by integrally bonding inorganic aggregates mainly composed of glass balloons with a water glass cured body. Lightweight decorative board that is one. A resin layer is provided on one surface of the natural stone plate, and the surface of the natural stone plate having this resin layer is coated with water glass containing a curing agent,
Hardening agent, water glass and a mixture of inorganic aggregates containing shirasu balloon as a main component are laminated thereon, pressure-molded into a plate shape at room temperature or under heating, and a light decorative plate characterized by curing. Production method.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a lightweight decorative board having a surface made of natural stone and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, calcined hirucite and / or calcined shirasu (shirasu balloon) is used as an inorganic aggregate,
A method for producing an inorganic lightweight building material by coating the surface thereof with water glass containing a curing agent, press-molding this and curing it is known (JP-A 1-131084, JP-A 1-3).
No. 17148). The building material obtained by such a method is lightweight and at the same time excellent in fire resistance, heat insulation and soundproofing, but its surface is formed in an uneven shape, and the end strength is weak, and the end breaks ( The surface properties were not good because of the drawbacks such as the generation of scratches) and the occurrence of surface cracks. On the other hand, in recent years, natural stones have been widely used as floor materials and wall materials in order to obtain a high-class feeling and a natural feeling. However, such a natural stone has a large specific gravity, is expensive, and requires a skilled worker for its construction. In order to solve such a problem, the present inventors have previously proposed a lightweight decorative board composed of a laminated board in which a natural stone board or a natural stone-like board is bonded onto an inorganic lightweight board containing Shirasu balloon as a main component. Did (Japanese Patent Application 2-2
75792). This decorative board is suitable as a wall material or a flooring material because it is inexpensive to manufacture, is lightweight, and has a constant size. However, according to the research conducted by the present inventors, it has been found that this lightweight decorative board has a drawback that a white flower phenomenon (powdering) occurs on the surface of natural stone due to contact with air for a long period of time.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lightweight decorative board which does not cause the white flower phenomenon on the surface of natural stone even if it is in contact with air for a long time, and a method for producing the same.

[0004]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, according to the present invention, a natural stone board is laminated with an inorganic lightweight board through a resin layer to form a laminate,
The inorganic lightweight board is a lightweight decorative board in which an inorganic aggregate mainly composed of glass balloons is integrally bonded and formed by a water glass cured body. Further, according to the present invention,
A resin layer is provided on one surface of the natural stone plate, and water glass containing a curing agent is applied to the surface of the natural stone plate having this resin layer, and then the curing agent, water glass and Shirasu balloon are contained as the main components. There is provided a method for producing a lightweight decorative board, which comprises laminating a mixture of inorganic aggregates, press-molding the mixture into a plate shape at room temperature or under heating, and curing the mixture.

As the natural stone plate used in the present invention, various kinds are used, but marble and granite are preferably used. The inorganic lightweight plate used in the present invention is a plate-like body in which the inorganic aggregate containing shirasu balloon as a main component is integrally joined by a water glass cured product cured with a curing agent. As the inorganic aggregate, shirasu balloons, pearlite, leeches, and other lightweight aggregates are used. In the present invention, shirasu balloons as the main component are used. The content of shirasu balloon in the aggregate is 50% by weight or more, and preferably 80 to 100% by weight.

As the shirasu balloon, commercially available products can be used as they are, but in the present invention, it is preferable to use a mixture of fine particles and coarse particles. A particularly preferred Shirasu balloon used in the present invention has a particle size of 63μ.
Content of m or less component (hereinafter referred to as A component) is 15 to 55 weight
%, Component with particle size in the range of 177 to 420 μm (hereinafter referred to as B component)
Content is 25-65% by weight and particles more than 63 μm and less than 177 μ Ingredient content and components more than 420 μm and less than 600 μm (hereinafter both are referred to as C components) Content has particle size distribution of 0-40% by weight It is a thing. A component is less than 15% by weight, B
When the component exceeds 65% by weight, the resulting lightweight board is
In some cases, shrinkage deformation becomes large, and irregularities become conspicuous on the surface. Further, if the A component exceeds 55% by weight, or the B component is less than 25% by weight, the resulting lightweight plate,
The shrinkage deformation increases and the warp easily occurs, and in some cases, a crack is generated (when the B component approaches 0). Further, when the C component exceeds 40% by weight, the plate amount plate obtained tends to have a large degree of shrinkage deformation.

The water glass used in the present invention means an aqueous solution of an alkali metal silicate such as sodium silicate, potassium silicate or lithium silicate. For example, JIS No. 1 standard product, JIS No. 2 standard product, JIS 3 standard product. No. standard products are commercially available. As the water glass curing agent, conventionally known ones, for example, inorganic acids such as phosphoric acid and boric acid and salts thereof, silicofluorides such as sodium silicofluoride, metal oxides such as zinc oxide and magnesium oxide, calcium carbonate,
Metal salts such as barium sulfate and condensed aluminum phosphate; acetic acid esters and the like can be mentioned.

In order to preferably produce the inorganic lightweight board used in the present invention, water glass, a curing agent and shirasu balloon are mixed, the mixture is put into a mold, pressure-molded, and then cured. The usage ratio of water glass is 30 in terms of solid content (alkali metal silicate) based on 100 parts by weight of Shirasu balloon.
˜150 parts by weight, preferably 40 to 130 parts by weight. When the usage ratio of water glass is less than the above lower limit value, the effect as a bonding material is poor, and the resulting lightweight plate has significantly reduced strength,
There may be a problem in practicality. On the other hand, when the amount exceeds the above upper limit, the proportion of unreacted water glass increases, so that the resulting lightweight plate is prone to shrinkage and easily cracks. The water glass curing agent is 20 to 50 parts by weight, preferably 30 to 40 parts by weight based on 100 parts by weight of the solid content of water glass.
Parts by weight. When the amount of the curing agent used is less than the above lower limit, the proportion of unreacted water glass increases, so that the resulting lightweight plate is prone to shrinkage and cracks easily occur. On the other hand, when the amount exceeds the upper limit, the reaction ratio between the curing agent and carbon dioxide gas in the air or water is significantly increased, so-called white flower phenomenon is recognized in the curing process, and the surface of the resulting light weight plate is observed. , The white powder deposits in spots, and the product value drops significantly.

In the present invention, a polymeric binder may be used in combination in order to increase the mechanical strength of the lightweight plate. A water-soluble polymer or polymer latex can be used as the polymer binder. Examples of the water-soluble polymer include water-soluble urea / formamide resin and guanamine resin, as well as polyvinyl alcohol and polyvinylpyrrolidone. As the polymer latex, styrene / budadiene-based latex, acrylic latex, vinylidene chloride-based latex, vinyl chloride-based latex, vinyl acetate-based latex and the like are used. The polymer binder is used in an amount of 0.5 parts by weight or more, preferably 1 to 40 parts by weight in terms of solid content, based on 100 parts by weight of shirasu balloon. Since the non-combustibility of the lightweight plate is impaired when the proportion of the polymer binder used increases, the proportion of the polymer binder used should be 5 parts by weight or less from the viewpoint of obtaining a non-combustible lightweight plate.

When the lightweight board used in the present invention is manufactured, reinforcing fibers can be used in combination in order to prevent cracking of the lightweight board and increase mechanical strength. As the reinforcing fiber, vinylon fiber, acrylic fiber, aramid fiber,
Polyester fiber, polyamide fiber, cellulose fiber,
In addition to synthetic fibers such as cotton and carbon fibers and natural fibers, various metals such as metal fibers, alumina fibers, glass fibers, gypsum whiskers and inorganic fibers are used. The thickness of the fiber is 1 to 100 μm, preferably 3 to 60 μm, and the fiber length is 1 mm or more, preferably 3 to 20 mm. The ratio of the reinforcing fibers used is 0.1 to 10 per 100 parts by weight of Shirasu balloon.
Parts by weight, preferably 0.5-5 parts by weight.

Further, in the case of manufacturing a light weight plate, unexpanded shirasu powder and inorganic powder such as mica and kaolin are used together in order to thicken the raw material mixture and prevent shrinkage during molding and curing. be able to. The average particle size of such inorganic powder is 70 μm or less, preferably 0.1 to 30 μm. In addition, the usage ratio of such inorganic powder is
It is 30 parts by weight or less, preferably 20 parts by weight or less, relative to 100 parts by weight. When manufacturing a lightweight plate in the present invention, the water content in the total raw material mixture is 20 to 50% by weight, preferably 2
It is preferable to maintain the content at 5 to 40% by weight and use it as a powdery material having fluidity. Such a mixture in the form of powder or granules can be put into a molding die and easily pressure-molded.

In the case of producing a lightweight plate, it is preferable that the powder-granular mixture is filled in a molding die, pressure-molded and then taken out of the molding die, and the pressure-molded material is cured at room temperature or under heating.
In this pressure molding, the molded product can be cured in the molding die, but the pressure molded product is a solid substance,
Since it is easy to handle, it is preferable to take out the molded product from the mold and hold it at room temperature or under heating to cure it. The pressure during pressure molding is 0.5 to 15 kg / cm
² G, preferably 6-19 kg / cm ² G. When the molded product is cured under heating, the heating temperature is 30 ° C. or higher, preferably 80 ° C. or lower, and the curing time is usually 1 to 3 hours. The heat-cured product of the molded product may be used as a lightweight plate as it is, but in order to further advance the curing reaction and improve the mechanical strength, at room temperature or a temperature near room temperature, 3 to 10 days, preferably 5 to 8 days. It is preferable to use it while holding it to some extent.

To manufacture the decorative board of the present invention, a resin layer is provided on one side or both sides of the lightweight board obtained as described above, and natural stone boards are laminated and adhered via this resin layer. The resin layer in this case can be formed using a thermoplastic resin, but it is preferable to use a room temperature curable resin, an electron beam curable resin, an ultraviolet curable resin, or a thermosetting resin. From the viewpoint of productivity, equipment cost, and cost, it is preferable to use an ultraviolet-curable resin. Furthermore,
Specific examples of the ultraviolet curable resin include urethane acrylate-based, epoxy acrylate-based, polyester acrylate-based, and polyether acrylate-based curable resins.

The natural stone plate and the lightweight plate can be bonded by using the above-mentioned resin layer, but can also be bonded by using an adhesive other than the resin layer. As the adhesive in this case, an epoxy resin or a polymer adhesive such as a urethane resin may be used, but preferably an inorganic adhesive, more preferably a cement adhesive or a water glass adhesive. To use. This water glass-based adhesive is water glass containing a curing agent, but preferably contains 2 to 5 parts of inorganic powder.
It was added at a ratio of 20% by weight. Examples of the water glass and the curing agent in this case include those described above. Examples of the inorganic powder include kaolin, clay, shirasu, diatomaceous earth, sepiolite, zeolite, silica, mica and the like. From the viewpoint of workability, it is preferable that the water glass adhesive has a viscosity higher than that of water glass containing a curing agent when the above-mentioned lightweight plate is used.

A preferred method for producing a decorative board according to the present invention is to apply a water glass-based adhesive to the surface of a resin layer of a natural stone board, and apply a curing agent, water glass and shirasu balloon to the inorganic bone as the main components on the applied surface. It is a method in which a mixture of materials is laminated, pressure-molded into a plate shape at room temperature or under heating, and then cured. According to this method, it is possible to simultaneously manufacture the lightweight plate and laminate and adhere the surface plate to the lightweight plate. In addition, the decorative board obtained by this method has an advantage that the adhesive strength between the surface board and the lightweight board is large and interface peeling hardly occurs. The thickness of the resin layer and the thickness of the adhesive layer in the decorative board of the present invention are each about 0.05 to 2.0 mm. Further, the total thickness of the decorative plate is about 15 to 100 mm, and the thickness of the lightweight plate is preferably specified in the range of 60 to 90% of the total thickness of the decorative plate.

[0016]

EFFECTS OF THE INVENTION The decorative board of the present invention is characterized by being lightweight and having a surface formed of a natural stone board, although it is composed mainly of an inorganic substance. The decorative board of the present invention has a structure in which a natural stone board is laminated and adhered to the surface of the lightweight board, so that the occurrence of cracks, which is a drawback of the lightweight board, and the end destruction and the like are prevented,
The strength of the lightweight plate is also reinforced so that it has excellent mechanical strength as a whole. The decorative board of the present invention effectively prevents the occurrence of the white flower phenomenon on the surface of the natural stone board. This white flower phenomenon is considered to be due to the alkali metal ions contained in the lightweight plate permeating the natural stone plate and reacting with carbon dioxide gas in the air to form a carbonate, but in the present invention, Since the resin layer is interposed between the lightweight plate and the natural stone plate and the resin layer prevents the alkali metal ions from permeating to the surface of the natural stone plate, the sinter phenomenon can be prevented. Further, since the decorative board manufacturing method of the present invention does not include a firing step, the equipment is simplified and advantageous in terms of thermal energy, and as a result, the product cost is low. Furthermore, the resulting decorative board has excellent mechanical strength and significantly excellent adhesive strength between the surface board and the lightweight board.

[0017]

EXAMPLES Next, the present invention will be described in more detail by way of examples. All parts and% shown below are based on weight.

Examples 1 to 4 First, a polyester acrylate UV curable resin was applied to one surface of natural stone in a thickness shown in Table 1 and cured using an UV irradiation lamp to form a resin layer. Next, JIS 3
To 100 parts of No. water glass, 14 parts of a curing agent (condensed aluminum phosphate) was added, and as inorganic powder, 12 parts of shirasu gemstone powder, 8 parts of mica and 8 to 14 parts of kaolin were added and mixed uniformly. Then, a water glass adhesive A was prepared. Also, JIS 3
128 parts of No. water glass, 1 hardener (condensed aluminum phosphate)
4 parts, rough shirasu powder 8.4 parts, mica 5.6 parts, kaolin 5.6 parts, reinforcing fiber (vinylon fiber) 1.5 parts and latex 4.5 parts were mixed and uniformly mixed to prepare a water glass adhesive B. On the other hand, as the raw material Shirasu balloon, the particle size is 180 to 420
A 100 μm component and 50 parts with a particle size of 38 μm or less were used. Next, about 0.5 mm of water glass adhesive A is applied to the entire surface of the resin layer on one side of the natural stone shown in Table 1, and the mold is formed with the coated surface facing upward (length: 400 mm, width: 400 mm, height 50 mm). ), And then a mixture of 150 parts of shirasu balloon and 165.2 parts of water glass adhesive B is filled in a mold, a pressing plate is placed on the mold, and a pressure of 6 kg / cm ² G is applied. After pressing, remove the molded product (decorative board) from the mold and place it in an oven at 40 ° C.
After heat-curing for 3 hours, the resulting decorative plate is further heated to room temperature at about 25
It was left for 7 days at ℃. The thickness, bending strength (JIS A 1408) and bulk density of the decorative board thus obtained were measured. The results are also shown in Table 1. The decorative board of the present invention showed a good appearance without interfacial peeling. It was also confirmed that the white flower phenomenon did not occur on the surface of the natural stone for a long period after the production.

[0019]

[Table 1]

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Claims (3)

[Claims] 1. A laminated body in which a natural stone board is laminated and adhered to an inorganic lightweight board through a resin layer, and the inorganic lightweight board is made by integrally bonding an inorganic aggregate mainly composed of shirasu balloon with a water glass cured body. A lightweight decorative board that has been formed. 2. The lightweight decorative board according to claim 1, wherein the resin layer surface of the natural stone board and the inorganic lightweight board are bonded with a cured body of a water glass adhesive containing a curing agent. 3. A resin layer is provided on the surface of a natural stone board, water glass containing a curing agent is applied to the surface of the natural stone board having the resin layer, and then a hardening agent, water glass and shirasu balloon are mainly formed on the surface. A method for producing a lightweight decorative board, which comprises laminating a mixture of inorganic aggregates as components, press-molding it into a plate shape at room temperature or under heating, and curing it.